SQLite

#
BCC = @BUILD_CC@ @BUILD_CFLAGS@

# C Compile and options for use in building executables that 
# will run on the target platform.  (BCC and TCC are usually the
# same unless your are cross-compiling.)
#
TCC = @CC@ @CPPFLAGS@ @CFLAGS@ -I. -I${TOP}/src -I${TOP}/ext/rtree

# Define this for the autoconf-based build, so that the code knows it can
# include the generated config.h
# 
TCC += -D_HAVE_SQLITE_CONFIG_H

# Define -DNDEBUG to compile without debugging (i.e., for production usage)

USE_AMALGAMATION = @USE_AMALGAMATION@

# Object files for the SQLite library (non-amalgamation).
#
LIBOBJS0 = alter.lo analyze.lo attach.lo auth.lo \
         backup.lo bitvec.lo btmutex.lo btree.lo build.lo \
         callback.lo complete.lo ctime.lo date.lo delete.lo \
         expr.lo fault.lo fkey.lo \
         fts3.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo fts3_porter.lo \
         fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo fts3_write.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo journal.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_os2.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_os2.lo os_unix.lo os_win.lo \
         pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo select.lo status.lo \
         table.lo tokenize.lo trigger.lo \
         update.lo util.lo vacuum.lo \
         vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbetrace.lo \
         wal.lo walker.lo where.lo utf.lo vtab.lo

# Object files for the amalgamation.
#
LIBOBJS1 = sqlite3.lo

# Determine the real value of LIBOBJ based on the 'configure' script
#

  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_func.c \
  $(TOP)/src/test_hexio.c \
  $(TOP)/src/test_init.c \
  $(TOP)/src/test_intarray.c \
  $(TOP)/src/test_journal.c \
  $(TOP)/src/test_malloc.c \
  $(TOP)/src/test_multiplex.c \
  $(TOP)/src/test_mutex.c \
  $(TOP)/src/test_onefile.c \
  $(TOP)/src/test_osinst.c \
  $(TOP)/src/test_pcache.c \
  $(TOP)/src/test_quota.c \
  $(TOP)/src/test_rtree.c \
  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_stat.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_wsd.c

  $(TOP)/ext/fts3/fts3Int.h \
  $(TOP)/ext/fts3/fts3_hash.h \
  $(TOP)/ext/fts3/fts3_tokenizer.h
EXTHDR += \
  $(TOP)/ext/rtree/rtree.h
EXTHDR += \
  $(TOP)/ext/icu/sqliteicu.h
EXTHDR += \
  $(TOP)/ext/rtree/sqlite3rtree.h
EXTHDR += \
  $(TOP)/ext/sqlrr/sqlrr.h

# If using the amalgamation, use sqlite3.c directly to build the test
# fixture.  Otherwise link against libsqlite3.la.  (This distinction is
# necessary because the test fixture requires non-API symbols which are
# hidden when the library is built via the amalgamation).

3.7.4

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

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

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

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

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

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

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

Defaults for the options are specified in brackets.

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

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.7.4:";;
   esac
  cat <<\_ACEOF

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

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

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

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

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

  $ $0 $@

_ACEOF
exec 5>>config.log
{

exec 6>&1

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

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

$config_commands

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

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

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

# define SQLITE_CORE 1
#endif

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>


#include "fts2.h"
#include "fts2_hash.h"
#include "fts2_tokenizer.h"
#include "sqlite3.h"
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

*/
/* TODO(shess) The snippet-generation code should be using the
** tokenizer-generated tokens rather than doing its own local
** tokenization.
*/
/* TODO(shess) Is __isascii() a portable version of (c&0x80)==0? */
static int safe_isspace(char c){
  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}
static int safe_tolower(char c){
  return (c>='A' && c<='Z') ? (c - 'A' + 'a') : c;
}
static int safe_isalnum(char c){
  return (c>='0' && c<='9') || (c>='A' && c<='Z') || (c>='a' && c<='z');
}

typedef enum DocListType {
  DL_DOCIDS,              /* docids only */
  DL_POSITIONS,           /* docids + positions */
  DL_POSITIONS_OFFSETS    /* docids + positions + offsets */
} DocListType;

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS2)


#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>


#include "fts2_tokenizer.h"

/*
** Class derived from sqlite3_tokenizer
*/
typedef struct porter_tokenizer {

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS2)


#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>


#include "fts2_tokenizer.h"

typedef struct simple_tokenizer {
  sqlite3_tokenizer base;
  char delim[128];             /* flag ASCII delimiters */
} simple_tokenizer;

      }
      t->delim[ch] = 1;
    }
  } else {
    /* Mark non-alphanumeric ASCII characters as delimiters */
    int i;
    for(i=1; i<0x80; i++){
      t->delim[i] = !((i>='0' && i<='9') || (i>='A' && i<='Z') ||
                      (i>='a' && i<='z'));
    }
  }

  *ppTokenizer = &t->base;
  return SQLITE_OK;
}

        if( c->pToken==NULL ) return SQLITE_NOMEM;
      }
      for(i=0; i<n; i++){
        /* TODO(shess) This needs expansion to handle UTF-8
        ** case-insensitivity.
        */
        unsigned char ch = p[iStartOffset+i];
        c->pToken[i] = (ch>='A' && ch<='Z') ? (ch - 'A' + 'a') : ch;
      }
      *ppToken = c->pToken;
      *pnBytes = n;
      *piStartOffset = iStartOffset;
      *piEndOffset = c->iOffset;
      *piPosition = c->iToken++;

** The xDisconnect() virtual table method.
*/
static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
  Fts3Table *p = (Fts3Table *)pVtab;
  int i;

  assert( p->nPendingData==0 );
  assert( p->pSegments==0 );

  /* Free any prepared statements held */
  for(i=0; i<SizeofArray(p->aStmt); i++){
    sqlite3_finalize(p->aStmt[i]);
  }



  sqlite3_free(p->zSegmentsTbl);


  /* Invoke the tokenizer destructor to free the tokenizer. */
  p->pTokenizer->pModule->xDestroy(p->pTokenizer);

  sqlite3_free(p);
  return SQLITE_OK;
}

/*
** Construct one or more SQL statements from the format string given
** and then evaluate those statements. The success code is written
** into *pRc.
**
** If *pRc is initially non-zero then this routine is a no-op.
*/
static void fts3DbExec(
  int *pRc,              /* Success code */
  sqlite3 *db,           /* Database in which to run SQL */

}


/*
** Invoke sqlite3_declare_vtab() to declare the schema for the FTS3 table
** passed as the first argument. This is done as part of the xConnect()
** and xCreate() methods.
**
** If *pRc is non-zero when this function is called, it is a no-op. 
** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
** before returning.
*/
static void fts3DeclareVtab(int *pRc, Fts3Table *p){
  if( *pRc==SQLITE_OK ){
    int i;                        /* Iterator variable */
    int rc;                       /* Return code */
    char *zSql;                   /* SQL statement passed to declare_vtab() */
    char *zCols;                  /* List of user defined columns */

    /* Create a list of user columns for the virtual table */
    zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
    for(i=1; zCols && i<p->nColumn; i++){
      zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
    }

    /* Create the whole "CREATE TABLE" statement to pass to SQLite */
    zSql = sqlite3_mprintf(
        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN)", zCols, p->zName
    );

    if( !zCols || !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_declare_vtab(p->db, zSql);
    }

    sqlite3_free(zSql);
    sqlite3_free(zCols);
    *pRc = rc;
  }
}

/*
** Create the backing store tables (%_content, %_segments and %_segdir)
** required by the FTS3 table passed as the only argument. This is done
** as part of the vtab xCreate() method.
**
** If the p->bHasDocsize boolean is true (indicating that this is an
** FTS4 table, not an FTS3 table) then also create the %_docsize and
** %_stat tables required by FTS4.
*/
static int fts3CreateTables(Fts3Table *p){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Iterator variable */
  char *zContentCols;             /* Columns of %_content table */
  sqlite3 *db = p->db;            /* The database connection */

  /* Create a list of user columns for the content table */

  zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
  for(i=0; zContentCols && i<p->nColumn; i++){
    char *z = p->azColumn[i];
    zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
  }
  if( zContentCols==0 ) rc = SQLITE_NOMEM;

  /* Create the content table */
  fts3DbExec(&rc, db, 
     "CREATE TABLE %Q.'%q_content'(%s)",
     p->zDb, p->zName, zContentCols
  );
  sqlite3_free(zContentCols);

  /* Create other tables */
  fts3DbExec(&rc, db, 
      "CREATE TABLE %Q.'%q_segments'(blockid INTEGER PRIMARY KEY, block BLOB);",
      p->zDb, p->zName
  );
  fts3DbExec(&rc, db, 
      "CREATE TABLE %Q.'%q_segdir'("

      p->zDb, p->zName
  );
  if( p->bHasDocsize ){
    fts3DbExec(&rc, db, 
        "CREATE TABLE %Q.'%q_docsize'(docid INTEGER PRIMARY KEY, size BLOB);",
        p->zDb, p->zName
    );
  }
  if( p->bHasStat ){
    fts3DbExec(&rc, db, 
        "CREATE TABLE %Q.'%q_stat'(id INTEGER PRIMARY KEY, value BLOB);",
        p->zDb, p->zName
    );
  }
  return rc;
}

/*
** Store the current database page-size in bytes in p->nPgsz.
**
** If *pRc is non-zero when this function is called, it is a no-op. 
** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
** before returning.
*/
static void fts3DatabasePageSize(int *pRc, Fts3Table *p){
  if( *pRc==SQLITE_OK ){
    int rc;                       /* Return code */
    char *zSql;                   /* SQL text "PRAGMA %Q.page_size" */
    sqlite3_stmt *pStmt;          /* Compiled "PRAGMA %Q.page_size" statement */
  
    zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);
    if( !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
      if( rc==SQLITE_OK ){
        sqlite3_step(pStmt);
        p->nPgsz = sqlite3_column_int(pStmt, 0);
        rc = sqlite3_finalize(pStmt);
      }
    }
    assert( p->nPgsz>0 || rc!=SQLITE_OK );
    sqlite3_free(zSql);
    *pRc = rc;
  }
}

/*

** "Special" FTS4 arguments are column specifications of the following form:
**
**   <key> = <value>
**
** There may not be whitespace surrounding the "=" character. The <value> 
** term may be quoted, but the <key> may not.
*/
static int fts3IsSpecialColumn(



  const char *z, 
  int *pnKey,
  char **pzValue

){


  char *zValue;
  const char *zCsr = z;

  while( *zCsr!='=' ){
    if( *zCsr=='\0' ) return 0;
    zCsr++;
  }

  *pnKey = zCsr-z;

  zValue = sqlite3_mprintf("%s", &zCsr[1]);
  if( zValue ){
    sqlite3Fts3Dequote(zValue);
  }
  *pzValue = zValue;

  return 1;
}

/*
** This function is the implementation of both the xConnect and xCreate
** methods of the FTS3 virtual table.
**
** The argv[] array contains the following:

  void *pAux,                     /* Hash table containing tokenizers */
  int argc,                       /* Number of elements in argv array */
  const char * const *argv,       /* xCreate/xConnect argument array */
  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
  char **pzErr                    /* Write any error message here */
){
  Fts3Hash *pHash = (Fts3Hash *)pAux;
  Fts3Table *p = 0;               /* Pointer to allocated vtab */
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Iterator variable */
  int nByte;                      /* Size of allocation used for *p */
  int iCol;                       /* Column index */
  int nString = 0;                /* Bytes required to hold all column names */
  int nCol = 0;                   /* Number of columns in the FTS table */
  char *zCsr;                     /* Space for holding column names */
  int nDb;                        /* Bytes required to hold database name */
  int nName;                      /* Bytes required to hold table name */
  int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */
  int bNoDocsize = 0;             /* True to omit %_docsize table */
  const char **aCol;              /* Array of column names */
  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */

  assert( strlen(argv[0])==4 );
  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
  );

  nDb = (int)strlen(argv[1]) + 1;
  nName = (int)strlen(argv[2]) + 1;

  aCol = (const char **)sqlite3_malloc(sizeof(const char *) * (argc-2) );
  if( !aCol ) return SQLITE_NOMEM;
  memset(aCol, 0, sizeof(const char *) * (argc-2));

  /* Loop through all of the arguments passed by the user to the FTS3/4
  ** module (i.e. all the column names and special arguments). This loop
  ** does the following:
  **
  **   + Figures out the number of columns the FTSX table will have, and
  **     the number of bytes of space that must be allocated to store copies
  **     of the column names.
  **
  **   + If there is a tokenizer specification included in the arguments,
  **     initializes the tokenizer pTokenizer.
  */
  for(i=3; rc==SQLITE_OK && i<argc; i++){
    char const *z = argv[i];


    int nKey;
    char *zVal;

    /* Check if this is a tokenizer specification */
    if( !pTokenizer 
     && strlen(z)>8
     && 0==sqlite3_strnicmp(z, "tokenize", 8) 
     && 0==sqlite3Fts3IsIdChar(z[8])
    ){
      rc = sqlite3Fts3InitTokenizer(pHash, &z[9], &pTokenizer, pzErr);
    }

    /* Check if it is an FTS4 special argument. */
    else if( isFts4 && fts3IsSpecialColumn(z, &nKey, &zVal) ){
      if( !zVal ){
        rc = SQLITE_NOMEM;
        goto fts3_init_out;
      }
      if( nKey==9 && 0==sqlite3_strnicmp(z, "matchinfo", 9) ){
        if( strlen(zVal)==4 && 0==sqlite3_strnicmp(zVal, "fts3", 4) ){
          bNoDocsize = 1;
        }else{
          *pzErr = sqlite3_mprintf("unrecognized matchinfo: %s", zVal);
          rc = SQLITE_ERROR;
        }
      }else{
        *pzErr = sqlite3_mprintf("unrecognized parameter: %s", z);
        rc = SQLITE_ERROR;
      }
      sqlite3_free(zVal);
    }

    /* Otherwise, the argument is a column name. */
    else {
      nString += (int)(strlen(z) + 1);
      aCol[nCol++] = z;
    }
  }
  if( rc!=SQLITE_OK ) goto fts3_init_out;

  if( nCol==0 ){
    assert( nString==0 );
    aCol[0] = "content";
    nString = 8;
    nCol = 1;
  }

  if( pTokenizer==0 ){
    rc = sqlite3Fts3InitTokenizer(pHash, "simple", &pTokenizer, pzErr);
    if( rc!=SQLITE_OK ) goto fts3_init_out;
  }
  assert( pTokenizer );


  /* Allocate and populate the Fts3Table structure. */
  nByte = sizeof(Fts3Table) +              /* Fts3Table */
          nCol * sizeof(char *) +              /* azColumn */
          nName +                              /* zName */
          nDb +                                /* zDb */
          nString;                             /* Space for azColumn strings */
  p = (Fts3Table*)sqlite3_malloc(nByte);
  if( p==0 ){
    rc = SQLITE_NOMEM;
    goto fts3_init_out;
  }
  memset(p, 0, nByte);

  p->db = db;
  p->nColumn = nCol;
  p->nPendingData = 0;
  p->azColumn = (char **)&p[1];
  p->pTokenizer = pTokenizer;
  p->nNodeSize = 1000;
  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
  p->bHasDocsize = (isFts4 && bNoDocsize==0);
  p->bHasStat = isFts4;
  fts3HashInit(&p->pendingTerms, FTS3_HASH_STRING, 1);

  /* Fill in the zName and zDb fields of the vtab structure. */
  zCsr = (char *)&p->azColumn[nCol];
  p->zName = zCsr;
  memcpy(zCsr, argv[2], nName);
  zCsr += nName;
  p->zDb = zCsr;
  memcpy(zCsr, argv[1], nDb);
  zCsr += nDb;

  /* Fill in the azColumn array */
  for(iCol=0; iCol<nCol; iCol++){


    char *z; 
    int n;
    z = (char *)sqlite3Fts3NextToken(aCol[iCol], &n);
    memcpy(zCsr, z, n);
    zCsr[n] = '\0';
    sqlite3Fts3Dequote(zCsr);
    p->azColumn[iCol] = zCsr;
    zCsr += n+1;
    assert( zCsr <= &((char *)p)[nByte] );





  }

  /* If this is an xCreate call, create the underlying tables in the 
  ** database. TODO: For xConnect(), it could verify that said tables exist.
  */
  if( isCreate ){


    rc = fts3CreateTables(p);




  }


  /* Figure out the page-size for the database. This is required in order to
  ** estimate the cost of loading large doclists from the database (see 
  ** function sqlite3Fts3SegReaderCost() for details).
  */
  fts3DatabasePageSize(&rc, p);


  /* Declare the table schema to SQLite. */
  fts3DeclareVtab(&rc, p);

fts3_init_out:

  sqlite3_free(aCol);
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
    }else if( pTokenizer ){
      pTokenizer->pModule->xDestroy(pTokenizer);
    }
  }else{
    *ppVTab = &p->base;
  }
  return rc;
}

/*
** The xConnect() and xCreate() methods for the virtual table. All the
** work is done in function fts3InitVtab().

  return SQLITE_OK;
}

/*
** Close the cursor.  For additional information see the documentation
** on the xClose method of the virtual table interface.
*/
static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  sqlite3_finalize(pCsr->pStmt);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  sqlite3Fts3FreeDeferredTokens(pCsr);
  sqlite3_free(pCsr->aDoclist);
  sqlite3_free(pCsr->aMatchinfo);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*

    }
  }else{
    return SQLITE_OK;
  }
}

/*
** This function is used to process a single interior node when searching
** a b-tree for a term or term prefix. The node data is passed to this 
** function via the zNode/nNode parameters. The term to search for is
** passed in zTerm/nTerm.
**
** If piFirst is not NULL, then this function sets *piFirst to the blockid
** of the child node that heads the sub-tree that may contain the term.
**
** If piLast is not NULL, then *piLast is set to the right-most child node
** that heads a sub-tree that may contain a term for which zTerm/nTerm is
** a prefix.
**
** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.


*/
static int fts3ScanInteriorNode(
  Fts3Table *p,                   /* Virtual table handle */
  const char *zTerm,              /* Term to select leaves for */
  int nTerm,                      /* Size of term zTerm in bytes */
  const char *zNode,              /* Buffer containing segment interior node */
  int nNode,                      /* Size of buffer at zNode */
  sqlite3_int64 *piFirst,         /* OUT: Selected child node */
  sqlite3_int64 *piLast           /* OUT: Selected child node */
){
  int rc = SQLITE_OK;             /* Return code */
  const char *zCsr = zNode;       /* Cursor to iterate through node */
  const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
  char *zBuffer = 0;              /* Buffer to load terms into */
  int nAlloc = 0;                 /* Size of allocated buffer */
  int isFirstTerm = 1;            /* True when processing first term on page */
  sqlite3_int64 iChild;           /* Block id of child node to descend to */

  /* Skip over the 'height' varint that occurs at the start of every 
  ** interior node. Then load the blockid of the left-child of the b-tree
  ** node into variable iChild.  
  **
  ** Even if the data structure on disk is corrupted, this (reading two
  ** varints from the buffer) does not risk an overread. If zNode is a
  ** root node, then the buffer comes from a SELECT statement. SQLite does
  ** not make this guarantee explicitly, but in practice there are always
  ** either more than 20 bytes of allocated space following the nNode bytes of
  ** contents, or two zero bytes. Or, if the node is read from the %_segments
  ** table, then there are always 20 bytes of zeroed padding following the
  ** nNode bytes of content (see sqlite3Fts3ReadBlock() for details).
  */
  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
  if( zCsr>=zEnd ){
    return SQLITE_CORRUPT;
  }
  
  while( zCsr<zEnd && (piFirst || piLast) ){
    int cmp;                      /* memcmp() result */
    int nSuffix;                  /* Size of term suffix */
    int nPrefix = 0;              /* Size of term prefix */
    int nBuffer;                  /* Total term size */
  
    /* Load the next term on the node into zBuffer. Use realloc() to expand
    ** the size of zBuffer if required.  */
    if( !isFirstTerm ){
      zCsr += sqlite3Fts3GetVarint32(zCsr, &nPrefix);
    }
    isFirstTerm = 0;
    zCsr += sqlite3Fts3GetVarint32(zCsr, &nSuffix);
    
    if( nPrefix<0 || nSuffix<0 || &zCsr[nSuffix]>zEnd ){
      rc = SQLITE_CORRUPT;
      goto finish_scan;
    }
    if( nPrefix+nSuffix>nAlloc ){
      char *zNew;
      nAlloc = (nPrefix+nSuffix) * 2;
      zNew = (char *)sqlite3_realloc(zBuffer, nAlloc);
      if( !zNew ){
        rc = SQLITE_NOMEM;
        goto finish_scan;
      }
      zBuffer = zNew;
    }
    memcpy(&zBuffer[nPrefix], zCsr, nSuffix);
    nBuffer = nPrefix + nSuffix;
    zCsr += nSuffix;

    /* Compare the term we are searching for with the term just loaded from
    ** the interior node. If the specified term is greater than or equal
    ** to the term from the interior node, then all terms on the sub-tree 
    ** headed by node iChild are smaller than zTerm. No need to search 
    ** iChild.
    **
    ** If the interior node term is larger than the specified term, then
    ** the tree headed by iChild may contain the specified term.
    */
    cmp = memcmp(zTerm, zBuffer, (nBuffer>nTerm ? nTerm : nBuffer));
    if( piFirst && (cmp<0 || (cmp==0 && nBuffer>nTerm)) ){
      *piFirst = iChild;
      piFirst = 0;
    }

    if( piLast && cmp<0 ){
      *piLast = iChild;
      piLast = 0;
    }

    iChild++;
  };

  if( piFirst ) *piFirst = iChild;
  if( piLast ) *piLast = iChild;

 finish_scan:
  sqlite3_free(zBuffer);
  return rc;
}


/*
** The buffer pointed to by argument zNode (size nNode bytes) contains an
** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)
** contains a term. This function searches the sub-tree headed by the zNode
** node for the range of leaf nodes that may contain the specified term
** or terms for which the specified term is a prefix.
**
** If piLeaf is not NULL, then *piLeaf is set to the blockid of the 
** left-most leaf node in the tree that may contain the specified term.
** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the
** right-most leaf node that may contain a term for which the specified
** term is a prefix.
**
** It is possible that the range of returned leaf nodes does not contain 
** the specified term or any terms for which it is a prefix. However, if the 
** segment does contain any such terms, they are stored within the identified
** range. Because this function only inspects interior segment nodes (and
** never loads leaf nodes into memory), it is not possible to be sure.

