SQLite

OPT_FEATURE_FLAGS = @OPT_FEATURE_FLAGS@

TCC += $(OPT_FEATURE_FLAGS)

# Add in any optional parameters specified on the make commane line
# ie.  make "OPTS=-DSQLITE_ENABLE_FOO=1 -DSQLITE_OMIT_FOO=1".
TCC += $(OPTS)

# Add in compile-time options for some libraries used by extensions
TCC += @HAVE_ZLIB@

# Version numbers and release number for the SQLite being compiled.
#
VERSION = @VERSION@
VERSION_NUMBER = @VERSION_NUMBER@
RELEASE = @RELEASE@

LTRCOMPILE = $(RCC) -r
LTLIB = lib.exe
LTLINK = $(TCC) -Fe$@

# If requested, link to the RPCRT4 library.
#
!IF $(USE_RPCRT4_LIB)!=0
LTLIBS = $(LTLIBS) rpcrt4.lib
!ENDIF

# If a platform was set, force the linker to target that.
# Note that the vcvars*.bat family of batch files typically
# set this for you.  Otherwise, the linker will attempt
# to deduce the binary type based on the object files.
!IFDEF PLATFORM

!ENDIF

# <<mark>>
# Start with the Tcl related linker options.
#
!IF $(NO_TCL)==0
LTLIBPATHS = /LIBPATH:$(TCLLIBDIR)
LTLIBS = $(LTLIBS) $(LIBTCL)
!ENDIF

# If ICU support is enabled, add the linker options for it.
#
!IF $(USE_ICU)!=0
LTLIBPATHS = $(LTLIBPATHS) /LIBPATH:$(ICULIBDIR)
LTLIBS = $(LTLIBS) $(LIBICU)

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

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

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

fts5parse.h:	fts5parse.c

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

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

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

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

fts5.dll:	fts5_ext.lo

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

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

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

## How It All Fits Together

SQLite is modular in design.

Key files:

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

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

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

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

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

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

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

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

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

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

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

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

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


## Contacts

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

LTRCOMPILE = $(RCC) -r
LTLIB = lib.exe
LTLINK = $(TCC) -Fe$@

# If requested, link to the RPCRT4 library.
#
!IF $(USE_RPCRT4_LIB)!=0
LTLIBS = $(LTLIBS) rpcrt4.lib
!ENDIF

# If a platform was set, force the linker to target that.
# Note that the vcvars*.bat family of batch files typically
# set this for you.  Otherwise, the linker will attempt
# to deduce the binary type based on the object files.
!IFDEF PLATFORM

#endif"

ac_subst_vars='LTLIBOBJS
LIBOBJS
BUILD_CFLAGS
USE_GCOV
OPT_FEATURE_FLAGS
HAVE_ZLIB
USE_AMALGAMATION
TARGET_DEBUG
TARGET_HAVE_EDITLINE
TARGET_HAVE_READLINE
TARGET_READLINE_INC
TARGET_READLINE_LIBS
HAVE_TCL

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking the name lister ($NM) interface" >&5
$as_echo_n "checking the name lister ($NM) interface... " >&6; }
if ${lt_cv_nm_interface+:} false; 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:3935: $ac_compile\"" >&5)
  (eval "$ac_compile" 2>conftest.err)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3938: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
  (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3941: 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:${as_lineno-$LINENO}: result: $lt_cv_nm_interface" >&5

	;;
    esac
  fi
  rm -rf conftest*
  ;;
*-*-irix6*)
  # Find out which ABI we are using.
  echo '#line 5147 "configure"' > conftest.$ac_ext
  if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_compile\""; } >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
  test $ac_status = 0; }; then
    if test "$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:6672: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:6676: \$? = $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:7011: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:7015: \$? = $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:7116: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7120: \$? = $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:7171: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7175: \$? = $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 9551 "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 9647 "configure"
#include "confdefs.h"

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

#include <stdio.h>

else
  use_amalgamation=yes
fi

if test "${use_amalgamation}" != "yes" ; then
  USE_AMALGAMATION=0
fi


#########
# Look for zlib.  Only needed by extensions and by the sqlite3.exe shell
for ac_header in zlib.h
do :
  ac_fn_c_check_header_mongrel "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
if test "x$ac_cv_header_zlib_h" = xyes; then :
  cat >>confdefs.h <<_ACEOF
#define HAVE_ZLIB_H 1
_ACEOF

fi

done

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing deflate" >&5
$as_echo_n "checking for library containing deflate... " >&6; }
if ${ac_cv_search_deflate+:} false; then :
  $as_echo_n "(cached) " >&6
else
  ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h.  */

/* Override any GCC internal prototype to avoid an error.
   Use char because int might match the return type of a GCC
   builtin and then its argument prototype would still apply.  */
#ifdef __cplusplus
extern "C"
#endif
char deflate ();
int
main ()
{
return deflate ();
  ;
  return 0;
}
_ACEOF
for ac_lib in '' z; do
  if test -z "$ac_lib"; then
    ac_res="none required"
  else
    ac_res=-l$ac_lib
    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
  fi
  if ac_fn_c_try_link "$LINENO"; then :
  ac_cv_search_deflate=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
    conftest$ac_exeext
  if ${ac_cv_search_deflate+:} false; then :
  break
fi
done
if ${ac_cv_search_deflate+:} false; then :

else
  ac_cv_search_deflate=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_deflate" >&5
$as_echo "$ac_cv_search_deflate" >&6; }
ac_res=$ac_cv_search_deflate
if test "$ac_res" != no; then :
  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
  HAVE_ZLIB="-DSQLITE_HAVE_ZLIB=1"
else
  HAVE_ZLIB=""
fi



#########
# See whether we should allow loadable extensions
# Check whether --enable-load-extension was given.
if test "${enable_load_extension+set}" = set; then :
  enableval=$enable_load_extension; use_loadextension=$enableval

      [Disable the amalgamation and instead build all files separately]),
      [use_amalgamation=$enableval],[use_amalgamation=yes])
if test "${use_amalgamation}" != "yes" ; then
  USE_AMALGAMATION=0
fi
AC_SUBST(USE_AMALGAMATION)

#########
# Look for zlib.  Only needed by extensions and by the sqlite3.exe shell
AC_CHECK_HEADERS(zlib.h)
AC_SEARCH_LIBS(deflate, z, [HAVE_ZLIB="-DSQLITE_HAVE_ZLIB=1"], [HAVE_ZLIB=""])
AC_SUBST(HAVE_ZLIB)

#########
# See whether we should allow loadable extensions
AC_ARG_ENABLE(load-extension, AC_HELP_STRING([--disable-load-extension],
      [Disable loading of external extensions]),
      [use_loadextension=$enableval],[use_loadextension=yes])
if test "${use_loadextension}" = "yes" ; then
  OPT_FEATURE_FLAGS=""

Fts5ExprPhrase *sqlite3Fts5ParseTerm(
  Fts5Parse *pParse, 
  Fts5ExprPhrase *pPhrase, 
  Fts5Token *pToken,
  int bPrefix
);

void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase*);

Fts5ExprNearset *sqlite3Fts5ParseNearset(
  Fts5Parse*, 
  Fts5ExprNearset*,
  Fts5ExprPhrase* 
);

#define fts5ExprNodeNext(a,b,c,d) (b)->xNext((a), (b), (c), (d))

/*
** An instance of the following structure represents a single search term
** or term prefix.
*/
struct Fts5ExprTerm {
  u8 bPrefix;                     /* True for a prefix term */
  u8 bFirst;                      /* True if token must be first in column */
  char *zTerm;                    /* nul-terminated term */
  Fts5IndexIter *pIter;           /* Iterator for this term */
  Fts5ExprTerm *pSynonym;         /* Pointer to first in list of synonyms */
};

/*
** A phrase. One or more terms that must appear in a contiguous sequence

    case '{':  tok = FTS5_LCP;   break;
    case '}':  tok = FTS5_RCP;   break;
    case ':':  tok = FTS5_COLON; break;
    case ',':  tok = FTS5_COMMA; break;
    case '+':  tok = FTS5_PLUS;  break;
    case '*':  tok = FTS5_STAR;  break;
    case '-':  tok = FTS5_MINUS; break;
    case '^':  tok = FTS5_CARET; break;
    case '\0': tok = FTS5_EOF;   break;

    case '"': {
      const char *z2;
      tok = FTS5_STRING;

      for(z2=&z[1]; 1; z2++){

  int *pbMatch                    /* OUT: Set to true if really a match */
){
  Fts5PoslistWriter writer = {0};
  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int i;
  int rc = SQLITE_OK;
  int bFirst = pPhrase->aTerm[0].bFirst;
  
  fts5BufferZero(&pPhrase->poslist);

  /* If the aStatic[] array is not large enough, allocate a large array
  ** using sqlite3_malloc(). This approach could be improved upon. */
  if( pPhrase->nTerm>ArraySize(aStatic) ){
    int nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;

          }
          if( pPos->iPos>iAdj ) iPos = pPos->iPos-i;
        }
      }
    }while( bMatch==0 );

    /* Append position iPos to the output */
    if( bFirst==0 || FTS5_POS2OFFSET(iPos)==0 ){
      rc = sqlite3Fts5PoslistWriterAppend(&pPhrase->poslist, &writer, iPos);
      if( rc!=SQLITE_OK ) goto ismatch_out;
    }

    for(i=0; i<pPhrase->nTerm; i++){
      if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) goto ismatch_out;
    }
  }

 ismatch_out:

    int i;

    /* Check that each phrase in the nearset matches the current row.
    ** Populate the pPhrase->poslist buffers at the same time. If any
    ** phrase is not a match, break out of the loop early.  */
    for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
      if( pPhrase->nTerm>1 || pPhrase->aTerm[0].pSynonym 
       || pNear->pColset || pPhrase->aTerm[0].bFirst
      ){
        int bMatch = 0;
        rc = fts5ExprPhraseIsMatch(pNode, pPhrase, &bMatch);
        if( bMatch==0 ) break;
      }else{
        Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;
        fts5BufferSet(&rc, &pPhrase->poslist, pIter->nData, pIter->pData);
      }

  int bMatch;                     /* True if all terms are at the same rowid */
  const int bDesc = pExpr->bDesc;

  /* Check that this node should not be FTS5_TERM */
  assert( pNear->nPhrase>1 
       || pNear->apPhrase[0]->nTerm>1 
       || pNear->apPhrase[0]->aTerm[0].pSynonym
       || pNear->apPhrase[0]->aTerm[0].bFirst
  );

  /* Initialize iLast, the "lastest" rowid any iterator points to. If the
  ** iterator skips through rowids in the default ascending order, this means
  ** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it
  ** means the minimum rowid.  */
  if( pLeft->aTerm[0].pSynonym ){

        sqlite3_free(pSyn);
      }
    }
    if( pPhrase->poslist.nSpace>0 ) fts5BufferFree(&pPhrase->poslist);
    sqlite3_free(pPhrase);
  }
}

/*
** Set the "bFirst" flag on the first token of the phrase passed as the
** only argument.
*/
void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase *pPhrase){
  if( pPhrase && pPhrase->nTerm ){
    pPhrase->aTerm[0].bFirst = 1;
  }
}

/*
** If argument pNear is NULL, then a new Fts5ExprNearset object is allocated
** and populated with pPhrase. Or, if pNear is not NULL, phrase pPhrase is
** appended to it and the results returned.
**
** If an OOM error occurs, both the pNear and pPhrase objects are freed and

        const char *zTerm = p->zTerm;
        rc = fts5ParseTokenize((void*)&sCtx, tflags, zTerm, (int)strlen(zTerm),
            0, 0);
        tflags = FTS5_TOKEN_COLOCATED;
      }
      if( rc==SQLITE_OK ){
        sCtx.pPhrase->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;
        sCtx.pPhrase->aTerm[i].bFirst = pOrig->aTerm[i].bFirst;
      }
    }
  }else{
    /* This happens when parsing a token or quoted phrase that contains
    ** no token characters at all. (e.g ... MATCH '""'). */
    sCtx.pPhrase = sqlite3Fts5MallocZero(&rc, sizeof(Fts5ExprPhrase));
  }

  if( rc==SQLITE_OK ){
    /* All the allocations succeeded. Put the expression object together. */
    pNew->pIndex = pExpr->pIndex;
    pNew->pConfig = pExpr->pConfig;
    pNew->nPhrase = 1;
    pNew->apExprPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->apPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->nPhrase = 1;
    sCtx.pPhrase->pNode = pNew->pRoot;

    if( pOrig->nTerm==1 
     && pOrig->aTerm[0].pSynonym==0 
     && pOrig->aTerm[0].bFirst==0 
    ){
      pNew->pRoot->eType = FTS5_TERM;
      pNew->pRoot->xNext = fts5ExprNodeNext_TERM;
    }else{
      pNew->pRoot->eType = FTS5_STRING;
      pNew->pRoot->xNext = fts5ExprNodeNext_STRING;
    }
  }else{

static void fts5ExprAssignXNext(Fts5ExprNode *pNode){
  switch( pNode->eType ){
    case FTS5_STRING: {
      Fts5ExprNearset *pNear = pNode->pNear;
      if( pNear->nPhrase==1 && pNear->apPhrase[0]->nTerm==1 
       && pNear->apPhrase[0]->aTerm[0].pSynonym==0
       && pNear->apPhrase[0]->aTerm[0].bFirst==0
      ){
        pNode->eType = FTS5_TERM;
        pNode->xNext = fts5ExprNodeNext_TERM;
      }else{
        pNode->xNext = fts5ExprNodeNext_STRING;
      }
      break;

          pNear->apPhrase[iPhrase]->pNode = pRet;
          if( pNear->apPhrase[iPhrase]->nTerm==0 ){
            pRet->xNext = 0;
            pRet->eType = FTS5_EOF;
          }
        }

        if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL ){
          Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
          if( pNear->nPhrase!=1 
           || pPhrase->nTerm>1
           || (pPhrase->nTerm>0 && pPhrase->aTerm[0].bFirst)
          ){
            assert( pParse->rc==SQLITE_OK );
            pParse->rc = SQLITE_ERROR;
            assert( pParse->zErr==0 );
            pParse->zErr = sqlite3_mprintf(
                "fts5: %s queries are not supported (detail!=full)", 
                pNear->nPhrase==1 ? "phrase": "NEAR"
                );
            sqlite3_free(pRet);
            pRet = 0;
          }
        }
      }else{
        fts5ExprAddChildren(pRet, pLeft);
        fts5ExprAddChildren(pRet, pRight);
      }
    }
  }

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

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

    while( 1 ){
      if( i1.iRowid<i2.iRowid ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);

