SQLite

#
LIBREADLINE = @TARGET_READLINE_LIBS@

# Should the database engine be compiled threadsafe
#
TCC += -DSQLITE_THREADSAFE=@SQLITE_THREADSAFE@

# Do threads override each others locks by default (1), or do we test (-1)
#
TCC += -DSQLITE_THREAD_OVERRIDE_LOCK=@THREADSOVERRIDELOCKS@

# Any target libraries which libsqlite must be linked against
# 
TLIBS = @LIBS@

# Flags controlling use of the in memory btree implementation
#
# SQLITE_TEMP_STORE is 0 to force temporary tables to be in a file, 1 to

3.7.4
3.7.5

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.62 for sqlite 3.7.4.
# Generated by GNU Autoconf 2.62 for sqlite 3.7.5.
#
# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
## --------------------- ##
## M4sh Initialization.  ##

MFLAGS=
MAKEFLAGS=
SHELL=${CONFIG_SHELL-/bin/sh}

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.7.4'
PACKAGE_STRING='sqlite 3.7.4'
PACKAGE_VERSION='3.7.5'
PACKAGE_STRING='sqlite 3.7.5'
PACKAGE_BUGREPORT=''

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

program_prefix
VERSION
RELEASE
VERSION_NUMBER
BUILD_CC
SQLITE_THREADSAFE
XTHREADCONNECT
THREADSOVERRIDELOCKS
ALLOWRELEASE
TEMP_STORE
BUILD_EXEEXT
SQLITE_OS_UNIX
SQLITE_OS_WIN
SQLITE_OS_OS2
TARGET_EXEEXT

enable_fast_install
with_gnu_ld
enable_libtool_lock
enable_largefile
with_hints
enable_threadsafe
enable_cross_thread_connections
enable_threads_override_locks
enable_releasemode
enable_tempstore
enable_tcl
with_tcl
enable_readline
with_readline_lib
with_readline_inc

#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.7.4 to adapt to many kinds of systems.
\`configure' configures sqlite 3.7.5 to adapt to many kinds of systems.

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

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

Defaults for the options are specified in brackets.

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

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.7.4:";;
     short | recursive ) echo "Configuration of sqlite 3.7.5:";;
   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]
  --enable-shared[=PKGS]  build shared libraries [default=yes]
  --enable-static[=PKGS]  build static libraries [default=yes]
  --enable-fast-install[=PKGS]
                          optimize for fast installation [default=yes]
  --disable-libtool-lock  avoid locking (might break parallel builds)
  --disable-largefile     omit support for large files
  --enable-threadsafe     Support threadsafe operation
  --enable-cross-thread-connections
                          Allow connection sharing across threads
  --enable-threads-override-locks
                          Threads can override each others locks
  --enable-releasemode    Support libtool link to release mode
  --enable-tempstore      Use an in-ram database for temporary tables
                          (never,no,yes,always)
  --disable-tcl           do not build TCL extension
  --disable-readline      disable readline support [default=detect]
  --enable-debug          enable debugging & verbose explain
  --disable-amalgamation  Disable the amalgamation and instead build all files

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

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.7.4
sqlite configure 3.7.5
generated by GNU Autoconf 2.62

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

It was created by sqlite $as_me 3.7.4, which was
It was created by sqlite $as_me 3.7.5, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{

{ $as_echo "$as_me:$LINENO: checking the name lister ($NM) interface" >&5
$as_echo_n "checking the name lister ($NM) interface... " >&6; }
if test "${lt_cv_nm_interface+set}" = set; then
  $as_echo_n "(cached) " >&6
else
  lt_cv_nm_interface="BSD nm"
  echo "int some_variable = 0;" > conftest.$ac_ext
  (eval echo "\"\$as_me:3741: $ac_compile\"" >&5)
  (eval echo "\"\$as_me:3737: $ac_compile\"" >&5)
  (eval "$ac_compile" 2>conftest.err)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3744: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
  (eval echo "\"\$as_me:3740: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
  (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3747: output\"" >&5)
  (eval echo "\"\$as_me:3743: output\"" >&5)
  cat conftest.out >&5
  if $GREP 'External.*some_variable' conftest.out > /dev/null; then
    lt_cv_nm_interface="MS dumpbin"
  fi
  rm -f conftest*
fi
{ $as_echo "$as_me:$LINENO: result: $lt_cv_nm_interface" >&5

	;;
    esac
  fi
  rm -rf conftest*
  ;;
*-*-irix6*)
  # Find out which ABI we are using.
  echo '#line 4969 "configure"' > conftest.$ac_ext
  echo '#line 4965 "configure"' > conftest.$ac_ext
  if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
  (exit $ac_status); }; then
    if test "$lt_cv_prog_gnu_ld" = yes; then
      case `/usr/bin/file conftest.$ac_objext` in

   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   # The option is referenced via a variable to avoid confusing sed.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:6838: $lt_compile\"" >&5)
   (eval echo "\"\$as_me:6834: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:6842: \$? = $ac_status" >&5
   echo "$as_me:6838: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' >conftest.exp
     $SED '/^$/d; /^ *+/d' conftest.err >conftest.er2
     if test ! -s conftest.er2 || diff conftest.exp conftest.er2 >/dev/null; then
       lt_cv_prog_compiler_rtti_exceptions=yes

   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   # The option is referenced via a variable to avoid confusing sed.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7177: $lt_compile\"" >&5)
   (eval echo "\"\$as_me:7173: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:7181: \$? = $ac_status" >&5
   echo "$as_me:7177: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' >conftest.exp
     $SED '/^$/d; /^ *+/d' conftest.err >conftest.er2
     if test ! -s conftest.er2 || diff conftest.exp conftest.er2 >/dev/null; then
       lt_cv_prog_compiler_pic_works=yes

   # (2) before a word containing "conftest.", or (3) at the end.
   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7282: $lt_compile\"" >&5)
   (eval echo "\"\$as_me:7278: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7286: \$? = $ac_status" >&5
   echo "$as_me:7282: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' > out/conftest.exp
     $SED '/^$/d; /^ *+/d' out/conftest.err >out/conftest.er2
     if test ! -s out/conftest.er2 || diff out/conftest.exp out/conftest.er2 >/dev/null; then

   # (2) before a word containing "conftest.", or (3) at the end.
   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7337: $lt_compile\"" >&5)
   (eval echo "\"\$as_me:7333: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7341: \$? = $ac_status" >&5
   echo "$as_me:7337: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' > out/conftest.exp
     $SED '/^$/d; /^ *+/d' out/conftest.err >out/conftest.er2
     if test ! -s out/conftest.er2 || diff out/conftest.exp out/conftest.er2 >/dev/null; then

else
  	  if test "$cross_compiling" = yes; then :
  lt_cv_dlopen_self=cross
else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
#line 10150 "configure"
#line 10146 "configure"
#include "confdefs.h"

#if HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#include <stdio.h>

else
  	  if test "$cross_compiling" = yes; then :
  lt_cv_dlopen_self_static=cross
else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
#line 10246 "configure"
#line 10242 "configure"
#include "confdefs.h"

#if HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#include <stdio.h>

$as_echo "no" >&6; }
else
  XTHREADCONNECT='-DSQLITE_ALLOW_XTHREAD_CONNECT=1'
  { $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
fi


##########
# Do we want to set threadsOverrideEachOthersLocks variable to be 1 (true) by
# default. Normally, a test at runtime is performed to determine the
# appropriate value of this variable. Use this option only if you're sure that
# threads can safely override each others locks in all runtime situations.
#
# Check whether --enable-threads-override-locks was given.
if test "${enable_threads_override_locks+set}" = set; then
  enableval=$enable_threads_override_locks;
else
  enable_threads_override_locks=no
fi

{ $as_echo "$as_me:$LINENO: checking whether threads can override each others locks" >&5
$as_echo_n "checking whether threads can override each others locks... " >&6; }
if test "$enable_threads_override_locks" = "no"; then
  THREADSOVERRIDELOCKS='-1'
  { $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
else
  THREADSOVERRIDELOCKS='1'
  { $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
fi


##########
# Do we want to support release
#
# Check whether --enable-releasemode was given.
if test "${enable_releasemode+set}" = set; then
  enableval=$enable_releasemode;

exec 6>&1

# Save the log message, to keep $[0] and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.7.4, which was
This file was extended by sqlite $as_me 3.7.5, which was
generated by GNU Autoconf 2.62.  Invocation command line was

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

$config_commands

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

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
sqlite config.status 3.7.4
sqlite config.status 3.7.5
configured by $0, generated by GNU Autoconf 2.62,
  with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"

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

  AC_MSG_RESULT([no])
else
  XTHREADCONNECT='-DSQLITE_ALLOW_XTHREAD_CONNECT=1'
  AC_MSG_RESULT([yes])
fi
AC_SUBST(XTHREADCONNECT)

##########
# Do we want to set threadsOverrideEachOthersLocks variable to be 1 (true) by
# default. Normally, a test at runtime is performed to determine the
# appropriate value of this variable. Use this option only if you're sure that
# threads can safely override each others locks in all runtime situations.
#
AC_ARG_ENABLE(threads-override-locks, 
AC_HELP_STRING([--enable-threads-override-locks],[Threads can override each others locks]),,enable_threads_override_locks=no)
AC_MSG_CHECKING([whether threads can override each others locks])
if test "$enable_threads_override_locks" = "no"; then
  THREADSOVERRIDELOCKS='-1'
  AC_MSG_RESULT([no])
else
  THREADSOVERRIDELOCKS='1'
  AC_MSG_RESULT([yes])
fi
AC_SUBST(THREADSOVERRIDELOCKS)

##########
# Do we want to support release
#
AC_ARG_ENABLE(releasemode, 
AC_HELP_STRING([--enable-releasemode],[Support libtool link to release mode]),,enable_releasemode=no)
AC_MSG_CHECKING([whether to support shared library linked as release mode or not])
if test "$enable_releasemode" = "no"; then

  Fts3Expr *pExpr,                /* Access this expressions doclist */
  sqlite3_int64 iDocid,           /* Docid associated with requested pos-list */
  int iCol                        /* Column of requested pos-list */
){
  assert( pExpr->isLoaded );
  if( pExpr->aDoclist ){
    char *pEnd = &pExpr->aDoclist[pExpr->nDoclist];
    char *pCsr = pExpr->pCurrent;
    char *pCsr;

    if( pExpr->pCurrent==0 ){
      pExpr->pCurrent = pExpr->aDoclist;
      pExpr->iCurrent = 0;
      pExpr->pCurrent += sqlite3Fts3GetVarint(pExpr->pCurrent,&pExpr->iCurrent);
    }
    pCsr = pExpr->pCurrent;
    assert( pCsr );

    while( pCsr<pEnd ){
      if( pExpr->iCurrent<iDocid ){
        fts3PoslistCopy(0, &pCsr);
        if( pCsr<pEnd ){
          fts3GetDeltaVarint(&pCsr, &pExpr->iCurrent);
        }
        pExpr->pCurrent = pCsr;

}

/*
** This is an fts3ExprIterate() callback used while loading the doclists
** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also
** fts3ExprLoadDoclists().
*/
static int fts3ExprLoadDoclistsCb1(Fts3Expr *pExpr, int iPhrase, void *ctx){
static int fts3ExprLoadDoclistsCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
  int rc = SQLITE_OK;
  LoadDoclistCtx *p = (LoadDoclistCtx *)ctx;

  UNUSED_PARAMETER(iPhrase);

  p->nPhrase++;
  p->nToken += pExpr->pPhrase->nToken;

  if( pExpr->isLoaded==0 ){
    rc = sqlite3Fts3ExprLoadDoclist(p->pCsr, pExpr);
    pExpr->isLoaded = 1;
    if( rc==SQLITE_OK ){
      rc = fts3ExprNearTrim(pExpr);
    }
  }

  return rc;
}

/*
** This is an fts3ExprIterate() callback used while loading the doclists
** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also
** fts3ExprLoadDoclists().
*/
static int fts3ExprLoadDoclistsCb2(Fts3Expr *pExpr, int iPhrase, void *ctx){
  UNUSED_PARAMETER(iPhrase);
  UNUSED_PARAMETER(ctx);
  if( pExpr->aDoclist ){
    pExpr->pCurrent = pExpr->aDoclist;
    pExpr->iCurrent = 0;
    pExpr->pCurrent += sqlite3Fts3GetVarint(pExpr->pCurrent, &pExpr->iCurrent);
  }
  return SQLITE_OK;
}

/*
** Load the doclists for each phrase in the query associated with FTS3 cursor
** pCsr. 
**
** If pnPhrase is not NULL, then *pnPhrase is set to the number of matchable 
** phrases in the expression (all phrases except those directly or 
** indirectly descended from the right-hand-side of a NOT operator). If 
** pnToken is not NULL, then it is set to the number of tokens in all
** matchable phrases of the expression.
*/
static int fts3ExprLoadDoclists(
  Fts3Cursor *pCsr,               /* Fts3 cursor for current query */
  int *pnPhrase,                  /* OUT: Number of phrases in query */
  int *pnToken                    /* OUT: Number of tokens in query */
){
  int rc;                         /* Return Code */
  LoadDoclistCtx sCtx = {0,0,0};  /* Context for fts3ExprIterate() */
  sCtx.pCsr = pCsr;
  rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb1, (void *)&sCtx);
  rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb, (void *)&sCtx);
  if( rc==SQLITE_OK ){
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb2, 0);
  }
  if( pnPhrase ) *pnPhrase = sCtx.nPhrase;
  if( pnToken ) *pnToken = sCtx.nToken;
  return rc;
}

static int fts3ExprPhraseCountCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
  (*(int *)ctx)++;

  sqlite3_int64 nDoc;

  if( !*ppStmt ){
    int rc = sqlite3Fts3SelectDoctotal(pTab, ppStmt);
    if( rc!=SQLITE_OK ) return rc;
  }
  pStmt = *ppStmt;
  assert( sqlite3_data_count(pStmt)==1 );

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

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

      ** varints, where nCol is the number of columns in the FTS3 table.
      ** The first varint is the number of documents currently stored in
      ** the table. The following nCol varints contain the total amount of
      ** data stored in all rows of each column of the table, from left
      ** to right.
      */
      sqlite3_stmt *pStmt;
      rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0);
      if( rc ) return rc;
      if( sqlite3_step(pStmt)==SQLITE_ROW ){
        sqlite3_int64 nDoc = 0;
        sqlite3_int64 nByte = 0;
        const char *a = sqlite3_column_blob(pStmt, 0);
        if( a ){
          const char *pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
          a += sqlite3Fts3GetVarint(a, &nDoc);
          while( a<pEnd ){
            a += sqlite3Fts3GetVarint(a, &nByte);
          }
        }

      sqlite3_int64 nDoc = 0;
      sqlite3_int64 nByte = 0;
      const char *a;
      rc = sqlite3Fts3SelectDoctotal(p, &pStmt);
      if( rc ) return rc;
      a = sqlite3_column_blob(pStmt, 0);
      if( a ){
        const char *pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
        a += sqlite3Fts3GetVarint(a, &nDoc);
        while( a<pEnd ){
          a += sqlite3Fts3GetVarint(a, &nByte);
        }
      }
      if( nDoc==0 || nByte==0 ){
        sqlite3_reset(pStmt);
        return SQLITE_CORRUPT;
      }
        pCsr->nRowAvg = (int)(((nByte / nDoc) + pgsz - 1) / pgsz);
      }

      pCsr->nRowAvg = (int)(((nByte / nDoc) + pgsz) / pgsz);
      assert( pCsr->nRowAvg>0 ); 
      rc = sqlite3_reset(pStmt);
      if( rc!=SQLITE_OK || pCsr->nRowAvg==0 ) return rc;
      if( rc!=SQLITE_OK ) return rc;
    }

    /* Assume that a blob flows over onto overflow pages if it is larger
    ** than (pgsz-35) bytes in size (the file-format documentation
    ** confirms this).
    */
    for(iBlock=pReader->iStartBlock; iBlock<=pReader->iLeafEndBlock; iBlock++){

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

        if( !isIgnoreEmpty || nList>0 ){
          nByte = sqlite3Fts3VarintLen(iDocid-iPrev) + (isRequirePos?nList+1:0);
          if( nDoclist+nByte>nAlloc ){
            char *aNew;
            nAlloc = nDoclist+nByte*2;
            nAlloc = (nDoclist+nByte)*2;
            aNew = sqlite3_realloc(aBuffer, nAlloc);
            if( !aNew ){
              rc = SQLITE_NOMEM;
              goto finished;
            }
            aBuffer = aNew;
          }

    ** the index b-tree.  */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);

    for(i=0; i<nCol; i++){
      CollSeq *pColl;
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol);
#ifdef SQLITE_ENABLE_STAT2
      if( i==0 ){
#ifdef SQLITE_ENABLE_STAT2
        /* Check if the record that cursor iIdxCur points to contains a
        ** value that should be stored in the sqlite_stat2 table. If so,
        ** store it.  */
        int ne = sqlite3VdbeAddOp3(v, OP_Ne, regRecno, 0, regSamplerecno);
        assert( regTabname+1==regIdxname 
             && regTabname+2==regSampleno
             && regTabname+3==regCol

        sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regTemp2);
        sqlite3VdbeAddOp3(v, OP_Subtract, regSampleno, regTemp2, regTemp2);
        sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regTemp, regTemp);
        sqlite3VdbeAddOp3(v, OP_Add, regSamplerecno, regTemp, regSamplerecno);

        sqlite3VdbeJumpHere(v, ne);
        sqlite3VdbeAddOp2(v, OP_AddImm, regRecno, 1);
      }
#endif

        /* Always record the very first row */
        sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1);
      }
      assert( pIdx->azColl!=0 );
      assert( pIdx->azColl[i]!=0 );
      pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
      sqlite3VdbeAddOp3(v, OP_Ne, regCol, 0, iMem+nCol+i+1);
      sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1,
      /**** TODO:  add collating sequence *****/
      sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
                       (char*)pColl, P4_COLLSEQ);
      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
    }
    if( db->mallocFailed ){
      /* If a malloc failure has occurred, then the result of the expression 
      ** passed as the second argument to the call to sqlite3VdbeJumpHere() 
      ** below may be negative. Which causes an assert() to fail (or an
      ** out-of-bounds write if SQLITE_DEBUG is not defined).  */
      return;
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){
      sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-(nCol*2));
      int addr2 = sqlite3VdbeCurrentAddr(v) - (nCol*2);
      if( i==0 ){
        sqlite3VdbeJumpHere(v, addr2-1);  /* Set jump dest for the OP_IfNot */
      }
      sqlite3VdbeJumpHere(v, addr2);      /* Set jump dest for the OP_Ne */
      sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
    }

    /* End of the analysis loop. */
    sqlite3VdbeResolveLabel(v, endOfLoop);
    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);

    }else{
      rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
      sqlite3DbFree(db, zSql);
    }

    if( rc==SQLITE_OK ){
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        char *zIndex;   /* Index name */
        Index *pIdx;    /* Pointer to the index object */

        char *zIndex = (char *)sqlite3_column_text(pStmt, 0);
        Index *pIdx = sqlite3FindIndex(db, zIndex, sInfo.zDatabase);
        zIndex = (char *)sqlite3_column_text(pStmt, 0);
        pIdx = zIndex ? sqlite3FindIndex(db, zIndex, sInfo.zDatabase) : 0;
        if( pIdx ){
          int iSample = sqlite3_column_int(pStmt, 1);
          if( iSample<SQLITE_INDEX_SAMPLES && iSample>=0 ){
            int eType = sqlite3_column_type(pStmt, 2);

            if( pIdx->aSample==0 ){
              static const int sz = sizeof(IndexSample)*SQLITE_INDEX_SAMPLES;

  if( i<0 ){
    sqlite3Error(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);
    return 0;
  }

  return pDb->aDb[i].pBt;
}

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

/*
** Create an sqlite3_backup process to copy the contents of zSrcDb from
** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
** a pointer to the new sqlite3_backup object.
**
** If an error occurs, NULL is returned and an error code and error message

    p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);
    p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
    p->pDestDb = pDestDb;
    p->pSrcDb = pSrcDb;
    p->iNext = 1;
    p->isAttached = 0;

    if( 0==p->pSrc || 0==p->pDest ){
      /* One (or both) of the named databases did not exist. An error has
      ** already been written into the pDestDb handle. All that is left
      ** to do here is free the sqlite3_backup structure.
    if( 0==p->pSrc || 0==p->pDest || setDestPgsz(p)==SQLITE_NOMEM ){
      /* One (or both) of the named databases did not exist or an OOM
      ** error was hit.  The error has already been written into the
      ** pDestDb handle.  All that is left to do here is free the
      ** sqlite3_backup structure.
      */
      sqlite3_free(p);
      p = 0;
    }
  }
  if( p ){
    p->pSrc->nBackup++;

        **
        **   * Data stored on the pages immediately following the 
        **     pending-byte page in the source database may need to be
        **     copied into the destination database.
        */
        const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
        sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
        i64 iOff;
        i64 iEnd;

        assert( pFile );
        assert( (i64)nDestTruncate*(i64)pgszDest >= iSize || (
              nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)
           && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
        ));

        /* This call ensures that all data required to recreate the original
        ** database has been stored in the journal for pDestPager and the
        ** journal synced to disk. So at this point we may safely modify
        ** the database file in any way, knowing that if a power failure
        ** occurs, the original database will be reconstructed from the 
        ** journal file.  */
        if( SQLITE_OK==(rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1))
         && SQLITE_OK==(rc = backupTruncateFile(pFile, iSize))
        rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);