**
** If an error occurs, an error code other than SQLITE_OK is returned.
*/ 
static int fts3SelectLeaf(
  Fts3Table *p,                   /* Virtual table handle */
  const char *zTerm,              /* Term to select leaves for */
  int nTerm,                      /* Size of term zTerm in bytes */
  const char *zNode,              /* Buffer containing segment interior node */
  int nNode,                      /* Size of buffer at zNode */
  sqlite3_int64 *piLeaf,          /* Selected leaf node */
  sqlite3_int64 *piLeaf2          /* Selected leaf node */
){
  int rc;                         /* Return code */



  int iHeight;                    /* Height of this node in tree */

  assert( piLeaf || piLeaf2 );





  sqlite3Fts3GetVarint32(zNode, &iHeight);

  rc = fts3ScanInteriorNode(p, zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
  assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );




  if( rc==SQLITE_OK && iHeight>1 ){
    char *zBlob = 0;              /* Blob read from %_segments table */
    int nBlob;                    /* Size of zBlob in bytes */


    if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
      rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob);









      if( rc==SQLITE_OK ){
        rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);
      }
      sqlite3_free(zBlob);
      piLeaf = 0;
      zBlob = 0;
    }














    if( rc==SQLITE_OK ){


      rc = sqlite3Fts3ReadBlock(p, piLeaf ? *piLeaf : *piLeaf2, &zBlob, &nBlob);
    }



    if( rc==SQLITE_OK ){
      rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);

    }
    sqlite3_free(zBlob);
  }






  return rc;
}

/*
** This function is used to create delta-encoded serialized lists of FTS3 
** varints. Each call to this function appends a single varint to a list.
*/

  *pp = p;
  *pp1 = p1 + 1;
  *pp2 = p2 + 1;
}

/*
** nToken==1 searches for adjacent positions.
**
** This function is used to merge two position lists into one. When it is
** called, *pp1 and *pp2 must both point to position lists. A position-list is
** the part of a doclist that follows each document id. For example, if a row
** contains:
**
**     'a b c'|'x y z'|'a b b a'
**
** Then the position list for this row for token 'b' would consist of:
**
**     0x02 0x01 0x02 0x03 0x03 0x00
**
** When this function returns, both *pp1 and *pp2 are left pointing to the
** byte following the 0x00 terminator of their respective position lists.
**
** If isSaveLeft is 0, an entry is added to the output position list for 
** each position in *pp2 for which there exists one or more positions in
** *pp1 so that (pos(*pp2)>pos(*pp1) && pos(*pp2)-pos(*pp1)<=nToken). i.e.
** when the *pp1 token appears before the *pp2 token, but not more than nToken
** slots before it.
*/
static int fts3PoslistPhraseMerge(
  char **pp,                      /* IN/OUT: Preallocated output buffer */
  int nToken,                     /* Maximum difference in token positions */
  int isSaveLeft,                 /* Save the left position */
  int isExact,                    /* If *pp1 is exactly nTokens before *pp2 */
  char **pp1,                     /* IN/OUT: Left input list */
  char **pp2                      /* IN/OUT: Right input list */
){
  char *p = (pp ? *pp : 0);
  char *p1 = *pp1;
  char *p2 = *pp2;

  int iCol1 = 0;
  int iCol2 = 0;

  /* Never set both isSaveLeft and isExact for the same invocation. */
  assert( isSaveLeft==0 || isExact==0 );

  assert( *p1!=0 && *p2!=0 );
  if( *p1==POS_COLUMN ){ 
    p1++;
    p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
  }
  if( *p2==POS_COLUMN ){ 
    p2++;

      assert( *p1!=POS_END && *p1!=POS_COLUMN );
      assert( *p2!=POS_END && *p2!=POS_COLUMN );
      fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
      fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;

      while( 1 ){
        if( iPos2==iPos1+nToken 
         || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken) 
        ){
          sqlite3_int64 iSave;
          if( !pp ){
            fts3PoslistCopy(0, &p2);
            fts3PoslistCopy(0, &p1);
            *pp1 = p1;
            *pp2 = p2;
            return 1;

  char **pp1,                     /* IN/OUT: Left input list */
  char **pp2                      /* IN/OUT: Right input list */
){
  char *p1 = *pp1;
  char *p2 = *pp2;

  if( !pp ){
    if( fts3PoslistPhraseMerge(0, nRight, 0, 0, pp1, pp2) ) return 1;
    *pp1 = p1;
    *pp2 = p2;
    return fts3PoslistPhraseMerge(0, nLeft, 0, 0, pp2, pp1);
  }else{
    char *pTmp1 = aTmp;
    char *pTmp2;
    char *aTmp2;
    int res = 1;

    fts3PoslistPhraseMerge(&pTmp1, nRight, 0, 0, pp1, pp2);
    aTmp2 = pTmp2 = pTmp1;
    *pp1 = p1;
    *pp2 = p2;
    fts3PoslistPhraseMerge(&pTmp2, nLeft, 1, 0, pp2, pp1);
    if( pTmp1!=aTmp && pTmp2!=aTmp2 ){
      fts3PoslistMerge(pp, &aTmp, &aTmp2);
    }else if( pTmp1!=aTmp ){
      fts3PoslistCopy(pp, &aTmp);
    }else if( pTmp2!=aTmp2 ){
      fts3PoslistCopy(pp, &aTmp2);
    }else{

  int nParam1,                    /* Used by MERGE_NEAR and MERGE_POS_NEAR */
  int nParam2,                    /* Used by MERGE_NEAR and MERGE_POS_NEAR */
  char *aBuffer,                  /* Pre-allocated output buffer */
  int *pnBuffer,                  /* OUT: Bytes written to aBuffer */
  char *a1,                       /* Buffer containing first doclist */
  int n1,                         /* Size of buffer a1 */
  char *a2,                       /* Buffer containing second doclist */
  int n2,                         /* Size of buffer a2 */
  int *pnDoc                      /* OUT: Number of docids in output */
){
  sqlite3_int64 i1 = 0;
  sqlite3_int64 i2 = 0;
  sqlite3_int64 iPrev = 0;

  char *p = aBuffer;
  char *p1 = a1;
  char *p2 = a2;
  char *pEnd1 = &a1[n1];
  char *pEnd2 = &a2[n2];
  int nDoc = 0;

  assert( mergetype==MERGE_OR     || mergetype==MERGE_POS_OR 
       || mergetype==MERGE_AND    || mergetype==MERGE_NOT
       || mergetype==MERGE_PHRASE || mergetype==MERGE_POS_PHRASE
       || mergetype==MERGE_NEAR   || mergetype==MERGE_POS_NEAR
  );

    case MERGE_AND:
      while( p1 && p2 ){
        if( i1==i2 ){
          fts3PutDeltaVarint(&p, &iPrev, i1);
          fts3GetDeltaVarint2(&p1, pEnd1, &i1);
          fts3GetDeltaVarint2(&p2, pEnd2, &i2);
          nDoc++;
        }else if( i1<i2 ){
          fts3GetDeltaVarint2(&p1, pEnd1, &i1);
        }else{
          fts3GetDeltaVarint2(&p2, pEnd2, &i2);
        }
      }
      break;

    case MERGE_PHRASE: {
      char **ppPos = (mergetype==MERGE_PHRASE ? 0 : &p);
      while( p1 && p2 ){
        if( i1==i2 ){
          char *pSave = p;
          sqlite3_int64 iPrevSave = iPrev;
          fts3PutDeltaVarint(&p, &iPrev, i1);
          if( 0==fts3PoslistPhraseMerge(ppPos, nParam1, 0, 1, &p1, &p2) ){
            p = pSave;
            iPrev = iPrevSave;
          }else{
            nDoc++;
          }
          fts3GetDeltaVarint2(&p1, pEnd1, &i1);
          fts3GetDeltaVarint2(&p2, pEnd2, &i2);
        }else if( i1<i2 ){
          fts3PoslistCopy(0, &p1);
          fts3GetDeltaVarint2(&p1, pEnd1, &i1);
        }else{

        }
      }
      sqlite3_free(aTmp);
      break;
    }
  }

  if( pnDoc ) *pnDoc = nDoc;
  *pnBuffer = (int)(p-aBuffer);
  return SQLITE_OK;
}

/* 
** A pointer to an instance of this structure is used as the context 
** argument to sqlite3Fts3SegReaderIterate()

  ** into a single doclist.
  */
  for(i=0; i<SizeofArray(pTS->aaOutput); i++){
    if( pTS->aaOutput[i] ){
      if( !aOut ){
        aOut = pTS->aaOutput[i];
        nOut = pTS->anOutput[i];
        pTS->aaOutput[i] = 0;
      }else{
        int nNew = nOut + pTS->anOutput[i];
        char *aNew = sqlite3_malloc(nNew);
        if( !aNew ){
          sqlite3_free(aOut);
          return SQLITE_NOMEM;
        }
        fts3DoclistMerge(mergetype, 0, 0,
            aNew, &nNew, pTS->aaOutput[i], pTS->anOutput[i], aOut, nOut, 0
        );
        sqlite3_free(pTS->aaOutput[i]);
        sqlite3_free(aOut);
        pTS->aaOutput[i] = 0;
        aOut = aNew;
        nOut = nNew;
      }

      aNew = sqlite3_malloc(nNew);
      if( !aNew ){
        if( aMerge!=aDoclist ){
          sqlite3_free(aMerge);
        }
        return SQLITE_NOMEM;
      }
      fts3DoclistMerge(mergetype, 0, 0, aNew, &nNew, 
          pTS->aaOutput[iOut], pTS->anOutput[iOut], aMerge, nMerge, 0
      );

      if( iOut>0 ) sqlite3_free(aMerge);
      sqlite3_free(pTS->aaOutput[iOut]);
      pTS->aaOutput[iOut] = 0;

      aMerge = aNew;
      nMerge = nNew;
      if( (iOut+1)==SizeofArray(pTS->aaOutput) ){
        pTS->aaOutput[iOut] = aMerge;
        pTS->anOutput[iOut] = nMerge;
      }
    }
  }
  return SQLITE_OK;
}

static int fts3DeferredTermSelect(
  Fts3DeferredToken *pToken,      /* Phrase token */
  int isTermPos,                  /* True to include positions */
  int *pnOut,                     /* OUT: Size of list */
  char **ppOut                    /* OUT: Body of list */
){
  char *aSource;
  int nSource;

  aSource = sqlite3Fts3DeferredDoclist(pToken, &nSource);
  if( !aSource ){
    *pnOut = 0;
    *ppOut = 0;
  }else if( isTermPos ){
    *ppOut = sqlite3_malloc(nSource);
    if( !*ppOut ) return SQLITE_NOMEM;
    memcpy(*ppOut, aSource, nSource);
    *pnOut = nSource;
  }else{
    sqlite3_int64 docid;
    *pnOut = sqlite3Fts3GetVarint(aSource, &docid);
    *ppOut = sqlite3_malloc(*pnOut);
    if( !*ppOut ) return SQLITE_NOMEM;
    sqlite3Fts3PutVarint(*ppOut, docid);
  }

  return SQLITE_OK;
}

/*
** An Fts3SegReaderArray is used to store an array of Fts3SegReader objects.
** Elements are added to the array using fts3SegReaderArrayAdd(). 
*/
struct Fts3SegReaderArray {
  int nSegment;                   /* Number of valid entries in apSegment[] */
  int nAlloc;                     /* Allocated size of apSegment[] */
  int nCost;                      /* The cost of executing SegReaderIterate() */
  Fts3SegReader *apSegment[1];    /* Array of seg-reader objects */
};


/*
** Free an Fts3SegReaderArray object. Also free all seg-readers in the
** array (using sqlite3Fts3SegReaderFree()).
*/
static void fts3SegReaderArrayFree(Fts3SegReaderArray *pArray){
  if( pArray ){
    int i;
    for(i=0; i<pArray->nSegment; i++){
      sqlite3Fts3SegReaderFree(0, pArray->apSegment[i]);
    }
    sqlite3_free(pArray);
  }
}

static int fts3SegReaderArrayAdd(
  Fts3SegReaderArray **ppArray, 
  Fts3SegReader *pNew
){
  Fts3SegReaderArray *pArray = *ppArray;

  if( !pArray || pArray->nAlloc==pArray->nSegment ){
    int nNew = (pArray ? pArray->nAlloc+16 : 16);
    pArray = (Fts3SegReaderArray *)sqlite3_realloc(pArray, 
        sizeof(Fts3SegReaderArray) + (nNew-1) * sizeof(Fts3SegReader*)
    );
    if( !pArray ){
      sqlite3Fts3SegReaderFree(0, pNew);
      return SQLITE_NOMEM;
    }
    if( nNew==16 ){
      pArray->nSegment = 0;
      pArray->nCost = 0;
    }
    pArray->nAlloc = nNew;
    *ppArray = pArray;
  }

  pArray->apSegment[pArray->nSegment++] = pNew;
  return SQLITE_OK;
}

static int fts3TermSegReaderArray(
  Fts3Cursor *pCsr,               /* Virtual table cursor handle */
  const char *zTerm,              /* Term to query for */
  int nTerm,                      /* Size of zTerm in bytes */
  int isPrefix,                   /* True for a prefix search */
  Fts3SegReaderArray **ppArray    /* OUT: Allocated seg-reader array */
){
  Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
  int rc;                         /* Return code */
  Fts3SegReaderArray *pArray = 0; /* Array object to build */
  Fts3SegReader *pReader = 0;     /* Seg-reader to add to pArray */ 
  sqlite3_stmt *pStmt = 0;        /* SQL statement to scan %_segdir table */
  int iAge = 0;                   /* Used to assign ages to segments */

  /* Allocate a seg-reader to scan the pending terms, if any. */
  rc = sqlite3Fts3SegReaderPending(p, zTerm, nTerm, isPrefix, &pReader);
  if( rc==SQLITE_OK && pReader ) {
    rc = fts3SegReaderArrayAdd(&pArray, pReader);
  }

  /* Loop through the entire %_segdir table. For each segment, create a
  ** Fts3SegReader to iterate through the subset of the segment leaves
  ** that may contain a term that matches zTerm/nTerm. For non-prefix
  ** searches, this is always a single leaf. For prefix searches, this
  ** may be a contiguous block of leaves.
  */
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3AllSegdirs(p, &pStmt);
  }
  while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
    Fts3SegReader *pNew = 0;
    int nRoot = sqlite3_column_bytes(pStmt, 4);
    char const *zRoot = sqlite3_column_blob(pStmt, 4);
    if( sqlite3_column_int64(pStmt, 1)==0 ){
      /* The entire segment is stored on the root node (which must be a
      ** leaf). Do not bother inspecting any data in this case, just
      ** create a Fts3SegReader to scan the single leaf. 
      */
      rc = sqlite3Fts3SegReaderNew(p, iAge, 0, 0, 0, zRoot, nRoot, &pNew);
    }else{
      sqlite3_int64 i1;           /* First leaf that may contain zTerm */
      sqlite3_int64 i2;           /* Final leaf that may contain zTerm */
      rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &i1, (isPrefix?&i2:0));
      if( isPrefix==0 ) i2 = i1;
      if( rc==SQLITE_OK ){
        rc = sqlite3Fts3SegReaderNew(p, iAge, i1, i2, 0, 0, 0, &pNew);
      }
    }
    assert( (pNew==0)==(rc!=SQLITE_OK) );

    /* If a new Fts3SegReader was allocated, add it to the array. */
    if( rc==SQLITE_OK ){
      rc = fts3SegReaderArrayAdd(&pArray, pNew);
    }
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts3SegReaderCost(pCsr, pNew, &pArray->nCost);
    }
    iAge++;
  }

  if( rc==SQLITE_DONE ){
    rc = sqlite3_reset(pStmt);
  }else{
    sqlite3_reset(pStmt);
  }
  if( rc!=SQLITE_OK ){
    fts3SegReaderArrayFree(pArray);
    pArray = 0;
  }
  *ppArray = pArray;
  return rc;
}

/*
** This function retreives the doclist for the specified term (or term
** prefix) from the database. 
**
** The returned doclist may be in one of two formats, depending on the 
** value of parameter isReqPos. If isReqPos is zero, then the doclist is
** a sorted list of delta-compressed docids (a bare doclist). If isReqPos
** is non-zero, then the returned list is in the same format as is stored 
** in the database without the found length specifier at the start of on-disk
** doclists.
*/
static int fts3TermSelect(
  Fts3Table *p,                   /* Virtual table handle */
  Fts3PhraseToken *pTok,          /* Token to query for */
  int iColumn,                    /* Column to query (or -ve for all columns) */



  int isReqPos,                   /* True to include position lists in output */
  int *pnOut,                     /* OUT: Size of buffer at *ppOut */
  char **ppOut                    /* OUT: Malloced result buffer */
){






  int rc;                         /* Return code */























  Fts3SegReaderArray *pArray;     /* Seg-reader array for this term */
















  TermSelect tsc;               /* Context object for fts3TermSelectCb() */












  Fts3SegFilter filter;         /* Segment term filter configuration */























  pArray = pTok->pArray;
  memset(&tsc, 0, sizeof(TermSelect));
  tsc.isReqPos = isReqPos;

  filter.flags = FTS3_SEGMENT_IGNORE_EMPTY 
        | (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
        | (isReqPos ? FTS3_SEGMENT_REQUIRE_POS : 0)
        | (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
  filter.iCol = iColumn;
  filter.zTerm = pTok->z;
  filter.nTerm = pTok->n;

  rc = sqlite3Fts3SegReaderIterate(p, pArray->apSegment, pArray->nSegment, 
      &filter, fts3TermSelectCb, (void *)&tsc
  );
  if( rc==SQLITE_OK ){
    rc = fts3TermSelectMerge(&tsc);
  }

  if( rc==SQLITE_OK ){
    *ppOut = tsc.aaOutput[0];
    *pnOut = tsc.anOutput[0];
  }else{
    int i;
    for(i=0; i<SizeofArray(tsc.aaOutput); i++){
      sqlite3_free(tsc.aaOutput[i]);
    }
  }

  fts3SegReaderArrayFree(pArray);
  pTok->pArray = 0;
  return rc;
}

/*
** This function counts the total number of docids in the doclist stored
** in buffer aList[], size nList bytes.
**
** If the isPoslist argument is true, then it is assumed that the doclist
** contains a position-list following each docid. Otherwise, it is assumed
** that the doclist is simply a list of docids stored as delta encoded 
** varints.
*/
static int fts3DoclistCountDocids(int isPoslist, char *aList, int nList){
  int nDoc = 0;                   /* Return value */
  if( aList ){
    char *aEnd = &aList[nList];   /* Pointer to one byte after EOF */
    char *p = aList;              /* Cursor */
    if( !isPoslist ){
      /* The number of docids in the list is the same as the number of 
      ** varints. In FTS3 a varint consists of a single byte with the 0x80 
      ** bit cleared and zero or more bytes with the 0x80 bit set. So to
      ** count the varints in the buffer, just count the number of bytes
      ** with the 0x80 bit clear.  */
      while( p<aEnd ) nDoc += (((*p++)&0x80)==0);
    }else{
      while( p<aEnd ){
        nDoc++;
        while( (*p++)&0x80 );     /* Skip docid varint */
        fts3PoslistCopy(0, &p);   /* Skip over position list */
      }
    }
  }

  return nDoc;
}

/*
** Call sqlite3Fts3DeferToken() for each token in the expression pExpr.
*/
static int fts3DeferExpression(Fts3Cursor *pCsr, Fts3Expr *pExpr){
  int rc = SQLITE_OK;
  if( pExpr ){
    rc = fts3DeferExpression(pCsr, pExpr->pLeft);
    if( rc==SQLITE_OK ){
      rc = fts3DeferExpression(pCsr, pExpr->pRight);
    }
    if( pExpr->eType==FTSQUERY_PHRASE ){
      int iCol = pExpr->pPhrase->iColumn;
      int i;
      for(i=0; rc==SQLITE_OK && i<pExpr->pPhrase->nToken; i++){
        Fts3PhraseToken *pToken = &pExpr->pPhrase->aToken[i];
        if( pToken->pDeferred==0 ){
          rc = sqlite3Fts3DeferToken(pCsr, pToken, iCol);
        }
      }
    }
  }
  return rc;
}

/*
** This function removes the position information from a doclist. When
** called, buffer aList (size *pnList bytes) contains a doclist that includes
** position information. This function removes the position information so
** that aList contains only docids, and adjusts *pnList to reflect the new
** (possibly reduced) size of the doclist.
*/
static void fts3DoclistStripPositions(
  char *aList,                    /* IN/OUT: Buffer containing doclist */
  int *pnList                     /* IN/OUT: Size of doclist in bytes */
){
  if( aList ){
    char *aEnd = &aList[*pnList]; /* Pointer to one byte after EOF */
    char *p = aList;              /* Input cursor */
    char *pOut = aList;           /* Output cursor */
  
    while( p<aEnd ){
      sqlite3_int64 delta;
      p += sqlite3Fts3GetVarint(p, &delta);
      fts3PoslistCopy(0, &p);
      pOut += sqlite3Fts3PutVarint(pOut, delta);
    }

    *pnList = (pOut - aList);
  }
}

/* 
** Return a DocList corresponding to the phrase *pPhrase.
**
** If this function returns SQLITE_OK, but *pnOut is set to a negative value,
** then no tokens in the phrase were looked up in the full-text index. This
** is only possible when this function is called from within xFilter(). The
** caller should assume that all documents match the phrase. The actual
** filtering will take place in xNext().
*/
static int fts3PhraseSelect(
  Fts3Cursor *pCsr,               /* Virtual table cursor handle */
  Fts3Phrase *pPhrase,            /* Phrase to return a doclist for */
  int isReqPos,                   /* True if output should contain positions */
  char **paOut,                   /* OUT: Pointer to malloc'd result buffer */
  int *pnOut                      /* OUT: Size of buffer at *paOut */
){
  char *pOut = 0;
  int nOut = 0;
  int rc = SQLITE_OK;
  int ii;
  int iCol = pPhrase->iColumn;
  int isTermPos = (pPhrase->nToken>1 || isReqPos);
  Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
  int isFirst = 1;

  int iPrevTok = 0;
  int nDoc = 0;

  /* If this is an xFilter() evaluation, create a segment-reader for each
  ** phrase token. Or, if this is an xNext() or snippet/offsets/matchinfo
  ** evaluation, only create segment-readers if there are no Fts3DeferredToken
  ** objects attached to the phrase-tokens.
  */
  for(ii=0; ii<pPhrase->nToken; ii++){
    Fts3PhraseToken *pTok = &pPhrase->aToken[ii];
    if( pTok->pArray==0 ){
      if( (pCsr->eEvalmode==FTS3_EVAL_FILTER)
       || (pCsr->eEvalmode==FTS3_EVAL_NEXT && pCsr->pDeferred==0) 
       || (pCsr->eEvalmode==FTS3_EVAL_MATCHINFO && pTok->bFulltext) 
      ){
        rc = fts3TermSegReaderArray(
            pCsr, pTok->z, pTok->n, pTok->isPrefix, &pTok->pArray
        );
        if( rc!=SQLITE_OK ) return rc;
      }
    }
  }

  for(ii=0; ii<pPhrase->nToken; ii++){
    Fts3PhraseToken *pTok;        /* Token to find doclist for */
    int iTok;                     /* The token being queried this iteration */
    char *pList;                  /* Pointer to token doclist */
    int nList;                    /* Size of buffer at pList */

    /* Select a token to process. If this is an xFilter() call, then tokens 
    ** are processed in order from least to most costly. Otherwise, tokens 
    ** are processed in the order in which they occur in the phrase.
    */
    if( pCsr->eEvalmode==FTS3_EVAL_MATCHINFO ){
      assert( isReqPos );
      iTok = ii;
      pTok = &pPhrase->aToken[iTok];
      if( pTok->bFulltext==0 ) continue;
    }else if( pCsr->eEvalmode==FTS3_EVAL_NEXT || isReqPos ){
      iTok = ii;
      pTok = &pPhrase->aToken[iTok];
    }else{
      int nMinCost = 0x7FFFFFFF;
      int jj;

      /* Find the remaining token with the lowest cost. */
      for(jj=0; jj<pPhrase->nToken; jj++){
        Fts3SegReaderArray *pArray = pPhrase->aToken[jj].pArray;
        if( pArray && pArray->nCost<nMinCost ){
          iTok = jj;
          nMinCost = pArray->nCost;
        }
      }
      pTok = &pPhrase->aToken[iTok];