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

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

%type nearset     {Fts5ExprNearset*}
%type nearphrases {Fts5ExprNearset*}
%destructor nearset { sqlite3Fts5ParseNearsetFree($$); }
%destructor nearphrases { sqlite3Fts5ParseNearsetFree($$); }

nearset(A) ::= phrase(Y). { A = sqlite3Fts5ParseNearset(pParse, 0, Y); }
nearset(A) ::= CARET phrase(Y). { 
  sqlite3Fts5ParseSetCaret(Y);
  A = sqlite3Fts5ParseNearset(pParse, 0, Y); 
}
nearset(A) ::= STRING(X) LP nearphrases(Y) neardist_opt(Z) RP. {
  sqlite3Fts5ParseNear(pParse, &X);
  sqlite3Fts5ParseSetDistance(pParse, Y, &Z);
  A = Y;
}

nearphrases(A) ::= phrase(X). { 

  A = sqlite3Fts5ParseTerm(pParse, 0, &Y, Z);
}

/*
** Optional "*" character.
*/
%type star_opt {int}

star_opt(A) ::= STAR. { A = 1; }
star_opt(A) ::= . { A = 0; }

}

do_faultsim_test 4.2 -faults oom* -body {
  execsql { SELECT rowid FROM t1('{a b c} : (a AND d)') }
} -test {
  faultsim_test_result {0 {2 3}}
}

#-------------------------------------------------------------------------
# Test OOM injection while parsing a CARET expression
#
reset_db
do_execsql_test 5.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a);
  INSERT INTO t1 VALUES('a b c d');  -- 1
  INSERT INTO t1 VALUES('d a b c');  -- 2
  INSERT INTO t1 VALUES('c d a b');  -- 3
  INSERT INTO t1 VALUES('b c d a');  -- 4
}
do_faultsim_test 5.1 -faults oom* -body {
  execsql { SELECT rowid FROM t1('^a OR ^b') }
} -test {
  faultsim_test_result {0 {1 4}}
}


finish_test

# 2017 November 25
#
# 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.
#
#***********************************************************************

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5first

ifcapable !fts5 {
  finish_test
  return
}


do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE x1 USING fts5(a, b);
}

foreach {tn expr ok} {
  1 {^abc}           1
  2 {^abc + def}     1
  3 {^ "abc def"}    1
  4 {^"abc def"}     1
  5 {abc ^def}       1
  6 {abc + ^def}     0
  7 {abc ^+ def}     0
  8 {"^abc"}         1
  9 {NEAR(^abc def)} 0
} {
  set res(0) {/1 {fts5: syntax error near .*}/}
  set res(1) {0 {}}

  do_catchsql_test 1.$tn { SELECT * FROM x1($expr) } $res($ok)
}

#-------------------------------------------------------------------------
# 
do_execsql_test 2.0 {
  INSERT INTO x1 VALUES('a b c', 'b c a');
}

foreach {tn expr match} {
  1 {^a} 1
  2 {^b} 1
  3 {^c} 0
  4 {^a + b} 1
  5 {^b + c} 1
  6 {^c + a} 0
  7 {^"c a"} 0
  8 {a:^a} 1
  9 {a:^b} 0
  10 {a:^"a b"} 1
} {
  do_execsql_test 2.$tn { SELECT EXISTS (SELECT rowid FROM x1($expr)) } $match
}

#-------------------------------------------------------------------------
# 
do_execsql_test 3.0 {
  DELETE FROM x1;
  INSERT INTO x1 VALUES('b a', 'c a');
  INSERT INTO x1 VALUES('a a', 'c c');
  INSERT INTO x1 VALUES('a b', 'a a');
}
fts5_aux_test_functions db

foreach {tn expr expect} {
  1 {^a} {{2 1}}
  2 {^c AND ^b} {{0 2} {1 0}}
} {
  do_execsql_test 3.$tn {
    SELECT fts5_test_queryphrase(x1) FROM x1($expr) LIMIT 1
  } [list $expect]
}

#-------------------------------------------------------------------------
# 
do_execsql_test 3.1 {
  CREATE VIRTUAL TABLE x2 USING fts5(a, b, c, detail=column);
}

do_catchsql_test 3.2 {
  SELECT * FROM x2('a + b');
} {1 {fts5: phrase queries are not supported (detail!=full)}}

do_catchsql_test 3.3 {
  SELECT * FROM x2('^a');
} {1 {fts5: phrase queries are not supported (detail!=full)}}
finish_test

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

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

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

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


finish_test

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

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

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

#include <assert.h>

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

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

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

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

  }

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



















/*
** Function to delete compiled regexp objects. Registered as
** a destructor function with sqlite3_set_auxdata().
*/
static void icuRegexpDelete(void *p){
  URegularExpression *pExpr = (URegularExpression *)p;
  uregex_close(pExpr);

      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }
  assert( 0 );     /* Unreachable */
}

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

/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){
  UCollator *p = (UCollator *)pCtx;
  ucol_close(p);

    const char *zName;                        /* Function name */
    unsigned char nArg;                       /* Number of arguments */
    unsigned short enc;                       /* Optimal text encoding */
    unsigned char iContext;                   /* sqlite3_user_data() context */
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } scalars[] = {
    {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)
    {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},
    {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
    {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */
  };
  int rc = SQLITE_OK;
  int i;

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

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

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

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

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

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

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

/*
** iSplitTopic/pSplitKey/nSplitKey:

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

/* 
** The first argument to this macro is a pointer to a Segment structure.
** Returns true if the structure instance indicates that the separators
** array is valid.
*/

  u32 iCmpId;                     /* Id of compression scheme */
  Level *pLevel;                  /* Pointer to level 0 of snapshot (or NULL) */
  i64 iId;                        /* Snapshot id */
  i64 iLogOff;                    /* Log file offset */
  Redirect redirect;              /* Block redirection array */

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

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

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

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

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

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

int lsmFsSectorSize(FileSystem *);

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

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

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

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

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

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

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

int lsmFsPageWritable(Page *);

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

LsmFile *lsmFsDeferClose(FileSystem *pFS);

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

void lsmFsFlushWaiting(FileSystem *, int *);

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

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

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

void lsmEnvSleep(lsm_env *, int);

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

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

void lsmFsPurgeCache(FileSystem *);

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

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

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

int lsmSaveWorker(lsm_db *, int);

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

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

static int ckptExportSnapshot( 

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

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

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

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

  assert( pFS->nMapLimit>=0 );

  return LSM_OK;
}

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

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

/*
** This is a helper function for lsmFsOpen(). It opens a single file on
** disk (either the database or log file).
*/

** Return the page number of the first page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset immediately following the 4-byte
** "previous block" pointer at the start of each block.
*/
static LsmPgno fsFirstPageOnBlock(FileSystem *pFS, int iBlock){
  LsmPgno iPg;
  if( pFS->pCompress ){
    if( iBlock==1 ){
      iPg = pFS->nMetasize * 2 + 4;
    }else{
      iPg = pFS->nBlocksize * (LsmPgno)(iBlock-1) + 4;
    }
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    if( iBlock==1 ){
      iPg = 1 + ((pFS->nMetasize*2 + pFS->nPagesize - 1) / pFS->nPagesize);
    }else{
      iPg = 1 + (iBlock-1) * nPagePerBlock;
    }
  }
  return iPg;
}

/*
** Return the page number of the last page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset of the byte immediately before 
** the 4-byte "next block" pointer at the end of each block.
*/
static LsmPgno fsLastPageOnBlock(FileSystem *pFS, int iBlock){
  if( pFS->pCompress ){
    return pFS->nBlocksize * (LsmPgno)iBlock - 1 - 4;
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    return iBlock * nPagePerBlock;
  }
}

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

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

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

  }
  return pPage->aData;
}

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

/*
** Page pPg is currently part of the LRU list belonging to pFS. Remove
** it from the list. pPg->pLruNext and pPg->pLruPrev are cleared by this

/*
** Search the hash-table for page iPg. If an entry is round, return a pointer
** to it. Otherwise, return NULL.
**
** Either way, if argument piHash is not NULL set *piHash to the hash slot
** number that page iPg would be stored in before returning.
*/
static Page *fsPageFindInHash(FileSystem *pFS, LsmPgno iPg, int *piHash){
  Page *p;                        /* Return value */
  int iHash = fsHashKey(pFS->nHash, iPg);

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

}

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

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

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

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

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

  }
  return rc;
}

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

/*
** Read nData bytes of data from offset iOff of the database file into
** buffer aData. If this means reading past the end of a block, follow
** the block pointer to the next block and continue reading.

** to the total number of free bytes before returning.
**
** If no error occurs, LSM_OK is returned. Otherwise, an lsm error code.
*/
static int fsPageGet(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Block redirection to use (or NULL) */
  LsmPgno iPg,                    /* Page id */
  int noContent,                  /* True to not load content from disk */
  Page **ppPg,                    /* OUT: New page handle */
  int *pnSpace                    /* OUT: Bytes of free space */
){
  Page *p;
  int iHash;
  int rc = LSM_OK;

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

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

  /* Search the hash-table for the page */

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

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

  if( fsRunEndsBetween(&pLevel->lhs, pIgnore, iFirst, iLast) ){
    return 1;
  }
  for(i=0; i<pLevel->nRight; i++){

static int fsFreeBlock(
  FileSystem *pFS,                /* File system object */
  Snapshot *pSnapshot,            /* Worker snapshot */
  Segment *pIgnore,               /* Ignore this run when searching */
  int iBlk                        /* Block number of block to free */
){
  int rc = LSM_OK;                /* Return code */
  LsmPgno iFirst;                 /* First page on block iBlk */
  LsmPgno iLast;                  /* Last page on block iBlk */
  Level *pLevel;                  /* Used to iterate through levels */

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

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

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

}

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

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

/*
** Return true if the second argument is not NULL and any of the first
** last or root pages lie on a redirected block. 
*/

** the segment pRun. This function gobbles from the start of the run to the
** first page that appears in aPgno[] (i.e. so that the aPgno[] entry is
** the new first page of the run).
*/
void lsmFsGobble(
  lsm_db *pDb,
  Segment *pRun, 
  LsmPgno *aPgno,
  int nPgno
){
  int rc = LSM_OK;
  FileSystem *pFS = pDb->pFS;
  Snapshot *pSnapshot = pDb->pWorker;
  int iBlk;

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

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

  while( rc==LSM_OK ){
    int iNext = 0;
    LsmPgno iFirst = firstOnBlock(pFS, iBlk, aPgno, nPgno);
    if( iFirst ){
      pRun->iFirst = iFirst;
      break;
    }
    rc = fsBlockNext(pFS, pRun, iBlk, &iNext);
    if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, pRun, iBlk);
    pRun->nSize -= (int)(

**   *piNext = iPg + nByte;
**
** But take block overflow and redirection into account.
*/
static int fsNextPageOffset(
  FileSystem *pFS,                /* File system object */
  Segment *pSeg,                  /* Segment to move within */
  LsmPgno iPg,                    /* Offset of current page */
  int nByte,                      /* Size of current page including headers */
  LsmPgno *piNext                 /* OUT: Offset of next page. Or zero (EOF) */
){
  LsmPgno iNext;
  int rc;

  assert( pFS->pCompress );

  rc = fsAddOffset(pFS, pSeg, iPg, nByte-1, &iNext);
  if( pSeg && iNext==pSeg->iLastPg ){
    iNext = 0;

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

  assert( pFS->pCompress );

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

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

    do {
      if( eDir>0 ){

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

  for(i=LSM_APPLIST_SZ-1; iRet==0 && i>=0; i--){
    if( (iRet = aiAppend[i]) ){
      if( pLvl ){
        int iBlk = fsPageToBlock(pFS, iRet);
        int j;
        for(j=0; iRet && j<pLvl->nRight; j++){

  Snapshot *pSnapshot,
  Level *pLvl,
  int bDefer,
  Page **ppOut
){
  int rc = LSM_OK;
  Page *pPg = 0;
  LsmPgno iApp = 0;
  LsmPgno iNext = 0;
  Segment *p = &pLvl->lhs;
  LsmPgno iPrev = p->iLastPg;

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

  if( pFS->pCompress || bDefer ){
    /* In compressed database mode the page is not assigned a page number
    ** or location in the database file at this point. This will be done

    ** Shift this extra block back to the free-block list. 
    **
    ** Otherwise, add the first free page in the last block used by the run
    ** to the lAppend list.
    */
    if( fsLastPageOnPagesBlock(pFS, p->iLastPg)!=p->iLastPg ){
      int i;
      LsmPgno *aiAppend = pFS->pDb->pWorker->aiAppend;
      for(i=0; i<LSM_APPLIST_SZ; i++){
        if( aiAppend[i]==0 ){
          aiAppend[i] = p->iLastPg+1;
          break;
        }
      }
    }else if( pFS->pCompress==0 ){

}

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

/*
** Obtain a reference to the last page in the segment passed as the 
** second argument.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg){
  int rc;
  LsmPgno iPg = pSeg->iLastPg;
  if( pFS->pCompress ){
    int nSpace;
    iPg++;
    do {
      nSpace = 0;
      rc = fsGetPageBefore(pFS, pSeg, iPg, &iPg);
      if( rc==LSM_OK ){

** number (*piPg) lies on block iFrom, then calculate the equivalent
** page on block iTo and set *piPg to this value before returning.
*/
static void fsMovePage(
  FileSystem *pFS,                /* File system object */
  int iTo,                        /* Destination block */
  int iFrom,                      /* Source block */
  LsmPgno *piPg                   /* IN/OUT: Page number */
){
  LsmPgno iPg = *piPg;
  if( iFrom==fsPageToBlock(pFS, iPg) ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS ->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    *piPg = iPg - (LsmPgno)(iFrom - iTo) * nPagePerBlock;
  }
}

/*
** Copy the contents of block iFrom to block iTo. 
**
** It is safe to assume that there are no outstanding references to pages 

/*
** Append raw data to a segment. Return the database file offset that the
** data is written to (this may be used as the page number if the data
** being appended is a new page record).
**
** This function is only used in compressed database mode.
*/
static LsmPgno fsAppendData(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Segment to append to */
  const u8 *aData,                /* Buffer containing data to write */
  int nData,                      /* Size of buffer aData[] in bytes */
  int *pRc                        /* IN/OUT: Error code */
){
  LsmPgno iRet = 0;
  int rc = *pRc;
  assert( pFS->pCompress );
  if( rc==LSM_OK ){
    int nRem = 0;
    int nWrite = 0;
    LsmPgno iLastOnBlock;
    LsmPgno iApp = pSeg->iLastPg+1;

    /* If this is the first data written into the segment, find an append-point
    ** or allocate a new block.  */
    if( iApp==1 ){
      pSeg->iFirst = iApp = findAppendPoint(pFS, 0);
      if( iApp==0 ){
        int iBlk;

          assert( iApp==(fsPageToBlock(pFS, iApp)*pFS->nBlocksize)-4 );
          lsmPutU32(aPtr, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iApp, aPtr, sizeof(aPtr));
        }