         && SQLITE_OK==(rc = sqlite3PagerSync(pDestPager))
        ){
          i64 iOff;
          i64 iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
          for(
            iOff=PENDING_BYTE+pgszSrc; 
            rc==SQLITE_OK && iOff<iEnd; 
            iOff+=pgszSrc
          ){
            PgHdr *pSrcPg = 0;
            const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
            if( rc==SQLITE_OK ){
              u8 *zData = sqlite3PagerGetData(pSrcPg);
              rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
            }
            sqlite3PagerUnref(pSrcPg);
          }
        /* Write the extra pages and truncate the database file as required. */
        iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
        for(
          iOff=PENDING_BYTE+pgszSrc; 
          rc==SQLITE_OK && iOff<iEnd; 
          iOff+=pgszSrc
        ){
          PgHdr *pSrcPg = 0;
          const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
          rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
          if( rc==SQLITE_OK ){
            u8 *zData = sqlite3PagerGetData(pSrcPg);
            rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
          }
          sqlite3PagerUnref(pSrcPg);
        }
        if( rc==SQLITE_OK ){
          rc = backupTruncateFile(pFile, iSize);
        }

        /* Sync the database file to disk. */
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerSync(pDestPager);
        }
      }else{
        rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
      }
  
      /* Finish committing the transaction to the destination database. */
      if( SQLITE_OK==rc

  pInfo->nHeader = n;
  testcase( nPayload==pPage->maxLocal );
  testcase( nPayload==pPage->maxLocal+1 );
  if( likely(nPayload<=pPage->maxLocal) ){
    /* This is the (easy) common case where the entire payload fits
    ** on the local page.  No overflow is required.
    */
    int nSize;          /* Total size of cell content in bytes */
    nSize = nPayload + n;
    if( (pInfo->nSize = (u16)(n+nPayload))<4 ) pInfo->nSize = 4;
    pInfo->nLocal = (u16)nPayload;
    pInfo->iOverflow = 0;
    if( (nSize & ~3)==0 ){
      nSize = 4;        /* Minimum cell size is 4 */
    }
    pInfo->nSize = (u16)nSize;
  }else{
    /* If the payload will not fit completely on the local page, we have
    ** to decide how much to store locally and how much to spill onto
    ** overflow pages.  The strategy is to minimize the amount of unused
    ** space on overflow pages while keeping the amount of local storage
    ** in between minLocal and maxLocal.
    **

      pBt->usableSize = usableSize;
      pBt->pageSize = pageSize;
      freeTempSpace(pBt);
      rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize,
                                   pageSize-usableSize);
      return rc;
    }
    if( nPageHeader>nPageFile ){
    if( (pBt->db->flags & SQLITE_RecoveryMode)==0 && nPageHeader>nPageFile ){
      rc = SQLITE_CORRUPT_BKPT;
      goto page1_init_failed;
    }
    if( usableSize<480 ){
      goto page1_init_failed;
    }
    pBt->pageSize = pageSize;

  u8 secureDelete;      /* True if secure_delete is enabled */
  u8 initiallyEmpty;    /* Database is empty at start of transaction */
  u8 openFlags;         /* Flags to sqlite3BtreeOpen() */
#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 autoVacuum;        /* True if auto-vacuum is enabled */
  u8 incrVacuum;        /* True if incr-vacuum is enabled */
#endif
  u8 inTransaction;     /* Transaction state */
  u8 doNotUseWAL;       /* If true, do not open write-ahead-log file */
  u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u8 inTransaction;     /* Transaction state */
  u8 doNotUseWAL;       /* If true, do not open write-ahead-log file */
  u32 pageSize;         /* Total number of bytes on a page */
  u32 usableSize;       /* Number of usable bytes on each page */
  int nTransaction;     /* Number of open transactions (read + write) */
  u32 nPage;            /* Number of pages in the database */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */

/*
** An instance of the following structure is used to hold information
** about a cell.  The parseCellPtr() function fills in this structure
** based on information extract from the raw disk page.
*/
typedef struct CellInfo CellInfo;
struct CellInfo {
  u8 *pCell;     /* Pointer to the start of cell content */
  i64 nKey;      /* The key for INTKEY tables, or number of bytes in key */
  u8 *pCell;     /* Pointer to the start of cell content */
  u32 nData;     /* Number of bytes of data */
  u32 nPayload;  /* Total amount of payload */
  u16 nHeader;   /* Size of the cell content header in bytes */
  u16 nLocal;    /* Amount of payload held locally */
  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
  u16 nSize;     /* Size of the cell content on the main b-tree page */
};

  Btree *pBtree;            /* The Btree to which this cursor belongs */
  BtShared *pBt;            /* The BtShared this cursor points to */
  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
  Pgno pgnoRoot;            /* The root page of this tree */
  sqlite3_int64 cachedRowid; /* Next rowid cache.  0 means not valid */
  CellInfo info;            /* A parse of the cell we are pointing at */
  i64 nKey;        /* Size of pKey, or last integer key */
  void *pKey;      /* Saved key that was cursor's last known position */
  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive */
  u8 wrFlag;                /* True if writable */
  u8 atLast;                /* Cursor pointing to the last entry */
  u8 validNKey;             /* True if info.nKey is valid */
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  void *pKey;      /* Saved key that was cursor's last known position */
  i64 nKey;        /* Size of pKey, or last integer key */
  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive */
#ifndef SQLITE_OMIT_INCRBLOB
  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
  Pgno *aOverflow;          /* Cache of overflow page locations */
  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
#endif
  i16 iPage;                            /* Index of current page in apPage */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
};

/*
** Potential values for BtCursor.eState.
**
** CURSOR_VALID:
**   Cursor points to a valid entry. getPayload() etc. may be called.

  "OMIT_AUTOINCREMENT",
#endif
#ifdef SQLITE_OMIT_AUTOINIT
  "OMIT_AUTOINIT",
#endif
#ifdef SQLITE_OMIT_AUTOMATIC_INDEX
  "OMIT_AUTOMATIC_INDEX",
#endif
#ifdef SQLITE_OMIT_AUTORESET
  "OMIT_AUTORESET",
#endif
#ifdef SQLITE_OMIT_AUTOVACUUM
  "OMIT_AUTOVACUUM",
#endif
#ifdef SQLITE_OMIT_BETWEEN_OPTIMIZATION
  "OMIT_BETWEEN_OPTIMIZATION",
#endif

void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
  struct compareInfo *pInfo;
  if( caseSensitive ){
    pInfo = (struct compareInfo*)&likeInfoAlt;
  }else{
    pInfo = (struct compareInfo*)&likeInfoNorm;
  }
  sqlite3CreateFunc(db, "like", 2, SQLITE_ANY, pInfo, likeFunc, 0, 0, 0);
  sqlite3CreateFunc(db, "like", 3, SQLITE_ANY, pInfo, likeFunc, 0, 0, 0);
  sqlite3CreateFunc(db, "glob", 2, SQLITE_ANY, 
  sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0);
  sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0);
  sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8, 
      (struct compareInfo*)&globInfo, likeFunc, 0, 0, 0);
  setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
  setLikeOptFlag(db, "like", 
      caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
}

/*

    /* SQLITE_BUSY        */ "database is locked",
    /* SQLITE_LOCKED      */ "database table is locked",
    /* SQLITE_NOMEM       */ "out of memory",
    /* SQLITE_READONLY    */ "attempt to write a readonly database",
    /* SQLITE_INTERRUPT   */ "interrupted",
    /* SQLITE_IOERR       */ "disk I/O error",
    /* SQLITE_CORRUPT     */ "database disk image is malformed",
    /* SQLITE_NOTFOUND    */ 0,
    /* SQLITE_NOTFOUND    */ "unknown operation",
    /* SQLITE_FULL        */ "database or disk is full",
    /* SQLITE_CANTOPEN    */ "unable to open database file",
    /* SQLITE_PROTOCOL    */ "locking protocol",
    /* SQLITE_EMPTY       */ "table contains no data",
    /* SQLITE_SCHEMA      */ "database schema has changed",
    /* SQLITE_TOOBIG      */ "string or blob too big",
    /* SQLITE_CONSTRAINT  */ "constraint failed",

#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
                 | SQLITE_RecTriggers
#endif
#if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
                 | SQLITE_ForeignKeys
#endif
      ;
  sqlite3HashInit(&db->aCollSeq);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  db->pVfs = sqlite3_vfs_find(zVfs);

      fd = sqlite3PagerFile(pPager);
      assert( fd!=0 );
      if( op==SQLITE_FCNTL_FILE_POINTER ){
        *(sqlite3_file**)pArg = fd;
        rc = SQLITE_OK;
      }else if( fd->pMethods ){
        rc = sqlite3OsFileControl(fd, op, pArg);
      }else{
        rc = SQLITE_NOTFOUND;
      }
      sqlite3BtreeLeave(pBtree);
    }
  }
  sqlite3_mutex_leave(db->mutex);
  return rc;   
}

  assert( db==0 || db->pnBytesFreed==0 );
#ifndef SQLITE_OMIT_LOOKASIDE
  if( db ){
    LookasideSlot *pBuf;
    if( db->mallocFailed ){
      return 0;
    }
    if( db->lookaside.bEnabled && n<=db->lookaside.sz
         && (pBuf = db->lookaside.pFree)!=0 ){
      db->lookaside.pFree = pBuf->pNext;
      db->lookaside.nOut++;
      if( db->lookaside.nOut>db->lookaside.mxOut ){
        db->lookaside.mxOut = db->lookaside.nOut;
      }
      return (void*)pBuf;
    if( db->lookaside.bEnabled ){
      if( n>db->lookaside.sz ){
        db->lookaside.anStat[1]++;
      }else if( (pBuf = db->lookaside.pFree)==0 ){
        db->lookaside.anStat[2]++;
      }else{
        db->lookaside.pFree = pBuf->pNext;
        db->lookaside.nOut++;
        db->lookaside.anStat[0]++;
        if( db->lookaside.nOut>db->lookaside.mxOut ){
          db->lookaside.mxOut = db->lookaside.nOut;
        }
        return (void*)pBuf;
      }
    }
  }
#else
  if( db && db->mallocFailed ){
    return 0;
  }
#endif

** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** <li>  SQLITE_MUTEX_STATIC_PMEM
** </ul>
**
** The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** <li>  SQLITE_MUTEX_STATIC_PMEM
** </ul>
**
** The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = ((os2File*)id)->locktype;
      OSTRACE(( "FCNTL_LOCKSTATE %d lock=%d\n",
                ((os2File*)id)->h, ((os2File*)id)->locktype ));
      return SQLITE_OK;
    }
  }
  return SQLITE_ERROR;
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#ifndef SQLITE_OMIT_WAL
#include <sys/mman.h>
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>
# if OS_VXWORKS
#  include <semaphore.h>
#  include <limits.h>
# else

      }
      if( trc ){
        return trc;
      }
      return rc;
    }
#endif /* (SQLITE_ENABLE_APPLE_SPI>0) && defined(__APPLE__) */
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;  /* A no-op */
  }
  return SQLITE_ERROR;
    }
  }
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**

/* Not always defined in the headers as it ought to be */
extern int gethostuuid(uuid_t id, const struct timespec *wait);

/* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 
** bytes of writable memory.
*/
static int proxyGetHostID(unsigned char *pHostID, int *pError){
  struct timespec timeout = {1, 0}; /* 1 sec timeout */
  
  assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
  memset(pHostID, 0, PROXY_HOSTIDLEN);
#if defined(__MAX_OS_X_VERSION_MIN_REQUIRED)\
               && __MAC_OS_X_VERSION_MIN_REQUIRED<1050
  {
    static const struct timespec timeout = {1, 0}; /* 1 sec timeout */
  if( gethostuuid(pHostID, &timeout) ){
    int err = errno;
    if( pError ){
      *pError = err;
    }
    return SQLITE_IOERR;
    if( gethostuuid(pHostID, &timeout) ){
      int err = errno;
      if( pError ){
        *pError = err;
      }
      return SQLITE_IOERR;
    }
  }
#endif
#ifdef SQLITE_TEST
  /* simulate multiple hosts by creating unique hostid file paths */
  if( sqlite3_hostid_num != 0){
    pHostID[0] = (char)(pHostID[0] + (char)(sqlite3_hostid_num & 0xFF));
  }

    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_int64 sz = *(sqlite3_int64*)pArg;
      SimulateIOErrorBenign(1);
      winTruncate(id, sz);
      SimulateIOErrorBenign(0);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;
  }
  return SQLITE_ERROR;
    }
  }
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**

  pPager->changeCountDone = pPager->tempFile;

  if( rc==SQLITE_OK ){
    zMaster = pPager->pTmpSpace;
    rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && !pPager->noSync 
  if( rc==SQLITE_OK
   && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)
  ){
    rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
    rc = sqlite3PagerSync(pPager);
  }
  if( rc==SQLITE_OK ){
    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
    testcase( rc!=SQLITE_OK );
  }
  if( rc==SQLITE_OK && zMaster[0] && res ){
    /* If there was a master journal and this routine will return success,

    rc = pagerUndoCallback((void *)pPager, pList->pgno);
    pList = pNext;
  }

  return rc;
}


/*
** Update the value of the change-counter at offsets 24 and 92 in
** the header and the sqlite version number at offset 96.
**
** This is an unconditional update.  See also the pager_incr_changecounter()
** routine which only updates the change-counter if the update is actually
** needed, as determined by the pPager->changeCountDone state variable.
*/
static void pager_write_changecounter(PgHdr *pPg){
  u32 change_counter;

  /* Increment the value just read and write it back to byte 24. */
  change_counter = sqlite3Get4byte((u8*)pPg->pPager->dbFileVers)+1;
  put32bits(((char*)pPg->pData)+24, change_counter);

  /* Also store the SQLite version number in bytes 96..99 and in
  ** bytes 92..95 store the change counter for which the version number
  ** is valid. */
  put32bits(((char*)pPg->pData)+92, change_counter);
  put32bits(((char*)pPg->pData)+96, SQLITE_VERSION_NUMBER);
}

/*
** This function is a wrapper around sqlite3WalFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed. 
** changed.
**
** The list of pages passed into this routine is always sorted by page number.
** Hence, if page 1 appears anywhere on the list, it will be the first page.
*/ 
static int pagerWalFrames(
  Pager *pPager,                  /* Pager object */
  PgHdr *pList,                   /* List of frames to log */
  Pgno nTruncate,                 /* Database size after this commit */
  int isCommit,                   /* True if this is a commit */
  int syncFlags                   /* Flags to pass to OsSync() (or 0) */
){
  int rc;                         /* Return code */
#if defined(SQLITE_DEBUG) || defined(SQLITE_CHECK_PAGES)
  PgHdr *p;                       /* For looping over pages */
#endif

  assert( pPager->pWal );
#ifdef SQLITE_DEBUG
  /* Verify that the page list is in accending order */
  for(p=pList; p && p->pDirty; p=p->pDirty){
    assert( p->pgno < p->pDirty->pgno );
  }
#endif

  if( pList->pgno==1 ) pager_write_changecounter(pList);
  rc = sqlite3WalFrames(pPager->pWal, 
      pPager->pageSize, pList, nTruncate, isCommit, syncFlags
  );
  if( rc==SQLITE_OK && pPager->pBackup ){
    PgHdr *p;
    for(p=pList; p; p=p->pDirty){
      sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
    }
  }

#ifdef SQLITE_CHECK_PAGES
  {
    PgHdr *p;
    for(p=pList; p; p=p->pDirty) pager_set_pagehash(p);
  for(p=pList; p; p=p->pDirty){
    pager_set_pagehash(p);
  }
#endif

  return rc;
}

/*

    ** set (set by sqlite3PagerDontWrite()).
    */
    if( pgno<=pPager->dbSize && 0==(pList->flags&PGHDR_DONT_WRITE) ){
      i64 offset = (pgno-1)*(i64)pPager->pageSize;   /* Offset to write */
      char *pData;                                   /* Data to write */    

      assert( (pList->flags&PGHDR_NEED_SYNC)==0 );
      if( pList->pgno==1 ) pager_write_changecounter(pList);

      /* Encode the database */
      CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM, pData);

      /* Write out the page data. */
      rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);

    pager_set_pagehash(pPg);
  }
}

/*
** This routine is called to increment the value of the database file 
** change-counter, stored as a 4-byte big-endian integer starting at 
** byte offset 24 of the pager file.
** byte offset 24 of the pager file.  The secondary change counter at
** 92 is also updated, as is the SQLite version number at offset 96.
**
** But this only happens if the pPager->changeCountDone flag is false.
** To avoid excess churning of page 1, the update only happens once.
** See also the pager_write_changecounter() routine that does an 
** unconditional update of the change counters.
**
** If the isDirectMode flag is zero, then this is done by calling 
** sqlite3PagerWrite() on page 1, then modifying the contents of the
** page data. In this case the file will be updated when the current
** transaction is committed.
**
** The isDirectMode flag may only be non-zero if the library was compiled

  UNUSED_PARAMETER(isDirectMode);
#else
# define DIRECT_MODE isDirectMode
#endif

  if( !pPager->changeCountDone && pPager->dbSize>0 ){
    PgHdr *pPgHdr;                /* Reference to page 1 */
    u32 change_counter;           /* Initial value of change-counter field */

    assert( !pPager->tempFile && isOpen(pPager->fd) );

    /* Open page 1 of the file for writing. */
    rc = sqlite3PagerGet(pPager, 1, &pPgHdr);
    assert( pPgHdr==0 || rc==SQLITE_OK );

    /* If page one was fetched successfully, and this function is not
    ** operating in direct-mode, make page 1 writable.  When not in 
    ** direct mode, page 1 is always held in cache and hence the PagerGet()
    ** above is always successful - hence the ALWAYS on rc==SQLITE_OK.
    */
    if( !DIRECT_MODE && ALWAYS(rc==SQLITE_OK) ){
      rc = sqlite3PagerWrite(pPgHdr);
    }

    if( rc==SQLITE_OK ){
      /* Increment the value just read and write it back to byte 24. */
      change_counter = sqlite3Get4byte((u8*)pPager->dbFileVers);
      change_counter++;
      /* Actually do the update of the change counter */
      put32bits(((char*)pPgHdr->pData)+24, change_counter);

      pager_write_changecounter(pPgHdr);
      /* Also store the SQLite version number in bytes 96..99 and in
      ** bytes 92..95 store the change counter for which the version number
      ** is valid. */
      put32bits(((char*)pPgHdr->pData)+92, change_counter);
      put32bits(((char*)pPgHdr->pData)+96, SQLITE_VERSION_NUMBER);

      /* If running in direct mode, write the contents of page 1 to the file. */
      if( DIRECT_MODE ){
        const void *zBuf;
        assert( pPager->dbFileSize>0 );
        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM, zBuf);
        if( rc==SQLITE_OK ){

** Sync the database file to disk. This is a no-op for in-memory databases
** or pages with the Pager.noSync flag set.
**
** If successful, or if called on a pager for which it is a no-op, this
** function returns SQLITE_OK. Otherwise, an IO error code is returned.
*/
int sqlite3PagerSync(Pager *pPager){
  int rc;                              /* Return code */
  assert( !MEMDB );
  int rc = SQLITE_OK;
  if( !pPager->noSync ){
    assert( !MEMDB );
  if( pPager->noSync ){
    rc = SQLITE_OK;
  }else{
    rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
  }else if( isOpen(pPager->fd) ){
    assert( !MEMDB );
    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC_OMITTED, (void *)&rc);
  }
  return rc;
}

/*
** This function may only be called while a write-transaction is active in
** rollback. If the connection is in WAL mode, this call is a no-op. 

        Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));
        assert( pPager->eState==PAGER_WRITER_DBMOD );
        rc = pager_truncate(pPager, nNew);
        if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
      }
  
      /* Finally, sync the database file. */
      if( !pPager->noSync && !noSync ){
        rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
      if( !noSync ){
        rc = sqlite3PagerSync(pPager);
      }
      IOTRACE(("DBSYNC %p\n", pPager))
    }
  }

commit_phase_one_exit:
  if( rc==SQLITE_OK && !pagerUseWal(pPager) ){

  if( pagerUseWal(pPager) ){
    int rc2;
    rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
    rc2 = pager_end_transaction(pPager, pPager->setMaster);
    if( rc==SQLITE_OK ) rc = rc2;
  }else if( !isOpen(pPager->jfd) || pPager->eState==PAGER_WRITER_LOCKED ){
    int eState = pPager->eState;
    rc = pager_end_transaction(pPager, 0);
    if( !MEMDB && eState>PAGER_WRITER_LOCKED ){
      /* This can happen using journal_mode=off. Move the pager to the error 
      ** state to indicate that the contents of the cache may not be trusted.
      ** Any active readers will get SQLITE_ABORT.
      */
      pPager->errCode = SQLITE_ABORT;
      pPager->eState = PAGER_ERROR;
      return rc;
    }
  }else{
    rc = pager_playback(pPager, 0);
  }

  assert( pPager->eState==PAGER_READER || rc!=SQLITE_OK );
  assert( rc==SQLITE_OK || rc==SQLITE_FULL || (rc&0xFF)==SQLITE_IOERR );

*/

#include "sqliteInt.h"

typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
typedef struct PGroup PGroup;

/* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
** of one or more PCaches that are able to recycle each others unpinned
** pages when they are under memory pressure.  A PGroup is an instance of
** the following object.
**
** This page cache implementation works in one of two modes:
**
**   (1)  Every PCache is the sole member of its own PGroup.  There is
**        one PGroup per PCache.
**
**   (2)  There is a single global PGroup that all PCaches are a member
**        of.
**
** Mode 1 uses more memory (since PCache instances are not able to rob
** unused pages from other PCaches) but it also operates without a mutex,
** and is therefore often faster.  Mode 2 requires a mutex in order to be
** threadsafe, but is able recycle pages more efficient.
**
** For mode (1), PGroup.mutex is NULL.  For mode (2) there is only a single
** PGroup which is the pcache1.grp global variable and its mutex is
** SQLITE_MUTEX_STATIC_LRU.
*/
struct PGroup {
  sqlite3_mutex *mutex;          /* MUTEX_STATIC_LRU or NULL */
  int nMaxPage;                  /* Sum of nMax for purgeable caches */
  int nMinPage;                  /* Sum of nMin for purgeable caches */
  int mxPinned;                  /* nMaxpage + 10 - nMinPage */
  int nCurrentPage;              /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;   /* LRU list of unpinned pages */
};

/* Each page cache is an instance of the following object.  Every
** open database file (including each in-memory database and each
** temporary or transient database) has a single page cache which
** is an instance of this object.
**
** Pointers to structures of this type are cast and returned as 
** opaque sqlite3_pcache* handles.
*/
struct PCache1 {
  /* Cache configuration parameters. Page size (szPage) and the purgeable
  ** flag (bPurgeable) are set when the cache is created. nMax may be 
  ** modified at any time by a call to the pcache1CacheSize() method.
  ** The global mutex must be held when accessing nMax.
  ** The PGroup mutex must be held when accessing nMax.
  */
  PGroup *pGroup;                     /* PGroup this cache belongs to */
  int szPage;                         /* Size of allocated pages in bytes */
  int bPurgeable;                     /* True if cache is purgeable */
  unsigned int nMin;                  /* Minimum number of pages reserved */
  unsigned int nMax;                  /* Configured "cache_size" value */
  unsigned int n90pct;                /* nMax*9/10 */

  /* Hash table of all pages. The following variables may only be accessed
  ** when the accessor is holding the global mutex (see pcache1EnterMutex() 
  ** when the accessor is holding the PGroup mutex.
  ** and pcache1LeaveMutex()).
  */
  unsigned int nRecyclable;           /* Number of pages in the LRU list */
  unsigned int nPage;                 /* Total number of pages in apHash */
  unsigned int nHash;                 /* Number of slots in apHash[] */
  PgHdr1 **apHash;                    /* Hash table for fast lookup by key */

  unsigned int iMaxKey;               /* Largest key seen since xTruncate() */

  PgFreeslot *pNext;  /* Next free slot */
};

/*
** Global data used by this cache.
*/
static SQLITE_WSD struct PCacheGlobal {
  sqlite3_mutex *mutex;               /* static mutex MUTEX_STATIC_LRU */

  PGroup grp;                    /* The global PGroup for mode (2) */
  int nMaxPage;                       /* Sum of nMaxPage for purgeable caches */
  int nMinPage;                       /* Sum of nMinPage for purgeable caches */
  int nCurrentPage;                   /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;        /* LRU list of unpinned pages */

  /* Variables related to SQLITE_CONFIG_PAGECACHE settings. */
  int szSlot;                         /* Size of each free slot */
  int nSlot;                          /* The number of pcache slots */
  /* Variables related to SQLITE_CONFIG_PAGECACHE settings.  The
  ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all
  ** fixed at sqlite3_initialize() time and do not require mutex protection.
  ** The nFreeSlot and pFree values do require mutex protection.
  */
  int isInit;                    /* True if initialized */
  int szSlot;                    /* Size of each free slot */
  int nSlot;                     /* The number of pcache slots */
  int nFreeSlot;                      /* Number of unused pcache slots */
  int nReserve;                       /* Try to keep nFreeSlot above this */
  void *pStart, *pEnd;                /* Bounds of pagecache malloc range */
  PgFreeslot *pFree;                  /* Free page blocks */
  int isInit;                         /* True if initialized */
  int nReserve;                  /* Try to keep nFreeSlot above this */
  void *pStart, *pEnd;           /* Bounds of pagecache malloc range */
  /* Above requires no mutex.  Use mutex below for variable that follow. */
  sqlite3_mutex *mutex;          /* Mutex for accessing the following: */
  int nFreeSlot;                 /* Number of unused pcache slots */
  PgFreeslot *pFree;             /* Free page blocks */
  /* The following value requires a mutex to change.  We skip the mutex on
  ** reading because (1) most platforms read a 32-bit integer atomically and
  ** (2) even if an incorrect value is read, no great harm is done since this
  ** is really just an optimization. */
  int bUnderPressure;            /* True if low on PAGECACHE memory */
} pcache1_g;

/*
** All code in this file should access the global structure above via the
** alias "pcache1". This ensures that the WSD emulation is used when
** compiling for systems that do not support real WSD.
*/

**
**   assert( PGHDR1_TO_PAGE(PAGE_TO_PGHDR1(pCache, X))==X );
*/
#define PGHDR1_TO_PAGE(p)    (void*)(((char*)p) - p->pCache->szPage)
#define PAGE_TO_PGHDR1(c, p) (PgHdr1*)(((char*)p) + c->szPage)

/*
** Macros to enter and leave the global LRU mutex.
** Macros to enter and leave the PCache LRU mutex.
*/
#define pcache1EnterMutex() sqlite3_mutex_enter(pcache1.mutex)
#define pcache1LeaveMutex() sqlite3_mutex_leave(pcache1.mutex)
#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)

/******************************************************************************/
/******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/

/*
** This function is called during initialization if a static buffer is 
** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE
** verb to sqlite3_config(). Parameter pBuf points to an allocation large
** enough to contain 'n' buffers of 'sz' bytes each.
**
** This routine is called from sqlite3_initialize() and so it is guaranteed
** to be serialized already.  There is no need for further mutexing.
*/
void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
  if( pcache1.isInit ){
    PgFreeslot *p;
    sz = ROUNDDOWN8(sz);
    pcache1.szSlot = sz;
    pcache1.nSlot = pcache1.nFreeSlot = n;
    pcache1.nReserve = n>90 ? 10 : (n/10 + 1);
    pcache1.pStart = pBuf;
    pcache1.pFree = 0;
    pcache1.bUnderPressure = 0;
    while( n-- ){
      p = (PgFreeslot*)pBuf;
      p->pNext = pcache1.pFree;
      pcache1.pFree = p;
      pBuf = (void*)&((char*)pBuf)[sz];
    }
    pcache1.pEnd = pBuf;
  }
}

/*
** Malloc function used within this file to allocate space from the buffer
** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 
** such buffer exists or there is no space left in it, this function falls 
** back to sqlite3Malloc().
**
** Multiple threads can run this routine at the same time.  Global variables
** in pcache1 need to be protected via mutex.
*/
static void *pcache1Alloc(int nByte){
  void *p;
  assert( sqlite3_mutex_held(pcache1.mutex) );
  void *p = 0;
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
  if( nByte<=pcache1.szSlot && pcache1.pFree ){
    assert( pcache1.isInit );
  if( nByte<=pcache1.szSlot ){
    sqlite3_mutex_enter(pcache1.mutex);
    p = (PgHdr1 *)pcache1.pFree;
    if( p ){
    pcache1.pFree = pcache1.pFree->pNext;
    pcache1.nFreeSlot--;
    assert( pcache1.nFreeSlot>=0 );
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
      pcache1.pFree = pcache1.pFree->pNext;
      pcache1.nFreeSlot--;
      pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
      assert( pcache1.nFreeSlot>=0 );
      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
  }else{

    /* Allocate a new buffer using sqlite3Malloc. Before doing so, exit the
    }
    sqlite3_mutex_leave(pcache1.mutex);
    ** global pcache mutex and unlock the pager-cache object pCache. This is 
    ** so that if the attempt to allocate a new buffer causes the the 
    ** configured soft-heap-limit to be breached, it will be possible to
    ** reclaim memory from this pager-cache.
  }
  if( p==0 ){
    /* Memory is not available in the SQLITE_CONFIG_PAGECACHE pool.  Get
    ** it from sqlite3Malloc instead.
    */
    pcache1LeaveMutex();
    p = sqlite3Malloc(nByte);
    pcache1EnterMutex();
    if( p ){
      int sz = sqlite3MallocSize(p);
      sqlite3_mutex_enter(pcache1.mutex);
      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
      sqlite3_mutex_leave(pcache1.mutex);
    }
    sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);
  }
  return p;
}

/*
** Free an allocated buffer obtained from pcache1Alloc().
*/
static void pcache1Free(void *p){
  assert( sqlite3_mutex_held(pcache1.mutex) );
  if( p==0 ) return;
  if( p>=pcache1.pStart && p<pcache1.pEnd ){
    PgFreeslot *pSlot;
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
    pSlot = (PgFreeslot*)p;
    pSlot->pNext = pcache1.pFree;
    pcache1.pFree = pSlot;
    pcache1.nFreeSlot++;
    pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
    assert( pcache1.nFreeSlot<=pcache1.nSlot );
    sqlite3_mutex_leave(pcache1.mutex);
  }else{
    int iSize;
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
    iSize = sqlite3MallocSize(p);
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -iSize);
    sqlite3_mutex_leave(pcache1.mutex);
    sqlite3_free(p);
  }
}

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*
** Return the size of a pcache allocation
*/
static int pcache1MemSize(void *p){
  assert( sqlite3_mutex_held(pcache1.mutex) );
  if( p>=pcache1.pStart && p<pcache1.pEnd ){
    return pcache1.szSlot;
  }else{
    int iSize;
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
    iSize = sqlite3MallocSize(p);

static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
  int nByte = sizeof(PgHdr1) + pCache->szPage;
  void *pPg = pcache1Alloc(nByte);
  PgHdr1 *p;
  if( pPg ){
    p = PAGE_TO_PGHDR1(pCache, pPg);
    if( pCache->bPurgeable ){
      pcache1.nCurrentPage++;
      pCache->pGroup->nCurrentPage++;
    }
  }else{
    p = 0;
  }
  return p;
}

/*
** Free a page object allocated by pcache1AllocPage().
**
** The pointer is allowed to be NULL, which is prudent.  But it turns out
** that the current implementation happens to never call this routine
** with a NULL pointer, so we mark the NULL test with ALWAYS().
*/
static void pcache1FreePage(PgHdr1 *p){
  if( ALWAYS(p) ){
    PCache1 *pCache = p->pCache;
    if( p->pCache->bPurgeable ){
      pcache1.nCurrentPage--;
    if( pCache->bPurgeable ){
      pCache->pGroup->nCurrentPage--;
    }
    pcache1Free(PGHDR1_TO_PAGE(p));
  }
}

/*
** Malloc function used by SQLite to obtain space from the buffer configured
** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer
** exists, this function falls back to sqlite3Malloc().
*/
void *sqlite3PageMalloc(int sz){
  void *p;
  pcache1EnterMutex();
  p = pcache1Alloc(sz);
  return pcache1Alloc(sz);
  pcache1LeaveMutex();
  return p;
}

/*
** Free an allocated buffer obtained from sqlite3PageMalloc().
*/
void sqlite3PageFree(void *p){
  pcache1EnterMutex();
  pcache1Free(p);
  pcache1LeaveMutex();
}


/*
** Return true if it desirable to avoid allocating a new page cache
** entry.
**
** If memory was allocated specifically to the page cache using
** SQLITE_CONFIG_PAGECACHE but that memory has all been used, then
** it is desirable to avoid allocating a new page cache entry because
** presumably SQLITE_CONFIG_PAGECACHE was suppose to be sufficient
** for all page cache needs and we should not need to spill the
** allocation onto the heap.
**
** Or, the heap is used for all page cache memory put the heap is
** under memory pressure, then again it is desirable to avoid
** allocating a new page cache entry in order to avoid stressing
** the heap even further.
*/
static int pcache1UnderMemoryPressure(PCache1 *pCache){
  assert( sqlite3_mutex_held(pcache1.mutex) );
  if( pcache1.nSlot && pCache->szPage<=pcache1.szSlot ){
    return pcache1.nFreeSlot<pcache1.nReserve;
    return pcache1.bUnderPressure;
  }else{
    return sqlite3HeapNearlyFull();
  }
}

/******************************************************************************/
/******** General Implementation Functions ************************************/

/*
** This function is used to resize the hash table used by the cache passed
** as the first argument.
**
** The global mutex must be held when this function is called.
** The PCache mutex must be held when this function is called.
*/
static int pcache1ResizeHash(PCache1 *p){
  PgHdr1 **apNew;
  unsigned int nNew;
  unsigned int i;

  assert( sqlite3_mutex_held(pcache1.mutex) );
  assert( sqlite3_mutex_held(p->pGroup->mutex) );

  nNew = p->nHash*2;
  if( nNew<256 ){
    nNew = 256;
  }

  pcache1LeaveMutex();
  pcache1LeaveMutex(p->pGroup);
  if( p->nHash ){ sqlite3BeginBenignMalloc(); }
  apNew = (PgHdr1 **)sqlite3_malloc(sizeof(PgHdr1 *)*nNew);
  if( p->nHash ){ sqlite3EndBenignMalloc(); }
  pcache1EnterMutex();
  pcache1EnterMutex(p->pGroup);
  if( apNew ){
    memset(apNew, 0, sizeof(PgHdr1 *)*nNew);
    for(i=0; i<p->nHash; i++){
      PgHdr1 *pPage;
      PgHdr1 *pNext = p->apHash[i];
      while( (pPage = pNext)!=0 ){
        unsigned int h = pPage->iKey % nNew;

  }

  return (p->apHash ? SQLITE_OK : SQLITE_NOMEM);
}

/*
** This function is used internally to remove the page pPage from the 
** global LRU list, if is part of it. If pPage is not part of the global
** PGroup LRU list, if is part of it. If pPage is not part of the PGroup
** LRU list, then this function is a no-op.
**
** The global mutex must be held when this function is called.
** The PGroup mutex must be held when this function is called.
**
** If pPage is NULL then this routine is a no-op.
*/
static void pcache1PinPage(PgHdr1 *pPage){
  PCache1 *pCache;
  PGroup *pGroup;

  if( pPage==0 ) return;
  pCache = pPage->pCache;
  pGroup = pCache->pGroup;
  assert( sqlite3_mutex_held(pcache1.mutex) );
  if( pPage && (pPage->pLruNext || pPage==pcache1.pLruTail) ){
  assert( sqlite3_mutex_held(pGroup->mutex) );
  if( pPage->pLruNext || pPage==pGroup->pLruTail ){
    if( pPage->pLruPrev ){
      pPage->pLruPrev->pLruNext = pPage->pLruNext;
    }
    if( pPage->pLruNext ){
      pPage->pLruNext->pLruPrev = pPage->pLruPrev;
    }
    if( pcache1.pLruHead==pPage ){
      pcache1.pLruHead = pPage->pLruNext;
    if( pGroup->pLruHead==pPage ){
      pGroup->pLruHead = pPage->pLruNext;
    }
    if( pcache1.pLruTail==pPage ){
      pcache1.pLruTail = pPage->pLruPrev;
    if( pGroup->pLruTail==pPage ){
      pGroup->pLruTail = pPage->pLruPrev;
    }
    pPage->pLruNext = 0;
    pPage->pLruPrev = 0;
    pPage->pCache->nRecyclable--;
  }
}


/*
** Remove the page supplied as an argument from the hash table 
** (PCache1.apHash structure) that it is currently stored in.
**
** The global mutex must be held when this function is called.
** The PGroup mutex must be held when this function is called.
*/
static void pcache1RemoveFromHash(PgHdr1 *pPage){
  unsigned int h;
  PCache1 *pCache = pPage->pCache;
  PgHdr1 **pp;

  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
  h = pPage->iKey % pCache->nHash;
  for(pp=&pCache->apHash[h]; (*pp)!=pPage; pp=&(*pp)->pNext);
  *pp = (*pp)->pNext;

  pCache->nPage--;
}

/*
** If there are currently more than pcache.nMaxPage pages allocated, try
** to recycle pages to reduce the number allocated to pcache.nMaxPage.
** If there are currently more than nMaxPage pages allocated, try
** to recycle pages to reduce the number allocated to nMaxPage.
*/
static void pcache1EnforceMaxPage(void){
  assert( sqlite3_mutex_held(pcache1.mutex) );
  while( pcache1.nCurrentPage>pcache1.nMaxPage && pcache1.pLruTail ){
    PgHdr1 *p = pcache1.pLruTail;
static void pcache1EnforceMaxPage(PGroup *pGroup){
  assert( sqlite3_mutex_held(pGroup->mutex) );
  while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){
    PgHdr1 *p = pGroup->pLruTail;
    assert( p->pCache->pGroup==pGroup );
    pcache1PinPage(p);
    pcache1RemoveFromHash(p);
    pcache1FreePage(p);
  }
}

/*
** Discard all pages from cache pCache with a page number (key value) 
** greater than or equal to iLimit. Any pinned pages that meet this 
** criteria are unpinned before they are discarded.
**
** The global mutex must be held when this function is called.
** The PCache mutex must be held when this function is called.
*/
static void pcache1TruncateUnsafe(
  PCache1 *pCache, 
  unsigned int iLimit 
  PCache1 *pCache,             /* The cache to truncate */
  unsigned int iLimit          /* Drop pages with this pgno or larger */
){
  TESTONLY( unsigned int nPage = 0; )      /* Used to assert pCache->nPage is correct */
  TESTONLY( unsigned int nPage = 0; )  /* To assert pCache->nPage is correct */
  unsigned int h;
  assert( sqlite3_mutex_held(pcache1.mutex) );
  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
  for(h=0; h<pCache->nHash; h++){
    PgHdr1 **pp = &pCache->apHash[h]; 
    PgHdr1 *pPage;
    while( (pPage = *pp)!=0 ){
      if( pPage->iKey>=iLimit ){
        pCache->nPage--;
        *pp = pPage->pNext;

** Implementation of the sqlite3_pcache.xInit method.
*/
static int pcache1Init(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  assert( pcache1.isInit==0 );
  memset(&pcache1, 0, sizeof(pcache1));
  if( sqlite3GlobalConfig.bCoreMutex ){
    pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM);
  }
  pcache1.grp.mxPinned = 10;
  pcache1.isInit = 1;
  return SQLITE_OK;
}

/*
** Implementation of the sqlite3_pcache.xShutdown method.
** Note that the static mutex allocated in xInit does 

/*
** Implementation of the sqlite3_pcache.xCreate method.
**
** Allocate a new cache.
*/
static sqlite3_pcache *pcache1Create(int szPage, int bPurgeable){
  PCache1 *pCache;
  PCache1 *pCache;      /* The newly created page cache */
  PGroup *pGroup;       /* The group the new page cache will belong to */
  int sz;               /* Bytes of memory required to allocate the new cache */

  /*
  ** The seperateCache variable is true if each PCache has its own private
  ** PGroup.  In other words, separateCache is true for mode (1) where no
  ** mutexing is required.
  **
  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
  **
  **   *  Always use a unified cache in single-threaded applications
  **
  **   *  Otherwise (if multi-threaded and ENABLE_MEMORY_MANAGEMENT is off)
  **      use separate caches (mode-1)
  */
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
  const int separateCache = 0;
#else
  int separateCache = sqlite3GlobalConfig.bCoreMutex>0;
#endif

  sz = sizeof(PCache1) + sizeof(PGroup)*separateCache;
  pCache = (PCache1 *)sqlite3_malloc(sizeof(PCache1));
  pCache = (PCache1 *)sqlite3_malloc(sz);
  if( pCache ){
    memset(pCache, 0, sizeof(PCache1));
    memset(pCache, 0, sz);
    if( separateCache ){
      pGroup = (PGroup*)&pCache[1];
      pGroup->mxPinned = 10;
    }else{
      pGroup = &pcache1_g.grp;
    }
    pCache->pGroup = pGroup;
    pCache->szPage = szPage;
    pCache->bPurgeable = (bPurgeable ? 1 : 0);
    if( bPurgeable ){
      pCache->nMin = 10;
      pcache1EnterMutex();
      pcache1.nMinPage += pCache->nMin;
      pcache1LeaveMutex();
      pcache1EnterMutex(pGroup);
      pGroup->nMinPage += pCache->nMin;
      pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
      pcache1LeaveMutex(pGroup);
    }
  }
  return (sqlite3_pcache *)pCache;
}

/*
** Implementation of the sqlite3_pcache.xCachesize method. 
**
** Configure the cache_size limit for a cache.
*/
static void pcache1Cachesize(sqlite3_pcache *p, int nMax){
  PCache1 *pCache = (PCache1 *)p;
  if( pCache->bPurgeable ){
    PGroup *pGroup = pCache->pGroup;
    pcache1EnterMutex();
    pcache1.nMaxPage += (nMax - pCache->nMax);
    pcache1EnterMutex(pGroup);
    pGroup->nMaxPage += (nMax - pCache->nMax);
    pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
    pCache->nMax = nMax;
    pCache->n90pct = pCache->nMax*9/10;
    pcache1EnforceMaxPage();
    pcache1LeaveMutex();
    pcache1EnforceMaxPage(pGroup);
    pcache1LeaveMutex(pGroup);
  }
}

/*
** Implementation of the sqlite3_pcache.xPagecount method. 
*/
static int pcache1Pagecount(sqlite3_pcache *p){
  int n;
  PCache1 *pCache = (PCache1*)p;
  pcache1EnterMutex();
  n = ((PCache1 *)p)->nPage;
  pcache1LeaveMutex();
  pcache1EnterMutex(pCache->pGroup);
  n = pCache->nPage;
  pcache1LeaveMutex(pCache->pGroup);
  return n;
}

/*
** Implementation of the sqlite3_pcache.xFetch method. 
**
** Fetch a page by key value.