      /* This branch is taken if it is determined that loading the doclist
      ** for the next token would require more IO than loading all documents
      ** currently identified by doclist pOut/nOut. No further doclists will
      ** be loaded from the full-text index for this phrase.
      */
      if( nMinCost>nDoc && ii>0 ){
        rc = fts3DeferExpression(pCsr, pCsr->pExpr);
        break;
      }
    }

    if( pCsr->eEvalmode==FTS3_EVAL_NEXT && pTok->pDeferred ){
      rc = fts3DeferredTermSelect(pTok->pDeferred, isTermPos, &nList, &pList);
    }else{
      assert( pTok->pArray );
      rc = fts3TermSelect(p, pTok, iCol, isTermPos, &nList, &pList);
      pTok->bFulltext = 1;
    }
    assert( rc!=SQLITE_OK || pCsr->eEvalmode || pTok->pArray==0 );
    if( rc!=SQLITE_OK ) break;

    if( isFirst ){
      pOut = pList;
      nOut = nList;
      if( pCsr->eEvalmode==FTS3_EVAL_FILTER && pPhrase->nToken>1 ){
        nDoc = fts3DoclistCountDocids(1, pOut, nOut);
      }
      isFirst = 0;
      iPrevTok = iTok;
    }else{
      /* Merge the new term list and the current output. */
      char *aLeft, *aRight;
      int nLeft, nRight;
      int nDist;
      int mt;

      /* If this is the final token of the phrase, and positions were not



      ** requested by the caller, use MERGE_PHRASE instead of POS_PHRASE.
      ** This drops the position information from the output list.
      */
      mt = MERGE_POS_PHRASE;
      if( ii==pPhrase->nToken-1 && !isReqPos ) mt = MERGE_PHRASE;

      assert( iPrevTok!=iTok );
      if( iPrevTok<iTok ){
        aLeft = pOut;
        nLeft = nOut;
        aRight = pList;
        nRight = nList;
        nDist = iTok-iPrevTok;
        iPrevTok = iTok;
      }else{
        aRight = pOut;
        nRight = nOut;
        aLeft = pList;
        nLeft = nList;
        nDist = iPrevTok-iTok;
      }
      pOut = aRight;
      fts3DoclistMerge(
          mt, nDist, 0, pOut, &nOut, aLeft, nLeft, aRight, nRight, &nDoc
      );
      sqlite3_free(aLeft);

    }
    assert( nOut==0 || pOut!=0 );
  }

  if( rc==SQLITE_OK ){
    if( ii!=pPhrase->nToken ){
      assert( pCsr->eEvalmode==FTS3_EVAL_FILTER && isReqPos==0 );
      fts3DoclistStripPositions(pOut, &nOut);
    }
    *paOut = pOut;
    *pnOut = nOut;
  }else{
    sqlite3_free(pOut);
  }
  return rc;
}

/*
** This function merges two doclists according to the requirements of a
** NEAR operator.
**
** Both input doclists must include position information. The output doclist 
** includes position information if the first argument to this function
** is MERGE_POS_NEAR, or does not if it is MERGE_NEAR.
*/
static int fts3NearMerge(
  int mergetype,                  /* MERGE_POS_NEAR or MERGE_NEAR */
  int nNear,                      /* Parameter to NEAR operator */
  int nTokenLeft,                 /* Number of tokens in LHS phrase arg */
  char *aLeft,                    /* Doclist for LHS (incl. positions) */
  int nLeft,                      /* Size of LHS doclist in bytes */
  int nTokenRight,                /* As nTokenLeft */
  char *aRight,                   /* As aLeft */
  int nRight,                     /* As nRight */
  char **paOut,                   /* OUT: Results of merge (malloced) */
  int *pnOut                      /* OUT: Sized of output buffer */
){
  char *aOut;                     /* Buffer to write output doclist to */
  int rc;                         /* Return code */

  assert( mergetype==MERGE_POS_NEAR || MERGE_NEAR );

  aOut = sqlite3_malloc(nLeft+nRight+1);
  if( aOut==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = fts3DoclistMerge(mergetype, nNear+nTokenRight, nNear+nTokenLeft, 
      aOut, pnOut, aLeft, nLeft, aRight, nRight, 0
    );
    if( rc!=SQLITE_OK ){
      sqlite3_free(aOut);
      aOut = 0;
    }
  }

  *paOut = aOut;
  return rc;
}

/*
** This function is used as part of the processing for the snippet() and
** offsets() functions.
**
** Both pLeft and pRight are expression nodes of type FTSQUERY_PHRASE. Both
** have their respective doclists (including position information) loaded
** in Fts3Expr.aDoclist/nDoclist. This function removes all entries from
** each doclist that are not within nNear tokens of a corresponding entry
** in the other doclist.
*/
int sqlite3Fts3ExprNearTrim(Fts3Expr *pLeft, Fts3Expr *pRight, int nNear){
  int rc;                         /* Return code */

  assert( pLeft->eType==FTSQUERY_PHRASE );
  assert( pRight->eType==FTSQUERY_PHRASE );
  assert( pLeft->isLoaded && pRight->isLoaded );

  if( pLeft->aDoclist==0 || pRight->aDoclist==0 ){
    sqlite3_free(pLeft->aDoclist);
    sqlite3_free(pRight->aDoclist);
    pRight->aDoclist = 0;
    pLeft->aDoclist = 0;
    rc = SQLITE_OK;
  }else{
    char *aOut;                   /* Buffer in which to assemble new doclist */
    int nOut;                     /* Size of buffer aOut in bytes */

    rc = fts3NearMerge(MERGE_POS_NEAR, nNear, 
        pLeft->pPhrase->nToken, pLeft->aDoclist, pLeft->nDoclist,
        pRight->pPhrase->nToken, pRight->aDoclist, pRight->nDoclist,
        &aOut, &nOut
    );
    if( rc!=SQLITE_OK ) return rc;

    sqlite3_free(pLeft->aDoclist);
    pLeft->aDoclist = aOut;
    pLeft->nDoclist = nOut;
  }
  return rc;
}


/*
** Allocate an Fts3SegReaderArray for each token in the expression pExpr. 
** The allocated objects are stored in the Fts3PhraseToken.pArray member
** variables of each token structure.
*/
static int fts3ExprAllocateSegReaders(
  Fts3Cursor *pCsr,               /* FTS3 table */
  Fts3Expr *pExpr,                /* Expression to create seg-readers for */
  int *pnExpr                     /* OUT: Number of AND'd expressions */
){
  int rc = SQLITE_OK;             /* Return code */

  assert( pCsr->eEvalmode==FTS3_EVAL_FILTER );
  if( pnExpr && pExpr->eType!=FTSQUERY_AND ){
    (*pnExpr)++;
    pnExpr = 0;
  }

  if( pExpr->eType==FTSQUERY_PHRASE ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;

    for(ii=0; rc==SQLITE_OK && ii<pPhrase->nToken; ii++){
      Fts3PhraseToken *pTok = &pPhrase->aToken[ii];
      if( pTok->pArray==0 ){
        rc = fts3TermSegReaderArray(
            pCsr, pTok->z, pTok->n, pTok->isPrefix, &pTok->pArray
        );
      }
    }
  }else{ 
    rc = fts3ExprAllocateSegReaders(pCsr, pExpr->pLeft, pnExpr);
    if( rc==SQLITE_OK ){
      rc = fts3ExprAllocateSegReaders(pCsr, pExpr->pRight, pnExpr);
    }
  }
  return rc;
}

/*
** Free the Fts3SegReaderArray objects associated with each token in the
** expression pExpr. In other words, this function frees the resources
** allocated by fts3ExprAllocateSegReaders().
*/
static void fts3ExprFreeSegReaders(Fts3Expr *pExpr){
  if( pExpr ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    if( pPhrase ){
      int kk;
      for(kk=0; kk<pPhrase->nToken; kk++){
        fts3SegReaderArrayFree(pPhrase->aToken[kk].pArray);
        pPhrase->aToken[kk].pArray = 0;
      }
    }
    fts3ExprFreeSegReaders(pExpr->pLeft);
    fts3ExprFreeSegReaders(pExpr->pRight);
  }
}

/*
** Return the sum of the costs of all tokens in the expression pExpr. This
** function must be called after Fts3SegReaderArrays have been allocated
** for all tokens using fts3ExprAllocateSegReaders().
*/
static int fts3ExprCost(Fts3Expr *pExpr){
  int nCost;                      /* Return value */
  if( pExpr->eType==FTSQUERY_PHRASE ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;
    nCost = 0;
    for(ii=0; ii<pPhrase->nToken; ii++){
      nCost += pPhrase->aToken[ii].pArray->nCost;
    }
  }else{
    nCost = fts3ExprCost(pExpr->pLeft) + fts3ExprCost(pExpr->pRight);
  }
  return nCost;
}

/*
** The following is a helper function (and type) for fts3EvalExpr(). It
** must be called after Fts3SegReaders have been allocated for every token
** in the expression. See the context it is called from in fts3EvalExpr()
** for further explanation.
*/
typedef struct ExprAndCost ExprAndCost;
struct ExprAndCost {
  Fts3Expr *pExpr;
  int nCost;
};
static void fts3ExprAssignCosts(
  Fts3Expr *pExpr,                /* Expression to create seg-readers for */
  ExprAndCost **ppExprCost        /* OUT: Write to *ppExprCost */
){
  if( pExpr->eType==FTSQUERY_AND ){
    fts3ExprAssignCosts(pExpr->pLeft, ppExprCost);
    fts3ExprAssignCosts(pExpr->pRight, ppExprCost);
  }else{
    (*ppExprCost)->pExpr = pExpr;
    (*ppExprCost)->nCost = fts3ExprCost(pExpr);;
    (*ppExprCost)++;
  }
}

/*
** Evaluate the full-text expression pExpr against FTS3 table pTab. Store
** the resulting doclist in *paOut and *pnOut. This routine mallocs for
** the space needed to store the output. The caller is responsible for
** freeing the space when it has finished.
**
** This function is called in two distinct contexts:
**
**   * From within the virtual table xFilter() method. In this case, the
**     output doclist contains entries for all rows in the table, based on
**     data read from the full-text index.
**
**     In this case, if the query expression contains one or more tokens that 
**     are very common, then the returned doclist may contain a superset of 
**     the documents that actually match the expression.
**
**   * From within the virtual table xNext() method. This call is only made
**     if the call from within xFilter() found that there were very common 
**     tokens in the query expression and did return a superset of the 
**     matching documents. In this case the returned doclist contains only
**     entries that correspond to the current row of the table. Instead of
**     reading the data for each token from the full-text index, the data is
**     already available in-memory in the Fts3PhraseToken.pDeferred structures.
**     See fts3EvalDeferred() for how it gets there.
**
** In the first case above, Fts3Cursor.doDeferred==0. In the second (if it is
** required) Fts3Cursor.doDeferred==1.
**
** If the SQLite invokes the snippet(), offsets() or matchinfo() function
** as part of a SELECT on an FTS3 table, this function is called on each
** individual phrase expression in the query. If there were very common tokens
** found in the xFilter() call, then this function is called once for phrase
** for each row visited, and the returned doclist contains entries for the
** current row only. Otherwise, if there were no very common tokens, then this
** function is called once only for each phrase in the query and the returned
** doclist contains entries for all rows of the table.
**
** Fts3Cursor.doDeferred==1 when this function is called on phrases as a
** result of a snippet(), offsets() or matchinfo() invocation.
*/
static int fts3EvalExpr(
  Fts3Cursor *p,                  /* Virtual table cursor handle */
  Fts3Expr *pExpr,                /* Parsed fts3 expression */
  char **paOut,                   /* OUT: Pointer to malloc'd result buffer */
  int *pnOut,                     /* OUT: Size of buffer at *paOut */
  int isReqPos                    /* Require positions in output buffer */
){
  int rc = SQLITE_OK;             /* Return code */

  /* Zero the output parameters. */
  *paOut = 0;
  *pnOut = 0;

  if( pExpr ){
    assert( pExpr->eType==FTSQUERY_NEAR   || pExpr->eType==FTSQUERY_OR     
         || pExpr->eType==FTSQUERY_AND    || pExpr->eType==FTSQUERY_NOT
         || pExpr->eType==FTSQUERY_PHRASE
    );
    assert( pExpr->eType==FTSQUERY_PHRASE || isReqPos==0 );

    if( pExpr->eType==FTSQUERY_PHRASE ){
      rc = fts3PhraseSelect(p, pExpr->pPhrase,
          isReqPos || (pExpr->pParent && pExpr->pParent->eType==FTSQUERY_NEAR),
          paOut, pnOut
      );
      fts3ExprFreeSegReaders(pExpr);
    }else if( p->eEvalmode==FTS3_EVAL_FILTER && pExpr->eType==FTSQUERY_AND ){
      ExprAndCost *aExpr = 0;     /* Array of AND'd expressions and costs */
      int nExpr = 0;              /* Size of aExpr[] */
      char *aRet = 0;             /* Doclist to return to caller */
      int nRet = 0;               /* Length of aRet[] in bytes */
      int nDoc = 0x7FFFFFFF;

      assert( !isReqPos );

      rc = fts3ExprAllocateSegReaders(p, pExpr, &nExpr);
      if( rc==SQLITE_OK ){
        assert( nExpr>1 );
        aExpr = sqlite3_malloc(sizeof(ExprAndCost) * nExpr);
        if( !aExpr ) rc = SQLITE_NOMEM;
      }
      if( rc==SQLITE_OK ){
        int ii;                   /* Used to iterate through expressions */

        fts3ExprAssignCosts(pExpr, &aExpr);
        aExpr -= nExpr;
        for(ii=0; ii<nExpr; ii++){
          char *aNew;
          int nNew;
          int jj;
          ExprAndCost *pBest = 0;
  
          for(jj=0; jj<nExpr; jj++){
            ExprAndCost *pCand = &aExpr[jj];
            if( pCand->pExpr && (pBest==0 || pCand->nCost<pBest->nCost) ){
              pBest = pCand;
            }
          }
  
          if( pBest->nCost>nDoc ){
            rc = fts3DeferExpression(p, p->pExpr);
            break;
          }else{
            rc = fts3EvalExpr(p, pBest->pExpr, &aNew, &nNew, 0);
            if( rc!=SQLITE_OK ) break;
            pBest->pExpr = 0;
            if( ii==0 ){
              aRet = aNew;
              nRet = nNew;
              nDoc = fts3DoclistCountDocids(0, aRet, nRet);
            }else{
              fts3DoclistMerge(
                  MERGE_AND, 0, 0, aRet, &nRet, aRet, nRet, aNew, nNew, &nDoc
              );
              sqlite3_free(aNew);
            }
          }
        }
      }

      *paOut = aRet;
      *pnOut = nRet;
      sqlite3_free(aExpr);
      fts3ExprFreeSegReaders(pExpr);

    }else{
      char *aLeft;
      char *aRight;
      int nLeft;
      int nRight;




      assert( pExpr->eType==FTSQUERY_NEAR 
           || pExpr->eType==FTSQUERY_OR
           || pExpr->eType==FTSQUERY_NOT
           || (pExpr->eType==FTSQUERY_AND && p->eEvalmode==FTS3_EVAL_NEXT)
      );

      if( 0==(rc = fts3EvalExpr(p, pExpr->pRight, &aRight, &nRight, isReqPos))
       && 0==(rc = fts3EvalExpr(p, pExpr->pLeft, &aLeft, &nLeft, isReqPos))
      ){
        switch( pExpr->eType ){
          case FTSQUERY_NEAR: {
            Fts3Expr *pLeft;
            Fts3Expr *pRight;
            int mergetype = MERGE_NEAR;

            if( pExpr->pParent && pExpr->pParent->eType==FTSQUERY_NEAR ){
              mergetype = MERGE_POS_NEAR;
            }
            pLeft = pExpr->pLeft;
            while( pLeft->eType==FTSQUERY_NEAR ){ 
              pLeft=pLeft->pRight;
            }

            /* Allocate a buffer for the output. The maximum size is the
            ** sum of the sizes of the two input buffers. The +1 term is
            ** so that a buffer of zero bytes is never allocated - this can
            ** cause fts3DoclistMerge() to incorrectly return SQLITE_NOMEM.
            */
            char *aBuffer = sqlite3_malloc(nRight+nLeft+1);
            rc = fts3DoclistMerge(MERGE_OR, 0, 0, aBuffer, pnOut,
                aLeft, nLeft, aRight, nRight, 0
            );
            *paOut = aBuffer;
            sqlite3_free(aLeft);
            break;
          }

          default: {
            assert( FTSQUERY_NOT==MERGE_NOT && FTSQUERY_AND==MERGE_AND );
            fts3DoclistMerge(pExpr->eType, 0, 0, aLeft, pnOut,
                aLeft, nLeft, aRight, nRight, 0
            );
            *paOut = aLeft;
            break;
          }
        }
      }
      sqlite3_free(aRight);
    }
  }

  return rc;
}

/*
** This function is called from within xNext() for each row visited by
** an FTS3 query. If evaluating the FTS3 query expression within xFilter()
** was able to determine the exact set of matching rows, this function sets
** *pbRes to true and returns SQLITE_IO immediately.
**
** Otherwise, if evaluating the query expression within xFilter() returned a
** superset of the matching documents instead of an exact set (this happens
** when the query includes very common tokens and it is deemed too expensive to
** load their doclists from disk), this function tests if the current row
** really does match the FTS3 query.
**
** If an error occurs, an SQLite error code is returned. Otherwise, SQLITE_OK
** is returned and *pbRes is set to true if the current row matches the
** FTS3 query (and should be included in the results returned to SQLite), or
** false otherwise.
*/
static int fts3EvalDeferred(
  Fts3Cursor *pCsr,               /* FTS3 cursor pointing at row to test */
  int *pbRes                      /* OUT: Set to true if row is a match */
){
  int rc = SQLITE_OK;
  if( pCsr->pDeferred==0 ){
    *pbRes = 1;
  }else{
    rc = fts3CursorSeek(0, pCsr);
    if( rc==SQLITE_OK ){
      sqlite3Fts3FreeDeferredDoclists(pCsr);
      rc = sqlite3Fts3CacheDeferredDoclists(pCsr);
    }
    if( rc==SQLITE_OK ){
      char *a = 0;
      int n = 0;
      rc = fts3EvalExpr(pCsr, pCsr->pExpr, &a, &n, 0);
      assert( n>=0 );
      *pbRes = (n>0);
      sqlite3_free(a);
    }
  }
  return rc;
}

/*
** Advance the cursor to the next row in the %_content table that
** matches the search criteria.  For a MATCH search, this will be
** the next row that matches. For a full-table scan, this will be
** simply the next row in the %_content table.  For a docid lookup,
** this routine simply sets the EOF flag.
**
** Return SQLITE_OK if nothing goes wrong.  SQLITE_OK is returned
** even if we reach end-of-file.  The fts3EofMethod() will be called
** subsequently to determine whether or not an EOF was hit.
*/
static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
  int res;
  int rc = SQLITE_OK;             /* Return code */
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  pCsr->eEvalmode = FTS3_EVAL_NEXT;
  do {
    if( pCsr->aDoclist==0 ){
      if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
        pCsr->isEof = 1;
        rc = sqlite3_reset(pCsr->pStmt);
        break;
      }
      pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
    }else{
      if( pCsr->pNextId>=&pCsr->aDoclist[pCsr->nDoclist] ){
        pCsr->isEof = 1;
        break;
      }
      sqlite3_reset(pCsr->pStmt);
      fts3GetDeltaVarint(&pCsr->pNextId, &pCsr->iPrevId);
      pCsr->isRequireSeek = 1;
      pCsr->isMatchinfoNeeded = 1;
    }
  }while( SQLITE_OK==(rc = fts3EvalDeferred(pCsr, &res)) && res==0 );

  return rc;
}

/*
** This is the xFilter interface for the virtual table.  See
** the virtual table xFilter method documentation for additional
** information.
**
** If idxNum==FTS3_FULLSCAN_SEARCH then do a full table scan against
** the %_content table.
**
** If idxNum==FTS3_DOCID_SEARCH then do a docid lookup for a single entry
** in the %_content table.
**
** If idxNum>=FTS3_FULLTEXT_SEARCH then use the full text index.  The
** column on the left-hand side of the MATCH operator is column
** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed.  argv[0] is the right-hand
** side of the MATCH operator.
*/





static int fts3FilterMethod(
  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( nVal==0 || nVal==1 );
  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );
  assert( p->pSegments==0 );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
















  if( idxNum!=FTS3_DOCID_SEARCH && idxNum!=FTS3_FULLSCAN_SEARCH ){


    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }

    rc = sqlite3Fts3ExprParse(p->pTokenizer, p->azColumn, p->nColumn, 
        iCol, zQuery, -1, &pCsr->pExpr
    );
    if( rc!=SQLITE_OK ){
      if( rc==SQLITE_ERROR ){
        p->base.zErrMsg = sqlite3_mprintf("malformed MATCH expression: [%s]",
                                          zQuery);
      }
      return rc;
    }

    rc = sqlite3Fts3ReadLock(p);
    if( rc!=SQLITE_OK ) return rc;

    rc = fts3EvalExpr(pCsr, pCsr->pExpr, &pCsr->aDoclist, &pCsr->nDoclist, 0);
    sqlite3Fts3SegmentsClose(p);
    if( rc!=SQLITE_OK ) return rc;
    pCsr->pNextId = pCsr->aDoclist;
    pCsr->iPrevId = 0;
  }

  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
  ** statement loops through all rows of the %_content table. For a
  ** full-text query or docid lookup, the statement retrieves a single
  ** row by docid.
  */
  zSql = sqlite3_mprintf(azSql[idxNum==FTS3_FULLSCAN_SEARCH], p->zDb, p->zName);
  if( !zSql ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pCsr->pStmt, 0);
    sqlite3_free(zSql);
  }
  if( rc==SQLITE_OK && idxNum==FTS3_DOCID_SEARCH ){
    rc = sqlite3_bind_value(pCsr->pStmt, 1, apVal[0]);
  }
  pCsr->eSearch = (i16)idxNum;

  if( rc!=SQLITE_OK ) return rc;
  return fts3NextMethod(pCursor);
}

/* 
** This is the xEof method of the virtual table. SQLite calls this 

** rowid should be written to *pRowid.
*/
static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
  if( pCsr->aDoclist ){
    *pRowid = pCsr->iPrevId;
  }else{
    /* This branch runs if the query is implemented using a full-table scan
    ** (not using the full-text index). In this case grab the rowid from the
    ** SELECT statement.
    */
    assert( pCsr->isRequireSeek==0 );
    *pRowid = sqlite3_column_int64(pCsr->pStmt, 0);
  }
  return SQLITE_OK;
}

/* 
** This is the xColumn method, called by SQLite to request a value from

}

/*
** Implementation of xSync() method. Flush the contents of the pending-terms
** hash-table to the database.
*/
static int fts3SyncMethod(sqlite3_vtab *pVtab){
  int rc = sqlite3Fts3PendingTermsFlush((Fts3Table *)pVtab);
  sqlite3Fts3SegmentsClose((Fts3Table *)pVtab);
  return rc;
}

/*
** Implementation of xBegin() method. This is a no-op.
*/
static int fts3BeginMethod(sqlite3_vtab *pVtab){
  UNUSED_PARAMETER(pVtab);

/*
** Load the doclist associated with expression pExpr to pExpr->aDoclist.
** The loaded doclist contains positions as well as the document ids.
** This is used by the matchinfo(), snippet() and offsets() auxillary
** functions.
*/
int sqlite3Fts3ExprLoadDoclist(Fts3Cursor *pCsr, Fts3Expr *pExpr){
  int rc;
  assert( pExpr->eType==FTSQUERY_PHRASE && pExpr->pPhrase );
  assert( pCsr->eEvalmode==FTS3_EVAL_NEXT );
  rc = fts3EvalExpr(pCsr, pExpr, &pExpr->aDoclist, &pExpr->nDoclist, 1);
  return rc;
}

int sqlite3Fts3ExprLoadFtDoclist(
  Fts3Cursor *pCsr, 
  Fts3Expr *pExpr,
  char **paDoclist,
  int *pnDoclist
){
  int rc;
  assert( pCsr->eEvalmode==FTS3_EVAL_NEXT );
  assert( pExpr->eType==FTSQUERY_PHRASE && pExpr->pPhrase );
  pCsr->eEvalmode = FTS3_EVAL_MATCHINFO;
  rc = fts3EvalExpr(pCsr, pExpr, paDoclist, pnDoclist, 1);
  pCsr->eEvalmode = FTS3_EVAL_NEXT;
  return rc;
}

