SQLite

sqlite3$(TEXE):	$(TOP)/src/shell.c sqlite3.c
	$(LTLINK) $(READLINE_FLAGS) $(SHELL_OPT) -o $@ \
		$(TOP)/src/shell.c sqlite3.c \
		$(LIBREADLINE) $(TLIBS) -rpath "$(libdir)"

sqldiff$(TEXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
	$(LTLINK) -o $@ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS)

scrub$(TEXE):	$(TOP)/ext/misc/scrub.c sqlite3.o
	$(LTLINK) -o $@ -I. -DSCRUB_STANDALONE \
		$(TOP)/ext/misc/scrub.c sqlite3.o $(TLIBS)

srcck1$(BEXE):	$(TOP)/tool/srcck1.c
	$(BCC) -o srcck1$(BEXE) $(TOP)/tool/srcck1.c

sourcetest:	srcck1$(BEXE) sqlite3.c
	./srcck1 sqlite3.c

	$(LTLINK) $(SHELL_COMPILE_OPTS) $(READLINE_FLAGS) $(TOP)\src\shell.c $(SHELL_CORE_SRC) \
		/link $(SQLITE3EXEPDB) $(LDFLAGS) $(LTLINKOPTS) $(SHELL_LINK_OPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LIBREADLINE) $(LTLIBS) $(TLIBS)

# <<mark>>
sqldiff.exe:	$(TOP)\tool\sqldiff.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) $(TOP)\tool\sqldiff.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

scrub.exe:	$(TOP)\ext\misc\scrub.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) $(TOP)\ext\misc\scrub.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

srcck1.exe:	$(TOP)\tool\srcck1.c
	$(BCC) $(NO_WARN) -Fe$@ $(TOP)\tool\srcck1.c

sourcetest:	srcck1.exe sqlite3.c
	srcck1.exe sqlite3.c

fuzzershell.exe:	$(TOP)\tool\fuzzershell.c $(SQLITE3C) $(SQLITE3H)

3.14.0

AC_ARG_ENABLE(editline, [AS_HELP_STRING(
  [--enable-editline], 
  [use BSD libedit])], 
  [], [enable_editline=yes])
AC_ARG_ENABLE(readline, [AS_HELP_STRING(
  [--enable-readline], 
  [use readline])], 
  [], [enable_readline=yes])
if test x"$enable_editline" != xno ; then
  sLIBS=$LIBS
  LIBS=""
  AC_SEARCH_LIBS([readline],[edit],[enable_readline=no],[enable_editline=no])
  READLINE_LIBS=$LIBS
  if test x"$LIBS" != "x"; then
    AC_DEFINE([HAVE_EDITLINE],1,Define to use BSD editline)
    enable_readline=no
  else
    unset ac_cv_search_readline
  fi
  LIBS=$sLIBS
fi
if test x"$enable_readline" != xno ; then
  sLIBS=$LIBS

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.69 for sqlite 3.14.0.
#
#
# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
#
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.

subdirs=
MFLAGS=
MAKEFLAGS=

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.14.0'
PACKAGE_STRING='sqlite 3.14.0'
PACKAGE_BUGREPORT=''
PACKAGE_URL=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H

#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.14.0 to adapt to many kinds of systems.

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

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

Defaults for the options are specified in brackets.

  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.14.0:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]

    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.14.0
generated by GNU Autoconf 2.69

Copyright (C) 2012 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit

  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno

} # ac_fn_c_check_header_mongrel
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.14.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{

          if test -f "$i/tclConfig.sh" ; then
            ac_cv_c_tclconfig="$i"
            break
          fi
        done
      fi
    fi

    # Recent versions of Xcode on Macs hid the tclConfig.sh file
    # in a strange place.
    if test x"${ac_cv_c_tclconfig}" = x ; then
      if test x"$cross_compiling" = xno; then
        for i in /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX*.sdk/usr/lib
        do
          if test -f "$i/tclConfig.sh" ; then
            ac_cv_c_tclconfig="$i"
            break
          fi
        done
      fi
    fi

    # then check for a private Tcl installation
    if test x"${ac_cv_c_tclconfig}" = x ; then
      for i in \
            ../tcl \
            `ls -dr ../tcl[8-9].[0-9].[0-9]* 2>/dev/null` \
            `ls -dr ../tcl[8-9].[0-9] 2>/dev/null` \

test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
# Save the log message, to keep $0 and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.14.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

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

Report bugs to the package provider."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
ac_cs_version="\\
sqlite config.status 3.14.0
configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

Copyright (C) 2012 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

    # On ubuntu 14.10, $auto_path on tclsh is not quite correct.
    # So try again after applying corrections.
    if test x"${ac_cv_c_tclconfig}" = x ; then
      if test x"$cross_compiling" = xno; then
        for i in `echo 'puts stdout $auto_path' | ${TCLSH_CMD} | sed 's,/tcltk/tcl,/tcl,g'`
        do
          if test -f "$i/tclConfig.sh" ; then
            ac_cv_c_tclconfig="$i"
            break
          fi
        done
      fi
    fi

    # Recent versions of Xcode on Macs hid the tclConfig.sh file
    # in a strange place.
    if test x"${ac_cv_c_tclconfig}" = x ; then
      if test x"$cross_compiling" = xno; then
        for i in /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX*.sdk/usr/lib
        do
          if test -f "$i/tclConfig.sh" ; then
            ac_cv_c_tclconfig="$i"
            break
          fi
        done
      fi
    fi

/*
** 2016-05-05
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a utility function (and a utility program) that
** makes a copy of an SQLite database while simultaneously zeroing out all
** deleted content.
**
** Normally (when PRAGMA secure_delete=OFF, which is the default) when SQLite
** deletes content, it does not overwrite the deleted content but rather marks
** the region of the file that held that content as being reusable.  This can
** cause deleted content to recoverable from the database file.  This stale
** content is removed by the VACUUM command, but VACUUM can be expensive for
** large databases.  When in PRAGMA secure_delete=ON mode, the deleted content
** is zeroed, but secure_delete=ON has overhead as well.
**
** This utility attempts to make a copy of a complete SQLite database where
** all of the deleted content is zeroed out in the copy, and it attempts to
** do so while being faster than running VACUUM.
**
** Usage:
**
**   int sqlite3_scrub_backup(
**       const char *zSourceFile,   // Source database filename
**       const char *zDestFile,     // Destination database filename
**       char **pzErrMsg            // Write error message here
**   );
**
** Simply call the API above specifying the filename of the source database
** and the name of the backup copy.  The source database must already exist
** and can be in active use. (A read lock is held during the backup.)  The
** destination file should not previously exist.  If the pzErrMsg parameter
** is non-NULL and if an error occurs, then an error message might be written
** into memory obtained from sqlite3_malloc() and *pzErrMsg made to point to
** that error message.  But if the error is an OOM, the error might not be
** reported.  The routine always returns non-zero if there is an error.
**
** If compiled with -DSCRUB_STANDALONE then a main() procedure is added and
** this file becomes a standalone program that can be run as follows:
**
**      ./sqlite3scrub SOURCE DEST
*/
#include "sqlite3.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>

typedef struct ScrubState ScrubState;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;


/* State information for a scrub-and-backup operation */
struct ScrubState {
  const char *zSrcFile;    /* Name of the source file */
  const char *zDestFile;   /* Name of the destination file */
  int rcErr;               /* Error code */
  char *zErr;              /* Error message text */
  sqlite3 *dbSrc;          /* Source database connection */
  sqlite3_file *pSrc;      /* Source file handle */
  sqlite3 *dbDest;         /* Destination database connection */
  sqlite3_file *pDest;     /* Destination file handle */
  u32 szPage;              /* Page size */
  u32 szUsable;            /* Usable bytes on each page */
  u32 nPage;               /* Number of pages */
  u8 *page1;               /* Content of page 1 */
};

/* Store an error message */
static void scrubBackupErr(ScrubState *p, const char *zFormat, ...){
  va_list ap;
  sqlite3_free(p->zErr);
  va_start(ap, zFormat);
  p->zErr = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  if( p->rcErr==0 ) p->rcErr = SQLITE_ERROR;
}

/* Allocate memory to hold a single page of content */
static u8 *scrubBackupAllocPage(ScrubState *p){
  u8 *pPage;
  if( p->rcErr ) return 0;
  pPage = sqlite3_malloc( p->szPage );
  if( pPage==0 ) p->rcErr = SQLITE_NOMEM;
  return pPage;
}

/* Read a page from the source database into memory.  Use the memory
** provided by pBuf if not NULL or allocate a new page if pBuf==NULL.
*/
static u8 *scrubBackupRead(ScrubState *p, int pgno, u8 *pBuf){
  int rc;
  sqlite3_int64 iOff;
  u8 *pOut = pBuf;
  if( p->rcErr ) return 0;
  if( pOut==0 ){
    pOut = scrubBackupAllocPage(p);
    if( pOut==0 ) return 0;
  }
  iOff = (pgno-1)*(sqlite3_int64)p->szPage;
  rc = p->pSrc->pMethods->xRead(p->pSrc, pOut, p->szPage, iOff);
  if( rc!=SQLITE_OK ){
    if( pBuf==0 ) sqlite3_free(pOut);
    pOut = 0;
    scrubBackupErr(p, "read failed for page %d", pgno);
    p->rcErr = SQLITE_IOERR;
  }
  return pOut;  
}

/* Write a page to the destination database */
static void scrubBackupWrite(ScrubState *p, int pgno, const u8 *pData){
  int rc;
  sqlite3_int64 iOff;
  if( p->rcErr ) return;
  iOff = (pgno-1)*(sqlite3_int64)p->szPage;
  rc = p->pDest->pMethods->xWrite(p->pDest, pData, p->szPage, iOff);
  if( rc!=SQLITE_OK ){
    scrubBackupErr(p, "write failed for page %d", pgno);
    p->rcErr = SQLITE_IOERR;
  }
}

/* Prepare a statement against the "db" database. */
static sqlite3_stmt *scrubBackupPrepare(
  ScrubState *p,      /* Backup context */
  sqlite3 *db,        /* Database to prepare against */
  const char *zSql    /* SQL statement */
){
  sqlite3_stmt *pStmt;
  if( p->rcErr ) return 0;
  p->rcErr = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( p->rcErr ){
    scrubBackupErr(p, "SQL error \"%s\" on \"%s\"",
                   sqlite3_errmsg(db), zSql);
    sqlite3_finalize(pStmt);
    return 0;
  }
  return pStmt;
}


