SQLite

# Object files for the SQLite library (non-amalgamation).
#
LIBOBJS0 = alter.lo analyze.lo attach.lo auth.lo \
         backup.lo bitvec.lo btmutex.lo btree.lo build.lo \
         callback.lo complete.lo ctime.lo date.lo delete.lo \
         expr.lo fault.lo fkey.lo \
         fts3.lo fts3_aux.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo fts3_porter.lo \
         fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo fts3_write.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo journal.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_os2.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_os2.lo os_unix.lo os_win.lo \

  $(TOP)/ext/fts2/fts2_tokenizer.h \
  $(TOP)/ext/fts2/fts2_tokenizer.c \
  $(TOP)/ext/fts2/fts2_tokenizer1.c
SRC += \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3.h \
  $(TOP)/ext/fts3/fts3Int.h \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \
  $(TOP)/ext/fts3/fts3_hash.c \
  $(TOP)/ext/fts3/fts3_hash.h \
  $(TOP)/ext/fts3/fts3_icu.c \
  $(TOP)/ext/fts3/fts3_porter.c \
  $(TOP)/ext/fts3/fts3_snippet.c \
  $(TOP)/ext/fts3/fts3_tokenizer.h \

  $(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_func.c \
  $(TOP)/src/test_fuzzer.c \
  $(TOP)/src/test_hexio.c \
  $(TOP)/src/test_init.c \
  $(TOP)/src/test_intarray.c \
  $(TOP)/src/test_journal.c \
  $(TOP)/src/test_malloc.c \
  $(TOP)/src/test_multiplex.c \
  $(TOP)/src/test_mutex.c \
  $(TOP)/src/test_onefile.c \
  $(TOP)/src/test_osinst.c \
  $(TOP)/src/test_pcache.c \
  $(TOP)/src/test_quota.c \
  $(TOP)/src/test_rtree.c \
  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_stat.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_wholenumber.c \
  $(TOP)/src/test_wsd.c

# Source code to the library files needed by the test fixture
#
TESTSRC2 = \
  $(TOP)/src/attach.c \
  $(TOP)/src/backup.c \

  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/where.c \
  parse.c \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \
  $(TOP)/ext/fts3/fts3_tokenizer.c \
  $(TOP)/ext/fts3/fts3_write.c \
  $(TOP)/ext/async/sqlite3async.c

# Header files used by all library source files.
#

fts2_tokenizer1.lo:	$(TOP)/ext/fts2/fts2_tokenizer1.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/fts2/fts2_tokenizer1.c

fts3.lo:	$(TOP)/ext/fts3/fts3.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3.c

fts3_aux.lo:	$(TOP)/ext/fts3/fts3_aux.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_aux.c

fts3_expr.lo:	$(TOP)/ext/fts3/fts3_expr.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_expr.c

fts3_hash.lo:	$(TOP)/ext/fts3/fts3_hash.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_hash.c

fts3_icu.lo:	$(TOP)/ext/fts3/fts3_icu.c $(HDR) $(EXTHDR)

3.7.6

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.62 for sqlite 3.7.6.
#
# 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='3.7.6'
PACKAGE_STRING='sqlite 3.7.6'
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 3.7.6 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 3.7.6:";;
   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 3.7.6
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 3.7.6, 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 3.7.6, 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 3.7.6
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."

  assert( p->pSegments==0 );

  /* Free any prepared statements held */
  for(i=0; i<SizeofArray(p->aStmt); i++){
    sqlite3_finalize(p->aStmt[i]);
  }
  sqlite3_free(p->zSegmentsTbl);
  sqlite3_free(p->zReadExprlist);
  sqlite3_free(p->zWriteExprlist);

  /* Invoke the tokenizer destructor to free the tokenizer. */
  p->pTokenizer->pModule->xDestroy(p->pTokenizer);

  sqlite3_free(p);
  return SQLITE_OK;
}

  zValue = sqlite3_mprintf("%s", &zCsr[1]);
  if( zValue ){
    sqlite3Fts3Dequote(zValue);
  }
  *pzValue = zValue;
  return 1;
}

/*
** Append the output of a printf() style formatting to an existing string.
*/
static void fts3Appendf(
  int *pRc,                       /* IN/OUT: Error code */
  char **pz,                      /* IN/OUT: Pointer to string buffer */
  const char *zFormat,            /* Printf format string to append */
  ...                             /* Arguments for printf format string */
){
  if( *pRc==SQLITE_OK ){
    va_list ap;
    char *z;
    va_start(ap, zFormat);
    z = sqlite3_vmprintf(zFormat, ap);
    if( z && *pz ){
      char *z2 = sqlite3_mprintf("%s%s", *pz, z);
      sqlite3_free(z);
      z = z2;
    }
    if( z==0 ) *pRc = SQLITE_NOMEM;
    sqlite3_free(*pz);
    *pz = z;
  }
}

/*
** Return a copy of input string zInput enclosed in double-quotes (") and
** with all double quote characters escaped. For example:
**
**     fts3QuoteId("un \"zip\"")   ->    "un \"\"zip\"\""
**
** The pointer returned points to memory obtained from sqlite3_malloc(). It
** is the callers responsibility to call sqlite3_free() to release this
** memory.
*/
static char *fts3QuoteId(char const *zInput){
  int nRet;
  char *zRet;
  nRet = 2 + strlen(zInput)*2 + 1;
  zRet = sqlite3_malloc(nRet);
  if( zRet ){
    int i;
    char *z = zRet;
    *(z++) = '"';
    for(i=0; zInput[i]; i++){
      if( zInput[i]=='"' ) *(z++) = '"';
      *(z++) = zInput[i];
    }
    *(z++) = '"';
    *(z++) = '\0';
  }
  return zRet;
}

/*
** Return a list of comma separated SQL expressions that could be used
** in a SELECT statement such as the following:
**
**     SELECT <list of expressions> FROM %_content AS x ...
**
** to return the docid, followed by each column of text data in order
** from left to write. If parameter zFunc is not NULL, then instead of
** being returned directly each column of text data is passed to an SQL
** function named zFunc first. For example, if zFunc is "unzip" and the
** table has the three user-defined columns "a", "b", and "c", the following
** string is returned:
**
**     "docid, unzip(x.'a'), unzip(x.'b'), unzip(x.'c')"
**
** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
** is the responsibility of the caller to eventually free it.
**
** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
** a NULL pointer is returned). Otherwise, if an OOM error is encountered
** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
** no error occurs, *pRc is left unmodified.
*/
static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){
  char *zRet = 0;
  char *zFree = 0;
  char *zFunction;
  int i;

  if( !zFunc ){
    zFunction = "";
  }else{
    zFree = zFunction = fts3QuoteId(zFunc);
  }
  fts3Appendf(pRc, &zRet, "docid");
  for(i=0; i<p->nColumn; i++){
    fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
  }
  sqlite3_free(zFree);
  return zRet;
}

/*
** Return a list of N comma separated question marks, where N is the number
** of columns in the %_content table (one for the docid plus one for each
** user-defined text column).
**
** If argument zFunc is not NULL, then all but the first question mark
** is preceded by zFunc and an open bracket, and followed by a closed
** bracket. For example, if zFunc is "zip" and the FTS3 table has three 
** user-defined text columns, the following string is returned:
**
**     "?, zip(?), zip(?), zip(?)"
**
** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
** is the responsibility of the caller to eventually free it.
**
** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
** a NULL pointer is returned). Otherwise, if an OOM error is encountered
** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
** no error occurs, *pRc is left unmodified.
*/
static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
  char *zRet = 0;
  char *zFree = 0;
  char *zFunction;
  int i;

  if( !zFunc ){
    zFunction = "";
  }else{
    zFree = zFunction = fts3QuoteId(zFunc);
  }
  fts3Appendf(pRc, &zRet, "?");
  for(i=0; i<p->nColumn; i++){
    fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
  }
  sqlite3_free(zFree);
  return zRet;
}

/*
** This function is the implementation of both the xConnect and xCreate
** methods of the FTS3 virtual table.
**
** The argv[] array contains the following:
**

  int nDb;                        /* Bytes required to hold database name */
  int nName;                      /* Bytes required to hold table name */
  int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */
  int bNoDocsize = 0;             /* True to omit %_docsize table */
  const char **aCol;              /* Array of column names */
  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */

  char *zCompress = 0;
  char *zUncompress = 0;

  assert( strlen(argv[0])==4 );
  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
  );

  nDb = (int)strlen(argv[1]) + 1;
  nName = (int)strlen(argv[2]) + 1;

      if( nKey==9 && 0==sqlite3_strnicmp(z, "matchinfo", 9) ){
        if( strlen(zVal)==4 && 0==sqlite3_strnicmp(zVal, "fts3", 4) ){
          bNoDocsize = 1;
        }else{
          *pzErr = sqlite3_mprintf("unrecognized matchinfo: %s", zVal);
          rc = SQLITE_ERROR;
        }
      }else if( nKey==8 && 0==sqlite3_strnicmp(z, "compress", 8) ){
        zCompress = zVal;
        zVal = 0;
      }else if( nKey==10 && 0==sqlite3_strnicmp(z, "uncompress", 10) ){
        zUncompress = zVal;
        zVal = 0;
      }else{
        *pzErr = sqlite3_mprintf("unrecognized parameter: %s", z);
        rc = SQLITE_ERROR;
      }
      sqlite3_free(zVal);
    }

    memcpy(zCsr, z, n);
    zCsr[n] = '\0';
    sqlite3Fts3Dequote(zCsr);
    p->azColumn[iCol] = zCsr;
    zCsr += n+1;
    assert( zCsr <= &((char *)p)[nByte] );
  }

  if( (zCompress==0)!=(zUncompress==0) ){
    char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
    rc = SQLITE_ERROR;
    *pzErr = sqlite3_mprintf("missing %s parameter in fts4 constructor", zMiss);
  }
  p->zReadExprlist = fts3ReadExprList(p, zUncompress, &rc);
  p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);
  if( rc!=SQLITE_OK ) goto fts3_init_out;

  /* If this is an xCreate call, create the underlying tables in the 
  ** database. TODO: For xConnect(), it could verify that said tables exist.
  */
  if( isCreate ){
    rc = fts3CreateTables(p);
  }

  /* Figure out the page-size for the database. This is required in order to
  ** estimate the cost of loading large doclists from the database (see 
  ** function sqlite3Fts3SegReaderCost() for details).
  */
  fts3DatabasePageSize(&rc, p);

  /* Declare the table schema to SQLite. */
  fts3DeclareVtab(&rc, p);

fts3_init_out:
  sqlite3_free(zCompress);
  sqlite3_free(zUncompress);
  sqlite3_free((void *)aCol);
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
    }else if( pTokenizer ){
      pTokenizer->pModule->xDestroy(pTokenizer);
    }

    if( !*ppOut ) return SQLITE_NOMEM;
    sqlite3Fts3PutVarint(*ppOut, docid);
  }

  return SQLITE_OK;
}





int sqlite3Fts3SegReaderCursor(
  Fts3Table *p,                   /* FTS3 table handle */
  int iLevel,                     /* Level of segments to scan */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  int isScan,                     /* True to scan from zTerm to EOF */
  Fts3SegReaderCursor *pCsr       /* Cursor object to populate */
){
  int rc = SQLITE_OK;
  int rc2;
  int iAge = 0;
  sqlite3_stmt *pStmt = 0;
  Fts3SegReader *pPending = 0;

  assert( iLevel==FTS3_SEGCURSOR_ALL 
      ||  iLevel==FTS3_SEGCURSOR_PENDING 
      ||  iLevel>=0
  );
  assert( FTS3_SEGCURSOR_PENDING<0 );
  assert( FTS3_SEGCURSOR_ALL<0 );
  assert( iLevel==FTS3_SEGCURSOR_ALL || (zTerm==0 && isPrefix==1) );
  assert( isPrefix==0 || isScan==0 );


  memset(pCsr, 0, sizeof(Fts3SegReaderCursor));

  /* If iLevel is less than 0, include a seg-reader for the pending-terms. */
  assert( isScan==0 || fts3HashCount(&p->pendingTerms)==0 );
  if( iLevel<0 && isScan==0 ){
    rc = sqlite3Fts3SegReaderPending(p, zTerm, nTerm, isPrefix, &pPending);
    if( rc==SQLITE_OK && pPending ){
      int nByte = (sizeof(Fts3SegReader *) * 16);

      pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc(nByte);
      if( pCsr->apSegment==0 ){
        rc = SQLITE_NOMEM;
      }else{
        pCsr->apSegment[0] = pPending;
        pCsr->nSegment = 1;

        pPending = 0;
      }

    }
  }

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts3AllSegdirs(p, iLevel, &pStmt);
    }
    while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){

      /* Read the values returned by the SELECT into local variables. */
      sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);
      sqlite3_int64 iLeavesEndBlock = sqlite3_column_int64(pStmt, 2);
      sqlite3_int64 iEndBlock = sqlite3_column_int64(pStmt, 3);
      int nRoot = sqlite3_column_bytes(pStmt, 4);
      char const *zRoot = sqlite3_column_blob(pStmt, 4);

      /* If nSegment is a multiple of 16 the array needs to be extended. */
      if( (pCsr->nSegment%16)==0 ){
        Fts3SegReader **apNew;
        int nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);
        apNew = (Fts3SegReader **)sqlite3_realloc(pCsr->apSegment, nByte);
        if( !apNew ){
          rc = SQLITE_NOMEM;
          goto finished;
        }
        pCsr->apSegment = apNew;
      }

      /* If zTerm is not NULL, and this segment is not stored entirely on its
      ** root node, the range of leaves scanned can be reduced. Do this. */
      if( iStartBlock && zTerm ){
        sqlite3_int64 *pi = (isPrefix ? &iLeavesEndBlock : 0);
        rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &iStartBlock, pi);
        if( rc!=SQLITE_OK ) goto finished;
        if( isPrefix==0 && isScan==0 ) iLeavesEndBlock = iStartBlock;
      }
 

      rc = sqlite3Fts3SegReaderNew(iAge, iStartBlock, iLeavesEndBlock,

          iEndBlock, zRoot, nRoot, &pCsr->apSegment[pCsr->nSegment]
      );
      if( rc!=SQLITE_OK ) goto finished;
      pCsr->nSegment++;

      iAge++;
    }



  }



 finished:
  rc2 = sqlite3_reset(pStmt);
  if( rc==SQLITE_DONE ) rc = rc2;
  sqlite3Fts3SegReaderFree(pPending);


  return rc;
}


static int fts3TermSegReaderCursor(
  Fts3Cursor *pCsr,               /* Virtual table cursor handle */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  Fts3SegReaderCursor **ppSegcsr  /* OUT: Allocated seg-reader cursor */
){


  Fts3SegReaderCursor *pSegcsr;   /* Object to allocate and return */



  int rc = SQLITE_NOMEM;          /* Return code */





  pSegcsr = sqlite3_malloc(sizeof(Fts3SegReaderCursor));






  if( pSegcsr ){



    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
    int i;

    int nCost = 0;


    rc = sqlite3Fts3SegReaderCursor(
        p, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr);









  




    for(i=0; rc==SQLITE_OK && i<pSegcsr->nSegment; i++){



      rc = sqlite3Fts3SegReaderCost(pCsr, pSegcsr->apSegment[i], &nCost);
    }


    pSegcsr->nCost = nCost;




  }




  *ppSegcsr = pSegcsr;
  return rc;
}

static void fts3SegReaderCursorFree(Fts3SegReaderCursor *pSegcsr){
  sqlite3Fts3SegReaderFinish(pSegcsr);
  sqlite3_free(pSegcsr);
}

/*
** This function retreives the doclist for the specified term (or term
** prefix) from the database. 
**
** The returned doclist may be in one of two formats, depending on the 
** value of parameter isReqPos. If isReqPos is zero, then the doclist is

  Fts3PhraseToken *pTok,          /* Token to query for */
  int iColumn,                    /* Column to query (or -ve for all columns) */
  int isReqPos,                   /* True to include position lists in output */
  int *pnOut,                     /* OUT: Size of buffer at *ppOut */
  char **ppOut                    /* OUT: Malloced result buffer */
){
  int rc;                         /* Return code */
  Fts3SegReaderCursor *pSegcsr;   /* Seg-reader cursor for this term */
  TermSelect tsc;                 /* Context object for fts3TermSelectCb() */
  Fts3SegFilter filter;           /* Segment term filter configuration */

  pSegcsr = pTok->pSegcsr;
  memset(&tsc, 0, sizeof(TermSelect));
  tsc.isReqPos = isReqPos;

  filter.flags = FTS3_SEGMENT_IGNORE_EMPTY 
        | (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
        | (isReqPos ? FTS3_SEGMENT_REQUIRE_POS : 0)
        | (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
  filter.iCol = iColumn;
  filter.zTerm = pTok->z;
  filter.nTerm = pTok->n;

  rc = sqlite3Fts3SegReaderStart(p, pSegcsr, &filter);
  while( SQLITE_OK==rc
      && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pSegcsr)) 
  ){
    rc = fts3TermSelectCb(p, (void *)&tsc, 
        pSegcsr->zTerm, pSegcsr->nTerm, pSegcsr->aDoclist, pSegcsr->nDoclist
    );
  }

  if( rc==SQLITE_OK ){
    rc = fts3TermSelectMerge(&tsc);
  }

  if( rc==SQLITE_OK ){
    *ppOut = tsc.aaOutput[0];
    *pnOut = tsc.anOutput[0];
  }else{
    int i;
    for(i=0; i<SizeofArray(tsc.aaOutput); i++){
      sqlite3_free(tsc.aaOutput[i]);
    }
  }

  fts3SegReaderCursorFree(pSegcsr);
  pTok->pSegcsr = 0;
  return rc;
}

/*
** This function counts the total number of docids in the doclist stored
** in buffer aList[], size nList bytes.
**

  /* If this is an xFilter() evaluation, create a segment-reader for each
  ** phrase token. Or, if this is an xNext() or snippet/offsets/matchinfo
  ** evaluation, only create segment-readers if there are no Fts3DeferredToken
  ** objects attached to the phrase-tokens.
  */
  for(ii=0; ii<pPhrase->nToken; ii++){
    Fts3PhraseToken *pTok = &pPhrase->aToken[ii];
    if( pTok->pSegcsr==0 ){
      if( (pCsr->eEvalmode==FTS3_EVAL_FILTER)
       || (pCsr->eEvalmode==FTS3_EVAL_NEXT && pCsr->pDeferred==0) 
       || (pCsr->eEvalmode==FTS3_EVAL_MATCHINFO && pTok->bFulltext) 
      ){
        rc = fts3TermSegReaderCursor(
            pCsr, pTok->z, pTok->n, pTok->isPrefix, &pTok->pSegcsr
        );
        if( rc!=SQLITE_OK ) return rc;
      }
    }
  }

  for(ii=0; ii<pPhrase->nToken; ii++){

      pTok = &pPhrase->aToken[iTok];
    }else{
      int nMinCost = 0x7FFFFFFF;
      int jj;

      /* Find the remaining token with the lowest cost. */
      for(jj=0; jj<pPhrase->nToken; jj++){
        Fts3SegReaderCursor *pSegcsr = pPhrase->aToken[jj].pSegcsr;
        if( pSegcsr && pSegcsr->nCost<nMinCost ){
          iTok = jj;
          nMinCost = pSegcsr->nCost;
        }
      }
      pTok = &pPhrase->aToken[iTok];

      /* This branch is taken if it is determined that loading the doclist
      ** for the next token would require more IO than loading all documents
      ** currently identified by doclist pOut/nOut. No further doclists will
      ** be loaded from the full-text index for this phrase.
      */
      if( nMinCost>nDoc && ii>0 ){
        rc = fts3DeferExpression(pCsr, pCsr->pExpr);
        break;
      }
    }

    if( pCsr->eEvalmode==FTS3_EVAL_NEXT && pTok->pDeferred ){
      rc = fts3DeferredTermSelect(pTok->pDeferred, isTermPos, &nList, &pList);
    }else{
      if( pTok->pSegcsr ){
        rc = fts3TermSelect(p, pTok, iCol, isTermPos, &nList, &pList);
      }
      pTok->bFulltext = 1;
    }
    assert( rc!=SQLITE_OK || pCsr->eEvalmode || pTok->pSegcsr==0 );
    if( rc!=SQLITE_OK ) break;

    if( isFirst ){
      pOut = pList;
      nOut = nList;
      if( pCsr->eEvalmode==FTS3_EVAL_FILTER && pPhrase->nToken>1 ){
        nDoc = fts3DoclistCountDocids(1, pOut, nOut);

  if( pExpr->eType==FTSQUERY_PHRASE ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;

    for(ii=0; rc==SQLITE_OK && ii<pPhrase->nToken; ii++){
      Fts3PhraseToken *pTok = &pPhrase->aToken[ii];
      if( pTok->pSegcsr==0 ){
        rc = fts3TermSegReaderCursor(
            pCsr, pTok->z, pTok->n, pTok->isPrefix, &pTok->pSegcsr
        );
      }
    }
  }else{ 
    rc = fts3ExprAllocateSegReaders(pCsr, pExpr->pLeft, pnExpr);
    if( rc==SQLITE_OK ){
      rc = fts3ExprAllocateSegReaders(pCsr, pExpr->pRight, pnExpr);