/*
** After ExprLoadDoclist() (see above) has been called, this function is
** used to iterate/search through the position lists that make up the doclist
** stored in pExpr->aDoclist.
*/

** message is written to context pContext and SQLITE_ERROR returned. The
** string passed via zFunc is used as part of the error message.
*/
static int fts3FunctionArg(
  sqlite3_context *pContext,      /* SQL function call context */
  const char *zFunc,              /* Function name */
  sqlite3_value *pVal,            /* argv[0] passed to function */
  Fts3Cursor **ppCsr              /* OUT: Store cursor handle here */
){
  Fts3Cursor *pRet;
  if( sqlite3_value_type(pVal)!=SQLITE_BLOB 
   || sqlite3_value_bytes(pVal)!=sizeof(Fts3Cursor *)
  ){
    char *zErr = sqlite3_mprintf("illegal first argument to %s", zFunc);
    sqlite3_result_error(pContext, zErr, -1);

*/
static void fts3MatchinfoFunc(
  sqlite3_context *pContext,      /* SQLite function call context */
  int nVal,                       /* Size of argument array */
  sqlite3_value **apVal           /* Array of arguments */
){
  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  assert( nVal==1 );





  if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){
    sqlite3Fts3Matchinfo(pContext, pCsr);
  }
}

/*
** This routine implements the xFindFunction method for the FTS3

** Implementation of FTS3 xRename method. Rename an fts3 table.
*/
static int fts3RenameMethod(
  sqlite3_vtab *pVtab,            /* Virtual table handle */
  const char *zName               /* New name of table */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  sqlite3 *db = p->db;            /* Database connection */
  int rc;                         /* Return Code */

  rc = sqlite3Fts3PendingTermsFlush(p);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  fts3DbExec(&rc, db,
    "ALTER TABLE %Q.'%q_content'  RENAME TO '%q_content';",
    p->zDb, p->zName, zName
  );

  if( p->bHasDocsize ){
    fts3DbExec(&rc, db,
      "ALTER TABLE %Q.'%q_docsize'  RENAME TO '%q_docsize';",
      p->zDb, p->zName, zName
    );
  }
  if( p->bHasStat ){
    fts3DbExec(&rc, db,
      "ALTER TABLE %Q.'%q_stat'  RENAME TO '%q_stat';",
      p->zDb, p->zName, zName
    );
  }
  fts3DbExec(&rc, db,
    "ALTER TABLE %Q.'%q_segments' RENAME TO '%q_segments';",

  /* iVersion      */ 0,
  /* xCreate       */ fts3CreateMethod,
  /* xConnect      */ fts3ConnectMethod,
  /* xBestIndex    */ fts3BestIndexMethod,
  /* xDisconnect   */ fts3DisconnectMethod,
  /* xDestroy      */ fts3DestroyMethod,
  /* xOpen         */ fts3OpenMethod,
  /* xClose        */ fts3CloseMethod,
  /* xFilter       */ fts3FilterMethod,
  /* xNext         */ fts3NextMethod,
  /* xEof          */ fts3EofMethod,
  /* xColumn       */ fts3ColumnMethod,
  /* xRowid        */ fts3RowidMethod,
  /* xUpdate       */ fts3UpdateMethod,
  /* xBegin        */ fts3BeginMethod,

static void hashDestroy(void *p){
  Fts3Hash *pHash = (Fts3Hash *)p;
  sqlite3Fts3HashClear(pHash);
  sqlite3_free(pHash);
}

/*
** The fts3 built-in tokenizers - "simple", "porter" and "icu"- are 
** implemented in files fts3_tokenizer1.c, fts3_porter.c and fts3_icu.c
** respectively. The following three forward declarations are for functions
** declared in these files used to retrieve the respective implementations.
**
** Calling sqlite3Fts3SimpleTokenizerModule() sets the value pointed
** to by the argument to point to the "simple" tokenizer implementation.

** And so on.
*/
void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
#ifdef SQLITE_ENABLE_ICU
void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
#endif

/*
** Initialise the fts3 extension. If this extension is built as part
** of the sqlite library, then this function is called directly by
** SQLite. If fts3 is built as a dynamically loadable extension, this
** function is called by the sqlite3_extension_init() entry point.
*/

  ** the two scalar functions. If this is successful, register the
  ** module with sqlite.
  */
  if( SQLITE_OK==rc 
   && SQLITE_OK==(rc = sqlite3Fts3InitHashTable(db, pHash, "fts3_tokenizer"))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))
  ){
    rc = sqlite3_create_module_v2(
        db, "fts3", &fts3Module, (void *)pHash, hashDestroy
    );
    if( rc==SQLITE_OK ){
      rc = sqlite3_create_module_v2(

** amalgamation.
*/
#ifndef SQLITE_AMALGAMATION
/*
** Macros indicating that conditional expressions are always true or
** false.
*/
#ifdef SQLITE_COVERAGE_TEST
# define ALWAYS(x) (1)
# define NEVER(X)  (0)
#else
# define ALWAYS(x) (x)
# define NEVER(X)  (x)
#endif

/*
** Internal types used by SQLite.
*/
typedef unsigned char u8;         /* 1-byte (or larger) unsigned integer */
typedef short int i16;            /* 2-byte (or larger) signed integer */
typedef unsigned int u32;         /* 4-byte unsigned integer */
typedef sqlite3_uint64 u64;       /* 8-byte unsigned integer */
/*
** Macro used to suppress compiler warnings for unused parameters.
*/
#define UNUSED_PARAMETER(x) (void)(x)
#endif

typedef struct Fts3Table Fts3Table;
typedef struct Fts3Cursor Fts3Cursor;
typedef struct Fts3Expr Fts3Expr;
typedef struct Fts3Phrase Fts3Phrase;
typedef struct Fts3PhraseToken Fts3PhraseToken;

typedef struct Fts3SegFilter Fts3SegFilter;
typedef struct Fts3DeferredToken Fts3DeferredToken;
typedef struct Fts3SegReader Fts3SegReader;
typedef struct Fts3SegReaderArray Fts3SegReaderArray;

/*
** A connection to a fulltext index is an instance of the following
** structure. The xCreate and xConnect methods create an instance
** of this structure and xDestroy and xDisconnect free that instance.
** All other methods receive a pointer to the structure as one of their
** arguments.
*/
struct Fts3Table {
  sqlite3_vtab base;              /* Base class used by SQLite core */
  sqlite3 *db;                    /* The database connection */
  const char *zDb;                /* logical database name */
  const char *zName;              /* virtual table name */
  int nColumn;                    /* number of named columns in virtual table */
  char **azColumn;                /* column names.  malloced */
  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */

  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[24];












  int nNodeSize;                  /* Soft limit for node size */
  u8 bHasStat;                    /* True if %_stat table exists */
  u8 bHasDocsize;                 /* True if %_docsize table exists */
  int nPgsz;                      /* Page size for host database */
  char *zSegmentsTbl;             /* Name of %_segments table */
  sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */

  /* The following hash table is used to buffer pending index updates during
  ** transactions. Variable nPendingData estimates the memory size of the 
  ** pending data, including hash table overhead, but not malloc overhead. 
  ** When nPendingData exceeds nMaxPendingData, the buffer is flushed 
  ** automatically. Variable iPrevDocid is the docid of the most recently
  ** inserted record.

struct Fts3Cursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  i16 eSearch;                    /* Search strategy (see below) */
  u8 isEof;                       /* True if at End Of Results */
  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
  Fts3Expr *pExpr;                /* Parsed MATCH query string */
  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
  u32 *aMatchinfo;                /* Information about most recent match */
  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */
};

#define FTS3_EVAL_FILTER    0
#define FTS3_EVAL_NEXT      1
#define FTS3_EVAL_MATCHINFO 2

/*
** The Fts3Cursor.eSearch member is always set to one of the following.
** Actualy, Fts3Cursor.eSearch can be greater than or equal to
** FTS3_FULLTEXT_SEARCH.  If so, then Fts3Cursor.eSearch - 2 is the index
** of the column to be searched.  For example, in
**

#define FTS3_FULLSCAN_SEARCH 0    /* Linear scan of %_content table */
#define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
#define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */

/*
** A "phrase" is a sequence of one or more tokens that must match in
** sequence.  A single token is the base case and the most common case.
** For a sequence of tokens contained in double-quotes (i.e. "one two three")
** nToken will be the number of tokens in the string.
**
** The nDocMatch and nMatch variables contain data that may be used by the
** matchinfo() function. They are populated when the full-text index is 
** queried for hits on the phrase. If one or more tokens in the phrase
** are deferred, the nDocMatch and nMatch variables are populated based
** on the assumption that the 
*/
struct Fts3PhraseToken {
  char *z;                        /* Text of the token */
  int n;                          /* Number of bytes in buffer z */
  int isPrefix;                   /* True if token ends with a "*" character */
  int bFulltext;                  /* True if full-text index was used */
  Fts3SegReaderArray *pArray;     /* Segment-reader for this token */
  Fts3DeferredToken *pDeferred;   /* Deferred token object for this token */
};

struct Fts3Phrase {
  /* Variables populated by fts3_expr.c when parsing a MATCH expression */
  int nToken;                /* Number of tokens in the phrase */
  int iColumn;               /* Index of column this phrase must match */
  int isNot;                 /* Phrase prefixed by unary not (-) operator */




  Fts3PhraseToken aToken[1]; /* One entry for each token in the phrase */
};

/*
** A tree of these objects forms the RHS of a MATCH operator.
**
** If Fts3Expr.eType is either FTSQUERY_NEAR or FTSQUERY_PHRASE and isLoaded
** is true, then aDoclist points to a malloced buffer, size nDoclist bytes, 

#define FTSQUERY_NEAR   1
#define FTSQUERY_NOT    2
#define FTSQUERY_AND    3
#define FTSQUERY_OR     4
#define FTSQUERY_PHRASE 5







/* fts3_write.c */
int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
int sqlite3Fts3PendingTermsFlush(Fts3Table *);
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(Fts3Table *,int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(Fts3Table*,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3Table *, Fts3SegReader *);
int sqlite3Fts3SegReaderIterate(
  Fts3Table *, Fts3SegReader **, int, Fts3SegFilter *,
  int (*)(Fts3Table *, void *, char *, int, char *, int),  void *
);
int sqlite3Fts3SegReaderCost(Fts3Cursor *, Fts3SegReader *, int *);
int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
int sqlite3Fts3MatchinfoDocsizeLocal(Fts3Cursor*, u32*);
int sqlite3Fts3MatchinfoDocsizeGlobal(Fts3Cursor*, u32*);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*);

void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *, int *);

void sqlite3Fts3SegmentsClose(Fts3Table *);

/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
#define FTS3_SEGMENT_PREFIX        0x00000008

int sqlite3Fts3PutVarint(char *, sqlite3_int64);
int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
int sqlite3Fts3GetVarint32(const char *, int *);
int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);

char *sqlite3Fts3FindPositions(Fts3Expr *, sqlite3_int64, int);
int sqlite3Fts3ExprLoadDoclist(Fts3Cursor *, Fts3Expr *);
int sqlite3Fts3ExprLoadFtDoclist(Fts3Cursor *, Fts3Expr *, char **, int *);
int sqlite3Fts3ExprNearTrim(Fts3Expr *, Fts3Expr *, int);

/* fts3_tokenizer.c */
const char *sqlite3Fts3NextToken(const char *, int *);
int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
    sqlite3_tokenizer **, char **
);
int sqlite3Fts3IsIdChar(char);

/* fts3_snippet.c */
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *);

** is defined to accept an argument of type char, and always returns 0 for
** any values that fall outside of the range of the unsigned char type (i.e.
** negative values).
*/
static int fts3isspace(char c){
  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}

/*
** Allocate nByte bytes of memory using sqlite3_malloc(). If successful,
** zero the memory before returning a pointer to it. If unsuccessful, 
** return NULL.
*/
static void *fts3MallocZero(int nByte){
  void *pRet = sqlite3_malloc(nByte);
  if( pRet ) memset(pRet, 0, nByte);
  return pRet;
}


/*
** Extract the next token from buffer z (length n) using the tokenizer
** and other information (column names etc.) in pParse. Create an Fts3Expr
** structure of type FTSQUERY_PHRASE containing a phrase consisting of this
** single token and set *ppExpr to point to it. If the end of the buffer is
** reached before a token is found, set *ppExpr to zero. It is the

    int nByte;                               /* total space to allocate */

    pCursor->pTokenizer = pTokenizer;
    rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);

    if( rc==SQLITE_OK ){
      nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;
      pRet = (Fts3Expr *)fts3MallocZero(nByte);
      if( !pRet ){
        rc = SQLITE_NOMEM;
      }else{

        pRet->eType = FTSQUERY_PHRASE;
        pRet->pPhrase = (Fts3Phrase *)&pRet[1];
        pRet->pPhrase->nToken = 1;
        pRet->pPhrase->iColumn = iCol;
        pRet->pPhrase->aToken[0].n = nToken;
        pRet->pPhrase->aToken[0].z = (char *)&pRet->pPhrase[1];
        memcpy(pRet->pPhrase->aToken[0].z, zToken, nToken);

    pCursor->pTokenizer = pTokenizer;
    for(ii=0; rc==SQLITE_OK; ii++){
      const char *zToken;
      int nToken, iBegin, iEnd, iPos;
      rc = pModule->xNext(pCursor, &zToken, &nToken, &iBegin, &iEnd, &iPos);
      if( rc==SQLITE_OK ){
        int nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase);
        p = fts3ReallocOrFree(p, nByte+ii*sizeof(Fts3PhraseToken));
        zTemp = fts3ReallocOrFree(zTemp, nTemp + nToken);
        if( !p || !zTemp ){
          goto no_mem;
        }
        if( ii==0 ){
          memset(p, 0, nByte);
          p->pPhrase = (Fts3Phrase *)&p[1];
        }
        p->pPhrase = (Fts3Phrase *)&p[1];
        memset(&p->pPhrase->aToken[ii], 0, sizeof(Fts3PhraseToken));
        p->pPhrase->nToken = ii+1;
        p->pPhrase->aToken[ii].n = nToken;
        memcpy(&zTemp[nTemp], zToken, nToken);
        nTemp += nToken;
        if( iEnd<nInput && zInput[iEnd]=='*' ){
          p->pPhrase->aToken[ii].isPrefix = 1;
        }else{

  }

  if( rc==SQLITE_DONE ){
    int jj;
    char *zNew = NULL;
    int nNew = 0;
    int nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase);
    nByte += (p?(p->pPhrase->nToken-1):0) * sizeof(Fts3PhraseToken);
    p = fts3ReallocOrFree(p, nByte + nTemp);
    if( !p ){
      goto no_mem;
    }
    if( zTemp ){
      zNew = &(((char *)p)[nByte]);
      memcpy(zNew, zTemp, nTemp);

      ** the next byte must contain either whitespace, an open or close
      ** parenthesis, a quote character, or EOF. 
      */
      cNext = zInput[nKey];
      if( fts3isspace(cNext) 
       || cNext=='"' || cNext=='(' || cNext==')' || cNext==0
      ){
        pRet = (Fts3Expr *)fts3MallocZero(sizeof(Fts3Expr));
        if( !pRet ){
          return SQLITE_NOMEM;
        }

        pRet->eType = pKey->eType;
        pRet->nNear = nNear;
        *ppExpr = pRet;
        *pnConsumed = (int)((zInput - z) + nKey);
        return SQLITE_OK;
      }

    if( rc==SQLITE_OK ){
      int isPhrase;

      if( !sqlite3_fts3_enable_parentheses 
       && p->eType==FTSQUERY_PHRASE && p->pPhrase->isNot 
      ){
        /* Create an implicit NOT operator. */
        Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
        if( !pNot ){
          sqlite3Fts3ExprFree(p);
          rc = SQLITE_NOMEM;
          goto exprparse_out;
        }

        pNot->eType = FTSQUERY_NOT;
        pNot->pRight = p;
        if( pNotBranch ){
          pNot->pLeft = pNotBranch;
        }
        pNotBranch = pNot;
        p = pPrev;

          goto exprparse_out;
        }
  
        if( isPhrase && !isRequirePhrase ){
          /* Insert an implicit AND operator. */
          Fts3Expr *pAnd;
          assert( pRet && pPrev );
          pAnd = fts3MallocZero(sizeof(Fts3Expr));
          if( !pAnd ){
            sqlite3Fts3ExprFree(p);
            rc = SQLITE_NOMEM;
            goto exprparse_out;
          }

          pAnd->eType = FTSQUERY_AND;
          insertBinaryOperator(&pRet, pPrev, pAnd);
          pPrev = pAnd;
        }

        /* This test catches attempts to make either operand of a NEAR
        ** operator something other than a phrase. For example, either of

/*
** Used as an fts3ExprIterate() context when loading phrase doclists to
** Fts3Expr.aDoclist[]/nDoclist.
*/
typedef struct LoadDoclistCtx LoadDoclistCtx;
struct LoadDoclistCtx {
  Fts3Cursor *pCsr;               /* FTS3 Cursor */
  int nPhrase;                    /* Number of phrases seen so far */
  int nToken;                     /* Number of tokens seen so far */
};

/*
** The following types are used as part of the implementation of the 
** fts3BestSnippet() routine.

  UNUSED_PARAMETER(iPhrase);

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

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

  return rc;

static int fts3ExprLoadDoclists(
  Fts3Cursor *pCsr,               /* Fts3 cursor for current query */
  int *pnPhrase,                  /* OUT: Number of phrases in query */
  int *pnToken                    /* OUT: Number of tokens in query */
){
  int rc;                         /* Return Code */
  LoadDoclistCtx sCtx = {0,0,0};  /* Context for fts3ExprIterate() */
  sCtx.pCsr = pCsr;
  rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb1, (void *)&sCtx);
  if( rc==SQLITE_OK ){
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb2, 0);
  }
  if( pnPhrase ) *pnPhrase = sCtx.nPhrase;
  if( pnToken ) *pnToken = sCtx.nToken;
  return rc;

*/
static int fts3ExprGlobalMatchinfoCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number (numbered from zero) */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;
  Fts3Cursor *pCsr = p->pCursor;
  char *pIter;
  char *pEnd;
  char *pFree = 0;
  const int iStart = 2 + (iPhrase * p->nCol * 3) + 1;

  assert( pExpr->isLoaded );
  assert( pExpr->eType==FTSQUERY_PHRASE );

  if( pCsr->pDeferred ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;
    for(ii=0; ii<pPhrase->nToken; ii++){
      if( pPhrase->aToken[ii].bFulltext ) break;
    }
    if( ii<pPhrase->nToken ){
      int nFree = 0;
      int rc = sqlite3Fts3ExprLoadFtDoclist(pCsr, pExpr, &pFree, &nFree);
      if( rc!=SQLITE_OK ) return rc;
      pIter = pFree;
      pEnd = &pFree[nFree];
    }else{
      int nDoc = p->aMatchinfo[2 + 3*p->nCol*p->aMatchinfo[0]];
      for(ii=0; ii<p->nCol; ii++){
        p->aMatchinfo[iStart + ii*3] = nDoc;
        p->aMatchinfo[iStart + ii*3 + 1] = nDoc;
      }
      return SQLITE_OK;
    }
  }else{
    pIter = pExpr->aDoclist;
    pEnd = &pExpr->aDoclist[pExpr->nDoclist];
  }

  /* Fill in the global hit count matrix row for this phrase. */
  while( pIter<pEnd ){
    while( *pIter++ & 0x80 );      /* Skip past docid. */
    fts3LoadColumnlistCounts(&pIter, &p->aMatchinfo[iStart], 1);
  }

  sqlite3_free(pFree);
  return SQLITE_OK;
}

/*
** fts3ExprIterate() callback used to collect the "local" matchinfo stats
** for a single query. The "local" stats are those elements of the matchinfo
** array that are different for each row returned by the query.

    sInfo.aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo);
    if( !sInfo.aMatchinfo ){ 
      return SQLITE_NOMEM;
    }
    memset(sInfo.aMatchinfo, 0, sizeof(u32)*nMatchinfo);


    /* First element of match-info is the number of phrases in the query */
    sInfo.aMatchinfo[0] = nPhrase;
    sInfo.aMatchinfo[1] = sInfo.nCol;

    if( pTab->bHasDocsize ){
      int ofst = 2 + 3*sInfo.aMatchinfo[0]*sInfo.aMatchinfo[1];
      rc = sqlite3Fts3MatchinfoDocsizeGlobal(pCsr, &sInfo.aMatchinfo[ofst]);
    }
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprGlobalMatchinfoCb,(void*)&sInfo);
    pCsr->aMatchinfo = sInfo.aMatchinfo;
    pCsr->isMatchinfoNeeded = 1;
  }

  sInfo.aMatchinfo = pCsr->aMatchinfo;
  if( rc==SQLITE_OK && pCsr->isMatchinfoNeeded ){
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLocalMatchinfoCb, (void*)&sInfo);

  for(i=0; i<nSnippet && rc==SQLITE_OK; i++){
    rc = fts3SnippetText(pCsr, &aSnippet[i], 
        i, (i==nSnippet-1), nFToken, zStart, zEnd, zEllipsis, &res
    );
  }

 snippet_out:
  sqlite3Fts3SegmentsClose(pTab);
  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pCtx, rc);
    sqlite3_free(res.z);
  }else{
    sqlite3_result_text(pCtx, res.z, -1, sqlite3_free);
  }
}

    pMod->xClose(pC);
    if( rc!=SQLITE_OK ) goto offsets_out;
  }

 offsets_out:
  sqlite3_free(sCtx.aTerm);
  assert( rc!=SQLITE_DONE );
  sqlite3Fts3SegmentsClose(pTab);
  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pCtx,  rc);
    sqlite3_free(res.z);
  }else{
    sqlite3_result_text(pCtx, res.z, res.n-1, sqlite3_free);
  }
  return;
}

/*
** Implementation of matchinfo() function.
*/
void sqlite3Fts3Matchinfo(sqlite3_context *pContext, Fts3Cursor *pCsr){
  int rc;
  if( !pCsr->pExpr ){
    sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
    return;
  }
  rc = fts3GetMatchinfo(pCsr);
  sqlite3Fts3SegmentsClose((Fts3Table *)pCsr->base.pVtab );
  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pContext, rc);
  }else{
    Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
    int n = sizeof(u32)*(2+pCsr->aMatchinfo[0]*pCsr->aMatchinfo[1]*3);
    if( pTab->bHasDocsize ){
      n += sizeof(u32)*(1 + 2*pTab->nColumn);
    }
    sqlite3_result_blob(pContext, pCsr->aMatchinfo, n, SQLITE_TRANSIENT);
  }
}

#endif

      return;
    }
  }

  sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
}

int sqlite3Fts3IsIdChar(char c){
  static const char isFtsIdChar[] = {
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 0x */
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 1x */
      0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 2x */
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */
      0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */

      case '[':
        z2 = &z1[1];
        while( *z2 && z2[0]!=']' ) z2++;
        if( *z2 ) z2++;
        break;

      default:
        if( sqlite3Fts3IsIdChar(*z1) ){
          z2 = &z1[1];
          while( sqlite3Fts3IsIdChar(*z2) ) z2++;
        }else{
          z1++;
        }
    }
  }