/* Open the source database file */
static void scrubBackupOpenSrc(ScrubState *p){
  sqlite3_stmt *pStmt;
  int rc;
  /* Open the source database file */
  p->rcErr = sqlite3_open_v2(p->zSrcFile, &p->dbSrc,
                 SQLITE_OPEN_READWRITE |
                 SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0);
  if( p->rcErr ){
    scrubBackupErr(p, "cannot open source database: %s",
                      sqlite3_errmsg(p->dbSrc));
    return;
  }
  p->rcErr = sqlite3_exec(p->dbSrc, "SELECT 1 FROM sqlite_master; BEGIN;",
                          0, 0, 0);
  if( p->rcErr ){
    scrubBackupErr(p,
       "cannot start a read transaction on the source database: %s",
       sqlite3_errmsg(p->dbSrc));
    return;
  }
  rc = sqlite3_wal_checkpoint_v2(p->dbSrc, "main", SQLITE_CHECKPOINT_FULL,
                                 0, 0);
  if( rc ){
    scrubBackupErr(p, "cannot checkpoint the source database");
    return;
  }
  pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_size");
  if( pStmt==0 ) return;
  rc = sqlite3_step(pStmt);
  if( rc==SQLITE_ROW ){
    p->szPage = sqlite3_column_int(pStmt, 0);
  }else{
    scrubBackupErr(p, "unable to determine the page size");
  }
  sqlite3_finalize(pStmt);
  if( p->rcErr ) return;
  pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_count");
  if( pStmt==0 ) return;
  rc = sqlite3_step(pStmt);
  if( rc==SQLITE_ROW ){
    p->nPage = sqlite3_column_int(pStmt, 0);
  }else{
    scrubBackupErr(p, "unable to determine the size of the source database");
  }
  sqlite3_finalize(pStmt);
  sqlite3_file_control(p->dbSrc, "main", SQLITE_FCNTL_FILE_POINTER, &p->pSrc);
  if( p->pSrc==0 || p->pSrc->pMethods==0 ){
    scrubBackupErr(p, "cannot get the source file handle");
    p->rcErr = SQLITE_ERROR;
  }
}

/* Create and open the destination file */
static void scrubBackupOpenDest(ScrubState *p){
  sqlite3_stmt *pStmt;
  int rc;
  char *zSql;
  if( p->rcErr ) return;
  p->rcErr = sqlite3_open_v2(p->zDestFile, &p->dbDest,
                 SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
                 SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0);
  if( p->rcErr ){
    scrubBackupErr(p, "cannot open destination database: %s",
                      sqlite3_errmsg(p->dbDest));
    return;
  }
  zSql = sqlite3_mprintf("PRAGMA page_size(%u);", p->szPage);
  if( zSql==0 ){
    p->rcErr = SQLITE_NOMEM;
    return;
  }
  p->rcErr = sqlite3_exec(p->dbDest, zSql, 0, 0, 0);
  sqlite3_free(zSql);
  if( p->rcErr ){
    scrubBackupErr(p,
       "cannot set the page size on the destination database: %s",
       sqlite3_errmsg(p->dbDest));
    return;
  }
  sqlite3_exec(p->dbDest, "PRAGMA journal_mode=OFF;", 0, 0, 0);
  p->rcErr = sqlite3_exec(p->dbDest, "BEGIN EXCLUSIVE;", 0, 0, 0);
  if( p->rcErr ){
    scrubBackupErr(p,
       "cannot start a write transaction on the destination database: %s",
       sqlite3_errmsg(p->dbDest));
    return;
  }
  pStmt = scrubBackupPrepare(p, p->dbDest, "PRAGMA page_count;");
  if( pStmt==0 ) return;
  rc = sqlite3_step(pStmt);
  if( rc!=SQLITE_ROW ){
    scrubBackupErr(p, "cannot measure the size of the destination");
  }else if( sqlite3_column_int(pStmt, 0)>1 ){
    scrubBackupErr(p, "destination database is not empty - holds %d pages",
                   sqlite3_column_int(pStmt, 0));
  }
  sqlite3_finalize(pStmt);
  sqlite3_file_control(p->dbDest, "main", SQLITE_FCNTL_FILE_POINTER, &p->pDest);
  if( p->pDest==0 || p->pDest->pMethods==0 ){
    scrubBackupErr(p, "cannot get the destination file handle");
    p->rcErr = SQLITE_ERROR;
  }
}

/* Read a 32-bit big-endian integer */
static u32 scrubBackupInt32(const u8 *a){
  u32 v = a[3];
  v += ((u32)a[2])<<8;
  v += ((u32)a[1])<<16;
  v += ((u32)a[0])<<24;
  return v;
}

/* Read a 16-bit big-endian integer */
static u32 scrubBackupInt16(const u8 *a){
  return (a[0]<<8) + a[1];
}

/*
** Read a varint.  Put the value in *pVal and return the number of bytes.
*/
static int scrubBackupVarint(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_int64 v = 0;
  int i;
  for(i=0; i<8; i++){
    v = (v<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; }
  }
  v = (v<<8) + (z[i]&0xff);
  *pVal = v;
  return 9;
}

/*
** Return the number of bytes in a varint.
*/
static int scrubBackupVarintSize(const u8 *z){
  int i;
  for(i=0; i<8; i++){
    if( (z[i]&0x80)==0 ){ return i+1; }
  }
  return 9;
}

/*
** Copy the freelist trunk page given, and all its descendents,
** zeroing out as much as possible in the process.
*/
static void scrubBackupFreelist(ScrubState *p, int pgno, u32 nFree){
  u8 *a, *aBuf;
  u32 n, mx;

  if( p->rcErr ) return;
  aBuf = scrubBackupAllocPage(p);
  if( aBuf==0 ) return;
 
  while( pgno && nFree){
    a = scrubBackupRead(p, pgno, aBuf);
    if( a==0 ) break;
    n = scrubBackupInt32(&a[4]);
    mx = p->szUsable/4 - 2;
    if( n<mx ){
      memset(&a[n*4+8], 0, 4*(mx-n));
    }
    scrubBackupWrite(p, pgno, a);
    pgno = scrubBackupInt32(a);
#if 0
    /* There is really no point in copying the freelist leaf pages.
    ** Simply leave them uninitialized in the destination database.  The
    ** OS filesystem should zero those pages for us automatically.
    */
    for(i=0; i<n && nFree; i++){
      u32 iLeaf = scrubBackupInt32(&a[i*4+8]);
      if( aZero==0 ){
        aZero = scrubBackupAllocPage(p);
        if( aZero==0 ){ pgno = 0; break; }
        memset(aZero, 0, p->szPage);
      }
      scrubBackupWrite(p, iLeaf, aZero);
      nFree--;
    }
#endif
  }
  sqlite3_free(aBuf);
}

/*
** Copy an overflow chain from source to destination.  Zero out any
** unused tail at the end of the overflow chain.
*/
static void scrubBackupOverflow(ScrubState *p, int pgno, u32 nByte){
  u8 *a, *aBuf;

  aBuf = scrubBackupAllocPage(p);
  if( aBuf==0 ) return;
  while( nByte>0 && pgno!=0 ){
    a = scrubBackupRead(p, pgno, aBuf);
    if( a==0 ) break;
    if( nByte >= (p->szUsable)-4 ){
      nByte -= (p->szUsable) - 4;
    }else{
      u32 x = (p->szUsable - 4) - nByte;
      u32 i = p->szUsable - x;
      memset(&a[i], 0, x);
      nByte = 0;
    }
    scrubBackupWrite(p, pgno, a);
    pgno = scrubBackupInt32(a);
  }
  sqlite3_free(aBuf);      
}
   

/*
** Copy B-Tree page pgno, and all of its children, from source to destination.
** Zero out deleted content during the copy.
*/
static void scrubBackupBtree(ScrubState *p, int pgno, int iDepth){
  u8 *a;
  u32 i, n, pc;
  u32 nCell;
  u32 nPrefix;
  u32 szHdr;
  u32 iChild;
  u8 *aTop;
  u8 *aCell;
  u32 x, y;
  int ln = 0;

  
  if( p->rcErr ) return;
  if( iDepth>50 ){
    scrubBackupErr(p, "corrupt: b-tree too deep at page %d", pgno);
    return;
  }
  if( pgno==1 ){
    a = p->page1;
  }else{
    a = scrubBackupRead(p, pgno, 0);
    if( a==0 ) return;
  }
  nPrefix = pgno==1 ? 100 : 0;
  aTop = &a[nPrefix];
  szHdr = 8 + 4*(aTop[0]==0x02 || aTop[0]==0x05);
  aCell = aTop + szHdr;
  nCell = scrubBackupInt16(&aTop[3]);

  /* Zero out the gap between the cell index and the start of the
  ** cell content area */
  x = scrubBackupInt16(&aTop[5]);  /* First byte of cell content area */
  if( x>p->szUsable ){ ln=__LINE__; goto btree_corrupt; }
  y = szHdr + nPrefix + nCell*2;
  if( y>x ){ ln=__LINE__; goto btree_corrupt; }
  if( y<x ) memset(a+y, 0, x-y);  /* Zero the gap */

  /* Zero out all the free blocks */  
  pc = scrubBackupInt16(&aTop[1]);
  if( pc>0 && pc<x ){ ln=__LINE__; goto btree_corrupt; }
  while( pc ){
    if( pc>(p->szUsable)-4 ){ ln=__LINE__; goto btree_corrupt; }
    n = scrubBackupInt16(&a[pc+2]);
    if( pc+n>(p->szUsable) ){ ln=__LINE__; goto btree_corrupt; }
    if( n>4 ) memset(&a[pc+4], 0, n-4);
    x = scrubBackupInt16(&a[pc]);
    if( x<pc+4 && x>0 ){ ln=__LINE__; goto btree_corrupt; }
    pc = x;
  }

  /* Write this one page */
  scrubBackupWrite(p, pgno, a);

  /* Walk the tree and process child pages */
  for(i=0; i<nCell; i++){
    u32 X, M, K, nLocal;
    sqlite3_int64 P;
    pc = scrubBackupInt16(&aCell[i*2]);
    if( pc <= szHdr ){ ln=__LINE__; goto btree_corrupt; }
    if( pc > p->szUsable-3 ){ ln=__LINE__; goto btree_corrupt; }
    if( aTop[0]==0x05 || aTop[0]==0x02 ){
      if( pc+4 > p->szUsable ){ ln=__LINE__; goto btree_corrupt; }
      iChild = scrubBackupInt32(&a[pc]);
      pc += 4;
      scrubBackupBtree(p, iChild, iDepth+1);
      if( aTop[0]==0x05 ) continue;
    }
    pc += scrubBackupVarint(&a[pc], &P);
    if( pc >= p->szUsable ){ ln=__LINE__; goto btree_corrupt; }
    if( aTop[0]==0x0d ){
      X = p->szUsable - 35;
    }else{
      X = ((p->szUsable - 12)*64/255) - 23;
    }
    if( P<=X ){
      /* All content is local.  No overflow */
      continue;
    }
    M = ((p->szUsable - 12)*32/255)-23;
    K = M + ((P-M)%(p->szUsable-4));
    if( aTop[0]==0x0d ){
      pc += scrubBackupVarintSize(&a[pc]);
      if( pc > (p->szUsable-4) ){ ln=__LINE__; goto btree_corrupt; }
    }
    nLocal = K<=X ? K : M;
    if( pc+nLocal > p->szUsable-4 ){ ln=__LINE__; goto btree_corrupt; }
    iChild = scrubBackupInt32(&a[pc+nLocal]);
    scrubBackupOverflow(p, iChild, P-nLocal);
  }