        /* Set the "prev" pointer on the new block */
        if( rc==LSM_OK ){
          LsmPgno iWrite;
          lsmPutU32(aPtr, fsPageToBlock(pFS, iApp));
          iWrite = fsFirstPageOnBlock(pFS, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iWrite-4, aPtr, sizeof(aPtr));
          if( nRem>0 ) iApp = iWrite;
        }
      }else{
        /* The next block is already allocated. */

** LSM_OK is returned if successful, or an lsm error code otherwise. If
** any value other than LSM_OK is returned, then the final value of all
** output variables is undefined.
*/
static int fsAppendPage(
  FileSystem *pFS, 
  Segment *pSeg,
  LsmPgno *piNew,
  int *piPrev,
  int *piNext
){
  LsmPgno iPrev = pSeg->iLastPg;
  int rc;
  assert( iPrev!=0 );

  *piPrev = 0;
  *piNext = 0;

  if( fsIsLast(pFS, iPrev) ){

  }
  *pRc = rc;
}

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

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

  if( p ){
    assert( p->nRef==0 || (p->flags & PAGE_FREE)==0 );

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

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

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

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

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

  for(pLvl=lsmDbSnapshotLevel(pWorker); pLvl && pSeg==0; pLvl=pLvl->pNext){
    if( 0==(pSeg = startsWith(&pLvl->lhs, iFirst)) ){
      int i;
      for(i=0; i<pLvl->nRight; i++){

** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayStructure(
  lsm_db *pDb, 
  int bBlock,                     /* True for block numbers only */
  LsmPgno iFirst,
  char **pzOut
){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pArray = 0;            /* Array to report on */
  int bUnlock = 0;

  }
  return rc;
}

int lsmFsSegmentContainsPg(
  FileSystem *pFS, 
  Segment *pSeg, 
  LsmPgno iPg, 
  int *pbRes
){
  Redirect *pRedir = pSeg->pRedirect;
  int rc = LSM_OK;
  int iBlk;
  int iLastBlk;
  int iPgBlock;                   /* Block containing page iPg */

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

  *pzOut = 0;
  if( iFirst==0 ) return LSM_ERROR;

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

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

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

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

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

** The following macros are used to access a page footer.
*/
#define SEGMENT_NRECORD_OFFSET(pgsz)        ((pgsz) - 2)
#define SEGMENT_FLAGS_OFFSET(pgsz)          ((pgsz) - 2 - 2)
#define SEGMENT_POINTER_OFFSET(pgsz)        ((pgsz) - 2 - 2 - 8)
#define SEGMENT_CELLPTR_OFFSET(pgsz, iCell) ((pgsz) - 2 - 2 - 8 - 2 - (iCell)*2)

#define SEGMENT_EOF(pgsz, nEntry) SEGMENT_CELLPTR_OFFSET(pgsz, nEntry-1)

#define SEGMENT_BTREE_FLAG     0x0001
#define PGFTR_SKIP_NEXT_FLAG   0x0002
#define PGFTR_SKIP_THIS_FLAG   0x0004


#ifndef LSM_SEGMENTPTR_FREE_THRESHOLD
# define LSM_SEGMENTPTR_FREE_THRESHOLD 1024
#endif

typedef struct SegmentPtr SegmentPtr;
typedef struct LsmBlob LsmBlob;

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

/*

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

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

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

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

/*
** Used to iterate through the keys stored in a b-tree hierarchy from start
** to finish. Only First() and Next() operations are required.
**
**   btreeCursorNew()

  int iPg;                        /* Current entry in aPg[]. -1 -> EOF. */
  BtreePg *aPg;                   /* Pages from root to current location */

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

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


/*
** A cursor used for merged searches or iterations through up to one
** Tree structure and any number of sorted files.
**

*/
struct MultiCursor {
  lsm_db *pDb;                    /* Connection that owns this cursor */
  MultiCursor *pNext;             /* Next cursor owned by connection pDb */
  int flags;                      /* Mask of CURSOR_XXX flags */

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

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

  /* Comparison results */
  int nTree;                      /* Size of aTree[] array */
  int *aTree;                     /* Array of comparison results */

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

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

/*
** The following constants are used to assign integers to each component
** cursor of a multi-cursor.
*/
#define CURSOR_DATA_TREE0     0   /* Current tree cursor (apTreeCsr[0]) */

  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */
  LsmPgno *aGobble;               /* Gobble point for each input segment */

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

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);

  aOut[3] = (u8)((nVal>>32) & 0xFF);
  aOut[4] = (u8)((nVal>>24) & 0xFF);
  aOut[5] = (u8)((nVal>>16) & 0xFF);
  aOut[6] = (u8)((nVal>> 8) & 0xFF);
  aOut[7] = (u8)((nVal    ) & 0xFF);
}

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

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

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

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

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

  return rc;
}

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

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

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

static u8 *pageGetCell(u8 *aData, int nData, int iCell){

  return pageGetNRec(aData, nData);
}

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

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

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

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

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

  return rc;
}

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

  aData = fsPageData(pPg, &nData);
  aCell = pageGetCell(aData, nData, iKey);
  assert( aCell[0]==0 );

#define GETVARINT64(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet64((a), &(i)))
#define GETVARINT32(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet32((a), &(i)))

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

  aData = fsPageData(pPg, &nData);
  assert( SEGMENT_BTREE_FLAG & pageGetFlags(aData, nData) );
  assert( iKey>=0 && iKey<pageGetNRec(aData, nData) );

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

  if( eType==0 ){
    int rc;
    LsmPgno iRef;               /* Page number of referenced page */
    Page *pRef;
    aCell += GETVARINT64(aCell, iRef);
    rc = lsmFsDbPageGet(lsmPageFS(pPg), pSeg, iRef, &pRef);
    if( rc!=LSM_OK ) return rc;
    pageGetKeyCopy(lsmPageEnv(pPg), pSeg, pRef, 0, &eType, pBlob);
    lsmFsPageRelease(pRef);
    *ppKey = pBlob->pData;

static int btreeCursorLoadKey(BtreeCursor *pCsr){
  int rc = LSM_OK;
  if( pCsr->iPg<0 ){
    pCsr->pKey = 0;
    pCsr->nKey = 0;
    pCsr->eType = 0;
  }else{
    LsmPgno dummy;
    int iPg = pCsr->iPg;
    int iCell = pCsr->aPg[iPg].iCell;
    while( iCell<0 && (--iPg)>=0 ){
      iCell = pCsr->aPg[iPg].iCell-1;
    }
    if( iPg<0 || iCell<0 ) return LSM_CORRUPT_BKPT;

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

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

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

  MergeInput *p
){
  int rc = LSM_OK;

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

    /* Decode the MergeInput structure */
    iLeaf = p->iPg;
    nDepth = (p->iCell & 0x00FF);
    iCell = (p->iCell >> 8) - 1;

      pCsr->nDepth = nDepth;
      pCsr->aPg[pCsr->iPg].iCell = iCell;
      rc = lsmFsDbPageGet(pCsr->pFS, pSeg, iLeaf, pp);
    }

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

      do {
        Page *pPg2;

          iMax = iCell2-1;
          iMin = 0;

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

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

      u8 *aData;
      int nData;

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

}

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

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

  pSeg = sortedSplitkeySegment(pLevel);
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, pSeg, pMerge->splitkey.iPg, &pPg);
  }
  if( rc==LSM_OK ){
    int iTopic;
    LsmBlob blob = {0, 0, 0, 0};
    u8 *aData;
    int nData;
  
    aData = lsmFsPageData(pPg, &nData);
    if( pageGetFlags(aData, nData) & SEGMENT_BTREE_FLAG ){
      void *pKey;
      int nKey;
      LsmPgno dummy;
      rc = pageGetBtreeKey(pSeg,
          pPg, pMerge->splitkey.iCell, &dummy, &iTopic, &pKey, &nKey, &blob
      );
      if( rc==LSM_OK && blob.pData!=pKey ){
        rc = sortedBlobSet(pEnv, &blob, pKey, nKey);
      }
    }else{

*/
static int assertKeyLocation(
  MultiCursor *pCsr, 
  SegmentPtr *pPtr, 
  void *pKey, int nKey
){
  lsm_env *pEnv = lsmFsEnv(pCsr->pDb->pFS);
  LsmBlob blob = {0, 0, 0};
  int eDir;
  int iTopic = 0;                 /* TODO: Fix me */

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

    lsmFsPageRef(pTest);

  return rc;
}

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

  do {

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

  if( pPtr->pSeg==&pLvl->lhs || pPtr->pSeg==&pLvl->aRhs[pLvl->nRight-1] ){
    if( pNext==0 
        || (pNext->nRight==0 && pNext->lhs.iRoot)
        || (pNext->nRight!=0 && pNext->aRhs[0].iRoot)
      ){
      /* Do nothing. The pointer will not be used anyway. */

  int *pbStop
){
  int (*xCmp)(void *, int, void *, int) = pCsr->pDb->xCmp;
  int res = 0;                        /* Result of comparison operation */
  int rc = LSM_OK;
  int iMin;
  int iMax;
  LsmPgno iPtrOut = 0;

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

}

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

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

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

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

        rc = pageGetBtreeKey(
            pSeg, pPg, iTry, &iPtr, &iTopicT, &pKeyT, &nKeyT, &blob
        );
        if( rc!=LSM_OK ) break;
        if( piFirst && pKeyT==blob.pData ){

*/
static int seekInLevel(
  MultiCursor *pCsr,              /* Sorted cursor object to seek */
  SegmentPtr *aPtr,               /* Pointer to array of (nRhs+1) SPs */
  int eSeek,                      /* Search bias - see above */
  int iTopic,                     /* Key topic to search for */
  void *pKey, int nKey,           /* Key to search for */
  LsmPgno *piPgno,                /* IN/OUT: fraction cascade pointer (or 0) */
  int *pbStop                     /* OUT: See above */
){
  Level *pLvl = aPtr[0].pLevel;   /* Level to seek within */
  int rc = LSM_OK;                /* Return code */
  int iOut = 0;                   /* Pointer to return to caller */
  int res = -1;                   /* Result of xCmp(pKey, split) */
  int nRhs = pLvl->nRight;        /* Number of right-hand-side segments */

  void *pKey, int nKey, 
  int eSeek
){
  int eESeek = eSeek;             /* Effective eSeek parameter */
  int bStop = 0;                  /* Set to true to halt search operation */
  int rc = LSM_OK;                /* Return code */
  int iPtr = 0;                   /* Used to iterate through pCsr->aPtr[] */
  LsmPgno iPgno = 0;              /* FC pointer value */

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

  if( eESeek==LSM_SEEK_LEFAST ) eESeek = LSM_SEEK_LE;

  assert( eESeek==LSM_SEEK_EQ || eESeek==LSM_SEEK_LE || eESeek==LSM_SEEK_GE );

** differences are:
**
**   1. The record format is (usually, see below) as follows:
**
**         + Type byte (always SORTED_SEPARATOR or SORTED_SYSTEM_SEPARATOR),
**         + Absolute pointer value (varint),
**         + Number of bytes in key (varint),
**         + LsmBlob containing key data.
**
**   2. All pointer values are stored as absolute values (not offsets 
**      relative to the footer pointer value).
**
**   3. Each pointer that is part of a record points to a page that 
**      contains keys smaller than the records key (note: not "equal to or
**      smaller than - smaller than").

**
** See function seekInBtree() for the code that traverses b-tree pages.
*/

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

  return rc;
}

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

/*
** Append the database key (iTopic/pKey/nKey) to the b-tree under 
** construction. This key has not yet been written to a segment page.
** The pointer that will accompany the new key in the b-tree - that
** points to the completed segment page that contains keys smaller than
** (pKey/nKey) is currently stored in pMW->aSave[0].iPgno.
*/
static int mergeWorkerPushHierarchy(
  MergeWorker *pMW,               /* Merge worker object */
  int iTopic,                     /* Topic value for this key */
  void *pKey,                     /* Pointer to key buffer */
  int nKey                        /* Size of pKey buffer in bytes */
){
  int rc = LSM_OK;                /* Return Code */
  LsmPgno iPtr;                   /* Pointer value to accompany pKey/nKey */

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

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

}

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

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

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

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

    nHdr = 1 + lsmVarintLen32(iRPtr) + lsmVarintLen32(nKey);
    if( rtIsWrite(eType) ) nHdr += lsmVarintLen32(nVal);

    /* If the entire header will not fit on page pPg, or if page pPg is 
    ** marked read-only, advance to the next page of the output run. */
    iOff = pMerge->iOutputOff;
    if( iOff<0 || pPg==0 || iOff+nHdr > SEGMENT_EOF(nData, nRec+1) ){
      if( iOff>=0 && pPg ){
        /* Zero any free space on the page */
        assert( aData );
        memset(&aData[iOff], 0, SEGMENT_EOF(nData, nRec)-iOff);
      }
      iFPtr = (int)*pMW->pCsr->pPrevMergePtr;
      iRPtr = iPtr - iFPtr;
      iOff = 0;
      nRec = 0;
      rc = mergeWorkerNextPage(pMW, iFPtr);
      pPg = pMW->pPage;
    }

  int i;                          /* Iterator variable */
  int rc = *pRc;
  MultiCursor *pCsr = pMW->pCsr;

  /* Unless the merge has finished, save the cursor position in the
  ** Merge.aInput[] array. See function mergeWorkerInit() for the 
  ** code to restore a cursor position based on aInput[].  */
  if( rc==LSM_OK && pCsr ){
    Merge *pMerge = pMW->pLevel->pMerge;
    if( lsmMCursorValid(pCsr) ){
      int bBtree = (pCsr->pBtCsr!=0);
      int iPtr;

      /* pMerge->nInput==0 indicates that this is a FlushTree() operation. */
      assert( pMerge->nInput==0 || pMW->pLevel->nRight>0 );
      assert( pMerge->nInput==0 || pMerge->nInput==(pCsr->nPtr+bBtree) );

      for(i=0; i<(pMerge->nInput-bBtree); i++){
        SegmentPtr *pPtr = &pCsr->aPtr[i];
        if( pPtr->pPg ){
          pMerge->aInput[i].iPg = lsmFsPageNumber(pPtr->pPg);
          pMerge->aInput[i].iCell = pPtr->iCell;
        }else{
          pMerge->aInput[i].iPg = 0;
          pMerge->aInput[i].iCell = 0;
        }
      }
      if( bBtree && pMerge->nInput ){
        assert( i==pCsr->nPtr );
        btreeCursorPosition(pCsr->pBtCsr, &pMerge->aInput[i]);
      }

