$(TOP)/ext/fts3/fts3_test.c 

# Statically linked extensions
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \

  $(TOP)/ext/misc/fileio.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \

  $(TOP)/ext/fts3/fts3_test.c 

# Statically linked extensions
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/eval.c \
  $(TOP)/ext/misc/fileio.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \

  $(TOP)\ext\fts3\fts3_test.c

# Statically linked extensions
#
TESTEXT = \
  $(TOP)\ext\misc\amatch.c \
  $(TOP)\ext\misc\closure.c \

  $(TOP)\ext\misc\fileio.c \
  $(TOP)\ext\misc\fuzzer.c \
  $(TOP)\ext\misc\ieee754.c \
  $(TOP)\ext\misc\nextchar.c \
  $(TOP)\ext\misc\percentile.c \
  $(TOP)\ext\misc\regexp.c \
  $(TOP)\ext\misc\spellfix.c \

  $(TOP)\ext\fts3\fts3_test.c

# Statically linked extensions
#
TESTEXT = \
  $(TOP)\ext\misc\amatch.c \
  $(TOP)\ext\misc\closure.c \
  $(TOP)\ext\misc\eval.c \
  $(TOP)\ext\misc\fileio.c \
  $(TOP)\ext\misc\fuzzer.c \
  $(TOP)\ext\misc\ieee754.c \
  $(TOP)\ext\misc\nextchar.c \
  $(TOP)\ext\misc\percentile.c \
  $(TOP)\ext\misc\regexp.c \
  $(TOP)\ext\misc\spellfix.c \

3.8.7

3.8.8

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.62 for sqlite 3.8.7.
#
# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
## --------------------- ##
## M4sh Initialization.  ##
................................................................................
MFLAGS=
MAKEFLAGS=
SHELL=${CONFIG_SHELL-/bin/sh}

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.8.7'
PACKAGE_STRING='sqlite 3.8.7'
PACKAGE_BUGREPORT=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
................................................................................
#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.8.7 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.
................................................................................
  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.8.7:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
................................................................................
    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.8.7
generated by GNU Autoconf 2.62

Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit
fi
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.8.7, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{
................................................................................

exec 6>&1

# Save the log message, to keep $[0] and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.8.7, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@
................................................................................
$config_commands

Report bugs to <bug-autoconf@gnu.org>."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
sqlite config.status 3.8.7
configured by $0, generated by GNU Autoconf 2.62,
  with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"

Copyright (C) 2008 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.62 for sqlite 3.8.8.
#
# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
## --------------------- ##
## M4sh Initialization.  ##
................................................................................
MFLAGS=
MAKEFLAGS=
SHELL=${CONFIG_SHELL-/bin/sh}

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.8.8'
PACKAGE_STRING='sqlite 3.8.8'
PACKAGE_BUGREPORT=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
................................................................................
#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.8.8 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.
................................................................................
  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.8.8:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
................................................................................
    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.8.8
generated by GNU Autoconf 2.62

Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit
fi
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.8.8, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{
................................................................................

exec 6>&1

# Save the log message, to keep $[0] and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.8.8, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@
................................................................................
$config_commands

Report bugs to <bug-autoconf@gnu.org>."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
sqlite config.status 3.8.8
configured by $0, generated by GNU Autoconf 2.62,
  with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"

Copyright (C) 2008 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

/*
** 2014-11-10
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements SQL function eval() which runs
** SQL statements recursively.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** Structure used to accumulate the output
*/
struct EvalResult {
  char *z;            /* Accumulated output */
  const char *zSep;   /* Separator */
  int szSep;          /* Size of the separator string */
  int nAlloc;         /* Number of bytes allocated for z[] */
  int nUsed;          /* Number of bytes of z[] actually used */
};

/*
** Callback from sqlite_exec() for the eval() function.
*/
static int callback(void *pCtx, int argc, char **argv, char **colnames){
  struct EvalResult *p = (struct EvalResult*)pCtx;
  int i; 
  for(i=0; i<argc; i++){
    const char *z = argv[i] ? argv[i] : "";
    size_t sz = strlen(z);
    if( sz+p->nUsed+p->szSep+1 > p->nAlloc ){
      char *zNew;
      p->nAlloc = p->nAlloc*2 + sz + p->szSep + 1;
      zNew = sqlite3_realloc(p->z, p->nAlloc);
      if( zNew==0 ){
        sqlite3_free(p->z);
        memset(p, 0, sizeof(*p));
        return 1;
      }
      p->z = zNew;
    }
    if( p->nUsed>0 ){
      memcpy(&p->z[p->nUsed], p->zSep, p->szSep);
      p->nUsed += p->szSep;
    }
    memcpy(&p->z[p->nUsed], z, sz);
    p->nUsed += sz;
  }
  return 0;
}

/*
** Implementation of the eval(X) and eval(X,Y) SQL functions.
**
** Evaluate the SQL text in X.  Return the results, using string
** Y as the separator.  If Y is omitted, use a single space character.
*/
static void sqlEvalFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zSql;
  sqlite3 *db;
  char *zErr = 0;
  int rc;
  struct EvalResult x;

  memset(&x, 0, sizeof(x));
  x.zSep = " ";
  zSql = (const char*)sqlite3_value_text(argv[0]);
  if( zSql==0 ) return;
  if( argc>1 ){
    x.zSep = (const char*)sqlite3_value_text(argv[1]);
    if( x.zSep==0 ) return;
  }
  x.szSep = (int)strlen(x.zSep);
  db = sqlite3_context_db_handle(context);
  rc = sqlite3_exec(db, zSql, callback, &x, &zErr);
  if( rc!=SQLITE_OK ){
    sqlite3_result_error(context, zErr, -1);
    sqlite3_free(zErr);
  }else if( x.zSep==0 ){
    sqlite3_result_error_nomem(context);
    sqlite3_free(x.z);
  }else{
    sqlite3_result_text(context, x.z, x.nUsed, sqlite3_free);
  }
}


#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_eval_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "eval", 1, SQLITE_UTF8, 0,
                               sqlEvalFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "eval", 2, SQLITE_UTF8, 0,
                                 sqlEvalFunc, 0, 0);
  }
  return rc;
}

  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC COVERING INDEX (v=?)}
}
do_eqp_test rtree6.2.4.2 {
  SELECT * FROM t1,t2 WHERE v=10 and x1<10 and x2>10
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC COVERING INDEX (v=?)}
}

do_eqp_test rtree6.2.5 {
  SELECT * FROM t1,t2 WHERE k=ii AND x1<v
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}

  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC COVERING INDEX (v=?)}
}
do_eqp_test rtree6.2.4.2 {
  SELECT * FROM t1,t2 WHERE v=10 and x1<10 and x2>10
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC PARTIAL COVERING INDEX (v=?)}
}

do_eqp_test rtree6.2.5 {
  SELECT * FROM t1,t2 WHERE k=ii AND x1<v
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}

  $(TOP)/src/test6.c \
  $(TOP)/src/test7.c \
  $(TOP)/src/test8.c \
  $(TOP)/src/test9.c \
  $(TOP)/src/test_autoext.c \
  $(TOP)/src/test_async.c \
  $(TOP)/src/test_backup.c \

  $(TOP)/src/test_btree.c \
  $(TOP)/src/test_config.c \
  $(TOP)/src/test_demovfs.c \
  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_fs.c \
  $(TOP)/src/test_func.c \
  $(TOP)/src/test_hexio.c \
................................................................................
  $(TOP)/src/test_wsd.c

# Extensions to be statically loaded.
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \

  $(TOP)/ext/misc/fileio.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \

  $(TOP)/src/test6.c \
  $(TOP)/src/test7.c \
  $(TOP)/src/test8.c \
  $(TOP)/src/test9.c \
  $(TOP)/src/test_autoext.c \
  $(TOP)/src/test_async.c \
  $(TOP)/src/test_backup.c \
  $(TOP)/src/test_blob.c \
  $(TOP)/src/test_btree.c \
  $(TOP)/src/test_config.c \
  $(TOP)/src/test_demovfs.c \
  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_fs.c \
  $(TOP)/src/test_func.c \
  $(TOP)/src/test_hexio.c \
................................................................................
  $(TOP)/src/test_wsd.c

# Extensions to be statically loaded.
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/eval.c \
  $(TOP)/ext/misc/fileio.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \

.\"                                      Hey, EMACS: -*- nroff -*-
.\" First parameter, NAME, should be all caps
.\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
.\" other parameters are allowed: see man(7), man(1)
.TH SQLITE3 1 "Mon Jan 31 11:14:00 2014"
.\" Please adjust this date whenever revising the manpage.
.\"
.\" Some roff macros, for reference:
.\" .nh        disable hyphenation
.\" .hy        enable hyphenation
.\" .ad l      left justify
.\" .ad b      justify to both left and right margins
................................................................................

For example, to create a new database file named "mydata.db", create
a table named "memos" and insert a couple of records into that table:
.sp
$ 
.B sqlite3 mydata.db
.br
SQLite version 3.8.3
.br
Enter ".help" for instructions
.br
sqlite>
.B create table memos(text, priority INTEGER);
.br
sqlite>
................................................................................

A list of available meta-commands can be viewed at any time by issuing
the '.help' command.  For example:
.sp
sqlite>
.B .help
.nf
.cc |
.backup ?DB? FILE      Backup DB (default "main") to FILE
.bail ON|OFF           Stop after hitting an error.  Default OFF

.databases             List names and files of attached databases
.dump ?TABLE? ...      Dump the database in an SQL text format
                         If TABLE specified, only dump tables matching
                         LIKE pattern TABLE.
.echo ON|OFF           Turn command echo on or off

.exit                  Exit this program
.explain ?ON|OFF?      Turn output mode suitable for EXPLAIN on or off.
                         With no args, it turns EXPLAIN on.

.header(s) ON|OFF      Turn display of headers on or off
.help                  Show this message
.import FILE TABLE     Import data from FILE into TABLE
.indices ?TABLE?       Show names of all indices
                         If TABLE specified, only show indices for tables
                         matching LIKE pattern TABLE.
.load FILE ?ENTRY?     Load an extension library
.log FILE|off          Turn logging on or off.  FILE can be stderr/stdout
.mode MODE ?TABLE?     Set output mode where MODE is one of:
                         csv      Comma-separated values
                         column   Left-aligned columns.  (See .width)
                         html     HTML <table> code
                         insert   SQL insert statements for TABLE
                         line     One value per line
                         list     Values delimited by .separator string
                         tabs     Tab-separated values
                         tcl      TCL list elements
.nullvalue STRING      Use STRING in place of NULL values

.open ?FILENAME?       Close existing database and reopen FILENAME
.output FILENAME       Send output to FILENAME
.output stdout         Send output to the screen
.print STRING...       Print literal STRING
.prompt MAIN CONTINUE  Replace the standard prompts
.quit                  Exit this program
.read FILENAME         Execute SQL in FILENAME
.restore ?DB? FILE     Restore content of DB (default "main") from FILE

.schema ?TABLE?        Show the CREATE statements
                         If TABLE specified, only show tables matching
                         LIKE pattern TABLE.
.separator STRING      Change separator used by output mode and .import


.show                  Show the current values for various settings
.stats ON|OFF          Turn stats on or off

.tables ?TABLE?        List names of tables
                         If TABLE specified, only list tables matching
                         LIKE pattern TABLE.
.timeout MS            Try opening locked tables for MS milliseconds

.trace FILE|off        Output each SQL statement as it is run
.vfsname ?AUX?         Print the name of the VFS stack
.width NUM1 NUM2 ...   Set column widths for "column" mode
.timer ON|OFF          Turn the CPU timer measurement on or off

sqlite>
|cc .
.sp
.fi
.SH OPTIONS
.B sqlite3
has the following options:
.TP
.B \-bail
................................................................................
read and processed.  It should generally only contain meta-commands.

o If the -init option is present, the specified file is processed.

o All other command line options are processed.

.SH SEE ALSO
http://www.sqlite.org/
.br
The sqlite3-doc package.
.SH AUTHOR
This manual page was originally written by Andreas Rottmann
<rotty@debian.org>, for the Debian GNU/Linux system (but may be used
by others). It was subsequently revised by Bill Bumgarner <bbum@mac.com> and
further updated by Laszlo Boszormenyi <gcs@debian.hu> .

.\"                                      Hey, EMACS: -*- nroff -*-
.\" First parameter, NAME, should be all caps
.\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
.\" other parameters are allowed: see man(7), man(1)
.TH SQLITE3 1 "Fri Oct 31 10:41:31 EDT 2014"
.\" Please adjust this date whenever revising the manpage.
.\"
.\" Some roff macros, for reference:
.\" .nh        disable hyphenation
.\" .hy        enable hyphenation
.\" .ad l      left justify
.\" .ad b      justify to both left and right margins
................................................................................

For example, to create a new database file named "mydata.db", create
a table named "memos" and insert a couple of records into that table:
.sp
$ 
.B sqlite3 mydata.db
.br
SQLite version 3.8.8
.br
Enter ".help" for instructions
.br
sqlite>
.B create table memos(text, priority INTEGER);
.br
sqlite>
................................................................................

A list of available meta-commands can be viewed at any time by issuing
the '.help' command.  For example:
.sp
sqlite>
.B .help
.nf
.tr %.
%backup ?DB? FILE      Backup DB (default "main") to FILE
%bail on|off           Stop after hitting an error.  Default OFF
%clone NEWDB           Clone data into NEWDB from the existing database
%databases             List names and files of attached databases
%dump ?TABLE? ...      Dump the database in an SQL text format
                         If TABLE specified, only dump tables matching
                         LIKE pattern TABLE.
%echo on|off           Turn command echo on or off
%eqp on|off            Enable or disable automatic EXPLAIN QUERY PLAN
%exit                  Exit this program
%explain ?on|off?      Turn output mode suitable for EXPLAIN on or off.
                         With no args, it turns EXPLAIN on.
%fullschema            Show schema and the content of sqlite_stat tables
%headers on|off        Turn display of headers on or off
%help                  Show this message
%import FILE TABLE     Import data from FILE into TABLE
%indices ?TABLE?       Show names of all indices
                         If TABLE specified, only show indices for tables
                         matching LIKE pattern TABLE.
%load FILE ?ENTRY?     Load an extension library
%log FILE|off          Turn logging on or off.  FILE can be stderr/stdout
%mode MODE ?TABLE?     Set output mode where MODE is one of:
                         csv      Comma-separated values
                         column   Left-aligned columns.  (See .width)
                         html     HTML <table> code
                         insert   SQL insert statements for TABLE
                         line     One value per line
                         list     Values delimited by .separator string
                         tabs     Tab-separated values
                         tcl      TCL list elements
%nullvalue STRING      Use STRING in place of NULL values
%once FILENAME         Output for the next SQL command only to FILENAME
%open ?FILENAME?       Close existing database and reopen FILENAME
%output ?FILENAME?     Send output to FILENAME or stdout

%print STRING...       Print literal STRING
%prompt MAIN CONTINUE  Replace the standard prompts
%quit                  Exit this program
%read FILENAME         Execute SQL in FILENAME
%restore ?DB? FILE     Restore content of DB (default "main") from FILE
%save FILE             Write in-memory database into FILE
%schema ?TABLE?        Show the CREATE statements
                         If TABLE specified, only show tables matching
                         LIKE pattern TABLE.
%separator STRING ?NL? Change separator used by output mode and .import
                         NL is the end-of-line mark for CSV
%shell CMD ARGS...     Run CMD ARGS... in a system shell
%show                  Show the current values for various settings
%stats on|off          Turn stats on or off
%system CMD ARGS...    Run CMD ARGS... in a system shell
%tables ?TABLE?        List names of tables
                         If TABLE specified, only list tables matching
                         LIKE pattern TABLE.
%timeout MS            Try opening locked tables for MS milliseconds
%timer on|off          Turn SQL timer on or off
%trace FILE|off        Output each SQL statement as it is run
%vfsname ?AUX?         Print the name of the VFS stack
%width NUM1 NUM2 ...   Set column widths for "column" mode

                         Negative values right-justify
sqlite>

.sp
.fi
.SH OPTIONS
.B sqlite3
has the following options:
.TP
.B \-bail
................................................................................
read and processed.  It should generally only contain meta-commands.

o If the -init option is present, the specified file is processed.

o All other command line options are processed.

.SH SEE ALSO
http://www.sqlite.org/cli.html
.br
The sqlite3-doc package.
.SH AUTHOR
This manual page was originally written by Andreas Rottmann
<rotty@debian.org>, for the Debian GNU/Linux system (but may be used
by others). It was subsequently revised by Bill Bumgarner <bbum@mac.com> and
further updated by Laszlo Boszormenyi <gcs@debian.hu> .

  int i;
  tRowcnt v;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( z==0 ) z = "";
#else
  assert( z!=0 );


#endif
  for(i=0; *z && i<nOut; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
................................................................................
  if( pIndex )
#endif
  while( z[0] ){
    if( sqlite3_strglob("unordered*", z)==0 ){
      pIndex->bUnordered = 1;
    }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
      pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));


    }
#ifdef SQLITE_ENABLE_COSTMULT
    else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
      pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
    }
#endif
    while( z[0]!=0 && z[0]!=' ' ) z++;
................................................................................
        nRow = pFinal->anLt[iCol];
        nDist100 = (i64)100 * pFinal->anDLt[iCol];
        nSample--;
      }else{
        nRow = pIdx->aiRowEst[0];
        nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];
      }


      /* Set nSum to the number of distinct (iCol+1) field prefixes that
      ** occur in the stat4 table for this index. Set sumEq to the sum of 
      ** the nEq values for column iCol for the same set (adding the value 
      ** only once where there exist duplicate prefixes).  */
      for(i=0; i<nSample; i++){
        if( i==(pIdx->nSample-1)
................................................................................
    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( rc==SQLITE_OK ){
    int lookasideEnabled = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;
    rc = loadStat4(db, sInfo.zDatabase);
    db->lookaside.bEnabled = lookasideEnabled;
  }
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);

  int i;
  tRowcnt v;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( z==0 ) z = "";
#else
  assert( z!=0 );
  pIndex->bUnordered = 0;
  pIndex->noSkipScan = 0;
#endif
  for(i=0; *z && i<nOut; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
................................................................................
  if( pIndex )
#endif
  while( z[0] ){
    if( sqlite3_strglob("unordered*", z)==0 ){
      pIndex->bUnordered = 1;
    }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
      pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));
    }else if( sqlite3_strglob("noskipscan*", z)==0 ){
      pIndex->noSkipScan = 1;
    }
#ifdef SQLITE_ENABLE_COSTMULT
    else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
      pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
    }
#endif
    while( z[0]!=0 && z[0]!=' ' ) z++;
................................................................................
        nRow = pFinal->anLt[iCol];
        nDist100 = (i64)100 * pFinal->anDLt[iCol];
        nSample--;
      }else{
        nRow = pIdx->aiRowEst[0];
        nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];
      }
      pIdx->nRowEst0 = nRow;

      /* Set nSum to the number of distinct (iCol+1) field prefixes that
      ** occur in the stat4 table for this index. Set sumEq to the sum of 
      ** the nEq values for column iCol for the same set (adding the value 
      ** only once where there exist duplicate prefixes).  */
      for(i=0; i<nSample; i++){
        if( i==(pIdx->nSample-1)
................................................................................
    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( rc==SQLITE_OK && OptimizationEnabled(db, SQLITE_Stat34) ){
    int lookasideEnabled = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;
    rc = loadStat4(db, sInfo.zDatabase);
    db->lookaside.bEnabled = lookasideEnabled;
  }
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);

** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){



  sqlite3_mutex_enter(db->mutex);
  db->xAuth = (sqlite3_xauth)xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->xAuth = (sqlite3_xauth)xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

** of the source.
*/
static int setDestPgsz(sqlite3_backup *p){
  int rc;
  rc = sqlite3BtreeSetPageSize(p->pDest,sqlite3BtreeGetPageSize(p->pSrc),-1,0);
  return rc;
}















/*
** Create an sqlite3_backup process to copy the contents of zSrcDb from
** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
** a pointer to the new sqlite3_backup object.
**
** If an error occurs, NULL is returned and an error code and error message
................................................................................
sqlite3_backup *sqlite3_backup_init(
  sqlite3* pDestDb,                     /* Database to write to */
  const char *zDestDb,                  /* Name of database within pDestDb */
  sqlite3* pSrcDb,                      /* Database connection to read from */
  const char *zSrcDb                    /* Name of database within pSrcDb */
){
  sqlite3_backup *p;                    /* Value to return */








  /* Lock the source database handle. The destination database
  ** handle is not locked in this routine, but it is locked in
  ** sqlite3_backup_step(). The user is required to ensure that no
  ** other thread accesses the destination handle for the duration
  ** of the backup operation.  Any attempt to use the destination
  ** database connection while a backup is in progress may cause
................................................................................
    p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);
    p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
    p->pDestDb = pDestDb;
    p->pSrcDb = pSrcDb;
    p->iNext = 1;
    p->isAttached = 0;


    if( 0==p->pSrc || 0==p->pDest || setDestPgsz(p)==SQLITE_NOMEM ){


      /* One (or both) of the named databases did not exist or an OOM

      ** error was hit.  The error has already been written into the
      ** pDestDb handle.  All that is left to do here is free the
      ** sqlite3_backup structure.
      */
      sqlite3_free(p);
      p = 0;
    }
  }
  if( p ){
    p->pSrc->nBackup++;
  }
................................................................................
*/
int sqlite3_backup_step(sqlite3_backup *p, int nPage){
  int rc;
  int destMode;       /* Destination journal mode */
  int pgszSrc = 0;    /* Source page size */
  int pgszDest = 0;   /* Destination page size */




  sqlite3_mutex_enter(p->pSrcDb->mutex);
  sqlite3BtreeEnter(p->pSrc);
  if( p->pDestDb ){
    sqlite3_mutex_enter(p->pDestDb->mutex);
  }

  rc = p->rc;
................................................................................
    while( *pp!=p ){
      pp = &(*pp)->pNext;
    }
    *pp = p->pNext;
  }

  /* If a transaction is still open on the Btree, roll it back. */
  sqlite3BtreeRollback(p->pDest, SQLITE_OK);

  /* Set the error code of the destination database handle. */
  rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
  if( p->pDestDb ){
    sqlite3Error(p->pDestDb, rc);

    /* Exit the mutexes and free the backup context structure. */
................................................................................
}

/*
** Return the number of pages still to be backed up as of the most recent
** call to sqlite3_backup_step().
*/
int sqlite3_backup_remaining(sqlite3_backup *p){






  return p->nRemaining;
}

/*
** Return the total number of pages in the source database as of the most 
** recent call to sqlite3_backup_step().
*/
int sqlite3_backup_pagecount(sqlite3_backup *p){






  return p->nPagecount;
}

/*
** This function is called after the contents of page iPage of the
** source database have been modified. If page iPage has already been 
** copied into the destination database, then the data written to the

** of the source.
*/
static int setDestPgsz(sqlite3_backup *p){
  int rc;
  rc = sqlite3BtreeSetPageSize(p->pDest,sqlite3BtreeGetPageSize(p->pSrc),-1,0);
  return rc;
}

/*
** Check that there is no open read-transaction on the b-tree passed as the
** second argument. If there is not, return SQLITE_OK. Otherwise, if there
** is an open read-transaction, return SQLITE_ERROR and leave an error 
** message in database handle db.
*/
static int checkReadTransaction(sqlite3 *db, Btree *p){
  if( sqlite3BtreeIsInReadTrans(p) ){
    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}

/*
** Create an sqlite3_backup process to copy the contents of zSrcDb from
** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
** a pointer to the new sqlite3_backup object.
**
** If an error occurs, NULL is returned and an error code and error message
................................................................................
sqlite3_backup *sqlite3_backup_init(
  sqlite3* pDestDb,                     /* Database to write to */
  const char *zDestDb,                  /* Name of database within pDestDb */
  sqlite3* pSrcDb,                      /* Database connection to read from */
  const char *zSrcDb                    /* Name of database within pSrcDb */
){
  sqlite3_backup *p;                    /* Value to return */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(pSrcDb)||!sqlite3SafetyCheckOk(pDestDb) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif

  /* Lock the source database handle. The destination database
  ** handle is not locked in this routine, but it is locked in
  ** sqlite3_backup_step(). The user is required to ensure that no
  ** other thread accesses the destination handle for the duration
  ** of the backup operation.  Any attempt to use the destination
  ** database connection while a backup is in progress may cause
................................................................................
    p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);
    p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
    p->pDestDb = pDestDb;
    p->pSrcDb = pSrcDb;
    p->iNext = 1;
    p->isAttached = 0;

    if( 0==p->pSrc || 0==p->pDest 
     || setDestPgsz(p)==SQLITE_NOMEM 
     || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 
     ){
      /* One (or both) of the named databases did not exist or an OOM
      ** error was hit. Or there is a transaction open on the destination
      ** database. The error has already been written into the pDestDb 
      ** handle. All that is left to do here is free the sqlite3_backup 
      ** structure.  */

      sqlite3_free(p);
      p = 0;
    }
  }
  if( p ){
    p->pSrc->nBackup++;
  }
................................................................................
*/
int sqlite3_backup_step(sqlite3_backup *p, int nPage){
  int rc;
  int destMode;       /* Destination journal mode */
  int pgszSrc = 0;    /* Source page size */
  int pgszDest = 0;   /* Destination page size */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( p==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(p->pSrcDb->mutex);
  sqlite3BtreeEnter(p->pSrc);
  if( p->pDestDb ){
    sqlite3_mutex_enter(p->pDestDb->mutex);
  }

  rc = p->rc;
................................................................................
    while( *pp!=p ){
      pp = &(*pp)->pNext;
    }
    *pp = p->pNext;
  }

  /* If a transaction is still open on the Btree, roll it back. */
  sqlite3BtreeRollback(p->pDest, SQLITE_OK, 0);

  /* Set the error code of the destination database handle. */
  rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
  if( p->pDestDb ){
    sqlite3Error(p->pDestDb, rc);

    /* Exit the mutexes and free the backup context structure. */
................................................................................
}

/*
** Return the number of pages still to be backed up as of the most recent
** call to sqlite3_backup_step().
*/
int sqlite3_backup_remaining(sqlite3_backup *p){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( p==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return p->nRemaining;
}

/*
** Return the total number of pages in the source database as of the most 
** recent call to sqlite3_backup_step().
*/
int sqlite3_backup_pagecount(sqlite3_backup *p){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( p==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return p->nPagecount;
}

/*
** This function is called after the contents of page iPage of the
** source database have been modified. If page iPage has already been 
** copied into the destination database, then the data written to the

/*
** Defragment the page given.  All Cells are moved to the
** end of the page and all free space is collected into one
** big FreeBlk that occurs in between the header and cell
** pointer array and the cell content area.





*/
static int defragmentPage(MemPage *pPage){
  int i;                     /* Loop counter */
  int pc;                    /* Address of the i-th cell */
  int hdr;                   /* Offset to the page header */
  int size;                  /* Size of a cell */
  int usableSize;            /* Number of usable bytes on a page */
  int cellOffset;            /* Offset to the cell pointer array */
  int cbrk;                  /* Offset to the cell content area */
  int nCell;                 /* Number of cells on the page */
  unsigned char *data;       /* The page data */
  unsigned char *temp;       /* Temp area for cell content */

  int iCellFirst;            /* First allowable cell index */
  int iCellLast;             /* Last possible cell index */


  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt!=0 );
  assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
  assert( pPage->nOverflow==0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
  data = pPage->aData;
  hdr = pPage->hdrOffset;
  cellOffset = pPage->cellOffset;
  nCell = pPage->nCell;
  assert( nCell==get2byte(&data[hdr+3]) );
  usableSize = pPage->pBt->usableSize;
  cbrk = get2byte(&data[hdr+5]);
  memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
  cbrk = usableSize;
  iCellFirst = cellOffset + 2*nCell;
  iCellLast = usableSize - 4;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
................................................................................
    ** if SQLITE_ENABLE_OVERSIZE_CELL_CHECK is defined 
    */
    if( pc<iCellFirst || pc>iCellLast ){
      return SQLITE_CORRUPT_BKPT;
    }
#endif
    assert( pc>=iCellFirst && pc<=iCellLast );
    size = cellSizePtr(pPage, &temp[pc]);
    cbrk -= size;
#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
    if( cbrk<iCellFirst ){
      return SQLITE_CORRUPT_BKPT;
    }
#else
    if( cbrk<iCellFirst || pc+size>usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
#endif
    assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
    testcase( cbrk+size==usableSize );
    testcase( pc+size==usableSize );
    memcpy(&data[cbrk], &temp[pc], size);
    put2byte(pAddr, cbrk);









  }
  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  data[hdr+7] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  if( cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_BKPT;
  }
  return SQLITE_OK;
}
































































/*
** Allocate nByte bytes of space from within the B-Tree page passed
** as the first argument. Write into *pIdx the index into pPage->aData[]
** of the first byte of allocated space. Return either SQLITE_OK or
** an error code (usually SQLITE_CORRUPT).
**
................................................................................
** allocation is being made in order to insert a new cell, so we will
** also end up needing a new cell pointer.
*/
static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
  const int hdr = pPage->hdrOffset;    /* Local cache of pPage->hdrOffset */
  u8 * const data = pPage->aData;      /* Local cache of pPage->aData */
  int top;                             /* First byte of cell content area */

  int gap;        /* First byte of gap between cell pointers and cell content */
  int rc;         /* Integer return code */
  int usableSize; /* Usable size of the page */
  
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nByte>=0 );  /* Minimum cell size is 4 */
  assert( pPage->nFree>=nByte );
  assert( pPage->nOverflow==0 );
  usableSize = pPage->pBt->usableSize;
  assert( nByte < usableSize-8 );

  assert( pPage->cellOffset == hdr + 12 - 4*pPage->leaf );
  gap = pPage->cellOffset + 2*pPage->nCell;
  assert( gap<=65536 );
  top = get2byte(&data[hdr+5]);
  if( gap>top ){
    if( top==0 ){
      top = 65536;
    }else{
      return SQLITE_CORRUPT_BKPT;
    }
  }

  /* If there is enough space between gap and top for one more cell pointer
  ** array entry offset, and if the freelist is not empty, then search the
  ** freelist looking for a free slot big enough to satisfy the request.
  */
  testcase( gap+2==top );
  testcase( gap+1==top );
  testcase( gap==top );
  if( gap+2<=top && (data[hdr+1] || data[hdr+2]) ){
    int pc, addr;
    for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
      int size;            /* Size of the free slot */
      if( pc>usableSize-4 || pc<addr+4 ){
        return SQLITE_CORRUPT_BKPT;
      }
      size = get2byte(&data[pc+2]);
      if( size>=nByte ){
        int x = size - nByte;
        testcase( x==4 );
        testcase( x==3 );
        if( x<4 ){
          if( data[hdr+7]>=60 ) goto defragment_page;
          /* Remove the slot from the free-list. Update the number of
          ** fragmented bytes within the page. */
          memcpy(&data[addr], &data[pc], 2);
          data[hdr+7] += (u8)x;
        }else if( size+pc > usableSize ){
          return SQLITE_CORRUPT_BKPT;
        }else{
          /* The slot remains on the free-list. Reduce its size to account
          ** for the portion used by the new allocation. */
          put2byte(&data[pc+2], x);
        }


        *pIdx = pc + x;
        return SQLITE_OK;
      }
    }
  }

  /* The request could not be fulfilled using a freelist slot.  Check
  ** to see if defragmentation is necessary.
  */
  testcase( gap+2+nByte==top );
  if( gap+2+nByte>top ){
defragment_page:
    testcase( pPage->nCell==0 );
    rc = defragmentPage(pPage);
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
    assert( gap+nByte<=top );
  }

................................................................................
  u32 iLast = pPage->pBt->usableSize-4; /* Largest possible freeblock offset */
  u32 iEnd = iStart + iSize;            /* First byte past the iStart buffer */
  unsigned char *data = pPage->aData;   /* Page content */

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
  assert( iEnd <= pPage->pBt->usableSize );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( iSize>=4 );   /* Minimum cell size is 4 */
  assert( iStart<=iLast );

  /* Overwrite deleted information with zeros when the secure_delete
  ** option is enabled */
  if( pPage->pBt->btsFlags & BTS_SECURE_DELETE ){
................................................................................
  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
  flagByte &= ~PTF_LEAF;
  pPage->childPtrSize = 4-4*pPage->leaf;
  pBt = pPage->pBt;
  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){






    pPage->intKey = 1;
    pPage->intKeyLeaf = pPage->leaf;
    pPage->noPayload = !pPage->leaf;
    pPage->maxLocal = pBt->maxLeaf;
    pPage->minLocal = pBt->minLeaf;
  }else if( flagByte==PTF_ZERODATA ){






    pPage->intKey = 0;
    pPage->intKeyLeaf = 0;
    pPage->noPayload = 0;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }else{


    return SQLITE_CORRUPT_BKPT;
  }
  pPage->max1bytePayload = pBt->max1bytePayload;
  return SQLITE_OK;
}

/*
................................................................................
    int iCellFirst;    /* First allowable cell or freeblock offset */
    int iCellLast;     /* Last possible cell or freeblock offset */

    pBt = pPage->pBt;

    hdr = pPage->hdrOffset;
    data = pPage->aData;


    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
    assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
    pPage->maskPage = (u16)(pBt->pageSize - 1);
    pPage->nOverflow = 0;
    usableSize = pBt->usableSize;
    pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
    pPage->aDataEnd = &data[usableSize];
    pPage->aCellIdx = &data[cellOffset];



    top = get2byteNotZero(&data[hdr+5]);


    pPage->nCell = get2byte(&data[hdr+3]);
    if( pPage->nCell>MX_CELL(pBt) ){
      /* To many cells for a single page.  The page must be corrupt */
      return SQLITE_CORRUPT_BKPT;
    }
    testcase( pPage->nCell==MX_CELL(pBt) );






    /* A malformed database page might cause us to read past the end
    ** of page when parsing a cell.  
    **
    ** The following block of code checks early to see if a cell extends
    ** past the end of a page boundary and causes SQLITE_CORRUPT to be 
    ** returned if it does.
................................................................................
          return SQLITE_CORRUPT_BKPT;
        }
      }
      if( !pPage->leaf ) iCellLast++;
    }  
#endif

    /* Compute the total free space on the page */



    pc = get2byte(&data[hdr+1]);
    nFree = data[hdr+7] + top;
    while( pc>0 ){
      u16 next, size;
      if( pc<iCellFirst || pc>iCellLast ){



        /* Start of free block is off the page */

        return SQLITE_CORRUPT_BKPT; 
      }
      next = get2byte(&data[pc]);
      size = get2byte(&data[pc+2]);
      if( (next>0 && next<=pc+size+3) || pc+size>usableSize ){
        /* Free blocks must be in ascending order. And the last byte of
        ** the free-block must lie on the database page.  */
................................................................................
  
    pBt->pCursor = 0;
    pBt->pPage1 = 0;
    if( sqlite3PagerIsreadonly(pBt->pPager) ) pBt->btsFlags |= BTS_READ_ONLY;
#ifdef SQLITE_SECURE_DELETE
    pBt->btsFlags |= BTS_SECURE_DELETE;
#endif



    pBt->pageSize = (zDbHeader[16]<<8) | (zDbHeader[17]<<16);
    if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
         || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
      pBt->pageSize = 0;
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the magic name ":memory:" will create an in-memory database, then
      ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if
................................................................................
      if( zFilename && !isMemdb ){
        pBt->autoVacuum = (SQLITE_DEFAULT_AUTOVACUUM ? 1 : 0);
        pBt->incrVacuum = (SQLITE_DEFAULT_AUTOVACUUM==2 ? 1 : 0);
      }
#endif
      nReserve = 0;
    }else{



      nReserve = zDbHeader[20];
      pBt->btsFlags |= BTS_PAGESIZE_FIXED;
#ifndef SQLITE_OMIT_AUTOVACUUM
      pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
      pBt->incrVacuum = (get4byte(&zDbHeader[36 + 7*4])?1:0);
#endif
    }
................................................................................
    }
  }

  /* Rollback any active transaction and free the handle structure.
  ** The call to sqlite3BtreeRollback() drops any table-locks held by
  ** this handle.
  */
  sqlite3BtreeRollback(p, SQLITE_OK);
  sqlite3BtreeLeave(p);

  /* If there are still other outstanding references to the shared-btree
  ** structure, return now. The remainder of this procedure cleans 
  ** up the shared-btree.
  */
  assert( p->wantToLock==0 && p->locked==0 );
................................................................................
    nPage = nPageFile;
  }
  if( nPage>0 ){
    u32 pageSize;
    u32 usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;



    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }

#ifdef SQLITE_OMIT_WAL
    if( page1[18]>1 ){
      pBt->btsFlags |= BTS_READ_ONLY;
................................................................................
        releasePage(pPage1);
        return SQLITE_OK;
      }
      rc = SQLITE_NOTADB;
    }
#endif

    /* The maximum embedded fraction must be exactly 25%.  And the minimum
    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.

    ** The original design allowed these amounts to vary, but as of
    ** version 3.6.0, we require them to be fixed.
    */
    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
      goto page1_init_failed;
    }



    pageSize = (page1[16]<<8) | (page1[17]<<16);


    if( ((pageSize-1)&pageSize)!=0
     || pageSize>SQLITE_MAX_PAGE_SIZE 
     || pageSize<=256 
    ){
      goto page1_init_failed;
    }
    assert( (pageSize & 7)==0 );







    usableSize = pageSize - page1[20];
    if( (u32)pageSize!=pBt->pageSize ){
      /* After reading the first page of the database assuming a page size
      ** of BtShared.pageSize, we have discovered that the page-size is
      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
      ** zero and return SQLITE_OK. The caller will call this function
      ** again with the correct page-size.
................................................................................
                                   pageSize-usableSize);
      return rc;
    }
    if( (pBt->db->flags & SQLITE_RecoveryMode)==0 && nPage>nPageFile ){
      rc = SQLITE_CORRUPT_BKPT;
      goto page1_init_failed;
    }



    if( usableSize<480 ){
      goto page1_init_failed;
    }
    pBt->pageSize = pageSize;
    pBt->usableSize = usableSize;
#ifndef SQLITE_OMIT_AUTOVACUUM
    pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
................................................................................
  }
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** This routine sets the state to CURSOR_FAULT and the error
** code to errCode for every cursor on BtShared that pBtree
** references.

**
** Every cursor is tripped, including cursors that belong
** to other database connections that happen to be sharing
** the cache with pBtree.
**
** This routine gets called when a rollback occurs.
** All cursors using the same cache must be tripped
** to prevent them from trying to use the btree after
** the rollback.  The rollback may have deleted tables
** or moved root pages, so it is not sufficient to
** save the state of the cursor.  The cursor must be
** invalidated.









*/
void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
  BtCursor *p;



  if( pBtree==0 ) return;
  sqlite3BtreeEnter(pBtree);
  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
    int i;









    sqlite3BtreeClearCursor(p);
    p->eState = CURSOR_FAULT;
    p->skipNext = errCode;

    for(i=0; i<=p->iPage; i++){
      releasePage(p->apPage[i]);
      p->apPage[i] = 0;
    }
  }
  sqlite3BtreeLeave(pBtree);
}



/*
** Rollback the transaction in progress.  All cursors will be



** invalided by this operation.  Any attempt to use a cursor
** that was open at the beginning of this operation will result
** in an error.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeRollback(Btree *p, int tripCode){
  int rc;
  BtShared *pBt = p->pBt;
  MemPage *pPage1;



  sqlite3BtreeEnter(p);
  if( tripCode==SQLITE_OK ){
    rc = tripCode = saveAllCursors(pBt, 0, 0);

  }else{
    rc = SQLITE_OK;
  }
  if( tripCode ){
    sqlite3BtreeTripAllCursors(p, tripCode);


  }
  btreeIntegrity(p);

  if( p->inTrans==TRANS_WRITE ){
    int rc2;

    assert( TRANS_WRITE==pBt->inTransaction );
................................................................................
**
** The caller must position the cursor prior to invoking this routine.
** 
** This routine cannot fail.  It always returns SQLITE_OK.  
*/
int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
  if( pCur->eState!=CURSOR_VALID ){
    *pSize = 0;
  }else{
    getCellInfo(pCur);
    *pSize = pCur->info.nKey;
  }
  return SQLITE_OK;
}

/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to.
**
................................................................................
  MemPage *pPrevTrunk = 0;
  Pgno mxPage;     /* Total size of the database file */

  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
  pPage1 = pBt->pPage1;
  mxPage = btreePagecount(pBt);


  n = get4byte(&pPage1->aData[36]);
  testcase( n==mxPage-1 );
  if( n>=mxPage ){
    return SQLITE_CORRUPT_BKPT;
  }
  if( n>0 ){
    /* There are pages on the freelist.  Reuse one of those pages. */
................................................................................
    ** is not true. Otherwise, it runs once for each trunk-page on the
    ** free-list until the page 'nearby' is located (eMode==BTALLOC_EXACT)
    ** or until a page less than 'nearby' is located (eMode==BTALLOC_LT)
    */
    do {
      pPrevTrunk = pTrunk;
      if( pPrevTrunk ){



        iTrunk = get4byte(&pPrevTrunk->aData[0]);
      }else{



        iTrunk = get4byte(&pPage1->aData[32]);
      }
      testcase( iTrunk==mxPage );
      if( iTrunk>mxPage ){
        rc = SQLITE_CORRUPT_BKPT;
      }else{
        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
................................................................................
      }
      if( rc ){
        pTrunk = 0;
        goto end_allocate_page;
      }
      assert( pTrunk!=0 );
      assert( pTrunk->aData!=0 );

      k = get4byte(&pTrunk->aData[4]); /* # of leaves on this trunk page */

      if( k==0 && !searchList ){
        /* The trunk has no leaves and the list is not being searched. 
        ** So extract the trunk page itself and use it as the newly 
        ** allocated page */
        assert( pPrevTrunk==0 );
        rc = sqlite3PagerWrite(pTrunk->pDbPage);
        if( rc ){
................................................................................
      ** 3.6.0, databases with freelist trunk pages holding more than
      ** usableSize/4 - 8 entries will be reported as corrupt.  In order
      ** to maintain backwards compatibility with older versions of SQLite,
      ** we will continue to restrict the number of entries to usableSize/4 - 8
      ** for now.  At some point in the future (once everyone has upgraded
      ** to 3.6.0 or later) we should consider fixing the conditional above
      ** to read "usableSize/4-2" instead of "usableSize/4-8".





      */
      rc = sqlite3PagerWrite(pTrunk->pDbPage);
      if( rc==SQLITE_OK ){
        put4byte(&pTrunk->aData[4], nLeaf+1);
        put4byte(&pTrunk->aData[8+nLeaf*4], iPage);
        if( pPage && (pBt->btsFlags & BTS_SECURE_DELETE)==0 ){
          sqlite3PagerDontWrite(pPage->pDbPage);
................................................................................
  }
  rc = freeSpace(pPage, pc, sz);
  if( rc ){
    *pRC = rc;
    return;
  }
  pPage->nCell--;







  memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
  put2byte(&data[hdr+3], pPage->nCell);
  pPage->nFree += 2;

}

/*
** Insert a new cell on pPage at cell index "i".  pCell points to the
** content of the cell.
**
** If the cell content will fit on the page, then put it there.  If it
................................................................................
      ptrmapPutOvflPtr(pPage, pCell, pRC);
    }
#endif
  }
}

/*
** Add a list of cells to a page.  The page should be initially empty.
** The cells are guaranteed to fit on the page.









*/
static void assemblePage(
  MemPage *pPage,   /* The page to be assembled */
  int nCell,        /* The number of cells to add to this page */


  u8 **apCell,      /* Pointers to cell bodies */
  u16 *aSize        /* Sizes of the cells */

){
  int i;            /* Loop counter */
  u8 *pCellptr;     /* Address of next cell pointer */
  int cellbody;     /* Address of next cell body */
  u8 * const data = pPage->aData;             /* Pointer to data for pPage */
  const int hdr = pPage->hdrOffset;           /* Offset of header on pPage */
  const int nUsable = pPage->pBt->usableSize; /* Usable size of page */



























  assert( pPage->nOverflow==0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nCell>=0 && nCell<=(int)MX_CELL(pPage->pBt)
            && (int)MX_CELL(pPage->pBt)<=10921);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  /* Check that the page has just been zeroed by zeroPage() */
  assert( pPage->nCell==0 );
  assert( get2byteNotZero(&data[hdr+5])==nUsable );





  pCellptr = &pPage->aCellIdx[nCell*2];
  cellbody = nUsable;
  for(i=nCell-1; i>=0; i--){
    u16 sz = aSize[i];



















































    pCellptr -= 2;






































    cellbody -= sz;
































    put2byte(pCellptr, cellbody);
    memcpy(&data[cellbody], apCell[i], sz);



  }
  put2byte(&data[hdr+3], nCell);
  put2byte(&data[hdr+5], cellbody);
  pPage->nFree -= (nCell*2 + nUsable - cellbody);























































  pPage->nCell = (u16)nCell;




















}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
................................................................................
    u8 *pCell = pPage->apOvfl[0];
    u16 szCell = cellSizePtr(pPage, pCell);
    u8 *pStop;

    assert( sqlite3PagerIswriteable(pNew->pDbPage) );
    assert( pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
    zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
    assemblePage(pNew, 1, &pCell, &szCell);


    /* If this is an auto-vacuum database, update the pointer map
    ** with entries for the new page, and any pointer from the 
    ** cell on the page to an overflow page. If either of these
    ** operations fails, the return code is set, but the contents
    ** of the parent page are still manipulated by thh code below.
    ** That is Ok, at this point the parent page is guaranteed to
................................................................................
  int usableSpace;             /* Bytes in pPage beyond the header */
  int pageFlags;               /* Value of pPage->aData[0] */
  int subtotal;                /* Subtotal of bytes in cells on one page */
  int iSpace1 = 0;             /* First unused byte of aSpace1[] */
  int iOvflSpace = 0;          /* First unused byte of aOvflSpace[] */
  int szScratch;               /* Size of scratch memory requested */
  MemPage *apOld[NB];          /* pPage and up to two siblings */
  MemPage *apCopy[NB];         /* Private copies of apOld[] pages */
  MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
  u8 *pRight;                  /* Location in parent of right-sibling pointer */
  u8 *apDiv[NB-1];             /* Divider cells in pParent */
  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */

  int szNew[NB+2];             /* Combined size of cells place on i-th page */
  u8 **apCell = 0;             /* All cells begin balanced */
  u16 *szCell;                 /* Local size of all cells in apCell[] */
  u8 *aSpace1;                 /* Space for copies of dividers cells */
  Pgno pgno;                   /* Temp var to store a page number in */






  pBt = pParent->pBt;
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( sqlite3PagerIswriteable(pParent->pDbPage) );

#if 0
  TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));
#endif
................................................................................
  /* Make nMaxCells a multiple of 4 in order to preserve 8-byte
  ** alignment */
  nMaxCells = (nMaxCells + 3)&~3;

  /*
  ** Allocate space for memory structures
  */
  k = pBt->pageSize + ROUND8(sizeof(MemPage));
  szScratch =
       nMaxCells*sizeof(u8*)                       /* apCell */
     + nMaxCells*sizeof(u16)                       /* szCell */
     + pBt->pageSize                               /* aSpace1 */
     + k*nOld;                                     /* Page copies (apCopy) */




  apCell = sqlite3ScratchMalloc( szScratch ); 
  if( apCell==0 ){
    rc = SQLITE_NOMEM;
    goto balance_cleanup;
  }
  szCell = (u16*)&apCell[nMaxCells];
  aSpace1 = (u8*)&szCell[nMaxCells];
  assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );

  /*
  ** Load pointers to all cells on sibling pages and the divider cells
  ** into the local apCell[] array.  Make copies of the divider cells
  ** into space obtained from aSpace1[] and remove the divider cells
  ** from pParent.
  **
  ** If the siblings are on leaf pages, then the child pointers of the
  ** divider cells are stripped from the cells before they are copied
  ** into aSpace1[].  In this way, all cells in apCell[] are without
  ** child pointers.  If siblings are not leaves, then all cell in
  ** apCell[] include child pointers.  Either way, all cells in apCell[]
  ** are alike.
................................................................................
  ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
  **       leafData:  1 if pPage holds key+data and pParent holds only keys.
  */
  leafCorrection = apOld[0]->leaf*4;
  leafData = apOld[0]->intKeyLeaf;
  for(i=0; i<nOld; i++){
    int limit;
    
    /* Before doing anything else, take a copy of the i'th original sibling
    ** The rest of this function will use data from the copies rather
    ** that the original pages since the original pages will be in the
    ** process of being overwritten.  */
    MemPage *pOld = apCopy[i] = (MemPage*)&aSpace1[pBt->pageSize + k*i];
    memcpy(pOld, apOld[i], sizeof(MemPage));
    pOld->aData = (void*)&pOld[1];
    memcpy(pOld->aData, apOld[i]->aData, pBt->pageSize);

    limit = pOld->nCell+pOld->nOverflow;
    if( pOld->nOverflow>0 ){
      for(j=0; j<limit; j++){
        assert( nCell<nMaxCells );
        apCell[nCell] = findOverflowCell(pOld, j);
        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
................................................................................
      for(j=0; j<limit; j++){
        assert( nCell<nMaxCells );
        apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
        nCell++;
      }
    }       

    if( i<nOld-1 && !leafData){
      u16 sz = (u16)szNew[i];
      u8 *pTemp;
      assert( nCell<nMaxCells );
      szCell[nCell] = sz;
      pTemp = &aSpace1[iSpace1];
      iSpace1 += sz;
................................................................................
  ** 
  */
  usableSpace = pBt->usableSize - 12 + leafCorrection;
  for(subtotal=k=i=0; i<nCell; i++){
    assert( i<nMaxCells );
    subtotal += szCell[i] + 2;
    if( subtotal > usableSpace ){
      szNew[k] = subtotal - szCell[i];
      cntNew[k] = i;
      if( leafData ){ i--; }
      subtotal = 0;
      k++;
      if( k>NB+1 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
    }
  }
  szNew[k] = subtotal;
  cntNew[k] = nCell;
  k++;

  /*
  ** The packing computed by the previous block is biased toward the siblings
  ** on the left side.  The left siblings are always nearly full, while the
  ** right-most sibling might be nearly empty.  This block of code attempts

  ** to adjust the packing of siblings to get a better balance.
  **
  ** This adjustment is more than an optimization.  The packing above might
  ** be so out of balance as to be illegal.  For example, the right-most
  ** sibling might be completely empty.  This adjustment is not optional.
  */
  for(i=k-1; i>0; i--){
    int szRight = szNew[i];  /* Size of sibling on the right */
................................................................................
      r = cntNew[i-1] - 1;
      d = r + 1 - leafData;
    }
    szNew[i] = szRight;
    szNew[i-1] = szLeft;
  }



  /* Either we found one or more cells (cntnew[0])>0) or pPage is
  ** a virtual root page.  A virtual root page is when the real root
  ** page is page 1 and we are the only child of that page.
  **
  ** UPDATE:  The assert() below is not necessarily true if the database
  ** file is corrupt.  The corruption will be detected and reported later
  ** in this procedure so there is no need to act upon it now.
  */
#if 0
  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) );
#endif

  TRACE(("BALANCE: old: %d %d %d  ",
    apOld[0]->pgno, 
    nOld>=2 ? apOld[1]->pgno : 0,
    nOld>=3 ? apOld[2]->pgno : 0
  ));

  /*
  ** Allocate k new pages.  Reuse old pages where possible.
  */
  if( apOld[0]->pgno<=1 ){
    rc = SQLITE_CORRUPT_BKPT;
................................................................................
      rc = sqlite3PagerWrite(pNew->pDbPage);
      nNew++;
      if( rc ) goto balance_cleanup;
    }else{
      assert( i>0 );
      rc = allocateBtreePage(pBt, &pNew, &pgno, (bBulk ? 1 : pgno), 0);
      if( rc ) goto balance_cleanup;

      apNew[i] = pNew;
      nNew++;


      /* Set the pointer-map entry for the new sibling page. */
      if( ISAUTOVACUUM ){
        ptrmapPut(pBt, pNew->pgno, PTRMAP_BTREE, pParent->pgno, &rc);
        if( rc!=SQLITE_OK ){
          goto balance_cleanup;
        }
      }
    }
  }

  /* Free any old pages that were not reused as new pages.
  */
  while( i<nOld ){
    freePage(apOld[i], &rc);
    if( rc ) goto balance_cleanup;
    releasePage(apOld[i]);
    apOld[i] = 0;
    i++;
  }

  /*
  ** Put the new pages in ascending order.  This helps to

  ** keep entries in the disk file in order so that a scan
  ** of the table is a linear scan through the file.  That
  ** in turn helps the operating system to deliver pages
  ** from the disk more rapidly.
  **
  ** An O(n^2) insertion sort algorithm is used, but since
  ** n is never more than NB (a small constant), that should
  ** not be a problem.
  **
  ** When NB==3, this one optimization makes the database
  ** about 25% faster for large insertions and deletions.
  */
  for(i=0; i<k-1; i++){

    int minV = apNew[i]->pgno;
    int minI = i;
    for(j=i+1; j<k; j++){
      if( apNew[j]->pgno<(unsigned)minV ){














        minI = j;
        minV = apNew[j]->pgno;


      }





    }
    if( minI>i ){
      MemPage *pT;

      pT = apNew[i];
      apNew[i] = apNew[minI];
      apNew[minI] = pT;
    }
  }
  TRACE(("new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",



    apNew[0]->pgno, szNew[0],
    nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,

    nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,

    nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,

    nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0));



  assert( sqlite3PagerIswriteable(pParent->pDbPage) );
  put4byte(pRight, apNew[nNew-1]->pgno);













  /*
  ** Evenly distribute the data in apCell[] across the new pages.
  ** Insert divider cells into pParent as necessary.