  /* Walk the right-most tree */
  if( aTop[0]==0x05 || aTop[0]==0x02 ){
    iChild = scrubBackupInt32(&aTop[8]);
    scrubBackupBtree(p, iChild, iDepth+1);
  }

  /* All done */
  if( pgno>1 ) sqlite3_free(a);
  return;

btree_corrupt:
  scrubBackupErr(p, "corruption on page %d of source database (errid=%d)",
                 pgno, ln);
  if( pgno>1 ) sqlite3_free(a);  
}

/*
** Copy all ptrmap pages from source to destination.
** This routine is only called if the source database is in autovacuum
** or incremental vacuum mode.
*/
static void scrubBackupPtrmap(ScrubState *p){
  u32 pgno = 2;
  u32 J = p->szUsable/5;
  u32 iLock = (1073742335/p->szPage)+1;
  u8 *a, *pBuf;
  if( p->rcErr ) return;
  pBuf = scrubBackupAllocPage(p);
  if( pBuf==0 ) return;
  while( pgno<=p->nPage ){
    a = scrubBackupRead(p, pgno, pBuf);
    if( a==0 ) break;
    scrubBackupWrite(p, pgno, a);
    pgno += J+1;
    if( pgno==iLock ) pgno++;
  }
  sqlite3_free(pBuf);
}

int sqlite3_scrub_backup(
  const char *zSrcFile,    /* Source file */
  const char *zDestFile,   /* Destination file */
  char **pzErr             /* Write error here if non-NULL */
){
  ScrubState s;
  u32 n, i;
  sqlite3_stmt *pStmt;

  memset(&s, 0, sizeof(s));
  s.zSrcFile = zSrcFile;
  s.zDestFile = zDestFile;

  /* Open both source and destination databases */
  scrubBackupOpenSrc(&s);
  scrubBackupOpenDest(&s);

  /* Read in page 1 */
  s.page1 = scrubBackupRead(&s, 1, 0);
  if( s.page1==0 ) goto scrub_abort;
  s.szUsable = s.szPage - s.page1[20];

  /* Copy the freelist */    
  n = scrubBackupInt32(&s.page1[36]);
  i = scrubBackupInt32(&s.page1[32]);
  if( n ) scrubBackupFreelist(&s, i, n);

  /* Copy ptrmap pages */
  n = scrubBackupInt32(&s.page1[52]);
  if( n ) scrubBackupPtrmap(&s);

  /* Copy all of the btrees */
  scrubBackupBtree(&s, 1, 0);
  pStmt = scrubBackupPrepare(&s, s.dbSrc,
       "SELECT rootpage FROM sqlite_master WHERE coalesce(rootpage,0)>0");
  if( pStmt==0 ) goto scrub_abort;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    i = (u32)sqlite3_column_int(pStmt, 0);
    scrubBackupBtree(&s, i, 0);
  }
  sqlite3_finalize(pStmt);

scrub_abort:    
  /* Close the destination database without closing the transaction. If we
  ** commit, page zero will be overwritten. */
  sqlite3_close(s.dbDest);

  /* But do close out the read-transaction on the source database */
  sqlite3_exec(s.dbSrc, "COMMIT;", 0, 0, 0);
  sqlite3_close(s.dbSrc);
  sqlite3_free(s.page1);
  if( pzErr ){
    *pzErr = s.zErr;
  }else{
    sqlite3_free(s.zErr);
  }
  return s.rcErr;
}   

#ifdef SCRUB_STANDALONE
/* Error and warning log */
static void errorLogCallback(void *pNotUsed, int iErr, const char *zMsg){
  const char *zType;
  switch( iErr&0xff ){
    case SQLITE_WARNING: zType = "WARNING";  break;
    case SQLITE_NOTICE:  zType = "NOTICE";   break;
    default:             zType = "ERROR";    break;
  }
  fprintf(stderr, "%s: %s\n", zType, zMsg);
}

/* The main() routine when this utility is run as a stand-alone program */
int main(int argc, char **argv){
  char *zErr = 0;
  int rc;
  if( argc!=3 ){
    fprintf(stderr,"Usage: %s SOURCE DESTINATION\n", argv[0]);
    exit(1);
  }
  sqlite3_config(SQLITE_CONFIG_LOG, errorLogCallback, 0);
  rc = sqlite3_scrub_backup(argv[1], argv[2], &zErr);
  if( rc==SQLITE_NOMEM ){
    fprintf(stderr, "%s: out of memory\n", argv[0]);
    exit(1);
  }
  if( zErr ){
    fprintf(stderr, "%s: %s\n", argv[0], zErr);
    sqlite3_free(zErr);
    exit(1);
  }
  return 0;
}
#endif

	$(TCCX) $(READLINE_FLAGS) -o sqlite3$(EXE) $(SHELL_OPT) \
		$(TOP)/src/shell.c libsqlite3.a $(LIBREADLINE) $(TLIBS) $(THREADLIB)

sqldiff$(EXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
	$(TCCX) -o sqldiff$(EXE) -DSQLITE_THREADSAFE=0 \
		$(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) $(THREADLIB)

scrub$(EXE):	$(TOP)/ext/misc/scrub.c sqlite3.o
	$(TCC) -I. -DSCRUB_STANDALONE -o scrub$(EXE) $(TOP)/ext/misc/scrub.c sqlite3.o $(THREADLIB)

srcck1$(EXE):	$(TOP)/tool/srcck1.c
	$(BCC) -o srcck1$(EXE) $(TOP)/tool/srcck1.c

sourcetest:	srcck1$(EXE) sqlite3.c
	./srcck1 sqlite3.c

fuzzershell$(EXE):	$(TOP)/tool/fuzzershell.c sqlite3.c sqlite3.h

  ** or an error code.
  */
  sqlite3_backup_step(&b, 0x7FFFFFFF);
  assert( b.rc!=SQLITE_OK );
  rc = sqlite3_backup_finish(&b);
  if( rc==SQLITE_OK ){
    pTo->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;


  }

  assert( sqlite3BtreeIsInTrans(pTo)==0 );
copy_finished:
  sqlite3BtreeLeave(pFrom);
  sqlite3BtreeLeave(pTo);
  return rc;

** area.  pCell might point to some temporary storage.  The cell will
** be constructed in this temporary area then copied into pPage->aData
** later.
*/
static int fillInCell(
  MemPage *pPage,                /* The page that contains the cell */
  unsigned char *pCell,          /* Complete text of the cell */


  const BtreePayload *pX,        /* Payload with which to construct the cell */
  int *pnSize                    /* Write cell size here */
){
  int nPayload;
  const u8 *pSrc;
  int nSrc, n, rc;
  int spaceLeft;
  MemPage *pOvfl = 0;

  /* pPage is not necessarily writeable since pCell might be auxiliary
  ** buffer space that is separate from the pPage buffer area */
  assert( pCell<pPage->aData || pCell>=&pPage->aData[pBt->pageSize]
            || sqlite3PagerIswriteable(pPage->pDbPage) );

  /* Fill in the header. */
  nHeader = pPage->childPtrSize;

  if( pPage->intKey ){
    nPayload = pX->nData + pX->nZero;
    pSrc = pX->pData;
    nSrc = pX->nData;
    assert( pPage->intKeyLeaf ); /* fillInCell() only called for leaves */
    nHeader += putVarint32(&pCell[nHeader], nPayload);
    nHeader += putVarint(&pCell[nHeader], *(u64*)&pX->nKey);
  }else{
    assert( pX->nData==0 );
    assert( pX->nZero==0 );









    assert( pX->nKey<=0x7fffffff && pX->pKey!=0 );
    nSrc = nPayload = (int)pX->nKey;
    pSrc = pX->pKey;

    nHeader += putVarint32(&pCell[nHeader], nPayload);
  }
  
  /* Fill in the payload */
  if( nPayload<=pPage->maxLocal ){
    n = nHeader + nPayload;
    testcase( n==3 );
    testcase( n==4 );
    if( n<4 ) n = 4;
    *pnSize = n;
    spaceLeft = nPayload;

  ** were computed correctly.
  */
#if SQLITE_DEBUG
  {
    CellInfo info;
    pPage->xParseCell(pPage, pCell, &info);
    assert( nHeader==(int)(info.pPayload - pCell) );
    assert( info.nKey==pX->nKey );
    assert( *pnSize == info.nSize );
    assert( spaceLeft == info.nLocal );
  }
#endif

  /* Write the payload into the local Cell and any extra into overflow pages */
  while( nPayload>0 ){

      memset(pPayload, 0, n);
    }
    nPayload -= n;
    pPayload += n;
    pSrc += n;
    nSrc -= n;
    spaceLeft -= n;




  }
  releasePage(pToRelease);
  return SQLITE_OK;
}

/*
** Remove the i-th cell from pPage.  This routine effects pPage only.

** If the cell content will fit on the page, then put it there.  If it
** will not fit, then make a copy of the cell content into pTemp if
** pTemp is not null.  Regardless of pTemp, allocate a new entry
** in pPage->apOvfl[] and make it point to the cell content (either
** in pTemp or the original pCell) and also record its index. 
** Allocating a new entry in pPage->aCell[] implies that 
** pPage->nOverflow is incremented.
**
** *pRC must be SQLITE_OK when this routine is called.
*/
static void insertCell(
  MemPage *pPage,   /* Page into which we are copying */
  int i,            /* New cell becomes the i-th cell of the page */
  u8 *pCell,        /* Content of the new cell */
  int sz,           /* Bytes of content in pCell */
  u8 *pTemp,        /* Temp storage space for pCell, if needed */
  Pgno iChild,      /* If non-zero, replace first 4 bytes with this value */
  int *pRC          /* Read and write return code from here */
){
  int idx = 0;      /* Where to write new cell content in data[] */
  int j;            /* Loop counter */
  u8 *data;         /* The content of the whole page */
  u8 *pIns;         /* The point in pPage->aCellIdx[] where no cell inserted */


  assert( *pRC==SQLITE_OK );
  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
  assert( MX_CELL(pPage->pBt)<=10921 );
  assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );
  assert( pPage->nOverflow<=ArraySize(pPage->apOvfl) );
  assert( ArraySize(pPage->apOvfl)==ArraySize(pPage->aiOvfl) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  /* The cell should normally be sized correctly.  However, when moving a

    pCell = findCell(pPage, pPage->nCell-1);
    pStop = &pCell[9];
    while( (*(pCell++)&0x80) && pCell<pStop );
    pStop = &pCell[9];
    while( ((*(pOut++) = *(pCell++))&0x80) && pCell<pStop );

    /* Insert the new divider cell into pParent. */
    if( rc==SQLITE_OK ){
      insertCell(pParent, pParent->nCell, pSpace, (int)(pOut-pSpace),
                   0, pPage->pgno, &rc);
    }

    /* Set the right-child pointer of pParent to point to the new page. */
    put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);
  