      /* Store the location of the split-key */
      iPtr = pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
      if( iPtr<pCsr->nPtr ){
        pMerge->splitkey = pMerge->aInput[iPtr];
      }else{
        btreeCursorSplitkey(pCsr->pBtCsr, &pMerge->splitkey);
      }
    }

    /* Zero any free space left on the final page. This helps with
    ** compression if using a compression hook. And prevents valgrind
    ** from complaining about uninitialized byte passed to write(). */
    if( pMW->pPage ){
      int nData;
      u8 *aData = fsPageData(pMW->pPage, &nData);
      int iOff = pMerge->iOutputOff;
      int iEof = SEGMENT_EOF(nData, pageGetNRec(aData, nData));
      memset(&aData[iOff], 0, iEof - iOff);
    }
    
    pMerge->iOutputOff = -1;
  }

  lsmMCursorClose(pCsr, 0);

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

  pCsr = pMW->pCsr;

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

      multiCursorIgnoreDelete(pCsr);
    }
  }

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

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

    pNew->pMerge = &merge;

  assert( pDb->pWorker );
  assert( pLevel->pMerge );
  assert( pLevel->nRight>0 );

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

  /* Create a multi-cursor to read the data to write to the new
  ** segment. The new segment contains:
  **
  **   1. Records from LHS of each of the nMerge levels being merged.
  **   2. Separators from either the last level being merged, or the
  **      separators attached to the LHS of the following level, or neither.

  lsm_db *pDb,                    /* Worker connection */
  MultiCursor *pCsr,              /* Multi-cursor being used for a merge */
  int iGobble                     /* pCsr->aPtr[] entry to operate on */
){
  int rc = LSM_OK;
  if( rtTopic(pCsr->eType)==0 ){
    Segment *pSeg = pCsr->aPtr[iGobble].pSeg;
    LsmPgno *aPg;
    int nPg;

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

    if( rc==LSM_OK ){

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

  char *z1;
  char *z2;
  int nPad;

  z1 = lsmMallocPrintf(pEnv, "%d.%d", iFirst, iLast);

    aBuf[0] = '\0';
  }

  return i;
}

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

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

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

    if( eType==0 ){
      LsmPgno iRef;               /* Page number of referenced page */
      aCell += lsmVarintGet64(aCell, &iRef);
      lsmFsDbPageGet(pDb->pFS, pRun, iRef, &pRef);
      aKey = pageGetKey(pRun, pRef, 0, &iTopic, &nKey, &blob);
    }else{
      aCell += lsmVarintGet32(aCell, &nKey);
      if( rtIsWrite(eType) ) aCell += lsmVarintGet32(aCell, &nVal);
      sortedReadData(0, pPg, (aCell-aData), nKey+nVal, (void **)&aKey, &blob);

  int bIndirect,                  /* True to follow indirect refs */
  Page *pPg,
  int iCell,
  int *peType,
  int *piPgPtr,
  u8 **paKey, int *pnKey,
  u8 **paVal, int *pnVal,
  LsmBlob *pBlob
){
  u8 *aData; int nData;           /* Page data */
  u8 *aKey; int nKey = 0;         /* Key */
  u8 *aVal = 0; int nVal = 0;     /* Value */
  int eType;
  int iPgPtr;
  Page *pRef = 0;                 /* Pointer to page iRef */
  u8 *aCell;

  aData = fsPageData(pPg, &nData);

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

  if( eType==0 ){
    int dummy;
    LsmPgno iRef;                 /* Page number of referenced page */
    aCell += lsmVarintGet64(aCell, &iRef);
    if( bIndirect ){
      lsmFsDbPageGet(pDb->pFS, pSeg, iRef, &pRef);
      pageGetKeyCopy(pDb->pEnv, pSeg, pRef, 0, &dummy, pBlob);
      aKey = (u8 *)pBlob->pData;
      nKey = pBlob->nData;
      lsmFsPageRelease(pRef);

#define INFO_PAGE_DUMP_DATA     0x01
#define INFO_PAGE_DUMP_VALUES   0x02
#define INFO_PAGE_DUMP_HEX      0x04
#define INFO_PAGE_DUMP_INDIRECT 0x08

static int infoPageDump(
  lsm_db *pDb,                    /* Database handle */
  LsmPgno iPg,                    /* Page number of page to dump */
  int flags,
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int rc = LSM_OK;                /* Return code */
  Page *pPg = 0;                  /* Handle for page iPg */
  int i, j;                       /* Loop counters */
  const int perLine = 16;         /* Bytes per line in the raw hex dump */

  ** to pass a NULL in place of the segment pointer as the second argument
  ** to lsmFsDbPageGet() here.  */
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, 0, iPg, &pPg);
  }

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

    if( bHex ) nKeyWidth = nKeyWidth * 2;

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

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

  }

  return rc;
}

int lsmInfoPageDump(
  lsm_db *pDb,                    /* Database handle */
  LsmPgno iPg,                    /* Page number of page to dump */
  int bHex,                       /* True to output key/value in hex form */
  char **pzOut                    /* OUT: lsmMalloc'd string */
){
  int flags = INFO_PAGE_DUMP_DATA | INFO_PAGE_DUMP_VALUES;
  if( bHex ) flags |= INFO_PAGE_DUMP_HEX;
  return infoPageDump(pDb, iPg, flags, pzOut);
}

  iHdr = SEGMENT_EOF(nOrig, nEntry);
  memmove(&aData[iHdr + (nData-nOrig)], &aData[iHdr], nOrig-iHdr);
}

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

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

    aData = lsmFsPageData(pPg, &nData);

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

  assert( pOne && pTwo );

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

  }

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

    /* Advance to the next page of segment pTwo that contains at least
    ** one cell. Break out of the loop if the iterator reaches EOF.  */
    do{
      rc = segmentPtrNextPage(&ptr2, 1);
      assert( rc==LSM_OK );
    }while( rc==LSM_OK && ptr2.pPg && ptr2.nCell==0 );

*/
static int assertBtreeOk(
  lsm_db *pDb,
  Segment *pSeg
){
  int rc = LSM_OK;                /* Return code */
  if( pSeg->iRoot ){
    LsmBlob blob = {0, 0, 0};     /* Buffer used to cache overflow keys */
    FileSystem *pFS = pDb->pFS;   /* File system to read from */
    Page *pPg = 0;                /* Main run page */
    BtreeCursor *pCsr = 0;        /* Btree cursor */

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

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

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

set G(hdr) {

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

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

}

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

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

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

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

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

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

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


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

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

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

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


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

fts5parse.h: fts5parse.c

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

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

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

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

sqlite3rbu.o:	$(TOP)/ext/rbu/sqlite3rbu.c $(HDR) $(EXTHDR)

	rm -f sqlite3_analyzer sqlite3_analyzer.exe sqlite3_analyzer.c
	rm -f sqlite-*-output.vsix
	rm -f mptester mptester.exe
	rm -f fuzzershell fuzzershell.exe
	rm -f fuzzcheck fuzzcheck.exe
	rm -f sqldiff sqldiff.exe
	rm -f fts5.* fts5parse.*
	rm -f lsm.h lsm1.c

  #define setSharedCacheTableLock(a,b,c) SQLITE_OK
  #define clearAllSharedCacheTableLocks(a)
  #define downgradeAllSharedCacheTableLocks(a)
  #define hasSharedCacheTableLock(a,b,c,d) 1
  #define hasReadConflicts(a, b) 0
#endif

/*
** Implementation of the SQLITE_CORRUPT_PAGE() macro. Takes a single
** (MemPage*) as an argument. The (MemPage*) must not be NULL.
**
** If SQLITE_DEBUG is not defined, then this macro is equivalent to
** SQLITE_CORRUPT_BKPT. Or, if SQLITE_DEBUG is set, then the log message
** normally produced as a side-effect of SQLITE_CORRUPT_BKPT is augmented
** with the page number and filename associated with the (MemPage*).
*/
#ifdef SQLITE_DEBUG
int corruptPageError(int lineno, MemPage *p){
  char *zMsg = sqlite3_mprintf("database corruption page %d of %s",
      (int)p->pgno, sqlite3PagerFilename(p->pBt->pPager, 0)
  );
  if( zMsg ){
    sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
  }
  sqlite3_free(zMsg);
  return SQLITE_CORRUPT_BKPT;
}
# define SQLITE_CORRUPT_PAGE(pMemPage) corruptPageError(__LINE__, pMemPage)
#else
# define SQLITE_CORRUPT_PAGE(pMemPage) SQLITE_CORRUPT_PGNO(pMemPage->pgno)
#endif

#ifndef SQLITE_OMIT_SHARED_CACHE

#ifdef SQLITE_DEBUG
/*
**** This function is only used as part of an assert() statement. ***
**
** Check to see if pBtree holds the required locks to read or write to the 

      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
        u8 *pEnd = &data[cellOffset + nCell*2];
        u8 *pAddr;
        int sz2 = 0;
        int sz = get2byte(&data[iFree+2]);
        int top = get2byte(&data[hdr+5]);
        if( top>=iFree ){
          return SQLITE_CORRUPT_PAGE(pPage);
        }
        if( iFree2 ){
          assert( iFree+sz<=iFree2 ); /* Verified by pageFindSlot() */
          sz2 = get2byte(&data[iFree2+2]);
          assert( iFree+sz+sz2+iFree2-(iFree+sz) <= usableSize );
          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));
          sz += sz2;

    pc = get2byte(pAddr);
    testcase( pc==iCellFirst );
    testcase( pc==iCellLast );
    /* These conditions have already been verified in btreeInitPage()
    ** if PRAGMA cell_size_check=ON.
    */
    if( pc<iCellFirst || pc>iCellLast ){
      return SQLITE_CORRUPT_PAGE(pPage);
    }
    assert( pc>=iCellFirst && pc<=iCellLast );
    size = pPage->xCellSize(pPage, &src[pc]);
    cbrk -= size;
    if( cbrk<iCellFirst || pc+size>usableSize ){
      return SQLITE_CORRUPT_PAGE(pPage);
    }
    assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
    testcase( cbrk+size==usableSize );
    testcase( pc+size==usableSize );
    put2byte(pAddr, cbrk);
    if( temp==0 ){
      int x;
      if( cbrk==pc ) continue;
      temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
      x = get2byte(&data[hdr+5]);
      memcpy(&temp[x], &data[x], (cbrk+size) - x);
      src = temp;
    }
    memcpy(&data[cbrk], &src[pc], size);
  }
  data[hdr+7] = 0;

 defragment_out:
  if( data[hdr+7]+cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );

    ** freeblock form a big-endian integer which is the size of the freeblock
    ** in bytes, including the 4-byte header. */
    size = get2byte(&aData[pc+2]);
    if( (x = size - nByte)>=0 ){
      testcase( x==4 );
      testcase( x==3 );
      if( size+pc > usableSize ){
        *pRc = SQLITE_CORRUPT_PAGE(pPg);
        return 0;
      }else if( x<4 ){
        /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
        ** number of bytes in fragments may not exceed 60. */
        if( aData[hdr+7]>57 ) return 0;

        /* Remove the slot from the free-list. Update the number of

      return &aData[pc + x];
    }
    iAddr = pc;
    pc = get2byte(&aData[pc]);
    if( pc<iAddr+size ) break;
  }
  if( pc ){
    *pRc = SQLITE_CORRUPT_PAGE(pPg);
  }

  return 0;
}

/*
** Allocate nByte bytes of space from within the B-Tree page passed

  ** integer, so a value of 0 is used in its place. */
  top = get2byte(&data[hdr+5]);
  assert( top<=(int)pPage->pBt->usableSize ); /* Prevent by getAndInitPage() */
  if( gap>top ){
    if( top==0 && pPage->pBt->usableSize==65536 ){
      top = 65536;
    }else{
      return SQLITE_CORRUPT_PAGE(pPage);
    }
  }

  /* If there is enough space between gap and top for one more cell pointer
  ** array entry offset, and if the freelist is not empty, then search the
  ** freelist looking for a free slot big enough to satisfy the request.
  */

  iPtr = hdr + 1;
  if( data[iPtr+1]==0 && data[iPtr]==0 ){
    iFreeBlk = 0;  /* Shortcut for the case when the freelist is empty */
  }else{
    while( (iFreeBlk = get2byte(&data[iPtr]))<iStart ){
      if( iFreeBlk<iPtr+4 ){
        if( iFreeBlk==0 ) break;
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      iPtr = iFreeBlk;
    }
    if( iFreeBlk>pPage->pBt->usableSize-4 ){
      return SQLITE_CORRUPT_PAGE(pPage);
    }
    assert( iFreeBlk>iPtr || iFreeBlk==0 );
  
    /* At this point:
    **    iFreeBlk:   First freeblock after iStart, or zero if none
    **    iPtr:       The address of a pointer to iFreeBlk
    **
    ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
    */
    if( iFreeBlk && iEnd+3>=iFreeBlk ){
      nFrag = iFreeBlk - iEnd;
      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_PAGE(pPage);
      iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
      if( iEnd > pPage->pBt->usableSize ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      iSize = iEnd - iStart;
      iFreeBlk = get2byte(&data[iFreeBlk]);
    }
  
    /* If iPtr is another freeblock (that is, if iPtr is not the freelist
    ** pointer in the page header) then check to see if iStart should be
    ** coalesced onto the end of iPtr.
    */
    if( iPtr>hdr+1 ){
      int iPtrEnd = iPtr + get2byte(&data[iPtr+2]);
      if( iPtrEnd+3>=iStart ){
        if( iPtrEnd>iStart ) return SQLITE_CORRUPT_PAGE(pPage);
        nFrag += iStart - iPtrEnd;
        iSize = iEnd - iPtr;
        iStart = iPtr;
      }
    }
    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_PAGE(pPage);
    data[hdr+7] -= nFrag;
  }
  x = get2byte(&data[hdr+5]);
  if( iStart<=x ){
    /* The new freeblock is at the beginning of the cell content area,
    ** so just extend the cell content area rather than create another
    ** freelist entry */
    if( iStart<x || iPtr!=hdr+1 ) return SQLITE_CORRUPT_PAGE(pPage);
    put2byte(&data[hdr+1], iFreeBlk);
    put2byte(&data[hdr+5], iEnd);
  }else{
    /* Insert the new freeblock into the freelist */
    put2byte(&data[iPtr], iStart);
  }
  if( pPage->pBt->btsFlags & BTS_FAST_SECURE ){

    pPage->intKeyLeaf = 0;
    pPage->xParseCell = btreeParseCellPtrIndex;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }else{
    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
    ** an error. */
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  pPage->max1bytePayload = pBt->max1bytePayload;
  return SQLITE_OK;
}

/*
** Initialize the auxiliary information for a disk block.