**      then attempt to recycle a page from the LRU list. If it is the right
**      size, return the recycled buffer. Otherwise, free the buffer and
**      proceed to step 5. 
**
**   5. Otherwise, allocate and return a new page buffer.
*/
static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){
  unsigned int nPinned;
  int nPinned;
  PCache1 *pCache = (PCache1 *)p;
  PGroup *pGroup;
  PgHdr1 *pPage = 0;

  assert( pCache->bPurgeable || createFlag!=1 );
  assert( pCache->bPurgeable || pCache->nMin==0 );
  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
  assert( pCache->nMin==0 || pCache->bPurgeable );
  pcache1EnterMutex();
  pcache1EnterMutex(pGroup = pCache->pGroup);
  if( createFlag==1 ) sqlite3BeginBenignMalloc();

  /* Search the hash table for an existing entry. */
  /* Step 1: Search the hash table for an existing entry. */
  if( pCache->nHash>0 ){
    unsigned int h = iKey % pCache->nHash;
    for(pPage=pCache->apHash[h]; pPage&&pPage->iKey!=iKey; pPage=pPage->pNext);
  }

  /* Step 2: Abort if no existing page is found and createFlag is 0 */
  if( pPage || createFlag==0 ){
    pcache1PinPage(pPage);
    goto fetch_out;
  }

  /* The pGroup local variable will normally be initialized by the
  ** pcache1EnterMutex() macro above.  But if SQLITE_MUTEX_OMIT is defined,
  ** then pcache1EnterMutex() is a no-op, so we have to initialize the
  ** local variable here.  Delaying the initialization of pGroup is an
  ** optimization:  The common case is to exit the module before reaching
  ** this point.
  */
#ifdef SQLITE_MUTEX_OMIT
  pGroup = pCache->pGroup;
#endif
  /* Step 3 of header comment. */


  /* Step 3: Abort if createFlag is 1 but the cache is nearly full */
  nPinned = pCache->nPage - pCache->nRecyclable;
  assert( nPinned>=0 );
  assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage );
  assert( pCache->n90pct == pCache->nMax*9/10 );
  if( createFlag==1 && (
        nPinned>=(pcache1.nMaxPage+pCache->nMin-pcache1.nMinPage)
     || nPinned>=(pCache->nMax * 9 / 10)
        nPinned>=pGroup->mxPinned
     || nPinned>=(int)pCache->n90pct
     || pcache1UnderMemoryPressure(pCache)
  )){
    goto fetch_out;
  }

  if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){
    goto fetch_out;
  }

  /* Step 4. Try to recycle a page buffer if appropriate. */
  if( pCache->bPurgeable && pcache1.pLruTail && (
  /* Step 4. Try to recycle a page. */
  if( pCache->bPurgeable && pGroup->pLruTail && (
         (pCache->nPage+1>=pCache->nMax)
      || pcache1.nCurrentPage>=pcache1.nMaxPage
      || pGroup->nCurrentPage>=pGroup->nMaxPage
      || pcache1UnderMemoryPressure(pCache)
  )){
    PCache1 *pOtherCache;
    pPage = pcache1.pLruTail;
    pPage = pGroup->pLruTail;
    pcache1RemoveFromHash(pPage);
    pcache1PinPage(pPage);
    if( pPage->pCache->szPage!=pCache->szPage ){
    if( (pOtherCache = pPage->pCache)->szPage!=pCache->szPage ){
      pcache1FreePage(pPage);
      pPage = 0;
    }else{
      pGroup->nCurrentPage -= 
      pcache1.nCurrentPage -= (pPage->pCache->bPurgeable - pCache->bPurgeable);
               (pOtherCache->bPurgeable - pCache->bPurgeable);
    }
  }

  /* Step 5. If a usable page buffer has still not been found, 
  ** attempt to allocate a new one. 
  */
  if( !pPage ){
    if( createFlag==1 ) sqlite3BeginBenignMalloc();
    pcache1LeaveMutex(pGroup);
    pPage = pcache1AllocPage(pCache);
    pcache1EnterMutex(pGroup);
    if( createFlag==1 ) sqlite3EndBenignMalloc();
  }

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
    pPage->pNext = pCache->apHash[h];
    pPage->pCache = pCache;
    pPage->pLruPrev = 0;
    pPage->pLruNext = 0;
    *(void **)(PGHDR1_TO_PAGE(pPage)) = 0;
    pCache->apHash[h] = pPage;
  }

fetch_out:
  if( pPage && iKey>pCache->iMaxKey ){
    pCache->iMaxKey = iKey;
  }
  if( createFlag==1 ) sqlite3EndBenignMalloc();
  pcache1LeaveMutex();
  pcache1LeaveMutex(pGroup);
  return (pPage ? PGHDR1_TO_PAGE(pPage) : 0);
}


/*
** Implementation of the sqlite3_pcache.xUnpin method.
**
** Mark a page as unpinned (eligible for asynchronous recycling).
*/
static void pcache1Unpin(sqlite3_pcache *p, void *pPg, int reuseUnlikely){
  PCache1 *pCache = (PCache1 *)p;
  PgHdr1 *pPage = PAGE_TO_PGHDR1(pCache, pPg);
  PGroup *pGroup = pCache->pGroup;
 
  assert( pPage->pCache==pCache );
  pcache1EnterMutex();
  pcache1EnterMutex(pGroup);

  /* It is an error to call this function if the page is already 
  ** part of the global LRU list.
  ** part of the PGroup LRU list.
  */
  assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
  assert( pcache1.pLruHead!=pPage && pcache1.pLruTail!=pPage );
  assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage );

  if( reuseUnlikely || pcache1.nCurrentPage>pcache1.nMaxPage ){
  if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
    pcache1RemoveFromHash(pPage);
    pcache1FreePage(pPage);
  }else{
    /* Add the page to the global LRU list. Normally, the page is added to
    /* Add the page to the PGroup LRU list. */
    ** the head of the list (last page to be recycled). However, if the 
    ** reuseUnlikely flag passed to this function is true, the page is added
    ** to the tail of the list (first page to be recycled).
    */
    if( pcache1.pLruHead ){
      pcache1.pLruHead->pLruPrev = pPage;
      pPage->pLruNext = pcache1.pLruHead;
      pcache1.pLruHead = pPage;
    if( pGroup->pLruHead ){
      pGroup->pLruHead->pLruPrev = pPage;
      pPage->pLruNext = pGroup->pLruHead;
      pGroup->pLruHead = pPage;
    }else{
      pcache1.pLruTail = pPage;
      pcache1.pLruHead = pPage;
      pGroup->pLruTail = pPage;
      pGroup->pLruHead = pPage;
    }
    pCache->nRecyclable++;
  }

  pcache1LeaveMutex();
  pcache1LeaveMutex(pCache->pGroup);
}

/*
** Implementation of the sqlite3_pcache.xRekey method. 
*/
static void pcache1Rekey(
  sqlite3_pcache *p,
  void *pPg,
  unsigned int iOld,
  unsigned int iNew
){
  PCache1 *pCache = (PCache1 *)p;
  PgHdr1 *pPage = PAGE_TO_PGHDR1(pCache, pPg);
  PgHdr1 **pp;
  unsigned int h; 
  assert( pPage->iKey==iOld );
  assert( pPage->pCache==pCache );

  pcache1EnterMutex();
  pcache1EnterMutex(pCache->pGroup);

  h = iOld%pCache->nHash;
  pp = &pCache->apHash[h];
  while( (*pp)!=pPage ){
    pp = &(*pp)->pNext;
  }
  *pp = pPage->pNext;

  h = iNew%pCache->nHash;
  pPage->iKey = iNew;
  pPage->pNext = pCache->apHash[h];
  pCache->apHash[h] = pPage;
  if( iNew>pCache->iMaxKey ){
    pCache->iMaxKey = iNew;
  }

  pcache1LeaveMutex();
  pcache1LeaveMutex(pCache->pGroup);
}

/*
** Implementation of the sqlite3_pcache.xTruncate method. 
**
** Discard all unpinned pages in the cache with a page number equal to
** or greater than parameter iLimit. Any pinned pages with a page number
** equal to or greater than iLimit are implicitly unpinned.
*/
static void pcache1Truncate(sqlite3_pcache *p, unsigned int iLimit){
  PCache1 *pCache = (PCache1 *)p;
  pcache1EnterMutex();
  pcache1EnterMutex(pCache->pGroup);
  if( iLimit<=pCache->iMaxKey ){
    pcache1TruncateUnsafe(pCache, iLimit);
    pCache->iMaxKey = iLimit-1;
  }
  pcache1LeaveMutex();
  pcache1LeaveMutex(pCache->pGroup);
}

/*
** Implementation of the sqlite3_pcache.xDestroy method. 
**
** Destroy a cache allocated using pcache1Create().
*/
static void pcache1Destroy(sqlite3_pcache *p){
  PCache1 *pCache = (PCache1 *)p;
  PGroup *pGroup = pCache->pGroup;
  assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) );
  pcache1EnterMutex();
  pcache1EnterMutex(pGroup);
  pcache1TruncateUnsafe(pCache, 0);
  pcache1.nMaxPage -= pCache->nMax;
  pcache1.nMinPage -= pCache->nMin;
  pcache1EnforceMaxPage();
  pcache1LeaveMutex();
  pGroup->nMaxPage -= pCache->nMax;
  pGroup->nMinPage -= pCache->nMin;
  pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
  pcache1EnforceMaxPage(pGroup);
  pcache1LeaveMutex(pGroup);
  sqlite3_free(pCache->apHash);
  sqlite3_free(pCache);
}

/*
** This function is called during initialization (sqlite3_initialize()) to
** install the default pluggable cache module, assuming the user has not

**
** nReq is the number of bytes of memory required. Once this much has
** been released, the function returns. The return value is the total number 
** of bytes of memory released.
*/
int sqlite3PcacheReleaseMemory(int nReq){
  int nFree = 0;
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( pcache1.pStart==0 ){
    PgHdr1 *p;
    pcache1EnterMutex();
    while( (nReq<0 || nFree<nReq) && ((p=pcache1.pLruTail)!=0) ){
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
      nFree += pcache1MemSize(PGHDR1_TO_PAGE(p));
      pcache1PinPage(p);
      pcache1RemoveFromHash(p);
      pcache1FreePage(p);
    }
    pcache1LeaveMutex();
    pcache1LeaveMutex(&pcache1.grp);
  }
  return nFree;
}
#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

#ifdef SQLITE_TEST
/*
** This function is used by test procedures to inspect the internal state
** of the global cache.
*/
void sqlite3PcacheStats(
  int *pnCurrent,      /* OUT: Total number of pages cached */
  int *pnMax,          /* OUT: Global maximum cache size */
  int *pnMin,          /* OUT: Sum of PCache1.nMin for purgeable caches */
  int *pnRecyclable    /* OUT: Total number of pages available for recycling */
){
  PgHdr1 *p;
  int nRecyclable = 0;
  for(p=pcache1.pLruHead; p; p=p->pLruNext){
  for(p=pcache1.grp.pLruHead; p; p=p->pLruNext){
    nRecyclable++;
  }
  *pnCurrent = pcache1.nCurrentPage;
  *pnMax = pcache1.nMaxPage;
  *pnMin = pcache1.nMinPage;
  *pnCurrent = pcache1.grp.nCurrentPage;
  *pnMax = pcache1.grp.nMaxPage;
  *pnMin = pcache1.grp.nMinPage;
  *pnRecyclable = nRecyclable;
}
#endif

#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare16(
  sqlite3 *db,              /* Database handle. */ 
  const void *zSql,         /* UTF-8 encoded SQL statement. */
  const void *zSql,         /* UTF-16 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  int saveSqlFlag,          /* True to save SQL text into the sqlite3_stmt */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const void **pzTail       /* OUT: End of parsed string */
){
  /* This function currently works by first transforming the UTF-16
  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The

** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step().  In the new version, the original SQL text is retained
** and the statement is automatically recompiled if an schema change
** occurs.
*/
int sqlite3_prepare16(
  sqlite3 *db,              /* Database handle. */ 
  const void *zSql,         /* UTF-8 encoded SQL statement. */
  const void *zSql,         /* UTF-16 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const void **pzTail       /* OUT: End of parsed string */
){
  int rc;
  rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
  return rc;
}
int sqlite3_prepare16_v2(
  sqlite3 *db,              /* Database handle. */ 
  const void *zSql,         /* UTF-8 encoded SQL statement. */
  const void *zSql,         /* UTF-16 encoded SQL statement. */
  int nBytes,               /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
  const void **pzTail       /* OUT: End of parsed string */
){
  int rc;
  rc = sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
  return rc;
}

#endif /* SQLITE_OMIT_UTF16 */

    if( !p->useMalloc ){
      p->tooBig = 1;
      N = p->nAlloc - p->nChar - 1;
      if( N<=0 ){
        return;
      }
    }else{
      char *zOld = (p->zText==p->zBase ? 0 : p->zText);
      i64 szNew = p->nChar;
      szNew += N + 1;
      if( szNew > p->mxAlloc ){
        sqlite3StrAccumReset(p);
        p->tooBig = 1;
        return;
      }else{
        p->nAlloc = (int)szNew;
      }
      if( p->useMalloc==1 ){
        zNew = sqlite3DbMallocRaw(p->db, p->nAlloc );
        zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
      }else{
        zNew = sqlite3_malloc(p->nAlloc);
        zNew = sqlite3_realloc(zOld, p->nAlloc);
      }
      if( zNew ){
        memcpy(zNew, p->zText, p->nChar);
        if( zOld==0 ) memcpy(zNew, p->zText, p->nChar);
        sqlite3StrAccumReset(p);
        p->zText = zNew;
      }else{
        p->mallocFailed = 1;
        sqlite3StrAccumReset(p);
        return;
      }
    }

}

/*
** sqlite3_snprintf() works like snprintf() except that it ignores the
** current locale settings.  This is important for SQLite because we
** are not able to use a "," as the decimal point in place of "." as
** specified by some locales.
**
** Oops:  The first two arguments of sqlite3_snprintf() are backwards
** from the snprintf() standard.  Unfortunately, it is too late to change
** this without breaking compatibility, so we just have to live with the
** mistake.
**
** sqlite3_vsnprintf() is the varargs version.
*/
char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
  StrAccum acc;
  if( n<=0 ) return zBuf;
  sqlite3StrAccumInit(&acc, zBuf, n, 0);
  acc.useMalloc = 0;
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  return sqlite3StrAccumFinish(&acc);
}
char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
  char *z;
  va_list ap;
  StrAccum acc;

  if( n<=0 ){
    return zBuf;
  }
  sqlite3StrAccumInit(&acc, zBuf, n, 0);
  acc.useMalloc = 0;
  va_start(ap,zFormat);
  sqlite3VXPrintf(&acc, 0, zFormat, ap);
  z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
  va_end(ap);
  z = sqlite3StrAccumFinish(&acc);
  return z;
}

/*
** This is the routine that actually formats the sqlite3_log() message.
** We house it in a separate routine from sqlite3_log() to avoid using
** stack space on small-stack systems when logging is disabled.

# include <sys/types.h>
#endif

#ifdef __OS2__
# include <unistd.h>
#endif

#ifdef HAVE_EDITLINE
# include <editline/editline.h>
#endif
#if defined(HAVE_READLINE) && HAVE_READLINE==1
# include <readline/readline.h>
# include <readline/history.h>
#else
#endif
#if !defined(HAVE_EDITLINE) && (!defined(HAVE_READLINE) || HAVE_READLINE!=1)
# define readline(p) local_getline(p,stdin)
# define add_history(X)
# define read_history(X)
# define write_history(X)
# define stifle_history(X)
#endif

  if( pArg && pArg->out ){
    
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MEMORY_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Memory Used:                         %d (max %d) bytes\n", iCur, iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Number of Allocations:               %d (max %d)\n", iCur, iHiwtr);
    fprintf(pArg->out, "Number of Outstanding Allocations:   %d (max %d)\n", iCur, iHiwtr);
/*
** Not currently used by the CLI.
**    iHiwtr = iCur = -1;
**    sqlite3_status(SQLITE_STATUS_PAGECACHE_USED, &iCur, &iHiwtr, bReset);
**    fprintf(pArg->out, "Number of Pcache Pages Used:         %d (max %d) pages\n", iCur, iHiwtr);
*/
    iHiwtr = iCur = -1;

#endif
  }

  if( pArg && pArg->out && db ){
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Lookaside Slots Used:                %d (max %d)\n", iCur, iHiwtr);
    sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_HIT, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Successful lookaside attempts:       %d\n", iHiwtr);
    sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Lookaside failures due to size:      %d\n", iHiwtr);
    sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Lookaside failures due to OOM:       %d\n", iHiwtr);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Pager Heap Usage:                    %d bytes\n", iCur); 
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
    fprintf(pArg->out, "Schema Heap Usage:                   %d bytes\n", iCur); 
    iHiwtr = iCur = -1;

  */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#endif

  /* Do an initial pass through the command-line argument to locate
  ** the name of the database file, the name of the initialization file,
  ** the size of the alternative malloc heap,
  ** and the first command to execute.
  */
  for(i=1; i<argc-1; i++){
    char *z;
    if( argv[i][0]!='-' ) break;
    z = argv[i];
    if( z[0]=='-' && z[1]=='-' ) z++;
    if( strcmp(argv[i],"-separator")==0 || strcmp(argv[i],"-nullvalue")==0 ){
      i++;
    }else if( strcmp(argv[i],"-init")==0 ){
      i++;
      zInitFile = argv[i];
    /* Need to check for batch mode here to so we can avoid printing
    ** informational messages (like from process_sqliterc) before 
    ** we do the actual processing of arguments later in a second pass.
    */
    }else if( strcmp(argv[i],"-batch")==0 ){
      stdin_is_interactive = 0;
    }else if( strcmp(argv[i],"-heap")==0 ){
      int j, c;
      const char *zSize;
      sqlite3_int64 szHeap;

      zSize = argv[++i];
      szHeap = atoi(zSize);
      for(j=0; (c = zSize[j])!=0; j++){
        if( c=='M' ){ szHeap *= 1000000; break; }
        if( c=='K' ){ szHeap *= 1000; break; }
        if( c=='G' ){ szHeap *= 1000000000; break; }
      }
      if( szHeap>0x7fff0000 ) szHeap = 0x7fff0000;
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
      sqlite3_config(SQLITE_CONFIG_HEAP, malloc((int)szHeap), (int)szHeap, 64);
#endif
    }
  }
  if( i<argc ){
#if defined(SQLITE_OS_OS2) && SQLITE_OS_OS2
    data.zDbFilename = (const char *)convertCpPathToUtf8( argv[i++] );
#else
    data.zDbFilename = argv[i++];

    }else if( strcmp(z,"-version")==0 ){
      printf("%s\n", sqlite3_libversion());
      return 0;
    }else if( strcmp(z,"-interactive")==0 ){
      stdin_is_interactive = 1;
    }else if( strcmp(z,"-batch")==0 ){
      stdin_is_interactive = 0;
    }else if( strcmp(z,"-heap")==0 ){
      i++;
    }else if( strcmp(z,"-help")==0 || strcmp(z, "--help")==0 ){
      usage(1);
    }else{
      fprintf(stderr,"%s: Error: unknown option: %s\n", Argv0, z);
      fprintf(stderr,"Use -help for a list of options.\n");
      return 1;
    }

      free(zHome);
    }else{
      rc = process_input(&data, stdin);
    }
  }
  set_table_name(&data, 0);
  if( data.db ){
    if( sqlite3_close(data.db)!=SQLITE_OK ){
    sqlite3_close(data.db);
      fprintf(stderr,"Error: cannot close database \"%s\"\n",
              sqlite3_errmsg(db));
      rc++;
    }
  }
  return rc;
}

#define SQLITE_BUSY         5   /* The database file is locked */
#define SQLITE_LOCKED       6   /* A table in the database is locked */
#define SQLITE_NOMEM        7   /* A malloc() failed */
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
#define SQLITE_FULL        13   /* Insertion failed because database is full */
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
#define SQLITE_EMPTY       16   /* Database is empty */
#define SQLITE_SCHEMA      17   /* The database schema changed */
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */

** write return values.  Potential uses for xFileControl() might be
** functions to enable blocking locks with timeouts, to change the
** locking strategy (for example to use dot-file locks), to inquire
** about the status of a lock, or to break stale locks.  The SQLite
** core reserves all opcodes less than 100 for its own use.
** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
** Applications that define a custom xFileControl method should use opcodes
** greater than 100 to avoid conflicts.
** greater than 100 to avoid conflicts.  VFS implementations should
** return [SQLITE_NOTFOUND] for file control opcodes that they do not
** recognize.
**
** The xSectorSize() method returns the sector size of the
** device that underlies the file.  The sector size is the
** minimum write that can be performed without disturbing
** other bytes in the file.  The xDeviceCharacteristics()
** method returns a bit vector describing behaviors of the
** underlying device:

** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
** extends and truncates the database file in chunks of a size specified
** by the user. The fourth argument to [sqlite3_file_control()] should 
** point to an integer (type int) containing the new chunk-size to use
** for the nominated database. Allocating database file space in large
** chunks (say 1MB at a time), may reduce file-system fragmentation and
** improve performance on some systems.
**
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
** to the [sqlite3_file] object associated with a particular database
** connection.  See the [sqlite3_file_control()] documentation for
** additional information.
**
** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
** SQLite and sent to all VFSes in place of a call to the xSync method
** when the database connection has [PRAGMA synchronous] set to OFF.)^
** Some specialized VFSes need this signal in order to operate correctly
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
** VFSes do not need this signal and should silently ignore this opcode.
** Applications should not call [sqlite3_file_control()] with this
** opcode as doing so may disrupt the operation of the specilized VFSes
** that do require it.  
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4
#define SQLITE_FCNTL_SIZE_HINT        5
#define SQLITE_FCNTL_CHUNK_SIZE       6
#define SQLITE_FCNTL_FILE_POINTER     7
#define SQLITE_FCNTL_SYNC_OMITTED     8


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks

** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
** results into memory obtained from [sqlite3_malloc()].
** The strings returned by these two routines should be
** released by [sqlite3_free()].  ^Both routines return a
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
** memory to hold the resulting string.
**
** ^(In sqlite3_snprintf() routine is similar to "snprintf()" from
** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
** the standard C library.  The result is written into the
** buffer supplied as the second parameter whose size is given by
** the first parameter. Note that the order of the
** first two parameters is reversed from snprintf().)^  This is an
** historical accident that cannot be fixed without breaking
** backwards compatibility.  ^(Note also that sqlite3_snprintf()
** returns a pointer to its buffer instead of the number of
** characters actually written into the buffer.)^  We admit that
** the number of characters written would be a more useful return
** value but we cannot change the implementation of sqlite3_snprintf()
** now without breaking compatibility.
**
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
** guarantees that the buffer is always zero-terminated.  ^The first
** parameter "n" is the total size of the buffer, including space for
** the zero terminator.  So the longest string that can be completely
** written will be n-1 characters.
**
** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
**
** These routines all implement some additional formatting
** options that are useful for constructing SQL statements.
** All of the usual printf() formatting options apply.  In addition, there
** is are "%q", "%Q", and "%z" options.
**
** ^(The %q option works like %s in that it substitutes a null-terminated

** ^(The "%z" formatting option works like "%s" but with the
** addition that after the string has been read and copied into
** the result, [sqlite3_free()] is called on the input string.)^
*/
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);
char *sqlite3_vsnprintf(int,char*,const char*, va_list);