    /* Release the reference to the new page. */
    releasePage(pNew);
  }

    sqlite3PageFree(pFree);
  }
  return rc;
}


/*
** Insert a new record into the BTree.  The content of the new record
** is described by the pX object.  The pCur cursor is used only to
** define what table the record should be inserted into, and is left
** pointing at a random location.
**
** For a table btree (used for rowid tables), only the pX.nKey value of
** the key is used. The pX.pKey value must be NULL.  The pX.nKey is the

** rowid or INTEGER PRIMARY KEY of the row.  The pX.nData,pData,nZero fields
** hold the content of the row.
**
** For an index btree (used for indexes and WITHOUT ROWID tables), the
** key is an arbitrary byte sequence stored in pX.pKey,nKey.  The 
** pX.pData,nData,nZero fields must be zero.
**
** If the seekResult parameter is non-zero, then a successful call to
** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
** been performed. seekResult is the search result returned (a negative
** number if pCur points at an entry that is smaller than (pKey, nKey), or
** a positive value if pCur points at an entry that is larger than 
** (pKey, nKey)). 
**
** If the seekResult parameter is non-zero, then the caller guarantees that
** cursor pCur is pointing at the existing copy of a row that is to be
** overwritten.  If the seekResult parameter is 0, then cursor pCur may
** point to any entry or to no entry at all and so this function has to seek
** the cursor before the new key can be inserted.
*/
int sqlite3BtreeInsert(
  BtCursor *pCur,                /* Insert data into the table of this cursor */


  const BtreePayload *pX,        /* Content of the row to be inserted */
  int appendBias,                /* True if this is likely an append */
  int seekResult                 /* Result of prior MovetoUnpacked() call */
){
  int rc;
  int loc = seekResult;          /* -1: before desired location  +1: after */
  int szNew = 0;
  int idx;

  assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );

  /* Assert that the caller has been consistent. If this cursor was opened
  ** expecting an index b-tree, then the caller should be inserting blob
  ** keys with no associated data. If the cursor was opened expecting an
  ** intkey table, the caller should be inserting integer keys with a
  ** blob of associated data.  */
  assert( (pX->pKey==0)==(pCur->pKeyInfo==0) );

  /* Save the positions of any other cursors open on this table.
  **
  ** In some cases, the call to btreeMoveto() below is a no-op. For
  ** example, when inserting data into a table with auto-generated integer
  ** keys, the VDBE layer invokes sqlite3BtreeLast() to figure out the 
  ** integer key to use. It then calls this function to actually insert the 
  ** data into the intkey B-Tree. In this case btreeMoveto() recognizes
  ** that the cursor is already where it needs to be and returns without
  ** doing any work. To avoid thwarting these optimizations, it is important
  ** not to clear the cursor here.
  */
  if( pCur->curFlags & BTCF_Multiple ){
    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
    if( rc ) return rc;
  }

  if( pCur->pKeyInfo==0 ){
    assert( pX->pKey==0 );
    /* If this is an insert into a table b-tree, invalidate any incrblob 
    ** cursors open on the row being replaced */
    invalidateIncrblobCursors(p, pX->nKey, 0);

    /* If the cursor is currently on the last row and we are appending a
    ** new row onto the end, set the "loc" to avoid an unnecessary
    ** btreeMoveto() call */
    if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey>0
      && pCur->info.nKey==pX->nKey-1 ){
       loc = -1;
    }else if( loc==0 ){
      rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, appendBias, &loc);
      if( rc ) return rc;
    }
  }else if( loc==0 ){
    rc = btreeMoveto(pCur, pX->pKey, pX->nKey, appendBias, &loc);
    if( rc ) return rc;
  }
  assert( pCur->eState==CURSOR_VALID || (pCur->eState==CURSOR_INVALID && loc) );

  pPage = pCur->apPage[pCur->iPage];
  assert( pPage->intKey || pX->nKey>=0 );
  assert( pPage->leaf || !pPage->intKey );

  TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
          pCur->pgnoRoot, pX->nKey, pX->nData, pPage->pgno,
          loc==0 ? "overwrite" : "new entry"));
  assert( pPage->isInit );
  newCell = pBt->pTmpSpace;
  assert( newCell!=0 );
  rc = fillInCell(pPage, newCell, pX, &szNew);
  if( rc ) goto end_insert;
  assert( szNew==pPage->xCellSize(pPage, newCell) );
  assert( szNew <= MX_CELL_SIZE(pBt) );
  idx = pCur->aiIdx[pCur->iPage];
  if( loc==0 ){
    u16 szOld;
    assert( idx<pPage->nCell );

  }else if( loc<0 && pPage->nCell>0 ){
    assert( pPage->leaf );
    idx = ++pCur->aiIdx[pCur->iPage];
  }else{
    assert( pPage->leaf );
  }
  insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);
  assert( pPage->nOverflow==0 || rc==SQLITE_OK );
  assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );

  /* If no error has occurred and pPage has an overflow cell, call balance() 
  ** to redistribute the cells within the tree. Since balance() may move
  ** the cursor, zero the BtCursor.info.nSize and BTCF_ValidNKey
  ** variables.
  **

  ** is advantageous to leave the cursor pointing to the last entry in
  ** the b-tree if possible. If the cursor is left pointing to the last
  ** entry in the table, and the next row inserted has an integer key
  ** larger than the largest existing key, it is possible to insert the
  ** row without seeking the cursor. This can be a big performance boost.
  */
  pCur->info.nSize = 0;
  if( pPage->nOverflow ){
    assert( rc==SQLITE_OK );
    pCur->curFlags &= ~(BTCF_ValidNKey);
    rc = balance(pCur);

    /* Must make sure nOverflow is reset to zero even if the balance()
    ** fails. Internal data structure corruption will result otherwise. 
    ** Also, set the cursor state to invalid. This stops saveCursorPosition()
    ** from trying to save the current position of the cursor.  */

    pCell = findCell(pLeaf, pLeaf->nCell-1);
    if( pCell<&pLeaf->aData[4] ) return SQLITE_CORRUPT_BKPT;
    nCell = pLeaf->xCellSize(pLeaf, pCell);
    assert( MX_CELL_SIZE(pBt) >= nCell );
    pTmp = pBt->pTmpSpace;
    assert( pTmp!=0 );
    rc = sqlite3PagerWrite(pLeaf->pDbPage);
    if( rc==SQLITE_OK ){
      insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
    }
    dropCell(pLeaf, pLeaf->nCell-1, nCell, &rc);
    if( rc ) return rc;
  }

  /* Balance the tree. If the entry deleted was located on a leaf page,
  ** then the cursor still points to that page. In this case the first
  ** call to balance() repairs the tree, and the if(...) condition is

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


int sqlite3BtreeOpen(
  sqlite3_vfs *pVfs,       /* VFS to use with this b-tree */
  const char *zFilename,   /* Name of database file to open */
  sqlite3 *db,             /* Associated database connection */
  Btree **ppBtree,         /* Return open Btree* here */

int sqlite3BtreeCursorRestore(BtCursor*, int*);
int sqlite3BtreeDelete(BtCursor*, u8 flags);

/* Allowed flags for the 2nd argument to sqlite3BtreeDelete() */
#define BTREE_SAVEPOSITION 0x02  /* Leave cursor pointing at NEXT or PREV */
#define BTREE_AUXDELETE    0x04  /* not the primary delete operation */

/* An instance of the BtreePayload object describes the content of a single
** entry in either an index or table btree.
**
** Index btrees (used for indexes and also WITHOUT ROWID tables) contain
** an arbitrary key and no data.  These btrees have pKey,nKey set to their
** key and pData,nData,nZero set to zero.
**
** Table btrees (used for rowid tables) contain an integer rowid used as
** the key and passed in the nKey field.  The pKey field is zero.  
** pData,nData hold the content of the new entry.  nZero extra zero bytes
** are appended to the end of the content when constructing the entry.
**
** This object is used to pass information into sqlite3BtreeInsert().  The
** same information used to be passed as five separate parameters.  But placing
** the information into this object helps to keep the interface more 
** organized and understandable, and it also helps the resulting code to
** run a little faster by using fewer registers for parameter passing.
*/
struct BtreePayload {
  const void *pKey;       /* Key content for indexes.  NULL for tables */
  sqlite3_int64 nKey;     /* Size of pKey for indexes.  PRIMARY KEY for tabs */
  const void *pData;      /* Data for tables.  NULL for indexes */
  int nData;              /* Size of pData.  0 if none. */
  int nZero;              /* Extra zero data appended after pData,nData */
};

int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,

                       int bias, int seekResult);
int sqlite3BtreeFirst(BtCursor*, int *pRes);
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int *pRes);
int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);

    ** to invalidate all pre-compiled statements.
    */
    if( pTblName ){
      sqlite3RefillIndex(pParse, pIndex, iMem);
      sqlite3ChangeCookie(pParse, iDb);
      sqlite3VdbeAddParseSchemaOp(v, iDb,
         sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
      sqlite3VdbeAddOp0(v, OP_Expire);
    }

    sqlite3VdbeJumpHere(v, pIndex->tnum);
  }

  /* When adding an index to the list of indices for a table, make
  ** sure all indices labeled OE_Replace come after all those labeled

** uses it opaquely as an argument to sqlite3BackupRestart() and
** sqlite3BackupUpdate() only.
*/
sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
  return &pPager->pBackup;
}











#ifndef SQLITE_OMIT_WAL
/*
** This function is called when the user invokes "PRAGMA wal_checkpoint",
** "PRAGMA wal_blocking_checkpoint" or calls the sqlite3_wal_checkpoint()
** or wal_blocking_checkpoint() API functions.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.

sqlite3_file *sqlite3PagerFile(Pager*);
sqlite3_file *sqlite3PagerWalFile(Pager *pPager);
sqlite3_file *sqlite3PagerJrnlFile(Pager*);
const char *sqlite3PagerJournalname(Pager*);
void *sqlite3PagerTempSpace(Pager*);
int sqlite3PagerIsMemdb(Pager*);
void sqlite3PagerCacheStat(Pager *, int, int, int *);

int sqlite3SectorSize(sqlite3_file *);

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

void sqlite3PagerRekey(DbPage*, Pgno, u16);

*/
void sqlite3PcacheClear(PCache *pCache){
  sqlite3PcacheTruncate(pCache, 0);
}

/*
** Merge two lists of pages connected by pDirty and in pgno order.
** Do not bother fixing the pDirtyPrev pointers.
*/
static PgHdr *pcacheMergeDirtyList(PgHdr *pA, PgHdr *pB){
  PgHdr result, *pTail;
  pTail = &result;
  assert( pA!=0 && pB!=0 );
  for(;;){
    if( pA->pgno<pB->pgno ){
      pTail->pDirty = pA;
      pTail = pA;
      pA = pA->pDirty;
      if( pA==0 ){
        pTail->pDirty = pB;
        break;
      }
    }else{
      pTail->pDirty = pB;
      pTail = pB;
      pB = pB->pDirty;
      if( pB==0 ){
        pTail->pDirty = pA;
        break;
      }
    }






  }
  return result.pDirty;
}

/*
** Sort the list of pages in accending order by pgno.  Pages are
** connected by pDirty pointers.  The pDirtyPrev pointers are