  */
  j = 0;
  for(i=0; i<nNew; i++){
    /* Assemble the new sibling page. */

    MemPage *pNew = apNew[i];
    assert( j<nMaxCells );
    zeroPage(pNew, pageFlags);
    assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
    assert( pNew->nCell>0 || (nNew==1 && cntNew[0]==0) );

    assert( pNew->nOverflow==0 );











    j = cntNew[i];



    /* If the sibling page assembled above was not the right-most sibling,
    ** insert a divider cell into the parent page.
    */
    assert( i<nNew-1 || j==nCell );
    if( j<nCell ){




















      u8 *pCell;
      u8 *pTemp;
      int sz;



      assert( j<nMaxCells );
      pCell = apCell[j];
      sz = szCell[j] + leafCorrection;
      pTemp = &aOvflSpace[iOvflSpace];
      if( !pNew->leaf ){
        memcpy(&pNew->aData[8], pCell, 4);
      }else if( leafData ){
        /* If the tree is a leaf-data tree, and the siblings are leaves, 
        ** then there is no divider cell in apCell[]. Instead, the divider 
        ** cell consists of the integer key for the right-most cell of 
        ** the sibling-page assembled above only.
        */
        CellInfo info;
        j--;
        btreeParseCellPtr(pNew, apCell[j], &info);
        pCell = pTemp;
        sz = 4 + putVarint(&pCell[4], info.nKey);
        pTemp = 0;
      }else{
        pCell -= 4;
        /* Obscure case for non-leaf-data trees: If the cell at pCell was
        ** previously stored on a leaf node, and its reported size was 4
        ** bytes, then it may actually be smaller than this 
        ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
        ** any cell). But it is important to pass the correct size to 
        ** insertCell(), so reparse the cell now.
        **
        ** Note that this can never happen in an SQLite data file, as all
        ** cells are at least 4 bytes. It only happens in b-trees used
        ** to evaluate "IN (SELECT ...)" and similar clauses.
        */
        if( szCell[j]==4 ){
          assert(leafCorrection==4);
          sz = cellSizePtr(pParent, pCell);
        }
      }
      iOvflSpace += sz;
      assert( sz<=pBt->maxLocal+23 );
      assert( iOvflSpace <= (int)pBt->pageSize );
      insertCell(pParent, nxDiv, pCell, sz, pTemp, pNew->pgno, &rc);
      if( rc!=SQLITE_OK ) goto balance_cleanup;
      assert( sqlite3PagerIswriteable(pParent->pDbPage) );

      j++;
      nxDiv++;
    }
































  }
  assert( j==nCell );




























  assert( nOld>0 );
  assert( nNew>0 );
  if( (pageFlags & PTF_LEAF)==0 ){
    u8 *zChild = &apCopy[nOld-1]->aData[8];
    memcpy(&apNew[nNew-1]->aData[8], zChild, 4);
  }

  if( isRoot && pParent->nCell==0 && pParent->hdrOffset<=apNew[0]->nFree ){
    /* The root page of the b-tree now contains no cells. The only sibling
    ** page is the right-child of the parent. Copy the contents of the
    ** child page into the parent, decreasing the overall height of the
    ** b-tree structure by one. This is described as the "balance-shallower"
    ** sub-algorithm in some documentation.
    **
    ** If this is an auto-vacuum database, the call to copyNodeContent() 
    ** sets all pointer-map entries corresponding to database image pages 
    ** for which the pointer is stored within the content being copied.
    **
    ** The second assert below verifies that the child page is defragmented
    ** (it must be, as it was just reconstructed using assemblePage()). This
    ** is important if the parent page happens to be page 1 of the database
    ** image.  */

    assert( nNew==1 );


    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2) 

    );
    copyNodeContent(apNew[0], pParent, &rc);
    freePage(apNew[0], &rc);
  }else if( ISAUTOVACUUM ){
    /* Fix the pointer-map entries for all the cells that were shifted around. 
    ** There are several different types of pointer-map entries that need to
    ** be dealt with by this routine. Some of these have been set already, but
    ** many have not. The following is a summary:
    **
    **   1) The entries associated with new sibling pages that were not
    **      siblings when this function was called. These have already
    **      been set. We don't need to worry about old siblings that were
    **      moved to the free-list - the freePage() code has taken care
    **      of those.
    **
    **   2) The pointer-map entries associated with the first overflow
    **      page in any overflow chains used by new divider cells. These 
    **      have also already been taken care of by the insertCell() code.
    **
    **   3) If the sibling pages are not leaves, then the child pages of
    **      cells stored on the sibling pages may need to be updated.
    **
    **   4) If the sibling pages are not internal intkey nodes, then any
    **      overflow pages used by these cells may need to be updated
    **      (internal intkey nodes never contain pointers to overflow pages).
    **
    **   5) If the sibling pages are not leaves, then the pointer-map
    **      entries for the right-child pages of each sibling may need
    **      to be updated.
    **
    ** Cases 1 and 2 are dealt with above by other code. The next
    ** block deals with cases 3 and 4 and the one after that, case 5. Since
    ** setting a pointer map entry is a relatively expensive operation, this
    ** code only sets pointer map entries for child or overflow pages that have
    ** actually moved between pages.  */
    MemPage *pNew = apNew[0];
    MemPage *pOld = apCopy[0];
    int nOverflow = pOld->nOverflow;
    int iNextOld = pOld->nCell + nOverflow;
    int iOverflow = (nOverflow ? pOld->aiOvfl[0] : -1);
    j = 0;                             /* Current 'old' sibling page */
    k = 0;                             /* Current 'new' sibling page */


    for(i=0; i<nCell; i++){
      int isDivider = 0;
      while( i==iNextOld ){
        /* Cell i is the cell immediately following the last cell on old
        ** sibling page j. If the siblings are not leaf pages of an
        ** intkey b-tree, then cell i was a divider cell. */
        assert( j+1 < ArraySize(apCopy) );
        assert( j+1 < nOld );
        pOld = apCopy[++j];
        iNextOld = i + !leafData + pOld->nCell + pOld->nOverflow;
        if( pOld->nOverflow ){
          nOverflow = pOld->nOverflow;
          iOverflow = i + !leafData + pOld->aiOvfl[0];


        }
        isDivider = !leafData;  
      }

      assert(nOverflow>0 || iOverflow<i );
      assert(nOverflow<2 || pOld->aiOvfl[0]==pOld->aiOvfl[1]-1);
      assert(nOverflow<3 || pOld->aiOvfl[1]==pOld->aiOvfl[2]-1);
      if( i==iOverflow ){
        isDivider = 1;
        if( (--nOverflow)>0 ){
          iOverflow++;
        }
      }

      if( i==cntNew[k] ){
        /* Cell i is the cell immediately following the last cell on new
        ** sibling page k. If the siblings are not leaf pages of an
        ** intkey b-tree, then cell i is a divider cell.  */
        pNew = apNew[++k];
        if( !leafData ) continue;
      }
      assert( j<nOld );
      assert( k<nNew );



      /* If the cell was originally divider cell (and is not now) or
      ** an overflow cell, or if the cell was located on a different sibling
      ** page before the balancing, then the pointer map entries associated
      ** with any child or overflow pages need to be updated.  */
      if( isDivider || pOld->pgno!=pNew->pgno ){
        if( !leafCorrection ){
          ptrmapPut(pBt, get4byte(apCell[i]), PTRMAP_BTREE, pNew->pgno, &rc);




        }
        if( szCell[i]>pNew->minLocal ){
          ptrmapPutOvflPtr(pNew, apCell[i], &rc);
        }
      }
    }

    if( !leafCorrection ){
      for(i=0; i<nNew; i++){
        u32 key = get4byte(&apNew[i]->aData[8]);
        ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
      }
    }

#if 0

    /* The ptrmapCheckPages() contains assert() statements that verify that
    ** all pointer map pages are set correctly. This is helpful while 
    ** debugging. This is usually disabled because a corrupt database may
    ** cause an assert() statement to fail.  */
    ptrmapCheckPages(apNew, nNew);
    ptrmapCheckPages(&pParent, 1);
#endif
  }

  assert( pParent->isInit );
  TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
          nOld, nNew, nCell));


  /*
  ** Cleanup before returning.
  */
balance_cleanup:
  sqlite3ScratchFree(apCell);
  for(i=0; i<nOld; i++){
................................................................................
  if( hit==0 ){
    pCheck->mallocFailed = 1;
  }else{
    int contentOffset = get2byteNotZero(&data[hdr+5]);
    assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
    memset(hit+contentOffset, 0, usableSize-contentOffset);
    memset(hit, 1, contentOffset);


    nCell = get2byte(&data[hdr+3]);


    cellStart = hdr + 12 - 4*pPage->leaf;


    for(i=0; i<nCell; i++){
      int pc = get2byte(&data[cellStart+i*2]);
      u32 size = 65536;
      int j;
      if( pc<=usableSize-4 ){
        size = cellSizePtr(pPage, &data[pc]);
      }
................................................................................
        pCheck->zPfx = 0;
        checkAppendMsg(pCheck,
            "Corruption detected in cell %d on page %d",i,iPage);
      }else{
        for(j=pc+size-1; j>=pc; j--) hit[j]++;
      }
    }



    i = get2byte(&data[hdr+1]);
    while( i>0 ){
      int size, j;
      assert( i<=usableSize-4 );     /* Enforced by btreeInitPage() */
      size = get2byte(&data[i+2]);
      assert( i+size<=usableSize );  /* Enforced by btreeInitPage() */
      for(j=i+size-1; j>=i; j--) hit[j]++;




      j = get2byte(&data[i]);


      assert( j==0 || j>i+size );  /* Enforced by btreeInitPage() */
      assert( j<=usableSize-4 );   /* Enforced by btreeInitPage() */
      i = j;
    }
    for(i=cnt=0; i<usableSize; i++){
      if( hit[i]==0 ){
        cnt++;
      }else if( hit[i]>1 ){
        checkAppendMsg(pCheck,
          "Multiple uses for byte %d of page %d", i, iPage);
        break;
      }
    }





    if( cnt!=data[hdr+7] ){
      checkAppendMsg(pCheck,
          "Fragmentation of %d bytes reported as %d on page %d",
          cnt, data[hdr+7], iPage);
    }
  }
  sqlite3PageFree(hit);
................................................................................

/*
** Return true if the given Btree is read-only.
*/
int sqlite3BtreeIsReadonly(Btree *p){
  return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
}

/*
** Defragment the page given.  All Cells are moved to the
** end of the page and all free space is collected into one
** big FreeBlk that occurs in between the header and cell
** pointer array and the cell content area.
**
** EVIDENCE-OF: R-44582-60138 SQLite may from time to time reorganize a
** b-tree page so that there are no freeblocks or fragment bytes, all
** unused bytes are contained in the unallocated space region, and all
** cells are packed tightly at the end of the page.
*/
static int defragmentPage(MemPage *pPage){
  int i;                     /* Loop counter */
  int pc;                    /* Address of the i-th cell */
  int hdr;                   /* Offset to the page header */
  int size;                  /* Size of a cell */
  int usableSize;            /* Number of usable bytes on a page */
  int cellOffset;            /* Offset to the cell pointer array */
  int cbrk;                  /* Offset to the cell content area */
  int nCell;                 /* Number of cells on the page */
  unsigned char *data;       /* The page data */
  unsigned char *temp;       /* Temp area for cell content */
  unsigned char *src;        /* Source of content */
  int iCellFirst;            /* First allowable cell index */
  int iCellLast;             /* Last possible cell index */


  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt!=0 );
  assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
  assert( pPage->nOverflow==0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  temp = 0;
  src = data = pPage->aData;
  hdr = pPage->hdrOffset;
  cellOffset = pPage->cellOffset;
  nCell = pPage->nCell;
  assert( nCell==get2byte(&data[hdr+3]) );
  usableSize = pPage->pBt->usableSize;


  cbrk = usableSize;
  iCellFirst = cellOffset + 2*nCell;
  iCellLast = usableSize - 4;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
................................................................................
    ** if SQLITE_ENABLE_OVERSIZE_CELL_CHECK is defined 
    */
    if( pc<iCellFirst || pc>iCellLast ){
      return SQLITE_CORRUPT_BKPT;
    }
#endif
    assert( pc>=iCellFirst && pc<=iCellLast );
    size = cellSizePtr(pPage, &src[pc]);
    cbrk -= size;
#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
    if( cbrk<iCellFirst ){
      return SQLITE_CORRUPT_BKPT;
    }
#else
    if( cbrk<iCellFirst || pc+size>usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
#endif
    assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
    testcase( cbrk+size==usableSize );
    testcase( pc+size==usableSize );

    put2byte(pAddr, cbrk);
    if( temp==0 ){
      int x;
      if( cbrk==pc ) continue;
      temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
      x = get2byte(&data[hdr+5]);
      memcpy(&temp[x], &data[x], (cbrk+size) - x);
      src = temp;
    }
    memcpy(&data[cbrk], &src[pc], size);
  }
  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  data[hdr+7] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  if( cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_BKPT;
  }
  return SQLITE_OK;
}

/*
** Search the free-list on page pPg for space to store a cell nByte bytes in
** size. If one can be found, return a pointer to the space and remove it
** from the free-list.
**
** If no suitable space can be found on the free-list, return NULL.
**
** This function may detect corruption within pPg.  If corruption is
** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.
**
** If a slot of at least nByte bytes is found but cannot be used because 
** there are already at least 60 fragmented bytes on the page, return NULL.
** In this case, if pbDefrag parameter is not NULL, set *pbDefrag to true.
*/
static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc, int *pbDefrag){
  const int hdr = pPg->hdrOffset;
  u8 * const aData = pPg->aData;
  int iAddr;
  int pc;
  int usableSize = pPg->pBt->usableSize;

  for(iAddr=hdr+1; (pc = get2byte(&aData[iAddr]))>0; iAddr=pc){
    int size;            /* Size of the free slot */
    /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
    ** increasing offset. */
    if( pc>usableSize-4 || pc<iAddr+4 ){
      *pRc = SQLITE_CORRUPT_BKPT;
      return 0;
    }
    /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each
    ** freeblock form a big-endian integer which is the size of the freeblock
    ** in bytes, including the 4-byte header. */
    size = get2byte(&aData[pc+2]);
    if( size>=nByte ){
      int x = size - nByte;
      testcase( x==4 );
      testcase( x==3 );
      if( x<4 ){
        /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
        ** number of bytes in fragments may not exceed 60. */
        if( aData[hdr+7]>=60 ){
          if( pbDefrag ) *pbDefrag = 1;
          return 0;
        }
        /* Remove the slot from the free-list. Update the number of
        ** fragmented bytes within the page. */
        memcpy(&aData[iAddr], &aData[pc], 2);
        aData[hdr+7] += (u8)x;
      }else if( size+pc > usableSize ){
        *pRc = SQLITE_CORRUPT_BKPT;
        return 0;
      }else{
        /* The slot remains on the free-list. Reduce its size to account
         ** for the portion used by the new allocation. */
        put2byte(&aData[pc+2], x);
      }
      return &aData[pc + x];
    }
  }

  return 0;
}

/*
** Allocate nByte bytes of space from within the B-Tree page passed
** as the first argument. Write into *pIdx the index into pPage->aData[]
** of the first byte of allocated space. Return either SQLITE_OK or
** an error code (usually SQLITE_CORRUPT).
**
................................................................................
** allocation is being made in order to insert a new cell, so we will
** also end up needing a new cell pointer.
*/
static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
  const int hdr = pPage->hdrOffset;    /* Local cache of pPage->hdrOffset */
  u8 * const data = pPage->aData;      /* Local cache of pPage->aData */
  int top;                             /* First byte of cell content area */
  int rc = SQLITE_OK;                  /* Integer return code */
  int gap;        /* First byte of gap between cell pointers and cell content */


  
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nByte>=0 );  /* Minimum cell size is 4 */
  assert( pPage->nFree>=nByte );
  assert( pPage->nOverflow==0 );
  assert( nByte < (int)(pPage->pBt->usableSize-8) );


  assert( pPage->cellOffset == hdr + 12 - 4*pPage->leaf );
  gap = pPage->cellOffset + 2*pPage->nCell;
  assert( gap<=65536 );
  /* EVIDENCE-OF: R-29356-02391 If the database uses a 65536-byte page size
  ** and the reserved space is zero (the usual value for reserved space)
  ** then the cell content offset of an empty page wants to be 65536.
  ** However, that integer is too large to be stored in a 2-byte unsigned
  ** integer, so a value of 0 is used in its place. */
  top = get2byteNotZero(&data[hdr+5]);
  if( gap>top ) return SQLITE_CORRUPT_BKPT;


  /* If there is enough space between gap and top for one more cell pointer
  ** array entry offset, and if the freelist is not empty, then search the
  ** freelist looking for a free slot big enough to satisfy the request.
  */
  testcase( gap+2==top );
  testcase( gap+1==top );
  testcase( gap==top );
  if( gap+2<=top && (data[hdr+1] || data[hdr+2]) ){
    int bDefrag = 0;
    u8 *pSpace = pageFindSlot(pPage, nByte, &rc, &bDefrag);
    if( rc ) return rc;









    if( bDefrag ) goto defragment_page;











    if( pSpace ){
      assert( pSpace>=data && (pSpace - data)<65536 );
      *pIdx = (int)(pSpace - data);
      return SQLITE_OK;

    }
  }

  /* The request could not be fulfilled using a freelist slot.  Check
  ** to see if defragmentation is necessary.
  */
  testcase( gap+2+nByte==top );
  if( gap+2+nByte>top ){
 defragment_page:
    testcase( pPage->nCell==0 );
    rc = defragmentPage(pPage);
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
    assert( gap+nByte<=top );
  }

................................................................................
  u32 iLast = pPage->pBt->usableSize-4; /* Largest possible freeblock offset */
  u32 iEnd = iStart + iSize;            /* First byte past the iStart buffer */
  unsigned char *data = pPage->aData;   /* Page content */

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
  assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( iSize>=4 );   /* Minimum cell size is 4 */
  assert( iStart<=iLast );

  /* Overwrite deleted information with zeros when the secure_delete
  ** option is enabled */
  if( pPage->pBt->btsFlags & BTS_SECURE_DELETE ){
................................................................................
  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
  flagByte &= ~PTF_LEAF;
  pPage->childPtrSize = 4-4*pPage->leaf;
  pBt = pPage->pBt;
  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
    /* EVIDENCE-OF: R-03640-13415 A value of 5 means the page is an interior
    ** table b-tree page. */
    assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
    /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf
    ** table b-tree page. */
    assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
    pPage->intKey = 1;
    pPage->intKeyLeaf = pPage->leaf;
    pPage->noPayload = !pPage->leaf;
    pPage->maxLocal = pBt->maxLeaf;
    pPage->minLocal = pBt->minLeaf;
  }else if( flagByte==PTF_ZERODATA ){
    /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior
    ** index b-tree page. */
    assert( (PTF_ZERODATA)==2 );
    /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf
    ** index b-tree page. */
    assert( (PTF_ZERODATA|PTF_LEAF)==10 );
    pPage->intKey = 0;
    pPage->intKeyLeaf = 0;
    pPage->noPayload = 0;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }else{
    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
    ** an error. */
    return SQLITE_CORRUPT_BKPT;
  }
  pPage->max1bytePayload = pBt->max1bytePayload;
  return SQLITE_OK;
}

/*
................................................................................
    int iCellFirst;    /* First allowable cell or freeblock offset */
    int iCellLast;     /* Last possible cell or freeblock offset */

    pBt = pPage->pBt;

    hdr = pPage->hdrOffset;
    data = pPage->aData;
    /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
    ** the b-tree page type. */
    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
    assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
    pPage->maskPage = (u16)(pBt->pageSize - 1);
    pPage->nOverflow = 0;
    usableSize = pBt->usableSize;
    pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
    pPage->aDataEnd = &data[usableSize];
    pPage->aCellIdx = &data[cellOffset];
    /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
    ** the start of the cell content area. A zero value for this integer is
    ** interpreted as 65536. */
    top = get2byteNotZero(&data[hdr+5]);
    /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
    ** number of cells on the page. */
    pPage->nCell = get2byte(&data[hdr+3]);
    if( pPage->nCell>MX_CELL(pBt) ){
      /* To many cells for a single page.  The page must be corrupt */
      return SQLITE_CORRUPT_BKPT;
    }
    testcase( pPage->nCell==MX_CELL(pBt) );
    /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
    ** possible for a root page of a table that contains no rows) then the
    ** offset to the cell content area will equal the page size minus the
    ** bytes of reserved space. */
    assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );

    /* A malformed database page might cause us to read past the end
    ** of page when parsing a cell.  
    **
    ** The following block of code checks early to see if a cell extends
    ** past the end of a page boundary and causes SQLITE_CORRUPT to be 
    ** returned if it does.
................................................................................
          return SQLITE_CORRUPT_BKPT;
        }
      }
      if( !pPage->leaf ) iCellLast++;
    }  
#endif

    /* Compute the total free space on the page
    ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
    ** start of the first freeblock on the page, or is zero if there are no
    ** freeblocks. */
    pc = get2byte(&data[hdr+1]);
    nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
    while( pc>0 ){
      u16 next, size;
      if( pc<iCellFirst || pc>iCellLast ){
        /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
        ** always be at least one cell before the first freeblock.
        **
        ** Or, the freeblock is off the end of the page
        */
        return SQLITE_CORRUPT_BKPT; 
      }
      next = get2byte(&data[pc]);
      size = get2byte(&data[pc+2]);
      if( (next>0 && next<=pc+size+3) || pc+size>usableSize ){
        /* Free blocks must be in ascending order. And the last byte of
        ** the free-block must lie on the database page.  */
................................................................................
  
    pBt->pCursor = 0;
    pBt->pPage1 = 0;
    if( sqlite3PagerIsreadonly(pBt->pPager) ) pBt->btsFlags |= BTS_READ_ONLY;
#ifdef SQLITE_SECURE_DELETE
    pBt->btsFlags |= BTS_SECURE_DELETE;
#endif
    /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
    ** determined by the 2-byte integer located at an offset of 16 bytes from
    ** the beginning of the database file. */
    pBt->pageSize = (zDbHeader[16]<<8) | (zDbHeader[17]<<16);
    if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
         || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
      pBt->pageSize = 0;
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the magic name ":memory:" will create an in-memory database, then
      ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if
................................................................................
      if( zFilename && !isMemdb ){
        pBt->autoVacuum = (SQLITE_DEFAULT_AUTOVACUUM ? 1 : 0);
        pBt->incrVacuum = (SQLITE_DEFAULT_AUTOVACUUM==2 ? 1 : 0);
      }
#endif
      nReserve = 0;
    }else{
      /* EVIDENCE-OF: R-37497-42412 The size of the reserved region is
      ** determined by the one-byte unsigned integer found at an offset of 20
      ** into the database file header. */
      nReserve = zDbHeader[20];
      pBt->btsFlags |= BTS_PAGESIZE_FIXED;
#ifndef SQLITE_OMIT_AUTOVACUUM
      pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
      pBt->incrVacuum = (get4byte(&zDbHeader[36 + 7*4])?1:0);
#endif
    }
................................................................................
    }
  }

  /* Rollback any active transaction and free the handle structure.
  ** The call to sqlite3BtreeRollback() drops any table-locks held by
  ** this handle.
  */
  sqlite3BtreeRollback(p, SQLITE_OK, 0);
  sqlite3BtreeLeave(p);

  /* If there are still other outstanding references to the shared-btree
  ** structure, return now. The remainder of this procedure cleans 
  ** up the shared-btree.
  */
  assert( p->wantToLock==0 && p->locked==0 );
................................................................................
    nPage = nPageFile;
  }
  if( nPage>0 ){
    u32 pageSize;
    u32 usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;
    /* EVIDENCE-OF: R-43737-39999 Every valid SQLite database file begins
    ** with the following 16 bytes (in hex): 53 51 4c 69 74 65 20 66 6f 72 6d
    ** 61 74 20 33 00. */
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }

#ifdef SQLITE_OMIT_WAL
    if( page1[18]>1 ){
      pBt->btsFlags |= BTS_READ_ONLY;
................................................................................
        releasePage(pPage1);
        return SQLITE_OK;
      }
      rc = SQLITE_NOTADB;
    }
#endif

    /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload
    ** fractions and the leaf payload fraction values must be 64, 32, and 32.
    **
    ** The original design allowed these amounts to vary, but as of
    ** version 3.6.0, we require them to be fixed.
    */
    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
      goto page1_init_failed;
    }
    /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
    ** determined by the 2-byte integer located at an offset of 16 bytes from
    ** the beginning of the database file. */
    pageSize = (page1[16]<<8) | (page1[17]<<16);
    /* EVIDENCE-OF: R-25008-21688 The size of a page is a power of two
    ** between 512 and 65536 inclusive. */
    if( ((pageSize-1)&pageSize)!=0
     || pageSize>SQLITE_MAX_PAGE_SIZE 
     || pageSize<=256 
    ){
      goto page1_init_failed;
    }
    assert( (pageSize & 7)==0 );
    /* EVIDENCE-OF: R-59310-51205 The "reserved space" size in the 1-byte
    ** integer at offset 20 is the number of bytes of space at the end of
    ** each page to reserve for extensions. 
    **
    ** EVIDENCE-OF: R-37497-42412 The size of the reserved region is
    ** determined by the one-byte unsigned integer found at an offset of 20
    ** into the database file header. */
    usableSize = pageSize - page1[20];
    if( (u32)pageSize!=pBt->pageSize ){
      /* After reading the first page of the database assuming a page size
      ** of BtShared.pageSize, we have discovered that the page-size is
      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
      ** zero and return SQLITE_OK. The caller will call this function
      ** again with the correct page-size.
................................................................................
                                   pageSize-usableSize);
      return rc;
    }
    if( (pBt->db->flags & SQLITE_RecoveryMode)==0 && nPage>nPageFile ){
      rc = SQLITE_CORRUPT_BKPT;
      goto page1_init_failed;
    }
    /* EVIDENCE-OF: R-28312-64704 However, the usable size is not allowed to
    ** be less than 480. In other words, if the page size is 512, then the
    ** reserved space size cannot exceed 32. */
    if( usableSize<480 ){
      goto page1_init_failed;
    }
    pBt->pageSize = pageSize;
    pBt->usableSize = usableSize;
#ifndef SQLITE_OMIT_AUTOVACUUM
    pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
................................................................................
  }
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** This routine sets the state to CURSOR_FAULT and the error
** code to errCode for every cursor on any BtShared that pBtree
** references.  Or if the writeOnly flag is set to 1, then only
** trip write cursors and leave read cursors unchanged.
**
** Every cursor is a candidate to be tripped, including cursors
** that belong to other database connections that happen to be
** sharing the cache with pBtree.
**
** This routine gets called when a rollback occurs. If the writeOnly

** flag is true, then only write-cursors need be tripped - read-only
** cursors save their current positions so that they may continue 
** following the rollback. Or, if writeOnly is false, all cursors are 
** tripped. In general, writeOnly is false if the transaction being
** rolled back modified the database schema. In this case b-tree root
** pages may be moved or deleted from the database altogether, making
** it unsafe for read cursors to continue.
**
** If the writeOnly flag is true and an error is encountered while 
** saving the current position of a read-only cursor, all cursors, 
** including all read-cursors are tripped.
**
** SQLITE_OK is returned if successful, or if an error occurs while
** saving a cursor position, an SQLite error code.
*/
int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int writeOnly){
  BtCursor *p;
  int rc = SQLITE_OK;

  assert( (writeOnly==0 || writeOnly==1) && BTCF_WriteFlag==1 );
  if( pBtree ){
    sqlite3BtreeEnter(pBtree);
    for(p=pBtree->pBt->pCursor; p; p=p->pNext){
      int i;
      if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){
        if( p->eState==CURSOR_VALID ){
          rc = saveCursorPosition(p);
          if( rc!=SQLITE_OK ){
            (void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);
            break;
          }
        }
      }else{
        sqlite3BtreeClearCursor(p);
        p->eState = CURSOR_FAULT;
        p->skipNext = errCode;
      }
      for(i=0; i<=p->iPage; i++){
        releasePage(p->apPage[i]);
        p->apPage[i] = 0;
      }
    }
    sqlite3BtreeLeave(pBtree);
  }
  return rc;
}

/*
** Rollback the transaction in progress.
**
** If tripCode is not SQLITE_OK then cursors will be invalidated (tripped).
** Only write cursors are tripped if writeOnly is true but all cursors are
** tripped if writeOnly is false.  Any attempt to use

** a tripped cursor will result in an error.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeRollback(Btree *p, int tripCode, int writeOnly){
  int rc;
  BtShared *pBt = p->pBt;
  MemPage *pPage1;

  assert( writeOnly==1 || writeOnly==0 );
  assert( tripCode==SQLITE_ABORT_ROLLBACK || tripCode==SQLITE_OK );
  sqlite3BtreeEnter(p);
  if( tripCode==SQLITE_OK ){
    rc = tripCode = saveAllCursors(pBt, 0, 0);
    if( rc ) writeOnly = 0;
  }else{
    rc = SQLITE_OK;
  }
  if( tripCode ){
    int rc2 = sqlite3BtreeTripAllCursors(p, tripCode, writeOnly);
    assert( rc==SQLITE_OK || (writeOnly==0 && rc2==SQLITE_OK) );
    if( rc2!=SQLITE_OK ) rc = rc2;
  }
  btreeIntegrity(p);

  if( p->inTrans==TRANS_WRITE ){
    int rc2;

    assert( TRANS_WRITE==pBt->inTransaction );
................................................................................
**
** The caller must position the cursor prior to invoking this routine.
** 
** This routine cannot fail.  It always returns SQLITE_OK.  
*/
int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );



  getCellInfo(pCur);
  *pSize = pCur->info.nKey;

  return SQLITE_OK;
}

/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to.
**
................................................................................
  MemPage *pPrevTrunk = 0;
  Pgno mxPage;     /* Total size of the database file */

  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
  pPage1 = pBt->pPage1;
  mxPage = btreePagecount(pBt);
  /* EVIDENCE-OF: R-05119-02637 The 4-byte big-endian integer at offset 36
  ** stores stores the total number of pages on the freelist. */
  n = get4byte(&pPage1->aData[36]);
  testcase( n==mxPage-1 );
  if( n>=mxPage ){
    return SQLITE_CORRUPT_BKPT;
  }
  if( n>0 ){
    /* There are pages on the freelist.  Reuse one of those pages. */
................................................................................
    ** is not true. Otherwise, it runs once for each trunk-page on the
    ** free-list until the page 'nearby' is located (eMode==BTALLOC_EXACT)
    ** or until a page less than 'nearby' is located (eMode==BTALLOC_LT)
    */
    do {
      pPrevTrunk = pTrunk;
      if( pPrevTrunk ){
        /* EVIDENCE-OF: R-01506-11053 The first integer on a freelist trunk page
        ** is the page number of the next freelist trunk page in the list or
        ** zero if this is the last freelist trunk page. */
        iTrunk = get4byte(&pPrevTrunk->aData[0]);
      }else{
        /* EVIDENCE-OF: R-59841-13798 The 4-byte big-endian integer at offset 32
        ** stores the page number of the first page of the freelist, or zero if
        ** the freelist is empty. */
        iTrunk = get4byte(&pPage1->aData[32]);
      }
      testcase( iTrunk==mxPage );
      if( iTrunk>mxPage ){
        rc = SQLITE_CORRUPT_BKPT;
      }else{
        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
................................................................................
      }
      if( rc ){
        pTrunk = 0;
        goto end_allocate_page;
      }
      assert( pTrunk!=0 );
      assert( pTrunk->aData!=0 );
      /* EVIDENCE-OF: R-13523-04394 The second integer on a freelist trunk page
      ** is the number of leaf page pointers to follow. */
      k = get4byte(&pTrunk->aData[4]);
      if( k==0 && !searchList ){
        /* The trunk has no leaves and the list is not being searched. 
        ** So extract the trunk page itself and use it as the newly 
        ** allocated page */
        assert( pPrevTrunk==0 );
        rc = sqlite3PagerWrite(pTrunk->pDbPage);
        if( rc ){
................................................................................
      ** 3.6.0, databases with freelist trunk pages holding more than
      ** usableSize/4 - 8 entries will be reported as corrupt.  In order
      ** to maintain backwards compatibility with older versions of SQLite,
      ** we will continue to restrict the number of entries to usableSize/4 - 8
      ** for now.  At some point in the future (once everyone has upgraded
      ** to 3.6.0 or later) we should consider fixing the conditional above
      ** to read "usableSize/4-2" instead of "usableSize/4-8".
      **
      ** EVIDENCE-OF: R-19920-11576 However, newer versions of SQLite still
      ** avoid using the last six entries in the freelist trunk page array in
      ** order that database files created by newer versions of SQLite can be
      ** read by older versions of SQLite.
      */
      rc = sqlite3PagerWrite(pTrunk->pDbPage);
      if( rc==SQLITE_OK ){
        put4byte(&pTrunk->aData[4], nLeaf+1);
        put4byte(&pTrunk->aData[8+nLeaf*4], iPage);
        if( pPage && (pBt->btsFlags & BTS_SECURE_DELETE)==0 ){
          sqlite3PagerDontWrite(pPage->pDbPage);
................................................................................
  }
  rc = freeSpace(pPage, pc, sz);
  if( rc ){
    *pRC = rc;
    return;
  }
  pPage->nCell--;
  if( pPage->nCell==0 ){
    memset(&data[hdr+1], 0, 4);
    data[hdr+7] = 0;
    put2byte(&data[hdr+5], pPage->pBt->usableSize);
    pPage->nFree = pPage->pBt->usableSize - pPage->hdrOffset
                       - pPage->childPtrSize - 8;
  }else{
    memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
    put2byte(&data[hdr+3], pPage->nCell);
    pPage->nFree += 2;
  }
}

/*
** Insert a new cell on pPage at cell index "i".  pCell points to the
** content of the cell.
**
** If the cell content will fit on the page, then put it there.  If it
................................................................................
      ptrmapPutOvflPtr(pPage, pCell, pRC);
    }
#endif
  }
}

/*
** Array apCell[] contains pointers to nCell b-tree page cells. The 
** szCell[] array contains the size in bytes of each cell. This function
** replaces the current contents of page pPg with the contents of the cell
** array.
**
** Some of the cells in apCell[] may currently be stored in pPg. This
** function works around problems caused by this by making a copy of any 
** such cells before overwriting the page data.
**
** The MemPage.nFree field is invalidated by this function. It is the 
** responsibility of the caller to set it correctly.
*/
static void rebuildPage(


  MemPage *pPg,                   /* Edit this page */
  int nCell,                      /* Final number of cells on page */
  u8 **apCell,                    /* Array of cells */

  u16 *szCell                     /* Array of cell sizes */
){






  const int hdr = pPg->hdrOffset;          /* Offset of header on pPg */
  u8 * const aData = pPg->aData;           /* Pointer to data for pPg */
  const int usableSize = pPg->pBt->usableSize;
  u8 * const pEnd = &aData[usableSize];
  int i;
  u8 *pCellptr = pPg->aCellIdx;
  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
  u8 *pData;

  i = get2byte(&aData[hdr+5]);
  memcpy(&pTmp[i], &aData[i], usableSize - i);

  pData = pEnd;
  for(i=0; i<nCell; i++){
    u8 *pCell = apCell[i];
    if( pCell>aData && pCell<pEnd ){
      pCell = &pTmp[pCell - aData];
    }
    pData -= szCell[i];
    memcpy(pData, pCell, szCell[i]);
    put2byte(pCellptr, (pData - aData));
    pCellptr += 2;
    assert( szCell[i]==cellSizePtr(pPg, pCell) );
  }

  /* The pPg->nFree field is now set incorrectly. The caller will fix it. */
  pPg->nCell = nCell;
  pPg->nOverflow = 0;








  put2byte(&aData[hdr+1], 0);
  put2byte(&aData[hdr+3], pPg->nCell);
  put2byte(&aData[hdr+5], pData - aData);
  aData[hdr+7] = 0x00;
}





/*
** Array apCell[] contains nCell pointers to b-tree cells. Array szCell
** contains the size in bytes of each such cell. This function attempts to 
** add the cells stored in the array to page pPg. If it cannot (because 
** the page needs to be defragmented before the cells will fit), non-zero
** is returned. Otherwise, if the cells are added successfully, zero is
** returned.
**
** Argument pCellptr points to the first entry in the cell-pointer array
** (part of page pPg) to populate. After cell apCell[0] is written to the
** page body, a 16-bit offset is written to pCellptr. And so on, for each
** cell in the array. It is the responsibility of the caller to ensure
** that it is safe to overwrite this part of the cell-pointer array.
**
** When this function is called, *ppData points to the start of the 
** content area on page pPg. If the size of the content area is extended,
** *ppData is updated to point to the new start of the content area
** before returning.
**
** Finally, argument pBegin points to the byte immediately following the
** end of the space required by this page for the cell-pointer area (for
** all cells - not just those inserted by the current call). If the content
** area must be extended to before this point in order to accomodate all
** cells in apCell[], then the cells do not fit and non-zero is returned.
*/
static int pageInsertArray(
  MemPage *pPg,                   /* Page to add cells to */
  u8 *pBegin,                     /* End of cell-pointer array */
  u8 **ppData,                    /* IN/OUT: Page content -area pointer */
  u8 *pCellptr,                   /* Pointer to cell-pointer area */
  int nCell,                      /* Number of cells to add to pPg */
  u8 **apCell,                    /* Array of cells */
  u16 *szCell                     /* Array of cell sizes */
){
  int i;
  u8 *aData = pPg->aData;
  u8 *pData = *ppData;
  const int bFreelist = aData[1] || aData[2];
  assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */
  for(i=0; i<nCell; i++){
    int sz = szCell[i];
    int rc;
    u8 *pSlot;
    if( bFreelist==0 || (pSlot = pageFindSlot(pPg, sz, &rc, 0))==0 ){
      pData -= sz;
      if( pData<pBegin ) return 1;
      pSlot = pData;
    }
    memcpy(pSlot, apCell[i], sz);
    put2byte(pCellptr, (pSlot - aData));
    pCellptr += 2;
  }
  *ppData = pData;
  return 0;
}

/*
** Array apCell[] contains nCell pointers to b-tree cells. Array szCell 
** contains the size in bytes of each such cell. This function adds the
** space associated with each cell in the array that is currently stored 
** within the body of pPg to the pPg free-list. The cell-pointers and other
** fields of the page are not updated.
**
** This function returns the total number of cells added to the free-list.
*/
static int pageFreeArray(
  MemPage *pPg,                   /* Page to edit */
  int nCell,                      /* Cells to delete */
  u8 **apCell,                    /* Array of cells */
  u16 *szCell                     /* Array of cell sizes */
){
  u8 * const aData = pPg->aData;
  u8 * const pEnd = &aData[pPg->pBt->usableSize];
  u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];
  int nRet = 0;
  int i;
  u8 *pFree = 0;
  int szFree = 0;

  for(i=0; i<nCell; i++){
    u8 *pCell = apCell[i];
    if( pCell>=pStart && pCell<pEnd ){
      int sz = szCell[i];
      if( pFree!=(pCell + sz) ){
        if( pFree ){
          assert( pFree>aData && (pFree - aData)<65536 );
          freeSpace(pPg, (u16)(pFree - aData), szFree);
        }
        pFree = pCell;
        szFree = sz;
        if( pFree+sz>pEnd ) return 0;
      }else{
        pFree = pCell;
        szFree += sz;
      }
      nRet++;
    }
  }
  if( pFree ){
    assert( pFree>aData && (pFree - aData)<65536 );
    freeSpace(pPg, (u16)(pFree - aData), szFree);
  }
  return nRet;
}

/*
** The pPg->nFree field is invalid when this function returns. It is the
** responsibility of the caller to set it correctly.
*/
static void editPage(
  MemPage *pPg,                   /* Edit this page */
  int iOld,                       /* Index of first cell currently on page */
  int iNew,                       /* Index of new first cell on page */
  int nNew,                       /* Final number of cells on page */
  u8 **apCell,                    /* Array of cells */
  u16 *szCell                     /* Array of cell sizes */
){
  u8 * const aData = pPg->aData;
  const int hdr = pPg->hdrOffset;
  u8 *pBegin = &pPg->aCellIdx[nNew * 2];
  int nCell = pPg->nCell;       /* Cells stored on pPg */
  u8 *pData;
  u8 *pCellptr;

  int i;
  int iOldEnd = iOld + pPg->nCell + pPg->nOverflow;
  int iNewEnd = iNew + nNew;




#ifdef SQLITE_DEBUG
  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
  memcpy(pTmp, aData, pPg->pBt->usableSize);
#endif

  /* Remove cells from the start and end of the page */
  if( iOld<iNew ){
    int nShift = pageFreeArray(
        pPg, iNew-iOld, &apCell[iOld], &szCell[iOld]
    );
    memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
    nCell -= nShift;
  }
  if( iNewEnd < iOldEnd ){
    nCell -= pageFreeArray(
        pPg, iOldEnd-iNewEnd, &apCell[iNewEnd], &szCell[iNewEnd]
    );
  }

  pData = &aData[get2byte(&aData[hdr+5])];
  if( pData<pBegin ) goto editpage_fail;

  /* Add cells to the start of the page */
  if( iNew<iOld ){
    int nAdd = iOld-iNew;
    pCellptr = pPg->aCellIdx;
    memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
    if( pageInsertArray(
          pPg, pBegin, &pData, pCellptr,
          nAdd, &apCell[iNew], &szCell[iNew]
    ) ) goto editpage_fail;
    nCell += nAdd;
  }

  /* Add any overflow cells */
  for(i=0; i<pPg->nOverflow; i++){
    int iCell = (iOld + pPg->aiOvfl[i]) - iNew;
    if( iCell>=0 && iCell<nNew ){
      pCellptr = &pPg->aCellIdx[iCell * 2];
      memmove(&pCellptr[2], pCellptr, (nCell - iCell) * 2);
      nCell++;
      if( pageInsertArray(
            pPg, pBegin, &pData, pCellptr,
            1, &apCell[iCell + iNew], &szCell[iCell + iNew]
      ) ) goto editpage_fail;
    }
  }

  /* Append cells to the end of the page */
  pCellptr = &pPg->aCellIdx[nCell*2];
  if( pageInsertArray(
        pPg, pBegin, &pData, pCellptr,
        nNew-nCell, &apCell[iNew+nCell], &szCell[iNew+nCell]
  ) ) goto editpage_fail;

  pPg->nCell = nNew;
  pPg->nOverflow = 0;

  put2byte(&aData[hdr+3], pPg->nCell);
  put2byte(&aData[hdr+5], pData - aData);

#ifdef SQLITE_DEBUG
  for(i=0; i<nNew && !CORRUPT_DB; i++){
    u8 *pCell = apCell[i+iNew];
    int iOff = get2byte(&pPg->aCellIdx[i*2]);
    if( pCell>=aData && pCell<&aData[pPg->pBt->usableSize] ){
      pCell = &pTmp[pCell - aData];
    }
    assert( 0==memcmp(pCell, &aData[iOff], szCell[i+iNew]) );
  }
#endif

  return;
 editpage_fail:
  /* Unable to edit this page. Rebuild it from scratch instead. */
  rebuildPage(pPg, nNew, &apCell[iNew], &szCell[iNew]);
}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
................................................................................
    u8 *pCell = pPage->apOvfl[0];
    u16 szCell = cellSizePtr(pPage, pCell);
    u8 *pStop;

    assert( sqlite3PagerIswriteable(pNew->pDbPage) );
    assert( pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
    zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
    rebuildPage(pNew, 1, &pCell, &szCell);
    pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;

    /* If this is an auto-vacuum database, update the pointer map
    ** with entries for the new page, and any pointer from the 
    ** cell on the page to an overflow page. If either of these
    ** operations fails, the return code is set, but the contents
    ** of the parent page are still manipulated by thh code below.
    ** That is Ok, at this point the parent page is guaranteed to
................................................................................
  int usableSpace;             /* Bytes in pPage beyond the header */
  int pageFlags;               /* Value of pPage->aData[0] */
  int subtotal;                /* Subtotal of bytes in cells on one page */
  int iSpace1 = 0;             /* First unused byte of aSpace1[] */
  int iOvflSpace = 0;          /* First unused byte of aOvflSpace[] */
  int szScratch;               /* Size of scratch memory requested */
  MemPage *apOld[NB];          /* pPage and up to two siblings */

  MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
  u8 *pRight;                  /* Location in parent of right-sibling pointer */
  u8 *apDiv[NB-1];             /* Divider cells in pParent */
  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */
  int cntOld[NB+2];            /* Old index in aCell[] after i-th page */
  int szNew[NB+2];             /* Combined size of cells placed on i-th page */
  u8 **apCell = 0;             /* All cells begin balanced */
  u16 *szCell;                 /* Local size of all cells in apCell[] */
  u8 *aSpace1;                 /* Space for copies of dividers cells */
  Pgno pgno;                   /* Temp var to store a page number in */
  u8 abDone[NB+2];             /* True after i'th new page is populated */
  Pgno aPgno[NB+2];            /* Page numbers of new pages before shuffling */
  Pgno aPgOrder[NB+2];         /* Copy of aPgno[] used for sorting pages */
  u16 aPgFlags[NB+2];          /* flags field of new pages before shuffling */

  memset(abDone, 0, sizeof(abDone));
  pBt = pParent->pBt;
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( sqlite3PagerIswriteable(pParent->pDbPage) );

#if 0
  TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));
#endif
................................................................................
  /* Make nMaxCells a multiple of 4 in order to preserve 8-byte
  ** alignment */
  nMaxCells = (nMaxCells + 3)&~3;

  /*
  ** Allocate space for memory structures
  */

  szScratch =
       nMaxCells*sizeof(u8*)                       /* apCell */
     + nMaxCells*sizeof(u16)                       /* szCell */

     + pBt->pageSize;                              /* aSpace1 */

  /* EVIDENCE-OF: R-28375-38319 SQLite will never request a scratch buffer
  ** that is more than 6 times the database page size. */
  assert( szScratch<=6*pBt->pageSize );
  apCell = sqlite3ScratchMalloc( szScratch ); 
  if( apCell==0 ){
    rc = SQLITE_NOMEM;
    goto balance_cleanup;
  }
  szCell = (u16*)&apCell[nMaxCells];
  aSpace1 = (u8*)&szCell[nMaxCells];
  assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );

  /*
  ** Load pointers to all cells on sibling pages and the divider cells
  ** into the local apCell[] array.  Make copies of the divider cells
  ** into space obtained from aSpace1[]. The divider cells have already
  ** been removed from pParent.
  **
  ** If the siblings are on leaf pages, then the child pointers of the
  ** divider cells are stripped from the cells before they are copied
  ** into aSpace1[].  In this way, all cells in apCell[] are without
  ** child pointers.  If siblings are not leaves, then all cell in
  ** apCell[] include child pointers.  Either way, all cells in apCell[]
  ** are alike.
................................................................................
  ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
  **       leafData:  1 if pPage holds key+data and pParent holds only keys.
  */
  leafCorrection = apOld[0]->leaf*4;
  leafData = apOld[0]->intKeyLeaf;
  for(i=0; i<nOld; i++){
    int limit;





    MemPage *pOld = apOld[i];




    limit = pOld->nCell+pOld->nOverflow;
    if( pOld->nOverflow>0 ){
      for(j=0; j<limit; j++){
        assert( nCell<nMaxCells );
        apCell[nCell] = findOverflowCell(pOld, j);
        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
................................................................................
      for(j=0; j<limit; j++){
        assert( nCell<nMaxCells );
        apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
        nCell++;
      }
    }       
    cntOld[i] = nCell;
    if( i<nOld-1 && !leafData){
      u16 sz = (u16)szNew[i];
      u8 *pTemp;
      assert( nCell<nMaxCells );
      szCell[nCell] = sz;
      pTemp = &aSpace1[iSpace1];
      iSpace1 += sz;
................................................................................
  ** 
  */
  usableSpace = pBt->usableSize - 12 + leafCorrection;
  for(subtotal=k=i=0; i<nCell; i++){
    assert( i<nMaxCells );
    subtotal += szCell[i] + 2;
    if( subtotal > usableSpace ){
      szNew[k] = subtotal - szCell[i] - 2;
      cntNew[k] = i;
      if( leafData ){ i--; }
      subtotal = 0;
      k++;
      if( k>NB+1 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
    }
  }
  szNew[k] = subtotal;
  cntNew[k] = nCell;
  k++;

  /*
  ** The packing computed by the previous block is biased toward the siblings
  ** on the left side (siblings with smaller keys). The left siblings are
  ** always nearly full, while the right-most sibling might be nearly empty.
  ** The next block of code attempts to adjust the packing of siblings to
  ** get a better balance.
  **
  ** This adjustment is more than an optimization.  The packing above might
  ** be so out of balance as to be illegal.  For example, the right-most
  ** sibling might be completely empty.  This adjustment is not optional.
  */
  for(i=k-1; i>0; i--){
    int szRight = szNew[i];  /* Size of sibling on the right */
................................................................................
      r = cntNew[i-1] - 1;
      d = r + 1 - leafData;
    }
    szNew[i] = szRight;
    szNew[i-1] = szLeft;
  }

  /* Sanity check:  For a non-corrupt database file one of the follwing
  ** must be true:
  **    (1) We found one or more cells (cntNew[0])>0), or
  **    (2) pPage is a virtual root page.  A virtual root page is when
  **        the real root page is page 1 and we are the only child of


  **        that page.

  */

  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) || CORRUPT_DB);


  TRACE(("BALANCE: old: %d(nc=%d) %d(nc=%d) %d(nc=%d)\n",
    apOld[0]->pgno, apOld[0]->nCell,
    nOld>=2 ? apOld[1]->pgno : 0, nOld>=2 ? apOld[1]->nCell : 0,
    nOld>=3 ? apOld[2]->pgno : 0, nOld>=3 ? apOld[2]->nCell : 0
  ));

  /*
  ** Allocate k new pages.  Reuse old pages where possible.
  */
  if( apOld[0]->pgno<=1 ){
    rc = SQLITE_CORRUPT_BKPT;
................................................................................
      rc = sqlite3PagerWrite(pNew->pDbPage);
      nNew++;
      if( rc ) goto balance_cleanup;
    }else{
      assert( i>0 );
      rc = allocateBtreePage(pBt, &pNew, &pgno, (bBulk ? 1 : pgno), 0);
      if( rc ) goto balance_cleanup;
      zeroPage(pNew, pageFlags);
      apNew[i] = pNew;
      nNew++;
      cntOld[i] = nCell;

      /* Set the pointer-map entry for the new sibling page. */
      if( ISAUTOVACUUM ){
        ptrmapPut(pBt, pNew->pgno, PTRMAP_BTREE, pParent->pgno, &rc);
        if( rc!=SQLITE_OK ){
          goto balance_cleanup;
        }
      }
    }
  }











  /*

  ** Reassign page numbers so that the new pages are in ascending order. 
  ** This helps to keep entries in the disk file in order so that a scan
  ** of the table is closer to a linear scan through the file. That in turn 
  ** helps the operating system to deliver pages from the disk more rapidly.

  **
  ** An O(n^2) insertion sort algorithm is used, but since n is never more 
  ** than (NB+2) (a small constant), that should not be a problem.

  **
  ** When NB==3, this one optimization makes the database about 25% faster 
  ** for large insertions and deletions.
  */
  for(i=0; i<nNew; i++){
    aPgOrder[i] = aPgno[i] = apNew[i]->pgno;
    aPgFlags[i] = apNew[i]->pDbPage->flags;



    for(j=0; j<i; j++){
      if( aPgno[j]==aPgno[i] ){
        /* This branch is taken if the set of sibling pages somehow contains
        ** duplicate entries. This can happen if the database is corrupt. 
        ** It would be simpler to detect this as part of the loop below, but
        ** we do the detection here in order to avoid populating the pager
        ** cache with two separate objects associated with the same
        ** page number.  */
        assert( CORRUPT_DB );
        rc = SQLITE_CORRUPT_BKPT;
        goto balance_cleanup;
      }
    }
  }
  for(i=0; i<nNew; i++){
    int iBest = 0;                /* aPgno[] index of page number to use */
    for(j=1; j<nNew; j++){
      if( aPgOrder[j]<aPgOrder[iBest] ) iBest = j;
    }
    pgno = aPgOrder[iBest];
    aPgOrder[iBest] = 0xffffffff;
    if( iBest!=i ){
      if( iBest>i ){
        sqlite3PagerRekey(apNew[iBest]->pDbPage, pBt->nPage+iBest+1, 0);
      }


      sqlite3PagerRekey(apNew[i]->pDbPage, pgno, aPgFlags[iBest]);
      apNew[i]->pgno = pgno;


    }
  }


  TRACE(("BALANCE: new: %d(%d nc=%d) %d(%d nc=%d) %d(%d nc=%d) "
         "%d(%d nc=%d) %d(%d nc=%d)\n",
    apNew[0]->pgno, szNew[0], cntNew[0],
    nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,
    nNew>=2 ? cntNew[1] - cntNew[0] - !leafData : 0,
    nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,
    nNew>=3 ? cntNew[2] - cntNew[1] - !leafData : 0,
    nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,
    nNew>=4 ? cntNew[3] - cntNew[2] - !leafData : 0,
    nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0,
    nNew>=5 ? cntNew[4] - cntNew[3] - !leafData : 0
  ));

  assert( sqlite3PagerIswriteable(pParent->pDbPage) );
  put4byte(pRight, apNew[nNew-1]->pgno);

  /* If the sibling pages are not leaves, ensure that the right-child pointer
  ** of the right-most new sibling page is set to the value that was 
  ** originally in the same field of the right-most old sibling page. */
  if( (pageFlags & PTF_LEAF)==0 && nOld!=nNew ){
    MemPage *pOld = (nNew>nOld ? apNew : apOld)[nOld-1];
    memcpy(&apNew[nNew-1]->aData[8], &pOld->aData[8], 4);
  }

  /* Make any required updates to pointer map entries associated with 
  ** cells stored on sibling pages following the balance operation. Pointer
  ** map entries associated with divider cells are set by the insertCell()
  ** routine. The associated pointer map entries are:
  **


  **   a) if the cell contains a reference to an overflow chain, the
  **      entry associated with the first page in the overflow chain, and
  **
  **   b) if the sibling pages are not leaves, the child page associated
  **      with the cell.
  **
  ** If the sibling pages are not leaves, then the pointer map entry 
  ** associated with the right-child of each sibling may also need to be 
  ** updated. This happens below, after the sibling pages have been 
  ** populated, not here.
  */



  if( ISAUTOVACUUM ){
    MemPage *pNew = apNew[0];




    u8 *aOld = pNew->aData;
    int cntOldNext = pNew->nCell + pNew->nOverflow;
    int usableSize = pBt->usableSize;
    int iNew = 0;
    int iOld = 0;

    for(i=0; i<nCell; i++){
      u8 *pCell = apCell[i];
      if( i==cntOldNext ){
        MemPage *pOld = (++iOld)<nNew ? apNew[iOld] : apOld[iOld];
        cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;
        aOld = pOld->aData;
      }
      if( i==cntNew[iNew] ){
        pNew = apNew[++iNew];
        if( !leafData ) continue;
      }






      /* Cell pCell is destined for new sibling page pNew. Originally, it
      ** was either part of sibling page iOld (possibly an overflow cell), 
      ** or else the divider cell to the left of sibling page iOld. So,
      ** if sibling page iOld had the same page number as pNew, and if
      ** pCell really was a part of sibling page iOld (not a divider or
      ** overflow cell), we can skip updating the pointer map entries.  */
      if( pNew->pgno!=aPgno[iOld] || pCell<aOld || pCell>=&aOld[usableSize] ){
        if( !leafCorrection ){
          ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
        }
        if( szCell[i]>pNew->minLocal ){
          ptrmapPutOvflPtr(pNew, pCell, &rc);
        }
      }
    }
  }

  /* Insert new divider cells into pParent. */
  for(i=0; i<nNew-1; i++){
    u8 *pCell;
    u8 *pTemp;
    int sz;
    MemPage *pNew = apNew[i];
    j = cntNew[i];

    assert( j<nMaxCells );
    pCell = apCell[j];
    sz = szCell[j] + leafCorrection;
    pTemp = &aOvflSpace[iOvflSpace];
    if( !pNew->leaf ){
      memcpy(&pNew->aData[8], pCell, 4);
    }else if( leafData ){
      /* If the tree is a leaf-data tree, and the siblings are leaves, 
      ** then there is no divider cell in apCell[]. Instead, the divider 
      ** cell consists of the integer key for the right-most cell of 
      ** the sibling-page assembled above only.
      */
      CellInfo info;
      j--;
      btreeParseCellPtr(pNew, apCell[j], &info);
      pCell = pTemp;
      sz = 4 + putVarint(&pCell[4], info.nKey);
      pTemp = 0;
    }else{
      pCell -= 4;
      /* Obscure case for non-leaf-data trees: If the cell at pCell was
      ** previously stored on a leaf node, and its reported size was 4
      ** bytes, then it may actually be smaller than this 
      ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
      ** any cell). But it is important to pass the correct size to 
      ** insertCell(), so reparse the cell now.
      **
      ** Note that this can never happen in an SQLite data file, as all
      ** cells are at least 4 bytes. It only happens in b-trees used
      ** to evaluate "IN (SELECT ...)" and similar clauses.
      */
      if( szCell[j]==4 ){
        assert(leafCorrection==4);
        sz = cellSizePtr(pParent, pCell);
      }
    }
    iOvflSpace += sz;
    assert( sz<=pBt->maxLocal+23 );
    assert( iOvflSpace <= (int)pBt->pageSize );
    insertCell(pParent, nxDiv+i, pCell, sz, pTemp, pNew->pgno, &rc);
    if( rc!=SQLITE_OK ) goto balance_cleanup;
    assert( sqlite3PagerIswriteable(pParent->pDbPage) );
  }



  /* Now update the actual sibling pages. The order in which they are updated
  ** is important, as this code needs to avoid disrupting any page from which
  ** cells may still to be read. In practice, this means:
  **
  **  (1) If cells are moving left (from apNew[iPg] to apNew[iPg-1])
  **      then it is not safe to update page apNew[iPg] until after
  **      the left-hand sibling apNew[iPg-1] has been updated.
  **
  **  (2) If cells are moving right (from apNew[iPg] to apNew[iPg+1])
  **      then it is not safe to update page apNew[iPg] until after
  **      the right-hand sibling apNew[iPg+1] has been updated.
  **
  ** If neither of the above apply, the page is safe to update.
  **
  ** The iPg value in the following loop starts at nNew-1 goes down
  ** to 0, then back up to nNew-1 again, thus making two passes over
  ** the pages.  On the initial downward pass, only condition (1) above
  ** needs to be tested because (2) will always be true from the previous
  ** step.  On the upward pass, both conditions are always true, so the
  ** upwards pass simply processes pages that were missed on the downward
  ** pass.
  */
  for(i=1-nNew; i<nNew; i++){
    int iPg = i<0 ? -i : i;
    assert( iPg>=0 && iPg<nNew );
    if( abDone[iPg] ) continue;         /* Skip pages already processed */
    if( i>=0                            /* On the upwards pass, or... */
     || cntOld[iPg-1]>=cntNew[iPg-1]    /* Condition (1) is true */
    ){
      int iNew;
      int iOld;
      int nNewCell;


      /* Verify condition (1):  If cells are moving left, update iPg
      ** only after iPg-1 has already been updated. */
      assert( iPg==0 || cntOld[iPg-1]>=cntNew[iPg-1] || abDone[iPg-1] );

      /* Verify condition (2):  If cells are moving right, update iPg
      ** only after iPg+1 has already been updated. */
      assert( cntNew[iPg]>=cntOld[iPg] || abDone[iPg+1] );

      if( iPg==0 ){
        iNew = iOld = 0;
        nNewCell = cntNew[0];
      }else{
        iOld = iPg<nOld ? (cntOld[iPg-1] + !leafData) : nCell;
        iNew = cntNew[iPg-1] + !leafData;
        nNewCell = cntNew[iPg] - iNew;
      }

      editPage(apNew[iPg], iOld, iNew, nNewCell, apCell, szCell);
      abDone[iPg]++;
      apNew[iPg]->nFree = usableSpace-szNew[iPg];
      assert( apNew[iPg]->nOverflow==0 );
      assert( apNew[iPg]->nCell==nNewCell );
    }
  }

  /* All pages have been processed exactly once */
  assert( memcmp(abDone, "\01\01\01\01\01", nNew)==0 );

  assert( nOld>0 );
  assert( nNew>0 );





  if( isRoot && pParent->nCell==0 && pParent->hdrOffset<=apNew[0]->nFree ){
    /* The root page of the b-tree now contains no cells. The only sibling
    ** page is the right-child of the parent. Copy the contents of the
    ** child page into the parent, decreasing the overall height of the
    ** b-tree structure by one. This is described as the "balance-shallower"
    ** sub-algorithm in some documentation.
    **
    ** If this is an auto-vacuum database, the call to copyNodeContent() 
    ** sets all pointer-map entries corresponding to database image pages 
    ** for which the pointer is stored within the content being copied.
    **
    ** It is critical that the child page be defragmented before being
    ** copied into the parent, because if the parent is page 1 then it will
    ** by smaller than the child due to the database header, and so all the
    ** free space needs to be up front.
    */
    assert( nNew==1 );
    rc = defragmentPage(apNew[0]);
    testcase( rc!=SQLITE_OK );
    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
      || rc!=SQLITE_OK
    );
    copyNodeContent(apNew[0], pParent, &rc);
    freePage(apNew[0], &rc);
  }else if( ISAUTOVACUUM && !leafCorrection ){











    /* Fix the pointer map entries associated with the right-child of each


























    ** sibling page. All other pointer map entries have already been taken
    ** care of.  */
    for(i=0; i<nNew; i++){












      u32 key = get4byte(&apNew[i]->aData[8]);
      ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
    }

  }


















  assert( pParent->isInit );

  TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
          nOld, nNew, nCell));








  /* Free any old pages that were not reused as new pages.
  */
  for(i=nNew; i<nOld; i++){
    freePage(apOld[i], &rc);
  }













#if 0
  if( ISAUTOVACUUM && rc==SQLITE_OK && apNew[0]->isInit ){
    /* The ptrmapCheckPages() contains assert() statements that verify that
    ** all pointer map pages are set correctly. This is helpful while 
    ** debugging. This is usually disabled because a corrupt database may
    ** cause an assert() statement to fail.  */
    ptrmapCheckPages(apNew, nNew);
    ptrmapCheckPages(&pParent, 1);

  }




#endif

  /*
  ** Cleanup before returning.
  */
balance_cleanup:
  sqlite3ScratchFree(apCell);
  for(i=0; i<nOld; i++){
................................................................................
  if( hit==0 ){
    pCheck->mallocFailed = 1;
  }else{
    int contentOffset = get2byteNotZero(&data[hdr+5]);
    assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
    memset(hit+contentOffset, 0, usableSize-contentOffset);
    memset(hit, 1, contentOffset);
    /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
    ** number of cells on the page. */
    nCell = get2byte(&data[hdr+3]);
    /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
    ** immediately follows the b-tree page header. */
    cellStart = hdr + 12 - 4*pPage->leaf;
    /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte
    ** integer offsets to the cell contents. */
    for(i=0; i<nCell; i++){
      int pc = get2byte(&data[cellStart+i*2]);
      u32 size = 65536;
      int j;
      if( pc<=usableSize-4 ){
        size = cellSizePtr(pPage, &data[pc]);
      }
................................................................................
        pCheck->zPfx = 0;
        checkAppendMsg(pCheck,
            "Corruption detected in cell %d on page %d",i,iPage);
      }else{
        for(j=pc+size-1; j>=pc; j--) hit[j]++;
      }
    }
    /* EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header
    ** is the offset of the first freeblock, or zero if there are no
    ** freeblocks on the page. */
    i = get2byte(&data[hdr+1]);
    while( i>0 ){
      int size, j;
      assert( i<=usableSize-4 );     /* Enforced by btreeInitPage() */
      size = get2byte(&data[i+2]);
      assert( i+size<=usableSize );  /* Enforced by btreeInitPage() */
      for(j=i+size-1; j>=i; j--) hit[j]++;
      /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a
      ** big-endian integer which is the offset in the b-tree page of the next
      ** freeblock in the chain, or zero if the freeblock is the last on the
      ** chain. */
      j = get2byte(&data[i]);
      /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
      ** increasing offset. */
      assert( j==0 || j>i+size );  /* Enforced by btreeInitPage() */
      assert( j<=usableSize-4 );   /* Enforced by btreeInitPage() */
      i = j;
    }
    for(i=cnt=0; i<usableSize; i++){
      if( hit[i]==0 ){
        cnt++;
      }else if( hit[i]>1 ){
        checkAppendMsg(pCheck,
          "Multiple uses for byte %d of page %d", i, iPage);
        break;
      }
    }
    /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments
    ** is stored in the fifth field of the b-tree page header.
    ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the
    ** number of fragmented free bytes within the cell content area.
    */
    if( cnt!=data[hdr+7] ){
      checkAppendMsg(pCheck,
          "Fragmentation of %d bytes reported as %d on page %d",
          cnt, data[hdr+7], iPage);
    }
  }
  sqlite3PageFree(hit);
................................................................................

