**
*************************************************************************
** This file contains code used to implement the sqlite3_set_authorizer()
** API.  This facility is an optional feature of the library.  Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
**
** $Id: auth.c,v 1.26 2007/05/14 11:34:47 drh Exp $
*/
#include "sqliteInt.h"

/*
** All of the code in this file may be omitted by defining a single
** macro.
*/
................................................................................
** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){

  db->xAuth = xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);

  return SQLITE_OK;
}

/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/

**
*************************************************************************
** This file contains code used to implement the sqlite3_set_authorizer()
** API.  This facility is an optional feature of the library.  Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
**
** $Id: auth.c,v 1.27 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"

/*
** All of the code in this file may be omitted by defining a single
** macro.
*/
................................................................................
** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){
  sqlite3_mutex_enter(db->mutex);
  db->xAuth = xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.405 2007/08/21 13:11:01 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
int sqlite3BtreeEof(BtCursor *pCur){
  /* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries
  ** have been deleted? This API will need to change to return an error code
  ** as well as the boolean result value.
  */
  return (CURSOR_VALID!=pCur->eState);
}








/*
** Advance the cursor to the next entry in the database.  If
** successful then set *pRes=0.  If the cursor
** was already pointing to the last entry in the database before
** this routine was called, then set *pRes=1.
*/

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.406 2007/08/21 19:33:56 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
int sqlite3BtreeEof(BtCursor *pCur){
  /* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries
  ** have been deleted? This API will need to change to return an error code
  ** as well as the boolean result value.
  */
  return (CURSOR_VALID!=pCur->eState);
}

/*
** Return the database connection handle for a cursor.
*/
sqlite3 *sqlite3BtreeCursorDb(const BtCursor *pCur){
  return pCur->pBtree->pSqlite;
}

/*
** Advance the cursor to the next entry in the database.  If
** successful then set *pRes=0.  If the cursor
** was already pointing to the last entry in the database before
** this routine was called, then set *pRes=1.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.84 2007/08/20 22:48:42 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
................................................................................
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreeFlags(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int *pRes);
int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);

const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.85 2007/08/21 19:33:56 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
................................................................................
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreeFlags(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int *pRes);
int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
sqlite3 *sqlite3BtreeCursorDb(const BtCursor*);
const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.436 2007/08/17 01:14:38 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
  int i;
  int nCol = pIdx->nColumn;
  int nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
  KeyInfo *pKey = (KeyInfo *)sqlite3DbMallocZero(pParse->db, nBytes);

  if( pKey ){

    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );
    for(i=0; i<nCol; i++){
      char *zColl = pIdx->azColl[i];
      assert( zColl );
      pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl, -1);
      pKey->aSortOrder[i] = pIdx->aSortOrder[i];

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.437 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
  int i;
  int nCol = pIdx->nColumn;
  int nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
  KeyInfo *pKey = (KeyInfo *)sqlite3DbMallocZero(pParse->db, nBytes);

  if( pKey ){
    pKey->db = pParse->db;
    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );
    for(i=0; i<nCol; i++){
      char *zColl = pIdx->azColl[i];
      assert( zColl );
      pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl, -1);
      pKey->aSortOrder[i] = pIdx->aSortOrder[i];

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
**
** $Id: callback.c,v 1.20 2007/08/16 10:09:02 danielk1977 Exp $
*/

#include "sqliteInt.h"

/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the database text encoding of name zName, length nName.
................................................................................
    db->xCollNeeded(db->pCollNeededArg, db, (int)ENC(db), zExternal);
    sqlite3_free(zExternal);
  }
#ifndef SQLITE_OMIT_UTF16
  if( db->xCollNeeded16 ){
    char const *zExternal;
    sqlite3_value *pTmp = sqlite3ValueNew(db);
    sqlite3ValueSetStr(db, pTmp, nName, zName, SQLITE_UTF8, SQLITE_STATIC);
    zExternal = sqlite3ValueText(db, pTmp, SQLITE_UTF16NATIVE);
    if( zExternal ){
      db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);
    }
    sqlite3ValueFree(pTmp);
  }
#endif
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
**
** $Id: callback.c,v 1.21 2007/08/21 19:33:56 drh Exp $
*/

#include "sqliteInt.h"

/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the database text encoding of name zName, length nName.
................................................................................
    db->xCollNeeded(db->pCollNeededArg, db, (int)ENC(db), zExternal);
    sqlite3_free(zExternal);
  }
#ifndef SQLITE_OMIT_UTF16
  if( db->xCollNeeded16 ){
    char const *zExternal;
    sqlite3_value *pTmp = sqlite3ValueNew(db);
    sqlite3ValueSetStr(pTmp, nName, zName, SQLITE_UTF8, SQLITE_STATIC);
    zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);
    if( zExternal ){
      db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);
    }
    sqlite3ValueFree(pTmp);
  }
#endif
}

** An tokenizer for SQL
**
** This file contains C code that implements the sqlite3_complete() API.
** This code used to be part of the tokenizer.c source file.  But by
** separating it out, the code will be automatically omitted from
** static links that do not use it.
**
** $Id: complete.c,v 1.4 2007/08/16 10:09:02 danielk1977 Exp $
*/
#include "sqliteInt.h"
#ifndef SQLITE_OMIT_COMPLETE

/*
** This is defined in tokenize.c.  We just have to import the definition.
*/
................................................................................
*/
int sqlite3_complete16(const void *zSql){
  sqlite3_value *pVal;
  char const *zSql8;
  int rc = SQLITE_NOMEM;

  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zSql8 = sqlite3ValueText(0, pVal, SQLITE_UTF8);
  if( zSql8 ){
    rc = sqlite3_complete(zSql8);
  }
  sqlite3ValueFree(pVal);
  return sqlite3ApiExit(0, rc);
}
#endif /* SQLITE_OMIT_UTF16 */
#endif /* SQLITE_OMIT_COMPLETE */

** An tokenizer for SQL
**
** This file contains C code that implements the sqlite3_complete() API.
** This code used to be part of the tokenizer.c source file.  But by
** separating it out, the code will be automatically omitted from
** static links that do not use it.
**
** $Id: complete.c,v 1.5 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#ifndef SQLITE_OMIT_COMPLETE

/*
** This is defined in tokenize.c.  We just have to import the definition.
*/
................................................................................
*/
int sqlite3_complete16(const void *zSql){
  sqlite3_value *pVal;
  char const *zSql8;
  int rc = SQLITE_NOMEM;

  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zSql8 ){
    rc = sqlite3_complete(zSql8);
  }
  sqlite3ValueFree(pVal);
  return sqlite3ApiExit(0, rc);
}
#endif /* SQLITE_OMIT_UTF16 */
#endif /* SQLITE_OMIT_COMPLETE */

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.70 2007/08/21 10:44:16 drh Exp $
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
................................................................................
static void ctimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(0, pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    timeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_date()
................................................................................
static void cdateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(0, pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    dateFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_timestamp()
................................................................................
static void ctimestampFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(0, pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    datetimeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

#ifdef SQLITE_OMIT_DATETIME_FUNCS

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.71 2007/08/21 19:33:56 drh Exp $
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
................................................................................
static void ctimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    timeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_date()
................................................................................
static void cdateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    dateFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_timestamp()
................................................................................
static void ctimestampFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    datetimeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

#ifdef SQLITE_OMIT_DATETIME_FUNCS

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.167 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

................................................................................
  char *zVal;
  int len;
  sqlite3 *db = sqlite3_user_data(pCtx);
 
  test_destructor_count_var++;
  assert( nArg==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  len = sqlite3ValueBytes(0, argv[0], ENC(db)); 
  zVal = sqlite3MallocZero(len+3);
  zVal[len] = 0;
  zVal[len-1] = 0;
  assert( zVal );
  zVal++;
  memcpy(zVal, sqlite3ValueText(0, argv[0], ENC(db)), len);
  if( ENC(db)==SQLITE_UTF8 ){
    sqlite3_result_text(pCtx, zVal, -1, destructor);
#ifndef SQLITE_OMIT_UTF16
  }else if( ENC(db)==SQLITE_UTF16LE ){
    sqlite3_result_text16le(pCtx, zVal, -1, destructor);
  }else{
    sqlite3_result_text16be(pCtx, zVal, -1, destructor);
................................................................................
    ** returns (void *)db, where db is the sqlite3* database pointer.
    ** Therefore the next statement sets variable 'max' to 1 for the max()
    ** aggregate, or 0 for min().
    */
    max = sqlite3_user_data(context)!=0;
    cmp = sqlite3MemCompare(pBest, pArg, pColl);
    if( (max && cmp<0) || (!max && cmp>0) ){
      sqlite3VdbeMemCopy(0, pBest, pArg);
    }
  }else{
    sqlite3VdbeMemCopy(0, pBest, pArg);
  }
}
static void minMaxFinalize(sqlite3_context *context){
  sqlite3_value *pRes;
  pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
  if( pRes ){
    if( pRes->flags ){

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.168 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

................................................................................
  char *zVal;
  int len;
  sqlite3 *db = sqlite3_user_data(pCtx);
 
  test_destructor_count_var++;
  assert( nArg==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  len = sqlite3ValueBytes(argv[0], ENC(db)); 
  zVal = sqlite3MallocZero(len+3);
  zVal[len] = 0;
  zVal[len-1] = 0;
  assert( zVal );
  zVal++;
  memcpy(zVal, sqlite3ValueText(argv[0], ENC(db)), len);
  if( ENC(db)==SQLITE_UTF8 ){
    sqlite3_result_text(pCtx, zVal, -1, destructor);
#ifndef SQLITE_OMIT_UTF16
  }else if( ENC(db)==SQLITE_UTF16LE ){
    sqlite3_result_text16le(pCtx, zVal, -1, destructor);
  }else{
    sqlite3_result_text16be(pCtx, zVal, -1, destructor);
................................................................................
    ** returns (void *)db, where db is the sqlite3* database pointer.
    ** Therefore the next statement sets variable 'max' to 1 for the max()
    ** aggregate, or 0 for min().
    */
    max = sqlite3_user_data(context)!=0;
    cmp = sqlite3MemCompare(pBest, pArg, pColl);
    if( (max && cmp<0) || (!max && cmp>0) ){
      sqlite3VdbeMemCopy(pBest, pArg);
    }
  }else{
    sqlite3VdbeMemCopy(pBest, pArg);
  }
}
static void minMaxFinalize(sqlite3_context *context){
  sqlite3_value *pRes;
  pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
  if( pRes ){
    if( pRes->flags ){

**
** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
**
** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with 
** error message text.  The calling function should free this memory
** by calling sqlite3_free().
*/
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
){
  sqlite3_vfs *pVfs = db->pVfs;
  void *handle;
................................................................................
  }
  sqlite3_free(db->aExtension);
  db->aExtension = aHandle;

  db->aExtension[db->nExtension-1] = handle;
  return SQLITE_OK;
}













/*
** Call this routine when the database connection is closing in order
** to clean up loaded extensions
*/
void sqlite3CloseExtensions(sqlite3 *db){
  int i;

  for(i=0; i<db->nExtension; i++){
    sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
  }
  sqlite3_free(db->aExtension);
}

/*
** Enable or disable extension loading.  Extension loading is disabled by
** default so as not to open security holes in older applications.
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff){

  if( onoff ){
    db->flags |= SQLITE_LoadExtension;
  }else{
    db->flags &= ~SQLITE_LoadExtension;
  }

  return SQLITE_OK;
}

/*
** The following object holds the list of automatically loaded
** extensions.
**

**
** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
**
** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with 
** error message text.  The calling function should free this memory
** by calling sqlite3_free().
*/
static int sqlite3LoadExtension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
){
  sqlite3_vfs *pVfs = db->pVfs;
  void *handle;
................................................................................
  }
  sqlite3_free(db->aExtension);
  db->aExtension = aHandle;

  db->aExtension[db->nExtension-1] = handle;
  return SQLITE_OK;
}
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
){
  int rc;
  sqlite3_mutex_enter(db->mutex);
  rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Call this routine when the database connection is closing in order
** to clean up loaded extensions
*/
void sqlite3CloseExtensions(sqlite3 *db){
  int i;
  assert( sqlite3_mutex_held(db->mutex) );
  for(i=0; i<db->nExtension; i++){
    sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
  }
  sqlite3_free(db->aExtension);
}

/*
** Enable or disable extension loading.  Extension loading is disabled by
** default so as not to open security holes in older applications.
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
  sqlite3_mutex_enter(db->mutex);
  if( onoff ){
    db->flags |= SQLITE_LoadExtension;
  }else{
    db->flags &= ~SQLITE_LoadExtension;
  }
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** The following object holds the list of automatically loaded
** extensions.
**

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.392 2007/08/21 16:15:56 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The version of the library
*/
................................................................................
  if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE ){
    return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  z = sqlite3_value_text16(db->pErr);
  if( z==0 ){
    sqlite3ValueSetStr(db, db->pErr, -1, sqlite3ErrStr(db->errCode),
         SQLITE_UTF8, SQLITE_STATIC);
    z = sqlite3_value_text16(db->pErr);
  }
  sqlite3ApiExit(0, 0);
  sqlite3_mutex_leave(db->mutex);
  return z;
}
................................................................................
  sqlite3_value *pVal;
  int rc = SQLITE_NOMEM;

  assert( zFilename );
  assert( ppDb );
  *ppDb = 0;
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(0, pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    if( rc==SQLITE_OK && *ppDb ){
      rc = sqlite3_exec(*ppDb, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
      if( rc!=SQLITE_OK ){
        sqlite3_close(*ppDb);

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.393 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The version of the library
*/
................................................................................
  if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE ){
    return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  z = sqlite3_value_text16(db->pErr);
  if( z==0 ){
    sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
         SQLITE_UTF8, SQLITE_STATIC);
    z = sqlite3_value_text16(db->pErr);
  }
  sqlite3ApiExit(0, 0);
  sqlite3_mutex_leave(db->mutex);
  return z;
}
................................................................................
  sqlite3_value *pVal;
  int rc = SQLITE_NOMEM;

  assert( zFilename );
  assert( ppDb );
  *ppDb = 0;
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    if( rc==SQLITE_OK && *ppDb ){
      rc = sqlite3_exec(*ppDb, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
      if( rc!=SQLITE_OK ){
        sqlite3_close(*ppDb);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Memory allocation functions used throughout sqlite.
**
**
** $Id: malloc.c,v 1.7 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

/*













** Set the soft heap-size limit for the current thread. Passing a negative
** value indicates no limit.
*/
void sqlite3_soft_heap_limit(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  ThreadData *pTd = sqlite3ThreadData();


  if( pTd ){


    pTd->nSoftHeapLimit = n;
  }
  sqlite3ReleaseThreadData();
#endif









}

/*
** Release memory held by SQLite instances created by the current thread.
*/
int sqlite3_release_memory(int n){
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
................................................................................
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
void *sqlite3DbMallocZero(sqlite3 *db, unsigned n){
  void *p = sqlite3_malloc(n);
  if( p ){
    memset(p, 0, n);
  }else{
    db->mallocFailed = 1;
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
................................................................................
  if( db && db->mallocFailed ){
    sqlite3Error(db, SQLITE_NOMEM, 0);
    db->mallocFailed = 0;
    rc = SQLITE_NOMEM;
  }
  return rc & (db ? db->errMask : 0xff);
}

#ifdef SQLITE_MEMDEBUG
/*
** This function sets a flag in the thread-specific-data structure that will
** cause an assert to fail if sqliteMalloc() or sqliteRealloc() is called.
*/
#if 0
void sqlite3MallocDisallow(){
#if 0
  assert( sqlite3_mallocDisallowed>=0 );
  sqlite3_mallocDisallowed++;
#endif
}

/*
** This function clears the flag set in the thread-specific-data structure set
** by sqlite3MallocDisallow().
*/
void sqlite3MallocAllow(){
#if 0
  assert( sqlite3_mallocDisallowed>0 );
  sqlite3_mallocDisallowed--;
#endif
}
#endif
#endif

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Memory allocation functions used throughout sqlite.
**
**
** $Id: malloc.c,v 1.8 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

/*
** This routine runs when the memory allocator sees that the
** total memory allocation is about to exceed the soft heap
** limit.
*/
static void softHeapLimitEnforcer(
  void *NotUsed, 
  sqlite3_uint64 inUse,
  unsigned int allocSize
){
  sqlite3_release_memory(allocSize);
}

/*
** Set the soft heap-size limit for the current thread. Passing a
** zero or negative value indicates no limit.
*/
void sqlite3_soft_heap_limit(int n){


  sqlite3_uint64 iLimit;
  int overage;
  if( n<0 ){
    iLimit = 0;
  }else{
    iLimit = n;
  }


  if( iLimit>0 ){
    sqlite3_memory_alarm(softHeapLimitEnforcer, 0, iLimit);
  }else{
    sqlite3_memory_alarm(0, 0, 0);
  }
  overage = sqlite3_memory_used() - n;
  if( overage>0 ){
    sqlite3_release_memory(overage);
  }
}

/*
** Release memory held by SQLite instances created by the current thread.
*/
int sqlite3_release_memory(int n){
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
................................................................................
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
void *sqlite3DbMallocZero(sqlite3 *db, unsigned n){
  void *p = sqlite3_malloc(n);
  if( p ){
    memset(p, 0, n);
  }else if( db ){
    db->mallocFailed = 1;
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
................................................................................
  if( db && db->mallocFailed ){
    sqlite3Error(db, SQLITE_NOMEM, 0);
    db->mallocFailed = 0;
    rc = SQLITE_NOMEM;
  }
  return rc & (db ? db->errMask : 0xff);
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.55 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  assert( !db->mallocFailed );

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }


  /* If any attached database schemas are locked, do not proceed with
  ** compilation. Instead return SQLITE_LOCKED immediately.
  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;
    if( pBt && sqlite3BtreeSchemaLocked(pBt) ){
................................................................................
  }

  rc = sqlite3ApiExit(db, rc);
  /* sqlite3ReleaseThreadData(); */
  assert( (rc&db->errMask)==rc );
  return rc;
}















/*
** Rerun the compilation of a statement after a schema change.
** Return true if the statement was recompiled successfully.
** Return false if there is an error of some kind.
*/
int sqlite3Reprepare(Vdbe *p){
  int rc;
  sqlite3_stmt *pNew;
  const char *zSql;
  sqlite3 *db;
  
  zSql = sqlite3VdbeGetSql(p);
  if( zSql==0 ){
    return 0;
  }
  db = sqlite3VdbeDb(p);

  rc = sqlite3Prepare(db, zSql, -1, 0, &pNew, 0);
  if( rc ){
    assert( pNew==0 );
    return 0;
  }else{
    assert( pNew!=0 );
  }
................................................................................
int sqlite3_prepare(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  return sqlite3Prepare(db,zSql,nBytes,0,ppStmt,pzTail);
}
int sqlite3_prepare_v2(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  return sqlite3Prepare(db,zSql,nBytes,1,ppStmt,pzTail);
}


#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
................................................................................
  char *zSql8;
  const char *zTail8 = 0;
  int rc = SQLITE_OK;

  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }

  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
  if( zSql8 ){
    rc = sqlite3Prepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
  }

  if( zTail8 && pzTail ){
    /* If sqlite3_prepare returns a tail pointer, we calculate the
................................................................................
    ** characters between zSql8 and zTail8, and then returning a pointer
    ** the same number of characters into the UTF-16 string.
    */
    int chars_parsed = sqlite3Utf8CharLen(zSql8, zTail8-zSql8);
    *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
  }
  sqlite3_free(zSql8); 
  return sqlite3ApiExit(db, rc);