  pBt = pPage->pBt;
  hdr = pPage->hdrOffset;
  data = pPage->aData;
  /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
  ** the b-tree page type. */
  if( decodeFlags(pPage, data[hdr]) ){
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
  pPage->maskPage = (u16)(pBt->pageSize - 1);
  pPage->nOverflow = 0;
  usableSize = pBt->usableSize;
  pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
  pPage->aDataEnd = &data[usableSize];
  pPage->aCellIdx = &data[cellOffset];
  pPage->aDataOfst = &data[pPage->childPtrSize];
  /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
  ** the start of the cell content area. A zero value for this integer is
  ** interpreted as 65536. */
  top = get2byteNotZero(&data[hdr+5]);
  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
  ** number of cells on the page. */
  pPage->nCell = get2byte(&data[hdr+3]);
  if( pPage->nCell>MX_CELL(pBt) ){
    /* To many cells for a single page.  The page must be corrupt */
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  testcase( pPage->nCell==MX_CELL(pBt) );
  /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
  ** possible for a root page of a table that contains no rows) then the
  ** offset to the cell content area will equal the page size minus the
  ** bytes of reserved space. */
  assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );

    if( !pPage->leaf ) iCellLast--;
    for(i=0; i<pPage->nCell; i++){
      pc = get2byteAligned(&data[cellOffset+i*2]);
      testcase( pc==iCellFirst );
      testcase( pc==iCellLast );
      if( pc<iCellFirst || pc>iCellLast ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      sz = pPage->xCellSize(pPage, &data[pc]);
      testcase( pc+sz==usableSize );
      if( pc+sz>usableSize ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
    }
    if( !pPage->leaf ) iCellLast++;
  }  

  /* Compute the total free space on the page
  ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
  ** start of the first freeblock on the page, or is zero if there are no
  ** freeblocks. */
  pc = get2byte(&data[hdr+1]);
  nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
  if( pc>0 ){
    u32 next, size;
    if( pc<iCellFirst ){
      /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
      ** always be at least one cell before the first freeblock.
      */
      return SQLITE_CORRUPT_PAGE(pPage); 
    }
    while( 1 ){
      if( pc>iCellLast ){
        /* Freeblock off the end of the page */
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      next = get2byte(&data[pc]);
      size = get2byte(&data[pc+2]);
      nFree = nFree + size;
      if( next<=pc+size+3 ) break;
      pc = next;
    }
    if( next>0 ){
      /* Freeblock not in ascending order */
      return SQLITE_CORRUPT_PAGE(pPage);
    }
    if( pc+size>(unsigned int)usableSize ){
      /* Last freeblock extends past page end */
      return SQLITE_CORRUPT_PAGE(pPage);
    }
  }

  /* At this point, nFree contains the sum of the offset to the start
  ** of the cell-content area plus the number of free bytes within
  ** the cell-content area. If this is greater than the usable-size
  ** of the page, then the page must be corrupted. This check also
  ** serves to verify that the offset to the start of the cell-content
  ** area, according to the page header, lies within the page.
  */
  if( nFree>usableSize ){
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  pPage->nFree = (u16)(nFree - iCellFirst);
  pPage->isInit = 1;
  return SQLITE_OK;
}

/*

*/
static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  if( eType==PTRMAP_OVERFLOW2 ){
    /* The pointer is always the first 4 bytes of the page in this case.  */
    if( get4byte(pPage->aData)!=iFrom ){
      return SQLITE_CORRUPT_PAGE(pPage);
    }
    put4byte(pPage->aData, iTo);
  }else{
    int i;
    int nCell;
    int rc;

    rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);
    if( rc ) return rc;
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        pPage->xParseCell(pPage, pCell, &info);
        if( info.nLocal<info.nPayload ){
          if( pCell+info.nSize > pPage->aData+pPage->pBt->usableSize ){
            return SQLITE_CORRUPT_PAGE(pPage);
          }
          if( iFrom==get4byte(pCell+info.nSize-4) ){
            put4byte(pCell+info.nSize-4, iTo);
            break;
          }
        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }
    }
  
    if( i==nCell ){
      if( eType!=PTRMAP_BTREE || 
          get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);
    }
  }
  return SQLITE_OK;
}

  assert( aPayload > pPage->aData );
  if( (uptr)(aPayload - pPage->aData) > (pBt->usableSize - pCur->info.nLocal) ){
    /* Trying to read or write past the end of the data is an error.  The
    ** conditional above is really:
    **    &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
    ** but is recast into its current form to avoid integer overflow problems
    */
    return SQLITE_CORRUPT_PAGE(pPage);
  }

  /* Check if data must be read/written to/from the btree page itself. */
  if( offset<pCur->info.nLocal ){
    int a = amt;
    if( a+offset>pCur->info.nLocal ){
      a = pCur->info.nLocal - offset;

      if( rc ) break;
      iIdx++;
    }
  }

  if( rc==SQLITE_OK && amt>0 ){
    /* Overflow chain ends prematurely */
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  return rc;
}

/*
** Read part of the payload for the row at which that cursor pCur is currently
** pointing.  "amt" bytes will be transferred into pBuf[].  The transfer

  ** Earlier versions of SQLite assumed that this test could not fail
  ** if the root page was already loaded when this function was called (i.e.
  ** if pCur->iPage>=0). But this is not so if the database is corrupted 
  ** in such a way that page pRoot is linked into a second b-tree table 
  ** (or the freelist).  */
  assert( pRoot->intKey==1 || pRoot->intKey==0 );
  if( pRoot->isInit==0 || (pCur->pKeyInfo==0)!=pRoot->intKey ){
    return SQLITE_CORRUPT_PAGE(pCur->pPage);
  }

skip_init:  
  pCur->ix = 0;
  pCur->info.nSize = 0;
  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);

    if( xRecordCompare==0 ){
      for(;;){
        i64 nCellKey;
        pCell = findCellPastPtr(pPage, idx);
        if( pPage->intKeyLeaf ){
          while( 0x80 <= *(pCell++) ){
            if( pCell>=pPage->aDataEnd ){
              return SQLITE_CORRUPT_PAGE(pPage);
            }
          }
        }
        getVarint(pCell, (u64*)&nCellKey);
        if( nCellKey<intKey ){
          lwr = idx+1;
          if( lwr>upr ){ c = -1; break; }

          pPage->xParseCell(pPage, pCellBody, &pCur->info);
          nCell = (int)pCur->info.nKey;
          testcase( nCell<0 );   /* True if key size is 2^32 or more */
          testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */
          testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */
          testcase( nCell==2 );  /* Minimum legal index key size */
          if( nCell<2 ){
            rc = SQLITE_CORRUPT_PAGE(pPage);
            goto moveto_finish;
          }
          pCellKey = sqlite3Malloc( nCell+18 );
          if( pCellKey==0 ){
            rc = SQLITE_NOMEM_BKPT;
            goto moveto_finish;
          }

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->xParseCell(pPage, pCell, pInfo);
  if( pInfo->nLocal==pInfo->nPayload ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }
  if( pCell+pInfo->nSize-1 > pPage->aData+pPage->maskPage ){
    /* Cell extends past end of page */
    return SQLITE_CORRUPT_PAGE(pPage);
  }
  ovflPgno = get4byte(pCell + pInfo->nSize - 4);
  pBt = pPage->pBt;
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (pInfo->nPayload - pInfo->nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( nOvfl>0 || 

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

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

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

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

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

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

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( !isView ){

**     SELECT <column1>, <column2>... FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephemeral table instead of an
** existing table.
**
** The inFlags parameter must contain, at a minimum, one of the bits
** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both.  If inFlags contains
** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
** membership test.  When the IN_INDEX_LOOP bit is set, the IN index will
** be used to loop over all values of the RHS of the IN operator.

**
** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
** through the set members) then the b-tree must not contain duplicates.
** An epheremal table will be created unless the selected columns are guaranteed
** to be unique - either because it is an INTEGER PRIMARY KEY or due to
** a UNIQUE constraint or index.
**
** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used 
** for fast set membership tests) then an epheremal table must 
** be used unless <columns> is a single INTEGER PRIMARY KEY column or an 
** index can be found with the specified <columns> as its left-most.

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

  }else if( flags & SQLITE_OPEN_NOMUTEX ){
    isThreadsafe = 0;
  }else if( flags & SQLITE_OPEN_FULLMUTEX ){
    isThreadsafe = 1;
  }else{
    isThreadsafe = sqlite3GlobalConfig.bFullMutex;
  }

  if( flags & SQLITE_OPEN_PRIVATECACHE ){
    flags &= ~SQLITE_OPEN_SHAREDCACHE;
  }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
    flags |= SQLITE_OPEN_SHAREDCACHE;
  }

  /* Remove harmful bits from the flags parameter

               SQLITE_OPEN_FULLMUTEX |
               SQLITE_OPEN_WAL
             );

  /* Allocate the sqlite data structure */
  db = sqlite3MallocZero( sizeof(sqlite3) );
  if( db==0 ) goto opendb_out;
  if( isThreadsafe 
#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
   || sqlite3GlobalConfig.bCoreMutex
#endif
  ){
    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
    if( db->mutex==0 ){
      sqlite3_free(db);
      db = 0;
      goto opendb_out;
    }
    if( isThreadsafe==0 ){
      sqlite3MutexWarnOnContention(db->mutex);
    }
  }
  sqlite3_mutex_enter(db->mutex);
  db->errMask = 0xff;
  db->nDb = 2;
  db->magic = SQLITE_MAGIC_BUSY;
  db->aDb = db->aDbStatic;

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

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

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

**
**   1.  Serve as a convenient place to set a breakpoint in a debugger
**       to detect when version error conditions occurs.
**
**   2.  Invoke sqlite3_log() to provide the source code location where
**       a low-level error is first detected.
*/
int sqlite3ReportError(int iErr, int lineno, const char *zType){
  sqlite3_log(iErr, "%s at line %d of [%.10s]",
              zType, lineno, 20+sqlite3_sourceid());
  return iErr;
}
int sqlite3CorruptError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
}
int sqlite3MisuseError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
}
int sqlite3CantopenError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
}
#ifdef SQLITE_DEBUG
int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
  char zMsg[100];
  sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
}
int sqlite3NomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
}
int sqlite3IoerrnomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
}
#endif

#ifndef SQLITE_OMIT_DEPRECATED
/*
** This is a convenience routine that makes sure that all thread-specific
** data for this thread has been deallocated.

** allocate a mutex while the system is uninitialized.
*/
static SQLITE_WSD int mutexIsInit = 0;
#endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */


#ifndef SQLITE_MUTEX_OMIT

#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
/*
** This block (enclosed by SQLITE_ENABLE_MULTITHREADED_CHECKS) contains
** the implementation of a wrapper around the system default mutex
** implementation (sqlite3DefaultMutex()). 
**
** Most calls are passed directly through to the underlying default
** mutex implementation. Except, if a mutex is configured by calling
** sqlite3MutexWarnOnContention() on it, then if contention is ever
** encountered within xMutexEnter() a warning is emitted via sqlite3_log().
**
** This type of mutex is used as the database handle mutex when testing
** apps that usually use SQLITE_CONFIG_MULTITHREAD mode.
*/

/* 
** Type for all mutexes used when SQLITE_ENABLE_MULTITHREADED_CHECKS
** is defined. Variable CheckMutex.mutex is a pointer to the real mutex
** allocated by the system mutex implementation. Variable iType is usually set
** to the type of mutex requested - SQLITE_MUTEX_RECURSIVE, SQLITE_MUTEX_FAST
** or one of the static mutex identifiers. Or, if this is a recursive mutex
** that has been configured using sqlite3MutexWarnOnContention(), it is
** set to SQLITE_MUTEX_WARNONCONTENTION.
*/
typedef struct CheckMutex CheckMutex;
struct CheckMutex {
  int iType;
  sqlite3_mutex *mutex;
};

#define SQLITE_MUTEX_WARNONCONTENTION  (-1)

/* 
** Pointer to real mutex methods object used by the CheckMutex
** implementation. Set by checkMutexInit(). 
*/
static SQLITE_WSD const sqlite3_mutex_methods *pGlobalMutexMethods;

#ifdef SQLITE_DEBUG
static int checkMutexHeld(sqlite3_mutex *p){
  return pGlobalMutexMethods->xMutexHeld(((CheckMutex*)p)->mutex);
}
static int checkMutexNotheld(sqlite3_mutex *p){
  return pGlobalMutexMethods->xMutexNotheld(((CheckMutex*)p)->mutex);
}
#endif

/*
** Initialize and deinitialize the mutex subsystem.
*/
static int checkMutexInit(void){ 
  pGlobalMutexMethods = sqlite3DefaultMutex();
  return SQLITE_OK; 
}
static int checkMutexEnd(void){ 
  pGlobalMutexMethods = 0;
  return SQLITE_OK; 
}

/*
** Allocate a mutex.
*/
static sqlite3_mutex *checkMutexAlloc(int iType){
  static CheckMutex staticMutexes[] = {
    {2, 0}, {3, 0}, {4, 0}, {5, 0},
    {6, 0}, {7, 0}, {8, 0}, {9, 0},
    {10, 0}, {11, 0}, {12, 0}, {13, 0}
  };
  CheckMutex *p = 0;

  assert( SQLITE_MUTEX_RECURSIVE==1 && SQLITE_MUTEX_FAST==0 );
  if( iType<2 ){
    p = sqlite3MallocZero(sizeof(CheckMutex));
    if( p==0 ) return 0;
    p->iType = iType;
  }else{
#ifdef SQLITE_ENABLE_API_ARMOR
    if( iType-2>=ArraySize(staticMutexes) ){
      (void)SQLITE_MISUSE_BKPT;
      return 0;
    }
#endif
    p = &staticMutexes[iType-2];
  }

  if( p->mutex==0 ){
    p->mutex = pGlobalMutexMethods->xMutexAlloc(iType);
    if( p->mutex==0 ){
      if( iType<2 ){
        sqlite3_free(p);
      }
      p = 0;
    }
  }

  return (sqlite3_mutex*)p;
}

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

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

/*
** Enter the mutex.
*/
static void checkMutexEnter(sqlite3_mutex *p){
  CheckMutex *pCheck = (CheckMutex*)p;
  if( pCheck->iType==SQLITE_MUTEX_WARNONCONTENTION ){
    if( SQLITE_OK==pGlobalMutexMethods->xMutexTry(pCheck->mutex) ){
      return;
    }
    sqlite3_log(SQLITE_MISUSE, 
        "illegal multi-threaded access to database connection"
    );
  }
  pGlobalMutexMethods->xMutexEnter(pCheck->mutex);
}