/*
** Return true if the given Btree is read-only.
*/
int sqlite3BtreeIsReadonly(Btree *p){
  return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
}

/*
** Return the size of the header added to each page by this module.
*/
int sqlite3HeaderSizeBtree(void){ return sizeof(MemPage); }

#endif
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*,int);
int sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *pBtree);
................................................................................
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_BLOBKEY    2    /* Table has keys only - no data */

int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int, int*);
int sqlite3BtreeClearTableOfCursor(BtCursor*);
void sqlite3BtreeTripAllCursors(Btree*, int);

void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

int sqlite3BtreeNewDb(Btree *p);

/*
................................................................................

int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeIncrblobCursor(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);
int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
void sqlite3BtreeCursorHints(BtCursor *, unsigned int mask);
int sqlite3BtreeIsReadonly(Btree *pBt);


#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif

#ifndef SQLITE_OMIT_BTREECOUNT
int sqlite3BtreeCount(BtCursor *, i64 *);

#endif
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*,int,int);
int sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *pBtree);
................................................................................
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_BLOBKEY    2    /* Table has keys only - no data */

int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int, int*);
int sqlite3BtreeClearTableOfCursor(BtCursor*);
int sqlite3BtreeTripAllCursors(Btree*, int, int);

void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

int sqlite3BtreeNewDb(Btree *p);

/*
................................................................................

int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeIncrblobCursor(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);
int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
void sqlite3BtreeCursorHints(BtCursor *, unsigned int mask);
int sqlite3BtreeIsReadonly(Btree *pBt);
int sqlite3HeaderSizeBtree(void);

#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif

#ifndef SQLITE_OMIT_BTREECOUNT
int sqlite3BtreeCount(BtCursor *, i64 *);

**
** A single database file can be shared by two more database connections,
** but cursors cannot be shared.  Each cursor is associated with a
** particular database connection identified BtCursor.pBtree.db.
**
** Fields in this structure are accessed under the BtShared.mutex
** found at self->pBt->mutex. 





*/
struct BtCursor {
  Btree *pBtree;            /* The Btree to which this cursor belongs */
  BtShared *pBt;            /* The BtShared this cursor points to */
  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
  Pgno *aOverflow;          /* Cache of overflow page locations */
  CellInfo info;            /* A parse of the cell we are pointing at */
  i64 nKey;                 /* Size of pKey, or last integer key */
  void *pKey;               /* Saved key that was cursor last known position */
  Pgno pgnoRoot;            /* The root page of this tree */
  int nOvflAlloc;           /* Allocated size of aOverflow[] array */
  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive */

  u8 curFlags;              /* zero or more BTCF_* flags defined below */
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  u8 hints;                             /* As configured by CursorSetHints() */
  i16 iPage;                            /* Index of current page in apPage */
  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
};
................................................................................
**   seek the cursor to the saved position.
**
** CURSOR_FAULT:
**   An unrecoverable error (an I/O error or a malloc failure) has occurred
**   on a different connection that shares the BtShared cache with this
**   cursor.  The error has left the cache in an inconsistent state.
**   Do nothing else with this cursor.  Any attempt to use the cursor
**   should return the error code stored in BtCursor.skip
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1
#define CURSOR_SKIPNEXT          2
#define CURSOR_REQUIRESEEK       3
#define CURSOR_FAULT             4

**
** A single database file can be shared by two more database connections,
** but cursors cannot be shared.  Each cursor is associated with a
** particular database connection identified BtCursor.pBtree.db.
**
** Fields in this structure are accessed under the BtShared.mutex
** found at self->pBt->mutex. 
**
** skipNext meaning:
**    eState==SKIPNEXT && skipNext>0:  Next sqlite3BtreeNext() is no-op.
**    eState==SKIPNEXT && skipNext<0:  Next sqlite3BtreePrevious() is no-op.
**    eState==FAULT:                   Cursor fault with skipNext as error code.
*/
struct BtCursor {
  Btree *pBtree;            /* The Btree to which this cursor belongs */
  BtShared *pBt;            /* The BtShared this cursor points to */
  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
  Pgno *aOverflow;          /* Cache of overflow page locations */
  CellInfo info;            /* A parse of the cell we are pointing at */
  i64 nKey;                 /* Size of pKey, or last integer key */
  void *pKey;               /* Saved key that was cursor last known position */
  Pgno pgnoRoot;            /* The root page of this tree */
  int nOvflAlloc;           /* Allocated size of aOverflow[] array */
  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.
                   ** Error code if eState==CURSOR_FAULT */
  u8 curFlags;              /* zero or more BTCF_* flags defined below */
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  u8 hints;                             /* As configured by CursorSetHints() */
  i16 iPage;                            /* Index of current page in apPage */
  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
};
................................................................................
**   seek the cursor to the saved position.
**
** CURSOR_FAULT:
**   An unrecoverable error (an I/O error or a malloc failure) has occurred
**   on a different connection that shares the BtShared cache with this
**   cursor.  The error has left the cache in an inconsistent state.
**   Do nothing else with this cursor.  Any attempt to use the cursor
**   should return the error code stored in BtCursor.skipNext
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1
#define CURSOR_SKIPNEXT          2
#define CURSOR_REQUIRESEEK       3
#define CURSOR_FAULT             4

** auxiliary databases added using the ATTACH command.
**
** See also sqlite3LocateTable().
*/
Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
  Table *p = 0;
  int i;
  assert( zName!=0 );





  /* All mutexes are required for schema access.  Make sure we hold them. */
  assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
#if SQLITE_USER_AUTHENTICATION
  /* Only the admin user is allowed to know that the sqlite_user table
  ** exists */
  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
    return 0;

** auxiliary databases added using the ATTACH command.
**
** See also sqlite3LocateTable().
*/
Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
  Table *p = 0;
  int i;


#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return 0;
#endif

  /* All mutexes are required for schema access.  Make sure we hold them. */
  assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
#if SQLITE_USER_AUTHENTICATION
  /* Only the admin user is allowed to know that the sqlite_user table
  ** exists */
  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
    return 0;

** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
** to recognize the end of a trigger can be omitted.  All we have to do
** is look for a semicolon that is not part of an string or comment.
*/
int sqlite3_complete(const char *zSql){
  u8 state = 0;   /* Current state, using numbers defined in header comment */
  u8 token;       /* Value of the next token */








#ifndef SQLITE_OMIT_TRIGGER
  /* A complex statement machine used to detect the end of a CREATE TRIGGER
  ** statement.  This is the normal case.
  */
  static const u8 trans[8][8] = {
                     /* Token:                                                */

** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
** to recognize the end of a trigger can be omitted.  All we have to do
** is look for a semicolon that is not part of an string or comment.
*/
int sqlite3_complete(const char *zSql){
  u8 state = 0;   /* Current state, using numbers defined in header comment */
  u8 token;       /* Value of the next token */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( zSql==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif

#ifndef SQLITE_OMIT_TRIGGER
  /* A complex statement machine used to detect the end of a CREATE TRIGGER
  ** statement.  This is the normal case.
  */
  static const u8 trans[8][8] = {
                     /* Token:                                                */

  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
#endif
#ifdef SQLITE_DISABLE_DIRSYNC
  "DISABLE_DIRSYNC",
#endif
#ifdef SQLITE_DISABLE_LFS
  "DISABLE_LFS",



#endif
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#ifdef SQLITE_ENABLE_CEROD
  "ENABLE_CEROD",
#endif
................................................................................
** was used and false if not.
**
** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
** is not required for a match.
*/
int sqlite3_compileoption_used(const char *zOptName){
  int i, n;







  if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
  n = sqlite3Strlen30(zOptName);

  /* Since ArraySize(azCompileOpt) is normally in single digits, a
  ** linear search is adequate.  No need for a binary search. */
  for(i=0; i<ArraySize(azCompileOpt); i++){
    if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0

  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
#endif
#ifdef SQLITE_DISABLE_DIRSYNC
  "DISABLE_DIRSYNC",
#endif
#ifdef SQLITE_DISABLE_LFS
  "DISABLE_LFS",
#endif
#ifdef SQLITE_ENABLE_API_ARMOR
  "ENABLE_API_ARMOR",
#endif
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#ifdef SQLITE_ENABLE_CEROD
  "ENABLE_CEROD",
#endif
................................................................................
** was used and false if not.
**
** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
** is not required for a match.
*/
int sqlite3_compileoption_used(const char *zOptName){
  int i, n;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( zOptName==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
  n = sqlite3Strlen30(zOptName);

  /* Since ArraySize(azCompileOpt) is normally in single digits, a
  ** linear search is adequate.  No need for a binary search. */
  for(i=0; i<ArraySize(azCompileOpt); i++){
    if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
................................................................................
** This implementation requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar.  Historians usually
** use the Julian calendar for dates prior to 1582-10-15 and for some
** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
................................................................................
    return 0;
  }else{
    return 1;
  }
}

/*
** Attempt to parse the given string into a Julian Day Number.  Return
** the number of errors.
**
** The following are acceptable forms for the input string:
**
**      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM
**      DDDD.DD 
**      now
................................................................................
**
** Return a string described by FORMAT.  Conversions as follows:
**
**   %d  day of month
**   %f  ** fractional seconds  SS.SSS
**   %H  hour 00-24
**   %j  day of year 000-366
**   %J  ** Julian day number
**   %m  month 01-12
**   %M  minute 00-59
**   %s  seconds since 1970-01-01
**   %S  seconds 00-59
**   %w  day of week 0-6  sunday==0
**   %W  week of year 00-53
**   %Y  year 0000-9999

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** SQLite processes all times and dates as julian day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
................................................................................
** This implementation requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar.  Historians usually
** use the julian calendar for dates prior to 1582-10-15 and for some
** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
................................................................................
    return 0;
  }else{
    return 1;
  }
}

/*
** Attempt to parse the given string into a julian day number.  Return
** the number of errors.
**
** The following are acceptable forms for the input string:
**
**      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM
**      DDDD.DD 
**      now
................................................................................
**
** Return a string described by FORMAT.  Conversions as follows:
**
**   %d  day of month
**   %f  ** fractional seconds  SS.SSS
**   %H  hour 00-24
**   %j  day of year 000-366
**   %J  ** julian day number
**   %m  month 01-12
**   %M  minute 00-59
**   %s  seconds since 1970-01-01
**   %S  seconds 00-59
**   %w  day of week 0-6  sunday==0
**   %W  week of year 00-53
**   %Y  year 0000-9999

    ** where-clause loop above.
    */
    if( okOnePass ){
      /* Just one row.  Hence the top-of-loop is a no-op */
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
      assert( !IsVirtual(pTab) );
      if( aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
      assert( nKey==0 );  /* OP_Found will use a composite key */

    ** where-clause loop above.
    */
    if( okOnePass ){
      /* Just one row.  Hence the top-of-loop is a no-op */
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
      assert( !IsVirtual(pTab) );
      if( aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 || pTab->pSelect!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
      assert( nKey==0 );  /* OP_Found will use a composite key */

    sqlite3DbFree(db, pItem->zSpan);
  }
  sqlite3DbFree(db, pList->a);
  sqlite3DbFree(db, pList);
}

/*
** These routines are Walker callbacks.  Walker.u.pi is a pointer
** to an integer.  These routines are checking an expression to see
** if it is a constant.  Set *Walker.u.i to 0 if the expression is
** not constant.
**
** These callback routines are used to implement the following:
**
**     sqlite3ExprIsConstant()                  pWalker->u.i==1
**     sqlite3ExprIsConstantNotJoin()           pWalker->u.i==2

**     sqlite3ExprIsConstantOrFunction()        pWalker->u.i==3 or 4
**



** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
** in a CREATE TABLE statement.  The Walker.u.i value is 4 when parsing
** an existing schema and 3 when processing a new statement.  A bound
** parameter raises an error for new statements, but is silently converted
** to NULL for existing schemas.  This allows sqlite_master tables that 
** contain a bound parameter because they were generated by older versions
** of SQLite to be parsed by newer versions of SQLite without raising a
** malformed schema error.
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){

  /* If pWalker->u.i is 2 then any term of the expression that comes from
  ** the ON or USING clauses of a join disqualifies the expression
  ** from being considered constant. */
  if( pWalker->u.i==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
    pWalker->u.i = 0;
    return WRC_Abort;
  }

  switch( pExpr->op ){
    /* Consider functions to be constant if all their arguments are constant
    ** and either pWalker->u.i==3 or 4 or the function as the SQLITE_FUNC_CONST
    ** flag. */
    case TK_FUNCTION:
      if( pWalker->u.i>=3 || ExprHasProperty(pExpr,EP_Constant) ){
        return WRC_Continue;



      }
      /* Fall through */
    case TK_ID:
    case TK_COLUMN:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
      testcase( pExpr->op==TK_ID );
      testcase( pExpr->op==TK_COLUMN );
      testcase( pExpr->op==TK_AGG_FUNCTION );
      testcase( pExpr->op==TK_AGG_COLUMN );



      pWalker->u.i = 0;
      return WRC_Abort;

    case TK_VARIABLE:
      if( pWalker->u.i==4 ){
        /* Silently convert bound parameters that appear inside of CREATE
        ** statements into a NULL when parsing the CREATE statement text out
        ** of the sqlite_master table */
        pExpr->op = TK_NULL;
      }else if( pWalker->u.i==3 ){
        /* A bound parameter in a CREATE statement that originates from
        ** sqlite3_prepare() causes an error */
        pWalker->u.i = 0;
        return WRC_Abort;
      }
      /* Fall through */
    default:
      testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
      testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
      return WRC_Continue;
  }
}
static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  pWalker->u.i = 0;
  return WRC_Abort;
}
static int exprIsConst(Expr *p, int initFlag){
  Walker w;
  memset(&w, 0, sizeof(w));
  w.u.i = initFlag;
  w.xExprCallback = exprNodeIsConstant;
  w.xSelectCallback = selectNodeIsConstant;

  sqlite3WalkExpr(&w, p);
  return w.u.i;
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables or function calls.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  return exprIsConst(p, 1);
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** that does no originate from the ON or USING clauses of a join.
** Return 0 if it involves variables or function calls or terms from
** an ON or USING clause.
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
  return exprIsConst(p, 2);
}

/*
** Walk an expression tree.  Return 1 if the expression is constant










** or a function call with constant arguments.  Return and 0 if there
** are any variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
  assert( isInit==0 || isInit==1 );
  return exprIsConst(p, 3+isInit);
}

/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue.  If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
................................................................................

        assert( !isRowid );
        sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
        dest.affSdst = (u8)affinity;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        pSelect->iLimit = 0;
        testcase( pSelect->selFlags & SF_Distinct );
        pSelect->selFlags &= ~SF_Distinct;
        testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
        if( sqlite3Select(pParse, pSelect, &dest) ){
          sqlite3KeyInfoUnref(pKeyInfo);
          return 0;
        }
        pEList = pSelect->pEList;
        assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
................................................................................
        (pExpr->iTable ? "new" : "old"),
        (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
        target
      ));

#ifndef SQLITE_OMIT_FLOATING_POINT
      /* If the column has REAL affinity, it may currently be stored as an
      ** integer. Use OP_RealAffinity to make sure it is really real.  */



      if( pExpr->iColumn>=0 
       && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
      ){
        sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
      }
#endif
      break;

    sqlite3DbFree(db, pItem->zSpan);
  }
  sqlite3DbFree(db, pList->a);
  sqlite3DbFree(db, pList);
}

/*
** These routines are Walker callbacks used to check expressions to
** see if they are "constant" for some definition of constant.  The
** Walker.eCode value determines the type of "constant" we are looking
** for.
**
** These callback routines are used to implement the following:
**
**     sqlite3ExprIsConstant()                  pWalker->eCode==1
**     sqlite3ExprIsConstantNotJoin()           pWalker->eCode==2
**     sqlite3ExprRefOneTableOnly()             pWalker->eCode==3
**     sqlite3ExprIsConstantOrFunction()        pWalker->eCode==4 or 5
**
** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
** is found to not be a constant.
**
** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
** in a CREATE TABLE statement.  The Walker.eCode value is 5 when parsing
** an existing schema and 4 when processing a new statement.  A bound
** parameter raises an error for new statements, but is silently converted
** to NULL for existing schemas.  This allows sqlite_master tables that 
** contain a bound parameter because they were generated by older versions
** of SQLite to be parsed by newer versions of SQLite without raising a
** malformed schema error.
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){

  /* If pWalker->eCode is 2 then any term of the expression that comes from
  ** the ON or USING clauses of a left join disqualifies the expression
  ** from being considered constant. */
  if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
    pWalker->eCode = 0;
    return WRC_Abort;
  }

  switch( pExpr->op ){
    /* Consider functions to be constant if all their arguments are constant
    ** and either pWalker->eCode==4 or 5 or the function has the
    ** SQLITE_FUNC_CONST flag. */
    case TK_FUNCTION:
      if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_Constant) ){
        return WRC_Continue;
      }else{
        pWalker->eCode = 0;
        return WRC_Abort;
      }

    case TK_ID:
    case TK_COLUMN:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
      testcase( pExpr->op==TK_ID );
      testcase( pExpr->op==TK_COLUMN );
      testcase( pExpr->op==TK_AGG_FUNCTION );
      testcase( pExpr->op==TK_AGG_COLUMN );
      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
        return WRC_Continue;
      }else{
        pWalker->eCode = 0;
        return WRC_Abort;
      }
    case TK_VARIABLE:
      if( pWalker->eCode==5 ){
        /* Silently convert bound parameters that appear inside of CREATE
        ** statements into a NULL when parsing the CREATE statement text out
        ** of the sqlite_master table */
        pExpr->op = TK_NULL;
      }else if( pWalker->eCode==4 ){
        /* A bound parameter in a CREATE statement that originates from
        ** sqlite3_prepare() causes an error */
        pWalker->eCode = 0;
        return WRC_Abort;
      }
      /* Fall through */
    default:
      testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
      testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
      return WRC_Continue;
  }
}
static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  pWalker->eCode = 0;
  return WRC_Abort;
}
static int exprIsConst(Expr *p, int initFlag, int iCur){
  Walker w;
  memset(&w, 0, sizeof(w));
  w.eCode = initFlag;
  w.xExprCallback = exprNodeIsConstant;
  w.xSelectCallback = selectNodeIsConstant;
  w.u.iCur = iCur;
  sqlite3WalkExpr(&w, p);
  return w.eCode;
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant
** and 0 if it involves variables or function calls.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  return exprIsConst(p, 1, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant
** that does no originate from the ON or USING clauses of a join.
** Return 0 if it involves variables or function calls or terms from
** an ON or USING clause.
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
  return exprIsConst(p, 2, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression constant
** for any single row of the table with cursor iCur.  In other words, the
** expression must not refer to any non-deterministic function nor any
** table other than iCur.
*/
int sqlite3ExprIsTableConstant(Expr *p, int iCur){
  return exprIsConst(p, 3, iCur);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant
** or a function call with constant arguments.  Return and 0 if there
** are any variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
  assert( isInit==0 || isInit==1 );
  return exprIsConst(p, 4+isInit, 0);
}

/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue.  If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
................................................................................

        assert( !isRowid );
        sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
        dest.affSdst = (u8)affinity;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        pSelect->iLimit = 0;
        testcase( pSelect->selFlags & SF_Distinct );

        testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
        if( sqlite3Select(pParse, pSelect, &dest) ){
          sqlite3KeyInfoUnref(pKeyInfo);
          return 0;
        }
        pEList = pSelect->pEList;
        assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
................................................................................
        (pExpr->iTable ? "new" : "old"),
        (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
        target
      ));

#ifndef SQLITE_OMIT_FLOATING_POINT
      /* If the column has REAL affinity, it may currently be stored as an
      ** integer. Use OP_RealAffinity to make sure it is really real.
      **
      ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
      ** floating point when extracting it from the record.  */
      if( pExpr->iColumn>=0 
       && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
      ){
        sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
      }
#endif
      break;

      /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
      sqlite3_result_null(context);
      break;
    }
    default: {
      /* Because sqlite3_value_double() returns 0.0 if the argument is not
      ** something that can be converted into a number, we have:
      ** IMP: R-57326-31541 Abs(X) return 0.0 if X is a string or blob that
      ** cannot be converted to a numeric value. 
      */
      double rVal = sqlite3_value_double(argv[0]);
      if( rVal<0 ) rVal = -rVal;
      sqlite3_result_double(context, rVal);
      break;
    }
  }

      /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
      sqlite3_result_null(context);
      break;
    }
    default: {
      /* Because sqlite3_value_double() returns 0.0 if the argument is not
      ** something that can be converted into a number, we have:
      ** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob
      ** that cannot be converted to a numeric value.
      */
      double rVal = sqlite3_value_double(argv[0]);
      if( rVal<0 ) rVal = -rVal;
      sqlite3_result_double(context, rVal);
      break;
    }
  }

/* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards
** compatibility for legacy applications, the URI filename capability is
** disabled by default.
**
** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.




*/
#ifndef SQLITE_USE_URI
# define  SQLITE_USE_URI 0
#endif





#ifndef SQLITE_ALLOW_COVERING_INDEX_SCAN
# define SQLITE_ALLOW_COVERING_INDEX_SCAN 1
#endif

/*
** The following singleton contains the global configuration for
** the SQLite library.
................................................................................
** a different position in the file.  This allows code that has to
** deal with the pending byte to run on files that are much smaller
** than 1 GiB.  The sqlite3_test_control() interface can be used to
** move the pending byte.
**
** IMPORTANT:  Changing the pending byte to any value other than
** 0x40000000 results in an incompatible database file format!
** Changing the pending byte during operating results in undefined
** and dileterious behavior.
*/
#ifndef SQLITE_OMIT_WSD
int sqlite3PendingByte = 0x40000000;
#endif

#include "opcodes.h"
/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** the vdbe.c file.  
*/
const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;

/* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards
** compatibility for legacy applications, the URI filename capability is
** disabled by default.
**
** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.
**
** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
** disabled. The default value may be changed by compiling with the
** SQLITE_USE_URI symbol defined.
*/
#ifndef SQLITE_USE_URI
# define  SQLITE_USE_URI 0
#endif

/* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if
** that compile-time option is omitted.
*/
#ifndef SQLITE_ALLOW_COVERING_INDEX_SCAN
# define SQLITE_ALLOW_COVERING_INDEX_SCAN 1
#endif

/*
** The following singleton contains the global configuration for
** the SQLite library.
................................................................................
** a different position in the file.  This allows code that has to
** deal with the pending byte to run on files that are much smaller
** than 1 GiB.  The sqlite3_test_control() interface can be used to
** move the pending byte.
**
** IMPORTANT:  Changing the pending byte to any value other than
** 0x40000000 results in an incompatible database file format!
** Changing the pending byte during operation will result in undefined
** and incorrect behavior.
*/
#ifndef SQLITE_OMIT_WSD
int sqlite3PendingByte = 0x40000000;
#endif

#include "opcodes.h"
/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** the vdbe.c file.  
*/
const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;

  ** the SQLite library is in use. */
  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;

  va_start(ap, op);
  switch( op ){

    /* Mutex configuration options are only available in a threadsafe
    ** compile. 
    */
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0
    case SQLITE_CONFIG_SINGLETHREAD: {
      /* Disable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 0;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }


    case SQLITE_CONFIG_MULTITHREAD: {
      /* Disable mutexing of database connections */
      /* Enable mutexing of core data structures */
      sqlite3GlobalConfig.bCoreMutex = 1;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }


    case SQLITE_CONFIG_SERIALIZED: {
      /* Enable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 1;
      sqlite3GlobalConfig.bFullMutex = 1;
      break;
    }


    case SQLITE_CONFIG_MUTEX: {
      /* Specify an alternative mutex implementation */
      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
      break;
    }


    case SQLITE_CONFIG_GETMUTEX: {
      /* Retrieve the current mutex implementation */
      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
      break;
    }
#endif


    case SQLITE_CONFIG_MALLOC: {

      /* Specify an alternative malloc implementation */



      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
      break;
    }
    case SQLITE_CONFIG_GETMALLOC: {
      /* Retrieve the current malloc() implementation */



      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
      break;
    }
    case SQLITE_CONFIG_MEMSTATUS: {
      /* Enable or disable the malloc status collection */


      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_SCRATCH: {
      /* Designate a buffer for scratch memory space */



      sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
      sqlite3GlobalConfig.szScratch = va_arg(ap, int);
      sqlite3GlobalConfig.nScratch = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_PAGECACHE: {
      /* Designate a buffer for page cache memory space */


      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
      sqlite3GlobalConfig.szPage = va_arg(ap, int);
      sqlite3GlobalConfig.nPage = va_arg(ap, int);
      break;











    }

    case SQLITE_CONFIG_PCACHE: {
      /* no-op */
      break;
    }
    case SQLITE_CONFIG_GETPCACHE: {
      /* now an error */
      rc = SQLITE_ERROR;
      break;
    }

    case SQLITE_CONFIG_PCACHE2: {



      /* Specify an alternative page cache implementation */
      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
      break;
    }
    case SQLITE_CONFIG_GETPCACHE2: {




      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
        sqlite3PCacheSetDefault();
      }
      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
      break;
    }




#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
    case SQLITE_CONFIG_HEAP: {
      /* Designate a buffer for heap memory space */



      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      sqlite3GlobalConfig.mnReq = va_arg(ap, int);

      if( sqlite3GlobalConfig.mnReq<1 ){
        sqlite3GlobalConfig.mnReq = 1;
      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
        /* cap min request size at 2^12 */
        sqlite3GlobalConfig.mnReq = (1<<12);
      }

      if( sqlite3GlobalConfig.pHeap==0 ){
        /* If the heap pointer is NULL, then restore the malloc implementation
        ** back to NULL pointers too.  This will cause the malloc to go




        ** back to its default implementation when sqlite3_initialize() is
        ** run.
        */
        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
      }else{
        /* The heap pointer is not NULL, then install one of the
        ** mem5.c/mem3.c methods.  The enclosing #if guarantees at
        ** least one of these methods is currently enabled.
        */
#ifdef SQLITE_ENABLE_MEMSYS3
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
#endif
#ifdef SQLITE_ENABLE_MEMSYS5
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
#endif
      }
................................................................................

    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
    ** can be changed at start-time using the
    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
    */
    case SQLITE_CONFIG_URI: {




      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
      break;
    }

    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {




      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
      break;
    }

#ifdef SQLITE_ENABLE_SQLLOG
    case SQLITE_CONFIG_SQLLOG: {
      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
................................................................................
      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
      break;
    }
#endif

    case SQLITE_CONFIG_MMAP_SIZE: {




      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);





      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){


        mxMmap = SQLITE_MAX_MMAP_SIZE;
      }
      sqlite3GlobalConfig.mxMmap = mxMmap;
      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
      if( szMmap>mxMmap) szMmap = mxMmap;

      sqlite3GlobalConfig.szMmap = szMmap;
      break;
    }

#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC)
    case SQLITE_CONFIG_WIN32_HEAPSIZE: {



      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      break;
    }
#endif

    default: {
      rc = SQLITE_ERROR;
................................................................................
  return SQLITE_OK;
}

/*
** Return the mutex associated with a database connection.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){






  return db->mutex;
}

/*
** Free up as much memory as we can from the given database
** connection.
*/
int sqlite3_db_release_memory(sqlite3 *db){
  int i;




  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      Pager *pPager = sqlite3BtreePager(pBt);
      sqlite3PagerShrink(pPager);
................................................................................
static int binCollFunc(
  void *padFlag,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  int rc, n;
  n = nKey1<nKey2 ? nKey1 : nKey2;



  rc = memcmp(pKey1, pKey2, n);
  if( rc==0 ){
    if( padFlag
     && allSpaces(((char*)pKey1)+n, nKey1-n)
     && allSpaces(((char*)pKey2)+n, nKey2-n)
    ){
      /* Leave rc unchanged at 0 */




    }else{
      rc = nKey1 - nKey2;
    }
  }
  return rc;
}

................................................................................
  return r;
}

/*
** Return the ROWID of the most recent insert
*/
sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){






  return db->lastRowid;
}

/*
** Return the number of changes in the most recent call to sqlite3_exec().
*/
int sqlite3_changes(sqlite3 *db){






  return db->nChange;
}

/*
** Return the number of changes since the database handle was opened.
*/
int sqlite3_total_changes(sqlite3 *db){






  return db->nTotalChange;
}

/*
** Close all open savepoints. This function only manipulates fields of the
** database handle object, it does not close any savepoints that may be open
** at the b-tree/pager level.
................................................................................
    sqlite3_free(db->lookaside.pStart);
  }
  sqlite3_free(db);
}

/*
** Rollback all database files.  If tripCode is not SQLITE_OK, then
** any open cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further
** attempts to use that cursor.

*/
void sqlite3RollbackAll(sqlite3 *db, int tripCode){
  int i;
  int inTrans = 0;

  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3BeginBenignMalloc();

  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
  ** This is important in case the transaction being rolled back has
  ** modified the database schema. If the b-tree mutexes are not taken
  ** here, then another shared-cache connection might sneak in between
  ** the database rollback and schema reset, which can cause false
  ** corruption reports in some cases.  */
  sqlite3BtreeEnterAll(db);


  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p ){
      if( sqlite3BtreeIsInTrans(p) ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(p, tripCode);
    }
  }
  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
    sqlite3ExpirePreparedStatements(db);
................................................................................
** given callback function with the given argument.
*/
int sqlite3_busy_handler(
  sqlite3 *db,
  int (*xBusy)(void*,int),
  void *pArg
){



  sqlite3_mutex_enter(db->mutex);
  db->busyHandler.xFunc = xBusy;
  db->busyHandler.pArg = pArg;
  db->busyHandler.nBusy = 0;
  db->busyTimeout = 0;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
................................................................................
*/
void sqlite3_progress_handler(
  sqlite3 *db, 
  int nOps,
  int (*xProgress)(void*), 
  void *pArg
){






  sqlite3_mutex_enter(db->mutex);
  if( nOps>0 ){
    db->xProgress = xProgress;
    db->nProgressOps = (unsigned)nOps;
    db->pProgressArg = pArg;
  }else{
    db->xProgress = 0;
................................................................................


/*
** This routine installs a default busy handler that waits for the
** specified number of milliseconds before returning 0.
*/
int sqlite3_busy_timeout(sqlite3 *db, int ms){



  if( ms>0 ){
    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
    db->busyTimeout = ms;
  }else{
    sqlite3_busy_handler(db, 0, 0);
  }
  return SQLITE_OK;
}

/*
** Cause any pending operation to stop at its earliest opportunity.
*/
void sqlite3_interrupt(sqlite3 *db){






  db->u1.isInterrupted = 1;
}


/*
** This function is exactly the same as sqlite3_create_function(), except
** that it is designed to be called by internal code. The difference is
................................................................................
  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xDestroy)(void *)
){
  int rc = SQLITE_ERROR;
  FuncDestructor *pArg = 0;






  sqlite3_mutex_enter(db->mutex);
  if( xDestroy ){
    pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
    if( !pArg ){
      xDestroy(p);
      goto out;
    }
................................................................................
  void *p,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
){
  int rc;
  char *zFunc8;




  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
  sqlite3DbFree(db, zFunc8);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
................................................................................
int sqlite3_overload_function(
  sqlite3 *db,
  const char *zName,
  int nArg
){
  int nName = sqlite3Strlen30(zName);
  int rc = SQLITE_OK;






  sqlite3_mutex_enter(db->mutex);
  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
    rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
                           0, sqlite3InvalidFunction, 0, 0, 0);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
................................................................................
**
** A NULL trace function means that no tracing is executes.  A non-NULL
** trace is a pointer to a function that is invoked at the start of each
** SQL statement.
*/
void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
  void *pOld;







  sqlite3_mutex_enter(db->mutex);
  pOld = db->pTraceArg;
  db->xTrace = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_profile(
  sqlite3 *db,
  void (*xProfile)(void*,const char*,sqlite_uint64),
  void *pArg
){
  void *pOld;







  sqlite3_mutex_enter(db->mutex);
  pOld = db->pProfileArg;
  db->xProfile = xProfile;
  db->pProfileArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_commit_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */
){
  void *pOld;







  sqlite3_mutex_enter(db->mutex);
  pOld = db->pCommitArg;
  db->xCommitCallback = xCallback;
  db->pCommitArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_update_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
  void *pArg                /* Argument to the function */
){
  void *pRet;







  sqlite3_mutex_enter(db->mutex);
  pRet = db->pUpdateArg;
  db->xUpdateCallback = xCallback;
  db->pUpdateArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}
................................................................................
*/
void *sqlite3_rollback_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*), /* Callback function */
  void *pArg                /* Argument to the function */
){
  void *pRet;







  sqlite3_mutex_enter(db->mutex);
  pRet = db->pRollbackArg;
  db->xRollbackCallback = xCallback;
  db->pRollbackArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}
................................................................................
** configured by this function.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
#ifdef SQLITE_OMIT_WAL
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(nFrame);
#else



  if( nFrame>0 ){
    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
  }else{
    sqlite3_wal_hook(db, 0, 0);
  }
#endif
  return SQLITE_OK;
................................................................................
void *sqlite3_wal_hook(
  sqlite3 *db,                    /* Attach the hook to this db handle */
  int(*xCallback)(void *, sqlite3*, const char*, int),
  void *pArg                      /* First argument passed to xCallback() */
){
#ifndef SQLITE_OMIT_WAL
  void *pRet;






  sqlite3_mutex_enter(db->mutex);
  pRet = db->pWalArg;
  db->xWalCallback = xCallback;
  db->pWalArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
#else
................................................................................
  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
){
#ifdef SQLITE_OMIT_WAL
  return SQLITE_OK;
#else
  int rc;                         /* Return code */
  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */





  /* Initialize the output variables to -1 in case an error occurs. */
  if( pnLog ) *pnLog = -1;
  if( pnCkpt ) *pnCkpt = -1;

  assert( SQLITE_CHECKPOINT_FULL>SQLITE_CHECKPOINT_PASSIVE );
  assert( SQLITE_CHECKPOINT_FULL<SQLITE_CHECKPOINT_RESTART );
................................................................................
** A new lower limit does not shrink existing constructs.
** It merely prevents new constructs that exceed the limit
** from forming.
*/
int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
  int oldLimit;








  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
  ** there is a hard upper bound set at compile-time by a C preprocessor
  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
  ** "_MAX_".)
  */
  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
................................................................................
  const char *zVfs = zDefaultVfs;
  char *zFile;
  char c;
  int nUri = sqlite3Strlen30(zUri);

  assert( *pzErrMsg==0 );


  if( ((flags & SQLITE_OPEN_URI) || sqlite3GlobalConfig.bOpenUri) 
   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
  ){
    char *zOpt;
    int eState;                   /* Parser state when parsing URI */
    int iIn;                      /* Input character index */
    int iOut = 0;                 /* Output character index */
    int nByte = nUri+2;           /* Bytes of space to allocate */
................................................................................
){
  sqlite3 *db;                    /* Store allocated handle here */
  int rc;                         /* Return code */
  int isThreadsafe;               /* True for threadsafe connections */
  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */




  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif

  /* Only allow sensible combinations of bits in the flags argument.  
................................................................................
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
  ** and UTF-16, so add a version for each to avoid any unnecessary
  ** conversions. The only error that can occur here is a malloc() failure.



  */
  createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
  createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
  createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);

  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
  if( db->mallocFailed ){
    goto opendb_out;
  }



  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
  assert( db->pDfltColl!=0 );

  /* Also add a UTF-8 case-insensitive collation sequence. */
  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);

  /* Parse the filename/URI argument. */
  db->openFlags = flags;
  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
    sqlite3_free(zErrMsg);
................................................................................
  const void *zFilename, 
  sqlite3 **ppDb
){
  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
  sqlite3_value *pVal;
  int rc;

  assert( zFilename );
  assert( ppDb );

  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif

  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    assert( *ppDb || rc==SQLITE_NOMEM );
................................................................................
int sqlite3_create_collation(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  int rc;
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, 0);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation_v2(
  sqlite3* db, 
................................................................................
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*),
  void(*xDel)(void*)
){
  int rc;




  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
................................................................................
  const void *zName,
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  int rc = SQLITE_OK;
  char *zName8;




  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
  if( zName8 ){
    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
    sqlite3DbFree(db, zName8);
  }
................................................................................
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
){



  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = xCollNeeded;
  db->xCollNeeded16 = 0;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}
................................................................................
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed16(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
){



  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = 0;
  db->xCollNeeded16 = xCollNeeded16;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}
................................................................................
/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
*/
int sqlite3_get_autocommit(sqlite3 *db){






  return db->autoCommit;
}

/*
** The following routines are substitutes for constants SQLITE_CORRUPT,
** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
** constants.  They serve two purposes:
................................................................................
  return rc;
}

/*
** Enable or disable the extended result codes.
*/
int sqlite3_extended_result_codes(sqlite3 *db, int onoff){



  sqlite3_mutex_enter(db->mutex);
  db->errMask = onoff ? 0xffffffff : 0xff;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Invoke the xFileControl method on a particular database.
*/
int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
  int rc = SQLITE_ERROR;
  Btree *pBtree;




  sqlite3_mutex_enter(db->mutex);
  pBtree = sqlite3DbNameToBtree(db, zDbName);
  if( pBtree ){
    Pager *pPager;
    sqlite3_file *fd;
    sqlite3BtreeEnter(pBtree);
    pPager = sqlite3BtreePager(pBtree);
................................................................................
** The zFilename argument is the filename pointer passed into the xOpen()
** method of a VFS implementation.  The zParam argument is the name of the
** query parameter we seek.  This routine returns the value of the zParam
** parameter if it exists.  If the parameter does not exist, this routine
** returns a NULL pointer.
*/
const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
  if( zFilename==0 ) return 0;
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] ){
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
................................................................................
}

/*
** Return the filename of the database associated with a database
** connection.
*/
const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){






  Btree *pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
}

/*
** Return 1 if database is read-only or 0 if read/write.  Return -1 if
** no such database exists.
*/
int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){






  Btree *pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
}

  ** the SQLite library is in use. */
  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;

  va_start(ap, op);
  switch( op ){

    /* Mutex configuration options are only available in a threadsafe
    ** compile.
    */
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
    case SQLITE_CONFIG_SINGLETHREAD: {
      /* Disable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 0;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
    case SQLITE_CONFIG_MULTITHREAD: {
      /* Disable mutexing of database connections */
      /* Enable mutexing of core data structures */
      sqlite3GlobalConfig.bCoreMutex = 1;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
    case SQLITE_CONFIG_SERIALIZED: {
      /* Enable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 1;
      sqlite3GlobalConfig.bFullMutex = 1;
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
    case SQLITE_CONFIG_MUTEX: {
      /* Specify an alternative mutex implementation */
      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
    case SQLITE_CONFIG_GETMUTEX: {
      /* Retrieve the current mutex implementation */
      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
      break;
    }
#endif


    case SQLITE_CONFIG_MALLOC: {
      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
      ** single argument which is a pointer to an instance of the
      ** sqlite3_mem_methods structure. The argument specifies alternative
      ** low-level memory allocation routines to be used in place of the memory
      ** allocation routines built into SQLite. */
      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
      break;
    }
    case SQLITE_CONFIG_GETMALLOC: {
      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
      ** single argument which is a pointer to an instance of the
      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
      ** filled with the currently defined memory allocation routines. */
      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
      break;
    }
    case SQLITE_CONFIG_MEMSTATUS: {
      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
      ** single argument of type int, interpreted as a boolean, which enables
      ** or disables the collection of memory allocation statistics. */
      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_SCRATCH: {
      /* EVIDENCE-OF: R-08404-60887 There are three arguments to
      ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
      ** which the scratch allocations will be drawn, the size of each scratch
      ** allocation (sz), and the maximum number of scratch allocations (N). */
      sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
      sqlite3GlobalConfig.szScratch = va_arg(ap, int);
      sqlite3GlobalConfig.nScratch = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_PAGECACHE: {
      /* EVIDENCE-OF: R-31408-40510 There are three arguments to
      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory, the size
      ** of each page buffer (sz), and the number of pages (N). */
      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
      sqlite3GlobalConfig.szPage = va_arg(ap, int);
      sqlite3GlobalConfig.nPage = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_PCACHE_HDRSZ: {
      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
      ** a single parameter which is a pointer to an integer and writes into
      ** that integer the number of extra bytes per page required for each page
      ** in SQLITE_CONFIG_PAGECACHE. */
      *va_arg(ap, int*) = 
          sqlite3HeaderSizeBtree() +
          sqlite3HeaderSizePcache() +
          sqlite3HeaderSizePcache1();
      break;
    }

    case SQLITE_CONFIG_PCACHE: {
      /* no-op */
      break;
    }
    case SQLITE_CONFIG_GETPCACHE: {
      /* now an error */
      rc = SQLITE_ERROR;
      break;
    }

    case SQLITE_CONFIG_PCACHE2: {
      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
      ** single argument which is a pointer to an sqlite3_pcache_methods2
      ** object. This object specifies the interface to a custom page cache
      ** implementation. */
      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
      break;
    }
    case SQLITE_CONFIG_GETPCACHE2: {
      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
      ** single argument which is a pointer to an sqlite3_pcache_methods2
      ** object. SQLite copies of the current page cache implementation into
      ** that object. */
      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
        sqlite3PCacheSetDefault();
      }
      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
      break;
    }

/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
    case SQLITE_CONFIG_HEAP: {

      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
      ** number of bytes in the memory buffer, and the minimum allocation size. */
      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      sqlite3GlobalConfig.mnReq = va_arg(ap, int);

      if( sqlite3GlobalConfig.mnReq<1 ){
        sqlite3GlobalConfig.mnReq = 1;
      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
        /* cap min request size at 2^12 */
        sqlite3GlobalConfig.mnReq = (1<<12);
      }

      if( sqlite3GlobalConfig.pHeap==0 ){
        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
        ** is NULL, then SQLite reverts to using its default memory allocator
        ** (the system malloc() implementation), undoing any prior invocation of
        ** SQLITE_CONFIG_MALLOC.
        **
        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
        ** revert to its default implementation when sqlite3_initialize() is run

        */
        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
      }else{
        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
        ** alternative memory allocator is engaged to handle all of SQLites
        ** memory allocation needs. */

#ifdef SQLITE_ENABLE_MEMSYS3
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
#endif
#ifdef SQLITE_ENABLE_MEMSYS5
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
#endif
      }
................................................................................

    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
    ** can be changed at start-time using the
    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
    */
    case SQLITE_CONFIG_URI: {
      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
      ** argument of type int. If non-zero, then URI handling is globally
      ** enabled. If the parameter is zero, then URI handling is globally
      ** disabled. */
      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
      break;
    }

    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
      ** option takes a single integer argument which is interpreted as a
      ** boolean in order to enable or disable the use of covering indices for
      ** full table scans in the query optimizer. */
      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
      break;
    }

#ifdef SQLITE_ENABLE_SQLLOG
    case SQLITE_CONFIG_SQLLOG: {
      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
................................................................................
      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
      break;
    }
#endif

    case SQLITE_CONFIG_MMAP_SIZE: {
      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
      ** integer (sqlite3_int64) values that are the default mmap size limit
      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
      ** mmap size limit. */
      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
      ** negative, then that argument is changed to its compile-time default.
      **
      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
      ** silently truncated if necessary so that it does not exceed the
      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
      ** compile-time option.
      */
      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ) mxMmap = SQLITE_MAX_MMAP_SIZE;


      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
      if( szMmap>mxMmap) szMmap = mxMmap;
      sqlite3GlobalConfig.mxMmap = mxMmap;
      sqlite3GlobalConfig.szMmap = szMmap;
      break;
    }

#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
      ** unsigned integer value that specifies the maximum size of the created
      ** heap. */
      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      break;
    }
#endif

    default: {
      rc = SQLITE_ERROR;
................................................................................
  return SQLITE_OK;
}

/*
** Return the mutex associated with a database connection.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->mutex;
}

/*
** Free up as much memory as we can from the given database
** connection.
*/
int sqlite3_db_release_memory(sqlite3 *db){
  int i;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      Pager *pPager = sqlite3BtreePager(pBt);
      sqlite3PagerShrink(pPager);
................................................................................
static int binCollFunc(
  void *padFlag,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  int rc, n;
  n = nKey1<nKey2 ? nKey1 : nKey2;
  /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
  ** strings byte by byte using the memcmp() function from the standard C
  ** library. */
  rc = memcmp(pKey1, pKey2, n);
  if( rc==0 ){
    if( padFlag
     && allSpaces(((char*)pKey1)+n, nKey1-n)
     && allSpaces(((char*)pKey2)+n, nKey2-n)
    ){
      /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
      ** spaces at the end of either string do not change the result. In other
      ** words, strings will compare equal to one another as long as they
      ** differ only in the number of spaces at the end.
      */
    }else{
      rc = nKey1 - nKey2;
    }
  }
  return rc;
}

................................................................................
  return r;
}

/*
** Return the ROWID of the most recent insert
*/
sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->lastRowid;
}

/*
** Return the number of changes in the most recent call to sqlite3_exec().
*/
int sqlite3_changes(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nChange;
}

/*
** Return the number of changes since the database handle was opened.
*/
int sqlite3_total_changes(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nTotalChange;
}

/*
** Close all open savepoints. This function only manipulates fields of the
** database handle object, it does not close any savepoints that may be open
** at the b-tree/pager level.
................................................................................
    sqlite3_free(db->lookaside.pStart);
  }
  sqlite3_free(db);
}

/*
** Rollback all database files.  If tripCode is not SQLITE_OK, then
** any write cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further
** attempts to use that cursor.  Read cursors remain open and valid
** but are "saved" in case the table pages are moved around.
*/
void sqlite3RollbackAll(sqlite3 *db, int tripCode){
  int i;
  int inTrans = 0;
  int schemaChange;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3BeginBenignMalloc();

  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
  ** This is important in case the transaction being rolled back has
  ** modified the database schema. If the b-tree mutexes are not taken
  ** here, then another shared-cache connection might sneak in between
  ** the database rollback and schema reset, which can cause false
  ** corruption reports in some cases.  */
  sqlite3BtreeEnterAll(db);
  schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;

  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p ){
      if( sqlite3BtreeIsInTrans(p) ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(p, tripCode, !schemaChange);
    }
  }
  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
    sqlite3ExpirePreparedStatements(db);
................................................................................
** given callback function with the given argument.
*/
int sqlite3_busy_handler(
  sqlite3 *db,
  int (*xBusy)(void*,int),
  void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->busyHandler.xFunc = xBusy;
  db->busyHandler.pArg = pArg;
  db->busyHandler.nBusy = 0;
  db->busyTimeout = 0;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
................................................................................
*/
void sqlite3_progress_handler(
  sqlite3 *db, 
  int nOps,
  int (*xProgress)(void*), 
  void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( nOps>0 ){
    db->xProgress = xProgress;
    db->nProgressOps = (unsigned)nOps;
    db->pProgressArg = pArg;
  }else{
    db->xProgress = 0;
................................................................................


/*
** This routine installs a default busy handler that waits for the
** specified number of milliseconds before returning 0.
*/
int sqlite3_busy_timeout(sqlite3 *db, int ms){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  if( ms>0 ){
    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
    db->busyTimeout = ms;
  }else{
    sqlite3_busy_handler(db, 0, 0);
  }
  return SQLITE_OK;
}

/*
** Cause any pending operation to stop at its earliest opportunity.
*/
void sqlite3_interrupt(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  db->u1.isInterrupted = 1;
}


/*
** This function is exactly the same as sqlite3_create_function(), except
** that it is designed to be called by internal code. The difference is
................................................................................
  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xDestroy)(void *)
){
  int rc = SQLITE_ERROR;
  FuncDestructor *pArg = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( xDestroy ){
    pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
    if( !pArg ){
      xDestroy(p);
      goto out;
    }
................................................................................
  void *p,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
){
  int rc;
  char *zFunc8;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
  sqlite3DbFree(db, zFunc8);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
................................................................................
int sqlite3_overload_function(
  sqlite3 *db,
  const char *zName,
  int nArg
){
  int nName = sqlite3Strlen30(zName);
  int rc = SQLITE_OK;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
    rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
                           0, sqlite3InvalidFunction, 0, 0, 0);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
................................................................................
**
** A NULL trace function means that no tracing is executes.  A non-NULL
** trace is a pointer to a function that is invoked at the start of each
** SQL statement.
*/
void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pTraceArg;
  db->xTrace = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_profile(
  sqlite3 *db,
  void (*xProfile)(void*,const char*,sqlite_uint64),
  void *pArg
){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pProfileArg;
  db->xProfile = xProfile;
  db->pProfileArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_commit_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */
){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pCommitArg;
  db->xCommitCallback = xCallback;
  db->pCommitArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
................................................................................
*/
void *sqlite3_update_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
  void *pArg                /* Argument to the function */
){
  void *pRet;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pUpdateArg;
  db->xUpdateCallback = xCallback;
  db->pUpdateArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}
................................................................................
*/
void *sqlite3_rollback_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*), /* Callback function */
  void *pArg                /* Argument to the function */
){
  void *pRet;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pRollbackArg;
  db->xRollbackCallback = xCallback;
  db->pRollbackArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}
................................................................................
** configured by this function.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
#ifdef SQLITE_OMIT_WAL
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(nFrame);
#else
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  if( nFrame>0 ){
    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
  }else{
    sqlite3_wal_hook(db, 0, 0);
  }
#endif
  return SQLITE_OK;
................................................................................
void *sqlite3_wal_hook(
  sqlite3 *db,                    /* Attach the hook to this db handle */
  int(*xCallback)(void *, sqlite3*, const char*, int),
  void *pArg                      /* First argument passed to xCallback() */
){
#ifndef SQLITE_OMIT_WAL
  void *pRet;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pWalArg;
  db->xWalCallback = xCallback;
  db->pWalArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
#else
................................................................................
  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
){
#ifdef SQLITE_OMIT_WAL
  return SQLITE_OK;
#else
  int rc;                         /* Return code */
  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif

  /* Initialize the output variables to -1 in case an error occurs. */
  if( pnLog ) *pnLog = -1;
  if( pnCkpt ) *pnCkpt = -1;

  assert( SQLITE_CHECKPOINT_FULL>SQLITE_CHECKPOINT_PASSIVE );
  assert( SQLITE_CHECKPOINT_FULL<SQLITE_CHECKPOINT_RESTART );
................................................................................
** A new lower limit does not shrink existing constructs.
** It merely prevents new constructs that exceed the limit
** from forming.
*/
int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
  int oldLimit;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return -1;
  }
#endif

  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
  ** there is a hard upper bound set at compile-time by a C preprocessor
  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
  ** "_MAX_".)
  */
  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
................................................................................
  const char *zVfs = zDefaultVfs;
  char *zFile;
  char c;
  int nUri = sqlite3Strlen30(zUri);

  assert( *pzErrMsg==0 );

  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
  ){
    char *zOpt;
    int eState;                   /* Parser state when parsing URI */
    int iIn;                      /* Input character index */
    int iOut = 0;                 /* Output character index */
    int nByte = nUri+2;           /* Bytes of space to allocate */
................................................................................
){
  sqlite3 *db;                    /* Store allocated handle here */
  int rc;                         /* Return code */
  int isThreadsafe;               /* True for threadsafe connections */
  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif

  /* Only allow sensible combinations of bits in the flags argument.  
................................................................................
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
  ** and UTF-16, so add a version for each to avoid any unnecessary
  ** conversions. The only error that can occur here is a malloc() failure.
  **
  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
  ** functions:
  */
  createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
  createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
  createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
  if( db->mallocFailed ){
    goto opendb_out;
  }
  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
  ** strings is BINARY. 
  */
  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
  assert( db->pDfltColl!=0 );




  /* Parse the filename/URI argument. */
  db->openFlags = flags;
  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
    sqlite3_free(zErrMsg);
................................................................................
  const void *zFilename, 
  sqlite3 **ppDb
){
  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
  sqlite3_value *pVal;
  int rc;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif
  if( zFilename==0 ) zFilename = "\000\000";
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    assert( *ppDb || rc==SQLITE_NOMEM );
................................................................................
int sqlite3_create_collation(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);






}

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation_v2(
  sqlite3* db, 
................................................................................
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*),
  void(*xDel)(void*)
){
  int rc;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
................................................................................
  const void *zName,
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  int rc = SQLITE_OK;
  char *zName8;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
  if( zName8 ){
    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
    sqlite3DbFree(db, zName8);
  }
................................................................................
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = xCollNeeded;
  db->xCollNeeded16 = 0;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}
................................................................................
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed16(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = 0;
  db->xCollNeeded16 = xCollNeeded16;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}
................................................................................
/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
*/
int sqlite3_get_autocommit(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->autoCommit;
}

/*
** The following routines are substitutes for constants SQLITE_CORRUPT,
** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
** constants.  They serve two purposes:
................................................................................
  return rc;
}

/*
** Enable or disable the extended result codes.
*/
int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->errMask = onoff ? 0xffffffff : 0xff;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Invoke the xFileControl method on a particular database.
*/
int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
  int rc = SQLITE_ERROR;
  Btree *pBtree;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  pBtree = sqlite3DbNameToBtree(db, zDbName);
  if( pBtree ){
    Pager *pPager;
    sqlite3_file *fd;
    sqlite3BtreeEnter(pBtree);
    pPager = sqlite3BtreePager(pBtree);
................................................................................
** The zFilename argument is the filename pointer passed into the xOpen()
** method of a VFS implementation.  The zParam argument is the name of the
** query parameter we seek.  This routine returns the value of the zParam
** parameter if it exists.  If the parameter does not exist, this routine
** returns a NULL pointer.
*/
const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
  if( zFilename==0 || zParam==0 ) return 0;
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] ){
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
................................................................................
}

/*
** Return the filename of the database associated with a database
** connection.
*/
const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  Btree *pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
}

/*
** Return 1 if database is read-only or 0 if read/write.  Return -1 if
** no such database exists.
*/
int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return -1;
  }
#endif
  Btree *pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
}

    }
    sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
  }
  assert( sqlite3_mutex_notheld(mem0.mutex) );


#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
  /* Verify that no more than two scratch allocations per thread
  ** are outstanding at one time.  (This is only checked in the
  ** single-threaded case since checking in the multi-threaded case
  ** would be much more complicated.) */

  assert( scratchAllocOut<=1 );
  if( p ) scratchAllocOut++;
#endif

  return p;
}
void sqlite3ScratchFree(void *p){
  if( p ){

    }
    sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
  }
  assert( sqlite3_mutex_notheld(mem0.mutex) );


#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
  /* EVIDENCE-OF: R-12970-05880 SQLite will not use more than one scratch
  ** buffers per thread.
  **
  ** This can only be checked in single-threaded mode.
  */
  assert( scratchAllocOut==0 );
  if( p ) scratchAllocOut++;
#endif

  return p;
}
void sqlite3ScratchFree(void *p){
  if( p ){

/*
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){
#ifndef SQLITE_OMIT_AUTOINIT
  if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;

#endif
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){
  if( !sqlite3GlobalConfig.bCoreMutex ){
    return 0;

/*
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){
#ifndef SQLITE_OMIT_AUTOINIT
  if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;
  if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;
#endif
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){
  if( !sqlite3GlobalConfig.bCoreMutex ){
    return 0;

        p->id = iType;
#endif
        pthread_mutex_init(&p->mutex, 0);
      }
      break;
    }
    default: {
      assert( iType-2 >= 0 );
      assert( iType-2 < ArraySize(staticMutexes) );




      p = &staticMutexes[iType-2];
#if SQLITE_MUTEX_NREF
      p->id = iType;
#endif
      break;
    }
  }

        p->id = iType;
#endif
        pthread_mutex_init(&p->mutex, 0);
      }
      break;
    }
    default: {
#ifdef SQLITE_ENABLE_API_ARMOR
      if( iType-2<0 || iType-2>=ArraySize(staticMutexes) ){
        (void)SQLITE_MISUSE_BKPT;
        return 0;
      }
#endif
      p = &staticMutexes[iType-2];
#if SQLITE_MUTEX_NREF
      p->id = iType;
#endif
      break;
    }
  }

*/
int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
  MUTEX_LOGIC(sqlite3_mutex *mutex;)
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return rc;
#endif




  MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  if( makeDflt || vfsList==0 ){
    pVfs->pNext = vfsList;
    vfsList = pVfs;
  }else{

*/
int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
  MUTEX_LOGIC(sqlite3_mutex *mutex;)
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return rc;
#endif
#ifdef SQLITE_ENABLE_API_ARMOR
  if( pVfs==0 ) return SQLITE_MISUSE_BKPT;
#endif

  MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  if( makeDflt || vfsList==0 ){
    pVfs->pNext = vfsList;
    vfsList = pVfs;
  }else{

** available in Windows platforms based on the NT kernel.
*/
#if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)
#  error "WAL mode requires support from the Windows NT kernel, compile\
 with SQLITE_OMIT_WAL."
#endif






/*
** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions
** based on the sub-platform)?
*/
#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(SQLITE_WIN32_NO_ANSI)
#  define SQLITE_WIN32_HAS_ANSI
#endif
................................................................................
*/
#ifndef winGetDirSep
#  define winGetDirSep()                '\\'
#endif

/*
** Do we need to manually define the Win32 file mapping APIs for use with WAL
** mode (e.g. these APIs are available in the Windows CE SDK; however, they
** are not present in the header file)?
*/
#if SQLITE_WIN32_FILEMAPPING_API && !defined(SQLITE_OMIT_WAL)

/*
** Two of the file mapping APIs are different under WinRT.  Figure out which
** set we need.
*/
#if SQLITE_OS_WINRT
WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \
        LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);
................................................................................
WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
#endif /* SQLITE_OS_WINRT */

/*
** This file mapping API is common to both Win32 and WinRT.
*/
WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
#endif /* SQLITE_WIN32_FILEMAPPING_API && !defined(SQLITE_OMIT_WAL) */

/*
** Some Microsoft compilers lack this definition.
*/
#ifndef INVALID_FILE_ATTRIBUTES
# define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
#endif
................................................................................
  { "CreateFileW",             (SYSCALL)0,                       0 },
#endif

#define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
        LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)

#if (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
        !defined(SQLITE_OMIT_WAL))
  { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
#else
  { "CreateFileMappingA",      (SYSCALL)0,                       0 },
#endif

#define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
        DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)

#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
        !defined(SQLITE_OMIT_WAL))
  { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
#else
  { "CreateFileMappingW",      (SYSCALL)0,                       0 },
#endif

#define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
        DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
................................................................................
#endif

#ifndef osLockFileEx
#define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[48].pCurrent)
#endif

#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL))

  { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
#else
  { "MapViewOfFile",           (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        SIZE_T))aSyscall[49].pCurrent)
................................................................................
#else
  { "UnlockFileEx",            (SYSCALL)0,                       0 },
#endif

#define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[58].pCurrent)

#if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL)
  { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
#else
  { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
#endif

#define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)

................................................................................
#else
  { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
#endif

#define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
        FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)

#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL)
  { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
#else
  { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
        SIZE_T))aSyscall[67].pCurrent)
................................................................................