/*
** CAPI3REF: Memory Allocation Subsystem
**
** The SQLite core uses these three routines for all of its own
** internal memory allocation needs. "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The

**
** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
** <dd>The database is opened for reading and writing if possible, or reading
** only if the file is write protected by the operating system.  In either
** case the database must already exist, otherwise an error is returned.</dd>)^
**
** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
** <dd>The database is opened for reading and writing, and is creates it if
** <dd>The database is opened for reading and writing, and is created if
** it does not already exist. This is the behavior that is always used for
** sqlite3_open() and sqlite3_open16().</dd>)^
** </dl>
**
** If the 3rd parameter to sqlite3_open_v2() is not one of the
** combinations shown above or one of the combinations shown above combined
** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX],

** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Determine If An SQL Statement Writes The Database
**
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
** the [prepared statement] X is [SELECT] statement and false (zero) if
** X is an [INSERT], [UPDATE], [DELETE], CREATE, DROP, [ANALYZE],
** [ALTER], or [REINDEX] statement.
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 
** and only if the [prepared statement] X makes no direct changes to
** the content of the database file.
**
** Note that [application-defined SQL functions] or
** [virtual tables] might change the database indirectly as a side effect.  
** ^(For example, if an application defines a function "eval()" that 
** calls [sqlite3_exec()], then the following SQL statement would
** change the database file through side-effects:
**
** <blockquote><pre>
**    SELECT eval('DELETE FROM t1') FROM t2;
** </pre></blockquote>
**
** But because the [SELECT] statement does not change the database file
** If X is a NULL pointer or any other kind of statement, including but
** not limited to [ATTACH], [DETACH], [COMMIT], [ROLLBACK], [RELEASE],
** [SAVEPOINT], [PRAGMA], or [VACUUM] the result of sqlite3_stmt_readonly(X) is
** directly, sqlite3_stmt_readonly() would still return true.)^
**
** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
** since the statements themselves do not actually modify the database but
** rather they control the timing of when other statements modify the 
** database.  ^The [ATTACH] and [DETACH] statements also cause
** sqlite3_stmt_readonly() to return true since, while those statements
** undefined.
** change the configuration of a database connection, they do not make 
** changes to the content of the database files on disk.
*/
int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Dynamically Typed Value Object
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**

** [SQLITE_MISUSE] means that the this routine was called inappropriately.
** Perhaps it was called on a [prepared statement] that has
** already been [sqlite3_finalize | finalized] or on one that had
** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
** be the case that the same database connection is being used by two or
** more threads at the same moment in time.
**
** For all versions of SQLite up to and including 3.6.23.1, it was required
** after sqlite3_step() returned anything other than [SQLITE_ROW] that
** [sqlite3_reset()] be called before any subsequent invocation of
** sqlite3_step().  Failure to invoke [sqlite3_reset()] in this way would
** result in an [SQLITE_MISUSE] return from sqlite3_step().  But after
** version 3.6.23.1, sqlite3_step() began calling [sqlite3_reset()] 
** automatically in this circumstance rather than returning [SQLITE_MISUSE].  
** For all versions of SQLite up to and including 3.6.23.1, a call to
** [sqlite3_reset()] was required after sqlite3_step() returned anything
** other than [SQLITE_ROW] before any subsequent invocation of
** sqlite3_step().  Failure to reset the prepared statement using 
** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
** calling [sqlite3_reset()] automatically in this circumstance rather
** than returning [SQLITE_MISUSE].  This is not considered a compatibility
** break because any application that ever receives an SQLITE_MISUSE error
** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
** can be used to restore the legacy behavior.
**
** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
** API always returns a generic error code, [SQLITE_ERROR], following any
** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
** specific [error codes] that better describes the error.
** We admit that this is a goofy design.  The problem has been fixed

** will pick the one that involves the least amount of data conversion.
** If there is only a single implementation which does not care what text
** encoding is used, then the fourth argument should be [SQLITE_ANY].
**
** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
** function can gain access to this pointer using [sqlite3_user_data()].)^
**
** ^The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL function or
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
** callback only; NULL pointers must be passed as the xStep and xFinal
** parameters. ^An aggregate SQL function requires an implementation of xStep
** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
** SQL function or aggregate, pass NULL poiners for all three function
** callbacks.
**
** ^(If the tenth parameter to sqlite3_create_function_v2() is not NULL,
** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
** then it is destructor for the application data pointer. 
** The destructor is invoked when the function is deleted, either by being
** overloaded or when the database connection closes.)^
** ^The destructor is also invoked if the call to
** sqlite3_create_function_v2() fails.
** ^When the destructor callback of the tenth parameter is invoked, it
** is passed a single argument which is a copy of the application data 

** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
** define callbacks that implement the SQL functions and aggregates.
** The 4th parameter to these callbacks is an array of pointers to
** The 3rd parameter to these callbacks is an array of pointers to
** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
** each parameter to the SQL function.  These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.

#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MASTER    2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */

/*
** CAPI3REF: Retrieve the mutex for a database connection
**
** ^This interface returns a pointer the [sqlite3_mutex] object that 
** serializes access to the [database connection] given in the argument
** when the [threading mode] is Serialized.

** <dd>This parameter records the largest memory allocation request
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
** internal equivalents).  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>)^
**
** ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
** <dd>This parameter records the number of separate memory allocations.</dd>)^
** <dd>This parameter records the number of separate memory allocations
** currently checked out.</dd>)^
**
** ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
** <dd>This parameter returns the number of pages used out of the
** [pagecache memory allocator] that was configured using 
** [SQLITE_CONFIG_PAGECACHE].  The
** value returned is in pages, not in bytes.</dd>)^
**

** The [sqlite3_db_status()] interface will return a non-zero error code
** if a discontinued or unsupported verb is invoked.
**
** <dl>
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
** <dd>This parameter returns the number of lookaside memory slots currently
** checked out.</dd>)^
**
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
** <dd>This parameter returns the number malloc attempts that were 
** satisfied using lookaside memory. Only the high-water value is meaningful;
** the current value is always zero.
** checked out.</dd>)^
**
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
** <dd>This parameter returns the number malloc attempts that might have
** been satisfied using lookaside memory but failed due to the amount of
** memory requested being larger than the lookaside slot size.
** Only the high-water value is meaningful;
** the current value is always zero.
** checked out.</dd>)^
**
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
** <dd>This parameter returns the number malloc attempts that might have
** been satisfied using lookaside memory but failed due to all lookaside
** memory already being in use.
** Only the high-water value is meaningful;
** the current value is always zero.
** checked out.</dd>)^
**
** ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
** <dd>This parameter returns the approximate number of of bytes of heap
** memory used by all pager caches associated with the database connection.)^
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
**
** ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>

** <dd>This parameter returns the approximate number of of bytes of heap
** and lookaside memory used by all prepared statements associated with
** the database connection.)^
** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
** </dd>
** </dl>
*/
#define SQLITE_DBSTATUS_LOOKASIDE_USED     0
#define SQLITE_DBSTATUS_CACHE_USED         1
#define SQLITE_DBSTATUS_SCHEMA_USED        2
#define SQLITE_DBSTATUS_STMT_USED          3
#define SQLITE_DBSTATUS_MAX                3   /* Largest defined DBSTATUS */
#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
#define SQLITE_DBSTATUS_CACHE_USED           1
#define SQLITE_DBSTATUS_SCHEMA_USED          2
#define SQLITE_DBSTATUS_STMT_USED            3
#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
#define SQLITE_DBSTATUS_MAX                  6   /* Largest defined DBSTATUS */


/*
** CAPI3REF: Prepared Statement Status
**
** ^(Each prepared statement maintains various
** [SQLITE_STMTSTATUS_SORT | counters] that measure the number

**
** ^SQLite invokes the xCreate() method to construct a new cache instance.
** SQLite will typically create one cache instance for each open database file,
** though this is not guaranteed. ^The
** first parameter, szPage, is the size in bytes of the pages that must
** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
** will the page size of the database file that is to be cached plus an
** increment (here called "R") of about 100 or 200.  SQLite will use the
** increment (here called "R") of less than 250.  SQLite will use the
** extra R bytes on each page to store metadata about the underlying
** database page on disk.  The value of R depends
** on the SQLite version, the target platform, and how SQLite was compiled.
** ^R is constant for a particular build of SQLite.  ^The second argument to
** ^(R is constant for a particular build of SQLite. Except, there are two
** distinct values of R when SQLite is compiled with the proprietary
** ZIPVFS extension.)^  ^The second argument to
** xCreate(), bPurgeable, is true if the cache being created will
** be used to cache database pages of a file stored on disk, or
** false if it is used for an in-memory database. The cache implementation
** does not have to do anything special based with the value of bPurgeable;
** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
** never invoke xUnpin() except to deliberately delete a page.
** ^In other words, calls to xUnpin() on a cache with bPurgeable set to

** 8-byte boundary. The page to be fetched is determined by the key. ^The
** mimimum key value is 1.  After it has been retrieved using xFetch, the page 
** is considered to be "pinned".
**
** If the requested page is already in the page cache, then the page cache
** implementation must return a pointer to the page buffer with its content
** intact.  If the requested page is not already in the cache, then the
** behavior of the cache implementation should use the value of the createFlag
** cache implementation should use the value of the createFlag
** parameter to help it determined what action to take:
**
** <table border=1 width=85% align=center>
** <tr><th> createFlag <th> Behaviour when page is not already in cache
** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
**                 Otherwise return NULL.

**
** The backup API copies the content of one database into another.
** It is useful either for creating backups of databases or
** for copying in-memory databases to or from persistent files. 
**
** See Also: [Using the SQLite Online Backup API]
**
** ^Exclusive access is required to the destination database for the 
** duration of the operation. ^However the source database is only
** read-locked while it is actually being read; it is not locked
** continuously for the entire backup operation. ^Thus, the backup may be
** performed on a live source database without preventing other users from
** ^SQLite holds a write transaction open on the destination database file
** for the duration of the backup operation.
** ^The source database is read-locked only while it is being read;
** it is not locked continuously for the entire backup operation.
** ^Thus, the backup may be performed on a live source database without
** preventing other database connections from
** reading or writing to the source database while the backup is underway.
** 
** ^(To perform a backup operation: 
**   <ol>
**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
**         backup, 
**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 

** ^The database name is "main" for the main database, "temp" for the
** temporary database, or the name specified after the AS keyword in
** an [ATTACH] statement for an attached database.
** ^The S and M arguments passed to 
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
** and database name of the source database, respectively.
** ^The source and destination [database connections] (parameters S and D)
** must be different or else sqlite3_backup_init(D,N,S,M) will file with
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
** an error.
**
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
** returned and an error code and error message are store3d in the
** returned and an error code and error message are stored in the
** destination [database connection] D.
** ^The error code and message for the failed call to sqlite3_backup_init()
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
** [sqlite3_errmsg16()] functions.
** ^A successful call to sqlite3_backup_init() returns a pointer to an
** [sqlite3_backup] object.
** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
** sqlite3_backup_finish() functions to perform the specified backup 
** operation.
**
** <b>sqlite3_backup_step()</b>
**
** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 
** the source and destination databases specified by [sqlite3_backup] object B.
** ^If N is negative, all remaining source pages are copied. 
** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
** are still more pages to be copied, then the function resturns [SQLITE_OK].
** are still more pages to be copied, then the function returns [SQLITE_OK].
** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
** from source to destination, then it returns [SQLITE_DONE].
** ^If an error occurs while running sqlite3_backup_step(B,N),
** then an [error code] is returned. ^As well as [SQLITE_OK] and
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
**
** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
** <ol>
** <li> the destination database was opened read-only, or
** <li> the destination database is using write-ahead-log journaling
** and the destination and source page sizes differ, or
** <li> The destination database is an in-memory database and the
** <li> the destination database is an in-memory database and the
** destination and source page sizes differ.
** </ol>)^
**
** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
** the [sqlite3_busy_handler | busy-handler function]
** is invoked (if one is specified). ^If the 
** busy-handler returns non-zero before the lock is available, then 

** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
** configured by this function.
**
** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
** from SQL.
**
** ^Every new [database connection] defaults to having the auto-checkpoint
** enabled with a threshold of 1000 pages.  The use of this interface
** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
** pages.  The use of this interface
** is only necessary if the default setting is found to be suboptimal
** for a particular application.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);

/*
** CAPI3REF: Checkpoint a database

*/
struct Lookaside {
  u16 sz;                 /* Size of each buffer in bytes */
  u8 bEnabled;            /* False to disable new lookaside allocations */
  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
  int nOut;               /* Number of buffers currently checked out */
  int mxOut;              /* Highwater mark for nOut */
  int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
  LookasideSlot *pFree;   /* List of available buffers */
  void *pStart;           /* First byte of available memory space */
  void *pEnd;             /* First byte past end of available space */
};
struct LookasideSlot {
  LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
};

    u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
  } init;
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared library handles */
  struct Vdbe *pVdbe;           /* List of active virtual machines */
  int activeVdbeCnt;            /* Number of VDBEs currently executing */
  int writeVdbeCnt;             /* Number of active VDBEs that are writing */
  int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
  void (*xTrace)(void*,const char*);        /* Trace function */
  void *pTraceArg;                          /* Argument to the trace function */
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   

      *pCurrent = db->lookaside.nOut;
      *pHighwater = db->lookaside.mxOut;
      if( resetFlag ){
        db->lookaside.mxOut = db->lookaside.nOut;
      }
      break;
    }

    case SQLITE_DBSTATUS_LOOKASIDE_HIT:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
      testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
      testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
      testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
      assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
      assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
      *pCurrent = 0;
      *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
      if( resetFlag ){
        db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
      }
      break;
    }

    /* 
    ** Return an approximation for the amount of memory currently used
    ** by all pagers associated with the given database connection.  The
    ** highwater mark is meaningless and is returned as zero.
    */
    case SQLITE_DBSTATUS_CACHE_USED: {

    extern int Sqlitetestintarray_Init(Tcl_Interp*);
    extern int Sqlitetestvfs_Init(Tcl_Interp *);
    extern int SqlitetestStat_Init(Tcl_Interp*);
    extern int Sqlitetestrtree_Init(Tcl_Interp*);
    extern int Sqlitequota_Init(Tcl_Interp*);
    extern int Sqlitemultiplex_Init(Tcl_Interp*);
    extern int SqliteSuperlock_Init(Tcl_Interp*);

#ifdef SQLITE_ENABLE_ZIPVFS
    extern int Zipvfs_Init(Tcl_Interp*);
    Zipvfs_Init(interp);
#endif

    Sqliteconfig_Init(interp);
    Sqlitetest1_Init(interp);
    Sqlitetest2_Init(interp);
    Sqlitetest3_Init(interp);
    Sqlitetest4_Init(interp);
    Sqlitetest5_Init(interp);

  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " DB", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  rc = sqlite3_file_control(db, 0, 0, &iArg);
  assert( rc==SQLITE_ERROR );
  assert( rc==SQLITE_NOTFOUND );
  rc = sqlite3_file_control(db, "notadatabase", SQLITE_FCNTL_LOCKSTATE, &iArg);
  assert( rc==SQLITE_ERROR );
  rc = sqlite3_file_control(db, "main", -1, &iArg);
  assert( rc==SQLITE_ERROR );
  assert( rc==SQLITE_NOTFOUND );
  rc = sqlite3_file_control(db, "temp", -1, &iArg);
  assert( rc==SQLITE_ERROR );
  assert( rc==SQLITE_NOTFOUND || rc==SQLITE_ERROR );

  return TCL_OK;
}


/*
** tclcmd:   file_control_lasterrno_test DB

#endif

#ifdef SQLITE_OMIT_AUTOMATIC_INDEX
  Tcl_SetVar2(interp, "sqlite_options", "autoindex", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "autoindex", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_AUTORESET
  Tcl_SetVar2(interp, "sqlite_options", "autoreset", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "autoreset", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_AUTOVACUUM
  Tcl_SetVar2(interp, "sqlite_options", "autovacuum", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "autovacuum", "1", TCL_GLOBAL_ONLY);
#endif /* SQLITE_OMIT_AUTOVACUUM */
#if !defined(SQLITE_DEFAULT_AUTOVACUUM)

  const char *zOpName;
  sqlite3 *db;
  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
  static const struct {
    const char *zName;
    int op;
  } aOp[] = {
    { "SQLITE_DBSTATUS_LOOKASIDE_USED",    SQLITE_DBSTATUS_LOOKASIDE_USED   },
    { "SQLITE_DBSTATUS_CACHE_USED",        SQLITE_DBSTATUS_CACHE_USED       },
    { "SQLITE_DBSTATUS_SCHEMA_USED",       SQLITE_DBSTATUS_SCHEMA_USED      },
    { "SQLITE_DBSTATUS_STMT_USED",         SQLITE_DBSTATUS_STMT_USED        }
    { "LOOKASIDE_USED",      SQLITE_DBSTATUS_LOOKASIDE_USED      },
    { "CACHE_USED",          SQLITE_DBSTATUS_CACHE_USED          },
    { "SCHEMA_USED",         SQLITE_DBSTATUS_SCHEMA_USED         },
    { "STMT_USED",           SQLITE_DBSTATUS_STMT_USED           },
    { "LOOKASIDE_HIT",       SQLITE_DBSTATUS_LOOKASIDE_HIT       },
    { "LOOKASIDE_MISS_SIZE", SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE },
    { "LOOKASIDE_MISS_FULL", SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL }
  };
  Tcl_Obj *pResult;
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "PARAMETER RESETFLAG");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zOpName = Tcl_GetString(objv[2]);
  if( memcmp(zOpName, "SQLITE_", 7)==0 ) zOpName += 7;
  if( memcmp(zOpName, "DBSTATUS_", 9)==0 ) zOpName += 9;
  for(i=0; i<ArraySize(aOp); i++){
    if( strcmp(aOp[i].zName, zOpName)==0 ){
      op = aOp[i].op;
      break;
    }
  }
  if( i>=ArraySize(aOp) ){

  int objc,
  Tcl_Obj *CONST objv[]
){
  Tcl_Obj *pRet;
  int ii;
  char *aName[8] = {
    "fast",        "recursive",   "static_master", "static_mem", 
    "static_open", "static_prng", "static_lru",    "static_lru2"
    "static_open", "static_prng", "static_lru",    "static_pmem"
  };

  if( objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "");
    return TCL_ERROR;
  }

** callback does enlarge the quota such that the total size of all
** files within the group is less than the new quota, then the write
** continues as if nothing had happened.
*/
#include "sqlite3.h"
#include <string.h>
#include <assert.h>

/*
** For an build without mutexes, no-op the mutex calls.
*/
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE==0
#define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
#define sqlite3_mutex_free(X)
#define sqlite3_mutex_enter(X)
#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)
#define sqlite3_mutex_held(X)     ((void)(X),1)
#define sqlite3_mutex_notheld(X)  ((void)(X),1)
#endif /* SQLITE_THREADSAFE==0 */


/************************ Object Definitions ******************************/

/* Forward declaration of all object types */
typedef struct quotaGroup quotaGroup;
typedef struct quotaConn quotaConn;
typedef struct quotaFile quotaFile;

struct SuperlockBusy {
  int (*xBusy)(void*,int);        /* Pointer to busy-handler function */
  void *pBusyArg;                 /* First arg to pass to xBusy */
  int nBusy;                      /* Number of times xBusy has been invoked */
};
typedef struct SuperlockBusy SuperlockBusy;

/*
** An instance of the following structure is allocated for each active
** superlock. The opaque handle returned by sqlite3demo_superlock() is
** actually a pointer to an instance of this structure.
*/
struct Superlock {
  sqlite3 *db;                    /* Database handle used to lock db */
  int bWal;                       /* True if db is a WAL database */
};
typedef struct Superlock Superlock;

/*
** The pCtx pointer passed to this function is actually a pointer to a
** SuperlockBusy structure. Invoke the busy-handler function encapsulated
** by the structure and return the result.
*/
static int superlockBusyHandler(void *pCtx, int UNUSED){
  SuperlockBusy *pBusy = (SuperlockBusy *)pCtx;
  if( pBusy->xBusy==0 ) return 0;
  return pBusy->xBusy(pBusy->pBusyArg, pBusy->nBusy++);
}

/*
** This function is used to determine if the main database file for 
** connection db is open in WAL mode or not. If no error occurs and the
** database file is in WAL mode, set *pbWal to true and return SQLITE_OK.
** If it is not in WAL mode, set *pbWal to false.
**
** If an error occurs, return an SQLite error code. The value of *pbWal
** is undefined in this case.
*/
static int superlockIsWal(sqlite3 *db, int *pbWal){
static int superlockIsWal(Superlock *pLock){
  int rc;                         /* Return Code */
  sqlite3_stmt *pStmt;            /* Compiled PRAGMA journal_mode statement */

  rc = sqlite3_prepare(db, "PRAGMA main.journal_mode", -1, &pStmt, 0);
  rc = sqlite3_prepare(pLock->db, "PRAGMA main.journal_mode", -1, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;

  *pbWal = 0;
  pLock->bWal = 0;
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    const char *zMode = (const char *)sqlite3_column_text(pStmt, 0);
    if( zMode && strlen(zMode)==3 && sqlite3_strnicmp("wal", zMode, 3)==0 ){
      *pbWal = 1;
      pLock->bWal = 1;
    }
  }

  return sqlite3_finalize(pStmt);
}

/*

  /* Obtain exclusive locks on all the "read-lock" slots. Once these locks
  ** are held, it is guaranteed that there are no active reader, writer or 
  ** checkpointer clients.
  */
  rc = superlockShmLock(fd, 3, SQLITE_SHM_NLOCK-3, pBusy);
  return rc;
}

/*
** Release a superlock held on a database file. The argument passed to 
** this function must have been obtained from a successful call to
** sqlite3demo_superlock().
*/
void sqlite3demo_superunlock(void *pLock){
  Superlock *p = (Superlock *)pLock;
  if( p->bWal ){
    int rc;                         /* Return code */
    int flags = SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE;
    sqlite3_file *fd = 0;
    rc = sqlite3_file_control(p->db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
    if( rc==SQLITE_OK ){
      fd->pMethods->xShmLock(fd, 2, 1, flags);
      fd->pMethods->xShmLock(fd, 3, SQLITE_SHM_NLOCK-3, flags);
    }
  }
  sqlite3_close(p->db);
  sqlite3_free(p);
}

