fts5parse.c fts5parse.h \
   $(TOP)\ext\fts5\fts5_storage.c \
   $(TOP)\ext\fts5\fts5_tokenize.c \
   $(TOP)\ext\fts5\fts5_unicode2.c \
   $(TOP)\ext\fts5\fts5_varint.c \
   $(TOP)\ext\fts5\fts5_vocab.c



















fts5parse.c:	$(TOP)\ext\fts5\fts5parse.y lemon.exe
	copy $(TOP)\ext\fts5\fts5parse.y .
	del /Q fts5parse.h 2>NUL
	.\lemon.exe $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) fts5parse.y

fts5parse.h:	fts5parse.c

fts5.c:	$(FTS5_SRC)
	$(TCLSH_CMD) $(TOP)\ext\fts5\tool\mkfts5c.tcl
	copy $(TOP)\ext\fts5\fts5.h .





fts5.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -DSQLITE_CORE -c fts5.c

fts5_ext.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(NO_WARN) -c fts5.c

fts5.dll:	fts5_ext.lo
................................................................................
	del /Q sqlite3.c sqlite3-*.c 2>NUL
	del /Q sqlite3rc.h 2>NUL
	del /Q shell.c sqlite3ext.h sqlite3session.h 2>NUL
	del /Q sqlite3_analyzer.exe sqlite3_analyzer.c 2>NUL
	del /Q sqlite-*-output.vsix 2>NUL
	del /Q fuzzershell.exe fuzzcheck.exe sqldiff.exe dbhash.exe 2>NUL
	del /Q fts5.* fts5parse.* 2>NUL

# <</mark>>

   fts5parse.c fts5parse.h \
   $(TOP)\ext\fts5\fts5_storage.c \
   $(TOP)\ext\fts5\fts5_tokenize.c \
   $(TOP)\ext\fts5\fts5_unicode2.c \
   $(TOP)\ext\fts5\fts5_varint.c \
   $(TOP)\ext\fts5\fts5_vocab.c

LSM1_SRC = \
   $(TOP)\ext\lsm1\lsm.h \
   $(TOP)\ext\lsm1\lsmInt.h \
   $(TOP)\ext\lsm1\lsm_ckpt.c \
   $(TOP)\ext\lsm1\lsm_file.c \
   $(TOP)\ext\lsm1\lsm_log.c \
   $(TOP)\ext\lsm1\lsm_main.c \
   $(TOP)\ext\lsm1\lsm_mem.c \
   $(TOP)\ext\lsm1\lsm_mutex.c \
   $(TOP)\ext\lsm1\lsm_shared.c \
   $(TOP)\ext\lsm1\lsm_sorted.c \
   $(TOP)\ext\lsm1\lsm_str.c \
   $(TOP)\ext\lsm1\lsm_tree.c \
   $(TOP)\ext\lsm1\lsm_unix.c \
   $(TOP)\ext\lsm1\lsm_varint.c \
   $(TOP)\ext\lsm1\lsm_vtab.c \
   $(TOP)\ext\lsm1\lsm_win32.c

fts5parse.c:	$(TOP)\ext\fts5\fts5parse.y lemon.exe
	copy $(TOP)\ext\fts5\fts5parse.y .
	del /Q fts5parse.h 2>NUL
	.\lemon.exe $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) fts5parse.y

fts5parse.h:	fts5parse.c

fts5.c:	$(FTS5_SRC)
	$(TCLSH_CMD) $(TOP)\ext\fts5\tool\mkfts5c.tcl
	copy $(TOP)\ext\fts5\fts5.h .

lsm1.c:	$(LSM1_SRC)
	$(TCLSH_CMD) $(TOP)\ext\lsm1\tool\mklsm1c.tcl
	copy $(TOP)\ext\lsm1\lsm.h .

fts5.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -DSQLITE_CORE -c fts5.c

fts5_ext.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(NO_WARN) -c fts5.c

fts5.dll:	fts5_ext.lo
................................................................................
	del /Q sqlite3.c sqlite3-*.c 2>NUL
	del /Q sqlite3rc.h 2>NUL
	del /Q shell.c sqlite3ext.h sqlite3session.h 2>NUL
	del /Q sqlite3_analyzer.exe sqlite3_analyzer.c 2>NUL
	del /Q sqlite-*-output.vsix 2>NUL
	del /Q fuzzershell.exe fuzzcheck.exe sqldiff.exe dbhash.exe 2>NUL
	del /Q fts5.* fts5parse.* 2>NUL
	del /Q lsm.h lsm1.c 2>NUL
# <</mark>>

tool/mksqlite3c.tcl script is run to copy them all together in just the
right order while resolving internal "#include" references.

The amalgamation source file is more than 200K lines long.  Some symbolic
debuggers (most notably MSVC) are unable to deal with files longer than 64K
lines.  To work around this, a separate Tcl script, tool/split-sqlite3c.tcl,
can be run on the amalgamation to break it up into a single small C file
called **sqlite3-all.c** that does #include on about five other files
named **sqlite3-1.c**, **sqlite3-2.c**, ..., **sqlite3-5.c**.  In this way,
all of the source code is contained within a single translation unit so
that the compiler can do extra cross-procedure optimization, but no
individual source file exceeds 32K lines in length.

## How It All Fits Together

SQLite is modular in design.
................................................................................
Key files:

  *  **sqlite.h.in** - This file defines the public interface to the SQLite
     library.  Readers will need to be familiar with this interface before
     trying to understand how the library works internally.

  *  **sqliteInt.h** - this header file defines many of the data objects
     used internally by SQLite.


  *  **parse.y** - This file describes the LALR(1) grammar that SQLite uses
     to parse SQL statements, and the actions that are taken at each step
     in the parsing process.

  *  **vdbe.c** - This file implements the virtual machine that runs
     prepared statements.  There are various helper files whose names
     begin with "vdbe".  The VDBE has access to the vdbeInt.h header file
     which defines internal data objects.  The rest of SQLite interacts
     with the VDBE through an interface defined by vdbe.h.


  *  **where.c** - This file analyzes the WHERE clause and generates
     virtual machine code to run queries efficiently.  This file is
     sometimes called the "query optimizer".  It has its own private
     header file, whereInt.h, that defines data objects used internally.

  *  **btree.c** - This file contains the implementation of the B-Tree
     storage engine used by SQLite.



  *  **pager.c** - This file contains the "pager" implementation, the
     module that implements transactions.


  *  **os_unix.c** and **os_win.c** - These two files implement the interface
     between SQLite and the underlying operating system using the run-time
     pluggable VFS interface.

  *  **shell.c** - This file is not part of the core SQLite library.  This
     is the file that, when linked against sqlite3.a, generates the
     "sqlite3.exe" command-line shell.


  *  **tclsqlite.c** - This file implements the Tcl bindings for SQLite.  It
     is not part of the core SQLite library.  But as most of the tests in this
     repository are written in Tcl, the Tcl language bindings are important.











There are many other source files.  Each has a succinct header comment that
describes its purpose and role within the larger system.


## Contacts

The main SQLite webpage is [http://www.sqlite.org/](http://www.sqlite.org/)
with geographically distributed backups at
[http://www2.sqlite.org/](http://www2.sqlite.org) and
[http://www3.sqlite.org/](http://www3.sqlite.org).

tool/mksqlite3c.tcl script is run to copy them all together in just the
right order while resolving internal "#include" references.

The amalgamation source file is more than 200K lines long.  Some symbolic
debuggers (most notably MSVC) are unable to deal with files longer than 64K
lines.  To work around this, a separate Tcl script, tool/split-sqlite3c.tcl,
can be run on the amalgamation to break it up into a single small C file
called **sqlite3-all.c** that does #include on about seven other files
named **sqlite3-1.c**, **sqlite3-2.c**, ..., **sqlite3-7.c**.  In this way,
all of the source code is contained within a single translation unit so
that the compiler can do extra cross-procedure optimization, but no
individual source file exceeds 32K lines in length.

## How It All Fits Together

SQLite is modular in design.
................................................................................
Key files:

  *  **sqlite.h.in** - This file defines the public interface to the SQLite
     library.  Readers will need to be familiar with this interface before
     trying to understand how the library works internally.

  *  **sqliteInt.h** - this header file defines many of the data objects
     used internally by SQLite.  In addition to "sqliteInt.h", some
     subsystems have their own header files.

  *  **parse.y** - This file describes the LALR(1) grammar that SQLite uses
     to parse SQL statements, and the actions that are taken at each step
     in the parsing process.

  *  **vdbe.c** - This file implements the virtual machine that runs
     prepared statements.  There are various helper files whose names
     begin with "vdbe".  The VDBE has access to the vdbeInt.h header file
     which defines internal data objects.  The rest of SQLite interacts
     with the VDBE through an interface defined by vdbe.h.

  *  **where.c** - This file (together with its helper files named
     by "where*.c") analyzes the WHERE clause and generates
     virtual machine code to run queries efficiently.  This file is
     sometimes called the "query optimizer".  It has its own private
     header file, whereInt.h, that defines data objects used internally.

  *  **btree.c** - This file contains the implementation of the B-Tree
     storage engine used by SQLite.  The interface to the rest of the system
     is defined by "btree.h".  The "btreeInt.h" header defines objects
     used internally by btree.c and not published to the rest of the system.

  *  **pager.c** - This file contains the "pager" implementation, the
     module that implements transactions.  The "pager.h" header file
     defines the interface between pager.c and the rest of the system.

  *  **os_unix.c** and **os_win.c** - These two files implement the interface
     between SQLite and the underlying operating system using the run-time
     pluggable VFS interface.

  *  **shell.c.in** - This file is not part of the core SQLite library.  This
     is the file that, when linked against sqlite3.a, generates the
     "sqlite3.exe" command-line shell.  The "shell.c.in" file is transformed
     into "shell.c" as part of the build process.

  *  **tclsqlite.c** - This file implements the Tcl bindings for SQLite.  It
     is not part of the core SQLite library.  But as most of the tests in this
     repository are written in Tcl, the Tcl language bindings are important.

  *  **test*.c** - Files in the src/ folder that begin with "test" go into
     building the "testfixture.exe" program.  The testfixture.exe program is
     an enhanced TCL shell.  The testfixture.exe program runs scripts in the
     test/ folder to validate the core SQLite code.  The testfixture program
     (and some other test programs too) is build and run when you type
     "make test".

  *  **ext/misc/json1.c** - This file implements the various JSON functions
     that are build into SQLite.

There are many other source files.  Each has a succinct header comment that
describes its purpose and role within the larger system.


## Contacts

The main SQLite webpage is [http://www.sqlite.org/](http://www.sqlite.org/)
with geographically distributed backups at
[http://www2.sqlite.org/](http://www2.sqlite.org) and
[http://www3.sqlite.org/](http://www3.sqlite.org).

  if( p2->n ){
    i64 iLastRowid = 0;
    Fts5DoclistIter i1;
    Fts5DoclistIter i2;
    Fts5Buffer out = {0, 0, 0};
    Fts5Buffer tmp = {0, 0, 0};







    if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n) ) return;
    fts5DoclistIterInit(p1, &i1);
    fts5DoclistIterInit(p2, &i2);

    while( 1 ){
      if( i1.iRowid<i2.iRowid ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
................................................................................
      fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
      fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
    }
    else if( i2.aPoslist ){
      fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
      fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
    }


    fts5BufferSet(&p->rc, p1, out.n, out.p);
    fts5BufferFree(&tmp);
    fts5BufferFree(&out);
  }
}

  if( p2->n ){
    i64 iLastRowid = 0;
    Fts5DoclistIter i1;
    Fts5DoclistIter i2;
    Fts5Buffer out = {0, 0, 0};
    Fts5Buffer tmp = {0, 0, 0};

    /* The maximum size of the output is equal to the sum of the two 
    ** input sizes + 1 varint (9 bytes). The extra varint is because if the
    ** first rowid in one input is a large negative number, and the first in
    ** the other a non-negative number, the delta for the non-negative
    ** number will be larger on disk than the literal integer value
    ** was.  */
    if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n + 9) ) return;
    fts5DoclistIterInit(p1, &i1);
    fts5DoclistIterInit(p2, &i2);

    while( 1 ){
      if( i1.iRowid<i2.iRowid ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
................................................................................
      fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
      fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
    }
    else if( i2.aPoslist ){
      fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
      fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
    }
    assert( out.n<=(p1->n+p2->n+9) );

    fts5BufferSet(&p->rc, p1, out.n, out.p);
    fts5BufferFree(&tmp);
    fts5BufferFree(&out);
  }
}

    foreach x [list bbb ddd fff hhh jjj lll nnn ppp rrr ttt] {
      set doc [string repeat "$x " 30]
      execsql { INSERT INTO t1 VALUES($doc) }
    }
    execsql COMMIT
  } {}

  do_execsql_test 1.$tn.2 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  set ret 1
  foreach x [list a c e g i k m o q s u] {
    do_execsql_test 2.$tn.3.$ret {
      SELECT rowid FROM t1 WHERE t1 MATCH $x || '*';
    } {}
    incr ret
  }
}












finish_test

    foreach x [list bbb ddd fff hhh jjj lll nnn ppp rrr ttt] {
      set doc [string repeat "$x " 30]
      execsql { INSERT INTO t1 VALUES($doc) }
    }
    execsql COMMIT
  } {}

  do_execsql_test 2.$tn.2 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  set ret 1
  foreach x [list a c e g i k m o q s u] {
    do_execsql_test 2.$tn.3.$ret {
      SELECT rowid FROM t1 WHERE t1 MATCH $x || '*';
    } {}
    incr ret
  }
}

reset_db
do_execsql_test 3.0 {
  CREATE VIRTUAL TABLE x1 USING fts5(a);
  INSERT INTO x1(rowid, a) VALUES(-1000000000000, 'toyota');
  INSERT INTO x1(rowid, a) VALUES(1, 'tarago');
}
do_execsql_test 3.1 {
  SELECT rowid FROM x1('t*');
} {-1000000000000 1}


finish_test

**
**   * Integration of ICU and SQLite collation sequences.
**
**   * An implementation of the LIKE operator that uses ICU to 
**     provide case-independent matching.
*/


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


/* Include ICU headers */
#include <unicode/utypes.h>
#include <unicode/uregex.h>
#include <unicode/ustring.h>
#include <unicode/ucol.h>

................................................................................
#ifndef SQLITE_CORE
  #include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#else
  #include "sqlite3.h"
#endif





















/*
** Maximum length (in bytes) of the pattern in a LIKE or GLOB
** operator.
*/
#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
#endif
................................................................................
  }

  if( zA && zB ){
    sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));
  }
}

/*
** This function is called when an ICU function called from within
** the implementation of an SQL scalar function returns an error.
**
** The scalar function context passed as the first argument is 
** loaded with an error message based on the following two args.
*/
static void icuFunctionError(
  sqlite3_context *pCtx,       /* SQLite scalar function context */
  const char *zName,           /* Name of ICU function that failed */
  UErrorCode e                 /* Error code returned by ICU function */
){
  char zBuf[128];
  sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));
  zBuf[127] = '\0';
  sqlite3_result_error(pCtx, zBuf, -1);
}

/*
** Function to delete compiled regexp objects. Registered as
** a destructor function with sqlite3_set_auxdata().
*/
static void icuRegexpDelete(void *p){
  URegularExpression *pExpr = (URegularExpression *)p;
  uregex_close(pExpr);
................................................................................
      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }
  assert( 0 );     /* Unreachable */
}



/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){
  UCollator *p = (UCollator *)pCtx;
  ucol_close(p);
................................................................................
    const char *zName;                        /* Function name */
    unsigned char nArg;                       /* Number of arguments */
    unsigned short enc;                       /* Optimal text encoding */
    unsigned char iContext;                   /* sqlite3_user_data() context */
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } scalars[] = {
    {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},

    {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},
    {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
    {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},

  };
  int rc = SQLITE_OK;
  int i;

  
  for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){
    const struct IcuScalar *p = &scalars[i];
    rc = sqlite3_create_function(
        db, p->zName, p->nArg, p->enc, 
        p->iContext ? (void*)db : (void*)0,
        p->xFunc, 0, 0

**
**   * Integration of ICU and SQLite collation sequences.
**
**   * An implementation of the LIKE operator that uses ICU to 
**     provide case-independent matching.
*/

#if !defined(SQLITE_CORE)                  \
 || defined(SQLITE_ENABLE_ICU)             \
 || defined(SQLITE_ENABLE_ICU_COLLATIONS)

/* Include ICU headers */
#include <unicode/utypes.h>
#include <unicode/uregex.h>
#include <unicode/ustring.h>
#include <unicode/ucol.h>

................................................................................
#ifndef SQLITE_CORE
  #include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#else
  #include "sqlite3.h"
#endif

/*
** This function is called when an ICU function called from within
** the implementation of an SQL scalar function returns an error.
**
** The scalar function context passed as the first argument is 
** loaded with an error message based on the following two args.
*/
static void icuFunctionError(
  sqlite3_context *pCtx,       /* SQLite scalar function context */
  const char *zName,           /* Name of ICU function that failed */
  UErrorCode e                 /* Error code returned by ICU function */
){
  char zBuf[128];
  sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));
  zBuf[127] = '\0';
  sqlite3_result_error(pCtx, zBuf, -1);
}

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

/*
** Maximum length (in bytes) of the pattern in a LIKE or GLOB
** operator.
*/
#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
#endif
................................................................................
  }

  if( zA && zB ){
    sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));
  }
}



















/*
** Function to delete compiled regexp objects. Registered as
** a destructor function with sqlite3_set_auxdata().
*/
static void icuRegexpDelete(void *p){
  URegularExpression *pExpr = (URegularExpression *)p;
  uregex_close(pExpr);
................................................................................
      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }
  assert( 0 );     /* Unreachable */
}

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

/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){
  UCollator *p = (UCollator *)pCtx;
  ucol_close(p);
................................................................................
    const char *zName;                        /* Function name */
    unsigned char nArg;                       /* Number of arguments */
    unsigned short enc;                       /* Optimal text encoding */
    unsigned char iContext;                   /* sqlite3_user_data() context */
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } scalars[] = {
    {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)
    {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},
    {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
    {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */
  };
  int rc = SQLITE_OK;
  int i;

  
  for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){
    const struct IcuScalar *p = &scalars[i];
    rc = sqlite3_create_function(
        db, p->zName, p->nArg, p->enc, 
        p->iContext ? (void*)db : (void*)0,
        p->xFunc, 0, 0

typedef unsigned short int u16;
typedef unsigned int u32;
typedef lsm_i64 i64;
typedef unsigned long long int u64;
#endif

/* A page number is a 64-bit integer. */
typedef i64 Pgno;

#ifdef LSM_DEBUG
int lsmErrorBkpt(int);
#else
# define lsmErrorBkpt(x) (x)
#endif

................................................................................
  void **apShm;                   /* Shared memory chunks */
  ShmHeader *pShmhdr;             /* Live shared-memory header */
  TreeHeader treehdr;             /* Local copy of tree-header */
  u32 aSnapshot[LSM_META_PAGE_SIZE / sizeof(u32)];
};

struct Segment {
  Pgno iFirst;                     /* First page of this run */
  Pgno iLastPg;                    /* Last page of this run */
  Pgno iRoot;                      /* Root page number (if any) */
  int nSize;                       /* Size of this run in pages */

  Redirect *pRedirect;             /* Block redirects (or NULL) */
};

/*
** iSplitTopic/pSplitKey/nSplitKey:
................................................................................
** access to the associated Level struct.
**
** iOutputOff:
**   The byte offset to write to next within the last page of the 
**   output segment.
*/
struct MergeInput {
  Pgno iPg;                       /* Page on which next input is stored */
  int iCell;                      /* Cell containing next input to merge */
};
struct Merge {
  int nInput;                     /* Number of input runs being merged */
  MergeInput *aInput;             /* Array nInput entries in size */
  MergeInput splitkey;            /* Location in file of current splitkey */
  int nSkip;                      /* Number of separators entries to skip */
  int iOutputOff;                 /* Write offset on output page */
  Pgno iCurrentPtr;               /* Current pointer value */
};

/* 
** The first argument to this macro is a pointer to a Segment structure.
** Returns true if the structure instance indicates that the separators
** array is valid.
*/
................................................................................
  u32 iCmpId;                     /* Id of compression scheme */
  Level *pLevel;                  /* Pointer to level 0 of snapshot (or NULL) */
  i64 iId;                        /* Snapshot id */
  i64 iLogOff;                    /* Log file offset */
  Redirect redirect;              /* Block redirection array */

  /* Used by worker snapshots only */
  int nBlock;                     /* Number of blocks in database file */
  Pgno aiAppend[LSM_APPLIST_SZ];  /* Append point list */
  Freelist freelist;              /* Free block list */
  u32 nWrite;                     /* Total number of pages written to disk */
};
#define LSM_INITIAL_SNAPSHOT_ID 11

/*
** Functions from file "lsm_ckpt.c".
*/
int lsmCheckpointWrite(lsm_db *, u32 *);
................................................................................

int lsmFsPageSize(FileSystem *);
void lsmFsSetPageSize(FileSystem *, int);

int lsmFsFileid(lsm_db *pDb, void **ppId, int *pnId);

/* Creating, populating, gobbling and deleting sorted runs. */
void lsmFsGobble(lsm_db *, Segment *, Pgno *, int);
int lsmFsSortedDelete(FileSystem *, Snapshot *, int, Segment *);
int lsmFsSortedFinish(FileSystem *, Segment *);
int lsmFsSortedAppend(FileSystem *, Snapshot *, Level *, int, Page **);
int lsmFsSortedPadding(FileSystem *, Snapshot *, Segment *);

/* Functions to retrieve the lsm_env pointer from a FileSystem or Page object */
lsm_env *lsmFsEnv(FileSystem *);
................................................................................

int lsmFsSectorSize(FileSystem *);

void lsmSortedSplitkey(lsm_db *, Level *, int *);

/* Reading sorted run content. */
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg);
int lsmFsDbPageGet(FileSystem *, Segment *, Pgno, Page **);
int lsmFsDbPageNext(Segment *, Page *, int eDir, Page **);

u8 *lsmFsPageData(Page *, int *);
int lsmFsPageRelease(Page *);
int lsmFsPagePersist(Page *);
void lsmFsPageRef(Page *);
Pgno lsmFsPageNumber(Page *);

int lsmFsNRead(FileSystem *);
int lsmFsNWrite(FileSystem *);

int lsmFsMetaPageGet(FileSystem *, int, int, MetaPage **);
int lsmFsMetaPageRelease(MetaPage *);
u8 *lsmFsMetaPageData(MetaPage *, int *);

#ifdef LSM_DEBUG
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg);
int lsmFsIntegrityCheck(lsm_db *);
#endif

Pgno lsmFsRedirectPage(FileSystem *, Redirect *, Pgno);

int lsmFsPageWritable(Page *);

/* Functions to read, write and sync the log file. */
int lsmFsWriteLog(FileSystem *pFS, i64 iOff, LsmString *pStr);
int lsmFsSyncLog(FileSystem *pFS);
int lsmFsReadLog(FileSystem *pFS, i64 iOff, int nRead, LsmString *pStr);
................................................................................

/* And to sync the db file */
int lsmFsSyncDb(FileSystem *, int);

void lsmFsFlushWaiting(FileSystem *, int *);

/* Used by lsm_info(ARRAY_STRUCTURE) and lsm_config(MMAP) */
int lsmInfoArrayStructure(lsm_db *pDb, int bBlock, Pgno iFirst, char **pzOut);
int lsmInfoArrayPages(lsm_db *pDb, Pgno iFirst, char **pzOut);
int lsmConfigMmap(lsm_db *pDb, int *piParam);

int lsmEnvOpen(lsm_env *, const char *, int, lsm_file **);
int lsmEnvClose(lsm_env *pEnv, lsm_file *pFile);
int lsmEnvLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int eLock);
int lsmEnvTestLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int nLock, int);

................................................................................
void lsmEnvShmBarrier(lsm_env *);
void lsmEnvShmUnmap(lsm_env *, lsm_file *, int);

void lsmEnvSleep(lsm_env *, int);

int lsmFsReadSyncedId(lsm_db *db, int, i64 *piVal);

int lsmFsSegmentContainsPg(FileSystem *pFS, Segment *, Pgno, int *);

void lsmFsPurgeCache(FileSystem *);

/*
** End of functions from "lsm_file.c".
**************************************************************************/

/* 
** Functions from file "lsm_sorted.c".
*/
int lsmInfoPageDump(lsm_db *, Pgno, int, char **);
void lsmSortedCleanup(lsm_db *);
int lsmSortedAutoWork(lsm_db *, int nUnit);

int lsmSortedWalkFreelist(lsm_db *, int, int (*)(void *, int, i64), void *);

int lsmSaveWorker(lsm_db *, int);

typedef unsigned short int u16;
typedef unsigned int u32;
typedef lsm_i64 i64;
typedef unsigned long long int u64;
#endif

/* A page number is a 64-bit integer. */
typedef i64 LsmPgno;

#ifdef LSM_DEBUG
int lsmErrorBkpt(int);
#else
# define lsmErrorBkpt(x) (x)
#endif

................................................................................
  void **apShm;                   /* Shared memory chunks */
  ShmHeader *pShmhdr;             /* Live shared-memory header */
  TreeHeader treehdr;             /* Local copy of tree-header */
  u32 aSnapshot[LSM_META_PAGE_SIZE / sizeof(u32)];
};

struct Segment {
  LsmPgno iFirst;                  /* First page of this run */
  LsmPgno iLastPg;                 /* Last page of this run */
  LsmPgno iRoot;                   /* Root page number (if any) */
  int nSize;                       /* Size of this run in pages */

  Redirect *pRedirect;             /* Block redirects (or NULL) */
};

/*
** iSplitTopic/pSplitKey/nSplitKey:
................................................................................
** access to the associated Level struct.
**
** iOutputOff:
**   The byte offset to write to next within the last page of the 
**   output segment.
*/
struct MergeInput {
  LsmPgno iPg;                    /* Page on which next input is stored */
  int iCell;                      /* Cell containing next input to merge */
};
struct Merge {
  int nInput;                     /* Number of input runs being merged */
  MergeInput *aInput;             /* Array nInput entries in size */
  MergeInput splitkey;            /* Location in file of current splitkey */
  int nSkip;                      /* Number of separators entries to skip */
  int iOutputOff;                 /* Write offset on output page */
  LsmPgno iCurrentPtr;            /* Current pointer value */
};

/* 
** The first argument to this macro is a pointer to a Segment structure.
** Returns true if the structure instance indicates that the separators
** array is valid.
*/
................................................................................
  u32 iCmpId;                     /* Id of compression scheme */
  Level *pLevel;                  /* Pointer to level 0 of snapshot (or NULL) */
  i64 iId;                        /* Snapshot id */
  i64 iLogOff;                    /* Log file offset */
  Redirect redirect;              /* Block redirection array */

  /* Used by worker snapshots only */
  int nBlock;                        /* Number of blocks in database file */
  LsmPgno aiAppend[LSM_APPLIST_SZ];  /* Append point list */
  Freelist freelist;                 /* Free block list */
  u32 nWrite;                        /* Total number of pages written to disk */
};
#define LSM_INITIAL_SNAPSHOT_ID 11

/*
** Functions from file "lsm_ckpt.c".
*/
int lsmCheckpointWrite(lsm_db *, u32 *);
................................................................................

int lsmFsPageSize(FileSystem *);
void lsmFsSetPageSize(FileSystem *, int);

int lsmFsFileid(lsm_db *pDb, void **ppId, int *pnId);

/* Creating, populating, gobbling and deleting sorted runs. */
void lsmFsGobble(lsm_db *, Segment *, LsmPgno *, int);
int lsmFsSortedDelete(FileSystem *, Snapshot *, int, Segment *);
int lsmFsSortedFinish(FileSystem *, Segment *);
int lsmFsSortedAppend(FileSystem *, Snapshot *, Level *, int, Page **);
int lsmFsSortedPadding(FileSystem *, Snapshot *, Segment *);

/* Functions to retrieve the lsm_env pointer from a FileSystem or Page object */
lsm_env *lsmFsEnv(FileSystem *);
................................................................................

int lsmFsSectorSize(FileSystem *);

void lsmSortedSplitkey(lsm_db *, Level *, int *);

/* Reading sorted run content. */
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg);
int lsmFsDbPageGet(FileSystem *, Segment *, LsmPgno, Page **);
int lsmFsDbPageNext(Segment *, Page *, int eDir, Page **);

u8 *lsmFsPageData(Page *, int *);
int lsmFsPageRelease(Page *);
int lsmFsPagePersist(Page *);
void lsmFsPageRef(Page *);
LsmPgno lsmFsPageNumber(Page *);

int lsmFsNRead(FileSystem *);
int lsmFsNWrite(FileSystem *);

int lsmFsMetaPageGet(FileSystem *, int, int, MetaPage **);
int lsmFsMetaPageRelease(MetaPage *);
u8 *lsmFsMetaPageData(MetaPage *, int *);

#ifdef LSM_DEBUG
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg);
int lsmFsIntegrityCheck(lsm_db *);
#endif

LsmPgno lsmFsRedirectPage(FileSystem *, Redirect *, LsmPgno);

int lsmFsPageWritable(Page *);

/* Functions to read, write and sync the log file. */
int lsmFsWriteLog(FileSystem *pFS, i64 iOff, LsmString *pStr);
int lsmFsSyncLog(FileSystem *pFS);
int lsmFsReadLog(FileSystem *pFS, i64 iOff, int nRead, LsmString *pStr);
................................................................................