#define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)

  { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },

#define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)

#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL)
  { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
#else
  { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
#endif

#define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
        LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)

** available in Windows platforms based on the NT kernel.
*/
#if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)
#  error "WAL mode requires support from the Windows NT kernel, compile\
 with SQLITE_OMIT_WAL."
#endif

#if !SQLITE_OS_WINNT && SQLITE_MAX_MMAP_SIZE>0
#  error "Memory mapped files require support from the Windows NT kernel,\
 compile with SQLITE_MAX_MMAP_SIZE=0."
#endif

/*
** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions
** based on the sub-platform)?
*/
#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(SQLITE_WIN32_NO_ANSI)
#  define SQLITE_WIN32_HAS_ANSI
#endif
................................................................................
*/
#ifndef winGetDirSep
#  define winGetDirSep()                '\\'
#endif

/*
** Do we need to manually define the Win32 file mapping APIs for use with WAL
** mode or memory mapped files (e.g. these APIs are available in the Windows
** CE SDK; however, they are not present in the header file)?
*/
#if SQLITE_WIN32_FILEMAPPING_API && \
        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
/*
** Two of the file mapping APIs are different under WinRT.  Figure out which
** set we need.
*/
#if SQLITE_OS_WINRT
WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \
        LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);
................................................................................
WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
#endif /* SQLITE_OS_WINRT */

/*
** This file mapping API is common to both Win32 and WinRT.
*/
WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
#endif /* SQLITE_WIN32_FILEMAPPING_API */

/*
** Some Microsoft compilers lack this definition.
*/
#ifndef INVALID_FILE_ATTRIBUTES
# define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
#endif
................................................................................
  { "CreateFileW",             (SYSCALL)0,                       0 },
#endif

#define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
        LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)

#if (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
  { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
#else
  { "CreateFileMappingA",      (SYSCALL)0,                       0 },
#endif

#define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
        DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)

#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
  { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
#else
  { "CreateFileMappingW",      (SYSCALL)0,                       0 },
#endif

#define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
        DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
................................................................................
#endif

#ifndef osLockFileEx
#define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[48].pCurrent)
#endif

#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \
        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
  { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
#else
  { "MapViewOfFile",           (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        SIZE_T))aSyscall[49].pCurrent)
................................................................................
#else
  { "UnlockFileEx",            (SYSCALL)0,                       0 },
#endif

#define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[58].pCurrent)

#if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
#else
  { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
#endif

#define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)

................................................................................
#else
  { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
#endif

#define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
        FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)

#if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
  { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
#else
  { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
        SIZE_T))aSyscall[67].pCurrent)
................................................................................

#define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)

  { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },

#define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)

#if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
  { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
#else
  { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
#endif

#define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
        LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)

      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
      sqlite3OsClose(pPager->jfd);
    }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
      if( pPager->journalOff==0 ){
        rc = SQLITE_OK;
      }else{
        rc = sqlite3OsTruncate(pPager->jfd, 0);








      }
      pPager->journalOff = 0;
    }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
      || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
    ){
      rc = zeroJournalHdr(pPager, hasMaster);
      pPager->journalOff = 0;
................................................................................
      ** of bytes 24..39 of the database.  Bytes 28..31 should always be
      ** zero or the size of the database in page. Bytes 32..35 and 35..39
      ** should be page numbers which are never 0xffffffff.  So filling
      ** pPager->dbFileVers[] with all 0xff bytes should suffice.
      **
      ** For an encrypted database, the situation is more complex:  bytes
      ** 24..39 of the database are white noise.  But the probability of
      ** white noising equaling 16 bytes of 0xff is vanishingly small so
      ** we should still be ok.
      */
      memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));
    }else{
      u8 *dbFileVers = &((u8*)pPg->pData)[24];
      memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
    }
................................................................................
    sqlite3PcacheMakeDirty(pPgHdr);
    sqlite3PagerUnrefNotNull(pPgHdr);
  }

  return SQLITE_OK;
}
#endif













/*
** Return a pointer to the data for the specified page.
*/
void *sqlite3PagerGetData(DbPage *pPg){
  assert( pPg->nRef>0 || pPg->pPager->memDb );
  return pPg->pData;

      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
      sqlite3OsClose(pPager->jfd);
    }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
      if( pPager->journalOff==0 ){
        rc = SQLITE_OK;
      }else{
        rc = sqlite3OsTruncate(pPager->jfd, 0);
        if( rc==SQLITE_OK && pPager->fullSync ){
          /* Make sure the new file size is written into the inode right away.
          ** Otherwise the journal might resurrect following a power loss and
          ** cause the last transaction to roll back.  See
          ** https://bugzilla.mozilla.org/show_bug.cgi?id=1072773
          */
          rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags);
        }
      }
      pPager->journalOff = 0;
    }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
      || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
    ){
      rc = zeroJournalHdr(pPager, hasMaster);
      pPager->journalOff = 0;
................................................................................
      ** of bytes 24..39 of the database.  Bytes 28..31 should always be
      ** zero or the size of the database in page. Bytes 32..35 and 35..39
      ** should be page numbers which are never 0xffffffff.  So filling
      ** pPager->dbFileVers[] with all 0xff bytes should suffice.
      **
      ** For an encrypted database, the situation is more complex:  bytes
      ** 24..39 of the database are white noise.  But the probability of
      ** white noise equaling 16 bytes of 0xff is vanishingly small so
      ** we should still be ok.
      */
      memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));
    }else{
      u8 *dbFileVers = &((u8*)pPg->pData)[24];
      memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
    }
................................................................................
    sqlite3PcacheMakeDirty(pPgHdr);
    sqlite3PagerUnrefNotNull(pPgHdr);
  }

  return SQLITE_OK;
}
#endif

/*
** The page handle passed as the first argument refers to a dirty page 
** with a page number other than iNew. This function changes the page's 
** page number to iNew and sets the value of the PgHdr.flags field to 
** the value passed as the third parameter.
*/
void sqlite3PagerRekey(DbPage *pPg, Pgno iNew, u16 flags){
  assert( pPg->pgno!=iNew );
  pPg->flags = flags;
  sqlite3PcacheMove(pPg, iNew);
}

/*
** Return a pointer to the data for the specified page.
*/
void *sqlite3PagerGetData(DbPage *pPg){
  assert( pPg->nRef>0 || pPg->pPager->memDb );
  return pPg->pData;

int sqlite3PagerIsMemdb(Pager*);
void sqlite3PagerCacheStat(Pager *, int, int, int *);
void sqlite3PagerClearCache(Pager *);
int sqlite3SectorSize(sqlite3_file *);

/* Functions used to truncate the database file. */
void sqlite3PagerTruncateImage(Pager*,Pgno);



#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL)
void *sqlite3PagerCodec(DbPage *);
#endif

/* Functions to support testing and debugging. */
#if !defined(NDEBUG) || defined(SQLITE_TEST)

int sqlite3PagerIsMemdb(Pager*);
void sqlite3PagerCacheStat(Pager *, int, int, int *);
void sqlite3PagerClearCache(Pager *);
int sqlite3SectorSize(sqlite3_file *);

/* Functions used to truncate the database file. */
void sqlite3PagerTruncateImage(Pager*,Pgno);

void sqlite3PagerRekey(DbPage*, Pgno, u16);

#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL)
void *sqlite3PagerCodec(DbPage *);
#endif

/* Functions to support testing and debugging. */
#if !defined(NDEBUG) || defined(SQLITE_TEST)

/*
** Free up as much memory as possible from the page cache.
*/
void sqlite3PcacheShrink(PCache *pCache){
  assert( pCache->pCache!=0 );
  sqlite3GlobalConfig.pcache2.xShrink(pCache->pCache);
}








#if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
/*
** For all dirty pages currently in the cache, invoke the specified
** callback. This is only used if the SQLITE_CHECK_PAGES macro is
** defined.
*/

/*
** Free up as much memory as possible from the page cache.
*/
void sqlite3PcacheShrink(PCache *pCache){
  assert( pCache->pCache!=0 );
  sqlite3GlobalConfig.pcache2.xShrink(pCache->pCache);
}

/*
** Return the size of the header added by this middleware layer
** in the page-cache hierarchy.
*/
int sqlite3HeaderSizePcache(void){ return sizeof(PgHdr); }


#if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
/*
** For all dirty pages currently in the cache, invoke the specified
** callback. This is only used if the SQLITE_CHECK_PAGES macro is
** defined.
*/

#ifdef SQLITE_TEST
void sqlite3PcacheStats(int*,int*,int*,int*);
#endif

void sqlite3PCacheSetDefault(void);





#endif /* _PCACHE_H_ */

#ifdef SQLITE_TEST
void sqlite3PcacheStats(int*,int*,int*,int*);
#endif

void sqlite3PCacheSetDefault(void);

/* Return the header size */
int sqlite3HeaderSizePcache(void);
int sqlite3HeaderSizePcache1(void);

#endif /* _PCACHE_H_ */

    pcache1Truncate,         /* xTruncate */
    pcache1Destroy,          /* xDestroy */
    pcache1Shrink            /* xShrink */
  };
  sqlite3_config(SQLITE_CONFIG_PCACHE2, &defaultMethods);
}






#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*
** This function is called to free superfluous dynamically allocated memory
** held by the pager system. Memory in use by any SQLite pager allocated
** by the current thread may be sqlite3_free()ed.
**
** nReq is the number of bytes of memory required. Once this much has

    pcache1Truncate,         /* xTruncate */
    pcache1Destroy,          /* xDestroy */
    pcache1Shrink            /* xShrink */
  };
  sqlite3_config(SQLITE_CONFIG_PCACHE2, &defaultMethods);
}

/*
** Return the size of the header on each page of this PCACHE implementation.
*/
int sqlite3HeaderSizePcache1(void){ return sizeof(PgHdr1); }

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*
** This function is called to free superfluous dynamically allocated memory
** held by the pager system. Memory in use by any SQLite pager allocated
** by the current thread may be sqlite3_free()ed.
**
** nReq is the number of bytes of memory required. Once this much has

  int nBytes,               /* Length of zSql in bytes. */
  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
  Vdbe *pOld,               /* VM being reprepared */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;
  assert( ppStmt!=0 );




  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
  if( rc==SQLITE_SCHEMA ){
    sqlite3_finalize(*ppStmt);
................................................................................
  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
  ** tricky bit is figuring out the pointer to return in *pzTail.
  */
  char *zSql8;
  const char *zTail8 = 0;
  int rc = SQLITE_OK;

  assert( ppStmt );


  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
  if( nBytes>=0 ){
    int sz;
    const char *z = (const char*)zSql;
    for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
    nBytes = sz;

  int nBytes,               /* Length of zSql in bytes. */
  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
  Vdbe *pOld,               /* VM being reprepared */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;


#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
    return SQLITE_MISUSE_BKPT;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
  if( rc==SQLITE_SCHEMA ){
    sqlite3_finalize(*ppStmt);
................................................................................
  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
  ** tricky bit is figuring out the pointer to return in *pzTail.
  */
  char *zSql8;
  const char *zTail8 = 0;
  int rc = SQLITE_OK;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
    return SQLITE_MISUSE_BKPT;
  }
  if( nBytes>=0 ){
    int sz;
    const char *z = (const char*)zSql;
    for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
    nBytes = sz;

/*
** If the strchrnul() library function is available, then set
** HAVE_STRCHRNUL.  If that routine is not available, this module
** will supply its own.  The built-in version is slower than
** the glibc version so the glibc version is definitely preferred.
*/
#if !defined(HAVE_STRCHRNUL)
# if defined(linux)
#  define HAVE_STRCHRNUL 1
# else
#  define HAVE_STRCHRNUL 0
# endif
#endif


/*
** Conversion types fall into various categories as defined by the
** following enumeration.
*/
................................................................................
  u8 useIntern;              /* Ok to use internal conversions (ex: %T) */
  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
  sqlite_uint64 longvalue;   /* Value for integer types */
  LONGDOUBLE_TYPE realvalue; /* Value for real types */
  const et_info *infop;      /* Pointer to the appropriate info structure */
  char *zOut;                /* Rendering buffer */
  int nOut;                  /* Size of the rendering buffer */
  char *zExtra;              /* Malloced memory used by some conversion */
#ifndef SQLITE_OMIT_FLOATING_POINT
  int  exp, e2;              /* exponent of real numbers */
  int nsd;                   /* Number of significant digits returned */
  double rounder;            /* Used for rounding floating point values */
  etByte flag_dp;            /* True if decimal point should be shown */
  etByte flag_rtz;           /* True if trailing zeros should be removed */
#endif
  PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
  char buf[etBUFSIZE];       /* Conversion buffer */








  bufpt = 0;
  if( bFlags ){
    if( (bArgList = (bFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
      pArgList = va_arg(ap, PrintfArguments*);
    }
    useIntern = bFlags & SQLITE_PRINTF_INTERNAL;
  }else{
................................................................................
          xtype = infop->type;
        }else{
          return;
        }
        break;
      }
    }
    zExtra = 0;

    /*
    ** At this point, variables are initialized as follows:
    **
    **   flag_alternateform          TRUE if a '#' is present.
    **   flag_altform2               TRUE if a '!' is present.
    **   flag_plussign               TRUE if a '+' is present.
................................................................................
      case etCHARX:
        if( bArgList ){
          bufpt = getTextArg(pArgList);
          c = bufpt ? bufpt[0] : 0;
        }else{
          c = va_arg(ap,int);
        }
        buf[0] = (char)c;
        if( precision>=0 ){
          for(idx=1; idx<precision; idx++) buf[idx] = (char)c;
          length = precision;
        }else{
          length =1;
        }



        bufpt = buf;
        break;
      case etSTRING:
      case etDYNSTRING:
        if( bArgList ){
          bufpt = getTextArg(pArgList);
        }else{
................................................................................
    }/* End switch over the format type */
    /*
    ** The text of the conversion is pointed to by "bufpt" and is
    ** "length" characters long.  The field width is "width".  Do
    ** the output.
    */
    width -= length;
    if( width>0 && !flag_leftjustify ) sqlite3AppendSpace(pAccum, width);
    sqlite3StrAccumAppend(pAccum, bufpt, length);
    if( width>0 && flag_leftjustify ) sqlite3AppendSpace(pAccum, width);


    if( zExtra ) sqlite3_free(zExtra);


  }/* End for loop over the format string */
} /* End of function */

/*
** Enlarge the memory allocation on a StrAccum object so that it is
** able to accept at least N more bytes of text.
**
................................................................................
    N = p->nAlloc - p->nChar - 1;
    setStrAccumError(p, STRACCUM_TOOBIG);
    return N;
  }else{
    char *zOld = (p->zText==p->zBase ? 0 : p->zText);
    i64 szNew = p->nChar;
    szNew += N + 1;





    if( szNew > p->mxAlloc ){
      sqlite3StrAccumReset(p);
      setStrAccumError(p, STRACCUM_TOOBIG);
      return 0;
    }else{
      p->nAlloc = (int)szNew;
    }
................................................................................
    }else{
      zNew = sqlite3_realloc(zOld, p->nAlloc);
    }
    if( zNew ){
      assert( p->zText!=0 || p->nChar==0 );
      if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
      p->zText = zNew;

    }else{
      sqlite3StrAccumReset(p);
      setStrAccumError(p, STRACCUM_NOMEM);
      return 0;
    }
  }
  return N;
}

/*
** Append N space characters to the given string buffer.
*/
void sqlite3AppendSpace(StrAccum *p, int N){
  if( p->nChar+N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ) return;
  while( (N--)>0 ) p->zText[p->nChar++] = ' ';
}

/*
** The StrAccum "p" is not large enough to accept N new bytes of z[].
** So enlarge if first, then do the append.
**
** This is a helper routine to sqlite3StrAccumAppend() that does special-case
................................................................................
** Print into memory obtained from sqlite3_malloc().  Omit the internal
** %-conversion extensions.
*/
char *sqlite3_vmprintf(const char *zFormat, va_list ap){
  char *z;
  char zBase[SQLITE_PRINT_BUF_SIZE];
  StrAccum acc;







#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
  acc.useMalloc = 2;
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  z = sqlite3StrAccumFinish(&acc);
................................................................................
** mistake.
**
** sqlite3_vsnprintf() is the varargs version.
*/
char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
  StrAccum acc;
  if( n<=0 ) return zBuf;







  sqlite3StrAccumInit(&acc, zBuf, n, 0);
  acc.useMalloc = 0;
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  return sqlite3StrAccumFinish(&acc);
}
char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
  char *z;

/*
** If the strchrnul() library function is available, then set
** HAVE_STRCHRNUL.  If that routine is not available, this module
** will supply its own.  The built-in version is slower than
** the glibc version so the glibc version is definitely preferred.
*/
#if !defined(HAVE_STRCHRNUL)



# define HAVE_STRCHRNUL 0

#endif


/*
** Conversion types fall into various categories as defined by the
** following enumeration.
*/
................................................................................
  u8 useIntern;              /* Ok to use internal conversions (ex: %T) */
  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
  sqlite_uint64 longvalue;   /* Value for integer types */
  LONGDOUBLE_TYPE realvalue; /* Value for real types */
  const et_info *infop;      /* Pointer to the appropriate info structure */
  char *zOut;                /* Rendering buffer */
  int nOut;                  /* Size of the rendering buffer */
  char *zExtra = 0;          /* Malloced memory used by some conversion */
#ifndef SQLITE_OMIT_FLOATING_POINT
  int  exp, e2;              /* exponent of real numbers */
  int nsd;                   /* Number of significant digits returned */
  double rounder;            /* Used for rounding floating point values */
  etByte flag_dp;            /* True if decimal point should be shown */
  etByte flag_rtz;           /* True if trailing zeros should be removed */
#endif
  PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
  char buf[etBUFSIZE];       /* Conversion buffer */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ap==0 ){
    (void)SQLITE_MISUSE_BKPT;
    sqlite3StrAccumReset(pAccum);
    return;
  }
#endif
  bufpt = 0;
  if( bFlags ){
    if( (bArgList = (bFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
      pArgList = va_arg(ap, PrintfArguments*);
    }
    useIntern = bFlags & SQLITE_PRINTF_INTERNAL;
  }else{
................................................................................
          xtype = infop->type;
        }else{
          return;
        }
        break;
      }
    }


    /*
    ** At this point, variables are initialized as follows:
    **
    **   flag_alternateform          TRUE if a '#' is present.
    **   flag_altform2               TRUE if a '!' is present.
    **   flag_plussign               TRUE if a '+' is present.
................................................................................
      case etCHARX:
        if( bArgList ){
          bufpt = getTextArg(pArgList);
          c = bufpt ? bufpt[0] : 0;
        }else{
          c = va_arg(ap,int);
        }
        if( precision>1 ){
          width -= precision-1;
          if( width>1 && !flag_leftjustify ){
            sqlite3AppendChar(pAccum, width-1, ' ');
            width = 0;
          }
          sqlite3AppendChar(pAccum, precision-1, c);
        }
        length = 1;
        buf[0] = c;
        bufpt = buf;
        break;
      case etSTRING:
      case etDYNSTRING:
        if( bArgList ){
          bufpt = getTextArg(pArgList);
        }else{
................................................................................
    }/* End switch over the format type */
    /*
    ** The text of the conversion is pointed to by "bufpt" and is
    ** "length" characters long.  The field width is "width".  Do
    ** the output.
    */
    width -= length;
    if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
    sqlite3StrAccumAppend(pAccum, bufpt, length);
    if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');

    if( zExtra ){
      sqlite3_free(zExtra);
      zExtra = 0;
    }
  }/* End for loop over the format string */
} /* End of function */

/*
** Enlarge the memory allocation on a StrAccum object so that it is
** able to accept at least N more bytes of text.
**
................................................................................
    N = p->nAlloc - p->nChar - 1;
    setStrAccumError(p, STRACCUM_TOOBIG);
    return N;
  }else{
    char *zOld = (p->zText==p->zBase ? 0 : p->zText);
    i64 szNew = p->nChar;
    szNew += N + 1;
    if( szNew+p->nChar<=p->mxAlloc ){
      /* Force exponential buffer size growth as long as it does not overflow,
      ** to avoid having to call this routine too often */
      szNew += p->nChar;
    }
    if( szNew > p->mxAlloc ){
      sqlite3StrAccumReset(p);
      setStrAccumError(p, STRACCUM_TOOBIG);
      return 0;
    }else{
      p->nAlloc = (int)szNew;
    }
................................................................................
    }else{
      zNew = sqlite3_realloc(zOld, p->nAlloc);
    }
    if( zNew ){
      assert( p->zText!=0 || p->nChar==0 );
      if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
      p->zText = zNew;
      p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
    }else{
      sqlite3StrAccumReset(p);
      setStrAccumError(p, STRACCUM_NOMEM);
      return 0;
    }
  }
  return N;
}

/*
** Append N copies of character c to the given string buffer.
*/
void sqlite3AppendChar(StrAccum *p, int N, char c){
  if( p->nChar+N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ) return;
  while( (N--)>0 ) p->zText[p->nChar++] = c;
}

/*
** The StrAccum "p" is not large enough to accept N new bytes of z[].
** So enlarge if first, then do the append.
**
** This is a helper routine to sqlite3StrAccumAppend() that does special-case
................................................................................
** Print into memory obtained from sqlite3_malloc().  Omit the internal
** %-conversion extensions.
*/
char *sqlite3_vmprintf(const char *zFormat, va_list ap){
  char *z;
  char zBase[SQLITE_PRINT_BUF_SIZE];
  StrAccum acc;

#ifdef SQLITE_ENABLE_API_ARMOR  
  if( zFormat==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
  acc.useMalloc = 2;
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  z = sqlite3StrAccumFinish(&acc);
................................................................................
** mistake.
**
** sqlite3_vsnprintf() is the varargs version.
*/
char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
  StrAccum acc;
  if( n<=0 ) return zBuf;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( zBuf==0 || zFormat==0 ) {
    (void)SQLITE_MISUSE_BKPT;
    if( zBuf && n>0 ) zBuf[0] = 0;
    return zBuf;
  }
#endif
  sqlite3StrAccumInit(&acc, zBuf, n, 0);
  acc.useMalloc = 0;
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  return sqlite3StrAccumFinish(&acc);
}
char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
  char *z;

  struct sqlite3PrngType *p = &GLOBAL(struct sqlite3PrngType, sqlite3Prng);
# define wsdPrng p[0]
#else
# define wsdPrng sqlite3Prng
#endif

#if SQLITE_THREADSAFE








  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);
  sqlite3_mutex_enter(mutex);
#endif


  if( N<=0 ){
    wsdPrng.isInit = 0;
    sqlite3_mutex_leave(mutex);
    return;
  }

  /* Initialize the state of the random number generator once,
  ** the first time this routine is called.  The seed value does

  struct sqlite3PrngType *p = &GLOBAL(struct sqlite3PrngType, sqlite3Prng);
# define wsdPrng p[0]
#else
# define wsdPrng sqlite3Prng
#endif

#if SQLITE_THREADSAFE
  sqlite3_mutex *mutex;
#endif

#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return;
#endif

#if SQLITE_THREADSAFE
  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);

#endif

  sqlite3_mutex_enter(mutex);
  if( N<=0 || pBuf==0 ){
    wsdPrng.isInit = 0;
    sqlite3_mutex_leave(mutex);
    return;
  }

  /* Initialize the state of the random number generator once,
  ** the first time this routine is called.  The seed value does

** This needs to occur when copying a TK_AGG_FUNCTION node from an
** outer query into an inner subquery.
**
** incrAggFunctionDepth(pExpr,n) is the main routine.  incrAggDepth(..)
** is a helper function - a callback for the tree walker.
*/
static int incrAggDepth(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.i;
  return WRC_Continue;
}
static void incrAggFunctionDepth(Expr *pExpr, int N){
  if( N>0 ){
    Walker w;
    memset(&w, 0, sizeof(w));
    w.xExprCallback = incrAggDepth;
    w.u.i = N;
    sqlite3WalkExpr(&w, pExpr);
  }
}

/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
................................................................................
*/
static int exprProbability(Expr *p){
  double r = -1.0;
  if( p->op!=TK_FLOAT ) return -1;
  sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
  assert( r>=0.0 );
  if( r>1.0 ) return -1;
  return (int)(r*1000.0);
}

/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree.  Return 0 to continue the search down
................................................................................
            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is short-hand for
            ** likelihood(X,0.0625).
            ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand for
            ** likelihood(X,0.9375).
            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent to
            ** likelihood(X,0.9375). */
            /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */
            pExpr->iTable = pDef->zName[0]=='u' ? 62 : 938;
          }             
        }
#ifndef SQLITE_OMIT_AUTHORIZATION
        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
        if( auth!=SQLITE_OK ){
          if( auth==SQLITE_DENY ){
            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",

** This needs to occur when copying a TK_AGG_FUNCTION node from an
** outer query into an inner subquery.
**
** incrAggFunctionDepth(pExpr,n) is the main routine.  incrAggDepth(..)
** is a helper function - a callback for the tree walker.
*/
static int incrAggDepth(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n;
  return WRC_Continue;
}
static void incrAggFunctionDepth(Expr *pExpr, int N){
  if( N>0 ){
    Walker w;
    memset(&w, 0, sizeof(w));
    w.xExprCallback = incrAggDepth;
    w.u.n = N;
    sqlite3WalkExpr(&w, pExpr);
  }
}

/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
................................................................................
*/
static int exprProbability(Expr *p){
  double r = -1.0;
  if( p->op!=TK_FLOAT ) return -1;
  sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
  assert( r>=0.0 );
  if( r>1.0 ) return -1;
  return (int)(r*134217728.0);
}

/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree.  Return 0 to continue the search down
................................................................................
            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is short-hand for
            ** likelihood(X,0.0625).
            ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand for
            ** likelihood(X,0.9375).
            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent to
            ** likelihood(X,0.9375). */
            /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */
            pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120;
          }             
        }
#ifndef SQLITE_OMIT_AUTHORIZATION
        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
        if( auth!=SQLITE_OK ){
          if( auth==SQLITE_DENY ){
            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",

#include <windows.h>

/* Saved resource information for the beginning of an operation */
static HANDLE hProcess;
static FILETIME ftKernelBegin;
static FILETIME ftUserBegin;
static sqlite3_int64 ftWallBegin;
typedef BOOL (WINAPI *GETPROCTIMES)(HANDLE, LPFILETIME, LPFILETIME, LPFILETIME, LPFILETIME);

static GETPROCTIMES getProcessTimesAddr = NULL;

/*
** Check to see if we have timer support.  Return 1 if necessary
** support found (or found previously).
*/
static int hasTimer(void){
  if( getProcessTimesAddr ){
    return 1;
  } else {
    /* GetProcessTimes() isn't supported in WIN95 and some other Windows versions.
    ** See if the version we are running on has it, and if it does, save off
    ** a pointer to it and the current process handle.
    */
    hProcess = GetCurrentProcess();
    if( hProcess ){
      HINSTANCE hinstLib = LoadLibrary(TEXT("Kernel32.dll"));
      if( NULL != hinstLib ){

        getProcessTimesAddr = (GETPROCTIMES) GetProcAddress(hinstLib, "GetProcessTimes");
        if( NULL != getProcessTimesAddr ){
          return 1;
        }
        FreeLibrary(hinstLib); 
      }
    }
  }
................................................................................

/*
** Begin timing an operation
*/
static void beginTimer(void){
  if( enableTimer && getProcessTimesAddr ){
    FILETIME ftCreation, ftExit;
    getProcessTimesAddr(hProcess, &ftCreation, &ftExit, &ftKernelBegin, &ftUserBegin);

    ftWallBegin = timeOfDay();
  }
}

/* Return the difference of two FILETIME structs in seconds */
static double timeDiff(FILETIME *pStart, FILETIME *pEnd){
  sqlite_int64 i64Start = *((sqlite_int64 *) pStart);
................................................................................
/*
** Print the timing results.
*/
static void endTimer(void){
  if( enableTimer && getProcessTimesAddr){
    FILETIME ftCreation, ftExit, ftKernelEnd, ftUserEnd;
    sqlite3_int64 ftWallEnd = timeOfDay();
    getProcessTimesAddr(hProcess, &ftCreation, &ftExit, &ftKernelEnd, &ftUserEnd);
    printf("Run Time: real %.3f user %f sys %f\n",
       (ftWallEnd - ftWallBegin)*0.001,
       timeDiff(&ftUserBegin, &ftUserEnd),
       timeDiff(&ftKernelBegin, &ftKernelEnd));
  }
}

................................................................................
*/
typedef struct ShellState ShellState;
struct ShellState {
  sqlite3 *db;           /* The database */
  int echoOn;            /* True to echo input commands */
  int autoEQP;           /* Run EXPLAIN QUERY PLAN prior to seach SQL stmt */
  int statsOn;           /* True to display memory stats before each finalize */

  int outCount;          /* Revert to stdout when reaching zero */
  int cnt;               /* Number of records displayed so far */
  FILE *out;             /* Write results here */
  FILE *traceOut;        /* Output for sqlite3_trace() */
  int nErr;              /* Number of errors seen */
  int mode;              /* An output mode setting */
  int writableSchema;    /* True if PRAGMA writable_schema=ON */
................................................................................
}
#endif

/*
** This is the callback routine that the shell
** invokes for each row of a query result.
*/
static int shell_callback(void *pArg, int nArg, char **azArg, char **azCol, int *aiType){






  int i;
  ShellState *p = (ShellState*)pArg;

  switch( p->mode ){
    case MODE_Line: {
      int w = 5;
      if( azArg==0 ) break;
................................................................................
  int iCur;
  int iHiwtr;

  if( pArg && pArg->out ){
    
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MEMORY_USED, &iCur, &iHiwtr, bReset);

    fprintf(pArg->out, "Memory Used:                         %d (max %d) bytes\n", iCur, iHiwtr);

    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Number of Outstanding Allocations:   %d (max %d)\n", iCur, iHiwtr);

    if( pArg->shellFlgs & SHFLG_Pagecache ){
      iHiwtr = iCur = -1;
      sqlite3_status(SQLITE_STATUS_PAGECACHE_USED, &iCur, &iHiwtr, bReset);

      fprintf(pArg->out, "Number of Pcache Pages Used:         %d (max %d) pages\n", iCur, iHiwtr);

    }
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PAGECACHE_OVERFLOW, &iCur, &iHiwtr, bReset);

    fprintf(pArg->out, "Number of Pcache Overflow Bytes:     %d (max %d) bytes\n", iCur, iHiwtr);

    if( pArg->shellFlgs & SHFLG_Scratch ){
      iHiwtr = iCur = -1;
      sqlite3_status(SQLITE_STATUS_SCRATCH_USED, &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Number of Scratch Allocations Used:  %d (max %d)\n", iCur, iHiwtr);

    }
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_SCRATCH_OVERFLOW, &iCur, &iHiwtr, bReset);

    fprintf(pArg->out, "Number of Scratch Overflow Bytes:    %d (max %d) bytes\n", iCur, iHiwtr);

    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MALLOC_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Allocation:                  %d bytes\n", iHiwtr);

    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PAGECACHE_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Pcache Allocation:           %d bytes\n", iHiwtr);

    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_SCRATCH_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Scratch Allocation:          %d bytes\n", iHiwtr);

#ifdef YYTRACKMAXSTACKDEPTH
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PARSER_STACK, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Deepest Parser Stack:                %d (max %d)\n", iCur, iHiwtr);

#endif
  }

  if( pArg && pArg->out && db ){
    if( pArg->shellFlgs & SHFLG_Lookaside ){
      iHiwtr = iCur = -1;
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED, &iCur, &iHiwtr, bReset);

      fprintf(pArg->out, "Lookaside Slots Used:                %d (max %d)\n", iCur, iHiwtr);

      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_HIT, &iCur, &iHiwtr, bReset);

      fprintf(pArg->out, "Successful lookaside attempts:       %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE, &iCur, &iHiwtr, bReset);

      fprintf(pArg->out, "Lookaside failures due to size:      %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL, &iCur, &iHiwtr, bReset);

      fprintf(pArg->out, "Lookaside failures due to OOM:       %d\n", iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Pager Heap Usage:                    %d bytes\n", iCur);    iHiwtr = iCur = -1;

    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_HIT, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache hits:                     %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_MISS, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache misses:                   %d\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_WRITE, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache writes:                   %d\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Schema Heap Usage:                   %d bytes\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_STMT_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Statement Heap/Lookaside Usage:      %d bytes\n", iCur); 
  }

  if( pArg && pArg->out && db && pArg->pStmt ){
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FULLSCAN_STEP, bReset);

    fprintf(pArg->out, "Fullscan Steps:                      %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_SORT, bReset);
    fprintf(pArg->out, "Sort Operations:                     %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_AUTOINDEX, bReset);
    fprintf(pArg->out, "Autoindex Inserts:                   %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP, bReset);
    fprintf(pArg->out, "Virtual Machine Steps:               %d\n", iCur);
  }

  return 0;
}














































/*
** Parameter azArray points to a zero-terminated array of strings. zStr
** points to a single nul-terminated string. Return non-zero if zStr
** is equal, according to strcmp(), to any of the strings in the array.
** Otherwise, return zero.
*/
................................................................................
  const char *z;                  /* Used to check if this is an EXPLAIN */
  int *abYield = 0;               /* True if op is an OP_Yield */
  int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
  int iOp;                        /* Index of operation in p->aiIndent[] */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext",
                           "NextIfOpen", "PrevIfOpen", 0 };
  const char *azYield[] = { "Yield", "SeekLT", "SeekGT", "RowSetRead", "Rewind", 0 };

  const char *azGoto[] = { "Goto", 0 };

  /* Try to figure out if this is really an EXPLAIN statement. If this
  ** cannot be verified, return early.  */
  zSql = sqlite3_sql(pSql);
  if( zSql==0 ) return;
  for(z=zSql; *z==' ' || *z=='\t' || *z=='\n' || *z=='\f' || *z=='\r'; z++);
................................................................................
        const char *zStmtSql = sqlite3_sql(pStmt);
        fprintf(pArg->out, "%s\n", zStmtSql ? zStmtSql : zSql);
      }

      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      if( pArg && pArg->autoEQP ){
        sqlite3_stmt *pExplain;
        char *zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s", sqlite3_sql(pStmt));

        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
        if( rc==SQLITE_OK ){
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            fprintf(pArg->out,"--EQP-- %d,", sqlite3_column_int(pExplain, 0));
            fprintf(pArg->out,"%d,", sqlite3_column_int(pExplain, 1));
            fprintf(pArg->out,"%d,", sqlite3_column_int(pExplain, 2));
            fprintf(pArg->out,"%s\n", sqlite3_column_text(pExplain, 3));
................................................................................

      explain_data_delete(pArg);

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }






      /* Finalize the statement just executed. If this fails, save a 
      ** copy of the error message. Otherwise, set zSql to point to the
      ** next statement to execute. */
      rc2 = sqlite3_finalize(pStmt);
      if( rc!=SQLITE_NOMEM ) rc = rc2;
      if( rc==SQLITE_OK ){
................................................................................
  ".output ?FILENAME?     Send output to FILENAME or stdout\n"
  ".print STRING...       Print literal STRING\n"
  ".prompt MAIN CONTINUE  Replace the standard prompts\n"
  ".quit                  Exit this program\n"
  ".read FILENAME         Execute SQL in FILENAME\n"
  ".restore ?DB? FILE     Restore content of DB (default \"main\") from FILE\n"
  ".save FILE             Write in-memory database into FILE\n"

  ".schema ?TABLE?        Show the CREATE statements\n"
  "                         If TABLE specified, only show tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".separator STRING ?NL? Change separator used by output mode and .import\n"
  "                         NL is the end-of-line mark for CSV\n"
  ".shell CMD ARGS...     Run CMD ARGS... in a system shell\n"
  ".show                  Show the current values for various settings\n"
................................................................................
    }else{
      fprintf(stderr, "Error: %s\n", sqlite3_errmsg(p->db));
      rc = 1;
    }
    sqlite3_close(pSrc);
  }else














  if( c=='s' && strncmp(azArg[0], "schema", n)==0 ){
    ShellState data;
    char *zErrMsg = 0;
    open_db(p, 0);
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.mode = MODE_Semi;
................................................................................
      }
      nPrintCol = 80/(maxlen+2);
      if( nPrintCol<1 ) nPrintCol = 1;
      nPrintRow = (nRow + nPrintCol - 1)/nPrintCol;
      for(i=0; i<nPrintRow; i++){
        for(j=i; j<nRow; j+=nPrintRow){
          char *zSp = j<nPrintRow ? "" : "  ";
          fprintf(p->out, "%s%-*s", zSp, maxlen, azResult[j] ? azResult[j] : "");
        }
        fprintf(p->out, "\n");
      }
    }
    for(ii=0; ii<nRow; ii++) sqlite3_free(azResult[ii]);
    sqlite3_free(azResult);
  }else
................................................................................
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(void){
  static char *home_dir = NULL;
  if( home_dir ) return home_dir;

#if !defined(_WIN32) && !defined(WIN32) && !defined(_WIN32_WCE) && !defined(__RTP__) && !defined(_WRS_KERNEL)

  {
    struct passwd *pwent;
    uid_t uid = getuid();
    if( (pwent=getpwuid(uid)) != NULL) {
      home_dir = pwent->pw_dir;
    }
  }
................................................................................
      data.showHeader = 0;
    }else if( strcmp(z,"-echo")==0 ){
      data.echoOn = 1;
    }else if( strcmp(z,"-eqp")==0 ){
      data.autoEQP = 1;
    }else if( strcmp(z,"-stats")==0 ){
      data.statsOn = 1;


    }else if( strcmp(z,"-bail")==0 ){
      bail_on_error = 1;
    }else if( strcmp(z,"-version")==0 ){
      printf("%s %s\n", sqlite3_libversion(), sqlite3_sourceid());
      return 0;
    }else if( strcmp(z,"-interactive")==0 ){
      stdin_is_interactive = 1;

#include <windows.h>

/* Saved resource information for the beginning of an operation */
static HANDLE hProcess;
static FILETIME ftKernelBegin;
static FILETIME ftUserBegin;
static sqlite3_int64 ftWallBegin;
typedef BOOL (WINAPI *GETPROCTIMES)(HANDLE, LPFILETIME, LPFILETIME,
                                    LPFILETIME, LPFILETIME);
static GETPROCTIMES getProcessTimesAddr = NULL;

/*
** Check to see if we have timer support.  Return 1 if necessary
** support found (or found previously).
*/
static int hasTimer(void){
  if( getProcessTimesAddr ){
    return 1;
  } else {
    /* GetProcessTimes() isn't supported in WIN95 and some other Windows
    ** versions. See if the version we are running on has it, and if it
    ** does, save off a pointer to it and the current process handle.
    */
    hProcess = GetCurrentProcess();
    if( hProcess ){
      HINSTANCE hinstLib = LoadLibrary(TEXT("Kernel32.dll"));
      if( NULL != hinstLib ){
        getProcessTimesAddr =
            (GETPROCTIMES) GetProcAddress(hinstLib, "GetProcessTimes");
        if( NULL != getProcessTimesAddr ){
          return 1;
        }
        FreeLibrary(hinstLib); 
      }
    }
  }
................................................................................

/*
** Begin timing an operation
*/
static void beginTimer(void){
  if( enableTimer && getProcessTimesAddr ){
    FILETIME ftCreation, ftExit;
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,
                        &ftKernelBegin,&ftUserBegin);
    ftWallBegin = timeOfDay();
  }
}

/* Return the difference of two FILETIME structs in seconds */
static double timeDiff(FILETIME *pStart, FILETIME *pEnd){
  sqlite_int64 i64Start = *((sqlite_int64 *) pStart);
................................................................................
/*
** Print the timing results.
*/
static void endTimer(void){
  if( enableTimer && getProcessTimesAddr){
    FILETIME ftCreation, ftExit, ftKernelEnd, ftUserEnd;
    sqlite3_int64 ftWallEnd = timeOfDay();
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,&ftKernelEnd,&ftUserEnd);
    printf("Run Time: real %.3f user %f sys %f\n",
       (ftWallEnd - ftWallBegin)*0.001,
       timeDiff(&ftUserBegin, &ftUserEnd),
       timeDiff(&ftKernelBegin, &ftKernelEnd));
  }
}

................................................................................
*/
typedef struct ShellState ShellState;
struct ShellState {
  sqlite3 *db;           /* The database */
  int echoOn;            /* True to echo input commands */
  int autoEQP;           /* Run EXPLAIN QUERY PLAN prior to seach SQL stmt */
  int statsOn;           /* True to display memory stats before each finalize */
  int scanstatsOn;       /* True to display scan stats before each finalize */
  int outCount;          /* Revert to stdout when reaching zero */
  int cnt;               /* Number of records displayed so far */
  FILE *out;             /* Write results here */
  FILE *traceOut;        /* Output for sqlite3_trace() */
  int nErr;              /* Number of errors seen */
  int mode;              /* An output mode setting */
  int writableSchema;    /* True if PRAGMA writable_schema=ON */
................................................................................
}
#endif

/*
** This is the callback routine that the shell
** invokes for each row of a query result.
*/
static int shell_callback(
  void *pArg,
  int nArg,        /* Number of result columns */
  char **azArg,    /* Text of each result column */
  char **azCol,    /* Column names */
  int *aiType      /* Column types */
){
  int i;
  ShellState *p = (ShellState*)pArg;

  switch( p->mode ){
    case MODE_Line: {
      int w = 5;
      if( azArg==0 ) break;
................................................................................
  int iCur;
  int iHiwtr;

  if( pArg && pArg->out ){
    
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MEMORY_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out,
            "Memory Used:                         %d (max %d) bytes\n",
            iCur, iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Number of Outstanding Allocations:   %d (max %d)\n",
            iCur, iHiwtr);
    if( pArg->shellFlgs & SHFLG_Pagecache ){
      iHiwtr = iCur = -1;
      sqlite3_status(SQLITE_STATUS_PAGECACHE_USED, &iCur, &iHiwtr, bReset);
      fprintf(pArg->out,
              "Number of Pcache Pages Used:         %d (max %d) pages\n",
              iCur, iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PAGECACHE_OVERFLOW, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out,
            "Number of Pcache Overflow Bytes:     %d (max %d) bytes\n",
            iCur, iHiwtr);
    if( pArg->shellFlgs & SHFLG_Scratch ){
      iHiwtr = iCur = -1;
      sqlite3_status(SQLITE_STATUS_SCRATCH_USED, &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Number of Scratch Allocations Used:  %d (max %d)\n",
              iCur, iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_SCRATCH_OVERFLOW, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out,
            "Number of Scratch Overflow Bytes:    %d (max %d) bytes\n",
            iCur, iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MALLOC_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Allocation:                  %d bytes\n",
            iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PAGECACHE_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Pcache Allocation:           %d bytes\n",
            iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_SCRATCH_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Largest Scratch Allocation:          %d bytes\n",
            iHiwtr);
#ifdef YYTRACKMAXSTACKDEPTH
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_PARSER_STACK, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Deepest Parser Stack:                %d (max %d)\n",
            iCur, iHiwtr);
#endif
  }

  if( pArg && pArg->out && db ){
    if( pArg->shellFlgs & SHFLG_Lookaside ){
      iHiwtr = iCur = -1;
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED,
                        &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Lookaside Slots Used:                %d (max %d)\n",
              iCur, iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_HIT,
                        &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Successful lookaside attempts:       %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE,
                        &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Lookaside failures due to size:      %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL,
                        &iCur, &iHiwtr, bReset);
      fprintf(pArg->out, "Lookaside failures due to OOM:       %d\n", iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Pager Heap Usage:                    %d bytes\n",iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_HIT, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache hits:                     %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_MISS, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache misses:                   %d\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_WRITE, &iCur, &iHiwtr, 1);
    fprintf(pArg->out, "Page cache writes:                   %d\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Schema Heap Usage:                   %d bytes\n",iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_STMT_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Statement Heap/Lookaside Usage:      %d bytes\n",iCur); 
  }

  if( pArg && pArg->out && db && pArg->pStmt ){
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FULLSCAN_STEP,
                               bReset);
    fprintf(pArg->out, "Fullscan Steps:                      %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_SORT, bReset);
    fprintf(pArg->out, "Sort Operations:                     %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_AUTOINDEX,bReset);
    fprintf(pArg->out, "Autoindex Inserts:                   %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP, bReset);
    fprintf(pArg->out, "Virtual Machine Steps:               %d\n", iCur);
  }

  return 0;
}

/*
** Display scan stats.
*/
static void display_scanstats(
  sqlite3 *db,                    /* Database to query */
  ShellState *pArg                /* Pointer to ShellState */
){
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  int i, k, n, mx;
  fprintf(pArg->out, "-------- scanstats --------\n");
  mx = 0;
  for(k=0; k<=mx; k++){
    double rEstLoop = 1.0;
    for(i=n=0; 1; i++){
      sqlite3_stmt *p = pArg->pStmt;
      sqlite3_int64 nLoop, nVisit;
      double rEst;
      int iSid;
      const char *zExplain;
      if( sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_NLOOP, (void*)&nLoop) ){
        break;
      }
      sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_SELECTID, (void*)&iSid);
      if( iSid>mx ) mx = iSid;
      if( iSid!=k ) continue;
      if( n==0 ){
        rEstLoop = (double)nLoop;
        if( k>0 ) fprintf(pArg->out, "-------- subquery %d -------\n", k);
      }
      n++;
      sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_NVISIT, (void*)&nVisit);
      sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_EST, (void*)&rEst);
      sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_EXPLAIN, (void*)&zExplain);
      fprintf(pArg->out, "Loop %2d: %s\n", n, zExplain);
      rEstLoop *= rEst;
      fprintf(pArg->out, 
          "         nLoop=%-8lld nRow=%-8lld estRow=%-8lld estRow/Loop=%-8g\n",
          nLoop, nVisit, (sqlite3_int64)(rEstLoop+0.5), rEst
      );
    }
  }
  fprintf(pArg->out, "---------------------------\n");
#endif
}

/*
** Parameter azArray points to a zero-terminated array of strings. zStr
** points to a single nul-terminated string. Return non-zero if zStr
** is equal, according to strcmp(), to any of the strings in the array.
** Otherwise, return zero.
*/
................................................................................
  const char *z;                  /* Used to check if this is an EXPLAIN */
  int *abYield = 0;               /* True if op is an OP_Yield */
  int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
  int iOp;                        /* Index of operation in p->aiIndent[] */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext",
                           "NextIfOpen", "PrevIfOpen", 0 };
  const char *azYield[] = { "Yield", "SeekLT", "SeekGT", "RowSetRead",
                            "Rewind", 0 };
  const char *azGoto[] = { "Goto", 0 };

  /* Try to figure out if this is really an EXPLAIN statement. If this
  ** cannot be verified, return early.  */
  zSql = sqlite3_sql(pSql);
  if( zSql==0 ) return;
  for(z=zSql; *z==' ' || *z=='\t' || *z=='\n' || *z=='\f' || *z=='\r'; z++);
................................................................................
        const char *zStmtSql = sqlite3_sql(pStmt);
        fprintf(pArg->out, "%s\n", zStmtSql ? zStmtSql : zSql);
      }

      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      if( pArg && pArg->autoEQP ){
        sqlite3_stmt *pExplain;
        char *zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s",
                                     sqlite3_sql(pStmt));
        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
        if( rc==SQLITE_OK ){
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            fprintf(pArg->out,"--EQP-- %d,", sqlite3_column_int(pExplain, 0));
            fprintf(pArg->out,"%d,", sqlite3_column_int(pExplain, 1));
            fprintf(pArg->out,"%d,", sqlite3_column_int(pExplain, 2));
            fprintf(pArg->out,"%s\n", sqlite3_column_text(pExplain, 3));
................................................................................

      explain_data_delete(pArg);

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }

      /* print loop-counters if required */
      if( pArg && pArg->scanstatsOn ){
        display_scanstats(db, pArg);
      }

      /* Finalize the statement just executed. If this fails, save a 
      ** copy of the error message. Otherwise, set zSql to point to the
      ** next statement to execute. */
      rc2 = sqlite3_finalize(pStmt);
      if( rc!=SQLITE_NOMEM ) rc = rc2;
      if( rc==SQLITE_OK ){
................................................................................
  ".output ?FILENAME?     Send output to FILENAME or stdout\n"
  ".print STRING...       Print literal STRING\n"
  ".prompt MAIN CONTINUE  Replace the standard prompts\n"
  ".quit                  Exit this program\n"
  ".read FILENAME         Execute SQL in FILENAME\n"
  ".restore ?DB? FILE     Restore content of DB (default \"main\") from FILE\n"
  ".save FILE             Write in-memory database into FILE\n"
  ".scanstats on|off      Turn sqlite3_stmt_scanstatus() metrics on or off\n"
  ".schema ?TABLE?        Show the CREATE statements\n"
  "                         If TABLE specified, only show tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".separator STRING ?NL? Change separator used by output mode and .import\n"
  "                         NL is the end-of-line mark for CSV\n"
  ".shell CMD ARGS...     Run CMD ARGS... in a system shell\n"
  ".show                  Show the current values for various settings\n"
................................................................................
    }else{
      fprintf(stderr, "Error: %s\n", sqlite3_errmsg(p->db));
      rc = 1;
    }
    sqlite3_close(pSrc);
  }else


  if( c=='s' && strncmp(azArg[0], "scanstats", n)==0 ){
    if( nArg==2 ){
      p->scanstatsOn = booleanValue(azArg[1]);
#ifndef SQLITE_ENABLE_STMT_SCANSTATUS
      fprintf(stderr, "Warning: .scanstats not available in this build.\n");
#endif
    }else{
      fprintf(stderr, "Usage: .scanstats on|off\n");
      rc = 1;
    }
  }else

  if( c=='s' && strncmp(azArg[0], "schema", n)==0 ){
    ShellState data;
    char *zErrMsg = 0;
    open_db(p, 0);
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.mode = MODE_Semi;
................................................................................
      }
      nPrintCol = 80/(maxlen+2);
      if( nPrintCol<1 ) nPrintCol = 1;
      nPrintRow = (nRow + nPrintCol - 1)/nPrintCol;
      for(i=0; i<nPrintRow; i++){
        for(j=i; j<nRow; j+=nPrintRow){
          char *zSp = j<nPrintRow ? "" : "  ";
          fprintf(p->out, "%s%-*s", zSp, maxlen, azResult[j] ? azResult[j]:"");
        }
        fprintf(p->out, "\n");
      }
    }
    for(ii=0; ii<nRow; ii++) sqlite3_free(azResult[ii]);
    sqlite3_free(azResult);
  }else
................................................................................
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(void){
  static char *home_dir = NULL;
  if( home_dir ) return home_dir;

#if !defined(_WIN32) && !defined(WIN32) && !defined(_WIN32_WCE) \
     && !defined(__RTP__) && !defined(_WRS_KERNEL)
  {
    struct passwd *pwent;
    uid_t uid = getuid();
    if( (pwent=getpwuid(uid)) != NULL) {
      home_dir = pwent->pw_dir;
    }
  }
................................................................................
      data.showHeader = 0;
    }else if( strcmp(z,"-echo")==0 ){
      data.echoOn = 1;
    }else if( strcmp(z,"-eqp")==0 ){
      data.autoEQP = 1;
    }else if( strcmp(z,"-stats")==0 ){
      data.statsOn = 1;
    }else if( strcmp(z,"-scanstats")==0 ){
      data.scanstatsOn = 1;
    }else if( strcmp(z,"-bail")==0 ){
      bail_on_error = 1;
    }else if( strcmp(z,"-version")==0 ){
      printf("%s %s\n", sqlite3_libversion(), sqlite3_sourceid());
      return 0;
    }else if( strcmp(z,"-interactive")==0 ){
      stdin_is_interactive = 1;

#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif

/*
** These no-op macros are used in front of interfaces to mark those
** interfaces as either deprecated or experimental.  New applications
** should not use deprecated interfaces - they are support for backwards
** compatibility only.  Application writers should be aware that
** experimental interfaces are subject to change in point releases.
**
** These macros used to resolve to various kinds of compiler magic that
** would generate warning messages when they were used.  But that
** compiler magic ended up generating such a flurry of bug reports
** that we have taken it all out and gone back to using simple
................................................................................
** ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** it is not possible to set the Serialized [threading mode] and
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
**
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The argument specifies

** alternative low-level memory allocation routines to be used in place of
** the memory allocation routines built into SQLite.)^ ^SQLite makes
** its own private copy of the content of the [sqlite3_mem_methods] structure
** before the [sqlite3_config()] call returns.</dd>
**
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]

** structure is filled with the currently defined memory allocation routines.)^
** This option can be used to overload the default memory allocation
** routines with a wrapper that simulations memory allocation failure or
** tracks memory usage, for example. </dd>
**
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd> ^This option takes single argument of type int, interpreted as a 
** boolean, which enables or disables the collection of memory allocation 
** statistics. ^(When memory allocation statistics are disabled, the 
** following SQLite interfaces become non-operational:
**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit64()]
**   <li> [sqlite3_status()]
**   </ul>)^
** ^Memory allocation statistics are enabled by default unless SQLite is
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
** allocation statistics are disabled by default.
** </dd>
**
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd> ^This option specifies a static memory buffer that SQLite can use for

** scratch memory.  There are three arguments:  A pointer an 8-byte
** aligned memory buffer from which the scratch allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N).  The sz
** argument must be a multiple of 16.
** The first argument must be a pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** ^SQLite will use no more than two scratch buffers per thread.  So
** N should be set to twice the expected maximum number of threads.
** ^SQLite will never require a scratch buffer that is more than 6

** times the database page size. ^If SQLite needs needs additional
** scratch memory beyond what is provided by this configuration option, then 
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>






**
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd> ^This option specifies a static memory buffer that SQLite can use for
** the database page cache with the default page cache implementation.  

** This configuration should not be used if an application-define page
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.

** There are three arguments to this option: A pointer to 8-byte aligned
** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument should be the size of the largest database page
** (a power of two between 512 and 32768) plus a little extra for each
** page header.  ^The page header size is 20 to 40 bytes depending on



** the host architecture.  ^It is harmless, apart from the wasted memory,
** to make sz a little too large.  The first


** argument should point to an allocation of at least sz*N bytes of memory.

** ^SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  ^If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
** The pointer in the first argument must
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
** will be undefined.</dd>
**
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
** <dd> ^This option specifies a static memory buffer that SQLite will use
** for all of its dynamic memory allocation needs beyond those provided
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
** There are three arguments: An 8-byte aligned pointer to the memory,

** the number of bytes in the memory buffer, and the minimum allocation size.
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
** to using its default memory allocator (the system malloc() implementation),
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
** allocator is engaged to handle all of SQLites memory allocation needs.
** The first pointer (the memory pointer) must be aligned to an 8-byte
** boundary or subsequent behavior of SQLite will be undefined.
** The minimum allocation size is capped at 2**12. Reasonable values
** for the minimum allocation size are 2**5 through 2**8.</dd>
**
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
** alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
** content of the [sqlite3_mutex_methods] structure before the call to
** [sqlite3_config()] returns. ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_methods]
** structure is filled with the currently defined mutex routines.)^
** This option can be used to overload the default mutex allocation
** routines with a wrapper used to track mutex usage for performance
** profiling or testing, for example.   ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
** <dd> ^(This option takes two arguments that determine the default
** memory allocation for the lookaside memory allocator on each
** [database connection].  The first argument is the
** size of each lookaside buffer slot and the second is the number of
** slots allocated to each database connection.)^  ^(This option sets the
** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
** verb to [sqlite3_db_config()] can be used to change the lookaside
** configuration on individual connections.)^ </dd>
**
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
** <dd> ^(This option takes a single argument which is a pointer to
** an [sqlite3_pcache_methods2] object.  This object specifies the interface
** to a custom page cache implementation.)^  ^SQLite makes a copy of the
** object and uses it for page cache memory allocations.</dd>
**
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** [sqlite3_pcache_methods2] object.  SQLite copies of the current
** page cache implementation into that object.)^ </dd>
**
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
** global [error log].
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
** function with a call signature of void(*)(void*,int,const char*), 
................................................................................
** log message after formatting via [sqlite3_snprintf()].
** The SQLite logging interface is not reentrant; the logger function
** supplied by the application must not invoke any SQLite interface.
** In a multi-threaded application, the application-defined logger
** function must be threadsafe. </dd>
**
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
** <dd>^(This option takes a single argument of type int. If non-zero, then
** URI handling is globally enabled. If the parameter is zero, then URI handling
** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
** connection is opened. ^If it is globally disabled, filenames are
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
** database connection is opened. ^(By default, URI handling is globally
** disabled. The default value may be changed by compiling with the
** [SQLITE_USE_URI] symbol defined.)^
**
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
** <dd>^This option takes a single integer argument which is interpreted as
** a boolean in order to enable or disable the use of covering indices for

** full table scans in the query optimizer.  ^The default setting is determined
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
** if that compile-time option is omitted.
** The ability to disable the use of covering indices for full table scans
** is because some incorrectly coded legacy applications might malfunction
** when the optimization is enabled.  Providing the ability to
** disable the optimization allows the older, buggy application code to work
** without change even with newer versions of SQLite.
................................................................................
** <dt>SQLITE_CONFIG_MMAP_SIZE
** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
** that are the default mmap size limit (the default setting for
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
** ^The default setting can be overridden by each database connection using
** either the [PRAGMA mmap_size] command, or by using the
** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
** cannot be changed at run-time.  Nor may the maximum allowed mmap size
** exceed the compile-time maximum mmap size set by the
** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
** ^If either argument to this option is negative, then that argument is
** changed to its compile-time default.
**
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
** <dd>^This option is only available if SQLite is compiled for Windows
** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
** that specifies the maximum size of the created heap.
** </dl>









*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
................................................................................
#define SQLITE_CONFIG_URI          17  /* int */
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */


/*
** CAPI3REF: Database Connection Configuration Options
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
................................................................................
** last insert [rowid].
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified
**
** ^This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the [database connection] specified by the first parameter.
** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
** or [DELETE] statement are counted.  Auxiliary changes caused by
** triggers or [foreign key actions] are not counted.)^ Use the
** [sqlite3_total_changes()] function to find the total number of changes
** including changes caused by triggers and foreign key actions.