/*
** Obtain a superlock on the database file identified by zPath, using the
** locking primitives provided by VFS zVfs. If successful, SQLITE_OK is
** returned and output variable *ppLock is populated with an opaque handle
** that may be used with sqlite3demo_superunlock() to release the lock.
**

int sqlite3demo_superlock(
  const char *zPath,              /* Path to database file to lock */
  const char *zVfs,               /* VFS to use to access database file */
  int (*xBusy)(void*,int),        /* Busy handler callback */
  void *pBusyArg,                 /* Context arg for busy handler */
  void **ppLock                   /* OUT: Context to pass to superunlock() */
){
  sqlite3 *db = 0;                /* Database handle open on zPath */
  SuperlockBusy busy = {0, 0, 0}; /* Busy handler wrapper object */
  int rc;                         /* Return code */
  Superlock *pLock;

  pLock = sqlite3_malloc(sizeof(Superlock));
  if( !pLock ) return SQLITE_NOMEM;
  memset(pLock, 0, sizeof(Superlock));

  /* Open a database handle on the file to superlock. */
  rc = sqlite3_open_v2(
      zPath, &db, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs
      zPath, &pLock->db, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs
  );

  /* Install a busy-handler and execute a BEGIN EXCLUSIVE. If this is not
  ** a WAL database, this is all we need to do.  
  **
  ** A wrapper function is used to invoke the busy-handler instead of
  ** registering the busy-handler function supplied by the user directly
  ** with SQLite. This is because the same busy-handler function may be
  ** invoked directly later on when attempting to obtain the extra locks
  ** required in WAL mode. By using the wrapper, we are able to guarantee
  ** that the "nBusy" integer parameter passed to the users busy-handler
  ** represents the total number of busy-handler invocations made within
  ** this call to sqlite3demo_superlock(), including any made during the
  ** "BEGIN EXCLUSIVE".
  */
  if( rc==SQLITE_OK ){
    busy.xBusy = xBusy;
    busy.pBusyArg = pBusyArg;
    sqlite3_busy_handler(db, superlockBusyHandler, (void *)&busy);
    rc = sqlite3_exec(db, "BEGIN EXCLUSIVE", 0, 0, 0);
    sqlite3_busy_handler(pLock->db, superlockBusyHandler, (void *)&busy);
    rc = sqlite3_exec(pLock->db, "BEGIN EXCLUSIVE", 0, 0, 0);
  }

  /* If the BEGIN EXCLUSIVE was executed successfully and this is a WAL
  ** database, call superlockWalLock() to obtain the extra locks required
  ** to prevent readers, writers and/or checkpointers from accessing the
  ** db while this process is holding the superlock.
  **
  ** Before attempting any WAL locks, commit the transaction started above
  ** to drop the WAL read and write locks currently held. Otherwise, the
  ** new WAL locks may conflict with the old.
  */
  if( rc==SQLITE_OK ){
    int bWal;                     /* True for a WAL database, false otherwise */
    if( SQLITE_OK==(rc = superlockIsWal(db, &bWal)) && bWal ){
      rc = sqlite3_exec(db, "COMMIT", 0, 0, 0);
    if( SQLITE_OK==(rc = superlockIsWal(pLock)) && pLock->bWal ){
      rc = sqlite3_exec(pLock->db, "COMMIT", 0, 0, 0);
      if( rc==SQLITE_OK ){
        rc = superlockWalLock(db, &busy);
        rc = superlockWalLock(pLock->db, &busy);
      }
    }
  }

  if( rc!=SQLITE_OK ){
    sqlite3_close(db);
    sqlite3demo_superunlock(pLock);
    *ppLock = 0;
  }else{
    *ppLock = (void *)db;
    *ppLock = pLock;
  }

  return rc;
}

/*
** Release a superlock held on a database file. The argument passed to 
** this function must have been obtained from a successful call to
** sqlite3demo_superlock().
*/
void sqlite3demo_superunlock(void *pLock){
  sqlite3_close((sqlite3 *)pLock);
}

/*
** End of example code. Everything below here is the test harness.
**************************************************************************
**************************************************************************
*************************************************************************/

  pFd = (TestvfsFd *)ckalloc(sizeof(TestvfsFd) + PARENTVFS(pVfs)->szOsFile);
  memset(pFd, 0, sizeof(TestvfsFd) + PARENTVFS(pVfs)->szOsFile);
  pFd->pShm = 0;
  pFd->pShmId = 0;
  pFd->zFilename = zName;
  pFd->pVfs = pVfs;
  pFd->pReal = (sqlite3_file *)&pFd[1];
  memset(pTestfile, 0, sizeof(TestvfsFile));
  pTestfile->pFd = pFd;

  /* Evaluate the Tcl script: 
  **
  **   SCRIPT xOpen FILENAME
  **
  ** If the script returns an SQLite error code other than SQLITE_OK, an

** The cursor can seek to a BTree entry with a particular key, or
** loop over all entries of the Btree.  You can also insert new BTree
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
** 
** Every cursor that the virtual machine has open is represented by an
** instance of the following structure.
**
** If the VdbeCursor.isTriggerRow flag is set it means that this cursor is
** really a single row that represents the NEW or OLD pseudo-table of
** a row trigger.  The data for the row is stored in VdbeCursor.pData and
** the rowid is in VdbeCursor.iKey.
*/
struct VdbeCursor {
  BtCursor *pCursor;    /* The cursor structure of the backend */
  Btree *pBt;           /* Separate file holding temporary table */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
  int pseudoTableReg;   /* Register holding pseudotable content. */
  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
  int nField;           /* Number of fields in the header */
  Bool zeroed;          /* True if zeroed out and ready for reuse */
  Bool rowidIsValid;    /* True if lastRowid is valid */
  Bool atFirst;         /* True if pointing to first entry */
  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
  Bool nullRow;         /* True if pointing to a row with no data */
  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
  Bool isTable;         /* True if a table requiring integer keys */
  Bool isIndex;         /* True if an index containing keys only - no data */
  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
  Btree *pBt;           /* Separate file holding temporary table */
  int pseudoTableReg;   /* Register holding pseudotable content. */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
  int nField;           /* Number of fields in the header */
  i64 seqCount;         /* Sequence counter */
  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */

  /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or 
  ** OP_IsUnique opcode on this cursor. */
  int seekResult;

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches

** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
#define CACHE_STALE 0

/*
** Internally, the vdbe manipulates nearly all SQL values as Mem
** structures. Each Mem struct may cache multiple representations (string,
** integer etc.) of the same value.  A value (and therefore Mem structure)
** integer etc.) of the same value.
** has the following properties:
**
** Each value has a manifest type. The manifest type of the value stored
** in a Mem struct is returned by the MemType(Mem*) macro. The type is
** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or
** SQLITE_BLOB.
*/
struct Mem {
  sqlite3 *db;        /* The associated database connection */
  char *z;            /* String or BLOB value */
  double r;           /* Real value */
  union {
    i64 i;              /* Integer value. */
    i64 i;              /* Integer value used when MEM_Int is set in flags */
    int nZero;          /* Used when bit MEM_Zero is set in flags */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
    RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
    VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
  } 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, excluding '\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 */
#ifdef SQLITE_DEBUG
  Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
  void *pFiller;      /* So that sizeof(Mem) is a multiple of 8 */

** No other flags may be set in this case.
**
** If the MEM_Str flag is set then Mem.z points at a string representation.
** Usually this is encoded in the same unicode encoding as the main
** database (see below for exceptions). If the MEM_Term flag is also
** set, then the string is nul terminated. The MEM_Int and MEM_Real 
** flags may coexist with the MEM_Str flag.
**
** Multiple of these values can appear in Mem.flags.  But only one
** at a time can appear in Mem.type.
*/
#define MEM_Null      0x0001   /* Value is NULL */
#define MEM_Str       0x0002   /* Value is a string */
#define MEM_Int       0x0004   /* Value is an integer */
#define MEM_Real      0x0008   /* Value is a real number */
#define MEM_Blob      0x0010   /* Value is a BLOB */
#define MEM_RowSet    0x0020   /* Value is a RowSet object */

  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
  Mem s;                /* The return value is stored here */
  Mem *pMem;            /* Memory cell used to store aggregate context */
  int isError;          /* Error code returned by the function. */
  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')
*/
typedef struct Set Set;
struct Set {
  Hash hash;             /* A set is just a hash table */
  HashElem *prev;        /* Previously accessed hash elemen */
};

/*
** An instance of the virtual machine.  This structure contains the complete
** state of the virtual machine.
**
** The "sqlite3_stmt" structure pointer that is returned by sqlite3_compile()
** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
** is really a pointer to an instance of this structure.
**
** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
** any virtual table method invocations made by the vdbe program. It is
** set to 2 for xDestroy method calls and 1 for all other methods. This
** variable is used for two purposes: to allow xDestroy methods to execute
** "DROP TABLE" statements and to prevent some nasty side effects of
** malloc failure when SQLite is invoked recursively by a virtual table 
** method function.
*/
struct Vdbe {
  sqlite3 *db;            /* The database connection that owns this statement */
  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
  int nOp;                /* Number of instructions in the program */
  int nOpAlloc;           /* Number of slots allocated for aOp[] */
  Op *aOp;                /* Space to hold the virtual machine's program */
  int nLabel;             /* Number of labels used */
  Mem *aMem;              /* The memory locations */
  int nLabelAlloc;        /* Number of slots allocated in aLabel[] */
  int *aLabel;            /* Space to hold the labels */
  Mem **apArg;            /* Arguments to currently executing user function */
  Mem *aColName;          /* Column names to return */
  Mem *pResultSet;        /* Pointer to an array of results */
  int nMem;               /* Number of memory locations currently allocated */
  int nOp;                /* Number of instructions in the program */
  int nOpAlloc;           /* Number of slots allocated for aOp[] */
  int nLabel;             /* Number of labels used */
  int nLabelAlloc;        /* Number of slots allocated in aLabel[] */
  int *aLabel;            /* Space to hold the labels */
  u16 nResColumn;         /* Number of columns in one row of the result set */
  u16 nCursor;            /* Number of slots in apCsr[] */
  u32 magic;              /* Magic number for sanity checking */
  char *zErrMsg;          /* Error message written here */
  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
  VdbeCursor **apCsr;     /* One element of this array for each open cursor */
  u8 errorAction;         /* Recovery action to do in case of an error */
  u8 okVar;               /* True if azVar[] has been initialized */
  ynVar nVar;             /* Number of entries in aVar[] */
  Mem *aVar;              /* Values for the OP_Variable opcode. */
  char **azVar;           /* Name of variables */
  u32 magic;              /* Magic number for sanity checking */
  int nMem;               /* Number of memory locations currently allocated */
  Mem *aMem;              /* The memory locations */
  ynVar nVar;             /* Number of entries in aVar[] */
  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
  u8 errorAction;         /* Recovery action to do in case of an error */
  char *zErrMsg;          /* Error message written here */
  u8 okVar;               /* True if azVar[] has been initialized */
  u8 explain;             /* True if EXPLAIN present on SQL command */
  u8 changeCntOn;         /* True to update the change-counter */
  u8 expired;             /* True if the VM needs to be recompiled */
  u8 runOnlyOnce;         /* Automatically expire on reset */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */
  u8 inVtabMethod;        /* See comments above */
  u8 usesStmtJournal;     /* True if uses a statement journal */
  u8 readOnly;            /* True for read-only statements */
  u8 isPrepareV2;         /* True if prepared with prepare_v2() */
  int nChange;            /* Number of db changes made since last reset */
  int btreeMask;          /* Bitmask of db->aDb[] entries referenced */
  i64 startTime;          /* Time when query started - used for profiling */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
  int aCounter[3];        /* Counters used by sqlite3_stmt_status() */
  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
  char *zSql;             /* Text of the SQL statement that generated this */
  void *pFree;            /* Free this when deleting the vdbe */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  char *zSql;             /* Text of the SQL statement that generated this */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  void *pFree;            /* Free this when deleting the vdbe */
#ifdef SQLITE_DEBUG
  FILE *trace;            /* Write an execution trace here, if not NULL */
#endif
  VdbeFrame *pFrame;      /* Parent frame */
  VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
  int nFrame;             /* Number of frames in pFrame list */
  u32 expmask;            /* Binding to these vars invalidates VM */

static int sqlite3Step(Vdbe *p){
  sqlite3 *db;
  int rc;

  assert(p);
  if( p->magic!=VDBE_MAGIC_RUN ){
    /* We used to require that sqlite3_reset() be called before retrying
    ** sqlite3_step() after any error.  But after 3.6.23, we changed this
    ** so that sqlite3_reset() would be called automatically instead of
    ** throwing the error.
    ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
    ** with version 3.7.0, we changed this so that sqlite3_reset() would
    ** be called automatically instead of throwing the SQLITE_MISUSE error.
    ** This "automatic-reset" change is not technically an incompatibility, 
    ** since any application that receives an SQLITE_MISUSE is broken by
    ** definition.
    **
    ** Nevertheless, some published applications that were originally written
    ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE 
    ** returns, and the so were broken by the automatic-reset change.  As a
    ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
    ** legacy behavior of returning SQLITE_MISUSE for cases where the 
    ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
    ** or SQLITE_BUSY error.
    */
#ifdef SQLITE_OMIT_AUTORESET
    if( p->rc==SQLITE_BUSY || p->rc==SQLITE_LOCKED ){
    sqlite3_reset((sqlite3_stmt*)p);
      sqlite3_reset((sqlite3_stmt*)p);
    }else{
      return SQLITE_MISUSE_BKPT;
    }
#else
    sqlite3_reset((sqlite3_stmt*)p);
#endif
  }

  /* Check that malloc() has not failed. If it has, return early. */
  db = p->db;
  if( db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
    return SQLITE_NOMEM;

  }
#ifndef SQLITE_OMIT_EXPLAIN
  if( p->explain ){
    rc = sqlite3VdbeList(p);
  }else
#endif /* SQLITE_OMIT_EXPLAIN */
  {
    db->vdbeExecCnt++;
    rc = sqlite3VdbeExec(p);
    db->vdbeExecCnt--;
  }

#ifndef SQLITE_OMIT_TRACE
  /* Invoke the profile callback if there is one
  */
  if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy && p->zSql ){
    sqlite3_int64 iNow;

    ** this assert() from failing, when building with SQLITE_DEBUG defined
    ** using gcc, force nullMem to be 8-byte aligned using the magical
    ** __attribute__((aligned(8))) macro.  */
    static const Mem nullMem 
#if defined(SQLITE_DEBUG) && defined(__GNUC__)
      __attribute__((aligned(8))) 
#endif
      = {{0}, (double)0, 0, "", 0, MEM_Null, SQLITE_NULL, 0, 0, 0 };
      = {0, "", (double)0, {0}, 0, MEM_Null, SQLITE_NULL, 0, 0, 0 };

    if( pVm && ALWAYS(pVm->db) ){
      sqlite3_mutex_enter(pVm->db->mutex);
      sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    }
    pOut = (Mem*)&nullMem;
  }

  p->readOnly = 1;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;

    pOp->opflags = sqlite3OpcodeProperty[opcode];
    if( opcode==OP_Function || opcode==OP_AggStep ){
      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
    }else if( opcode==OP_Transaction && pOp->p2!=0 ){
    }else if( (opcode==OP_Transaction && pOp->p2!=0) || opcode==OP_Vacuum ){
      p->readOnly = 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    }else if( opcode==OP_VUpdate ){
      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );

    nTotal += n;
    zSql += n;
  }
  return nTotal;
}

/*
** This function returns a pointer to a nul-terminated string in memory
** Return a pointer to a string in memory obtained form sqlite3DbMalloc() which
** holds a copy of zRawSql but with host parameters expanded to their
** current bindings.
** obtained from sqlite3DbMalloc(). If sqlite3.vdbeExecCnt is 1, then the
** string contains a copy of zRawSql but with host parameters expanded to 
** their current bindings. Or, if sqlite3.vdbeExecCnt is greater than 1, 
** then the returned string holds a copy of zRawSql with "-- " prepended
** to each line of text.
**
** The calling function is responsible for making sure the memory returned
** is eventually freed.
**
** ALGORITHM:  Scan the input string looking for host parameters in any of
** these forms:  ?, ?N, $A, @A, :A.  Take care to avoid text within
** string literals, quoted identifier names, and comments.  For text forms,

  StrAccum out;            /* Accumulate the output here */
  char zBase[100];         /* Initial working space */

  db = p->db;
  sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
                      db->aLimit[SQLITE_LIMIT_LENGTH]);
  out.db = db;
  if( db->vdbeExecCnt>1 ){
    while( *zRawSql ){
      const char *zStart = zRawSql;
      while( *(zRawSql++)!='\n' && *zRawSql );
      sqlite3StrAccumAppend(&out, "-- ", 3);
      sqlite3StrAccumAppend(&out, zStart, zRawSql-zStart);
    }
  }else{
  while( zRawSql[0] ){
    n = findNextHostParameter(zRawSql, &nToken);
    assert( n>0 );
    sqlite3StrAccumAppend(&out, zRawSql, n);
    zRawSql += n;
    assert( zRawSql[0] || nToken==0 );
    if( nToken==0 ) break;
    if( zRawSql[0]=='?' ){
      if( nToken>1 ){
        assert( sqlite3Isdigit(zRawSql[1]) );
        sqlite3GetInt32(&zRawSql[1], &idx);
      }else{
        idx = nextIndex;
      }
    }else{
      assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' );
      testcase( zRawSql[0]==':' );
      testcase( zRawSql[0]=='$' );
      testcase( zRawSql[0]=='@' );
      idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken);
      assert( idx>0 );
    }
    zRawSql += nToken;
    nextIndex = idx + 1;
    assert( idx>0 && idx<=p->nVar );
    pVar = &p->aVar[idx-1];
    if( pVar->flags & MEM_Null ){
      sqlite3StrAccumAppend(&out, "NULL", 4);
    }else if( pVar->flags & MEM_Int ){
      sqlite3XPrintf(&out, "%lld", pVar->u.i);
    }else if( pVar->flags & MEM_Real ){
      sqlite3XPrintf(&out, "%!.15g", pVar->r);
    }else if( pVar->flags & MEM_Str ){
    while( zRawSql[0] ){
      n = findNextHostParameter(zRawSql, &nToken);
      assert( n>0 );
      sqlite3StrAccumAppend(&out, zRawSql, n);
      zRawSql += n;
      assert( zRawSql[0] || nToken==0 );
      if( nToken==0 ) break;
      if( zRawSql[0]=='?' ){
        if( nToken>1 ){
          assert( sqlite3Isdigit(zRawSql[1]) );
          sqlite3GetInt32(&zRawSql[1], &idx);
        }else{
          idx = nextIndex;
        }
      }else{
        assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' );
        testcase( zRawSql[0]==':' );
        testcase( zRawSql[0]=='$' );
        testcase( zRawSql[0]=='@' );
        idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken);
        assert( idx>0 );
      }
      zRawSql += nToken;
      nextIndex = idx + 1;
      assert( idx>0 && idx<=p->nVar );
      pVar = &p->aVar[idx-1];
      if( pVar->flags & MEM_Null ){
        sqlite3StrAccumAppend(&out, "NULL", 4);
      }else if( pVar->flags & MEM_Int ){
        sqlite3XPrintf(&out, "%lld", pVar->u.i);
      }else if( pVar->flags & MEM_Real ){
        sqlite3XPrintf(&out, "%!.15g", pVar->r);
      }else if( pVar->flags & MEM_Str ){
#ifndef SQLITE_OMIT_UTF16
      u8 enc = ENC(db);
      if( enc!=SQLITE_UTF8 ){
        Mem utf8;
        memset(&utf8, 0, sizeof(utf8));
        utf8.db = db;
        sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
        sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
        sqlite3XPrintf(&out, "'%.*q'", utf8.n, utf8.z);
        sqlite3VdbeMemRelease(&utf8);
      }else
        u8 enc = ENC(db);
        if( enc!=SQLITE_UTF8 ){
          Mem utf8;
          memset(&utf8, 0, sizeof(utf8));
          utf8.db = db;
          sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
          sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
          sqlite3XPrintf(&out, "'%.*q'", utf8.n, utf8.z);
          sqlite3VdbeMemRelease(&utf8);
        }else
#endif
      {
        sqlite3XPrintf(&out, "'%.*q'", pVar->n, pVar->z);
      }
    }else if( pVar->flags & MEM_Zero ){
      sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero);
    }else{
      assert( pVar->flags & MEM_Blob );
      sqlite3StrAccumAppend(&out, "x'", 2);
      for(i=0; i<pVar->n; i++){
        sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff);
      }
      sqlite3StrAccumAppend(&out, "'", 1);
        {
          sqlite3XPrintf(&out, "'%.*q'", pVar->n, pVar->z);
        }
      }else if( pVar->flags & MEM_Zero ){
        sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero);
      }else{
        assert( pVar->flags & MEM_Blob );
        sqlite3StrAccumAppend(&out, "x'", 2);
        for(i=0; i<pVar->n; i++){
          sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff);
        }
        sqlite3StrAccumAppend(&out, "'", 1);
      }
    }
  }
  return sqlite3StrAccumFinish(&out);
}

#endif /* #ifndef SQLITE_OMIT_TRACE */

**   walIteratorNext() - Step an iterator,
**   walIteratorFree() - Free an iterator.
**
** This functionality is used by the checkpoint code (see walCheckpoint()).
*/
struct WalIterator {
  int iPrior;                     /* Last result returned from the iterator */
  int nSegment;                   /* Size of the aSegment[] array */
  int nSegment;                   /* Number of entries in aSegment[] */
  struct WalSegment {
    int iNext;                    /* Next slot in aIndex[] not yet returned */
    ht_slot *aIndex;              /* i0, i1, i2... such that aPgno[iN] ascend */
    u32 *aPgno;                   /* Array of page numbers. */
    int nEntry;                   /* Max size of aPgno[] and aIndex[] arrays */
    int nEntry;                   /* Nr. of entries in aPgno[] and aIndex[] */
    int iZero;                    /* Frame number associated with aPgno[0] */
  } aSegment[1];                  /* One for every 32KB page in the WAL */
  } aSegment[1];                  /* One for every 32KB page in the wal-index */
};