/*
** Enter the mutex (do not block).
*/
static int checkMutexTry(sqlite3_mutex *p){
  CheckMutex *pCheck = (CheckMutex*)p;
  return pGlobalMutexMethods->xMutexTry(pCheck->mutex);
}

/*
** Leave the mutex.
*/
static void checkMutexLeave(sqlite3_mutex *p){
  CheckMutex *pCheck = (CheckMutex*)p;
  pGlobalMutexMethods->xMutexLeave(pCheck->mutex);
}

sqlite3_mutex_methods const *multiThreadedCheckMutex(void){
  static const sqlite3_mutex_methods sMutex = {
    checkMutexInit,
    checkMutexEnd,
    checkMutexAlloc,
    checkMutexFree,
    checkMutexEnter,
    checkMutexTry,
    checkMutexLeave,
#ifdef SQLITE_DEBUG
    checkMutexHeld,
    checkMutexNotheld
#else
    0,
    0
#endif
  };
  return &sMutex;
}

/*
** Mark the SQLITE_MUTEX_RECURSIVE mutex passed as the only argument as
** one on which there should be no contention.
*/
void sqlite3MutexWarnOnContention(sqlite3_mutex *p){
  if( sqlite3GlobalConfig.mutex.xMutexAlloc==checkMutexAlloc ){
    CheckMutex *pCheck = (CheckMutex*)p;
    assert( pCheck->iType==SQLITE_MUTEX_RECURSIVE );
    pCheck->iType = SQLITE_MUTEX_WARNONCONTENTION;
  }
}
#endif   /* ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS */

/*
** Initialize the mutex system.
*/
int sqlite3MutexInit(void){ 
  int rc = SQLITE_OK;
  if( !sqlite3GlobalConfig.mutex.xMutexAlloc ){
    /* If the xMutexAlloc method has not been set, then the user did not
    ** install a mutex implementation via sqlite3_config() prior to 
    ** sqlite3_initialize() being called. This block copies pointers to
    ** the default implementation into the sqlite3GlobalConfig structure.
    */
    sqlite3_mutex_methods const *pFrom;
    sqlite3_mutex_methods *pTo = &sqlite3GlobalConfig.mutex;

    if( sqlite3GlobalConfig.bCoreMutex ){
#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
      pFrom = multiThreadedCheckMutex();
#else
      pFrom = sqlite3DefaultMutex();
#endif
    }else{
      pFrom = sqlite3NoopMutex();
    }
    pTo->xMutexInit = pFrom->xMutexInit;
    pTo->xMutexEnd = pFrom->xMutexEnd;
    pTo->xMutexFree = pFrom->xMutexFree;
    pTo->xMutexEnter = pFrom->xMutexEnter;

int sqlite3_mutex_notheld(sqlite3_mutex *p){
  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld );
  return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
}
#endif

#endif /* !defined(SQLITE_MUTEX_OMIT) */

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

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

#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)

){
  unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */
  struct flock f;        /* The posix advisory locking structure */
  int rc = SQLITE_OK;    /* Result code form fcntl() */

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

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

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

  struct statfs fsInfo;
#endif

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

  /* If argument zPath is a NULL pointer, this function is required to open
  ** a temporary file. Use this buffer to store the file name in.

    /* Database filenames are double-zero terminated if they are not
    ** URIs with parameters.  Hence, they can always be passed into
    ** sqlite3_uri_parameter(). */
    assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );

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

    /* Generated temporary filenames are always double-zero terminated

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

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

#endif

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

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

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

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

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

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

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

end_prepare:

  sqlite3ParserReset(&sParse);


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

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



  sqlite3BtreeLeaveAll(db);
  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
  sqlite3_mutex_leave(db->mutex);

  return rc;
}

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

         || (z[i]==p->colSeparator[0] &&
             (nSep==1 || memcmp(z, p->colSeparator, nSep)==0)) ){
        i = 0;
        break;
      }
    }
    if( i==0 ){
      char *zQuoted = sqlite3_mprintf("\"%w\"", z);

      utf8_printf(out, "%s", zQuoted);
      sqlite3_free(zQuoted);


    }else{
      utf8_printf(out, "%s", z);
    }
  }
  if( bSep ){
    utf8_printf(p->out, "%s", p->colSeparator);
  }

  /*
  ** This SELECT statement returns one row for each foreign key constraint
  ** in the schema of the main database. The column values are:
  **
  ** 0. The text of an SQL statement similar to:
  **
  **      "EXPLAIN QUERY PLAN SELECT 1 FROM child_table WHERE child_key=?"
  **
  **    This SELECT is similar to the one that the foreign keys implementation
  **    needs to run internally on child tables. If there is an index that can
  **    be used to optimize this query, then it can also be used by the FK
  **    implementation to optimize DELETE or UPDATE statements on the parent
  **    table.
  **
  ** 1. A GLOB pattern suitable for sqlite3_strglob(). If the plan output by
  **    the EXPLAIN QUERY PLAN command matches this pattern, then the schema
  **    contains an index that can be used to optimize the query.

  **
  ** 5. The name of the parent table.
  **
  ** These six values are used by the C logic below to generate the report.
  */
  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT 1 FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH TABLE ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "

      sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "%s", azArg[1]);
    }else{
      sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "?");
    }
  }else

#ifndef SQLITE_UNTESTABLE
  if( c=='t' && n>=8 && strncmp(azArg[0], "testctrl", n)==0 ){
    static const struct {
       const char *zCtrlName;   /* Name of a test-control option */
       int ctrlCode;            /* Integer code for that option */
       const char *zUsage;      /* Usage notes */
    } aCtrl[] = {
      { "always",             SQLITE_TESTCTRL_ALWAYS,        "BOOLEAN"            },
      { "assert",             SQLITE_TESTCTRL_ASSERT,        "BOOLEAN"            },
    /*{ "benign_malloc_hooks",SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS, ""          },*/
    /*{ "bitvec_test",        SQLITE_TESTCTRL_BITVEC_TEST,   ""                },*/
      { "byteorder",          SQLITE_TESTCTRL_BYTEORDER,     ""                   },
    /*{ "fault_install",      SQLITE_TESTCTRL_FAULT_INSTALL, ""                }, */
      { "imposter",           SQLITE_TESTCTRL_IMPOSTER,   "SCHEMA ON/OFF ROOTPAGE"},
#ifdef SQLITE_N_KEYWORD
      { "iskeyword",          SQLITE_TESTCTRL_ISKEYWORD,     "IDENTIFIER"         },
#endif
      { "localtime_fault",    SQLITE_TESTCTRL_LOCALTIME_FAULT,"BOOLEAN"           },
      { "never_corrupt",      SQLITE_TESTCTRL_NEVER_CORRUPT, "BOOLEAN"            },
      { "optimizations",      SQLITE_TESTCTRL_OPTIMIZATIONS, "DISABLE-MASK"       },
      { "pending_byte",       SQLITE_TESTCTRL_PENDING_BYTE,  "OFFSET  "           },
      { "prng_reset",         SQLITE_TESTCTRL_PRNG_RESET,    ""                   },
      { "prng_restore",       SQLITE_TESTCTRL_PRNG_RESTORE,  ""                   },
      { "prng_save",          SQLITE_TESTCTRL_PRNG_SAVE,     ""                   },
      { "reserve",            SQLITE_TESTCTRL_RESERVE,       "BYTES-OF-RESERVE"   },
    };
    int testctrl = -1;
    int iCtrl = -1;
    int rc2 = 0;    /* 0: usage.  1: %d  2: %x  3: no-output */
    int isOk = 0;
    int i, n2;
    const char *zCmd = 0;

    open_db(p, 0);
    zCmd = nArg>=2 ? azArg[1] : "help";

    /* The argument can optionally begin with "-" or "--" */
    if( zCmd[0]=='-' && zCmd[1] ){
      zCmd++;
      if( zCmd[0]=='-' && zCmd[1] ) zCmd++;
    }

    /* --help lists all test-controls */
    if( strcmp(zCmd,"help")==0 ){
      utf8_printf(p->out, "Available test-controls:\n");
      for(i=0; i<ArraySize(aCtrl); i++){
        utf8_printf(p->out, "  .testctrl %s %s\n",
                    aCtrl[i].zCtrlName, aCtrl[i].zUsage);
      }
      rc = 1;
      goto meta_command_exit;
    }

    /* convert testctrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n2 = strlen30(zCmd);
    for(i=0; i<ArraySize(aCtrl); i++){
      if( strncmp(zCmd, aCtrl[i].zCtrlName, n2)==0 ){
        if( testctrl<0 ){
          testctrl = aCtrl[i].ctrlCode;
          iCtrl = i;
        }else{
          utf8_printf(stderr, "Error: ambiguous test-control: \"%s\"\n"
                              "Use \".testctrl --help\" for help\n", zCmd);
          rc = 1;
          goto meta_command_exit;
        }
      }
    }
    if( testctrl<0 ){

      utf8_printf(stderr,"Error: unknown test-control: %s\n"
                         "Use \".testctrl --help\" for help\n", zCmd);
    }else{
      switch(testctrl){

        /* sqlite3_test_control(int, db, int) */
        case SQLITE_TESTCTRL_OPTIMIZATIONS:
        case SQLITE_TESTCTRL_RESERVE:
          if( nArg==3 ){
            int opt = (int)strtol(azArg[2], 0, 0);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);

            isOk = 3;


          }
          break;

        /* sqlite3_test_control(int) */
        case SQLITE_TESTCTRL_PRNG_SAVE:
        case SQLITE_TESTCTRL_PRNG_RESTORE:
        case SQLITE_TESTCTRL_PRNG_RESET:
        case SQLITE_TESTCTRL_BYTEORDER:
          if( nArg==2 ){
            rc2 = sqlite3_test_control(testctrl);


            isOk = testctrl==SQLITE_TESTCTRL_BYTEORDER ? 1 : 3;

          }
          break;

        /* sqlite3_test_control(int, uint) */
        case SQLITE_TESTCTRL_PENDING_BYTE:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)integerValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);

            isOk = 3;


          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_ASSERT:
        case SQLITE_TESTCTRL_ALWAYS:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 1;
          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_LOCALTIME_FAULT:
        case SQLITE_TESTCTRL_NEVER_CORRUPT:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);

            isOk = 3;


          }
          break;

        /* sqlite3_test_control(int, char *) */
#ifdef SQLITE_N_KEYWORD
        case SQLITE_TESTCTRL_ISKEYWORD:
          if( nArg==3 ){
            const char *opt = azArg[2];
            rc2 = sqlite3_test_control(testctrl, opt);

            isOk = 1;



          }
          break;
#endif

        case SQLITE_TESTCTRL_IMPOSTER:
          if( nArg==5 ){
            rc2 = sqlite3_test_control(testctrl, p->db,
                          azArg[2],
                          integerValue(azArg[3]),
                          integerValue(azArg[4]));

            isOk = 3;

          }
          break;
      }








    }
    if( isOk==0 && iCtrl>=0 ){
      utf8_printf(p->out, "Usage: .testctrl %s %s\n", zCmd, aCtrl[iCtrl].zUsage);
      rc = 1;
    }else if( isOk==1 ){
      raw_printf(p->out, "%d\n", rc2);
    }else if( isOk==2 ){
      raw_printf(p->out, "0x%08x\n", rc2);
    }
  }else
#endif /* !defined(SQLITE_UNTESTABLE) */

  if( c=='t' && n>4 && strncmp(azArg[0], "timeout", n)==0 ){
    open_db(p, 0);
    sqlite3_busy_timeout(p->db, nArg>=2 ? (int)integerValue(azArg[1]) : 0);

** support for additional result codes that provide more detailed information
** about errors. These [extended result codes] are enabled or disabled
** on a per database connection basis using the
** [sqlite3_extended_result_codes()] API.  Or, the extended code for
** the most recent error can be obtained using
** [sqlite3_extended_errcode()].
*/
#define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
#define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))

#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))
#define SQLITE_READONLY_DIRECTORY      (SQLITE_READONLY | (6<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))

  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */
  unsigned bNoQuery:1;     /* Do not use this index to optimize queries */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */

  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */

/*
** The SQLITE_*_BKPT macros are substitutes for the error codes with
** the same name but without the _BKPT suffix.  These macros invoke
** routines that report the line-number on which the error originated
** using sqlite3_log().  The routines also provide a convenient place
** to set a debugger breakpoint.
*/
int sqlite3ReportError(int iErr, int lineno, const char *zType);
int sqlite3CorruptError(int);
int sqlite3MisuseError(int);
int sqlite3CantopenError(int);
#define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
#define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
#define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
#ifdef SQLITE_DEBUG

void sqlite3StatusDown(int, int);
void sqlite3StatusHighwater(int, int);
int sqlite3LookasideUsed(sqlite3*,int*);

/* Access to mutexes used by sqlite3_status() */
sqlite3_mutex *sqlite3Pcache1Mutex(void);
sqlite3_mutex *sqlite3MallocMutex(void);

#if defined(SQLITE_ENABLE_MULTITHREADED_CHECKS) && !defined(SQLITE_MUTEX_OMIT)
void sqlite3MutexWarnOnContention(sqlite3_mutex*);
#else
# define sqlite3MutexWarnOnContention(x)
#endif

#ifndef SQLITE_OMIT_FLOATING_POINT
  int sqlite3IsNaN(double);
#else
# define sqlite3IsNaN(X)  0
#endif

#endif

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

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

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

#endif

#if defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
  Tcl_SetVar2(interp, "sqlite_options", "unlock_notify", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "unlock_notify", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_FAST_SECURE_DELETE
  Tcl_SetVar2(interp, "sqlite_options", "fast_secure_delete", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "fast_secure_delete", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_SECURE_DELETE
  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "0", TCL_GLOBAL_ONLY);
#endif

    if( iEndTrigger ){
      sqlite3VdbeResolveLabel(v, iEndTrigger);
    }
    sqlite3VdbeAddOp0(v, OP_Halt);
    VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));

    transferParseError(pParse, pSubParse);
    if( db->mallocFailed==0 && pParse->nErr==0 ){
      pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);
    }
    pProgram->nMem = pSubParse->nMem;
    pProgram->nCsr = pSubParse->nTab;
    pProgram->token = (void *)pTrigger;
    pPrg->aColmask[0] = pSubParse->oldmask;
    pPrg->aColmask[1] = pSubParse->newmask;

      };
      Pager *pPager;   /* Pager associated with pBt */
      needXcommit = 1;
      sqlite3BtreeEnter(pBt);
      pPager = sqlite3BtreePager(pBt);
      if( db->aDb[i].safety_level!=PAGER_SYNCHRONOUS_OFF
       && aMJNeeded[sqlite3PagerGetJournalMode(pPager)]
       && sqlite3PagerIsMemdb(pPager)==0
      ){ 
        assert( i!=1 );
        nTrans++;
      }
      rc = sqlite3PagerExclusiveLock(pPager);
      sqlite3BtreeLeave(pBt);
    }