**
** ^Changes to a view that are simulated by an [INSTEAD OF trigger]



** are not counted.  Only real table changes are counted.
**
** ^(A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of [REPLACE] constraint resolution,
** rollback, ABORT processing, [DROP TABLE], or by any other
** mechanisms do not count as direct row changes.)^



**
** A "trigger context" is a scope of execution that begins and
** ends with the script of a [CREATE TRIGGER | trigger]. 
** Most SQL statements are
** evaluated outside of any trigger.  This is the "top level"
** trigger context.  If a trigger fires from the top level, a
** new trigger context is entered for the duration of that one
** trigger.  Subtriggers create subcontexts for their duration.
**
** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** ^This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** ^Thus, when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.  ^(Within the body of a trigger,
** the sqlite3_changes() interface can be called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the same trigger.
** However, the number returned does not include changes
** caused by subtriggers since those have their own context.)^
**
** See also the [sqlite3_total_changes()] interface, the
** [count_changes pragma], and the [changes() SQL function].
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_changes()] is running then the value returned
** is unpredictable and not meaningful.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified
**
** ^This function returns the number of row changes caused by [INSERT],
** [UPDATE] or [DELETE] statements since the [database connection] was opened.


** ^(The count returned by sqlite3_total_changes() includes all changes
** from all [CREATE TRIGGER | trigger] contexts and changes made by
** [foreign key actions]. However,
** the count does not include changes used to implement [REPLACE] constraints,
** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
** count does not include rows of views that fire an [INSTEAD OF trigger],
** though if the INSTEAD OF trigger makes changes of its own, those changes 
** are counted.)^
** ^The sqlite3_total_changes() function counts the changes as soon as
** the statement that makes them is completed (when the statement handle
** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
**
** See also the [sqlite3_changes()] interface, the
** [count_changes pragma], and the [total_changes() SQL function].
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_total_changes()] is running then the value
** returned is unpredictable and not meaningful.
*/
................................................................................
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random [ROWID | ROWIDs] when inserting new records into a table that
** already uses the largest possible [ROWID].  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** applications to access the same PRNG for other purposes.
**
** ^A call to this routine stores N bytes of randomness into buffer P.
** ^If N is less than one, then P can be a NULL pointer.
**
** ^If this routine has not been previously called or if the previous
** call had N less than one, then the PRNG is seeded using randomness

** obtained from the xRandomness method of the default [sqlite3_vfs] object.
** ^If the previous call to this routine had an N of 1 or more then
** the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.
*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks
................................................................................

/*
** CAPI3REF: Text Encodings
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

/*
** CAPI3REF: Function Flags
**
................................................................................
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same BLOB that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
** </pre>)^
**
** ^If the flags parameter is non-zero, then the BLOB is opened for read
** and write access. ^If it is zero, the BLOB is opened for read access.
** ^It is not possible to open a column that is part of an index or primary 
** key for writing. ^If [foreign key constraints] are enabled, it is 
** not possible to open a column that is part of a [child key] for writing.
**
** ^Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** appears after the AS keyword when the database is connected using [ATTACH].
** ^For the main database file, the database name is "main".
** ^For TEMP tables, the database name is "temp".
**




** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set


** to be a null pointer.)^


















** ^This function sets the [database connection] error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
** functions. ^Note that the *ppBlob variable is always initialized in a
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
** regardless of the success or failure of this routine.

**
** ^(If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.)^
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
................................................................................
** commit if the transaction continues to completion.)^
**
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  ^The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a
** blob.
**
** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
** table.  Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
**
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
** and the built-in [zeroblob] SQL function can be used, if desired,
** to create an empty, zero-filled blob in which to read or write using
** this interface.

**
** To avoid a resource leak, every open [BLOB handle] should eventually
** be released by a call to [sqlite3_blob_close()].
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
................................................................................
** ^This function sets the database handle error code and message.
*/
SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);

/*
** CAPI3REF: Close A BLOB Handle
**
** ^Closes an open [BLOB handle].
**
** ^Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in [autocommit mode].
** ^If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit.
**
** ^(Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  Any errors that occur during
** closing are reported as a non-zero return value.)^
**
** ^(The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.)^
**
** ^Calling this routine with a null pointer (such as would be returned
** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF: Return The Size Of An Open BLOB
**
** ^Returns the size in bytes of the BLOB accessible via the 
................................................................................
** See also: [sqlite3_blob_write()].
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally
**
** ^This function is used to write data into an open [BLOB handle] from a
** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
** into the open BLOB, starting at offset iOffset.






**
** ^If the [BLOB handle] passed as the first argument was not opened for
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
** this function returns [SQLITE_READONLY].
**
** ^This function may only modify the contents of the BLOB; it is
** not possible to increase the size of a BLOB using this API.
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is written.  ^If N is
** less than zero [SQLITE_ERROR] is returned and no data is written.
** The size of the BLOB (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.

**
** ^An attempt to write to an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
** before the [BLOB handle] expired are not rolled back by the
** expiration of the handle, though of course those changes might
** have been overwritten by the statement that expired the BLOB handle
** or by other independent statements.
**
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
** Otherwise, an  [error code] or an [extended error code] is returned.)^
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_read()].
*/
................................................................................
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  ^(The following
** implementations are available in the SQLite core:
**
** <ul>
** <li>   SQLITE_MUTEX_PTHREADS
** <li>   SQLITE_MUTEX_W32
** <li>   SQLITE_MUTEX_NOOP
** </ul>)^
**
** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
** that does no real locking and is appropriate for use in
** a single-threaded application.  ^The SQLITE_MUTEX_PTHREADS and
** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
** and Windows.
**
** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. In this case the
** application must supply a custom mutex implementation using the
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
** before calling sqlite3_initialize() or any other public sqlite3_
** function that calls sqlite3_initialize().)^
**
** ^The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. ^If it returns NULL
** that means that a mutex could not be allocated.  ^SQLite
** will unwind its stack and return an error.  ^(The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2

** </ul>)^
**
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
** cause sqlite3_mutex_alloc() to create
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  ^SQLite will only request a recursive mutex in
** cases where it really needs one.  ^If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
** a pointer to a static preexisting mutex.  ^Six static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  ^But for the static
** mutex types, the same mutex is returned on every call that has
** the same type number.
**
** ^The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex.  ^SQLite is careful to deallocate every
** dynamic mutex that it allocates.  The dynamic mutexes must not be in
** use when they are deallocated.  Attempting to deallocate a static
** mutex results in undefined behavior.  ^SQLite never deallocates
** a static mutex.
**
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  ^If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
** upon successful entry.  ^(Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.)^  ^(If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** SQLite will never exhibit
** such behavior in its own use of mutexes.)^
**
** ^(Some systems (for example, Windows 95) do not support the operation
** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
** will always return SQLITE_BUSY.  The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^

**
** ^The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.   ^(The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.  SQLite will
** never do either.)^
**
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
** behave as no-ops.
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
................................................................................
/*
** CAPI3REF: Mutex Methods Object
**
** An instance of this structure defines the low-level routines
** used to allocate and use mutexes.
**
** Usually, the default mutex implementations provided by SQLite are
** sufficient, however the user has the option of substituting a custom
** implementation for specialized deployments or systems for which SQLite
** does not provide a suitable implementation. In this case, the user
** creates and populates an instance of this structure to pass
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
** Additionally, an instance of this structure can be used as an
** output variable when querying the system for the current mutex
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
**
** ^The xMutexInit method defined by this structure is invoked as
................................................................................
** above silently ignore any invocations that pass a NULL pointer instead
** of a valid mutex handle. The implementations of the methods defined
** by this structure are not required to handle this case, the results
** of passing a NULL pointer instead of a valid mutex handle are undefined
** (i.e. it is acceptable to provide an implementation that segfaults if
** it is passed a NULL pointer).
**
** The xMutexInit() method must be threadsafe.  ^It must be harmless to
** invoke xMutexInit() multiple times within the same process and without
** intervening calls to xMutexEnd().  Second and subsequent calls to
** xMutexInit() must be no-ops.
**
** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
** memory allocation for a fast or recursive mutex.
**
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
** If xMutexInit fails in any way, it is expected to clean up after itself
** prior to returning.
................................................................................
  int (*xMutexNotheld)(sqlite3_mutex *);
};

/*
** CAPI3REF: Mutex Verification Routines
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements.  ^The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  ^The SQLite core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  ^External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** ^These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread.
**
** ^The implementation is not required to provide versions of these
** routines that actually work. If the implementation does not provide working
** versions of these routines, it should at least provide stubs that always
** return true so that one does not get spurious assertion failures.
**
** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1.   This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist.  But
** the reason the mutex does not exist is because the build is not
** using mutexes.  And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
** interface should also return 1 when given a NULL pointer.
*/
#ifndef NDEBUG
int sqlite3_mutex_held(sqlite3_mutex*);
int sqlite3_mutex_notheld(sqlite3_mutex*);
#endif

................................................................................
** an [ATTACH] statement for an attached database.
** ^The S and M arguments passed to 
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
** and database name of the source database, respectively.
** ^The source and destination [database connections] (parameters S and D)
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
** an error.




**
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
** returned and an error code and error message are stored in the
** destination [database connection] D.
** ^The error code and message for the failed call to sqlite3_backup_init()
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
** [sqlite3_errmsg16()] functions.
................................................................................
  int bDelete,                    /* Zero for insert, non-zero for delete */
  const char *zIndex,             /* Index to write to */
  sqlite3_stmt**,                 /* OUT: New statement handle */
  const char ***pazColl,          /* OUT: Collation sequences for each column */
  int **paiCol, int *pnCol        /* OUT: See above */
);






























































































/*
** Incremental checkpoint API.
**
** An incremental checkpoint handle is opened using the sqlite3_ckpt_open()
** API. To begin a new checkpoint, the second and third arguments should both
** be passed zero. To resume an earlier checkpoint, the second and third
** arguments should specify a buffer returned by an earlier call to

#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif

/*
** These no-op macros are used in front of interfaces to mark those
** interfaces as either deprecated or experimental.  New applications
** should not use deprecated interfaces - they are supported for backwards
** compatibility only.  Application writers should be aware that
** experimental interfaces are subject to change in point releases.
**
** These macros used to resolve to various kinds of compiler magic that
** would generate warning messages when they were used.  But that
** compiler magic ended up generating such a flurry of bug reports
** that we have taken it all out and gone back to using simple
................................................................................
** ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** it is not possible to set the Serialized [threading mode] and
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
**
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 
** a pointer to an instance of the [sqlite3_mem_methods] structure.
** The argument specifies
** alternative low-level memory allocation routines to be used in place of
** the memory allocation routines built into SQLite.)^ ^SQLite makes
** its own private copy of the content of the [sqlite3_mem_methods] structure
** before the [sqlite3_config()] call returns.</dd>
**
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
** is a pointer to an instance of the [sqlite3_mem_methods] structure.
** The [sqlite3_mem_methods]
** structure is filled with the currently defined memory allocation routines.)^
** This option can be used to overload the default memory allocation
** routines with a wrapper that simulations memory allocation failure or
** tracks memory usage, for example. </dd>
**
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
** interpreted as a boolean, which enables or disables the collection of
** memory allocation statistics. ^(When memory allocation statistics are disabled, the 
** following SQLite interfaces become non-operational:
**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit64()]
**   <li> [sqlite3_status()]
**   </ul>)^
** ^Memory allocation statistics are enabled by default unless SQLite is
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
** allocation statistics are disabled by default.
** </dd>
**
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
** that SQLite can use for scratch memory.  ^(There are three arguments
** to SQLITE_CONFIG_SCRATCH:  A pointer an 8-byte
** aligned memory buffer from which the scratch allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N).)^

** The first argument must be a pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** ^SQLite will not use more than one scratch buffers per thread.

** ^SQLite will never request a scratch buffer that is more than 6
** times the database page size.
** ^If SQLite needs needs additional
** scratch memory beyond what is provided by this configuration option, then 
** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
** ^When the application provides any amount of scratch memory using
** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
** [sqlite3_malloc|heap allocations].
** This can help [Robson proof|prevent memory allocation failures] due to heap
** fragmentation in low-memory embedded systems.
** </dd>
**
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer
** that SQLite can use for the database page cache with the default page
** cache implementation.  
** This configuration should not be used if an application-define page
** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]
** configuration option.
** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned
** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument should be the size of the largest database page
** (a power of two between 512 and 32768) plus some extra bytes for each

** page header.  ^The number of extra bytes needed by the page header
** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 
** to [sqlite3_config()].
** ^It is harmless, apart from the wasted memory,

** for the sz parameter to be larger than necessary.  The first
** argument should pointer to an 8-byte aligned block of memory that
** is at least sz*N bytes of memory, otherwise subsequent behavior is
** undefined.
** ^SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  ^If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd>
**
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 
** that SQLite will use for all of its dynamic memory allocation needs
** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
** [SQLITE_ERROR] if invoked otherwise.
** ^There are three arguments to SQLITE_CONFIG_HEAP:
** An 8-byte aligned pointer to the memory,
** the number of bytes in the memory buffer, and the minimum allocation size.
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
** to using its default memory allocator (the system malloc() implementation),
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
** memory pointer is not NULL then the alternative memory

** allocator is engaged to handle all of SQLites memory allocation needs.
** The first pointer (the memory pointer) must be aligned to an 8-byte
** boundary or subsequent behavior of SQLite will be undefined.
** The minimum allocation size is capped at 2**12. Reasonable values
** for the minimum allocation size are 2**5 through 2**8.</dd>
**
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
** pointer to an instance of the [sqlite3_mutex_methods] structure.
** The argument specifies alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
** content of the [sqlite3_mutex_methods] structure before the call to
** [sqlite3_config()] returns. ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_methods]
** structure is filled with the currently defined mutex routines.)^
** This option can be used to overload the default mutex allocation
** routines with a wrapper used to track mutex usage for performance
** profiling or testing, for example.   ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
** the default size of lookaside memory on each [database connection].
** The first argument is the
** size of each lookaside buffer slot and the second is the number of
** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
** option to [sqlite3_db_config()] can be used to change the lookaside
** configuration on individual connections.)^ </dd>
**
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 
** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
** the interface to a custom page cache implementation.)^
** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
**
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of the current
** page cache implementation into that object.)^ </dd>
**
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
** global [error log].
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
** function with a call signature of void(*)(void*,int,const char*), 
................................................................................
** log message after formatting via [sqlite3_snprintf()].
** The SQLite logging interface is not reentrant; the logger function
** supplied by the application must not invoke any SQLite interface.
** In a multi-threaded application, the application-defined logger
** function must be threadsafe. </dd>
**
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
** If non-zero, then URI handling is globally enabled. If the parameter is zero,
** then URI handling is globally disabled.)^ ^If URI handling is globally enabled,
** all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
** connection is opened. ^If it is globally disabled, filenames are
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
** database connection is opened. ^(By default, URI handling is globally
** disabled. The default value may be changed by compiling with the
** [SQLITE_USE_URI] symbol defined.)^
**
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
** argument which is interpreted as a boolean in order to enable or disable
** the use of covering indices for full table scans in the query optimizer.
** ^The default setting is determined
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
** if that compile-time option is omitted.
** The ability to disable the use of covering indices for full table scans
** is because some incorrectly coded legacy applications might malfunction
** when the optimization is enabled.  Providing the ability to
** disable the optimization allows the older, buggy application code to work
** without change even with newer versions of SQLite.
................................................................................
** <dt>SQLITE_CONFIG_MMAP_SIZE
** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
** that are the default mmap size limit (the default setting for
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
** ^The default setting can be overridden by each database connection using
** either the [PRAGMA mmap_size] command, or by using the
** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
** will be silently truncated if necessary so that it does not exceed the
** compile-time maximum mmap size set by the
** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
** ^If either argument to this option is negative, then that argument is
** changed to its compile-time default.
**
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
** ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
** that specifies the maximum size of the created heap.
** </dl>
**
** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
** is a pointer to an integer and writes into that integer the number of extra
** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. The amount of
** extra space required can change depending on the compiler,
** target platform, and SQLite version.
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
................................................................................
#define SQLITE_CONFIG_URI          17  /* int */
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */

/*
** CAPI3REF: Database Connection Configuration Options
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
................................................................................
** last insert [rowid].
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified
**
** ^This function returns the number of rows modified, inserted or
** deleted by the most recently completed INSERT, UPDATE or DELETE
** statement on the database connection specified by the only parameter.
** ^Executing any other type of SQL statement does not modify the value
** returned by this function.
**
** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 
** [foreign key actions] or [REPLACE] constraint resolution are not counted.
** 
** Changes to a view that are intercepted by 
** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 
** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 
** DELETE statement run on a view is always zero. Only changes made to real 
** tables are counted.
**




** Things are more complicated if the sqlite3_changes() function is
** executed while a trigger program is running. This may happen if the
** program uses the [changes() SQL function], or if some other callback
** function invokes sqlite3_changes() directly. Essentially:
** 



** <ul>
**   <li> ^(Before entering a trigger program the value returned by
**        sqlite3_changes() function is saved. After the trigger program 
**        has finished, the original value is restored.)^
** 
**   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 
**        statement sets the value returned by sqlite3_changes() 
**        upon completion as normal. Of course, this value will not include 
**        any changes performed by sub-triggers, as the sqlite3_changes() 
**        value will be saved and restored after each sub-trigger has run.)^
** </ul>
** 
** ^This means that if the changes() SQL function (or similar) is used
** by the first INSERT, UPDATE or DELETE statement within a trigger, it 
** returns the value as set when the calling statement began executing.
** ^If it is used by the second or subsequent such statement within a trigger 
** program, the value returned reflects the number of rows modified by the 
** previous INSERT, UPDATE or DELETE statement within the same trigger.


**
** See also the [sqlite3_total_changes()] interface, the
** [count_changes pragma], and the [changes() SQL function].
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_changes()] is running then the value returned
** is unpredictable and not meaningful.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified
**
** ^This function returns the total number of rows inserted, modified or
** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
** since the database connection was opened, including those executed as
** part of trigger programs. ^Executing any other type of SQL statement
** does not affect the value returned by sqlite3_total_changes().
** 
** ^Changes made as part of [foreign key actions] are included in the
** count, but those made as part of REPLACE constraint resolution are
** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 


** are not counted.



** 
** See also the [sqlite3_changes()] interface, the
** [count_changes pragma], and the [total_changes() SQL function].
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_total_changes()] is running then the value
** returned is unpredictable and not meaningful.
*/
................................................................................
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random [ROWID | ROWIDs] when inserting new records into a table that
** already uses the largest possible [ROWID].  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** applications to access the same PRNG for other purposes.
**
** ^A call to this routine stores N bytes of randomness into buffer P.
** ^The P parameter can be a NULL pointer.
**
** ^If this routine has not been previously called or if the previous
** call had N less than one or a NULL pointer for P, then the PRNG is
** seeded using randomness obtained from the xRandomness method of
** the default [sqlite3_vfs] object.
** ^If the previous call to this routine had an N of 1 or more and a
** non-NULL P then the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.
*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks
................................................................................

/*
** CAPI3REF: Text Encodings
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

/*
** CAPI3REF: Function Flags
**
................................................................................
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same BLOB that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
** </pre>)^
**






** ^(Parameter zDb is not the filename that contains the database, but 
** rather the symbolic name of the database. For attached databases, this is
** the name that appears after the AS keyword in the [ATTACH] statement.
** For the main database file, the database name is "main". For TEMP
** tables, the database name is "temp".)^
**
** ^If the flags parameter is non-zero, then the BLOB is opened for read
** and write access. ^If the flags parameter is zero, the BLOB is opened for
** read-only access.
**
** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
** in *ppBlob. Otherwise an [error code] is returned and, unless the error
** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
** the API is not misused, it is always safe to call [sqlite3_blob_close()] 
** on *ppBlob after this function it returns.
**
** This function fails with SQLITE_ERROR if any of the following are true:
** <ul>
**   <li> ^(Database zDb does not exist)^, 
**   <li> ^(Table zTable does not exist within database zDb)^, 
**   <li> ^(Table zTable is a WITHOUT ROWID table)^, 
**   <li> ^(Column zColumn does not exist)^,
**   <li> ^(Row iRow is not present in the table)^,
**   <li> ^(The specified column of row iRow contains a value that is not
**         a TEXT or BLOB value)^,
**   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 
**         constraint and the blob is being opened for read/write access)^,
**   <li> ^([foreign key constraints | Foreign key constraints] are enabled, 
**         column zColumn is part of a [child key] definition and the blob is
**         being opened for read/write access)^.
** </ul>
**
** ^Unless it returns SQLITE_MISUSE, this function sets the 
** [database connection] error code and message accessible via 
** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 



**
**
** ^(If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.)^
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
................................................................................
** commit if the transaction continues to completion.)^
**
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  ^The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a
** blob.
**



** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
** and the built-in [zeroblob] SQL function may be used to create a 


** zero-filled blob to read or write using the incremental-blob interface.
**
** To avoid a resource leak, every open [BLOB handle] should eventually
** be released by a call to [sqlite3_blob_close()].
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
................................................................................
** ^This function sets the database handle error code and message.
*/
SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);

/*
** CAPI3REF: Close A BLOB Handle
**
** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
** unconditionally.  Even if this routine returns an error code, the 
** handle is still closed.)^
**
** ^If the blob handle being closed was opened for read-write access, and if
** the database is in auto-commit mode and there are no other open read-write
** blob handles or active write statements, the current transaction is
** committed. ^If an error occurs while committing the transaction, an error
** code is returned and the transaction rolled back.
**
** Calling this function with an argument that is not a NULL pointer or an
** open blob handle results in undefined behaviour. ^Calling this routine 
** with a null pointer (such as would be returned by a failed call to 
** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
** is passed a valid open blob handle, the values returned by the 
** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.


*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF: Return The Size Of An Open BLOB
**
** ^Returns the size in bytes of the BLOB accessible via the 
................................................................................
** See also: [sqlite3_blob_write()].
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally
**
** ^(This function is used to write data into an open [BLOB handle] from a
** caller-supplied buffer. N bytes of data are copied from the buffer Z
** into the open BLOB, starting at offset iOffset.)^
**
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
** Otherwise, an  [error code] or an [extended error code] is returned.)^
** ^Unless SQLITE_MISUSE is returned, this function sets the 
** [database connection] error code and message accessible via 
** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 
**
** ^If the [BLOB handle] passed as the first argument was not opened for
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
** this function returns [SQLITE_READONLY].
**
** This function may only modify the contents of the BLOB; it is
** not possible to increase the size of a BLOB using this API.
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is written. The size of the 

** BLOB (and hence the maximum value of N+iOffset) can be determined 
** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 
** than zero [SQLITE_ERROR] is returned and no data is written.
**
** ^An attempt to write to an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
** before the [BLOB handle] expired are not rolled back by the
** expiration of the handle, though of course those changes might
** have been overwritten by the statement that expired the BLOB handle
** or by other independent statements.
**



** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_read()].
*/
................................................................................
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  The following
** implementations are available in the SQLite core:
**
** <ul>
** <li>   SQLITE_MUTEX_PTHREADS
** <li>   SQLITE_MUTEX_W32
** <li>   SQLITE_MUTEX_NOOP
** </ul>
**
** The SQLITE_MUTEX_NOOP implementation is a set of routines
** that does no real locking and is appropriate for use in
** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
** and Windows.
**
** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. In this case the
** application must supply a custom mutex implementation using the
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
** before calling sqlite3_initialize() or any other public sqlite3_
** function that calls sqlite3_initialize().
**
** ^The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
** routine returns NULL if it is unable to allocate the requested
** mutex.  The argument to sqlite3_mutex_alloc() must one of these
** integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2
** <li>  SQLITE_MUTEX_STATIC_APP3
** </ul>
**
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
** cause sqlite3_mutex_alloc() to create
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  SQLite will only request a recursive mutex in
** cases where it really needs one.  If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
** a pointer to a static preexisting mutex.  ^Nine static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  ^For the static
** mutex types, the same mutex is returned on every call that has
** the same type number.
**
** ^The sqlite3_mutex_free() routine deallocates a previously


** allocated dynamic mutex.  Attempting to deallocate a static
** mutex results in undefined behavior.

**
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  ^If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
** upon successful entry.  ^(Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** In such cases, the
** mutex must be exited an equal number of times before another thread
** can enter.)^  If the same thread tries to enter any mutex other
** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.


**
** ^(Some systems (for example, Windows 95) do not support the operation
** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
** will always return SQLITE_BUSY. The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable 
** behavior.)^
**
** ^The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.   The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.

**
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
** behave as no-ops.
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
................................................................................
/*
** CAPI3REF: Mutex Methods Object
**
** An instance of this structure defines the low-level routines
** used to allocate and use mutexes.
**
** Usually, the default mutex implementations provided by SQLite are
** sufficient, however the application has the option of substituting a custom
** implementation for specialized deployments or systems for which SQLite
** does not provide a suitable implementation. In this case, the application
** creates and populates an instance of this structure to pass
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
** Additionally, an instance of this structure can be used as an
** output variable when querying the system for the current mutex
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
**
** ^The xMutexInit method defined by this structure is invoked as
................................................................................
** above silently ignore any invocations that pass a NULL pointer instead
** of a valid mutex handle. The implementations of the methods defined
** by this structure are not required to handle this case, the results
** of passing a NULL pointer instead of a valid mutex handle are undefined
** (i.e. it is acceptable to provide an implementation that segfaults if
** it is passed a NULL pointer).
**
** The xMutexInit() method must be threadsafe.  It must be harmless to
** invoke xMutexInit() multiple times within the same process and without
** intervening calls to xMutexEnd().  Second and subsequent calls to
** xMutexInit() must be no-ops.
**
** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
** memory allocation for a fast or recursive mutex.
**
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
** If xMutexInit fails in any way, it is expected to clean up after itself
** prior to returning.
................................................................................
  int (*xMutexNotheld)(sqlite3_mutex *);
};

/*
** CAPI3REF: Mutex Verification Routines
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements.  The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  The SQLite core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread.
**
** The implementation is not required to provide versions of these
** routines that actually work. If the implementation does not provide working
** versions of these routines, it should at least provide stubs that always
** return true so that one does not get spurious assertion failures.
**
** If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1.   This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist.  But
** the reason the mutex does not exist is because the build is not
** using mutexes.  And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do.  The sqlite3_mutex_notheld()
** interface should also return 1 when given a NULL pointer.
*/
#ifndef NDEBUG
int sqlite3_mutex_held(sqlite3_mutex*);
int sqlite3_mutex_notheld(sqlite3_mutex*);
#endif

................................................................................
** an [ATTACH] statement for an attached database.
** ^The S and M arguments passed to 
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
** and database name of the source database, respectively.
** ^The source and destination [database connections] (parameters S and D)
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
** an error.
**
** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 
** there is already a read or read-write transaction open on the 
** destination database.
**
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
** returned and an error code and error message are stored in the
** destination [database connection] D.
** ^The error code and message for the failed call to sqlite3_backup_init()
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
** [sqlite3_errmsg16()] functions.
................................................................................
  int bDelete,                    /* Zero for insert, non-zero for delete */
  const char *zIndex,             /* Index to write to */
  sqlite3_stmt**,                 /* OUT: New statement handle */
  const char ***pazColl,          /* OUT: Collation sequences for each column */
  int **paiCol, int *pnCol        /* OUT: See above */
);

/*
** CAPI3REF: Prepared Statement Scan Status Opcodes
** KEYWORDS: {scanstatus options}
**
** The following constants can be used for the T parameter to the
** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
** different metric for sqlite3_stmt_scanstatus() to return.
**
** <dl>
** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the
** total number of times that the X-th loop has run.</dd>
**
** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the
** total number of rows examined by all iterations of the X-th loop.</dd>
**
** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
** <dd>^The "double" variable pointed to by the T parameter will be set to the
** query planner's estimate for the average number of rows output from each
** iteration of the X-th loop.  If the query planner's estimates was accurate,
** then this value will approximate the quotient NVISIT/NLOOP and the
** product of this value for all prior loops with the same SELECTID will
** be the NLOOP value for the current loop.
**
** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
** a zero-terminated UTF-8 string containing the name of the index or table used
** for the X-th loop.
**
** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
** a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] description
** for the X-th loop.
**
** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
** <dd>^The "int" variable pointed to by the T parameter will be set to the
** "select-id" for the X-th loop.  The select-id identifies which query or
** subquery the loop is part of.  The main query has a select-id of zero.
** The select-id is the same value as is output in the first column
** of an [EXPLAIN QUERY PLAN] query.
** </dl>
*/
#define SQLITE_SCANSTAT_NLOOP    0
#define SQLITE_SCANSTAT_NVISIT   1
#define SQLITE_SCANSTAT_EST      2
#define SQLITE_SCANSTAT_NAME     3
#define SQLITE_SCANSTAT_EXPLAIN  4
#define SQLITE_SCANSTAT_SELECTID 5

/*
** CAPI3REF: Prepared Statement Scan Status
**
** Return status data for a single loop within query pStmt.
**
** The "iScanStatusOp" parameter determines which status information to return.
** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior of
** this interface is undefined.
** ^The requested measurement is written into a variable pointed to by
** the "pOut" parameter.
** Parameter "idx" identifies the specific loop to retrieve statistics for.
** Loops are numbered starting from zero. ^If idx is out of range - less than
** zero or greater than or equal to the total number of loops used to implement
** the statement - a non-zero value is returned and the variable that pOut
** points to is unchanged.
**
** ^Statistics might not be available for all loops in all statements. ^In cases
** where there exist loops with no available statistics, this function behaves
** as if the loop did not exist - it returns non-zero and leave the variable
** that pOut points to unchanged.
**
** This API is only available if the library is built with pre-processor
** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
**
** See also: [sqlite3_stmt_scanstatus_reset()]
*/
SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus(
  sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
  int idx,                  /* Index of loop to report on */
  int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
  void *pOut                /* Result written here */
);     

/*
** CAPI3REF: Zero Scan-Status Counters
**
** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
**
** This API is only available if the library is built with pre-processor
** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
*/
SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);

/*
** Incremental checkpoint API.
**
** An incremental checkpoint handle is opened using the sqlite3_ckpt_open()
** API. To begin a new checkpoint, the second and third arguments should both
** be passed zero. To resume an earlier checkpoint, the second and third
** arguments should specify a buffer returned by an earlier call to

** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
*/
#ifndef SQLITE_POWERSAFE_OVERWRITE
# define SQLITE_POWERSAFE_OVERWRITE 1
#endif

/*
** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
** It determines whether or not the features related to 
** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
** be overridden at runtime using the sqlite3_config() API.
*/
#if !defined(SQLITE_DEFAULT_MEMSTATUS)
# define SQLITE_DEFAULT_MEMSTATUS 1
#endif

/*
** Exactly one of the following macros must be defined in order to
................................................................................

/*
** Estimated quantities used for query planning are stored as 16-bit
** logarithms.  For quantity X, the value stored is 10*log2(X).  This
** gives a possible range of values of approximately 1.0e986 to 1e-986.
** But the allowed values are "grainy".  Not every value is representable.
** For example, quantities 16 and 17 are both represented by a LogEst
** of 40.  However, since LogEst quantaties are suppose to be estimates,
** not exact values, this imprecision is not a problem.
**
** "LogEst" is short for "Logarithmic Estimate".
**
** Examples:
**      1 -> 0              20 -> 43          10000 -> 132
**      2 -> 10             25 -> 46          25000 -> 146
................................................................................
/*                not used    0x0010   // Was: SQLITE_IdxRealAsInt */
#define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
#define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
#define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
#define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
#define SQLITE_Transitive     0x0200   /* Transitive constraints */
#define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
#define SQLITE_Stat3          0x0800   /* Use the SQLITE_STAT3 table */
#define SQLITE_AllOpts        0xffff   /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#ifndef SQLITE_OMIT_BUILTIN_TEST
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
................................................................................
  u16 nColumn;             /* Number of columns stored in the index */
  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this table */

#endif
};

/*
** Allowed values for Index.idxType
*/
#define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */
................................................................................

#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
  int iTable;            /* TK_COLUMN: cursor number of table holding column
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old
                         ** EP_Unlikely:  1000 times likelihood */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1). */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 op2;                /* TK_REGISTER: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
................................................................................
*/
struct Walker {
  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */
  int walkerDepth;                          /* Number of subqueries */

  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int i;                                     /* Integer value */

    SrcList *pSrcList;                         /* FROM clause */
    struct SrcCount *pSrcCount;                /* Counting column references */
  } u;
};

/* Forward declarations */
int sqlite3WalkExpr(Walker*, Expr*);
................................................................................
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);

int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
................................................................................
);
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

void sqlite3StrAccumInit(StrAccum*, char*, int, int);
void sqlite3StrAccumAppend(StrAccum*,const char*,int);
void sqlite3StrAccumAppendAll(StrAccum*,const char*);
void sqlite3AppendSpace(StrAccum*,int);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumReset(StrAccum*);
void sqlite3SelectDestInit(SelectDest*,int,int);
Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

void sqlite3BackupRestart(sqlite3_backup *);
void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
*/
#ifndef SQLITE_POWERSAFE_OVERWRITE
# define SQLITE_POWERSAFE_OVERWRITE 1
#endif

/*
** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by
** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in
** which case memory allocation statistics are disabled by default.

*/
#if !defined(SQLITE_DEFAULT_MEMSTATUS)
# define SQLITE_DEFAULT_MEMSTATUS 1
#endif

/*
** Exactly one of the following macros must be defined in order to
................................................................................

/*
** Estimated quantities used for query planning are stored as 16-bit
** logarithms.  For quantity X, the value stored is 10*log2(X).  This
** gives a possible range of values of approximately 1.0e986 to 1e-986.
** But the allowed values are "grainy".  Not every value is representable.
** For example, quantities 16 and 17 are both represented by a LogEst
** of 40.  However, since LogEst quantities are suppose to be estimates,
** not exact values, this imprecision is not a problem.
**
** "LogEst" is short for "Logarithmic Estimate".
**
** Examples:
**      1 -> 0              20 -> 43          10000 -> 132
**      2 -> 10             25 -> 46          25000 -> 146
................................................................................
/*                not used    0x0010   // Was: SQLITE_IdxRealAsInt */
#define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
#define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
#define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
#define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
#define SQLITE_Transitive     0x0200   /* Transitive constraints */
#define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
#define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
#define SQLITE_AllOpts        0xffff   /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#ifndef SQLITE_OMIT_BUILTIN_TEST
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
................................................................................
  u16 nColumn;             /* Number of columns stored in the index */
  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
#endif
};

/*
** Allowed values for Index.idxType
*/
#define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */
................................................................................

#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
  int iTable;            /* TK_COLUMN: cursor number of table holding column
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old
                         ** EP_Unlikely:  134217728 times likelihood */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1). */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 op2;                /* TK_REGISTER: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
................................................................................
*/
struct Walker {
  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */
  int walkerDepth;                          /* Number of subqueries */
  u8 eCode;                                 /* A small processing code */
  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int n;                                     /* A counter */
    int iCur;                                  /* A cursor number */
    SrcList *pSrcList;                         /* FROM clause */
    struct SrcCount *pSrcCount;                /* Counting column references */
  } u;
};

/* Forward declarations */
int sqlite3WalkExpr(Walker*, Expr*);
................................................................................
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);
int sqlite3ExprIsTableConstant(Expr*,int);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
................................................................................
);
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

void sqlite3StrAccumInit(StrAccum*, char*, int, int);
void sqlite3StrAccumAppend(StrAccum*,const char*,int);
void sqlite3StrAccumAppendAll(StrAccum*,const char*);
void sqlite3AppendChar(StrAccum*,int,char);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumReset(StrAccum*);
void sqlite3SelectDestInit(SelectDest*,int,int);
Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

void sqlite3BackupRestart(sqlite3_backup *);
void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

** then this routine is not threadsafe.
*/
int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
  wsdStatInit;
  if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
    return SQLITE_MISUSE_BKPT;
  }



  *pCurrent = wsdStat.nowValue[op];
  *pHighwater = wsdStat.mxValue[op];
  if( resetFlag ){
    wsdStat.mxValue[op] = wsdStat.nowValue[op];
  }
  return SQLITE_OK;
}
................................................................................
  sqlite3 *db,          /* The database connection whose status is desired */
  int op,               /* Status verb */
  int *pCurrent,        /* Write current value here */
  int *pHighwater,      /* Write high-water mark here */
  int resetFlag         /* Reset high-water mark if true */
){
  int rc = SQLITE_OK;   /* Return code */





  sqlite3_mutex_enter(db->mutex);
  switch( op ){
    case SQLITE_DBSTATUS_LOOKASIDE_USED: {
      *pCurrent = db->lookaside.nOut;
      *pHighwater = db->lookaside.mxOut;
      if( resetFlag ){
        db->lookaside.mxOut = db->lookaside.nOut;

** then this routine is not threadsafe.
*/
int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
  wsdStatInit;
  if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
    return SQLITE_MISUSE_BKPT;
  }
#ifdef SQLITE_ENABLE_API_ARMOR
  if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *pCurrent = wsdStat.nowValue[op];
  *pHighwater = wsdStat.mxValue[op];
  if( resetFlag ){
    wsdStat.mxValue[op] = wsdStat.nowValue[op];
  }
  return SQLITE_OK;
}
................................................................................
  sqlite3 *db,          /* The database connection whose status is desired */
  int op,               /* Status verb */
  int *pCurrent,        /* Write current value here */
  int *pHighwater,      /* Write high-water mark here */
  int resetFlag         /* Reset high-water mark if true */
){
  int rc = SQLITE_OK;   /* Return code */
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  switch( op ){
    case SQLITE_DBSTATUS_LOOKASIDE_USED: {
      *pCurrent = db->lookaside.nOut;
      *pHighwater = db->lookaside.mxOut;
      if( resetFlag ){
        db->lookaside.mxOut = db->lookaside.nOut;

  int *pnRow,                 /* Write the number of rows in the result here */
  int *pnColumn,              /* Write the number of columns of result here */
  char **pzErrMsg             /* Write error messages here */
){
  int rc;
  TabResult res;




  *pazResult = 0;
  if( pnColumn ) *pnColumn = 0;
  if( pnRow ) *pnRow = 0;
  if( pzErrMsg ) *pzErrMsg = 0;
  res.zErrMsg = 0;
  res.nRow = 0;
  res.nColumn = 0;

  int *pnRow,                 /* Write the number of rows in the result here */
  int *pnColumn,              /* Write the number of columns of result here */
  char **pzErrMsg             /* Write error messages here */
){
  int rc;
  TabResult res;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( pazResult==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *pazResult = 0;
  if( pnColumn ) *pnColumn = 0;
  if( pnRow ) *pnRow = 0;
  if( pzErrMsg ) *pzErrMsg = 0;
  res.zErrMsg = 0;
  res.nRow = 0;
  res.nColumn = 0;

  }

  pDb->bLegacyPrepare = bPrepare;

  Tcl_ResetResult(interp);
  return TCL_OK;
}







































#endif

/*
** Configure the interpreter passed as the first argument to have access
** to the commands and linked variables that make up:
**
**   * the [sqlite3] extension itself, 
................................................................................
    extern int Sqlitetest5_Init(Tcl_Interp*);
    extern int Sqlitetest6_Init(Tcl_Interp*);
    extern int Sqlitetest7_Init(Tcl_Interp*);
    extern int Sqlitetest8_Init(Tcl_Interp*);
    extern int Sqlitetest9_Init(Tcl_Interp*);
    extern int Sqlitetestasync_Init(Tcl_Interp*);
    extern int Sqlitetest_autoext_Init(Tcl_Interp*);

    extern int Sqlitetest_demovfs_Init(Tcl_Interp *);
    extern int Sqlitetest_func_Init(Tcl_Interp*);
    extern int Sqlitetest_hexio_Init(Tcl_Interp*);
    extern int Sqlitetest_init_Init(Tcl_Interp*);
    extern int Sqlitetest_malloc_Init(Tcl_Interp*);
    extern int Sqlitetest_mutex_Init(Tcl_Interp*);
    extern int Sqlitetestschema_Init(Tcl_Interp*);
................................................................................
    Sqlitetest5_Init(interp);
    Sqlitetest6_Init(interp);
    Sqlitetest7_Init(interp);
    Sqlitetest8_Init(interp);
    Sqlitetest9_Init(interp);
    Sqlitetestasync_Init(interp);
    Sqlitetest_autoext_Init(interp);

    Sqlitetest_demovfs_Init(interp);
    Sqlitetest_func_Init(interp);
    Sqlitetest_hexio_Init(interp);
    Sqlitetest_init_Init(interp);
    Sqlitetest_malloc_Init(interp);
    Sqlitetest_mutex_Init(interp);
    Sqlitetestschema_Init(interp);
................................................................................

    Tcl_CreateObjCommand(
        interp, "load_testfixture_extensions", init_all_cmd, 0, 0
    );
    Tcl_CreateObjCommand(
        interp, "db_use_legacy_prepare", db_use_legacy_prepare_cmd, 0, 0
    );




#ifdef SQLITE_SSE
    Sqlitetestsse_Init(interp);
#endif
  }
#endif
}

  }

  pDb->bLegacyPrepare = bPrepare;

  Tcl_ResetResult(interp);
  return TCL_OK;
}

/*
** Tclcmd: db_last_stmt_ptr DB
**
**   If the statement cache associated with database DB is not empty,
**   return the text representation of the most recently used statement
**   handle.
*/
static int db_last_stmt_ptr(
  ClientData cd,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  extern int sqlite3TestMakePointerStr(Tcl_Interp*, char*, void*);
  Tcl_CmdInfo cmdInfo;
  SqliteDb *pDb;
  sqlite3_stmt *pStmt = 0;
  char zBuf[100];

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }

  if( !Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &cmdInfo) ){
    Tcl_AppendResult(interp, "no such db: ", Tcl_GetString(objv[1]), (char*)0);
    return TCL_ERROR;
  }
  pDb = (SqliteDb*)cmdInfo.objClientData;

  if( pDb->stmtList ) pStmt = pDb->stmtList->pStmt;
  if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ){
    return TCL_ERROR;
  }
  Tcl_SetResult(interp, zBuf, TCL_VOLATILE);

  return TCL_OK;
}
#endif

/*
** Configure the interpreter passed as the first argument to have access
** to the commands and linked variables that make up:
**
**   * the [sqlite3] extension itself, 
................................................................................
    extern int Sqlitetest5_Init(Tcl_Interp*);
    extern int Sqlitetest6_Init(Tcl_Interp*);
    extern int Sqlitetest7_Init(Tcl_Interp*);
    extern int Sqlitetest8_Init(Tcl_Interp*);
    extern int Sqlitetest9_Init(Tcl_Interp*);
    extern int Sqlitetestasync_Init(Tcl_Interp*);
    extern int Sqlitetest_autoext_Init(Tcl_Interp*);
    extern int Sqlitetest_blob_Init(Tcl_Interp*);
    extern int Sqlitetest_demovfs_Init(Tcl_Interp *);
    extern int Sqlitetest_func_Init(Tcl_Interp*);
    extern int Sqlitetest_hexio_Init(Tcl_Interp*);
    extern int Sqlitetest_init_Init(Tcl_Interp*);
    extern int Sqlitetest_malloc_Init(Tcl_Interp*);
    extern int Sqlitetest_mutex_Init(Tcl_Interp*);
    extern int Sqlitetestschema_Init(Tcl_Interp*);
................................................................................
    Sqlitetest5_Init(interp);
    Sqlitetest6_Init(interp);
    Sqlitetest7_Init(interp);
    Sqlitetest8_Init(interp);
    Sqlitetest9_Init(interp);
    Sqlitetestasync_Init(interp);
    Sqlitetest_autoext_Init(interp);
    Sqlitetest_blob_Init(interp);
    Sqlitetest_demovfs_Init(interp);
    Sqlitetest_func_Init(interp);
    Sqlitetest_hexio_Init(interp);
    Sqlitetest_init_Init(interp);
    Sqlitetest_malloc_Init(interp);
    Sqlitetest_mutex_Init(interp);
    Sqlitetestschema_Init(interp);
................................................................................

    Tcl_CreateObjCommand(
        interp, "load_testfixture_extensions", init_all_cmd, 0, 0
    );
    Tcl_CreateObjCommand(
        interp, "db_use_legacy_prepare", db_use_legacy_prepare_cmd, 0, 0
    );
    Tcl_CreateObjCommand(
        interp, "db_last_stmt_ptr", db_last_stmt_ptr, 0, 0
    );

#ifdef SQLITE_SSE
    Sqlitetestsse_Init(interp);
#endif
  }
#endif
}

    instanceData = Tcl_GetChannelInstanceData(channel);
    *ppBlob = *((sqlite3_blob **)instanceData);
  }

  return TCL_OK;
}

/*
** sqlite3_blob_bytes  CHANNEL
*/
static int test_blob_bytes(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int nByte;
  
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  nByte = sqlite3_blob_bytes(pBlob);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(nByte));

  return TCL_OK;
}

/*
** sqlite3_blob_close  CHANNEL
*/
static int test_blob_close(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  sqlite3_blob_close(pBlob);

  return TCL_OK;
}

/*
** sqlite3_blob_read  CHANNEL OFFSET N
**
**   This command is used to test the sqlite3_blob_read() in ways that
**   the Tcl channel interface does not. The first argument should
**   be the name of a valid channel created by the [incrblob] method
**   of a database handle. This function calls sqlite3_blob_read()
**   to read N bytes from offset OFFSET from the underlying SQLite
**   blob handle.
**
**   On success, a byte-array object containing the read data is 
**   returned. On failure, the interpreter result is set to the
**   text representation of the returned error code (i.e. "SQLITE_NOMEM")
**   and a Tcl exception is thrown.
*/
static int test_blob_read(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int nByte;
  int iOffset;
  unsigned char *zBuf = 0;
  int rc;
  
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET N");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  if( TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[3], &nByte)
  ){ 
    return TCL_ERROR;
  }

  if( nByte>0 ){
    zBuf = (unsigned char *)Tcl_Alloc(nByte);
  }
  rc = sqlite3_blob_read(pBlob, zBuf, nByte, iOffset);
  if( rc==SQLITE_OK ){
    Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zBuf, nByte));
  }else{
    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
  }
  Tcl_Free((char *)zBuf);

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}

/*
** sqlite3_blob_write CHANNEL OFFSET DATA ?NDATA?
**
**   This command is used to test the sqlite3_blob_write() in ways that
**   the Tcl channel interface does not. The first argument should
**   be the name of a valid channel created by the [incrblob] method
**   of a database handle. This function calls sqlite3_blob_write()
**   to write the DATA byte-array to the underlying SQLite blob handle.
**   at offset OFFSET.
**
**   On success, an empty string is returned. On failure, the interpreter
**   result is set to the text representation of the returned error code 
**   (i.e. "SQLITE_NOMEM") and a Tcl exception is thrown.
*/
static int test_blob_write(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int iOffset;
  int rc;

  unsigned char *zBuf;
  int nBuf;
  
  if( objc!=4 && objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET DATA ?NDATA?");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  if( TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset) ){ 
    return TCL_ERROR;
  }

  zBuf = Tcl_GetByteArrayFromObj(objv[3], &nBuf);
  if( objc==5 && Tcl_GetIntFromObj(interp, objv[4], &nBuf) ){
    return TCL_ERROR;
  }
  rc = sqlite3_blob_write(pBlob, zBuf, nBuf, iOffset);
  if( rc!=SQLITE_OK ){
    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
  }

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}

static int test_blob_reopen(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_WideInt iRowid;
................................................................................
    if( Tcl_GetIntFromObj(interp, objv[2], &op) ) return TCL_ERROR;
  }
  if( Tcl_GetBooleanFromObj(interp, objv[3], &resetFlag) ) return TCL_ERROR;
  iValue = sqlite3_stmt_status(pStmt, op, resetFlag);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(iValue));
  return TCL_OK;
}








































































/*
** Usage:  sqlite3_next_stmt  DB  STMT
**
** Return the next statment in sequence after STMT.
*/
static int test_next_stmt(
................................................................................
    { "factor-constants",    SQLITE_FactorOutConst },
    { "distinct-opt",        SQLITE_DistinctOpt    },
    { "cover-idx-scan",      SQLITE_CoverIdxScan   },
    { "order-by-idx-join",   SQLITE_OrderByIdxJoin },
    { "transitive",          SQLITE_Transitive     },
    { "subquery-coroutine",  SQLITE_SubqCoroutine  },
    { "omit-noop-join",      SQLITE_OmitNoopJoin   },
    { "stat3",               SQLITE_Stat3          },

  };

  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB OPT BOOLEAN");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
................................................................................
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  extern int sqlite3_amatch_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_closure_init(sqlite3*,char**,const sqlite3_api_routines*);

  extern int sqlite3_fileio_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_percentile_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
................................................................................
  extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
  static const struct {
    const char *zExtName;
    int (*pInit)(sqlite3*,char**,const sqlite3_api_routines*);
  } aExtension[] = {
    { "amatch",                sqlite3_amatch_init               },
    { "closure",               sqlite3_closure_init              },

    { "fileio",                sqlite3_fileio_init               },
    { "fuzzer",                sqlite3_fuzzer_init               },
    { "ieee754",               sqlite3_ieee_init                 },
    { "nextchar",              sqlite3_nextchar_init             },
    { "percentile",            sqlite3_percentile_init           },
    { "regexp",                sqlite3_regexp_init               },
    { "spellfix",              sqlite3_spellfix_init             },
................................................................................
     { "sqlite3_shared_cache_report", sqlite3BtreeSharedCacheReport, 0},
#endif
     { "sqlite3_libversion_number", test_libversion_number, 0  },
#ifdef SQLITE_ENABLE_COLUMN_METADATA
     { "sqlite3_table_column_metadata", test_table_column_metadata, 0  },
#endif
#ifndef SQLITE_OMIT_INCRBLOB
     { "sqlite3_blob_read",   test_blob_read, 0  },
     { "sqlite3_blob_write",  test_blob_write, 0  },
     { "sqlite3_blob_reopen", test_blob_reopen, 0  },
     { "sqlite3_blob_bytes",  test_blob_bytes, 0  },
     { "sqlite3_blob_close",  test_blob_close, 0  },
#endif
     { "pcache_stats",       test_pcache_stats, 0  },
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
     { "sqlite3_unlock_notify", test_unlock_notify, 0  },
#endif
     { "sqlite3_wal_checkpoint",   test_wal_checkpoint, 0  },
     { "sqlite3_wal_checkpoint_v2",test_wal_checkpoint_v2, 0  },
................................................................................
     { "sorter_test_sort4_helper", sorter_test_sort4_helper },
#ifdef SQLITE_USER_AUTHENTICATION
     { "sqlite3_user_authenticate", test_user_authenticate, 0 },
     { "sqlite3_user_add",          test_user_add,          0 },
     { "sqlite3_user_change",       test_user_change,       0 },
     { "sqlite3_user_delete",       test_user_delete,       0 },
#endif





  };

  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;

    instanceData = Tcl_GetChannelInstanceData(channel);
    *ppBlob = *((sqlite3_blob **)instanceData);
  }

  return TCL_OK;
}





















































































































































static int test_blob_reopen(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_WideInt iRowid;
................................................................................
    if( Tcl_GetIntFromObj(interp, objv[2], &op) ) return TCL_ERROR;
  }
  if( Tcl_GetBooleanFromObj(interp, objv[3], &resetFlag) ) return TCL_ERROR;
  iValue = sqlite3_stmt_status(pStmt, op, resetFlag);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(iValue));
  return TCL_OK;
}

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
/*
** Usage:  sqlite3_stmt_scanstatus STMT IDX
*/
static int test_stmt_scanstatus(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_stmt *pStmt;            /* First argument */
  int idx;                        /* Second argument */

  const char *zName;
  const char *zExplain;
  sqlite3_int64 nLoop;
  sqlite3_int64 nVisit;
  double rEst;
  int res;

  if( objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "STMT IDX");
    return TCL_ERROR;
  }
  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &idx) ) return TCL_ERROR;

  res = sqlite3_stmt_scanstatus(pStmt, idx, SQLITE_SCANSTAT_NLOOP, (void*)&nLoop);
  if( res==0 ){
    Tcl_Obj *pRet = Tcl_NewObj();
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj("nLoop", -1));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewWideIntObj(nLoop));
    sqlite3_stmt_scanstatus(pStmt, idx, SQLITE_SCANSTAT_NVISIT, (void*)&nVisit);
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj("nVisit", -1));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewWideIntObj(nVisit));
    sqlite3_stmt_scanstatus(pStmt, idx, SQLITE_SCANSTAT_EST, (void*)&rEst);
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj("nEst", -1));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewDoubleObj(rEst));
    sqlite3_stmt_scanstatus(pStmt, idx, SQLITE_SCANSTAT_NAME, (void*)&zName);
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj("zName", -1));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zName, -1));
    sqlite3_stmt_scanstatus(pStmt, idx, SQLITE_SCANSTAT_EXPLAIN, (void*)&zExplain);
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj("zExplain", -1));
    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zExplain, -1));
    Tcl_SetObjResult(interp, pRet);
  }else{
    Tcl_ResetResult(interp);
  }
  return TCL_OK;
}

/*
** Usage:  sqlite3_stmt_scanstatus_reset  STMT
*/
static int test_stmt_scanstatus_reset(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_stmt *pStmt;            /* First argument */
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "STMT");
    return TCL_ERROR;
  }
  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
  sqlite3_stmt_scanstatus_reset(pStmt);
  return TCL_OK;
}
#endif

/*
** Usage:  sqlite3_next_stmt  DB  STMT
**
** Return the next statment in sequence after STMT.
*/
static int test_next_stmt(
................................................................................
    { "factor-constants",    SQLITE_FactorOutConst },
    { "distinct-opt",        SQLITE_DistinctOpt    },
    { "cover-idx-scan",      SQLITE_CoverIdxScan   },
    { "order-by-idx-join",   SQLITE_OrderByIdxJoin },
    { "transitive",          SQLITE_Transitive     },
    { "subquery-coroutine",  SQLITE_SubqCoroutine  },
    { "omit-noop-join",      SQLITE_OmitNoopJoin   },
    { "stat3",               SQLITE_Stat34         },
    { "stat4",               SQLITE_Stat34         },
  };

  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB OPT BOOLEAN");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
................................................................................
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  extern int sqlite3_amatch_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_closure_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_eval_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_fileio_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_percentile_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
................................................................................
  extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
  static const struct {
    const char *zExtName;
    int (*pInit)(sqlite3*,char**,const sqlite3_api_routines*);
  } aExtension[] = {
    { "amatch",                sqlite3_amatch_init               },
    { "closure",               sqlite3_closure_init              },
    { "eval",                  sqlite3_eval_init                 },
    { "fileio",                sqlite3_fileio_init               },
    { "fuzzer",                sqlite3_fuzzer_init               },
    { "ieee754",               sqlite3_ieee_init                 },
    { "nextchar",              sqlite3_nextchar_init             },
    { "percentile",            sqlite3_percentile_init           },
    { "regexp",                sqlite3_regexp_init               },
    { "spellfix",              sqlite3_spellfix_init             },
................................................................................
     { "sqlite3_shared_cache_report", sqlite3BtreeSharedCacheReport, 0},
#endif
     { "sqlite3_libversion_number", test_libversion_number, 0  },
#ifdef SQLITE_ENABLE_COLUMN_METADATA
     { "sqlite3_table_column_metadata", test_table_column_metadata, 0  },
#endif
#ifndef SQLITE_OMIT_INCRBLOB


     { "sqlite3_blob_reopen", test_blob_reopen, 0  },


#endif
     { "pcache_stats",       test_pcache_stats, 0  },
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
     { "sqlite3_unlock_notify", test_unlock_notify, 0  },
#endif
     { "sqlite3_wal_checkpoint",   test_wal_checkpoint, 0  },
     { "sqlite3_wal_checkpoint_v2",test_wal_checkpoint_v2, 0  },
................................................................................
     { "sorter_test_sort4_helper", sorter_test_sort4_helper },
#ifdef SQLITE_USER_AUTHENTICATION
     { "sqlite3_user_authenticate", test_user_authenticate, 0 },
     { "sqlite3_user_add",          test_user_add,          0 },
     { "sqlite3_user_change",       test_user_change,       0 },
     { "sqlite3_user_delete",       test_user_delete,       0 },
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
     { "sqlite3_stmt_scanstatus",       test_stmt_scanstatus,   0 },
     { "sqlite3_stmt_scanstatus_reset", test_stmt_scanstatus_reset,   0 },
#endif
  };

  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;

/*
** 2014 October 30
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

/* These functions are implemented in main.c. */
extern const char *sqlite3ErrName(int);