/*
** Define the parameters of the hash tables in the wal-index file. There
** is a hash-table following every HASHTABLE_NPAGE page numbers in the
** wal-index.
**

  *piPage = p->iPrior = iRet;
  return (iRet==0xFFFFFFFF);
}

/*
** This function merges two sorted lists into a single sorted list.
**
** aLeft[] and aRight[] are arrays of indices.  The sort key is
** aContent[aLeft[]] and aContent[aRight[]].  Upon entry, the following
** is guaranteed for all J<K:
**
**        aContent[aLeft[J]] < aContent[aLeft[K]]
**        aContent[aRight[J]] < aContent[aRight[K]]
**
** This routine overwrites aRight[] with a new (probably longer) sequence
** of indices such that the aRight[] contains every index that appears in
** either aLeft[] or the old aRight[] and such that the second condition
** above is still met.
**
** The aContent[aLeft[X]] values will be unique for all X.  And the
** aContent[aRight[X]] values will be unique too.  But there might be
** one or more combinations of X and Y such that
**
**      aLeft[X]!=aRight[Y]  &&  aContent[aLeft[X]] == aContent[aRight[Y]]
**
** When that happens, omit the aLeft[X] and use the aRight[Y] index.
*/
static void walMerge(
  u32 *aContent,                  /* Pages in wal */
  const u32 *aContent,            /* Pages in wal - keys for the sort */
  ht_slot *aLeft,                 /* IN: Left hand input list */
  int nLeft,                      /* IN: Elements in array *paLeft */
  ht_slot **paRight,              /* IN/OUT: Right hand input list */
  int *pnRight,                   /* IN/OUT: Elements in *paRight */
  ht_slot *aTmp                   /* Temporary buffer */
){
  int iLeft = 0;                  /* Current index in aLeft */

  *paRight = aLeft;
  *pnRight = iOut;
  memcpy(aLeft, aTmp, sizeof(aTmp[0])*iOut);
}

/*
** Sort the elements in list aList, removing any duplicates.
** Sort the elements in list aList using aContent[] as the sort key.
** Remove elements with duplicate keys, preferring to keep the
** larger aList[] values.
**
** The aList[] entries are indices into aContent[].  The values in
** aList[] are to be sorted so that for all J<K:
**
**      aContent[aList[J]] < aContent[aList[K]]
**
** For any X and Y such that
**
**      aContent[aList[X]] == aContent[aList[Y]]
**
** Keep the larger of the two values aList[X] and aList[Y] and discard
** the smaller.
*/
static void walMergesort(
  u32 *aContent,                  /* Pages in wal */
  const u32 *aContent,            /* Pages in wal */
  ht_slot *aBuffer,               /* Buffer of at least *pnList items to use */
  ht_slot *aList,                 /* IN/OUT: List to sort */
  int *pnList                     /* IN/OUT: Number of elements in aList[] */
){
  struct Sublist {
    int nList;                    /* Number of elements in aList */
    ht_slot *aList;               /* Pointer to sub-list content */

static void walIteratorFree(WalIterator *p){
  sqlite3ScratchFree(p);
}

/*
** Construct a WalInterator object that can be used to loop over all 
** pages in the WAL in ascending order. The caller must hold the checkpoint
** lock.
**
** On success, make *pp point to the newly allocated WalInterator object
** return SQLITE_OK. Otherwise, return an error code. If this routine
** returns an error, the value of *pp is undefined.
**
** The calling routine should invoke walIteratorFree() to destroy the
** WalIterator object when it has finished with it.

  u32 mxPage;                     /* Max database page to write */
  int i;                          /* Loop counter */
  volatile WalCkptInfo *pInfo;    /* The checkpoint status information */

  szPage = (pWal->hdr.szPage&0xfe00) + ((pWal->hdr.szPage&0x0001)<<16);
  testcase( szPage<=32768 );
  testcase( szPage>=65536 );
  pInfo = walCkptInfo(pWal);
  if( pWal->hdr.mxFrame==0 ) return SQLITE_OK;
  if( pInfo->nBackfill>=pWal->hdr.mxFrame ) return SQLITE_OK;

  /* Allocate the iterator */
  rc = walIteratorInit(pWal, &pIter);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  assert( pIter );

  /* Compute in mxSafeFrame the index of the last frame of the WAL that is
  ** safe to write into the database.  Frames beyond mxSafeFrame might
  ** overwrite database pages that are in use by active readers and thus
  ** cannot be backfilled from the WAL.
  */
  mxSafeFrame = pWal->hdr.mxFrame;
  mxPage = pWal->hdr.nPage;
  pInfo = walCkptInfo(pWal);
  for(i=1; i<WAL_NREADER; i++){
    u32 y = pInfo->aReadMark[i];
    if( mxSafeFrame>=y ){
      assert( y<=pWal->hdr.mxFrame );
      rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
      if( rc==SQLITE_OK ){
        pInfo->aReadMark[i] = READMARK_NOT_USED;

#ifdef SQLITE_ENABLE_STAT2
static int valueFromExpr(
  Parse *pParse, 
  Expr *pExpr, 
  u8 aff, 
  sqlite3_value **pp
){
  /* The evalConstExpr() function will have already converted any TK_VARIABLE
  ** expression involved in an comparison into a TK_REGISTER. */
  assert( pExpr->op!=TK_VARIABLE );
  if( pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE ){
  if( pExpr->op==TK_VARIABLE
   || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
  ){
    int iVar = pExpr->iColumn;
    sqlite3VdbeSetVarmask(pParse->pVdbe, iVar); /* IMP: R-23257-02778 */
    *pp = sqlite3VdbeGetValue(pParse->pReprepare, iVar, aff);
    return SQLITE_OK;
  }
  return sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, aff, pp);
}

# 2011 January 04
#
# 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. This file 
# implements tests for ANALYZE to verify that multiple rows containing
# a NULL value count as distinct rows for the purposes of analyze 
# statistics.
#
# Also include test cases for collating sequences on indices.
#

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

do_test analyze4-1.0 {
  db eval {
    CREATE TABLE t1(a,b);
    CREATE INDEX t1a ON t1(a);
    CREATE INDEX t1b ON t1(b);
    INSERT INTO t1 VALUES(1,NULL);
    INSERT INTO t1 SELECT a+1, b FROM t1;
    INSERT INTO t1 SELECT a+2, b FROM t1;
    INSERT INTO t1 SELECT a+4, b FROM t1;
    INSERT INTO t1 SELECT a+8, b FROM t1;
    INSERT INTO t1 SELECT a+16, b FROM t1;
    INSERT INTO t1 SELECT a+32, b FROM t1;
    INSERT INTO t1 SELECT a+64, b FROM t1;
    ANALYZE;
  }

  # Should choose the t1a index since it is more specific than t1b.
  db eval {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=5 AND b IS NULL}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}

# Verify that the t1b index shows that it does not narrow down the
# search any at all.
#
do_test analyze4-1.1 {
  db eval {
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1a {128 1} t1b {128 128}}

# Change half of the b values from NULL to a constant.  Verify
# that the number of rows selected in stat1 is half the total 
# number of rows.
#
do_test analyze4-1.2 {
  db eval {
    UPDATE t1 SET b='x' WHERE a%2;
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1a {128 1} t1b {128 64}}

# Change the t1.b values all back to NULL.  Add columns t1.c and t1.d.
# Create a multi-column indices using t1.b and verify that ANALYZE 
# processes them correctly.
#
do_test analyze4-1.3 {
  db eval {
    UPDATE t1 SET b=NULL;
    ALTER TABLE t1 ADD COLUMN c;
    ALTER TABLE t1 ADD COLUMN d;
    UPDATE t1 SET c=a/4, d=a/2;
    CREATE INDEX t1bcd ON t1(b,c,d);
    CREATE INDEX t1cdb ON t1(c,d,b);
    CREATE INDEX t1cbd ON t1(c,b,d);
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1a {128 1} t1b {128 128} t1bcd {128 128 4 2} t1cbd {128 4 4 2} t1cdb {128 4 2 2}}

# Verify that collating sequences are taken into account when computing
# ANALYZE statistics.
#
do_test analyze4-2.0 {
  db eval {
    CREATE TABLE t2(
      x INTEGER PRIMARY KEY,
      a TEXT COLLATE nocase,
      b TEXT COLLATE rtrim,
      c TEXT COLLATE binary
    );
    CREATE INDEX t2a ON t2(a);
    CREATE INDEX t2b ON t2(b);
    CREATE INDEX t2c ON t2(c);
    CREATE INDEX t2c2 ON t2(c COLLATE nocase);
    CREATE INDEX t2c3 ON t2(c COLLATE rtrim);
    INSERT INTO t2 VALUES(1, 'abc', 'abc', 'abc');
    INSERT INTO t2 VALUES(2, 'abC', 'abC', 'abC');
    INSERT INTO t2 VALUES(3, 'abc ', 'abc ', 'abc ');
    INSERT INTO t2 VALUES(4, 'abC ', 'abC ', 'abC ');
    INSERT INTO t2 VALUES(5, 'aBc', 'aBc', 'aBc');
    INSERT INTO t2 VALUES(6, 'aBC', 'aBC', 'aBC');
    INSERT INTO t2 VALUES(7, 'aBc ', 'aBc ', 'aBc ');
    INSERT INTO t2 VALUES(8, 'aBC ', 'aBC ', 'aBC ');
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t2' ORDER BY idx;
  }
} {t2a {8 4} t2b {8 2} t2c {8 1} t2c2 {8 4} t2c3 {8 2}}

finish_test

} {SQLITE_DONE}
do_test capi2-1.7 {
  list [sqlite3_column_count $VM] [get_row_values $VM] [get_column_names $VM]
} {2 {} {name rowid text INTEGER}}

# This used to be SQLITE_MISUSE.  But now we automatically reset prepared
# statements.
ifcapable autoreset {
do_test capi2-1.8 {
  sqlite3_step $VM
} {SQLITE_ROW}
  do_test capi2-1.8 {
    sqlite3_step $VM
  } {SQLITE_ROW}
} else {
  do_test capi2-1.8 {
    sqlite3_step $VM
  } {SQLITE_MISUSE}
}

# Update: In v2, once SQLITE_MISUSE is returned the statement handle cannot
# be interrogated for more information. However in v3, since the column
# count, names and types are determined at compile time, these are still
# accessible after an SQLITE_MISUSE error.
do_test capi2-1.9 {
  sqlite3_reset $VM

}
do_test exclusive2-1.10 {
  pagerChangeCounter test.db 2
} {2}
do_test exclusive2-1.11 {
  expr {[t1sig] eq $::sig}
} {0}
db2 close

#--------------------------------------------------------------------
# These tests - exclusive2-2.X - are similar to exclusive2-1.X, 
# except that they are run with locking_mode=EXCLUSIVE.
#
# 1-3:   Build a database with exclusive-access connection 1, 
#        calculate a signature.

# These tests - exclusive2-3.X - verify that the pager change-counter
# is only incremented by the first change when in exclusive access
# mode. In normal mode, the change-counter is incremented once
# per write-transaction.
#

db close
db2 close
catch {close $::fd}
file delete -force test.db
file delete -force test.db-journal

do_test exclusive2-3.0 {
  sqlite3 db test.db
  execsql {
    BEGIN;
    CREATE TABLE t1(a UNIQUE);
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
    INSERT INTO t1 VALUES(randstr(200, 200));
    COMMIT;
  }
  readPagerChangeCounter test.db
} {1}
do_test exclusive2-3.1 {
  execsql {
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {2}
do_test exclusive2-3.2 {
  execsql {
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {3}
do_test exclusive2-3.3 {
  execsql {
    PRAGMA locking_mode = exclusive;
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {4}
do_test exclusive2-3.4 {
breakpoint
  execsql {
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {4}
do_test exclusive2-3.5 {
  execsql {
    PRAGMA locking_mode = normal;
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {4}
do_test exclusive2-3.6 {
  execsql {
    INSERT INTO t1 VALUES(randstr(10, 400));
    INSERT INTO t1 VALUES(randstr(200, 200));
  }
  readPagerChangeCounter test.db
} {5}
sqlite3_soft_heap_limit $cmdlinearg(soft-heap-limit)

finish_test

    INSERT INTO one VALUES(1, 2, 3);
  }
} {1}
do_test fkey2-17.1.2 {
  set STMT [sqlite3_prepare_v2 db "INSERT INTO two VALUES(4, 5, 6)" -1 dummy]
  sqlite3_step $STMT
} {SQLITE_CONSTRAINT}
ifcapable autoreset {
do_test fkey2-17.1.3 {
  sqlite3_step $STMT
} {SQLITE_CONSTRAINT}
  do_test fkey2-17.1.3 {
    sqlite3_step $STMT
  } {SQLITE_CONSTRAINT}
} else {
  do_test fkey2-17.1.3 {
    sqlite3_step $STMT
  } {SQLITE_MISUSE}
}
do_test fkey2-17.1.4 {
  sqlite3_finalize $STMT
} {SQLITE_CONSTRAINT}
do_test fkey2-17.1.5 {
  execsql {
    INSERT INTO one VALUES(2, 3, 4);
    INSERT INTO one VALUES(3, 4, 5);

  SELECT typeof(matchinfo(t10)), length(matchinfo(t10)) FROM t10 WHERE docid=1;
} {blob 0}
do_execsql_test 7.4 {
  SELECT typeof(matchinfo(t10)), length(matchinfo(t10)) 
  FROM t10 WHERE t10 MATCH 'record'
} {blob 20 blob 20}

#-------------------------------------------------------------------------
# Test a special case - matchinfo('nxa') with many zero length documents. 
# Special because "x" internally uses a statement used by both "n" and "a". 
# This was causing a problem at one point in the obscure case where the
# total number of bytes of data stored in an fts3 table was greater than
# the number of rows. i.e. when the following query returns true:
#
#   SELECT sum(length(content)) < count(*) FROM fts4table;
#
do_execsql_test 8.1 {
  CREATE VIRTUAL TABLE t11 USING fts4;
  INSERT INTO t11(t11) VALUES('nodesize=24');
  INSERT INTO t11 VALUES('quitealongstringoftext');
  INSERT INTO t11 VALUES('anotherquitealongstringoftext');
  INSERT INTO t11 VALUES('athirdlongstringoftext');
  INSERT INTO t11 VALUES('andonemoreforgoodluck');
}
do_test 8.2 {
  for {set i 0} {$i < 200} {incr i} {
    execsql { INSERT INTO t11 VALUES('') }
  }
  execsql { INSERT INTO t11(t11) VALUES('optimize') }
} {}
do_execsql_test 8.3 {
  SELECT mit(matchinfo(t11, 'nxa')) FROM t11 WHERE t11 MATCH 'a*'
} {{204 1 3 3 0} {204 1 3 3 0} {204 1 3 3 0}}

# Corruption related tests.
do_execsql_test  8.4.1.1 { UPDATE t11_stat SET value = X'0000'; }
do_catchsql_test 8.5.1.2 {
  SELECT mit(matchinfo(t11, 'nxa')) FROM t11 WHERE t11 MATCH 'a*'
} {1 {database disk image is malformed}}

do_execsql_test  8.4.2.1 { UPDATE t11_stat SET value = X'00'; }
do_catchsql_test 8.5.2.2 {
  SELECT mit(matchinfo(t11, 'nxa')) FROM t11 WHERE t11 MATCH 'a*'
} {1 {database disk image is malformed}}

do_execsql_test  8.4.3.1 { UPDATE t11_stat SET value = NULL; }
do_catchsql_test 8.5.3.2 {
  SELECT mit(matchinfo(t11, 'nxa')) FROM t11 WHERE t11 MATCH 'a*'
} {1 {database disk image is malformed}}

finish_test

do_test jrnlmode3-1.2 {
  db eval {
    BEGIN;
    INSERT INTO t1 VALUES(2);
    ROLLBACK;
    SELECT * FROM t1;
  }
} {1 2}
} {1}

db close
file delete -force test.db test.db-journal
sqlite3 db test.db

do_test jrnlmode3-2.1 {
  db eval {

do_test jrnlmode3-2.2 {
  db eval {
    BEGIN;
    INSERT INTO t1 VALUES(2);
    ROLLBACK;
    SELECT * FROM t1;
  }
} {1 2}
} {1}

# Test cases to verify that we can move from any journal_mode
# to any other, as long as we are not in a transaction.  Verify
# that we cannot change journal_mode while a transaction is active.
#
set all_journal_modes {delete persist truncate memory off}
set cnt 0

        CREATE TABLE t1(x);
        BEGIN;
        INSERT INTO t1 VALUES($cnt);
      }
      db eval "PRAGMA journal_mode=$tojmode"
    } $fromjmode

    # Rollback the transaction.  Verify that the rollback occurred
    # Rollback the transaction.  
    # if journal_mode!=OFF.
    #
    do_test jrnlmode3-3.$cnt.4 {
      db eval {
        ROLLBACK;
        SELECT * FROM t1;
      }
    } [expr {$fromjmode=="off"?$cnt:""}]
    } {}

    # Now change the journal mode again.  This time the new mode
    # should take.
    #
    do_test jrnlmode3-3.$cnt.5 {
      db eval "PRAGMA journal_mode=$tojmode"
    } $tojmode

        BEGIN;
        INSERT INTO t1 VALUES(1);
      }
      db eval ROLLBACK
      db eval {
        SELECT * FROM t1;
      }
    } [expr {$tojmode=="off"?"1":""}]
    } {}
  }
}

finish_test

do_test lookaside-1.1 {
  catch {sqlite3_config_error db}
} {0}

do_test lookaside-1.2 {
  sqlite3_db_config_lookaside db 1 18 18
} {0}
do_test lookaside-1.3 {
  sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0
do_test lookaside-1.3.1 {
  sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0
} {0 0 0}
do_test lookaside-1.3.2 {
  sqlite3_db_status db DBSTATUS_LOOKASIDE_HIT 0
} {0 0 0}
do_test lookaside-1.3.3 {
  sqlite3_db_status db DBSTATUS_LOOKASIDE_MISS_SIZE 0
} {0 0 0}
do_test lookaside-1.3.4 {
  sqlite3_db_status db DBSTATUS_LOOKASIDE_MISS_FULL 0
} {0 0 0}

do_test lookaside-1.4 {
  db eval {CREATE TABLE t1(w,x,y,z);}
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break
  expr {$x==0 && $y<$z && $z==18}
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0] break
  set p [lindex [sqlite3_db_status db DBSTATUS_LOOKASIDE_HIT 0] 2]
  set q [lindex [sqlite3_db_status db DBSTATUS_LOOKASIDE_MISS_SIZE 0] 2]
  set r [lindex [sqlite3_db_status db DBSTATUS_LOOKASIDE_MISS_FULL 0] 2]
  expr {$x==0 && $y<$z && $z==18 && $p>0 && $q>0 && $r>0}
} {0}
do_test lookaside-1.5 {
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 1] break
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 1] break
  expr {$x==0 && $y<$z && $z==18}
} {0}
do_test lookaside-1.6 {
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0] break
  expr {$x==0 && $y==$z && $y<18}
} {1}
do_test lookaside-1.7 {
  db cache flush
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0] break
  expr {$x==0 && $y==0 && $z<18}
} {1}
do_test lookaside-1.8 {
  db cache flush
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 1] break
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 1] break
  expr {$x==0 && $y==0 && $z<18}
} {1}
do_test lookaside-1.9 {
  db cache flush
  sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0
  sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0
} {0 0 0}

do_test lookaside-2.1 {
  sqlite3_db_config_lookaside db 0 100 1000
} {0}
do_test lookaside-2.2 {
  db eval {CREATE TABLE t2(x);}
  foreach {x y z} [sqlite3_db_status db SQLITE_DBSTATUS_LOOKASIDE_USED 0] break
  foreach {x y z} [sqlite3_db_status db DBSTATUS_LOOKASIDE_USED 0] break
  expr {$x==0 && $y<$z && $z>10 && $z<100}
} {1}
do_test lookaside-2.3 {
  sqlite3_db_config_lookaside db 0 50 50
} {5}  ;# SQLITE_BUSY
do_test lookaside-2.4 {
  db cache flush

#
#     -prep             Script to execute before -body.
#
#     -body             Script to execute (with fault injection).
#
#     -test             Script to execute after -body.
#
#     -install          Script to execute after faultsim -injectinstall
#
#     -uninstall        Script to execute after faultsim -uninjectinstall
#
proc do_faultsim_test {name args} {
  global FAULTSIM
  
  set DEFAULT(-faults)        [array names FAULTSIM]
  set DEFAULT(-prep)          ""
  set DEFAULT(-body)          ""
  set DEFAULT(-test)          ""
  set DEFAULT(-install)          ""
  set DEFAULT(-uninstall)          ""

  fix_testname name

  array set O [array get DEFAULT]
  array set O $args
  foreach o [array names O] {
    if {[info exists DEFAULT($o)]==0} { error "unknown option: $o" }
  }

  set faultlist [list]
  foreach f $O(-faults) {
    set flist [array names FAULTSIM $f]
    if {[llength $flist]==0} { error "unknown fault: $f" }
    set faultlist [concat $faultlist $flist]
  }

  set testspec [list -prep $O(-prep) -body $O(-body) -test $O(-test)]
  set testspec [list -prep $O(-prep) -body $O(-body) \
      -test $O(-test) -install $O(-install) -uninstall $O(-uninstall)
  ]
  foreach f [lsort -unique $faultlist] {
    eval do_one_faultsim_test "$name-$f" $FAULTSIM($f) $testspec
  }
}