*/
static void fts3ExprFreeSegReaders(Fts3Expr *pExpr){
  if( pExpr ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    if( pPhrase ){
      int kk;
      for(kk=0; kk<pPhrase->nToken; kk++){
        fts3SegReaderCursorFree(pPhrase->aToken[kk].pSegcsr);
        pPhrase->aToken[kk].pSegcsr = 0;
      }
    }
    fts3ExprFreeSegReaders(pExpr->pLeft);
    fts3ExprFreeSegReaders(pExpr->pRight);
  }
}

/*
** Return the sum of the costs of all tokens in the expression pExpr. This
** function must be called after Fts3SegReaderArrays have been allocated
** for all tokens using fts3ExprAllocateSegReaders().
*/
static int fts3ExprCost(Fts3Expr *pExpr){
  int nCost;                      /* Return value */
  if( pExpr->eType==FTSQUERY_PHRASE ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;
    nCost = 0;
    for(ii=0; ii<pPhrase->nToken; ii++){
      Fts3SegReaderCursor *pSegcsr = pPhrase->aToken[ii].pSegcsr;

      if( pSegcsr ) nCost += pSegcsr->nCost;

    }
  }else{
    nCost = fts3ExprCost(pExpr->pLeft) + fts3ExprCost(pExpr->pRight);
  }
  return nCost;
}

  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){
  const char *azSql[] = {
    "SELECT %s FROM %Q.'%q_content' AS x WHERE docid = ?", /* non-full-scan */
    "SELECT %s FROM %Q.'%q_content' AS x ",                /* full-scan */
  };
  int rc;                         /* Return code */
  char *zSql;                     /* SQL statement used to access %_content */
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  UNUSED_PARAMETER(idxStr);

  }

  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
  ** statement loops through all rows of the %_content table. For a
  ** full-text query or docid lookup, the statement retrieves a single
  ** row by docid.
  */
  zSql = (char *)azSql[idxNum==FTS3_FULLSCAN_SEARCH];
  zSql = sqlite3_mprintf(zSql, p->zReadExprlist, p->zDb, p->zName);
  if( !zSql ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pCsr->pStmt, 0);
    sqlite3_free(zSql);
  }
  if( rc==SQLITE_OK && idxNum==FTS3_DOCID_SEARCH ){

  const sqlite3_tokenizer_module *pPorter = 0;

#ifdef SQLITE_ENABLE_ICU
  const sqlite3_tokenizer_module *pIcu = 0;
  sqlite3Fts3IcuTokenizerModule(&pIcu);
#endif

  rc = sqlite3Fts3InitAux(db);
  if( rc!=SQLITE_OK ) return rc;

  sqlite3Fts3SimpleTokenizerModule(&pSimple);
  sqlite3Fts3PorterTokenizerModule(&pPorter);

  /* Allocate and initialise the hash-table used to store tokenizers. */
  pHash = sqlite3_malloc(sizeof(Fts3Hash));
  if( !pHash ){
    rc = SQLITE_NOMEM;

typedef struct Fts3Expr Fts3Expr;
typedef struct Fts3Phrase Fts3Phrase;
typedef struct Fts3PhraseToken Fts3PhraseToken;

typedef struct Fts3SegFilter Fts3SegFilter;
typedef struct Fts3DeferredToken Fts3DeferredToken;
typedef struct Fts3SegReader Fts3SegReader;
typedef struct Fts3SegReaderCursor Fts3SegReaderCursor;

/*
** A connection to a fulltext index is an instance of the following
** structure. The xCreate and xConnect methods create an instance
** of this structure and xDestroy and xDisconnect free that instance.
** All other methods receive a pointer to the structure as one of their
** arguments.

  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */

  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[24];

  char *zReadExprlist;
  char *zWriteExprlist;

  int nNodeSize;                  /* Soft limit for node size */
  u8 bHasStat;                    /* True if %_stat table exists */
  u8 bHasDocsize;                 /* True if %_docsize table exists */
  int nPgsz;                      /* Page size for host database */
  char *zSegmentsTbl;             /* Name of %_segments table */
  sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */

** on the assumption that the 
*/
struct Fts3PhraseToken {
  char *z;                        /* Text of the token */
  int n;                          /* Number of bytes in buffer z */
  int isPrefix;                   /* True if token ends with a "*" character */
  int bFulltext;                  /* True if full-text index was used */
  Fts3SegReaderCursor *pSegcsr;   /* Segment-reader for this token */
  Fts3DeferredToken *pDeferred;   /* Deferred token object for this token */
};

struct Fts3Phrase {
  /* Variables populated by fts3_expr.c when parsing a MATCH expression */
  int nToken;                /* Number of tokens in the phrase */
  int iColumn;               /* Index of column this phrase must match */

int sqlite3Fts3PendingTermsFlush(Fts3Table *);
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(Fts3Table*,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3SegReader *);




int sqlite3Fts3SegReaderCost(Fts3Cursor *, Fts3SegReader *, int *);
int sqlite3Fts3AllSegdirs(Fts3Table*, int, sqlite3_stmt **);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*);

int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);

void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *, int *);
void sqlite3Fts3SegmentsClose(Fts3Table *);

#define FTS3_SEGCURSOR_PENDING -1
#define FTS3_SEGCURSOR_ALL     -2

int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3SegReaderCursor*, Fts3SegFilter*);
int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3SegReaderCursor *);
void sqlite3Fts3SegReaderFinish(Fts3SegReaderCursor *);
int sqlite3Fts3SegReaderCursor(
    Fts3Table *, int, const char *, int, int, int, Fts3SegReaderCursor *);

/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
#define FTS3_SEGMENT_PREFIX        0x00000008
#define FTS3_SEGMENT_SCAN          0x00000010

/* Type passed as 4th argument to SegmentReaderIterate() */
struct Fts3SegFilter {
  const char *zTerm;
  int nTerm;
  int iCol;
  int flags;
};

struct Fts3SegReaderCursor {
  /* Used internally by sqlite3Fts3SegReaderXXX() calls */
  Fts3SegReader **apSegment;      /* Array of Fts3SegReader objects */
  int nSegment;                   /* Size of apSegment array */
  int nAdvance;                   /* How many seg-readers to advance */
  Fts3SegFilter *pFilter;         /* Pointer to filter object */
  char *aBuffer;                  /* Buffer to merge doclists in */
  int nBuffer;                    /* Allocated size of aBuffer[] in bytes */

  /* Cost of running this iterator. Used by fts3.c only. */
  int nCost;

  /* Output values. Valid only after Fts3SegReaderStep() returns SQLITE_ROW. */
  char *zTerm;                    /* Pointer to term buffer */
  int nTerm;                      /* Size of zTerm in bytes */
  char *aDoclist;                 /* Pointer to doclist buffer */
  int nDoclist;                   /* Size of aDoclist[] in bytes */
};

/* fts3.c */
int sqlite3Fts3PutVarint(char *, sqlite3_int64);
int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
int sqlite3Fts3GetVarint32(const char *, int *);
int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);

  char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif

/* fts3_aux.c */
int sqlite3Fts3InitAux(sqlite3 *db);

#endif /* _FTSINT_H */

/*
** 2011 Jan 27
**
** 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.
**
******************************************************************************
**
*/

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#include "fts3Int.h"
#include <string.h>
#include <assert.h>

typedef struct Fts3auxTable Fts3auxTable;
typedef struct Fts3auxCursor Fts3auxCursor;

struct Fts3auxTable {
  sqlite3_vtab base;              /* Base class used by SQLite core */
  Fts3Table *pFts3Tab;
};

struct Fts3auxCursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  Fts3SegReaderCursor csr;        /* Must be right after "base" */
  Fts3SegFilter filter;
  char *zStop;
  int nStop;                      /* Byte-length of string zStop */
  int isEof;                      /* True if cursor is at EOF */
  sqlite3_int64 iRowid;           /* Current rowid */

  int iCol;                       /* Current value of 'col' column */
  int nStat;                      /* Size of aStat[] array */
  struct Fts3auxColstats {
    sqlite3_int64 nDoc;           /* 'documents' values for current csr row */
    sqlite3_int64 nOcc;           /* 'occurrences' values for current csr row */
  } *aStat;
};

/*
** Schema of the terms table.
*/
#define FTS3_TERMS_SCHEMA "CREATE TABLE x(term, col, documents, occurrences)"

/*
** This function does all the work for both the xConnect and xCreate methods.
** These tables have no persistent representation of their own, so xConnect
** and xCreate are identical operations.
*/
static int fts3auxConnectMethod(
  sqlite3 *db,                    /* Database connection */
  void *pUnused,                  /* Unused */
  int argc,                       /* Number of elements in argv array */
  const char * const *argv,       /* xCreate/xConnect argument array */
  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
){
  char const *zDb;                /* Name of database (e.g. "main") */
  char const *zFts3;              /* Name of fts3 table */
  int nDb;                        /* Result of strlen(zDb) */
  int nFts3;                      /* Result of strlen(zFts3) */
  int nByte;                      /* Bytes of space to allocate here */
  int rc;                         /* value returned by declare_vtab() */
  Fts3auxTable *p;                /* Virtual table object to return */

  /* The user should specify a single argument - the name of an fts3 table. */
  if( argc!=4 ){
    *pzErr = sqlite3_mprintf(
        "wrong number of arguments to fts4aux constructor"
    );
    return SQLITE_ERROR;
  }

  zDb = argv[1]; 
  nDb = strlen(zDb);
  zFts3 = argv[3];
  nFts3 = strlen(zFts3);

  rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA);
  if( rc!=SQLITE_OK ) return rc;

  nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
  p = (Fts3auxTable *)sqlite3_malloc(nByte);
  if( !p ) return SQLITE_NOMEM;
  memset(p, 0, nByte);

  p->pFts3Tab = (Fts3Table *)&p[1];
  p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1];
  p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1];
  p->pFts3Tab->db = db;

  memcpy((char *)p->pFts3Tab->zDb, zDb, nDb);
  memcpy((char *)p->pFts3Tab->zName, zFts3, nFts3);
  sqlite3Fts3Dequote((char *)p->pFts3Tab->zName);

  *ppVtab = (sqlite3_vtab *)p;
  return SQLITE_OK;
}

/*
** This function does the work for both the xDisconnect and xDestroy methods.
** These tables have no persistent representation of their own, so xDisconnect
** and xDestroy are identical operations.
*/
static int fts3auxDisconnectMethod(sqlite3_vtab *pVtab){
  Fts3auxTable *p = (Fts3auxTable *)pVtab;
  Fts3Table *pFts3 = p->pFts3Tab;
  int i;

  /* Free any prepared statements held */
  for(i=0; i<SizeofArray(pFts3->aStmt); i++){
    sqlite3_finalize(pFts3->aStmt[i]);
  }
  sqlite3_free(pFts3->zSegmentsTbl);
  sqlite3_free(p);
  return SQLITE_OK;
}

#define FTS4AUX_EQ_CONSTRAINT 1
#define FTS4AUX_GE_CONSTRAINT 2
#define FTS4AUX_LE_CONSTRAINT 4

/*
** xBestIndex - Analyze a WHERE and ORDER BY clause.
*/
static int fts3auxBestIndexMethod(
  sqlite3_vtab *pVTab, 
  sqlite3_index_info *pInfo
){
  int i;
  int iEq = -1;
  int iGe = -1;
  int iLe = -1;

  /* This vtab delivers always results in "ORDER BY term ASC" order. */
  if( pInfo->nOrderBy==1 
   && pInfo->aOrderBy[0].iColumn==0 
   && pInfo->aOrderBy[0].desc==0
  ){
    pInfo->orderByConsumed = 1;
  }

  /* Search for equality and range constraints on the "term" column. */
  for(i=0; i<pInfo->nConstraint; i++){
    if( pInfo->aConstraint[i].usable && pInfo->aConstraint[i].iColumn==0 ){
      int op = pInfo->aConstraint[i].op;
      if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
      if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
      if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
      if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
      if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
    }
  }

  if( iEq>=0 ){
    pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT;
    pInfo->aConstraintUsage[iEq].argvIndex = 1;
    pInfo->estimatedCost = 5;
  }else{
    pInfo->idxNum = 0;
    pInfo->estimatedCost = 20000;
    if( iGe>=0 ){
      pInfo->idxNum += FTS4AUX_GE_CONSTRAINT;
      pInfo->aConstraintUsage[iGe].argvIndex = 1;
      pInfo->estimatedCost /= 2;
    }
    if( iLe>=0 ){
      pInfo->idxNum += FTS4AUX_LE_CONSTRAINT;
      pInfo->aConstraintUsage[iLe].argvIndex = 1 + (iGe>=0);
      pInfo->estimatedCost /= 2;
    }
  }

  return SQLITE_OK;
}

/*
** xOpen - Open a cursor.
*/
static int fts3auxOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
  Fts3auxCursor *pCsr;            /* Pointer to cursor object to return */

  pCsr = (Fts3auxCursor *)sqlite3_malloc(sizeof(Fts3auxCursor));
  if( !pCsr ) return SQLITE_NOMEM;
  memset(pCsr, 0, sizeof(Fts3auxCursor));

  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** xClose - Close a cursor.
*/
static int fts3auxCloseMethod(sqlite3_vtab_cursor *pCursor){
  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  sqlite3Fts3SegmentsClose(pFts3);
  sqlite3Fts3SegReaderFinish(&pCsr->csr);
  sqlite3_free((void *)pCsr->filter.zTerm);
  sqlite3_free(pCsr->zStop);
  sqlite3_free(pCsr->aStat);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

static int fts3auxGrowStatArray(Fts3auxCursor *pCsr, int nSize){
  if( nSize>pCsr->nStat ){
    struct Fts3auxColstats *aNew;
    aNew = (struct Fts3auxColstats *)sqlite3_realloc(pCsr->aStat, 
        sizeof(struct Fts3auxColstats) * nSize
    );
    if( aNew==0 ) return SQLITE_NOMEM;
    memset(&aNew[pCsr->nStat], 0, 
        sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat)
    );
    pCsr->aStat = aNew;
    pCsr->nStat = nSize;
  }
  return SQLITE_OK;
}

/*
** xNext - Advance the cursor to the next row, if any.
*/
static int fts3auxNextMethod(sqlite3_vtab_cursor *pCursor){
  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
  int rc;

  /* Increment our pretend rowid value. */
  pCsr->iRowid++;

  for(pCsr->iCol++; pCsr->iCol<pCsr->nStat; pCsr->iCol++){
    if( pCsr->aStat[pCsr->iCol].nDoc>0 ) return SQLITE_OK;
  }

  rc = sqlite3Fts3SegReaderStep(pFts3, &pCsr->csr);
  if( rc==SQLITE_ROW ){
    int i = 0;
    int nDoclist = pCsr->csr.nDoclist;
    char *aDoclist = pCsr->csr.aDoclist;
    int iCol;

    int eState = 0;

    if( pCsr->zStop ){
      int n = (pCsr->nStop<pCsr->csr.nTerm) ? pCsr->nStop : pCsr->csr.nTerm;
      int mc = memcmp(pCsr->zStop, pCsr->csr.zTerm, n);
      if( mc<0 || (mc==0 && pCsr->csr.nTerm>pCsr->nStop) ){
        pCsr->isEof = 1;
        return SQLITE_OK;
      }
    }

    if( fts3auxGrowStatArray(pCsr, 2) ) return SQLITE_NOMEM;
    memset(pCsr->aStat, 0, sizeof(struct Fts3auxColstats) * pCsr->nStat);
    iCol = 0;

    while( i<nDoclist ){
      sqlite3_int64 v = 0;

      i += sqlite3Fts3GetVarint(&aDoclist[i], &v);
      switch( eState ){
        /* State 0. In this state the integer just read was a docid. */
        case 0:
          pCsr->aStat[0].nDoc++;
          eState = 1;
          iCol = 0;
          break;

        /* State 1. In this state we are expecting either a 1, indicating
        ** that the following integer will be a column number, or the
        ** start of a position list for column 0.  
        ** 
        ** The only difference between state 1 and state 2 is that if the
        ** integer encountered in state 1 is not 0 or 1, then we need to
        ** increment the column 0 "nDoc" count for this term.
        */
        case 1:
          assert( iCol==0 );
          if( v>1 ){
            pCsr->aStat[1].nDoc++;
          }
          eState = 2;
          /* fall through */

        case 2:
          if( v==0 ){       /* 0x00. Next integer will be a docid. */
            eState = 0;
          }else if( v==1 ){ /* 0x01. Next integer will be a column number. */
            eState = 3;
          }else{            /* 2 or greater. A position. */
            pCsr->aStat[iCol+1].nOcc++;
            pCsr->aStat[0].nOcc++;
          }
          break;

        /* State 3. The integer just read is a column number. */
        default: assert( eState==3 );
          iCol = (int)v;
          if( fts3auxGrowStatArray(pCsr, iCol+2) ) return SQLITE_NOMEM;
          pCsr->aStat[iCol+1].nDoc++;
          eState = 2;
          break;
      }
    }

    pCsr->iCol = 0;
    rc = SQLITE_OK;
  }else{
    pCsr->isEof = 1;
  }
  return rc;
}

/*
** xFilter - Initialize a cursor to point at the start of its data.
*/
static int fts3auxFilterMethod(
  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){
  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
  int rc;
  int isScan;

  assert( idxStr==0 );
  assert( idxNum==FTS4AUX_EQ_CONSTRAINT || idxNum==0
       || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT
       || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT)
  );
  isScan = (idxNum!=FTS4AUX_EQ_CONSTRAINT);

  /* In case this cursor is being reused, close and zero it. */
  testcase(pCsr->filter.zTerm);
  sqlite3Fts3SegReaderFinish(&pCsr->csr);
  sqlite3_free((void *)pCsr->filter.zTerm);
  sqlite3_free(pCsr->aStat);
  memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);

  pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
  if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;

  if( idxNum&(FTS4AUX_EQ_CONSTRAINT|FTS4AUX_GE_CONSTRAINT) ){
    const unsigned char *zStr = sqlite3_value_text(apVal[0]);
    if( zStr ){
      pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);
      pCsr->filter.nTerm = sqlite3_value_bytes(apVal[0]);
      if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;
    }
  }
  if( idxNum&FTS4AUX_LE_CONSTRAINT ){
    int iIdx = (idxNum&FTS4AUX_GE_CONSTRAINT) ? 1 : 0;
    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iIdx]));
    pCsr->nStop = sqlite3_value_bytes(apVal[iIdx]);
    if( pCsr->zStop==0 ) return SQLITE_NOMEM;
  }

  rc = sqlite3Fts3SegReaderCursor(pFts3, FTS3_SEGCURSOR_ALL,
      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
  }

  if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);
  return rc;
}

/*
** xEof - Return true if the cursor is at EOF, or false otherwise.
*/
static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){
  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
  return pCsr->isEof;
}

/*
** xColumn - Return a column value.
*/
static int fts3auxColumnMethod(
  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
  sqlite3_context *pContext,      /* Context for sqlite3_result_xxx() calls */
  int iCol                        /* Index of column to read value from */
){
  Fts3auxCursor *p = (Fts3auxCursor *)pCursor;

  assert( p->isEof==0 );
  if( iCol==0 ){        /* Column "term" */
    sqlite3_result_text(pContext, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
  }else if( iCol==1 ){  /* Column "col" */
    if( p->iCol ){
      sqlite3_result_int(pContext, p->iCol-1);
    }else{
      sqlite3_result_text(pContext, "*", -1, SQLITE_STATIC);
    }
  }else if( iCol==2 ){  /* Column "documents" */
    sqlite3_result_int64(pContext, p->aStat[p->iCol].nDoc);
  }else{                /* Column "occurrences" */
    sqlite3_result_int64(pContext, p->aStat[p->iCol].nOcc);
  }

  return SQLITE_OK;
}

/*
** xRowid - Return the current rowid for the cursor.
*/
static int fts3auxRowidMethod(
  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
  sqlite_int64 *pRowid            /* OUT: Rowid value */
){
  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}