/* From test1.c: */
extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
extern void *sqlite3TestTextToPtr(const char *z);

/*
** Return a pointer to a buffer containing a text representation of the
** pointer passed as the only argument. The original pointer may be extracted
** from the text using sqlite3TestTextToPtr().
*/
static char *ptrToText(void *p){
  static char buf[100];
  sqlite3_snprintf(sizeof(buf)-1, buf, "%p", p);
  return buf;
}

/*
** Attempt to extract a blob handle (type sqlite3_blob*) from the Tcl
** object passed as the second argument. If successful, set *ppBlob to
** point to the blob handle and return TCL_OK. Otherwise, store an error
** message in the tcl interpreter and return TCL_ERROR. The final value
** of *ppBlob is undefined in this case.
**
** If the object contains a string that begins with "incrblob_", then it
** is assumed to be the name of a Tcl channel opened using the [db incrblob] 
** command (see tclsqlite.c). Otherwise, it is assumed to be a pointer 
** encoded using the ptrToText() routine or similar.
*/
static int blobHandleFromObj(
  Tcl_Interp *interp, 
  Tcl_Obj *pObj,
  sqlite3_blob **ppBlob
){
  char *z;
  int n;

  z = Tcl_GetStringFromObj(pObj, &n);
  if( n==0 ){
    *ppBlob = 0;
  }else if( n>9 && 0==memcmp("incrblob_", z, 9) ){
    int notUsed;
    Tcl_Channel channel;
    ClientData instanceData;
    
    channel = Tcl_GetChannel(interp, z, &notUsed);
    if( !channel ) return TCL_ERROR;

    Tcl_Flush(channel);
    Tcl_Seek(channel, 0, SEEK_SET);

    instanceData = Tcl_GetChannelInstanceData(channel);
    *ppBlob = *((sqlite3_blob **)instanceData);
  }else{
    *ppBlob = (sqlite3_blob*)sqlite3TestTextToPtr(z);
  }

  return TCL_OK;
}

/*
** Like Tcl_GetString(), except that if the string is 0 bytes in size, a
** NULL Pointer is returned.
*/
static char *blobStringFromObj(Tcl_Obj *pObj){
  int n;
  char *z;
  z = Tcl_GetStringFromObj(pObj, &n);
  return (n ? z : 0);
}

/*
** sqlite3_blob_open DB DATABASE TABLE COLUMN ROWID FLAGS VARNAME
**
** Tcl test harness for the sqlite3_blob_open() function.
*/
static int test_blob_open(
  ClientData clientData,          /* Not used */
  Tcl_Interp *interp,             /* Calling TCL interpreter */
  int objc,                       /* Number of arguments */
  Tcl_Obj *CONST objv[]           /* Command arguments */
){
  sqlite3 *db;
  const char *zDb;
  const char *zTable;
  const char *zColumn;
  sqlite_int64 iRowid;
  int flags;
  const char *zVarname;
  int nVarname;

  sqlite3_blob *pBlob = (sqlite3_blob*)0xFFFFFFFF;
  int rc;

  if( objc!=8 ){
    const char *zUsage = "DB DATABASE TABLE COLUMN ROWID FLAGS VARNAME";
    Tcl_WrongNumArgs(interp, 1, objv, zUsage);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zDb = Tcl_GetString(objv[2]);
  zTable = blobStringFromObj(objv[3]);
  zColumn = Tcl_GetString(objv[4]);
  if( Tcl_GetWideIntFromObj(interp, objv[5], &iRowid) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[6], &flags) ) return TCL_ERROR;
  zVarname = Tcl_GetStringFromObj(objv[7], &nVarname);

  if( nVarname>0 ){
    rc = sqlite3_blob_open(db, zDb, zTable, zColumn, iRowid, flags, &pBlob);
    Tcl_SetVar(interp, zVarname, ptrToText(pBlob), 0);
  }else{
    rc = sqlite3_blob_open(db, zDb, zTable, zColumn, iRowid, flags, 0);
  }

  if( rc==SQLITE_OK ){
    Tcl_ResetResult(interp);
  }else{
    Tcl_SetResult(interp, (char*)sqlite3ErrName(rc), TCL_VOLATILE);
    return TCL_ERROR;
  }
  return TCL_OK;
}


/*
** sqlite3_blob_close  HANDLE
*/
static int test_blob_close(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int rc;
  
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "HANDLE");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  rc = sqlite3_blob_close(pBlob);

  if( rc ){
    Tcl_SetResult(interp, (char*)sqlite3ErrName(rc), TCL_VOLATILE);
  }else{
    Tcl_ResetResult(interp);
  }
  return TCL_OK;
}

/*
** sqlite3_blob_bytes  HANDLE
*/
static int test_blob_bytes(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int nByte;
  
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "HANDLE");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  nByte = sqlite3_blob_bytes(pBlob);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(nByte));

  return TCL_OK;
}

/*
** sqlite3_blob_read  CHANNEL OFFSET N
**
**   This command is used to test the sqlite3_blob_read() in ways that
**   the Tcl channel interface does not. The first argument should
**   be the name of a valid channel created by the [incrblob] method
**   of a database handle. This function calls sqlite3_blob_read()
**   to read N bytes from offset OFFSET from the underlying SQLite
**   blob handle.
**
**   On success, a byte-array object containing the read data is 
**   returned. On failure, the interpreter result is set to the
**   text representation of the returned error code (i.e. "SQLITE_NOMEM")
**   and a Tcl exception is thrown.
*/
static int test_blob_read(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int nByte;
  int iOffset;
  unsigned char *zBuf = 0;
  int rc;
  
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET N");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  if( TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[3], &nByte)
  ){ 
    return TCL_ERROR;
  }

  if( nByte>0 ){
    zBuf = (unsigned char *)Tcl_Alloc(nByte);
  }
  rc = sqlite3_blob_read(pBlob, zBuf, nByte, iOffset);
  if( rc==SQLITE_OK ){
    Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zBuf, nByte));
  }else{
    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
  }
  Tcl_Free((char *)zBuf);

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}

/*
** sqlite3_blob_write HANDLE OFFSET DATA ?NDATA?
**
**   This command is used to test the sqlite3_blob_write() in ways that
**   the Tcl channel interface does not. The first argument should
**   be the name of a valid channel created by the [incrblob] method
**   of a database handle. This function calls sqlite3_blob_write()
**   to write the DATA byte-array to the underlying SQLite blob handle.
**   at offset OFFSET.
**
**   On success, an empty string is returned. On failure, the interpreter
**   result is set to the text representation of the returned error code 
**   (i.e. "SQLITE_NOMEM") and a Tcl exception is thrown.
*/
static int test_blob_write(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3_blob *pBlob;
  int iOffset;
  int rc;

  unsigned char *zBuf;
  int nBuf;
  
  if( objc!=4 && objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "HANDLE OFFSET DATA ?NDATA?");
    return TCL_ERROR;
  }

  if( blobHandleFromObj(interp, objv[1], &pBlob) ) return TCL_ERROR;
  if( TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset) ){ 
    return TCL_ERROR;
  }

  zBuf = Tcl_GetByteArrayFromObj(objv[3], &nBuf);
  if( objc==5 && Tcl_GetIntFromObj(interp, objv[4], &nBuf) ){
    return TCL_ERROR;
  }
  rc = sqlite3_blob_write(pBlob, zBuf, nBuf, iOffset);
  if( rc!=SQLITE_OK ){
    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
  }

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}


/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest_blob_Init(Tcl_Interp *interp){
  static struct {
     char *zName;
     Tcl_ObjCmdProc *xProc;
  } aObjCmd[] = {
     { "sqlite3_blob_open",            test_blob_open        },
     { "sqlite3_blob_close",           test_blob_close       },
     { "sqlite3_blob_bytes",           test_blob_bytes       },
     { "sqlite3_blob_read",            test_blob_read        },
     { "sqlite3_blob_write",           test_blob_write       },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
  }
  return TCL_OK;
}

#endif

#ifdef SQLITE_OMIT_ANALYZE
  Tcl_SetVar2(interp, "sqlite_options", "analyze", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "analyze", "1", TCL_GLOBAL_ONLY);
#endif







#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "0", TCL_GLOBAL_ONLY);
#endif

................................................................................
  Tcl_SetVar2(interp, "sqlite_options", "stat4", "0", TCL_GLOBAL_ONLY);
#endif
#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4)
  Tcl_SetVar2(interp, "sqlite_options", "stat3", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "stat3", "0", TCL_GLOBAL_ONLY);
#endif







#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
#  if defined(__APPLE__)
#    define SQLITE_ENABLE_LOCKING_STYLE 1
#  else
#    define SQLITE_ENABLE_LOCKING_STYLE 0
#  endif

#endif

#ifdef SQLITE_OMIT_ANALYZE
  Tcl_SetVar2(interp, "sqlite_options", "analyze", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "analyze", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_ENABLE_API_ARMOR
  Tcl_SetVar2(interp, "sqlite_options", "api_armor", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "api_armor", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "atomicwrite", "0", TCL_GLOBAL_ONLY);
#endif

................................................................................
  Tcl_SetVar2(interp, "sqlite_options", "stat4", "0", TCL_GLOBAL_ONLY);
#endif
#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4)
  Tcl_SetVar2(interp, "sqlite_options", "stat3", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "stat3", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  Tcl_SetVar2(interp, "sqlite_options", "scanstatus", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "scanstatus", "0", TCL_GLOBAL_ONLY);
#endif

#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
#  if defined(__APPLE__)
#    define SQLITE_ENABLE_LOCKING_STYLE 1
#  else
#    define SQLITE_ENABLE_LOCKING_STYLE 0
#  endif

    }
    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen,
                               0, 0);
  }

  /* Top of the update loop */
  if( okOnePass ){
    if( aToOpen[iDataCur-iBaseCur] ){
      assert( pPk!=0 );
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
      VdbeCoverageNeverTaken(v);
    }
    labelContinue = labelBreak;
    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
    VdbeCoverageIf(v, pPk==0);
    VdbeCoverageIf(v, pPk!=0);

    }
    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen,
                               0, 0);
  }

  /* Top of the update loop */
  if( okOnePass ){
    if( aToOpen[iDataCur-iBaseCur] && !isView ){
      assert( pPk );
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
      VdbeCoverageNeverTaken(v);
    }
    labelContinue = labelBreak;
    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
    VdbeCoverageIf(v, pPk==0);
    VdbeCoverageIf(v, pPk!=0);

** sqlite3_strnicmp() APIs allow applications and extensions to compare
** the contents of two buffers containing UTF-8 strings in a
** case-independent fashion, using the same definition of "case
** independence" that SQLite uses internally when comparing identifiers.
*/
int sqlite3_stricmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;





  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return UpperToLower[*a] - UpperToLower[*b];
}
int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
  register unsigned char *a, *b;





  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
}

/*

** sqlite3_strnicmp() APIs allow applications and extensions to compare
** the contents of two buffers containing UTF-8 strings in a
** case-independent fashion, using the same definition of "case
** independence" that SQLite uses internally when comparing identifiers.
*/
int sqlite3_stricmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;
  if( zLeft==0 ){
    return zRight ? -1 : 0;
  }else if( zRight==0 ){
    return 1;
  }
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return UpperToLower[*a] - UpperToLower[*b];
}
int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
  register unsigned char *a, *b;
  if( zLeft==0 ){
    return zRight ? -1 : 0;
  }else if( zRight==0 ){
    return 1;
  }
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
}

/*

** original database is required.  Every page of the database is written
** approximately 3 times:  Once for step (2) and twice for step (3).
** Two writes per page are required in step (3) because the original
** database content must be written into the rollback journal prior to
** overwriting the database with the vacuumed content.
**
** Only 1x temporary space and only 1x writes would be required if
** the copy of step (3) were replace by deleting the original database
** and renaming the transient database as the original.  But that will
** not work if other processes are attached to the original database.
** And a power loss in between deleting the original and renaming the
** transient would cause the database file to appear to be deleted
** following reboot.
*/
void sqlite3Vacuum(Parse *pParse){

** original database is required.  Every page of the database is written
** approximately 3 times:  Once for step (2) and twice for step (3).
** Two writes per page are required in step (3) because the original
** database content must be written into the rollback journal prior to
** overwriting the database with the vacuumed content.
**
** Only 1x temporary space and only 1x writes would be required if
** the copy of step (3) were replaced by deleting the original database
** and renaming the transient database as the original.  But that will
** not work if other processes are attached to the original database.
** And a power loss in between deleting the original and renaming the
** transient would cause the database file to appear to be deleted
** following reboot.
*/
void sqlite3Vacuum(Parse *pParse){

    assert( pc>=0 && pc<p->nOp );
    if( db->mallocFailed ) goto no_mem;
#ifdef VDBE_PROFILE
    start = sqlite3Hwtime();
#endif
    nVmStep++;
    pOp = &aOp[pc];




    /* Only allow tracing if SQLITE_DEBUG is defined.
    */
#ifdef SQLITE_DEBUG
    if( db->flags & SQLITE_VdbeTrace ){
      sqlite3VdbePrintOp(stdout, pc, pOp);
    }
................................................................................
        assert( pC->pseudoTableReg>0 );
        pReg = &aMem[pC->pseudoTableReg];
        assert( pReg->flags & MEM_Blob );
        assert( memIsValid(pReg) );
        pC->payloadSize = pC->szRow = avail = pReg->n;
        pC->aRow = (u8*)pReg->z;
      }else{
        MemSetTypeFlag(pDest, MEM_Null);
        goto op_column_out;
      }
    }else{
      assert( pCrsr );
      if( pC->isTable==0 ){
        assert( sqlite3BtreeCursorIsValid(pCrsr) );
        VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
................................................................................
    ** still not up to p2, that means that the record has fewer than p2
    ** columns.  So the result will be either the default value or a NULL.
    */
    if( pC->nHdrParsed<=p2 ){
      if( pOp->p4type==P4_MEM ){
        sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
      }else{
        MemSetTypeFlag(pDest, MEM_Null);
      }
      goto op_column_out;
    }
  }

  /* Extract the content for the p2+1-th column.  Control can only
  ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are
................................................................................
    }
    nData += len;
    testcase( serial_type==127 );
    testcase( serial_type==128 );
    nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
  }while( (--pRec)>=pData0 );

  /* Add the initial header varint and total the size */



  testcase( nHdr==126 );
  testcase( nHdr==127 );
  if( nHdr<=126 ){
    /* The common case */
    nHdr += 1;
  }else{
    /* Rare case of a really large header */
................................................................................
  /* Write the record */
  i = putVarint32(zNewRecord, nHdr);
  j = nHdr;
  assert( pData0<=pLast );
  pRec = pData0;
  do{
    serial_type = pRec->uTemp;


    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */


    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
  }while( (++pRec)<=pLast );
  assert( i==nHdr );
  assert( j==nByte );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pOut->n = (int)nByte;
................................................................................
          db->autoCommit = 0;
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }
        db->isTransactionSavepoint = 0;
        rc = p->rc;
      }else{

        iSavepoint = db->nSavepoint - iSavepoint - 1;
        if( p1==SAVEPOINT_ROLLBACK ){

          for(ii=0; ii<db->nDb; ii++){
            sqlite3BtreeTripAllCursors(db->aDb[ii].pBt, SQLITE_ABORT);



          }


        }
        for(ii=0; ii<db->nDb; ii++){
          rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);
          if( rc!=SQLITE_OK ){
            goto abort_due_to_error;
          }
        }
        if( p1==SAVEPOINT_ROLLBACK && (db->flags&SQLITE_InternChanges)!=0 ){
          sqlite3ExpirePreparedStatements(db);
          sqlite3ResetAllSchemasOfConnection(db);
          db->flags = (db->flags | SQLITE_InternChanges);
        }
      }
  
      /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all 
................................................................................
  assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR))==pOp->p5 );
  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 );
  assert( p->bIsReader );
  assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx
          || p->readOnly==0 );

  if( p->expired ){
    rc = SQLITE_ABORT;
    break;
  }

  nField = 0;
  pKeyInfo = 0;
  p2 = pOp->p2;
  iDb = pOp->p3;
................................................................................
      if( ii ) REGISTER_TRACE(pOp->p3+ii, &r.aMem[ii]);
#endif
    }
    pIdxKey = &r;
  }else{
    pIdxKey = sqlite3VdbeAllocUnpackedRecord(
        pC->pKeyInfo, aTempRec, sizeof(aTempRec), &pFree
    ); 
    if( pIdxKey==0 ) goto no_mem;
    assert( pIn3->flags & MEM_Blob );
    assert( (pIn3->flags & MEM_Zero)==0 );  /* zeroblobs already expanded */
    sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z, pIdxKey);
  }
  pIdxKey->default_rc = 0;
  if( pOp->opcode==OP_NoConflict ){
    /* For the OP_NoConflict opcode, take the jump if any of the
    ** input fields are NULL, since any key with a NULL will not
    ** conflict */
................................................................................
    rc = pModule->xRowid(pC->pVtabCursor, &v);
    sqlite3VtabImportErrmsg(p, pVtab);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( pC->pCursor!=0 );
    rc = sqlite3VdbeCursorRestore(pC);
    if( rc ) goto abort_due_to_error;




    rc = sqlite3BtreeKeySize(pC->pCursor, &v);
    assert( rc==SQLITE_OK );  /* Always so because of CursorRestore() above */
  }
  pOut->u.i = v;
  break;
}

................................................................................
  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end.  In other words, the cursor is
** configured to use Next, not Prev.
*/
case OP_Rewind: {        /* jump */
  VdbeCursor *pC;
................................................................................
    pFrame->apCsr = p->apCsr;
    pFrame->nCursor = p->nCursor;
    pFrame->aOp = p->aOp;
    pFrame->nOp = p->nOp;
    pFrame->token = pProgram->token;
    pFrame->aOnceFlag = p->aOnceFlag;
    pFrame->nOnceFlag = p->nOnceFlag;




    pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
    for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
      pMem->flags = MEM_Undefined;
      pMem->db = db;
    }
  }else{
................................................................................
    assert( pc==pFrame->pc );
  }

  p->nFrame++;
  pFrame->pParent = p->pFrame;
  pFrame->lastRowid = lastRowid;
  pFrame->nChange = p->nChange;

  p->nChange = 0;
  p->pFrame = pFrame;
  p->aMem = aMem = &VdbeFrameMem(pFrame)[-1];
  p->nMem = pFrame->nChildMem;
  p->nCursor = (u16)pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
  p->aOp = aOp = pProgram->aOp;
  p->nOp = pProgram->nOp;
  p->aOnceFlag = (u8 *)&p->apCsr[p->nCursor];
  p->nOnceFlag = pProgram->nOnce;



  pc = -1;
  memset(p->aOnceFlag, 0, p->nOnceFlag);

  break;
}

/* Opcode: Param P1 P2 * * *

    assert( pc>=0 && pc<p->nOp );
    if( db->mallocFailed ) goto no_mem;
#ifdef VDBE_PROFILE
    start = sqlite3Hwtime();
#endif
    nVmStep++;
    pOp = &aOp[pc];
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    if( p->anExec ) p->anExec[pc]++;
#endif

    /* Only allow tracing if SQLITE_DEBUG is defined.
    */
#ifdef SQLITE_DEBUG
    if( db->flags & SQLITE_VdbeTrace ){
      sqlite3VdbePrintOp(stdout, pc, pOp);
    }
................................................................................
        assert( pC->pseudoTableReg>0 );
        pReg = &aMem[pC->pseudoTableReg];
        assert( pReg->flags & MEM_Blob );
        assert( memIsValid(pReg) );
        pC->payloadSize = pC->szRow = avail = pReg->n;
        pC->aRow = (u8*)pReg->z;
      }else{
        sqlite3VdbeMemSetNull(pDest);
        goto op_column_out;
      }
    }else{
      assert( pCrsr );
      if( pC->isTable==0 ){
        assert( sqlite3BtreeCursorIsValid(pCrsr) );
        VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
................................................................................
    ** still not up to p2, that means that the record has fewer than p2
    ** columns.  So the result will be either the default value or a NULL.
    */
    if( pC->nHdrParsed<=p2 ){
      if( pOp->p4type==P4_MEM ){
        sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
      }else{
        sqlite3VdbeMemSetNull(pDest);
      }
      goto op_column_out;
    }
  }

  /* Extract the content for the p2+1-th column.  Control can only
  ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are
................................................................................
    }
    nData += len;
    testcase( serial_type==127 );
    testcase( serial_type==128 );
    nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
  }while( (--pRec)>=pData0 );

  /* EVIDENCE-OF: R-22564-11647 The header begins with a single varint
  ** which determines the total number of bytes in the header. The varint
  ** value is the size of the header in bytes including the size varint
  ** itself. */
  testcase( nHdr==126 );
  testcase( nHdr==127 );
  if( nHdr<=126 ){
    /* The common case */
    nHdr += 1;
  }else{
    /* Rare case of a really large header */
................................................................................
  /* Write the record */
  i = putVarint32(zNewRecord, nHdr);
  j = nHdr;
  assert( pData0<=pLast );
  pRec = pData0;
  do{
    serial_type = pRec->uTemp;
    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
    ** additional varints, one per column. */
    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */
    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
    ** immediately follow the header. */
    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
  }while( (++pRec)<=pLast );
  assert( i==nHdr );
  assert( j==nByte );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pOut->n = (int)nByte;
................................................................................
          db->autoCommit = 0;
          p->rc = rc = SQLITE_BUSY;
          goto vdbe_return;
        }
        db->isTransactionSavepoint = 0;
        rc = p->rc;
      }else{
        int isSchemaChange;
        iSavepoint = db->nSavepoint - iSavepoint - 1;
        if( p1==SAVEPOINT_ROLLBACK ){
          isSchemaChange = (db->flags & SQLITE_InternChanges)!=0;
          for(ii=0; ii<db->nDb; ii++){
            rc = sqlite3BtreeTripAllCursors(db->aDb[ii].pBt,
                                       SQLITE_ABORT_ROLLBACK,
                                       isSchemaChange==0);
            if( rc!=SQLITE_OK ) goto abort_due_to_error;
          }
        }else{
          isSchemaChange = 0;
        }
        for(ii=0; ii<db->nDb; ii++){
          rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);
          if( rc!=SQLITE_OK ){
            goto abort_due_to_error;
          }
        }
        if( isSchemaChange ){
          sqlite3ExpirePreparedStatements(db);
          sqlite3ResetAllSchemasOfConnection(db);
          db->flags = (db->flags | SQLITE_InternChanges);
        }
      }
  
      /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all 
................................................................................
  assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR))==pOp->p5 );
  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 );
  assert( p->bIsReader );
  assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx
          || p->readOnly==0 );

  if( p->expired ){
    rc = SQLITE_ABORT_ROLLBACK;
    break;
  }

  nField = 0;
  pKeyInfo = 0;
  p2 = pOp->p2;
  iDb = pOp->p3;
................................................................................
      if( ii ) REGISTER_TRACE(pOp->p3+ii, &r.aMem[ii]);
#endif
    }
    pIdxKey = &r;
  }else{
    pIdxKey = sqlite3VdbeAllocUnpackedRecord(
        pC->pKeyInfo, aTempRec, sizeof(aTempRec), &pFree
    );
    if( pIdxKey==0 ) goto no_mem;
    assert( pIn3->flags & MEM_Blob );
    ExpandBlob(pIn3);
    sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z, pIdxKey);
  }
  pIdxKey->default_rc = 0;
  if( pOp->opcode==OP_NoConflict ){
    /* For the OP_NoConflict opcode, take the jump if any of the
    ** input fields are NULL, since any key with a NULL will not
    ** conflict */
................................................................................
    rc = pModule->xRowid(pC->pVtabCursor, &v);
    sqlite3VtabImportErrmsg(p, pVtab);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( pC->pCursor!=0 );
    rc = sqlite3VdbeCursorRestore(pC);
    if( rc ) goto abort_due_to_error;
    if( pC->nullRow ){
      pOut->flags = MEM_Null;
      break;
    }
    rc = sqlite3BtreeKeySize(pC->pCursor, &v);
    assert( rc==SQLITE_OK );  /* Always so because of CursorRestore() above */
  }
  pOut->u.i = v;
  break;
}

................................................................................
  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty, jump immediately to P2.
** If the table or index is not empty, fall through to the following 
** instruction.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end.  In other words, the cursor is
** configured to use Next, not Prev.
*/
case OP_Rewind: {        /* jump */
  VdbeCursor *pC;
................................................................................
    pFrame->apCsr = p->apCsr;
    pFrame->nCursor = p->nCursor;
    pFrame->aOp = p->aOp;
    pFrame->nOp = p->nOp;
    pFrame->token = pProgram->token;
    pFrame->aOnceFlag = p->aOnceFlag;
    pFrame->nOnceFlag = p->nOnceFlag;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    pFrame->anExec = p->anExec;
#endif

    pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
    for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
      pMem->flags = MEM_Undefined;
      pMem->db = db;
    }
  }else{
................................................................................
    assert( pc==pFrame->pc );
  }

  p->nFrame++;
  pFrame->pParent = p->pFrame;
  pFrame->lastRowid = lastRowid;
  pFrame->nChange = p->nChange;
  pFrame->nDbChange = p->db->nChange;
  p->nChange = 0;
  p->pFrame = pFrame;
  p->aMem = aMem = &VdbeFrameMem(pFrame)[-1];
  p->nMem = pFrame->nChildMem;
  p->nCursor = (u16)pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
  p->aOp = aOp = pProgram->aOp;
  p->nOp = pProgram->nOp;
  p->aOnceFlag = (u8 *)&p->apCsr[p->nCursor];
  p->nOnceFlag = pProgram->nOnce;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  p->anExec = 0;
#endif
  pc = -1;
  memset(p->aOnceFlag, 0, p->nOnceFlag);

  break;
}

/* Opcode: Param P1 P2 * * *

#else
# define VdbeCoverage(v)
# define VdbeCoverageIf(v,x)
# define VdbeCoverageAlwaysTaken(v)
# define VdbeCoverageNeverTaken(v)
# define VDBE_OFFSET_LINENO(x) 0
#endif





#endif

#else
# define VdbeCoverage(v)
# define VdbeCoverageIf(v,x)
# define VdbeCoverageAlwaysTaken(v)
# define VdbeCoverageNeverTaken(v)
# define VDBE_OFFSET_LINENO(x) 0
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
#else
# define sqlite3VdbeScanStatus(a,b,c,d,e)
#endif

#endif

** set to NULL if the currently executing frame is the main program.
*/
typedef struct VdbeFrame VdbeFrame;
struct VdbeFrame {
  Vdbe *v;                /* VM this frame belongs to */
  VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
  Op *aOp;                /* Program instructions for parent frame */

  Mem *aMem;              /* Array of memory cells for parent frame */
  u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
  VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
  void *token;            /* Copy of SubProgram.token */
  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
  int nCursor;            /* Number of entries in apCsr */
  int pc;                 /* Program Counter in parent (calling) frame */
  int nOp;                /* Size of aOp array */
  int nMem;               /* Number of entries in aMem */
  int nOnceFlag;          /* Number of entries in aOnceFlag */
  int nChildMem;          /* Number of memory cells for child frame */
  int nChildCsr;          /* Number of cursors for child frame */
  int nChange;            /* Statement changes (Vdbe.nChanges)     */

};

#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

/*
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
................................................................................
};

/* A bitfield type for use inside of structures.  Always follow with :N where
** N is the number of bits.
*/
typedef unsigned bft;  /* Bit Field Type */











/*
** An instance of the virtual machine.  This structure contains the complete
** state of the virtual machine.
**
** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
** is really a pointer to an instance of this structure.
**
................................................................................
  VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
  int nFrame;             /* Number of frames in pFrame list */
  u32 expmask;            /* Binding to these vars invalidates VM */
  SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
  int nOnceFlag;          /* Size of array aOnceFlag[] */
  u8 *aOnceFlag;          /* Flags for OP_Once */
  AuxData *pAuxData;      /* Linked list of auxdata allocations */





};

/*
** The following are allowed values for Vdbe.magic
*/
#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */

** set to NULL if the currently executing frame is the main program.
*/
typedef struct VdbeFrame VdbeFrame;
struct VdbeFrame {
  Vdbe *v;                /* VM this frame belongs to */
  VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
  Op *aOp;                /* Program instructions for parent frame */
  i64 *anExec;            /* Event counters from parent frame */
  Mem *aMem;              /* Array of memory cells for parent frame */
  u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
  VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
  void *token;            /* Copy of SubProgram.token */
  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
  int nCursor;            /* Number of entries in apCsr */
  int pc;                 /* Program Counter in parent (calling) frame */
  int nOp;                /* Size of aOp array */
  int nMem;               /* Number of entries in aMem */
  int nOnceFlag;          /* Number of entries in aOnceFlag */
  int nChildMem;          /* Number of memory cells for child frame */
  int nChildCsr;          /* Number of cursors for child frame */
  int nChange;            /* Statement changes (Vdbe.nChange)     */
  int nDbChange;          /* Value of db->nChange */
};

#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

/*
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
................................................................................
};

/* A bitfield type for use inside of structures.  Always follow with :N where
** N is the number of bits.
*/
typedef unsigned bft;  /* Bit Field Type */

typedef struct ScanStatus ScanStatus;
struct ScanStatus {
  int addrExplain;                /* OP_Explain for loop */
  int addrLoop;                   /* Address of "loops" counter */
  int addrVisit;                  /* Address of "rows visited" counter */
  int iSelectID;                  /* The "Select-ID" for this loop */
  LogEst nEst;                    /* Estimated output rows per loop */
  char *zName;                    /* Name of table or index */
};

/*
** An instance of the virtual machine.  This structure contains the complete
** state of the virtual machine.
**
** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
** is really a pointer to an instance of this structure.
**
................................................................................
  VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
  int nFrame;             /* Number of frames in pFrame list */
  u32 expmask;            /* Binding to these vars invalidates VM */
  SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
  int nOnceFlag;          /* Size of array aOnceFlag[] */
  u8 *aOnceFlag;          /* Flags for OP_Once */
  AuxData *pAuxData;      /* Linked list of auxdata allocations */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  i64 *anExec;            /* Number of times each op has been executed */
  int nScan;              /* Entries in aScan[] */
  ScanStatus *aScan;      /* Scan definitions for sqlite3_stmt_scanstatus() */
#endif
};

/*
** The following are allowed values for Vdbe.magic
*/
#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */

*/
static const void *columnName(
  sqlite3_stmt *pStmt,
  int N,
  const void *(*xFunc)(Mem*),
  int useType
){
  const void *ret = 0;
  Vdbe *p = (Vdbe *)pStmt;
  int n;
  sqlite3 *db = p->db;




  




  assert( db!=0 );
  n = sqlite3_column_count(pStmt);
  if( N<n && N>=0 ){
    N += useType*n;
    sqlite3_mutex_enter(db->mutex);
    assert( db->mallocFailed==0 );
    ret = xFunc(&p->aColName[N]);
................................................................................
** Return a pointer to the next prepared statement after pStmt associated
** with database connection pDb.  If pStmt is NULL, return the first
** prepared statement for the database connection.  Return NULL if there
** are no more.
*/
sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
  sqlite3_stmt *pNext;






  sqlite3_mutex_enter(pDb->mutex);
  if( pStmt==0 ){
    pNext = (sqlite3_stmt*)pDb->pVdbe;
  }else{
    pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
  }
  sqlite3_mutex_leave(pDb->mutex);
................................................................................
}

/*
** Return the value of a status counter for a prepared statement
*/
int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
  Vdbe *pVdbe = (Vdbe*)pStmt;







  u32 v = pVdbe->aCounter[op];
  if( resetFlag ) pVdbe->aCounter[op] = 0;
  return (int)v;
}

*/
static const void *columnName(
  sqlite3_stmt *pStmt,
  int N,
  const void *(*xFunc)(Mem*),
  int useType
){
  const void *ret;
  Vdbe *p;
  int n;
  sqlite3 *db;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( pStmt==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  ret = 0;
  p = (Vdbe *)pStmt;
  db = p->db;
  assert( db!=0 );
  n = sqlite3_column_count(pStmt);
  if( N<n && N>=0 ){
    N += useType*n;
    sqlite3_mutex_enter(db->mutex);
    assert( db->mallocFailed==0 );
    ret = xFunc(&p->aColName[N]);
................................................................................
** Return a pointer to the next prepared statement after pStmt associated
** with database connection pDb.  If pStmt is NULL, return the first
** prepared statement for the database connection.  Return NULL if there
** are no more.
*/
sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
  sqlite3_stmt *pNext;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(pDb) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(pDb->mutex);
  if( pStmt==0 ){
    pNext = (sqlite3_stmt*)pDb->pVdbe;
  }else{
    pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
  }
  sqlite3_mutex_leave(pDb->mutex);
................................................................................
}

/*
** Return the value of a status counter for a prepared statement
*/
int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
  Vdbe *pVdbe = (Vdbe*)pStmt;
  u32 v;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !pStmt ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  v = pVdbe->aCounter[op];
  if( resetFlag ) pVdbe->aCounter[op] = 0;
  return (int)v;
}

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
/*
** Return status data for a single loop within query pStmt.
*/
int sqlite3_stmt_scanstatus(
  sqlite3_stmt *pStmt,            /* Prepared statement being queried */
  int idx,                        /* Index of loop to report on */
  int iScanStatusOp,              /* Which metric to return */
  void *pOut                      /* OUT: Write the answer here */
){
  Vdbe *p = (Vdbe*)pStmt;
  ScanStatus *pScan;
  if( idx<0 || idx>=p->nScan ) return 1;
  pScan = &p->aScan[idx];
  switch( iScanStatusOp ){
    case SQLITE_SCANSTAT_NLOOP: {
      *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
      break;
    }
    case SQLITE_SCANSTAT_NVISIT: {
      *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
      break;
    }
    case SQLITE_SCANSTAT_EST: {
      double r = 1.0;
      LogEst x = pScan->nEst;
      while( x<100 ){
        x += 10;
        r *= 0.5;
      }
      *(double*)pOut = r*sqlite3LogEstToInt(x);
      break;
    }
    case SQLITE_SCANSTAT_NAME: {
      *(const char**)pOut = pScan->zName;
      break;
    }
    case SQLITE_SCANSTAT_EXPLAIN: {
      if( pScan->addrExplain ){
        *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
      }else{
        *(const char**)pOut = 0;
      }
      break;
    }
    case SQLITE_SCANSTAT_SELECTID: {
      if( pScan->addrExplain ){
        *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
      }else{
        *(int*)pOut = -1;
      }
      break;
    }
    default: {
      return 1;
    }
  }
  return 0;
}

/*
** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
*/
void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
  Vdbe *p = (Vdbe*)pStmt;
  memset(p->anExec, 0, p->nOp * sizeof(i64));
}
#endif /* SQLITE_ENABLE_STMT_SCANSTATUS */

      }
#endif
    }
    p->nOp += nOp;
  }
  return addr;
}





























/*
** Change the value of the P1 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
*/
................................................................................
    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
                          &zCsr, zEnd, &nByte);
    p->aOnceFlag = allocSpace(p->aOnceFlag, nOnce, &zCsr, zEnd, &nByte);



    if( nByte ){
      p->pFree = sqlite3DbMallocZero(db, nByte);
    }
    zCsr = p->pFree;
    zEnd = &zCsr[nByte];
  }while( nByte && !db->mallocFailed );

................................................................................
/*
** Copy the values stored in the VdbeFrame structure to its Vdbe. This
** is used, for example, when a trigger sub-program is halted to restore
** control to the main program.
*/
int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
  Vdbe *v = pFrame->v;



  v->aOnceFlag = pFrame->aOnceFlag;
  v->nOnceFlag = pFrame->nOnceFlag;
  v->aOp = pFrame->aOp;
  v->nOp = pFrame->nOp;
  v->aMem = pFrame->aMem;
  v->nMem = pFrame->nMem;
  v->apCsr = pFrame->apCsr;
  v->nCursor = pFrame->nCursor;
  v->db->lastRowid = pFrame->lastRowid;
  v->nChange = pFrame->nChange;

  return pFrame->pc;
}

/*
** Close all cursors.
**
** Also release any dynamic memory held by the VM in the Vdbe.aMem memory 
................................................................................
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */
          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
          sqlite3CloseSavepoints(db);
          db->autoCommit = 1;

        }
      }
    }

    /* Check for immediate foreign key violations. */
    if( p->rc==SQLITE_OK ){
      sqlite3VdbeCheckFk(p, 0);
................................................................................
        }
        if( rc==SQLITE_BUSY && p->readOnly ){
          sqlite3VdbeLeave(p);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db, SQLITE_OK);

        }else{
          db->nDeferredCons = 0;
          db->nDeferredImmCons = 0;
          db->flags &= ~SQLITE_DeferFKs;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);

      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){
      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
        eStatementOp = SAVEPOINT_RELEASE;
      }else if( p->errorAction==OE_Abort ){
        eStatementOp = SAVEPOINT_ROLLBACK;
      }else{
        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;

      }
    }
  
    /* If eStatementOp is non-zero, then a statement transaction needs to
    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
    ** do so. If this operation returns an error, and the current statement
    ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the
................................................................................
          p->rc = rc;
          sqlite3DbFree(db, p->zErrMsg);
          p->zErrMsg = 0;
        }
        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;

      }
    }
  
    /* If this was an INSERT, UPDATE or DELETE and no statement transaction
    ** has been rolled back, update the database connection change-counter. 
    */
    if( p->changeCntOn ){
................................................................................
    sqlite3DbFree(db, pSub);
  }
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);






}

/*
** Delete an entire VDBE.
*/
void sqlite3VdbeDelete(Vdbe *p){
  sqlite3 *db;
................................................................................
  }
  if( flags&MEM_Int ){
    /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */
#   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
    i64 i = pMem->u.i;
    u64 u;
    if( i<0 ){
      if( i<(-MAX_6BYTE) ) return 6;
      /* Previous test prevents:  u = -(-9223372036854775808) */
      u = -i;
    }else{
      u = i;
    }
    if( u<=127 ){
      return ((i&1)==i && file_format>=4) ? 8+(u32)u : 1;
    }
    if( u<=32767 ) return 2;
................................................................................
  u32 serial_type,              /* Serial type to deserialize */
  Mem *pMem                     /* Memory cell to write value into */
){
  u64 x = FOUR_BYTE_UINT(buf);
  u32 y = FOUR_BYTE_UINT(buf+4);
  x = (x<<32) + y;
  if( serial_type==6 ){


    pMem->u.i = *(i64*)&x;
    pMem->flags = MEM_Int;
    testcase( pMem->u.i<0 );
  }else{


#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
    /* Verify that integers and floating point values use the same
    ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
    ** defined that 64-bit floating point values really are mixed
    ** endian.
    */
    static const u64 t1 = ((u64)0x3ff00000)<<32;
................................................................................
  const unsigned char *buf,     /* Buffer to deserialize from */
  u32 serial_type,              /* Serial type to deserialize */
  Mem *pMem                     /* Memory cell to write value into */
){
  switch( serial_type ){
    case 10:   /* Reserved for future use */
    case 11:   /* Reserved for future use */
    case 0: {  /* NULL */

      pMem->flags = MEM_Null;
      break;
    }
    case 1: { /* 1-byte signed integer */


      pMem->u.i = ONE_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 1;
    }
    case 2: { /* 2-byte signed integer */


      pMem->u.i = TWO_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 2;
    }
    case 3: { /* 3-byte signed integer */


      pMem->u.i = THREE_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 3;
    }
    case 4: { /* 4-byte signed integer */


      pMem->u.i = FOUR_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 4;
    }
    case 5: { /* 6-byte signed integer */


      pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 6;
    }
    case 6:   /* 8-byte signed integer */
    case 7: { /* IEEE floating point */
      /* These use local variables, so do them in a separate routine
      ** to avoid having to move the frame pointer in the common case */
      return serialGet(buf,serial_type,pMem);
    }
    case 8:    /* Integer 0 */
    case 9: {  /* Integer 1 */


      pMem->u.i = serial_type-8;
      pMem->flags = MEM_Int;
      return 0;
    }
    default: {




      static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
      pMem->z = (char *)buf;
      pMem->n = (serial_type-12)/2;
      pMem->flags = aFlag[serial_type&1];
      return pMem->n;
    }
  }

      }
#endif
    }
    p->nOp += nOp;
  }
  return addr;
}

#if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
/*
** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().
*/
void sqlite3VdbeScanStatus(
  Vdbe *p,                        /* VM to add scanstatus() to */
  int addrExplain,                /* Address of OP_Explain (or 0) */
  int addrLoop,                   /* Address of loop counter */ 
  int addrVisit,                  /* Address of rows visited counter */
  LogEst nEst,                    /* Estimated number of output rows */
  const char *zName               /* Name of table or index being scanned */
){
  int nByte = (p->nScan+1) * sizeof(ScanStatus);
  ScanStatus *aNew;
  aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);
  if( aNew ){
    ScanStatus *pNew = &aNew[p->nScan++];
    pNew->addrExplain = addrExplain;
    pNew->addrLoop = addrLoop;
    pNew->addrVisit = addrVisit;
    pNew->nEst = nEst;
    pNew->zName = sqlite3DbStrDup(p->db, zName);
    p->aScan = aNew;
  }
}
#endif


/*
** Change the value of the P1 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
*/
................................................................................
    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
                          &zCsr, zEnd, &nByte);
    p->aOnceFlag = allocSpace(p->aOnceFlag, nOnce, &zCsr, zEnd, &nByte);
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    p->anExec = allocSpace(p->anExec, p->nOp*sizeof(i64), &zCsr, zEnd, &nByte);
#endif
    if( nByte ){
      p->pFree = sqlite3DbMallocZero(db, nByte);
    }
    zCsr = p->pFree;
    zEnd = &zCsr[nByte];
  }while( nByte && !db->mallocFailed );

................................................................................
/*
** Copy the values stored in the VdbeFrame structure to its Vdbe. This
** is used, for example, when a trigger sub-program is halted to restore
** control to the main program.
*/
int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
  Vdbe *v = pFrame->v;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  v->anExec = pFrame->anExec;
#endif
  v->aOnceFlag = pFrame->aOnceFlag;
  v->nOnceFlag = pFrame->nOnceFlag;
  v->aOp = pFrame->aOp;
  v->nOp = pFrame->nOp;
  v->aMem = pFrame->aMem;
  v->nMem = pFrame->nMem;
  v->apCsr = pFrame->apCsr;
  v->nCursor = pFrame->nCursor;
  v->db->lastRowid = pFrame->lastRowid;
  v->nChange = pFrame->nChange;
  v->db->nChange = pFrame->nDbChange;
  return pFrame->pc;
}

/*
** Close all cursors.
**
** Also release any dynamic memory held by the VM in the Vdbe.aMem memory 
................................................................................
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */
          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
          sqlite3CloseSavepoints(db);
          db->autoCommit = 1;
          p->nChange = 0;
        }
      }
    }

    /* Check for immediate foreign key violations. */
    if( p->rc==SQLITE_OK ){
      sqlite3VdbeCheckFk(p, 0);
................................................................................
        }
        if( rc==SQLITE_BUSY && p->readOnly ){
          sqlite3VdbeLeave(p);
          return SQLITE_BUSY;
        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db, SQLITE_OK);
          p->nChange = 0;
        }else{
          db->nDeferredCons = 0;
          db->nDeferredImmCons = 0;
          db->flags &= ~SQLITE_DeferFKs;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);
        p->nChange = 0;
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){
      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
        eStatementOp = SAVEPOINT_RELEASE;
      }else if( p->errorAction==OE_Abort ){
        eStatementOp = SAVEPOINT_ROLLBACK;
      }else{
        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
        p->nChange = 0;
      }
    }
  
    /* If eStatementOp is non-zero, then a statement transaction needs to
    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
    ** do so. If this operation returns an error, and the current statement
    ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the
................................................................................
          p->rc = rc;
          sqlite3DbFree(db, p->zErrMsg);
          p->zErrMsg = 0;
        }
        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
        sqlite3CloseSavepoints(db);
        db->autoCommit = 1;
        p->nChange = 0;
      }
    }
  
    /* If this was an INSERT, UPDATE or DELETE and no statement transaction
    ** has been rolled back, update the database connection change-counter. 
    */
    if( p->changeCntOn ){
................................................................................
    sqlite3DbFree(db, pSub);
  }
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  for(i=0; i<p->nScan; i++){
    sqlite3DbFree(db, p->aScan[i].zName);
  }
  sqlite3DbFree(db, p->aScan);
#endif
}

/*
** Delete an entire VDBE.
*/
void sqlite3VdbeDelete(Vdbe *p){
  sqlite3 *db;
................................................................................
  }
  if( flags&MEM_Int ){
    /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */
#   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
    i64 i = pMem->u.i;
    u64 u;
    if( i<0 ){


      u = ~i;
    }else{
      u = i;
    }
    if( u<=127 ){
      return ((i&1)==i && file_format>=4) ? 8+(u32)u : 1;
    }
    if( u<=32767 ) return 2;
................................................................................
  u32 serial_type,              /* Serial type to deserialize */
  Mem *pMem                     /* Memory cell to write value into */
){
  u64 x = FOUR_BYTE_UINT(buf);
  u32 y = FOUR_BYTE_UINT(buf+4);
  x = (x<<32) + y;
  if( serial_type==6 ){
    /* EVIDENCE-OF: R-29851-52272 Value is a big-endian 64-bit
    ** twos-complement integer. */
    pMem->u.i = *(i64*)&x;
    pMem->flags = MEM_Int;
    testcase( pMem->u.i<0 );
  }else{
    /* EVIDENCE-OF: R-57343-49114 Value is a big-endian IEEE 754-2008 64-bit
    ** floating point number. */
#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
    /* Verify that integers and floating point values use the same
    ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
    ** defined that 64-bit floating point values really are mixed
    ** endian.
    */
    static const u64 t1 = ((u64)0x3ff00000)<<32;
................................................................................
  const unsigned char *buf,     /* Buffer to deserialize from */
  u32 serial_type,              /* Serial type to deserialize */
  Mem *pMem                     /* Memory cell to write value into */
){
  switch( serial_type ){
    case 10:   /* Reserved for future use */
    case 11:   /* Reserved for future use */
    case 0: {  /* Null */
      /* EVIDENCE-OF: R-24078-09375 Value is a NULL. */
      pMem->flags = MEM_Null;
      break;
    }
    case 1: {
      /* EVIDENCE-OF: R-44885-25196 Value is an 8-bit twos-complement
      ** integer. */
      pMem->u.i = ONE_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 1;
    }
    case 2: { /* 2-byte signed integer */
      /* EVIDENCE-OF: R-49794-35026 Value is a big-endian 16-bit
      ** twos-complement integer. */
      pMem->u.i = TWO_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 2;
    }
    case 3: { /* 3-byte signed integer */
      /* EVIDENCE-OF: R-37839-54301 Value is a big-endian 24-bit
      ** twos-complement integer. */
      pMem->u.i = THREE_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 3;
    }
    case 4: { /* 4-byte signed integer */
      /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit
      ** twos-complement integer. */
      pMem->u.i = FOUR_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 4;
    }
    case 5: { /* 6-byte signed integer */
      /* EVIDENCE-OF: R-50385-09674 Value is a big-endian 48-bit
      ** twos-complement integer. */
      pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
      pMem->flags = MEM_Int;
      testcase( pMem->u.i<0 );
      return 6;
    }
    case 6:   /* 8-byte signed integer */
    case 7: { /* IEEE floating point */
      /* These use local variables, so do them in a separate routine
      ** to avoid having to move the frame pointer in the common case */
      return serialGet(buf,serial_type,pMem);
    }
    case 8:    /* Integer 0 */
    case 9: {  /* Integer 1 */
      /* EVIDENCE-OF: R-12976-22893 Value is the integer 0. */
      /* EVIDENCE-OF: R-18143-12121 Value is the integer 1. */
      pMem->u.i = serial_type-8;
      pMem->flags = MEM_Int;
      return 0;
    }
    default: {
      /* EVIDENCE-OF: R-14606-31564 Value is a BLOB that is (N-12)/2 bytes in
      ** length.
      ** EVIDENCE-OF: R-28401-00140 Value is a string in the text encoding and
      ** (N-13)/2 bytes in length. */
      static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
      pMem->z = (char *)buf;
      pMem->n = (serial_type-12)/2;
      pMem->flags = aFlag[serial_type&1];
      return pMem->n;
    }
  }

  int rc = SQLITE_OK;
  char *zErr = 0;
  Table *pTab;
  Parse *pParse = 0;
  Incrblob *pBlob = 0;






  flags = !!flags;                /* flags = (flags ? 1 : 0); */
  *ppBlob = 0;

  sqlite3_mutex_enter(db->mutex);

  pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
  if( !pBlob ) goto blob_open_out;
................................................................................
  db = p->db;
  sqlite3_mutex_enter(db->mutex);
  v = (Vdbe*)p->pStmt;

  if( n<0 || iOffset<0 || (iOffset+n)>p->nByte ){
    /* Request is out of range. Return a transient error. */
    rc = SQLITE_ERROR;
    sqlite3Error(db, SQLITE_ERROR);
  }else if( v==0 ){
    /* If there is no statement handle, then the blob-handle has
    ** already been invalidated. Return SQLITE_ABORT in this case.
    */
    rc = SQLITE_ABORT;
  }else{
    /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
................................................................................
    sqlite3BtreeEnterCursor(p->pCsr);
    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
    sqlite3BtreeLeaveCursor(p->pCsr);
    if( rc==SQLITE_ABORT ){
      sqlite3VdbeFinalize(v);
      p->pStmt = 0;
    }else{
      db->errCode = rc;
      v->rc = rc;
    }
  }

  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Read data from a blob handle.

  int rc = SQLITE_OK;
  char *zErr = 0;
  Table *pTab;
  Parse *pParse = 0;
  Incrblob *pBlob = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || ppBlob==0 || zTable==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  flags = !!flags;                /* flags = (flags ? 1 : 0); */
  *ppBlob = 0;

  sqlite3_mutex_enter(db->mutex);

  pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
  if( !pBlob ) goto blob_open_out;
................................................................................
  db = p->db;
  sqlite3_mutex_enter(db->mutex);
  v = (Vdbe*)p->pStmt;

  if( n<0 || iOffset<0 || (iOffset+n)>p->nByte ){
    /* Request is out of range. Return a transient error. */
    rc = SQLITE_ERROR;

  }else if( v==0 ){
    /* If there is no statement handle, then the blob-handle has
    ** already been invalidated. Return SQLITE_ABORT in this case.
    */
    rc = SQLITE_ABORT;
  }else{
    /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
................................................................................
    sqlite3BtreeEnterCursor(p->pCsr);
    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
    sqlite3BtreeLeaveCursor(p->pCsr);
    if( rc==SQLITE_ABORT ){
      sqlite3VdbeFinalize(v);
      p->pStmt = 0;
    }else{

      v->rc = rc;
    }
  }
  sqlite3Error(db, rc);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Read data from a blob handle.

** calling thread usually launches a worker thread to do so. Except, if
** there are already N worker threads running, the main thread does the work
** itself.
**
** The sorter is running in multi-threaded mode if (a) the library was built
** with pre-processor symbol SQLITE_MAX_WORKER_THREADS set to a value greater
** than zero, and (b) worker threads have been enabled at runtime by calling
** sqlite3_config(SQLITE_CONFIG_WORKER_THREADS, ...).
**
** When Rewind() is called, any data remaining in memory is flushed to a 
** final PMA. So at this point the data is stored in some number of sorted
** PMAs within temporary files on disk.
**
** If there are fewer than SORTER_MAX_MERGE_COUNT PMAs in total and the
** sorter is running in single-threaded mode, then these PMAs are merged
................................................................................

    if( !sqlite3TempInMemory(db) ){
      pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
      mxCache = db->aDb[0].pSchema->cache_size;
      if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
      pSorter->mxPmaSize = mxCache * pgsz;

      /* If the application has not configure scratch memory using
      ** SQLITE_CONFIG_SCRATCH then we assume it is OK to do large memory
      ** allocations.  If scratch memory has been configured, then assume
      ** large memory allocations should be avoided to prevent heap
      ** fragmentation.
      */
      if( sqlite3GlobalConfig.pScratch==0 ){
        assert( pSorter->iMemory==0 );
        pSorter->nMemory = pgsz;
        pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);
        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM;
      }

** calling thread usually launches a worker thread to do so. Except, if
** there are already N worker threads running, the main thread does the work
** itself.
**
** The sorter is running in multi-threaded mode if (a) the library was built
** with pre-processor symbol SQLITE_MAX_WORKER_THREADS set to a value greater
** than zero, and (b) worker threads have been enabled at runtime by calling
** "PRAGMA threads=N" with some value of N greater than 0.
**
** When Rewind() is called, any data remaining in memory is flushed to a 
** final PMA. So at this point the data is stored in some number of sorted
** PMAs within temporary files on disk.
**
** If there are fewer than SORTER_MAX_MERGE_COUNT PMAs in total and the
** sorter is running in single-threaded mode, then these PMAs are merged
................................................................................

    if( !sqlite3TempInMemory(db) ){
      pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
      mxCache = db->aDb[0].pSchema->cache_size;
      if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
      pSorter->mxPmaSize = mxCache * pgsz;

      /* EVIDENCE-OF: R-26747-61719 When the application provides any amount of
      ** scratch memory using SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary
      ** large heap allocations.