}

/*
** Two versions of the official API.  Legacy and new use.  In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step().  In the new version, the original SQL text is retained

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.56 2007/08/21 19:33:56 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  assert( !db->mallocFailed );

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }
  assert( sqlite3_mutex_held(db->mutex) );

  /* If any attached database schemas are locked, do not proceed with
  ** compilation. Instead return SQLITE_LOCKED immediately.
  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;
    if( pBt && sqlite3BtreeSchemaLocked(pBt) ){
................................................................................
  }

  rc = sqlite3ApiExit(db, rc);
  /* sqlite3ReleaseThreadData(); */
  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. */
  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;
  sqlite3_mutex_enter(db->mutex);
  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.
** Return true if the statement was recompiled successfully.
** Return false if there is an error of some kind.
*/
int sqlite3Reprepare(Vdbe *p){
  int rc;
  sqlite3_stmt *pNew;
  const char *zSql;
  sqlite3 *db;

  zSql = sqlite3VdbeGetSql(p);
  if( zSql==0 ){
    return 0;
  }
  db = sqlite3VdbeDb(p);
  assert( sqlite3_mutex_held(db->mutex) );
  rc = sqlite3Prepare(db, zSql, -1, 0, &pNew, 0);
  if( rc ){
    assert( pNew==0 );
    return 0;
  }else{
    assert( pNew!=0 );
  }
................................................................................
int sqlite3_prepare(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  return sqlite3LockAndPrepare(db,zSql,nBytes,0,ppStmt,pzTail);
}
int sqlite3_prepare_v2(
  sqlite3 *db,              /* Database handle. */
  const char *zSql,         /* UTF-8 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const char **pzTail       /* OUT: End of parsed string */
){
  return sqlite3LockAndPrepare(db,zSql,nBytes,1,ppStmt,pzTail);
}


#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
................................................................................
  char *zSql8;
  const char *zTail8 = 0;
  int rc = SQLITE_OK;

  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);
  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
  if( zSql8 ){
    rc = sqlite3Prepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
  }

  if( zTail8 && pzTail ){
    /* If sqlite3_prepare returns a tail pointer, we calculate the
................................................................................
    ** characters between zSql8 and zTail8, and then returning a pointer
    ** the same number of characters into the UTF-16 string.
    */
    int chars_parsed = sqlite3Utf8CharLen(zSql8, zTail8-zSql8);
    *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
  }
  sqlite3_free(zSql8); 
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Two versions of the official API.  Legacy and new use.  In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step().  In the new version, the original SQL text is retained

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.233 2007/08/21 16:15:56 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
**
** The pUserData parameter to the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines
** used to register user functions is available to
** the implementation of the function using this call.
**
** This routine must be called from the same thread in which
** the SQL function was originally invoked.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data
**
** The following two functions may be used by scalar SQL functions to
................................................................................
** data pointer to release it when it is no longer required. If the 
** destructor is NULL, it is not invoked.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routine must be called from the same thread in which
** the SQL function was originally invoked.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int);
void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior
................................................................................
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  But if it
** is unable to reduce memory usage below the soft limit, execution will
** continue without error or notification.  This is why the limit is 
** called a "soft" limit.  It is advisory only.






**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied cumulatively to all threads.
*/
void sqlite3_soft_heap_limit(int);

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.234 2007/08/21 19:33:56 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
**
** The pUserData parameter to the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines
** used to register user functions is available to
** the implementation of the function using this call.
**
** This routine must be called from the same thread in which
** the SQL function is running.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data
**
** The following two functions may be used by scalar SQL functions to
................................................................................
** data pointer to release it when it is no longer required. If the 
** destructor is NULL, it is not invoked.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int);
void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior
................................................................................
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  But if it
** is unable to reduce memory usage below the soft limit, execution will
** continue without error or notification.  This is why the limit is 
** called a "soft" limit.  It is advisory only.
**
** The soft heap limit is implemented using the [sqlite3_memory_alarm()]
** interface.  Only a single memory alarm is available in the default
** implementation.  This means that if the application also uses the
** memory alarm interface it will interfere with the operation of the
** soft heap limit and undefined behavior will result.  
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied cumulatively to all threads.
*/
void sqlite3_soft_heap_limit(int);

**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.594 2007/08/21 13:51:23 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
#include "sqliteLimit.h"


#if defined(SQLITE_TCL) || defined(TCLSH)
................................................................................
** comparison of the two index keys.
**
** If the KeyInfo.incrKey value is true and the comparison would
** otherwise be equal, then return a result as if the second key
** were larger.
*/
struct KeyInfo {

  u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
  u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
  int nField;         /* Number of entries in aColl[] */
  u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
};

................................................................................
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);

const void *sqlite3ValueText(sqlite3 *db, sqlite3_value*, u8);
int sqlite3ValueBytes(sqlite3 *db, sqlite3_value*, u8);
void sqlite3ValueSetStr(sqlite3 *,sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
void sqlite3ValueFree(sqlite3_value*);
sqlite3_value *sqlite3ValueNew(sqlite3 *);
char *sqlite3Utf16to8(sqlite3 *, const void*, int);
int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
void sqlite3ValueApplyAffinity(sqlite3 *, sqlite3_value *, u8, u8);
extern const unsigned char sqlite3UpperToLower[];
void sqlite3RootPageMoved(Db*, int, int);
void sqlite3Reindex(Parse*, Token*, Token*);
void sqlite3AlterFunctions(sqlite3*);
void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite3GetToken(const unsigned char *, int *);
void sqlite3NestedParse(Parse*, const char*, ...);

**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.595 2007/08/21 19:33:56 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
#include "sqliteLimit.h"


#if defined(SQLITE_TCL) || defined(TCLSH)
................................................................................
** comparison of the two index keys.
**
** If the KeyInfo.incrKey value is true and the comparison would
** otherwise be equal, then return a result as if the second key
** were larger.
*/
struct KeyInfo {
  sqlite3 *db;        /* The database connection */
  u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
  u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
  int nField;         /* Number of entries in aColl[] */
  u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
};

................................................................................
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);

const void *sqlite3ValueText(sqlite3_value*, u8);
int sqlite3ValueBytes(sqlite3_value*, u8);
void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
void sqlite3ValueFree(sqlite3_value*);
sqlite3_value *sqlite3ValueNew(sqlite3 *);
char *sqlite3Utf16to8(sqlite3 *, const void*, int);
int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
extern const unsigned char sqlite3UpperToLower[];
void sqlite3RootPageMoved(Db*, int, int);
void sqlite3Reindex(Parse*, Token*, Token*);
void sqlite3AlterFunctions(sqlite3*);
void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite3GetToken(const unsigned char *, int *);
void sqlite3NestedParse(Parse*, const char*, ...);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.266 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

/*
................................................................................
  if( rc==SQLITE_OK ){
    sqlite3_value *pVal;
#if 0
    if( sqlite3_iMallocFail>0 ){
      sqlite3_iMallocFail++;
    }
#endif 
    pVal = sqlite3ValueNew(0);
    sqlite3ValueSetStr(0,pVal, -1, "x_sqlite_exec", SQLITE_UTF8, SQLITE_STATIC);
    rc = sqlite3_create_function16(db, 
              sqlite3ValueText(0, pVal, SQLITE_UTF16NATIVE),
              1, SQLITE_UTF16, db, sqlite3ExecFunc, 0, 0);
    sqlite3ValueFree(pVal);
  }
#endif

  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), 0);
................................................................................
      Tcl_ListObjAppendElement(i,pX,Tcl_NewStringObj("UTF-16BE",-1));
      break;
    default:
      assert(0);
  }

  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, nA, zA, encin, SQLITE_STATIC);
  n = sqlite3_value_bytes(pVal);
  Tcl_ListObjAppendElement(i,pX,
      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
  sqlite3ValueSetStr(0, pVal, nB, zB, encin, SQLITE_STATIC);
  n = sqlite3_value_bytes(pVal);
  Tcl_ListObjAppendElement(i,pX,
      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
  sqlite3ValueFree(pVal);

  Tcl_EvalObjEx(i, pX, 0);
  Tcl_DecrRefCount(pX);
................................................................................

#ifdef SQLITE_MEMDEBUG
    if( sqlite3_iMallocFail>0 ){
      sqlite3_iMallocFail++;
    }
#endif
    pVal = sqlite3ValueNew(0);
    sqlite3ValueSetStr(0, pVal, -1, "test_collate", SQLITE_UTF8, SQLITE_STATIC);
    rc = sqlite3_create_collation16(db, 
          sqlite3ValueText(0, pVal, SQLITE_UTF16NATIVE), SQLITE_UTF16BE, 
          (void *)SQLITE_UTF16BE, val?test_collate_func:0);
    sqlite3ValueFree(pVal);
  }
  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
................................................................................
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-8", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  sqlite3_result_text(pCtx, Tcl_GetStringResult(interp), -1, SQLITE_TRANSIENT);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text16be(pCtx, sqlite3_value_text16be(pVal),
      -1, SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
static void test_function_utf16le(
  sqlite3_context *pCtx, 
................................................................................
  Tcl_IncrRefCount(pX);
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16LE", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text(pCtx,(char*)sqlite3_value_text(pVal),-1,SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
static void test_function_utf16be(
  sqlite3_context *pCtx, 
  int nArg,
................................................................................
  Tcl_IncrRefCount(pX);
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16BE", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(0, pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text16le(pCtx, sqlite3_value_text16le(pVal),
      -1, SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
#endif /* SQLITE_OMIT_UTF16 */
static int test_function(

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.267 2007/08/21 19:33:57 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

/*
................................................................................
  if( rc==SQLITE_OK ){
    sqlite3_value *pVal;
#if 0
    if( sqlite3_iMallocFail>0 ){
      sqlite3_iMallocFail++;
    }
#endif 
    pVal = sqlite3ValueNew(db);
    sqlite3ValueSetStr(pVal, -1, "x_sqlite_exec", SQLITE_UTF8, SQLITE_STATIC);
    rc = sqlite3_create_function16(db, 
              sqlite3ValueText(pVal, SQLITE_UTF16NATIVE),
              1, SQLITE_UTF16, db, sqlite3ExecFunc, 0, 0);
    sqlite3ValueFree(pVal);
  }
#endif

  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), 0);
................................................................................
      Tcl_ListObjAppendElement(i,pX,Tcl_NewStringObj("UTF-16BE",-1));
      break;
    default:
      assert(0);
  }

  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, nA, zA, encin, SQLITE_STATIC);
  n = sqlite3_value_bytes(pVal);
  Tcl_ListObjAppendElement(i,pX,
      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
  sqlite3ValueSetStr(pVal, nB, zB, encin, SQLITE_STATIC);
  n = sqlite3_value_bytes(pVal);
  Tcl_ListObjAppendElement(i,pX,
      Tcl_NewStringObj((char*)sqlite3_value_text(pVal),n));
  sqlite3ValueFree(pVal);

  Tcl_EvalObjEx(i, pX, 0);
  Tcl_DecrRefCount(pX);
................................................................................

#ifdef SQLITE_MEMDEBUG
    if( sqlite3_iMallocFail>0 ){
      sqlite3_iMallocFail++;
    }
#endif
    pVal = sqlite3ValueNew(0);
    sqlite3ValueSetStr(pVal, -1, "test_collate", SQLITE_UTF8, SQLITE_STATIC);
    rc = sqlite3_create_collation16(db, 
          sqlite3ValueText(pVal, SQLITE_UTF16NATIVE), SQLITE_UTF16BE, 
          (void *)SQLITE_UTF16BE, val?test_collate_func:0);
    sqlite3ValueFree(pVal);
  }
  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
................................................................................
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-8", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  sqlite3_result_text(pCtx, Tcl_GetStringResult(interp), -1, SQLITE_TRANSIENT);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text16be(pCtx, sqlite3_value_text16be(pVal),
      -1, SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
static void test_function_utf16le(
  sqlite3_context *pCtx, 
................................................................................
  Tcl_IncrRefCount(pX);
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16LE", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text(pCtx,(char*)sqlite3_value_text(pVal),-1,SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
static void test_function_utf16be(
  sqlite3_context *pCtx, 
  int nArg,
................................................................................
  Tcl_IncrRefCount(pX);
  Tcl_ListObjAppendElement(interp, pX, Tcl_NewStringObj("UTF-16BE", -1));
  Tcl_ListObjAppendElement(interp, pX, 
      Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1));
  Tcl_EvalObjEx(interp, pX, 0);
  Tcl_DecrRefCount(pX);
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, Tcl_GetStringResult(interp), 
      SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_result_text16le(pCtx, sqlite3_value_text16le(pVal),
      -1, SQLITE_TRANSIENT);
  sqlite3ValueFree(pVal);
}
#endif /* SQLITE_OMIT_UTF16 */
static int test_function(

*************************************************************************
** Code for testing the utf.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library. Specifically, the code in this file
** is used for testing the SQLite routines for converting between
** the various supported unicode encodings.
**
** $Id: test5.c,v 1.19 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  pVal = sqlite3ValueNew(0);

  if( enc_from==SQLITE_UTF8 ){
    z = Tcl_GetString(objv[1]);
    if( objc==5 ){
      z = sqlite3StrDup(z);
    }
    sqlite3ValueSetStr(0, pVal, -1, z, enc_from, xDel);
  }else{
    z = (char*)Tcl_GetByteArrayFromObj(objv[1], &len);
    if( objc==5 ){
      char *zTmp = z;
      z = sqlite3_malloc(len);
      memcpy(z, zTmp, len);
    }
    sqlite3ValueSetStr(0, pVal, -1, z, enc_from, xDel);
  }

  z = (char *)sqlite3ValueText(0, pVal, enc_to);
  len = sqlite3ValueBytes(0, pVal, enc_to) + (enc_to==SQLITE_UTF8?1:2);
  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj((u8*)z, len));

  sqlite3ValueFree(pVal);

  return TCL_OK;
}

*************************************************************************
** Code for testing the utf.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library. Specifically, the code in this file
** is used for testing the SQLite routines for converting between
** the various supported unicode encodings.
**
** $Id: test5.c,v 1.20 2007/08/21 19:33:57 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  pVal = sqlite3ValueNew(0);

  if( enc_from==SQLITE_UTF8 ){
    z = Tcl_GetString(objv[1]);
    if( objc==5 ){
      z = sqlite3StrDup(z);
    }
    sqlite3ValueSetStr(pVal, -1, z, enc_from, xDel);
  }else{
    z = (char*)Tcl_GetByteArrayFromObj(objv[1], &len);
    if( objc==5 ){
      char *zTmp = z;
      z = sqlite3_malloc(len);
      memcpy(z, zTmp, len);
    }
    sqlite3ValueSetStr(pVal, -1, z, enc_from, xDel);
  }

  z = (char *)sqlite3ValueText(pVal, enc_to);
  len = sqlite3ValueBytes(pVal, enc_to) + (enc_to==SQLITE_UTF8?1:2);
  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj((u8*)z, len));

  sqlite3ValueFree(pVal);

  return TCL_OK;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used to translate between UTF-8, 
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id: utf.c,v 1.55 2007/08/16 10:09:03 danielk1977 Exp $
**
** Notes on UTF-8:
**
**   Byte-0    Byte-1    Byte-2    Byte-3    Value
**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx
................................................................................

#ifndef SQLITE_OMIT_UTF16
/*
** This routine transforms the internal text encoding used by pMem to
** desiredEnc. It is an error if the string is already of the desired
** encoding, or if *pMem does not contain a string value.
*/
int sqlite3VdbeMemTranslate(sqlite3 *db, Mem *pMem, u8 desiredEnc){
  unsigned char zShort[NBFS]; /* Temporary short output buffer */
  int len;                    /* Maximum length of output string in bytes */
  unsigned char *zOut;                  /* Output buffer */
  unsigned char *zIn;                   /* Input iterator */
  unsigned char *zTerm;                 /* End of input */
  unsigned char *z;                     /* Output iterator */
  unsigned int c;


  assert( pMem->flags&MEM_Str );
  assert( pMem->enc!=desiredEnc );
  assert( pMem->enc!=0 );
  assert( pMem->n>=0 );

#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
  {
................................................................................
  /* If the translation is between UTF-16 little and big endian, then 
  ** all that is required is to swap the byte order. This case is handled
  ** differently from the others.
  */
  if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){
    u8 temp;
    int rc;
    rc = sqlite3VdbeMemMakeWriteable(db, pMem);
    if( rc!=SQLITE_OK ){
      assert( rc==SQLITE_NOMEM );
      return SQLITE_NOMEM;
    }
    zIn = (u8*)pMem->z;
    zTerm = &zIn[pMem->n];
    while( zIn<zTerm ){
................................................................................
  ** Variable zOut is set to point at the output buffer. This may be space
  ** obtained from sqlite3_malloc(), or Mem.zShort, if it large enough and
  ** not in use, or the zShort array on the stack (see above).
  */
  zIn = (u8*)pMem->z;
  zTerm = &zIn[pMem->n];
  if( len>NBFS ){
    zOut = sqlite3DbMallocRaw(db, len);

    if( !zOut ) return SQLITE_NOMEM;

  }else{
    zOut = zShort;
  }
  z = zOut;

  if( pMem->enc==SQLITE_UTF8 ){
    if( desiredEnc==SQLITE_UTF16LE ){
................................................................................
** UTF-16 string stored in *pMem. If one is present, it is removed and
** the encoding of the Mem adjusted. This routine does not do any
** byte-swapping, it just sets Mem.enc appropriately.
**
** The allocation (static, dynamic etc.) and encoding of the Mem may be
** changed by this function.
*/
int sqlite3VdbeMemHandleBom(sqlite3 *db, Mem *pMem){
  int rc = SQLITE_OK;
  u8 bom = 0;

  if( pMem->n<0 || pMem->n>1 ){
    u8 b1 = *(u8 *)pMem->z;
    u8 b2 = *(((u8 *)pMem->z) + 1);
    if( b1==0xFE && b2==0xFF ){
................................................................................
    assert( !(pMem->flags&MEM_Short) );
    assert( !(pMem->flags&MEM_Dyn) || pMem->xDel );
    if( pMem->flags & MEM_Dyn ){
      void (*xDel)(void*) = pMem->xDel;
      char *z = pMem->z;
      pMem->z = 0;
      pMem->xDel = 0;
      rc = sqlite3VdbeMemSetStr(db, pMem, &z[2], pMem->n-2, bom, 
          SQLITE_TRANSIENT);
      xDel(z);
    }else{
      rc = sqlite3VdbeMemSetStr(db, pMem, &pMem->z[2], pMem->n-2, bom, 
          SQLITE_TRANSIENT);
    }
  }
  return rc;
}
#endif /* SQLITE_OMIT_UTF16 */

................................................................................
** be freed by the calling function.
**
** NULL is returned if there is an allocation error.
*/
char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte){
  Mem m;
  memset(&m, 0, sizeof(m));

  sqlite3VdbeMemSetStr(db, &m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  sqlite3VdbeChangeEncoding(db, &m, SQLITE_UTF8);
  assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
  assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
  return (m.flags & MEM_Dyn)!=0 ? m.z : sqlite3DbStrDup(db, m.z);
}

/*
** pZ is a UTF-16 encoded unicode string. If nChar is less than zero,

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used to translate between UTF-8, 
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id: utf.c,v 1.56 2007/08/21 19:33:57 drh Exp $
**
** Notes on UTF-8:
**
**   Byte-0    Byte-1    Byte-2    Byte-3    Value
**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx
................................................................................