      ** the input list.  But that is impossible.
      */
      a[i] = pcacheMergeDirtyList(a[i], p);
    }
  }
  p = a[0];
  for(i=1; i<N_SORT_BUCKET; i++){
    if( a[i]==0 ) continue;
    p = p ? pcacheMergeDirtyList(p, a[i]) : a[i];
  }
  return p;
}

/*
** Return a list of all dirty pages in the cache, sorted by page number.
*/

        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
      }

      /* Many of the flag-pragmas modify the code generated by the SQL 
      ** compiler (eg. count_changes). So add an opcode to expire all
      ** compiled SQL statements after modifying a pragma value.
      */
      sqlite3VdbeAddOp0(v, OP_Expire);
      setAllPagerFlags(db);
    }
    break;
  }
#endif /* SQLITE_OMIT_FLAG_PRAGMAS */

#ifndef SQLITE_OMIT_SCHEMA_PRAGMAS

  struct RowSetEntry *pA,    /* First sorted list to be merged */
  struct RowSetEntry *pB     /* Second sorted list to be merged */
){
  struct RowSetEntry head;
  struct RowSetEntry *pTail;

  pTail = &head;
  assert( pA!=0 && pB!=0 );
  for(;;){
    assert( pA->pRight==0 || pA->v<=pA->pRight->v );
    assert( pB->pRight==0 || pB->v<=pB->pRight->v );
    if( pA->v<=pB->v ){
      if( pA->v<pB->v ) pTail = pTail->pRight = pA;
      pA = pA->pRight;
      if( pA==0 ){
        pTail->pRight = pB;
        break;
      }
    }else{
      pTail = pTail->pRight = pB;
      pB = pB->pRight;
      if( pB==0 ){
        pTail->pRight = pA;
        break;

      }
    }






  }
  return head.pRight;
}

/*
** Sort all elements on the list of RowSetEntry objects into order of
** increasing v.

    for(i=0; aBucket[i]; i++){
      pIn = rowSetEntryMerge(aBucket[i], pIn);
      aBucket[i] = 0;
    }
    aBucket[i] = pIn;
    pIn = pNext;
  }
  pIn = aBucket[0];
  for(i=1; i<sizeof(aBucket)/sizeof(aBucket[0]); i++){
    if( aBucket[i]==0 ) continue;
    pIn = pIn ? rowSetEntryMerge(pIn, aBucket[i]) : aBucket[i];
  }
  return pIn;
}


/*
** The input, pIn, is a binary tree (or subtree) of RowSetEntry objects.

  int nOBSat;           /* Number of ORDER BY terms satisfied by indices */
  int iECursor;         /* Cursor number for the sorter */
  int regReturn;        /* Register holding block-output return address */
  int labelBkOut;       /* Start label for the block-output subroutine */
  int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */
  int labelDone;        /* Jump here when done, ex: LIMIT reached */
  u8 sortFlags;         /* Zero or more SORTFLAG_* bits */
  u8 bOrderedInnerLoop; /* ORDER BY correctly sorts the inner loop */
};
#define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */

/*
** Delete all the content of a Select structure.  Deallocate the structure
** itself only if bFree is true.
*/

    op = OP_SorterInsert;
  }else{
    op = OP_IdxInsert;
  }
  sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
  if( iLimit ){
    int addr;
    int r1 = 0;
    /* Fill the sorter until it contains LIMIT+OFFSET entries.  (The iLimit
    ** register is initialized with value of LIMIT+OFFSET.)  After the sorter
    ** fills up, delete the least entry in the sorter after each insert.
    ** Thus we never hold more than the LIMIT+OFFSET rows in memory at once */
    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, 1); VdbeCoverage(v);
    sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
    if( pSort->bOrderedInnerLoop ){
      r1 = ++pParse->nMem;
      sqlite3VdbeAddOp3(v, OP_Column, pSort->iECursor, nExpr, r1);
      VdbeComment((v, "seq"));
    }
    sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
    if( pSort->bOrderedInnerLoop ){
      /* If the inner loop is driven by an index such that values from
      ** the same iteration of the inner loop are in sorted order, then
      ** immediately jump to the next iteration of an inner loop if the
      ** entry from the current iteration does not fit into the top
      ** LIMIT+OFFSET entries of the sorter. */
      int iBrk = sqlite3VdbeCurrentAddr(v) + 2;
      sqlite3VdbeAddOp3(v, OP_Eq, regBase+nExpr, iBrk, r1);
      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
      VdbeCoverage(v);
    }
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Add code to implement the OFFSET
*/

      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
    }
    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
      sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
    }
    if( sSort.pOrderBy ){
      sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
      sSort.bOrderedInnerLoop = sqlite3WhereOrderedInnerLoop(pWInfo);
      if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
        sSort.pOrderBy = 0;
      }
    }

    /* If sorting index that was created by a prior OP_OpenEphemeral 
    ** instruction ended up not being needed, then change the OP_OpenEphemeral

** Value constraints (enforced via assert()):
**     WHERE_USE_LIMIT  == SF_FixedLimit
*/
#define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
#define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_ONEPASS_MULTIROW 0x0008 /* ONEPASS is ok with multiple rows */
#define WHERE_DUPLICATES_OK    0x0010 /* Ok to return a row more than once */
#define WHERE_OR_SUBCLAUSE     0x0020 /* Processing a sub-WHERE as part of

                                      ** the OR optimization  */

#define WHERE_GROUPBY          0x0040 /* pOrderBy is really a GROUP BY */
#define WHERE_DISTINCTBY       0x0080 /* pOrderby is really a DISTINCT clause */
#define WHERE_WANT_DISTINCT    0x0100 /* All output needs to be distinct */
#define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */
#define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */
#define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */
                        /*     0x1000    not currently used */
                        /*     0x2000    not currently used */
#define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */
                        /*     0x8000    not currently used */

/* Allowed return values from sqlite3WhereIsDistinct()
*/
#define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
#define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
#define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
#define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */

void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
void sqlite3WhereEnd(WhereInfo*);
LogEst sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereOrderedInnerLoop(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
int sqlite3WhereContinueLabel(WhereInfo*);
int sqlite3WhereBreakLabel(WhereInfo*);
int sqlite3WhereOkOnePass(WhereInfo*, int*);
#define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */
#define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */
#define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */

  ClientData clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *const objv[]
){
  BtCursor *pCur;
  int rc;
  BtreePayload x;




  if( objc!=4 && objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?-intkey? CSR KEY VALUE");
    return TCL_ERROR;
  }

  memset(&x, 0, sizeof(x));
  if( objc==4 ){
    if( Tcl_GetIntFromObj(interp, objv[2], &rc) ) return TCL_ERROR;
    x.nKey = rc;
    x.pData = (void*)Tcl_GetByteArrayFromObj(objv[3], &x.nData);
  }else{
    x.pKey = (void*)Tcl_GetByteArrayFromObj(objv[2], &rc);
    x.nKey = rc;
  }
  pCur = (BtCursor*)sqlite3TestTextToPtr(Tcl_GetString(objv[1]));

  sqlite3_mutex_enter(pCur->pBtree->db->mutex);
  sqlite3BtreeEnter(pCur->pBtree);
  rc = sqlite3BtreeInsert(pCur, &x, 0, 0);
  sqlite3BtreeLeave(pCur->pBtree);
  sqlite3_mutex_leave(pCur->pBtree->db->mutex);

  Tcl_ResetResult(interp);
  if( rc ){
    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
    return TCL_ERROR;

  Mem *pReg;         /* PseudoTable input register */

  pC = p->apCsr[pOp->p1];
  p2 = pOp->p2;

  /* If the cursor cache is stale, bring it up-to-date */
  rc = sqlite3VdbeCursorMoveto(&pC, &p2);
  if( rc ) goto abort_due_to_error;

  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pC!=0 );
  assert( p2<pC->nField );
  aOffset = pC->aOffset;
  assert( pC->eCurType!=CURTYPE_VTAB );
  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
  assert( pC->eCurType!=CURTYPE_SORTER );
  pCrsr = pC->uc.pCursor;


  if( pC->cacheStatus!=p->cacheCtr ){                /*OPTIMIZATION-IF-FALSE*/
    if( pC->nullRow ){
      if( pC->eCurType==CURTYPE_PSEUDO ){
        assert( pC->uc.pseudoTableReg>0 );
        pReg = &aMem[pC->uc.pseudoTableReg];
        assert( pReg->flags & MEM_Blob );
        assert( memIsValid(pReg) );
        pC->payloadSize = pC->szRow = avail = pReg->n;

    }
    pC->cacheStatus = p->cacheCtr;
    pC->iHdrOffset = getVarint32(pC->aRow, offset);
    pC->nHdrParsed = 0;
    aOffset[0] = offset;


    if( avail<offset ){      /*OPTIMIZATION-IF-FALSE*/
      /* pC->aRow does not have to hold the entire row, but it does at least
      ** need to cover the header of the record.  If pC->aRow does not contain
      ** the complete header, then set it to zero, forcing the header to be
      ** dynamically allocated. */
      pC->aRow = 0;
      pC->szRow = 0;

      /* Make sure a corrupt database has not given us an oversize header.
      ** Do this now to avoid an oversize memory allocation.
      **
      ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte
      ** types use so much data space that there can only be 4096 and 32 of
      ** them, respectively.  So the maximum header length results from a
      ** 3-byte type for each of the maximum of 32768 columns plus three
      ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
      */
      if( offset > 98307 || offset > pC->payloadSize ){
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }

    }else if( offset>0 ){ /*OPTIMIZATION-IF-TRUE*/
      /* The following goto is an optimization.  It can be omitted and
      ** everything will still work.  But OP_Column is measurably faster
      ** by skipping the subsequent conditional, which is always true.
      */
      zData = pC->aRow;
      assert( pC->nHdrParsed<=p2 );         /* Conditional skipped */
      goto op_column_read_header;
    }
  }

  /* Make sure at least the first p2+1 entries of the header have been
  ** parsed and valid information is in aOffset[] and pC->aType[].
  */
  if( pC->nHdrParsed<=p2 ){
    /* If there is more header available for parsing in the record, try
    ** to extract additional fields up through the p2+1-th field 
    */

    if( pC->iHdrOffset<aOffset[0] ){
      /* Make sure zData points to enough of the record to cover the header. */
      if( pC->aRow==0 ){
        memset(&sMem, 0, sizeof(sMem));
        rc = sqlite3VdbeMemFromBtree(pCrsr, 0, aOffset[0], !pC->isTable, &sMem);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
        zData = (u8*)sMem.z;
      }else{
        zData = pC->aRow;
      }
  
      /* Fill in pC->aType[i] and aOffset[i] values through the p2-th field. */
    op_column_read_header:
      i = pC->nHdrParsed;
      offset64 = aOffset[i];
      zHdr = zData + pC->iHdrOffset;
      zEndHdr = zData + aOffset[0];

      do{
        if( (t = zHdr[0])<0x80 ){
          zHdr++;
          offset64 += sqlite3VdbeOneByteSerialTypeLen(t);
        }else{
          zHdr += sqlite3GetVarint32(zHdr, &t);
          offset64 += sqlite3VdbeSerialTypeLen(t);
        }
        pC->aType[i++] = t;
        aOffset[i] = (u32)(offset64 & 0xffffffff);
      }while( i<=p2 && zHdr<zEndHdr );



      /* The record is corrupt if any of the following are true:
      ** (1) the bytes of the header extend past the declared header size
      ** (2) the entire header was used but not all data was used
      ** (3) the end of the data extends beyond the end of the record.
      */
      if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset64!=pC->payloadSize))
       || (offset64 > pC->payloadSize)
      ){
        if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }


      pC->nHdrParsed = i;
      pC->iHdrOffset = (u32)(zHdr - zData);
      if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
    }else{
      t = 0;
    }

    /* If after trying to extract new entries from the header, nHdrParsed is
    ** still not up to p2, that means that the record has fewer than p2
    ** columns.  So the result will be either the default value or a NULL.