/* And to sync the db file */
int lsmFsSyncDb(FileSystem *, int);

void lsmFsFlushWaiting(FileSystem *, int *);

/* Used by lsm_info(ARRAY_STRUCTURE) and lsm_config(MMAP) */
int lsmInfoArrayStructure(lsm_db *pDb, int bBlock, LsmPgno iFirst, char **pz);
int lsmInfoArrayPages(lsm_db *pDb, LsmPgno iFirst, char **pzOut);
int lsmConfigMmap(lsm_db *pDb, int *piParam);

int lsmEnvOpen(lsm_env *, const char *, int, lsm_file **);
int lsmEnvClose(lsm_env *pEnv, lsm_file *pFile);
int lsmEnvLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int eLock);
int lsmEnvTestLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int nLock, int);

................................................................................
void lsmEnvShmBarrier(lsm_env *);
void lsmEnvShmUnmap(lsm_env *, lsm_file *, int);

void lsmEnvSleep(lsm_env *, int);

int lsmFsReadSyncedId(lsm_db *db, int, i64 *piVal);

int lsmFsSegmentContainsPg(FileSystem *pFS, Segment *, LsmPgno, int *);

void lsmFsPurgeCache(FileSystem *);

/*
** End of functions from "lsm_file.c".
**************************************************************************/

/* 
** Functions from file "lsm_sorted.c".
*/
int lsmInfoPageDump(lsm_db *, LsmPgno, int, char **);
void lsmSortedCleanup(lsm_db *);
int lsmSortedAutoWork(lsm_db *, int nUnit);

int lsmSortedWalkFreelist(lsm_db *, int, int (*)(void *, int, i64), void *);

int lsmSaveWorker(lsm_db *, int);

static void ckptExportAppendlist(
  lsm_db *db,                     /* Database connection */
  CkptBuffer *p,                  /* Checkpoint buffer to write to */
  int *piOut,                     /* IN/OUT: Offset within checkpoint buffer */
  int *pRc                        /* IN/OUT: Error code */
){
  int i;
  Pgno *aiAppend = db->pWorker->aiAppend;

  for(i=0; i<LSM_APPLIST_SZ; i++){
    ckptAppend64(p, piOut, aiAppend[i], pRc);
  }
};

static int ckptExportSnapshot( 

static void ckptExportAppendlist(
  lsm_db *db,                     /* Database connection */
  CkptBuffer *p,                  /* Checkpoint buffer to write to */
  int *piOut,                     /* IN/OUT: Offset within checkpoint buffer */
  int *pRc                        /* IN/OUT: Error code */
){
  int i;
  LsmPgno *aiAppend = db->pWorker->aiAppend;

  for(i=0; i<LSM_APPLIST_SZ; i++){
    ckptAppend64(p, piOut, aiAppend[i], pRc);
  }
};

static int ckptExportSnapshot( 

**   The lsmFsSortedAppend() function sets the pSeg pointer to point to the
**   segment that the new page will be a part of. It is unset by
**   lsmFsPagePersist() after the page is written to disk.
*/
struct Page {
  u8 *aData;                      /* Buffer containing page data */
  int nData;                      /* Bytes of usable data at aData[] */
  Pgno iPg;                       /* Page number */
  int nRef;                       /* Number of outstanding references */
  int flags;                      /* Combination of PAGE_XXX flags */
  Page *pHashNext;                /* Next page in hash table slot */
  Page *pLruNext;                 /* Next page in LRU list */
  Page *pLruPrev;                 /* Previous page in LRU list */
  FileSystem *pFS;                /* File system that owns this page */

................................................................................
#else
# define IOERR_WRAPPER(rc) (rc)
#endif

#ifdef NDEBUG
# define assert_lists_are_ok(x)
#else
static Page *fsPageFindInHash(FileSystem *pFS, Pgno iPg, int *piHash);

static void assert_lists_are_ok(FileSystem *pFS){
#if 0
  Page *p;

  assert( pFS->nMapLimit>=0 );

................................................................................
  return LSM_OK;
}

/*
** Return true if page iReal of the database should be accessed using mmap.
** False otherwise.
*/
static int fsMmapPage(FileSystem *pFS, Pgno iReal){
  return ((i64)iReal*pFS->nPagesize <= pFS->nMapLimit);
}

/*
** Given that there are currently nHash slots in the hash table, return 
** the hash key for file iFile, page iPg.
*/
static int fsHashKey(int nHash, Pgno iPg){
  return (iPg % nHash);
}

/*
** This is a helper function for lsmFsOpen(). It opens a single file on
** disk (either the database or log file).
*/
................................................................................
** Return the page number of the first page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset immediately following the 4-byte
** "previous block" pointer at the start of each block.
*/
static Pgno fsFirstPageOnBlock(FileSystem *pFS, int iBlock){
  Pgno iPg;
  if( pFS->pCompress ){
    if( iBlock==1 ){
      iPg = pFS->nMetasize * 2 + 4;
    }else{
      iPg = pFS->nBlocksize * (Pgno)(iBlock-1) + 4;
    }
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    if( iBlock==1 ){
      iPg = 1 + ((pFS->nMetasize*2 + pFS->nPagesize - 1) / pFS->nPagesize);
    }else{
      iPg = 1 + (iBlock-1) * nPagePerBlock;
................................................................................
** Return the page number of the last page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset of the byte immediately before 
** the 4-byte "next block" pointer at the end of each block.
*/
static Pgno fsLastPageOnBlock(FileSystem *pFS, int iBlock){
  if( pFS->pCompress ){
    return pFS->nBlocksize * (Pgno)iBlock - 1 - 4;
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    return iBlock * nPagePerBlock;
  }
}

/*
** Return the block number of the block that page iPg is located on. 
** Blocks are numbered starting from 1.
*/
static int fsPageToBlock(FileSystem *pFS, Pgno iPg){
  if( pFS->pCompress ){
    return (int)((iPg / pFS->nBlocksize) + 1);
  }else{
    return (int)(1 + ((iPg-1) / (pFS->nBlocksize / pFS->nPagesize)));
  }
}

/*
** Return true if page iPg is the last page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsLast(FileSystem *pFS, Pgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( iPg && (iPg % nPagePerBlock)==0 );
}

/*
** Return true if page iPg is the first page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsFirst(FileSystem *pFS, Pgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( (iPg % nPagePerBlock)==1
        || (iPg<nPagePerBlock && iPg==fsFirstPageOnBlock(pFS, 1))
  );
}

................................................................................
  }
  return pPage->aData;
}

/*
** Return the page number of a page.
*/
Pgno lsmFsPageNumber(Page *pPage){
  /* assert( (pPage->flags & PAGE_DIRTY)==0 ); */
  return pPage ? pPage->iPg : 0;
}

/*
** Page pPg is currently part of the LRU list belonging to pFS. Remove
** it from the list. pPg->pLruNext and pPg->pLruPrev are cleared by this
................................................................................
/*
** Search the hash-table for page iPg. If an entry is round, return a pointer
** to it. Otherwise, return NULL.
**
** Either way, if argument piHash is not NULL set *piHash to the hash slot
** number that page iPg would be stored in before returning.
*/
static Page *fsPageFindInHash(FileSystem *pFS, Pgno iPg, int *piHash){
  Page *p;                        /* Return value */
  int iHash = fsHashKey(pFS->nHash, iPg);

  if( piHash ) *piHash = iHash;
  for(p=pFS->apHash[iHash]; p; p=p->pHashNext){
    if( p->iPg==iPg) break;
  }
................................................................................
}

/*
** If page iPg has been redirected according to the redirections in the
** object passed as the second argument, return the destination page to
** which it is redirected. Otherwise, return a copy of iPg.
*/
Pgno lsmFsRedirectPage(FileSystem *pFS, Redirect *pRedir, Pgno iPg){
  Pgno iReal = iPg;

  if( pRedir ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    int iBlk = fsPageToBlock(pFS, iPg);
    int i;
    for(i=0; i<pRedir->n; i++){
      int iFrom = pRedir->a[i].iFrom;
      if( iFrom>iBlk ) break;
      if( iFrom==iBlk ){
        int iTo = pRedir->a[i].iTo;
        iReal = iPg - (Pgno)(iFrom - iTo) * nPagePerBlock;
        if( iTo==1 ){
          iReal += (fsFirstPageOnBlock(pFS, 1)-1);
        }
        break;
      }
    }
  }

  assert( iReal!=0 );
  return iReal;
}

/* Required by the circular fsBlockNext<->fsPageGet dependency. */
static int fsPageGet(FileSystem *, Segment *, Pgno, int, Page **, int *);

/*
** Parameter iBlock is a database file block. This function reads the value 
** stored in the blocks "next block" pointer and stores it in *piNext.
** LSM_OK is returned if everything is successful, or an LSM error code
** otherwise.
*/
................................................................................
  }
  return rc;
}

/*
** Return the page number of the last page on the same block as page iPg.
*/
Pgno fsLastPageOnPagesBlock(FileSystem *pFS, Pgno iPg){
  return fsLastPageOnBlock(pFS, fsPageToBlock(pFS, iPg));
}

/*
** Read nData bytes of data from offset iOff of the database file into
** buffer aData. If this means reading past the end of a block, follow
** the block pointer to the next block and continue reading.
................................................................................
** to the total number of free bytes before returning.
**
** If no error occurs, LSM_OK is returned. Otherwise, an lsm error code.
*/
static int fsPageGet(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Block redirection to use (or NULL) */
  Pgno iPg,                       /* Page id */
  int noContent,                  /* True to not load content from disk */
  Page **ppPg,                    /* OUT: New page handle */
  int *pnSpace                    /* OUT: Bytes of free space */
){
  Page *p;
  int iHash;
  int rc = LSM_OK;

  /* In most cases iReal is the same as iPg. Except, if pSeg->pRedirect is 
  ** not NULL, and the block containing iPg has been redirected, then iReal
  ** is the page number after redirection.  */
  Pgno iReal = lsmFsRedirectPage(pFS, (pSeg ? pSeg->pRedirect : 0), iPg);

  assert_lists_are_ok(pFS);
  assert( iPg>=fsFirstPageOnBlock(pFS, 1) );
  assert( iReal>=fsFirstPageOnBlock(pFS, 1) );
  *ppPg = 0;

  /* Search the hash-table for the page */
................................................................................
/*
** Return true if the first or last page of segment pRun falls between iFirst
** and iLast, inclusive, and pRun is not equal to pIgnore.
*/
static int fsRunEndsBetween(
  Segment *pRun, 
  Segment *pIgnore, 
  Pgno iFirst, 
  Pgno iLast
){
  return (pRun!=pIgnore && (
        (pRun->iFirst>=iFirst && pRun->iFirst<=iLast)
     || (pRun->iLastPg>=iFirst && pRun->iLastPg<=iLast)
  ));
}

................................................................................
/*
** Return true if level pLevel contains a segment other than pIgnore for
** which the first or last page is between iFirst and iLast, inclusive.
*/
static int fsLevelEndsBetween(
  Level *pLevel, 
  Segment *pIgnore, 
  Pgno iFirst, 
  Pgno iLast
){
  int i;

  if( fsRunEndsBetween(&pLevel->lhs, pIgnore, iFirst, iLast) ){
    return 1;
  }
  for(i=0; i<pLevel->nRight; i++){
................................................................................
static int fsFreeBlock(
  FileSystem *pFS,                /* File system object */
  Snapshot *pSnapshot,            /* Worker snapshot */
  Segment *pIgnore,               /* Ignore this run when searching */
  int iBlk                        /* Block number of block to free */
){
  int rc = LSM_OK;                /* Return code */
  Pgno iFirst;                    /* First page on block iBlk */
  Pgno iLast;                     /* Last page on block iBlk */
  Level *pLevel;                  /* Used to iterate through levels */

  int iIn;                        /* Used to iterate through append points */
  int iOut = 0;                   /* Used to output append points */
  Pgno *aApp = pSnapshot->aiAppend;

  iFirst = fsFirstPageOnBlock(pFS, iBlk);
  iLast = fsLastPageOnBlock(pFS, iBlk);

  /* Check if any other run in the snapshot has a start or end page 
  ** within this block. If there is such a run, return early. */
  for(pLevel=lsmDbSnapshotLevel(pSnapshot); pLevel; pLevel=pLevel->pNext){
................................................................................
}

/*
** aPgno is an array containing nPgno page numbers. Return the smallest page
** number from the array that falls on block iBlk. Or, if none of the pages
** in aPgno[] fall on block iBlk, return 0.
*/
static Pgno firstOnBlock(FileSystem *pFS, int iBlk, Pgno *aPgno, int nPgno){





  Pgno iRet = 0;
  int i;
  for(i=0; i<nPgno; i++){
    Pgno iPg = aPgno[i];
    if( fsPageToBlock(pFS, iPg)==iBlk && (iRet==0 || iPg<iRet) ){
      iRet = iPg;
    }
  }
  return iRet;
}

#ifndef NDEBUG
/*
** Return true if page iPg, which is a part of segment p, lies on
** a redirected block. 
*/
static int fsPageRedirects(FileSystem *pFS, Segment *p, Pgno iPg){
  return (iPg!=0 && iPg!=lsmFsRedirectPage(pFS, p->pRedirect, iPg));
}

/*
** Return true if the second argument is not NULL and any of the first
** last or root pages lie on a redirected block. 
*/
................................................................................
** the segment pRun. This function gobbles from the start of the run to the
** first page that appears in aPgno[] (i.e. so that the aPgno[] entry is
** the new first page of the run).
*/
void lsmFsGobble(
  lsm_db *pDb,
  Segment *pRun, 
  Pgno *aPgno,
  int nPgno
){
  int rc = LSM_OK;
  FileSystem *pFS = pDb->pFS;
  Snapshot *pSnapshot = pDb->pWorker;
  int iBlk;

................................................................................
  assert( nPgno>0 && 0==fsPageRedirects(pFS, pRun, aPgno[0]) );

  iBlk = fsPageToBlock(pFS, pRun->iFirst);
  pRun->nSize += (int)(pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));

  while( rc==LSM_OK ){
    int iNext = 0;
    Pgno iFirst = firstOnBlock(pFS, iBlk, aPgno, nPgno);
    if( iFirst ){
      pRun->iFirst = iFirst;
      break;
    }
    rc = fsBlockNext(pFS, pRun, iBlk, &iNext);
    if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, pRun, iBlk);
    pRun->nSize -= (int)(
................................................................................
**   *piNext = iPg + nByte;
**
** But take block overflow and redirection into account.
*/
static int fsNextPageOffset(
  FileSystem *pFS,                /* File system object */
  Segment *pSeg,                  /* Segment to move within */
  Pgno iPg,                       /* Offset of current page */
  int nByte,                      /* Size of current page including headers */
  Pgno *piNext                    /* OUT: Offset of next page. Or zero (EOF) */
){
  Pgno iNext;
  int rc;

  assert( pFS->pCompress );

  rc = fsAddOffset(pFS, pSeg, iPg, nByte-1, &iNext);
  if( pSeg && iNext==pSeg->iLastPg ){
    iNext = 0;
................................................................................
** LSM_OK is returned if no error occurs. Otherwise, an lsm error code.
** If any value other than LSM_OK is returned, then the final value of
** *piPrev is undefined.
*/
static int fsGetPageBefore(
  FileSystem *pFS, 
  Segment *pSeg, 
  Pgno iPg, 
  Pgno *piPrev
){
  u8 aSz[3];
  int rc;
  i64 iRead;

  assert( pFS->pCompress );

................................................................................
**
** Page references returned by this function should be released by the 
** caller using lsmFsPageRelease().
*/
int lsmFsDbPageNext(Segment *pRun, Page *pPg, int eDir, Page **ppNext){
  int rc = LSM_OK;
  FileSystem *pFS = pPg->pFS;
  Pgno iPg = pPg->iPg;

  assert( 0==fsSegmentRedirects(pFS, pRun) );
  if( pFS->pCompress ){
    int nSpace = pPg->nCompress + 2*3;

    do {
      if( eDir>0 ){
................................................................................
** already allocated block. If it is possible, the page number of the first
** page to use for the new segment is returned. Otherwise zero.
**
** If argument pLvl is not NULL, then this function will not attempt to
** start the new segment immediately following any segment that is part
** of the right-hand-side of pLvl.
*/
static Pgno findAppendPoint(FileSystem *pFS, Level *pLvl){
  int i;
  Pgno *aiAppend = pFS->pDb->pWorker->aiAppend;
  Pgno iRet = 0;

  for(i=LSM_APPLIST_SZ-1; iRet==0 && i>=0; i--){
    if( (iRet = aiAppend[i]) ){
      if( pLvl ){
        int iBlk = fsPageToBlock(pFS, iRet);
        int j;
        for(j=0; iRet && j<pLvl->nRight; j++){
................................................................................
  Snapshot *pSnapshot,
  Level *pLvl,
  int bDefer,
  Page **ppOut
){
  int rc = LSM_OK;
  Page *pPg = 0;
  Pgno iApp = 0;
  Pgno iNext = 0;
  Segment *p = &pLvl->lhs;
  Pgno iPrev = p->iLastPg;

  *ppOut = 0;
  assert( p->pRedirect==0 );

  if( pFS->pCompress || bDefer ){
    /* In compressed database mode the page is not assigned a page number
    ** or location in the database file at this point. This will be done
................................................................................
    ** Shift this extra block back to the free-block list. 
    **
    ** Otherwise, add the first free page in the last block used by the run
    ** to the lAppend list.
    */
    if( fsLastPageOnPagesBlock(pFS, p->iLastPg)!=p->iLastPg ){
      int i;
      Pgno *aiAppend = pFS->pDb->pWorker->aiAppend;
      for(i=0; i<LSM_APPLIST_SZ; i++){
        if( aiAppend[i]==0 ){
          aiAppend[i] = p->iLastPg+1;
          break;
        }
      }
    }else if( pFS->pCompress==0 ){
................................................................................
}

/*
** Obtain a reference to page number iPg.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageGet(FileSystem *pFS, Segment *pSeg, Pgno iPg, Page **ppPg){
  return fsPageGet(pFS, pSeg, iPg, 0, ppPg, 0);
}

/*
** Obtain a reference to the last page in the segment passed as the 
** second argument.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg){
  int rc;
  Pgno iPg = pSeg->iLastPg;
  if( pFS->pCompress ){
    int nSpace;
    iPg++;
    do {
      nSpace = 0;
      rc = fsGetPageBefore(pFS, pSeg, iPg, &iPg);
      if( rc==LSM_OK ){
................................................................................
** number (*piPg) lies on block iFrom, then calculate the equivalent
** page on block iTo and set *piPg to this value before returning.
*/
static void fsMovePage(
  FileSystem *pFS,                /* File system object */
  int iTo,                        /* Destination block */
  int iFrom,                      /* Source block */
  Pgno *piPg                      /* IN/OUT: Page number */
){
  Pgno iPg = *piPg;
  if( iFrom==fsPageToBlock(pFS, iPg) ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS ->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    *piPg = iPg - (Pgno)(iFrom - iTo) * nPagePerBlock;
  }
}

/*
** Copy the contents of block iFrom to block iTo. 
**
** It is safe to assume that there are no outstanding references to pages 
................................................................................
/*
** Append raw data to a segment. Return the database file offset that the
** data is written to (this may be used as the page number if the data
** being appended is a new page record).
**
** This function is only used in compressed database mode.
*/
static Pgno fsAppendData(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Segment to append to */
  const u8 *aData,                /* Buffer containing data to write */
  int nData,                      /* Size of buffer aData[] in bytes */
  int *pRc                        /* IN/OUT: Error code */
){
  Pgno iRet = 0;
  int rc = *pRc;
  assert( pFS->pCompress );
  if( rc==LSM_OK ){
    int nRem = 0;
    int nWrite = 0;
    Pgno iLastOnBlock;
    Pgno iApp = pSeg->iLastPg+1;

    /* If this is the first data written into the segment, find an append-point
    ** or allocate a new block.  */
    if( iApp==1 ){
      pSeg->iFirst = iApp = findAppendPoint(pFS, 0);
      if( iApp==0 ){
        int iBlk;
................................................................................
          assert( iApp==(fsPageToBlock(pFS, iApp)*pFS->nBlocksize)-4 );
          lsmPutU32(aPtr, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iApp, aPtr, sizeof(aPtr));
        }

        /* Set the "prev" pointer on the new block */
        if( rc==LSM_OK ){
          Pgno iWrite;
          lsmPutU32(aPtr, fsPageToBlock(pFS, iApp));
          iWrite = fsFirstPageOnBlock(pFS, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iWrite-4, aPtr, sizeof(aPtr));
          if( nRem>0 ) iApp = iWrite;
        }
      }else{
        /* The next block is already allocated. */
................................................................................
** LSM_OK is returned if successful, or an lsm error code otherwise. If
** any value other than LSM_OK is returned, then the final value of all
** output variables is undefined.
*/
static int fsAppendPage(
  FileSystem *pFS, 
  Segment *pSeg,
  Pgno *piNew,
  int *piPrev,
  int *piNext
){
  Pgno iPrev = pSeg->iLastPg;
  int rc;
  assert( iPrev!=0 );

  *piPrev = 0;
  *piNext = 0;

  if( fsIsLast(pFS, iPrev) ){
................................................................................
  }
  *pRc = rc;
}

/*
** If there exists a hash-table entry associated with page iPg, remove it.
*/
static void fsRemoveHashEntry(FileSystem *pFS, Pgno iPg){
  Page *p;
  int iHash = fsHashKey(pFS->nHash, iPg);

  for(p=pFS->apHash[iHash]; p && p->iPg!=iPg; p=p->pHashNext);

  if( p ){
    assert( p->nRef==0 || (p->flags & PAGE_FREE)==0 );
................................................................................
int lsmFsSortedPadding(
  FileSystem *pFS, 
  Snapshot *pSnapshot,
  Segment *pSeg
){
  int rc = LSM_OK;
  if( pFS->pCompress && pSeg->iFirst ){
    Pgno iLast2;
    Pgno iLast = pSeg->iLastPg;     /* Current last page of segment */
    int nPad;                       /* Bytes of padding required */
    u8 aSz[3];

    iLast2 = (1 + iLast/pFS->szSector) * pFS->szSector - 1;
    assert( fsPageToBlock(pFS, iLast)==fsPageToBlock(pFS, iLast2) );
    nPad = (int)(iLast2 - iLast);

................................................................................
int lsmFsSectorSize(FileSystem *pFS){
  return pFS->szSector;
}

/*
** Helper function for lsmInfoArrayStructure().
*/
static Segment *startsWith(Segment *pRun, Pgno iFirst){
  return (iFirst==pRun->iFirst) ? pRun : 0;
}

/*
** Return the segment that starts with page iFirst, if any. If no such segment
** can be found, return NULL.
*/
static Segment *findSegment(Snapshot *pWorker, Pgno iFirst){
  Level *pLvl;                    /* Used to iterate through db levels */
  Segment *pSeg = 0;              /* Pointer to segment to return */

  for(pLvl=lsmDbSnapshotLevel(pWorker); pLvl && pSeg==0; pLvl=pLvl->pNext){
    if( 0==(pSeg = startsWith(&pLvl->lhs, iFirst)) ){
      int i;
      for(i=0; i<pLvl->nRight; i++){
................................................................................
** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayStructure(
  lsm_db *pDb, 
  int bBlock,                     /* True for block numbers only */
  Pgno iFirst,
  char **pzOut
){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pArray = 0;            /* Array to report on */
  int bUnlock = 0;

................................................................................
  }
  return rc;
}

int lsmFsSegmentContainsPg(
  FileSystem *pFS, 
  Segment *pSeg, 
  Pgno iPg, 
  int *pbRes
){
  Redirect *pRedir = pSeg->pRedirect;
  int rc = LSM_OK;
  int iBlk;
  int iLastBlk;
  int iPgBlock;                   /* Block containing page iPg */
................................................................................
** This function implements the lsm_info(LSM_INFO_ARRAY_PAGES) request.
** If successful, *pzOut is set to point to a nul-terminated string 
** containing the array structure and LSM_OK is returned. The caller should
** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayPages(lsm_db *pDb, Pgno iFirst, char **pzOut){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pSeg = 0;              /* Array to report on */
  int bUnlock = 0;

  *pzOut = 0;
  if( iFirst==0 ) return LSM_ERROR;
................................................................................
#ifndef NDEBUG
/*
** Return true if pPg happens to be the last page in segment pSeg. Or false
** otherwise. This function is only invoked as part of assert() conditions.
*/
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg){
  if( pPg->pFS->pCompress ){
    Pgno iNext = 0;
    int rc;
    rc = fsNextPageOffset(pPg->pFS, pSeg, pPg->iPg, pPg->nCompress+6, &iNext);
    return (rc!=LSM_OK || iNext==0);
  }
  return (pPg->iPg==pSeg->iLastPg);
}
#endif

**   The lsmFsSortedAppend() function sets the pSeg pointer to point to the
**   segment that the new page will be a part of. It is unset by
**   lsmFsPagePersist() after the page is written to disk.
*/
struct Page {
  u8 *aData;                      /* Buffer containing page data */
  int nData;                      /* Bytes of usable data at aData[] */
  LsmPgno iPg;                    /* Page number */
  int nRef;                       /* Number of outstanding references */
  int flags;                      /* Combination of PAGE_XXX flags */
  Page *pHashNext;                /* Next page in hash table slot */
  Page *pLruNext;                 /* Next page in LRU list */
  Page *pLruPrev;                 /* Previous page in LRU list */
  FileSystem *pFS;                /* File system that owns this page */

................................................................................
#else
# define IOERR_WRAPPER(rc) (rc)
#endif

#ifdef NDEBUG
# define assert_lists_are_ok(x)
#else
static Page *fsPageFindInHash(FileSystem *pFS, LsmPgno iPg, int *piHash);

static void assert_lists_are_ok(FileSystem *pFS){
#if 0
  Page *p;

  assert( pFS->nMapLimit>=0 );

................................................................................
  return LSM_OK;
}

/*
** Return true if page iReal of the database should be accessed using mmap.
** False otherwise.
*/
static int fsMmapPage(FileSystem *pFS, LsmPgno iReal){
  return ((i64)iReal*pFS->nPagesize <= pFS->nMapLimit);
}

/*
** Given that there are currently nHash slots in the hash table, return 
** the hash key for file iFile, page iPg.
*/
static int fsHashKey(int nHash, LsmPgno iPg){
  return (iPg % nHash);
}

/*
** This is a helper function for lsmFsOpen(). It opens a single file on
** disk (either the database or log file).
*/
................................................................................
** Return the page number of the first page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset immediately following the 4-byte
** "previous block" pointer at the start of each block.
*/
static LsmPgno fsFirstPageOnBlock(FileSystem *pFS, int iBlock){
  LsmPgno iPg;
  if( pFS->pCompress ){
    if( iBlock==1 ){
      iPg = pFS->nMetasize * 2 + 4;
    }else{
      iPg = pFS->nBlocksize * (LsmPgno)(iBlock-1) + 4;
    }
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    if( iBlock==1 ){
      iPg = 1 + ((pFS->nMetasize*2 + pFS->nPagesize - 1) / pFS->nPagesize);
    }else{
      iPg = 1 + (iBlock-1) * nPagePerBlock;
................................................................................
** Return the page number of the last page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset of the byte immediately before 
** the 4-byte "next block" pointer at the end of each block.
*/
static LsmPgno fsLastPageOnBlock(FileSystem *pFS, int iBlock){
  if( pFS->pCompress ){
    return pFS->nBlocksize * (LsmPgno)iBlock - 1 - 4;
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    return iBlock * nPagePerBlock;
  }
}

/*
** Return the block number of the block that page iPg is located on. 
** Blocks are numbered starting from 1.
*/
static int fsPageToBlock(FileSystem *pFS, LsmPgno iPg){
  if( pFS->pCompress ){
    return (int)((iPg / pFS->nBlocksize) + 1);
  }else{
    return (int)(1 + ((iPg-1) / (pFS->nBlocksize / pFS->nPagesize)));
  }
}