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

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

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

  }
#endif

  *ppVal = pVal;
  return rc;

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

  }

  assert( pWal->nWiData>0 );
  assert( pWal->apWiData[0]!=0 );
  pInfo = walCkptInfo(pWal);
  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame
#ifdef SQLITE_ENABLE_SNAPSHOT
   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0)

#endif
  ){
    /* The WAL has been completely backfilled (or it is empty).
    ** and can be safely ignored.
    */
    rc = walLockShared(pWal, WAL_READ_LOCK(0));
    walShmBarrier(pWal);

                          ** changes "x IN (?)" into "x=?". */
      }
    }else if( eOp & (WO_EQ|WO_IS) ){
      int iCol = pProbe->aiColumn[saved_nEq];
      pNew->wsFlags |= WHERE_COLUMN_EQ;
      assert( saved_nEq==pNew->u.btree.nEq );
      if( iCol==XN_ROWID 
       || (iCol>=0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
      ){
        if( iCol>=0 && pProbe->uniqNotNull==0 ){
          pNew->wsFlags |= WHERE_UNQ_WANTED;
        }else{
          pNew->wsFlags |= WHERE_ONEROW;
        }
      }

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

    }
    sqlite3DebugPrintf("\n");
    for(ii=0; ii<pWInfo->nLevel; ii++){
      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
    }
  }
#endif

  /* Attempt to omit tables from the join that do not affect the result.
  ** For a table to not affect the result, the following must be true:
  **
  **   1) The query must not be an aggregate.
  **   2) The table must be the RHS of a LEFT JOIN.
  **   3) Either the query must be DISTINCT, or else the ON or USING clause
  **      must contain a constraint that limits the scan of the table to 
  **      at most a single row.
  **   4) The table must not be referenced by any part of the query apart
  **      from its own USING or ON clause.
  **
  ** For example, given:
  **
  **     CREATE TABLE t1(ipk INTEGER PRIMARY KEY, v1);
  **     CREATE TABLE t2(ipk INTEGER PRIMARY KEY, v2);
  **     CREATE TABLE t3(ipk INTEGER PRIMARY KEY, v3);
  **
  ** then table t2 can be omitted from the following:
  **
  **     SELECT v1, v3 FROM t1 
  **       LEFT JOIN t2 USING (t1.ipk=t2.ipk)
  **       LEFT JOIN t3 USING (t1.ipk=t3.ipk)
  **
  ** or from:
  **
  **     SELECT DISTINCT v1, v3 FROM t1 
  **       LEFT JOIN t2
  **       LEFT JOIN t3 USING (t1.ipk=t3.ipk)
  */
  notReady = ~(Bitmask)0;
  if( pWInfo->nLevel>=2
   && pResultSet!=0               /* guarantees condition (1) above */
   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
  ){
    int i;
    Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet);
    if( sWLB.pOrderBy ){
      tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);
    }
    for(i=pWInfo->nLevel-1; i>=1; i--){
      WhereTerm *pTerm, *pEnd;
      struct SrcList_item *pItem;
      pLoop = pWInfo->a[i].pWLoop;
      pItem = &pWInfo->pTabList->a[pLoop->iTab];
      if( (pItem->fg.jointype & JT_LEFT)==0 ) continue;
      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
       && (pLoop->wsFlags & WHERE_ONEROW)==0
      ){
        continue;
      }
      if( (tabUsed & pLoop->maskSelf)!=0 ) continue;
      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
      for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){
        if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){
          if( !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
           || pTerm->pExpr->iRightJoinTable!=pItem->iCursor
          ){
            break;
          }
        }
      }
      if( pTerm<pEnd ) continue;
      WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
      notReady &= ~pLoop->maskSelf;
      for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){
        if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){
          pTerm->wtFlags |= TERM_CODED;
        }
      }
      if( i!=pWInfo->nLevel-1 ){
        int nByte = (pWInfo->nLevel-1-i) * sizeof(WhereLevel);
        memmove(&pWInfo->a[i], &pWInfo->a[i+1], nByte);
      }
      pWInfo->nLevel--;
      nTabList--;
    }
  }
  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;

  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
  if( db->mallocFailed ) goto whereBeginError;

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
  ** program.
  */

  for(ii=0; ii<nTabList; ii++){
    int addrExplain;
    int wsFlags;
    pLevel = &pWInfo->a[ii];
    wsFlags = pLevel->pWLoop->wsFlags;
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){

    pLoop = pLevel->pWLoop;
    if( pLevel->op!=OP_Noop ){
#ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT
      int addrSeek = 0;
      Index *pIdx;
      int n;
      if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED
       && i==pWInfo->nLevel-1  /* Ticket [ef9318757b152e3] 2017-10-21 */
       && (pLoop->wsFlags & WHERE_INDEXED)!=0
       && (pIdx = pLoop->u.btree.pIndex)->hasStat1
       && (n = pLoop->u.btree.nIdxCol)>0
       && pIdx->aiRowLogEst[n]>=36
      ){
        int r1 = pParse->nMem+1;
        int j, op;

    }
#endif
    if( pLevel->iLeftJoin ){
      int ws = pLoop->wsFlags;
      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
      assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 );
      if( (ws & WHERE_IDX_ONLY)==0 ){
        assert( pLevel->iTabCur==pTabList->a[pLevel->iFrom].iCursor );
        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur);
      }
      if( (ws & WHERE_INDEXED) 
       || ((ws & WHERE_MULTI_OR) && pLevel->u.pCovidx) 
      ){
        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
      }
      if( pLevel->op==OP_Return ){

    if( sqlite3CompareAffinity(p, zAff[i])==SQLITE_AFF_BLOB
     || sqlite3ExprNeedsNoAffinityChange(p, zAff[i])
    ){
      zAff[i] = SQLITE_AFF_BLOB;
    }
  }
}


/*
** pX is an expression of the form:  (vector) IN (SELECT ...)
** In other words, it is a vector IN operator with a SELECT clause on the
** LHS.  But not all terms in the vector are indexable and the terms might
** not be in the correct order for indexing.
**
** This routine makes a copy of the input pX expression and then adjusts
** the vector on the LHS with corresponding changes to the SELECT so that
** the vector contains only index terms and those terms are in the correct
** order.  The modified IN expression is returned.  The caller is responsible
** for deleting the returned expression.
**
** Example:
**
**    CREATE TABLE t1(a,b,c,d,e,f);
**    CREATE INDEX t1x1 ON t1(e,c);
**    SELECT * FROM t1 WHERE (a,b,c,d,e) IN (SELECT v,w,x,y,z FROM t2)
**                           \_______________________________________/
**                                     The pX expression
**
** Since only columns e and c can be used with the index, in that order,
** the modified IN expression that is returned will be:
**
**        (e,c) IN (SELECT z,x FROM t2)
**
** The reduced pX is different from the original (obviously) and thus is
** only used for indexing, to improve performance.  The original unaltered
** IN expression must also be run on each output row for correctness.
*/
static Expr *removeUnindexableInClauseTerms(
  Parse *pParse,        /* The parsing context */
  int iEq,              /* Look at loop terms starting here */
  WhereLoop *pLoop,     /* The current loop */
  Expr *pX              /* The IN expression to be reduced */
){
  sqlite3 *db = pParse->db;
  Expr *pNew = sqlite3ExprDup(db, pX, 0);
  if( db->mallocFailed==0 ){
    ExprList *pOrigRhs = pNew->x.pSelect->pEList;  /* Original unmodified RHS */
    ExprList *pOrigLhs = pNew->pLeft->x.pList;     /* Original unmodified LHS */
    ExprList *pRhs = 0;         /* New RHS after modifications */
    ExprList *pLhs = 0;         /* New LHS after mods */
    int i;                      /* Loop counter */
    Select *pSelect;            /* Pointer to the SELECT on the RHS */

    for(i=iEq; i<pLoop->nLTerm; i++){
      if( pLoop->aLTerm[i]->pExpr==pX ){
        int iField = pLoop->aLTerm[i]->iField - 1;
        assert( pOrigRhs->a[iField].pExpr!=0 );
        pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr);
        pOrigRhs->a[iField].pExpr = 0;
        assert( pOrigLhs->a[iField].pExpr!=0 );
        pLhs = sqlite3ExprListAppend(pParse, pLhs, pOrigLhs->a[iField].pExpr);
        pOrigLhs->a[iField].pExpr = 0;
      }
    }
    sqlite3ExprListDelete(db, pOrigRhs);
    sqlite3ExprListDelete(db, pOrigLhs);
    pNew->pLeft->x.pList = pLhs;
    pNew->x.pSelect->pEList = pRhs;
    if( pLhs && pLhs->nExpr==1 ){
      /* Take care here not to generate a TK_VECTOR containing only a
      ** single value. Since the parser never creates such a vector, some
      ** of the subroutines do not handle this case.  */
      Expr *p = pLhs->a[0].pExpr;
      pLhs->a[0].pExpr = 0;
      sqlite3ExprDelete(db, pNew->pLeft);
      pNew->pLeft = p;
    }
    pSelect = pNew->x.pSelect;
    if( pSelect->pOrderBy ){
      /* If the SELECT statement has an ORDER BY clause, zero the 
      ** iOrderByCol variables. These are set to non-zero when an 
      ** ORDER BY term exactly matches one of the terms of the 
      ** result-set. Since the result-set of the SELECT statement may
      ** have been modified or reordered, these variables are no longer 
      ** set correctly.  Since setting them is just an optimization, 
      ** it's easiest just to zero them here.  */
      ExprList *pOrderBy = pSelect->pOrderBy;
      for(i=0; i<pOrderBy->nExpr; i++){
        pOrderBy->a[i].u.x.iOrderByCol = 0;
      }
    }

#if 0
    printf("For indexing, change the IN expr:\n");
    sqlite3TreeViewExpr(0, pX, 0);
    printf("Into:\n");
    sqlite3TreeViewExpr(0, pNew, 0);
#endif
  }
  return pNew;
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
** coded.
**
** The current value for the constraint is left in a register, the index

    for(i=0; i<iEq; i++){
      if( pLoop->aLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){
        disableTerm(pLevel, pTerm);
        return iTarget;
      }
    }
    for(i=iEq;i<pLoop->nLTerm; i++){
      assert( pLoop->aLTerm[i]!=0 );
      if( pLoop->aLTerm[i]->pExpr==pX ) nEq++;
    }

    if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){
      eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0);
    }else{

      sqlite3 *db = pParse->db;





      pX = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);










      if( !db->mallocFailed ){























        aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*nEq);




        eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap);




        pTerm->pExpr->iTable = pX->iTable;
      }
      sqlite3ExprDelete(db, pX);
      pX = pTerm->pExpr;
    }

    if( eType==IN_INDEX_INDEX_DESC ){
      testcase( bRev );
      bRev = !bRev;
    }
    iTab = pX->iTable;

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

    /* Top of the loop body */

  WXYZ WXYZ WXYz WXYz WXyZ WXyZ WXyz WXyz WxYZ
  WxYZ WxYz WxYz WxyZ WxyZ Wxyz Wxyz
  aBCD aBCD aBCd aBCd aBcD aBcD aBcd aBcd abCD
  abCD abCd abCd abcD abcD abcd abcd
  wXYZ wXYZ wXYz wXYz wXyZ wXyZ wXyz wXyz wxYZ
  wxYZ wxYz wxYz wxyZ wxyZ wxyz wxyz
}

# Ticket https://sqlite.org/src/info/ef9318757b152e3a on 2017-11-21
# Incorrect result due to a skip-ahead-distinct optimization on a
# join where no rows of the inner loop appear in the result set.
#
db close
sqlite3 db :memory:
do_execsql_test 1000 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b INTEGER);
  CREATE INDEX t1b ON t1(b);
  CREATE TABLE t2(x INTEGER PRIMARY KEY, y INTEGER);
  CREATE INDEX t2y ON t2(y);
  WITH RECURSIVE c(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM c WHERE x<49)
    INSERT INTO t1(b) SELECT x/10 - 1 FROM c;
  WITH RECURSIVE c(x) AS (VALUES(-1) UNION ALL SELECT x+1 FROM c WHERE x<19)
    INSERT INTO t2(x,y) SELECT x, 1 FROM c;
  SELECT DISTINCT y FROM t1, t2 WHERE b=x AND b<>-1;
  ANALYZE;
  SELECT DISTINCT y FROM t1, t2 WHERE b=x AND b<>-1;
} {1 1}
db close
sqlite3 db :memory:
do_execsql_test 1010 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b INTEGER);
  CREATE INDEX t1b ON t1(b);
  CREATE TABLE t2(x INTEGER PRIMARY KEY, y INTEGER);
  CREATE INDEX t2y ON t2(y);
  WITH RECURSIVE c(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM c WHERE x<49)
    INSERT INTO t1(b) SELECT -(x/10 - 1) FROM c;
  WITH RECURSIVE c(x) AS (VALUES(-1) UNION ALL SELECT x+1 FROM c WHERE x<19)
    INSERT INTO t2(x,y) SELECT -x, 1 FROM c;
  SELECT DISTINCT y FROM t1, t2 WHERE b=x AND b<>1 ORDER BY y DESC;
  ANALYZE;
  SELECT DISTINCT y FROM t1, t2 WHERE b=x AND b<>1 ORDER BY y DESC;
} {1 1}
db close
sqlite3 db :memory:
do_execsql_test 1020 {
  CREATE TABLE t1(a, b);
  CREATE INDEX t1a ON t1(a, b);
  -- Lots of rows of (1, 'no'), followed by a single (1, 'yes').
  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
    INSERT INTO t1(a, b) SELECT 1, 'no' FROM c;
  INSERT INTO t1(a, b) VALUES(1, 'yes');
  CREATE TABLE t2(x PRIMARY KEY);
  INSERT INTO t2 VALUES('yes');
  SELECT DISTINCT a FROM t1, t2 WHERE x=b;
  ANALYZE;
  SELECT DISTINCT a FROM t1, t2 WHERE x=b;
} {1 1}


finish_test

  do_test 2.2 {
    set stmt [sqlite3_prepare_v2 db "INSERT INTO cX VALUES(11, ?)" -1]
    sqlite3_bind_zeroblob $stmt 1 45
    sqlite3_step $stmt
    sqlite3_finalize $stmt
  } {SQLITE_CONSTRAINT}
}

ifcapable stat4 {
  do_execsql_test 3.0 {
    CREATE TABLE p4 (id INTEGER NOT NULL PRIMARY KEY);
    INSERT INTO p4 VALUES(1), (2), (3);