/*
** Register the fts3aux module with database connection db. Return SQLITE_OK
** if successful or an error code if sqlite3_create_module() fails.
*/
int sqlite3Fts3InitAux(sqlite3 *db){
  static const sqlite3_module fts3aux_module = {
     0,                           /* iVersion      */
     fts3auxConnectMethod,        /* xCreate       */
     fts3auxConnectMethod,        /* xConnect      */
     fts3auxBestIndexMethod,      /* xBestIndex    */
     fts3auxDisconnectMethod,     /* xDisconnect   */
     fts3auxDisconnectMethod,     /* xDestroy      */
     fts3auxOpenMethod,           /* xOpen         */
     fts3auxCloseMethod,          /* xClose        */
     fts3auxFilterMethod,         /* xFilter       */
     fts3auxNextMethod,           /* xNext         */
     fts3auxEofMethod,            /* xEof          */
     fts3auxColumnMethod,         /* xColumn       */
     fts3auxRowidMethod,          /* xRowid        */
     0,                           /* xUpdate       */
     0,                           /* xBegin        */
     0,                           /* xSync         */
     0,                           /* xCommit       */
     0,                           /* xRollback     */
     0,                           /* xFindFunction */
     0                            /* xRename       */
  };
  int rc;                         /* Return code */

  rc = sqlite3_create_module(db, "fts4aux", &fts3aux_module, 0);
  return rc;
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

*/
static int fts3ExprLocalHitsCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;
  int iStart = iPhrase * p->nCol * 3;
  int i;

  for(i=0; i<p->nCol; i++) p->aMatchinfo[iStart+i*3] = 0;

  if( pExpr->aDoclist ){
    char *pCsr;





    pCsr = sqlite3Fts3FindPositions(pExpr, p->pCursor->iPrevId, -1);
    if( pCsr ){
      fts3LoadColumnlistCounts(&pCsr, &p->aMatchinfo[iStart], 0);
    }
  }

    if( rc!=SQLITE_OK ) return rc;
  }
  pStmt = *ppStmt;
  assert( sqlite3_data_count(pStmt)==1 );

  a = sqlite3_column_blob(pStmt, 0);
  a += sqlite3Fts3GetVarint(a, &nDoc);
  if( nDoc==0 ) return SQLITE_CORRUPT;
  *pnDoc = (u32)nDoc;

  if( paLen ) *paLen = a;
  return SQLITE_OK;
}

/*

          sqlite3_int64 nDoc;     /* Number of rows in table */
          const char *a;          /* Aggregate column length array */

          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);
          if( rc==SQLITE_OK ){
            int iCol;
            for(iCol=0; iCol<pInfo->nCol; iCol++){
              u32 iVal;
              sqlite3_int64 nToken;
              a += sqlite3Fts3GetVarint(a, &nToken);
              iVal = (u32)(((u32)(nToken&0xffffffff)+nDoc/2)/nDoc);
              pInfo->aMatchinfo[iCol] = iVal;
            }
          }
        }
        break;

      case FTS3_MATCHINFO_LENGTH: {
        sqlite3_stmt *pSelectDocsize = 0;

/* 0  */  "DELETE FROM %Q.'%q_content' WHERE rowid = ?",
/* 1  */  "SELECT NOT EXISTS(SELECT docid FROM %Q.'%q_content' WHERE rowid!=?)",
/* 2  */  "DELETE FROM %Q.'%q_content'",
/* 3  */  "DELETE FROM %Q.'%q_segments'",
/* 4  */  "DELETE FROM %Q.'%q_segdir'",
/* 5  */  "DELETE FROM %Q.'%q_docsize'",
/* 6  */  "DELETE FROM %Q.'%q_stat'",
/* 7  */  "SELECT %s FROM %Q.'%q_content' AS x WHERE rowid=?",
/* 8  */  "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1",
/* 9  */  "INSERT INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)",
/* 10 */  "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)",
/* 11 */  "INSERT INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)",

          /* Return segments in order from oldest to newest.*/ 
/* 12 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
            "FROM %Q.'%q_segdir' WHERE level = ? ORDER BY idx ASC",
/* 13 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
            "FROM %Q.'%q_segdir' ORDER BY level DESC, idx ASC",

/* 14 */  "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?",
/* 15 */  "SELECT count(*), max(level) FROM %Q.'%q_segdir'",

/* 16 */  "DELETE FROM %Q.'%q_segdir' WHERE level = ?",
/* 17 */  "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?",
/* 18 */  "INSERT INTO %Q.'%q_content' VALUES(%s)",
/* 19 */  "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
/* 20 */  "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
/* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=0",
/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
  };
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt;

  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
  assert( eStmt<SizeofArray(azSql) && eStmt>=0 );
  
  pStmt = p->aStmt[eStmt];
  if( !pStmt ){
    char *zSql;
    if( eStmt==SQL_CONTENT_INSERT ){


      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist);
    }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){









      zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist, p->zDb, p->zName);
    }else{
      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName);
    }
    if( !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, NULL);

  rc = fts3SqlStmt(pTab, eStmt, &pStmt, 0);
  if( rc==SQLITE_OK ){
    if( eStmt==SQL_SELECT_DOCSIZE ){
      sqlite3_bind_int64(pStmt, 1, iDocid);
    }
    rc = sqlite3_step(pStmt);
    if( rc!=SQLITE_ROW || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){
      rc = sqlite3_reset(pStmt);
      if( rc==SQLITE_OK ) rc = SQLITE_CORRUPT;
      pStmt = 0;
    }else{
      rc = SQLITE_OK;
    }
  }

**
**   0: idx
**   1: start_block
**   2: leaves_end_block
**   3: end_block
**   4: root
*/
int sqlite3Fts3AllSegdirs(Fts3Table *p, int iLevel, sqlite3_stmt **ppStmt){
  int rc;
  sqlite3_stmt *pStmt = 0;
  if( iLevel<0 ){
    rc = fts3SqlStmt(p, SQL_SELECT_ALL_LEVEL, &pStmt, 0);
  }else{
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
    if( rc==SQLITE_OK ) sqlite3_bind_int(pStmt, 1, iLevel);
  }
  *ppStmt = pStmt;
  return rc;
}


/*
** Append a single varint to a PendingList buffer. SQLITE_OK is returned
** if successful, or an SQLite error code otherwise.
**

      ** the table. The following nCol varints contain the total amount of
      ** data stored in all rows of each column of the table, from left
      ** to right.
      */
      sqlite3_stmt *pStmt;
      sqlite3_int64 nDoc = 0;
      sqlite3_int64 nByte = 0;
      const char *pEnd;
      const char *a;

      rc = sqlite3Fts3SelectDoctotal(p, &pStmt);
      if( rc!=SQLITE_OK ) return rc;
      a = sqlite3_column_blob(pStmt, 0);
      assert( a );

      pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
      a += sqlite3Fts3GetVarint(a, &nDoc);
      while( a<pEnd ){
        a += sqlite3Fts3GetVarint(a, &nByte);

      }
      if( nDoc==0 || nByte==0 ){
        sqlite3_reset(pStmt);
        return SQLITE_CORRUPT;
      }

      pCsr->nRowAvg = (int)(((nByte / nDoc) + pgsz) / pgsz);

  if( isPrefix ){
    sqlite3_free(aElem);
  }
  *ppReader = pReader;
  return rc;
}





































/*
** Compare the entries pointed to by two Fts3SegReader structures. 
** Comparison is as follows:
**
**   1) EOF is greater than not EOF.
**
**   2) The current terms (if any) are compared using memcmp(). If one

      *pisEmpty = sqlite3_column_int(pStmt, 0);
    }
    rc = sqlite3_reset(pStmt);
  }
  return rc;
}




















/*
** Set *pnSegment to the total number of segments in the database. Set
** *pnMax to the largest segment level in the database (segment levels
** are stored in the 'level' column of the %_segdir table).
**
** Return SQLITE_OK if successful, or an SQLite error code if not.
*/

      rc = sqlite3_reset(pDelete);
    }
  }
  if( rc!=SQLITE_OK ){
    return rc;
  }

  if( iLevel==FTS3_SEGCURSOR_ALL ){
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0);
  }else if( iLevel==FTS3_SEGCURSOR_PENDING ){
    sqlite3Fts3PendingTermsClear(p);
  }else{
    assert( iLevel>=0 );
    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_BY_LEVEL, &pDelete, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int(pDelete, 1, iLevel);
      sqlite3_step(pDelete);
      rc = sqlite3_reset(pDelete);
    }


  }

  return rc;
}

/*
** When this function is called, buffer *ppList (size *pnList bytes) contains 

    p += sqlite3Fts3GetVarint32(p, &iCurrent);
  }

  *ppList = pList;
  *pnList = nList;
}


























































int sqlite3Fts3SegReaderStart(
  Fts3Table *p,                   /* Virtual table handle */
  Fts3SegReaderCursor *pCsr,      /* Cursor object */

  Fts3SegFilter *pFilter          /* Restrictions on range of iteration */


){
  int i;








  /* Initialize the cursor object */




  pCsr->pFilter = pFilter;

  /* If the Fts3SegFilter defines a specific term (or term prefix) to search 
  ** for, then advance each segment iterator until it points to a term of
  ** equal or greater value than the specified term. This prevents many
  ** unnecessary merge/sort operations for the case where single segment
  ** b-tree leaf nodes contain more than one term.
  */
  for(i=0; i<pCsr->nSegment; i++){
    int nTerm = pFilter->nTerm;
    const char *zTerm = pFilter->zTerm;
    Fts3SegReader *pSeg = pCsr->apSegment[i];
    do {
      int rc = fts3SegReaderNext(p, pSeg);
      if( rc!=SQLITE_OK ) return rc;
    }while( zTerm && fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 );
  }
  fts3SegReaderSort(
      pCsr->apSegment, pCsr->nSegment, pCsr->nSegment, fts3SegReaderCmp);

  return SQLITE_OK;
}

int sqlite3Fts3SegReaderStep(
  Fts3Table *p,                   /* Virtual table handle */
  Fts3SegReaderCursor *pCsr       /* Cursor object */
){
  int rc = SQLITE_OK;

  int isIgnoreEmpty =  (pCsr->pFilter->flags & FTS3_SEGMENT_IGNORE_EMPTY);
  int isRequirePos =   (pCsr->pFilter->flags & FTS3_SEGMENT_REQUIRE_POS);
  int isColFilter =    (pCsr->pFilter->flags & FTS3_SEGMENT_COLUMN_FILTER);
  int isPrefix =       (pCsr->pFilter->flags & FTS3_SEGMENT_PREFIX);
  int isScan =         (pCsr->pFilter->flags & FTS3_SEGMENT_SCAN);

  Fts3SegReader **apSegment = pCsr->apSegment;
  int nSegment = pCsr->nSegment;
  Fts3SegFilter *pFilter = pCsr->pFilter;

  if( pCsr->nSegment==0 ) return SQLITE_OK;

  do {
    int nMerge;
    int i;
  
    /* Advance the first pCsr->nAdvance entries in the apSegment[] array
    ** forward. Then sort the list in order of current term again.  
    */
    for(i=0; i<pCsr->nAdvance; i++){
      rc = fts3SegReaderNext(p, apSegment[i]);
      if( rc!=SQLITE_OK ) return rc;
    }
    fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp);
    pCsr->nAdvance = 0;

    /* If all the seg-readers are at EOF, we're finished. return SQLITE_OK. */
    assert( rc==SQLITE_OK );
    if( apSegment[0]->aNode==0 ) break;

    pCsr->nTerm = apSegment[0]->nTerm;
    pCsr->zTerm = apSegment[0]->zTerm;


    /* If this is a prefix-search, and if the term that apSegment[0] points
    ** to does not share a suffix with pFilter->zTerm/nTerm, then all 
    ** required callbacks have been made. In this case exit early.
    **
    ** Similarly, if this is a search for an exact match, and the first term
    ** of segment apSegment[0] is not a match, exit early.
    */
    if( pFilter->zTerm && !isScan ){
      if( pCsr->nTerm<pFilter->nTerm 
       || (!isPrefix && pCsr->nTerm>pFilter->nTerm)
       || memcmp(pCsr->zTerm, pFilter->zTerm, pFilter->nTerm) 
      ){
        break;
      }
    }

    nMerge = 1;
    while( nMerge<nSegment 
        && apSegment[nMerge]->aNode
        && apSegment[nMerge]->nTerm==pCsr->nTerm 
        && 0==memcmp(pCsr->zTerm, apSegment[nMerge]->zTerm, pCsr->nTerm)
    ){
      nMerge++;
    }

    assert( isIgnoreEmpty || (isRequirePos && !isColFilter) );
    if( nMerge==1 && !isIgnoreEmpty ){
      pCsr->aDoclist = apSegment[0]->aDoclist;
      pCsr->nDoclist = apSegment[0]->nDoclist;
      rc = SQLITE_ROW;
    }else{
      int nDoclist = 0;           /* Size of doclist */
      sqlite3_int64 iPrev = 0;    /* Previous docid stored in doclist */

      /* The current term of the first nMerge entries in the array
      ** of Fts3SegReader objects is the same. The doclists must be merged
      ** and a single term returned with the merged doclist.
      */
      for(i=0; i<nMerge; i++){
        fts3SegReaderFirstDocid(apSegment[i]);
      }
      fts3SegReaderSort(apSegment, nMerge, nMerge, fts3SegReaderDoclistCmp);
      while( apSegment[0]->pOffsetList ){
        int j;                    /* Number of segments that share a docid */

        if( isColFilter ){
          fts3ColumnFilter(pFilter->iCol, &pList, &nList);
        }

        if( !isIgnoreEmpty || nList>0 ){
          nByte = sqlite3Fts3VarintLen(iDocid-iPrev) + (isRequirePos?nList+1:0);
          if( nDoclist+nByte>pCsr->nBuffer ){
            char *aNew;
            pCsr->nBuffer = (nDoclist+nByte)*2;
            aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);
            if( !aNew ){
              return SQLITE_NOMEM;

            }
            pCsr->aBuffer = aNew;
          }
          nDoclist += sqlite3Fts3PutVarint(
              &pCsr->aBuffer[nDoclist], iDocid-iPrev
          );
          iPrev = iDocid;
          if( isRequirePos ){
            memcpy(&pCsr->aBuffer[nDoclist], pList, nList);
            nDoclist += nList;
            pCsr->aBuffer[nDoclist++] = '\0';
          }
        }

        fts3SegReaderSort(apSegment, nMerge, j, fts3SegReaderDoclistCmp);
      }

      if( nDoclist>0 ){
        pCsr->aDoclist = pCsr->aBuffer;
        pCsr->nDoclist = nDoclist;
        rc = SQLITE_ROW;
      }
    }
    pCsr->nAdvance = nMerge;
  }while( rc==SQLITE_OK );


  return rc;




}

void sqlite3Fts3SegReaderFinish(
  Fts3SegReaderCursor *pCsr       /* Cursor object */
){
  if( pCsr ){
    int i;
    for(i=0; i<pCsr->nSegment; i++){
      sqlite3Fts3SegReaderFree(pCsr->apSegment[i]);

    }
    sqlite3_free(pCsr->apSegment);
    sqlite3_free(pCsr->aBuffer);

    pCsr->nSegment = 0;
    pCsr->apSegment = 0;
    pCsr->aBuffer = 0;
  }



}

/*
** Merge all level iLevel segments in the database into a single 
** iLevel+1 segment. Or, if iLevel<0, merge all segments into a
** single segment with a level equal to the numerically largest level 
** currently present in the database.
**
** If this function is called with iLevel<0, but there is only one
** segment in the database, SQLITE_DONE is returned immediately. 
** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(Fts3Table *p, int iLevel){

  int rc;                         /* Return code */
  int iIdx = 0;                   /* Index of new segment */
  int iNewLevel = 0;              /* Level to create new segment at */

  SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */



  Fts3SegFilter filter;           /* Segment term filter condition */
  Fts3SegReaderCursor csr;        /* Cursor to iterate through level(s) */

  rc = sqlite3Fts3SegReaderCursor(p, iLevel, 0, 0, 1, 0, &csr);
  if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;

  if( iLevel==FTS3_SEGCURSOR_ALL ){
    /* This call is to merge all segments in the database to a single
    ** segment. The level of the new segment is equal to the the numerically 
    ** greatest segment level currently present in the database. The index
    ** of the new segment is always 0.  */






    int nDummy; /* TODO: Remove this */
    if( csr.nSegment==1 ){
      rc = SQLITE_DONE;
      goto finished;
    }
    rc = fts3SegmentCountMax(p, &nDummy, &iNewLevel);
  }else{
    /* This call is to merge all segments at level iLevel. Find the next
    ** available segment index at level iLevel+1. The call to
    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
    ** a single iLevel+2 segment if necessary.  */

    iNewLevel = iLevel+1;
    rc = fts3AllocateSegdirIdx(p, iNewLevel, &iIdx);



  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( csr.nSegment>0 );
  assert( iNewLevel>=0 );


  memset(&filter, 0, sizeof(Fts3SegFilter));

  filter.flags = FTS3_SEGMENT_REQUIRE_POS;

  filter.flags |= (iLevel==FTS3_SEGCURSOR_ALL ? FTS3_SEGMENT_IGNORE_EMPTY : 0);


  rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);






  while( SQLITE_OK==rc ){


    rc = sqlite3Fts3SegReaderStep(p, &csr);
    if( rc!=SQLITE_ROW ) break;



    rc = fts3SegWriterAdd(p, &pWriter, 1, 



        csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
  }

  if( rc!=SQLITE_OK ) goto finished;
  assert( pWriter );




  rc = fts3DeleteSegdir(p, iLevel, csr.apSegment, csr.nSegment);


  if( rc!=SQLITE_OK ) goto finished;



  rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);


 finished:
  fts3SegWriterFree(pWriter);






  sqlite3Fts3SegReaderFinish(&csr);

  return rc;
}


/* 
** Flush the contents of pendingTerms to a level 0 segment.
*/
int sqlite3Fts3PendingTermsFlush(Fts3Table *p){




  return fts3SegmentMerge(p, FTS3_SEGCURSOR_PENDING);












































}

/*
** Encode N integers as varints into a blob.
*/
static void fts3EncodeIntArray(
  int N,             /* The number of integers to encode */

  int rc;                         /* Return Code */
  const char *zVal = (const char *)sqlite3_value_text(pVal);
  int nVal = sqlite3_value_bytes(pVal);

  if( !zVal ){
    return SQLITE_NOMEM;
  }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){
    rc = fts3SegmentMerge(p, FTS3_SEGCURSOR_ALL);
    if( rc==SQLITE_DONE ){
      rc = SQLITE_OK;
    }else{
      sqlite3Fts3PendingTermsClear(p);
    }
#ifdef SQLITE_TEST
  }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){

** merge all segments in the database (including the new segment, if 
** there was any data to flush) into a single segment. 
*/
int sqlite3Fts3Optimize(Fts3Table *p){
  int rc;
  rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = fts3SegmentMerge(p, FTS3_SEGCURSOR_ALL);
    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
      if( rc==SQLITE_OK ){
        sqlite3Fts3PendingTermsClear(p);
      }
    }else{
      sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0);

**
** The second of each pair of bytes identifies the coordinate column
** to which the constraint applies. The leftmost coordinate column
** is 'a', the second from the left 'b' etc.
*/
static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int rc = SQLITE_OK;
  int ii;

  int iIdx = 0;
  char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
  memset(zIdxStr, 0, sizeof(zIdxStr));
  UNUSED_PARAMETER(tab);

  assert( pIdxInfo->idxStr==0 );
  for(ii=0; ii<pIdxInfo->nConstraint && iIdx<(sizeof(zIdxStr)-1); ii++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];

    if( p->usable && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      /* We have an equality constraint on the rowid. Use strategy 1. */
      int jj;
      for(jj=0; jj<ii; jj++){
        pIdxInfo->aConstraintUsage[jj].argvIndex = 0;