/*
** Return true if page iPg is the last page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsLast(FileSystem *pFS, LsmPgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( iPg && (iPg % nPagePerBlock)==0 );
}

/*
** Return true if page iPg is the first page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsFirst(FileSystem *pFS, LsmPgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( (iPg % nPagePerBlock)==1
        || (iPg<nPagePerBlock && iPg==fsFirstPageOnBlock(pFS, 1))
  );
}

................................................................................
  }
  return pPage->aData;
}

/*
** Return the page number of a page.
*/
LsmPgno lsmFsPageNumber(Page *pPage){
  /* assert( (pPage->flags & PAGE_DIRTY)==0 ); */
  return pPage ? pPage->iPg : 0;
}

/*
** Page pPg is currently part of the LRU list belonging to pFS. Remove
** it from the list. pPg->pLruNext and pPg->pLruPrev are cleared by this
................................................................................
/*
** Search the hash-table for page iPg. If an entry is round, return a pointer
** to it. Otherwise, return NULL.
**
** Either way, if argument piHash is not NULL set *piHash to the hash slot
** number that page iPg would be stored in before returning.
*/
static Page *fsPageFindInHash(FileSystem *pFS, LsmPgno iPg, int *piHash){
  Page *p;                        /* Return value */
  int iHash = fsHashKey(pFS->nHash, iPg);

  if( piHash ) *piHash = iHash;
  for(p=pFS->apHash[iHash]; p; p=p->pHashNext){
    if( p->iPg==iPg) break;
  }
................................................................................
}

/*
** If page iPg has been redirected according to the redirections in the
** object passed as the second argument, return the destination page to
** which it is redirected. Otherwise, return a copy of iPg.
*/
LsmPgno lsmFsRedirectPage(FileSystem *pFS, Redirect *pRedir, LsmPgno iPg){
  LsmPgno iReal = iPg;

  if( pRedir ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    int iBlk = fsPageToBlock(pFS, iPg);
    int i;
    for(i=0; i<pRedir->n; i++){
      int iFrom = pRedir->a[i].iFrom;
      if( iFrom>iBlk ) break;
      if( iFrom==iBlk ){
        int iTo = pRedir->a[i].iTo;
        iReal = iPg - (LsmPgno)(iFrom - iTo) * nPagePerBlock;
        if( iTo==1 ){
          iReal += (fsFirstPageOnBlock(pFS, 1)-1);
        }
        break;
      }
    }
  }

  assert( iReal!=0 );
  return iReal;
}

/* Required by the circular fsBlockNext<->fsPageGet dependency. */
static int fsPageGet(FileSystem *, Segment *, LsmPgno, int, Page **, int *);

/*
** Parameter iBlock is a database file block. This function reads the value 
** stored in the blocks "next block" pointer and stores it in *piNext.
** LSM_OK is returned if everything is successful, or an LSM error code
** otherwise.
*/
................................................................................
  }
  return rc;
}

/*
** Return the page number of the last page on the same block as page iPg.
*/
LsmPgno fsLastPageOnPagesBlock(FileSystem *pFS, LsmPgno iPg){
  return fsLastPageOnBlock(pFS, fsPageToBlock(pFS, iPg));
}

/*
** Read nData bytes of data from offset iOff of the database file into
** buffer aData. If this means reading past the end of a block, follow
** the block pointer to the next block and continue reading.
................................................................................
** to the total number of free bytes before returning.
**
** If no error occurs, LSM_OK is returned. Otherwise, an lsm error code.
*/
static int fsPageGet(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Block redirection to use (or NULL) */
  LsmPgno iPg,                    /* Page id */
  int noContent,                  /* True to not load content from disk */
  Page **ppPg,                    /* OUT: New page handle */
  int *pnSpace                    /* OUT: Bytes of free space */
){
  Page *p;
  int iHash;
  int rc = LSM_OK;

  /* In most cases iReal is the same as iPg. Except, if pSeg->pRedirect is 
  ** not NULL, and the block containing iPg has been redirected, then iReal
  ** is the page number after redirection.  */
  LsmPgno iReal = lsmFsRedirectPage(pFS, (pSeg ? pSeg->pRedirect : 0), iPg);

  assert_lists_are_ok(pFS);
  assert( iPg>=fsFirstPageOnBlock(pFS, 1) );
  assert( iReal>=fsFirstPageOnBlock(pFS, 1) );
  *ppPg = 0;

  /* Search the hash-table for the page */
................................................................................
/*
** Return true if the first or last page of segment pRun falls between iFirst
** and iLast, inclusive, and pRun is not equal to pIgnore.
*/
static int fsRunEndsBetween(
  Segment *pRun, 
  Segment *pIgnore, 
  LsmPgno iFirst, 
  LsmPgno iLast
){
  return (pRun!=pIgnore && (
        (pRun->iFirst>=iFirst && pRun->iFirst<=iLast)
     || (pRun->iLastPg>=iFirst && pRun->iLastPg<=iLast)
  ));
}

................................................................................
/*
** Return true if level pLevel contains a segment other than pIgnore for
** which the first or last page is between iFirst and iLast, inclusive.
*/
static int fsLevelEndsBetween(
  Level *pLevel, 
  Segment *pIgnore, 
  LsmPgno iFirst, 
  LsmPgno iLast
){
  int i;

  if( fsRunEndsBetween(&pLevel->lhs, pIgnore, iFirst, iLast) ){
    return 1;
  }
  for(i=0; i<pLevel->nRight; i++){
................................................................................
static int fsFreeBlock(
  FileSystem *pFS,                /* File system object */
  Snapshot *pSnapshot,            /* Worker snapshot */
  Segment *pIgnore,               /* Ignore this run when searching */
  int iBlk                        /* Block number of block to free */
){
  int rc = LSM_OK;                /* Return code */
  LsmPgno iFirst;                 /* First page on block iBlk */
  LsmPgno iLast;                  /* Last page on block iBlk */
  Level *pLevel;                  /* Used to iterate through levels */

  int iIn;                        /* Used to iterate through append points */
  int iOut = 0;                   /* Used to output append points */
  LsmPgno *aApp = pSnapshot->aiAppend;

  iFirst = fsFirstPageOnBlock(pFS, iBlk);
  iLast = fsLastPageOnBlock(pFS, iBlk);

  /* Check if any other run in the snapshot has a start or end page 
  ** within this block. If there is such a run, return early. */
  for(pLevel=lsmDbSnapshotLevel(pSnapshot); pLevel; pLevel=pLevel->pNext){
................................................................................
}

/*
** aPgno is an array containing nPgno page numbers. Return the smallest page
** number from the array that falls on block iBlk. Or, if none of the pages
** in aPgno[] fall on block iBlk, return 0.
*/
static LsmPgno firstOnBlock(
  FileSystem *pFS, 
  int iBlk, 
  LsmPgno *aPgno, 
  int nPgno
){
  LsmPgno iRet = 0;
  int i;
  for(i=0; i<nPgno; i++){
    LsmPgno iPg = aPgno[i];
    if( fsPageToBlock(pFS, iPg)==iBlk && (iRet==0 || iPg<iRet) ){
      iRet = iPg;
    }
  }
  return iRet;
}

#ifndef NDEBUG
/*
** Return true if page iPg, which is a part of segment p, lies on
** a redirected block. 
*/
static int fsPageRedirects(FileSystem *pFS, Segment *p, LsmPgno iPg){
  return (iPg!=0 && iPg!=lsmFsRedirectPage(pFS, p->pRedirect, iPg));
}

/*
** Return true if the second argument is not NULL and any of the first
** last or root pages lie on a redirected block. 
*/
................................................................................
** the segment pRun. This function gobbles from the start of the run to the
** first page that appears in aPgno[] (i.e. so that the aPgno[] entry is
** the new first page of the run).
*/
void lsmFsGobble(
  lsm_db *pDb,
  Segment *pRun, 
  LsmPgno *aPgno,
  int nPgno
){
  int rc = LSM_OK;
  FileSystem *pFS = pDb->pFS;
  Snapshot *pSnapshot = pDb->pWorker;
  int iBlk;

................................................................................
  assert( nPgno>0 && 0==fsPageRedirects(pFS, pRun, aPgno[0]) );

  iBlk = fsPageToBlock(pFS, pRun->iFirst);
  pRun->nSize += (int)(pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));

  while( rc==LSM_OK ){
    int iNext = 0;
    LsmPgno iFirst = firstOnBlock(pFS, iBlk, aPgno, nPgno);
    if( iFirst ){
      pRun->iFirst = iFirst;
      break;
    }
    rc = fsBlockNext(pFS, pRun, iBlk, &iNext);
    if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, pRun, iBlk);
    pRun->nSize -= (int)(
................................................................................
**   *piNext = iPg + nByte;
**
** But take block overflow and redirection into account.
*/
static int fsNextPageOffset(
  FileSystem *pFS,                /* File system object */
  Segment *pSeg,                  /* Segment to move within */
  LsmPgno iPg,                    /* Offset of current page */
  int nByte,                      /* Size of current page including headers */
  LsmPgno *piNext                 /* OUT: Offset of next page. Or zero (EOF) */
){
  LsmPgno iNext;
  int rc;

  assert( pFS->pCompress );

  rc = fsAddOffset(pFS, pSeg, iPg, nByte-1, &iNext);
  if( pSeg && iNext==pSeg->iLastPg ){
    iNext = 0;
................................................................................
** LSM_OK is returned if no error occurs. Otherwise, an lsm error code.
** If any value other than LSM_OK is returned, then the final value of
** *piPrev is undefined.
*/
static int fsGetPageBefore(
  FileSystem *pFS, 
  Segment *pSeg, 
  LsmPgno iPg, 
  LsmPgno *piPrev
){
  u8 aSz[3];
  int rc;
  i64 iRead;

  assert( pFS->pCompress );

................................................................................
**
** Page references returned by this function should be released by the 
** caller using lsmFsPageRelease().
*/
int lsmFsDbPageNext(Segment *pRun, Page *pPg, int eDir, Page **ppNext){
  int rc = LSM_OK;
  FileSystem *pFS = pPg->pFS;
  LsmPgno iPg = pPg->iPg;

  assert( 0==fsSegmentRedirects(pFS, pRun) );
  if( pFS->pCompress ){
    int nSpace = pPg->nCompress + 2*3;

    do {
      if( eDir>0 ){
................................................................................
** already allocated block. If it is possible, the page number of the first
** page to use for the new segment is returned. Otherwise zero.
**
** If argument pLvl is not NULL, then this function will not attempt to
** start the new segment immediately following any segment that is part
** of the right-hand-side of pLvl.
*/
static LsmPgno findAppendPoint(FileSystem *pFS, Level *pLvl){
  int i;
  LsmPgno *aiAppend = pFS->pDb->pWorker->aiAppend;
  LsmPgno iRet = 0;

  for(i=LSM_APPLIST_SZ-1; iRet==0 && i>=0; i--){
    if( (iRet = aiAppend[i]) ){
      if( pLvl ){
        int iBlk = fsPageToBlock(pFS, iRet);
        int j;
        for(j=0; iRet && j<pLvl->nRight; j++){
................................................................................
  Snapshot *pSnapshot,
  Level *pLvl,
  int bDefer,
  Page **ppOut
){
  int rc = LSM_OK;
  Page *pPg = 0;
  LsmPgno iApp = 0;
  LsmPgno iNext = 0;
  Segment *p = &pLvl->lhs;
  LsmPgno iPrev = p->iLastPg;

  *ppOut = 0;
  assert( p->pRedirect==0 );

  if( pFS->pCompress || bDefer ){
    /* In compressed database mode the page is not assigned a page number
    ** or location in the database file at this point. This will be done
................................................................................
    ** Shift this extra block back to the free-block list. 
    **
    ** Otherwise, add the first free page in the last block used by the run
    ** to the lAppend list.
    */
    if( fsLastPageOnPagesBlock(pFS, p->iLastPg)!=p->iLastPg ){
      int i;
      LsmPgno *aiAppend = pFS->pDb->pWorker->aiAppend;
      for(i=0; i<LSM_APPLIST_SZ; i++){
        if( aiAppend[i]==0 ){
          aiAppend[i] = p->iLastPg+1;
          break;
        }
      }
    }else if( pFS->pCompress==0 ){
................................................................................
}

/*
** Obtain a reference to page number iPg.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageGet(FileSystem *pFS, Segment *pSeg, LsmPgno iPg, Page **ppPg){
  return fsPageGet(pFS, pSeg, iPg, 0, ppPg, 0);
}

/*
** Obtain a reference to the last page in the segment passed as the 
** second argument.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg){
  int rc;
  LsmPgno iPg = pSeg->iLastPg;
  if( pFS->pCompress ){
    int nSpace;
    iPg++;
    do {
      nSpace = 0;
      rc = fsGetPageBefore(pFS, pSeg, iPg, &iPg);
      if( rc==LSM_OK ){
................................................................................
** number (*piPg) lies on block iFrom, then calculate the equivalent
** page on block iTo and set *piPg to this value before returning.
*/
static void fsMovePage(
  FileSystem *pFS,                /* File system object */
  int iTo,                        /* Destination block */
  int iFrom,                      /* Source block */
  LsmPgno *piPg                   /* IN/OUT: Page number */
){
  LsmPgno iPg = *piPg;
  if( iFrom==fsPageToBlock(pFS, iPg) ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS ->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    *piPg = iPg - (LsmPgno)(iFrom - iTo) * nPagePerBlock;
  }
}

/*
** Copy the contents of block iFrom to block iTo. 
**
** It is safe to assume that there are no outstanding references to pages 
................................................................................
/*
** Append raw data to a segment. Return the database file offset that the
** data is written to (this may be used as the page number if the data
** being appended is a new page record).
**
** This function is only used in compressed database mode.
*/
static LsmPgno fsAppendData(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Segment to append to */
  const u8 *aData,                /* Buffer containing data to write */
  int nData,                      /* Size of buffer aData[] in bytes */
  int *pRc                        /* IN/OUT: Error code */
){
  LsmPgno iRet = 0;
  int rc = *pRc;
  assert( pFS->pCompress );
  if( rc==LSM_OK ){
    int nRem = 0;
    int nWrite = 0;
    LsmPgno iLastOnBlock;
    LsmPgno iApp = pSeg->iLastPg+1;

    /* If this is the first data written into the segment, find an append-point
    ** or allocate a new block.  */
    if( iApp==1 ){
      pSeg->iFirst = iApp = findAppendPoint(pFS, 0);
      if( iApp==0 ){
        int iBlk;
................................................................................
          assert( iApp==(fsPageToBlock(pFS, iApp)*pFS->nBlocksize)-4 );
          lsmPutU32(aPtr, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iApp, aPtr, sizeof(aPtr));
        }

        /* Set the "prev" pointer on the new block */
        if( rc==LSM_OK ){
          LsmPgno iWrite;
          lsmPutU32(aPtr, fsPageToBlock(pFS, iApp));
          iWrite = fsFirstPageOnBlock(pFS, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iWrite-4, aPtr, sizeof(aPtr));
          if( nRem>0 ) iApp = iWrite;
        }
      }else{
        /* The next block is already allocated. */
................................................................................
** LSM_OK is returned if successful, or an lsm error code otherwise. If
** any value other than LSM_OK is returned, then the final value of all
** output variables is undefined.
*/
static int fsAppendPage(
  FileSystem *pFS, 
  Segment *pSeg,
  LsmPgno *piNew,
  int *piPrev,
  int *piNext
){
  LsmPgno iPrev = pSeg->iLastPg;
  int rc;
  assert( iPrev!=0 );

  *piPrev = 0;
  *piNext = 0;

  if( fsIsLast(pFS, iPrev) ){
................................................................................
  }
  *pRc = rc;
}

/*
** If there exists a hash-table entry associated with page iPg, remove it.
*/
static void fsRemoveHashEntry(FileSystem *pFS, LsmPgno iPg){
  Page *p;
  int iHash = fsHashKey(pFS->nHash, iPg);

  for(p=pFS->apHash[iHash]; p && p->iPg!=iPg; p=p->pHashNext);

  if( p ){
    assert( p->nRef==0 || (p->flags & PAGE_FREE)==0 );
................................................................................
int lsmFsSortedPadding(
  FileSystem *pFS, 
  Snapshot *pSnapshot,
  Segment *pSeg
){
  int rc = LSM_OK;
  if( pFS->pCompress && pSeg->iFirst ){
    LsmPgno iLast2;
    LsmPgno iLast = pSeg->iLastPg;  /* Current last page of segment */
    int nPad;                       /* Bytes of padding required */
    u8 aSz[3];

    iLast2 = (1 + iLast/pFS->szSector) * pFS->szSector - 1;
    assert( fsPageToBlock(pFS, iLast)==fsPageToBlock(pFS, iLast2) );
    nPad = (int)(iLast2 - iLast);

................................................................................
int lsmFsSectorSize(FileSystem *pFS){
  return pFS->szSector;
}

/*
** Helper function for lsmInfoArrayStructure().
*/
static Segment *startsWith(Segment *pRun, LsmPgno iFirst){
  return (iFirst==pRun->iFirst) ? pRun : 0;
}

/*
** Return the segment that starts with page iFirst, if any. If no such segment
** can be found, return NULL.
*/
static Segment *findSegment(Snapshot *pWorker, LsmPgno iFirst){
  Level *pLvl;                    /* Used to iterate through db levels */
  Segment *pSeg = 0;              /* Pointer to segment to return */

  for(pLvl=lsmDbSnapshotLevel(pWorker); pLvl && pSeg==0; pLvl=pLvl->pNext){
    if( 0==(pSeg = startsWith(&pLvl->lhs, iFirst)) ){
      int i;
      for(i=0; i<pLvl->nRight; i++){
................................................................................
** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayStructure(
  lsm_db *pDb, 
  int bBlock,                     /* True for block numbers only */
  LsmPgno iFirst,
  char **pzOut
){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pArray = 0;            /* Array to report on */
  int bUnlock = 0;

................................................................................
  }
  return rc;
}

int lsmFsSegmentContainsPg(
  FileSystem *pFS, 
  Segment *pSeg, 
  LsmPgno iPg, 
  int *pbRes
){
  Redirect *pRedir = pSeg->pRedirect;
  int rc = LSM_OK;
  int iBlk;
  int iLastBlk;
  int iPgBlock;                   /* Block containing page iPg */
................................................................................
** This function implements the lsm_info(LSM_INFO_ARRAY_PAGES) request.
** If successful, *pzOut is set to point to a nul-terminated string 
** containing the array structure and LSM_OK is returned. The caller should
** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayPages(lsm_db *pDb, LsmPgno iFirst, char **pzOut){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pSeg = 0;              /* Array to report on */
  int bUnlock = 0;

  *pzOut = 0;
  if( iFirst==0 ) return LSM_ERROR;
................................................................................
#ifndef NDEBUG
/*
** Return true if pPg happens to be the last page in segment pSeg. Or false
** otherwise. This function is only invoked as part of assert() conditions.
*/
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg){
  if( pPg->pFS->pCompress ){
    LsmPgno iNext = 0;
    int rc;
    rc = fsNextPageOffset(pPg->pFS, pSeg, pPg->iPg, pPg->nCompress+6, &iNext);
    return (rc!=LSM_OK || iNext==0);
  }
  return (pPg->iPg==pSeg->iLastPg);
}
#endif

    case LSM_INFO_DB_STRUCTURE: {
      char **pzVal = va_arg(ap, char **);
      rc = lsmStructList(pDb, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_STRUCTURE: {
      Pgno pgno = va_arg(ap, Pgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayStructure(pDb, 0, pgno, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_PAGES: {
      Pgno pgno = va_arg(ap, Pgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayPages(pDb, pgno, pzVal);
      break;
    }

    case LSM_INFO_PAGE_HEX_DUMP:
    case LSM_INFO_PAGE_ASCII_DUMP: {
      Pgno pgno = va_arg(ap, Pgno);
      char **pzVal = va_arg(ap, char **);
      int bUnlock = 0;
      rc = infoGetWorker(pDb, 0, &bUnlock);
      if( rc==LSM_OK ){
        int bHex = (eParam==LSM_INFO_PAGE_HEX_DUMP);
        rc = lsmInfoPageDump(pDb, pgno, bHex, pzVal);
      }

    case LSM_INFO_DB_STRUCTURE: {
      char **pzVal = va_arg(ap, char **);
      rc = lsmStructList(pDb, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_STRUCTURE: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayStructure(pDb, 0, pgno, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_PAGES: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayPages(pDb, pgno, pzVal);
      break;
    }

    case LSM_INFO_PAGE_HEX_DUMP:
    case LSM_INFO_PAGE_ASCII_DUMP: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      int bUnlock = 0;
      rc = infoGetWorker(pDb, 0, &bUnlock);
      if( rc==LSM_OK ){
        int bHex = (eParam==LSM_INFO_PAGE_HEX_DUMP);
        rc = lsmInfoPageDump(pDb, pgno, bHex, pzVal);
      }

#ifndef LSM_SEGMENTPTR_FREE_THRESHOLD
# define LSM_SEGMENTPTR_FREE_THRESHOLD 1024
#endif

typedef struct SegmentPtr SegmentPtr;
typedef struct Blob Blob;

struct Blob {
  lsm_env *pEnv;
  void *pData;
  int nData;
  int nAlloc;
};

/*
................................................................................
  Level *pLevel;                /* Level object segment is part of */
  Segment *pSeg;                /* Segment to access */

  /* Current page. See segmentPtrLoadPage(). */
  Page *pPg;                    /* Current page */
  u16 flags;                    /* Copy of page flags field */
  int nCell;                    /* Number of cells on pPg */
  Pgno iPtr;                    /* Base cascade pointer */

  /* Current cell. See segmentPtrLoadCell() */
  int iCell;                    /* Current record within page pPg */
  int eType;                    /* Type of current record */
  Pgno iPgPtr;                  /* Cascade pointer offset */
  void *pKey; int nKey;         /* Key associated with current record */
  void *pVal; int nVal;         /* Current record value (eType==WRITE only) */

  /* Blobs used to allocate buffers for pKey and pVal as required */
  Blob blob1;
  Blob blob2;
};

/*
** Used to iterate through the keys stored in a b-tree hierarchy from start
** to finish. Only First() and Next() operations are required.
**
**   btreeCursorNew()
................................................................................
  int iPg;                        /* Current entry in aPg[]. -1 -> EOF. */
  BtreePg *aPg;                   /* Pages from root to current location */

  /* Cache of current entry. pKey==0 for EOF. */
  void *pKey;
  int nKey;
  int eType;
  Pgno iPtr;

  /* Storage for key, if not local */
  Blob blob;
};


/*
** A cursor used for merged searches or iterations through up to one
** Tree structure and any number of sorted files.
**
................................................................................
*/
struct MultiCursor {
  lsm_db *pDb;                    /* Connection that owns this cursor */
  MultiCursor *pNext;             /* Next cursor owned by connection pDb */
  int flags;                      /* Mask of CURSOR_XXX flags */

  int eType;                      /* Cache of current key type */
  Blob key;                       /* Cache of current key (or NULL) */
  Blob val;                       /* Cache of current value */

  /* All the component cursors: */
  TreeCursor *apTreeCsr[2];       /* Up to two tree cursors */
  int iFree;                      /* Next element of free-list (-ve for eof) */
  SegmentPtr *aPtr;               /* Array of segment pointers */
  int nPtr;                       /* Size of array aPtr[] */
  BtreeCursor *pBtCsr;            /* b-tree cursor (db writes only) */
................................................................................
  int nTree;                      /* Size of aTree[] array */
  int *aTree;                     /* Array of comparison results */

  /* Used by cursors flushing the in-memory tree only */
  void *pSystemVal;               /* Pointer to buffer to free */

  /* Used by worker cursors only */
  Pgno *pPrevMergePtr;
};

/*
** The following constants are used to assign integers to each component
** cursor of a multi-cursor.
*/
#define CURSOR_DATA_TREE0     0   /* Current tree cursor (apTreeCsr[0]) */
................................................................................
  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */
  Pgno *aGobble;                  /* Gobble point for each input segment */

  Pgno iIndirect;
  struct SavedPgno {
    Pgno iPgno;
    int bStore;
  } aSave[2];
};

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);
................................................................................
  aOut[3] = (u8)((nVal>>32) & 0xFF);
  aOut[4] = (u8)((nVal>>24) & 0xFF);
  aOut[5] = (u8)((nVal>>16) & 0xFF);
  aOut[6] = (u8)((nVal>> 8) & 0xFF);
  aOut[7] = (u8)((nVal    ) & 0xFF);
}

static int sortedBlobGrow(lsm_env *pEnv, Blob *pBlob, int nData){
  assert( pBlob->pEnv==pEnv || (pBlob->pEnv==0 && pBlob->pData==0) );
  if( pBlob->nAlloc<nData ){
    pBlob->pData = lsmReallocOrFree(pEnv, pBlob->pData, nData);
    if( !pBlob->pData ) return LSM_NOMEM_BKPT;
    pBlob->nAlloc = nData;
    pBlob->pEnv = pEnv;
  }
  return LSM_OK;
}

static int sortedBlobSet(lsm_env *pEnv, Blob *pBlob, void *pData, int nData){
  if( sortedBlobGrow(pEnv, pBlob, nData) ) return LSM_NOMEM;
  memcpy(pBlob->pData, pData, nData);
  pBlob->nData = nData;
  return LSM_OK;
}

#if 0
static int sortedBlobCopy(Blob *pDest, Blob *pSrc){
  return sortedBlobSet(pDest, pSrc->pData, pSrc->nData);
}
#endif

static void sortedBlobFree(Blob *pBlob){
  assert( pBlob->pEnv || pBlob->pData==0 );
  if( pBlob->pData ) lsmFree(pBlob->pEnv, pBlob->pData);
  memset(pBlob, 0, sizeof(Blob));
}

static int sortedReadData(
  Segment *pSeg,
  Page *pPg,
  int iOff,
  int nByte,
  void **ppData,
  Blob *pBlob
){
  int rc = LSM_OK;
  int iEnd;
  int nData;
  int nCell;
  u8 *aData;

................................................................................
  return rc;
}

static int pageGetNRec(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_NRECORD_OFFSET(nData)]);
}

static Pgno pageGetPtr(u8 *aData, int nData){
  return (Pgno)lsmGetU64(&aData[SEGMENT_POINTER_OFFSET(nData)]);
}

static int pageGetFlags(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_FLAGS_OFFSET(nData)]);
}

static u8 *pageGetCell(u8 *aData, int nData, int iCell){
................................................................................
  return pageGetNRec(aData, nData);
}

/*
** Return the decoded (possibly relative) pointer value stored in cell 
** iCell from page aData/nData.
*/
static Pgno pageGetRecordPtr(u8 *aData, int nData, int iCell){
  Pgno iRet;                      /* Return value */
  u8 *aCell;                      /* Pointer to cell iCell */

  assert( iCell<pageGetNRec(aData, nData) && iCell>=0 );
  aCell = pageGetCell(aData, nData, iCell);
  lsmVarintGet64(&aCell[1], &iRet);
  return iRet;
}
................................................................................

static u8 *pageGetKey(
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  int *pnKey,                     /* OUT: Size of key in bytes */
  Blob *pBlob                     /* If required, use this for dynamic memory */
){
  u8 *pKey;
  int nDummy;
  int eType;
  u8 *aData;
  int nData;

................................................................................

static int pageGetKeyCopy(
  lsm_env *pEnv,                  /* Environment handle */
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  Blob *pBlob                     /* If required, use this for dynamic memory */
){
  int rc = LSM_OK;
  int nKey;
  u8 *aKey;

  aKey = pageGetKey(pSeg, pPg, iCell, piTopic, &nKey, pBlob);
  assert( (void *)aKey!=pBlob->pData || nKey==pBlob->nData );
................................................................................
  if( (void *)aKey!=pBlob->pData ){
    rc = sortedBlobSet(pEnv, pBlob, aKey, nKey);
  }

  return rc;
}

static Pgno pageGetBtreeRef(Page *pPg, int iKey){
  Pgno iRef;
  u8 *aData;
  int nData;
  u8 *aCell;

  aData = fsPageData(pPg, &nData);
  aCell = pageGetCell(aData, nData, iKey);
  assert( aCell[0]==0 );
................................................................................
#define GETVARINT64(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet64((a), &(i)))
#define GETVARINT32(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet32((a), &(i)))

static int pageGetBtreeKey(
  Segment *pSeg,                  /* Segment page pPg belongs to */
  Page *pPg,
  int iKey, 
  Pgno *piPtr, 
  int *piTopic, 
  void **ppKey,
  int *pnKey,
  Blob *pBlob
){
  u8 *aData;
  int nData;
  u8 *aCell;
  int eType;

  aData = fsPageData(pPg, &nData);
................................................................................