#ifndef SQLITE_OMIT_UTF16
/*
** This routine transforms the internal text encoding used by pMem to
** desiredEnc. It is an error if the string is already of the desired
** encoding, or if *pMem does not contain a string value.
*/
int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
  unsigned char zShort[NBFS]; /* Temporary short output buffer */
  int len;                    /* Maximum length of output string in bytes */
  unsigned char *zOut;                  /* Output buffer */
  unsigned char *zIn;                   /* Input iterator */
  unsigned char *zTerm;                 /* End of input */
  unsigned char *z;                     /* Output iterator */
  unsigned int c;

  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( pMem->flags&MEM_Str );
  assert( pMem->enc!=desiredEnc );
  assert( pMem->enc!=0 );
  assert( pMem->n>=0 );

#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
  {
................................................................................
  /* If the translation is between UTF-16 little and big endian, then 
  ** all that is required is to swap the byte order. This case is handled
  ** differently from the others.
  */
  if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){
    u8 temp;
    int rc;
    rc = sqlite3VdbeMemMakeWriteable(pMem);
    if( rc!=SQLITE_OK ){
      assert( rc==SQLITE_NOMEM );
      return SQLITE_NOMEM;
    }
    zIn = (u8*)pMem->z;
    zTerm = &zIn[pMem->n];
    while( zIn<zTerm ){
................................................................................
  ** Variable zOut is set to point at the output buffer. This may be space
  ** obtained from sqlite3_malloc(), or Mem.zShort, if it large enough and
  ** not in use, or the zShort array on the stack (see above).
  */
  zIn = (u8*)pMem->z;
  zTerm = &zIn[pMem->n];
  if( len>NBFS ){
    zOut = sqlite3DbMallocRaw(pMem->db, len);
    if( !zOut ){
      return SQLITE_NOMEM;
    }
  }else{
    zOut = zShort;
  }
  z = zOut;

  if( pMem->enc==SQLITE_UTF8 ){
    if( desiredEnc==SQLITE_UTF16LE ){
................................................................................
** UTF-16 string stored in *pMem. If one is present, it is removed and
** the encoding of the Mem adjusted. This routine does not do any
** byte-swapping, it just sets Mem.enc appropriately.
**
** The allocation (static, dynamic etc.) and encoding of the Mem may be
** changed by this function.
*/
int sqlite3VdbeMemHandleBom(Mem *pMem){
  int rc = SQLITE_OK;
  u8 bom = 0;

  if( pMem->n<0 || pMem->n>1 ){
    u8 b1 = *(u8 *)pMem->z;
    u8 b2 = *(((u8 *)pMem->z) + 1);
    if( b1==0xFE && b2==0xFF ){
................................................................................
    assert( !(pMem->flags&MEM_Short) );
    assert( !(pMem->flags&MEM_Dyn) || pMem->xDel );
    if( pMem->flags & MEM_Dyn ){
      void (*xDel)(void*) = pMem->xDel;
      char *z = pMem->z;
      pMem->z = 0;
      pMem->xDel = 0;
      rc = sqlite3VdbeMemSetStr(pMem, &z[2], pMem->n-2, bom, 
          SQLITE_TRANSIENT);
      xDel(z);
    }else{
      rc = sqlite3VdbeMemSetStr(pMem, &pMem->z[2], pMem->n-2, bom, 
          SQLITE_TRANSIENT);
    }
  }
  return rc;
}
#endif /* SQLITE_OMIT_UTF16 */

................................................................................
** be freed by the calling function.
**
** NULL is returned if there is an allocation error.
*/
char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte){
  Mem m;
  memset(&m, 0, sizeof(m));
  m.db = db;
  sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
  assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
  assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
  return (m.flags & MEM_Dyn)!=0 ? m.z : sqlite3DbStrDup(db, m.z);
}

/*
** pZ is a UTF-16 encoded unicode string. If nChar is less than zero,

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.210 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>


/*
................................................................................
    db->errCode = err_code;
    if( zFormat ){
      char *z;
      va_list ap;
      va_start(ap, zFormat);
      z = sqlite3VMPrintf(db, zFormat, ap);
      va_end(ap);
      sqlite3ValueSetStr(db, db->pErr, -1, z, SQLITE_UTF8, sqlite3_free);
    }else{
      sqlite3ValueSetStr(db, db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
    }
  }
}

/*
** Add an error message to pParse->zErrMsg and increment pParse->nErr.
** The following formatting characters are allowed:

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.211 2007/08/21 19:33:57 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>


/*
................................................................................
    db->errCode = err_code;
    if( zFormat ){
      char *z;
      va_list ap;
      va_start(ap, zFormat);
      z = sqlite3VMPrintf(db, zFormat, ap);
      va_end(ap);
      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, sqlite3_free);
    }else{
      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
    }
  }
}

/*
** Add an error message to pParse->zErrMsg and increment pParse->nErr.
** The following formatting characters are allowed:

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.643 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <math.h>
#include "vdbeInt.h"

/*
................................................................................
*/
#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }

/*
** Convert the given stack entity into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/
#define Stringify(db, P, enc) \
   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(db,P,enc)) \
     { goto no_mem; }

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macro takes advantage this fact to provide a fast decode
** of the integers in a record header.  It is faster for the common case
................................................................................
** does not control the string, it might be deleted without the stack
** entry knowing it.
**
** This routine converts an ephemeral string into a dynamically allocated
** string that the stack entry itself controls.  In other words, it
** converts an MEM_Ephem string into an MEM_Dyn string.
*/
#define Deephemeralize(db,P) \
   if( ((P)->flags&MEM_Ephem)!=0 \
       && sqlite3VdbeMemMakeWriteable(db, P) ){ goto no_mem;}

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define ExpandBlob(D,P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(D,P):0)

/*
** Argument pMem points at a memory cell that will be passed to a
** user-defined function or returned to the user as the result of a query.
** The second argument, 'db_enc' is the text encoding used by the vdbe for
** stack variables.  This routine sets the pMem->enc and pMem->type
** variables used by the sqlite3_value_*() routines.
................................................................................

/*
** Try to convert a value into a numeric representation if we can
** do so without loss of information.  In other words, if the string
** looks like a number, convert it into a number.  If it does not
** look like a number, leave it alone.
*/
static void applyNumericAffinity(sqlite3 *db, Mem *pRec){
  if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
    int realnum;
    sqlite3VdbeMemNulTerminate(db, pRec);
    if( (pRec->flags&MEM_Str)
         && sqlite3IsNumber(pRec->z, &realnum, pRec->enc) ){
      i64 value;
      sqlite3VdbeChangeEncoding(db, pRec, SQLITE_UTF8);
      if( !realnum && sqlite3Atoi64(pRec->z, &value) ){
        sqlite3VdbeMemRelease(pRec);
        pRec->u.i = value;
        pRec->flags = MEM_Int;
      }else{
        sqlite3VdbeMemRealify(pRec);
      }
................................................................................
** SQLITE_AFF_TEXT:
**    Convert pRec to a text representation.
**
** SQLITE_AFF_NONE:
**    No-op.  pRec is unchanged.
*/
static void applyAffinity(
  sqlite3 *db,        /* Report malloc() errors to this db connection */
  Mem *pRec,          /* The value to apply affinity to */
  char affinity,      /* The affinity to be applied */
  u8 enc              /* Use this text encoding */
){
  if( affinity==SQLITE_AFF_TEXT ){
    /* Only attempt the conversion to TEXT if there is an integer or real
    ** representation (blob and NULL do not get converted) but no string
    ** representation.
    */
    if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
      sqlite3VdbeMemStringify(db, pRec, enc);
    }
    pRec->flags &= ~(MEM_Real|MEM_Int);
  }else if( affinity!=SQLITE_AFF_NONE ){
    assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
             || affinity==SQLITE_AFF_NUMERIC );
    applyNumericAffinity(db, pRec);
    if( pRec->flags & MEM_Real ){
      sqlite3VdbeIntegerAffinity(pRec);
    }
  }
}

/*
................................................................................
** is appropriate.  But only do the conversion if it is possible without
** loss of information and return the revised type of the argument.
**
** This is an EXPERIMENTAL api and is subject to change or removal.
*/
int sqlite3_value_numeric_type(sqlite3_value *pVal){
  Mem *pMem = (Mem*)pVal;
  applyNumericAffinity(0, pMem);
  storeTypeInfo(pMem, 0);
  return pMem->type;
}

/*
** Exported version of applyAffinity(). This one works on sqlite3_value*, 
** not the internal Mem* type.
*/
void sqlite3ValueApplyAffinity(
  sqlite3 *db, 
  sqlite3_value *pVal, 
  u8 affinity, 
  u8 enc
){
  applyAffinity(db, (Mem *)pVal, affinity, enc);
}

#ifdef SQLITE_DEBUG
/*
** Write a nice string representation of the contents of cell pMem
** into buffer zBuf, length nBuf.
*/
................................................................................
  pTos++;
  pTos->flags = MEM_Str|MEM_Static|MEM_Term;
  pTos->z = pOp->p3;
  pTos->n = strlen(pTos->z);
  pTos->enc = SQLITE_UTF8;
  pTos->r = sqlite3VdbeRealValue(pTos);
  pTos->flags |= MEM_Real;
  sqlite3VdbeChangeEncoding(db, pTos, encoding);
  break;
}

/* Opcode: String8 * * P3
**
** P3 points to a nul terminated UTF-8 string. This opcode is transformed 
** into an OP_String before it is executed for the first time.
................................................................................
  pOp->p1 = strlen(pOp->p3);
  assert( SQLITE_MAX_SQL_LENGTH < SQLITE_MAX_LENGTH );
  assert( pOp->p1 < SQLITE_MAX_LENGTH );

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    pTos++;
    sqlite3VdbeMemSetStr(db, pTos, pOp->p3, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(db, pTos, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemDynamicify(db, pTos) ) goto no_mem;
    pTos->flags &= ~(MEM_Dyn);
    pTos->flags |= MEM_Static;
    if( pOp->p3type==P3_DYNAMIC ){
      sqlite3_free(pOp->p3);
    }
    pOp->p3type = P3_DYNAMIC;
    pOp->p3 = pTos->z;
................................................................................
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P3. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {
  pTos++;
  assert( pOp->p1 < SQLITE_MAX_LENGTH ); /* Due to SQLITE_MAX_SQL_LENGTH */
  sqlite3VdbeMemSetStr(db, pTos, pOp->p3, pOp->p1, 0, 0);
  pTos->enc = encoding;
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 * *
**
................................................................................
*/
case OP_Dup: {
  Mem *pFrom = &pTos[-pOp->p1];
  assert( pFrom<=pTos && pFrom>=p->aStack );
  pTos++;
  sqlite3VdbeMemShallowCopy(pTos, pFrom, MEM_Ephem);
  if( pOp->p2 ){
    Deephemeralize(db, pTos);
  }
  break;
}

/* Opcode: Pull P1 * *
**
** The P1-th element is removed from its current location on 
................................................................................
*/
case OP_Pull: {            /* no-push */
  Mem *pFrom = &pTos[-pOp->p1];
  int i;
  Mem ts;

  ts = *pFrom;
  Deephemeralize(db, pTos);
  for(i=0; i<pOp->p1; i++, pFrom++){
    Deephemeralize(db, &pFrom[1]);
    assert( (pFrom[1].flags & MEM_Ephem)==0 );
    *pFrom = pFrom[1];
    if( pFrom->flags & MEM_Short ){
      assert( pFrom->flags & (MEM_Str|MEM_Blob) );
      assert( pFrom->z==pFrom[1].zShort );
      pFrom->z = pFrom->zShort;
    }
................................................................................
** stack (P1==0 is the top of the stack) with the value
** of the top of the stack.  Then pop the top of the stack.
*/
case OP_Push: {            /* no-push */
  Mem *pTo = &pTos[-pOp->p1];

  assert( pTo>=p->aStack );
  sqlite3VdbeMemMove(db, pTo, pTos);
  pTos--;
  break;
}

/* Opcode: Callback P1 * *
**
** The top P1 values on the stack represent a single result row from
................................................................................
  ** in between the return from this sqlite3_step() call and the
  ** next call to sqlite3_step().  So deephermeralize everything on 
  ** the stack.  Note that ephemeral data is never stored in memory 
  ** cells so we do not have to worry about them.
  */
  pFirstColumn = &pTos[0-pOp->p1];
  for(pMem = p->aStack; pMem<pFirstColumn; pMem++){
    Deephemeralize(db, pMem);
  }

  /* Invalidate all ephemeral cursor row caches */
  p->cacheCtr = (p->cacheCtr + 2)|1;

  /* Make sure the results of the current row are \000 terminated
  ** and have an assigned type.  The results are deephemeralized as
  ** as side effect.
  */
  for(; pMem<=pTos; pMem++ ){
    sqlite3VdbeMemNulTerminate(db, pMem);
    storeTypeInfo(pMem, encoding);
  }

  /* Set up the statement structure so that it will pop the current
  ** results from the stack when the statement returns.
  */
  p->resOnStack = 1;
................................................................................
  nByte = 0;
  for(i=0; i<nField; i++, pTerm++){
    assert( pOp->p2==0 || (pTerm->flags&MEM_Str) );
    if( pTerm->flags&MEM_Null ){
      nByte = -1;
      break;
    }
    ExpandBlob(db, pTerm);
    Stringify(db, pTerm, encoding);
    nByte += pTerm->n;
  }

  if( nByte<0 ){
    /* If nByte is less than zero, then there is a NULL value on the stack.
    ** In this case just pop the values off the stack (if required) and
    ** push on a NULL.
................................................................................
    ctx.pVdbeFunc = (VdbeFunc*)pOp->p3;
    ctx.pFunc = ctx.pVdbeFunc->pFunc;
  }

  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;

  ctx.isError = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3;
  }
................................................................................
  /* If the function returned an error, throw an exception */
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }

  /* Copy the result of the function to the top of the stack */
  sqlite3VdbeChangeEncoding(db, &ctx.s, encoding);
  pTos++;
  pTos->flags = 0;
  sqlite3VdbeMemMove(db, pTos, &ctx.s);
  if( sqlite3VdbeMemTooBig(pTos) ){
    goto too_big;
  }
  break;
}

/* Opcode: BitAnd * * *
................................................................................
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: {            /* no-push */
  i64 v;
  assert( pTos>=p->aStack );
  applyAffinity(db, pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
    Release(pTos);
    pTos--;
    pc = pOp->p2 - 1;
    break;
  }
  if( pTos->flags & MEM_Int ){
................................................................................
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: {            /* no-push */
  assert( pTos>=p->aStack );
  applyAffinity(db, pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & MEM_Int)==0 ){
    if( pOp->p2==0 ){
      rc = SQLITE_MISMATCH;
      goto abort_due_to_error;
    }else{
      if( pOp->p1 ) popStack(&pTos, 1);
      pc = pOp->p2 - 1;
................................................................................
** A NULL value is not changed by this routine.  It remains NULL.
*/
case OP_ToText: {                  /* same as TK_TO_TEXT, no-push */
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ) break;
  assert( MEM_Str==(MEM_Blob>>3) );
  pTos->flags |= (pTos->flags&MEM_Blob)>>3;
  applyAffinity(db, pTos, SQLITE_AFF_TEXT, encoding);
  rc = ExpandBlob(db, pTos);
  assert( pTos->flags & MEM_Str );
  pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
  break;
}

/* Opcode: ToBlob * * *
**
................................................................................
**
** A NULL value is not changed by this routine.  It remains NULL.
*/
case OP_ToBlob: {                  /* same as TK_TO_BLOB, no-push */
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ) break;
  if( (pTos->flags & MEM_Blob)==0 ){
    applyAffinity(db, pTos, SQLITE_AFF_TEXT, encoding);
    assert( pTos->flags & MEM_Str );
    pTos->flags |= MEM_Blob;
  }
  pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Str);
  break;
}

................................................................................
      }
      break;
    }
  }

  affinity = pOp->p1 & 0xFF;
  if( affinity ){
    applyAffinity(db, pNos, affinity, encoding);
    applyAffinity(db, pTos, affinity, encoding);
  }

  assert( pOp->p3type==P3_COLLSEQ || pOp->p3==0 );
  ExpandBlob(db, pNos);
  ExpandBlob(db, pTos);
  res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3);
  switch( pOp->opcode ){
    case OP_Eq:    res = res==0;     break;
    case OP_Ne:    res = res!=0;     break;
    case OP_Lt:    res = res<0;      break;
    case OP_Le:    res = res<=0;     break;
    case OP_Gt:    res = res>0;      break;
................................................................................
    /* The KeyFetch() or DataFetch() above are fast and will get the entire
    ** record header in most cases.  But they will fail to get the complete
    ** record header if the record header does not fit on a single page
    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
    ** acquire the complete header text.
    */
    if( !zRec && avail<offset ){
      rc = sqlite3VdbeMemFromBtree(db, pCrsr, 0, offset, pC->isIndex, &sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
      }
      zData = sMem.z;
    }
    zEndHdr = (u8 *)&zData[offset];
    zIdx = (u8 *)&zData[szHdrSz];
................................................................................
  */
  if( aOffset[p2] ){
    assert( rc==SQLITE_OK );
    if( zRec ){
      zData = &zRec[aOffset[p2]];
    }else{
      len = sqlite3VdbeSerialTypeLen(aType[p2]);
      rc = sqlite3VdbeMemFromBtree(
          db, pCrsr, aOffset[p2], len, pC->isIndex, &sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
      }
      zData = sMem.z;
    }
    sqlite3VdbeSerialGet((u8*)zData, aType[p2], pTos);
    pTos->enc = encoding;
................................................................................
    assert( sMem.flags & MEM_Term );
    pTos->flags &= ~MEM_Ephem;
    pTos->flags |= MEM_Dyn|MEM_Term;
  }

  /* pTos->z might be pointing to sMem.zShort[].  Fix that so that we
  ** can abandon sMem */
  rc = sqlite3VdbeMemMakeWriteable(db, pTos);

op_column_out:
  break;
}

/* Opcode: MakeRecord P1 P2 P3
**
................................................................................