    CREATE TABLE c4(x INTEGER REFERENCES p4(id) DEFERRABLE INITIALLY DEFERRED);
    CREATE INDEX c4_x ON c4(x);
    INSERT INTO c4 VALUES(1), (2), (3);

    ANALYZE;
    INSERT INTO p4(id) VALUES(4);
  }
}

finish_test

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

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

ifcapable !icu&&!icu_collations {
  finish_test
  return
}

# Create a table to work with.
#
execsql {CREATE TABLE test1(i1 int, i2 int, r1 real, r2 real, t1 text, t2 text)}
execsql {INSERT INTO test1 VALUES(1,2,1.1,2.2,'hello','world')}
proc test_expr {name settings expr result} {
  do_test $name [format {
    lindex [db eval {
      BEGIN; 
      UPDATE test1 SET %s; 
      SELECT %s FROM test1; 
      ROLLBACK;
    }] 0
  } $settings $expr] $result
}

ifcapable icu {

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

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

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

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

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

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

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

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

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

#-------------------------------------------------------------------------
# Test that it is not possible to call the ICU regex() function with 
# anything other than exactly two arguments. See also:
#
#   http://src.chromium.org/viewvc/chrome/trunk/src/third_party/sqlite/icu-regexp.patch?revision=34807&view=markup
#
ifcapable icu {
  do_catchsql_test icu-5.1 { SELECT regexp('a[abc]c.*', 'abc') } {0 1}
  do_catchsql_test icu-5.2 { 
    SELECT regexp('a[abc]c.*') 
  } {1 {wrong number of arguments to function regexp()}}
  do_catchsql_test icu-5.3 { 
    SELECT regexp('a[abc]c.*', 'abc', 'c') 
  } {1 {wrong number of arguments to function regexp()}}
  do_catchsql_test icu-5.4 { 
    SELECT 'abc' REGEXP 'a[abc]c.*'
  } {0 1}
  do_catchsql_test icu-5.4 {SELECT 'abc' REGEXP }   {1 {near " ": syntax error}}
  do_catchsql_test icu-5.5 {SELECT 'abc' REGEXP, 1} {1 {near ",": syntax error}}
 

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

finish_test

do_catchsql_test 2.1 {
  SELECT * FROM aa LEFT JOIN cc ON (a=b) JOIN bb ON (b=c);
} {1 {ON clause references tables to its right}}
do_catchsql_test 2.2 {
  SELECT * FROM aa JOIN cc ON (a=b) JOIN bb ON (b=c);
} {0 {one one one}}

#-------------------------------------------------------------------------
# Test that a problem causing where.c to overlook opportunities to
# omit unnecessary tables from a LEFT JOIN when UNIQUE, NOT NULL column 
# that makes this possible happens to be the leftmost in its table.
#
reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1(k1 INTEGER PRIMARY KEY, k2, k3);
  CREATE TABLE t2(k2 INTEGER PRIMARY KEY, v2);

  -- Prior to this problem being fixed, table t3_2 would be omitted from
  -- the join queries below, but if t3_1 were used in its place it would
  -- not.
  CREATE TABLE t3_1(k3 PRIMARY KEY, v3) WITHOUT ROWID;
  CREATE TABLE t3_2(v3, k3 PRIMARY KEY) WITHOUT ROWID;
}

do_eqp_test 3.1 {
  SELECT v2 FROM t1 LEFT JOIN t2 USING (k2) LEFT JOIN t3_1 USING (k3);
} {
  0 0 0 {SCAN TABLE t1} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
}

do_eqp_test 3.2 {
  SELECT v2 FROM t1 LEFT JOIN t2 USING (k2) LEFT JOIN t3_2 USING (k3);
} {
  0 0 0 {SCAN TABLE t1} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
}

#-------------------------------------------------------------------------
# Test that tables other than the rightmost can be omitted from a
# LEFT JOIN query.
#
do_execsql_test 4.0 {
  CREATE TABLE c1(k INTEGER PRIMARY KEY, v1);
  CREATE TABLE c2(k INTEGER PRIMARY KEY, v2);
  CREATE TABLE c3(k INTEGER PRIMARY KEY, v3);

  INSERT INTO c1 VALUES(1, 2);
  INSERT INTO c2 VALUES(2, 3);
  INSERT INTO c3 VALUES(3, 'v3');

  INSERT INTO c1 VALUES(111, 1112);
  INSERT INTO c2 VALUES(112, 1113);
  INSERT INTO c3 VALUES(113, 'v1113');
}
do_execsql_test 4.1.1 {
  SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v2);
} {2 v3 1112 {}}
do_execsql_test 4.1.2 {
  SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v1+1);
} {2 v3 1112 {}}

do_execsql_test 4.1.3 {
  SELECT DISTINCT v1, v3 FROM c1 LEFT JOIN c2 LEFT JOIN c3 ON (c3.k=v1+1);
} {2 v3 1112 {}}

do_execsql_test 4.1.4 {
  SELECT v1, v3 FROM c1 LEFT JOIN c2 LEFT JOIN c3 ON (c3.k=v1+1);
} {2 v3 2 v3 1112 {} 1112 {}}

do_eqp_test 4.2.1 {
  SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v2);
} {
  0 0 0 {SCAN TABLE c1} 
  0 1 1 {SEARCH TABLE c2 USING INTEGER PRIMARY KEY (rowid=?)}
  0 2 2 {SEARCH TABLE c3 USING INTEGER PRIMARY KEY (rowid=?)}
}
do_eqp_test 4.2.2 {
  SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v1+1);
} {
  0 0 0 {SCAN TABLE c1} 
  0 1 2 {SEARCH TABLE c3 USING INTEGER PRIMARY KEY (rowid=?)}
}

# 2017-11-23 (Thanksgiving day)
# OSSFuzz found an assertion fault in the new LEFT JOIN eliminator code.
#
do_execsql_test 4.3.0 {
  DROP TABLE IF EXISTS t1;
  DROP TABLE IF EXISTS t2;
  CREATE TABLE t1(x PRIMARY KEY) WITHOUT ROWID;
  CREATE TABLE t2(x);
  SELECT a.x
    FROM t1 AS a
    LEFT JOIN t1 AS b ON (a.x=b.x)
    LEFT JOIN t2 AS c ON (a.x=c.x);
} {}
do_execsql_test 4.3.1 {
  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<10)
    INSERT INTO t1(x) SELECT x FROM c;
  INSERT INTO t2(x) SELECT x+9 FROM t1;
  SELECT a.x, c.x
    FROM t1 AS a
    LEFT JOIN t1 AS b ON (a.x=b.x)
    LEFT JOIN t2 AS c ON (a.x=c.x);
} {1 {} 2 {} 3 {} 4 {} 5 {} 6 {} 7 {} 8 {} 9 {} 10 10}

finish_test

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

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

finish_test

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

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

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

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

  hexio_write test1 0 abcd
} {2}

do_execsql_test 1.6 {
  SELECT * FROM t1;
}

#-------------------------------------------------------------------------
# Check that master journals are not created if the transaction involves
# multiple temp files.
#
db close
testvfs tvfs
tvfs filter xOpen
tvfs script open_cb
set ::open ""
proc open_cb {method file arglist} {
  lappend ::open $file
}

proc contains_mj {} {
  foreach f $::open {
    set t [file tail $f]
    if {[string match *mj* $t]} { return 1 }
  }
  return 0
}

# Like [do_execsql_test], except that a boolean indicating whether or
# not a master journal file was opened ([file tail] contains "mj") or
# not. Example:
#
#   do_hasmj_test 1.0 { SELECT 'a', 'b' } {0 a b}
#
proc do_hasmj_test {tn sql expected} {
  set ::open [list]
  uplevel [list do_test $tn [subst -nocommands {
    set res [execsql "$sql"]
    concat [contains_mj] [set res]
  }] [list {*}$expected]]
}

forcedelete test.db
forcedelete test.db2
forcedelete test.db3
sqlite3 db test.db -vfs tvfs

do_execsql_test 2.0 {
  ATTACH 'test.db2' AS dbfile;
  ATTACH ''         AS dbtemp;
  ATTACH ':memory:'  AS dbmem;

  CREATE TABLE t1(x);
  CREATE TABLE dbfile.t2(x);
  CREATE TABLE dbtemp.t3(x);
  CREATE TABLE dbmem.t4(x);
}

# Two real files.
do_hasmj_test 2.1 {
  BEGIN;
    INSERT INTO t1 VALUES(1);
    INSERT INTO t2 VALUES(1);
  COMMIT;
} {1}

# One real, one temp file.
do_hasmj_test 2.2 {
  BEGIN;
    INSERT INTO t1 VALUES(1);
    INSERT INTO t3 VALUES(1);
  COMMIT;
} {0}

# One file, one :memory: db.
do_hasmj_test 2.3 {
  BEGIN;
    INSERT INTO t1 VALUES(1);
    INSERT INTO t4 VALUES(1);
  COMMIT;
} {0}

finish_test

#

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

unset -nocomplain DEFAULT_SECDEL
set DEFAULT_SECDEL 0
ifcapable fast_secure_delete {
  set DEFAULT_SECDEL 2
} else {
  ifcapable secure_delete {
    set DEFAULT_SECDEL 1
  }
}


do_test securedel-1.0 {
  db eval {PRAGMA secure_delete;}
} $DEFAULT_SECDEL

  }

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

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

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

  set expected ""

# 2016 September 23
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. The focus
# of this file is the sqlite3_snapshot_xxx() APIs.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !snapshot {finish_test; return}
set testprefix snapshot3

# This test does not work with the inmemory_journal permutation. The reason
# is that each connection opened as part of this permutation executes
# "PRAGMA journal_mode=memory", which fails if the database is in wal mode
# and there are one or more existing connections.
if {[permutation]=="inmemory_journal"} {
  finish_test
  return
}

#-------------------------------------------------------------------------
# This block of tests verifies that it is not possible to wrap the wal
# file - using a writer or a "PRAGMA wal_checkpoint = TRUNCATE" - while
# there is an open snapshot transaction (transaction opened using
# sqlite3_snapshot_open()).
#
do_execsql_test 1.0 {
  CREATE TABLE t1(y);
  PRAGMA journal_mode = wal;
  INSERT INTO t1 VALUES(1);
  INSERT INTO t1 VALUES(2);
  INSERT INTO t1 VALUES(3);
  INSERT INTO t1 VALUES(4);
} {wal}

do_test 1.1 {
  sqlite3 db2 test.db
  sqlite3 db3 test.db

  execsql {SELECT * FROM sqlite_master} db2
  execsql {SELECT * FROM sqlite_master} db3

  db2 trans { set snap [sqlite3_snapshot_get_blob db2 main] }
  db2 eval { SELECT * FROM t1 }
} {1 2 3 4}

do_test 1.2 {
  execsql BEGIN db2
  sqlite3_snapshot_open_blob db2 main $snap
  db2 eval { SELECT * FROM t1 }
} {1 2 3 4}

do_test 1.2 {
  execsql END db2
  execsql { PRAGMA wal_checkpoint }

  execsql BEGIN db2
  sqlite3_snapshot_open_blob db2 main $snap
  db2 eval { SELECT * FROM t1 }
} {1 2 3 4}

set sz [file size test.db-wal]
do_test 1.3 {
  execsql { PRAGMA wal_checkpoint = truncate }
  file size test.db-wal
} $sz

do_test 1.4 {
  execsql BEGIN db3
  list [catch { sqlite3_snapshot_open_blob db3 main $snap } msg] $msg
} {0 {}}

do_test 1.5 {
  db3 eval { SELECT * FROM t1; END }
} {1 2 3 4}

do_test 1.6 {
  db2 eval { SELECT * FROM t1; END }
} {1 2 3 4}

do_test 1.7 {
  execsql { PRAGMA wal_checkpoint = truncate }
  file size test.db-wal
} 0

do_test 1.8 {
  execsql BEGIN db3
  list [catch { sqlite3_snapshot_open_blob db3 main $snap } msg] $msg
} {1 SQLITE_BUSY_SNAPSHOT}

finish_test

# Flushing the cache clears all of the prepared statements.
#
db cache flush
do_execsql_test stmtvtab1-160 {
  SELECT * FROM sqlite_stmt WHERE NOT busy;
} {}

finish_test

do_test bug-20100512-3 {
  sqlite3_bind_int $STMT 1 123
  sqlite3_bind_int $STMT 2 456
  sqlite3_step $STMT
  sqlite3_column_int $STMT 0
} {555}
sqlite3_finalize $STMT

finish_test

do_execsql_test tkt-7a31705a7e6-1.1 {
  CREATE TABLE t1 (a INTEGER PRIMARY KEY);
  CREATE TABLE t2 (a INTEGER PRIMARY KEY, b INTEGER);
  CREATE TABLE t2x (b INTEGER PRIMARY KEY);
  SELECT t1.a FROM ((t1 JOIN t2 ON t1.a=t2.a) AS x JOIN t2x ON x.b=t2x.b) as y;
} {}

finish_test

} {-9.22337203685478e+18}
do_execsql_test 4.5 {
  SELECT '9223372036854775806x'+'1x';
} {9.22337203685478e+18}
do_execsql_test 4.6 {
  SELECT '1234x'/'10y';
} {123.4}

finish_test

  }
} {1 1 1}
do_test tkt3334-1.10 {
  execsql {
    SELECT count(*) FROM (SELECT a FROM t1) WHERE a=1;
  }
} {3}

finish_test

                    WHERE xx.a IN (1,2,3,4)
                      AND yy.a IN (2,3,4,5);
  END;

  INSERT INTO t3 VALUES(2);
  SELECT b FROM t2 ORDER BY b;
} {20202 20203 20302 20303 30202 30203 30302 30303 40202 40203 40302 40303 50202 50203 50302 50303}

# At one point the following was causing an assert() to fail.
#
do_execsql_test 300 {
  CREATE TABLE t4(x);
  CREATE TRIGGER tr4 AFTER INSERT ON t4 BEGIN
    SELECT 0x2147483648e0e0099 AS y WHERE y;
  END;
}

do_catchsql_test 310 {
  INSERT INTO t4 VALUES(1);
} {1 {hex literal too big: 0x2147483648e0e0099}}

finish_test

      c120, c121, c122, c123, c124, c125, c126, c127, c128, c129,
      c130, c131, c132, c133, c134, c135, c136, c137, c138, c139,
      c140, c141, c142, c143, c144, c145, c146, c147, c148, c149
    );
    VACUUM;
  }
} {}

finish_test

      incr cnt
      do_test varint-1.$cnt {
        btree_varint_test $start $mult 5000 $incr
      } {}
    }
  }
}

finish_test

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

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

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

faultsim_save_and_close
testvfs T -default 1
faultsim_restore_and_reopen
T filter xShmLock
T script lock_callback

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

db close
db2 close

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

db close
db2 close
T delete

finish_test

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

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