  aCell = pageGetCell(aData, nData, iKey);
  eType = *aCell++;
  aCell += GETVARINT64(aCell, *piPtr);

  if( eType==0 ){
    int rc;
    Pgno iRef;                  /* Page number of referenced page */
    Page *pRef;
    aCell += GETVARINT64(aCell, iRef);
    rc = lsmFsDbPageGet(lsmPageFS(pPg), pSeg, iRef, &pRef);
    if( rc!=LSM_OK ) return rc;
    pageGetKeyCopy(lsmPageEnv(pPg), pSeg, pRef, 0, &eType, pBlob);
    lsmFsPageRelease(pRef);
    *ppKey = pBlob->pData;
................................................................................
static int btreeCursorLoadKey(BtreeCursor *pCsr){
  int rc = LSM_OK;
  if( pCsr->iPg<0 ){
    pCsr->pKey = 0;
    pCsr->nKey = 0;
    pCsr->eType = 0;
  }else{
    Pgno dummy;
    int iPg = pCsr->iPg;
    int iCell = pCsr->aPg[iPg].iCell;
    while( iCell<0 && (--iPg)>=0 ){
      iCell = pCsr->aPg[iPg].iCell-1;
    }
    if( iPg<0 || iCell<0 ) return LSM_CORRUPT_BKPT;

................................................................................
  assert( pCsr->iPg==pCsr->nDepth-1 );

  aData = fsPageData(pPg->pPage, &nData);
  nCell = pageGetNRec(aData, nData);
  assert( pPg->iCell<=nCell );
  pPg->iCell++;
  if( pPg->iCell==nCell ){
    Pgno iLoad;

    /* Up to parent. */
    lsmFsPageRelease(pPg->pPage);
    pPg->pPage = 0;
    pCsr->iPg--;
    while( pCsr->iPg>=0 ){
      pPg = &pCsr->aPg[pCsr->iPg];
................................................................................
  MergeInput *p
){
  int rc = LSM_OK;

  if( p->iPg ){
    lsm_env *pEnv = lsmFsEnv(pCsr->pFS);
    int iCell;                    /* Current cell number on leaf page */
    Pgno iLeaf;                   /* Page number of current leaf page */
    int nDepth;                   /* Depth of b-tree structure */
    Segment *pSeg = pCsr->pSeg;

    /* Decode the MergeInput structure */
    iLeaf = p->iPg;
    nDepth = (p->iCell & 0x00FF);
    iCell = (p->iCell >> 8) - 1;
................................................................................
      pCsr->nDepth = nDepth;
      pCsr->aPg[pCsr->iPg].iCell = iCell;
      rc = lsmFsDbPageGet(pCsr->pFS, pSeg, iLeaf, pp);
    }

    /* Populate any other aPg[] array entries */
    if( rc==LSM_OK && nDepth>1 ){
      Blob blob = {0,0,0};
      void *pSeek;
      int nSeek;
      int iTopicSeek;
      int iPg = 0;
      int iLoad = (int)pSeg->iRoot;
      Page *pPg = pCsr->aPg[nDepth-1].pPage;
 
................................................................................
        ** In this case, set the iTopicSeek/pSeek/nSeek key to a value
        ** greater than any real key.  */
        assert( iCell==-1 );
        iTopicSeek = 1000;
        pSeek = 0;
        nSeek = 0;
      }else{
        Pgno dummy;
        rc = pageGetBtreeKey(pSeg, pPg,
            0, &dummy, &iTopicSeek, &pSeek, &nSeek, &pCsr->blob
        );
      }

      do {
        Page *pPg2;
................................................................................
          iMax = iCell2-1;
          iMin = 0;

          while( iMax>=iMin ){
            int iTry = (iMin+iMax)/2;
            void *pKey; int nKey;         /* Key for cell iTry */
            int iTopic;                   /* Topic for key pKeyT/nKeyT */
            Pgno iPtr;                    /* Pointer for cell iTry */
            int res;                      /* (pSeek - pKeyT) */

            rc = pageGetBtreeKey(
                pSeg, pPg2, iTry, &iPtr, &iTopic, &pKey, &nKey, &blob
            );
            if( rc!=LSM_OK ) break;

................................................................................
      u8 *aData;
      int nData;

      pBtreePg = &pCsr->aPg[pCsr->iPg];
      aData = fsPageData(pBtreePg->pPage, &nData);
      pCsr->iPtr = btreeCursorPtr(aData, nData, pBtreePg->iCell+1);
      if( pBtreePg->iCell<0 ){
        Pgno dummy;
        int i;
        for(i=pCsr->iPg-1; i>=0; i--){
          if( pCsr->aPg[i].iCell>0 ) break;
        }
        assert( i>=0 );
        rc = pageGetBtreeKey(pSeg,
            pCsr->aPg[i].pPage, pCsr->aPg[i].iCell-1,
................................................................................
}

static int segmentPtrReadData(
  SegmentPtr *pPtr,
  int iOff,
  int nByte,
  void **ppData,
  Blob *pBlob
){
  return sortedReadData(pPtr->pSeg, pPtr->pPg, iOff, nByte, ppData, pBlob);
}

static int segmentPtrNextPage(
  SegmentPtr *pPtr,              /* Load page into this SegmentPtr object */
  int eDir                       /* +1 for next(), -1 for prev() */
................................................................................

  pSeg = sortedSplitkeySegment(pLevel);
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, pSeg, pMerge->splitkey.iPg, &pPg);
  }
  if( rc==LSM_OK ){
    int iTopic;
    Blob blob = {0, 0, 0, 0};
    u8 *aData;
    int nData;
  
    aData = lsmFsPageData(pPg, &nData);
    if( pageGetFlags(aData, nData) & SEGMENT_BTREE_FLAG ){
      void *pKey;
      int nKey;
      Pgno dummy;
      rc = pageGetBtreeKey(pSeg,
          pPg, pMerge->splitkey.iCell, &dummy, &iTopic, &pKey, &nKey, &blob
      );
      if( rc==LSM_OK && blob.pData!=pKey ){
        rc = sortedBlobSet(pEnv, &blob, pKey, nKey);
      }
    }else{
................................................................................
*/
static int assertKeyLocation(
  MultiCursor *pCsr, 
  SegmentPtr *pPtr, 
  void *pKey, int nKey
){
  lsm_env *pEnv = lsmFsEnv(pCsr->pDb->pFS);
  Blob blob = {0, 0, 0};
  int eDir;
  int iTopic = 0;                 /* TODO: Fix me */

  for(eDir=-1; eDir<=1; eDir+=2){
    Page *pTest = pPtr->pPg;

    lsmFsPageRef(pTest);
................................................................................
  return rc;
}

static int ptrFwdPointer(
  Page *pPage,
  int iCell,
  Segment *pSeg,
  Pgno *piPtr,
  int *pbFound
){
  Page *pPg = pPage;
  int iFirst = iCell;
  int rc = LSM_OK;

  do {
................................................................................
**   much better if the multi-cursor could do this lazily - only seek to the
**   level (N+1) page after the user has moved the cursor on level N passed
**   the big range-delete.
*/
static int segmentPtrFwdPointer(
  MultiCursor *pCsr,              /* Multi-cursor pPtr belongs to */
  SegmentPtr *pPtr,               /* Segment-pointer to extract FC ptr from */
  Pgno *piPtr                     /* OUT: FC pointer value */
){
  Level *pLvl = pPtr->pLevel;
  Level *pNext = pLvl->pNext;
  Page *pPg = pPtr->pPg;
  int rc;
  int bFound;
  Pgno iOut = 0;

  if( pPtr->pSeg==&pLvl->lhs || pPtr->pSeg==&pLvl->aRhs[pLvl->nRight-1] ){
    if( pNext==0 
        || (pNext->nRight==0 && pNext->lhs.iRoot)
        || (pNext->nRight!=0 && pNext->aRhs[0].iRoot)
      ){
      /* Do nothing. The pointer will not be used anyway. */
................................................................................
  int *pbStop
){
  int (*xCmp)(void *, int, void *, int) = pCsr->pDb->xCmp;
  int res = 0;                        /* Result of comparison operation */
  int rc = LSM_OK;
  int iMin;
  int iMax;
  Pgno iPtrOut = 0;

  /* If the current page contains an oversized entry, then there are no
  ** pointers to one or more of the subsequent pages in the sorted run.
  ** The following call ensures that the segment-ptr points to the correct 
  ** page in this case.  */
  rc = segmentPtrSearchOversized(pCsr, pPtr, iTopic, pKey, nKey);
  iPtrOut = pPtr->iPtr;
................................................................................
}

static int seekInBtree(
  MultiCursor *pCsr,              /* Multi-cursor object */
  Segment *pSeg,                  /* Seek within this segment */
  int iTopic,
  void *pKey, int nKey,           /* Key to seek to */
  Pgno *aPg,                      /* OUT: Page numbers */
  Page **ppPg                     /* OUT: Leaf (sorted-run) page reference */
){
  int i = 0;
  int rc;
  int iPg;
  Page *pPg = 0;
  Blob blob = {0, 0, 0};

  iPg = (int)pSeg->iRoot;
  do {
    Pgno *piFirst = 0;
    if( aPg ){
      aPg[i++] = iPg;
      piFirst = &aPg[i];
    }

    rc = lsmFsDbPageGet(pCsr->pDb->pFS, pSeg, iPg, &pPg);
    assert( rc==LSM_OK || pPg==0 );
................................................................................

      iMin = 0;
      iMax = nRec-1;
      while( iMax>=iMin ){
        int iTry = (iMin+iMax)/2;
        void *pKeyT; int nKeyT;       /* Key for cell iTry */
        int iTopicT;                  /* Topic for key pKeyT/nKeyT */
        Pgno iPtr;                    /* Pointer associated with cell iTry */
        int res;                      /* (pKey - pKeyT) */

        rc = pageGetBtreeKey(
            pSeg, pPg, iTry, &iPtr, &iTopicT, &pKeyT, &nKeyT, &blob
        );
        if( rc!=LSM_OK ) break;
        if( piFirst && pKeyT==blob.pData ){
................................................................................
*/
static int seekInLevel(
  MultiCursor *pCsr,              /* Sorted cursor object to seek */
  SegmentPtr *aPtr,               /* Pointer to array of (nRhs+1) SPs */
  int eSeek,                      /* Search bias - see above */
  int iTopic,                     /* Key topic to search for */
  void *pKey, int nKey,           /* Key to search for */
  Pgno *piPgno,                   /* IN/OUT: fraction cascade pointer (or 0) */
  int *pbStop                     /* OUT: See above */
){
  Level *pLvl = aPtr[0].pLevel;   /* Level to seek within */
  int rc = LSM_OK;                /* Return code */
  int iOut = 0;                   /* Pointer to return to caller */
  int res = -1;                   /* Result of xCmp(pKey, split) */
  int nRhs = pLvl->nRight;        /* Number of right-hand-side segments */
................................................................................
  void *pKey, int nKey, 
  int eSeek
){
  int eESeek = eSeek;             /* Effective eSeek parameter */
  int bStop = 0;                  /* Set to true to halt search operation */
  int rc = LSM_OK;                /* Return code */
  int iPtr = 0;                   /* Used to iterate through pCsr->aPtr[] */
  Pgno iPgno = 0;                 /* FC pointer value */

  assert( pCsr->apTreeCsr[0]==0 || iTopic==0 );
  assert( pCsr->apTreeCsr[1]==0 || iTopic==0 );

  if( eESeek==LSM_SEEK_LEFAST ) eESeek = LSM_SEEK_LE;

  assert( eESeek==LSM_SEEK_EQ || eESeek==LSM_SEEK_LE || eESeek==LSM_SEEK_GE );
................................................................................
** differences are:
**
**   1. The record format is (usually, see below) as follows:
**
**         + Type byte (always SORTED_SEPARATOR or SORTED_SYSTEM_SEPARATOR),
**         + Absolute pointer value (varint),
**         + Number of bytes in key (varint),
**         + Blob containing key data.
**
**   2. All pointer values are stored as absolute values (not offsets 
**      relative to the footer pointer value).
**
**   3. Each pointer that is part of a record points to a page that 
**      contains keys smaller than the records key (note: not "equal to or
**      smaller than - smaller than").
................................................................................
**
** See function seekInBtree() for the code that traverses b-tree pages.
*/

static int mergeWorkerBtreeWrite(
  MergeWorker *pMW,
  u8 eType,
  Pgno iPtr,
  Pgno iKeyPg,
  void *pKey,
  int nKey
){
  Hierarchy *p = &pMW->hier;
  lsm_db *pDb = pMW->pDb;         /* Database handle */
  int rc = LSM_OK;                /* Return Code */
  int iLevel;                     /* Level of b-tree hierachy to write to */
................................................................................

  return rc;
}

static int mergeWorkerBtreeIndirect(MergeWorker *pMW){
  int rc = LSM_OK;
  if( pMW->iIndirect ){
    Pgno iKeyPg = pMW->aSave[1].iPgno;
    rc = mergeWorkerBtreeWrite(pMW, 0, pMW->iIndirect, iKeyPg, 0, 0);
    pMW->iIndirect = 0;
  }
  return rc;
}

/*
................................................................................
static int mergeWorkerPushHierarchy(
  MergeWorker *pMW,               /* Merge worker object */
  int iTopic,                     /* Topic value for this key */
  void *pKey,                     /* Pointer to key buffer */
  int nKey                        /* Size of pKey buffer in bytes */
){
  int rc = LSM_OK;                /* Return Code */
  Pgno iPtr;                      /* Pointer value to accompany pKey/nKey */

  assert( pMW->aSave[0].bStore==0 );
  assert( pMW->aSave[1].bStore==0 );
  rc = mergeWorkerBtreeIndirect(pMW);

  /* Obtain the absolute pointer value to store along with the key in the
  ** page body. This pointer points to a page that contains keys that are
................................................................................
}

static int mergeWorkerFinishHierarchy(
  MergeWorker *pMW                /* Merge worker object */
){
  int i;                          /* Used to loop through apHier[] */
  int rc = LSM_OK;                /* Return code */
  Pgno iPtr;                      /* New right-hand-child pointer value */

  iPtr = pMW->aSave[0].iPgno;
  for(i=0; i<pMW->hier.nHier && rc==LSM_OK; i++){
    Page *pPg = pMW->hier.apHier[i];
    int nData;                    /* Size of aData[] in bytes */
    u8 *aData;                    /* Page data for pPg */

................................................................................
** zero records. The flags field is cleared. The page footer pointer field
** is set to iFPtr.
**
** If successful, LSM_OK is returned. Otherwise, an error code.
*/
static int mergeWorkerNextPage(
  MergeWorker *pMW,               /* Merge worker object to append page to */
  Pgno iFPtr                      /* Pointer value for footer of new page */
){
  int rc = LSM_OK;                /* Return code */
  Page *pNext = 0;                /* New page appended to run */
  lsm_db *pDb = pMW->pDb;         /* Database handle */

  rc = lsmFsSortedAppend(pDb->pFS, pDb->pWorker, pMW->pLevel, 0, &pNext);
  assert( rc || pMW->pLevel->lhs.iFirst>0 || pMW->pDb->compress.xCompress );
................................................................................

static int mergeWorkerStep(MergeWorker *pMW){
  lsm_db *pDb = pMW->pDb;       /* Database handle */
  MultiCursor *pCsr;            /* Cursor to read input data from */
  int rc = LSM_OK;              /* Return code */
  int eType;                    /* SORTED_SEPARATOR, WRITE or DELETE */
  void *pKey; int nKey;         /* Key */
  Pgno iPtr;
  int iVal;

  pCsr = pMW->pCsr;

  /* Pull the next record out of the source cursor. */
  lsmMCursorKey(pCsr, &pKey, &nKey);
  eType = pCsr->eType;
................................................................................
      multiCursorIgnoreDelete(pCsr);
    }
  }

  if( rc!=LSM_OK ){
    lsmMCursorClose(pCsr, 0);
  }else{
    Pgno iLeftPtr = 0;
    Merge merge;                  /* Merge object used to create new level */
    MergeWorker mergeworker;      /* MergeWorker object for the same purpose */

    memset(&merge, 0, sizeof(Merge));
    memset(&mergeworker, 0, sizeof(MergeWorker));

    pNew->pMerge = &merge;
................................................................................
  assert( pDb->pWorker );
  assert( pLevel->pMerge );
  assert( pLevel->nRight>0 );

  memset(pMW, 0, sizeof(MergeWorker));
  pMW->pDb = pDb;
  pMW->pLevel = pLevel;
  pMW->aGobble = lsmMallocZeroRc(pDb->pEnv, sizeof(Pgno) * pLevel->nRight, &rc);

  /* Create a multi-cursor to read the data to write to the new
  ** segment. The new segment contains:
  **
  **   1. Records from LHS of each of the nMerge levels being merged.
  **   2. Separators from either the last level being merged, or the
  **      separators attached to the LHS of the following level, or neither.
................................................................................
  lsm_db *pDb,                    /* Worker connection */
  MultiCursor *pCsr,              /* Multi-cursor being used for a merge */
  int iGobble                     /* pCsr->aPtr[] entry to operate on */
){
  int rc = LSM_OK;
  if( rtTopic(pCsr->eType)==0 ){
    Segment *pSeg = pCsr->aPtr[iGobble].pSeg;
    Pgno *aPg;
    int nPg;

    /* Seek from the root of the b-tree to the segment leaf that may contain
    ** a key equal to the one multi-cursor currently points to. Record the
    ** page number of each b-tree page and the leaf. The segment may be
    ** gobbled up to (but not including) the first of these page numbers.
    */
    assert( pSeg->iRoot>0 );
    aPg = lsmMallocZeroRc(pDb->pEnv, sizeof(Pgno)*32, &rc);
    if( rc==LSM_OK ){
      rc = seekInBtree(pCsr, pSeg, 
          rtTopic(pCsr->eType), pCsr->key.pData, pCsr->key.nData, aPg, 0
      ); 
    }

    if( rc==LSM_OK ){
................................................................................
/*
** Return a string representation of the segment passed as the only argument.
** Space for the returned string is allocated using lsmMalloc(), and should
** be freed by the caller using lsmFree().
*/
static char *segToString(lsm_env *pEnv, Segment *pSeg, int nMin){
  int nSize = pSeg->nSize;
  Pgno iRoot = pSeg->iRoot;
  Pgno iFirst = pSeg->iFirst;
  Pgno iLast = pSeg->iLastPg;
  char *z;

  char *z1;
  char *z2;
  int nPad;

  z1 = lsmMallocPrintf(pEnv, "%d.%d", iFirst, iLast);
................................................................................
    aBuf[0] = '\0';
  }

  return i;
}

void sortedDumpPage(lsm_db *pDb, Segment *pRun, Page *pPg, int bVals){
  Blob blob = {0, 0, 0};         /* Blob used for keys */
  LsmString s;
  int i;

  int nRec;
  int iPtr;
  int flags;
  u8 *aData;
................................................................................

    aCell = pageGetCell(aData, nData, i);
    eType = *aCell++;
    assert( (flags & SEGMENT_BTREE_FLAG) || eType!=0 );
    aCell += lsmVarintGet32(aCell, &iPgPtr);

    if( eType==0 ){
      Pgno iRef;                  /* Page number of referenced page */
      aCell += lsmVarintGet64(aCell, &iRef);
      lsmFsDbPageGet(pDb->pFS, pRun, iRef, &pRef);
      aKey = pageGetKey(pRun, pRef, 0, &iTopic, &nKey, &blob);
    }else{
      aCell += lsmVarintGet32(aCell, &nKey);
      if( rtIsWrite(eType) ) aCell += lsmVarintGet32(aCell, &nVal);
      sortedReadData(0, pPg, (aCell-aData), nKey+nVal, (void **)&aKey, &blob);
................................................................................
  int bIndirect,                  /* True to follow indirect refs */
  Page *pPg,
  int iCell,
  int *peType,
  int *piPgPtr,
  u8 **paKey, int *pnKey,
  u8 **paVal, int *pnVal,
  Blob *pBlob
){
  u8 *aData; int nData;           /* Page data */
  u8 *aKey; int nKey = 0;         /* Key */
  u8 *aVal = 0; int nVal = 0;     /* Value */
  int eType;
  int iPgPtr;
  Page *pRef = 0;                 /* Pointer to page iRef */
................................................................................

  aCell = pageGetCell(aData, nData, iCell);
  eType = *aCell++;
  aCell += lsmVarintGet32(aCell, &iPgPtr);

  if( eType==0 ){
    int dummy;
    Pgno iRef;                  /* Page number of referenced page */
    aCell += lsmVarintGet64(aCell, &iRef);
    if( bIndirect ){
      lsmFsDbPageGet(pDb->pFS, pSeg, iRef, &pRef);
      pageGetKeyCopy(pDb->pEnv, pSeg, pRef, 0, &dummy, pBlob);
      aKey = (u8 *)pBlob->pData;
      nKey = pBlob->nData;
      lsmFsPageRelease(pRef);
................................................................................
#define INFO_PAGE_DUMP_DATA     0x01
#define INFO_PAGE_DUMP_VALUES   0x02
#define INFO_PAGE_DUMP_HEX      0x04
#define INFO_PAGE_DUMP_INDIRECT 0x08

static int infoPageDump(
  lsm_db *pDb,                    /* Database handle */
  Pgno iPg,                       /* Page number of page to dump */
  int flags,
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int rc = LSM_OK;                /* Return code */
  Page *pPg = 0;                  /* Handle for page iPg */
  int i, j;                       /* Loop counters */
  const int perLine = 16;         /* Bytes per line in the raw hex dump */
................................................................................
  ** to pass a NULL in place of the segment pointer as the second argument
  ** to lsmFsDbPageGet() here.  */
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, 0, iPg, &pPg);
  }

  if( rc==LSM_OK ){
    Blob blob = {0, 0, 0, 0};
    int nKeyWidth = 0;
    LsmString str;
    int nRec;
    int iPtr;
    int flags2;
    int iCell;
    u8 *aData; int nData;         /* Page data and size thereof */
................................................................................
    if( bHex ) nKeyWidth = nKeyWidth * 2;

    for(iCell=0; iCell<nRec; iCell++){
      u8 *aKey; int nKey = 0;       /* Key */
      u8 *aVal; int nVal = 0;       /* Value */
      int iPgPtr;
      int eType;
      Pgno iAbsPtr;
      char zFlags[8];

      infoCellDump(pDb, pSeg, bIndirect, pPg, iCell, &eType, &iPgPtr,
          &aKey, &nKey, &aVal, &nVal, &blob
      );
      iAbsPtr = iPgPtr + ((flags2 & SEGMENT_BTREE_FLAG) ? 0 : iPtr);

................................................................................
  }

  return rc;
}

int lsmInfoPageDump(
  lsm_db *pDb,                    /* Database handle */
  Pgno iPg,                       /* Page number of page to dump */
  int bHex,                       /* True to output key/value in hex form */
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int flags = INFO_PAGE_DUMP_DATA | INFO_PAGE_DUMP_VALUES;
  if( bHex ) flags |= INFO_PAGE_DUMP_HEX;
  return infoPageDump(pDb, iPg, flags, pzOut);
}
................................................................................
  iHdr = SEGMENT_EOF(nOrig, nEntry);
  memmove(&aData[iHdr + (nData-nOrig)], &aData[iHdr], nOrig-iHdr);
}

#ifdef LSM_DEBUG_EXPENSIVE
static void assertRunInOrder(lsm_db *pDb, Segment *pSeg){
  Page *pPg = 0;
  Blob blob1 = {0, 0, 0, 0};
  Blob blob2 = {0, 0, 0, 0};

  lsmFsDbPageGet(pDb->pFS, pSeg, pSeg->iFirst, &pPg);
  while( pPg ){
    u8 *aData; int nData;
    Page *pNext;

    aData = lsmFsPageData(pPg, &nData);
................................................................................
  Segment *pOne,                  /* Segment containing pointers */
  Segment *pTwo,                  /* Segment containing pointer targets */
  int bRhs                        /* True if pTwo may have been Gobble()d */
){
  int rc = LSM_OK;                /* Error code */
  SegmentPtr ptr1;                /* Iterates through pOne */
  SegmentPtr ptr2;                /* Iterates through pTwo */
  Pgno iPrev;

  assert( pOne && pTwo );

  memset(&ptr1, 0, sizeof(ptr1));
  memset(&ptr2, 0, sizeof(ptr1));
  ptr1.pSeg = pOne;
  ptr2.pSeg = pTwo;
................................................................................
  }

  if( rc==LSM_OK && ptr1.nCell>0 ){
    rc = segmentPtrLoadCell(&ptr1, 0);
  }
      
  while( rc==LSM_OK && ptr2.pPg ){
    Pgno iThis;

    /* Advance to the next page of segment pTwo that contains at least
    ** one cell. Break out of the loop if the iterator reaches EOF.  */
    do{
      rc = segmentPtrNextPage(&ptr2, 1);
      assert( rc==LSM_OK );
    }while( rc==LSM_OK && ptr2.pPg && ptr2.nCell==0 );
................................................................................
*/
static int assertBtreeOk(
  lsm_db *pDb,
  Segment *pSeg
){
  int rc = LSM_OK;                /* Return code */
  if( pSeg->iRoot ){
    Blob blob = {0, 0, 0};        /* Buffer used to cache overflow keys */
    FileSystem *pFS = pDb->pFS;   /* File system to read from */
    Page *pPg = 0;                /* Main run page */
    BtreeCursor *pCsr = 0;        /* Btree cursor */

    rc = btreeCursorNew(pDb, pSeg, &pCsr);
    if( rc==LSM_OK ){
      rc = btreeCursorFirst(pCsr);

#ifndef LSM_SEGMENTPTR_FREE_THRESHOLD
# define LSM_SEGMENTPTR_FREE_THRESHOLD 1024
#endif

typedef struct SegmentPtr SegmentPtr;
typedef struct LsmBlob LsmBlob;

struct LsmBlob {
  lsm_env *pEnv;
  void *pData;
  int nData;
  int nAlloc;
};

/*
................................................................................
  Level *pLevel;                /* Level object segment is part of */
  Segment *pSeg;                /* Segment to access */

  /* Current page. See segmentPtrLoadPage(). */
  Page *pPg;                    /* Current page */
  u16 flags;                    /* Copy of page flags field */
  int nCell;                    /* Number of cells on pPg */
  LsmPgno iPtr;                 /* Base cascade pointer */

  /* Current cell. See segmentPtrLoadCell() */
  int iCell;                    /* Current record within page pPg */
  int eType;                    /* Type of current record */
  LsmPgno iPgPtr;               /* Cascade pointer offset */
  void *pKey; int nKey;         /* Key associated with current record */
  void *pVal; int nVal;         /* Current record value (eType==WRITE only) */

  /* Blobs used to allocate buffers for pKey and pVal as required */
  LsmBlob blob1;
  LsmBlob blob2;
};

/*
** Used to iterate through the keys stored in a b-tree hierarchy from start
** to finish. Only First() and Next() operations are required.
**
**   btreeCursorNew()
................................................................................
  int iPg;                        /* Current entry in aPg[]. -1 -> EOF. */
  BtreePg *aPg;                   /* Pages from root to current location */

  /* Cache of current entry. pKey==0 for EOF. */
  void *pKey;
  int nKey;
  int eType;
  LsmPgno iPtr;

  /* Storage for key, if not local */
  LsmBlob blob;
};


/*
** A cursor used for merged searches or iterations through up to one
** Tree structure and any number of sorted files.
**
................................................................................
*/
struct MultiCursor {
  lsm_db *pDb;                    /* Connection that owns this cursor */
  MultiCursor *pNext;             /* Next cursor owned by connection pDb */
  int flags;                      /* Mask of CURSOR_XXX flags */

  int eType;                      /* Cache of current key type */
  LsmBlob key;                    /* Cache of current key (or NULL) */
  LsmBlob val;                    /* Cache of current value */

  /* All the component cursors: */
  TreeCursor *apTreeCsr[2];       /* Up to two tree cursors */
  int iFree;                      /* Next element of free-list (-ve for eof) */
  SegmentPtr *aPtr;               /* Array of segment pointers */
  int nPtr;                       /* Size of array aPtr[] */
  BtreeCursor *pBtCsr;            /* b-tree cursor (db writes only) */
................................................................................
  int nTree;                      /* Size of aTree[] array */
  int *aTree;                     /* Array of comparison results */

  /* Used by cursors flushing the in-memory tree only */
  void *pSystemVal;               /* Pointer to buffer to free */

  /* Used by worker cursors only */
  LsmPgno *pPrevMergePtr;
};