      */
      if( sqlite3GlobalConfig.pScratch==0 ){
        assert( pSorter->iMemory==0 );
        pSorter->nMemory = pgsz;
        pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);
        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM;
      }

*/
int sqlite3_create_module(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
  const sqlite3_module *pModule,  /* The definition of the module */
  void *pAux                      /* Context pointer for xCreate/xConnect */
){



  return createModule(db, zName, pModule, pAux, 0);
}

/*
** External API function used to create a new virtual-table module.
*/
int sqlite3_create_module_v2(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
  const sqlite3_module *pModule,  /* The definition of the module */
  void *pAux,                     /* Context pointer for xCreate/xConnect */
  void (*xDestroy)(void *)        /* Module destructor function */
){



  return createModule(db, zName, pModule, pAux, xDestroy);
}

/*
** Lock the virtual table so that it cannot be disconnected.
** Locks nest.  Every lock should have a corresponding unlock.
** If an unlock is omitted, resources leaks will occur.  
................................................................................
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  Parse *pParse;

  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;




  sqlite3_mutex_enter(db->mutex);
  if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
    sqlite3Error(db, SQLITE_MISUSE);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE_BKPT;
  }
  assert( (pTab->tabFlags & TF_Virtual)!=0 );
................................................................................
** The results of this routine are undefined unless it is called from
** within an xUpdate method.
*/
int sqlite3_vtab_on_conflict(sqlite3 *db){
  static const unsigned char aMap[] = { 
    SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 
  };



  assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
  assert( OE_Ignore==4 && OE_Replace==5 );
  assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
  return (int)aMap[db->vtabOnConflict-1];
}

/*
................................................................................
** the SQLite core with additional information about the behavior
** of the virtual table being implemented.
*/
int sqlite3_vtab_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc = SQLITE_OK;




  sqlite3_mutex_enter(db->mutex);

  va_start(ap, op);
  switch( op ){
    case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
      VtabCtx *p = db->pVtabCtx;
      if( !p ){
        rc = SQLITE_MISUSE_BKPT;
      }else{

*/
int sqlite3_create_module(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
  const sqlite3_module *pModule,  /* The definition of the module */
  void *pAux                      /* Context pointer for xCreate/xConnect */
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  return createModule(db, zName, pModule, pAux, 0);
}

/*
** External API function used to create a new virtual-table module.
*/
int sqlite3_create_module_v2(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
  const sqlite3_module *pModule,  /* The definition of the module */
  void *pAux,                     /* Context pointer for xCreate/xConnect */
  void (*xDestroy)(void *)        /* Module destructor function */
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  return createModule(db, zName, pModule, pAux, xDestroy);
}

/*
** Lock the virtual table so that it cannot be disconnected.
** Locks nest.  Every lock should have a corresponding unlock.
** If an unlock is omitted, resources leaks will occur.  
................................................................................
int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  Parse *pParse;

  int rc = SQLITE_OK;
  Table *pTab;
  char *zErr = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
    sqlite3Error(db, SQLITE_MISUSE);
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_MISUSE_BKPT;
  }
  assert( (pTab->tabFlags & TF_Virtual)!=0 );
................................................................................
** The results of this routine are undefined unless it is called from
** within an xUpdate method.
*/
int sqlite3_vtab_on_conflict(sqlite3 *db){
  static const unsigned char aMap[] = { 
    SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 
  };
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
  assert( OE_Ignore==4 && OE_Replace==5 );
  assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
  return (int)aMap[db->vtabOnConflict-1];
}

/*
................................................................................
** the SQLite core with additional information about the behavior
** of the virtual table being implemented.
*/
int sqlite3_vtab_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc = SQLITE_OK;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);

  va_start(ap, op);
  switch( op ){
    case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
      VtabCtx *p = db->pVtabCtx;
      if( !p ){
        rc = SQLITE_MISUSE_BKPT;
      }else{

#endif
}

/* 
** Free an iterator allocated by walIteratorInit().
*/
static void walIteratorFree(WalIterator *p){
  sqlite3ScratchFree(p);
}

/*
** Construct a WalInterator object that can be used to loop over all 
** pages in the WAL in ascending order. The caller must hold the checkpoint
** lock.
**
................................................................................
  iLast = pWal->hdr.mxFrame;

  /* Allocate space for the WalIterator object. */
  nSegment = walFramePage(iLast) + 1;
  nByte = sizeof(WalIterator) 
        + (nSegment-1)*sizeof(struct WalSegment)
        + iLast*sizeof(ht_slot);
  p = (WalIterator *)sqlite3ScratchMalloc(nByte);
  if( !p ){
    return SQLITE_NOMEM;
  }
  memset(p, 0, nByte);
  p->nSegment = nSegment;

  /* Allocate temporary space used by the merge-sort routine. This block
  ** of memory will be freed before this function returns.
  */
  aTmp = (ht_slot *)sqlite3ScratchMalloc(
      sizeof(ht_slot) * (iLast>HASHTABLE_NPAGE?HASHTABLE_NPAGE:iLast)
  );
  if( !aTmp ){
    rc = SQLITE_NOMEM;
  }

  for(i=0; rc==SQLITE_OK && i<nSegment; i++){
................................................................................
      walMergesort((u32 *)aPgno, aTmp, aIndex, &nEntry);
      p->aSegment[i].iZero = iZero;
      p->aSegment[i].nEntry = nEntry;
      p->aSegment[i].aIndex = aIndex;
      p->aSegment[i].aPgno = (u32 *)aPgno;
    }
  }
  sqlite3ScratchFree(aTmp);

  if( rc!=SQLITE_OK ){
    walIteratorFree(p);
    p = 0;
  }
  *pp = p;
  return rc;
................................................................................
      ** committed. As a result, the call to xUndo may not fail.
      */
      assert( walFramePgno(pWal, iFrame)!=1 );
      rc = xUndo(pUndoCtx, walFramePgno(pWal, iFrame));
    }
    if( iMax!=pWal->hdr.mxFrame ) walCleanupHash(pWal);
  }
  assert( rc==SQLITE_OK );
  return rc;
}

/* 
** Argument aWalData must point to an array of WAL_SAVEPOINT_NDATA u32 
** values. This function populates the array with values required to 
** "rollback" the write position of the WAL handle back to the current 

#endif
}

/* 
** Free an iterator allocated by walIteratorInit().
*/
static void walIteratorFree(WalIterator *p){
  sqlite3_free(p);
}

/*
** Construct a WalInterator object that can be used to loop over all 
** pages in the WAL in ascending order. The caller must hold the checkpoint
** lock.
**
................................................................................
  iLast = pWal->hdr.mxFrame;

  /* Allocate space for the WalIterator object. */
  nSegment = walFramePage(iLast) + 1;
  nByte = sizeof(WalIterator) 
        + (nSegment-1)*sizeof(struct WalSegment)
        + iLast*sizeof(ht_slot);
  p = (WalIterator *)sqlite3_malloc(nByte);
  if( !p ){
    return SQLITE_NOMEM;
  }
  memset(p, 0, nByte);
  p->nSegment = nSegment;

  /* Allocate temporary space used by the merge-sort routine. This block
  ** of memory will be freed before this function returns.
  */
  aTmp = (ht_slot *)sqlite3_malloc(
      sizeof(ht_slot) * (iLast>HASHTABLE_NPAGE?HASHTABLE_NPAGE:iLast)
  );
  if( !aTmp ){
    rc = SQLITE_NOMEM;
  }

  for(i=0; rc==SQLITE_OK && i<nSegment; i++){
................................................................................
      walMergesort((u32 *)aPgno, aTmp, aIndex, &nEntry);
      p->aSegment[i].iZero = iZero;
      p->aSegment[i].nEntry = nEntry;
      p->aSegment[i].aIndex = aIndex;
      p->aSegment[i].aPgno = (u32 *)aPgno;
    }
  }
  sqlite3_free(aTmp);

  if( rc!=SQLITE_OK ){
    walIteratorFree(p);
    p = 0;
  }
  *pp = p;
  return rc;
................................................................................
      ** committed. As a result, the call to xUndo may not fail.
      */
      assert( walFramePgno(pWal, iFrame)!=1 );
      rc = xUndo(pUndoCtx, walFramePgno(pWal, iFrame));
    }
    if( iMax!=pWal->hdr.mxFrame ) walCleanupHash(pWal);
  }

  return rc;
}

/* 
** Argument aWalData must point to an array of WAL_SAVEPOINT_NDATA u32 
** values. This function populates the array with values required to 
** "rollback" the write position of the WAL handle back to the current 

    if( pOld!=pWC->aStatic ){
      sqlite3DbFree(db, pOld);
    }
    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
  }
  pTerm = &pWC->a[idx = pWC->nTerm++];
  if( p && ExprHasProperty(p, EP_Unlikely) ){
    pTerm->truthProb = sqlite3LogEst(p->iTable) - 99;
  }else{
    pTerm->truthProb = 1;
  }
  pTerm->pExpr = sqlite3ExprSkipCollate(p);
  pTerm->wtFlags = wtFlags;
  pTerm->pWC = pWC;
  pTerm->iParent = -1;
................................................................................
*/
static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
  if( pDerived ){
    pDerived->flags |= pBase->flags & EP_FromJoin;
    pDerived->iRightJoinTable = pBase->iRightJoinTable;
  }
}










#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
/*
** Analyze a term that consists of two or more OR-connected
** subterms.  So in:
**
**     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
................................................................................
        transferJoinMarkings(pNew, pExpr);
        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
        pNew->x.pList = pList;
        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
        testcase( idxNew==0 );
        exprAnalyze(pSrc, pWC, idxNew);
        pTerm = &pWC->a[idxTerm];
        pWC->a[idxNew].iParent = idxTerm;
        pTerm->nChild = 1;
      }else{
        sqlite3ExprListDelete(db, pList);
      }
      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 2 */
    }
  }
}
................................................................................
        if( db->mallocFailed ){
          sqlite3ExprDelete(db, pDup);
          return;
        }
        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
        if( idxNew==0 ) return;
        pNew = &pWC->a[idxNew];
        pNew->iParent = idxTerm;
        pTerm = &pWC->a[idxTerm];
        pTerm->nChild = 1;
        pTerm->wtFlags |= TERM_COPIED;
        if( pExpr->op==TK_EQ
         && !ExprHasProperty(pExpr, EP_FromJoin)
         && OptimizationEnabled(db, SQLITE_Transitive)
        ){
          pTerm->eOperator |= WO_EQUIV;
          eExtraOp = WO_EQUIV;
................................................................................
                             sqlite3ExprDup(db, pExpr->pLeft, 0),
                             sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
      transferJoinMarkings(pNewExpr, pExpr);
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      exprAnalyze(pSrc, pWC, idxNew);
      pTerm = &pWC->a[idxTerm];
      pWC->a[idxNew].iParent = idxTerm;
    }
    pTerm->nChild = 2;
  }
#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */

#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
  /* Analyze a term that is composed of two or more subterms connected by
  ** an OR operator.
  */
................................................................................
           pStr2, 0);
    transferJoinMarkings(pNewExpr2, pExpr);
    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew2==0 );
    exprAnalyze(pSrc, pWC, idxNew2);
    pTerm = &pWC->a[idxTerm];
    if( isComplete ){
      pWC->a[idxNew1].iParent = idxTerm;
      pWC->a[idxNew2].iParent = idxTerm;
      pTerm->nChild = 2;
    }
  }
#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */

#ifndef SQLITE_OMIT_VIRTUALTABLE
  /* Add a WO_MATCH auxiliary term to the constraint set if the
  ** current expression is of the form:  column MATCH expr.
................................................................................
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      pNewTerm = &pWC->a[idxNew];
      pNewTerm->prereqRight = prereqExpr;
      pNewTerm->leftCursor = pLeft->iTable;
      pNewTerm->u.leftColumn = pLeft->iColumn;
      pNewTerm->eOperator = WO_MATCH;
      pNewTerm->iParent = idxTerm;
      pTerm = &pWC->a[idxTerm];
      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
................................................................................
  ** TERM_VNULL tag will suppress the not-null check at the beginning
  ** of the loop.  Without the TERM_VNULL flag, the not-null check at
  ** the start of the loop will prevent any results from being returned.
  */
  if( pExpr->op==TK_NOTNULL
   && pExpr->pLeft->op==TK_COLUMN
   && pExpr->pLeft->iColumn>=0
   && OptimizationEnabled(db, SQLITE_Stat3)
  ){
    Expr *pNewExpr;
    Expr *pLeft = pExpr->pLeft;
    int idxNew;
    WhereTerm *pNewTerm;

    pNewExpr = sqlite3PExpr(pParse, TK_GT,
................................................................................
                              TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
    if( idxNew ){
      pNewTerm = &pWC->a[idxNew];
      pNewTerm->prereqRight = 0;
      pNewTerm->leftCursor = pLeft->iTable;
      pNewTerm->u.leftColumn = pLeft->iColumn;
      pNewTerm->eOperator = WO_GT;
      pNewTerm->iParent = idxTerm;
      pTerm = &pWC->a[idxTerm];
      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
................................................................................
  int mxBitCol;               /* Maximum column in pSrc->colUsed */
  CollSeq *pColl;             /* Collating sequence to on a column */
  WhereLoop *pLoop;           /* The Loop object */
  char *zNotUsed;             /* Extra space on the end of pIdx */
  Bitmask idxCols;            /* Bitmap of columns used for indexing */
  Bitmask extraCols;          /* Bitmap of additional columns */
  u8 sentWarning = 0;         /* True if a warnning has been issued */



  /* Generate code to skip over the creation and initialization of the
  ** transient index on 2nd and subsequent iterations of the loop. */
  v = pParse->pVdbe;
  assert( v!=0 );
  addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v);

................................................................................
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;
  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){






    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol = pTerm->u.leftColumn;
      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
      testcase( iCol==BMS );
      testcase( iCol==BMS-1 );
      if( !sentWarning ){
        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
            "automatic index on %s(%s)", pTable->zName,
            pTable->aCol[iCol].zName);
        sentWarning = 1;
      }
      if( (idxCols & cMask)==0 ){
        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ) return;


        pLoop->aLTerm[nKeyCol++] = pTerm;
        idxCols |= cMask;
      }
    }
  }
  assert( nKeyCol>0 );
  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
................................................................................
  ** columns that are needed by the query.  With a covering index, the
  ** original table never needs to be accessed.  Automatic indices must
  ** be a covering index because the index will not be updated if the
  ** original table changes and the index and table cannot both be used
  ** if they go out of sync.
  */
  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
  mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol;
  testcase( pTable->nCol==BMS-1 );
  testcase( pTable->nCol==BMS-2 );
  for(i=0; i<mxBitCol; i++){
    if( extraCols & MASKBIT(i) ) nKeyCol++;
  }
  if( pSrc->colUsed & MASKBIT(BMS-1) ){
    nKeyCol += pTable->nCol - BMS + 1;
  }
  pLoop->wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY;

  /* Construct the Index object to describe this index */
  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
  if( pIdx==0 ) return;
  pLoop->u.btree.pIndex = pIdx;
  pIdx->zName = "auto-index";
  pIdx->pTable = pTable;
  n = 0;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
................................................................................
  assert( pLevel->iIdxCur>=0 );
  pLevel->iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
  VdbeComment((v, "for %s", pTable->zName));

  /* Fill the automatic index with content */

  addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);





  regRecord = sqlite3GetTempReg(pParse);
  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
  sqlite3VdbeJumpHere(v, addrTop);
  sqlite3ReleaseTempReg(pParse, regRecord);

  
  /* Jump here when skipping the initialization */
  sqlite3VdbeJumpHere(v, addrInit);



}
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Allocate and populate an sqlite3_index_info structure. It is the 
** responsibility of the caller to eventually release the structure
................................................................................
    }
  }

  return pParse->nErr;
}
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */


#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Estimate the location of a particular key among all keys in an
** index.  Store the results in aStat as follows:
**
**    aStat[0]      Est. number of rows less than pVal
**    aStat[1]      Est. number of rows equal to pVal
**
** Return SQLITE_OK on success.

*/
static void whereKeyStats(
  Parse *pParse,              /* Database connection */
  Index *pIdx,                /* Index to consider domain of */
  UnpackedRecord *pRec,       /* Vector of values to consider */
  int roundUp,                /* Round up if true.  Round down if false */
  tRowcnt *aStat              /* OUT: stats written here */
){
  IndexSample *aSample = pIdx->aSample;
................................................................................
    if( roundUp ){
      iGap = (iGap*2)/3;
    }else{
      iGap = iGap/3;
    }
    aStat[0] = iLower + iGap;
  }

}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

/*
** If it is not NULL, pTerm is a term that provides an upper or lower
** bound on a range scan. Without considering pTerm, it is estimated 
** that the scan will visit nNew rows. This function returns the number
................................................................................
**                    |_____|   |_____|
**                       |         |
**                     pLower    pUpper
**
** If either of the upper or lower bound is not present, then NULL is passed in
** place of the corresponding WhereTerm.
**
** The value in (pBuilder->pNew->u.btree.nEq) is the index of the index
** column subject to the range constraint. Or, equivalently, the number of
** equality constraints optimized by the proposed index scan. For example,
** assuming index p is on t1(a, b), and the SQL query is:
**
**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
**
** then nEq is set to 1 (as the range restricted column, b, is the second 
................................................................................
**
**   ... FROM t1 WHERE a > ? AND a < ? ...
**
** then nEq is set to 0.
**
** When this function is called, *pnOut is set to the sqlite3LogEst() of the
** number of rows that the index scan is expected to visit without 
** considering the range constraints. If nEq is 0, this is the number of 
** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
** to account for the range constraints pLower and pUpper.
** 
** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
** used, a single range inequality reduces the search space by a factor of 4. 
** and a pair of constraints (x>? AND x<?) reduces the expected number of
** rows visited by a factor of 64.
................................................................................
  int nOut = pLoop->nOut;
  LogEst nNew;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  Index *p = pLoop->u.btree.pIndex;
  int nEq = pLoop->u.btree.nEq;

  if( p->nSample>0
   && nEq<p->nSampleCol
   && OptimizationEnabled(pParse->db, SQLITE_Stat3) 
  ){
    if( nEq==pBuilder->nRecValid ){
      UnpackedRecord *pRec = pBuilder->pRec;
      tRowcnt a[2];
      u8 aff;

      /* Variable iLower will be set to the estimate of the number of rows in 
      ** the index that are less than the lower bound of the range query. The
................................................................................
      ** key-prefix formed by the nEq values matched against the nEq left-most
      ** columns of the index, and $L is the value in pLower.
      **
      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
      ** is not a simple variable or literal value), the lower bound of the
      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
      ** if $L is available, whereKeyStats() is called for both ($P) and 
      ** ($P:$L) and the larger of the two returned values used.
      **
      ** Similarly, iUpper is to be set to the estimate of the number of rows
      ** less than the upper bound of the range query. Where the upper bound
      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
      ** of iUpper are requested of whereKeyStats() and the smaller used.


      */
      tRowcnt iLower;
      tRowcnt iUpper;



      if( pRec ){
        testcase( pRec->nField!=pBuilder->nRecValid );
        pRec->nField = pBuilder->nRecValid;
      }
      if( nEq==p->nKeyCol ){
        aff = SQLITE_AFF_INTEGER;
      }else{
        aff = p->pTable->aCol[p->aiColumn[nEq]].affinity;
      }
      /* Determine iLower and iUpper using ($P) only. */
      if( nEq==0 ){
        iLower = 0;
        iUpper = sqlite3LogEstToInt(p->aiRowLogEst[0]);
      }else{
        /* Note: this call could be optimized away - since the same values must 
        ** have been requested when testing key $P in whereEqualScanEst().  */
        whereKeyStats(pParse, p, pRec, 0, a);
        iLower = a[0];
        iUpper = a[0] + a[1];
      }
................................................................................
      /* If possible, improve on the iLower estimate using ($P:$L). */
      if( pLower ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pLower->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          whereKeyStats(pParse, p, pRec, 0, a);
          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew>iLower ) iLower = iNew;
          nOut--;
          pLower = 0;
        }
      }

................................................................................
      /* If possible, improve on the iUpper estimate using ($P:$U). */
      if( pUpper ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pUpper->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          whereKeyStats(pParse, p, pRec, 1, a);
          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew<iUpper ) iUpper = iNew;
          nOut--;
          pUpper = 0;
        }
      }

      pBuilder->pRec = pRec;
      if( rc==SQLITE_OK ){
        if( iUpper>iLower ){
          nNew = sqlite3LogEst(iUpper - iLower);





        }else{
          nNew = 10;        assert( 10==sqlite3LogEst(2) );
        }
        if( nNew<nOut ){
          nOut = nNew;
        }
        WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",
................................................................................
  UNUSED_PARAMETER(pBuilder);
  assert( pLower || pUpper );
#endif
  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
  nNew = whereRangeAdjust(pLower, nOut);
  nNew = whereRangeAdjust(pUpper, nNew);

  /* TUNING: If there is both an upper and lower limit, assume the range is

  ** reduced by an additional 75%. This means that, by default, an open-ended
  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
  ** match 1/64 of the index. */ 

  if( pLower && pUpper ) nNew -= 20;


  nOut -= (pLower!=0) + (pUpper!=0);
  if( nNew<10 ) nNew = 10;
  if( nNew<nOut ) nOut = nNew;
#if defined(WHERETRACE_ENABLED)
  if( pLoop->nOut>nOut ){
    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
................................................................................
  int nReg;                     /* Number of registers to allocate */
  char *zAff;                   /* Affinity string to return */

  /* This module is only called on query plans that use an index. */
  pLoop = pLevel->pWLoop;
  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
  nEq = pLoop->u.btree.nEq;
  nSkip = pLoop->u.btree.nSkip;
  pIdx = pLoop->u.btree.pIndex;
  assert( pIdx!=0 );

  /* Figure out how many memory cells we will need then allocate them.
  */
  regBase = pParse->nMem + 1;
  nReg = pLoop->u.btree.nEq + nExtraReg;
................................................................................
** string similar to:
**
**   "a=? AND b>?"
*/
static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
  Index *pIndex = pLoop->u.btree.pIndex;
  u16 nEq = pLoop->u.btree.nEq;
  u16 nSkip = pLoop->u.btree.nSkip;
  int i, j;
  Column *aCol = pTab->aCol;
  i16 *aiColumn = pIndex->aiColumn;

  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
  sqlite3StrAccumAppend(pStr, " (", 2);
  for(i=0; i<nEq; i++){
................................................................................
    explainAppendTerm(pStr, i, z, "<");
  }
  sqlite3StrAccumAppend(pStr, ")", 1);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
** command. If the query being compiled is an EXPLAIN QUERY PLAN, a single

** record is added to the output to describe the table scan strategy in 
** pLevel.



*/
static void explainOneScan(
  Parse *pParse,                  /* Parse context */
  SrcList *pTabList,              /* Table list this loop refers to */
  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
  int iLevel,                     /* Value for "level" column of output */
  int iFrom,                      /* Value for "from" column of output */
  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
){
#ifndef SQLITE_DEBUG

  if( pParse->explain==2 )
#endif
  {
    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
    sqlite3 *db = pParse->db;     /* Database handle */
    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
................................................................................
    u32 flags;                    /* Flags that describe this loop */
    char *zMsg;                   /* Text to add to EQP output */
    StrAccum str;                 /* EQP output string */
    char zBuf[100];               /* Initial space for EQP output string */

    pLoop = pLevel->pWLoop;
    flags = pLoop->wsFlags;
    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return;

    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

    sqlite3StrAccumInit(&str, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
    str.db = db;
................................................................................
      assert( pLoop->u.btree.pIndex!=0 );
      pIdx = pLoop->u.btree.pIndex;
      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
        if( isSearch ){
          zFmt = "PRIMARY KEY";
        }


      }else if( flags & WHERE_AUTO_INDEX ){
        zFmt = "AUTOMATIC COVERING INDEX";
      }else if( flags & WHERE_IDX_ONLY ){
        zFmt = "COVERING INDEX %s";
      }else{
        zFmt = "INDEX %s";
      }
................................................................................
    if( pLoop->nOut>=10 ){
      sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
    }else{
      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
    }
#endif
    zMsg = sqlite3StrAccumFinish(&str);
    sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC);
  }

}
#else
# define explainOneScan(u,v,w,x,y,z)
#endif /* SQLITE_OMIT_EXPLAIN */


































/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
static Bitmask codeOneLoopStart(
................................................................................
    char *zStartAff;             /* Affinity for start of range constraint */
    char cEndAff = 0;            /* Affinity for end of range constraint */
    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */

    pIdx = pLoop->u.btree.pIndex;
    iIdxCur = pLevel->iIdxCur;
    assert( nEq>=pLoop->u.btree.nSkip );

    /* If this loop satisfies a sort order (pOrderBy) request that 
    ** was passed to this function to implement a "SELECT min(x) ..." 
    ** query, then the caller will only allow the loop to run for
    ** a single iteration. This means that the first row returned
    ** should not have a NULL value stored in 'x'. If column 'x' is
    ** the first one after the nEq equality constraints in the index,
................................................................................
    assert( pWInfo->pOrderBy==0
         || pWInfo->pOrderBy->nExpr==1
         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
     && pWInfo->nOBSat>0
     && (pIdx->nKeyCol>nEq)
    ){
      assert( pLoop->u.btree.nSkip==0 );
      bSeekPastNull = 1;
      nExtraReg = 1;
    }

    /* Find any inequality constraint terms for the start and end 
    ** of the range. 
    */
................................................................................
        /* Loop through table entries that match term pOrTerm. */
        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
                                      wctrlFlags, iCovCur);
        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
        if( pSubWInfo ){
          WhereLoop *pSubLoop;
          explainOneScan(
              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
          );


          /* This is the sub-WHERE clause body.  First skip over
          ** duplicate rows from prior sub-WHERE clauses, and record the
          ** rowid (or PRIMARY KEY) for the current row so that the same
          ** row will be skipped in subsequent sub-WHERE clauses.
          */
          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
            int r;
................................................................................
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
      VdbeCoverageIf(v, bRev==0);
      VdbeCoverageIf(v, bRev!=0);
      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
    }
  }





  /* Insert code to test every subexpression that can be completely
  ** computed using the current set of tables.
  */
  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
    Expr *pE;
    testcase( pTerm->wtFlags & TERM_VIRTUAL );
................................................................................
    }else{
      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
    }
    sqlite3DebugPrintf(" %-19s", z);
    sqlite3_free(z);
  }
  if( p->wsFlags & WHERE_SKIPSCAN ){
    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->u.btree.nSkip);
  }else{
    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
  }
  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
    int i;
    for(i=0; i<p->nLTerm; i++){
................................................................................
      whereLoopDelete(db, p);
    }
    sqlite3DbFree(db, pWInfo);
  }
}

/*
** Return TRUE if both of the following are true:
**
**   (1)  X has the same or lower cost that Y
**   (2)  X is a proper subset of Y

**
** By "proper subset" we mean that X uses fewer WHERE clause terms
** than Y and that every WHERE clause term used by X is also used
** by Y.
**
** If X is a proper subset of Y then Y is a better choice and ought
** to have a lower cost.  This routine returns TRUE when that cost 
** relationship is inverted and needs to be adjusted.


*/
static int whereLoopCheaperProperSubset(
  const WhereLoop *pX,       /* First WhereLoop to compare */
  const WhereLoop *pY        /* Compare against this WhereLoop */
){
  int i, j;

  if( pX->nLTerm >= pY->nLTerm ) return 0; /* X is not a subset of Y */


  if( pX->rRun >= pY->rRun ){
    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
  }
  for(i=pX->nLTerm-1; i>=0; i--){

    for(j=pY->nLTerm-1; j>=0; j--){
      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
    }
    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
  }
  return 1;  /* All conditions meet */
}
................................................................................
**
**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
**       is a proper subset.
**
** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
** WHERE clause terms than Y and that every WHERE clause term used by X is
** also used by Y.
**
** This adjustment is omitted for SKIPSCAN loops.  In a SKIPSCAN loop, the
** WhereLoop.nLTerm field is not an accurate measure of the number of WHERE
** clause terms covered, since some of the first nLTerm entries in aLTerm[]
** will be NULL (because they are skipped).  That makes it more difficult
** to compare the loops.  We could add extra code to do the comparison, and
** perhaps we will someday.  But SKIPSCAN is sufficiently uncommon, and this
** adjustment is sufficient minor, that it is very difficult to construct
** a test case where the extra code would improve the query plan.  Better
** to avoid the added complexity and just omit cost adjustments to SKIPSCAN
** loops.
*/
static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
  if( (pTemplate->wsFlags & WHERE_SKIPSCAN)!=0 ) return;
  for(; p; p=p->pNextLoop){
    if( p->iTab!=pTemplate->iTab ) continue;
    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
    if( (p->wsFlags & WHERE_SKIPSCAN)!=0 ) continue;
    if( whereLoopCheaperProperSubset(p, pTemplate) ){
      /* Adjust pTemplate cost downward so that it is cheaper than its 
      ** subset p */


      pTemplate->rRun = p->rRun;
      pTemplate->nOut = p->nOut - 1;
    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
      /* Adjust pTemplate cost upward so that it is costlier than p since
      ** pTemplate is a proper subset of p */


      pTemplate->rRun = p->rRun;
      pTemplate->nOut = p->nOut + 1;
    }
  }
}

/*
................................................................................
    /* whereLoopAddBtree() always generates and inserts the automatic index
    ** case first.  Hence compatible candidate WhereLoops never have a larger
    ** rSetup. Call this SETUP-INVARIANT */
    assert( p->rSetup>=pTemplate->rSetup );

    /* Any loop using an appliation-defined index (or PRIMARY KEY or
    ** UNIQUE constraint) with one or more == constraints is better
    ** than an automatic index. */
    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0

     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
    ){
      break;
    }

................................................................................
  WhereLoop *pNew;                /* Template WhereLoop under construction */
  WhereTerm *pTerm;               /* A WhereTerm under consideration */
  int opMask;                     /* Valid operators for constraints */
  WhereScan scan;                 /* Iterator for WHERE terms */
  Bitmask saved_prereq;           /* Original value of pNew->prereq */
  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
  u16 saved_nSkip;                /* Original value of pNew->u.btree.nSkip */
  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
  LogEst saved_nOut;              /* Original value of pNew->nOut */
  int iCol;                       /* Index of the column in the table */
  int rc = SQLITE_OK;             /* Return code */
  LogEst rSize;                   /* Number of rows in the table */
  LogEst rLogSize;                /* Logarithm of table size */
  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
................................................................................

  assert( pNew->u.btree.nEq<pProbe->nColumn );
  iCol = pProbe->aiColumn[pNew->u.btree.nEq];

  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
                        opMask, pProbe);
  saved_nEq = pNew->u.btree.nEq;
  saved_nSkip = pNew->u.btree.nSkip;
  saved_nLTerm = pNew->nLTerm;
  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pNew->rSetup = 0;
  rSize = pProbe->aiRowLogEst[0];
  rLogSize = estLog(rSize);

  /* Consider using a skip-scan if there are no WHERE clause constraints
  ** available for the left-most terms of the index, and if the average
  ** number of repeats in the left-most terms is at least 18. 
  **
  ** The magic number 18 is selected on the basis that scanning 17 rows
  ** is almost always quicker than an index seek (even though if the index
  ** contains fewer than 2^17 rows we assume otherwise in other parts of
  ** the code). And, even if it is not, it should not be too much slower. 
  ** On the other hand, the extra seeks could end up being significantly
  ** more expensive.  */
  assert( 42==sqlite3LogEst(18) );
  if( saved_nEq==saved_nSkip
   && saved_nEq+1<pProbe->nKeyCol
   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
  ){
    LogEst nIter;
    pNew->u.btree.nEq++;
    pNew->u.btree.nSkip++;
    pNew->aLTerm[pNew->nLTerm++] = 0;
    pNew->wsFlags |= WHERE_SKIPSCAN;
    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
    if( pTerm ){
      /* TUNING:  When estimating skip-scan for a term that is also indexable,
      ** multiply the cost of the skip-scan by 2.0, to make it a little less
      ** desirable than the regular index lookup. */
      nIter += 10;  assert( 10==sqlite3LogEst(2) );
    }
    pNew->nOut -= nIter;
    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
    nIter += 5;
    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
    pNew->nOut = saved_nOut;
    pNew->u.btree.nEq = saved_nEq;
    pNew->u.btree.nSkip = saved_nSkip;
  }
  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
    LogEst rCostIdx;
    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
    int nIn = 0;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    int nRecValid = pBuilder->nRecValid;
................................................................................
        pNew->nOut -= nIn;
      }else{
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
        tRowcnt nOut = 0;
        if( nInMul==0 
         && pProbe->nSample 
         && pNew->u.btree.nEq<=pProbe->nSampleCol
         && OptimizationEnabled(db, SQLITE_Stat3) 
         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
        ){
          Expr *pExpr = pTerm->pExpr;
          if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){
            testcase( eOp & WO_EQ );
            testcase( eOp & WO_ISNULL );
            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
................................................................................
    pNew->nOut = saved_nOut;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    pBuilder->nRecValid = nRecValid;
#endif
  }
  pNew->prereq = saved_prereq;
  pNew->u.btree.nEq = saved_nEq;
  pNew->u.btree.nSkip = saved_nSkip;
  pNew->wsFlags = saved_wsFlags;
  pNew->nOut = saved_nOut;
  pNew->nLTerm = saved_nLTerm;



































  return rc;
}

/*
** Return True if it is possible that pIndex might be useful in
** implementing the ORDER BY clause in pBuilder.
**
................................................................................
    /* Generate auto-index WhereLoops */
    WhereTerm *pTerm;
    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
      if( pTerm->prereqRight & pNew->maskSelf ) continue;
      if( termCanDriveIndex(pTerm, pSrc, 0) ){
        pNew->u.btree.nEq = 1;
        pNew->u.btree.nSkip = 0;
        pNew->u.btree.pIndex = 0;
        pNew->nLTerm = 1;
        pNew->aLTerm[0] = pTerm;
        /* TUNING: One-time cost for computing the automatic index is
        ** estimated to be X*N*log2(N) where N is the number of rows in
        ** the table being indexed and where X is 7 (LogEst=28) for normal
        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
................................................................................
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
    pNew->u.btree.nSkip = 0;
    pNew->nLTerm = 0;
    pNew->iSortIdx = 0;
    pNew->rSetup = 0;
    pNew->prereq = mExtra;
    pNew->nOut = rSize;
    pNew->u.btree.pIndex = pProbe;
    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
................................................................................
      rev = revSet = 0;
      distinctColumns = 0;
      for(j=0; j<nColumn; j++){
        u8 bOnce;   /* True to run the ORDER BY search loop */

        /* Skip over == and IS NULL terms */
        if( j<pLoop->u.btree.nEq
         && pLoop->u.btree.nSkip==0
         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
        ){
          if( i & WO_ISNULL ){
            testcase( isOrderDistinct );
            isOrderDistinct = 0;
          }
          continue;  
................................................................................
            }
          }
        }
      }
    }

#ifdef WHERETRACE_ENABLED  /* >=2 */
    if( sqlite3WhereTrace>=2 ){
      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
      for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
        sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
           wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
        if( pTo->isOrdered>0 ){
          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
................................................................................
  pTab = pItem->pTab;
  if( IsVirtual(pTab) ) return 0;
  if( pItem->zIndex ) return 0;
  iCur = pItem->iCursor;
  pWC = &pWInfo->sWC;
  pLoop = pBuilder->pNew;
  pLoop->wsFlags = 0;
  pLoop->u.btree.nSkip = 0;
  pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0);
  if( pTerm ){
    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
    pLoop->aLTerm[0] = pTerm;
    pLoop->nLTerm = 1;
    pLoop->u.btree.nEq = 1;
    /* TUNING: Cost of a rowid lookup is 10 */
    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
  }else{
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pLoop->aLTermSpace==pLoop->aLTerm );
      assert( ArraySize(pLoop->aLTermSpace)==4 );
      if( !IsUniqueIndex(pIdx)
       || pIdx->pPartIdxWhere!=0 
       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
      ) continue;
      for(j=0; j<pIdx->nKeyCol; j++){
        pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
        if( pTerm==0 ) break;
................................................................................

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
  ** program.
  */
  notReady = ~(Bitmask)0;
  for(ii=0; ii<nTabList; ii++){


    pLevel = &pWInfo->a[ii];

#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
      constructAutomaticIndex(pParse, &pWInfo->sWC,
                &pTabList->a[pLevel->iFrom], notReady, pLevel);
      if( db->mallocFailed ) goto whereBeginError;
    }
#endif

    explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags);

    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
    notReady = codeOneLoopStart(pWInfo, ii, notReady);
    pWInfo->iContinue = pLevel->addrCont;



  }

  /* Done. */
  VdbeModuleComment((v, "Begin WHERE-core"));
  return pWInfo;

  /* Jump here if malloc fails */

    if( pOld!=pWC->aStatic ){
      sqlite3DbFree(db, pOld);
    }
    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
  }
  pTerm = &pWC->a[idx = pWC->nTerm++];
  if( p && ExprHasProperty(p, EP_Unlikely) ){
    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
  }else{
    pTerm->truthProb = 1;
  }
  pTerm->pExpr = sqlite3ExprSkipCollate(p);
  pTerm->wtFlags = wtFlags;
  pTerm->pWC = pWC;
  pTerm->iParent = -1;
................................................................................
*/
static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
  if( pDerived ){
    pDerived->flags |= pBase->flags & EP_FromJoin;
    pDerived->iRightJoinTable = pBase->iRightJoinTable;
  }
}

/*
** Mark term iChild as being a child of term iParent
*/
static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
  pWC->a[iChild].iParent = iParent;
  pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
  pWC->a[iParent].nChild++;
}

#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
/*
** Analyze a term that consists of two or more OR-connected
** subterms.  So in:
**
**     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
................................................................................
        transferJoinMarkings(pNew, pExpr);
        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
        pNew->x.pList = pList;
        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
        testcase( idxNew==0 );
        exprAnalyze(pSrc, pWC, idxNew);
        pTerm = &pWC->a[idxTerm];
        markTermAsChild(pWC, idxNew, idxTerm);

      }else{
        sqlite3ExprListDelete(db, pList);
      }
      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 2 */
    }
  }
}
................................................................................
        if( db->mallocFailed ){
          sqlite3ExprDelete(db, pDup);
          return;
        }
        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
        if( idxNew==0 ) return;
        pNew = &pWC->a[idxNew];
        markTermAsChild(pWC, idxNew, idxTerm);
        pTerm = &pWC->a[idxTerm];

        pTerm->wtFlags |= TERM_COPIED;
        if( pExpr->op==TK_EQ
         && !ExprHasProperty(pExpr, EP_FromJoin)
         && OptimizationEnabled(db, SQLITE_Transitive)
        ){
          pTerm->eOperator |= WO_EQUIV;
          eExtraOp = WO_EQUIV;
................................................................................
                             sqlite3ExprDup(db, pExpr->pLeft, 0),
                             sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
      transferJoinMarkings(pNewExpr, pExpr);
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      exprAnalyze(pSrc, pWC, idxNew);
      pTerm = &pWC->a[idxTerm];
      markTermAsChild(pWC, idxNew, idxTerm);
    }

  }
#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */

#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
  /* Analyze a term that is composed of two or more subterms connected by
  ** an OR operator.
  */
................................................................................
           pStr2, 0);
    transferJoinMarkings(pNewExpr2, pExpr);
    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew2==0 );
    exprAnalyze(pSrc, pWC, idxNew2);
    pTerm = &pWC->a[idxTerm];
    if( isComplete ){
      markTermAsChild(pWC, idxNew1, idxTerm);
      markTermAsChild(pWC, idxNew2, idxTerm);

    }
  }
#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */

#ifndef SQLITE_OMIT_VIRTUALTABLE
  /* Add a WO_MATCH auxiliary term to the constraint set if the
  ** current expression is of the form:  column MATCH expr.
................................................................................
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      pNewTerm = &pWC->a[idxNew];
      pNewTerm->prereqRight = prereqExpr;
      pNewTerm->leftCursor = pLeft->iTable;
      pNewTerm->u.leftColumn = pLeft->iColumn;
      pNewTerm->eOperator = WO_MATCH;
      markTermAsChild(pWC, idxNew, idxTerm);
      pTerm = &pWC->a[idxTerm];

      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
................................................................................
  ** TERM_VNULL tag will suppress the not-null check at the beginning
  ** of the loop.  Without the TERM_VNULL flag, the not-null check at
  ** the start of the loop will prevent any results from being returned.
  */
  if( pExpr->op==TK_NOTNULL
   && pExpr->pLeft->op==TK_COLUMN
   && pExpr->pLeft->iColumn>=0
   && OptimizationEnabled(db, SQLITE_Stat34)
  ){
    Expr *pNewExpr;
    Expr *pLeft = pExpr->pLeft;
    int idxNew;
    WhereTerm *pNewTerm;

    pNewExpr = sqlite3PExpr(pParse, TK_GT,
................................................................................
                              TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
    if( idxNew ){
      pNewTerm = &pWC->a[idxNew];
      pNewTerm->prereqRight = 0;
      pNewTerm->leftCursor = pLeft->iTable;
      pNewTerm->u.leftColumn = pLeft->iColumn;
      pNewTerm->eOperator = WO_GT;
      markTermAsChild(pWC, idxNew, idxTerm);
      pTerm = &pWC->a[idxTerm];

      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
................................................................................
  int mxBitCol;               /* Maximum column in pSrc->colUsed */
  CollSeq *pColl;             /* Collating sequence to on a column */
  WhereLoop *pLoop;           /* The Loop object */
  char *zNotUsed;             /* Extra space on the end of pIdx */
  Bitmask idxCols;            /* Bitmap of columns used for indexing */
  Bitmask extraCols;          /* Bitmap of additional columns */
  u8 sentWarning = 0;         /* True if a warnning has been issued */
  Expr *pPartial = 0;         /* Partial Index Expression */
  int iContinue = 0;          /* Jump here to skip excluded rows */

  /* Generate code to skip over the creation and initialization of the
  ** transient index on 2nd and subsequent iterations of the loop. */
  v = pParse->pVdbe;
  assert( v!=0 );
  addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v);

................................................................................
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;
  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    if( pLoop->prereq==0
     && (pTerm->wtFlags & TERM_VIRTUAL)==0
     && sqlite3ExprIsTableConstant(pTerm->pExpr, pSrc->iCursor) ){
      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
                                sqlite3ExprDup(pParse->db, pTerm->pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol = pTerm->u.leftColumn;
      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
      testcase( iCol==BMS );
      testcase( iCol==BMS-1 );
      if( !sentWarning ){
        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
            "automatic index on %s(%s)", pTable->zName,
            pTable->aCol[iCol].zName);
        sentWarning = 1;
      }
      if( (idxCols & cMask)==0 ){
        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
          goto end_auto_index_create;
        }
        pLoop->aLTerm[nKeyCol++] = pTerm;
        idxCols |= cMask;
      }
    }
  }
  assert( nKeyCol>0 );
  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
................................................................................
  ** columns that are needed by the query.  With a covering index, the
  ** original table never needs to be accessed.  Automatic indices must
  ** be a covering index because the index will not be updated if the
  ** original table changes and the index and table cannot both be used
  ** if they go out of sync.
  */
  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
  mxBitCol = MIN(BMS-1,pTable->nCol);
  testcase( pTable->nCol==BMS-1 );
  testcase( pTable->nCol==BMS-2 );
  for(i=0; i<mxBitCol; i++){
    if( extraCols & MASKBIT(i) ) nKeyCol++;
  }
  if( pSrc->colUsed & MASKBIT(BMS-1) ){
    nKeyCol += pTable->nCol - BMS + 1;
  }


  /* Construct the Index object to describe this index */
  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
  if( pIdx==0 ) goto end_auto_index_create;
  pLoop->u.btree.pIndex = pIdx;
  pIdx->zName = "auto-index";
  pIdx->pTable = pTable;
  n = 0;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
................................................................................
  assert( pLevel->iIdxCur>=0 );
  pLevel->iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
  VdbeComment((v, "for %s", pTable->zName));

  /* Fill the automatic index with content */
  sqlite3ExprCachePush(pParse);
  addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
  if( pPartial ){
    iContinue = sqlite3VdbeMakeLabel(v);
    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
    pLoop->wsFlags |= WHERE_PARTIALIDX;
  }
  regRecord = sqlite3GetTempReg(pParse);
  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
  sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
  sqlite3VdbeJumpHere(v, addrTop);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ExprCachePop(pParse);
  
  /* Jump here when skipping the initialization */
  sqlite3VdbeJumpHere(v, addrInit);

end_auto_index_create:
  sqlite3ExprDelete(pParse->db, pPartial);
}
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Allocate and populate an sqlite3_index_info structure. It is the 
** responsibility of the caller to eventually release the structure
................................................................................
    }
  }

  return pParse->nErr;
}
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */


#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Estimate the location of a particular key among all keys in an
** index.  Store the results in aStat as follows:
**
**    aStat[0]      Est. number of rows less than pVal
**    aStat[1]      Est. number of rows equal to pVal
**
** Return the index of the sample that is the smallest sample that
** is greater than or equal to pRec.
*/
static int whereKeyStats(
  Parse *pParse,              /* Database connection */
  Index *pIdx,                /* Index to consider domain of */
  UnpackedRecord *pRec,       /* Vector of values to consider */
  int roundUp,                /* Round up if true.  Round down if false */
  tRowcnt *aStat              /* OUT: stats written here */
){
  IndexSample *aSample = pIdx->aSample;
................................................................................
    if( roundUp ){
      iGap = (iGap*2)/3;
    }else{
      iGap = iGap/3;
    }
    aStat[0] = iLower + iGap;
  }
  return i;
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

/*
** If it is not NULL, pTerm is a term that provides an upper or lower
** bound on a range scan. Without considering pTerm, it is estimated 
** that the scan will visit nNew rows. This function returns the number
................................................................................
**                    |_____|   |_____|
**                       |         |
**                     pLower    pUpper
**
** If either of the upper or lower bound is not present, then NULL is passed in
** place of the corresponding WhereTerm.
**
** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
** column subject to the range constraint. Or, equivalently, the number of
** equality constraints optimized by the proposed index scan. For example,
** assuming index p is on t1(a, b), and the SQL query is:
**
**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
**
** then nEq is set to 1 (as the range restricted column, b, is the second 
................................................................................
**
**   ... FROM t1 WHERE a > ? AND a < ? ...
**
** then nEq is set to 0.
**
** When this function is called, *pnOut is set to the sqlite3LogEst() of the
** number of rows that the index scan is expected to visit without 
** considering the range constraints. If nEq is 0, then *pnOut is the number of 
** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
** to account for the range constraints pLower and pUpper.
** 
** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
** used, a single range inequality reduces the search space by a factor of 4. 
** and a pair of constraints (x>? AND x<?) reduces the expected number of
** rows visited by a factor of 64.
................................................................................
  int nOut = pLoop->nOut;
  LogEst nNew;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  Index *p = pLoop->u.btree.pIndex;
  int nEq = pLoop->u.btree.nEq;


  if( p->nSample>0 && nEq<p->nSampleCol ){


    if( nEq==pBuilder->nRecValid ){
      UnpackedRecord *pRec = pBuilder->pRec;
      tRowcnt a[2];
      u8 aff;

      /* Variable iLower will be set to the estimate of the number of rows in 
      ** the index that are less than the lower bound of the range query. The
................................................................................
      ** key-prefix formed by the nEq values matched against the nEq left-most
      ** columns of the index, and $L is the value in pLower.
      **
      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
      ** is not a simple variable or literal value), the lower bound of the
      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
      ** if $L is available, whereKeyStats() is called for both ($P) and 
      ** ($P:$L) and the larger of the two returned values is used.
      **
      ** Similarly, iUpper is to be set to the estimate of the number of rows
      ** less than the upper bound of the range query. Where the upper bound
      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
      ** of iUpper are requested of whereKeyStats() and the smaller used.
      **
      ** The number of rows between the two bounds is then just iUpper-iLower.
      */
      tRowcnt iLower;     /* Rows less than the lower bound */
      tRowcnt iUpper;     /* Rows less than the upper bound */
      int iLwrIdx = -2;   /* aSample[] for the lower bound */
      int iUprIdx = -1;   /* aSample[] for the upper bound */

      if( pRec ){
        testcase( pRec->nField!=pBuilder->nRecValid );
        pRec->nField = pBuilder->nRecValid;
      }
      if( nEq==p->nKeyCol ){
        aff = SQLITE_AFF_INTEGER;
      }else{
        aff = p->pTable->aCol[p->aiColumn[nEq]].affinity;
      }
      /* Determine iLower and iUpper using ($P) only. */
      if( nEq==0 ){
        iLower = 0;
        iUpper = p->nRowEst0;
      }else{
        /* Note: this call could be optimized away - since the same values must 
        ** have been requested when testing key $P in whereEqualScanEst().  */
        whereKeyStats(pParse, p, pRec, 0, a);
        iLower = a[0];
        iUpper = a[0] + a[1];
      }
................................................................................
      /* If possible, improve on the iLower estimate using ($P:$L). */
      if( pLower ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pLower->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew>iLower ) iLower = iNew;
          nOut--;
          pLower = 0;
        }
      }

................................................................................
      /* If possible, improve on the iUpper estimate using ($P:$U). */
      if( pUpper ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pUpper->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew<iUpper ) iUpper = iNew;
          nOut--;
          pUpper = 0;
        }
      }

      pBuilder->pRec = pRec;
      if( rc==SQLITE_OK ){
        if( iUpper>iLower ){
          nNew = sqlite3LogEst(iUpper - iLower);
          /* TUNING:  If both iUpper and iLower are derived from the same
          ** sample, then assume they are 4x more selective.  This brings
          ** the estimated selectivity more in line with what it would be
          ** if estimated without the use of STAT3/4 tables. */
          if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );
        }else{
          nNew = 10;        assert( 10==sqlite3LogEst(2) );
        }
        if( nNew<nOut ){
          nOut = nNew;
        }
        WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",
................................................................................
  UNUSED_PARAMETER(pBuilder);
  assert( pLower || pUpper );
#endif
  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
  nNew = whereRangeAdjust(pLower, nOut);
  nNew = whereRangeAdjust(pUpper, nNew);

  /* TUNING: If there is both an upper and lower limit and neither limit
  ** has an application-defined likelihood(), assume the range is
  ** reduced by an additional 75%. This means that, by default, an open-ended
  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
  ** match 1/64 of the index. */ 
  if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
    nNew -= 20;
  }

  nOut -= (pLower!=0) + (pUpper!=0);
  if( nNew<10 ) nNew = 10;
  if( nNew<nOut ) nOut = nNew;
#if defined(WHERETRACE_ENABLED)
  if( pLoop->nOut>nOut ){
    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
................................................................................
  int nReg;                     /* Number of registers to allocate */
  char *zAff;                   /* Affinity string to return */

  /* This module is only called on query plans that use an index. */
  pLoop = pLevel->pWLoop;
  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
  nEq = pLoop->u.btree.nEq;
  nSkip = pLoop->nSkip;
  pIdx = pLoop->u.btree.pIndex;
  assert( pIdx!=0 );

  /* Figure out how many memory cells we will need then allocate them.
  */
  regBase = pParse->nMem + 1;
  nReg = pLoop->u.btree.nEq + nExtraReg;
................................................................................
** string similar to:
**
**   "a=? AND b>?"
*/
static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
  Index *pIndex = pLoop->u.btree.pIndex;
  u16 nEq = pLoop->u.btree.nEq;
  u16 nSkip = pLoop->nSkip;
  int i, j;
  Column *aCol = pTab->aCol;
  i16 *aiColumn = pIndex->aiColumn;

  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
  sqlite3StrAccumAppend(pStr, " (", 2);
  for(i=0; i<nEq; i++){
................................................................................
    explainAppendTerm(pStr, i, z, "<");
  }
  sqlite3StrAccumAppend(pStr, ")", 1);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 
** is added to the output to describe the table scan strategy in pLevel.

**
** If an OP_Explain opcode is added to the VM, its address is returned.
** Otherwise, if no OP_Explain is coded, zero is returned.
*/
static int explainOneScan(
  Parse *pParse,                  /* Parse context */
  SrcList *pTabList,              /* Table list this loop refers to */
  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
  int iLevel,                     /* Value for "level" column of output */
  int iFrom,                      /* Value for "from" column of output */
  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
){
  int ret = 0;
#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
  if( pParse->explain==2 )
#endif
  {
    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
    sqlite3 *db = pParse->db;     /* Database handle */
    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
................................................................................
    u32 flags;                    /* Flags that describe this loop */
    char *zMsg;                   /* Text to add to EQP output */
    StrAccum str;                 /* EQP output string */
    char zBuf[100];               /* Initial space for EQP output string */

    pLoop = pLevel->pWLoop;
    flags = pLoop->wsFlags;
    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return 0;

    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

    sqlite3StrAccumInit(&str, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
    str.db = db;
................................................................................
      assert( pLoop->u.btree.pIndex!=0 );
      pIdx = pLoop->u.btree.pIndex;
      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
        if( isSearch ){
          zFmt = "PRIMARY KEY";
        }
      }else if( flags & WHERE_PARTIALIDX ){
        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
      }else if( flags & WHERE_AUTO_INDEX ){
        zFmt = "AUTOMATIC COVERING INDEX";
      }else if( flags & WHERE_IDX_ONLY ){
        zFmt = "COVERING INDEX %s";
      }else{
        zFmt = "INDEX %s";
      }
................................................................................
    if( pLoop->nOut>=10 ){
      sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
    }else{
      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
    }
#endif
    zMsg = sqlite3StrAccumFinish(&str);
    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
  }
  return ret;
}
#else
# define explainOneScan(u,v,w,x,y,z) 0
#endif /* SQLITE_OMIT_EXPLAIN */

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
/*
** Configure the VM passed as the first argument with an
** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 
** implement level pLvl. Argument pSrclist is a pointer to the FROM 
** clause that the scan reads data from.
**
** If argument addrExplain is not 0, it must be the address of an 
** OP_Explain instruction that describes the same loop.
*/
static void addScanStatus(
  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
  int addrExplain                 /* Address of OP_Explain (or 0) */
){
  const char *zObj = 0;
  WhereLoop *pLoop = pLvl->pWLoop;
  if( (pLoop->wsFlags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
    zObj = pLoop->u.btree.pIndex->zName;
  }else{
    zObj = pSrclist->a[pLvl->iFrom].zName;
  }
  sqlite3VdbeScanStatus(
      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
  );
}
#else
# define addScanStatus(a, b, c, d) ((void)d)
#endif



/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
static Bitmask codeOneLoopStart(
................................................................................
    char *zStartAff;             /* Affinity for start of range constraint */
    char cEndAff = 0;            /* Affinity for end of range constraint */
    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */

    pIdx = pLoop->u.btree.pIndex;
    iIdxCur = pLevel->iIdxCur;
    assert( nEq>=pLoop->nSkip );

    /* If this loop satisfies a sort order (pOrderBy) request that 
    ** was passed to this function to implement a "SELECT min(x) ..." 
    ** query, then the caller will only allow the loop to run for
    ** a single iteration. This means that the first row returned
    ** should not have a NULL value stored in 'x'. If column 'x' is
    ** the first one after the nEq equality constraints in the index,
................................................................................
    assert( pWInfo->pOrderBy==0
         || pWInfo->pOrderBy->nExpr==1
         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
     && pWInfo->nOBSat>0
     && (pIdx->nKeyCol>nEq)
    ){
      assert( pLoop->nSkip==0 );
      bSeekPastNull = 1;
      nExtraReg = 1;
    }

    /* Find any inequality constraint terms for the start and end 
    ** of the range. 
    */
................................................................................
        /* Loop through table entries that match term pOrTerm. */
        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
                                      wctrlFlags, iCovCur);
        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
        if( pSubWInfo ){
          WhereLoop *pSubLoop;
          int addrExplain = explainOneScan(
              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
          );
          addScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);

          /* This is the sub-WHERE clause body.  First skip over
          ** duplicate rows from prior sub-WHERE clauses, and record the
          ** rowid (or PRIMARY KEY) for the current row so that the same
          ** row will be skipped in subsequent sub-WHERE clauses.
          */
          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
            int r;
................................................................................
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
      VdbeCoverageIf(v, bRev==0);
      VdbeCoverageIf(v, bRev!=0);
      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
    }
  }

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
#endif

  /* Insert code to test every subexpression that can be completely
  ** computed using the current set of tables.
  */
  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
    Expr *pE;
    testcase( pTerm->wtFlags & TERM_VIRTUAL );
................................................................................
    }else{
      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
    }
    sqlite3DebugPrintf(" %-19s", z);
    sqlite3_free(z);
  }
  if( p->wsFlags & WHERE_SKIPSCAN ){
    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
  }else{
    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
  }
  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
    int i;
    for(i=0; i<p->nLTerm; i++){
................................................................................
      whereLoopDelete(db, p);
    }
    sqlite3DbFree(db, pWInfo);
  }
}

/*
** Return TRUE if all of the following are true:
**
**   (1)  X has the same or lower cost that Y
**   (2)  X is a proper subset of Y
**   (3)  X skips at least as many columns as Y
**
** By "proper subset" we mean that X uses fewer WHERE clause terms
** than Y and that every WHERE clause term used by X is also used
** by Y.
**
** If X is a proper subset of Y then Y is a better choice and ought
** to have a lower cost.  This routine returns TRUE when that cost 
** relationship is inverted and needs to be adjusted.  The third rule
** was added because if X uses skip-scan less than Y it still might
** deserve a lower cost even if it is a proper subset of Y.
*/
static int whereLoopCheaperProperSubset(
  const WhereLoop *pX,       /* First WhereLoop to compare */
  const WhereLoop *pY        /* Compare against this WhereLoop */
){
  int i, j;
  if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
    return 0; /* X is not a subset of Y */
  }
  if( pY->nSkip > pX->nSkip ) return 0;
  if( pX->rRun >= pY->rRun ){
    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
  }
  for(i=pX->nLTerm-1; i>=0; i--){
    if( pX->aLTerm[i]==0 ) continue;
    for(j=pY->nLTerm-1; j>=0; j--){
      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
    }
    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
  }
  return 1;  /* All conditions meet */
}
................................................................................
**
**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
**       is a proper subset.
**
** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
** WHERE clause terms than Y and that every WHERE clause term used by X is
** also used by Y.











*/
static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;

  for(; p; p=p->pNextLoop){
    if( p->iTab!=pTemplate->iTab ) continue;
    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;

    if( whereLoopCheaperProperSubset(p, pTemplate) ){
      /* Adjust pTemplate cost downward so that it is cheaper than its 
      ** subset p. */
      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
      pTemplate->rRun = p->rRun;
      pTemplate->nOut = p->nOut - 1;
    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
      /* Adjust pTemplate cost upward so that it is costlier than p since
      ** pTemplate is a proper subset of p */
      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
      pTemplate->rRun = p->rRun;
      pTemplate->nOut = p->nOut + 1;
    }
  }
}

/*
................................................................................
    /* whereLoopAddBtree() always generates and inserts the automatic index
    ** case first.  Hence compatible candidate WhereLoops never have a larger
    ** rSetup. Call this SETUP-INVARIANT */
    assert( p->rSetup>=pTemplate->rSetup );

    /* Any loop using an appliation-defined index (or PRIMARY KEY or
    ** UNIQUE constraint) with one or more == constraints is better
    ** than an automatic index. Unless it is a skip-scan. */
    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
     && (pTemplate->nSkip)==0
     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
    ){
      break;
    }

................................................................................
  WhereLoop *pNew;                /* Template WhereLoop under construction */
  WhereTerm *pTerm;               /* A WhereTerm under consideration */
  int opMask;                     /* Valid operators for constraints */
  WhereScan scan;                 /* Iterator for WHERE terms */
  Bitmask saved_prereq;           /* Original value of pNew->prereq */
  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
  u16 saved_nSkip;                /* Original value of pNew->nSkip */
  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
  LogEst saved_nOut;              /* Original value of pNew->nOut */
  int iCol;                       /* Index of the column in the table */
  int rc = SQLITE_OK;             /* Return code */
  LogEst rSize;                   /* Number of rows in the table */
  LogEst rLogSize;                /* Logarithm of table size */
  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
................................................................................

  assert( pNew->u.btree.nEq<pProbe->nColumn );
  iCol = pProbe->aiColumn[pNew->u.btree.nEq];

  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
                        opMask, pProbe);
  saved_nEq = pNew->u.btree.nEq;
  saved_nSkip = pNew->nSkip;
  saved_nLTerm = pNew->nLTerm;
  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pNew->rSetup = 0;
  rSize = pProbe->aiRowLogEst[0];
  rLogSize = estLog(rSize);






































  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
    LogEst rCostIdx;
    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
    int nIn = 0;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    int nRecValid = pBuilder->nRecValid;
................................................................................
        pNew->nOut -= nIn;
      }else{
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
        tRowcnt nOut = 0;
        if( nInMul==0 
         && pProbe->nSample 
         && pNew->u.btree.nEq<=pProbe->nSampleCol

         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
        ){
          Expr *pExpr = pTerm->pExpr;
          if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){
            testcase( eOp & WO_EQ );
            testcase( eOp & WO_ISNULL );
            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
................................................................................
    pNew->nOut = saved_nOut;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    pBuilder->nRecValid = nRecValid;
#endif
  }
  pNew->prereq = saved_prereq;
  pNew->u.btree.nEq = saved_nEq;
  pNew->nSkip = saved_nSkip;
  pNew->wsFlags = saved_wsFlags;
  pNew->nOut = saved_nOut;
  pNew->nLTerm = saved_nLTerm;

  /* Consider using a skip-scan if there are no WHERE clause constraints
  ** available for the left-most terms of the index, and if the average
  ** number of repeats in the left-most terms is at least 18. 
  **
  ** The magic number 18 is selected on the basis that scanning 17 rows
  ** is almost always quicker than an index seek (even though if the index
  ** contains fewer than 2^17 rows we assume otherwise in other parts of
  ** the code). And, even if it is not, it should not be too much slower. 
  ** On the other hand, the extra seeks could end up being significantly
  ** more expensive.  */
  assert( 42==sqlite3LogEst(18) );
  if( saved_nEq==saved_nSkip
   && saved_nEq+1<pProbe->nKeyCol
   && pProbe->noSkipScan==0
   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
  ){
    LogEst nIter;
    pNew->u.btree.nEq++;
    pNew->nSkip++;
    pNew->aLTerm[pNew->nLTerm++] = 0;
    pNew->wsFlags |= WHERE_SKIPSCAN;
    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
    pNew->nOut -= nIter;
    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
    nIter += 5;
    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
    pNew->nOut = saved_nOut;
    pNew->u.btree.nEq = saved_nEq;
    pNew->nSkip = saved_nSkip;
    pNew->wsFlags = saved_wsFlags;
  }

  return rc;
}

/*
** Return True if it is possible that pIndex might be useful in
** implementing the ORDER BY clause in pBuilder.
**
................................................................................
    /* Generate auto-index WhereLoops */
    WhereTerm *pTerm;
    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
      if( pTerm->prereqRight & pNew->maskSelf ) continue;
      if( termCanDriveIndex(pTerm, pSrc, 0) ){
        pNew->u.btree.nEq = 1;
        pNew->nSkip = 0;
        pNew->u.btree.pIndex = 0;
        pNew->nLTerm = 1;
        pNew->aLTerm[0] = pTerm;
        /* TUNING: One-time cost for computing the automatic index is
        ** estimated to be X*N*log2(N) where N is the number of rows in
        ** the table being indexed and where X is 7 (LogEst=28) for normal
        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
................................................................................
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
    pNew->nSkip = 0;
    pNew->nLTerm = 0;
    pNew->iSortIdx = 0;
    pNew->rSetup = 0;
    pNew->prereq = mExtra;
    pNew->nOut = rSize;
    pNew->u.btree.pIndex = pProbe;
    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
................................................................................
      rev = revSet = 0;
      distinctColumns = 0;
      for(j=0; j<nColumn; j++){
        u8 bOnce;   /* True to run the ORDER BY search loop */

        /* Skip over == and IS NULL terms */
        if( j<pLoop->u.btree.nEq
         && pLoop->nSkip==0
         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
        ){
          if( i & WO_ISNULL ){
            testcase( isOrderDistinct );
            isOrderDistinct = 0;
          }
          continue;  
................................................................................
            }
          }
        }
      }
    }

#ifdef WHERETRACE_ENABLED  /* >=2 */
    if( sqlite3WhereTrace & 0x02 ){
      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
      for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
        sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
           wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
        if( pTo->isOrdered>0 ){
          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
................................................................................
  pTab = pItem->pTab;
  if( IsVirtual(pTab) ) return 0;
  if( pItem->zIndex ) return 0;
  iCur = pItem->iCursor;
  pWC = &pWInfo->sWC;
  pLoop = pBuilder->pNew;
  pLoop->wsFlags = 0;
  pLoop->nSkip = 0;
  pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0);
  if( pTerm ){
    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
    pLoop->aLTerm[0] = pTerm;
    pLoop->nLTerm = 1;
    pLoop->u.btree.nEq = 1;
    /* TUNING: Cost of a rowid lookup is 10 */
    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
  }else{
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pLoop->aLTermSpace==pLoop->aLTerm );

      if( !IsUniqueIndex(pIdx)
       || pIdx->pPartIdxWhere!=0 
       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
      ) continue;
      for(j=0; j<pIdx->nKeyCol; j++){
        pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
        if( pTerm==0 ) break;
................................................................................