      ** sqlite uses an internal cost of 0.0).
      */ 
      pIdxInfo->estimatedCost = 10.0;
      return SQLITE_OK;
    }

    if( p->usable && (p->iColumn>0 || p->op==SQLITE_INDEX_CONSTRAINT_MATCH) ){


      u8 op;
      switch( p->op ){
        case SQLITE_INDEX_CONSTRAINT_EQ: op = RTREE_EQ; break;
        case SQLITE_INDEX_CONSTRAINT_GT: op = RTREE_GT; break;
        case SQLITE_INDEX_CONSTRAINT_LE: op = RTREE_LE; break;
        case SQLITE_INDEX_CONSTRAINT_LT: op = RTREE_LT; break;
        case SQLITE_INDEX_CONSTRAINT_GE: op = RTREE_GE; break;
        default:
          assert( p->op==SQLITE_INDEX_CONSTRAINT_MATCH );
          op = RTREE_MATCH; 
          break;
      }


























      zIdxStr[iIdx++] = op;
      zIdxStr[iIdx++] = p->iColumn - 1 + 'a';
      pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);
      pIdxInfo->aConstraintUsage[ii].omit = 1;

    }
  }

  pIdxInfo->idxNum = 2;
  pIdxInfo->needToFreeIdxStr = 1;
  if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){
    return SQLITE_NOMEM;

  for(ii=0; ii<NCELL(&node); ii++){
    char zCell[512];
    int nCell = 0;
    RtreeCell cell;
    int jj;

    nodeGetCell(&tree, &node, ii, &cell);
    sqlite3_snprintf(512-nCell,&zCell[nCell],"%lld", cell.iRowid);
    nCell = strlen(zCell);
    for(jj=0; jj<tree.nDim*2; jj++){
      sqlite3_snprintf(512-nCell,&zCell[nCell]," %f",(double)cell.aCoord[jj].f);
      nCell = strlen(zCell);
    }

    if( zText ){

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 rows)} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
}

do_execsql_test rtree6-3.1 {
  CREATE VIRTUAL TABLE t3 USING rtree(id, x1, x2, y1, y2);
  INSERT INTO t3 VALUES(NULL, 1, 1, 2, 2);
  SELECT * FROM t3 WHERE 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5;
} {1 1.0 1.0 2.0 2.0}

do_test rtree6.3.2 {
  rtree_strategy {
    SELECT * FROM t3 WHERE 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 
  }
} {EaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEa}
do_test rtree6.3.3 {
  rtree_strategy {
    SELECT * FROM t3 WHERE 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
      x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5
  }
} {EaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEa}

do_execsql_test rtree6-3.4 {
  SELECT * FROM t3 WHERE x1>0.5 AND x1>0.8 AND x1>1.1
} {}
do_execsql_test rtree6-3.5 {
  SELECT * FROM t3 WHERE 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
    x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>1.1
} {}


finish_test

# 2011 March 2
#
# 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.
#
#***********************************************************************
# Make sure the rtreenode() testing function can handle entries with
# 64-bit rowids.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

do_test rtreeB-1.1 {
  db eval {
    CREATE VIRTUAL TABLE t1 USING rtree(ii, x0, y0, x1, y1);
    INSERT INTO t1 VALUES(1073741824, 0.0, 0.0, 100.0, 100.0);
    INSERT INTO t1 VALUES(2147483646, 0.0, 0.0, 200.0, 200.0);
    INSERT INTO t1 VALUES(4294967296, 0.0, 0.0, 300.0, 300.0);
    INSERT INTO t1 VALUES(8589934592, 20.0, 20.0, 150.0, 150.0);
    INSERT INTO t1 VALUES(9223372036854775807, 150, 150, 400, 400);
    SELECT rtreenode(2, data) FROM t1_node;
  }
} {{{1073741824 0.000000 0.000000 100.000000 100.000000} {2147483646 0.000000 0.000000 200.000000 200.000000} {4294967296 0.000000 0.000000 300.000000 300.000000} {8589934592 20.000000 20.000000 150.000000 150.000000} {9223372036854775807 150.000000 150.000000 400.000000 400.000000}}}


finish_test

TCCX += -I$(TOP)/ext/async

# Object files for the SQLite library.
#
LIBOBJ+= alter.o analyze.o attach.o auth.o \
         backup.o bitvec.o btmutex.o btree.o build.o \
         callback.o complete.o ctime.o date.o delete.o expr.o fault.o fkey.o \
         fts3.o fts3_aux.o fts3_expr.o fts3_hash.o fts3_icu.o fts3_porter.o \
         fts3_snippet.o fts3_tokenizer.o fts3_tokenizer1.o fts3_write.o \
         func.o global.o hash.o \
         icu.o insert.o journal.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_os2.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_os2.o os_unix.o os_win.o \

  $(TOP)/ext/fts2/fts2_tokenizer.h \
  $(TOP)/ext/fts2/fts2_tokenizer.c \
  $(TOP)/ext/fts2/fts2_tokenizer1.c
SRC += \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3.h \
  $(TOP)/ext/fts3/fts3Int.h \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \
  $(TOP)/ext/fts3/fts3_hash.c \
  $(TOP)/ext/fts3/fts3_hash.h \
  $(TOP)/ext/fts3/fts3_icu.c \
  $(TOP)/ext/fts3/fts3_porter.c \
  $(TOP)/ext/fts3/fts3_snippet.c \
  $(TOP)/ext/fts3/fts3_tokenizer.h \

  $(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_func.c \
  $(TOP)/src/test_fuzzer.c \
  $(TOP)/src/test_hexio.c \
  $(TOP)/src/test_init.c \
  $(TOP)/src/test_intarray.c \
  $(TOP)/src/test_journal.c \
  $(TOP)/src/test_malloc.c \
  $(TOP)/src/test_multiplex.c \
  $(TOP)/src/test_mutex.c \
  $(TOP)/src/test_onefile.c \
  $(TOP)/src/test_osinst.c \
  $(TOP)/src/test_pcache.c \
  $(TOP)/src/test_quota.c \
  $(TOP)/src/test_rtree.c \
  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_stat.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_wholenumber.c \
  $(TOP)/src/test_wsd.c

#TESTSRC += $(TOP)/ext/fts2/fts2_tokenizer.c
#TESTSRC += $(TOP)/ext/fts3/fts3_tokenizer.c

TESTSRC2 = \
  $(TOP)/src/attach.c \

  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/where.c \
  parse.c \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \
  $(TOP)/ext/fts3/fts3_tokenizer.c \
  $(TOP)/ext/fts3/fts3_write.c \
  $(TOP)/ext/async/sqlite3async.c

# Header files used by all library source files.
#

	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts2/fts2_tokenizer.c

fts2_tokenizer1.o:	$(TOP)/ext/fts2/fts2_tokenizer1.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts2/fts2_tokenizer1.c

fts3.o:	$(TOP)/ext/fts3/fts3.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3.c

fts3_aux.o:	$(TOP)/ext/fts3/fts3_aux.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_aux.c

fts3_expr.o:	$(TOP)/ext/fts3/fts3_expr.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_expr.c

fts3_hash.o:	$(TOP)/ext/fts3/fts3_hash.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_hash.c

test:	testfixture$(EXE) sqlite3$(EXE)
	./testfixture$(EXE) $(TOP)/test/veryquick.test

# The next two rules are used to support the "threadtest" target. Building
# threadtest runs a few thread-safety tests that are implemented in C. This
# target is invoked by the releasetest.tcl script.
# 
threadtest3$(EXE): sqlite3.o $(TOP)/test/threadtest3.c $(TOP)/test/tt3_checkpoint.c
	$(TCCX) -O2 sqlite3.o $(TOP)/test/threadtest3.c \
		-o threadtest3$(EXE) $(THREADLIB)

threadtest: threadtest3$(EXE)
	./threadtest3$(EXE)

sqlite3_analyzer$(EXE):	$(TOP)/src/tclsqlite.c sqlite3.c $(TESTSRC) \
			$(TOP)/tool/spaceanal.tcl

  ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. 
  */
  if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
    sqlite3VdbeAddOp4(v, OP_ParseSchema, 1, 0, 0, zWhere, P4_DYNAMIC);
  }
#endif
}

/*
** Parameter zName is the name of a table that is about to be altered
** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
** If the table is a system table, this function leaves an error message
** in pParse->zErr (system tables may not be altered) and returns non-zero.
**
** Or, if zName is not a system table, zero is returned.
*/
static int isSystemTable(Parse *pParse, const char *zName){
  if( sqlite3Strlen30(zName)>6 && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
    sqlite3ErrorMsg(pParse, "table %s may not be altered", zName);
    return 1;
  }
  return 0;
}

/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
** command. 
*/
void sqlite3AlterRenameTable(
  Parse *pParse,            /* Parser context. */

        "there is already another table or index with this name: %s", zName);
    goto exit_rename_table;
  }

  /* Make sure it is not a system table being altered, or a reserved name
  ** that the table is being renamed to.
  */



  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
    goto exit_rename_table;
  }
  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
    exit_rename_table;
  }

#ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
    goto exit_rename_table;
  }

  }
#endif

  /* Make sure this is not an attempt to ALTER a view. */
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
    goto exit_begin_add_column;
  }
  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
    goto exit_begin_add_column;
  }

  assert( pTab->addColOffset>0 );
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  /* Put a copy of the Table struct in Parse.pNewTable for the
  ** sqlite3AddColumn() function and friends to modify.  But modify

** with the named table are deleted. If zWhere==0, then code is generated
** to delete all stat table entries.
*/
static void openStatTable(
  Parse *pParse,          /* Parsing context */
  int iDb,                /* The database we are looking in */
  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
  const char *zWhere,     /* Delete entries for this table or index */
  const char *zWhereType  /* Either "tbl" or "idx" */
){
  static const struct {
    const char *zName;
    const char *zCols;
  } aTable[] = {
    { "sqlite_stat1", "tbl,idx,stat" },
#ifdef SQLITE_ENABLE_STAT2

      /* The table already exists. If zWhere is not NULL, delete all entries 
      ** associated with the table zWhere. If zWhere is NULL, delete the
      ** entire contents of the table. */
      aRoot[i] = pStat->tnum;
      sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
      if( zWhere ){
        sqlite3NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q", pDb->zName, zTab, zWhereType, zWhere
        );
      }else{
        /* The sqlite_stat[12] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
  Parse *pParse,   /* Parser context */
  Table *pTab,     /* Table whose indices are to be analyzed */
  Index *pOnlyIdx, /* If not NULL, only analyze this one index */
  int iStatCur,    /* Index of VdbeCursor that writes the sqlite_stat1 table */
  int iMem         /* Available memory locations begin here */
){
  sqlite3 *db = pParse->db;    /* Database handle */
  Index *pIdx;                 /* An index to being analyzed */
  int iIdxCur;                 /* Cursor open on index being analyzed */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */
  int topOfLoop;               /* The top of the loop */
  int endOfLoop;               /* The end of the loop */

  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regSampleno = iMem++;    /* Register containing next sample number */
  int regCol = iMem++;         /* Content of a column analyzed table */
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
  int regRowid = iMem++;       /* Rowid for the inserted record */

#ifdef SQLITE_ENABLE_STAT2
  int addr = 0;                /* Instruction address */
  int regTemp2 = iMem++;       /* Temporary use register */
  int regSamplerecno = iMem++; /* Index of next sample to record */
  int regRecno = iMem++;       /* Current sample index */
  int regLast = iMem++;        /* Index of last sample to record */
  int regFirst = iMem++;       /* Index of first sample to record */
#endif

  /* Establish a read-lock on the table at the shared-cache level. */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    int nCol;
    KeyInfo *pKey;

    if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
    nCol = pIdx->nColumn;
    pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    if( iMem+1+(nCol*2)>pParse->nMem ){
      pParse->nMem = iMem+1+(nCol*2);
    }

    /* Open a cursor to the index to be analyzed. */
    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,

    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno);
    if( jZeroRows<0 ){
      jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
    }
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);

  ** containing NULL as the index name and the row count as the content.
  */
  if( pTab->pIndex==0 ){
    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
    VdbeComment((v, "%s", pTab->zName));
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regSampleno);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regSampleno);
  }else{
    sqlite3VdbeJumpHere(v, jZeroRows);
    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);

  }
  sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
  sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
  sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
  sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
  sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
  if( pParse->nMem<regRec ) pParse->nMem = regRec;

  sqlite3VdbeJumpHere(v, jZeroRows);

}

/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){

  HashElem *k;
  int iStatCur;
  int iMem;

  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 2;
  openStatTable(pParse, iDb, iStatCur, 0, 0);
  iMem = pParse->nMem+1;
  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
    Table *pTab = (Table*)sqliteHashData(k);
    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem);
  }
  loadAnalysis(pParse, iDb);
}

/*
** Generate code that will do an analysis of a single table in
** a database.  If pOnlyIdx is not NULL then it is a single index
** in pTab that should be analyzed.
*/
static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){
  int iDb;
  int iStatCur;

  assert( pTab!=0 );
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 2;
  if( pOnlyIdx ){
    openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");
  }else{
    openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");
  }
  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur, pParse->nMem+1);
  loadAnalysis(pParse, iDb);
}

/*
** Generate code for the ANALYZE command.  The parser calls this routine
** when it recognizes an ANALYZE command.
**

*/
void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
  sqlite3 *db = pParse->db;
  int iDb;
  int i;
  char *z, *zDb;
  Table *pTab;
  Index *pIdx;
  Token *pTableName;

  /* Read the database schema. If an error occurs, leave an error message
  ** and code in pParse and return NULL. */
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    return;

    /* Form 2:  Analyze the database or table named */
    iDb = sqlite3FindDb(db, pName1);
    if( iDb>=0 ){
      analyzeDatabase(pParse, iDb);
    }else{
      z = sqlite3NameFromToken(db, pName1);
      if( z ){
        if( (pIdx = sqlite3FindIndex(db, z, 0))!=0 ){
          analyzeTable(pParse, pIdx->pTable, pIdx);
        }else if( (pTab = sqlite3LocateTable(pParse, 0, z, 0))!=0 ){


          analyzeTable(pParse, pTab, 0);
        }
        sqlite3DbFree(db, z);
      }
    }
  }else{
    /* Form 3: Analyze the fully qualified table name */
    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);
    if( iDb>=0 ){
      zDb = db->aDb[iDb].zName;
      z = sqlite3NameFromToken(db, pTableName);
      if( z ){
        if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){
          analyzeTable(pParse, pIdx->pTable, pIdx);
        }else if( (pTab = sqlite3LocateTable(pParse, 0, z, zDb))!=0 ){


          analyzeTable(pParse, pTab, 0);
        }
        sqlite3DbFree(db, z);
      }
    }   
  }
}

/*
** Used to pass information from the analyzer reader through to the

  ){
    pParse->nErr++;
    goto attach_end;
  }

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( pAuthArg ){
    char *zAuthArg;
    if( pAuthArg->op==TK_STRING ){
      zAuthArg = pAuthArg->u.zToken;
    }else{
      zAuthArg = 0;

    }
    rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
    if(rc!=SQLITE_OK ){
      goto attach_end;
    }
  }
#endif /* SQLITE_OMIT_AUTHORIZATION */

        }
      }else{
        rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
      }
  
      /* Finish committing the transaction to the destination database. */
      if( SQLITE_OK==rc
       && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0))
      ){
        rc = SQLITE_DONE;
      }
    }
  
    /* If bCloseTrans is true, then this function opened a read transaction
    ** on the source database. Close the read transaction here. There is
    ** no need to check the return values of the btree methods here, as
    ** "committing" a read-only transaction cannot fail.
    */
    if( bCloseTrans ){
      TESTONLY( int rc2 );
      TESTONLY( rc2  = ) sqlite3BtreeCommitPhaseOne(p->pSrc, 0);
      TESTONLY( rc2 |= ) sqlite3BtreeCommitPhaseTwo(p->pSrc, 0);
      assert( rc2==SQLITE_OK );
    }
  
    if( rc==SQLITE_IOERR_NOMEM ){
      rc = SQLITE_NOMEM;
    }
    p->rc = rc;

}

/*
** Release the BtShared mutex associated with B-Tree handle p and
** clear the p->locked boolean.
*/
static void unlockBtreeMutex(Btree *p){
  BtShared *pBt = p->pBt;
  assert( p->locked==1 );
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( sqlite3_mutex_held(p->db->mutex) );
  assert( p->db==pBt->db );

  pBt->iMutexCounter++;
  sqlite3_mutex_leave(pBt->mutex);
  p->locked = 0;
}

#ifdef SQLITE_DEBUG
/*
** Return the number of times that the mutex has been exited for
** the given btree.
**
** This is a small circular counter that wraps around to zero on
** overflow.  It is used only for sanity checking - to verify that
** mutexes are held continously by asserting that the value of
** this counter at the beginning of a region is the same as at
** the end.
*/
u32 sqlite3BtreeMutexCounter(Btree *p){
  assert( p->locked==1 || p->sharable==0 );
  return p->pBt->iMutexCounter;
}
#endif

/*
** Enter a mutex on the given BTree object.
**
** If the object is not sharable, then no mutex is ever required
** and this routine is a no-op.  The underlying mutex is non-recursive.
** But we keep a reference count in Btree.wantToLock so the behavior

  /* Unless the database is sharable and unlocked, then BtShared.db
  ** should already be set correctly. */
  assert( (p->locked==0 && p->sharable) || p->pBt->db==p->db );

  if( !p->sharable ) return;
  p->wantToLock++;
  if( p->locked ) return;

  /* Increment the mutex counter on all locked btrees in the same
  ** database connection.  This simulates the unlocking that would
  ** occur on a worst-case mutex dead-lock avoidance scenario.
  */
#ifdef SQLITE_DEBUG
  {
    int ii;
    sqlite3 *db = p->db;
    Btree *pOther;
    for(ii=0; ii<db->nDb; ii++){
      if( ii==1 ) continue;
      pOther = db->aDb[ii].pBt;
      if( pOther==0 || pOther->sharable==0 || pOther->locked==0 ) continue;
      pOther->pBt->iMutexCounter++;
    }
  }
#endif

  /* In most cases, we should be able to acquire the lock we
  ** want without having to go throught the ascending lock
  ** procedure that follows.  Just be sure not to block.
  */
  if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
    p->pBt->db = p->db;

    p = db->aDb[i].pBt;
    assert( !p || (p->locked==0 && p->sharable) || p->pBt->db==p->db );
    if( p && p->sharable ){
      p->wantToLock++;
      if( !p->locked ){
        assert( p->wantToLock==1 );
        while( p->pPrev ) p = p->pPrev;
        /* Reason for ALWAYS:  There must be at least one unlocked Btree in
        ** the chain.  Otherwise the !p->locked test above would have failed */
        while( p->locked && ALWAYS(p->pNext) ) p = p->pNext;
        for(pLater = p->pNext; pLater; pLater=pLater->pNext){
          if( pLater->locked ){
            unlockBtreeMutex(pLater);
          }
        }

      return 0;
    }
  }
  return 1;
}
#endif /* NDEBUG */









































#else /* SQLITE_THREADSAFE>0 above.  SQLITE_THREADSAFE==0 below */
/*











** The following are special cases for mutex enter routines for use


** in single threaded applications that use shared cache.  Except for



** these two routines, all mutex operations are no-ops in that case and






** are null #defines in btree.h.
**
** If shared cache is disabled, then all btree mutex routines, including
** the ones below, are no-ops and are null #defines in btree.h.
*/




















void sqlite3BtreeEnter(Btree *p){
  p->pBt->db = p->db;
}
void sqlite3BtreeEnterAll(sqlite3 *db){
  int i;
  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;

      pBt->usableSize = usableSize;
      pBt->pageSize = pageSize;
      freeTempSpace(pBt);
      rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize,
                                   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;

** sqlite3BtreeCommitPhaseOne() routine does the first phase and should
** be invoked prior to calling this routine.  The sqlite3BtreeCommitPhaseOne()
** routine did all the work of writing information out to disk and flushing the
** contents so that they are written onto the disk platter.  All this
** routine has to do is delete or truncate or zero the header in the
** the rollback journal (which causes the transaction to commit) and
** drop locks.
**
** Normally, if an error occurs while the pager layer is attempting to 
** finalize the underlying journal file, this function returns an error and
** the upper layer will attempt a rollback. However, if the second argument
** is non-zero then this b-tree transaction is part of a multi-file 
** transaction. In this case, the transaction has already been committed 
** (by deleting a master journal file) and the caller will ignore this 
** functions return code. So, even if an error occurs in the pager layer,
** reset the b-tree objects internal state to indicate that the write
** transaction has been closed. This is quite safe, as the pager will have
** transitioned to the error state.
**
** This will release the write lock on the database file.  If there
** are no active cursors, it also releases the read lock.
*/
int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){

  if( p->inTrans==TRANS_NONE ) return SQLITE_OK;
  sqlite3BtreeEnter(p);
  btreeIntegrity(p);