#-------------------------------------------------------------------------

  set DEFAULT(-injectstop)      "expr 0"
  set DEFAULT(-injecterrlist)   [list]
  set DEFAULT(-injectinstall)   ""
  set DEFAULT(-injectuninstall) ""
  set DEFAULT(-prep)            ""
  set DEFAULT(-body)            ""
  set DEFAULT(-test)            ""
  set DEFAULT(-install)         ""
  set DEFAULT(-uninstall)       ""

  array set O [array get DEFAULT]
  array set O $args
  foreach o [array names O] {
    if {[info exists DEFAULT($o)]==0} { error "unknown option: $o" }
  }

  proc faultsim_test_proc {testrc testresult testnfail} $O(-test)
  proc faultsim_test_result {args} "
    uplevel faultsim_test_result_int \$args [list $O(-injecterrlist)]
  "

  eval $O(-injectinstall)
  eval $O(-install)

  set stop 0
  for {set iFail 1} {!$stop} {incr iFail} {

    # Evaluate the -prep script.
    #
    eval $O(-prep)

    # If no faults where injected this trial, don't bother running
    # any more. This test is finished.
    #
    if {$nfail==0} { set stop 1 }
  }

  eval $O(-uninstall)
  eval $O(-injectuninstall)
}

# Usage: do_malloc_test <test number> <options...>
#
# The first argument, <test number>, is an integer used to name the
# tests executed by this proc. Options are as follows:

db close
sqlite3_shutdown
sqlite3_config_pagecache [expr 1024+$xtra_size] 20
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-2 {PRAGMA page_size=1024}
#show_memstats
set MEMORY_MANAGEMENT $sqlite_options(memorymanage)
do_test memsubsys1-2.3 {
  set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]
} [expr ($AUTOVACUUM+$TEMP_STORE>=2)*1024]
} [expr ($TEMP_STORE>1 || $MEMORY_MANAGEMENT==0)*1024]
do_test memsubsys1-2.4 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 20
do_test memsubsys1-2.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0

#   * Multi-threaded mode,
#   * Single-threaded mode.
#
ifcapable threadsafe&&shared_cache {
  set enable_shared_cache [sqlite3_enable_shared_cache 1]
  foreach {mode mutexes} {
    singlethread {}
    multithread  {
    multithread  {fast static_lru static_master static_mem static_open static_prng }
    serialized  {fast recursive static_lru static_master static_mem static_open static_prng}
      fast static_lru static_master static_mem static_open static_prng 
      static_pmem
    }
    serialized  {
      fast recursive static_lru static_master static_mem static_open 
      static_prng static_pmem
    }
  } {

    do_test mutex1.2.$mode.1 {
      catch {db close}
      sqlite3_shutdown
      sqlite3_config $mode
    } SQLITE_OK

    do_test mutex1.2.$mode.2 {
      sqlite3_initialize
      clear_mutex_counters
      sqlite3 db test.db -nomutex 0 -fullmutex 0
      catchsql { CREATE TABLE abc(a, b, c) }
      db eval {
        INSERT INTO abc VALUES(1, 2, 3);
      }
    } {}
    ifcapable !memorymanage {
      regsub { static_lru} $mutexes {} mutexes
  
    }
    do_test mutex1.2.$mode.3 {
      mutex_counters counters
  
      set res [list]
      foreach {key value} [array get counters] {
        if {$key ne "total" && $value > 0} {
          lappend res $key

do_catchsql_test pager1-14.1.2 {
  BEGIN;
    INSERT INTO t1 VALUES(3, 4);
  ROLLBACK;
} {0 {}}
do_execsql_test pager1-14.1.3 {
  SELECT * FROM t1;
} {1 2 3 4}
} {1 2}
do_catchsql_test pager1-14.1.4 {
  BEGIN;
    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
} {1 {PRIMARY KEY must be unique}}
do_execsql_test pager1-14.1.5 {
  COMMIT;
  SELECT * FROM t1;
} {1 2 3 4 2 2 4 4}
} {1 2 2 2}

#-------------------------------------------------------------------------
# Test opening and closing the pager sub-system with different values
# for the sqlite3_vfs.szOsFile variable.
#
faultsim_delete_and_reopen
do_execsql_test pager1-15.0 {

    CREATE TABLE t1(a, b);
    PRAGMA journal_mode = off;
    BEGIN;
      INSERT INTO t1 VALUES(1, 2);
    ROLLBACK;
    SELECT * FROM t1;
  }
} {off 1 2}
} {off}
do_test pager2-2.2 {
  faultsim_delete_and_reopen
  execsql {
    PRAGMA auto_vacuum = incremental;
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = off;
    CREATE TABLE t1(a, b);

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

# Do not use a codec for tests in this file, as the database file is
# manipulated directly using tcl scripts (using the [hexio_write] command).
#
do_not_use_codec

# Only works with a mode-2 pcache where all pcaches share a single set
# of pages.
#
ifcapable {!memorymanage && threadsafe} {
  finish_test
  return
}

# The pcache module limits the number of pages available to purgeable
# caches to the sum of the 'cache_size' values for the set of open
# caches. This block of tests, pcache-1.*, test that the library behaves
# corrctly when it is forced to exceed this limit.
#
do_test pcache-1.1 {

        INSERT INTO t1 VALUES(13, 14);
        SAVEPOINT s1;
          INSERT INTO t1 VALUES(15, 16);
        ROLLBACK TO s1;
      ROLLBACK;
      SELECT * FROM t1;
    }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16}
  } {1 2 3 4 5 6 7 8 9 10 11 12}
}

db close
file delete test.db
do_multiclient_test tn {
  do_test savepoint-14.$tn.1 {
    sql1 {

    list [catch {sqlite3demo_superlock unlock test.db} msg] $msg
  } {1 {database is locked}}
  do_test 5.$tn.12 { 
    sql3 COMMIT
    list [catch {sqlite3demo_superlock unlock test.db} msg] $msg
  } {0 unlock}
  unlock


  do_test 5.$tn.13 { sql1 { SELECT * FROM t1 } } {1 2 3 4 5 6}
  do_test 5.$tn.14 { sql2 { SELECT * FROM t1 } } {1 2 3 4 5 6}
  do_test 5.$tn.15 { sqlite3demo_superlock unlock test.db } {unlock}
  do_test 5.$tn.16 { unlock } {}
  do_test 5.$tn.17 { sql2 { SELECT * FROM t1 } } {1 2 3 4 5 6}
  do_test 5.$tn.18 { sql1 { SELECT * FROM t1 } } {1 2 3 4 5 6}
  do_test 5.$tn.19 { sql2 { SELECT * FROM t1 } } {1 2 3 4 5 6}
}

proc read_content {file} {
  if {[file exists $file]==0} {return ""}
  set fd [open $file]
  fconfigure $fd -encoding binary -translation binary
  set content [read $fd]

# 2011 January 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [5d863f876e] has been
# fixed.  
#

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

do_multiclient_test tn {
  do_test $tn.1 {
    sql1 {
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
      INSERT INTO t1 VALUES(3, 4);
      PRAGMA journal_mode = WAL;
      VACUUM;
      PRAGMA journal_mode = DELETE;
    }
  } {wal delete}

  do_test $tn.2 {
    sql2 { SELECT * FROM t1 } 
  } {1 2 3 4}

  do_test $tn.3 {
    sql1 {
      INSERT INTO t1 VALUES(5, 6);
      PRAGMA journal_mode = WAL;
      VACUUM;
      PRAGMA journal_mode = DELETE;
    }
  } {wal delete}

  do_test $tn.2 {
    sql2 { PRAGMA integrity_check }
  } {ok}
}


finish_test

# 2011 Jan 21
#
# 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.
#
# This file implements tests for the "sqlite3_trace()" API. Specifically,
# it tests the special handling of nested SQL statements (those executed
# by virtual table or user function callbacks). These statements are treated
# differently in two respects:
#
#   1. Each line of the statement is prefixed with "-- " to turn it into
#      an SQL comment.
#
#   2. Parameter expansion is not performed.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !trace { finish_test ; return }
set ::testprefix trace2

proc sql {zSql} { db one $zSql }
proc trace {zSql} { lappend ::trace $zSql }

db func sql sql
db trace trace

proc do_trace_test {tn sql expected} {
  # Test that the list of string passed to the trace callback when $sql
  # is executed is equivalent to the list of strings in $expected.
  #
  set ::trace [list]
  execsql $sql
  uplevel do_test $tn [list {set ::trace}] [list [list {*}$expected]]
}

proc do_trace_select_test {tn sql expected} {

  uplevel [list do_trace_test ${tn}.a $sql $expected]

  # Now execute each SQL statement passed to the trace callback in the
  # block above. Check that this causes the same set of strings to be
  # passed to the trace callback again. i.e. that executing the output
  # of the trace callback is equivalent to the SQL script in $sql.
  #
  set sqllist $::trace
  set ::trace [list]
  foreach item $sqllist { execsql $item }
  uplevel do_test $tn.b [list {set ::trace}] [list $sqllist]
}

do_trace_select_test 1.1  {
  SELECT 1, 2, 3;
} {
  "SELECT 1, 2, 3;"
}

do_trace_select_test 1.2  {
  SELECT sql('SELECT 1, 2, 3');
} {
  "SELECT sql('SELECT 1, 2, 3');"
  "-- SELECT 1, 2, 3"
}

do_trace_select_test 1.3  {
  SELECT sql('SELECT 1, 
    2, 
    3'
  );
} {
  "SELECT sql('SELECT 1, 
    2, 
    3'
  );"
  "-- SELECT 1, 
--     2, 
--     3"
}

do_trace_select_test 1.4  {
  SELECT sql('SELECT 1, 


    3'
  );
} {
  "SELECT sql('SELECT 1, 


    3'
  );"
  "-- SELECT 1, 
-- 
-- 
--     3"
}

do_trace_select_test 1.5  {
  SELECT $var, sql('SELECT 1, 
    $var, 
    3'
  );
} {
  "SELECT NULL, sql('SELECT 1, 
    $var, 
    3'
  );"
  "-- SELECT 1, 
--     $var, 
--     3"
}

ifcapable fts3 {
  do_execsql_test 2.1 {
    CREATE VIRTUAL TABLE x1 USING fts4;
    INSERT INTO x1 VALUES('Cloudy, with a high near 16');
    INSERT INTO x1 VALUES('Wind chill values as low as -13');
  }

  do_trace_test 2.2 {
    INSERT INTO x1 VALUES('North northwest wind between 8 and 14 mph');
  } {
    "INSERT INTO x1 VALUES('North northwest wind between 8 and 14 mph');" 
    "-- INSERT INTO 'main'.'x1_content' VALUES(?,?)" 
    "-- REPLACE INTO 'main'.'x1_docsize' VALUES(?,?)" 
    "-- SELECT value FROM 'main'.'x1_stat' WHERE id=0" 
    "-- REPLACE INTO 'main'.'x1_stat' VALUES(0,?)" 
    "-- SELECT (SELECT max(idx) FROM 'main'.'x1_segdir' WHERE level = ?) + 1" 
    "-- SELECT coalesce((SELECT max(blockid) FROM 'main'.'x1_segments') + 1, 1)"
    "-- INSERT INTO 'main'.'x1_segdir' VALUES(?,?,?,?,?,?)"
  }

  do_trace_test 2.3 {
    INSERT INTO x1(x1) VALUES('optimize');
  } {
    "INSERT INTO x1(x1) VALUES('optimize');"
    "-- SELECT count(*), max(level) FROM 'main'.'x1_segdir'"
    "-- SELECT idx, start_block, leaves_end_block, end_block, root FROM 'main'.'x1_segdir' ORDER BY level DESC, idx ASC"
    "-- SELECT coalesce((SELECT max(blockid) FROM 'main'.'x1_segments') + 1, 1)"
    "-- DELETE FROM 'main'.'x1_segdir'"
    "-- INSERT INTO 'main'.'x1_segdir' VALUES(?,?,?,?,?,?)"
  }
}

finish_test

# Get the fossil-scm check-in date from the "D" card of $TOP/manifest.
#
set in [open $TOP/manifest]
set zDate {}
while {![eof $in]} {
  set line [gets $in]
  if {[regexp {^D (2.*[0-9])} $line all date]} {
  if {[regexp {^D (2[-0-9T:]+)} $line all date]} {
    set zDate [string map {T { }} $date]
    break
  }
}
close $in

# Set up patterns for recognizing API declarations.

  list $rc \
       [regexp {Error: missing argument for option: -nullvalue} $res]
} {1 1}

# -version             show SQLite version
do_test shell1-1.16.1 {
  catchcmd "-version test.db" "" 
} {0 3.7.3}
} {0 3.7.5}

#----------------------------------------------------------------------------
# Test cases shell1-2.*: Basic "dot" command token parsing.
#

# check first token handling
do_test shell1-2.1.1 {

** Read content from the file.
**
** Space to hold the content is obtained from malloc() and needs to be
** freed by the caller.
*/
static unsigned char *getContent(int ofst, int nByte){
  unsigned char *aData;
  aData = malloc(nByte);
  aData = malloc(nByte+32);
  if( aData==0 ) out_of_memory();
  memset(aData, 0, nByte+32);
  lseek(db, ofst, SEEK_SET);
  read(db, aData, nByte);
  return aData;
}

/*
** Print a range of bytes as hex and as ascii.

  print_decode_line(aData, 80, 4, "meta[10]");
  print_decode_line(aData, 84, 4, "meta[11]");
  print_decode_line(aData, 88, 4, "meta[12]");
  print_decode_line(aData, 92, 4, "Change counter for version number");
  print_decode_line(aData, 96, 4, "SQLite version number");
}

/*
** Describe cell content.
*/
static int describeContent(
  unsigned char *a,       /* Cell content */
  int nLocal,             /* Bytes in a[] */
  char *zDesc             /* Write description here */
){
  int nDesc = 0;
  int n, i, j;
  i64 x, v;
  const unsigned char *pData;
  const unsigned char *pLimit;
  char sep = ' ';

  pLimit = &a[nLocal];
  n = decodeVarint(a, &x);
  pData = &a[x];
  a += n;
  i = x - n;
  while( i>0 && pData<=pLimit ){
    n = decodeVarint(a, &x);
    a += n;
    i -= n;
    nLocal -= n;
    zDesc[0] = sep;
    sep = ',';
    nDesc++;
    zDesc++;
    if( x==0 ){
      sprintf(zDesc, "*");     /* NULL is a "*" */
    }else if( x>=1 && x<=6 ){
      v = (signed char)pData[0];
      pData++;
      switch( x ){
        case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
        case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
        case 4:  v = (v<<8) + pData[0];  pData++;
        case 3:  v = (v<<8) + pData[0];  pData++;
        case 2:  v = (v<<8) + pData[0];  pData++;
      }
      sprintf(zDesc, "%lld", v);
    }else if( x==7 ){
      sprintf(zDesc, "real");
      pData += 8;
    }else if( x==8 ){
      sprintf(zDesc, "0");
    }else if( x==9 ){
      sprintf(zDesc, "1");
    }else if( x>=12 ){
      int size = (x-12)/2;
      if( (x&1)==0 ){
        sprintf(zDesc, "blob(%d)", size);
      }else{
        sprintf(zDesc, "txt(%d)", size);
      }
      pData += size;
    }
    j = strlen(zDesc);
    zDesc += j;
    nDesc += j;
  }
  return nDesc;
}

/*
** Compute the local payload size given the total payload size and
** the page size.
*/
static int localPayload(i64 nPayload, char cType){
  int maxLocal;
  int minLocal;
  int surplus;
  int nLocal;
  if( cType==13 ){
    /* Table leaf */
    maxLocal = pagesize-35;
    minLocal = (pagesize-12)*32/255-23;
  }else{
    maxLocal = (pagesize-12)*64/255-23;
    minLocal = (pagesize-12)*32/255-23;
  }
  if( nPayload>maxLocal ){
    surplus = minLocal + (nPayload-minLocal)%(pagesize-4);
    if( surplus<=maxLocal ){
      nLocal = surplus;
    }else{
      nLocal = minLocal;
    }
  }else{
    nLocal = nPayload;
  }
  return nLocal;
}
  

/*
** Create a description for a single cell.
**
** The return value is the local cell size.
*/
static int describeCell(unsigned char cType, unsigned char *a, char **pzDesc){
static int describeCell(
  unsigned char cType,    /* Page type */
  unsigned char *a,       /* Cell content */
  int showCellContent,    /* Show cell content if true */
  char **pzDesc           /* Store description here */
){
  int i;
  int nDesc = 0;
  int n = 0;
  int leftChild;
  i64 nPayload;
  i64 rowid;
  int nLocal;
  static char zDesc[100];
  static char zDesc[1000];
  i = 0;
  if( cType<=5 ){
    leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3];
    a += 4;
    n += 4;
    sprintf(zDesc, "left-child: %d ", leftChild);
    sprintf(zDesc, "lx: %d ", leftChild);
    nDesc = strlen(zDesc);
  }
  if( cType!=5 ){
    i = decodeVarint(a, &nPayload);
    a += i;
    n += i;
    sprintf(&zDesc[nDesc], "sz: %lld ", nPayload);
    sprintf(&zDesc[nDesc], "n: %lld ", nPayload);
    nDesc += strlen(&zDesc[nDesc]);
    nLocal = localPayload(nPayload, cType);
  }else{
    nPayload = nLocal = 0;
  }
  if( cType==5 || cType==13 ){
    i = decodeVarint(a, &rowid);
    a += i;
    n += i;
    sprintf(&zDesc[nDesc], "rowid: %lld ", rowid);
    sprintf(&zDesc[nDesc], "r: %lld ", rowid);
    nDesc += strlen(&zDesc[nDesc]);
  }
  if( nLocal<nPayload ){
    int ovfl;
    unsigned char *b = &a[nLocal];
    ovfl = ((b[0]*256 + b[1])*256 + b[2])*256 + b[3];
    sprintf(&zDesc[nDesc], "ov: %d ", ovfl);
    nDesc += strlen(&zDesc[nDesc]);
    n += 4;
  }
  if( showCellContent && cType!=5 ){
    nDesc += describeContent(a, nLocal, &zDesc[nDesc-1]);
  }
  *pzDesc = zDesc;
  return n;
  return nLocal+n;
}

/*
** Decode a btree page
*/
static void decode_btree_page(unsigned char *a, int pgno, int hdrSize){
static void decode_btree_page(
  unsigned char *a,   /* Page content */
  int pgno,           /* Page number */
  int hdrSize,        /* Size of the page header.  0 or 100 */
  char *zArgs         /* Flags to control formatting */
){
  const char *zType = "unknown";
  int nCell;
  int i;
  int i, j;
  int iCellPtr;
  int showCellContent = 0;
  int showMap = 0;
  char *zMap = 0;
  switch( a[0] ){
    case 2:  zType = "index interior node";  break;
    case 5:  zType = "table interior node";  break;
    case 10: zType = "index leaf";           break;
    case 13: zType = "table leaf";           break;
  }
  while( zArgs[0] ){
    switch( zArgs[0] ){
      case 'c': showCellContent = 1;  break;
      case 'm': showMap = 1;          break;
    }
    zArgs++;
  }
  printf("Decode of btree page %d:\n", pgno);
  print_decode_line(a, 0, 1, zType);
  print_decode_line(a, 1, 2, "Offset to first freeblock");
  print_decode_line(a, 3, 2, "Number of cells on this page");
  nCell = a[3]*256 + a[4];
  print_decode_line(a, 5, 2, "Offset to cell content area");
  print_decode_line(a, 7, 1, "Fragmented byte count");
  if( a[0]==2 || a[0]==5 ){
    print_decode_line(a, 8, 4, "Right child");
    iCellPtr = 12;
  }else{
    iCellPtr = 8;
  }
  if( nCell>0 ){
    printf(" key: lx=left-child n=payload-size r=rowid\n");
  }
  if( showMap ){
    zMap = malloc(pagesize);
    memset(zMap, '.', pagesize);
    memset(zMap, '1', hdrSize);
    memset(&zMap[hdrSize], 'H', iCellPtr);
    memset(&zMap[hdrSize+iCellPtr], 'P', 2*nCell);
  }
  for(i=0; i<nCell; i++){
    int cofst = iCellPtr + i*2;
    char *zDesc;
    int n;

    cofst = a[cofst]*256 + a[cofst+1];
    describeCell(a[0], &a[cofst-hdrSize], &zDesc);
    n = describeCell(a[0], &a[cofst-hdrSize], showCellContent, &zDesc);
    if( showMap ){
      char zBuf[30];
      memset(&zMap[cofst], '*', n);
      zMap[cofst] = '[';
      zMap[cofst+n-1] = ']';
      sprintf(zBuf, "%d", i);
      j = strlen(zBuf);
      if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
    }
    printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
  }
  if( showMap ){
    for(i=0; i<pagesize; i+=64){
      printf(" %03x: %.64s\n", i, &zMap[i]);
    }
    free(zMap);
  }  
}

/*
** Decode a freelist trunk page.
*/
static void decode_trunk_page(
  int pgno,             /* The page number */

  fprintf(stderr, "Usage %s FILENAME ?args...?\n\n", argv0);
  fprintf(stderr,
    "args:\n"
    "    dbheader        Show database header\n"
    "    NNN..MMM        Show hex of pages NNN through MMM\n"
    "    NNN..end        Show hex of pages NNN through end of file\n"
    "    NNNb            Decode btree page NNN\n"
    "    NNNbc           Decode btree page NNN and show content\n"
    "    NNNbm           Decode btree page NNN and show a layout map\n"
    "    NNNt            Decode freelist trunk page NNN\n"
    "    NNNtd           Show leave freelist pages on the decode\n"
    "    NNNtr           Recurisvely decode freelist starting at NNN\n"
  );
}

int main(int argc, char **argv){

          nByte = pagesize-100;
        }else{
          hdrSize = 0;
          ofst = (iStart-1)*pagesize;
          nByte = pagesize;
        }
        a = getContent(ofst, nByte);
        decode_btree_page(a, iStart, hdrSize);
        decode_btree_page(a, iStart, hdrSize, &zLeft[1]);
        free(a);
        continue;
      }else if( zLeft && zLeft[0]=='t' ){
        unsigned char *a;
        int detail = 0;
        int recursive = 0;
        int i;