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  for(pRec=pData0; pRec<=pTos; pRec++){
    int len;
    if( zAffinity ){
      applyAffinity(db, pRec, zAffinity[pRec-pData0], encoding);
    }
    if( pRec->flags&MEM_Null ){
      containsNull = 1;
    }
    if( pRec->flags&MEM_Zero && pRec->n>0 ){
      ExpandBlob(db, pRec);
    }
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    len = sqlite3VdbeSerialTypeLen(serial_type);
    nData += len;
    nHdr += sqlite3VarintLen(serial_type);
    if( pRec->flags & MEM_Zero ){
      /* Only pure zero-filled BLOBs can be input to this Opcode.
................................................................................
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pC->lastRowid = pTos->u.i;
      pC->rowidIsValid = res==0;
    }else{
      assert( pTos->flags & MEM_Blob );
      ExpandBlob(db, pTos);
      rc = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pC->rowidIsValid = 0;
    }
    pC->deferredMoveto = 0;
................................................................................
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res, rx;
    assert( pC->isTable==0 );
    assert( pTos->flags & MEM_Blob );
    Stringify(db, pTos, encoding);
    rx = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
    alreadyExists = rx==SQLITE_OK && res==0;
    pC->deferredMoveto = 0;
    pC->cacheStatus = CACHE_STALE;
  }
  if( pOp->opcode==OP_Found ){
    if( alreadyExists ) pc = pOp->p2 - 1;
................................................................................
    int nKey;      /* Number of bytes in K */
    int len;       /* Number of bytes in K without the rowid at the end */
    int szRowid;   /* Size of the rowid column at the end of zKey */

    /* Make sure K is a string and make zKey point to K
    */
    assert( pNos->flags & MEM_Blob );
    Stringify(db, pNos, encoding);
    zKey = pNos->z;
    nKey = pNos->n;

    szRowid = sqlite3VdbeIdxRowidLen((u8*)zKey);
    len = nKey-szRowid;

    /* Search for an entry in P1 where all but the last four bytes match K.
................................................................................
    if( res<0 ){
      rc = sqlite3BtreeNext(pCrsr, &res);
      if( res ){
        pc = pOp->p2 - 1;
        break;
      }
    }
    rc = sqlite3VdbeIdxKeyCompare(db, pCx, len, (u8*)zKey, &res); 
    if( rc!=SQLITE_OK ) goto abort_due_to_error;
    if( res>0 ){
      pc = pOp->p2 - 1;
      break;
    }

    /* At this point, pCrsr is pointing to an entry in P1 where all but
    ** the final entry (the rowid) matches K.  Check to see if the
    ** final rowid column is different from R.  If it equals R then jump
    ** immediately to P2.
    */
    rc = sqlite3VdbeIdxRowid(db, pCrsr, &v);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    if( v==R ){
      pc = pOp->p2 - 1;
      break;
    }
................................................................................
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  assert( pTos->flags & MEM_Blob );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    assert( pC->isTable==0 );
    rc = ExpandBlob(db, pTos);
    if( rc==SQLITE_OK ){
      int nKey = pTos->n;
      const char *zKey = pTos->z;
      rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p2);
      assert( pC->deferredMoveto==0 );
      pC->cacheStatus = CACHE_STALE;
    }
................................................................................
    i64 rowid;

    assert( pC->deferredMoveto==0 );
    assert( pC->isTable==0 );
    if( pC->nullRow ){
      pTos->flags = MEM_Null;
    }else{
      rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pTos->flags = MEM_Int;
      pTos->u.i = rowid;
    }
  }
................................................................................
  assert( p->apCsr[i]!=0 );
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res;
 
    assert( pTos->flags & MEM_Blob );  /* Created using OP_MakeRecord */
    assert( pC->deferredMoveto==0 );
    ExpandBlob(db, pTos);
    *pC->pIncrKey = pOp->p3!=0;
    assert( pOp->p3==0 || pOp->opcode!=OP_IdxGT );
    rc = sqlite3VdbeIdxKeyCompare(db, pC, pTos->n, (u8*)pTos->z, &res);
    *pC->pIncrKey = 0;
    if( rc!=SQLITE_OK ){
      break;
    }
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
    }else if( pOp->opcode==OP_IdxGE ){
................................................................................
  }else{
    pTos->z = z;
    pTos->n = strlen(z);
    pTos->flags = MEM_Str | MEM_Dyn | MEM_Term;
    pTos->xDel = 0;
  }
  pTos->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(db, pTos, encoding);
  sqlite3_free(aRoot);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/* Opcode: FifoWrite * * *
**
................................................................................
** After the data is stored in the memory location, the
** stack is popped once if P2 is 1.  If P2 is zero, then
** the original data remains on the stack.
*/
case OP_MemStore: {        /* no-push */
  assert( pTos>=p->aStack );
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  rc = sqlite3VdbeMemMove(db, &p->aMem[pOp->p1], pTos);
  pTos--;

  /* If P2 is 0 then fall thru to the next opcode, OP_MemLoad, that will
  ** restore the top of the stack to its original value.
  */
  if( pOp->p2 ){
    break;
................................................................................
** Move the content of memory cell P2 over to memory cell P1.
** Any prior content of P1 is erased.  Memory cell P2 is left
** containing a NULL.
*/
case OP_MemMove: {
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  assert( pOp->p2>=0 && pOp->p2<p->nMem );
  rc = sqlite3VdbeMemMove(db, &p->aMem[pOp->p1], &p->aMem[pOp->p2]);
  break;
}

/* Opcode: AggStep P1 P2 P3
**
** Execute the step function for an aggregate.  The
** function has P2 arguments.  P3 is a pointer to the FuncDef
................................................................................
  ctx.pFunc = (FuncDef*)pOp->p3;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  ctx.pMem = pMem = &p->aMem[pOp->p1];
  pMem->n++;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;

  ctx.isError = 0;
  ctx.pColl = 0;
  ctx.db = db;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3;
  }
  (ctx.pFunc->xStep)(&ctx, n, apVal);
................................................................................
  if( pModule->xColumn==0 ){
    sqlite3SetString(&p->zErrMsg, "Unsupported module operation: xColumn", 0);
    rc = SQLITE_ERROR;
  } else {
    sqlite3_context sContext;
    memset(&sContext, 0, sizeof(sContext));
    sContext.s.flags = MEM_Null;

    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
    rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);

    /* Copy the result of the function to the top of the stack. We
    ** do this regardless of whether or not an error occured to ensure any
    ** dynamic allocation in sContext.s (a Mem struct) is  released.
    */
    sqlite3VdbeChangeEncoding(db, &sContext.s, encoding);
    pTos++;
    pTos->flags = 0;
    sqlite3VdbeMemMove(db, pTos, &sContext.s);

    if( sqlite3SafetyOn(db) ){
      goto abort_due_to_misuse;
    }
    if( sqlite3VdbeMemTooBig(pTos) ){
      goto too_big;
    }
................................................................................
** on the top of the stack is popped and passed as the zName argument
** to the xRename method.
*/
case OP_VRename: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3);
  assert( pVtab->pModule->xRename );

  Stringify(db, pTos, encoding);

  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  sqlite3VtabLock(pVtab);
  rc = pVtab->pModule->xRename(pVtab, pTos->z);
  sqlite3VtabUnlock(db, pVtab);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;

................................................................................
#ifndef NDEBUG
    /* Sanity checking on the top element of the stack. If the previous
    ** instruction was VNoChange, then the flags field of the top
    ** of the stack is set to 0. This is technically invalid for a memory
    ** cell, so avoid calling MemSanity() in this case.
    */
    if( pTos>=p->aStack && pTos->flags ){

      sqlite3VdbeMemSanity(pTos);
      assert( !sqlite3VdbeMemTooBig(pTos) );
    }
    assert( pc>=-1 && pc<p->nOp );

#ifdef SQLITE_DEBUG
    /* Code for tracing the vdbe stack. */

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.644 2007/08/21 19:33:57 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <math.h>
#include "vdbeInt.h"

/*
................................................................................
*/
#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }

/*
** Convert the given stack entity into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/
#define Stringify(P, enc) \
   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
     { goto no_mem; }

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macro takes advantage this fact to provide a fast decode
** of the integers in a record header.  It is faster for the common case
................................................................................
** does not control the string, it might be deleted without the stack
** entry knowing it.
**
** This routine converts an ephemeral string into a dynamically allocated
** string that the stack entry itself controls.  In other words, it
** converts an MEM_Ephem string into an MEM_Dyn string.
*/
#define Deephemeralize(P) \
   if( ((P)->flags&MEM_Ephem)!=0 \
       && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)

/*
** Argument pMem points at a memory cell that will be passed to a
** user-defined function or returned to the user as the result of a query.
** The second argument, 'db_enc' is the text encoding used by the vdbe for
** stack variables.  This routine sets the pMem->enc and pMem->type
** variables used by the sqlite3_value_*() routines.
................................................................................

/*
** Try to convert a value into a numeric representation if we can
** do so without loss of information.  In other words, if the string
** looks like a number, convert it into a number.  If it does not
** look like a number, leave it alone.
*/
static void applyNumericAffinity(Mem *pRec){
  if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
    int realnum;
    sqlite3VdbeMemNulTerminate(pRec);
    if( (pRec->flags&MEM_Str)
         && sqlite3IsNumber(pRec->z, &realnum, pRec->enc) ){
      i64 value;
      sqlite3VdbeChangeEncoding(pRec, SQLITE_UTF8);
      if( !realnum && sqlite3Atoi64(pRec->z, &value) ){
        sqlite3VdbeMemRelease(pRec);
        pRec->u.i = value;
        pRec->flags = MEM_Int;
      }else{
        sqlite3VdbeMemRealify(pRec);
      }
................................................................................
** SQLITE_AFF_TEXT:
**    Convert pRec to a text representation.
**
** SQLITE_AFF_NONE:
**    No-op.  pRec is unchanged.
*/
static void applyAffinity(

  Mem *pRec,          /* The value to apply affinity to */
  char affinity,      /* The affinity to be applied */
  u8 enc              /* Use this text encoding */
){
  if( affinity==SQLITE_AFF_TEXT ){
    /* Only attempt the conversion to TEXT if there is an integer or real
    ** representation (blob and NULL do not get converted) but no string
    ** representation.
    */
    if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
      sqlite3VdbeMemStringify(pRec, enc);
    }
    pRec->flags &= ~(MEM_Real|MEM_Int);
  }else if( affinity!=SQLITE_AFF_NONE ){
    assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
             || affinity==SQLITE_AFF_NUMERIC );
    applyNumericAffinity(pRec);
    if( pRec->flags & MEM_Real ){
      sqlite3VdbeIntegerAffinity(pRec);
    }
  }
}

/*
................................................................................
** is appropriate.  But only do the conversion if it is possible without
** loss of information and return the revised type of the argument.
**
** This is an EXPERIMENTAL api and is subject to change or removal.
*/
int sqlite3_value_numeric_type(sqlite3_value *pVal){
  Mem *pMem = (Mem*)pVal;
  applyNumericAffinity(pMem);
  storeTypeInfo(pMem, 0);
  return pMem->type;
}

/*
** Exported version of applyAffinity(). This one works on sqlite3_value*, 
** not the internal Mem* type.
*/
void sqlite3ValueApplyAffinity(

  sqlite3_value *pVal, 
  u8 affinity, 
  u8 enc
){
  applyAffinity((Mem *)pVal, affinity, enc);
}

#ifdef SQLITE_DEBUG
/*
** Write a nice string representation of the contents of cell pMem
** into buffer zBuf, length nBuf.
*/
................................................................................
  pTos++;
  pTos->flags = MEM_Str|MEM_Static|MEM_Term;
  pTos->z = pOp->p3;
  pTos->n = strlen(pTos->z);
  pTos->enc = SQLITE_UTF8;
  pTos->r = sqlite3VdbeRealValue(pTos);
  pTos->flags |= MEM_Real;
  sqlite3VdbeChangeEncoding(pTos, encoding);
  break;
}

/* Opcode: String8 * * P3
**
** P3 points to a nul terminated UTF-8 string. This opcode is transformed 
** into an OP_String before it is executed for the first time.
................................................................................
  pOp->p1 = strlen(pOp->p3);
  assert( SQLITE_MAX_SQL_LENGTH < SQLITE_MAX_LENGTH );
  assert( pOp->p1 < SQLITE_MAX_LENGTH );

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    pTos++;
    sqlite3VdbeMemSetStr(pTos, pOp->p3, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pTos, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pTos) ) goto no_mem;
    pTos->flags &= ~(MEM_Dyn);
    pTos->flags |= MEM_Static;
    if( pOp->p3type==P3_DYNAMIC ){
      sqlite3_free(pOp->p3);
    }
    pOp->p3type = P3_DYNAMIC;
    pOp->p3 = pTos->z;
................................................................................
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P3. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {
  pTos++;
  assert( pOp->p1 < SQLITE_MAX_LENGTH ); /* Due to SQLITE_MAX_SQL_LENGTH */
  sqlite3VdbeMemSetStr(pTos, pOp->p3, pOp->p1, 0, 0);
  pTos->enc = encoding;
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 * *
**
................................................................................
*/
case OP_Dup: {
  Mem *pFrom = &pTos[-pOp->p1];
  assert( pFrom<=pTos && pFrom>=p->aStack );
  pTos++;
  sqlite3VdbeMemShallowCopy(pTos, pFrom, MEM_Ephem);
  if( pOp->p2 ){
    Deephemeralize(pTos);
  }
  break;
}

/* Opcode: Pull P1 * *
**
** The P1-th element is removed from its current location on 
................................................................................
*/
case OP_Pull: {            /* no-push */
  Mem *pFrom = &pTos[-pOp->p1];
  int i;
  Mem ts;

  ts = *pFrom;
  Deephemeralize(pTos);
  for(i=0; i<pOp->p1; i++, pFrom++){
    Deephemeralize(&pFrom[1]);
    assert( (pFrom[1].flags & MEM_Ephem)==0 );
    *pFrom = pFrom[1];
    if( pFrom->flags & MEM_Short ){
      assert( pFrom->flags & (MEM_Str|MEM_Blob) );
      assert( pFrom->z==pFrom[1].zShort );
      pFrom->z = pFrom->zShort;
    }
................................................................................
** stack (P1==0 is the top of the stack) with the value
** of the top of the stack.  Then pop the top of the stack.
*/
case OP_Push: {            /* no-push */
  Mem *pTo = &pTos[-pOp->p1];

  assert( pTo>=p->aStack );
  sqlite3VdbeMemMove(pTo, pTos);
  pTos--;
  break;
}

/* Opcode: Callback P1 * *
**
** The top P1 values on the stack represent a single result row from
................................................................................
  ** in between the return from this sqlite3_step() call and the
  ** next call to sqlite3_step().  So deephermeralize everything on 
  ** the stack.  Note that ephemeral data is never stored in memory 
  ** cells so we do not have to worry about them.
  */
  pFirstColumn = &pTos[0-pOp->p1];
  for(pMem = p->aStack; pMem<pFirstColumn; pMem++){
    Deephemeralize(pMem);
  }

  /* Invalidate all ephemeral cursor row caches */
  p->cacheCtr = (p->cacheCtr + 2)|1;

  /* Make sure the results of the current row are \000 terminated
  ** and have an assigned type.  The results are deephemeralized as
  ** as side effect.
  */
  for(; pMem<=pTos; pMem++ ){
    sqlite3VdbeMemNulTerminate(pMem);
    storeTypeInfo(pMem, encoding);
  }

  /* Set up the statement structure so that it will pop the current
  ** results from the stack when the statement returns.
  */
  p->resOnStack = 1;
................................................................................
  nByte = 0;
  for(i=0; i<nField; i++, pTerm++){
    assert( pOp->p2==0 || (pTerm->flags&MEM_Str) );
    if( pTerm->flags&MEM_Null ){
      nByte = -1;
      break;
    }
    ExpandBlob(pTerm);
    Stringify(pTerm, encoding);
    nByte += pTerm->n;
  }

  if( nByte<0 ){
    /* If nByte is less than zero, then there is a NULL value on the stack.
    ** In this case just pop the values off the stack (if required) and
    ** push on a NULL.
................................................................................
    ctx.pVdbeFunc = (VdbeFunc*)pOp->p3;
    ctx.pFunc = ctx.pVdbeFunc->pFunc;
  }

  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3;
  }
................................................................................
  /* If the function returned an error, throw an exception */
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }

  /* Copy the result of the function to the top of the stack */
  sqlite3VdbeChangeEncoding(&ctx.s, encoding);
  pTos++;
  pTos->flags = 0;
  sqlite3VdbeMemMove(pTos, &ctx.s);
  if( sqlite3VdbeMemTooBig(pTos) ){
    goto too_big;
  }
  break;
}

/* Opcode: BitAnd * * *
................................................................................
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: {            /* no-push */
  i64 v;
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
    Release(pTos);
    pTos--;
    pc = pOp->p2 - 1;
    break;
  }
  if( pTos->flags & MEM_Int ){
................................................................................
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: {            /* no-push */
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & MEM_Int)==0 ){
    if( pOp->p2==0 ){
      rc = SQLITE_MISMATCH;
      goto abort_due_to_error;
    }else{
      if( pOp->p1 ) popStack(&pTos, 1);
      pc = pOp->p2 - 1;
................................................................................
** A NULL value is not changed by this routine.  It remains NULL.
*/
case OP_ToText: {                  /* same as TK_TO_TEXT, no-push */
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ) break;
  assert( MEM_Str==(MEM_Blob>>3) );
  pTos->flags |= (pTos->flags&MEM_Blob)>>3;
  applyAffinity(pTos, SQLITE_AFF_TEXT, encoding);
  rc = ExpandBlob(pTos);
  assert( pTos->flags & MEM_Str );
  pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
  break;
}

/* Opcode: ToBlob * * *
**
................................................................................
**
** A NULL value is not changed by this routine.  It remains NULL.
*/
case OP_ToBlob: {                  /* same as TK_TO_BLOB, no-push */
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ) break;
  if( (pTos->flags & MEM_Blob)==0 ){
    applyAffinity(pTos, SQLITE_AFF_TEXT, encoding);
    assert( pTos->flags & MEM_Str );
    pTos->flags |= MEM_Blob;
  }
  pTos->flags &= ~(MEM_Int|MEM_Real|MEM_Str);
  break;
}

................................................................................
      }
      break;
    }
  }

  affinity = pOp->p1 & 0xFF;
  if( affinity ){
    applyAffinity(pNos, affinity, encoding);
    applyAffinity(pTos, affinity, encoding);
  }

  assert( pOp->p3type==P3_COLLSEQ || pOp->p3==0 );
  ExpandBlob(pNos);
  ExpandBlob(pTos);
  res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3);
  switch( pOp->opcode ){
    case OP_Eq:    res = res==0;     break;
    case OP_Ne:    res = res!=0;     break;
    case OP_Lt:    res = res<0;      break;
    case OP_Le:    res = res<=0;     break;
    case OP_Gt:    res = res>0;      break;
................................................................................
    /* The KeyFetch() or DataFetch() above are fast and will get the entire
    ** record header in most cases.  But they will fail to get the complete
    ** record header if the record header does not fit on a single page
    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
    ** acquire the complete header text.
    */
    if( !zRec && avail<offset ){
      rc = sqlite3VdbeMemFromBtree(pCrsr, 0, offset, pC->isIndex, &sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
      }
      zData = sMem.z;
    }
    zEndHdr = (u8 *)&zData[offset];
    zIdx = (u8 *)&zData[szHdrSz];
................................................................................
  */
  if( aOffset[p2] ){
    assert( rc==SQLITE_OK );
    if( zRec ){
      zData = &zRec[aOffset[p2]];
    }else{
      len = sqlite3VdbeSerialTypeLen(aType[p2]);

      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex, &sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
      }
      zData = sMem.z;
    }
    sqlite3VdbeSerialGet((u8*)zData, aType[p2], pTos);
    pTos->enc = encoding;
................................................................................
    assert( sMem.flags & MEM_Term );
    pTos->flags &= ~MEM_Ephem;
    pTos->flags |= MEM_Dyn|MEM_Term;
  }

  /* pTos->z might be pointing to sMem.zShort[].  Fix that so that we
  ** can abandon sMem */
  rc = sqlite3VdbeMemMakeWriteable(pTos);

op_column_out:
  break;
}

/* Opcode: MakeRecord P1 P2 P3
**
................................................................................