  *pn = (int)(z2-z1);
  return z1;
}

int sqlite3Fts3InitTokenizer(
  Fts3Hash *pHash,                /* Tokenizer hash table */
  const char *zArg,               /* Tokenizer name */
  sqlite3_tokenizer **ppTok,      /* OUT: Tokenizer (if applicable) */

  char **pzErr                    /* OUT: Set to malloced error message */
){
  int rc;
  char *z = (char *)zArg;
  int n;
  char *zCopy;
  char *zEnd;                     /* Pointer to nul-term of zCopy */
  sqlite3_tokenizer_module *m;


  zCopy = sqlite3_mprintf("%s", zArg);







  if( !zCopy ) return SQLITE_NOMEM;



  zEnd = &zCopy[strlen(zCopy)];

  z = (char *)sqlite3Fts3NextToken(zCopy, &n);
  z[n] = '\0';
  sqlite3Fts3Dequote(z);

  m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);
  if( !m ){
    *pzErr = sqlite3_mprintf("unknown tokenizer: %s", z);
    rc = SQLITE_ERROR;
  }else{
    char const **aArg = 0;
    int iArg = 0;
    z = &z[n+1];

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#include "fts3Int.h"
#include <string.h>
#include <assert.h>
#include <stdlib.h>

/*
** When full-text index nodes are loaded from disk, the buffer that they
** are loaded into has the following number of bytes of padding at the end 
** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer
** of 920 bytes is allocated for it.
**
** This means that if we have a pointer into a buffer containing node data,
** it is always safe to read up to two varints from it without risking an
** overread, even if the node data is corrupted.
*/
#define FTS3_NODE_PADDING (FTS3_VARINT_MAX*2)

typedef struct PendingList PendingList;
typedef struct SegmentNode SegmentNode;
typedef struct SegmentWriter SegmentWriter;

/*
** Data structure used while accumulating terms in the pending-terms hash
** table. The hash table entry maps from term (a string) to a malloc'd
** instance of this structure.
*/
struct PendingList {
  int nData;
  char *aData;
  int nSpace;
  sqlite3_int64 iLastDocid;
  sqlite3_int64 iLastCol;
  sqlite3_int64 iLastPos;
};


/*
** Each cursor has a (possibly empty) linked list of the following objects.
*/
struct Fts3DeferredToken {
  Fts3PhraseToken *pToken;        /* Pointer to corresponding expr token */
  int iCol;                       /* Column token must occur in */
  Fts3DeferredToken *pNext;       /* Next in list of deferred tokens */
  PendingList *pList;             /* Doclist is assembled here */
};

/*
** An instance of this structure is used to iterate through the terms on
** a contiguous set of segment b-tree leaf nodes. Although the details of
** this structure are only manipulated by code in this file, opaque handles
** of type Fts3SegReader* are also used by code in fts3.c to iterate through
** terms when querying the full-text index. See functions:
**
**   sqlite3Fts3SegReaderNew()
**   sqlite3Fts3SegReaderFree()
**   sqlite3Fts3SegReaderCost()
**   sqlite3Fts3SegReaderIterate()
**
** Methods used to manipulate Fts3SegReader structures:
**
**   fts3SegReaderNext()
**   fts3SegReaderFirstDocid()
**   fts3SegReaderNextDocid()
*/
struct Fts3SegReader {
  int iIdx;                       /* Index within level, or 0x7FFFFFFF for PT */

  sqlite3_int64 iStartBlock;      /* Rowid of first leaf block to traverse */
  sqlite3_int64 iLeafEndBlock;    /* Rowid of final leaf block to traverse */
  sqlite3_int64 iEndBlock;        /* Rowid of final block in segment (or 0) */
  sqlite3_int64 iCurrentBlock;    /* Current leaf block (or 0) */

  char *aNode;                    /* Pointer to node data (or NULL) */
  int nNode;                      /* Size of buffer at aNode (or 0) */

  Fts3HashElem **ppNextElem;

  /* Variables set by fts3SegReaderNext(). These may be read directly
  ** by the caller. They are valid from the time SegmentReaderNew() returns
  ** until SegmentReaderNext() returns something other than SQLITE_OK
  ** (i.e. SQLITE_DONE).
  */
  int nTerm;                      /* Number of bytes in current term */
  char *zTerm;                    /* Pointer to current term */
  int nTermAlloc;                 /* Allocated size of zTerm buffer */
  char *aDoclist;                 /* Pointer to doclist of current entry */
  int nDoclist;                   /* Size of doclist in current entry */

  /* The following variables are used to iterate through the current doclist */
  char *pOffsetList;
  sqlite3_int64 iDocid;
};

#define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0)
#define fts3SegReaderIsRootOnly(p) ((p)->aNode==(char *)&(p)[1])

/*
** An instance of this structure is used to create a segment b-tree in the
** database. The internal details of this type are only accessed by the
** following functions:
**
**   fts3SegWriterAdd()

#define SQL_SELECT_LEVEL              12
#define SQL_SELECT_ALL_LEVEL          13
#define SQL_SELECT_LEVEL_COUNT        14
#define SQL_SELECT_SEGDIR_COUNT_MAX   15
#define SQL_DELETE_SEGDIR_BY_LEVEL    16
#define SQL_DELETE_SEGMENTS_RANGE     17
#define SQL_CONTENT_INSERT            18

#define SQL_DELETE_DOCSIZE            19
#define SQL_REPLACE_DOCSIZE           20
#define SQL_SELECT_DOCSIZE            21
#define SQL_SELECT_DOCTOTAL           22
#define SQL_REPLACE_DOCTOTAL          23

/*
** This function is used to obtain an SQLite prepared statement handle
** for the statement identified by the second argument. If successful,
** *pp is set to the requested statement handle and SQLITE_OK returned.
** Otherwise, an SQLite error code is returned and *pp is set to 0.
**

/* 14 */  "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?",
/* 15 */  "SELECT count(*), max(level) FROM %Q.'%q_segdir'",

/* 16 */  "DELETE FROM %Q.'%q_segdir' WHERE level = ?",
/* 17 */  "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?",
/* 18 */  "INSERT INTO %Q.'%q_content' VALUES(%z)",

/* 19 */  "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
/* 20 */  "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
/* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=0",
/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
  };
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt;

  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
  assert( eStmt<SizeofArray(azSql) && eStmt>=0 );
  

    rc = sqlite3_reset(pStmt);
  }
  *pRC = rc;
}


/*
** This function ensures that the caller has obtained a shared-cache
** table-lock on the %_content table. This is required before reading
** data from the fts3 table. If this lock is not acquired first, then
** the caller may end up holding read-locks on the %_segments and %_segdir
** tables, but no read-lock on the %_content table. If this happens 
** a second connection will be able to write to the fts3 table, but
** attempting to commit those writes might return SQLITE_LOCKED or
** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain 
** write-locks on the %_segments and %_segdir ** tables). 
**

** We try to avoid this because if FTS3 returns any error when committing
** a transaction, the whole transaction will be rolled back. And this is
** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can
** still happen if the user reads data directly from the %_segments or




** %_segdir tables instead of going through FTS3 though.
*/
int sqlite3Fts3ReadLock(Fts3Table *p){



  int rc;                         /* Return code */

  sqlite3_stmt *pStmt;            /* Statement used to obtain lock */




  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_null(pStmt, 1);
    sqlite3_step(pStmt);



    rc = sqlite3_reset(pStmt);




  }

  return rc;
}

/*
** Set *ppStmt to a statement handle that may be used to iterate through
** all rows in the %_segdir table, from oldest to newest. If successful,
** return SQLITE_OK. If an error occurs while preparing the statement, 
** return an SQLite error code.

** Tokenize the nul-terminated string zText and add all tokens to the
** pending-terms hash-table. The docid used is that currently stored in
** p->iPrevDocid, and the column is specified by argument iCol.
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
*/
static int fts3PendingTermsAdd(
  Fts3Table *p,                   /* Table into which text will be inserted */
  const char *zText,              /* Text of document to be inserted */
  int iCol,                       /* Column into which text is being inserted */
  u32 *pnWord                     /* OUT: Number of tokens inserted */
){
  int rc;
  int iStart;
  int iEnd;
  int iPos;
  int nWord = 0;

    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  return SQLITE_OK;
}

/*
** Discard the contents of the pending-terms hash table. 
*/
void sqlite3Fts3PendingTermsClear(Fts3Table *p){
  Fts3HashElem *pElem;
  for(pElem=fts3HashFirst(&p->pendingTerms); pElem; pElem=fts3HashNext(pElem)){
    sqlite3_free(fts3HashData(pElem));
  }
  fts3HashClear(&p->pendingTerms);
  p->nPendingData = 0;

    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
    if( zText ){
      int rc = fts3PendingTermsAdd(p, zText, i-2, &aSz[i-2]);
      if( rc!=SQLITE_OK ){
        return rc;
      }
    }
    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
  }
  return SQLITE_OK;
}

/*
** This function is called by the xUpdate() method for an INSERT operation.
** The apVal parameter is passed a copy of the apVal argument passed by

  /* Delete everything from the %_content, %_segments and %_segdir tables. */
  fts3SqlExec(&rc, p, SQL_DELETE_ALL_CONTENT, 0);
  fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGMENTS, 0);
  fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0);
  if( p->bHasDocsize ){
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0);
  }
  if( p->bHasStat ){
    fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0);
  }
  return rc;
}

/*
** The first element in the apVal[] array is assumed to contain the docid
** (an integer) of a row about to be deleted. Remove all terms from the
** full-text index.
*/
static void fts3DeleteTerms( 
  int *pRC,               /* Result code */
  Fts3Table *p,           /* The FTS table to delete from */
  sqlite3_value **apVal,  /* apVal[] contains the docid to be deleted */
  u32 *aSz                /* Sizes of deleted document written here */
){
  int rc;
  sqlite3_stmt *pSelect;

        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
        rc = fts3PendingTermsAdd(p, zText, -1, &aSz[i-1]);
        if( rc!=SQLITE_OK ){
          sqlite3_reset(pSelect);
          *pRC = rc;
          return;
        }
        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
      }
    }
    rc = sqlite3_reset(pSelect);
  }else{
    sqlite3_reset(pSelect);
  }
  *pRC = rc;

    }else{
      *piIdx = iNext;
    }
  }

  return rc;
}

/*
** The %_segments table is declared as follows:
**
**   CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB)
**
** This function reads data from a single row of the %_segments table. The
** specific row is identified by the iBlockid parameter. If paBlob is not
** NULL, then a buffer is allocated using sqlite3_malloc() and populated
** with the contents of the blob stored in the "block" column of the 
** identified table row is. Whether or not paBlob is NULL, *pnBlob is set
** to the size of the blob in bytes before returning.
**
** If an error occurs, or the table does not contain the specified row,
** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If
** paBlob is non-NULL, then it is the responsibility of the caller to
** eventually free the returned buffer.
**
** This function may leave an open sqlite3_blob* handle in the
** Fts3Table.pSegments variable. This handle is reused by subsequent calls
** to this function. The handle may be closed by calling the
** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy
** performance improvement, but the blob handle should always be closed
** before control is returned to the user (to prevent a lock being held
** on the database file for longer than necessary). Thus, any virtual table
** method (xFilter etc.) that may directly or indirectly call this function
** must call sqlite3Fts3SegmentsClose() before returning.
*/
int sqlite3Fts3ReadBlock(
  Fts3Table *p,                   /* FTS3 table handle */
  sqlite3_int64 iBlockid,         /* Access the row with blockid=$iBlockid */
  char **paBlob,                  /* OUT: Blob data in malloc'd buffer */
  int *pnBlob                     /* OUT: Size of blob data */
){
  int rc;                         /* Return code */

  /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */
  assert( pnBlob);

  if( p->pSegments ){
    rc = sqlite3_blob_reopen(p->pSegments, iBlockid);
  }else{
    if( 0==p->zSegmentsTbl ){
      p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName);
      if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM;
    }
    rc = sqlite3_blob_open(
       p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments
    );
  }

  if( rc==SQLITE_OK ){
    int nByte = sqlite3_blob_bytes(p->pSegments);
    if( paBlob ){
      char *aByte = sqlite3_malloc(nByte + FTS3_NODE_PADDING);
      if( !aByte ){
        rc = SQLITE_NOMEM;
      }else{
        rc = sqlite3_blob_read(p->pSegments, aByte, nByte, 0);
        memset(&aByte[nByte], 0, FTS3_NODE_PADDING);
        if( rc!=SQLITE_OK ){
          sqlite3_free(aByte);
          aByte = 0;
        }
      }
      *paBlob = aByte;
    }
    *pnBlob = nByte;
  }

  return rc;
}

/*
** Close the blob handle at p->pSegments, if it is open. See comments above
** the sqlite3Fts3ReadBlock() function for details.
*/
void sqlite3Fts3SegmentsClose(Fts3Table *p){
  sqlite3_blob_close(p->pSegments);
  p->pSegments = 0;
}

/*
** Move the iterator passed as the first argument to the next term in the
** segment. If successful, SQLITE_OK is returned. If there is no next term,
** SQLITE_DONE. Otherwise, an SQLite error code.
*/
static int fts3SegReaderNext(Fts3Table *p, Fts3SegReader *pReader){
  char *pNext;                    /* Cursor variable */
  int nPrefix;                    /* Number of bytes in term prefix */
  int nSuffix;                    /* Number of bytes in term suffix */

  if( !pReader->aDoclist ){
    pNext = pReader->aNode;
  }else{
    pNext = &pReader->aDoclist[pReader->nDoclist];
  }

  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){
    int rc;                       /* Return code from Fts3ReadBlock() */

    if( fts3SegReaderIsPending(pReader) ){
      Fts3HashElem *pElem = *(pReader->ppNextElem);
      if( pElem==0 ){
        pReader->aNode = 0;
      }else{
        PendingList *pList = (PendingList *)fts3HashData(pElem);
        pReader->zTerm = (char *)fts3HashKey(pElem);
        pReader->nTerm = fts3HashKeysize(pElem);
        pReader->nNode = pReader->nDoclist = pList->nData + 1;
        pReader->aNode = pReader->aDoclist = pList->aData;
        pReader->ppNextElem++;
        assert( pReader->aNode );
      }
      return SQLITE_OK;
    }

    if( !fts3SegReaderIsRootOnly(pReader) ){
      sqlite3_free(pReader->aNode);
    }
    pReader->aNode = 0;

    /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf 
    ** blocks have already been traversed.  */
    assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock );
    if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){
      return SQLITE_OK;
    }





    rc = sqlite3Fts3ReadBlock(
        p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode
    );
    if( rc!=SQLITE_OK ) return rc;
    pNext = pReader->aNode;
  }
  
  /* Because of the FTS3_NODE_PADDING bytes of padding, the following is 
  ** safe (no risk of overread) even if the node data is corrupted.  
  */
  pNext += sqlite3Fts3GetVarint32(pNext, &nPrefix);
  pNext += sqlite3Fts3GetVarint32(pNext, &nSuffix);
  if( nPrefix<0 || nSuffix<=0 
   || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] 
  ){
    return SQLITE_CORRUPT;
  }

  if( nPrefix+nSuffix>pReader->nTermAlloc ){
    int nNew = (nPrefix+nSuffix)*2;
    char *zNew = sqlite3_realloc(pReader->zTerm, nNew);
    if( !zNew ){
      return SQLITE_NOMEM;
    }
    pReader->zTerm = zNew;
    pReader->nTermAlloc = nNew;
  }
  memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);
  pReader->nTerm = nPrefix+nSuffix;
  pNext += nSuffix;
  pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist);

  pReader->aDoclist = pNext;
  pReader->pOffsetList = 0;

  /* Check that the doclist does not appear to extend past the end of the
  ** b-tree node. And that the final byte of the doclist is 0x00. If either 
  ** of these statements is untrue, then the data structure is corrupt.
  */
  if( &pReader->aDoclist[pReader->nDoclist]>&pReader->aNode[pReader->nNode] 
   || pReader->aDoclist[pReader->nDoclist-1]
  ){
    return SQLITE_CORRUPT;
  }
  return SQLITE_OK;
}

/*
** Set the SegReader to point to the first docid in the doclist associated
** with the current term.
*/

    pReader->pOffsetList = 0;
  }else{
    sqlite3_int64 iDelta;
    pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta);
    pReader->iDocid += iDelta;
  }
}

/*
** This function is called to estimate the amount of data that will be 
** loaded from the disk If SegReaderIterate() is called on this seg-reader,
** in units of average document size.
** 
** This can be used as follows: If the caller has a small doclist that 
** contains references to N documents, and is considering merging it with
** a large doclist (size X "average documents"), it may opt not to load
** the large doclist if X>N.
*/
int sqlite3Fts3SegReaderCost(
  Fts3Cursor *pCsr,               /* FTS3 cursor handle */
  Fts3SegReader *pReader,         /* Segment-reader handle */
  int *pnCost                     /* IN/OUT: Number of bytes read */
){
  Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;
  int rc = SQLITE_OK;             /* Return code */
  int nCost = 0;                  /* Cost in bytes to return */
  int pgsz = p->nPgsz;            /* Database page size */

  /* If this seg-reader is reading the pending-terms table, or if all data
  ** for the segment is stored on the root page of the b-tree, then the cost
  ** is zero. In this case all required data is already in main memory.
  */
  if( p->bHasStat 
   && !fts3SegReaderIsPending(pReader) 
   && !fts3SegReaderIsRootOnly(pReader) 
  ){
    int nBlob = 0;
    sqlite3_int64 iBlock;

    if( pCsr->nRowAvg==0 ){
      /* The average document size, which is required to calculate the cost
      ** of each doclist, has not yet been determined. Read the required 
      ** data from the %_stat table to calculate it.
      **
      ** Entry 0 of the %_stat table is a blob containing (nCol+1) FTS3 
      ** varints, where nCol is the number of columns in the FTS3 table.
      ** The first varint is the number of documents currently stored in
      ** the table. The following nCol varints contain the total amount of
      ** data stored in all rows of each column of the table, from left
      ** to right.
      */
      sqlite3_stmt *pStmt;
      rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0);
      if( rc ) return rc;
      if( sqlite3_step(pStmt)==SQLITE_ROW ){
        sqlite3_int64 nDoc = 0;
        sqlite3_int64 nByte = 0;
        const char *a = sqlite3_column_blob(pStmt, 0);
        if( a ){
          const char *pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
          a += sqlite3Fts3GetVarint(a, &nDoc);
          while( a<pEnd ){
            a += sqlite3Fts3GetVarint(a, &nByte);
          }
        }

        pCsr->nRowAvg = (((nByte / nDoc) + pgsz - 1) / pgsz);
      }
      rc = sqlite3_reset(pStmt);
      if( rc!=SQLITE_OK || pCsr->nRowAvg==0 ) return rc;
    }

    /* Assume that a blob flows over onto overflow pages if it is larger
    ** than (pgsz-35) bytes in size (the file-format documentation
    ** confirms this).
    */
    for(iBlock=pReader->iStartBlock; iBlock<=pReader->iLeafEndBlock; iBlock++){
      rc = sqlite3Fts3ReadBlock(p, iBlock, 0, &nBlob);
      if( rc!=SQLITE_OK ) break;
      if( (nBlob+35)>pgsz ){
        int nOvfl = (nBlob + 34)/pgsz;
        nCost += ((nOvfl + pCsr->nRowAvg - 1)/pCsr->nRowAvg);
      }
    }
  }

  *pnCost += nCost;
  return rc;
}

/*
** Free all allocations associated with the iterator passed as the 
** second argument.
*/
void sqlite3Fts3SegReaderFree(Fts3Table *p, Fts3SegReader *pReader){
  if( pReader && !fts3SegReaderIsPending(pReader) ){
    sqlite3_free(pReader->zTerm);







    if( !fts3SegReaderIsRootOnly(pReader) ){
      sqlite3_free(pReader->aNode);
    }

  }
  sqlite3_free(pReader);
}

/*
** Allocate a new SegReader object.
*/
int sqlite3Fts3SegReaderNew(
  Fts3Table *p,                   /* Virtual table handle */
  int iAge,                       /* Segment "age". */
  sqlite3_int64 iStartLeaf,       /* First leaf to traverse */
  sqlite3_int64 iEndLeaf,         /* Final leaf to traverse */
  sqlite3_int64 iEndBlock,        /* Final block of segment */
  const char *zRoot,              /* Buffer containing root node */
  int nRoot,                      /* Size of buffer containing root node */
  Fts3SegReader **ppReader        /* OUT: Allocated Fts3SegReader */
){
  int rc = SQLITE_OK;             /* Return code */
  Fts3SegReader *pReader;         /* Newly allocated SegReader object */
  int nExtra = 0;                 /* Bytes to allocate segment root node */

  assert( iStartLeaf<=iEndLeaf );
  if( iStartLeaf==0 ){
    nExtra = nRoot + FTS3_NODE_PADDING;
  }

  pReader = (Fts3SegReader *)sqlite3_malloc(sizeof(Fts3SegReader) + nExtra);
  if( !pReader ){
    return SQLITE_NOMEM;
  }
  memset(pReader, 0, sizeof(Fts3SegReader));
  pReader->iIdx = iAge;
  pReader->iStartBlock = iStartLeaf;
  pReader->iLeafEndBlock = iEndLeaf;
  pReader->iEndBlock = iEndBlock;

  if( nExtra ){
    /* The entire segment is stored in the root node. */
    pReader->aNode = (char *)&pReader[1];
    pReader->nNode = nRoot;
    memcpy(pReader->aNode, zRoot, nRoot);















    memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING);






















  }else{


    pReader->iCurrentBlock = iStartLeaf-1;



  }



  if( rc==SQLITE_OK ){
    *ppReader = pReader;
  }else{
    sqlite3Fts3SegReaderFree(p, pReader);
  }
  return rc;
}

    if( !pReader ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pReader, 0, nByte);
      pReader->iIdx = 0x7FFFFFFF;
      pReader->ppNextElem = (Fts3HashElem **)&pReader[1];
      memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *));

    }
  }

  if( isPrefix ){
    sqlite3_free(aElem);
  }
  *ppReader = pReader;

}

/*
** Add term zTerm to the SegmentNode. It is guaranteed that zTerm is larger
** (according to memcmp) than the previous term.
*/
static int fts3NodeAddTerm(
  Fts3Table *p,                   /* Virtual table handle */
  SegmentNode **ppTree,           /* IN/OUT: SegmentNode handle */ 
  int isCopyTerm,                 /* True if zTerm/nTerm is transient */
  const char *zTerm,              /* Pointer to buffer containing term */
  int nTerm                       /* Size of term in bytes */
){
  SegmentNode *pTree = *ppTree;
  int rc;

  /* If the Fts3SegFilter defines a specific term (or term prefix) to search 
  ** for, then advance each segment iterator until it points to a term of
  ** equal or greater value than the specified term. This prevents many
  ** unnecessary merge/sort operations for the case where single segment
  ** b-tree leaf nodes contain more than one term.
  */
  for(i=0; i<nSegment; i++){
    int nTerm = pFilter->nTerm;
    const char *zTerm = pFilter->zTerm;

    Fts3SegReader *pSeg = apSegment[i];

    do {
      rc = fts3SegReaderNext(p, pSeg);
      if( rc!=SQLITE_OK ) goto finished;

    }while( zTerm && fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 );
  }

  fts3SegReaderSort(apSegment, nSegment, nSegment, fts3SegReaderCmp);
  while( apSegment[0]->aNode ){
    int nTerm = apSegment[0]->nTerm;
    char *zTerm = apSegment[0]->zTerm;
    int nMerge = 1;

    ** term (if such a term exists in the index) has already been made.
    */
    if( pFilter->zTerm && !isPrefix ){
      goto finished;
    }

    for(i=0; i<nMerge; i++){
      rc = fts3SegReaderNext(p, apSegment[i]);
      if( rc!=SQLITE_OK ) goto finished;
    }
    fts3SegReaderSort(apSegment, nSegment, nMerge, fts3SegReaderCmp);
  }

 finished:
  sqlite3_free(aBuffer);

** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(Fts3Table *p, int iLevel){
  int i;                          /* Iterator variable */
  int rc;                         /* Return code */
  int iIdx;                       /* Index of new segment */
  int iNewLevel = 0;              /* Level to create new segment at */
  sqlite3_stmt *pStmt = 0;
  SegmentWriter *pWriter = 0;
  int nSegment = 0;               /* Number of segments being merged */
  Fts3SegReader **apSegment = 0;  /* Array of Segment iterators */
  Fts3SegReader *pPending = 0;    /* Iterator for pending-terms */
  Fts3SegFilter filter;           /* Segment term filter condition */

  sqlite3_bind_int64(pStmt, 1, p->iPrevDocid);
  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, sqlite3_free);
  sqlite3_step(pStmt);
  *pRC = sqlite3_reset(pStmt);
}

/*
** Record 0 of the %_stat table contains a blob consisting of N varints,
** where N is the number of user defined columns in the fts3 table plus
** two. If nCol is the number of user defined columns, then values of the 
** varints are set as follows:
**
**   Varint 0:       Total number of rows in the table.
**
**   Varint 1..nCol: For each column, the total number of tokens stored in
**                   the column for all rows of the table.
**
**   Varint 1+nCol:  The total size, in bytes, of all text values in all
**                   columns of all rows of the table.
**
*/
static void fts3UpdateDocTotals(
  int *pRC,                       /* The result code */
  Fts3Table *p,                   /* Table being updated */
  u32 *aSzIns,                    /* Size increases */
  u32 *aSzDel,                    /* Size decreases */
  int nChng                       /* Change in the number of documents */
){
  char *pBlob;             /* Storage for BLOB written into %_stat */
  int nBlob;               /* Size of BLOB written into %_stat */
  u32 *a;                  /* Array of integers that becomes the BLOB */
  sqlite3_stmt *pStmt;     /* Statement for reading and writing */
  int i;                   /* Loop counter */
  int rc;                  /* Result code from subfunctions */

  const int nStat = p->nColumn+2;

  if( *pRC ) return;
  a = sqlite3_malloc( (sizeof(u32)+10)*nStat );
  if( a==0 ){
    *pRC = SQLITE_NOMEM;
    return;
  }
  pBlob = (char*)&a[nStat];
  rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0);
  if( rc ){
    sqlite3_free(a);
    *pRC = rc;
    return;
  }
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    fts3DecodeIntArray(nStat, a,
         sqlite3_column_blob(pStmt, 0),
         sqlite3_column_bytes(pStmt, 0));
  }else{
    memset(a, 0, sizeof(u32)*(nStat) );
  }
  sqlite3_reset(pStmt);
  if( nChng<0 && a[0]<(u32)(-nChng) ){
    a[0] = 0;
  }else{
    a[0] += nChng;
  }
  for(i=0; i<p->nColumn+1; i++){
    u32 x = a[i+1];
    if( x+aSzIns[i] < aSzDel[i] ){
      x = 0;
    }else{
      x = x + aSzIns[i] - aSzDel[i];
    }
    a[i+1] = x;
  }
  fts3EncodeIntArray(nStat, a, pBlob, &nBlob);
  rc = fts3SqlStmt(p, SQL_REPLACE_DOCTOTAL, &pStmt, 0);
  if( rc ){
    sqlite3_free(a);
    *pRC = rc;
    return;
  }
  sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC);

  }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
    p->nMaxPendingData = atoi(&zVal[11]);
    rc = SQLITE_OK;
#endif
  }else{
    rc = SQLITE_ERROR;
  }

  sqlite3Fts3SegmentsClose(p);
  return rc;
}

/*
** Return the deferred doclist associated with deferred token pDeferred.
** This function assumes that sqlite3Fts3CacheDeferredDoclists() has already
** been called to allocate and populate the doclist.
*/
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *pDeferred, int *pnByte){
  if( pDeferred->pList ){
    *pnByte = pDeferred->pList->nData;
    return pDeferred->pList->aData;
  }
  *pnByte = 0;
  return 0;
}

/*
** Helper fucntion for FreeDeferredDoclists(). This function removes all
** references to deferred doclists from within the tree of Fts3Expr 
** structures headed by 
*/
static void fts3DeferredDoclistClear(Fts3Expr *pExpr){
  if( pExpr ){
    fts3DeferredDoclistClear(pExpr->pLeft);
    fts3DeferredDoclistClear(pExpr->pRight);
    if( pExpr->isLoaded ){
      sqlite3_free(pExpr->aDoclist);
      pExpr->isLoaded = 0;
      pExpr->aDoclist = 0;
      pExpr->nDoclist = 0;
      pExpr->pCurrent = 0;
      pExpr->iCurrent = 0;
    }
  }
}

/*
** Delete all cached deferred doclists. Deferred doclists are cached
** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function.
*/
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *pCsr){
  Fts3DeferredToken *pDef;
  for(pDef=pCsr->pDeferred; pDef; pDef=pDef->pNext){
    sqlite3_free(pDef->pList);
    pDef->pList = 0;
  }
  if( pCsr->pDeferred ){
    fts3DeferredDoclistClear(pCsr->pExpr);
  }
}

/*
** Free all entries in the pCsr->pDeffered list. Entries are added to 
** this list using sqlite3Fts3DeferToken().
*/
void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *pCsr){
  Fts3DeferredToken *pDef;
  Fts3DeferredToken *pNext;
  for(pDef=pCsr->pDeferred; pDef; pDef=pNext){
    pNext = pDef->pNext;
    sqlite3_free(pDef->pList);
    sqlite3_free(pDef);
  }
  pCsr->pDeferred = 0;
}

/*
** Generate deferred-doclists for all tokens in the pCsr->pDeferred list
** based on the row that pCsr currently points to.
**
** A deferred-doclist is like any other doclist with position information
** included, except that it only contains entries for a single row of the
** table, not for all rows.
*/
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){
  int rc = SQLITE_OK;             /* Return code */
  if( pCsr->pDeferred ){
    int i;                        /* Used to iterate through table columns */
    sqlite3_int64 iDocid;         /* Docid of the row pCsr points to */
    Fts3DeferredToken *pDef;      /* Used to iterate through deferred tokens */
  
    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
    sqlite3_tokenizer *pT = p->pTokenizer;
    sqlite3_tokenizer_module const *pModule = pT->pModule;
   
    assert( pCsr->isRequireSeek==0 );
    iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
  
    for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
      sqlite3_tokenizer_cursor *pTC = 0;
  
      rc = pModule->xOpen(pT, zText, -1, &pTC);
      while( rc==SQLITE_OK ){
        char const *zToken;       /* Buffer containing token */
        int nToken;               /* Number of bytes in token */
        int iDum1, iDum2;         /* Dummy variables */
        int iPos;                 /* Position of token in zText */
  
        pTC->pTokenizer = pT;
        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
          Fts3PhraseToken *pPT = pDef->pToken;
          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
           && (0==memcmp(zToken, pPT->z, pPT->n))
          ){
            fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
          }
        }
      }
      if( pTC ) pModule->xClose(pTC);
      if( rc==SQLITE_DONE ) rc = SQLITE_OK;
    }
  
    for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
      if( pDef->pList ){
        rc = fts3PendingListAppendVarint(&pDef->pList, 0);
      }
    }
  }

  return rc;
}

/*
** Add an entry for token pToken to the pCsr->pDeferred list.
*/
int sqlite3Fts3DeferToken(
  Fts3Cursor *pCsr,               /* Fts3 table cursor */
  Fts3PhraseToken *pToken,        /* Token to defer */
  int iCol                        /* Column that token must appear in (or -1) */
){
  Fts3DeferredToken *pDeferred;
  pDeferred = sqlite3_malloc(sizeof(*pDeferred));
  if( !pDeferred ){
    return SQLITE_NOMEM;
  }
  memset(pDeferred, 0, sizeof(*pDeferred));
  pDeferred->pToken = pToken;
  pDeferred->pNext = pCsr->pDeferred; 
  pDeferred->iCol = iCol;
  pCsr->pDeferred = pDeferred;

  assert( pToken->pDeferred==0 );
  pToken->pDeferred = pDeferred;

  return SQLITE_OK;
}


/*
** This function does the work for the xUpdate method of FTS3 virtual
** tables.
*/
int sqlite3Fts3UpdateMethod(
  sqlite3_vtab *pVtab,            /* FTS3 vtab object */
  int nArg,                       /* Size of argument array */
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  sqlite3_int64 iRemove = 0;      /* Rowid removed by UPDATE or DELETE */
  u32 *aSzIns;                    /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */

  assert( p->pSegments==0 );

  /* Allocate space to hold the change in document sizes */
  aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 );
  if( aSzIns==0 ) return SQLITE_NOMEM;
  aSzDel = &aSzIns[p->nColumn+1];
  memset(aSzIns, 0, sizeof(aSzIns[0])*(p->nColumn+1)*2);

  /* If this is a DELETE or UPDATE operation, remove the old record. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    int isEmpty = 0;
    rc = fts3IsEmpty(p, apVal, &isEmpty);
    if( rc==SQLITE_OK ){
      if( isEmpty ){
        /* Deleting this row means the whole table is empty. In this case
        ** delete the contents of all three tables and throw away any
        ** data in the pendingTerms hash table.
        */
        rc = fts3DeleteAll(p);
      }else{
        isRemove = 1;
        iRemove = sqlite3_value_int64(apVal[0]);
        rc = fts3PendingTermsDocid(p, iRemove);
        fts3DeleteTerms(&rc, p, apVal, aSzDel);
        fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, apVal);
        if( p->bHasDocsize ){
          fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, apVal);

        }
        nChng--;
      }
    }
  }else if( sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL ){
    sqlite3_free(aSzIns);
    return fts3SpecialInsert(p, apVal[p->nColumn+2]);
  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    rc = fts3InsertData(p, apVal, pRowid);
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=iRemove) ){
      rc = fts3PendingTermsDocid(p, *pRowid);
    }
    if( rc==SQLITE_OK ){
      rc = fts3InsertTerms(p, apVal, aSzIns);
    }
    if( p->bHasDocsize ){

      fts3InsertDocsize(&rc, p, aSzIns);
    }
    nChng++;
  }

  if( p->bHasStat ){
    fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng);
  }

  sqlite3_free(aSzIns);
  sqlite3Fts3SegmentsClose(p);
  return rc;
}

/* 
** Flush any data in the pending-terms hash table to disk. If successful,
** merge all segments in the database (including the new segment, if 
** there was any data to flush) into a single segment. 

        sqlite3Fts3PendingTermsClear(p);
      }
    }else{
      sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0);
      sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
    }
  }
  sqlite3Fts3SegmentsClose(p);
  return rc;
}

#endif

#--------------------------------------------------------------------------
# This script contains several sub-programs used to test FTS3/FTS4 
# performance. It does not run the queries directly, but generates SQL
# scripts that can be run using the shell tool.
#
# The following cases are tested:
#
#   1. Inserting documents into an FTS3 table.
#   2. Optimizing an FTS3 table (i.e. "INSERT INTO t1 VALUES('optimize')").
#   3. Deleting documents from an FTS3 table.
#   4. Querying FTS3 tables.
#

# Number of tokens in vocabulary. And number of tokens in each document.
#
set VOCAB_SIZE  2000
set DOC_SIZE     100

set NUM_INSERTS 100000
set NUM_SELECTS 1000

# Force everything in this script to be deterministic.
#
expr {srand(0)}

proc usage {} {
  puts stderr "Usage: $::argv0 <rows> <selects>"
  exit -1
}

proc sql {sql} {
  puts $::fd $sql
}


# Return a list of $nWord randomly generated tokens each between 2 and 10
# characters in length.
#
proc build_vocab {nWord} {
  set ret [list]
  set chars [list a b c d e f g h i j k l m n o p q r s t u v w x y z]
  for {set i 0} {$i<$nWord} {incr i} {
    set len [expr {int((rand()*9.0)+2)}]
    set term ""
    for {set j 0} {$j<$len} {incr j} {
      append term [lindex $chars [expr {int(rand()*[llength $chars])}]]
    }
    lappend ret $term
  }
  set ret
}

proc select_term {} {
  set n [llength $::vocab]
  set t [expr int(rand()*$n*3)]
  if {$t>=2*$n} { set t [expr {($t-2*$n)/100}] }
  if {$t>=$n} { set t [expr {($t-$n)/10}] }
  lindex $::vocab $t
}

proc select_doc {nTerm} {
  set ret [list]
  for {set i 0} {$i<$nTerm} {incr i} {
    lappend ret [select_term]
  }
  set ret
}

proc test_1 {nInsert} {
  sql "PRAGMA synchronous = OFF;"
  sql "DROP TABLE IF EXISTS t1;"
  sql "CREATE VIRTUAL TABLE t1 USING fts4;"
  for {set i 0} {$i < $nInsert} {incr i} {
    set doc [select_doc $::DOC_SIZE]
    sql "INSERT INTO t1 VALUES('$doc');"
  }
}

proc test_2 {} {
  sql "INSERT INTO t1(t1) VALUES('optimize');"
}

proc test_3 {nSelect} {
  for {set i 0} {$i < $nSelect} {incr i} {
    sql "SELECT count(*) FROM t1 WHERE t1 MATCH '[select_term]';"
  }
}

proc test_4 {nSelect} {
  for {set i 0} {$i < $nSelect} {incr i} {
    sql "SELECT count(*) FROM t1 WHERE t1 MATCH '[select_term] [select_term]';"
  }
}

if {[llength $argv]!=0} usage

set ::vocab [build_vocab $::VOCAB_SIZE]

set ::fd [open fts3speed_insert.sql w]
test_1 $NUM_INSERTS
close $::fd

set ::fd [open fts3speed_select.sql w]
test_3 $NUM_SELECTS
close $::fd

set ::fd [open fts3speed_select2.sql w]
test_4 $NUM_SELECTS
close $::fd

set ::fd [open fts3speed_optimize.sql w]
test_2
close $::fd

puts "Success. Created files:"
puts "  fts3speed_insert.sql"
puts "  fts3speed_select.sql"
puts "  fts3speed_select2.sql"
puts "  fts3speed_optimize.sql"

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code for implementations of the r-tree and r*-tree
** algorithms packaged as an SQLite virtual table module.
*/

/*
** Database Format of R-Tree Tables
** --------------------------------
**
** The data structure for a single virtual r-tree table is stored in three 
** native SQLite tables declared as follows. In each case, the '%' character
** in the table name is replaced with the user-supplied name of the r-tree
** table.
**
**   CREATE TABLE %_node(nodeno INTEGER PRIMARY KEY, data BLOB)
**   CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)
**   CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER)
**
** The data for each node of the r-tree structure is stored in the %_node
** table. For each node that is not the root node of the r-tree, there is
** an entry in the %_parent table associating the node with its parent.
** And for each row of data in the table, there is an entry in the %_rowid
** table that maps from the entries rowid to the id of the node that it
** is stored on.
**
** The root node of an r-tree always exists, even if the r-tree table is
** empty. The nodeno of the root node is always 1. All other nodes in the
** table must be the same size as the root node. The content of each node
** is formatted as follows:
**
**   1. If the node is the root node (node 1), then the first 2 bytes
**      of the node contain the tree depth as a big-endian integer.
**      For non-root nodes, the first 2 bytes are left unused.
**
**   2. The next 2 bytes contain the number of entries currently 
**      stored in the node.
**
**   3. The remainder of the node contains the node entries. Each entry
**      consists of a single 8-byte integer followed by an even number
**      of 4-byte coordinates. For leaf nodes the integer is the rowid
**      of a record. For internal nodes it is the node number of a
**      child page.
*/

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

/*
** This file contains an implementation of a couple of different variants
** of the r-tree algorithm. See the README file for further details. The 
** same data-structure is used for all, but the algorithms for insert and

  #define PickSeeds LinearPickSeeds
  #define AssignCells splitNodeGuttman
#endif
#if VARIANT_RSTARTREE_SPLIT
  #define AssignCells splitNodeStartree
#endif

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

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

#include <string.h>
#include <assert.h>
#include <stdint.h>

#ifndef SQLITE_AMALGAMATION
#include "sqlite3rtree.h"
typedef sqlite3_int64 i64;
typedef unsigned char u8;
typedef unsigned int u32;
#endif

typedef struct Rtree Rtree;
typedef struct RtreeCursor RtreeCursor;
typedef struct RtreeNode RtreeNode;
typedef struct RtreeCell RtreeCell;
typedef struct RtreeConstraint RtreeConstraint;
typedef struct RtreeMatchArg RtreeMatchArg;
typedef struct RtreeGeomCallback RtreeGeomCallback;
typedef union RtreeCoord RtreeCoord;

/* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
#define RTREE_MAX_DIMENSIONS 5

/* Size of hash table Rtree.aHash. This hash table is not expected to
** ever contain very many entries, so a fixed number of buckets is 

** If an R*-tree "Reinsert" operation is required, the same number of
** cells are removed from the overfull node and reinserted into the tree.
*/
#define RTREE_MINCELLS(p) ((((p)->iNodeSize-4)/(p)->nBytesPerCell)/3)
#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
#define RTREE_MAXCELLS 51

/* 
** The smallest possible node-size is (512-64)==448 bytes. And the largest
** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
** Therefore all non-root nodes must contain at least 3 entries. Since 
** 2^40 is greater than 2^64, an r-tree structure always has a depth of
** 40 or less.
*/
#define RTREE_MAX_DEPTH 40

/* 
** An rtree cursor object.
*/
struct RtreeCursor {
  sqlite3_vtab_cursor base;
  RtreeNode *pNode;                 /* Node cursor is currently pointing at */
  int iCell;                        /* Index of current cell in pNode */

    ((double)coord.i)                             \
)

/*
** A search constraint.
*/
struct RtreeConstraint {
  int iCoord;                     /* Index of constrained coordinate */
  int op;                         /* Constraining operation */
  double rValue;                  /* Constraint value. */
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  sqlite3_rtree_geometry *pGeom;  /* Constraint callback argument for a MATCH */
};

/* Possible values for RtreeConstraint.op */
#define RTREE_EQ    0x41
#define RTREE_LE    0x42
#define RTREE_LT    0x43
#define RTREE_GE    0x44
#define RTREE_GT    0x45
#define RTREE_MATCH 0x46

/* 
** An rtree structure node.















*/
struct RtreeNode {
  RtreeNode *pParent;               /* Parent node */
  i64 iNode;
  int nRef;
  int isDirty;
  u8 *zData;
  RtreeNode *pNext;                 /* Next node in this hash chain */
};
#define NCELL(pNode) readInt16(&(pNode)->zData[2])

/* 
** Structure to store a deserialized rtree record.
*/
struct RtreeCell {
  i64 iRowid;
  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
};


/*
** Value for the first field of every RtreeMatchArg object. The MATCH
** operator tests that the first field of a blob operand matches this
** value to avoid operating on invalid blobs (which could cause a segfault).
*/
#define RTREE_GEOMETRY_MAGIC 0x891245AB

/*
** An instance of this structure must be supplied as a blob argument to
** the right-hand-side of an SQL MATCH operator used to constrain an
** r-tree query.
*/
struct RtreeMatchArg {
  u32 magic;                      /* Always RTREE_GEOMETRY_MAGIC */
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  void *pContext;
  int nParam;
  double aParam[1];
};

/*
** When a geometry callback is created (see sqlite3_rtree_geometry_callback),
** a single instance of the following structure is allocated. It is used
** as the context for the user-function created by by s_r_g_c(). The object
** is eventually deleted by the destructor mechanism provided by
** sqlite3_create_function_v2() (which is called by s_r_g_c() to create
** the geometry callback function).
*/
struct RtreeGeomCallback {
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  void *pContext;
};

#ifndef MAX
# define MAX(x,y) ((x) < (y) ? (y) : (x))
#endif
#ifndef MIN
# define MIN(x,y) ((x) > (y) ? (y) : (x))
#endif

  }
}

/*
** Clear the content of node p (set all bytes to 0x00).
*/
static void nodeZero(Rtree *pRtree, RtreeNode *p){

  memset(&p->zData[2], 0, pRtree->iNodeSize-2);
  p->isDirty = 1;

}

/*
** Given a node number iNode, return the corresponding key to use
** in the Rtree.aHash table.
*/
static int nodeHash(i64 iNode){
  return (
    (iNode>>56) ^ (iNode>>48) ^ (iNode>>40) ^ (iNode>>32) ^ 
    (iNode>>24) ^ (iNode>>16) ^ (iNode>> 8) ^ (iNode>> 0)
  ) % HASHSIZE;
}

/*
** Search the node hash table for node iNode. If found, return a pointer
** to it. Otherwise, return 0.
*/
static RtreeNode *nodeHashLookup(Rtree *pRtree, i64 iNode){
  RtreeNode *p;

  for(p=pRtree->aHash[nodeHash(iNode)]; p && p->iNode!=iNode; p=p->pNext);
  return p;
}

/*
** Add node pNode to the node hash table.
*/
static void nodeHashInsert(Rtree *pRtree, RtreeNode *pNode){

  int iHash;
  assert( pNode->pNext==0 );
  iHash = nodeHash(pNode->iNode);
  pNode->pNext = pRtree->aHash[iHash];
  pRtree->aHash[iHash] = pNode;

}

/*
** Remove node pNode from the node hash table.
*/
static void nodeHashDelete(Rtree *pRtree, RtreeNode *pNode){
  RtreeNode **pp;

/*
** Allocate and return new r-tree node. Initially, (RtreeNode.iNode==0),
** indicating that node has not yet been assigned a node number. It is
** assigned a node number when nodeWrite() is called to write the
** node contents out to the database.
*/
static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
  RtreeNode *pNode;
  pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode) + pRtree->iNodeSize);
  if( pNode ){
    memset(pNode, 0, sizeof(RtreeNode) + pRtree->iNodeSize);
    pNode->zData = (u8 *)&pNode[1];
    pNode->nRef = 1;
    pNode->pParent = pParent;
    pNode->isDirty = 1;
    nodeReference(pParent);
  }
  return pNode;
}

/*
** Obtain a reference to an r-tree node.
*/
static int
nodeAcquire(
  Rtree *pRtree,             /* R-tree structure */
  i64 iNode,                 /* Node number to load */
  RtreeNode *pParent,        /* Either the parent node or NULL */
  RtreeNode **ppNode         /* OUT: Acquired node */
){
  int rc;
  int rc2 = SQLITE_OK;
  RtreeNode *pNode;

  /* Check if the requested node is already in the hash table. If so,
  ** increase its reference count and return it.
  */
  if( (pNode = nodeHashLookup(pRtree, iNode)) ){
    assert( !pParent || !pNode->pParent || pNode->pParent==pParent );
    if( pParent && !pNode->pParent ){
      nodeReference(pParent);
      pNode->pParent = pParent;
    }
    pNode->nRef++;
    *ppNode = pNode;
    return SQLITE_OK;
  }

  sqlite3_bind_int64(pRtree->pReadNode, 1, iNode);
  rc = sqlite3_step(pRtree->pReadNode);
  if( rc==SQLITE_ROW ){
    const u8 *zBlob = sqlite3_column_blob(pRtree->pReadNode, 0);
    if( pRtree->iNodeSize==sqlite3_column_bytes(pRtree->pReadNode, 0) ){
      pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
      if( !pNode ){

        rc2 = SQLITE_NOMEM;
      }else{
        pNode->pParent = pParent;
        pNode->zData = (u8 *)&pNode[1];
        pNode->nRef = 1;
        pNode->iNode = iNode;
        pNode->isDirty = 0;
        pNode->pNext = 0;
        memcpy(pNode->zData, zBlob, pRtree->iNodeSize);
        nodeReference(pParent);
      }

    }
  }
  rc = sqlite3_reset(pRtree->pReadNode);
  if( rc==SQLITE_OK ) rc = rc2;

  /* If the root node was just loaded, set pRtree->iDepth to the height
  ** of the r-tree structure. A height of zero means all data is stored on
  ** the root node. A height of one means the children of the root node
  ** are the leaves, and so on. If the depth as specified on the root node
  ** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.
  */
  if( pNode && iNode==1 ){
    pRtree->iDepth = readInt16(pNode->zData);
    if( pRtree->iDepth>RTREE_MAX_DEPTH ){
      rc = SQLITE_CORRUPT;
    }
  }

  /* If no error has occurred so far, check if the "number of entries"
  ** field on the node is too large. If so, set the return code to 
  ** SQLITE_CORRUPT.
  */
  if( pNode && rc==SQLITE_OK ){
    if( NCELL(pNode)>((pRtree->iNodeSize-4)/pRtree->nBytesPerCell) ){
      rc = SQLITE_CORRUPT;
    }
  }

  if( rc==SQLITE_OK ){
    if( pNode!=0 ){
      nodeHashInsert(pRtree, pNode);
    }else{
      rc = SQLITE_CORRUPT;
    }
    *ppNode = pNode;
  }else{
    sqlite3_free(pNode);
    *ppNode = 0;













  }

  return rc;
}

/*
** Overwrite cell iCell of node pNode with the contents of pCell.