/*
** The following constants are used to assign integers to each component
** cursor of a multi-cursor.
*/
#define CURSOR_DATA_TREE0     0   /* Current tree cursor (apTreeCsr[0]) */
................................................................................
  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */
  LsmPgno *aGobble;               /* Gobble point for each input segment */

  LsmPgno iIndirect;
  struct SavedPgno {
    LsmPgno iPgno;
    int bStore;
  } aSave[2];
};

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);
................................................................................
  aOut[3] = (u8)((nVal>>32) & 0xFF);
  aOut[4] = (u8)((nVal>>24) & 0xFF);
  aOut[5] = (u8)((nVal>>16) & 0xFF);
  aOut[6] = (u8)((nVal>> 8) & 0xFF);
  aOut[7] = (u8)((nVal    ) & 0xFF);
}

static int sortedBlobGrow(lsm_env *pEnv, LsmBlob *pBlob, int nData){
  assert( pBlob->pEnv==pEnv || (pBlob->pEnv==0 && pBlob->pData==0) );
  if( pBlob->nAlloc<nData ){
    pBlob->pData = lsmReallocOrFree(pEnv, pBlob->pData, nData);
    if( !pBlob->pData ) return LSM_NOMEM_BKPT;
    pBlob->nAlloc = nData;
    pBlob->pEnv = pEnv;
  }
  return LSM_OK;
}

static int sortedBlobSet(lsm_env *pEnv, LsmBlob *pBlob, void *pData, int nData){
  if( sortedBlobGrow(pEnv, pBlob, nData) ) return LSM_NOMEM;
  memcpy(pBlob->pData, pData, nData);
  pBlob->nData = nData;
  return LSM_OK;
}

#if 0
static int sortedBlobCopy(LsmBlob *pDest, LsmBlob *pSrc){
  return sortedBlobSet(pDest, pSrc->pData, pSrc->nData);
}
#endif

static void sortedBlobFree(LsmBlob *pBlob){
  assert( pBlob->pEnv || pBlob->pData==0 );
  if( pBlob->pData ) lsmFree(pBlob->pEnv, pBlob->pData);
  memset(pBlob, 0, sizeof(LsmBlob));
}

static int sortedReadData(
  Segment *pSeg,
  Page *pPg,
  int iOff,
  int nByte,
  void **ppData,
  LsmBlob *pBlob
){
  int rc = LSM_OK;
  int iEnd;
  int nData;
  int nCell;
  u8 *aData;

................................................................................
  return rc;
}

static int pageGetNRec(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_NRECORD_OFFSET(nData)]);
}

static LsmPgno pageGetPtr(u8 *aData, int nData){
  return (LsmPgno)lsmGetU64(&aData[SEGMENT_POINTER_OFFSET(nData)]);
}

static int pageGetFlags(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_FLAGS_OFFSET(nData)]);
}

static u8 *pageGetCell(u8 *aData, int nData, int iCell){
................................................................................
  return pageGetNRec(aData, nData);
}

/*
** Return the decoded (possibly relative) pointer value stored in cell 
** iCell from page aData/nData.
*/
static LsmPgno pageGetRecordPtr(u8 *aData, int nData, int iCell){
  LsmPgno iRet;                   /* Return value */
  u8 *aCell;                      /* Pointer to cell iCell */

  assert( iCell<pageGetNRec(aData, nData) && iCell>=0 );
  aCell = pageGetCell(aData, nData, iCell);
  lsmVarintGet64(&aCell[1], &iRet);
  return iRet;
}
................................................................................

static u8 *pageGetKey(
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  int *pnKey,                     /* OUT: Size of key in bytes */
  LsmBlob *pBlob                  /* If required, use this for dynamic memory */
){
  u8 *pKey;
  int nDummy;
  int eType;
  u8 *aData;
  int nData;

................................................................................

static int pageGetKeyCopy(
  lsm_env *pEnv,                  /* Environment handle */
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  LsmBlob *pBlob                  /* If required, use this for dynamic memory */
){
  int rc = LSM_OK;
  int nKey;
  u8 *aKey;

  aKey = pageGetKey(pSeg, pPg, iCell, piTopic, &nKey, pBlob);
  assert( (void *)aKey!=pBlob->pData || nKey==pBlob->nData );
................................................................................
  if( (void *)aKey!=pBlob->pData ){
    rc = sortedBlobSet(pEnv, pBlob, aKey, nKey);
  }

  return rc;
}

static LsmPgno pageGetBtreeRef(Page *pPg, int iKey){
  LsmPgno iRef;
  u8 *aData;
  int nData;
  u8 *aCell;

  aData = fsPageData(pPg, &nData);
  aCell = pageGetCell(aData, nData, iKey);
  assert( aCell[0]==0 );
................................................................................
#define GETVARINT64(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet64((a), &(i)))
#define GETVARINT32(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet32((a), &(i)))

static int pageGetBtreeKey(
  Segment *pSeg,                  /* Segment page pPg belongs to */
  Page *pPg,
  int iKey, 
  LsmPgno *piPtr, 
  int *piTopic, 
  void **ppKey,
  int *pnKey,
  LsmBlob *pBlob
){
  u8 *aData;
  int nData;
  u8 *aCell;
  int eType;

  aData = fsPageData(pPg, &nData);
................................................................................

  aCell = pageGetCell(aData, nData, iKey);
  eType = *aCell++;
  aCell += GETVARINT64(aCell, *piPtr);

  if( eType==0 ){
    int rc;
    LsmPgno iRef;               /* Page number of referenced page */
    Page *pRef;
    aCell += GETVARINT64(aCell, iRef);
    rc = lsmFsDbPageGet(lsmPageFS(pPg), pSeg, iRef, &pRef);
    if( rc!=LSM_OK ) return rc;
    pageGetKeyCopy(lsmPageEnv(pPg), pSeg, pRef, 0, &eType, pBlob);
    lsmFsPageRelease(pRef);
    *ppKey = pBlob->pData;
................................................................................
static int btreeCursorLoadKey(BtreeCursor *pCsr){
  int rc = LSM_OK;
  if( pCsr->iPg<0 ){
    pCsr->pKey = 0;
    pCsr->nKey = 0;
    pCsr->eType = 0;
  }else{
    LsmPgno dummy;
    int iPg = pCsr->iPg;
    int iCell = pCsr->aPg[iPg].iCell;
    while( iCell<0 && (--iPg)>=0 ){
      iCell = pCsr->aPg[iPg].iCell-1;
    }
    if( iPg<0 || iCell<0 ) return LSM_CORRUPT_BKPT;

................................................................................
  assert( pCsr->iPg==pCsr->nDepth-1 );

  aData = fsPageData(pPg->pPage, &nData);
  nCell = pageGetNRec(aData, nData);
  assert( pPg->iCell<=nCell );
  pPg->iCell++;
  if( pPg->iCell==nCell ){
    LsmPgno iLoad;

    /* Up to parent. */
    lsmFsPageRelease(pPg->pPage);
    pPg->pPage = 0;
    pCsr->iPg--;
    while( pCsr->iPg>=0 ){
      pPg = &pCsr->aPg[pCsr->iPg];
................................................................................
  MergeInput *p
){
  int rc = LSM_OK;

  if( p->iPg ){
    lsm_env *pEnv = lsmFsEnv(pCsr->pFS);
    int iCell;                    /* Current cell number on leaf page */
    LsmPgno iLeaf;                /* Page number of current leaf page */
    int nDepth;                   /* Depth of b-tree structure */
    Segment *pSeg = pCsr->pSeg;

    /* Decode the MergeInput structure */
    iLeaf = p->iPg;
    nDepth = (p->iCell & 0x00FF);
    iCell = (p->iCell >> 8) - 1;
................................................................................
      pCsr->nDepth = nDepth;
      pCsr->aPg[pCsr->iPg].iCell = iCell;
      rc = lsmFsDbPageGet(pCsr->pFS, pSeg, iLeaf, pp);
    }

    /* Populate any other aPg[] array entries */
    if( rc==LSM_OK && nDepth>1 ){
      LsmBlob blob = {0,0,0};
      void *pSeek;
      int nSeek;
      int iTopicSeek;
      int iPg = 0;
      int iLoad = (int)pSeg->iRoot;
      Page *pPg = pCsr->aPg[nDepth-1].pPage;
 
................................................................................
        ** In this case, set the iTopicSeek/pSeek/nSeek key to a value
        ** greater than any real key.  */
        assert( iCell==-1 );
        iTopicSeek = 1000;
        pSeek = 0;
        nSeek = 0;
      }else{
        LsmPgno dummy;
        rc = pageGetBtreeKey(pSeg, pPg,
            0, &dummy, &iTopicSeek, &pSeek, &nSeek, &pCsr->blob
        );
      }

      do {
        Page *pPg2;
................................................................................
          iMax = iCell2-1;
          iMin = 0;

          while( iMax>=iMin ){
            int iTry = (iMin+iMax)/2;
            void *pKey; int nKey;         /* Key for cell iTry */
            int iTopic;                   /* Topic for key pKeyT/nKeyT */
            LsmPgno iPtr;                 /* Pointer for cell iTry */
            int res;                      /* (pSeek - pKeyT) */

            rc = pageGetBtreeKey(
                pSeg, pPg2, iTry, &iPtr, &iTopic, &pKey, &nKey, &blob
            );
            if( rc!=LSM_OK ) break;

................................................................................
      u8 *aData;
      int nData;

      pBtreePg = &pCsr->aPg[pCsr->iPg];
      aData = fsPageData(pBtreePg->pPage, &nData);
      pCsr->iPtr = btreeCursorPtr(aData, nData, pBtreePg->iCell+1);
      if( pBtreePg->iCell<0 ){
        LsmPgno dummy;
        int i;
        for(i=pCsr->iPg-1; i>=0; i--){
          if( pCsr->aPg[i].iCell>0 ) break;
        }
        assert( i>=0 );
        rc = pageGetBtreeKey(pSeg,
            pCsr->aPg[i].pPage, pCsr->aPg[i].iCell-1,
................................................................................
}

static int segmentPtrReadData(
  SegmentPtr *pPtr,
  int iOff,
  int nByte,
  void **ppData,
  LsmBlob *pBlob
){
  return sortedReadData(pPtr->pSeg, pPtr->pPg, iOff, nByte, ppData, pBlob);
}

static int segmentPtrNextPage(
  SegmentPtr *pPtr,              /* Load page into this SegmentPtr object */
  int eDir                       /* +1 for next(), -1 for prev() */
................................................................................

  pSeg = sortedSplitkeySegment(pLevel);
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, pSeg, pMerge->splitkey.iPg, &pPg);
  }
  if( rc==LSM_OK ){
    int iTopic;
    LsmBlob blob = {0, 0, 0, 0};
    u8 *aData;
    int nData;
  
    aData = lsmFsPageData(pPg, &nData);
    if( pageGetFlags(aData, nData) & SEGMENT_BTREE_FLAG ){
      void *pKey;
      int nKey;
      LsmPgno dummy;
      rc = pageGetBtreeKey(pSeg,
          pPg, pMerge->splitkey.iCell, &dummy, &iTopic, &pKey, &nKey, &blob
      );
      if( rc==LSM_OK && blob.pData!=pKey ){
        rc = sortedBlobSet(pEnv, &blob, pKey, nKey);
      }
    }else{
................................................................................
*/
static int assertKeyLocation(
  MultiCursor *pCsr, 
  SegmentPtr *pPtr, 
  void *pKey, int nKey
){
  lsm_env *pEnv = lsmFsEnv(pCsr->pDb->pFS);
  LsmBlob blob = {0, 0, 0};
  int eDir;
  int iTopic = 0;                 /* TODO: Fix me */

  for(eDir=-1; eDir<=1; eDir+=2){
    Page *pTest = pPtr->pPg;

    lsmFsPageRef(pTest);
................................................................................
  return rc;
}

static int ptrFwdPointer(
  Page *pPage,
  int iCell,
  Segment *pSeg,
  LsmPgno *piPtr,
  int *pbFound
){
  Page *pPg = pPage;
  int iFirst = iCell;
  int rc = LSM_OK;

  do {
................................................................................
**   much better if the multi-cursor could do this lazily - only seek to the
**   level (N+1) page after the user has moved the cursor on level N passed
**   the big range-delete.
*/
static int segmentPtrFwdPointer(
  MultiCursor *pCsr,              /* Multi-cursor pPtr belongs to */
  SegmentPtr *pPtr,               /* Segment-pointer to extract FC ptr from */
  LsmPgno *piPtr                  /* OUT: FC pointer value */
){
  Level *pLvl = pPtr->pLevel;
  Level *pNext = pLvl->pNext;
  Page *pPg = pPtr->pPg;
  int rc;
  int bFound;
  LsmPgno iOut = 0;

  if( pPtr->pSeg==&pLvl->lhs || pPtr->pSeg==&pLvl->aRhs[pLvl->nRight-1] ){
    if( pNext==0 
        || (pNext->nRight==0 && pNext->lhs.iRoot)
        || (pNext->nRight!=0 && pNext->aRhs[0].iRoot)
      ){
      /* Do nothing. The pointer will not be used anyway. */
................................................................................
  int *pbStop
){
  int (*xCmp)(void *, int, void *, int) = pCsr->pDb->xCmp;
  int res = 0;                        /* Result of comparison operation */
  int rc = LSM_OK;
  int iMin;
  int iMax;
  LsmPgno iPtrOut = 0;

  /* If the current page contains an oversized entry, then there are no
  ** pointers to one or more of the subsequent pages in the sorted run.
  ** The following call ensures that the segment-ptr points to the correct 
  ** page in this case.  */
  rc = segmentPtrSearchOversized(pCsr, pPtr, iTopic, pKey, nKey);
  iPtrOut = pPtr->iPtr;
................................................................................
}

static int seekInBtree(
  MultiCursor *pCsr,              /* Multi-cursor object */
  Segment *pSeg,                  /* Seek within this segment */
  int iTopic,
  void *pKey, int nKey,           /* Key to seek to */
  LsmPgno *aPg,                   /* OUT: Page numbers */
  Page **ppPg                     /* OUT: Leaf (sorted-run) page reference */
){
  int i = 0;
  int rc;
  int iPg;
  Page *pPg = 0;
  LsmBlob blob = {0, 0, 0};

  iPg = (int)pSeg->iRoot;
  do {
    LsmPgno *piFirst = 0;
    if( aPg ){
      aPg[i++] = iPg;
      piFirst = &aPg[i];
    }

    rc = lsmFsDbPageGet(pCsr->pDb->pFS, pSeg, iPg, &pPg);
    assert( rc==LSM_OK || pPg==0 );
................................................................................

      iMin = 0;
      iMax = nRec-1;
      while( iMax>=iMin ){
        int iTry = (iMin+iMax)/2;
        void *pKeyT; int nKeyT;       /* Key for cell iTry */
        int iTopicT;                  /* Topic for key pKeyT/nKeyT */
        LsmPgno iPtr;                 /* Pointer associated with cell iTry */
        int res;                      /* (pKey - pKeyT) */

        rc = pageGetBtreeKey(
            pSeg, pPg, iTry, &iPtr, &iTopicT, &pKeyT, &nKeyT, &blob
        );
        if( rc!=LSM_OK ) break;
        if( piFirst && pKeyT==blob.pData ){
................................................................................
*/
static int seekInLevel(
  MultiCursor *pCsr,              /* Sorted cursor object to seek */
  SegmentPtr *aPtr,               /* Pointer to array of (nRhs+1) SPs */
  int eSeek,                      /* Search bias - see above */
  int iTopic,                     /* Key topic to search for */
  void *pKey, int nKey,           /* Key to search for */
  LsmPgno *piPgno,                /* IN/OUT: fraction cascade pointer (or 0) */
  int *pbStop                     /* OUT: See above */
){
  Level *pLvl = aPtr[0].pLevel;   /* Level to seek within */
  int rc = LSM_OK;                /* Return code */
  int iOut = 0;                   /* Pointer to return to caller */
  int res = -1;                   /* Result of xCmp(pKey, split) */
  int nRhs = pLvl->nRight;        /* Number of right-hand-side segments */
................................................................................
  void *pKey, int nKey, 
  int eSeek
){
  int eESeek = eSeek;             /* Effective eSeek parameter */
  int bStop = 0;                  /* Set to true to halt search operation */
  int rc = LSM_OK;                /* Return code */
  int iPtr = 0;                   /* Used to iterate through pCsr->aPtr[] */
  LsmPgno iPgno = 0;              /* FC pointer value */

  assert( pCsr->apTreeCsr[0]==0 || iTopic==0 );
  assert( pCsr->apTreeCsr[1]==0 || iTopic==0 );

  if( eESeek==LSM_SEEK_LEFAST ) eESeek = LSM_SEEK_LE;

  assert( eESeek==LSM_SEEK_EQ || eESeek==LSM_SEEK_LE || eESeek==LSM_SEEK_GE );
................................................................................
** differences are:
**
**   1. The record format is (usually, see below) as follows:
**
**         + Type byte (always SORTED_SEPARATOR or SORTED_SYSTEM_SEPARATOR),
**         + Absolute pointer value (varint),
**         + Number of bytes in key (varint),
**         + LsmBlob containing key data.
**
**   2. All pointer values are stored as absolute values (not offsets 
**      relative to the footer pointer value).
**
**   3. Each pointer that is part of a record points to a page that 
**      contains keys smaller than the records key (note: not "equal to or
**      smaller than - smaller than").
................................................................................
**
** See function seekInBtree() for the code that traverses b-tree pages.
*/

static int mergeWorkerBtreeWrite(
  MergeWorker *pMW,
  u8 eType,
  LsmPgno iPtr,
  LsmPgno iKeyPg,
  void *pKey,
  int nKey
){
  Hierarchy *p = &pMW->hier;
  lsm_db *pDb = pMW->pDb;         /* Database handle */
  int rc = LSM_OK;                /* Return Code */
  int iLevel;                     /* Level of b-tree hierachy to write to */
................................................................................

  return rc;
}

static int mergeWorkerBtreeIndirect(MergeWorker *pMW){
  int rc = LSM_OK;
  if( pMW->iIndirect ){
    LsmPgno iKeyPg = pMW->aSave[1].iPgno;
    rc = mergeWorkerBtreeWrite(pMW, 0, pMW->iIndirect, iKeyPg, 0, 0);
    pMW->iIndirect = 0;
  }
  return rc;
}

/*
................................................................................
static int mergeWorkerPushHierarchy(
  MergeWorker *pMW,               /* Merge worker object */
  int iTopic,                     /* Topic value for this key */
  void *pKey,                     /* Pointer to key buffer */
  int nKey                        /* Size of pKey buffer in bytes */
){
  int rc = LSM_OK;                /* Return Code */
  LsmPgno iPtr;                   /* Pointer value to accompany pKey/nKey */

  assert( pMW->aSave[0].bStore==0 );
  assert( pMW->aSave[1].bStore==0 );
  rc = mergeWorkerBtreeIndirect(pMW);

  /* Obtain the absolute pointer value to store along with the key in the
  ** page body. This pointer points to a page that contains keys that are
................................................................................
}

static int mergeWorkerFinishHierarchy(
  MergeWorker *pMW                /* Merge worker object */
){
  int i;                          /* Used to loop through apHier[] */
  int rc = LSM_OK;                /* Return code */
  LsmPgno iPtr;                   /* New right-hand-child pointer value */

  iPtr = pMW->aSave[0].iPgno;
  for(i=0; i<pMW->hier.nHier && rc==LSM_OK; i++){
    Page *pPg = pMW->hier.apHier[i];
    int nData;                    /* Size of aData[] in bytes */
    u8 *aData;                    /* Page data for pPg */

................................................................................
** zero records. The flags field is cleared. The page footer pointer field
** is set to iFPtr.
**
** If successful, LSM_OK is returned. Otherwise, an error code.
*/
static int mergeWorkerNextPage(
  MergeWorker *pMW,               /* Merge worker object to append page to */
  LsmPgno iFPtr                   /* Pointer value for footer of new page */
){
  int rc = LSM_OK;                /* Return code */
  Page *pNext = 0;                /* New page appended to run */
  lsm_db *pDb = pMW->pDb;         /* Database handle */

  rc = lsmFsSortedAppend(pDb->pFS, pDb->pWorker, pMW->pLevel, 0, &pNext);
  assert( rc || pMW->pLevel->lhs.iFirst>0 || pMW->pDb->compress.xCompress );
................................................................................

static int mergeWorkerStep(MergeWorker *pMW){
  lsm_db *pDb = pMW->pDb;       /* Database handle */
  MultiCursor *pCsr;            /* Cursor to read input data from */
  int rc = LSM_OK;              /* Return code */
  int eType;                    /* SORTED_SEPARATOR, WRITE or DELETE */
  void *pKey; int nKey;         /* Key */
  LsmPgno iPtr;
  int iVal;

  pCsr = pMW->pCsr;

  /* Pull the next record out of the source cursor. */
  lsmMCursorKey(pCsr, &pKey, &nKey);
  eType = pCsr->eType;
................................................................................
      multiCursorIgnoreDelete(pCsr);
    }
  }

  if( rc!=LSM_OK ){
    lsmMCursorClose(pCsr, 0);
  }else{
    LsmPgno iLeftPtr = 0;
    Merge merge;                  /* Merge object used to create new level */
    MergeWorker mergeworker;      /* MergeWorker object for the same purpose */

    memset(&merge, 0, sizeof(Merge));
    memset(&mergeworker, 0, sizeof(MergeWorker));

    pNew->pMerge = &merge;
................................................................................
  assert( pDb->pWorker );
  assert( pLevel->pMerge );
  assert( pLevel->nRight>0 );

  memset(pMW, 0, sizeof(MergeWorker));
  pMW->pDb = pDb;
  pMW->pLevel = pLevel;
  pMW->aGobble = lsmMallocZeroRc(pDb->pEnv, sizeof(LsmPgno)*pLevel->nRight,&rc);

  /* Create a multi-cursor to read the data to write to the new
  ** segment. The new segment contains:
  **
  **   1. Records from LHS of each of the nMerge levels being merged.
  **   2. Separators from either the last level being merged, or the
  **      separators attached to the LHS of the following level, or neither.
................................................................................
  lsm_db *pDb,                    /* Worker connection */
  MultiCursor *pCsr,              /* Multi-cursor being used for a merge */
  int iGobble                     /* pCsr->aPtr[] entry to operate on */
){
  int rc = LSM_OK;
  if( rtTopic(pCsr->eType)==0 ){
    Segment *pSeg = pCsr->aPtr[iGobble].pSeg;
    LsmPgno *aPg;
    int nPg;

    /* Seek from the root of the b-tree to the segment leaf that may contain
    ** a key equal to the one multi-cursor currently points to. Record the
    ** page number of each b-tree page and the leaf. The segment may be
    ** gobbled up to (but not including) the first of these page numbers.
    */
    assert( pSeg->iRoot>0 );
    aPg = lsmMallocZeroRc(pDb->pEnv, sizeof(LsmPgno)*32, &rc);
    if( rc==LSM_OK ){
      rc = seekInBtree(pCsr, pSeg, 
          rtTopic(pCsr->eType), pCsr->key.pData, pCsr->key.nData, aPg, 0
      ); 
    }

    if( rc==LSM_OK ){
................................................................................
/*
** Return a string representation of the segment passed as the only argument.
** Space for the returned string is allocated using lsmMalloc(), and should
** be freed by the caller using lsmFree().
*/
static char *segToString(lsm_env *pEnv, Segment *pSeg, int nMin){
  int nSize = pSeg->nSize;
  LsmPgno iRoot = pSeg->iRoot;
  LsmPgno iFirst = pSeg->iFirst;
  LsmPgno iLast = pSeg->iLastPg;
  char *z;

  char *z1;
  char *z2;
  int nPad;

  z1 = lsmMallocPrintf(pEnv, "%d.%d", iFirst, iLast);
................................................................................
    aBuf[0] = '\0';
  }

  return i;
}

void sortedDumpPage(lsm_db *pDb, Segment *pRun, Page *pPg, int bVals){
  LsmBlob blob = {0, 0, 0};       /* LsmBlob used for keys */
  LsmString s;
  int i;

  int nRec;
  int iPtr;
  int flags;
  u8 *aData;
................................................................................

    aCell = pageGetCell(aData, nData, i);
    eType = *aCell++;
    assert( (flags & SEGMENT_BTREE_FLAG) || eType!=0 );
    aCell += lsmVarintGet32(aCell, &iPgPtr);

    if( eType==0 ){
      LsmPgno iRef;               /* Page number of referenced page */
      aCell += lsmVarintGet64(aCell, &iRef);
      lsmFsDbPageGet(pDb->pFS, pRun, iRef, &pRef);
      aKey = pageGetKey(pRun, pRef, 0, &iTopic, &nKey, &blob);
    }else{
      aCell += lsmVarintGet32(aCell, &nKey);
      if( rtIsWrite(eType) ) aCell += lsmVarintGet32(aCell, &nVal);
      sortedReadData(0, pPg, (aCell-aData), nKey+nVal, (void **)&aKey, &blob);
................................................................................
  int bIndirect,                  /* True to follow indirect refs */
  Page *pPg,
  int iCell,
  int *peType,
  int *piPgPtr,
  u8 **paKey, int *pnKey,
  u8 **paVal, int *pnVal,
  LsmBlob *pBlob
){
  u8 *aData; int nData;           /* Page data */
  u8 *aKey; int nKey = 0;         /* Key */
  u8 *aVal = 0; int nVal = 0;     /* Value */
  int eType;
  int iPgPtr;
  Page *pRef = 0;                 /* Pointer to page iRef */
................................................................................

  aCell = pageGetCell(aData, nData, iCell);
  eType = *aCell++;
  aCell += lsmVarintGet32(aCell, &iPgPtr);

  if( eType==0 ){
    int dummy;
    LsmPgno iRef;                 /* Page number of referenced page */
    aCell += lsmVarintGet64(aCell, &iRef);
    if( bIndirect ){
      lsmFsDbPageGet(pDb->pFS, pSeg, iRef, &pRef);
      pageGetKeyCopy(pDb->pEnv, pSeg, pRef, 0, &dummy, pBlob);
      aKey = (u8 *)pBlob->pData;
      nKey = pBlob->nData;
      lsmFsPageRelease(pRef);
................................................................................
#define INFO_PAGE_DUMP_DATA     0x01
#define INFO_PAGE_DUMP_VALUES   0x02
#define INFO_PAGE_DUMP_HEX      0x04
#define INFO_PAGE_DUMP_INDIRECT 0x08

static int infoPageDump(
  lsm_db *pDb,                    /* Database handle */
  LsmPgno iPg,                    /* Page number of page to dump */
  int flags,
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int rc = LSM_OK;                /* Return code */
  Page *pPg = 0;                  /* Handle for page iPg */
  int i, j;                       /* Loop counters */
  const int perLine = 16;         /* Bytes per line in the raw hex dump */
................................................................................
  ** to pass a NULL in place of the segment pointer as the second argument
  ** to lsmFsDbPageGet() here.  */
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, 0, iPg, &pPg);
  }

  if( rc==LSM_OK ){
    LsmBlob blob = {0, 0, 0, 0};
    int nKeyWidth = 0;
    LsmString str;
    int nRec;
    int iPtr;
    int flags2;
    int iCell;
    u8 *aData; int nData;         /* Page data and size thereof */
................................................................................
    if( bHex ) nKeyWidth = nKeyWidth * 2;

    for(iCell=0; iCell<nRec; iCell++){
      u8 *aKey; int nKey = 0;       /* Key */
      u8 *aVal; int nVal = 0;       /* Value */
      int iPgPtr;
      int eType;
      LsmPgno iAbsPtr;
      char zFlags[8];

      infoCellDump(pDb, pSeg, bIndirect, pPg, iCell, &eType, &iPgPtr,
          &aKey, &nKey, &aVal, &nVal, &blob
      );
      iAbsPtr = iPgPtr + ((flags2 & SEGMENT_BTREE_FLAG) ? 0 : iPtr);

................................................................................
  }

  return rc;
}

int lsmInfoPageDump(
  lsm_db *pDb,                    /* Database handle */
  LsmPgno iPg,                    /* Page number of page to dump */
  int bHex,                       /* True to output key/value in hex form */
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int flags = INFO_PAGE_DUMP_DATA | INFO_PAGE_DUMP_VALUES;
  if( bHex ) flags |= INFO_PAGE_DUMP_HEX;
  return infoPageDump(pDb, iPg, flags, pzOut);
}
................................................................................
  iHdr = SEGMENT_EOF(nOrig, nEntry);
  memmove(&aData[iHdr + (nData-nOrig)], &aData[iHdr], nOrig-iHdr);
}