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  for(pRec=pData0; pRec<=pTos; pRec++){
    int len;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
    }
    if( pRec->flags&MEM_Null ){
      containsNull = 1;
    }
    if( pRec->flags&MEM_Zero && pRec->n>0 ){
      ExpandBlob(pRec);
    }
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    len = sqlite3VdbeSerialTypeLen(serial_type);
    nData += len;
    nHdr += sqlite3VarintLen(serial_type);
    if( pRec->flags & MEM_Zero ){
      /* Only pure zero-filled BLOBs can be input to this Opcode.
................................................................................
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pC->lastRowid = pTos->u.i;
      pC->rowidIsValid = res==0;
    }else{
      assert( pTos->flags & MEM_Blob );
      ExpandBlob(pTos);
      rc = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pC->rowidIsValid = 0;
    }
    pC->deferredMoveto = 0;
................................................................................
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res, rx;
    assert( pC->isTable==0 );
    assert( pTos->flags & MEM_Blob );
    Stringify(pTos, encoding);
    rx = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, 0, &res);
    alreadyExists = rx==SQLITE_OK && res==0;
    pC->deferredMoveto = 0;
    pC->cacheStatus = CACHE_STALE;
  }
  if( pOp->opcode==OP_Found ){
    if( alreadyExists ) pc = pOp->p2 - 1;
................................................................................
    int nKey;      /* Number of bytes in K */
    int len;       /* Number of bytes in K without the rowid at the end */
    int szRowid;   /* Size of the rowid column at the end of zKey */

    /* Make sure K is a string and make zKey point to K
    */
    assert( pNos->flags & MEM_Blob );
    Stringify(pNos, encoding);
    zKey = pNos->z;
    nKey = pNos->n;

    szRowid = sqlite3VdbeIdxRowidLen((u8*)zKey);
    len = nKey-szRowid;

    /* Search for an entry in P1 where all but the last four bytes match K.
................................................................................
    if( res<0 ){
      rc = sqlite3BtreeNext(pCrsr, &res);
      if( res ){
        pc = pOp->p2 - 1;
        break;
      }
    }
    rc = sqlite3VdbeIdxKeyCompare(pCx, len, (u8*)zKey, &res); 
    if( rc!=SQLITE_OK ) goto abort_due_to_error;
    if( res>0 ){
      pc = pOp->p2 - 1;
      break;
    }

    /* At this point, pCrsr is pointing to an entry in P1 where all but
    ** the final entry (the rowid) matches K.  Check to see if the
    ** final rowid column is different from R.  If it equals R then jump
    ** immediately to P2.
    */
    rc = sqlite3VdbeIdxRowid(pCrsr, &v);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    if( v==R ){
      pc = pOp->p2 - 1;
      break;
    }
................................................................................
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  assert( pTos->flags & MEM_Blob );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    assert( pC->isTable==0 );
    rc = ExpandBlob(pTos);
    if( rc==SQLITE_OK ){
      int nKey = pTos->n;
      const char *zKey = pTos->z;
      rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p2);
      assert( pC->deferredMoveto==0 );
      pC->cacheStatus = CACHE_STALE;
    }
................................................................................
    i64 rowid;

    assert( pC->deferredMoveto==0 );
    assert( pC->isTable==0 );
    if( pC->nullRow ){
      pTos->flags = MEM_Null;
    }else{
      rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pTos->flags = MEM_Int;
      pTos->u.i = rowid;
    }
  }
................................................................................
  assert( p->apCsr[i]!=0 );
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res;
 
    assert( pTos->flags & MEM_Blob );  /* Created using OP_MakeRecord */
    assert( pC->deferredMoveto==0 );
    ExpandBlob(pTos);
    *pC->pIncrKey = pOp->p3!=0;
    assert( pOp->p3==0 || pOp->opcode!=OP_IdxGT );
    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, (u8*)pTos->z, &res);
    *pC->pIncrKey = 0;
    if( rc!=SQLITE_OK ){
      break;
    }
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
    }else if( pOp->opcode==OP_IdxGE ){
................................................................................
  }else{
    pTos->z = z;
    pTos->n = strlen(z);
    pTos->flags = MEM_Str | MEM_Dyn | MEM_Term;
    pTos->xDel = 0;
  }
  pTos->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(pTos, encoding);
  sqlite3_free(aRoot);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/* Opcode: FifoWrite * * *
**
................................................................................
** After the data is stored in the memory location, the
** stack is popped once if P2 is 1.  If P2 is zero, then
** the original data remains on the stack.
*/
case OP_MemStore: {        /* no-push */
  assert( pTos>=p->aStack );
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], pTos);
  pTos--;

  /* If P2 is 0 then fall thru to the next opcode, OP_MemLoad, that will
  ** restore the top of the stack to its original value.
  */
  if( pOp->p2 ){
    break;
................................................................................
** Move the content of memory cell P2 over to memory cell P1.
** Any prior content of P1 is erased.  Memory cell P2 is left
** containing a NULL.
*/
case OP_MemMove: {
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  assert( pOp->p2>=0 && pOp->p2<p->nMem );
  rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], &p->aMem[pOp->p2]);
  break;
}

/* Opcode: AggStep P1 P2 P3
**
** Execute the step function for an aggregate.  The
** function has P2 arguments.  P3 is a pointer to the FuncDef
................................................................................
  ctx.pFunc = (FuncDef*)pOp->p3;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  ctx.pMem = pMem = &p->aMem[pOp->p1];
  pMem->n++;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  ctx.pColl = 0;

  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3;
  }
  (ctx.pFunc->xStep)(&ctx, n, apVal);
................................................................................
  if( pModule->xColumn==0 ){
    sqlite3SetString(&p->zErrMsg, "Unsupported module operation: xColumn", 0);
    rc = SQLITE_ERROR;
  } else {
    sqlite3_context sContext;
    memset(&sContext, 0, sizeof(sContext));
    sContext.s.flags = MEM_Null;
    sContext.s.db = db;
    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
    rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);

    /* Copy the result of the function to the top of the stack. We
    ** do this regardless of whether or not an error occured to ensure any
    ** dynamic allocation in sContext.s (a Mem struct) is  released.
    */
    sqlite3VdbeChangeEncoding(&sContext.s, encoding);
    pTos++;
    pTos->flags = 0;
    sqlite3VdbeMemMove(pTos, &sContext.s);

    if( sqlite3SafetyOn(db) ){
      goto abort_due_to_misuse;
    }
    if( sqlite3VdbeMemTooBig(pTos) ){
      goto too_big;
    }
................................................................................
** on the top of the stack is popped and passed as the zName argument
** to the xRename method.
*/
case OP_VRename: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3);
  assert( pVtab->pModule->xRename );

  Stringify(pTos, encoding);

  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  sqlite3VtabLock(pVtab);
  rc = pVtab->pModule->xRename(pVtab, pTos->z);
  sqlite3VtabUnlock(db, pVtab);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;

................................................................................
#ifndef NDEBUG
    /* Sanity checking on the top element of the stack. If the previous
    ** instruction was VNoChange, then the flags field of the top
    ** of the stack is set to 0. This is technically invalid for a memory
    ** cell, so avoid calling MemSanity() in this case.
    */
    if( pTos>=p->aStack && pTos->flags ){
      assert( pTos->db==db );
      sqlite3VdbeMemSanity(pTos);
      assert( !sqlite3VdbeMemTooBig(pTos) );
    }
    assert( pc>=-1 && pc<p->nOp );

#ifdef SQLITE_DEBUG
    /* Code for tracing the vdbe stack. */

*/
struct Mem {
  union {
    i64 i;              /* Integer value. Or FuncDef* when flags==MEM_Agg */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
  } u;
  double r;           /* Real value */

  char *z;            /* String or BLOB value */
  int n;              /* Number of characters in string value, including '\0' */
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
  char zShort[NBFS];  /* Space for short strings */
................................................................................
struct sqlite3_context {
  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
  Mem s;                /* The return value is stored here */
  Mem *pMem;            /* Memory cell used to store aggregate context */
  u8 isError;           /* Set to true for an error */
  CollSeq *pColl;       /* Collating sequence */
  sqlite3 *db;          /* Database connection */
};

/*
** A Set structure is used for quick testing to see if a value
** is part of a small set.  Sets are used to implement code like
** this:
**            x.y IN ('hi','hoo','hum')
................................................................................
int sqlite3VdbeSerialTypeLen(u32);
u32 sqlite3VdbeSerialType(Mem*, int);
int sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);

int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
int sqlite3VdbeIdxKeyCompare(sqlite3*,Cursor*,int,const unsigned char*,int*);
int sqlite3VdbeIdxRowid(sqlite3 *, BtCursor *, i64 *);
int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
int sqlite3VdbeRecordCompare(void*,int,const void*,int, const void*);
int sqlite3VdbeIdxRowidLen(const u8*);
int sqlite3VdbeExec(Vdbe*);
int sqlite3VdbeList(Vdbe*);
int sqlite3VdbeHalt(Vdbe*);
int sqlite3VdbeChangeEncoding(sqlite3 *, Mem *, int);
int sqlite3VdbeMemTooBig(Mem*);
int sqlite3VdbeMemCopy(sqlite3*, Mem*, const Mem*);
void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
int sqlite3VdbeMemMove(sqlite3*, Mem*, Mem*);
int sqlite3VdbeMemNulTerminate(sqlite3 *, Mem*);
int sqlite3VdbeMemSetStr(sqlite3 *, Mem*, const char*, int, u8, void(*)(void*));
void sqlite3VdbeMemSetInt64(Mem*, i64);
void sqlite3VdbeMemSetDouble(Mem*, double);
void sqlite3VdbeMemSetNull(Mem*);
void sqlite3VdbeMemSetZeroBlob(Mem*,int);
int sqlite3VdbeMemMakeWriteable(sqlite3 *, Mem*);
int sqlite3VdbeMemDynamicify(sqlite3 *, Mem*);
int sqlite3VdbeMemStringify(sqlite3*, Mem*, int);
i64 sqlite3VdbeIntValue(Mem*);
int sqlite3VdbeMemIntegerify(Mem*);
double sqlite3VdbeRealValue(Mem*);
void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
int sqlite3VdbeMemFromBtree(sqlite3*,BtCursor*,int,int,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);
int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
#ifndef NDEBUG
  void sqlite3VdbeMemSanity(Mem*);
  int sqlite3VdbeOpcodeNoPush(u8);
#endif
int sqlite3VdbeMemTranslate(sqlite3 *, Mem*, u8);
#ifdef SQLITE_DEBUG
  void sqlite3VdbePrintSql(Vdbe*);
  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
#endif
int sqlite3VdbeMemHandleBom(sqlite3 *, Mem *pMem);
void sqlite3VdbeFifoInit(Fifo*);
int sqlite3VdbeFifoPush(Fifo*, i64);
int sqlite3VdbeFifoPop(Fifo*, i64*);
void sqlite3VdbeFifoClear(Fifo*);

#ifndef SQLITE_OMIT_INCRBLOB
  int sqlite3VdbeMemExpandBlob(sqlite3 *, Mem *);
#else
  #define sqlite3VdbeMemExpandBlob(d,x) SQLITE_OK
#endif

#endif /* !defined(_VDBEINT_H_) */

*/
struct Mem {
  union {
    i64 i;              /* Integer value. Or FuncDef* when flags==MEM_Agg */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
  } u;
  double r;           /* Real value */
  sqlite3 *db;        /* The associated database connection */
  char *z;            /* String or BLOB value */
  int n;              /* Number of characters in string value, including '\0' */
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
  char zShort[NBFS];  /* Space for short strings */
................................................................................
struct sqlite3_context {
  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
  Mem s;                /* The return value is stored here */
  Mem *pMem;            /* Memory cell used to store aggregate context */
  u8 isError;           /* Set to true for an error */
  CollSeq *pColl;       /* Collating sequence */

};

/*
** A Set structure is used for quick testing to see if a value
** is part of a small set.  Sets are used to implement code like
** this:
**            x.y IN ('hi','hoo','hum')
................................................................................
int sqlite3VdbeSerialTypeLen(u32);
u32 sqlite3VdbeSerialType(Mem*, int);
int sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);

int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
int sqlite3VdbeIdxKeyCompare(Cursor*,int,const unsigned char*,int*);
int sqlite3VdbeIdxRowid(BtCursor *, i64 *);
int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
int sqlite3VdbeRecordCompare(void*,int,const void*,int, const void*);
int sqlite3VdbeIdxRowidLen(const u8*);
int sqlite3VdbeExec(Vdbe*);
int sqlite3VdbeList(Vdbe*);
int sqlite3VdbeHalt(Vdbe*);
int sqlite3VdbeChangeEncoding(Mem *, int);
int sqlite3VdbeMemTooBig(Mem*);
int sqlite3VdbeMemCopy(Mem*, const Mem*);
void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
int sqlite3VdbeMemMove(Mem*, Mem*);
int sqlite3VdbeMemNulTerminate(Mem*);
int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
void sqlite3VdbeMemSetInt64(Mem*, i64);
void sqlite3VdbeMemSetDouble(Mem*, double);
void sqlite3VdbeMemSetNull(Mem*);
void sqlite3VdbeMemSetZeroBlob(Mem*,int);
int sqlite3VdbeMemMakeWriteable(Mem*);
int sqlite3VdbeMemDynamicify(Mem*);
int sqlite3VdbeMemStringify(Mem*, int);
i64 sqlite3VdbeIntValue(Mem*);
int sqlite3VdbeMemIntegerify(Mem*);
double sqlite3VdbeRealValue(Mem*);
void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);
int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
#ifndef NDEBUG
  void sqlite3VdbeMemSanity(Mem*);
  int sqlite3VdbeOpcodeNoPush(u8);
#endif
int sqlite3VdbeMemTranslate(Mem*, u8);
#ifdef SQLITE_DEBUG
  void sqlite3VdbePrintSql(Vdbe*);
  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
#endif
int sqlite3VdbeMemHandleBom(Mem *pMem);
void sqlite3VdbeFifoInit(Fifo*);
int sqlite3VdbeFifoPush(Fifo*, i64);
int sqlite3VdbeFifoPop(Fifo*, i64*);
void sqlite3VdbeFifoClear(Fifo*);

#ifndef SQLITE_OMIT_INCRBLOB
  int sqlite3VdbeMemExpandBlob(Mem *);
#else
  #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
#endif

#endif /* !defined(_VDBEINT_H_) */

/**************************** sqlite3_value_  *******************************
** The following routines extract information from a Mem or sqlite3_value
** structure.
*/
const void *sqlite3_value_blob(sqlite3_value *pVal){
  Mem *p = (Mem*)pVal;
  if( p->flags & (MEM_Blob|MEM_Str) ){
    sqlite3VdbeMemExpandBlob(0, p);
    p->flags &= ~MEM_Str;
    p->flags |= MEM_Blob;
    return p->z;
  }else{
    return sqlite3_value_text(pVal);
  }
}
int sqlite3_value_bytes(sqlite3_value *pVal){
  return sqlite3ValueBytes(0, pVal, SQLITE_UTF8);
}
int sqlite3_value_bytes16(sqlite3_value *pVal){
  return sqlite3ValueBytes(0, pVal, SQLITE_UTF16NATIVE);
}
double sqlite3_value_double(sqlite3_value *pVal){
  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(0, pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(0, pVal, SQLITE_UTF16NATIVE);
}
const void *sqlite3_value_text16be(sqlite3_value *pVal){
  return sqlite3ValueText(0, pVal, SQLITE_UTF16BE);
}
const void *sqlite3_value_text16le(sqlite3_value *pVal){
  return sqlite3ValueText(0, pVal, SQLITE_UTF16LE);
}
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_value_type(sqlite3_value* pVal){
  return pVal->type;
}
/* sqlite3_value_numeric_type() defined in vdbe.c */

................................................................................
void sqlite3_result_blob(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( n>=0 );
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, 0, xDel);
}
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
}
#endif
void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
}
void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
................................................................................
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF8, xDel);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_text16(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF16NATIVE, xDel);
}
void sqlite3_result_text16be(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF16BE, xDel);
}
void sqlite3_result_text16le(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(0, &pCtx->s, z, n, SQLITE_UTF16LE, xDel);
}
#endif /* SQLITE_OMIT_UTF16 */
void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
  sqlite3VdbeMemCopy(0, &pCtx->s, pValue);
}
void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
}

/* Force an SQLITE_TOOBIG error. */
void sqlite3_result_error_toobig(sqlite3_context *pCtx){
................................................................................
/*
** This is the top-level implementation of sqlite3_step().  Call
** sqlite3Step() to do most of the work.  If a schema error occurs,
** call sqlite3Reprepare() and try again.
*/
#ifdef SQLITE_OMIT_PARSER
int sqlite3_step(sqlite3_stmt *pStmt){




  return sqlite3Step((Vdbe*)pStmt);


}
#else
int sqlite3_step(sqlite3_stmt *pStmt){
  int cnt = 0;
  int rc;
  Vdbe *v = (Vdbe*)pStmt;

  while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
         && cnt++ < 5
         && sqlite3Reprepare(v) ){
    sqlite3_reset(pStmt);
    v->expired = 0;
  }

  return rc;
}
#endif

/*
** Extract the user data from a sqlite3_context structure and return a
** pointer to it.
................................................................................