){
  int nCell;                    /* Current number of cells in pNode */
  int nMaxCell;                 /* Maximum number of cells for pNode */

  nMaxCell = (pRtree->iNodeSize-4)/pRtree->nBytesPerCell;
  nCell = NCELL(pNode);

  assert( nCell<=nMaxCell );

  if( nCell<nMaxCell ){
    nodeOverwriteCell(pRtree, pNode, pCell, nCell);
    writeInt16(&pNode->zData[2], nCell+1);
    pNode->isDirty = 1;
  }

  return (nCell==nMaxCell);

    rc = SQLITE_OK;
  }
  *ppCursor = (sqlite3_vtab_cursor *)pCsr;

  return rc;
}


/*
** Free the RtreeCursor.aConstraint[] array and its contents.
*/
static void freeCursorConstraints(RtreeCursor *pCsr){
  if( pCsr->aConstraint ){
    int i;                        /* Used to iterate through constraint array */
    for(i=0; i<pCsr->nConstraint; i++){
      sqlite3_rtree_geometry *pGeom = pCsr->aConstraint[i].pGeom;
      if( pGeom ){
        if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
        sqlite3_free(pGeom);
      }
    }
    sqlite3_free(pCsr->aConstraint);
    pCsr->aConstraint = 0;
  }
}

/* 
** Rtree virtual table module xClose method.
*/
static int rtreeClose(sqlite3_vtab_cursor *cur){
  Rtree *pRtree = (Rtree *)(cur->pVtab);
  int rc;
  RtreeCursor *pCsr = (RtreeCursor *)cur;
  freeCursorConstraints(pCsr);
  rc = nodeRelease(pRtree, pCsr->pNode);
  sqlite3_free(pCsr);
  return rc;
}

/*
** Rtree virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid 
** record (i.e if the scan has finished), or zero otherwise.
*/
static int rtreeEof(sqlite3_vtab_cursor *cur){
  RtreeCursor *pCsr = (RtreeCursor *)cur;
  return (pCsr->pNode==0);
}

/* 
** The r-tree constraint passed as the second argument to this function is
** guaranteed to be a MATCH constraint.
*/
static int testRtreeGeom(
  Rtree *pRtree,                  /* R-Tree object */
  RtreeConstraint *pConstraint,   /* MATCH constraint to test */
  RtreeCell *pCell,               /* Cell to test */
  int *pbRes                      /* OUT: Test result */
){
  int i;
  double aCoord[RTREE_MAX_DIMENSIONS*2];
  int nCoord = pRtree->nDim*2;

  assert( pConstraint->op==RTREE_MATCH );
  assert( pConstraint->pGeom );

  for(i=0; i<nCoord; i++){
    aCoord[i] = DCOORD(pCell->aCoord[i]);
  }
  return pConstraint->xGeom(pConstraint->pGeom, nCoord, aCoord, pbRes);
}

/* 
** Cursor pCursor currently points to a cell in a non-leaf page.
** Set *pbEof to true if the sub-tree headed by the cell is filtered
** (excluded) by the constraints in the pCursor->aConstraint[] 
** array, or false otherwise.
**
** Return SQLITE_OK if successful or an SQLite error code if an error
** occurs within a geometry callback.
*/
static int testRtreeCell(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
  RtreeCell cell;
  int ii;
  int bRes = 0;

  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
  for(ii=0; bRes==0 && ii<pCursor->nConstraint; ii++){
    RtreeConstraint *p = &pCursor->aConstraint[ii];
    double cell_min = DCOORD(cell.aCoord[(p->iCoord>>1)*2]);
    double cell_max = DCOORD(cell.aCoord[(p->iCoord>>1)*2+1]);

    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
    );

    switch( p->op ){
      case RTREE_LE: case RTREE_LT: 
        bRes = p->rValue<cell_min; 
        break;

      case RTREE_GE: case RTREE_GT: 
        bRes = p->rValue>cell_max; 
        break;

      case RTREE_EQ: 
        bRes = (p->rValue>cell_max || p->rValue<cell_min);
        break;

      default: {
        int rc;
        assert( p->op==RTREE_MATCH );
        rc = testRtreeGeom(pRtree, p, &cell, &bRes);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        bRes = !bRes;
        break;
      }
    }
  }

  *pbEof = bRes;
  return SQLITE_OK;
}

/* 
** Test if the cell that cursor pCursor currently points to
** would be filtered (excluded) by the constraints in the 
** pCursor->aConstraint[] array. If so, set *pbEof to true before
** returning. If the cell is not filtered (excluded) by the constraints,
** set pbEof to zero.
**
** Return SQLITE_OK if successful or an SQLite error code if an error
** occurs within a geometry callback.
**
** This function assumes that the cell is part of a leaf node.
*/
static int testRtreeEntry(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
  RtreeCell cell;
  int ii;
  *pbEof = 0;

  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
  for(ii=0; ii<pCursor->nConstraint; ii++){
    RtreeConstraint *p = &pCursor->aConstraint[ii];
    double coord = DCOORD(cell.aCoord[p->iCoord]);
    int res;
    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
    );
    switch( p->op ){
      case RTREE_LE: res = (coord<=p->rValue); break;
      case RTREE_LT: res = (coord<p->rValue);  break;
      case RTREE_GE: res = (coord>=p->rValue); break;
      case RTREE_GT: res = (coord>p->rValue);  break;
      case RTREE_EQ: res = (coord==p->rValue); break;
      default: {
        int rc;
        assert( p->op==RTREE_MATCH );
        rc = testRtreeGeom(pRtree, p, &cell, &res);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        break;
      }
    }

    if( !res ){
      *pbEof = 1;
      return SQLITE_OK;
    }
  }

  return SQLITE_OK;
}

/*
** Cursor pCursor currently points at a node that heads a sub-tree of
** height iHeight (if iHeight==0, then the node is a leaf). Descend
** to point to the left-most cell of the sub-tree that matches the 
** configured constraints.

  RtreeNode *pSavedNode = pCursor->pNode;
  int iSavedCell = pCursor->iCell;

  assert( iHeight>=0 );

  if( iHeight==0 ){
    rc = testRtreeEntry(pRtree, pCursor, &isEof);
  }else{
    rc = testRtreeCell(pRtree, pCursor, &isEof);
  }
  if( rc!=SQLITE_OK || isEof || iHeight==0 ){
    *pEof = isEof;
    return rc;
  }

  iRowid = nodeGetRowid(pRtree, pCursor->pNode, pCursor->iCell);
  rc = nodeAcquire(pRtree, iRowid, pCursor->pNode, &pChild);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  return SQLITE_OK;
}

/*
** One of the cells in node pNode is guaranteed to have a 64-bit 
** integer value equal to iRowid. Return the index of this cell.
*/
static int nodeRowidIndex(
  Rtree *pRtree, 
  RtreeNode *pNode, 
  i64 iRowid,
  int *piIndex
){
  int ii;
  int nCell = NCELL(pNode);
  for(ii=0; ii<nCell; ii++){
    if( nodeGetRowid(pRtree, pNode, ii)==iRowid ){
      *piIndex = ii;
      return SQLITE_OK;
    }
  }
  return SQLITE_CORRUPT;
}

/*
** Return the index of the cell containing a pointer to node pNode
** in its parent. If pNode is the root node, return -1.
*/
static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){
  RtreeNode *pParent = pNode->pParent;
  if( pParent ){
    return nodeRowidIndex(pRtree, pParent, pNode->iNode, piIndex);
  }
  *piIndex = -1;
  return SQLITE_OK;
}

/* 
** Rtree virtual table module xNext method.
*/
static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
  Rtree *pRtree = (Rtree *)(pVtabCursor->pVtab);
  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
  int rc = SQLITE_OK;

  /* RtreeCursor.pNode must not be NULL. If is is NULL, then this cursor is
  ** already at EOF. It is against the rules to call the xNext() method of
  ** a cursor that has already reached EOF.
  */
  assert( pCsr->pNode );

  if( pCsr->iStrategy==1 ){
    /* This "scan" is a direct lookup by rowid. There is no next entry. */
    nodeRelease(pRtree, pCsr->pNode);
    pCsr->pNode = 0;
  }else{


    /* Move to the next entry that matches the configured constraints. */
    int iHeight = 0;
    while( pCsr->pNode ){
      RtreeNode *pNode = pCsr->pNode;
      int nCell = NCELL(pNode);
      for(pCsr->iCell++; pCsr->iCell<nCell; pCsr->iCell++){
        int isEof;
        rc = descendToCell(pRtree, pCsr, iHeight, &isEof);
        if( rc!=SQLITE_OK || !isEof ){
          return rc;
        }
      }
      pCsr->pNode = pNode->pParent;
      rc = nodeParentIndex(pRtree, pNode, &pCsr->iCell);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      nodeReference(pCsr->pNode);
      nodeRelease(pRtree, pNode);
      iHeight++;
    }
  }

  return rc;

    sqlite3_reset(pRtree->pReadRowid);
  }else{
    rc = sqlite3_reset(pRtree->pReadRowid);
  }
  return rc;
}

/*
** This function is called to configure the RtreeConstraint object passed
** as the second argument for a MATCH constraint. The value passed as the
** first argument to this function is the right-hand operand to the MATCH
** operator.
*/
static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
  RtreeMatchArg *p;
  sqlite3_rtree_geometry *pGeom;
  int nBlob;

  /* Check that value is actually a blob. */
  if( !sqlite3_value_type(pValue)==SQLITE_BLOB ) return SQLITE_ERROR;

  /* Check that the blob is roughly the right size. */
  nBlob = sqlite3_value_bytes(pValue);
  if( nBlob<sizeof(RtreeMatchArg) 
   || ((nBlob-sizeof(RtreeMatchArg))%sizeof(double))!=0
  ){
    return SQLITE_ERROR;
  }

  pGeom = (sqlite3_rtree_geometry *)sqlite3_malloc(
      sizeof(sqlite3_rtree_geometry) + nBlob
  );
  if( !pGeom ) return SQLITE_NOMEM;
  memset(pGeom, 0, sizeof(sqlite3_rtree_geometry));
  p = (RtreeMatchArg *)&pGeom[1];

  memcpy(p, sqlite3_value_blob(pValue), nBlob);
  if( p->magic!=RTREE_GEOMETRY_MAGIC 
   || nBlob!=(sizeof(RtreeMatchArg) + (p->nParam-1)*sizeof(double))
  ){
    sqlite3_free(pGeom);
    return SQLITE_ERROR;
  }

  pGeom->pContext = p->pContext;
  pGeom->nParam = p->nParam;
  pGeom->aParam = p->aParam;

  pCons->xGeom = p->xGeom;
  pCons->pGeom = pGeom;
  return SQLITE_OK;
}

/* 
** Rtree virtual table module xFilter method.
*/
static int rtreeFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;

  RtreeNode *pRoot = 0;
  int ii;
  int rc = SQLITE_OK;

  rtreeReference(pRtree);


  freeCursorConstraints(pCsr);
  pCsr->iStrategy = idxNum;

  if( idxNum==1 ){
    /* Special case - lookup by rowid. */
    RtreeNode *pLeaf;        /* Leaf on which the required cell resides */
    i64 iRowid = sqlite3_value_int64(argv[0]);
    rc = findLeafNode(pRtree, iRowid, &pLeaf);
    pCsr->pNode = pLeaf; 
    if( pLeaf ){
      assert( rc==SQLITE_OK );
      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &pCsr->iCell);
    }
  }else{
    /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 
    ** with the configured constraints. 
    */
    if( argc>0 ){
      pCsr->aConstraint = sqlite3_malloc(sizeof(RtreeConstraint)*argc);
      pCsr->nConstraint = argc;
      if( !pCsr->aConstraint ){
        rc = SQLITE_NOMEM;
      }else{
        memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);
        assert( (idxStr==0 && argc==0) || strlen(idxStr)==argc*2 );
        for(ii=0; ii<argc; ii++){
          RtreeConstraint *p = &pCsr->aConstraint[ii];
          p->op = idxStr[ii*2];
          p->iCoord = idxStr[ii*2+1]-'a';
          if( p->op==RTREE_MATCH ){
            /* A MATCH operator. The right-hand-side must be a blob that
            ** can be cast into an RtreeMatchArg object. One created using
            ** an sqlite3_rtree_geometry_callback() SQL user function.
            */
            rc = deserializeGeometry(argv[ii], p);
            if( rc!=SQLITE_OK ){
              break;
            }
          }else{
            p->rValue = sqlite3_value_double(argv[ii]);
          }
        }
      }
    }
  
    if( rc==SQLITE_OK ){
      pCsr->pNode = 0;
      rc = nodeAcquire(pRtree, 1, 0, &pRoot);

**   Operator    Byte Value
**   ----------------------
**      =        0x41 ('A')
**     <=        0x42 ('B')
**      <        0x43 ('C')
**     >=        0x44 ('D')
**      >        0x45 ('E')
**   MATCH       0x46 ('F')
**   ----------------------
**
** The second of each pair of bytes identifies the coordinate column
** to which the constraint applies. The leftmost coordinate column
** is 'a', the second from the left 'b' etc.
*/
static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

      ** considered almost as quick as a direct rowid lookup (for which 
      ** sqlite uses an internal cost of 0.0).
      */ 
      pIdxInfo->estimatedCost = 10.0;
      return SQLITE_OK;
    }

    if( p->usable && (p->iColumn>0 || p->op==SQLITE_INDEX_CONSTRAINT_MATCH) ){
      int j, opmsk;
      static const unsigned char compatible[] = { 0, 0, 1, 1, 2, 2 };
      u8 op = 0;
      switch( p->op ){
        case SQLITE_INDEX_CONSTRAINT_EQ: op = RTREE_EQ; break;
        case SQLITE_INDEX_CONSTRAINT_GT: op = RTREE_GT; break;
        case SQLITE_INDEX_CONSTRAINT_LE: op = RTREE_LE; break;
        case SQLITE_INDEX_CONSTRAINT_LT: op = RTREE_LT; break;
        case SQLITE_INDEX_CONSTRAINT_GE: op = RTREE_GE; break;
        default:
          assert( p->op==SQLITE_INDEX_CONSTRAINT_MATCH );
          op = RTREE_MATCH; 
          break;
      }
      assert( op!=0 );

      /* Make sure this particular constraint has not been used before.
      ** If it has been used before, ignore it.
      **
      ** A <= or < can be used if there is a prior >= or >.
      ** A >= or > can be used if there is a prior < or <=.
      ** A <= or < is disqualified if there is a prior <=, <, or ==.
      ** A >= or > is disqualified if there is a prior >=, >, or ==.
      ** A == is disqualifed if there is any prior constraint.
      */


      assert( compatible[RTREE_EQ & 7]==0 );
      assert( compatible[RTREE_LT & 7]==1 );
      assert( compatible[RTREE_LE & 7]==1 );
      assert( compatible[RTREE_GT & 7]==2 );
      assert( compatible[RTREE_GE & 7]==2 );
      cCol = p->iColumn - 1 + 'a';
      opmsk = compatible[op & 7];
      for(j=0; j<iIdx; j+=2){
        if( zIdxStr[j+1]==cCol && (compatible[zIdxStr[j] & 7] & opmsk)!=0 ){
          op = 0;
          break;

        }
      }
      if( op ){
        assert( iIdx<sizeof(zIdxStr)-1 );
        zIdxStr[iIdx++] = op;
        zIdxStr[iIdx++] = cCol;
        pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);

  RtreeCell *aCell, 
  int nCell, 
  int iExclude
){
  int ii;
  float overlap = 0.0;
  for(ii=0; ii<nCell; ii++){
#if VARIANT_RSTARTREE_CHOOSESUBTREE
    if( ii!=iExclude )
#else
    assert( iExclude==-1 );
#endif
    {
      int jj;
      float o = 1.0;
      for(jj=0; jj<(pRtree->nDim*2); jj+=2){
        double x1;
        double x2;

        x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));

#endif

    /* Select the child node which will be enlarged the least if pCell
    ** is inserted into it. Resolve ties by choosing the entry with
    ** the smallest area.
    */
    for(iCell=0; iCell<nCell; iCell++){
      int bBest = 0;
      float growth;
      float area;
      float overlap = 0.0;
      nodeGetCell(pRtree, pNode, iCell, &cell);
      growth = cellGrowth(pRtree, &cell, pCell);
      area = cellArea(pRtree, &cell);

#if VARIANT_RSTARTREE_CHOOSESUBTREE
      if( ii==(pRtree->iDepth-1) ){
        overlap = cellOverlapEnlargement(pRtree,&cell,pCell,aCell,nCell,iCell);
      }

      if( (iCell==0) 
       || (overlap<fMinOverlap) 
       || (overlap==fMinOverlap && growth<fMinGrowth)
       || (overlap==fMinOverlap && growth==fMinGrowth && area<fMinArea)
      ){
        bBest = 1;
      }
#else
      if( iCell==0||growth<fMinGrowth||(growth==fMinGrowth && area<fMinArea) ){
        bBest = 1;
      }
#endif
      if( bBest ){
        fMinOverlap = overlap;
        fMinGrowth = growth;
        fMinArea = area;
        iBest = cell.iRowid;
      }
    }

}

/*
** A cell with the same content as pCell has just been inserted into
** the node pNode. This function updates the bounding box cells in
** all ancestor elements.
*/
static int AdjustTree(
  Rtree *pRtree,                    /* Rtree table */
  RtreeNode *pNode,                 /* Adjust ancestry of this node. */
  RtreeCell *pCell                  /* This cell was just inserted */
){
  RtreeNode *p = pNode;
  while( p->pParent ){
    RtreeNode *pParent = p->pParent;
    RtreeCell cell;
    int iCell;

    if( nodeParentIndex(pRtree, p, &iCell) ){
      return SQLITE_CORRUPT;
    }

    nodeGetCell(pRtree, pParent, iCell, &cell);
    if( !cellContains(pRtree, &cell, pCell) ){
      cellUnion(pRtree, &cell, pCell);
      nodeOverwriteCell(pRtree, pParent, &cell, iCell);
    }
 
    p = pParent;
  }
  return SQLITE_OK;
}

/*
** Write mapping (iRowid->iNode) to the <rtree>_rowid table.
*/
static int rowidWrite(Rtree *pRtree, sqlite3_int64 iRowid, sqlite3_int64 iNode){
  sqlite3_bind_int64(pRtree->pWriteRowid, 1, iRowid);

    nodeGetCell(pRtree, pNode, i, &aCell[i]);
  }
  nodeZero(pRtree, pNode);
  memcpy(&aCell[nCell], pCell, sizeof(RtreeCell));
  nCell++;

  if( pNode->iNode==1 ){
    pRight = nodeNew(pRtree, pNode);
    pLeft = nodeNew(pRtree, pNode);
    pRtree->iDepth++;
    pNode->isDirty = 1;
    writeInt16(pNode->zData, pRtree->iDepth);
  }else{
    pLeft = pNode;
    pRight = nodeNew(pRtree, pLeft->pParent);
    nodeReference(pLeft);
  }

  if( !pLeft || !pRight ){
    rc = SQLITE_NOMEM;
    goto splitnode_out;
  }

  memset(pLeft->zData, 0, pRtree->iNodeSize);
  memset(pRight->zData, 0, pRtree->iNodeSize);

  rc = AssignCells(pRtree, aCell, nCell, pLeft, pRight, &leftbbox, &rightbbox);
  if( rc!=SQLITE_OK ){
    goto splitnode_out;
  }

  /* Ensure both child nodes have node numbers assigned to them by calling
  ** nodeWrite(). Node pRight always needs a node number, as it was created
  ** by nodeNew() above. But node pLeft sometimes already has a node number.
  ** In this case avoid the all to nodeWrite().
  */
  if( SQLITE_OK!=(rc = nodeWrite(pRtree, pRight))
   || (0==pLeft->iNode && SQLITE_OK!=(rc = nodeWrite(pRtree, pLeft)))
  ){
    goto splitnode_out;
  }

  rightbbox.iRowid = pRight->iNode;
  leftbbox.iRowid = pLeft->iNode;

  if( pNode->iNode==1 ){
    rc = rtreeInsertCell(pRtree, pLeft->pParent, &leftbbox, iHeight+1);
    if( rc!=SQLITE_OK ){
      goto splitnode_out;
    }
  }else{
    RtreeNode *pParent = pLeft->pParent;
    int iCell;
    rc = nodeParentIndex(pRtree, pLeft, &iCell);
    if( rc==SQLITE_OK ){
      nodeOverwriteCell(pRtree, pParent, &leftbbox, iCell);
      rc = AdjustTree(pRtree, pParent, &leftbbox);
    }
    if( rc!=SQLITE_OK ){
      goto splitnode_out;
    }
  }
  if( (rc = rtreeInsertCell(pRtree, pRight->pParent, &rightbbox, iHeight+1)) ){
    goto splitnode_out;
  }

  for(i=0; i<NCELL(pRight); i++){
    i64 iRowid = nodeGetRowid(pRtree, pRight, i);

splitnode_out:
  nodeRelease(pRtree, pRight);
  nodeRelease(pRtree, pLeft);
  sqlite3_free(aCell);
  return rc;
}

/*
** If node pLeaf is not the root of the r-tree and its pParent pointer is 
** still NULL, load all ancestor nodes of pLeaf into memory and populate
** the pLeaf->pParent chain all the way up to the root node.
**
** This operation is required when a row is deleted (or updated - an update
** is implemented as a delete followed by an insert). SQLite provides the
** rowid of the row to delete, which can be used to find the leaf on which
** the entry resides (argument pLeaf). Once the leaf is located, this 
** function is called to determine its ancestry.
*/
static int fixLeafParent(Rtree *pRtree, RtreeNode *pLeaf){
  int rc = SQLITE_OK;
  RtreeNode *pChild = pLeaf;
  while( rc==SQLITE_OK && pChild->iNode!=1 && pChild->pParent==0 ){
    int rc2 = SQLITE_OK;          /* sqlite3_reset() return code */
    sqlite3_bind_int64(pRtree->pReadParent, 1, pChild->iNode);
    rc = sqlite3_step(pRtree->pReadParent);
    if( rc==SQLITE_ROW ){
      RtreeNode *pTest;           /* Used to test for reference loops */
      i64 iNode;                  /* Node number of parent node */

      /* Before setting pChild->pParent, test that we are not creating a
      ** loop of references (as we would if, say, pChild==pParent). We don't
      ** want to do this as it leads to a memory leak when trying to delete
      ** the referenced counted node structures.
      */
      iNode = sqlite3_column_int64(pRtree->pReadParent, 0);
      for(pTest=pLeaf; pTest && pTest->iNode!=iNode; pTest=pTest->pParent);
      if( !pTest ){
        rc2 = nodeAcquire(pRtree, iNode, 0, &pChild->pParent);