#ifdef LSM_DEBUG_EXPENSIVE
static void assertRunInOrder(lsm_db *pDb, Segment *pSeg){
  Page *pPg = 0;
  LsmBlob blob1 = {0, 0, 0, 0};
  LsmBlob blob2 = {0, 0, 0, 0};

  lsmFsDbPageGet(pDb->pFS, pSeg, pSeg->iFirst, &pPg);
  while( pPg ){
    u8 *aData; int nData;
    Page *pNext;

    aData = lsmFsPageData(pPg, &nData);
................................................................................
  Segment *pOne,                  /* Segment containing pointers */
  Segment *pTwo,                  /* Segment containing pointer targets */
  int bRhs                        /* True if pTwo may have been Gobble()d */
){
  int rc = LSM_OK;                /* Error code */
  SegmentPtr ptr1;                /* Iterates through pOne */
  SegmentPtr ptr2;                /* Iterates through pTwo */
  LsmPgno iPrev;

  assert( pOne && pTwo );

  memset(&ptr1, 0, sizeof(ptr1));
  memset(&ptr2, 0, sizeof(ptr1));
  ptr1.pSeg = pOne;
  ptr2.pSeg = pTwo;
................................................................................
  }

  if( rc==LSM_OK && ptr1.nCell>0 ){
    rc = segmentPtrLoadCell(&ptr1, 0);
  }
      
  while( rc==LSM_OK && ptr2.pPg ){
    LsmPgno iThis;

    /* Advance to the next page of segment pTwo that contains at least
    ** one cell. Break out of the loop if the iterator reaches EOF.  */
    do{
      rc = segmentPtrNextPage(&ptr2, 1);
      assert( rc==LSM_OK );
    }while( rc==LSM_OK && ptr2.pPg && ptr2.nCell==0 );
................................................................................
*/
static int assertBtreeOk(
  lsm_db *pDb,
  Segment *pSeg
){
  int rc = LSM_OK;                /* Return code */
  if( pSeg->iRoot ){
    LsmBlob blob = {0, 0, 0};     /* Buffer used to cache overflow keys */
    FileSystem *pFS = pDb->pFS;   /* File system to read from */
    Page *pPg = 0;                /* Main run page */
    BtreeCursor *pCsr = 0;        /* Btree cursor */

    rc = btreeCursorNew(pDb, pSeg, &pCsr);
    if( rc==LSM_OK ){
      rc = btreeCursorFirst(pCsr);

#!/bin/sh
# restart with tclsh \
exec tclsh "$0" "$@"

set srcdir [file dirname [file dirname [info script]]]
set G(src) [string map [list %dir% $srcdir] {
  %dir%/lsm.h
  %dir%/lsmInt.h
  %dir%/lsm_vtab.c
  %dir%/lsm_ckpt.c
  %dir%/lsm_file.c
  %dir%/lsm_log.c
  %dir%/lsm_main.c
  %dir%/lsm_mem.c
  %dir%/lsm_mutex.c
  %dir%/lsm_shared.c
  %dir%/lsm_sorted.c
  %dir%/lsm_str.c
  %dir%/lsm_tree.c
  %dir%/lsm_unix.c
  %dir%/lsm_varint.c
  %dir%/lsm_win32.c
}]

set G(hdr) {

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_LSM1) 

#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
# define NDEBUG 1
#endif
#if defined(NDEBUG) && defined(SQLITE_DEBUG)
# undef NDEBUG
#endif

}

set G(footer) {
    
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_LSM1) */
}

#-------------------------------------------------------------------------
# Read and return the entire contents of text file $zFile from disk.
#
proc readfile {zFile} {
  set fd [open $zFile]
  set data [read $fd]
  close $fd
  return $data
}

proc lsm1c_init {zOut} {
  global G
  set G(fd) stdout
  set G(fd) [open $zOut w]

  puts -nonewline $G(fd) $G(hdr)
}

proc lsm1c_printfile {zIn} {
  global G
  set data [readfile $zIn]
  set zTail [file tail $zIn]
  puts $G(fd) "#line 1 \"$zTail\""

  foreach line [split $data "\n"] {
    if {[regexp {^# *include.*lsm} $line]} {
      set line "/* $line */"
    } elseif { [regexp {^(const )?[a-zA-Z][a-zA-Z0-9]* [*]?lsm[^_]} $line] } {
      set line "static $line"
    }
    puts $G(fd) $line
  }
}

proc lsm1c_close {} {
  global G
  puts -nonewline $G(fd) $G(footer)
  if {$G(fd)!="stdout"} {
    close $G(fd)
  }
}


lsm1c_init lsm1.c
foreach f $G(src) { lsm1c_printfile $f }
lsm1c_close

  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const unsigned char *zIn;
  int nIn;
  unsigned char *zOut;
  char *zToFree = 0;
  int i;
  char zTemp[100];
  assert( argc==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  zIn = (const unsigned char*)sqlite3_value_text(argv[0]);
  nIn = sqlite3_value_bytes(argv[0]);
  if( nIn<sizeof(zTemp)-1 ){
    zOut = zTemp;
  }else{
    zOut = zToFree = sqlite3_malloc( nIn+1 );
    if( zOut==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  for(i=0; i<nIn; i++) zOut[i] = rot13(zIn[i]);
  zOut[i] = 0;

  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const unsigned char *zIn;
  int nIn;
  unsigned char *zOut;
  unsigned char *zToFree = 0;
  int i;
  unsigned char zTemp[100];
  assert( argc==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  zIn = (const unsigned char*)sqlite3_value_text(argv[0]);
  nIn = sqlite3_value_bytes(argv[0]);
  if( nIn<sizeof(zTemp)-1 ){
    zOut = zTemp;
  }else{
    zOut = zToFree = (unsigned char*)sqlite3_malloc64( nIn+1 );
    if( zOut==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  for(i=0; i<nIn; i++) zOut[i] = rot13(zIn[i]);
  zOut[i] = 0;

**     3. The smallest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
**     4. The largest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
** SWARMVTAB


**
**   A "swarmvtab" virtual table is created similarly to a unionvtab table:
**
**     CREATE VIRTUAL TABLE <name>
**      USING swarmvtab(<sql-statement>, <callback>);
**
**   The difference is that for a swarmvtab table, the first column returned
**   by the <sql statement> must return a path or URI that can be used to open
**   the database file containing the source table.  The <callback> option
**   is optional.  If included, it is the name of an application-defined
**   SQL function that is invoked with the URI of the file, if the file
**   does not already exist on disk.
































































*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>


#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Largest and smallest possible 64-bit signed integers. These macros
** copied from sqliteInt.h.
*/
................................................................................
  char *zDb;                      /* Database containing source table */
  char *zTab;                     /* Source table name */
  sqlite3_int64 iMin;             /* Minimum rowid */
  sqlite3_int64 iMax;             /* Maximum rowid */

  /* Fields used by swarmvtab only */
  char *zFile;                    /* Database file containing table zTab */

  int nUser;                      /* Current number of users */
  sqlite3 *db;                    /* Database handle */
  UnionSrc *pNextClosable;        /* Next in list of closable sources */
};

/*
** Virtual table  type for union vtab.
................................................................................
  sqlite3 *db;                    /* Database handle */
  int bSwarm;                     /* 1 for "swarmvtab", 0 for "unionvtab" */
  int iPK;                        /* INTEGER PRIMARY KEY column, or -1 */
  int nSrc;                       /* Number of elements in the aSrc[] array */
  UnionSrc *aSrc;                 /* Array of source tables, sorted by rowid */

  /* Used by swarmvtab only */

  char *zSourceStr;               /* Expected unionSourceToStr() value */
  char *zNotFoundCallback;        /* UDF to invoke if file not found on open */


  UnionSrc *pClosable;            /* First in list of closable sources */
  int nOpen;                      /* Current number of open sources */
  int nMaxOpen;                   /* Maximum number of open sources */
};

/*
** Virtual table cursor type for union vtab.
................................................................................
  if( *pRc==SQLITE_OK ){
    *pRc = rc;
    if( rc ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
    }
  }
}


































/*
** This function is a no-op for unionvtab. For swarmvtab, it attempts to
** close open database files until at most nMax are open. An SQLite error
** code is returned if an error occurs, or SQLITE_OK otherwise.
*/
static void unionCloseSources(UnionTab *pTab, int nMax){
  while( pTab->pClosable && pTab->nOpen>nMax ){

    UnionSrc **pp;
    for(pp=&pTab->pClosable; (*pp)->pNextClosable; pp=&(*pp)->pNextClosable);

    assert( (*pp)->db );
    sqlite3_close((*pp)->db);
    (*pp)->db = 0;
    *pp = 0;
    pTab->nOpen--;

  }
}

/*
** xDisconnect method.
*/
static int unionDisconnect(sqlite3_vtab *pVtab){
  if( pVtab ){
    UnionTab *pTab = (UnionTab*)pVtab;
    int i;
    for(i=0; i<pTab->nSrc; i++){
      UnionSrc *pSrc = &pTab->aSrc[i];



      sqlite3_free(pSrc->zDb);
      sqlite3_free(pSrc->zTab);
      sqlite3_free(pSrc->zFile);

      sqlite3_close(pSrc->db);
    }


    sqlite3_free(pTab->zSourceStr);
    sqlite3_free(pTab->zNotFoundCallback);
    sqlite3_free(pTab->aSrc);
    sqlite3_free(pTab);
  }
  return SQLITE_OK;
}

/*
................................................................................
    sqlite3_free(z);
  }
  sqlite3_free(z0);

  return rc;
}


/*
** Try to open the swarmvtab database.  If initially unable, invoke the
** not-found callback UDF and then try again.
*/
static int unionOpenDatabaseInner(UnionTab *pTab, UnionSrc *pSrc, char **pzErr){
  int rc = SQLITE_OK;
  static const int openFlags = 
       SQLITE_OPEN_READONLY | SQLITE_OPEN_URI;





  rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  if( rc==SQLITE_OK ) return rc;
  if( pTab->zNotFoundCallback ){
    char *zSql = sqlite3_mprintf("SELECT \"%w\"(%Q);",
                    pTab->zNotFoundCallback, pSrc->zFile);
    sqlite3_close(pSrc->db);
    pSrc->db = 0;
    if( zSql==0 ){
      *pzErr = sqlite3_mprintf("out of memory");
      return SQLITE_NOMEM;

    }
    rc = sqlite3_exec(pTab->db, zSql, 0, 0, pzErr);
    sqlite3_free(zSql);


    if( rc ) return rc;

    rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  }
  if( rc!=SQLITE_OK ){
    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pSrc->db));
  }
  return rc;
}
................................................................................
    if( rc==SQLITE_OK ){
      pSrc->pNextClosable = pTab->pClosable;
      pTab->pClosable = pSrc;
      pTab->nOpen++;
    }else{
      sqlite3_close(pSrc->db);
      pSrc->db = 0;

    }
  }

  return rc;
}


................................................................................
        pTab->pClosable = pSrc;
      }
      unionCloseSources(pTab, pTab->nMaxOpen);
    }
  }
  return rc;
}































































































































/* 
** xConnect/xCreate method.
**
** The argv[] array contains the following:
**
**   argv[0]   -> module name  ("unionvtab" or "swarmvtab")
................................................................................
  int bSwarm = (pAux==0 ? 0 : 1);
  const char *zVtab = (bSwarm ? "swarmvtab" : "unionvtab");

  if( sqlite3_stricmp("temp", argv[1]) ){
    /* unionvtab tables may only be created in the temp schema */
    *pzErr = sqlite3_mprintf("%s tables must be created in TEMP schema", zVtab);
    rc = SQLITE_ERROR;
  }else if( argc!=4 && argc!=5 ){
    *pzErr = sqlite3_mprintf("wrong number of arguments for %s", zVtab);
    rc = SQLITE_ERROR;
  }else{
    int nAlloc = 0;               /* Allocated size of pTab->aSrc[] */
    sqlite3_stmt *pStmt = 0;      /* Argument statement */
    char *zArg = unionStrdup(&rc, argv[3]);      /* Copy of argument to CVT */

................................................................................
    unionDequote(zArg);
    pStmt = unionPreparePrintf(&rc, pzErr, db, 
        "SELECT * FROM (%z) ORDER BY 3", zArg
    );

    /* Allocate the UnionTab structure */
    pTab = unionMalloc(&rc, sizeof(UnionTab));












    /* Iterate through the rows returned by the SQL statement specified
    ** as an argument to the CREATE VIRTUAL TABLE statement. */
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zDb = (const char*)sqlite3_column_text(pStmt, 0);
      const char *zTab = (const char*)sqlite3_column_text(pStmt, 1);
      sqlite3_int64 iMin = sqlite3_column_int64(pStmt, 2);
................................................................................
        pSrc->iMin = iMin;
        pSrc->iMax = iMax;
        if( bSwarm ){
          pSrc->zFile = unionStrdup(&rc, zDb);
        }else{
          pSrc->zDb = unionStrdup(&rc, zDb);
        }




      }
    }
    unionFinalize(&rc, pStmt, pzErr);
    pStmt = 0;

    /* Capture the not-found callback UDF name */
    if( rc==SQLITE_OK && argc>=5 ){
      pTab->zNotFoundCallback = unionStrdup(&rc, argv[4]);
      unionDequote(pTab->zNotFoundCallback);
    }

    /* It is an error if the SELECT statement returned zero rows. If only
    ** because there is no way to determine the schema of the virtual 
    ** table in this case.  */
    if( rc==SQLITE_OK && pTab->nSrc==0 ){
      *pzErr = sqlite3_mprintf("no source tables configured");
      rc = SQLITE_ERROR;
    }

    /* For unionvtab, verify that all source tables exist and have 
    ** compatible schemas. For swarmvtab, attach the first database and
    ** check that the first table is a rowid table only.  */
    if( rc==SQLITE_OK ){
      pTab->db = db;
      pTab->bSwarm = bSwarm;
      pTab->nMaxOpen = SWARMVTAB_MAX_OPEN;
      if( bSwarm ){
        rc = unionOpenDatabase(pTab, 0, pzErr);
      }else{
        rc = unionSourceCheck(pTab, pzErr);
      }
    }

**     3. The smallest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
**     4. The largest rowid in the range of rowids that may be stored in the
**        database table (an integer).
**
** SWARMVTAB
**
**  LEGACY SYNTAX:
**
**   A "swarmvtab" virtual table is created similarly to a unionvtab table:
**
**     CREATE VIRTUAL TABLE <name>
**      USING swarmvtab(<sql-statement>, <callback>);
**
**   The difference is that for a swarmvtab table, the first column returned
**   by the <sql statement> must return a path or URI that can be used to open
**   the database file containing the source table.  The <callback> option
**   is optional.  If included, it is the name of an application-defined
**   SQL function that is invoked with the URI of the file, if the file
**   does not already exist on disk when required by swarmvtab.
**
**  NEW SYNTAX:
**
**   Using the new syntax, a swarmvtab table is created with:
**
**      CREATE VIRTUAL TABLE <name> USING swarmvtab(
**        <sql-statement> [, <options>]
**      );
**
**   where valid <options> are:
**
**      missing=<udf-function-name>
**      openclose=<udf-function-name>
**      maxopen=<integer>
**      <sql-parameter>=<text-value>
**
**   The <sql-statement> must return the same 4 columns as for a swarmvtab
**   table in legacy mode. However, it may also return a 5th column - the
**   "context" column. The text value returned in this column is not used
**   at all by the swarmvtab implementation, except that it is passed as
**   an additional argument to the two UDF functions that may be invoked
**   (see below).
**
**   The "missing" option, if present, specifies the name of an SQL UDF
**   function to be invoked if a database file is not already present on
**   disk when required by swarmvtab. If the <sql-statement> did not provide
**   a context column, it is invoked as:
**
**     SELECT <missing-udf>(<database filename/uri>);
**
**   Or, if there was a context column:
**
**     SELECT <missing-udf>(<database filename/uri>, <context>);
**
**   The "openclose" option may also specify a UDF function. This function
**   is invoked right before swarmvtab opens a database, and right after
**   it closes one. The first argument - or first two arguments, if
**   <sql-statement> supplied the context column - is the same as for
**   the "missing" UDF. Following this, the UDF is passed integer value
**   0 before a db is opened, and 1 right after it is closed. If both
**   a missing and openclose UDF is supplied, the application should expect
**   the following sequence of calls (for a single database):
**
**      SELECT <openclose-udf>(<db filename>, <context>, 0);
**      if( db not already on disk ){
**          SELECT <missing-udf>(<db filename>, <context>);
**      }
**      ... swarmvtab uses database ...
**      SELECT <openclose-udf>(<db filename>, <context>, 1);
**
**   The "maxopen" option is used to configure the maximum number of
**   database files swarmvtab will hold open simultaneously (default 9).
**
**   If an option name begins with a ":" character, then it is assumed
**   to be an SQL parameter. In this case, the specified text value is
**   bound to the same variable of the <sql-statement> before it is 
**   executed. It is an error of the named SQL parameter does not exist.
**   For example:
**
**     CREATE VIRTUAL TABLE swarm USING swarmvtab(
**       'SELECT :path || localfile, tbl, min, max FROM swarmdir',
**       :path='/home/user/databases/'
**       missing='missing_func'
**     );
*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <stdlib.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Largest and smallest possible 64-bit signed integers. These macros
** copied from sqliteInt.h.
*/
................................................................................
  char *zDb;                      /* Database containing source table */
  char *zTab;                     /* Source table name */
  sqlite3_int64 iMin;             /* Minimum rowid */
  sqlite3_int64 iMax;             /* Maximum rowid */

  /* Fields used by swarmvtab only */
  char *zFile;                    /* Database file containing table zTab */
  char *zContext;                 /* Context string, if any */
  int nUser;                      /* Current number of users */
  sqlite3 *db;                    /* Database handle */
  UnionSrc *pNextClosable;        /* Next in list of closable sources */
};

/*
** Virtual table  type for union vtab.
................................................................................
  sqlite3 *db;                    /* Database handle */
  int bSwarm;                     /* 1 for "swarmvtab", 0 for "unionvtab" */
  int iPK;                        /* INTEGER PRIMARY KEY column, or -1 */
  int nSrc;                       /* Number of elements in the aSrc[] array */
  UnionSrc *aSrc;                 /* Array of source tables, sorted by rowid */

  /* Used by swarmvtab only */
  int bHasContext;                /* Has context strings */
  char *zSourceStr;               /* Expected unionSourceToStr() value */
  sqlite3_stmt *pNotFound;        /* UDF to invoke if file not found on open */
  sqlite3_stmt *pOpenClose;       /* UDF to invoke on open and close */

  UnionSrc *pClosable;            /* First in list of closable sources */
  int nOpen;                      /* Current number of open sources */
  int nMaxOpen;                   /* Maximum number of open sources */
};

/*
** Virtual table cursor type for union vtab.
................................................................................
  if( *pRc==SQLITE_OK ){
    *pRc = rc;
    if( rc ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
    }
  }
}

/*
** If an "openclose" UDF was supplied when this virtual table was created,
** invoke it now. The first argument passed is the name of the database
** file for source pSrc. The second is integer value bClose.
**
** If successful, return SQLITE_OK. Otherwise an SQLite error code. In this
** case if argument pzErr is not NULL, also set (*pzErr) to an English
** language error message. The caller is responsible for eventually freeing 
** any error message using sqlite3_free().
*/
static int unionInvokeOpenClose(
  UnionTab *pTab, 
  UnionSrc *pSrc, 
  int bClose,
  char **pzErr
){
  int rc = SQLITE_OK;
  if( pTab->pOpenClose ){
    sqlite3_bind_text(pTab->pOpenClose, 1, pSrc->zFile, -1, SQLITE_STATIC);
    if( pTab->bHasContext ){
      sqlite3_bind_text(pTab->pOpenClose, 2, pSrc->zContext, -1, SQLITE_STATIC);
    }
    sqlite3_bind_int(pTab->pOpenClose, 2+pTab->bHasContext, bClose);
    sqlite3_step(pTab->pOpenClose);
    if( SQLITE_OK!=(rc = sqlite3_reset(pTab->pOpenClose)) ){
      if( pzErr ){
        *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
      }
    }
  }
  return rc;
}

/*
** This function is a no-op for unionvtab. For swarmvtab, it attempts to
** close open database files until at most nMax are open. An SQLite error
** code is returned if an error occurs, or SQLITE_OK otherwise.
*/
static void unionCloseSources(UnionTab *pTab, int nMax){
  while( pTab->pClosable && pTab->nOpen>nMax ){
    UnionSrc *p;
    UnionSrc **pp;
    for(pp=&pTab->pClosable; (*pp)->pNextClosable; pp=&(*pp)->pNextClosable);
    p = *pp;
    assert( p->db );
    sqlite3_close(p->db);
    p->db = 0;
    *pp = 0;
    pTab->nOpen--;
    unionInvokeOpenClose(pTab, p, 1, 0);
  }
}

/*
** xDisconnect method.
*/
static int unionDisconnect(sqlite3_vtab *pVtab){
  if( pVtab ){
    UnionTab *pTab = (UnionTab*)pVtab;
    int i;
    for(i=0; i<pTab->nSrc; i++){
      UnionSrc *pSrc = &pTab->aSrc[i];
      if( pSrc->db ){
        unionInvokeOpenClose(pTab, pSrc, 1, 0);
      }
      sqlite3_free(pSrc->zDb);
      sqlite3_free(pSrc->zTab);
      sqlite3_free(pSrc->zFile);
      sqlite3_free(pSrc->zContext);
      sqlite3_close(pSrc->db);
    }
    sqlite3_finalize(pTab->pNotFound);
    sqlite3_finalize(pTab->pOpenClose);
    sqlite3_free(pTab->zSourceStr);

    sqlite3_free(pTab->aSrc);
    sqlite3_free(pTab);
  }
  return SQLITE_OK;
}

/*
................................................................................
    sqlite3_free(z);
  }
  sqlite3_free(z0);

  return rc;
}


/*
** Try to open the swarmvtab database.  If initially unable, invoke the
** not-found callback UDF and then try again.
*/
static int unionOpenDatabaseInner(UnionTab *pTab, UnionSrc *pSrc, char **pzErr){


  static const int openFlags = SQLITE_OPEN_READONLY | SQLITE_OPEN_URI;
  int rc;

  rc = unionInvokeOpenClose(pTab, pSrc, 0, pzErr);
  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  if( rc==SQLITE_OK ) return rc;
  if( pTab->pNotFound ){


    sqlite3_close(pSrc->db);
    pSrc->db = 0;

    sqlite3_bind_text(pTab->pNotFound, 1, pSrc->zFile, -1, SQLITE_STATIC);
    if( pTab->bHasContext ){
      sqlite3_bind_text(pTab->pNotFound, 2, pSrc->zContext, -1, SQLITE_STATIC);
    }

    sqlite3_step(pTab->pNotFound);
    if( SQLITE_OK!=(rc = sqlite3_reset(pTab->pNotFound)) ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
      return rc;
    }
    rc = sqlite3_open_v2(pSrc->zFile, &pSrc->db, openFlags, 0);
  }
  if( rc!=SQLITE_OK ){
    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pSrc->db));
  }
  return rc;
}
................................................................................
    if( rc==SQLITE_OK ){
      pSrc->pNextClosable = pTab->pClosable;
      pTab->pClosable = pSrc;
      pTab->nOpen++;
    }else{
      sqlite3_close(pSrc->db);
      pSrc->db = 0;
      unionInvokeOpenClose(pTab, pSrc, 1, 0);
    }
  }

  return rc;
}


................................................................................
        pTab->pClosable = pSrc;
      }
      unionCloseSources(pTab, pTab->nMaxOpen);
    }
  }
  return rc;
}

/* 
** Return true if the argument is a space, tab, CR or LF character.
*/
static int union_isspace(char c){
  return (c==' ' || c=='\n' || c=='\r' || c=='\t');
}

/* 
** Return true if the argument is an alphanumeric character in the 
** ASCII range.
*/
static int union_isidchar(char c){
  return ((c>='a' && c<='z') || (c>='A' && c<'Z') || (c>='0' && c<='9'));
}

/*
** This function is called to handle all arguments following the first 
** (the SQL statement) passed to a swarmvtab (not unionvtab) CREATE 
** VIRTUAL TABLE statement. It may bind parameters to the SQL statement 
** or configure members of the UnionTab object passed as the second
** argument.
**
** Refer to header comments at the top of this file for a description
** of the arguments parsed.
**
** This function is a no-op if *pRc is other than SQLITE_OK when it is
** called. Otherwise, if an error occurs, *pRc is set to an SQLite error
** code. In this case *pzErr may be set to point to a buffer containing
** an English language error message. It is the responsibility of the 
** caller to eventually free the buffer using sqlite3_free().
*/
static void unionConfigureVtab(
  int *pRc,                       /* IN/OUT: Error code */
  UnionTab *pTab,                 /* Table to configure */
  sqlite3_stmt *pStmt,            /* SQL statement to find sources */
  int nArg,                       /* Number of entries in azArg[] array */
  const char * const *azArg,      /* Array of arguments to consider */
  char **pzErr                    /* OUT: Error message */
){
  int rc = *pRc;
  int i;
  if( rc==SQLITE_OK ){
    pTab->bHasContext = (sqlite3_column_count(pStmt)>4);
  }
  for(i=0; rc==SQLITE_OK && i<nArg; i++){
    char *zArg = unionStrdup(&rc, azArg[i]);
    if( zArg ){
      int nOpt = 0;               /* Size of option name in bytes */
      char *zOpt;                 /* Pointer to option name */
      char *zVal;                 /* Pointer to value */

      unionDequote(zArg);
      zOpt = zArg;
      while( union_isspace(*zOpt) ) zOpt++;
      zVal = zOpt;
      if( *zVal==':' ) zVal++;
      while( union_isidchar(*zVal) ) zVal++;
      nOpt = zVal-zOpt;

      while( union_isspace(*zVal) ) zVal++;
      if( *zVal=='=' ){
        zOpt[nOpt] = '\0';
        zVal++;
        while( union_isspace(*zVal) ) zVal++;
        zVal = unionStrdup(&rc, zVal);
        if( zVal ){
          unionDequote(zVal);
          if( zOpt[0]==':' ){
            /* A value to bind to the SQL statement */
            int iParam = sqlite3_bind_parameter_index(pStmt, zOpt);
            if( iParam==0 ){
              *pzErr = sqlite3_mprintf(
                  "swarmvtab: no such SQL parameter: %s", zOpt
              );
              rc = SQLITE_ERROR;
            }else{
              rc = sqlite3_bind_text(pStmt, iParam, zVal, -1, SQLITE_TRANSIENT);
            }
          }else if( nOpt==7 && 0==sqlite3_strnicmp(zOpt, "maxopen", 7) ){
            pTab->nMaxOpen = atoi(zVal);
            if( pTab->nMaxOpen<=0 ){
              *pzErr = sqlite3_mprintf("swarmvtab: illegal maxopen value");
              rc = SQLITE_ERROR;
            }
          }else if( nOpt==7 && 0==sqlite3_strnicmp(zOpt, "missing", 7) ){
            if( pTab->pNotFound ){
              *pzErr = sqlite3_mprintf(
                  "swarmvtab: duplicate \"missing\" option");
              rc = SQLITE_ERROR;
            }else{
              pTab->pNotFound = unionPreparePrintf(&rc, pzErr, pTab->db,
                  "SELECT \"%w\"(?%s)", zVal, pTab->bHasContext ? ",?" : ""
              );
            }
          }else if( nOpt==9 && 0==sqlite3_strnicmp(zOpt, "openclose", 9) ){
            if( pTab->pOpenClose ){
              *pzErr = sqlite3_mprintf(
                  "swarmvtab: duplicate \"openclose\" option");
              rc = SQLITE_ERROR;
            }else{
              pTab->pOpenClose = unionPreparePrintf(&rc, pzErr, pTab->db,
                  "SELECT \"%w\"(?,?%s)", zVal, pTab->bHasContext ? ",?" : ""
              );
            }
          }else{
            *pzErr = sqlite3_mprintf("swarmvtab: unrecognized option: %s",zOpt);
            rc = SQLITE_ERROR;
          }
          sqlite3_free(zVal);
        }
      }else{
        if( i==0 && nArg==1 ){
          pTab->pNotFound = unionPreparePrintf(&rc, pzErr, pTab->db,
              "SELECT \"%w\"(?)", zArg
          );
        }else{
          *pzErr = sqlite3_mprintf( "swarmvtab: parse error: %s", azArg[i]);
          rc = SQLITE_ERROR;
        }
      }
      sqlite3_free(zArg);
    }
  }
  *pRc = rc;
}