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
*/
void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
  Mem *pMem = p->pMem;
  assert( p && p->pFunc && p->pFunc->xStep );


  if( (pMem->flags & MEM_Agg)==0 ){
    if( nByte==0 ){
      assert( pMem->flags==MEM_Null );
      pMem->z = 0;
    }else{
      pMem->flags = MEM_Agg;
      pMem->xDel = sqlite3_free;
      pMem->u.pDef = p->pFunc;
      if( nByte<=NBFS ){
        pMem->z = pMem->zShort;
        memset(pMem->z, 0, nByte);
      }else{
        pMem->z = sqlite3DbMallocZero(p->db, nByte);
      }
    }
  }
  return (void*)pMem->z;
}

/*
** Return the auxilary data pointer, if any, for the iArg'th argument to
** the user-function defined by pCtx.
*/
void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){



  VdbeFunc *pVdbeFunc = pCtx->pVdbeFunc;
  if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
    return 0;
  }
  return pVdbeFunc->apAux[iArg].pAux;
}

/*
................................................................................
  void *pAux, 
  void (*xDelete)(void*)
){
  struct AuxData *pAuxData;
  VdbeFunc *pVdbeFunc;
  if( iArg<0 ) goto failed;


  pVdbeFunc = pCtx->pVdbeFunc;
  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
    int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
    pVdbeFunc = sqlite3_realloc(pVdbeFunc, nMalloc);
    if( !pVdbeFunc ){
      pCtx->db->mallocFailed = 1;
      goto failed;
    }
    pCtx->pVdbeFunc = pVdbeFunc;
    memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
    pVdbeFunc->nAux = iArg+1;
    pVdbeFunc->pFunc = pCtx->pFunc;
  }
................................................................................
** If iCol is not valid, return a pointer to a Mem which has a value
** of NULL.
*/
static Mem *columnMem(sqlite3_stmt *pStmt, int i){
  Vdbe *pVm = (Vdbe *)pStmt;
  int vals = sqlite3_data_count(pStmt);
  if( pVm==0 || pVm->resOnStack==0 || i>=pVm->nResColumn || i<0 ){
    static const Mem nullMem = {{0}, 0.0, "", 0, MEM_Null, SQLITE_NULL };
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return (Mem*)&nullMem;
  }
  return &pVm->pTos[(1-vals)+i];
}

/*
................................................................................
  }
  sqlite3_mutex_enter(p->db->mutex);
  rc = vdbeUnbind(p, i);
  if( rc || zData==0 ){
    return rc;
  }
  pVar = &p->aVar[i-1];
  rc = sqlite3VdbeMemSetStr(p->db, pVar, zData, nData, encoding, xDel);
  if( rc==SQLITE_OK && encoding!=0 ){
    rc = sqlite3VdbeChangeEncoding(p->db, pVar, ENC(p->db));
  }
  sqlite3Error(p->db, rc, 0);
  rc = sqlite3ApiExit(p->db, rc);
  sqlite3_mutex_leave(p->db->mutex);
  return rc;
}

................................................................................
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
  sqlite3_mutex_enter(p->db->mutex);
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    rc = sqlite3VdbeMemCopy(0, &p->aVar[i-1], pValue);
  }
  sqlite3_mutex_leave(p->db->mutex);
  return rc;
}
int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
................................................................................
    return SQLITE_MISUSE;
  }
  if( pFrom->nVar!=pTo->nVar ){
    return SQLITE_ERROR;
  }
  for(i=0; rc==SQLITE_OK && i<pFrom->nVar; i++){
    sqlite3MallocDisallow();
    rc = sqlite3VdbeMemMove(0, &pTo->aVar[i], &pFrom->aVar[i]);
    sqlite3MallocAllow();
  }
  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
  return rc;
}

/*

/**************************** sqlite3_value_  *******************************
** The following routines extract information from a Mem or sqlite3_value
** structure.
*/
const void *sqlite3_value_blob(sqlite3_value *pVal){
  Mem *p = (Mem*)pVal;
  if( p->flags & (MEM_Blob|MEM_Str) ){
    sqlite3VdbeMemExpandBlob(p);
    p->flags &= ~MEM_Str;
    p->flags |= MEM_Blob;
    return p->z;
  }else{
    return sqlite3_value_text(pVal);
  }
}
int sqlite3_value_bytes(sqlite3_value *pVal){
  return sqlite3ValueBytes(pVal, SQLITE_UTF8);
}
int sqlite3_value_bytes16(sqlite3_value *pVal){
  return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
}
double sqlite3_value_double(sqlite3_value *pVal){
  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
}
const void *sqlite3_value_text16be(sqlite3_value *pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16BE);
}
const void *sqlite3_value_text16le(sqlite3_value *pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16LE);
}
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_value_type(sqlite3_value* pVal){
  return pVal->type;
}
/* sqlite3_value_numeric_type() defined in vdbe.c */

................................................................................
void sqlite3_result_blob(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( n>=0 );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, 0, xDel);
}
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
}
#endif
void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
}
void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
................................................................................
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, xDel);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_text16(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, xDel);
}
void sqlite3_result_text16be(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16BE, xDel);
}
void sqlite3_result_text16le(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16LE, xDel);
}
#endif /* SQLITE_OMIT_UTF16 */
void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
  sqlite3VdbeMemCopy(&pCtx->s, pValue);
}
void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
}

/* Force an SQLITE_TOOBIG error. */
void sqlite3_result_error_toobig(sqlite3_context *pCtx){
................................................................................
/*
** This is the top-level implementation of sqlite3_step().  Call
** sqlite3Step() to do most of the work.  If a schema error occurs,
** call sqlite3Reprepare() and try again.
*/
#ifdef SQLITE_OMIT_PARSER
int sqlite3_step(sqlite3_stmt *pStmt){
  int rc;
  Vdbe *v;
  v = (Vdbe*)pStmt;
  sqlite3_mutex_enter(v->db->mutex);
  rc = sqlite3Step(v);
  sqlite3_mutex_leave(v->db->mutex);
  return rc;
}
#else
int sqlite3_step(sqlite3_stmt *pStmt){
  int cnt = 0;
  int rc;
  Vdbe *v = (Vdbe*)pStmt;
  sqlite3_mutex_enter(v->db->mutex);
  while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
         && cnt++ < 5
         && sqlite3Reprepare(v) ){
    sqlite3_reset(pStmt);
    v->expired = 0;
  }
  sqlite3_mutex_leave(v->db->mutex);
  return rc;
}
#endif

/*
** Extract the user data from a sqlite3_context structure and return a
** pointer to it.
................................................................................

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
*/
void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
  Mem *pMem;
  assert( p && p->pFunc && p->pFunc->xStep );
  assert( sqlite3_mutex_held(p->s.db->mutex) );
  pMem = p->pMem;
  if( (pMem->flags & MEM_Agg)==0 ){
    if( nByte==0 ){
      assert( pMem->flags==MEM_Null );
      pMem->z = 0;
    }else{
      pMem->flags = MEM_Agg;
      pMem->xDel = sqlite3_free;
      pMem->u.pDef = p->pFunc;
      if( nByte<=NBFS ){
        pMem->z = pMem->zShort;
        memset(pMem->z, 0, nByte);
      }else{
        pMem->z = sqlite3DbMallocZero(p->s.db, nByte);
      }
    }
  }
  return (void*)pMem->z;
}

/*
** Return the auxilary data pointer, if any, for the iArg'th argument to
** the user-function defined by pCtx.
*/
void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
  VdbeFunc *pVdbeFunc;

  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pVdbeFunc = pCtx->pVdbeFunc;
  if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
    return 0;
  }
  return pVdbeFunc->apAux[iArg].pAux;
}

/*
................................................................................
  void *pAux, 
  void (*xDelete)(void*)
){
  struct AuxData *pAuxData;
  VdbeFunc *pVdbeFunc;
  if( iArg<0 ) goto failed;

  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pVdbeFunc = pCtx->pVdbeFunc;
  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
    int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
    pVdbeFunc = sqlite3_realloc(pVdbeFunc, nMalloc);
    if( !pVdbeFunc ){
      pCtx->s.db->mallocFailed = 1;
      goto failed;
    }
    pCtx->pVdbeFunc = pVdbeFunc;
    memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
    pVdbeFunc->nAux = iArg+1;
    pVdbeFunc->pFunc = pCtx->pFunc;
  }
................................................................................
** If iCol is not valid, return a pointer to a Mem which has a value
** of NULL.
*/
static Mem *columnMem(sqlite3_stmt *pStmt, int i){
  Vdbe *pVm = (Vdbe *)pStmt;
  int vals = sqlite3_data_count(pStmt);
  if( pVm==0 || pVm->resOnStack==0 || i>=pVm->nResColumn || i<0 ){
    static const Mem nullMem = {{0}, 0.0, 0, "", 0, MEM_Null, SQLITE_NULL };
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return (Mem*)&nullMem;
  }
  return &pVm->pTos[(1-vals)+i];
}

/*
................................................................................
  }
  sqlite3_mutex_enter(p->db->mutex);
  rc = vdbeUnbind(p, i);
  if( rc || zData==0 ){
    return rc;
  }
  pVar = &p->aVar[i-1];
  rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
  if( rc==SQLITE_OK && encoding!=0 ){
    rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
  }
  sqlite3Error(p->db, rc, 0);
  rc = sqlite3ApiExit(p->db, rc);
  sqlite3_mutex_leave(p->db->mutex);
  return rc;
}

................................................................................
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
  sqlite3_mutex_enter(p->db->mutex);
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    rc = sqlite3VdbeMemCopy(&p->aVar[i-1], pValue);
  }
  sqlite3_mutex_leave(p->db->mutex);
  return rc;
}
int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
................................................................................
    return SQLITE_MISUSE;
  }
  if( pFrom->nVar!=pTo->nVar ){
    return SQLITE_ERROR;
  }
  for(i=0; rc==SQLITE_OK && i<pFrom->nVar; i++){
    sqlite3MallocDisallow();
    rc = sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
    sqlite3MallocAllow();
  }
  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
  return rc;
}

/*

/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
  if( p ){
    while( N-->0 ){

      sqlite3VdbeMemRelease(p++);
    }
  }
}

#ifndef SQLITE_OMIT_EXPLAIN
/*
................................................................................
      p->okVar = 0;
      p->apArg = (Mem**)&p->aVar[nVar];
      p->azVar = (char**)&p->apArg[nArg];
      p->apCsr = (Cursor**)&p->azVar[nVar];
      p->nCursor = nCursor;
      for(n=0; n<nVar; n++){
        p->aVar[n].flags = MEM_Null;




      }
    }
  }
  for(n=0; n<p->nMem; n++){
    p->aMem[n].flags = MEM_Null;

  }

  p->pTos = &p->aStack[-1];
  p->pc = -1;
  p->rc = SQLITE_OK;
  p->uniqueCnt = 0;
  p->returnDepth = 0;
................................................................................
  Mem *pColName;
  assert( idx<p->nResColumn );
  assert( var<COLNAME_N );
  if( p->db->mallocFailed ) return SQLITE_NOMEM;
  assert( p->aColName!=0 );
  pColName = &(p->aColName[idx+var*p->nResColumn]);
  if( N==P3_DYNAMIC || N==P3_STATIC ){
    rc = sqlite3VdbeMemSetStr(p->db, 
        pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
  }else{
    rc = sqlite3VdbeMemSetStr(p->db, 
        pColName, zName, N, SQLITE_UTF8, SQLITE_TRANSIENT);
  }
  if( rc==SQLITE_OK && N==P3_DYNAMIC ){
    pColName->flags = (pColName->flags&(~MEM_Static))|MEM_Dyn;
    pColName->xDel = 0;
  }
  return rc;
}
................................................................................
  /* If the VDBE has be run even partially, then transfer the error code
  ** and error message from the VDBE into the main database structure.  But
  ** if the VDBE has just been set to run but has not actually executed any
  ** instructions yet, leave the main database error information unchanged.
  */
  if( p->pc>=0 ){
    if( p->zErrMsg ){
      sqlite3ValueSetStr(db,db->pErr,-1,p->zErrMsg,SQLITE_UTF8,sqlite3_free);
      db->errCode = p->rc;
      p->zErrMsg = 0;
    }else if( p->rc ){
      sqlite3Error(db, p->rc, 0);
    }else{
      sqlite3Error(db, SQLITE_OK, 0);
    }
................................................................................
  int rc = 0;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;

  Mem mem1;
  Mem mem2;
  mem1.enc = pKeyInfo->enc;

  mem2.enc = pKeyInfo->enc;

  
  idx1 = GetVarint(aKey1, szHdr1);
  d1 = szHdr1;
  idx2 = GetVarint(aKey2, szHdr2);
  d2 = szHdr2;
  nField = pKeyInfo->nField;
  while( idx1<szHdr1 && idx2<szHdr2 ){
................................................................................
  

/*
** pCur points at an index entry created using the OP_MakeRecord opcode.
** Read the rowid (the last field in the record) and store it in *rowid.
** Return SQLITE_OK if everything works, or an error code otherwise.
*/
int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
  i64 nCellKey = 0;
  int rc;
  u32 szHdr;        /* Size of the header */
  u32 typeRowid;    /* Serial type of the rowid */
  u32 lenRowid;     /* Size of the rowid */
  Mem m, v;

  sqlite3BtreeKeySize(pCur, &nCellKey);
  if( nCellKey<=0 ){
    return SQLITE_CORRUPT_BKPT;
  }
  rc = sqlite3VdbeMemFromBtree(db, pCur, 0, nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  sqlite3GetVarint32((u8*)m.z, &szHdr);
  sqlite3GetVarint32((u8*)&m.z[szHdr-1], &typeRowid);
  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
  sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
................................................................................
** or greater than pKey.  Return SQLITE_OK on success.
**
** pKey is either created without a rowid or is truncated so that it
** omits the rowid at the end.  The rowid at the end of the index entry
** is ignored as well.
*/
int sqlite3VdbeIdxKeyCompare(
  sqlite3 *db,
  Cursor *pC,                 /* The cursor to compare against */
  int nKey, const u8 *pKey,   /* The key to compare */
  int *res                    /* Write the comparison result here */
){
  i64 nCellKey = 0;
  int rc;
  BtCursor *pCur = pC->pCursor;
................................................................................
  Mem m;

  sqlite3BtreeKeySize(pCur, &nCellKey);
  if( nCellKey<=0 ){
    *res = 0;
    return SQLITE_OK;
  }
  rc = sqlite3VdbeMemFromBtree(db, pC->pCursor, 0, nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  lenRowid = sqlite3VdbeIdxRowidLen((u8*)m.z);
  *res = sqlite3VdbeRecordCompare(pC->pKeyInfo, m.n-lenRowid, m.z, nKey, pKey);
  sqlite3VdbeMemRelease(&m);
  return SQLITE_OK;
................................................................................
}

/*
** This routine sets the value to be returned by subsequent calls to
** sqlite3_changes() on the database handle 'db'. 
*/
void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){

  db->nChange = nChange;
  db->nTotalChange += nChange;
}

/*
** Set a flag in the vdbe to update the change counter when it is finalised
** or reset.

/*
** Release an array of N Mem elements
*/
static void releaseMemArray(Mem *p, int N){
  if( p ){
    while( N-->0 ){
      assert( N<2 || p[0].db==p[1].db );
      sqlite3VdbeMemRelease(p++);
    }
  }
}

#ifndef SQLITE_OMIT_EXPLAIN
/*
................................................................................
      p->okVar = 0;
      p->apArg = (Mem**)&p->aVar[nVar];
      p->azVar = (char**)&p->apArg[nArg];
      p->apCsr = (Cursor**)&p->azVar[nVar];
      p->nCursor = nCursor;
      for(n=0; n<nVar; n++){
        p->aVar[n].flags = MEM_Null;
        p->aVar[n].db = db;
      }
      for(n=0; n<nStack; n++){
        p->aStack[n].db = db;
      }
    }
  }
  for(n=0; n<p->nMem; n++){
    p->aMem[n].flags = MEM_Null;
    p->aMem[n].db = db;
  }

  p->pTos = &p->aStack[-1];
  p->pc = -1;
  p->rc = SQLITE_OK;
  p->uniqueCnt = 0;
  p->returnDepth = 0;
................................................................................
  Mem *pColName;
  assert( idx<p->nResColumn );
  assert( var<COLNAME_N );
  if( p->db->mallocFailed ) return SQLITE_NOMEM;
  assert( p->aColName!=0 );
  pColName = &(p->aColName[idx+var*p->nResColumn]);
  if( N==P3_DYNAMIC || N==P3_STATIC ){

    rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
  }else{

    rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
  }
  if( rc==SQLITE_OK && N==P3_DYNAMIC ){
    pColName->flags = (pColName->flags&(~MEM_Static))|MEM_Dyn;
    pColName->xDel = 0;
  }
  return rc;
}
................................................................................
  /* If the VDBE has be run even partially, then transfer the error code
  ** and error message from the VDBE into the main database structure.  But
  ** if the VDBE has just been set to run but has not actually executed any
  ** instructions yet, leave the main database error information unchanged.
  */
  if( p->pc>=0 ){
    if( p->zErrMsg ){
      sqlite3ValueSetStr(db->pErr,-1,p->zErrMsg,SQLITE_UTF8,sqlite3_free);
      db->errCode = p->rc;
      p->zErrMsg = 0;
    }else if( p->rc ){
      sqlite3Error(db, p->rc, 0);
    }else{
      sqlite3Error(db, SQLITE_OK, 0);
    }
................................................................................
  int rc = 0;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;

  Mem mem1;
  Mem mem2;
  mem1.enc = pKeyInfo->enc;
  mem1.db = pKeyInfo->db;
  mem2.enc = pKeyInfo->enc;
  mem2.db = pKeyInfo->db;
  
  idx1 = GetVarint(aKey1, szHdr1);
  d1 = szHdr1;
  idx2 = GetVarint(aKey2, szHdr2);
  d2 = szHdr2;
  nField = pKeyInfo->nField;
  while( idx1<szHdr1 && idx2<szHdr2 ){
................................................................................
  

/*
** pCur points at an index entry created using the OP_MakeRecord opcode.
** Read the rowid (the last field in the record) and store it in *rowid.
** Return SQLITE_OK if everything works, or an error code otherwise.
*/
int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
  i64 nCellKey = 0;
  int rc;
  u32 szHdr;        /* Size of the header */
  u32 typeRowid;    /* Serial type of the rowid */
  u32 lenRowid;     /* Size of the rowid */
  Mem m, v;

  sqlite3BtreeKeySize(pCur, &nCellKey);
  if( nCellKey<=0 ){
    return SQLITE_CORRUPT_BKPT;
  }
  rc = sqlite3VdbeMemFromBtree(pCur, 0, nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  sqlite3GetVarint32((u8*)m.z, &szHdr);
  sqlite3GetVarint32((u8*)&m.z[szHdr-1], &typeRowid);
  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
  sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
................................................................................
** or greater than pKey.  Return SQLITE_OK on success.
**
** pKey is either created without a rowid or is truncated so that it
** omits the rowid at the end.  The rowid at the end of the index entry
** is ignored as well.
*/
int sqlite3VdbeIdxKeyCompare(

  Cursor *pC,                 /* The cursor to compare against */
  int nKey, const u8 *pKey,   /* The key to compare */
  int *res                    /* Write the comparison result here */
){
  i64 nCellKey = 0;
  int rc;
  BtCursor *pCur = pC->pCursor;
................................................................................
  Mem m;

  sqlite3BtreeKeySize(pCur, &nCellKey);
  if( nCellKey<=0 ){
    *res = 0;
    return SQLITE_OK;
  }
  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  lenRowid = sqlite3VdbeIdxRowidLen((u8*)m.z);
  *res = sqlite3VdbeRecordCompare(pC->pKeyInfo, m.n-lenRowid, m.z, nKey, pKey);
  sqlite3VdbeMemRelease(&m);
  return SQLITE_OK;
................................................................................
}

/*
** This routine sets the value to be returned by subsequent calls to
** sqlite3_changes() on the database handle 'db'. 
*/
void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){
  assert( sqlite3_mutex_held(db->mutex) );
  db->nChange = nChange;
  db->nTotalChange += nChange;
}

/*
** Set a flag in the vdbe to update the change counter when it is finalised
** or reset.