  /* If the handle has a write-transaction open, commit the shared-btrees 
  ** transaction and set the shared state to TRANS_READ.
  */
  if( p->inTrans==TRANS_WRITE ){
    int rc;
    BtShared *pBt = p->pBt;
    assert( pBt->inTransaction==TRANS_WRITE );
    assert( pBt->nTransaction>0 );
    rc = sqlite3PagerCommitPhaseTwo(pBt->pPager);
    if( rc!=SQLITE_OK && bCleanup==0 ){
      sqlite3BtreeLeave(p);
      return rc;
    }
    pBt->inTransaction = TRANS_READ;
  }

  btreeEndTransaction(p);
  sqlite3BtreeLeave(p);
  return SQLITE_OK;
}

/*
** Do both phases of a commit.
*/
int sqlite3BtreeCommit(Btree *p){
  int rc;
  sqlite3BtreeEnter(p);
  rc = sqlite3BtreeCommitPhaseOne(p, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeCommitPhaseTwo(p, 0);
  }
  sqlite3BtreeLeave(p);
  return rc;
}

#ifndef NDEBUG
/*

        if( rc ){
          goto end_allocate_page;
        }
        if( nearby>0 ){
          u32 i;
          int dist;
          closest = 0;
          dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);

          for(i=1; i<k; i++){
            int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);

            if( d2<dist ){
              closest = i;
              dist = d2;
            }
          }
        }else{
          closest = 0;

    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],

#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on the Btree passed as the first argument.
**
** Return SQLITE_LOCKED if this or any other connection has an open 
** transaction on the shared-cache the argument Btree is connected to.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
int sqlite3BtreeCheckpoint(Btree *p, int eMode, int *pnLog, int *pnCkpt){
  int rc = SQLITE_OK;
  if( p ){
    BtShared *pBt = p->pBt;
    sqlite3BtreeEnter(p);
    if( pBt->inTransaction!=TRANS_NONE ){
      rc = SQLITE_LOCKED;
    }else{
      rc = sqlite3PagerCheckpoint(pBt->pPager, eMode, pnLog, pnCkpt);
    }
    sqlite3BtreeLeave(p);
  }
  return rc;
}
#endif

**
** If the nBytes parameter is 0 and the blob of memory has not yet been
** allocated, a null pointer is returned. If the blob has already been
** allocated, it is returned as normal.
**
** Just before the shared-btree is closed, the function passed as the 
** xFree argument when the memory allocation was made is invoked on the 
** blob of allocated memory. The xFree function should not call sqlite3_free()
** on the memory, the btree layer does that.
*/
void *sqlite3BtreeSchema(Btree *p, int nBytes, void(*xFree)(void *)){
  BtShared *pBt = p->pBt;
  sqlite3BtreeEnter(p);
  if( !pBt->pSchema && nBytes ){
    pBt->pSchema = sqlite3DbMallocZero(0, nBytes);

/*
** Forward declarations of structure
*/
typedef struct Btree Btree;
typedef struct BtCursor BtCursor;
typedef struct BtShared BtShared;














int sqlite3BtreeOpen(
  const char *zFilename,   /* Name of database file to open */
  sqlite3 *db,             /* Associated database connection */
  Btree **ppBtree,         /* Return open Btree* here */
  int flags,               /* Flags */

u32 sqlite3BtreeLastPage(Btree*);
int sqlite3BtreeSecureDelete(Btree*,int);
int sqlite3BtreeGetReserve(Btree*);
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 sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);

#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
#endif

#ifndef SQLITE_OMIT_WAL
  int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);
#endif

/*
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#ifndef SQLITE_OMIT_SHARED_CACHE
  void sqlite3BtreeEnter(Btree*);
  void sqlite3BtreeEnterAll(sqlite3*);
#else
# define sqlite3BtreeEnter(X) 
# define sqlite3BtreeEnterAll(X)
#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
  void sqlite3BtreeLeave(Btree*);
  void sqlite3BtreeEnterCursor(BtCursor*);
  void sqlite3BtreeLeaveCursor(BtCursor*);
  void sqlite3BtreeLeaveAll(sqlite3*);



#ifndef NDEBUG
  /* These routines are used inside assert() statements only. */
  int sqlite3BtreeHoldsMutex(Btree*);
  int sqlite3BtreeHoldsAllMutexes(sqlite3*);
  u32 sqlite3BtreeMutexCounter(Btree*);
#endif
#else

# define sqlite3BtreeLeave(X)
# define sqlite3BtreeMutexCounter(X) 0
# define sqlite3BtreeEnterCursor(X)
# define sqlite3BtreeLeaveCursor(X)
# define sqlite3BtreeLeaveAll(X)




# define sqlite3BtreeHoldsMutex(X) 1
# define sqlite3BtreeHoldsAllMutexes(X) 1
#endif


#endif /* _BTREE_H_ */

** points to the same BtShared object.  The database cache and the
** schema associated with the database file are all contained within
** the BtShared object.
**
** All fields in this structure are accessed under sqlite3.mutex.
** The pBt pointer itself may not be changed while there exists cursors 
** in the referenced BtShared that point back to this Btree since those
** cursors have to go through this Btree to find their BtShared and
** they often do so without holding sqlite3.mutex.
*/
struct Btree {
  sqlite3 *db;       /* The database connection holding this btree */
  BtShared *pBt;     /* Sharable content of this btree */
  u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
  u8 sharable;       /* True if we can share pBt with another db */

  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u32 pageSize;         /* Total number of bytes on a page */
  u32 usableSize;       /* Number of usable bytes on each page */
  int nTransaction;     /* Number of open transactions (read + write) */
  u32 nPage;            /* Number of pages in the database */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this object */
  Bitvec *pHasContent;  /* Set of pages moved to free-list this transaction */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nRef;             /* Number of references to this structure */
  BtShared *pNext;      /* Next on a list of sharable BtShared structs */
  BtLock *pLock;        /* List of locks held on this shared-btree struct */
  Btree *pWriter;       /* Btree with currently open write transaction */
  u8 isExclusive;       /* True if pWriter has an EXCLUSIVE lock on the db */
  u8 isPending;         /* If waiting for read-locks to clear */
  u16 iMutexCounter;    /* The number of mutex_leave(mutex) calls */
#endif
  u8 *pTmpSpace;        /* BtShared.pageSize bytes of space for tmp use */
};

/*
** An instance of the following structure is used to hold information
** about a cell.  The parseCellPtr() function fills in this structure

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    if( pParse->cookieGoto>0 ){
      yDbMask mask;
      int iDb;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeUsesBtree(v, iDb);
        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        if( db->init.busy==0 ){
          sqlite3VdbeAddOp3(v, OP_VerifyCookie,
                            iDb, pParse->cookieValue[iDb],
                            db->aDb[iDb].pSchema->iGeneration);
        }
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      {
        int i;
        for(i=0; i<pParse->nVtabLock; i++){
          char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);

void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
  Index *pIndex;
  int len;
  Hash *pHash = &db->aDb[iDb].pSchema->idxHash;

  len = sqlite3Strlen30(zIdxName);
  pIndex = sqlite3HashInsert(pHash, zIdxName, len, 0);
  if( ALWAYS(pIndex) ){
    if( pIndex->pTable->pIndex==pIndex ){
      pIndex->pTable->pIndex = pIndex->pNext;
    }else{
      Index *p;
      /* Justification of ALWAYS();  The index must be on the list of
      ** indices. */
      p = pIndex->pTable->pIndex;

  if( pToplevel->cookieGoto==0 ){
    Vdbe *v = sqlite3GetVdbe(pToplevel);
    if( v==0 ) return;  /* This only happens if there was a prior error */
    pToplevel->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    sqlite3 *db = pToplevel->db;
    yDbMask mask;

    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<SQLITE_MAX_ATTACHED+2 );
    mask = ((yDbMask)1)<<iDb;
    if( (pToplevel->cookieMask & mask)==0 ){
      pToplevel->cookieMask |= mask;
      pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
      if( !OMIT_TEMPDB && iDb==1 ){
        sqlite3OpenTempDatabase(pToplevel);
      }
    }

** rollback the whole transaction.  For operations where all constraints
** can be checked before any changes are made to the database, it is never
** necessary to undo a write and the checkpoint should not be set.
*/
void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);
  sqlite3CodeVerifySchema(pParse, iDb);
  pToplevel->writeMask |= ((yDbMask)1)<<iDb;
  pToplevel->isMultiWrite |= setStatement;
}

/*
** Indicate that the statement currently under construction might write
** more than one entry (example: deleting one row then inserting another,
** inserting multiple rows in a table, or inserting a row and index entries.)

  for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    sqlite3DeleteTable(0, pTab);
  }
  sqlite3HashClear(&temp1);
  sqlite3HashClear(&pSchema->fkeyHash);
  pSchema->pSeqTab = 0;
  if( pSchema->flags & DB_SchemaLoaded ){
    pSchema->iGeneration++;
    pSchema->flags &= ~DB_SchemaLoaded;
  }
}

/*
** Find and return the schema associated with a BTree.  Create
** a new one if necessary.
*/
Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){

  "OMIT_TRACE",
#endif
#ifdef SQLITE_OMIT_TRIGGER
  "OMIT_TRIGGER",
#endif
#ifdef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  "OMIT_TRUNCATE_OPTIMIZATION",
#endif
#ifdef SQLITE_OMIT_UNIQUE_ENFORCEMENT
  "OMIT_UNIQUE_ENFORCEMENT",
#endif
#ifdef SQLITE_OMIT_UTF16
  "OMIT_UTF16",
#endif
#ifdef SQLITE_OMIT_VACUUM
  "OMIT_VACUUM",
#endif

/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op;
    pColl = p->pColl;
    if( pColl ) break;
    op = p->op;
    if( p->pTab!=0 && (
        op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER
    )){

  int nExtra = 0;
  int iValue = 0;

  if( pToken ){
    if( op!=TK_INTEGER || pToken->z==0
          || sqlite3GetInt32(pToken->z, &iValue)==0 ){
      nExtra = pToken->n+1;
      assert( iValue>=0 );
    }
  }
  pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
  if( pNew ){
    pNew->op = (u8)op;
    pNew->iAgg = -1;
    if( pToken ){

}

/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(sqlite3 *db, Expr *p){
  if( p==0 ) return;
  /* Sanity check: Assert that the IntValue is non-negative if it exists */
  assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
  if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
    sqlite3ExprDelete(db, p->pLeft);
    sqlite3ExprDelete(db, p->pRight);
    if( !ExprHasProperty(p, EP_Reduced) && (p->flags2 & EP2_MallocedToken)!=0 ){
      sqlite3DbFree(db, p->u.zToken);
    }
    if( ExprHasProperty(p, EP_xIsSelect) ){

** 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.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
  int rc = 0;

  /* If an expression is an integer literal that fits in a signed 32-bit
  ** integer, then the EP_IntValue flag will have already been set */
  assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
           || sqlite3GetInt32(p->u.zToken, &rc)==0 );

  if( p->flags & EP_IntValue ){
    *pValue = p->u.iValue;
    return 1;
  }
  switch( p->op ){





    case TK_UPLUS: {
      rc = sqlite3ExprIsInteger(p->pLeft, pValue);
      break;
    }
    case TK_UMINUS: {
      int v;
      if( sqlite3ExprIsInteger(p->pLeft, &v) ){
        *pValue = -v;
        rc = 1;
      }
      break;
    }
    default: break;
  }







  return rc;
}

/*
** Return FALSE if there is no chance that the expression can be NULL.
**
** If the expression might be NULL or if the expression is too complex

**
** Expr.u.zToken is always UTF8 and zero-terminated.
*/
static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
  Vdbe *v = pParse->pVdbe;
  if( pExpr->flags & EP_IntValue ){
    int i = pExpr->u.iValue;
    assert( i>=0 );
    if( negFlag ) i = -i;
    sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
  }else{
    int c;
    i64 value;
    const char *z = pExpr->u.zToken;
    assert( z!=0 );
    c = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
    if( c==0 || (c==2 && negFlag) ){
      char *zV;
      if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
      zV = dup8bytes(v, (char*)&value);
      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
    }else{
#ifdef SQLITE_OMIT_FLOATING_POINT
      sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
#else
      codeReal(v, z, negFlag, iMem);

      break;
    }
    case TK_BETWEEN: {
      testcase( jumpIfNull==0 );
      exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      int destIfFalse = sqlite3VdbeMakeLabel(v);
      int destIfNull = jumpIfNull ? dest : destIfFalse;
      sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
      sqlite3VdbeResolveLabel(v, destIfFalse);
      break;
    }
#endif
    default: {
      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
      sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
      testcase( regFree1==0 );
      testcase( jumpIfNull==0 );
      break;
    }

      break;
    }
    case TK_BETWEEN: {
      testcase( jumpIfNull==0 );
      exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      if( jumpIfNull ){
        sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
      }else{
        int destIfNull = sqlite3VdbeMakeLabel(v);
        sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
        sqlite3VdbeResolveLabel(v, destIfNull);
      }
      break;
    }
#endif
    default: {
      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
      sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
      testcase( regFree1==0 );
      testcase( jumpIfNull==0 );
      break;
    }

void sqlite3FkCheck(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Row is being deleted from this table */ 
  int regOld,                     /* Previous row data is stored here */
  int regNew                      /* New row data is stored here */
){
  sqlite3 *db = pParse->db;       /* Database handle */

  FKey *pFKey;                    /* Used to iterate through FKs */
  int iDb;                        /* Index of database containing pTab */
  const char *zDb;                /* Name of database containing pTab */
  int isIgnoreErrors = pParse->disableTriggers;

  /* Exactly one of regOld and regNew should be non-zero. */
  assert( (regOld==0)!=(regNew==0) );

  /* If foreign-keys are disabled, this function is a no-op. */
  if( (db->flags&SQLITE_ForeignKeys)==0 ) return;


  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  zDb = db->aDb[iDb].zName;

  /* Loop through all the foreign key constraints for which pTab is the
  ** child table (the table that the foreign key definition is part of).  */
  for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
    Table *pTo;                   /* Parent table of foreign key pFKey */

  p = sqlite3_aggregate_context(context, sizeof(*p));
  type = sqlite3_value_numeric_type(argv[0]);
  if( p && type!=SQLITE_NULL ){
    p->cnt++;
    if( type==SQLITE_INTEGER ){
      i64 v = sqlite3_value_int64(argv[0]);
      p->rSum += v;
      if( (p->approx|p->overflow)==0 && sqlite3AddInt64(&p->iSum, v) ){




        p->overflow = 1;

      }
    }else{
      p->rSum += sqlite3_value_double(argv[0]);
      p->approx = 1;
    }
  }
}

  /* Register allocations */
  int regFromSelect = 0;/* Base register for data coming from SELECT */
  int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
  int regRowCount = 0;  /* Memory cell used for the row counter */
  int regIns;           /* Block of regs holding rowid+data being inserted */
  int regRowid;         /* registers holding insert rowid */
  int regData;          /* register holding first column to insert */

  int regEof = 0;       /* Register recording end of SELECT data */
  int *aRegIdx = 0;     /* One register allocated to each index */

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                 /* True if attempting to insert into a view */
  Trigger *pTrigger;          /* List of triggers on pTab, if required */
  int tmask;                  /* Mask of trigger times */

    addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
    addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
  }

  /* Allocate registers for holding the rowid of the new row,
  ** the content of the new row, and the assemblied row record.
  */

  regRowid = regIns = pParse->nMem+1;
  pParse->nMem += pTab->nCol + 1;
  if( IsVirtual(pTab) ){
    regRowid++;
    pParse->nMem++;
  }
  regData = regRowid+1;

        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Abort:
        sqlite3MayAbort(pParse);
      case OE_Rollback:
      case OE_Fail: {
        char *zMsg;
        sqlite3VdbeAddOp3(v, OP_HaltIfNull,
                                  SQLITE_CONSTRAINT, onError, regData+i);
        zMsg = sqlite3MPrintf(pParse->db, "%s.%s may not be NULL",
                              pTab->zName, pTab->aCol[i].zName);
        sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
        break;
      }
      case OE_Ignore: {

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */
  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
    int regIdx;
#ifndef SQLITE_OMIT_UNIQUE_ENFORCEMENT
    int regR;
#endif
    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */

    /* Create a key for accessing the index entry */
    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
    for(i=0; i<pIdx->nColumn; i++){
      int idx = pIdx->aiColumn[i];
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
      }
    }
    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), 0);
    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);

#ifdef SQLITE_OMIT_UNIQUE_ENFORCEMENT
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
    continue;  /* Treat pIdx as if it is not a UNIQUE index */
#else

    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ){ 
      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
      continue;  /* pIdx is not a UNIQUE index */
    }

        );
        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeJumpHere(v, j3);
    sqlite3ReleaseTempReg(pParse, regR);
#endif
  }
  
  if( pbMayReplace ){
    *pbMayReplace = seenReplace;
  }
}

#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.
        */

      void *pBuf = va_arg(ap, void*); /* IMP: R-21112-12275 */
      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
      rc = setupLookaside(db, pBuf, sz, cnt);
      break;
    }
    default: {
      static const struct {
        int op;      /* The opcode */
        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
      } aFlagOp[] = {
        { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
        { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
      };
      unsigned int i;
      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
      for(i=0; i<ArraySize(aFlagOp); i++){
        if( aFlagOp[i].op==op ){
          int onoff = va_arg(ap, int);
          int *pRes = va_arg(ap, int*);
          int oldFlags = db->flags;
          if( onoff>0 ){
            db->flags |= aFlagOp[i].mask;
          }else if( onoff==0 ){
            db->flags &= ~aFlagOp[i].mask;
          }
          if( oldFlags!=db->flags ){
            sqlite3ExpirePreparedStatements(db);
          }
          if( pRes ){
            *pRes = (db->flags & aFlagOp[i].mask)!=0;
          }
          rc = SQLITE_OK;
          break;
        }
      }
      break;
    }
  }
  va_end(ap);
  return rc;
}

  sqlite3_mutex_leave(db->mutex);
  return pRet;
#else
  return 0;
#endif
}


/*
** Checkpoint database zDb.