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
  ** program.
  */
  notReady = ~(Bitmask)0;
  for(ii=0; ii<nTabList; ii++){
    int addrExplain;
    int wsFlags;
    pLevel = &pWInfo->a[ii];
    wsFlags = pLevel->pWLoop->wsFlags;
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
      constructAutomaticIndex(pParse, &pWInfo->sWC,
                &pTabList->a[pLevel->iFrom], notReady, pLevel);
      if( db->mallocFailed ) goto whereBeginError;
    }
#endif
    addrExplain = explainOneScan(
        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
    );
    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
    notReady = codeOneLoopStart(pWInfo, ii, notReady);
    pWInfo->iContinue = pLevel->addrCont;
    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_ONETABLE_ONLY)==0 ){
      addScanStatus(v, pTabList, pLevel, addrExplain);
    }
  }

  /* Done. */
  VdbeModuleComment((v, "Begin WHERE-core"));
  return pWInfo;

  /* Jump here if malloc fails */

        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
      } *aInLoop;           /* Information about each nested IN operator */
    } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
  } u;
  struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
  Bitmask notReady;          /* FROM entries not usable at this level */



};

/*
** Each instance of this object represents an algorithm for evaluating one
** term of a join.  Every term of the FROM clause will have at least
** one corresponding WhereLoop object (unless INDEXED BY constraints
** prevent a query solution - which is an error) and many terms of the
................................................................................
  u8 iSortIdx;          /* Sorting index number.  0==None */
  LogEst rSetup;        /* One-time setup cost (ex: create transient index) */
  LogEst rRun;          /* Cost of running each loop */
  LogEst nOut;          /* Estimated number of output rows */
  union {
    struct {               /* Information for internal btree tables */
      u16 nEq;               /* Number of equality constraints */
      u16 nSkip;             /* Number of initial index columns to skip */
      Index *pIndex;         /* Index used, or NULL */
    } btree;
    struct {               /* Information for virtual tables */
      int idxNum;            /* Index number */
      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
      i8 isOrdered;          /* True if satisfies ORDER BY */
      u16 omitMask;          /* Terms that may be omitted */
      char *idxStr;          /* Index identifier string */
    } vtab;
  } u;
  u32 wsFlags;          /* WHERE_* flags describing the plan */
  u16 nLTerm;           /* Number of entries in aLTerm[] */

  /**** whereLoopXfer() copies fields above ***********************/
# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
  u16 nLSlot;           /* Number of slots allocated for aLTerm[] */
  WhereTerm **aLTerm;   /* WhereTerms used */
  WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
  WhereTerm *aLTermSpace[4];  /* Initial aLTerm[] space */
};

/* This object holds the prerequisites and the cost of running a
** subquery on one operand of an OR operator in the WHERE clause.
** See WhereOrSet for additional information 
*/
struct WhereOrCost {
................................................................................
#define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */
#define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */
#define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
#define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
#define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
#define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */
#define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/

        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
      } *aInLoop;           /* Information about each nested IN operator */
    } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
  } u;
  struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
  Bitmask notReady;          /* FROM entries not usable at this level */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  int addrVisit;        /* Address at which row is visited */
#endif
};

/*
** Each instance of this object represents an algorithm for evaluating one
** term of a join.  Every term of the FROM clause will have at least
** one corresponding WhereLoop object (unless INDEXED BY constraints
** prevent a query solution - which is an error) and many terms of the
................................................................................
  u8 iSortIdx;          /* Sorting index number.  0==None */
  LogEst rSetup;        /* One-time setup cost (ex: create transient index) */
  LogEst rRun;          /* Cost of running each loop */
  LogEst nOut;          /* Estimated number of output rows */
  union {
    struct {               /* Information for internal btree tables */
      u16 nEq;               /* Number of equality constraints */

      Index *pIndex;         /* Index used, or NULL */
    } btree;
    struct {               /* Information for virtual tables */
      int idxNum;            /* Index number */
      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
      i8 isOrdered;          /* True if satisfies ORDER BY */
      u16 omitMask;          /* Terms that may be omitted */
      char *idxStr;          /* Index identifier string */
    } vtab;
  } u;
  u32 wsFlags;          /* WHERE_* flags describing the plan */
  u16 nLTerm;           /* Number of entries in aLTerm[] */
  u16 nSkip;            /* Number of NULL aLTerm[] entries */
  /**** whereLoopXfer() copies fields above ***********************/
# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
  u16 nLSlot;           /* Number of slots allocated for aLTerm[] */
  WhereTerm **aLTerm;   /* WhereTerms used */
  WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
  WhereTerm *aLTermSpace[3];  /* Initial aLTerm[] space */
};

/* This object holds the prerequisites and the cost of running a
** subquery on one operand of an OR operator in the WHERE clause.
** See WhereOrSet for additional information 
*/
struct WhereOrCost {
................................................................................
#define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */
#define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */
#define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
#define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
#define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
#define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */
#define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/
#define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */

} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b>? AND b<?)}}

# There are many more values of c between 0 and 100000 than there are
# between 800000 and 900000.  So t1c is more selective for the latter
# range.
# 
# Test 3.2 is a little unstable. It depends on the planner estimating
# that (b BETWEEN 50 AND 54) will match more rows than (c BETWEEN
# 800000 AND 900000). Which is a pretty close call (50 vs. 32), so
# the planner could get it wrong with an unlucky set of samples. This
# case happens to work, but others ("b BETWEEN 40 AND 44" for example) 
# will fail.
#
do_execsql_test 3.0 {
  SELECT count(*) FROM t1 WHERE b BETWEEN 50 AND 54;
  SELECT count(*) FROM t1 WHERE c BETWEEN 0 AND 100000;
  SELECT count(*) FROM t1 WHERE c BETWEEN 800000 AND 900000;
} {50 376 32}
do_test 3.1 {
  eqp {SELECT * FROM t1 WHERE b BETWEEN 50 AND 54 AND c BETWEEN 0 AND 100000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b>? AND b<?)}}
do_test 3.2 {
  eqp {SELECT * FROM t1
       WHERE b BETWEEN 50 AND 54 AND c BETWEEN 800000 AND 900000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1c (c>? AND c<?)}}
do_test 3.3 {
  eqp {SELECT * FROM t1 WHERE a=100 AND c BETWEEN 0 AND 100000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?)}}
do_test 3.4 {
  eqp {SELECT * FROM t1
       WHERE a=100 AND c BETWEEN 800000 AND 900000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1c (c>? AND c<?)}}

finish_test

} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b>? AND b<?)}}

# There are many more values of c between 0 and 100000 than there are
# between 800000 and 900000.  So t1c is more selective for the latter
# range.
# 
# Test 3.2 is a little unstable. It depends on the planner estimating
# that (b BETWEEN 30 AND 34) will match more rows than (c BETWEEN
# 800000 AND 900000). Which is a pretty close call (50 vs. 32), so
# the planner could get it wrong with an unlucky set of samples. This
# case happens to work, but others ("b BETWEEN 40 AND 44" for example) 
# will fail.
#
do_execsql_test 3.0 {
  SELECT count(*) FROM t1 WHERE b BETWEEN 30 AND 34;
  SELECT count(*) FROM t1 WHERE c BETWEEN 0 AND 100000;
  SELECT count(*) FROM t1 WHERE c BETWEEN 800000 AND 900000;
} {50 376 32}
do_test 3.1 {
  eqp {SELECT * FROM t1 WHERE b BETWEEN 30 AND 34 AND c BETWEEN 0 AND 100000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b>? AND b<?)}}
do_test 3.2 {
  eqp {SELECT * FROM t1
       WHERE b BETWEEN 30 AND 34 AND c BETWEEN 800000 AND 900000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1c (c>? AND c<?)}}
do_test 3.3 {
  eqp {SELECT * FROM t1 WHERE a=100 AND c BETWEEN 0 AND 100000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?)}}
do_test 3.4 {
  eqp {SELECT * FROM t1
       WHERE a=100 AND c BETWEEN 800000 AND 900000}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1c (c>? AND c<?)}}

finish_test

# focus of this script is testing automatic index creation logic,
# and specifically that an automatic index will not be created that
# shadows a declared index.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl


# The t1b and t2d indexes are not very selective.  It used to be that
# the autoindex mechanism would create automatic indexes on t1(b) or
# t2(d), make assumptions that they were reasonably selective, and use
# them instead of t1b or t2d.  But that would be cheating, because the
# automatic index cannot be any more selective than the real index.
#
................................................................................
} {/AUTO/}
do_execsql_test autoindex3-130 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IS NULL AND x=y;
} {/AUTO/}
do_execsql_test autoindex3-140 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IN (5,b) AND x=y;
} {/AUTO/}



































finish_test

# focus of this script is testing automatic index creation logic,
# and specifically that an automatic index will not be created that
# shadows a declared index.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix autoindex3

# The t1b and t2d indexes are not very selective.  It used to be that
# the autoindex mechanism would create automatic indexes on t1(b) or
# t2(d), make assumptions that they were reasonably selective, and use
# them instead of t1b or t2d.  But that would be cheating, because the
# automatic index cannot be any more selective than the real index.
#
................................................................................
} {/AUTO/}
do_execsql_test autoindex3-130 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IS NULL AND x=y;
} {/AUTO/}
do_execsql_test autoindex3-140 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IN (5,b) AND x=y;
} {/AUTO/}

reset_db
do_execsql_test 210 {
  CREATE TABLE v(b, d, e);
  CREATE TABLE u(a, b, c);
  ANALYZE sqlite_master;
  INSERT INTO "sqlite_stat1" VALUES('u','uab','40000 400 1');
  INSERT INTO "sqlite_stat1" VALUES('v','vbde','40000 400 1 1');
  INSERT INTO "sqlite_stat1" VALUES('v','ve','40000 21');

  CREATE INDEX uab on u(a, b);
  CREATE INDEX ve on v(e);
  CREATE INDEX vbde on v(b,d,e);

  DROP TABLE IF EXISTS sqlite_stat4;
  ANALYZE sqlite_master;
}

# At one point, SQLite was using the inferior plan:
#
#   0|0|1|SEARCH TABLE v USING INDEX ve (e>?)
#   0|1|0|SEARCH TABLE u USING COVERING INDEX uab (ANY(a) AND b=?)
#
# on the basis that the real index "uab" must be better than the automatic
# index. This is not right - a skip-scan is not necessarily better than an
# automatic index scan.
#
do_eqp_test 220 {
  select count(*) from u, v where u.b = v.b and v.e > 34;
} {
  0 0 1 {SEARCH TABLE v USING INDEX ve (e>?)} 
  0 1 0 {SEARCH TABLE u USING AUTOMATIC COVERING INDEX (b=?)}
}


finish_test

# 2014-10-24
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#*************************************************************************
#
# This file implements regression tests for SQLite library.  The
# focus of this script is testing automatic index creation logic,
# and specifically creation of automatic partial indexes.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_execsql_test autoindex4-1.0 {
  CREATE TABLE t1(a,b);
  INSERT INTO t1 VALUES(123,'abc'),(234,'def'),(234,'ghi'),(345,'jkl');
  CREATE TABLE t2(x,y);
  INSERT INTO t2 VALUES(987,'zyx'),(654,'wvu'),(987,'rqp');

  SELECT *, '|' FROM t1, t2 WHERE a=234 AND x=987 ORDER BY +b;
} {234 def 987 rqp | 234 def 987 zyx | 234 ghi 987 rqp | 234 ghi 987 zyx |}
do_execsql_test autoindex4-1.1 {
  SELECT *, '|' FROM t1, t2 WHERE a=234 AND x=555;
} {}

do_execsql_test autoindex4-1.2 {
  SELECT *, '|' FROM t1 LEFT JOIN t2 ON a=234 AND x=555;
} {123 abc {} {} | 234 def {} {} | 234 ghi {} {} | 345 jkl {} {} |}
do_execsql_test autoindex4-1.3 {
  SELECT *, '|' FROM t1 LEFT JOIN t2 ON x=555 WHERE a=234;
} {234 def {} {} | 234 ghi {} {} |}
do_execsql_test autoindex4-1.4 {
  SELECT *, '|' FROM t1 LEFT JOIN t2 WHERE a=234 AND x=555;
} {}


do_execsql_test autoindex4-2.0 {
  CREATE TABLE t3(e,f);
  INSERT INTO t3 VALUES(123,654),(555,444),(234,987);

  SELECT (SELECT count(*) FROM t1, t2 WHERE a=e AND x=f), e, f, '|'
    FROM t3
   ORDER BY rowid;
} {1 123 654 | 0 555 444 | 4 234 987 |}

finish_test

        CREATE INDEX ${file_dest}.i1 ON t1(a, b);
      " $db_dest
      for {set ii 0} {$ii < $rows_dest} {incr ii} {
        execsql "
          INSERT INTO ${file_dest}.t1 VALUES(1, randstr(1000,1000))
        " $db_dest
      }

    }
  
    # Backup the source database.
    do_test backup-2.$iTest.1 {
      sqlite3_backup B $db_dest $file_dest db main
      while {[B step $nPagePerStep]=="SQLITE_OK"} {}
      B finish

        CREATE INDEX ${file_dest}.i1 ON t1(a, b);
      " $db_dest
      for {set ii 0} {$ii < $rows_dest} {incr ii} {
        execsql "
          INSERT INTO ${file_dest}.t1 VALUES(1, randstr(1000,1000))
        " $db_dest
      }
      execsql COMMIT $db_dest
    }
  
    # Backup the source database.
    do_test backup-2.$iTest.1 {
      sqlite3_backup B $db_dest $file_dest db main
      while {[B step $nPagePerStep]=="SQLITE_OK"} {}
      B finish

# 2014 November 13
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix backup5

forcedelete test2.db

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(a, b);
  INSERT INTO t2 VALUES(1, 1);
  INSERT INTO t2 VALUES(2, 2);
  INSERT INTO t2 VALUES(3, 3);
}

do_test 1.1 {
  forcecopy test.db test.db2
  db eval {
    DROP TABLE t2;
    INSERT INTO t1 VALUES(zeroblob(1000), zeroblob(1000));
    INSERT INTO t1 VALUES(randomblob(1000), randomblob(1000));
  }
} {}

do_test 1.2 {
  sqlite3 db2 test.db2
  set stmt [sqlite3_prepare_v2 db2 "SELECT * FROM t2" -1 dummy]
  sqlite3_step $stmt
} {SQLITE_ROW}

do_test 1.3 {
  list [catch { sqlite3_backup B db2 main db main } msg] $msg
} {1 {sqlite3_backup_init() failed}}

do_test 1.4 {
  sqlite3_errmsg db2
} {destination database is in use}

do_test 1.5 {
  sqlite3_reset $stmt
  sqlite3_backup B db2 main db main
  B step 200
  B finish
} {SQLITE_OK}

do_test 1.6 {
  list [sqlite3_step $stmt] [sqlite3_finalize $stmt]
} {SQLITE_ERROR SQLITE_ERROR}

do_test 1.7 {
  sqlite3_errmsg db2
} {no such table: t2}

finish_test

  }
} {0 {}}
do_test capi3-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.10 {
  sqlite3_step $STMT
} {SQLITE_ERROR}
ifcapable !autoreset {
  # If SQLITE_OMIT_AUTORESET is defined, then the statement must be
  # reset() before it can be passed to step() again.
  do_test capi3-11.11a { sqlite3_step $STMT } {SQLITE_MISUSE}
  do_test capi3-11.11b { sqlite3_reset $STMT } {SQLITE_ABORT}
}
do_test capi3-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3-11.14 {
  execsql {
    SELECT a FROM t2;
  }

  }
} {0 {}}
do_test capi3-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3-11.10 {
  sqlite3_step $STMT
} {SQLITE_ROW}
ifcapable !autoreset {
  # If SQLITE_OMIT_AUTORESET is defined, then the statement must be
  # reset() before it can be passed to step() again.
  do_test capi3-11.11a { sqlite3_step $STMT } {SQLITE_MISUSE}
  do_test capi3-11.11b { sqlite3_reset $STMT } {SQLITE_ABORT}
}
do_test capi3-11.11 {
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3-11.14 {
  execsql {
    SELECT a FROM t2;
  }

  }
} {0 {}}
do_test capi3c-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.10 {
  sqlite3_step $STMT
} {SQLITE_ABORT}
ifcapable !autoreset {
  # If SQLITE_OMIT_AUTORESET is defined, then the statement must be
  # reset() before it can be passed to step() again.
  do_test capi3-11.11a { sqlite3_step $STMT } {SQLITE_MISUSE}
  do_test capi3-11.11b { sqlite3_reset $STMT } {SQLITE_ABORT}
}
do_test capi3c-11.11 {
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3c-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3c-11.14 {
  execsql {
    SELECT a FROM t2;
  }

  }
} {0 {}}
do_test capi3c-11.9.3 {
  sqlite3_get_autocommit $DB
} 1
do_test capi3c-11.10 {
  sqlite3_step $STMT
} {SQLITE_ROW}
ifcapable !autoreset {
  # If SQLITE_OMIT_AUTORESET is defined, then the statement must be
  # reset() before it can be passed to step() again.
  do_test capi3-11.11a { sqlite3_step $STMT } {SQLITE_MISUSE}
  do_test capi3-11.11b { sqlite3_reset $STMT } {SQLITE_ABORT}
}
do_test capi3c-11.11 {
  sqlite3_step $STMT
} {SQLITE_DONE}
do_test capi3c-11.12 {
  sqlite3_step $STMT
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-11.13 {
  sqlite3_finalize $STMT
} {SQLITE_OK}
do_test capi3c-11.14 {
  execsql {
    SELECT a FROM t2;
  }

do_execsql_test capi3d-4.1 {
  CREATE TABLE t4(x,y);
  BEGIN;
}

do_test capi3d-4.2.1 {
  breakpoint
  set ::s1 [sqlite3_prepare_v2 db "ROLLBACK" -1 notused]
  sqlite3_step $::s1
} {SQLITE_DONE}

do_test capi3d-4.2.2 {
  sqlite3_stmt_busy $::s1
} {1}

do_execsql_test capi3d-4.1 {
  CREATE TABLE t4(x,y);
  BEGIN;
}

do_test capi3d-4.2.1 {

  set ::s1 [sqlite3_prepare_v2 db "ROLLBACK" -1 notused]
  sqlite3_step $::s1
} {SQLITE_DONE}

do_test capi3d-4.2.2 {
  sqlite3_stmt_busy $::s1
} {1}

  }
  db close
  hexio_write test.db [expr {($r(t2)-1)*1024 + 11}] [format %.2X $r(t1)]
  sqlite3 db test.db
} {}

do_test 1.3 {
breakpoint
  db eval { PRAGMA secure_delete=1 }
  list [catch {
    db eval { SELECT * FROM t1 WHERE a IN (1, 2) } {
      db eval { DELETE FROM t2 }
    }
  } msg] $msg
} {1 {database disk image is malformed}}

  }
  db close
  hexio_write test.db [expr {($r(t2)-1)*1024 + 11}] [format %.2X $r(t1)]
  sqlite3 db test.db
} {}

do_test 1.3 {

  db eval { PRAGMA secure_delete=1 }
  list [catch {
    db eval { SELECT * FROM t1 WHERE a IN (1, 2) } {
      db eval { DELETE FROM t2 }
    }
  } msg] $msg
} {1 {database disk image is malformed}}

# 2014 October 30
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix e_blobbytes

do_execsql_test 1.0 {
  CREATE TABLE q1(r INTEGER PRIMARY KEY, s TEXT);
  WITH d(a, b) AS (
    SELECT 0, '' 
      UNION ALL
    SELECT a+1, b||'.' FROM d WHERE a<10000
  )
  INSERT INTO q1 SELECT * FROM d;
}


# EVIDENCE-OF: R-07796-55423 Returns the size in bytes of the BLOB
# accessible via the successfully opened BLOB handle in its only
# argument.
#
proc check_blob_size {tn rowid bytes} {
  uplevel [list do_test $tn [subst -nocommands {
    sqlite3_blob_open db main q1 s $rowid 0 B
    set res [sqlite3_blob_bytes [set B]]
    sqlite3_blob_close [set B]
    set res
  }] $bytes]
}
check_blob_size 1.1 43 43
check_blob_size 1.2 391 391
check_blob_size 1.3 6349 6349
check_blob_size 1.4 2621 2621
check_blob_size 1.5 7771 7771
check_blob_size 1.6 7949 7949
check_blob_size 1.7 4374 4374
check_blob_size 1.8 2578 2578
check_blob_size 1.9 7004 7004
check_blob_size 1.10 2180 2180
check_blob_size 1.11 3796 3796
check_blob_size 1.12 7101 7101
check_blob_size 1.13 7449 7449
check_blob_size 1.14 7224 7224
check_blob_size 1.15 3038 3038
check_blob_size 1.16 1083 1083
check_blob_size 1.17 5157 5157
check_blob_size 1.18 6686 6686
check_blob_size 1.19 6592 6592
check_blob_size 1.20 0 0


# EVIDENCE-OF: R-53088-19343 The incremental blob I/O routines can only
# read or overwriting existing blob content; they cannot change the size
# of a blob.
#
#   Also demonstrated in other e_blobXXX.test files.
#
do_test 2.1 {
  sqlite3_blob_open db main q1 s 86 1 B
  list [catch { sqlite3_blob_write $B 86 "1" 1 } msg] $msg
} {1 SQLITE_ERROR}
sqlite3_blob_close $B

finish_test

# 2014 October 30
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix e_blobclose

set dots [string repeat . 40]
do_execsql_test 1.0 {
  CREATE TABLE x1(a INTEGER PRIMARY KEY, b DOTS);
  INSERT INTO x1 VALUES(-1, $dots);
  INSERT INTO x1 VALUES(-10, $dots);
  INSERT INTO x1 VALUES(-100, $dots);
  INSERT INTO x1 VALUES(-1000, $dots);
  INSERT INTO x1 VALUES(-10000, $dots);
}

# EVIDENCE-OF: R-03145-46390 This function closes an open BLOB handle.
#
#   It's not clear how to test that a blob handle really is closed.
#   Attempting to use a closed blob handle will likely crash the process.
#   Assume here that if the SHARED lock on the db file is released,
#   the blob handle has been closed.
#
do_execsql_test 1.1 { PRAGMA lock_status } {main unlocked temp closed}
sqlite3_blob_open db main x1 b -1 0 B
do_execsql_test 1.2 { PRAGMA lock_status } {main shared temp closed}
sqlite3_blob_close $B
do_execsql_test 1.3 { PRAGMA lock_status } {main unlocked temp closed}


# EVIDENCE-OF: R-34027-00617 If the blob handle being closed was opened
# for read-write access, and if the database is in auto-commit mode and
# there are no other open read-write blob handles or active write
# statements, the current transaction is committed.
#
#   2.1.*: Transaction is not committed if there are other open 
#          read-write blob handles.
#
#   2.2.*: Transaction is not committed if not in auto-commit mode.
#
#   2.3.*: Active write statements.
#
do_test 2.1.1 {
  sqlite3_blob_open db main x1 b -100 1 B1
  sqlite3_blob_open db main x1 b -1000 1 B2
  sqlite3_blob_open db main x1 b -10000 1 B3
  sqlite3_blob_open db main x1 b -10000 0 B4      ;# B4 is read-only!
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.1.2 {
  sqlite3_blob_close $B1 
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.1.3 {
  sqlite3_blob_close $B2 
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.1.4 {
  sqlite3_blob_close $B3 
  execsql { PRAGMA lock_status }
} {main shared temp closed}
do_test 2.1.5 {
  sqlite3_blob_close $B4 
  execsql { PRAGMA lock_status }
} {main unlocked temp closed}

do_test 2.2.1 {
  sqlite3_blob_open db main x1 b -100 1 B1
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.2.2 {
  execsql { BEGIN }
  sqlite3_blob_close $B1 
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.2.3 {
  execsql { COMMIT }
  execsql { PRAGMA lock_status }
} {main unlocked temp closed}

proc val {} { 
  sqlite3_blob_close $::B 
  db eval { PRAGMA lock_status }
}
db func val val
do_test 2.3.1 {
  sqlite3_blob_open db main x1 b -100 1 B
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.3.2 {
  execsql { INSERT INTO x1 VALUES(15, val()) }
  execsql { PRAGMA lock_status }
} {main unlocked temp closed}
do_test 2.3.3 {
  execsql { SELECT * FROM x1 WHERE a = 15 }
} {15 {main reserved temp closed}}

# A reader does not inhibit commit.
do_test 2.3.4 {
  sqlite3_blob_open db main x1 b -100 1 B
  execsql { PRAGMA lock_status }
} {main reserved temp closed}
do_test 2.3.5 {
  execsql { SELECT a, val() FROM x1 LIMIT 1 }
} {-10000 {main shared temp closed}}


do_test 3.1 {
  sqlite3_blob_open db main x1 b -10 1 B
  execsql {
    INSERT INTO x1 VALUES(1, 'abc');
    SELECT * FROM x1 WHERE a=1;
  }
} {1 abc}
do_test 3.2 {
  sqlite3_blob_write $B 0 "abcdefghij" 10
  execsql { SELECT * FROM x1 WHERE a=-10 }
} {-10 abcdefghij..............................}

do_test 3.3 {
  sqlite3 db2 test.db
  execsql { BEGIN ; SELECT * FROM x1 } db2
  sqlite3_blob_close $B 
} {SQLITE_BUSY}

# EVIDENCE-OF: R-41959-38737 Otherwise, if this function is passed a
# valid open blob handle, the values returned by the sqlite3_errcode()
# and sqlite3_errmsg() functions are set before returning.
#
do_test 3.4 {
  list [sqlite3_errcode db] [sqlite3_errmsg db]
} {SQLITE_BUSY {database is locked}}

# EVIDENCE-OF: R-37801-37633 The BLOB handle is closed unconditionally.
# Even if this routine returns an error code, the handle is still
# closed.
#
#   Test that the lock has been released. Assume this means the handle
#   is closed, even though blob_close() returned SQLITE_BUSY.
#
do_execsql_test 3.4 { PRAGMA lock_status } {main unlocked temp closed}

# EVIDENCE-OF: R-35111-05628 If an error occurs while committing the
# transaction, an error code is returned and the transaction rolled
# back.
#
#   Row 1 is removed (it was inserted this transaction) and row -10
#   is restored to its original state. Transaction has been rolled back.
#
do_execsql_test 3.5 {
  SELECT * FROM x1 WHERE a IN (1, -10);
} {-10 ........................................}

# EVIDENCE-OF: R-25894-51060 Calling this routine with a null pointer
# (such as would be returned by a failed call to sqlite3_blob_open()) is
# a harmless no-op.
#
do_test 4.0 { sqlite3_blob_close 0 } {}

finish_test

# 2014 October 30
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix e_blobopen

forcedelete test.db2

do_execsql_test 1.0 {
  ATTACH 'test.db2' AS aux;

  CREATE TABLE main.t1(a INTEGER PRIMARY KEY, b TEXT, c BLOB);
  CREATE TEMP TABLE t1(a INTEGER PRIMARY KEY, b TEXT, c BLOB);
  CREATE TABLE aux.t1(a INTEGER PRIMARY KEY, b TEXT, c BLOB);

  CREATE TABLE main.x1(a INTEGER PRIMARY KEY, b TEXT, c BLOB);
  CREATE TEMP TABLE x2(a INTEGER PRIMARY KEY, b TEXT, c BLOB);
  CREATE TABLE aux.x3(a INTEGER PRIMARY KEY, b TEXT, c BLOB);

  INSERT INTO main.t1 VALUES(1, 'main one', X'0101');
  INSERT INTO main.t1 VALUES(2, 'main two', X'0102');
  INSERT INTO main.t1 VALUES(3, 'main three', X'0103');
  INSERT INTO main.t1 VALUES(4, 'main four', X'0104');
  INSERT INTO main.t1 VALUES(5, 'main five', X'0105');

  INSERT INTO main.x1 VALUES(1, 'x main one', X'000101');
  INSERT INTO main.x1 VALUES(2, 'x main two', X'000102');
  INSERT INTO main.x1 VALUES(3, 'x main three', X'000103');
  INSERT INTO main.x1 VALUES(4, 'x main four', X'000104');
  INSERT INTO main.x1 VALUES(5, 'x main five', X'000105');

  INSERT INTO temp.t1 VALUES(1, 'temp one', X'0201');
  INSERT INTO temp.t1 VALUES(2, 'temp two', X'0202');
  INSERT INTO temp.t1 VALUES(3, 'temp three', X'0203');
  INSERT INTO temp.t1 VALUES(4, 'temp four', X'0204');
  INSERT INTO temp.t1 VALUES(5, 'temp five', X'0205');

  INSERT INTO temp.x2 VALUES(1, 'x temp one', X'000201');
  INSERT INTO temp.x2 VALUES(2, 'x temp two', X'000202');
  INSERT INTO temp.x2 VALUES(3, 'x temp three', X'000203');
  INSERT INTO temp.x2 VALUES(4, 'x temp four', X'000204');
  INSERT INTO temp.x2 VALUES(5, 'x temp five', X'000205');

  INSERT INTO aux.t1 VALUES(1, 'aux one', X'0301');
  INSERT INTO aux.t1 VALUES(2, 'aux two', X'0302');
  INSERT INTO aux.t1 VALUES(3, 'aux three', X'0303');
  INSERT INTO aux.t1 VALUES(4, 'aux four', X'0304');
  INSERT INTO aux.t1 VALUES(5, 'aux five', X'0305');

  INSERT INTO aux.x3 VALUES(1, 'x aux one', X'000301');
  INSERT INTO aux.x3 VALUES(2, 'x aux two', X'000302');
  INSERT INTO aux.x3 VALUES(3, 'x aux three', X'000303');
  INSERT INTO aux.x3 VALUES(4, 'x aux four', X'000304');
  INSERT INTO aux.x3 VALUES(5, 'x aux five', X'000305');
}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-37639-55938 This interfaces opens a handle to the BLOB
# located in row iRow, column zColumn, table zTable in database zDb; in
# other words, the same BLOB that would be selected by: SELECT zColumn
# FROM zDb.zTable WHERE rowid = iRow;
#
proc read_blob {zDb zTab zCol iRow} {
  sqlite3_blob_open db $zDb $zTab $zCol $iRow 0 B
  set nByte [sqlite3_blob_bytes $B]
  set data [sqlite3_blob_read $B 0 $nByte]
  sqlite3_blob_close $B
  return $data
}

do_test 1.1.1 { read_blob main t1 b 1 } "main one"
do_test 1.1.2 { read_blob main t1 c 1 } "\01\01"
do_test 1.1.3 { read_blob temp t1 b 1 } "temp one"
do_test 1.1.4 { read_blob temp t1 c 1 } "\02\01"
do_test 1.1.6 { read_blob aux  t1 b 1 } "aux one"
do_test 1.1.7 { read_blob aux  t1 c 1 } "\03\01"

do_test 1.2.1 { read_blob main t1 b 4 } "main four"
do_test 1.2.2 { read_blob main t1 c 4 } "\01\04"
do_test 1.2.3 { read_blob temp t1 b 4 } "temp four"
do_test 1.2.4 { read_blob temp t1 c 4 } "\02\04"
do_test 1.2.6 { read_blob aux  t1 b 4 } "aux four"
do_test 1.2.7 { read_blob aux  t1 c 4 } "\03\04"

do_test 1.3.1 { read_blob main x1 b 2 } "x main two"
do_test 1.3.2 { read_blob main x1 c 2 } "\00\01\02"
do_test 1.3.3 { read_blob temp x2 b 2 } "x temp two"
do_test 1.3.4 { read_blob temp x2 c 2 } "\00\02\02"
do_test 1.3.6 { read_blob aux  x3 b 2 } "x aux two"
do_test 1.3.7 { read_blob aux  x3 c 2 } "\00\03\02"

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-27234-05761 Parameter zDb is not the filename that
# contains the database, but rather the symbolic name of the database.
# For attached databases, this is the name that appears after the AS
# keyword in the ATTACH statement. For the main database file, the
# database name is "main". For TEMP tables, the database name is "temp".
#
#   The test cases immediately above demonstrate that the database name
#   for the main db, for TEMP tables and for those in attached databases
#   is correct. The following tests check that filenames cannot be
#   used as well.
#
do_test 2.1 {
  list [catch { sqlite3_blob_open db "test.db" t1 b 1 0 B } msg] $msg
} {1 SQLITE_ERROR}
do_test 2.2 {
  list [catch { sqlite3_blob_open db "test.db2" t1 b 1 0 B } msg] $msg
} {1 SQLITE_ERROR}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-50854-53979 If the flags parameter is non-zero, then
# the BLOB is opened for read and write access.
#
# EVIDENCE-OF: R-03922-41160 If the flags parameter is zero, the BLOB is
# opened for read-only access.
#
foreach {tn iRow flags} {
  1 1   0
  2 2   1
  3 3  -1
  4 4   2147483647
  5 5  -2147483648
} {
  do_test 3.$tn.1 {
    sqlite3_blob_open db main x1 c $iRow $flags B
    set n [sqlite3_blob_bytes $B]
    sqlite3_blob_read $B 0 $n
  } [binary format ccc 0 1 $iRow]

  if {$flags==0} {
    # Blob was opened for read-only access - writing returns an error.
    do_test 3.$tn.2 {
      list [catch { sqlite3_blob_write $B 0 xxx 3 } msg] $msg
    } {1 SQLITE_READONLY}

    do_execsql_test 3.$tn.3 {
      SELECT c FROM x1 WHERE a=$iRow;
    } [binary format ccc 0 1 $iRow]
  } else {
    # Blob was opened for read/write access - writing succeeds
    do_test 3.$tn.4 {
      list [catch { sqlite3_blob_write $B 0 xxx 3 } msg] $msg
    } {0 {}}

    do_execsql_test 3.$tn.5 {
      SELECT c FROM x1 WHERE a=$iRow;
    } {xxx}
  }

  sqlite3_blob_close $B
}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 4.0 {
  CREATE TABLE t1(x, y);
  INSERT INTO t1 VALUES('abcd', 152);
  INSERT INTO t1 VALUES(NULL, X'00010203');
  INSERT INTO t1 VALUES('', 154.2);

  CREATE TABLE t2(x PRIMARY KEY, y) WITHOUT ROWID;
  INSERT INTO t2 VALUES(1, 'blob');

  CREATE TABLE t3(a PRIMARY KEY, b, c, d, e, f, UNIQUE(e, f));
  INSERT INTO t3 VALUES('aaaa', 'bbbb', 'cccc', 'dddd', 'eeee', 'ffff');
  CREATE INDEX t3b ON t3(b);

  CREATE TABLE p1(x PRIMARY KEY);
  INSERT INTO p1 VALUES('abc');

  CREATE TABLE c1(a INTEGER PRIMARY KEY, b REFERENCES p1);
  INSERT INTO c1 VALUES(45, 'abc');
}

proc test_blob_open {tn zDb zTab zCol iRow flags    errcode errmsg} {
  global B
  set B "0x1234"

  if {$errcode=="SQLITE_OK"} {
    set expected "0 {}"
  } else {
    set expected "1 $errcode"
  }

  set ::res [list [
    catch { sqlite3_blob_open db $zDb $zTab $zCol $iRow $flags B } msg
  ] $msg]
  do_test 4.$tn.1 { set ::res } $expected

  # EVIDENCE-OF: R-08940-21305 Unless it returns SQLITE_MISUSE, this
  # function sets the database connection error code and message
  # accessible via sqlite3_errcode() and sqlite3_errmsg() and related
  # functions.
  #
  #   This proc (test_blob_open) is used below to test various error and
  #   non-error conditions. But never SQLITE_MISUSE conditions. So these
  #   test cases are considered as partly verifying the requirement above.
  #   See below for a test of the SQLITE_MISUSE case.
  #
  do_test 4.$tn.2 {
    sqlite3_errcode db
  } $errcode
  do_test 4.$tn.3 {
    sqlite3_errmsg db
  } $errmsg

  # EVIDENCE-OF: R-31086-35521 On success, SQLITE_OK is returned and the
  # new BLOB handle is stored in *ppBlob. Otherwise an error code is
  # returned and, unless the error code is SQLITE_MISUSE, *ppBlob is set
  # to NULL.
  #
  do_test 4.$tn.4 {
    expr {$B == "0"}
  } [expr {$errcode != "SQLITE_OK"}]

  # EVIDENCE-OF: R-63421-15521 This means that, provided the API is not
  # misused, it is always safe to call sqlite3_blob_close() on *ppBlob
  # after this function it returns.
  do_test 4.$tn.5 {
    sqlite3_blob_close $B
  } {}
}

# EVIDENCE-OF: R-31204-44780 Database zDb does not exist
test_blob_open 1 nosuchdb t1 x 1 0 SQLITE_ERROR "no such table: nosuchdb.t1"

# EVIDENCE-OF: R-28676-08005 Table zTable does not exist within database zDb
test_blob_open 2 main tt1 x 1 0    SQLITE_ERROR "no such table: main.tt1"

# EVIDENCE-OF: R-40134-30296 Table zTable is a WITHOUT ROWID table
test_blob_open 3 main t2 y 1 0     SQLITE_ERROR \
    "cannot open table without rowid: t2"

# EVIDENCE-OF: R-56376-21261 Column zColumn does not exist
test_blob_open 4 main t1 z 2 0     SQLITE_ERROR "no such column: \"z\""

# EVIDENCE-OF: R-28258-23166 Row iRow is not present in the table
test_blob_open 5 main t1 y 6 0     SQLITE_ERROR "no such rowid: 6"

# EVIDENCE-OF: R-11683-62380 The specified column of row iRow contains a
# value that is not a TEXT or BLOB value
test_blob_open 6 main t1 x 2 0 SQLITE_ERROR "cannot open value of type null"
test_blob_open 7 main t1 y 1 0 SQLITE_ERROR "cannot open value of type integer"
test_blob_open 8 main t1 y 3 0 SQLITE_ERROR "cannot open value of type real"

# EVIDENCE-OF: R-34146-30782 Column zColumn is part of an index, PRIMARY
# KEY or UNIQUE constraint and the blob is being opened for read/write
# access
#
# Test cases 8.1.* show that such columns can be opened for read-access. 
# Tests 8.2.* show that read-write access is different. Columns "c" and "c"
# are not part of an index, PK or UNIQUE constraint, so they work in both
# cases.
#
test_blob_open 8.1.1 main t3 a 1 0 SQLITE_OK "not an error"
test_blob_open 8.1.2 main t3 b 1 0 SQLITE_OK "not an error"
test_blob_open 8.1.3 main t3 c 1 0 SQLITE_OK "not an error"
test_blob_open 8.1.4 main t3 d 1 0 SQLITE_OK "not an error"
test_blob_open 8.1.5 main t3 e 1 0 SQLITE_OK "not an error"
test_blob_open 8.1.6 main t3 f 1 0 SQLITE_OK "not an error"

set cannot "cannot open indexed column for writing"
test_blob_open 8.2.1 main t3 a 1 8 SQLITE_ERROR $cannot
test_blob_open 8.2.2 main t3 b 1 8 SQLITE_ERROR $cannot
test_blob_open 8.2.3 main t3 c 1 8 SQLITE_OK "not an error"
test_blob_open 8.2.4 main t3 d 1 8 SQLITE_OK "not an error"
test_blob_open 8.2.5 main t3 e 1 8 SQLITE_ERROR $cannot
test_blob_open 8.2.6 main t3 f 1 8 SQLITE_ERROR $cannot

# EVIDENCE-OF: R-50117-55204 Foreign key constraints are enabled, column
# zColumn is part of a child key definition and the blob is being opened
# for read/write access
#
#   9.1: FK disabled, read-only access.
#   9.2: FK disabled, read-only access.
#   9.3: FK enabled, read/write access.
#   9.4: FK enabled, read/write access.
#
test_blob_open 9.1 main c1 b 45 0 SQLITE_OK "not an error"
test_blob_open 9.2 main c1 b 45 1 SQLITE_OK "not an error"
execsql { PRAGMA foreign_keys = ON }
test_blob_open 9.3 main c1 b 45 0 SQLITE_OK "not an error"
test_blob_open 9.4 main c1 b 45 1 SQLITE_ERROR \
        "cannot open foreign key column for writing"

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-08940-21305 Unless it returns SQLITE_MISUSE, this
# function sets the database connection error code and message
# accessible via sqlite3_errcode() and sqlite3_errmsg() and related
# functions.
#
#   This requirement is partially verified by the many uses of test
#   command [test_blob_open] above. All that is left is to verify the
#   SQLITE_MISUSE case.
#
#   SQLITE_MISUSE is only returned if SQLITE_ENABLE_API_ARMOR is defined
#   during compilation.
#
ifcapable api_armor {
  sqlite3_blob_open db main t1 x 1 0 B

  do_test 10.1.1 {
    list [catch {sqlite3_blob_open $B main t1 x 1 0 B2} msg] $msg
  } {1 SQLITE_MISUSE}
  do_test 10.1.2 {
    list [sqlite3_errcode db] [sqlite3_errmsg db]
  } {SQLITE_OK {not an error}}
  sqlite3_blob_close $B

  do_test 10.2.1 {
    list [catch {sqlite3_blob_open db main {} x 1 0 B} msg] $msg
  } {1 SQLITE_MISUSE}
  do_test 10.2.2 {
    list [sqlite3_errcode db] [sqlite3_errmsg db]
  } {SQLITE_OK {not an error}}
}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-50542-62589 If the row that a BLOB handle points to is
# modified by an UPDATE, DELETE, or by ON CONFLICT side-effects then the
# BLOB handle is marked as "expired". This is true if any column of the
# row is changed, even a column other than the one the BLOB handle is
# open on.
#
# EVIDENCE-OF: R-48367-20048 Calls to sqlite3_blob_read() and
# sqlite3_blob_write() for an expired BLOB handle fail with a return
# code of SQLITE_ABORT.
#
#   11.2: read-only handle, DELETE.
#   11.3: read-only handle, UPDATE.
#   11.4: read-only handle, REPLACE.
#   11.5: read/write handle, DELETE.
#   11.6: read/write handle, UPDATE.
#   11.7: read/write handle, REPLACE.
#
do_execsql_test 11.1 {
  CREATE TABLE b1(a INTEGER PRIMARY KEY, b, c UNIQUE);
  INSERT INTO b1 VALUES(1, '1234567890', 1);
  INSERT INTO b1 VALUES(2, '1234567890', 2);
  INSERT INTO b1 VALUES(3, '1234567890', 3);
  INSERT INTO b1 VALUES(4, '1234567890', 4);
  INSERT INTO b1 VALUES(5, '1234567890', 5);
  INSERT INTO b1 VALUES(6, '1234567890', 6);

  CREATE TABLE b2(a INTEGER PRIMARY KEY, b, c UNIQUE);
  INSERT INTO b2 VALUES(1, '1234567890', 1);
  INSERT INTO b2 VALUES(2, '1234567890', 2);
  INSERT INTO b2 VALUES(3, '1234567890', 3);
  INSERT INTO b2 VALUES(4, '1234567890', 4);
  INSERT INTO b2 VALUES(5, '1234567890', 5);
  INSERT INTO b2 VALUES(6, '1234567890', 6);
}

do_test 11.2.1 {
  sqlite3_blob_open db main b1 b 2 0 B
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.2.2 {
  # Deleting a different row does not invalidate the blob handle.
  execsql { DELETE FROM b1 WHERE a = 1 }
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.2.3 {
  execsql { DELETE FROM b1 WHERE a = 2 }
  list [catch { sqlite3_blob_read $B 0 10 } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.2.4 {
  sqlite3_blob_close $B
} {}

do_test 11.3.1 {
  sqlite3_blob_open db main b1 b 3 0 B
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.3.2 {
  # Updating a different row
  execsql { UPDATE b1 SET c = 42 WHERE a=4 }
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.3.3 {
  execsql { UPDATE b1 SET c = 43 WHERE a=3 }
  list [catch { sqlite3_blob_read $B 0 10 } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.3.4 {
  sqlite3_blob_close $B
} {}

do_test 11.4.1 {
  sqlite3_blob_open db main b1 b 6 0 B
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.4.2 {
  # Replace a different row
  execsql { INSERT OR REPLACE INTO b1 VALUES(10, 'abcdefghij', 5) }
  sqlite3_blob_read $B 0 10
} {1234567890}
do_test 11.4.3 {
  execsql { INSERT OR REPLACE INTO b1 VALUES(11, 'abcdefghij', 6) }
  list [catch { sqlite3_blob_read $B 0 10 } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.4.4 {
  sqlite3_blob_close $B
} {}

do_test 11.4.1 {
  sqlite3_blob_open db main b2 b 2 1 B
  sqlite3_blob_write $B 0 "abcdefghij"
} {}
do_test 11.4.2 {
  # Deleting a different row does not invalidate the blob handle.
  execsql { DELETE FROM b2 WHERE a = 1 }
  sqlite3_blob_write $B 0 "ABCDEFGHIJ"
} {}
do_test 11.4.3 {
  execsql { DELETE FROM b2 WHERE a = 2 }
  list [catch { sqlite3_blob_write $B 0 "0987654321" } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.4.4 {
  sqlite3_blob_close $B
} {}

do_test 11.5.1 {
  sqlite3_blob_open db main b2 b 3 1 B
  sqlite3_blob_write $B 0 "abcdefghij"
} {}
do_test 11.5.2 {
  # Updating a different row
  execsql { UPDATE b2 SET c = 42 WHERE a=4 }
  sqlite3_blob_write $B 0 "ABCDEFGHIJ"
} {}
do_test 11.5.3 {
  execsql { UPDATE b2 SET c = 43 WHERE a=3 }
  list [catch { sqlite3_blob_write $B 0 "0987654321" } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.5.4 {
  sqlite3_blob_close $B
} {}

do_test 11.6.1 {
  sqlite3_blob_open db main b2 b 6 1 B
  sqlite3_blob_write $B 0 "abcdefghij"
} {}
do_test 11.6.2 {
  # Replace a different row
  execsql { INSERT OR REPLACE INTO b2 VALUES(10, 'abcdefghij', 5) }
  sqlite3_blob_write $B 0 "ABCDEFGHIJ"
} {}
do_test 11.6.3 {
  execsql { INSERT OR REPLACE INTO b2 VALUES(11, 'abcdefghij', 6) }
  list [catch { sqlite3_blob_write $B 0 "0987654321" } msg] $msg
} {1 SQLITE_ABORT}
do_test 11.6.4 {
  sqlite3_blob_close $B
} {}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-45408-40694 Changes written into a BLOB prior to the
# BLOB expiring are not rolled back by the expiration of the BLOB. Such
# changes will eventually commit if the transaction continues to
# completion.
#
do_execsql_test 12.1 {
  CREATE TABLE b3(x INTEGER PRIMARY KEY, y TEXT, z INTEGER);
  INSERT INTO b3 VALUES(22, '..........', NULL);
}
do_test 12.2 {
  sqlite3_blob_open db main b3 y 22 1 B
  sqlite3_blob_write $B 0 "xxxxx" 5
} {}
do_execsql_test 12.3 {
  UPDATE b3 SET z = 'not null';
}
do_test 12.4 {
  list [catch {sqlite3_blob_write $B 5 "xxxxx" 5} msg] $msg
} {1 SQLITE_ABORT}
do_execsql_test 12.5 {
  SELECT * FROM b3;
} {22 xxxxx..... {not null}}
do_test 12.5 {
  sqlite3_blob_close $B
} {}
do_execsql_test 12.6 {
  SELECT * FROM b3;
} {22 xxxxx..... {not null}}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-58813-55036 The sqlite3_bind_zeroblob() and
# sqlite3_result_zeroblob() interfaces and the built-in zeroblob SQL
# function may be used to create a zero-filled blob to read or write
# using the incremental-blob interface.
#
do_execsql_test 13.1 {
  CREATE TABLE c2(i INTEGER PRIMARY KEY, j);
  INSERT INTO c2 VALUES(10, zeroblob(24));
}

do_test 13.2 {
  set stmt [sqlite3_prepare_v2 db "INSERT INTO c2 VALUES(11, ?)" -1]
  sqlite3_bind_zeroblob $stmt 1 45
  sqlite3_step $stmt
  sqlite3_finalize $stmt
} {SQLITE_OK}

# The blobs can be read:
#
do_test 13.3.1 {
  sqlite3_blob_open db main c2 j 10 1 B
  sqlite3_blob_open db main c2 j 11 1 B2
  list [sqlite3_blob_bytes $B] [sqlite3_blob_bytes $B2]
} {24 45}
do_test 13.3.2 {
  sqlite3_blob_read $B 0 24
} [string repeat [binary format c 0] 24]
do_test 13.3.3 {
  sqlite3_blob_read $B2 0 45
} [string repeat [binary format c 0] 45]

# And also written:
#
do_test 13.4.1 {
  sqlite3_blob_write $B 0 [string repeat [binary format c 1] 24]
} {}
do_test 13.4.2 {
  sqlite3_blob_write $B2 0 [string repeat [binary format c 1] 45]
} {}
do_test 13.5 {
  sqlite3_blob_close $B
  sqlite3_blob_close $B2
  execsql { SELECT j FROM c2 }
} [list \
    [string repeat [binary format c 1] 24] \
    [string repeat [binary format c 1] 45] \
]


finish_test

# 2014 October 30
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix e_blobwrite

#--------------------------------------------------------------------------
# EVIDENCE-OF: R-62898-22698 This function is used to write data into an
# open BLOB handle from a caller-supplied buffer. N bytes of data are
# copied from the buffer Z into the open BLOB, starting at offset
# iOffset.
#
set dots [string repeat . 40]
do_execsql_test 1.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, t TEXT);
  INSERT INTO t1 VALUES(-1, $dots);
  INSERT INTO t1 VALUES(-2, $dots);
  INSERT INTO t1 VALUES(-3, $dots);
  INSERT INTO t1 VALUES(-4, $dots);
  INSERT INTO t1 VALUES(-5, $dots);
  INSERT INTO t1 VALUES(-6, $dots);
}

proc blob_write_test {tn id iOffset blob nData final} {
  sqlite3_blob_open db main t1 t $id 1 B

  # EVIDENCE-OF: R-45864-01884 On success, sqlite3_blob_write() returns
  # SQLITE_OK. Otherwise, an error code or an extended error code is
  # returned.
  #
  #   This block tests the SQLITE_OK case in the requirement above (the
  #   Tcl sqlite3_blob_write() wrapper uses an empty string in place of
  #   "SQLITE_OK"). The error cases are tested by the "blob_write_error_test"
  #   tests below.
  #
  set res [sqlite3_blob_write $B $iOffset $blob $nData]
  uplevel [list do_test $tn.1 [list set {} $res] {}]

  sqlite3_blob_close $B
  uplevel [list do_execsql_test $tn.3 "SELECT t FROM t1 WHERE a=$id" $final]
}

set blob "0123456789012345678901234567890123456789"
blob_write_test 1.1 -1 0 $blob 10  { 0123456789.............................. }
blob_write_test 1.2 -2 8 $blob 10  { ........0123456789...................... }
blob_write_test 1.3 -3 8 $blob 1   { ........0............................... }
blob_write_test 1.4 -4 18 $blob 22 { ..................0123456789012345678901 }
blob_write_test 1.5 -5 18 $blob 0  { ........................................ }
blob_write_test 1.6 -6 0 $blob 40  { 0123456789012345678901234567890123456789 }


proc blob_write_error_test {tn B iOffset blob nData errcode errmsg} {

  # In cases where the underlying sqlite3_blob_write() function returns
  # SQLITE_OK, the Tcl wrapper returns an empty string. If the underlying
  # function returns an error, the Tcl wrapper throws an exception with
  # the error code as the Tcl exception message.
  #
  if {$errcode=="SQLITE_OK"} {
    set ret ""
    set isError 0
  } else {
    set ret $errcode
    set isError 1
  }

  set cmd [list sqlite3_blob_write $B $iOffset $blob $nData]
  uplevel [list do_test $tn.1 [subst -nocommands {
    list [catch {$cmd} msg] [set msg]              
  }] [list $isError $ret]]

  # EVIDENCE-OF: R-34782-18311 Unless SQLITE_MISUSE is returned, this
  # function sets the database connection error code and message
  # accessible via sqlite3_errcode() and sqlite3_errmsg() and related
  # functions.
  #
  if {$errcode == "SQLITE_MISUSE"} { error "test proc misuse!" }
  uplevel [list do_test $tn.2 [list sqlite3_errcode db] $errcode]
  uplevel [list do_test $tn.3 [list sqlite3_errmsg db] $errmsg]
}

do_execsql_test 2.0 {
  CREATE TABLE t2(a TEXT, b INTEGER PRIMARY KEY);
  INSERT INTO t2 VALUES($dots, 43);
  INSERT INTO t2 VALUES($dots, 44);
  INSERT INTO t2 VALUES($dots, 45);
}

# EVIDENCE-OF: R-63341-57517 If the BLOB handle passed as the first
# argument was not opened for writing (the flags parameter to
# sqlite3_blob_open() was zero), this function returns SQLITE_READONLY.
#
sqlite3_blob_open db main t2 a 43 0 B
blob_write_error_test 2.1 $B 0 $blob 10   \
    SQLITE_READONLY {attempt to write a readonly database}
sqlite3_blob_close $B

# EVIDENCE-OF: R-29804-27366 If offset iOffset is less than N bytes from
# the end of the BLOB, SQLITE_ERROR is returned and no data is written.
#
sqlite3_blob_open db main t2 a 44 3 B
blob_write_error_test 2.2.1 $B 31 $blob 10   \
    SQLITE_ERROR {SQL logic error or missing database}

# Make a successful write to the blob handle. This shows that the
# sqlite3_errcode() and sqlite3_errmsg() values are set even if the
# blob_write() call succeeds (see requirement in the [blob_write_error_test]
# proc).
blob_write_error_test 2.2.1 $B 30 $blob 10 SQLITE_OK {not an error}

# EVIDENCE-OF: R-58570-38916 If N or iOffset are less than zero
# SQLITE_ERROR is returned and no data is written.
#
blob_write_error_test 2.2.2 $B 31 $blob -1   \
    SQLITE_ERROR {SQL logic error or missing database}
blob_write_error_test 2.2.3 $B 20 $blob 10 SQLITE_OK {not an error}
blob_write_error_test 2.2.4 $B -1 $blob 10   \
    SQLITE_ERROR {SQL logic error or missing database}
sqlite3_blob_close $B

# EVIDENCE-OF: R-20958-54138 An attempt to write to an expired BLOB
# handle fails with an error code of SQLITE_ABORT.
#
do_test 2.3 {
  sqlite3_blob_open db main t2 a 43 0 B
  execsql { DELETE FROM t2 WHERE b=43 }
} {}
blob_write_error_test 2.3.1 $B 5 $blob 5 \
    SQLITE_ABORT {callback requested query abort}
do_test 2.3.2 {
  execsql { SELECT 1, 2, 3 }
  sqlite3_errcode db
} {SQLITE_OK}
blob_write_error_test 2.3.3 $B 5 $blob 5 \
    SQLITE_ABORT {callback requested query abort}
sqlite3_blob_close $B

# EVIDENCE-OF: R-08382-59936 Writes to the BLOB that occurred before the
# BLOB handle expired are not rolled back by the expiration of the
# handle, though of course those changes might have been overwritten by
# the statement that expired the BLOB handle or by other independent
# statements.
#
#   3.1.*: not rolled back, 
#   3.2.*: overwritten.
#
do_execsql_test 3.0 {
  CREATE TABLE t3(i INTEGER PRIMARY KEY, j TEXT, k TEXT);
  INSERT INTO t3 VALUES(1, $dots, $dots);
  INSERT INTO t3 VALUES(2, $dots, $dots);
  SELECT * FROM t3 WHERE i=1;
} {
  1
  ........................................
  ........................................
}
sqlite3_blob_open db main t3 j 1 1 B
blob_write_error_test 3.1.1 $B 5 $blob 10 SQLITE_OK {not an error}
do_execsql_test 3.1.2 {
  UPDATE t3 SET k = 'xyz' WHERE i=1;
  SELECT * FROM t3 WHERE i=1;
} {
  1 .....0123456789......................... xyz
}
blob_write_error_test 3.1.3 $B 15 $blob 10 \
    SQLITE_ABORT {callback requested query abort}
sqlite3_blob_close $B
do_execsql_test 3.1.4 {
  SELECT * FROM t3 WHERE i=1;
} {
  1 .....0123456789......................... xyz
}

sqlite3_blob_open db main t3 j 2 1 B
blob_write_error_test 3.2.1 $B 5 $blob 10 SQLITE_OK {not an error}
do_execsql_test 3.2.2 {
  UPDATE t3 SET j = 'xyz' WHERE i=2;
  SELECT * FROM t3 WHERE i=2;
} {
  2 xyz ........................................
}
blob_write_error_test 3.2.3 $B 15 $blob 10 \
    SQLITE_ABORT {callback requested query abort}
sqlite3_blob_close $B
do_execsql_test 3.2.4 {
  SELECT * FROM t3 WHERE i=2;
} {
  2 xyz ........................................
}



finish_test