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement incremental BLOB I/O.
**
** $Id: vdbeblob.c,v 1.13 2007/08/21 15:13:19 drh Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

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

/*
** Close a blob handle that was previously created using
** sqlite3_blob_open().
*/
int sqlite3_blob_close(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;
  sqlite3_stmt *pStmt;
  sqlite3_mutex *mutex = p->db->mutex;
  int rc;

  sqlite3_mutex_enter(mutex);
  rc = sqlite3_finalize(p->pStmt);
  sqlite3_mutex_leave(mutex);
  sqlite3_free(p);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement incremental BLOB I/O.
**
** $Id: vdbeblob.c,v 1.14 2007/08/21 19:33:57 drh Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

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

/*
** Close a blob handle that was previously created using
** sqlite3_blob_open().
*/
int sqlite3_blob_close(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;

  sqlite3_mutex *mutex = p->db->mutex;
  int rc;

  sqlite3_mutex_enter(mutex);
  rc = sqlite3_finalize(p->pStmt);
  sqlite3_mutex_leave(mutex);
  sqlite3_free(p);

#include <ctype.h>
#include "vdbeInt.h"

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define expandBlob(D,P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(D,P):0)

/*
** If pMem is an object with a valid string representation, this routine
** ensures the internal encoding for the string representation is
** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
**
** If pMem is not a string object, or the encoding of the string
................................................................................
** representation is already stored using the requested encoding, then this
** routine is a no-op.
**
** SQLITE_OK is returned if the conversion is successful (or not required).
** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
int sqlite3VdbeChangeEncoding(sqlite3 *db, Mem *pMem, int desiredEnc){
  int rc;
  if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
    return SQLITE_OK;
  }

#ifdef SQLITE_OMIT_UTF16
  return SQLITE_ERROR;
#else

  /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
  ** then the encoding of the value may not have changed.
  */
  rc = sqlite3VdbeMemTranslate(db, pMem, desiredEnc);
  assert(rc==SQLITE_OK    || rc==SQLITE_NOMEM);
  assert(rc==SQLITE_OK    || pMem->enc!=desiredEnc);
  assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);
  return rc;
#endif
}

/*
** Make the given Mem object MEM_Dyn.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemDynamicify(sqlite3 *db, Mem *pMem){
  int n;
  u8 *z;

  expandBlob(db, pMem);
  if( (pMem->flags & (MEM_Ephem|MEM_Static|MEM_Short))==0 ){
    return SQLITE_OK;
  }
  assert( (pMem->flags & MEM_Dyn)==0 );
  n = pMem->n;
  assert( pMem->flags & (MEM_Str|MEM_Blob) );
  z = sqlite3_malloc( n+2 );
  if( z==0 ){
    return SQLITE_NOMEM;
  }
  pMem->flags |= MEM_Dyn|MEM_Term;
  pMem->xDel = 0;
  memcpy(z, pMem->z, n );
  z[n] = 0;
................................................................................
}

/*
** If the given Mem* has a zero-filled tail, turn it into an ordinary
** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
int sqlite3VdbeMemExpandBlob(sqlite3 *db, Mem *pMem){
  if( pMem->flags & MEM_Zero ){
    char *pNew;
    int nByte;
    assert( (pMem->flags & MEM_Blob)!=0 );
    nByte = pMem->n + pMem->u.i;
    if( nByte<=0 ) nByte = 1;
    pNew = sqlite3_malloc(nByte);
    if( pNew==0 ){
      if( db ) db->mallocFailed = 1;
      return SQLITE_NOMEM;
    }
    memcpy(pNew, pMem->z, pMem->n);
    memset(&pNew[pMem->n], 0, pMem->u.i);
    sqlite3VdbeMemRelease(pMem);
    pMem->z = pNew;
    pMem->n += pMem->u.i;
................................................................................

/*
** Make the given Mem object either MEM_Short or MEM_Dyn so that bytes
** of the Mem.z[] array can be modified.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(sqlite3 *db, Mem *pMem){
  int n;
  u8 *z;

  expandBlob(db, pMem);
  if( (pMem->flags & (MEM_Ephem|MEM_Static))==0 ){
    return SQLITE_OK;
  }
  assert( (pMem->flags & MEM_Dyn)==0 );
  assert( pMem->flags & (MEM_Str|MEM_Blob) );
  if( (n = pMem->n)+2<sizeof(pMem->zShort) ){
    z = (u8*)pMem->zShort;
    pMem->flags |= MEM_Short|MEM_Term;
  }else{
    z = sqlite3_malloc( n+2 );
    if( z==0 ){
      db->mallocFailed = 1;
      return SQLITE_NOMEM;
    }
    pMem->flags |= MEM_Dyn|MEM_Term;
    pMem->xDel = 0;
  }
  memcpy(z, pMem->z, n );
  z[n] = 0;
................................................................................
  assert(0==(1&(int)pMem->z));
  return SQLITE_OK;
}

/*
** Make sure the given Mem is \u0000 terminated.
*/
int sqlite3VdbeMemNulTerminate(sqlite3 *db, Mem *pMem){

  if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
    return SQLITE_OK;   /* Nothing to do */
  }
  if( pMem->flags & (MEM_Static|MEM_Ephem) ){
    return sqlite3VdbeMemMakeWriteable(db, pMem);
  }else{
    char *z; 
    sqlite3VdbeMemExpandBlob(db, pMem);
    z = sqlite3_malloc(pMem->n+2);
    if( !z ){
       db->mallocFailed = 1;
       return SQLITE_NOMEM;
    }
    memcpy(z, pMem->z, pMem->n);
    z[pMem->n] = 0;
    z[pMem->n+1] = 0;
    if( pMem->xDel ){
      pMem->xDel(pMem->z);
................................................................................
**
** A MEM_Null value will never be passed to this function. This function is
** used for converting values to text for returning to the user (i.e. via
** sqlite3_value_text()), or for ensuring that values to be used as btree
** keys are strings. In the former case a NULL pointer is returned the
** user and the later is an internal programming error.
*/
int sqlite3VdbeMemStringify(sqlite3 *db, Mem *pMem, int enc){
  int rc = SQLITE_OK;
  int fg = pMem->flags;
  char *z = pMem->zShort;


  assert( !(fg&MEM_Zero) );
  assert( !(fg&(MEM_Str|MEM_Blob)) );
  assert( fg&(MEM_Int|MEM_Real) );

  /* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
  ** string representation of the value. Then, if the required encoding
  ** is UTF-16le or UTF-16be do a translation.
................................................................................
    assert( fg & MEM_Real );
    sqlite3_snprintf(NBFS, z, "%!.15g", pMem->r);
  }
  pMem->n = strlen(z);
  pMem->z = z;
  pMem->enc = SQLITE_UTF8;
  pMem->flags |= MEM_Str | MEM_Short | MEM_Term;
  sqlite3VdbeChangeEncoding(db, pMem, enc);
  return rc;
}

/*
** Memory cell pMem contains the context of an aggregate function.
** This routine calls the finalize method for that function.  The
** result of the aggregate is stored back into pMem.
................................................................................
** otherwise.
*/
int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
  int rc = SQLITE_OK;
  if( pFunc && pFunc->xFinalize ){
    sqlite3_context ctx;
    assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );

    ctx.s.flags = MEM_Null;
    ctx.s.z = pMem->zShort;

    ctx.pMem = pMem;
    ctx.pFunc = pFunc;
    ctx.isError = 0;
    pFunc->xFinalize(&ctx);
    if( pMem->z && pMem->z!=pMem->zShort ){
      sqlite3_free( pMem->z );
    }
................................................................................

/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
void sqlite3VdbeMemRelease(Mem *p){

  if( p->flags & (MEM_Dyn|MEM_Agg) ){
    if( p->xDel ){
      if( p->flags & MEM_Agg ){
        sqlite3VdbeMemFinalize(p, p->u.pDef);
        assert( (p->flags & MEM_Agg)==0 );
        sqlite3VdbeMemRelease(p);
      }else{
................................................................................
** a floating-point then the value returned is the integer part.
** If pMem is a string or blob, then we make an attempt to convert
** it into a integer and return that.  If pMem is NULL, return 0.
**
** If pMem is a string, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem){


  int flags = pMem->flags;
  if( flags & MEM_Int ){
    return pMem->u.i;
  }else if( flags & MEM_Real ){
    return (i64)pMem->r;
  }else if( flags & (MEM_Str|MEM_Blob) ){
    i64 value;
    pMem->flags |= MEM_Str;
    if( sqlite3VdbeChangeEncoding(0, pMem, SQLITE_UTF8)
       || sqlite3VdbeMemNulTerminate(0, pMem) ){
      return 0;
    }
    assert( pMem->z );
    sqlite3Atoi64(pMem->z, &value);
    return value;
  }else{
    return 0;
................................................................................
/*
** Return the best representation of pMem that we can get into a
** double.  If pMem is already a double or an integer, return its
** value.  If it is a string or blob, try to convert it to a double.
** If it is a NULL, return 0.0.
*/
double sqlite3VdbeRealValue(Mem *pMem){

  if( pMem->flags & MEM_Real ){
    return pMem->r;
  }else if( pMem->flags & MEM_Int ){
    return (double)pMem->u.i;
  }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
    double val = 0.0;
    pMem->flags |= MEM_Str;
    if( sqlite3VdbeChangeEncoding(0, pMem, SQLITE_UTF8)
       || sqlite3VdbeMemNulTerminate(0, pMem) ){
      return 0.0;
    }
    assert( pMem->z );
    sqlite3AtoF(pMem->z, &val);
    return val;
  }else{
    return 0.0;
................................................................................

/*
** The MEM structure is already a MEM_Real.  Try to also make it a
** MEM_Int if we can.
*/
void sqlite3VdbeIntegerAffinity(Mem *pMem){
  assert( pMem->flags & MEM_Real );

  pMem->u.i = pMem->r;
  if( ((double)pMem->u.i)==pMem->r ){
    pMem->flags |= MEM_Int;
  }
}

/*
** Convert pMem to type integer.  Invalidate any prior representations.
*/
int sqlite3VdbeMemIntegerify(Mem *pMem){

  pMem->u.i = sqlite3VdbeIntValue(pMem);
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Int;
  return SQLITE_OK;
}

/*
** Convert pMem so that it is of type MEM_Real.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemRealify(Mem *pMem){

  pMem->r = sqlite3VdbeRealValue(pMem);
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Real;
  return SQLITE_OK;
}

/*
................................................................................
** Invalidate any prior representations.
*/
int sqlite3VdbeMemNumerify(Mem *pMem){
  double r1, r2;
  i64 i;
  assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))==0 );
  assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );

  r1 = sqlite3VdbeRealValue(pMem);
  i = (i64)r1;
  r2 = (double)i;
  if( r1==r2 ){
    sqlite3VdbeMemIntegerify(pMem);
  }else{
    pMem->r = r1;
................................................................................
  }
}

/*
** Make a full copy of pFrom into pTo.  Prior contents of pTo are
** freed before the copy is made.
*/
int sqlite3VdbeMemCopy(sqlite3 *db, Mem *pTo, const Mem *pFrom){
  int rc;
  if( pTo->flags & MEM_Dyn ){
    sqlite3VdbeMemRelease(pTo);
  }
  sqlite3VdbeMemShallowCopy(pTo, pFrom, MEM_Ephem);
  if( pTo->flags & MEM_Ephem ){
    rc = sqlite3VdbeMemMakeWriteable(db, pTo);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

/*
................................................................................
** Transfer the contents of pFrom to pTo. Any existing value in pTo is
** freed. If pFrom contains ephemeral data, a copy is made.
**
** pFrom contains an SQL NULL when this routine returns.  SQLITE_NOMEM
** might be returned if pFrom held ephemeral data and we were unable
** to allocate enough space to make a copy.
*/
int sqlite3VdbeMemMove(sqlite3 *db, Mem *pTo, Mem *pFrom){
  int rc;



  if( pTo->flags & MEM_Dyn ){
    sqlite3VdbeMemRelease(pTo);
  }
  memcpy(pTo, pFrom, sizeof(Mem));
  if( pFrom->flags & MEM_Short ){
    pTo->z = pTo->zShort;
  }
  pFrom->flags = MEM_Null;
  pFrom->xDel = 0;
  if( pTo->flags & MEM_Ephem ){
    rc = sqlite3VdbeMemMakeWriteable(db, pTo);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

/*
** Change the value of a Mem to be a string or a BLOB.
*/
int sqlite3VdbeMemSetStr(
  sqlite3 *db,
  Mem *pMem,          /* Memory cell to set to string value */
  const char *z,      /* String pointer */
  int n,              /* Bytes in string, or negative */
  u8 enc,             /* Encoding of z.  0 for BLOBs */
  void (*xDel)(void*) /* Destructor function */
){

  sqlite3VdbeMemRelease(pMem);
  if( !z ){
    pMem->flags = MEM_Null;
    pMem->type = SQLITE_NULL;
    return SQLITE_OK;
  }

  pMem->z = (char *)z;
  if( xDel==SQLITE_STATIC ){
    pMem->flags = MEM_Static;
  }else if( xDel==SQLITE_TRANSIENT ){
    pMem->flags = MEM_Ephem;
  }else{
    pMem->flags = MEM_Dyn;
................................................................................
    case SQLITE_UTF16LE:
    case SQLITE_UTF16BE:
      pMem->flags |= MEM_Str;
      if( pMem->n<0 ){
        pMem->n = sqlite3Utf16ByteLen(pMem->z,-1);
        pMem->flags |= MEM_Term;
      }
      if( sqlite3VdbeMemHandleBom(db, pMem) ){
        return SQLITE_NOMEM;
      }
#endif /* SQLITE_OMIT_UTF16 */
  }
  if( pMem->flags&MEM_Ephem ){
    return sqlite3VdbeMemMakeWriteable(db, pMem);
  }
  return SQLITE_OK;
}

/*
** Compare the values contained by the two memory cells, returning
** negative, zero or positive if pMem1 is less than, equal to, or greater
................................................................................
        return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
      }else{
        u8 origEnc = pMem1->enc;
        const void *v1, *v2;
        int n1, n2;
        /* Convert the strings into the encoding that the comparison
        ** function expects */
        v1 = sqlite3ValueText(0, (sqlite3_value*)pMem1, pColl->enc);
        n1 = v1==0 ? 0 : pMem1->n;
        assert( n1==sqlite3ValueBytes(0, (sqlite3_value*)pMem1, pColl->enc) );
        v2 = sqlite3ValueText(0, (sqlite3_value*)pMem2, pColl->enc);
        n2 = v2==0 ? 0 : pMem2->n;
        assert( n2==sqlite3ValueBytes(0, (sqlite3_value*)pMem2, pColl->enc) );
        /* Do the comparison */
        rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
        /* Convert the strings back into the database encoding */
        sqlite3ValueText(0, (sqlite3_value*)pMem1, origEnc);
        sqlite3ValueText(0, (sqlite3_value*)pMem2, origEnc);
        return rc;
      }
    }
    /* If a NULL pointer was passed as the collate function, fall through
    ** to the blob case and use memcmp().  */
  }
 
................................................................................
** The pMem structure is assumed to be uninitialized.  Any prior content
** is overwritten without being freed.
**
** If this routine fails for any reason (malloc returns NULL or unable
** to read from the disk) then the pMem is left in an inconsistent state.
*/
int sqlite3VdbeMemFromBtree(
  sqlite3 *db,      /* Database connect to report malloc errors to */
  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  int offset,       /* Offset from the start of data to return bytes from. */
  int amt,          /* Number of bytes to return. */
  int key,          /* If true, retrieve from the btree key, not data. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  char *zData;       /* Data from the btree layer */
  int available = 0; /* Number of bytes available on the local btree page */




  if( key ){
    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
  }else{
    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
  }
  assert( zData!=0 );


  pMem->n = amt;
  if( offset+amt<=available ){
    pMem->z = &zData[offset];
    pMem->flags = MEM_Blob|MEM_Ephem;
  }else{
    int rc;
    if( amt>NBFS-2 ){
      zData = (char *)sqlite3_malloc(amt+2);
      if( !zData ){
        db->mallocFailed = 1;
        return SQLITE_NOMEM;
      }
      pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
      pMem->xDel = 0;
    }else{
      zData = &(pMem->zShort[0]);
      pMem->flags = MEM_Blob|MEM_Short|MEM_Term;
................................................................................
** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
** SQLITE_UTF8.
**
** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
** If that is the case, then the result must be aligned on an even byte
** boundary.
*/
const void *sqlite3ValueText(sqlite3 *db, sqlite3_value* pVal, u8 enc){
  if( !pVal ) return 0;


  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );

  if( pVal->flags&MEM_Null ){
    return 0;
  }
  assert( (MEM_Blob>>3) == MEM_Str );
  pVal->flags |= (pVal->flags & MEM_Blob)>>3;
  expandBlob(db, pVal);
  if( pVal->flags&MEM_Str ){
    sqlite3VdbeChangeEncoding(db, pVal, enc & ~SQLITE_UTF16_ALIGNED);
    if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&(int)pVal->z) ){
      assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
      if( sqlite3VdbeMemMakeWriteable(db, pVal)!=SQLITE_OK ){
        return 0;
      }
    }
    sqlite3VdbeMemNulTerminate(db, pVal);
  }else{
    assert( (pVal->flags&MEM_Blob)==0 );
    sqlite3VdbeMemStringify(db, pVal, enc);
    assert( 0==(1&(int)pVal->z) );
  }
  assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || db->mallocFailed );

  if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
    return pVal->z;
  }else{
    return 0;
  }
}

................................................................................
** Create a new sqlite3_value object.
*/
sqlite3_value *sqlite3ValueNew(sqlite3 *db){
  Mem *p = sqlite3MallocZero(sizeof(*p));
  if( p ){
    p->flags = MEM_Null;
    p->type = SQLITE_NULL;

  }else{
    db->mallocFailed = 1;
  }
  return p;
}

/*
................................................................................
** token (i.e. "5", "5.1", "NULL", "'a string'"). If the expression can
** be converted directly into a value, then the value is allocated and
** a pointer written to *ppVal. The caller is responsible for deallocating
** the value by passing it to sqlite3ValueFree() later on. If the expression
** cannot be converted to a value, then *ppVal is set to NULL.
*/
int sqlite3ValueFromExpr(
  sqlite3 *db,              /* Report malloc() errors here */
  Expr *pExpr,              /* The expression to evaluate */
  u8 enc,                   /* Encoding to use */
  u8 affinity,              /* Affinity to use */
  sqlite3_value **ppVal     /* Write the new value here */
){
  int op;
  char *zVal = 0;
................................................................................
  op = pExpr->op;

  if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
    zVal = sqlite3StrNDup((char*)pExpr->token.z, pExpr->token.n);
    pVal = sqlite3ValueNew(db);
    if( !zVal || !pVal ) goto no_mem;
    sqlite3Dequote(zVal);
    sqlite3ValueSetStr(db, pVal, -1, zVal, SQLITE_UTF8, sqlite3_free);
    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
      sqlite3ValueApplyAffinity(db, pVal, SQLITE_AFF_NUMERIC, enc);
    }else{
      sqlite3ValueApplyAffinity(db, pVal, affinity, enc);
    }
  }else if( op==TK_UMINUS ) {
    if( SQLITE_OK==sqlite3ValueFromExpr(db, pExpr->pLeft, enc, affinity, &pVal) ){
      pVal->u.i = -1 * pVal->u.i;
      pVal->r = -1.0 * pVal->r;
    }
  }
#ifndef SQLITE_OMIT_BLOB_LITERAL
  else if( op==TK_BLOB ){
    int nVal;
    pVal = sqlite3ValueNew(db);
    zVal = sqlite3StrNDup((char*)pExpr->token.z+1, pExpr->token.n-1);
    if( !zVal || !pVal ) goto no_mem;
    sqlite3Dequote(zVal);
    nVal = strlen(zVal)/2;
    sqlite3VdbeMemSetStr(
        db, pVal, sqlite3HexToBlob(db, zVal), nVal, 0, sqlite3_free);
    sqlite3_free(zVal);
  }
#endif

  *ppVal = pVal;
  return SQLITE_OK;

................................................................................
  return SQLITE_NOMEM;
}

/*
** Change the string value of an sqlite3_value object
*/
void sqlite3ValueSetStr(
  sqlite3 *db,          /* Report malloc errors here */
  sqlite3_value *v,     /* Value to be set */
  int n,                /* Length of string z */
  const void *z,        /* Text of the new string */
  u8 enc,               /* Encoding to use */
  void (*xDel)(void*)   /* Destructor for the string */
){
  if( v ) sqlite3VdbeMemSetStr(db, (Mem *)v, z, n, enc, xDel);
}