*/
int sqlite3_wal_checkpoint_v2(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Name of attached database (or NULL) */
  int eMode,                      /* SQLITE_CHECKPOINT_* value */
  int *pnLog,                     /* OUT: Size of WAL log in frames */
  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 );
  assert( SQLITE_CHECKPOINT_PASSIVE+2==SQLITE_CHECKPOINT_RESTART );
  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_RESTART ){
    return SQLITE_MISUSE;
  }

  sqlite3_mutex_enter(db->mutex);
  if( zDb && zDb[0] ){
    iDb = sqlite3FindDbName(db, zDb);
  }
  if( iDb<0 ){
    rc = SQLITE_ERROR;
    sqlite3Error(db, SQLITE_ERROR, "unknown database: %s", zDb);
  }else{
    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
    sqlite3Error(db, rc, 0);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
#endif
}


/*
** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
** to contains a zero-length string, all attached databases are 
** checkpointed.
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
  return sqlite3_wal_checkpoint_v2(db, zDb, SQLITE_CHECKPOINT_PASSIVE, 0, 0);
}

#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on database iDb. This is a no-op if database iDb is
** not currently open in WAL mode.
**
** If a transaction is open on the database being checkpointed, this 
** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
** an error occurs while running the checkpoint, an SQLite error code is 
** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
**
** The mutex on database handle db should be held by the caller. The mutex
** associated with the specific b-tree being checkpointed is taken by
** this function while the checkpoint is running.
**
** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
** checkpointed. If an error is encountered it is returned immediately -
** no attempt is made to checkpoint any remaining databases.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterate through attached dbs */
  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */

  assert( sqlite3_mutex_held(db->mutex) );
  assert( !pnLog || *pnLog==-1 );
  assert( !pnCkpt || *pnCkpt==-1 );

  for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
      pnLog = 0;
      pnCkpt = 0;
      if( rc==SQLITE_BUSY ){
        bBusy = 1;
        rc = SQLITE_OK;
      }
    }
  }

  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
}
#endif /* SQLITE_OMIT_WAL */

/*
** This function returns true if main-memory should be used instead of
** a temporary file for transient pager files and statement journals.
** The value returned depends on the value of db->temp_store (runtime

#endif
#if SQLITE_MAX_VDBE_OP<40
# error SQLITE_MAX_VDBE_OP must be at least 40
#endif
#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
#endif
#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>62
# error SQLITE_MAX_ATTACHED must be between 0 and 62
#endif
#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
#endif
#if SQLITE_MAX_COLUMN>32767
# error SQLITE_MAX_COLUMN must not exceed 32767
#endif

  }

  /* Remove harmful bits from the flags parameter
  **
  ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
  ** dealt with in the previous code block.  Besides these, the only
  ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
  ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
  ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
  ** off all other flags.
  */
  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
               SQLITE_OPEN_EXCLUSIVE |
               SQLITE_OPEN_MAIN_DB |
               SQLITE_OPEN_TEMP_DB | 
               SQLITE_OPEN_TRANSIENT_DB | 

  db->aDb = db->aDbStatic;

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->nextPagesize = 0;
  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS

**             memsys5Log(4) -> 2
**             memsys5Log(5) -> 3
**             memsys5Log(8) -> 3
**             memsys5Log(9) -> 4
*/
static int memsys5Log(int iValue){
  int iLog;
  for(iLog=0; (iLog<((sizeof(int)*8)-1)) && (1<<iLog)<iValue; iLog++);
  return iLog;
}

/*
** Initialize the memory allocator.
**
** This routine is not threadsafe.  The caller must be holding a mutex

  */
  assert( (sizeof(Mem5Link)&(sizeof(Mem5Link)-1))==0 );

  nByte = sqlite3GlobalConfig.nHeap;
  zByte = (u8*)sqlite3GlobalConfig.pHeap;
  assert( zByte!=0 );  /* sqlite3_config() does not allow otherwise */

  /* boundaries on sqlite3GlobalConfig.mnReq are enforced in sqlite3_config() */
  nMinLog = memsys5Log(sqlite3GlobalConfig.mnReq);
  mem5.szAtom = (1<<nMinLog);
  while( (int)sizeof(Mem5Link)>mem5.szAtom ){
    mem5.szAtom = mem5.szAtom << 1;
  }

  mem5.nBlock = (nByte / (mem5.szAtom+sizeof(u8)));

/*
** The mutex object
** Each recursive mutex is an instance of the following structure.
*/
struct sqlite3_mutex {
  HMTX mutex;       /* Mutex controlling the lock */
  int  id;          /* Mutex type */
#ifdef SQLITE_DEBUG
 int   trace;       /* True to trace changes */
#endif
};

#ifdef SQLITE_DEBUG
#define SQLITE3_MUTEX_INITIALIZER { 0, 0, 0 }
#else
#define SQLITE3_MUTEX_INITIALIZER { 0, 0 }
#endif

/*
** Initialize and deinitialize the mutex subsystem.
*/
static int os2MutexInit(void){ return SQLITE_OK; }
static int os2MutexEnd(void){ return SQLITE_OK; }

/*
** 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_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** </ul>
**
** The first two constants 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.  But 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() 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

          p = NULL;
        }
      }
      break;
    }
    default: {
      static volatile int isInit = 0;
      static sqlite3_mutex staticMutexes[6] = {
        SQLITE3_MUTEX_INITIALIZER,
        SQLITE3_MUTEX_INITIALIZER,
        SQLITE3_MUTEX_INITIALIZER,
        SQLITE3_MUTEX_INITIALIZER,
        SQLITE3_MUTEX_INITIALIZER,
        SQLITE3_MUTEX_INITIALIZER,
      };
      if ( !isInit ){
        APIRET rc;
        PTIB ptib;
        PPIB ppib;
        HMTX mutex;
        char name[32];

/*
** This routine deallocates a previously allocated mutex.
** SQLite is careful to deallocate every mutex that it allocates.
*/
static void os2MutexFree(sqlite3_mutex *p){
#ifdef SQLITE_DEBUG
  TID tid;
  PID pid;
  ULONG ulCount;
  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  assert( ulCount==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
#endif
  DosCloseMutexSem( p->mutex );
  sqlite3_free( p );
}

#ifdef SQLITE_DEBUG
/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
static int os2MutexHeld(sqlite3_mutex *p){
  TID tid;
  PID pid;
  ULONG ulCount;
  PTIB ptib;

  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  if( ulCount==0 || ( ulCount>1 && p->id!=SQLITE_MUTEX_RECURSIVE ) )
    return 0;
  DosGetInfoBlocks(&ptib, NULL);
  return tid==ptib->tib_ptib2->tib2_ultid;


}
static int os2MutexNotheld(sqlite3_mutex *p){
  TID tid;
  PID pid;
  ULONG ulCount;
  PTIB ptib;

  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  if( ulCount==0 )
    return 1;
  DosGetInfoBlocks(&ptib, NULL);
  return tid!=ptib->tib_ptib2->tib2_ultid;
}
static void os2MutexTrace(sqlite3_mutex *p, char *pAction){
  TID   tid;
  PID   pid;
  ULONG ulCount;
  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
  printf("%s mutex %p (%d) with nRef=%ld\n", pAction, (void*)p, p->trace, ulCount);
}
#endif

/*
** 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.
*/
static void os2MutexEnter(sqlite3_mutex *p){




  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
  DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
#ifdef SQLITE_DEBUG
  if( p->trace ) os2MutexTrace(p, "enter");

#endif
}
static int os2MutexTry(sqlite3_mutex *p){
  int rc = SQLITE_BUSY;




  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
  if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR ) {



    rc = SQLITE_OK;

#ifdef SQLITE_DEBUG
    if( p->trace ) os2MutexTrace(p, "try");
#endif
  }

  return rc;
}

/*
** 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 or
** is not currently allocated.  SQLite will never do either.
*/
static void os2MutexLeave(sqlite3_mutex *p){




  assert( os2MutexHeld(p) );




  DosReleaseMutexSem(p->mutex);
#ifdef SQLITE_DEBUG
  if( p->trace ) os2MutexTrace(p, "leave");
#endif
}

SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
  static const sqlite3_mutex_methods sMutex = {
    os2MutexInit,
    os2MutexEnd,
    os2MutexAlloc,
    os2MutexFree,
    os2MutexEnter,
    os2MutexTry,
    os2MutexLeave,
#ifdef SQLITE_DEBUG
    os2MutexHeld,
    os2MutexNotheld
#else
    0,
    0
#endif
  };

  return &sMutex;
}
#endif /* SQLITE_MUTEX_OS2 */

    rc = SQLITE_OK;
  }
#else
  UNUSED_PARAMETER(p);
#endif
#ifdef SQLITE_DEBUG
  if( rc==SQLITE_OK && p->trace ){
    printf("try mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
  }
#endif
  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was

}

/*
** This vector defines all the methods that can operate on an
** sqlite3_file for os2.
*/
static const sqlite3_io_methods os2IoMethod = {
  1,                              /* iVersion */
  os2Close,                       /* xClose */
  os2Read,                        /* xRead */
  os2Write,                       /* xWrite */
  os2Truncate,                    /* xTruncate */
  os2Sync,                        /* xSync */
  os2FileSize,                    /* xFileSize */
  os2Lock,                        /* xLock */
  os2Unlock,                      /* xUnlock */
  os2CheckReservedLock,           /* xCheckReservedLock */
  os2FileControl,                 /* xFileControl */
  os2SectorSize,                  /* xSectorSize */
  os2DeviceCharacteristics,       /* xDeviceCharacteristics */
  0,                              /* xShmMap */
  0,                              /* xShmLock */
  0,                              /* xShmBarrier */
  0                               /* xShmUnmap */
};

/***************************************************************************
** Here ends the I/O methods that form the sqlite3_io_methods object.
**
** The next block of code implements the VFS methods.
****************************************************************************/

/*
** Open a file.
*/
static int os2Open(
  sqlite3_vfs *pVfs,            /* Not used */
  const char *zName,            /* Name of the file (UTF-8) */
  sqlite3_file *id,             /* Write the SQLite file handle here */
  int flags,                    /* Open mode flags */
  int *pOutFlags                /* Status return flags */
){
  HFILE h;

  ULONG ulOpenFlags = 0;
  ULONG ulOpenMode = 0;
  ULONG ulAction = 0;
  ULONG rc;
  os2File *pFile = (os2File*)id;
  const char *zUtf8Name = zName;

  char *zNameCp;
  char  zTmpname[CCHMAXPATH];

  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
#ifndef NDEBUG
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
  int eType        = (flags & 0xFFFFFF00);
  int isOpenJournal = (isCreate && (
        eType==SQLITE_OPEN_MASTER_JOURNAL 
     || eType==SQLITE_OPEN_MAIN_JOURNAL 
     || eType==SQLITE_OPEN_WAL
  ));
#endif

  UNUSED_PARAMETER(pVfs);
  assert( id!=0 );

  /* Check the following statements are true: 
  **
  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 
  **   (b) if CREATE is set, then READWRITE must also be set, and
  **   (c) if EXCLUSIVE is set, then CREATE must also be set.
  **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
  */
  assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
  assert(isCreate==0 || isReadWrite);
  assert(isExclusive==0 || isCreate);
  assert(isDelete==0 || isCreate);

  /* The main DB, main journal, WAL file and master journal are never 
  ** automatically deleted. Nor are they ever temporary files.  */
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );
  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );

  /* Assert that the upper layer has set one of the "file-type" flags. */
  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 
       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 
       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL 
       || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
  );

  memset( pFile, 0, sizeof(*pFile) );
  pFile->pMethod = &os2IoMethod;

  /* If the second argument to this function is NULL, generate a 
  ** temporary file name to use 
  */
  if( !zUtf8Name ){
    assert(isDelete && !isOpenJournal);
    rc = getTempname(CCHMAXPATH, zTmpname);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    zUtf8Name = zTmpname;
  }

  if( isReadWrite ){





    ulOpenMode |= OPEN_ACCESS_READWRITE;

  }else{
    ulOpenMode |= OPEN_ACCESS_READONLY;

  }








  /* Open in random access mode for possibly better speed.  Allow full







  ** sharing because file locks will provide exclusive access when needed.












  */

  ulOpenMode |= OPEN_FLAGS_RANDOM;
  ulOpenMode |= OPEN_FLAGS_FAIL_ON_ERROR;
  ulOpenMode |= OPEN_FLAGS_NOINHERIT;
  ulOpenMode |= OPEN_SHARE_DENYNONE;

  /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is 
  ** created. SQLite doesn't use it to indicate "exclusive access" 
  ** as it is usually understood.
  */
  if( isExclusive ){
    /* Creates a new file, only if it does not already exist. */
    /* If the file exists, it fails. */
    ulOpenFlags |= OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_FAIL_IF_EXISTS;
  }else if( isCreate ){
    /* Open existing file, or create if it doesn't exist */
    ulOpenFlags |= OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS;
  }else{
    /* Opens a file, only if it exists. */
    ulOpenFlags |= OPEN_ACTION_FAIL_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS;
  }

  /* For DELETEONCLOSE, save a pointer to the converted filename */
  if( isDelete ){
    char pathUtf8[CCHMAXPATH];
    os2FullPathname( pVfs, zUtf8Name, CCHMAXPATH, pathUtf8 );
    pFile->pathToDel = convertUtf8PathToCp( pathUtf8 );
  }

  zNameCp = convertUtf8PathToCp( zUtf8Name );
  rc = DosOpen( (PSZ)zNameCp,
                &h,
                &ulAction,
                0L,
                FILE_NORMAL,
                ulOpenFlags,
                ulOpenMode,
                (PEAOP2)NULL );
  free( zNameCp );

  if( rc != NO_ERROR ){
    OSTRACE(( "OPEN Invalid handle rc=%d: zName=%s, ulAction=%#lx, ulFlags=%#lx, ulMode=%#lx\n",
              rc, zUtf8Name, ulAction, ulOpenFlags, ulOpenMode ));
    if( pFile->pathToDel )
      free( pFile->pathToDel );
    pFile->pathToDel = NULL;

    if( isReadWrite ){

      return os2Open( pVfs, zName, id,
                      ((flags|SQLITE_OPEN_READONLY)&~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
                      pOutFlags );
    }else{
      return SQLITE_CANTOPEN;
    }
  }

  if( pOutFlags ){
    *pOutFlags = isReadWrite ? SQLITE_OPEN_READWRITE : SQLITE_OPEN_READONLY;
  }


  pFile->h = h;
  OpenCounter(+1);
  OSTRACE(( "OPEN %d pOutFlags=%d\n", pFile->h, pOutFlags ));
  return SQLITE_OK;
}

/*
** Delete the named file.
*/
static int os2Delete(
  sqlite3_vfs *pVfs,                     /* Not used on os2 */
  const char *zFilename,                 /* Name of file to delete */
  int syncDir                            /* Not used on os2 */
){
  APIRET rc;
  char *zFilenameCp;
  SimulateIOError( return SQLITE_IOERR_DELETE );
  zFilenameCp = convertUtf8PathToCp( zFilename );
  rc = DosDelete( (PSZ)zFilenameCp );
  free( zFilenameCp );
  OSTRACE(( "DELETE \"%s\"\n", zFilename ));
  return (rc == NO_ERROR ||
          rc == ERROR_FILE_NOT_FOUND ||
          rc == ERROR_PATH_NOT_FOUND ) ? SQLITE_OK : SQLITE_IOERR_DELETE;
}

/*
** Check the existance and status of a file.
*/
static int os2Access(
  sqlite3_vfs *pVfs,        /* Not used on os2 */

/*
** A no-op since the error code is returned on the DosLoadModule call.
** os2Dlopen returns zero if DosLoadModule is not successful.
*/
static void os2DlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
/* no-op */
}
static void (*os2DlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol))(void){
  PFN pfn;
  APIRET rc;
  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, zSymbol, &pfn);
  if( rc != NO_ERROR ){
    /* if the symbol itself was not found, search again for the same
     * symbol with an extra underscore, that might be needed depending
     * on the calling convention */
    char _zSymbol[256] = "_";
    strncat(_zSymbol, zSymbol, 255);
    rc = DosQueryProcAddr((HMODULE)pHandle, 0L, _zSymbol, &pfn);
  }
  return rc != NO_ERROR ? 0 : (void(*)(void))pfn;
}
static void os2DlClose(sqlite3_vfs *pVfs, void *pHandle){
  DosFreeModule((HMODULE)pHandle);
}
#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
  #define os2DlOpen 0
  #define os2DlError 0

** Find the current time (in Universal Coordinated Time).  Write the
** current time and date as a Julian Day number into *prNow and
** return 0.  Return 1 if the time and date cannot be found.
*/
int os2CurrentTime( sqlite3_vfs *pVfs, double *prNow ){
  double now;
  SHORT minute; /* needs to be able to cope with negative timezone offset */
  USHORT hundredths, second, hour,
         day, month, year;
  DATETIME dt;
  DosGetDateTime( &dt );
  hundredths = (USHORT)dt.hundredths;
  second = (USHORT)dt.seconds;
  minute = (SHORT)dt.minutes + dt.timezone;
  hour = (USHORT)dt.hours;
  day = (USHORT)dt.day;
  month = (USHORT)dt.month;
  year = (USHORT)dt.year;

  /* Calculations from http://www.astro.keele.ac.uk/~rno/Astronomy/hjd.html
     http://www.astro.keele.ac.uk/~rno/Astronomy/hjd-0.1.c */
  /* Calculate the Julian days */
  now = day - 32076 +
    1461*(year + 4800 + (month - 14)/12)/4 +
    367*(month - 2 - (month - 14)/12*12)/12 -
    3*((year + 4900 + (month - 14)/12)/100)/4;

  /* Add the fractional hours, mins and seconds */
  now += (hour + 12.0)/24.0;
  now += minute/1440.0;
  now += second/86400.0;
  now += hundredths/8640000.0;
  *prNow = now;
#ifdef SQLITE_TEST
  if( sqlite3_current_time ){
    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
  }
#endif
  return 0;
}

/*
** Find the current time (in Universal Coordinated Time).  Write into *piNow
** the current time and date as a Julian Day number times 86_400_000.  In
** other words, write into *piNow the number of milliseconds since the Julian
** epoch of noon in Greenwich on November 24, 4714 B.C according to the
** proleptic Gregorian calendar.
**
** On success, return 0.  Return 1 if the time and date cannot be found.
*/
static int os2CurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
  double now;
  os2CurrentTime(pVfs, &now);
  *piNow = now * 86400000;
  return 0;
}

static int os2GetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
  return 0;
}

/*
** Initialize and deinitialize the operating system interface.
*/
int sqlite3_os_init(void){
  static sqlite3_vfs os2Vfs = {
    3,                 /* iVersion */
    sizeof(os2File),   /* szOsFile */
    CCHMAXPATH,        /* mxPathname */
    0,                 /* pNext */
    "os2",             /* zName */
    0,                 /* pAppData */

    os2Open,           /* xOpen */
    os2Delete,         /* xDelete */
    os2Access,         /* xAccess */
    os2FullPathname,   /* xFullPathname */
    os2DlOpen,         /* xDlOpen */
    os2DlError,        /* xDlError */
    os2DlSym,          /* xDlSym */
    os2DlClose,        /* xDlClose */
    os2Randomness,     /* xRandomness */
    os2Sleep,          /* xSleep */
    os2CurrentTime,    /* xCurrentTime */
    os2GetLastError,   /* xGetLastError */
    os2CurrentTimeInt64 /* xCurrentTimeInt64 */
    0,                 /* xSetSystemCall */
    0,                 /* xGetSystemCall */
    0,                 /* xNextSystemCall */
  };
  sqlite3_vfs_register(&os2Vfs, 1);
  initUconvObjects();
  return SQLITE_OK;
}
int sqlite3_os_end(void){
  freeUconvObjects();
  return SQLITE_OK;
}

#endif /* SQLITE_OS_OS2 */

typedef struct unixFile unixFile;
struct unixFile {
  sqlite3_io_methods const *pMethod;  /* Always the first entry */
  unixInodeInfo *pInode;              /* Info about locks on this inode */
  int h;                              /* The file descriptor */
  int dirfd;                          /* File descriptor for the directory */
  unsigned char eFileLock;            /* The type of lock held on this fd */
  unsigned char ctrlFlags;            /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */

  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)

  ** it is larger than the struct CrashFile defined in test6.c.
  */
  char aPadding[32];
#endif
};

/*
** Allowed values for the unixFile.ctrlFlags bitmask:
*/
#define UNIXFILE_EXCL   0x01     /* Connections from one process only */
#define UNIXFILE_RDONLY 0x02     /* Connection is read only */

/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*

#ifndef O_NOFOLLOW
# define O_NOFOLLOW 0
#endif
#ifndef O_BINARY
# define O_BINARY 0
#endif











/*
** The threadid macro resolves to the thread-id or to 0.  Used for
** testing and debugging only.
*/
#if SQLITE_THREADSAFE
#define threadid pthread_self()
#else
#define threadid 0
#endif

/*
** Many system calls are accessed through pointer-to-functions so that
** they may be overridden at runtime to facilitate fault injection during
** testing and sandboxing.  The following array holds the names and pointers
** to all overrideable system calls.
*/
static struct unix_syscall {
  const char *zName;            /* Name of the sytem call */
  sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
  sqlite3_syscall_ptr pDefault; /* Default value */
} aSyscall[] = {
  { "open",         (sqlite3_syscall_ptr)open,       0  },
#define osOpen      ((int(*)(const char*,int,int))aSyscall[0].pCurrent)

  { "close",        (sqlite3_syscall_ptr)close,      0  },
#define osClose     ((int(*)(int))aSyscall[1].pCurrent)

  { "access",       (sqlite3_syscall_ptr)access,     0  },
#define osAccess    ((int(*)(const char*,int))aSyscall[2].pCurrent)

  { "getcwd",       (sqlite3_syscall_ptr)getcwd,     0  },
#define osGetcwd    ((char*(*)(char*,size_t))aSyscall[3].pCurrent)

  { "stat",         (sqlite3_syscall_ptr)stat,       0  },
#define osStat      ((int(*)(const char*,struct stat*))aSyscall[4].pCurrent)

/*
** The DJGPP compiler environment looks mostly like Unix, but it
** lacks the fcntl() system call.  So redefine fcntl() to be something
** that always succeeds.  This means that locking does not occur under
** DJGPP.  But it is DOS - what did you expect?
*/
#ifdef __DJGPP__
  { "fstat",        0,                 0  },
#define osFstat(a,b,c)    0
#else     
  { "fstat",        (sqlite3_syscall_ptr)fstat,      0  },
#define osFstat     ((int(*)(int,struct stat*))aSyscall[5].pCurrent)
#endif