/* 
** xConnect/xCreate method.
**
** The argv[] array contains the following:
**
**   argv[0]   -> module name  ("unionvtab" or "swarmvtab")
................................................................................
  int bSwarm = (pAux==0 ? 0 : 1);
  const char *zVtab = (bSwarm ? "swarmvtab" : "unionvtab");

  if( sqlite3_stricmp("temp", argv[1]) ){
    /* unionvtab tables may only be created in the temp schema */
    *pzErr = sqlite3_mprintf("%s tables must be created in TEMP schema", zVtab);
    rc = SQLITE_ERROR;
  }else if( argc<4 || (argc>4 && bSwarm==0) ){
    *pzErr = sqlite3_mprintf("wrong number of arguments for %s", zVtab);
    rc = SQLITE_ERROR;
  }else{
    int nAlloc = 0;               /* Allocated size of pTab->aSrc[] */
    sqlite3_stmt *pStmt = 0;      /* Argument statement */
    char *zArg = unionStrdup(&rc, argv[3]);      /* Copy of argument to CVT */

................................................................................
    unionDequote(zArg);
    pStmt = unionPreparePrintf(&rc, pzErr, db, 
        "SELECT * FROM (%z) ORDER BY 3", zArg
    );

    /* Allocate the UnionTab structure */
    pTab = unionMalloc(&rc, sizeof(UnionTab));
    if( pTab ){
      assert( rc==SQLITE_OK );
      pTab->db = db;
      pTab->bSwarm = bSwarm;
      pTab->nMaxOpen = SWARMVTAB_MAX_OPEN;
    }

    /* Parse other CVT arguments, if any */
    if( bSwarm ){
      unionConfigureVtab(&rc, pTab, pStmt, argc-4, &argv[4], pzErr);
    }

    /* Iterate through the rows returned by the SQL statement specified
    ** as an argument to the CREATE VIRTUAL TABLE statement. */
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zDb = (const char*)sqlite3_column_text(pStmt, 0);
      const char *zTab = (const char*)sqlite3_column_text(pStmt, 1);
      sqlite3_int64 iMin = sqlite3_column_int64(pStmt, 2);
................................................................................
        pSrc->iMin = iMin;
        pSrc->iMax = iMax;
        if( bSwarm ){
          pSrc->zFile = unionStrdup(&rc, zDb);
        }else{
          pSrc->zDb = unionStrdup(&rc, zDb);
        }
        if( pTab->bHasContext ){
          const char *zContext = (const char*)sqlite3_column_text(pStmt, 4);
          pSrc->zContext = unionStrdup(&rc, zContext);
        }
      }
    }
    unionFinalize(&rc, pStmt, pzErr);
    pStmt = 0;







    /* It is an error if the SELECT statement returned zero rows. If only
    ** because there is no way to determine the schema of the virtual 
    ** table in this case.  */
    if( rc==SQLITE_OK && pTab->nSrc==0 ){
      *pzErr = sqlite3_mprintf("no source tables configured");
      rc = SQLITE_ERROR;
    }

    /* For unionvtab, verify that all source tables exist and have 
    ** compatible schemas. For swarmvtab, attach the first database and
    ** check that the first table is a rowid table only.  */
    if( rc==SQLITE_OK ){



      if( bSwarm ){
        rc = unionOpenDatabase(pTab, 0, pzErr);
      }else{
        rc = unionSourceCheck(pTab, pzErr);
      }
    }

  Rtree *pRtree,               /* Rtree table */
  RtreeCell *pCell,            /* Cell to insert into rtree */
  int iHeight,                 /* Height of sub-tree rooted at pCell */
  RtreeNode **ppLeaf           /* OUT: Selected leaf page */
){
  int rc;
  int ii;
  RtreeNode *pNode;
  rc = nodeAcquire(pRtree, 1, 0, &pNode);

  for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){
    int iCell;
    sqlite3_int64 iBest = 0;

    RtreeDValue fMinGrowth = RTREE_ZERO;
................................................................................
  **
  ** This is equivalent to copying the contents of the child into
  ** the root node (the operation that Gutman's paper says to perform 
  ** in this scenario).
  */
  if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){
    int rc2;
    RtreeNode *pChild;
    i64 iChild = nodeGetRowid(pRtree, pRoot, 0);
    rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);
    if( rc==SQLITE_OK ){
      rc = removeNode(pRtree, pChild, pRtree->iDepth-1);
    }
    rc2 = nodeRelease(pRtree, pChild);
    if( rc==SQLITE_OK ) rc = rc2;

  Rtree *pRtree,               /* Rtree table */
  RtreeCell *pCell,            /* Cell to insert into rtree */
  int iHeight,                 /* Height of sub-tree rooted at pCell */
  RtreeNode **ppLeaf           /* OUT: Selected leaf page */
){
  int rc;
  int ii;
  RtreeNode *pNode = 0;
  rc = nodeAcquire(pRtree, 1, 0, &pNode);

  for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){
    int iCell;
    sqlite3_int64 iBest = 0;

    RtreeDValue fMinGrowth = RTREE_ZERO;
................................................................................
  **
  ** This is equivalent to copying the contents of the child into
  ** the root node (the operation that Gutman's paper says to perform 
  ** in this scenario).
  */
  if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){
    int rc2;
    RtreeNode *pChild = 0;
    i64 iChild = nodeGetRowid(pRtree, pRoot, 0);
    rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);
    if( rc==SQLITE_OK ){
      rc = removeNode(pRtree, pChild, pRtree->iDepth-1);
    }
    rc2 = nodeRelease(pRtree, pChild);
    if( rc==SQLITE_OK ) rc = rc2;

   fts5parse.c \
   $(TOP)/ext/fts5/fts5_storage.c \
   $(TOP)/ext/fts5/fts5_tokenize.c \
   $(TOP)/ext/fts5/fts5_unicode2.c \
   $(TOP)/ext/fts5/fts5_varint.c \
   $(TOP)/ext/fts5/fts5_vocab.c  \




















# Generated source code files
#
SRC += \
  keywordhash.h \
  opcodes.c \
  opcodes.h \
................................................................................

fts5parse.h: fts5parse.c

fts5.c: $(FTS5_SRC) $(FTS5_HDR)
	tclsh $(TOP)/ext/fts5/tool/mkfts5c.tcl
	cp $(TOP)/ext/fts5/fts5.h .





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

sqlite3session.o:	$(TOP)/ext/session/sqlite3session.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/session/sqlite3session.c

sqlite3rbu.o:	$(TOP)/ext/rbu/sqlite3rbu.c $(HDR) $(EXTHDR)
................................................................................
	rm -f sqlite3_expert sqlite3_expert.exe 
	rm -f sqlite-*-output.vsix
	rm -f mptester mptester.exe
	rm -f fuzzershell fuzzershell.exe
	rm -f fuzzcheck fuzzcheck.exe
	rm -f sqldiff sqldiff.exe
	rm -f fts5.* fts5parse.*

   fts5parse.c \
   $(TOP)/ext/fts5/fts5_storage.c \
   $(TOP)/ext/fts5/fts5_tokenize.c \
   $(TOP)/ext/fts5/fts5_unicode2.c \
   $(TOP)/ext/fts5/fts5_varint.c \
   $(TOP)/ext/fts5/fts5_vocab.c  \

LSM1_SRC = \
   $(TOP)/ext/lsm1/lsm.h \
   $(TOP)/ext/lsm1/lsmInt.h \
   $(TOP)/ext/lsm1/lsm_ckpt.c \
   $(TOP)/ext/lsm1/lsm_file.c \
   $(TOP)/ext/lsm1/lsm_log.c \
   $(TOP)/ext/lsm1/lsm_main.c \
   $(TOP)/ext/lsm1/lsm_mem.c \
   $(TOP)/ext/lsm1/lsm_mutex.c \
   $(TOP)/ext/lsm1/lsm_shared.c \
   $(TOP)/ext/lsm1/lsm_sorted.c \
   $(TOP)/ext/lsm1/lsm_str.c \
   $(TOP)/ext/lsm1/lsm_tree.c \
   $(TOP)/ext/lsm1/lsm_unix.c \
   $(TOP)/ext/lsm1/lsm_varint.c \
   $(TOP)/ext/lsm1/lsm_vtab.c \
   $(TOP)/ext/lsm1/lsm_win32.c


# Generated source code files
#
SRC += \
  keywordhash.h \
  opcodes.c \
  opcodes.h \
................................................................................

fts5parse.h: fts5parse.c

fts5.c: $(FTS5_SRC) $(FTS5_HDR)
	tclsh $(TOP)/ext/fts5/tool/mkfts5c.tcl
	cp $(TOP)/ext/fts5/fts5.h .

lsm1.c: $(LSM1_SRC)
	tclsh $(TOP)/ext/lsm1/tool/mklsm1c.tcl
	cp $(TOP)/ext/lsm1/lsm.h .

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

sqlite3session.o:	$(TOP)/ext/session/sqlite3session.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/session/sqlite3session.c

sqlite3rbu.o:	$(TOP)/ext/rbu/sqlite3rbu.c $(HDR) $(EXTHDR)
................................................................................
	rm -f sqlite3_expert sqlite3_expert.exe 
	rm -f sqlite-*-output.vsix
	rm -f mptester mptester.exe
	rm -f fuzzershell fuzzershell.exe
	rm -f fuzzcheck fuzzcheck.exe
	rm -f sqldiff sqldiff.exe
	rm -f fts5.* fts5parse.*
	rm -f lsm.h lsm1.c

    for(i=0; i<nCol; i++){
      const char *zColl = pIdx->azColl[i];
      pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
                        sqlite3LocateCollSeq(pParse, zColl);
      pKey->aSortOrder[i] = pIdx->aSortOrder[i];
    }
    if( pParse->nErr ){












      sqlite3KeyInfoUnref(pKey);
      pKey = 0;
    }
  }
  return pKey;
}

    for(i=0; i<nCol; i++){
      const char *zColl = pIdx->azColl[i];
      pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
                        sqlite3LocateCollSeq(pParse, zColl);
      pKey->aSortOrder[i] = pIdx->aSortOrder[i];
    }
    if( pParse->nErr ){
      assert( pParse->rc==SQLITE_ERROR_MISSING_COLLSEQ );
      if( pIdx->bNoQuery==0 ){
        /* Deactivate the index because it contains an unknown collating
        ** sequence.  The only way to reactive the index is to reload the
        ** schema.  Adding the missing collating sequence later does not
        ** reactive the index.  The application had the chance to register
        ** the missing index using the collation-needed callback.  For
        ** simplicity, SQLite will not give the application a second chance.
        */
        pIdx->bNoQuery = 1;
        pParse->rc = SQLITE_ERROR_RETRY;
      }
      sqlite3KeyInfoUnref(pKey);
      pKey = 0;
    }
  }
  return pKey;
}

  }
  if( p && !p->xCmp && synthCollSeq(db, p) ){
    p = 0;
  }
  assert( !p || p->xCmp );
  if( p==0 ){
    sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);

  }
  return p;
}

/*
** This routine is called on a collation sequence before it is used to
** check that it is defined. An undefined collation sequence exists when

  }
  if( p && !p->xCmp && synthCollSeq(db, p) ){
    p = 0;
  }
  assert( !p || p->xCmp );
  if( p==0 ){
    sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
    pParse->rc = SQLITE_ERROR_MISSING_COLLSEQ;
  }
  return p;
}

/*
** This routine is called on a collation sequence before it is used to
** check that it is defined. An undefined collation sequence exists when

** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBM 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/
#include "sqliteInt.h"
#include <stdlib.h>
#include <assert.h>
#include <time.h>

** dates afterwards, depending on locale.  Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBN 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/
#include "sqliteInt.h"
#include <stdlib.h>
#include <assert.h>
#include <time.h>

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
  isView = pTab->pSelect!=0;
  bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
#else
# define pTrigger 0
# define isView 0
#endif

#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( !isView ){

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
  isView = pTab->pSelect!=0;

#else
# define pTrigger 0
# define isView 0
#endif
  bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( !isView ){

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
#ifdef SQLITE_ENABLE_RTREE
# include "rtree.h"
#endif
#ifdef SQLITE_ENABLE_ICU
# include "sqliteicu.h"
#endif
#ifdef SQLITE_ENABLE_JSON1
int sqlite3Json1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
int sqlite3StmtVtabInit(sqlite3*);
................................................................................

#ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
  if( !db->mallocFailed && rc==SQLITE_OK ){
    rc = sqlite3Fts3Init(db);
  }
#endif

#ifdef SQLITE_ENABLE_ICU
  if( !db->mallocFailed && rc==SQLITE_OK ){
    rc = sqlite3IcuInit(db);
  }
#endif

#ifdef SQLITE_ENABLE_RTREE
  if( !db->mallocFailed && rc==SQLITE_OK){

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
#ifdef SQLITE_ENABLE_RTREE
# include "rtree.h"
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
# include "sqliteicu.h"
#endif
#ifdef SQLITE_ENABLE_JSON1
int sqlite3Json1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
int sqlite3StmtVtabInit(sqlite3*);
................................................................................

#ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
  if( !db->mallocFailed && rc==SQLITE_OK ){
    rc = sqlite3Fts3Init(db);
  }
#endif

#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
  if( !db->mallocFailed && rc==SQLITE_OK ){
    rc = sqlite3IcuInit(db);
  }
#endif

#ifdef SQLITE_ENABLE_RTREE
  if( !db->mallocFailed && rc==SQLITE_OK){

*/
static void checkMutexFree(sqlite3_mutex *p){
  assert( SQLITE_MUTEX_RECURSIVE<2 );
  assert( SQLITE_MUTEX_FAST<2 );
  assert( SQLITE_MUTEX_WARNONCONTENTION<2 );

#if SQLITE_ENABLE_API_ARMOR
  if( p->iType<2 ){
#endif
  {
    CheckMutex *pCheck = (CheckMutex*)p;
    pGlobalMutexMethods->xMutexFree(pCheck->mutex);
    sqlite3_free(pCheck);
  }
#ifdef SQLITE_ENABLE_API_ARMOR

*/
static void checkMutexFree(sqlite3_mutex *p){
  assert( SQLITE_MUTEX_RECURSIVE<2 );
  assert( SQLITE_MUTEX_FAST<2 );
  assert( SQLITE_MUTEX_WARNONCONTENTION<2 );

#if SQLITE_ENABLE_API_ARMOR
  if( ((CheckMutex*)p)->iType<2 )
#endif
  {
    CheckMutex *pCheck = (CheckMutex*)p;
    pGlobalMutexMethods->xMutexFree(pCheck->mutex);
    sqlite3_free(pCheck);
  }
#ifdef SQLITE_ENABLE_API_ARMOR

#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
#else
  { "munmap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMunmap ((void*(*)(void*,size_t))aSyscall[23].pCurrent)

#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)
................................................................................
){
  unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */
  struct flock f;        /* The posix advisory locking structure */
  int rc = SQLITE_OK;    /* Result code form fcntl() */

  /* Access to the unixShmNode object is serialized by the caller */
  pShmNode = pFile->pInode->pShmNode;
  assert( sqlite3_mutex_held(pShmNode->mutex) || pShmNode->nRef==0 );

  /* 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 );

................................................................................
  struct statfs fsInfo;
#endif

  /* If creating a master or main-file journal, this function will open
  ** a file-descriptor on the directory too. The first time unixSync()
  ** is called the directory file descriptor will be fsync()ed and close()d.
  */
  int syncDir = (isCreate && (
        eType==SQLITE_OPEN_MASTER_JOURNAL 
     || eType==SQLITE_OPEN_MAIN_JOURNAL 
     || eType==SQLITE_OPEN_WAL
  ));

  /* If argument zPath is a NULL pointer, this function is required to open
  ** a temporary file. Use this buffer to store the file name in.
................................................................................
    /* Database filenames are double-zero terminated if they are not
    ** URIs with parameters.  Hence, they can always be passed into
    ** sqlite3_uri_parameter(). */
    assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );

  }else if( !zName ){
    /* If zName is NULL, the upper layer is requesting a temp file. */
    assert(isDelete && !syncDir);
    rc = unixGetTempname(pVfs->mxPathname, zTmpname);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    zName = zTmpname;

    /* Generated temporary filenames are always double-zero terminated
................................................................................
      flags |= SQLITE_OPEN_READONLY;
      openFlags |= O_RDONLY;
      isReadonly = 1;
      fd = robust_open(zName, openFlags, openMode);
    }
    if( fd<0 ){
      rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);



      goto open_finished;
    }

    /* If this process is running as root and if creating a new rollback
    ** journal or WAL file, set the ownership of the journal or WAL to be
    ** the same as the original database.
    */
................................................................................
#endif

  /* Set up appropriate ctrlFlags */
  if( isDelete )                ctrlFlags |= UNIXFILE_DELETE;
  if( isReadonly )              ctrlFlags |= UNIXFILE_RDONLY;
  noLock = eType!=SQLITE_OPEN_MAIN_DB;
  if( noLock )                  ctrlFlags |= UNIXFILE_NOLOCK;
  if( syncDir )                 ctrlFlags |= UNIXFILE_DIRSYNC;
  if( flags & SQLITE_OPEN_URI ) ctrlFlags |= UNIXFILE_URI;

#if SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_PREFER_PROXY_LOCKING
  isAutoProxy = 1;
#endif
  if( isAutoProxy && (zPath!=NULL) && (!noLock) && pVfs->xOpen ){

#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
#else
  { "munmap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMunmap ((int(*)(void*,size_t))aSyscall[23].pCurrent)

#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)
................................................................................
){
  unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */
  struct flock f;        /* The posix advisory locking structure */
  int rc = SQLITE_OK;    /* Result code form fcntl() */

  /* Access to the unixShmNode object is serialized by the caller */
  pShmNode = pFile->pInode->pShmNode;
  assert( pShmNode->nRef==0 || sqlite3_mutex_held(pShmNode->mutex) );

  /* 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 );

................................................................................
  struct statfs fsInfo;
#endif

  /* If creating a master or main-file journal, this function will open
  ** a file-descriptor on the directory too. The first time unixSync()
  ** is called the directory file descriptor will be fsync()ed and close()d.
  */
  int isNewJrnl = (isCreate && (
        eType==SQLITE_OPEN_MASTER_JOURNAL 
     || eType==SQLITE_OPEN_MAIN_JOURNAL 
     || eType==SQLITE_OPEN_WAL
  ));

  /* If argument zPath is a NULL pointer, this function is required to open
  ** a temporary file. Use this buffer to store the file name in.
................................................................................
    /* Database filenames are double-zero terminated if they are not
    ** URIs with parameters.  Hence, they can always be passed into
    ** sqlite3_uri_parameter(). */
    assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );

  }else if( !zName ){
    /* If zName is NULL, the upper layer is requesting a temp file. */
    assert(isDelete && !isNewJrnl);
    rc = unixGetTempname(pVfs->mxPathname, zTmpname);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    zName = zTmpname;

    /* Generated temporary filenames are always double-zero terminated
................................................................................
      flags |= SQLITE_OPEN_READONLY;
      openFlags |= O_RDONLY;
      isReadonly = 1;
      fd = robust_open(zName, openFlags, openMode);
    }
    if( fd<0 ){
      rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);
      /* If unable to create a journal, change the error code to
      ** indicate that the directory permissions are wrong. */
      if( isNewJrnl && osAccess(zName, F_OK) ) rc = SQLITE_READONLY_DIRECTORY;
      goto open_finished;
    }

    /* If this process is running as root and if creating a new rollback
    ** journal or WAL file, set the ownership of the journal or WAL to be
    ** the same as the original database.
    */
................................................................................
#endif

  /* Set up appropriate ctrlFlags */
  if( isDelete )                ctrlFlags |= UNIXFILE_DELETE;
  if( isReadonly )              ctrlFlags |= UNIXFILE_RDONLY;
  noLock = eType!=SQLITE_OPEN_MAIN_DB;
  if( noLock )                  ctrlFlags |= UNIXFILE_NOLOCK;
  if( isNewJrnl )               ctrlFlags |= UNIXFILE_DIRSYNC;
  if( flags & SQLITE_OPEN_URI ) ctrlFlags |= UNIXFILE_URI;

#if SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_PREFER_PROXY_LOCKING
  isAutoProxy = 1;
#endif
  if( isAutoProxy && (zPath!=NULL) && (!noLock) && pVfs->xOpen ){

  int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
  int ofst,             /* Offset to first byte to be locked/unlocked */
  int nByte             /* Number of bytes to lock or unlock */
){
  int rc = 0;           /* Result code form Lock/UnlockFileEx() */

  /* Access to the winShmNode object is serialized by the caller */
  assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 );

  OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
           pFile->hFile.h, lockType, ofst, nByte));

  /* Release/Acquire the system-level lock */
  if( lockType==WINSHM_UNLCK ){
    rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);

  int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
  int ofst,             /* Offset to first byte to be locked/unlocked */
  int nByte             /* Number of bytes to lock or unlock */
){
  int rc = 0;           /* Result code form Lock/UnlockFileEx() */

  /* Access to the winShmNode object is serialized by the caller */
  assert( pFile->nRef==0 || sqlite3_mutex_held(pFile->mutex) );

  OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
           pFile->hFile.h, lockType, ofst, nByte));

  /* Release/Acquire the system-level lock */
  if( lockType==WINSHM_UNLCK ){
    rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);

    sParse.pTriggerPrg = pT->pNext;
    sqlite3DbFree(db, pT);
  }

end_prepare:

  sqlite3ParserReset(&sParse);
  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
  return rc;
}
static int sqlite3LockAndPrepare(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
  Vdbe *pOld,               /* VM being reprepared */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;


#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
    return SQLITE_MISUSE_BKPT;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
  if( rc==SQLITE_SCHEMA ){
    sqlite3ResetOneSchema(db, -1);
    sqlite3_finalize(*ppStmt);
    rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  assert( rc==SQLITE_OK || *ppStmt==0 );



  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.
**
** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,

    sParse.pTriggerPrg = pT->pNext;
    sqlite3DbFree(db, pT);
  }

end_prepare:

  sqlite3ParserReset(&sParse);


  return rc;
}
static int sqlite3LockAndPrepare(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
  Vdbe *pOld,               /* VM being reprepared */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;
  int cnt = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
    return SQLITE_MISUSE_BKPT;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  do{
    /* Make multiple attempts to compile the SQL, until it either succeeds
    ** or encounters a permanent error.  A schema problem after one schema
    ** reset is considered a permanent error. */
    rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
    assert( rc==SQLITE_OK || *ppStmt==0 );
  }while( rc==SQLITE_ERROR_RETRY
       || (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) );
  sqlite3BtreeLeaveAll(db);
  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.
**
** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,

  /*
  ** This SELECT statement returns one row for each foreign key constraint
  ** in the schema of the main database. The column values are:
  **
  ** 0. The text of an SQL statement similar to:
  **
  **      "EXPLAIN QUERY PLAN SELECT rowid FROM child_table WHERE child_key=?"
  **
  **    This is the same SELECT that the foreign keys implementation needs
  **    to run internally on child tables. If there is an index that can
  **    be used to optimize this query, then it can also be used by the FK
  **    implementation to optimize DELETE or UPDATE statements on the parent
  **    table.
  **
  ** 1. A GLOB pattern suitable for sqlite3_strglob(). If the plan output by
  **    the EXPLAIN QUERY PLAN command matches this pattern, then the schema
  **    contains an index that can be used to optimize the query.
................................................................................
  **
  ** 5. The name of the parent table.
  **
  ** These six values are used by the C logic below to generate the report.
  */
  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT rowid FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH TABLE ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "

  /*
  ** This SELECT statement returns one row for each foreign key constraint
  ** in the schema of the main database. The column values are:
  **
  ** 0. The text of an SQL statement similar to:
  **
  **      "EXPLAIN QUERY PLAN SELECT 1 FROM child_table WHERE child_key=?"
  **
  **    This SELECT is similar to the one that the foreign keys implementation
  **    needs to run internally on child tables. If there is an index that can
  **    be used to optimize this query, then it can also be used by the FK
  **    implementation to optimize DELETE or UPDATE statements on the parent
  **    table.
  **
  ** 1. A GLOB pattern suitable for sqlite3_strglob(). If the plan output by
  **    the EXPLAIN QUERY PLAN command matches this pattern, then the schema
  **    contains an index that can be used to optimize the query.
................................................................................
  **
  ** 5. The name of the parent table.
  **
  ** These six values are used by the C logic below to generate the report.
  */
  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT 1 FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH TABLE ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "

** support for additional result codes that provide more detailed information
** about errors. These [extended result codes] are enabled or disabled
** on a per database connection basis using the
** [sqlite3_extended_result_codes()] API.  Or, the extended code for
** the most recent error can be obtained using
** [sqlite3_extended_errcode()].
*/


#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
................................................................................
#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))

#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))

** support for additional result codes that provide more detailed information
** about errors. These [extended result codes] are enabled or disabled
** on a per database connection basis using the
** [sqlite3_extended_result_codes()] API.  Or, the extended code for
** the most recent error can be obtained using
** [sqlite3_extended_errcode()].
*/
#define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
#define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
................................................................................
#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))
#define SQLITE_READONLY_DIRECTORY      (SQLITE_READONLY | (6<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))

  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
................................................................................
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table for associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */

  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */
  unsigned bNoQuery:1;     /* Do not use this index to optimize queries */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
................................................................................
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */

#endif

#ifdef SQLITE_ENABLE_ICU
  Tcl_SetVar2(interp, "sqlite_options", "icu", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "icu", "0", TCL_GLOBAL_ONLY);
#endif







#ifdef SQLITE_OMIT_INCRBLOB
  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "1", TCL_GLOBAL_ONLY);
#endif /* SQLITE_OMIT_AUTOVACUUM */

#endif

#ifdef SQLITE_ENABLE_ICU
  Tcl_SetVar2(interp, "sqlite_options", "icu", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "icu", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_ENABLE_ICU_COLLATIONS
  Tcl_SetVar2(interp, "sqlite_options", "icu_collations", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "icu_collations", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_INCRBLOB
  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "incrblob", "1", TCL_GLOBAL_ONLY);
#endif /* SQLITE_OMIT_AUTOVACUUM */

  sqlite3_value *pVal = 0;
  int negInt = 1;
  const char *zNeg = "";
  int rc = SQLITE_OK;

  assert( pExpr!=0 );
  while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;

  if( op==TK_REGISTER ) op = pExpr->op2;




  /* Compressed expressions only appear when parsing the DEFAULT clause
  ** on a table column definition, and hence only when pCtx==0.  This
  ** check ensures that an EP_TokenOnly expression is never passed down
  ** into valueFromFunction(). */
  assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );

................................................................................
  }
#endif

  *ppVal = pVal;
  return rc;

no_mem:



  sqlite3OomFault(db);
  sqlite3DbFree(db, zVal);
  assert( *ppVal==0 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pCtx==0 ) sqlite3ValueFree(pVal);
#else
  assert( pCtx==0 ); sqlite3ValueFree(pVal);
#endif

  sqlite3_value *pVal = 0;
  int negInt = 1;
  const char *zNeg = "";
  int rc = SQLITE_OK;

  assert( pExpr!=0 );
  while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;
#if defined(SQLITE_ENABLE_STAT3_OR_STAT4)
  if( op==TK_REGISTER ) op = pExpr->op2;
#else
  if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
#endif

  /* Compressed expressions only appear when parsing the DEFAULT clause
  ** on a table column definition, and hence only when pCtx==0.  This
  ** check ensures that an EP_TokenOnly expression is never passed down
  ** into valueFromFunction(). */
  assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );

................................................................................
  }
#endif

  *ppVal = pVal;
  return rc;

no_mem:
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pCtx==0 || pCtx->pParse->nErr==0 )
#endif
    sqlite3OomFault(db);
  sqlite3DbFree(db, zVal);
  assert( *ppVal==0 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pCtx==0 ) sqlite3ValueFree(pVal);
#else
  assert( pCtx==0 ); sqlite3ValueFree(pVal);
#endif

      pProbe=(pSrc->pIBIndex ? 0 : pProbe->pNext), iSortIdx++
  ){
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }

    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
    pNew->u.btree.nBtm = 0;
    pNew->u.btree.nTop = 0;
    pNew->nSkip = 0;
    pNew->nLTerm = 0;
    pNew->iSortIdx = 0;

      pProbe=(pSrc->pIBIndex ? 0 : pProbe->pNext), iSortIdx++
  ){
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    if( pProbe->bNoQuery ) continue;
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
    pNew->u.btree.nBtm = 0;
    pNew->u.btree.nTop = 0;
    pNew->nSkip = 0;
    pNew->nLTerm = 0;
    pNew->iSortIdx = 0;

      if( sqlite3ExprIsVector(pRight)==0 ){
        disableTerm(pLevel, pRangeEnd);
      }else{
        endEq = 1;
      }
    }else if( bStopAtNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);

      endEq = 0;
      nConstraint++;
    }
    sqlite3DbFree(db, zStartAff);
    sqlite3DbFree(db, zEndAff);

    /* Top of the loop body */

      if( sqlite3ExprIsVector(pRight)==0 ){
        disableTerm(pLevel, pRangeEnd);
      }else{
        endEq = 1;
      }
    }else if( bStopAtNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
      endEq = 0;
      nConstraint++;
    }
    sqlite3DbFree(db, zStartAff);
    sqlite3DbFree(db, zEndAff);

    /* Top of the loop body */

#
# $Id: icu.test,v 1.2 2008/07/12 14:52:20 drh Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !icu {
  finish_test
  return
}

# Create a table to work with.
#
execsql {CREATE TABLE test1(i1 int, i2 int, r1 real, r2 real, t1 text, t2 text)}
................................................................................
      UPDATE test1 SET %s; 
      SELECT %s FROM test1; 
      ROLLBACK;
    }] 0
  } $settings $expr] $result
}



# Tests of the REGEXP operator.
#
test_expr icu-1.1 {i1='hello'} {i1 REGEXP 'hello'}  1
test_expr icu-1.2 {i1='hello'} {i1 REGEXP '.ello'}  1
test_expr icu-1.3 {i1='hello'} {i1 REGEXP '.ell'}   0
test_expr icu-1.4 {i1='hello'} {i1 REGEXP '.ell.*'} 1
test_expr icu-1.5 {i1=NULL}    {i1 REGEXP '.ell.*'} {}

# Some non-ascii characters with defined case mappings
#
set ::EGRAVE "\xC8"
set ::egrave "\xE8"

set ::OGRAVE "\xD2"
set ::ograve "\xF2"

# That German letter that looks a bit like a B. The
# upper-case version of which is "SS" (two characters).
#
set ::szlig "\xDF" 

# Tests of the upper()/lower() functions.
#
test_expr icu-2.1 {i1='HellO WorlD'} {upper(i1)} {HELLO WORLD}
test_expr icu-2.2 {i1='HellO WorlD'} {lower(i1)} {hello world}
test_expr icu-2.3 {i1=$::egrave} {lower(i1)}     $::egrave
test_expr icu-2.4 {i1=$::egrave} {upper(i1)}     $::EGRAVE
test_expr icu-2.5 {i1=$::ograve} {lower(i1)}     $::ograve
test_expr icu-2.6 {i1=$::ograve} {upper(i1)}     $::OGRAVE
test_expr icu-2.3 {i1=$::EGRAVE} {lower(i1)}     $::egrave
test_expr icu-2.4 {i1=$::EGRAVE} {upper(i1)}     $::EGRAVE
test_expr icu-2.5 {i1=$::OGRAVE} {lower(i1)}     $::ograve
test_expr icu-2.6 {i1=$::OGRAVE} {upper(i1)}     $::OGRAVE

test_expr icu-2.7 {i1=$::szlig} {upper(i1)}      "SS"
test_expr icu-2.8 {i1='SS'} {lower(i1)}          "ss"

do_execsql_test icu-2.9 {
  SELECT upper(char(0xfb04,0xfb04,0xfb04,0xfb04));
} {FFLFFLFFLFFL}

# In turkish (locale="tr_TR"), the lower case version of I
# is "small dotless i" (code point 0x131 (decimal 305)).
#
set ::small_dotless_i "\u0131"
test_expr icu-3.1 {i1='I'} {lower(i1)}           "i"
test_expr icu-3.2 {i1='I'} {lower(i1, 'tr_tr')}  $::small_dotless_i
test_expr icu-3.3 {i1='I'} {lower(i1, 'en_AU')}  "i"


#--------------------------------------------------------------------
# Test the collation sequence function.
#
do_test icu-4.1 {
  execsql {
    CREATE TABLE fruit(name);
................................................................................