/*
** Free an sqlite3_value object
*/
void sqlite3ValueFree(sqlite3_value *v){
  if( !v ) return;
  sqlite3ValueSetStr(0, v, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_free(v);
}

/*
** Return the number of bytes in the sqlite3_value object assuming
** that it uses the encoding "enc"
*/
int sqlite3ValueBytes(sqlite3 *db, sqlite3_value *pVal, u8 enc){
  Mem *p = (Mem*)pVal;
  if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(db, pVal, enc) ){
    if( p->flags & MEM_Zero ){
      return p->n+p->u.i;
    }else{
      return p->n;
    }
  }
  return 0;
}

#include <ctype.h>
#include "vdbeInt.h"

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define expandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)

/*
** If pMem is an object with a valid string representation, this routine
** ensures the internal encoding for the string representation is
** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
**
** If pMem is not a string object, or the encoding of the string
................................................................................
** representation is already stored using the requested encoding, then this
** routine is a no-op.
**
** SQLITE_OK is returned if the conversion is successful (or not required).
** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
  int rc;
  if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
    return SQLITE_OK;
  }
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
#ifdef SQLITE_OMIT_UTF16
  return SQLITE_ERROR;
#else

  /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
  ** then the encoding of the value may not have changed.
  */
  rc = sqlite3VdbeMemTranslate(pMem, desiredEnc);
  assert(rc==SQLITE_OK    || rc==SQLITE_NOMEM);
  assert(rc==SQLITE_OK    || pMem->enc!=desiredEnc);
  assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);
  return rc;
#endif
}

/*
** Make the given Mem object MEM_Dyn.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemDynamicify(Mem *pMem){
  int n;
  u8 *z;
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  expandBlob(pMem);
  if( (pMem->flags & (MEM_Ephem|MEM_Static|MEM_Short))==0 ){
    return SQLITE_OK;
  }
  assert( (pMem->flags & MEM_Dyn)==0 );
  n = pMem->n;
  assert( pMem->flags & (MEM_Str|MEM_Blob) );
  z = sqlite3DbMallocRaw(pMem->db, n+2 );
  if( z==0 ){
    return SQLITE_NOMEM;
  }
  pMem->flags |= MEM_Dyn|MEM_Term;
  pMem->xDel = 0;
  memcpy(z, pMem->z, n );
  z[n] = 0;
................................................................................
}

/*
** If the given Mem* has a zero-filled tail, turn it into an ordinary
** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
int sqlite3VdbeMemExpandBlob(Mem *pMem){
  if( pMem->flags & MEM_Zero ){
    char *pNew;
    int nByte;
    assert( (pMem->flags & MEM_Blob)!=0 );
    nByte = pMem->n + pMem->u.i;
    if( nByte<=0 ) nByte = 1;
    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
    pNew = sqlite3DbMallocRaw(pMem->db, nByte);
    if( pNew==0 ){
      return SQLITE_NOMEM;
    }
    memcpy(pNew, pMem->z, pMem->n);
    memset(&pNew[pMem->n], 0, pMem->u.i);
    sqlite3VdbeMemRelease(pMem);
    pMem->z = pNew;
    pMem->n += pMem->u.i;
................................................................................

/*
** Make the given Mem object either MEM_Short or MEM_Dyn so that bytes
** of the Mem.z[] array can be modified.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
  int n;
  u8 *z;
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  expandBlob(pMem);
  if( (pMem->flags & (MEM_Ephem|MEM_Static))==0 ){
    return SQLITE_OK;
  }
  assert( (pMem->flags & MEM_Dyn)==0 );
  assert( pMem->flags & (MEM_Str|MEM_Blob) );
  if( (n = pMem->n)+2<sizeof(pMem->zShort) ){
    z = (u8*)pMem->zShort;
    pMem->flags |= MEM_Short|MEM_Term;
  }else{
    z = sqlite3DbMallocRaw(pMem->db, n+2 );
    if( z==0 ){

      return SQLITE_NOMEM;
    }
    pMem->flags |= MEM_Dyn|MEM_Term;
    pMem->xDel = 0;
  }
  memcpy(z, pMem->z, n );
  z[n] = 0;
................................................................................
  assert(0==(1&(int)pMem->z));
  return SQLITE_OK;
}

/*
** Make sure the given Mem is \u0000 terminated.
*/
int sqlite3VdbeMemNulTerminate(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
    return SQLITE_OK;   /* Nothing to do */
  }
  if( pMem->flags & (MEM_Static|MEM_Ephem) ){
    return sqlite3VdbeMemMakeWriteable(pMem);
  }else{
    char *z; 
    sqlite3VdbeMemExpandBlob(pMem);
    z = sqlite3DbMallocRaw(pMem->db, pMem->n+2);
    if( !z ){

       return SQLITE_NOMEM;
    }
    memcpy(z, pMem->z, pMem->n);
    z[pMem->n] = 0;
    z[pMem->n+1] = 0;
    if( pMem->xDel ){
      pMem->xDel(pMem->z);
................................................................................
**
** A MEM_Null value will never be passed to this function. This function is
** used for converting values to text for returning to the user (i.e. via
** sqlite3_value_text()), or for ensuring that values to be used as btree
** keys are strings. In the former case a NULL pointer is returned the
** user and the later is an internal programming error.
*/
int sqlite3VdbeMemStringify(Mem *pMem, int enc){
  int rc = SQLITE_OK;
  int fg = pMem->flags;
  char *z = pMem->zShort;

  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !(fg&MEM_Zero) );
  assert( !(fg&(MEM_Str|MEM_Blob)) );
  assert( fg&(MEM_Int|MEM_Real) );

  /* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
  ** string representation of the value. Then, if the required encoding
  ** is UTF-16le or UTF-16be do a translation.
................................................................................
    assert( fg & MEM_Real );
    sqlite3_snprintf(NBFS, z, "%!.15g", pMem->r);
  }
  pMem->n = strlen(z);
  pMem->z = z;
  pMem->enc = SQLITE_UTF8;
  pMem->flags |= MEM_Str | MEM_Short | MEM_Term;
  sqlite3VdbeChangeEncoding(pMem, enc);
  return rc;
}

/*
** Memory cell pMem contains the context of an aggregate function.
** This routine calls the finalize method for that function.  The
** result of the aggregate is stored back into pMem.
................................................................................
** otherwise.
*/
int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
  int rc = SQLITE_OK;
  if( pFunc && pFunc->xFinalize ){
    sqlite3_context ctx;
    assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
    ctx.s.flags = MEM_Null;
    ctx.s.z = pMem->zShort;
    ctx.s.db = pMem->db;
    ctx.pMem = pMem;
    ctx.pFunc = pFunc;
    ctx.isError = 0;
    pFunc->xFinalize(&ctx);
    if( pMem->z && pMem->z!=pMem->zShort ){
      sqlite3_free( pMem->z );
    }
................................................................................

/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
void sqlite3VdbeMemRelease(Mem *p){
  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
  if( p->flags & (MEM_Dyn|MEM_Agg) ){
    if( p->xDel ){
      if( p->flags & MEM_Agg ){
        sqlite3VdbeMemFinalize(p, p->u.pDef);
        assert( (p->flags & MEM_Agg)==0 );
        sqlite3VdbeMemRelease(p);
      }else{
................................................................................
** a floating-point then the value returned is the integer part.
** If pMem is a string or blob, then we make an attempt to convert
** it into a integer and return that.  If pMem is NULL, return 0.
**
** If pMem is a string, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem){
  int flags;
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  flags = pMem->flags;
  if( flags & MEM_Int ){
    return pMem->u.i;
  }else if( flags & MEM_Real ){
    return (i64)pMem->r;
  }else if( flags & (MEM_Str|MEM_Blob) ){
    i64 value;
    pMem->flags |= MEM_Str;
    if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
       || sqlite3VdbeMemNulTerminate(pMem) ){
      return 0;
    }
    assert( pMem->z );
    sqlite3Atoi64(pMem->z, &value);
    return value;
  }else{
    return 0;
................................................................................
/*
** Return the best representation of pMem that we can get into a
** double.  If pMem is already a double or an integer, return its
** value.  If it is a string or blob, try to convert it to a double.
** If it is a NULL, return 0.0.
*/
double sqlite3VdbeRealValue(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  if( pMem->flags & MEM_Real ){
    return pMem->r;
  }else if( pMem->flags & MEM_Int ){
    return (double)pMem->u.i;
  }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
    double val = 0.0;
    pMem->flags |= MEM_Str;
    if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
       || sqlite3VdbeMemNulTerminate(pMem) ){
      return 0.0;
    }
    assert( pMem->z );
    sqlite3AtoF(pMem->z, &val);
    return val;
  }else{
    return 0.0;
................................................................................

/*
** The MEM structure is already a MEM_Real.  Try to also make it a
** MEM_Int if we can.
*/
void sqlite3VdbeIntegerAffinity(Mem *pMem){
  assert( pMem->flags & MEM_Real );
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  pMem->u.i = pMem->r;
  if( ((double)pMem->u.i)==pMem->r ){
    pMem->flags |= MEM_Int;
  }
}

/*
** Convert pMem to type integer.  Invalidate any prior representations.
*/
int sqlite3VdbeMemIntegerify(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  pMem->u.i = sqlite3VdbeIntValue(pMem);
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Int;
  return SQLITE_OK;
}

/*
** Convert pMem so that it is of type MEM_Real.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemRealify(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  pMem->r = sqlite3VdbeRealValue(pMem);
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Real;
  return SQLITE_OK;
}

/*
................................................................................
** Invalidate any prior representations.
*/
int sqlite3VdbeMemNumerify(Mem *pMem){
  double r1, r2;
  i64 i;
  assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))==0 );
  assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  r1 = sqlite3VdbeRealValue(pMem);
  i = (i64)r1;
  r2 = (double)i;
  if( r1==r2 ){
    sqlite3VdbeMemIntegerify(pMem);
  }else{
    pMem->r = r1;
................................................................................
  }
}

/*
** Make a full copy of pFrom into pTo.  Prior contents of pTo are
** freed before the copy is made.
*/
int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
  int rc;
  if( pTo->flags & MEM_Dyn ){
    sqlite3VdbeMemRelease(pTo);
  }
  sqlite3VdbeMemShallowCopy(pTo, pFrom, MEM_Ephem);
  if( pTo->flags & MEM_Ephem ){
    rc = sqlite3VdbeMemMakeWriteable(pTo);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

/*
................................................................................
** Transfer the contents of pFrom to pTo. Any existing value in pTo is
** freed. If pFrom contains ephemeral data, a copy is made.
**
** pFrom contains an SQL NULL when this routine returns.  SQLITE_NOMEM
** might be returned if pFrom held ephemeral data and we were unable
** to allocate enough space to make a copy.
*/
int sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
  int rc;
  assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
  assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
  assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
  if( pTo->flags & MEM_Dyn ){
    sqlite3VdbeMemRelease(pTo);
  }
  memcpy(pTo, pFrom, sizeof(Mem));
  if( pFrom->flags & MEM_Short ){
    pTo->z = pTo->zShort;
  }
  pFrom->flags = MEM_Null;
  pFrom->xDel = 0;
  if( pTo->flags & MEM_Ephem ){
    rc = sqlite3VdbeMemMakeWriteable(pTo);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

/*
** Change the value of a Mem to be a string or a BLOB.
*/
int sqlite3VdbeMemSetStr(

  Mem *pMem,          /* Memory cell to set to string value */
  const char *z,      /* String pointer */
  int n,              /* Bytes in string, or negative */
  u8 enc,             /* Encoding of z.  0 for BLOBs */
  void (*xDel)(void*) /* Destructor function */
){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  sqlite3VdbeMemRelease(pMem);
  if( !z ){
    pMem->flags = MEM_Null;
    pMem->type = SQLITE_NULL;
    return SQLITE_OK;
  }

  pMem->z = (char *)z;
  if( xDel==SQLITE_STATIC ){
    pMem->flags = MEM_Static;
  }else if( xDel==SQLITE_TRANSIENT ){
    pMem->flags = MEM_Ephem;
  }else{
    pMem->flags = MEM_Dyn;
................................................................................
    case SQLITE_UTF16LE:
    case SQLITE_UTF16BE:
      pMem->flags |= MEM_Str;
      if( pMem->n<0 ){
        pMem->n = sqlite3Utf16ByteLen(pMem->z,-1);
        pMem->flags |= MEM_Term;
      }
      if( sqlite3VdbeMemHandleBom(pMem) ){
        return SQLITE_NOMEM;
      }
#endif /* SQLITE_OMIT_UTF16 */
  }
  if( pMem->flags&MEM_Ephem ){
    return sqlite3VdbeMemMakeWriteable(pMem);
  }
  return SQLITE_OK;
}

/*
** Compare the values contained by the two memory cells, returning
** negative, zero or positive if pMem1 is less than, equal to, or greater
................................................................................
        return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
      }else{
        u8 origEnc = pMem1->enc;
        const void *v1, *v2;
        int n1, n2;
        /* Convert the strings into the encoding that the comparison
        ** function expects */
        v1 = sqlite3ValueText((sqlite3_value*)pMem1, pColl->enc);
        n1 = v1==0 ? 0 : pMem1->n;
        assert( n1==sqlite3ValueBytes((sqlite3_value*)pMem1, pColl->enc) );
        v2 = sqlite3ValueText((sqlite3_value*)pMem2, pColl->enc);
        n2 = v2==0 ? 0 : pMem2->n;
        assert( n2==sqlite3ValueBytes((sqlite3_value*)pMem2, pColl->enc) );
        /* Do the comparison */
        rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
        /* Convert the strings back into the database encoding */
        sqlite3ValueText((sqlite3_value*)pMem1, origEnc);
        sqlite3ValueText((sqlite3_value*)pMem2, origEnc);
        return rc;
      }
    }
    /* If a NULL pointer was passed as the collate function, fall through
    ** to the blob case and use memcmp().  */
  }
 
................................................................................
** The pMem structure is assumed to be uninitialized.  Any prior content
** is overwritten without being freed.
**
** If this routine fails for any reason (malloc returns NULL or unable
** to read from the disk) then the pMem is left in an inconsistent state.
*/
int sqlite3VdbeMemFromBtree(

  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  int offset,       /* Offset from the start of data to return bytes from. */
  int amt,          /* Number of bytes to return. */
  int key,          /* If true, retrieve from the btree key, not data. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  char *zData;       /* Data from the btree layer */
  int available = 0; /* Number of bytes available on the local btree page */
  sqlite3 *db;       /* Database connection */

  db = sqlite3BtreeCursorDb(pCur);
  assert( sqlite3_mutex_held(db->mutex) );
  if( key ){
    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
  }else{
    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
  }
  assert( zData!=0 );

  pMem->db = db;
  pMem->n = amt;
  if( offset+amt<=available ){
    pMem->z = &zData[offset];
    pMem->flags = MEM_Blob|MEM_Ephem;
  }else{
    int rc;
    if( amt>NBFS-2 ){
      zData = (char *)sqlite3DbMallocRaw(db, amt+2);
      if( !zData ){

        return SQLITE_NOMEM;
      }
      pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
      pMem->xDel = 0;
    }else{
      zData = &(pMem->zShort[0]);
      pMem->flags = MEM_Blob|MEM_Short|MEM_Term;
................................................................................
** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
** SQLITE_UTF8.
**
** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
** If that is the case, then the result must be aligned on an even byte
** boundary.
*/
const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
  if( !pVal ) return 0;

  assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );

  if( pVal->flags&MEM_Null ){
    return 0;
  }
  assert( (MEM_Blob>>3) == MEM_Str );
  pVal->flags |= (pVal->flags & MEM_Blob)>>3;
  expandBlob(pVal);
  if( pVal->flags&MEM_Str ){
    sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
    if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&(int)pVal->z) ){
      assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
      if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
        return 0;
      }
    }
    sqlite3VdbeMemNulTerminate(pVal);
  }else{
    assert( (pVal->flags&MEM_Blob)==0 );
    sqlite3VdbeMemStringify(pVal, enc);
    assert( 0==(1&(int)pVal->z) );
  }
  assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
              || pVal->db->mallocFailed );
  if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
    return pVal->z;
  }else{
    return 0;
  }
}

................................................................................
** Create a new sqlite3_value object.
*/
sqlite3_value *sqlite3ValueNew(sqlite3 *db){
  Mem *p = sqlite3MallocZero(sizeof(*p));
  if( p ){
    p->flags = MEM_Null;
    p->type = SQLITE_NULL;
    p->db = db;
  }else{
    db->mallocFailed = 1;
  }
  return p;
}

/*
................................................................................
** token (i.e. "5", "5.1", "NULL", "'a string'"). If the expression can
** be converted directly into a value, then the value is allocated and
** a pointer written to *ppVal. The caller is responsible for deallocating
** the value by passing it to sqlite3ValueFree() later on. If the expression
** cannot be converted to a value, then *ppVal is set to NULL.
*/
int sqlite3ValueFromExpr(
  sqlite3 *db,              /* The database connection */
  Expr *pExpr,              /* The expression to evaluate */
  u8 enc,                   /* Encoding to use */
  u8 affinity,              /* Affinity to use */
  sqlite3_value **ppVal     /* Write the new value here */
){
  int op;
  char *zVal = 0;
................................................................................
  op = pExpr->op;

  if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
    zVal = sqlite3StrNDup((char*)pExpr->token.z, pExpr->token.n);
    pVal = sqlite3ValueNew(db);
    if( !zVal || !pVal ) goto no_mem;
    sqlite3Dequote(zVal);
    sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, sqlite3_free);
    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
      sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, enc);
    }else{
      sqlite3ValueApplyAffinity(pVal, affinity, enc);
    }
  }else if( op==TK_UMINUS ) {
    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) ){
      pVal->u.i = -1 * pVal->u.i;
      pVal->r = -1.0 * pVal->r;
    }
  }
#ifndef SQLITE_OMIT_BLOB_LITERAL
  else if( op==TK_BLOB ){
    int nVal;
    pVal = sqlite3ValueNew(db);
    zVal = sqlite3StrNDup((char*)pExpr->token.z+1, pExpr->token.n-1);
    if( !zVal || !pVal ) goto no_mem;
    sqlite3Dequote(zVal);
    nVal = strlen(zVal)/2;

    sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal), nVal,0,sqlite3_free);
    sqlite3_free(zVal);
  }
#endif

  *ppVal = pVal;
  return SQLITE_OK;

................................................................................
  return SQLITE_NOMEM;
}

/*
** Change the string value of an sqlite3_value object
*/
void sqlite3ValueSetStr(

  sqlite3_value *v,     /* Value to be set */
  int n,                /* Length of string z */
  const void *z,        /* Text of the new string */
  u8 enc,               /* Encoding to use */
  void (*xDel)(void*)   /* Destructor for the string */
){
  if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);
}

/*
** Free an sqlite3_value object
*/
void sqlite3ValueFree(sqlite3_value *v){
  if( !v ) return;
  sqlite3ValueSetStr(v, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
  sqlite3_free(v);
}

/*
** Return the number of bytes in the sqlite3_value object assuming
** that it uses the encoding "enc"
*/
int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
  Mem *p = (Mem*)pVal;
  if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(pVal, enc) ){
    if( p->flags & MEM_Zero ){
      return p->n+p->u.i;
    }else{
      return p->n;
    }
  }
  return 0;
}