  { "ftruncate",    (sqlite3_syscall_ptr)ftruncate,  0  },
#define osFtruncate ((int(*)(int,off_t))aSyscall[6].pCurrent)

  { "fcntl",        (sqlite3_syscall_ptr)fcntl,      0  },
#define osFcntl     ((int(*)(int,int,...))aSyscall[7].pCurrent)

  { "read",         (sqlite3_syscall_ptr)read,       0  },
#define osRead      ((ssize_t(*)(int,void*,size_t))aSyscall[8].pCurrent)

#if defined(USE_PREAD) || defined(SQLITE_ENABLE_LOCKING_STYLE)
  { "pread",        (sqlite3_syscall_ptr)pread,      0  },
#else
  { "pread",        (sqlite3_syscall_ptr)0,          0  },
#endif
#define osPread     ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[9].pCurrent)

#if defined(USE_PREAD64)
  { "pread64",      (sqlite3_syscall_ptr)pread64,    0  },
#else
  { "pread64",      (sqlite3_syscall_ptr)0,          0  },
#endif
#define osPread64   ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[10].pCurrent)

  { "write",        (sqlite3_syscall_ptr)write,      0  },
#define osWrite     ((ssize_t(*)(int,const void*,size_t))aSyscall[11].pCurrent)

#if defined(USE_PREAD) || defined(SQLITE_ENABLE_LOCKING_STYLE)
  { "pwrite",       (sqlite3_syscall_ptr)pwrite,     0  },
#else
  { "pwrite",       (sqlite3_syscall_ptr)0,          0  },
#endif
#define osPwrite    ((ssize_t(*)(int,const void*,size_t,off_t))\
                    aSyscall[12].pCurrent)

#if defined(USE_PREAD64)
  { "pwrite64",     (sqlite3_syscall_ptr)pwrite64,   0  },
#else
  { "pwrite64",     (sqlite3_syscall_ptr)0,          0  },
#endif
#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
                    aSyscall[13].pCurrent)

  { "fchmod",       (sqlite3_syscall_ptr)fchmod,     0  },
#define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
  { "fallocate",    (sqlite3_syscall_ptr)posix_fallocate,  0 },
#else
  { "fallocate",    (sqlite3_syscall_ptr)0,                0 },
#endif
#define osFallocate ((int(*)(int,off_t,off_t))aSyscall[15].pCurrent)

}; /* End of the overrideable system calls */

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
** system call named zName.
*/
static int unixSetSystemCall(
  sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */
  const char *zName,            /* Name of system call to override */
  sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */
){
  unsigned int i;
  int rc = SQLITE_NOTFOUND;

  UNUSED_PARAMETER(pNotUsed);
  if( zName==0 ){
    /* If no zName is given, restore all system calls to their default
    ** settings and return NULL
    */
    rc = SQLITE_OK;
    for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
      if( aSyscall[i].pDefault ){
        aSyscall[i].pCurrent = aSyscall[i].pDefault;
      }
    }
  }else{
    /* If zName is specified, operate on only the one system call
    ** specified.
    */
    for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
      if( strcmp(zName, aSyscall[i].zName)==0 ){
        if( aSyscall[i].pDefault==0 ){
          aSyscall[i].pDefault = aSyscall[i].pCurrent;
        }
        rc = SQLITE_OK;
        if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;
        aSyscall[i].pCurrent = pNewFunc;
        break;
      }
    }
  }
  return rc;
}

/*
** Return the value of a system call.  Return NULL if zName is not a
** recognized system call name.  NULL is also returned if the system call
** is currently undefined.
*/
static sqlite3_syscall_ptr unixGetSystemCall(
  sqlite3_vfs *pNotUsed,
  const char *zName
){
  unsigned int i;

  UNUSED_PARAMETER(pNotUsed);
  for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
    if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;
  }
  return 0;
}

/*
** Return the name of the first system call after zName.  If zName==NULL
** then return the name of the first system call.  Return NULL if zName
** is the last system call or if zName is not the name of a valid
** system call.
*/
static const char *unixNextSystemCall(sqlite3_vfs *p, const char *zName){
  int i = -1;

  UNUSED_PARAMETER(p);
  if( zName ){
    for(i=0; i<ArraySize(aSyscall)-1; i++){
      if( strcmp(zName, aSyscall[i].zName)==0 ) break;
    }
  }
  for(i++; i<ArraySize(aSyscall); i++){
    if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
  }
  return 0;
}

/*
** Retry open() calls that fail due to EINTR
*/
static int robust_open(const char *z, int f, int m){
  int rc;
  do{ rc = osOpen(z,f,m); }while( rc<0 && errno==EINTR );
  return rc;
}

/*
** Helper functions to obtain and relinquish the global mutex. The
** global mutex is used to protect the unixInodeInfo and
** vxworksFileId objects used by this file, all of which may be 
** shared by multiple threads.
**

  int s;
  int savedErrno;
  if( op==F_GETLK ){
    zOpName = "GETLK";
  }else if( op==F_SETLK ){
    zOpName = "SETLK";
  }else{
    s = osFcntl(fd, op, p);
    sqlite3DebugPrintf("fcntl unknown %d %d %d\n", fd, op, s);
    return s;
  }
  if( p->l_type==F_RDLCK ){
    zType = "RDLCK";
  }else if( p->l_type==F_WRLCK ){
    zType = "WRLCK";
  }else if( p->l_type==F_UNLCK ){
    zType = "UNLCK";
  }else{
    assert( 0 );
  }
  assert( p->l_whence==SEEK_SET );
  s = osFcntl(fd, op, p);
  savedErrno = errno;
  sqlite3DebugPrintf("fcntl %d %d %s %s %d %d %d %d\n",
     threadid, fd, zOpName, zType, (int)p->l_start, (int)p->l_len,
     (int)p->l_pid, s);
  if( s==(-1) && op==F_SETLK && (p->l_type==F_RDLCK || p->l_type==F_WRLCK) ){
    struct flock l2;
    l2 = *p;
    osFcntl(fd, F_GETLK, &l2);
    if( l2.l_type==F_RDLCK ){
      zType = "RDLCK";
    }else if( l2.l_type==F_WRLCK ){
      zType = "WRLCK";
    }else if( l2.l_type==F_UNLCK ){
      zType = "UNLCK";
    }else{
      assert( 0 );
    }
    sqlite3DebugPrintf("fcntl-failure-reason: %s %d %d %d\n",
       zType, (int)l2.l_start, (int)l2.l_len, (int)l2.l_pid);
  }
  errno = savedErrno;
  return s;
}
#undef osFcntl
#define osFcntl lockTrace
#endif /* SQLITE_LOCK_TRACE */

/*
** Retry ftruncate() calls that fail due to EINTR
*/
static int robust_ftruncate(int h, sqlite3_int64 sz){
  int rc;
  do{ rc = osFtruncate(h,sz); }while( rc<0 && errno==EINTR );
  return rc;
}

/*
** This routine translates a standard POSIX errno code into something
** useful to the clients of the sqlite3 functions.  Specifically, it is
** intended to translate a variety of "try again" errors into SQLITE_BUSY
** and a variety of "please close the file descriptor NOW" errors into 
** SQLITE_IOERR
** 
** Errors during initialization of locks, or file system support for locks,
** should handle ENOLCK, ENOTSUP, EOPNOTSUPP separately.
*/
static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
  switch (posixError) {
#if 0
  /* At one point this code was not commented out. In theory, this branch
  ** should never be hit, as this function should only be called after
  ** a locking-related function (i.e. fcntl()) has returned non-zero with
  ** the value of errno as the first argument. Since a system call has failed,
  ** errno should be non-zero.
  **
  ** Despite this, if errno really is zero, we still don't want to return
  ** SQLITE_OK. The system call failed, and *some* SQLite error should be
  ** propagated back to the caller. Commenting this branch out means errno==0
  ** will be handled by the "default:" case below.
  */
  case 0: 
    return SQLITE_OK;
#endif

  case EAGAIN:
  case ETIMEDOUT:
  case EBUSY:
  case EINTR:
  case ENOLCK:  
    /* random NFS retry error, unless during file system support 
     * introspection, in which it actually means what it says */

	(sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) ){
      return SQLITE_BUSY;
    }
    /* else fall through */
  case EPERM: 
    return SQLITE_PERM;
    
  /* EDEADLK is only possible if a call to fcntl(F_SETLKW) is made. And
  ** this module never makes such a call. And the code in SQLite itself 
  ** asserts that SQLITE_IOERR_BLOCKED is never returned. For these reasons
  ** this case is also commented out. If the system does set errno to EDEADLK,
  ** the default SQLITE_IOERR_XXX code will be returned. */
#if 0
  case EDEADLK:
    return SQLITE_IOERR_BLOCKED;
#endif
    
#if EOPNOTSUPP!=ENOTSUP
  case EOPNOTSUPP: 
    /* something went terribly awry, unless during file system support 
     * introspection, in which it actually means what it says */
#endif
#ifdef ENOTSUP

** A single inode can have multiple file descriptors, so each unixFile
** structure contains a pointer to an instance of this object and this
** object keeps a count of the number of unixFile pointing to it.
*/
struct unixInodeInfo {
  struct unixFileId fileId;       /* The lookup key */
  int nShared;                    /* Number of SHARED locks held */
  unsigned char eFileLock;        /* One of SHARED_LOCK, RESERVED_LOCK etc. */
  unsigned char bProcessLock;     /* An exclusive process lock is held */
  int nRef;                       /* Number of pointers to this structure */
  unixShmNode *pShmNode;          /* Shared memory associated with this inode */
  int nLock;                      /* Number of outstanding file locks */
  UnixUnusedFd *pUnused;          /* Unused file descriptors to close */
  unixInodeInfo *pNext;           /* List of all unixInodeInfo objects */
  unixInodeInfo *pPrev;           /*    .... doubly linked */
#if defined(SQLITE_ENABLE_LOCKING_STYLE)
  unsigned long long sharedByte;  /* for AFP simulated shared lock */
#endif
#if OS_VXWORKS
  sem_t *pSem;                    /* Named POSIX semaphore */
  char aSemName[MAX_PATHNAME+2];  /* Name of that semaphore */
#endif
};

/*
** A lists of all unixInodeInfo objects.
*/
static unixInodeInfo *inodeList = 0;

/*
**
** This function - unixLogError_x(), is only ever called via the macro
** unixLogError().
**
** It is invoked after an error occurs in an OS function and errno has been
** set. It logs a message using sqlite3_log() containing the current value of
** errno and, if possible, the human-readable equivalent from strerror() or
** strerror_r().
**
** The first argument passed to the macro should be the error code that
** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN). 
** The two subsequent arguments should be the name of the OS function that
** failed (e.g. "unlink", "open") and the the associated file-system path,
** if any.
*/
#define unixLogError(a,b,c)     unixLogErrorAtLine(a,b,c,__LINE__)
static int unixLogErrorAtLine(
  int errcode,                    /* SQLite error code */
  const char *zFunc,              /* Name of OS function that failed */
  const char *zPath,              /* File path associated with error */
  int iLine                       /* Source line number where error occurred */
){
  char *zErr;                     /* Message from strerror() or equivalent */
  int iErrno = errno;             /* Saved syscall error number */

  /* If this is not a threadsafe build (SQLITE_THREADSAFE==0), then use
  ** the strerror() function to obtain the human-readable error message
  ** equivalent to errno. Otherwise, use strerror_r().
  */ 
#if SQLITE_THREADSAFE && defined(HAVE_STRERROR_R)
  char aErr[80];
  memset(aErr, 0, sizeof(aErr));
  zErr = aErr;

  /* If STRERROR_R_CHAR_P (set by autoconf scripts) or __USE_GNU is defined,
  ** assume that the system provides the the GNU version of strerror_r() that 
  ** returns a pointer to a buffer containing the error message. That pointer 
  ** may point to aErr[], or it may point to some static storage somewhere. 
  ** Otherwise, assume that the system provides the POSIX version of 
  ** strerror_r(), which always writes an error message into aErr[].
  **
  ** If the code incorrectly assumes that it is the POSIX version that is
  ** available, the error message will often be an empty string. Not a
  ** huge problem. Incorrectly concluding that the GNU version is available 
  ** could lead to a segfault though.
  */
#if defined(STRERROR_R_CHAR_P) || defined(__USE_GNU)
  zErr = 
# endif
  strerror_r(iErrno, aErr, sizeof(aErr)-1);

#elif SQLITE_THREADSAFE
  /* This is a threadsafe build, but strerror_r() is not available. */
  zErr = "";
#else
  /* Non-threadsafe build, use strerror(). */
  zErr = strerror(iErrno);
#endif

  assert( errcode!=SQLITE_OK );
  if( zPath==0 ) zPath = "";
  sqlite3_log(errcode,
      "os_unix.c:%d: (%d) %s(%s) - %s",
      iLine, iErrno, zFunc, zPath, zErr
  );

  return errcode;
}

/*
** Close a file descriptor.
**
** We assume that close() almost always works, since it is only in a
** very sick application or on a very sick platform that it might fail.
** If it does fail, simply leak the file descriptor, but do log the
** error.
**
** Note that it is not safe to retry close() after EINTR since the
** file descriptor might have already been reused by another thread.
** So we don't even try to recover from an EINTR.  Just log the error
** and move on.
*/
static void robust_close(unixFile *pFile, int h, int lineno){
  if( osClose(h) ){
    unixLogErrorAtLine(SQLITE_IOERR_CLOSE, "close",
                       pFile ? pFile->zPath : 0, lineno);
  }
}

/*
** Close all file descriptors accumuated in the unixInodeInfo->pUnused list.
*/ 
static void closePendingFds(unixFile *pFile){

  unixInodeInfo *pInode = pFile->pInode;

  UnixUnusedFd *p;
  UnixUnusedFd *pNext;
  for(p=pInode->pUnused; p; p=pNext){
    pNext = p->pNext;
    robust_close(pFile, p->fd, __LINE__);





    sqlite3_free(p);
  }

  pInode->pUnused = 0;

}

/*
** Release a unixInodeInfo structure previously allocated by findInodeInfo().
**
** The mutex entered using the unixEnterMutex() function must be held
** when this function is called.
*/
static void releaseInodeInfo(unixFile *pFile){
  unixInodeInfo *pInode = pFile->pInode;
  assert( unixMutexHeld() );
  if( ALWAYS(pInode) ){
    pInode->nRef--;
    if( pInode->nRef==0 ){
      assert( pInode->pShmNode==0 );
      closePendingFds(pFile);
      if( pInode->pPrev ){
        assert( pInode->pPrev->pNext==pInode );
        pInode->pPrev->pNext = pInode->pNext;

  assert( unixMutexHeld() );

  /* Get low-level information about the file that we can used to
  ** create a unique name for the file.
  */
  fd = pFile->h;
  rc = osFstat(fd, &statbuf);
  if( rc!=0 ){
    pFile->lastErrno = errno;
#ifdef EOVERFLOW
    if( pFile->lastErrno==EOVERFLOW ) return SQLITE_NOLFS;
#endif
    return SQLITE_IOERR;
  }

#ifdef __APPLE__
  /* On OS X on an msdos filesystem, the inode number is reported
  ** incorrectly for zero-size files.  See ticket #3260.  To work
  ** around this problem (we consider it a bug in OS X, not SQLite)
  ** we always increase the file size to 1 by writing a single byte
  ** prior to accessing the inode number.  The one byte written is
  ** an ASCII 'S' character which also happens to be the first byte
  ** in the header of every SQLite database.  In this way, if there
  ** is a race condition such that another thread has already populated
  ** the first page of the database, no damage is done.
  */
  if( statbuf.st_size==0 && (pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS)!=0 ){
    do{ rc = osWrite(fd, "S", 1); }while( rc<0 && errno==EINTR );
    if( rc!=1 ){
      pFile->lastErrno = errno;
      return SQLITE_IOERR;
    }
    rc = osFstat(fd, &statbuf);
    if( rc!=0 ){
      pFile->lastErrno = errno;
      return SQLITE_IOERR;
    }
  }
#endif

  if( pFile->pInode->eFileLock>SHARED_LOCK ){
    reserved = 1;
  }

  /* Otherwise see if some other process holds it.
  */
#ifndef __DJGPP__
  if( !reserved && !pFile->pInode->bProcessLock ){
    struct flock lock;
    lock.l_whence = SEEK_SET;
    lock.l_start = RESERVED_BYTE;
    lock.l_len = 1;
    lock.l_type = F_WRLCK;
    if( osFcntl(pFile->h, F_GETLK, &lock) ){

      rc = SQLITE_IOERR_CHECKRESERVEDLOCK;
      pFile->lastErrno = errno;
    } else if( lock.l_type!=F_UNLCK ){
      reserved = 1;
    }
  }
#endif
  
  unixLeaveMutex();
  OSTRACE(("TEST WR-LOCK %d %d %d (unix)\n", pFile->h, rc, reserved));

  *pResOut = reserved;
  return rc;
}

/*
** Attempt to set a system-lock on the file pFile.  The lock is 
** described by pLock.
**
** If the pFile was opened read/write from unix-excl, then the only lock
** ever obtained is an exclusive lock, and it is obtained exactly once
** the first time any lock is attempted.  All subsequent system locking
** operations become no-ops.  Locking operations still happen internally,
** in order to coordinate access between separate database connections
** within this process, but all of that is handled in memory and the
** operating system does not participate.
**
** This function is a pass-through to fcntl(F_SETLK) if pFile is using
** any VFS other than "unix-excl" or if pFile is opened on "unix-excl"
** and is read-only.
**
** Zero is returned if the call completes successfully, or -1 if a call
** to fcntl() fails. In this case, errno is set appropriately (by fcntl()).
*/
static int unixFileLock(unixFile *pFile, struct flock *pLock){
  int rc;
  unixInodeInfo *pInode = pFile->pInode;
  assert( unixMutexHeld() );
  assert( pInode!=0 );
  if( ((pFile->ctrlFlags & UNIXFILE_EXCL)!=0 || pInode->bProcessLock)
   && ((pFile->ctrlFlags & UNIXFILE_RDONLY)==0)
  ){
    if( pInode->bProcessLock==0 ){
      struct flock lock;
      assert( pInode->nLock==0 );
      lock.l_whence = SEEK_SET;
      lock.l_start = SHARED_FIRST;
      lock.l_len = SHARED_SIZE;
      lock.l_type = F_WRLCK;
      rc = osFcntl(pFile->h, F_SETLK, &lock);
      if( rc<0 ) return rc;
      pInode->bProcessLock = 1;
      pInode->nLock++;
    }else{
      rc = 0;
    }
  }else{
    rc = osFcntl(pFile->h, F_SETLK, pLock);
  }
  return rc;
}

/*
** Lock the file with the lock specified by parameter eFileLock - one
** of the following:
**
**     (1) SHARED_LOCK
**     (2) RESERVED_LOCK

  ** locking a random byte from a range, concurrent SHARED locks may exist
  ** even if the locking primitive used is always a write-lock.
  */
  int rc = SQLITE_OK;
  unixFile *pFile = (unixFile*)id;
  unixInodeInfo *pInode = pFile->pInode;
  struct flock lock;

  int tErrno = 0;

  assert( pFile );
  OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (unix)\n", pFile->h,
      azFileLock(eFileLock), azFileLock(pFile->eFileLock),
      azFileLock(pInode->eFileLock), pInode->nShared , getpid()));

  lock.l_len = 1L;
  lock.l_whence = SEEK_SET;
  if( eFileLock==SHARED_LOCK 
      || (eFileLock==EXCLUSIVE_LOCK && pFile->eFileLock<PENDING_LOCK)
  ){
    lock.l_type = (eFileLock==SHARED_LOCK?F_RDLCK:F_WRLCK);
    lock.l_start = PENDING_BYTE;
    if( unixFileLock(pFile, &lock) ){

      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( rc!=SQLITE_BUSY ){
        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }
  }


  /* If control gets to this point, then actually go ahead and make
  ** operating system calls for the specified lock.
  */
  if( eFileLock==SHARED_LOCK ){
    assert( pInode->nShared==0 );
    assert( pInode->eFileLock==0 );
    assert( rc==SQLITE_OK );

    /* Now get the read-lock */
    lock.l_start = SHARED_FIRST;
    lock.l_len = SHARED_SIZE;
    if( unixFileLock(pFile, &lock) ){
      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
    }

    /* Drop the temporary PENDING lock */
    lock.l_start = PENDING_BYTE;
    lock.l_len = 1L;
    lock.l_type = F_UNLCK;
    if( unixFileLock(pFile, &lock) && rc==SQLITE_OK ){