  /* Extract the content for the p2+1-th column.  Control can only
  ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are
  ** all valid.
  */
  assert( p2<pC->nHdrParsed );
  assert( rc==SQLITE_OK );
  assert( sqlite3VdbeCheckMemInvariants(pDest) );
  if( VdbeMemDynamic(pDest) ){
    sqlite3VdbeMemSetNull(pDest);
  }
  assert( t==pC->aType[p2] );

  if( pC->szRow>=aOffset[p2+1] ){
    /* This is the common case where the desired content fits on the original
    ** page - where the content is not on an overflow page */
    zData = pC->aRow + aOffset[p2];
    if( t<12 ){
      sqlite3VdbeSerialGet(zData, t, pDest);
    }else{
      /* If the column value is a string, we need a persistent value, not
      ** a MEM_Ephem value.  This branch is a fast short-cut that is equivalent
      ** to calling sqlite3VdbeSerialGet() and sqlite3VdbeDeephemeralize().
      */
      static const u16 aFlag[] = { MEM_Blob, MEM_Str|MEM_Term };
      pDest->n = len = (t-12)/2;
      pDest->enc = encoding;
      if( pDest->szMalloc < len+2 ){
        pDest->flags = MEM_Null;
        if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;
      }else{
        pDest->z = pDest->zMalloc;
      }
      memcpy(pDest->z, zData, len);
      pDest->z[len] = 0;
      pDest->z[len+1] = 0;
      pDest->flags = aFlag[t&1];
    }
  }else{
    pDest->enc = encoding;
    /* This branch happens only when content is on overflow pages */
    if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
          && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))
     || (len = sqlite3VdbeSerialTypeLen(t))==0
    ){
      /* Content is irrelevant for
      **    1. the typeof() function,

** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert: 
case OP_InsertInt: {
  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */

  VdbeCursor *pC;   /* Cursor to table into which insert is written */

  int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
  const char *zDb;  /* database name - used by the update hook */
  Table *pTab;      /* Table structure - used by update and pre-update hooks */
  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
  BtreePayload x;   /* Payload to be inserted */

  op = 0;
  pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(pData) );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->isTable );
  assert( pOp->p4type==P4_TABLE || pOp->p4type>=P4_STATIC );
  REGISTER_TRACE(pOp->p2, pData);

  if( pOp->opcode==OP_Insert ){
    pKey = &aMem[pOp->p3];
    assert( pKey->flags & MEM_Int );
    assert( memIsValid(pKey) );
    REGISTER_TRACE(pOp->p3, pKey);
    x.nKey = pKey->u.i;
  }else{
    assert( pOp->opcode==OP_InsertInt );
    x.nKey = pOp->p3;
  }

  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
    assert( pC->isTable );
    assert( pC->iDb>=0 );
    zDb = db->aDb[pC->iDb].zName;
    pTab = pOp->p4.pTab;
    assert( HasRowid(pTab) );
    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
  }else{
    pTab = 0; /* Not needed.  Silence a comiler warning. */
    zDb = 0;  /* Not needed.  Silence a compiler warning. */
  }

#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
  /* Invoke the pre-update hook, if any */
  if( db->xPreUpdateCallback 
   && pOp->p4type==P4_TABLE
   && !(pOp->p5 & OPFLAG_ISUPDATE)
  ){
    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey, pOp->p2);
  }
#endif

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = x.nKey;
  if( pData->flags & MEM_Null ){
    x.pData = 0;
    x.nData = 0;
  }else{
    assert( pData->flags & (MEM_Blob|MEM_Str) );
    x.pData = pData->z;
    x.nData = pData->n;
  }
  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
  if( pData->flags & MEM_Zero ){
    x.nZero = pData->u.nZero;
  }else{
    x.nZero = 0;
  }
  x.pKey = 0;
  rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,

                          (pOp->p5 & OPFLAG_APPEND)!=0, seekResult
  );
  pC->deferredMoveto = 0;
  pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc ) goto abort_due_to_error;
  if( db->xUpdateCallback && op ){
    db->xUpdateCallback(db->pUpdateArg, op, zDb, pTab->zName, x.nKey);
  }
  break;
}

/* Opcode: Delete P1 P2 P3 P4 P5
**
** Delete the record at which the P1 cursor is currently pointing.

**
** This instruction only works for indices.  The equivalent instruction
** for tables is OP_Insert.
*/
case OP_SorterInsert:       /* in2 */
case OP_IdxInsert: {        /* in2 */
  VdbeCursor *pC;
  BtreePayload x;


  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );
  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  assert( pC->eCurType==CURTYPE_BTREE || pOp->opcode==OP_SorterInsert );
  assert( pC->isTable==0 );
  rc = ExpandBlob(pIn2);
  if( rc ) goto abort_due_to_error;
  if( pOp->opcode==OP_SorterInsert ){
    rc = sqlite3VdbeSorterWrite(pC, pIn2);
  }else{
    x.nKey = pIn2->n;
    x.pKey = pIn2->z;
    x.nData = 0;
    x.nZero = 0;
    x.pData = 0;
    rc = sqlite3BtreeInsert(pC->uc.pCursor, &x, pOp->p3, 
        ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
        );
    assert( pC->deferredMoveto==0 );
    pC->cacheStatus = CACHE_STALE;
  }
  if( rc) goto abort_due_to_error;
  break;

/*
** If the input FuncDef structure is ephemeral, then free it.  If
** the FuncDef is not ephermal, then do nothing.
*/
static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
  if( (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
    sqlite3DbFree(db, pDef);
  }
}

static void vdbeFreeOpArray(sqlite3 *, Op *, int);

/*
** Delete a P4 value if necessary.
*/
static SQLITE_NOINLINE void freeP4Mem(sqlite3 *db, Mem *p){
  if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
  sqlite3DbFree(db, p);
}
static SQLITE_NOINLINE void freeP4FuncCtx(sqlite3 *db, sqlite3_context *p){
  freeEphemeralFunction(db, p->pFunc);
  sqlite3DbFree(db, p);
}
static void freeP4(sqlite3 *db, int p4type, void *p4){
  assert( db );
  switch( p4type ){
    case P4_FUNCCTX: {
      freeP4FuncCtx(db, (sqlite3_context*)p4);
      break;
    }
    case P4_REAL:
    case P4_INT64:
    case P4_DYNAMIC:
    case P4_INTARRAY: {
      sqlite3DbFree(db, p4);
      break;

      freeEphemeralFunction(db, (FuncDef*)p4);
      break;
    }
    case P4_MEM: {
      if( db->pnBytesFreed==0 ){
        sqlite3ValueFree((sqlite3_value*)p4);
      }else{
        freeP4Mem(db, (Mem*)p4);


      }
      break;
    }
    case P4_VTAB : {
      if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
      break;
    }

  }
  return SQLITE_OK;
}


/*
** Merge the two sorted lists p1 and p2 into a single list.

*/
static SorterRecord *vdbeSorterMerge(
  SortSubtask *pTask,             /* Calling thread context */
  SorterRecord *p1,               /* First list to merge */
  SorterRecord *p2                /* Second list to merge */

){
  SorterRecord *pFinal = 0;
  SorterRecord **pp = &pFinal;
  int bCached = 0;

  assert( p1!=0 && p2!=0 );
  for(;;){
    int res;
    res = pTask->xCompare(
        pTask, &bCached, SRVAL(p1), p1->nVal, SRVAL(p2), p2->nVal
    );

    if( res<=0 ){
      *pp = p1;
      pp = &p1->u.pNext;
      p1 = p1->u.pNext;
      if( p1==0 ){
        *pp = p2;
        break;
      }
    }else{
      *pp = p2;
      pp = &p2->u.pNext;
      p2 = p2->u.pNext;
      bCached = 0;
      if( p2==0 ){
        *pp = p1;
        break;
      }
    }

  }
  return pFinal;
}

/*
** Return the SorterCompare function to compare values collected by the
** sorter object passed as the only argument.
*/
static SorterCompare vdbeSorterGetCompare(VdbeSorter *p){

      }
    }else{
      pNext = p->u.pNext;
    }

    p->u.pNext = 0;
    for(i=0; aSlot[i]; i++){
      p = vdbeSorterMerge(pTask, p, aSlot[i]);
      aSlot[i] = 0;
    }
    aSlot[i] = p;
    p = pNext;
  }

  p = 0;
  for(i=0; i<64; i++){
    if( aSlot[i]==0 ) continue;
    p = p ? vdbeSorterMerge(pTask, p, aSlot[i]) : aSlot[i];
  }
  pList->pList = p;

  sqlite3_free(aSlot);
  assert( pTask->pUnpacked->errCode==SQLITE_OK 
       || pTask->pUnpacked->errCode==SQLITE_NOMEM 
  );

      zStmt,
      pParse->regRowid
    );
    sqlite3DbFree(db, zStmt);
    v = sqlite3GetVdbe(pParse);
    sqlite3ChangeCookie(pParse, iDb);

    sqlite3VdbeAddOp0(v, OP_Expire);
    zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
    sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);

    iReg = ++pParse->nMem;
    sqlite3VdbeLoadString(v, iReg, pTab->zName);
    sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
  }

/*
** Return TRUE if the WHERE clause returns rows in ORDER BY order.
** Return FALSE if the output needs to be sorted.
*/
int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
  return pWInfo->nOBSat;
}

/*
** Return TRUE if the innermost loop of the WHERE clause implementation
** returns rows in ORDER BY order for complete run of the inner loop.
**
** Across multiple iterations of outer loops, the output rows need not be
** sorted.  As long as rows are sorted for just the innermost loop, this
** routine can return TRUE.
*/
int sqlite3WhereOrderedInnerLoop(WhereInfo *pWInfo){
  return pWInfo->bOrderedInnerLoop;
}

/*
** Return the VDBE address or label to jump to in order to continue
** immediately with the next row of a WHERE clause.
*/
int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
  assert( pWInfo->iContinue!=0 );

  }
  rSize = pTab->nRowLogEst;
  rLogSize = estLog(rSize);