#-------------------------------------------------------------------------
# Test that it is not possible to call the ICU regex() function with 
# anything other than exactly two arguments. See also:
#
#   http://src.chromium.org/viewvc/chrome/trunk/src/third_party/sqlite/icu-regexp.patch?revision=34807&view=markup
#

do_catchsql_test icu-5.1 { SELECT regexp('a[abc]c.*', 'abc') } {0 1}
do_catchsql_test icu-5.2 { 
  SELECT regexp('a[abc]c.*') 
} {1 {wrong number of arguments to function regexp()}}
do_catchsql_test icu-5.3 { 
  SELECT regexp('a[abc]c.*', 'abc', 'c') 
} {1 {wrong number of arguments to function regexp()}}
do_catchsql_test icu-5.4 { 
  SELECT 'abc' REGEXP 'a[abc]c.*'
} {0 1}
do_catchsql_test icu-5.4 { SELECT 'abc' REGEXP }    {1 {near " ": syntax error}}

do_catchsql_test icu-5.5 { SELECT 'abc' REGEXP, 1 } {1 {near ",": syntax error}}


do_malloc_test icu-6.10 -sqlbody {
  SELECT upper(char(0xfb04,0xdf,0xfb04,0xe8,0xfb04));
}


finish_test

#
# $Id: icu.test,v 1.2 2008/07/12 14:52:20 drh Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !icu&&!icu_collations {
  finish_test
  return
}

# Create a table to work with.
#
execsql {CREATE TABLE test1(i1 int, i2 int, r1 real, r2 real, t1 text, t2 text)}
................................................................................
      UPDATE test1 SET %s; 
      SELECT %s FROM test1; 
      ROLLBACK;
    }] 0
  } $settings $expr] $result
}

ifcapable icu {

  # Tests of the REGEXP operator.
  #
  test_expr icu-1.1 {i1='hello'} {i1 REGEXP 'hello'}  1
  test_expr icu-1.2 {i1='hello'} {i1 REGEXP '.ello'}  1
  test_expr icu-1.3 {i1='hello'} {i1 REGEXP '.ell'}   0
  test_expr icu-1.4 {i1='hello'} {i1 REGEXP '.ell.*'} 1
  test_expr icu-1.5 {i1=NULL}    {i1 REGEXP '.ell.*'} {}

  # Some non-ascii characters with defined case mappings
  #
  set ::EGRAVE "\xC8"
  set ::egrave "\xE8"

  set ::OGRAVE "\xD2"
  set ::ograve "\xF2"

  # That German letter that looks a bit like a B. The
  # upper-case version of which is "SS" (two characters).
  #
  set ::szlig "\xDF" 

  # Tests of the upper()/lower() functions.
  #
  test_expr icu-2.1 {i1='HellO WorlD'} {upper(i1)} {HELLO WORLD}
  test_expr icu-2.2 {i1='HellO WorlD'} {lower(i1)} {hello world}
  test_expr icu-2.3 {i1=$::egrave} {lower(i1)}     $::egrave
  test_expr icu-2.4 {i1=$::egrave} {upper(i1)}     $::EGRAVE
  test_expr icu-2.5 {i1=$::ograve} {lower(i1)}     $::ograve
  test_expr icu-2.6 {i1=$::ograve} {upper(i1)}     $::OGRAVE
  test_expr icu-2.3 {i1=$::EGRAVE} {lower(i1)}     $::egrave
  test_expr icu-2.4 {i1=$::EGRAVE} {upper(i1)}     $::EGRAVE
  test_expr icu-2.5 {i1=$::OGRAVE} {lower(i1)}     $::ograve
  test_expr icu-2.6 {i1=$::OGRAVE} {upper(i1)}     $::OGRAVE

  test_expr icu-2.7 {i1=$::szlig} {upper(i1)}      "SS"
  test_expr icu-2.8 {i1='SS'} {lower(i1)}          "ss"

  do_execsql_test icu-2.9 {
    SELECT upper(char(0xfb04,0xfb04,0xfb04,0xfb04));
  } {FFLFFLFFLFFL}

  # In turkish (locale="tr_TR"), the lower case version of I
  # is "small dotless i" (code point 0x131 (decimal 305)).
  #
  set ::small_dotless_i "\u0131"
  test_expr icu-3.1 {i1='I'} {lower(i1)}           "i"
  test_expr icu-3.2 {i1='I'} {lower(i1, 'tr_tr')}  $::small_dotless_i
  test_expr icu-3.3 {i1='I'} {lower(i1, 'en_AU')}  "i"
}

#--------------------------------------------------------------------
# Test the collation sequence function.
#
do_test icu-4.1 {
  execsql {
    CREATE TABLE fruit(name);
................................................................................

#-------------------------------------------------------------------------
# Test that it is not possible to call the ICU regex() function with 
# anything other than exactly two arguments. See also:
#
#   http://src.chromium.org/viewvc/chrome/trunk/src/third_party/sqlite/icu-regexp.patch?revision=34807&view=markup
#
ifcapable icu {
  do_catchsql_test icu-5.1 { SELECT regexp('a[abc]c.*', 'abc') } {0 1}
  do_catchsql_test icu-5.2 { 
    SELECT regexp('a[abc]c.*') 
  } {1 {wrong number of arguments to function regexp()}}
  do_catchsql_test icu-5.3 { 
    SELECT regexp('a[abc]c.*', 'abc', 'c') 
  } {1 {wrong number of arguments to function regexp()}}
  do_catchsql_test icu-5.4 { 
    SELECT 'abc' REGEXP 'a[abc]c.*'
  } {0 1}

  do_catchsql_test icu-5.4 {SELECT 'abc' REGEXP }   {1 {near " ": syntax error}}
  do_catchsql_test icu-5.5 {SELECT 'abc' REGEXP, 1} {1 {near ",": syntax error}}
 

  do_malloc_test icu-6.10 -sqlbody {
    SELECT upper(char(0xfb04,0xdf,0xfb04,0xe8,0xfb04));
  }
}

finish_test

  INSERT INTO t502 VALUES(1, 5);
  INSERT INTO t502 VALUES(2, 4);
  INSERT INTO t502 VALUES(3, 3);
  INSERT INTO t502 VALUES(4, 6);
  INSERT INTO t502 VALUES(5, 1);
  SELECT j FROM t502 WHERE i IN (1,2,3,4,5) ORDER BY j LIMIT 3;
} {1 3 4}


















finish_test

  INSERT INTO t502 VALUES(1, 5);
  INSERT INTO t502 VALUES(2, 4);
  INSERT INTO t502 VALUES(3, 3);
  INSERT INTO t502 VALUES(4, 6);
  INSERT INTO t502 VALUES(5, 1);
  SELECT j FROM t502 WHERE i IN (1,2,3,4,5) ORDER BY j LIMIT 3;
} {1 3 4}

# Ticket https://www.sqlite.org/src/info/123c9ba32130a6c9 2017-12-13
# Incorrect result when an idnex is used for an ordered join.
#
# This test case is in the limit2.test module because the problem was first
# exposed by check-in https://www.sqlite.org/src/info/559733b09e which 
# implemented the ORDER BY LIMIT optimization that limit2.test strives to
# test.
#
do_execsql_test 600 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(a, b);  INSERT INTO t1 VALUES(1,2);
  DROP TABLE IF EXISTS t2;
  CREATE TABLE t2(x, y);  INSERT INTO t2 VALUES(1,3);
  CREATE INDEX t1ab ON t1(a,b);
  SELECT y FROM t1, t2 WHERE a=x AND b<=y ORDER BY b DESC;
} {3}

finish_test

#***********************************************************************
# This file implements regression tests for SQLite library.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix mjournal






# Test that nothing bad happens if a journal file contains a pointer to
# a master journal file that does not have a "-" in the name. At one point
# this was causing a segfault on unix.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);

#***********************************************************************
# This file implements regression tests for SQLite library.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix mjournal

if {[permutation]=="inmemory_journal"} {
  finish_test
  return
}

# Test that nothing bad happens if a journal file contains a pointer to
# a master journal file that does not have a "-" in the name. At one point
# this was causing a segfault on unix.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);

  }

  9 {
    CREATE TABLE p1(a, b UNIQUE);
    CREATE TABLE c1(x INTEGER PRIMARY KEY REFERENCES p1(b));
  } {
  }









} {
  forcedelete test.db
  sqlite3 db test.db
  execsql $schema

  set expected ""

  }

  9 {
    CREATE TABLE p1(a, b UNIQUE);
    CREATE TABLE c1(x INTEGER PRIMARY KEY REFERENCES p1(b));
  } {
  }

  10 {
    CREATE TABLE parent (id INTEGER PRIMARY KEY); 
    CREATE TABLE child2 (id INT PRIMARY KEY, parentID INT REFERENCES parent) 
      WITHOUT ROWID;
  } {
    CREATE INDEX 'child2_parentID' ON 'child2'('parentID'); --> parent(id)
  }

} {
  forcedelete test.db
  sqlite3 db test.db
  execsql $schema

  set expected ""

do_catchsql_test 3.1 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db_no_such_function'
  );
} {1 {no such function: fetch_db_no_such_function}}

do_catchsql_test 3.2 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db'

do_catchsql_test 3.1 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db_no_such_function'
  );
} {1 {sql error: no such function: fetch_db_no_such_function}}

do_catchsql_test 3.2 {
  CREATE VIRTUAL TABLE temp.xyz USING swarmvtab(
    'VALUES
        ("test.db1", "t1", 1, 10),
        ("test.db2", "t1", 11, 20)
    ', 'fetch_db'

#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab
do_not_use_codec

ifcapable !vtab {
  finish_test
  return
}

#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab2
do_not_use_codec

ifcapable !vtab {
  finish_test
  return
}

# 2017-07-15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab3
do_not_use_codec

ifcapable !vtab {
  finish_test
  return
}

load_static_extension db unionvtab

set nFile $sqlite_open_file_count

do_execsql_test 1.0 {
  CREATE TEMP TABLE swarm(id, tbl, minval, maxval);
}

# Set up 100 databases with filenames "remote_test.dbN", where N is between
# 0 and 99.
do_test 1.1 {
  for {set i 0} {$i < 100} {incr i} {
    set file remote_test.db$i
    forcedelete $file
    forcedelete test.db$i
    sqlite3 rrr $file
    rrr eval {
      CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
      INSERT INTO t1 VALUES($i, $i);
    }
    rrr close
    db eval {
      INSERT INTO swarm VALUES($i, 't1', $i, $i);
    }
    set ::dbcache(test.db$i) 0
  }
} {}

proc missing_db {filename} {
  set remote "remote_$filename"
  forcedelete $filename
  file copy $remote $filename
}
db func missing_db missing_db

proc openclose_db {filename bClose} {
  if {$bClose} {
    incr ::dbcache($filename) -1
  } else {
    incr ::dbcache($filename) 1
  }
  if {$::dbcache($filename)==0} {
    forcedelete $filename
  }
}
db func openclose_db openclose_db

proc check_dbcache {} {
  set n 0
  for {set i 0} {$i<100} {incr i} {
    set exists [file exists test.db$i]
    if {$exists!=($::dbcache(test.db$i)!=0)} {
      error "inconsistent ::dbcache and disk"
    }
    incr n $exists
  }
  return $n
}

foreach {tn nMaxOpen cvt} {
  1 5 {
    CREATE VIRTUAL TABLE temp.s USING swarmvtab(
        'SELECT :prefix || id, tbl, minval, minval FROM swarm',
        :prefix='test.db',
        missing=missing_db,
        openclose=openclose_db,
        maxopen=5
    )
  }

  2 3 {
    CREATE VIRTUAL TABLE temp.s USING swarmvtab(
        'SELECT :prefix || id, tbl, minval, minval FROM swarm',
        :prefix='test.db',
        missing =       'missing_db',
        openclose=[openclose_db],
        maxopen = 3
    )
  }

  3 1 {
    CREATE VIRTUAL TABLE temp.s USING swarmvtab(
        'SELECT :prefix||''.''||:suffix||id, tbl, minval, minval FROM swarm',
        :prefix=test, :suffix=db,
        missing =       'missing_db',
        openclose=[openclose_db],
        maxopen = 1
    )
  }

} {
  execsql { DROP TABLE IF EXISTS s }
  
  do_execsql_test 1.$tn.1 $cvt

  do_execsql_test 1.$tn.2 {
    SELECT b FROM s WHERE a<10;
  } {0 1 2 3 4 5 6 7 8 9}

  do_test 1.$tn.3 { check_dbcache } $nMaxOpen

  do_execsql_test 1.$tn.4 {
    SELECT b FROM s WHERE (b%10)=0;
  } {0 10 20 30 40 50 60 70 80 90}

  do_test 1.$tn.5 { check_dbcache } $nMaxOpen
}

execsql { DROP TABLE IF EXISTS s }
for {set i 0} {$i < 100} {incr i} {
  forcedelete remote_test.db$i
}

#----------------------------------------------------------------------------
#
do_execsql_test 2.0 {
  DROP TABLE IF EXISTS swarm;
  CREATE TEMP TABLE swarm(file, tbl, minval, maxval, ctx);
}

catch { array unset ::dbcache }

# Set up 100 databases with filenames "remote_test.dbN", where N is a
# random integer between 0 and 1,000,000
# 0 and 99.
do_test 2.1 {
  for {set i 0} {$i < 100} {incr i} {
    while 1 {
      set ctx [expr abs(int(rand() *1000000))]
      if {[info exists ::dbcache($ctx)]==0} break
    }

    set file test_remote.db$ctx
    forcedelete $file
    forcedelete test.db$i
    sqlite3 rrr $file
    rrr eval {
      CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
      INSERT INTO t1 VALUES($i, $i);
    }
    rrr close
    db eval {
      INSERT INTO swarm VALUES('test.db' || $i, 't1', $i, $i, $file)
    }
    set ::dbcache(test.db$i) 0
  }
} {}

proc missing_db {filename ctx} {
  file copy $ctx $filename
}
db func missing_db missing_db

proc openclose_db {filename ctx bClose} {
  if {$bClose} {
    incr ::dbcache($filename) -1
  } else {
    incr ::dbcache($filename) 1
  }
  if {$::dbcache($filename)==0} {
    forcedelete $filename
  }
}
db func openclose_db openclose_db

proc check_dbcache {} {
  set n 0
  foreach k [array names ::dbcache] {
    set exists [file exists $k]
    if {$exists!=($::dbcache($k)!=0)} {
      error "inconsistent ::dbcache and disk ($k)"
    }
    incr n $exists
  }
  return $n
}

foreach {tn nMaxOpen cvt} {
  2 5 {
    CREATE VIRTUAL TABLE temp.s USING swarmvtab(
        'SELECT file, tbl, minval, minval, ctx FROM swarm',
        missing=missing_db,
        openclose=openclose_db,
        maxopen=5
    )
  }
} {
  execsql { DROP TABLE IF EXISTS s }
  
  do_execsql_test 1.$tn.1 $cvt

  do_execsql_test 1.$tn.2 {
    SELECT b FROM s WHERE a<10;
  } {0 1 2 3 4 5 6 7 8 9}

  do_test 1.$tn.3 { check_dbcache } $nMaxOpen

  do_execsql_test 1.$tn.4 {
    SELECT b FROM s WHERE (b%10)=0;
  } {0 10 20 30 40 50 60 70 80 90}

  do_test 1.$tn.5 { check_dbcache } $nMaxOpen
}

db close
forcedelete {*}[glob test_remote.db*]

finish_test

do_test 1.1 {
  testvfs T
  T filter xShmLock 
  T script lock_callback
  set ::locks [list]
  sqlite3 db test.db -vfs T
  execsql { SELECT * FROM x }
  lrange $::locks 0 3
} [list {0 1 lock exclusive} {1 7 lock exclusive}      \
        {1 7 unlock exclusive} {0 1 unlock exclusive}  \
]
do_test 1.2 {
  db close
  set ::locks [list]
  sqlite3 db test.db -vfs T
  execsql { SELECT * FROM x }
  lrange $::locks 0 3
} [list {0 1 lock exclusive} {1 7 lock exclusive}      \
        {1 7 unlock exclusive} {0 1 unlock exclusive}  \
]
proc lock_callback {method filename handle lock} {
  if {$lock == "1 7 lock exclusive"} { return SQLITE_BUSY }
  return SQLITE_OK
}
puts "# Warning: This next test case causes SQLite to call xSleep(1) 100 times."
puts "# Normally this equates to a delay of roughly 10 seconds, but if SQLite"
puts "# is built on unix without HAVE_USLEEP defined, it may be much longer."
do_test 1.3 {
  db close
................................................................................

puts "# Warning: Same again!"
proc lock_callback {method filename handle lock} {
  if {$lock == "0 1 lock exclusive"} { return SQLITE_BUSY }
  return SQLITE_OK
}
do_test 1.4 {












  db close
  set ::locks [list]
  sqlite3 db test.db -vfs T
  catchsql { SELECT * FROM x }
} {1 {locking protocol}}
db close
T delete
................................................................................
faultsim_save_and_close
testvfs T -default 1
faultsim_restore_and_reopen
T filter xShmLock
T script lock_callback

proc lock_callback {method file handle spec} {
  if {$spec == "1 7 unlock exclusive"} {
    T filter {}
    set ::r [catchsql { SELECT * FROM b } db2]
  }
}
sqlite3 db test.db
sqlite3 db2 test.db

do_test 2.5 {
  execsql { SELECT * FROM b }
} {Tehran Qom Markazi Qazvin Gilan Ardabil}
do_test 2.6 {
  set ::r
} {1 {locking protocol}}

................................................................................
db2 close

faultsim_restore_and_reopen
sqlite3 db2 test.db
T filter xShmLock
T script lock_callback
proc lock_callback {method file handle spec} {
  if {$spec == "1 7 unlock exclusive"} {
    T filter {}
    set ::r [catchsql { SELECT * FROM b } db2]
  }
}
unset ::r

do_test 2.7 {
  execsql { SELECT * FROM b }
} {Tehran Qom Markazi Qazvin Gilan Ardabil}
do_test 2.8 {
  set ::r
} {1 {locking protocol}}

db close
db2 close
T delete

finish_test

do_test 1.1 {
  testvfs T
  T filter xShmLock 
  T script lock_callback
  set ::locks [list]
  sqlite3 db test.db -vfs T
  execsql { SELECT * FROM x }
  lrange $::locks 0 5
} [list {0 1 lock exclusive} {1 2 lock exclusive} {4 4 lock exclusive} \
        {1 2 unlock exclusive} {4 4 unlock exclusive} {0 1 unlock exclusive}  \
]
do_test 1.2 {
  db close
  set ::locks [list]
  sqlite3 db test.db -vfs T
  execsql { SELECT * FROM x }
  lrange $::locks 0 5
} [list {0 1 lock exclusive} {1 2 lock exclusive} {4 4 lock exclusive} \
        {1 2 unlock exclusive} {4 4 unlock exclusive} {0 1 unlock exclusive}  \
]
proc lock_callback {method filename handle lock} {
  if {$lock == "1 2 lock exclusive"} { return SQLITE_BUSY }
  return SQLITE_OK
}
puts "# Warning: This next test case causes SQLite to call xSleep(1) 100 times."
puts "# Normally this equates to a delay of roughly 10 seconds, but if SQLite"
puts "# is built on unix without HAVE_USLEEP defined, it may be much longer."
do_test 1.3 {
  db close
................................................................................

puts "# Warning: Same again!"
proc lock_callback {method filename handle lock} {
  if {$lock == "0 1 lock exclusive"} { return SQLITE_BUSY }
  return SQLITE_OK
}
do_test 1.4 {
  db close
  set ::locks [list]
  sqlite3 db test.db -vfs T
  catchsql { SELECT * FROM x }
} {1 {locking protocol}}

puts "# Warning: Third time!"
proc lock_callback {method filename handle lock} {
  if {$lock == "4 4 lock exclusive"} { return SQLITE_BUSY }
  return SQLITE_OK
}
do_test 1.5 {
  db close
  set ::locks [list]
  sqlite3 db test.db -vfs T
  catchsql { SELECT * FROM x }
} {1 {locking protocol}}
db close
T delete
................................................................................
faultsim_save_and_close
testvfs T -default 1
faultsim_restore_and_reopen
T filter xShmLock
T script lock_callback

proc lock_callback {method file handle spec} {
  if {$spec == "1 2 unlock exclusive"} {
    T filter {}
    set ::r [catchsql { SELECT * FROM b } db2]
  }
}
sqlite3 db test.db
sqlite3 db2 test.db
puts "# Warning: Another slow test!"
do_test 2.5 {
  execsql { SELECT * FROM b }
} {Tehran Qom Markazi Qazvin Gilan Ardabil}
do_test 2.6 {
  set ::r
} {1 {locking protocol}}

................................................................................
db2 close

faultsim_restore_and_reopen
sqlite3 db2 test.db
T filter xShmLock
T script lock_callback
proc lock_callback {method file handle spec} {
  if {$spec == "1 2 unlock exclusive"} {
    T filter {}
    set ::r [catchsql { SELECT * FROM b } db2]
  }
}
unset ::r
puts "# Warning: Last one!"
do_test 2.7 {
  execsql { SELECT * FROM b }
} {Tehran Qom Markazi Qazvin Gilan Ardabil}
do_test 2.8 {
  set ::r
} {1 {locking protocol}}

db close
db2 close
T delete

finish_test

          SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<500
          )
        INSERT INTO t2 SELECT randomblob(500) FROM s;
        SELECT count(*) FROM t2;
    } 
  } {500}
  do_test $TN.4.2.2 {
    file size test.db-wal

  } {461152}
  do_test $TN.4.2.4 {
    file_control_persist_wal db 1; db close

    copy_to_test2 $bZeroShm
    code2 { sqlite3 db2 file:test.db2?readonly_shm=1 }
    sql2 {
      SELECT * FROM t1;

          SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<500
          )
        INSERT INTO t2 SELECT randomblob(500) FROM s;
        SELECT count(*) FROM t2;
    } 
  } {500}
  do_test $TN.4.2.2 {
    set sz [file size test.db-wal]
    expr {$sz>400000 && $sz<500000}
  } {1}
  do_test $TN.4.2.4 {
    file_control_persist_wal db 1; db close

    copy_to_test2 $bZeroShm
    code2 { sqlite3 db2 file:test.db2?readonly_shm=1 }
    sql2 {
      SELECT * FROM t1;

};

static void yy_accept(yyParser*);  /* Forward Declaration */

/*
** Perform a reduce action and the shift that must immediately
** follow the reduce.






*/
static void yy_reduce(
  yyParser *yypParser,         /* The parser */
  unsigned int yyruleno        /* Number of the rule by which to reduce */


){
  int yygoto;                     /* The next state */
  int yyact;                      /* The next action */
  yyStackEntry *yymsp;            /* The top of the parser's stack */
  int yysize;                     /* Amount to pop the stack */
  ParseARG_FETCH;
  yymsp = yypParser->yytos;
................................................................................
    if( yyact <= YY_MAX_SHIFTREDUCE ){
      yy_shift(yypParser,yyact,yymajor,yyminor);
#ifndef YYNOERRORRECOVERY
      yypParser->yyerrcnt--;
#endif
      yymajor = YYNOCODE;
    }else if( yyact <= YY_MAX_REDUCE ){
      yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
    }else{
      assert( yyact == YY_ERROR_ACTION );
      yyminorunion.yy0 = yyminor;
#ifdef YYERRORSYMBOL
      int yymx;
#endif
#ifndef NDEBUG

};

static void yy_accept(yyParser*);  /* Forward Declaration */

/*
** Perform a reduce action and the shift that must immediately
** follow the reduce.
**
** The yyLookahead and yyLookaheadToken parameters provide reduce actions
** access to the lookahead token (if any).  The yyLookahead will be YYNOCODE
** if the lookahead token has already been consumed.  As this procedure is
** only called from one place, optimizing compilers will in-line it, which
** means that the extra parameters have no performance impact.
*/
static void yy_reduce(
  yyParser *yypParser,         /* The parser */
  unsigned int yyruleno,       /* Number of the rule by which to reduce */
  int yyLookahead,             /* Lookahead token, or YYNOCODE if none */
  ParseTOKENTYPE yyLookaheadToken  /* Value of the lookahead token */
){
  int yygoto;                     /* The next state */
  int yyact;                      /* The next action */
  yyStackEntry *yymsp;            /* The top of the parser's stack */
  int yysize;                     /* Amount to pop the stack */
  ParseARG_FETCH;
  yymsp = yypParser->yytos;
................................................................................
    if( yyact <= YY_MAX_SHIFTREDUCE ){
      yy_shift(yypParser,yyact,yymajor,yyminor);
#ifndef YYNOERRORRECOVERY
      yypParser->yyerrcnt--;
#endif
      yymajor = YYNOCODE;
    }else if( yyact <= YY_MAX_REDUCE ){
      yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,yyminor);
    }else{
      assert( yyact == YY_ERROR_ACTION );
      yyminorunion.yy0 = yyminor;
#ifdef YYERRORSYMBOL
      int yymx;
#endif
#ifndef NDEBUG