      /* This could happen with a network mount */
      tErrno = errno;
      rc = SQLITE_IOERR_UNLOCK; 


    }



    if( rc ){
      if( rc!=SQLITE_BUSY ){

        pFile->lastErrno = tErrno;
      }
      goto end_lock;
    }else{
      pFile->eFileLock = SHARED_LOCK;
      pInode->nLock++;
      pInode->nShared = 1;
    }
  }else if( eFileLock==EXCLUSIVE_LOCK && pInode->nShared>1 ){
    /* We are trying for an exclusive lock but another thread in this
    ** same process is still holding a shared lock. */
    rc = SQLITE_BUSY;
  }else{
    /* The request was for a RESERVED or EXCLUSIVE lock.  It is
    ** assumed that there is a SHARED or greater lock on the file
    ** already.
    */
    assert( 0!=pFile->eFileLock );
    lock.l_type = F_WRLCK;

    assert( eFileLock==RESERVED_LOCK || eFileLock==EXCLUSIVE_LOCK );
    if( eFileLock==RESERVED_LOCK ){
      lock.l_start = RESERVED_BYTE;
      lock.l_len = 1L;
    }else{

      lock.l_start = SHARED_FIRST;
      lock.l_len = SHARED_SIZE;



    }

    if( unixFileLock(pFile, &lock) ){
      tErrno = errno;
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( rc!=SQLITE_BUSY ){
        pFile->lastErrno = tErrno;
      }
    }
  }
  

#ifndef NDEBUG

** 
** If handleNFSUnlock is true, then on downgrading an EXCLUSIVE_LOCK to SHARED
** the byte range is divided into 2 parts and the first part is unlocked then
** set to a read lock, then the other part is simply unlocked.  This works 
** around a bug in BSD NFS lockd (also seen on MacOSX 10.3+) that fails to 
** remove the write lock on a region when a read lock is set.
*/
static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
  unixFile *pFile = (unixFile*)id;
  unixInodeInfo *pInode;
  struct flock lock;
  int rc = SQLITE_OK;
  int h;


  assert( pFile );
  OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (unix)\n", pFile->h, eFileLock,
      pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,
      getpid()));

  assert( eFileLock<=SHARED_LOCK );

    ** write lock until the rest is covered by a read lock:
    **  1:   [WWWWW]
    **  2:   [....W]
    **  3:   [RRRRW]
    **  4:   [RRRR.]
    */
    if( eFileLock==SHARED_LOCK ){

#if !defined(__APPLE__) || !SQLITE_ENABLE_LOCKING_STYLE
      (void)handleNFSUnlock;
      assert( handleNFSUnlock==0 );
#endif
#if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE
      if( handleNFSUnlock ){
        int tErrno;               /* Error code from system call errors */
        off_t divSize = SHARED_SIZE - 1;
        
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
          rc = SQLITE_IOERR_UNLOCK;
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
          rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_RDLOCK);
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST+divSize;
        lock.l_len = SHARED_SIZE-divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
          rc = SQLITE_IOERR_UNLOCK;
          if( IS_LOCK_ERROR(rc) ){
            pFile->lastErrno = tErrno;
          }
          goto end_unlock;
        }
      }else
#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
      {
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = SHARED_SIZE;
        if( unixFileLock(pFile, &lock) ){
          /* In theory, the call to unixFileLock() cannot fail because another
          ** process is holding an incompatible lock. If it does, this 
          ** indicates that the other process is not following the locking
          ** protocol. If this happens, return SQLITE_IOERR_RDLOCK. Returning
          ** SQLITE_BUSY would confuse the upper layer (in practice it causes 
          ** an assert to fail). */ 
          rc = SQLITE_IOERR_RDLOCK;

          pFile->lastErrno = errno;

          goto end_unlock;
        }
      }
    }
    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = PENDING_BYTE;
    lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );
    if( unixFileLock(pFile, &lock)==0 ){
      pInode->eFileLock = SHARED_LOCK;
    }else{

      rc = SQLITE_IOERR_UNLOCK;

      pFile->lastErrno = errno;

      goto end_unlock;
    }
  }
  if( eFileLock==NO_LOCK ){
    /* Decrement the shared lock counter.  Release the lock using an
    ** OS call only when all threads in this same process have released
    ** the lock.
    */
    pInode->nShared--;
    if( pInode->nShared==0 ){
      lock.l_type = F_UNLCK;
      lock.l_whence = SEEK_SET;
      lock.l_start = lock.l_len = 0L;
      SimulateIOErrorBenign(1);
      SimulateIOError( h=(-1) )
      SimulateIOErrorBenign(0);
      if( unixFileLock(pFile, &lock)==0 ){
        pInode->eFileLock = NO_LOCK;
      }else{

        rc = SQLITE_IOERR_UNLOCK;

	pFile->lastErrno = errno;

        pInode->eFileLock = NO_LOCK;
        pFile->eFileLock = NO_LOCK;
      }
    }

    /* Decrement the count of locks against this same file.  When the
    ** count reaches zero, close any other file descriptors whose close
    ** was deferred because of outstanding locks.
    */
    pInode->nLock--;
    assert( pInode->nLock>=0 );
    if( pInode->nLock==0 ){
      closePendingFds(pFile);



    }
  }
	
end_unlock:
  unixLeaveMutex();
  if( rc==SQLITE_OK ) pFile->eFileLock = eFileLock;
  return rc;
}

/*
** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock
** must be either NO_LOCK or SHARED_LOCK.
**
** If the locking level of the file descriptor is already at or below
** the requested locking level, this routine is a no-op.
*/
static int unixUnlock(sqlite3_file *id, int eFileLock){
  return posixUnlock(id, eFileLock, 0);
}

/*
** This function performs the parts of the "close file" operation 
** common to all locking schemes. It closes the directory and file
** handles, if they are valid, and sets all fields of the unixFile
** structure to 0.
**
** It is *not* necessary to hold the mutex when this routine is called,
** even on VxWorks.  A mutex will be acquired on VxWorks by the
** vxworksReleaseFileId() routine.
*/
static int closeUnixFile(sqlite3_file *id){
  unixFile *pFile = (unixFile*)id;

  if( pFile->dirfd>=0 ){
    robust_close(pFile, pFile->dirfd, __LINE__);




    pFile->dirfd=-1;
  }

  if( pFile->h>=0 ){
    robust_close(pFile, pFile->h, __LINE__);

    pFile->h = -1;

  }

#if OS_VXWORKS
  if( pFile->pId ){
    if( pFile->isDelete ){
      unlink(pFile->pId->zCanonicalName);
    }
    vxworksReleaseFileId(pFile->pId);
    pFile->pId = 0;
  }
#endif
  OSTRACE(("CLOSE   %-3d\n", pFile->h));
  OpenCounter(-1);
  sqlite3_free(pFile->pUnused);
  memset(pFile, 0, sizeof(unixFile));

  return SQLITE_OK;
}

/*
** Close a file.
*/
static int unixClose(sqlite3_file *id){
  int rc = SQLITE_OK;

  unixFile *pFile = (unixFile *)id;
  unixUnlock(id, NO_LOCK);
  unixEnterMutex();

  /* unixFile.pInode is always valid here. Otherwise, a different close
  ** routine (e.g. nolockClose()) would be called instead.
  */
  assert( pFile->pInode->nLock>0 || pFile->pInode->bProcessLock==0 );
  if( ALWAYS(pFile->pInode) && pFile->pInode->nLock ){
    /* If there are outstanding locks, do not actually close the file just
    ** yet because that would clear those locks.  Instead, add the file
    ** descriptor to pInode->pUnused list.  It will be automatically closed 
    ** when the last lock is cleared.
    */
    setPendingFd(pFile);
  }
  releaseInodeInfo(pFile);
  rc = closeUnixFile(id);
  unixLeaveMutex();

  return rc;
}

/************** End of the posix advisory lock implementation *****************
******************************************************************************/

/******************************************************************************

  if( pFile->eFileLock>SHARED_LOCK ){
    /* Either this connection or some other connection in the same process
    ** holds a lock on the file.  No need to check further. */
    reserved = 1;
  }else{
    /* The lock is held if and only if the lockfile exists */
    const char *zLockFile = (const char*)pFile->lockingContext;
    reserved = osAccess(zLockFile, 0)==0;
  }
  OSTRACE(("TEST WR-LOCK %d %d %d (dotlock)\n", pFile->h, rc, reserved));
  *pResOut = reserved;
  return rc;
}

/*

    /* Always update the timestamp on the old file */
    utimes(zLockFile, NULL);
#endif
    return SQLITE_OK;
  }
  
  /* grab an exclusive lock */
  fd = robust_open(zLockFile,O_RDONLY|O_CREAT|O_EXCL,0600);
  if( fd<0 ){
    /* failed to open/create the file, someone else may have stolen the lock */
    int tErrno = errno;
    if( EEXIST == tErrno ){
      rc = SQLITE_BUSY;
    } else {
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( IS_LOCK_ERROR(rc) ){
        pFile->lastErrno = tErrno;
      }
    }
    return rc;
  } 
  robust_close(pFile, fd, __LINE__);



  
  /* got it, set the type and return ok */
  pFile->eFileLock = eFileLock;
  return rc;
}

/*

  
  /* To fully unlock the database, delete the lock file */
  assert( eFileLock==NO_LOCK );
  if( unlink(zLockFile) ){
    int rc = 0;
    int tErrno = errno;
    if( ENOENT != tErrno ){
      rc = SQLITE_IOERR_UNLOCK;
    }
    if( IS_LOCK_ERROR(rc) ){
      pFile->lastErrno = tErrno;
    }
    return rc; 
  }
  pFile->eFileLock = NO_LOCK;

** only a single process can be reading the database at a time.
**
** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off or if
** compiling for VXWORKS.
*/
#if SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS

/*
** Retry flock() calls that fail with EINTR
*/
#ifdef EINTR
static int robust_flock(int fd, int op){
  int rc;
  do{ rc = flock(fd,op); }while( rc<0 && errno==EINTR );
  return rc;
}
#else
# define robust_flock(a,b) flock(a,b)
#endif
     

/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, set *pResOut
** to a non-zero value otherwise *pResOut is set to zero.  The return value
** is set to SQLITE_OK unless an I/O error occurs during lock checking.
*/
static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){

  if( pFile->eFileLock>SHARED_LOCK ){
    reserved = 1;
  }
  
  /* Otherwise see if some other process holds it. */
  if( !reserved ){
    /* attempt to get the lock */
    int lrc = robust_flock(pFile->h, LOCK_EX | LOCK_NB);
    if( !lrc ){
      /* got the lock, unlock it */
      lrc = robust_flock(pFile->h, LOCK_UN);
      if ( lrc ) {
        int tErrno = errno;
        /* unlock failed with an error */
        lrc = SQLITE_IOERR_UNLOCK; 
        if( IS_LOCK_ERROR(lrc) ){
          pFile->lastErrno = tErrno;
          rc = lrc;
        }
      }
    } else {
      int tErrno = errno;

  if (pFile->eFileLock > NO_LOCK) {
    pFile->eFileLock = eFileLock;
    return SQLITE_OK;
  }
  
  /* grab an exclusive lock */
  
  if (robust_flock(pFile->h, LOCK_EX | LOCK_NB)) {
    int tErrno = errno;
    /* didn't get, must be busy */
    rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
    if( IS_LOCK_ERROR(rc) ){
      pFile->lastErrno = tErrno;
    }
  } else {

  /* shared can just be set because we always have an exclusive */
  if (eFileLock==SHARED_LOCK) {
    pFile->eFileLock = eFileLock;
    return SQLITE_OK;
  }
  
  /* no, really, unlock. */
  if( robust_flock(pFile->h, LOCK_UN) ){






#ifdef SQLITE_IGNORE_FLOCK_LOCK_ERRORS

    return SQLITE_OK;

#endif /* SQLITE_IGNORE_FLOCK_LOCK_ERRORS */

    return SQLITE_IOERR_UNLOCK;
  }else{
    pFile->eFileLock = NO_LOCK;
    return SQLITE_OK;
  }
}

/*
** Close a file.

        pFile->eFileLock = NO_LOCK;
      }
    }
    if( rc==SQLITE_OK ){
      pInode->nLock--;
      assert( pInode->nLock>=0 );
      if( pInode->nLock==0 ){
        closePendingFds(pFile);
      }
    }
  }
  
  unixLeaveMutex();
  if( rc==SQLITE_OK ) pFile->eFileLock = eFileLock;
  return rc;

 ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock
 ** must be either NO_LOCK or SHARED_LOCK.
 **
 ** If the locking level of the file descriptor is already at or below
 ** the requested locking level, this routine is a no-op.
 */
static int nfsUnlock(sqlite3_file *id, int eFileLock){
  return posixUnlock(id, eFileLock, 1);
}

#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
/*
** The code above is the NFS lock implementation.  The code is specific
** to MacOSX and does not work on other unix platforms.  No alternative
** is available.  

static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
  int got;
#if (!defined(USE_PREAD) && !defined(USE_PREAD64))
  i64 newOffset;
#endif
  TIMER_START;
#if defined(USE_PREAD)
  do{ got = osPread(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
  SimulateIOError( got = -1 );
#elif defined(USE_PREAD64)
  do{ got = osPread64(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR);
  SimulateIOError( got = -1 );
#else
  newOffset = lseek(id->h, offset, SEEK_SET);
  SimulateIOError( newOffset-- );
  if( newOffset!=offset ){
    if( newOffset == -1 ){
      ((unixFile*)id)->lastErrno = errno;
    }else{
      ((unixFile*)id)->lastErrno = 0;			
    }
    return -1;
  }
  do{ got = osRead(id->h, pBuf, cnt); }while( got<0 && errno==EINTR );
#endif
  TIMER_END;
  if( got<0 ){
    ((unixFile*)id)->lastErrno = errno;
  }
  OSTRACE(("READ    %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
  return got;

static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
  int got;
#if (!defined(USE_PREAD) && !defined(USE_PREAD64))
  i64 newOffset;
#endif
  TIMER_START;
#if defined(USE_PREAD)
  do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
#elif defined(USE_PREAD64)
  do{ got = osPwrite64(id->h, pBuf, cnt, offset);}while( got<0 && errno==EINTR);
#else
  newOffset = lseek(id->h, offset, SEEK_SET);
  SimulateIOError( newOffset-- );
  if( newOffset!=offset ){
    if( newOffset == -1 ){
      ((unixFile*)id)->lastErrno = errno;
    }else{
      ((unixFile*)id)->lastErrno = 0;			
    }
    return -1;
  }
  do{ got = osWrite(id->h, pBuf, cnt); }while( got<0 && errno==EINTR );
#endif
  TIMER_END;
  if( got<0 ){
    ((unixFile*)id)->lastErrno = errno;
  }

  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));

  ** no-op
  */
#ifdef SQLITE_NO_SYNC
  rc = SQLITE_OK;
#elif HAVE_FULLFSYNC
  if( fullSync ){
#ifdef SQLITE_USE_REQUEST_FULLFSYNC
    rc = osFsync(fd);
    if (!rc) {
      OSSpinLockLock(&notify_lock);
      rc = notify_post(REQUEST_FULLSYNC_NOTIFICATION);
      OSSpinLockUnlock(&notify_lock);
    }
#else
    rc = osFcntl(fd, F_FULLFSYNC, 0);
#endif
  }else{
    rc = 1;
  }
  /* If the FULLFSYNC failed, fall back to attempting an fsync().
  ** It shouldn't be possible for fullfsync to fail on the local 
  ** file system (on OSX), so failure indicates that FULLFSYNC

  assert( pFile );
  OSTRACE(("SYNC    %-3d\n", pFile->h));
  rc = full_fsync(pFile->h, isFullsync, isDataOnly);
  SimulateIOError( rc=1 );
  if( rc ){
    pFile->lastErrno = errno;
    return unixLogError(SQLITE_IOERR_FSYNC, "full_fsync", pFile->zPath);
  }
  if( pFile->dirfd>=0 ){

    OSTRACE(("DIRSYNC %-3d (have_fullfsync=%d fullsync=%d)\n", pFile->dirfd,
            HAVE_FULLFSYNC, isFullsync));
#ifndef SQLITE_DISABLE_DIRSYNC
    /* The directory sync is only attempted if full_fsync is
    ** turned off or unavailable.  If a full_fsync occurred above,
    ** then the directory sync is superfluous.
    */
    if( (!HAVE_FULLFSYNC || !isFullsync) && full_fsync(pFile->dirfd,0,0) ){
       /*
       ** We have received multiple reports of fsync() returning
       ** errors when applied to directories on certain file systems.
       ** A failed directory sync is not a big deal.  So it seems
       ** better to ignore the error.  Ticket #1657
       */
       /* pFile->lastErrno = errno; */
       /* return SQLITE_IOERR; */
    }
#endif
    /* Only need to sync once, so close the  directory when we are done */
    robust_close(pFile, pFile->dirfd, __LINE__);
    pFile->dirfd = -1;




  }
  return rc;
}

/*
** Truncate an open file to a specified size
*/

  ** actual file size after the operation may be larger than the requested
  ** size).
  */
  if( pFile->szChunk ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  rc = robust_ftruncate(pFile->h, (off_t)nByte);
  if( rc ){
    pFile->lastErrno = errno;
    return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
  }else{
#ifndef NDEBUG
    /* If we are doing a normal write to a database file (as opposed to
    ** doing a hot-journal rollback or a write to some file other than a
    ** normal database file) and we truncate the file to zero length,
    ** that effectively updates the change counter.  This might happen
    ** when restoring a database using the backup API from a zero-length

/*
** Determine the current size of a file in bytes
*/
static int unixFileSize(sqlite3_file *id, i64 *pSize){
  int rc;
  struct stat buf;
  assert( id );
  rc = osFstat(((unixFile*)id)->h, &buf);
  SimulateIOError( rc=1 );
  if( rc!=0 ){
    ((unixFile*)id)->lastErrno = errno;
    return SQLITE_IOERR_FSTAT;
  }
  *pSize = buf.st_size;

** SQLITE_FCNTL_SIZE_HINT operation is a no-op for Unix.
*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){
  if( pFile->szChunk ){
    i64 nSize;                    /* Required file size */
    struct stat buf;              /* Used to hold return values of fstat() */
   
    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;

    nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;
    if( nSize>(i64)buf.st_size ){

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
      /* The code below is handling the return value of osFallocate() 
      ** correctly. posix_fallocate() is defined to "returns zero on success, 
      ** or an error number on  failure". See the manpage for details. */
      int err;
      do{
        err = osFallocate(pFile->h, buf.st_size, nSize-buf.st_size);
      }while( err==EINTR );
      if( err ) return SQLITE_IOERR_WRITE;

#else
      /* If the OS does not have posix_fallocate(), fake it. First use
      ** ftruncate() to set the file size, then write a single byte to
      ** the last byte in each block within the extended region. This
      ** is the same technique used by glibc to implement posix_fallocate()
      ** on systems that do not have a real fallocate() system call.
      */
      int nBlk = buf.st_blksize;  /* File-system block size */
      i64 iWrite;                 /* Next offset to write to */
      int nWrite;                 /* Return value from seekAndWrite() */

      if( robust_ftruncate(pFile->h, nSize) ){
        pFile->lastErrno = errno;
        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
      }
      iWrite = ((buf.st_size + 2*nBlk - 1)/nBlk)*nBlk-1;
      do {
        nWrite = seekAndWrite(pFile, iWrite, "", 1);
        iWrite += nBlk;
      } while( nWrite==1 && iWrite<nSize );
      if( nWrite!=1 ) return SQLITE_IOERR_WRITE;

  /* Shared locks never span more than one byte */
  assert( n==1 || lockType!=F_RDLCK );

  /* Locks are within range */
  assert( n>=1 && n<SQLITE_SHM_NLOCK );

  if( pShmNode->h>=0 ){
    /* Initialize the locking parameters */
    memset(&f, 0, sizeof(f));
    f.l_type = lockType;
    f.l_whence = SEEK_SET;
    f.l_start = ofst;
    f.l_len = n;

    rc = osFcntl(pShmNode->h, F_SETLK, &f);
    rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;
  }

  /* Update the global lock state and do debug tracing */
#ifdef SQLITE_DEBUG
  { u16 mask;
  OSTRACE(("SHM-LOCK "));
  mask = (1<<(ofst+n)) - (1<<ofst);
  if( rc==SQLITE_OK ){