#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
  /* Automatic indexes */
  if( !pBuilder->pOrSet      /* Not part of an OR optimization */
   && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
   && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */
   && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */
   && HasRowid(pTab)         /* Not WITHOUT ROWID table. (FIXME: Why not?) */
   && !pSrc->fg.isCorrelated /* Not a correlated subquery */
   && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */
  ){

** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
** pOrderBy terms must be matched in strict left-to-right order.
*/
static i8 wherePathSatisfiesOrderBy(
  WhereInfo *pWInfo,    /* The WHERE clause */
  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
  WherePath *pPath,     /* The WherePath to check */
  u16 wctrlFlags,       /* WHERE_GROUPBY or _DISTINCTBY or _ORDERBY_LIMIT */
  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
){
  u8 revSet;            /* True if rev is known */
  u8 rev;               /* Composite sort order */
  u8 revIdx;            /* Index sort order */
  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
  u16 eqOpMask;         /* Allowed equality operators */
  u16 nKeyCol;          /* Number of key columns in pIndex */
  u16 nColumn;          /* Total number of ordered columns in the index */
  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
  int iLoop;            /* Index of WhereLoop in pPath being processed */
  int i, j;             /* Loop counters */
  int iCur;             /* Cursor number for current WhereLoop */
  int iColumn;          /* A column number within table iCur */

  nOrderBy = pOrderBy->nExpr;
  testcase( nOrderBy==BMS-1 );
  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
  isOrderDistinct = 1;
  obDone = MASKBIT(nOrderBy)-1;
  orderDistinctMask = 0;
  ready = 0;
  eqOpMask = WO_EQ | WO_IS | WO_ISNULL;
  if( wctrlFlags & WHERE_ORDERBY_LIMIT ) eqOpMask |= WO_IN;
  for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
    if( iLoop>0 ) ready |= pLoop->maskSelf;
    if( iLoop<nLoop ){
      pLoop = pPath->aLoop[iLoop];
      if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
    }else{
      pLoop = pLast;
    }
    if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
      if( pLoop->u.vtab.isOrdered ) obSat = obDone;
      break;
    }
    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;

    /* Mark off any ORDER BY term X that is a column in the table of
    ** the current loop for which there is term in the WHERE
    ** clause of the form X IS NULL or X=? that reference only outer
    ** loops.
    */
    for(i=0; i<nOrderBy; i++){
      if( MASKBIT(i) & obSat ) continue;
      pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
      if( pOBExpr->op!=TK_COLUMN ) continue;
      if( pOBExpr->iTable!=iCur ) continue;
      pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
                       ~ready, eqOpMask, 0);
      if( pTerm==0 ) continue;
      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
        const char *z1, *z2;
        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
        if( !pColl ) pColl = db->pDfltColl;
        z1 = pColl->zName;
        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);

      ** that are not constrained by == or IN.
      */
      rev = revSet = 0;
      distinctColumns = 0;
      for(j=0; j<nColumn; j++){
        u8 bOnce;   /* True to run the ORDER BY search loop */

        /* Skip over == and IS and ISNULL terms.
        ** (Also skip IN terms when doing WHERE_ORDERBY_LIMIT processing)
        */
        if( j<pLoop->u.btree.nEq
         && pLoop->nSkip==0
         && ((i = pLoop->aLTerm[j]->eOperator) & eqOpMask)!=0
        ){
          if( i & WO_ISNULL ){
            testcase( isOrderDistinct );
            isOrderDistinct = 0;
          }
          continue;  
        }

  if( pWInfo->pOrderBy ){
    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
      }
    }else{
      pWInfo->nOBSat = pFrom->isOrdered;
      pWInfo->revMask = pFrom->revLoop;
      if( pWInfo->nOBSat<=0 ){
        pWInfo->nOBSat = 0;
        if( nLoop>0 ){
          Bitmask m;
          int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,
                      WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);
          if( rc==pWInfo->pOrderBy->nExpr ){
            pWInfo->bOrderedInnerLoop = 1;
            pWInfo->revMask = m;
          }
        }
      }
    }
    if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
        && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
    ){
      Bitmask revMask = 0;
      int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 
          pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask

  WhereLoop *pLoop;
  int iCur;
  int j;
  Table *pTab;
  Index *pIdx;

  pWInfo = pBuilder->pWInfo;
  if( pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE ) return 0;
  assert( pWInfo->pTabList->nSrc>=1 );
  pItem = pWInfo->pTabList->a;
  pTab = pItem->pTab;
  if( IsVirtual(pTab) ) return 0;
  if( pItem->fg.isIndexedBy ) return 0;
  iCur = pItem->iCursor;
  pWC = &pWInfo->sWC;

**
** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
** if there is one.  If there is no ORDER BY clause or if this routine
** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
**
** The iIdxCur parameter is the cursor number of an index.  If 
** WHERE_OR_SUBCLAUSE is set, iIdxCur is the cursor number of an index
** to use for OR clause processing.  The WHERE clause should use this
** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
** the first cursor in an array of cursors for all indices.  iIdxCur should
** be used to compute the appropriate cursor depending on which index is
** used.
*/
WhereInfo *sqlite3WhereBegin(
  Parse *pParse,          /* The parser context */
  SrcList *pTabList,      /* FROM clause: A list of all tables to be scanned */
  Expr *pWhere,           /* The WHERE clause */
  ExprList *pOrderBy,     /* An ORDER BY (or GROUP BY) clause, or NULL */
  ExprList *pDistinctSet, /* Try not to output two rows that duplicate these */
  u16 wctrlFlags,         /* The WHERE_* flags defined in sqliteInt.h */
  int iAuxArg             /* If WHERE_OR_SUBCLAUSE is set, index cursor number
                          ** If WHERE_USE_LIMIT, then the limit amount */
){
  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
  int nTabList;              /* Number of elements in pTabList */
  WhereInfo *pWInfo;         /* Will become the return value of this function */
  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
  Bitmask notReady;          /* Cursors that are not yet positioned */
  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
  int ii;                    /* Loop counter */
  sqlite3 *db;               /* Database connection */
  int rc;                    /* Return code */
  u8 bFordelete = 0;         /* OPFLAG_FORDELETE or zero, as appropriate */

  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
     && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 
  ));

  /* Only one of WHERE_OR_SUBCLAUSE or WHERE_USE_LIMIT */
  assert( (wctrlFlags & WHERE_OR_SUBCLAUSE)==0
            || (wctrlFlags & WHERE_USE_LIMIT)==0 );

  /* Variable initialization */
  db = pParse->db;
  memset(&sWLB, 0, sizeof(sWLB));

  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */

  testcase( pTabList->nSrc==BMS );
  if( pTabList->nSrc>BMS ){
    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
    return 0;
  }

  /* This function normally generates a nested loop for all tables in 
  ** pTabList.  But if the WHERE_OR_SUBCLAUSE flag is set, then we should
  ** only generate code for the first table in pTabList and assume that
  ** any cursors associated with subsequent tables are uninitialized.
  */
  nTabList = (wctrlFlags & WHERE_OR_SUBCLAUSE) ? 1 : pTabList->nSrc;

  /* Allocate and initialize the WhereInfo structure that will become the
  ** return value. A single allocation is used to store the WhereInfo
  ** struct, the contents of WhereInfo.a[], the WhereClause structure
  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
  ** some architectures. Hence the ROUND8() below.

  ** a table T, then X-1 is the bitmask for all other tables to the left of T.
  ** Knowing the bitmask for all tables to the left of a left join is
  ** important.  Ticket #3015.
  **
  ** Note that bitmasks are created for all pTabList->nSrc tables in
  ** pTabList, not just the first nTabList tables.  nTabList is normally
  ** equal to pTabList->nSrc but might be shortened to 1 if the
  ** WHERE_OR_SUBCLAUSE flag is set.
  */
  for(ii=0; ii<pTabList->nSrc; ii++){
    createMask(pMaskSet, pTabList->a[ii].iCursor);
    sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
  }
#ifdef SQLITE_DEBUG
  for(ii=0; ii<pTabList->nSrc; ii++){

      int iCur = pTabItem->iCursor;
      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
    }else if( IsVirtual(pTab) ){
      /* noop */
    }else
#endif
    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
         && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){
      int op = OP_OpenRead;
      if( pWInfo->eOnePass!=ONEPASS_OFF ){
        op = OP_OpenWrite;
        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
      };
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
      assert( pTabItem->iCursor==pLevel->iTabCur );

    if( pLoop->wsFlags & WHERE_INDEXED ){
      Index *pIx = pLoop->u.btree.pIndex;
      int iIndexCur;
      int op = OP_OpenRead;
      /* iAuxArg is always set if to a positive value if ONEPASS is possible */
      assert( iAuxArg!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );
      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
       && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0
      ){
        /* This is one term of an OR-optimization using the PRIMARY KEY of a
        ** WITHOUT ROWID table.  No need for a separate index */
        iIndexCur = pLevel->iTabCur;
        op = 0;
      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
        Index *pJ = pTabItem->pTab->pIndex;
        iIndexCur = iAuxArg;
        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
        while( ALWAYS(pJ) && pJ!=pIx ){
          iIndexCur++;
          pJ = pJ->pNext;
        }
        op = OP_OpenWrite;
        pWInfo->aiCurOnePass[1] = iIndexCur;
      }else if( iAuxArg && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 ){
        iIndexCur = iAuxArg;
        op = OP_ReopenIdx;
      }else{
        iIndexCur = pParse->nTab++;
      }
      pLevel->iIdxCur = iIndexCur;
      assert( pIx->pSchema==pTab->pSchema );
      assert( iIndexCur>=0 );
      if( op ){

#endif
    addrExplain = sqlite3WhereExplainOneScan(
        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
    );
    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
    notReady = sqlite3WhereCodeOneLoopStart(pWInfo, ii, notReady);
    pWInfo->iContinue = pLevel->addrCont;
    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_OR_SUBCLAUSE)==0 ){
      sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);
    }
  }

  /* Done. */
  VdbeModuleComment((v, "Begin WHERE-core"));
  return pWInfo;

      translateColumnToCopy(v, pLevel->addrBody, pLevel->iTabCur,
                            pTabItem->regResult, 0);
      continue;
    }

    /* Close all of the cursors that were opened by sqlite3WhereBegin.
    ** Except, do not close cursors that will be reused by the OR optimization
    ** (WHERE_OR_SUBCLAUSE).  And do not close the OP_OpenWrite cursors
    ** created for the ONEPASS optimization.
    */
    if( (pTab->tabFlags & TF_Ephemeral)==0
     && pTab->pSelect==0
     && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
    ){
      int ws = pLoop->wsFlags;
      if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
      }
      if( (ws & WHERE_INDEXED)!=0
       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 

  LogEst nRowOut;           /* Estimated number of output rows */
  LogEst iLimit;            /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
  i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
  u8 sorted;                /* True if really sorted (not just grouped) */
  u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */
  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values */
  u8 nLevel;                /* Number of nested loop */
  u8 bOrderedInnerLoop;     /* True if only the inner-most loop is ordered */
  int iTop;                 /* The very beginning of the WHERE loop */
  int iContinue;            /* Jump here to continue with next record */
  int iBreak;               /* Jump here to break out of the loop */
  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
  WhereClause sWC;          /* Decomposition of the WHERE clause */

    u32 flags;                    /* Flags that describe this loop */
    char *zMsg;                   /* Text to add to EQP output */
    StrAccum str;                 /* EQP output string */
    char zBuf[100];               /* Initial space for EQP output string */

    pLoop = pLevel->pWLoop;
    flags = pLoop->wsFlags;
    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;

    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");

  Parse *pParse = pWInfo->pParse; /* Parse context */
  Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */

  assert( iIdxCur>0 );
  assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
  
  sqlite3VdbeAddOp3(v, OP_Seek, iIdxCur, 0, iCur);
  if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
   && DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
  ){
    int i;
    Table *pTab = pIdx->pTable;
    int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
    if( ai ){
      ai[0] = pTab->nCol;

  pLevel = &pWInfo->a[iLevel];
  pLoop = pLevel->pWLoop;
  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
  iCur = pTabItem->iCursor;
  pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
  bRev = (pWInfo->revMask>>iLevel)&1;
  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
           && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;
  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));

  /* Create labels for the "break" and "continue" instructions
  ** for the current loop.  Jump to addrBrk to break out of a loop.
  ** Jump to cont to go immediately to the next iteration of the
  ** loop.
  **

      }
    }

    /* Run a separate WHERE clause for each term of the OR clause.  After
    ** eliminating duplicates from other WHERE clauses, the action for each
    ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
    */




    wctrlFlags =  WHERE_OR_SUBCLAUSE | (pWInfo->wctrlFlags & WHERE_SEEK_TABLE);
    for(ii=0; ii<pOrWc->nTerm; ii++){
      WhereTerm *pOrTerm = &pOrWc->a[ii];
      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
        WhereInfo *pSubWInfo;           /* Info for single OR-term scan */
        Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
        int jmp1 = 0;                   /* Address of jump operation */
        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){

          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
           && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
          ){
            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
            pCov = pSubLoop->u.btree.pIndex;

          }else{
            pCov = 0;
          }

          /* Finish the loop through table entries that match term pOrTerm. */
          sqlite3WhereEnd(pSubWInfo);
        }

    Expr *pE;
    int skipLikeAddr = 0;
    testcase( pTerm->wtFlags & TERM_VIRTUAL );
    testcase( pTerm->wtFlags & TERM_CODED );
    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
      testcase( pWInfo->untestedTerms==0
               && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
      pWInfo->untestedTerms = 1;
      continue;
    }
    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;

do_test fts3expr-8.8 { test_fts3expr "(,(blah-),)" } {PHRASE 3 0 blah}

set sqlite_fts3_enable_parentheses 0

do_test fts3expr-9.1 {
  test_fts3expr "f (e NEAR/2 a)"
} {AND {PHRASE 3 0 f} {NEAR/2 {PHRASE 3 0 e} {PHRASE 3 0 a}}}

do_test fts3expr-10.1 { test_fts3expr "abc *" } {PHRASE 3 0 abc}
do_test fts3expr-10.2 { test_fts3expr "*" } {}
do_test fts3expr-10.3 { test_fts3expr "abc*" } {PHRASE 3 0 abc+}

finish_test

# 2016-05-20
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the LIMIT in combination with ORDER BY
# and in particular, the optimizations in the inner loop that cause an
# early exit of the inner loop when the LIMIT is reached and the inner
# loop is emitting rows in ORDER BY order.


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

do_execsql_test limit2-100 {
  CREATE TABLE t1(a,b);
  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<1000)
    INSERT INTO t1(a,b) SELECT 1, (x*17)%1000 + 1000 FROM c;
  INSERT INTO t1(a,b) VALUES(2,2),(3,1006),(4,4),(5,9999);
  CREATE INDEX t1ab ON t1(a,b);
}
set sqlite_search_count 0
do_execsql_test limit2-100.1 {
  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY b LIMIT 5;
} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
set fast_count $sqlite_search_count
set sqlite_search_count 0
do_execsql_test limit2-100.2 {
  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY +b LIMIT 5;
} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
do_test limit2-100.3 {
  set slow_count $sqlite_search_count
  expr {$fast_count < 0.02*$slow_count}
} {1}

do_execsql_test limit2-110 {
  CREATE TABLE t2(x,y);
  INSERT INTO t2(x,y) VALUES('a',1),('a',2),('a',3),('a',4);
  INSERT INTO t2(x,y) VALUES('b',1),('c',2),('d',3),('e',4);
  CREATE INDEX t2xy ON t2(x,y);
}
set sqlite_search_count 0
do_execsql_test limit2-110.1 {
  SELECT a, b, '|' FROM t2, t1 WHERE t2.x='a' AND t1.a=t2.y ORDER BY t1.b LIMIT 5;
} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
set fast_count $sqlite_search_count
set sqlite_search_count 0
do_execsql_test limit2-110.2 {
  SELECT a, b, '|' FROM t2, t1 WHERE t2.x='a' AND t1.a=t2.y ORDER BY +t1.b LIMIT 5;
} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
set slow_count $sqlite_search_count
do_test limit2-110.3 {
  expr {$fast_count < 0.02*$slow_count}
} {1}

do_execsql_test limit2-120 {
  DROP INDEX t1ab;
  CREATE INDEX t1ab ON t1(a,b DESC);
}
set sqlite_search_count 0
do_execsql_test limit2-120.1 {
  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY b DESC LIMIT 5;
} {5 9999 | 1 1999 | 1 1998 | 1 1997 | 1 1996 |}
set fast_count $sqlite_search_count
set sqlite_search_count 0
do_execsql_test limit2-120.2 {
  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY +b DESC LIMIT 5;
} {5 9999 | 1 1999 | 1 1998 | 1 1997 | 1 1996 |}
do_test limit2-120.3 {
  set slow_count $sqlite_search_count
  expr {$fast_count < 0.02*$slow_count}
} {1}



finish_test

#!/usr/bin/tclsh
#
# Run this script, redirecting input from cachegrind output, to compute the
# number of CPU cycles used by each VDBE opcode.
#
# The cachegrind output should be configured so that it reports a single
# column of Ir at the left margin. Ex:
#
#    cg_annotation --show=Ir --auto=yes cachegrind.out.* | tclsh opcodesum.tcl
#
set currentop x
set ncycle(x) 0
while {![eof stdin]} {
  set line [string map {\173 x \175 x \042 x} [gets stdin]]
  if {[regexp {  \.  case OP_.*:} $line]} {
    regexp {OP_(.+):} $line all currentop
    set ncycle($currentop) 0
  } elseif {[lindex $line 1]=="default:"
            && [regexp {really OP_Noop and OP_Explain} $line]} {
    break
  } elseif {[lindex $line 0]!="."} {
    regsub -all {[^0-9]} [lindex $line 0] {} n
    if {$n!=""} {incr ncycle($currentop) $n}
  }
}
unset ncycle(x)
set results {}
foreach op [lsort [array names ncycle]] {
  if {$ncycle($op)==0} continue
  lappend results [list $ncycle($op) $op]
}
foreach entry [lsort -index 0 -int -decr $results] {
  puts [format {%-16s %10d} [lindex $entry 1] [lindex $entry 0]]
}

#!/bin/bash
#
# This is a template for a script used for day-to-day size and 
# performance monitoring of SQLite.  Typical usage:
#
#     sh run-speed-test.sh trunk  #  Baseline measurement of trunk
#     sh run-speed-test.sh x1     # Measure some experimental change
#     fossil test-diff --tk cout-trunk.txt cout-x1.txt   # View chanages
#
# There are multiple output files, all with a base name given by
# the first argument:
#
#     summary-$BASE.txt           # Copy of standard output
#     cout-$BASE.txt              # cachegrind output
#     explain-$BASE.txt           # EXPLAIN listings (only with --explain)
#
if test "$1" = ""
then
  echo "Usage: $0 OUTPUTFILE [OPTIONS]"
  exit
fi
NAME=$1
shift
CC_OPTS="-DSQLITE_ENABLE_RTREE -DSQLITE_ENABLE_MEMSYS5"
SPEEDTEST_OPTS="--shrink-memory --reprepare --heap 10000000 64"
SIZE=5
doExplain=0
doCachegrind=1
while test "$1" != ""; do
  case $1 in
    --reprepare)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --autovacuum)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --utf16be)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --stats)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --without-rowid)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --nomemstat)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS $1"
        ;;
    --temp)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS --temp 6"
        ;;
    --wal)
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS --journal wal"
        ;;
    --size)
        shift; SIZE=$1
        ;;
    --explain)
        doExplain=1
        ;;
    --vdbeprofile)
        rm -f vdbe_profile.out
        CC_OPTS="$CC_OPTS -DVDBE_PROFILE"
        doCachegrind=0
        ;;
    --heap)
        CC_OPTS="$CC_OPTS -DSQLITE_ENABLE_MEMSYS5"
        shift;
        SPEEDTEST_OPTS="$SPEEDTEST_OPTS --heap $1 64"
        ;;
    *)
        CC_OPTS="$CC_OPTS $1"
        ;;
  esac
  shift
done
SPEEDTEST_OPTS="$SPEEDTEST_OPTS --size $SIZE"
echo "NAME           = $NAME" | tee summary-$NAME.txt
echo "SPEEDTEST_OPTS = $SPEEDTEST_OPTS" | tee -a summary-$NAME.txt
echo "CC_OPTS        = $CC_OPTS" | tee -a summary-$NAME.txt
rm -f cachegrind.out.* speedtest1 speedtest1.db sqlite3.o
gcc -g -Os -Wall -I. $CC_OPTS -c sqlite3.c
size sqlite3.o | tee -a summary-$NAME.txt
if test $doExplain -eq 1; then
  gcc -g -Os -Wall -I. $CC_OPTS \
     -DSQLITE_ENABLE_EXPLAIN_COMMENTS \
    ./shell.c ./sqlite3.c -o sqlite3 -ldl -lpthread
fi
SRC=./speedtest1.c
gcc -g -Os -Wall -I. $CC_OPTS $SRC ./sqlite3.o -o speedtest1 -ldl -lpthread
ls -l speedtest1 | tee -a summary-$NAME.txt
if test $doCachegrind -eq 1; then
  valgrind --tool=cachegrind ./speedtest1 speedtest1.db \
      $SPEEDTEST_OPTS 2>&1 | tee -a summary-$NAME.txt
else
  ./speedtest1 speedtest1.db $SPEEDTEST_OPTS 2>&1 | tee -a summary-$NAME.txt
fi
size sqlite3.o | tee -a summary-$NAME.txt
wc sqlite3.c
if test $doCachegrind -eq 1; then
  cg_anno.tcl cachegrind.out.* >cout-$NAME.txt
fi
if test $doExplain -eq 1; then
  ./speedtest1 --explain $SPEEDTEST_OPTS | ./sqlite3 >explain-$NAME.txt
fi