      }
    }
    rc = sqlite3_reset(pRtree->pReadParent);
    if( rc==SQLITE_OK ) rc = rc2;
    if( rc==SQLITE_OK && !pChild->pParent ) rc = SQLITE_CORRUPT;
    pChild = pChild->pParent;

  }
  return rc;
}

static int deleteCell(Rtree *, RtreeNode *, int, int);

static int removeNode(Rtree *pRtree, RtreeNode *pNode, int iHeight){
  int rc;
  int rc2;
  RtreeNode *pParent;
  int iCell;

  assert( pNode->nRef==1 );

  /* Remove the entry in the parent cell. */
  rc = nodeParentIndex(pRtree, pNode, &iCell);
  if( rc==SQLITE_OK ){
    pParent = pNode->pParent;
    pNode->pParent = 0;
    rc = deleteCell(pRtree, pParent, iCell, iHeight+1);
  }
  rc2 = nodeRelease(pRtree, pParent);
  if( rc==SQLITE_OK ){
    rc = rc2;
  }
  if( rc!=SQLITE_OK ){
    return rc;
  }

  /* Remove the xxx_node entry. */
  sqlite3_bind_int64(pRtree->pDeleteNode, 1, pNode->iNode);
  sqlite3_step(pRtree->pDeleteNode);
  if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteNode)) ){

  pNode->pNext = pRtree->pDeleted;
  pNode->nRef++;
  pRtree->pDeleted = pNode;

  return SQLITE_OK;
}

static int fixBoundingBox(Rtree *pRtree, RtreeNode *pNode){
  RtreeNode *pParent = pNode->pParent;
  int rc = SQLITE_OK; 
  if( pParent ){
    int ii; 
    int nCell = NCELL(pNode);
    RtreeCell box;                            /* Bounding box for pNode */
    nodeGetCell(pRtree, pNode, 0, &box);
    for(ii=1; ii<nCell; ii++){
      RtreeCell cell;
      nodeGetCell(pRtree, pNode, ii, &cell);
      cellUnion(pRtree, &box, &cell);
    }
    box.iRowid = pNode->iNode;
    rc = nodeParentIndex(pRtree, pNode, &ii);
    if( rc==SQLITE_OK ){
      nodeOverwriteCell(pRtree, pParent, &box, ii);
      rc = fixBoundingBox(pRtree, pParent);
    }
  }
  return rc;
}

/*
** Delete the cell at index iCell of node pNode. After removing the
** cell, adjust the r-tree data structure if required.
*/
static int deleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell, int iHeight){
  RtreeNode *pParent;
  int rc;

  if( SQLITE_OK!=(rc = fixLeafParent(pRtree, pNode)) ){
    return rc;
  }

  /* Remove the cell from the node. This call just moves bytes around
  ** the in-memory node image, so it cannot fail.
  */
  nodeDeleteCell(pRtree, pNode, iCell);

  /* If the node is not the tree root and now has less than the minimum
  ** number of cells, remove it from the tree. Otherwise, update the
  ** cell in the parent node so that it tightly contains the updated
  ** node.
  */

  pParent = pNode->pParent;
  assert( pParent || pNode->iNode==1 );
  if( pParent ){
    if( NCELL(pNode)<RTREE_MINCELLS(pRtree) ){

      rc = removeNode(pRtree, pNode, iHeight);
    }else{
      rc = fixBoundingBox(pRtree, pNode);
    }
  }

  return rc;
}

static int Reinsert(

        rc = rowidWrite(pRtree, p->iRowid, pNode->iNode);
      }else{
        rc = parentWrite(pRtree, p->iRowid, pNode->iNode);
      }
    }
  }
  if( rc==SQLITE_OK ){
    rc = fixBoundingBox(pRtree, pNode);
  }
  for(; rc==SQLITE_OK && ii<nCell; ii++){
    /* Find a node to store this cell in. pNode->iNode currently contains
    ** the height of the sub-tree headed by the cell.
    */
    RtreeNode *pInsert;
    RtreeCell *p = &aCell[aOrder[ii]];

      pRtree->iReinsertHeight = iHeight;
      rc = Reinsert(pRtree, pNode, pCell, iHeight);
    }
#else
    rc = SplitNode(pRtree, pNode, pCell, iHeight);
#endif
  }else{
    rc = AdjustTree(pRtree, pNode, pCell);
    if( rc==SQLITE_OK ){
      if( iHeight==0 ){
        rc = rowidWrite(pRtree, pCell->iRowid, pNode->iNode);
      }else{
        rc = parentWrite(pRtree, pCell->iRowid, pNode->iNode);
      }
    }
  }
  return rc;
}

static int reinsertNodeContent(Rtree *pRtree, RtreeNode *pNode){
  int ii;

  sqlite3_bind_null(pRtree->pWriteRowid, 2);
  sqlite3_step(pRtree->pWriteRowid);
  rc = sqlite3_reset(pRtree->pWriteRowid);
  *piRowid = sqlite3_last_insert_rowid(pRtree->db);
  return rc;
}











/*
** The xUpdate method for rtree module virtual tables.
*/
static int rtreeUpdate(
  sqlite3_vtab *pVtab, 
  int nData, 
  sqlite3_value **azData, 
  sqlite_int64 *pRowid
){
  Rtree *pRtree = (Rtree *)pVtab;
  int rc = SQLITE_OK;

  rtreeReference(pRtree);

  assert(nData>=1);


  /* If azData[0] is not an SQL NULL value, it is the rowid of a
  ** record to delete from the r-tree table. The following block does
  ** just that.
  */
  if( sqlite3_value_type(azData[0])!=SQLITE_NULL ){
    i64 iDelete;                /* The rowid to delete */

      iDelete = sqlite3_value_int64(azData[0]);
      rc = findLeafNode(pRtree, iDelete, &pLeaf);
    }

    /* Delete the cell in question from the leaf node. */
    if( rc==SQLITE_OK ){
      int rc2;
      rc = nodeRowidIndex(pRtree, pLeaf, iDelete, &iCell);
      if( rc==SQLITE_OK ){
        rc = deleteCell(pRtree, pLeaf, iCell, 0);
      }
      rc2 = nodeRelease(pRtree, pLeaf);
      if( rc==SQLITE_OK ){
        rc = rc2;
      }
    }

    /* Delete the corresponding entry in the <rtree>_rowid table. */

    ** it, schedule the contents of the child for reinsertion and 
    ** reduce the tree height by one.
    **
    ** This is equivalent to copying the contents of the child into
    ** the root node (the operation that Gutman's paper says to perform 
    ** in this scenario).
    */
    if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){
      int rc2;
      RtreeNode *pChild;
      i64 iChild = nodeGetRowid(pRtree, pRoot, 0);
      rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);
      if( rc==SQLITE_OK ){
        rc = removeNode(pRtree, pChild, pRtree->iDepth-1);
      }
      rc2 = nodeRelease(pRtree, pChild);
      if( rc==SQLITE_OK ) rc = rc2;
      if( rc==SQLITE_OK ){
        pRtree->iDepth--;
        writeInt16(pRoot->zData, pRtree->iDepth);
        pRoot->isDirty = 1;

      }
    }

    /* Re-insert the contents of any underfull nodes removed from the tree. */
    for(pLeaf=pRtree->pDeleted; pLeaf; pLeaf=pRtree->pDeleted){
      if( rc==SQLITE_OK ){
        rc = reinsertNodeContent(pRtree, pLeaf);

  char **pzErr,                       /* OUT: Error message, if any */
  int isCreate                        /* True for xCreate, false for xConnect */
){
  int rc = SQLITE_OK;
  Rtree *pRtree;
  int nDb;              /* Length of string argv[1] */
  int nName;            /* Length of string argv[2] */
  int eCoordType = (pAux ? RTREE_COORD_INT32 : RTREE_COORD_REAL32);

  const char *aErrMsg[] = {
    0,                                                    /* 0 */
    "Wrong number of columns for an rtree table",         /* 1 */
    "Too few columns for an rtree table",                 /* 2 */
    "Too many columns for an rtree table"                 /* 3 */
  };

/*
** Register the r-tree module with database handle db. This creates the
** virtual table module "rtree" and the debugging/analysis scalar 
** function "rtreenode".
*/
int sqlite3RtreeInit(sqlite3 *db){
  const int utf8 = SQLITE_UTF8;
  int rc;



  rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);

  if( rc==SQLITE_OK ){
    int utf8 = SQLITE_UTF8;
    rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
  }
  if( rc==SQLITE_OK ){
    void *c = (void *)RTREE_COORD_REAL32;
    rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);
  }
  if( rc==SQLITE_OK ){
    void *c = (void *)RTREE_COORD_INT32;
    rc = sqlite3_create_module_v2(db, "rtree_i32", &rtreeModule, c, 0);
  }

  return rc;
}

/*
** A version of sqlite3_free() that can be used as a callback. This is used
** in two places - as the destructor for the blob value returned by the
** invocation of a geometry function, and as the destructor for the geometry
** functions themselves.
*/
static void doSqlite3Free(void *p){
  sqlite3_free(p);
}

/*
** Each call to sqlite3_rtree_geometry_callback() creates an ordinary SQLite
** scalar user function. This C function is the callback used for all such
** registered SQL functions.
**
** The scalar user functions return a blob that is interpreted by r-tree
** table MATCH operators.
*/
static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
  RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);
  RtreeMatchArg *pBlob;
  int nBlob;

  nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(double);
  pBlob = (RtreeMatchArg *)sqlite3_malloc(nBlob);
  if( !pBlob ){
    sqlite3_result_error_nomem(ctx);
  }else{
    int i;
    pBlob->magic = RTREE_GEOMETRY_MAGIC;
    pBlob->xGeom = pGeomCtx->xGeom;
    pBlob->pContext = pGeomCtx->pContext;
    pBlob->nParam = nArg;
    for(i=0; i<nArg; i++){
      pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
    }
    sqlite3_result_blob(ctx, pBlob, nBlob, doSqlite3Free);
  }
}

/*
** Register a new geometry function for use with the r-tree MATCH operator.
*/
int sqlite3_rtree_geometry_callback(
  sqlite3 *db,
  const char *zGeom,
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *),
  void *pContext
){
  RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */

  /* Allocate and populate the context object. */
  pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
  if( !pGeomCtx ) return SQLITE_NOMEM;
  pGeomCtx->xGeom = xGeom;
  pGeomCtx->pContext = pContext;

  /* Create the new user-function. Register a destructor function to delete
  ** the context object when it is no longer required.  */
  return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY, 
      (void *)pGeomCtx, geomCallback, 0, 0, doSqlite3Free
  );
}

#if !SQLITE_CORE
int sqlite3_extension_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi)
  return sqlite3RtreeInit(db);
}
#endif

#endif

#
#***********************************************************************
#
# The focus of this file is testing the r-tree extension.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
}
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl

# Test plan:
#
#   rtree-1.*: Creating/destroying r-tree tables.

#
#***********************************************************************
#
# The focus of this file is testing the r-tree extension.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

set ::NROW   1000
set ::NDEL     10
set ::NSELECT 100

if {[info exists G(isquick)] && $G(isquick)} {
  set ::NROW 100
  set ::NSELECT 10
}

foreach module {rtree_i32 rtree} {
  for {set nDim 1} {$nDim <= 5} {incr nDim} {
  

#***********************************************************************
#
# The focus of this file is testing that the r-tree correctly handles
# out-of-memory conditions.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl
source $testdir/malloc_common.tcl
ifcapable !rtree {
  finish_test
  return
}

# Test summary:
#
#   rtree3-1: Test OOM in simple CREATE TABLE, INSERT, DELETE and SELECT 
#             commands on an almost empty table.


#
#   rtree3-2: Test OOM in a DROP TABLE command.

#
#   rtree3-3a: Test OOM during a transaction to insert 100 pseudo-random rows.
#
#   rtree3-3b: Test OOM during a transaction deleting all entries in the
#              database constructed in [rtree3-3a] in pseudo-random order.
#
#   rtree3-4a: OOM during "SELECT count(*) FROM ..." on a big table.
#
#   rtree3-4b: OOM while deleting rows from a big table.
#
#   rtree3-5: Test OOM while inserting rows into a big table.
#
#   rtree3-6: Test OOM while deleting all rows of a table, one at a time.
#
#   rtree3-7: OOM during an ALTER TABLE RENAME TABLE command.
#
#   rtree3-8: Test OOM while registering the r-tree module with sqlite.
#

do_faultsim_test rtree3-1 -faults oom* -prep {
  faultsim_delete_and_reopen
} -body {
  execsql {
    BEGIN TRANSACTION;
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
    INSERT INTO rt VALUES(NULL, 3, 5, 7, 9);
    INSERT INTO rt VALUES(NULL, 13, 15, 17, 19);
    DELETE FROM rt WHERE ii = 1;
    SELECT * FROM rt;
    SELECT ii FROM rt WHERE ii = 2;
    COMMIT;
  }
}

do_test rtree3-2.prep {
  faultsim_delete_and_reopen
  execsql {
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
    INSERT INTO rt VALUES(NULL, 3, 5, 7, 9);
  }
  faultsim_save_and_close
} {}
do_faultsim_test rtree3-2 -faults oom* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql { DROP TABLE rt } 
}


do_malloc_test rtree3-3.prep {
  faultsim_delete_and_reopen
  execsql {
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
    INSERT INTO rt VALUES(NULL, 3, 5, 7, 9);
  }
  faultsim_save_and_close
} {}

do_faultsim_test rtree3-3a -faults oom* -prep {
  faultsim_restore_and_reopen
} -body {
  db eval BEGIN
  for {set ii 0} {$ii < 100} {incr ii} {
    set f [expr rand()]
    db eval {INSERT INTO rt VALUES(NULL, $f*10.0, $f*10.0, $f*15.0, $f*15.0)}
  }
  db eval COMMIT
}
faultsim_save_and_close

do_faultsim_test rtree3-3b -faults oom* -prep {
  faultsim_restore_and_reopen
} -body {
  db eval BEGIN
  for {set ii 0} {$ii < 100} {incr ii} {
    set f [expr rand()]
    db eval { DELETE FROM rt WHERE x1<($f*10.0) AND x1>($f*10.5) }
  }
  db eval COMMIT
} 

do_test rtree3-4.prep {
  faultsim_delete_and_reopen
  execsql {
    BEGIN;
    PRAGMA page_size = 512;
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
  }
  for {set i 0} {$i < 1500} {incr i} {
    execsql { INSERT INTO rt VALUES($i, $i, $i+1, $i, $i+1) }
  }
  execsql { COMMIT }
  faultsim_save_and_close
} {}

do_faultsim_test rtree3-4a -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  db eval { SELECT count(*) FROM rt }
} -test {
  faultsim_test_result {0 1500}
}

do_faultsim_test rtree3-4b -faults oom-transient -prep {
  faultsim_restore_and_reopen
} -body {
  db eval { DELETE FROM rt WHERE ii BETWEEN 1 AND 100 }
} -test {
  faultsim_test_result {0 {}}
}

do_test rtree3-5.prep {
  faultsim_delete_and_reopen
  execsql {
    BEGIN;
    PRAGMA page_size = 512;
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
  }
  for {set i 0} {$i < 100} {incr i} {
    execsql { INSERT INTO rt VALUES($i, $i, $i+1, $i, $i+1) }
  }
  execsql { COMMIT }
  faultsim_save_and_close
} {}
do_faultsim_test rtree3-5 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  for {set i 100} {$i < 110} {incr i} {
    execsql { INSERT INTO rt VALUES($i, $i, $i+1, $i, $i+1) }
  }
} -test {
  faultsim_test_result {0 {}}
}

do_test rtree3-6.prep {
  faultsim_delete_and_reopen
  execsql {
    BEGIN;
    PRAGMA page_size = 512;
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2);
  }
  for {set i 0} {$i < 50} {incr i} {
    execsql { INSERT INTO rt VALUES($i, $i, $i+1, $i, $i+1) }
  }
  execsql { COMMIT }
  faultsim_save_and_close
} {}
do_faultsim_test rtree3-6 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql BEGIN
  for {set i 0} {$i < 50} {incr i} {
    execsql { DELETE FROM rt WHERE ii=$i }
  }
  execsql COMMIT
} -test {
  faultsim_test_result {0 {}}
}

do_test rtree3-7.prep {
  faultsim_delete_and_reopen
  execsql { CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2) }
  faultsim_save_and_close
} {}
do_faultsim_test rtree3-7 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql { ALTER TABLE rt RENAME TO rt2 }
} -test {
  faultsim_test_result {0 {}}
}

do_faultsim_test rtree3-8 -faults oom-* -prep {
  catch { db close }
} -body {
  sqlite3 db test.db
} 

do_faultsim_test rtree3-9 -faults oom-* -prep {
  sqlite3 db :memory:
} -body {
  set rc [register_cube_geom db]
  if {$rc != "SQLITE_OK"} { error $rc }
} -test {
  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
}

do_test rtree3-10.prep {
  faultsim_delete_and_reopen
  execsql { 
    CREATE VIRTUAL TABLE rt USING rtree(ii, x1, x2, y1, y2, z1, z2);
    INSERT INTO rt VALUES(1,  10, 10, 10, 11, 11, 11);
    INSERT INTO rt VALUES(2,  5, 6, 6, 7, 7, 8);
  }
  faultsim_save_and_close
} {}
do_faultsim_test rtree3-10 -faults oom-* -prep {
  faultsim_restore_and_reopen
  register_cube_geom db
  execsql { SELECT * FROM rt }
} -body {
  execsql { SELECT ii FROM rt WHERE ii MATCH cube(4.5, 5.5, 6.5, 1, 1, 1) }
} -test {
  faultsim_test_result {0 2}
}

finish_test

#
#***********************************************************************
#
# Randomized test cases for the rtree extension.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

set ::NROW 2500
if {[info exists G(isquick)] && $G(isquick)} {
  set ::NROW 250
}

# Return a floating point number between -X and X.
# 
proc rand {X} {
  return [expr {int((rand()-0.5)*1024.0*$X)/512.0}]

  # contained-within queries after each insert to verify that all
  # is well.
  #
  unset -nocomplain where
  for {set i 1} {$i<$::NROW} {incr i} {
    # Do a random insert
    #
    do_test rtree4-$nDim.2.$i.1 {
      set vlist {}
      for {set j 0} {$j<$nDim} {incr j} {
        set mn [rand 10000]
        set mx [expr {$mn+[randincr 50]}]
        lappend vlist $mn $mx
      }
      db eval "INSERT INTO rx VALUES(NULL, [join $vlist ,])"
      db eval "INSERT INTO bx VALUES(NULL, [join $vlist ,])"
    } {}

    # Do a contained-in query on all dimensions
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mn$j>=$mn mx$j<=$mx
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.2 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do an overlaps query on all dimensions
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mx$j>=$mn mn$j<=$mx
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.3 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do a contained-in query with surplus contraints at the beginning.
    # This should force a full-table scan on the rtree.
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      lappend where mn$j>-10000 mx$j<10000
    }
    for {set j 0} {$j<$nDim} {incr j} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mn$j>=$mn mx$j<=$mx
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.3 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do an overlaps query with surplus contraints at the beginning.
    # This should force a full-table scan on the rtree.
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      lappend where mn$j>=-10000 mx$j<=10000
    }
    for {set j 0} {$j<$nDim} {incr j} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mx$j>$mn mn$j<$mx
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.4 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do a contained-in query with surplus contraints at the end
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mn$j>=$mn mx$j<$mx
    }
    for {set j [expr {$nDim-1}]} {$j>=0} {incr j -1} {
      lappend where mn$j>=-10000 mx$j<10000
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.5 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do an overlaps query with surplus contraints at the end
    #
    set where {}
    for {set j [expr {$nDim-1}]} {$j>=0} {incr j -1} {
      set mn [rand 10000]
      set mx [expr {$mn+[randincr 500]}]
      lappend where mx$j>$mn mn$j<=$mx
    }
    for {set j 0} {$j<$nDim} {incr j} {
      lappend where mx$j>-10000 mn$j<=10000
    }
    set where "WHERE [join $where { AND }]"
    do_test rtree4-$nDim.2.$i.6 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do a contained-in query with surplus contraints where the 
    # constraints appear in a random order.
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      set mn1 [rand 10000]
      set mn2 [expr {$mn1+[randincr 100]}]
      set mx1 [expr {$mn2+[randincr 400]}]
      set mx2 [expr {$mx1+[randincr 100]}]
      lappend where mn$j>=$mn1 mn$j>$mn2 mx$j<$mx1 mx$j<=$mx2
    }
    set where "WHERE [join [scramble $where] { AND }]"
    do_test rtree4-$nDim.2.$i.7 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]

    # Do an overlaps query with surplus contraints where the
    # constraints appear in a random order.
    #
    set where {}
    for {set j 0} {$j<$nDim} {incr j} {
      set mn1 [rand 10000]
      set mn2 [expr {$mn1+[randincr 100]}]
      set mx1 [expr {$mn2+[randincr 400]}]
      set mx2 [expr {$mx1+[randincr 100]}]
      lappend where mx$j>=$mn1 mx$j>$mn2 mn$j<$mx1 mn$j<=$mx2
    }
    set where "WHERE [join [scramble $where] { AND }]"
    do_test rtree4-$nDim.2.$i.8 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]
  }

}

finish_test

#***********************************************************************
#
# The focus of this file is testing the r-tree extension when it is
# configured to store values as 32 bit integers.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# 
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

  rtree_strategy {SELECT * FROM t1,t2 WHERE k=ii AND x1<10}
} {Ca}

do_test rtree6-1.5 {
  rtree_strategy {SELECT * FROM t1,t2 WHERE k=+ii AND x1<10}
} {Ca}

do_eqp_test rtree6.2.1 {
  SELECT * FROM t1,t2 WHERE k=+ii AND x1<10
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}

}

do_eqp_test rtree6.2.2 {
  SELECT * FROM t1,t2 WHERE k=ii AND x1<10
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}

}

do_eqp_test rtree6.2.3 {
  SELECT * FROM t1,t2 WHERE k=ii
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}

}

do_eqp_test rtree6.2.4 {
  SELECT * FROM t1,t2 WHERE v=10 and x1<10 and x2>10
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:CaEb (~0 rows)} 
  0 1 1 {SCAN TABLE t2 (~100000 rows)}

}

do_eqp_test rtree6.2.5 {
  SELECT * FROM t1,t2 WHERE k=ii AND x1<v
} {
  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}

}

finish_test

# 
# Test that nothing goes wrong if an rtree table is created, then the
# database page-size is modified. At one point (3.6.22), this was causing
# malfunctions.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl

ifcapable !rtree||!vacuum {
  finish_test
  return
}

# 2010 February 16
#
# 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.
#
#***********************************************************************
# 
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

#-------------------------------------------------------------------------
# The following block of tests - rtree8-1.* - feature reading and writing
# an r-tree table while there exist open cursors on it.
#
proc populate_t1 {n} {
  execsql { DELETE FROM t1 }
  for {set i 1} {$i <= $n} {incr i} {
    execsql { INSERT INTO t1 VALUES($i, $i, $i+2) }
  }
}

# A DELETE while a cursor is reading the table.
#
do_test rtree8-1.1.1 {
  execsql { PRAGMA page_size = 512 }
  execsql { CREATE VIRTUAL TABLE t1 USING rtree_i32(id, x1, x2) }
  populate_t1 5
} {}
do_test rtree8-1.1.2 {
  set res [list]
  db eval { SELECT * FROM t1 } { 
    lappend res $x1 $x2
    if {$id==3} { db eval { DELETE FROM t1 WHERE id>3 } }
  }
  set res
} {1 3 2 4 3 5}
do_test rtree8-1.1.3 {
  execsql { SELECT * FROM t1 }
} {1 1 3 2 2 4 3 3 5}

# Many SELECTs on the same small table.
#
proc nested_select {n} {
  set ::max $n
  db eval { SELECT * FROM t1 } {
    if {$id == $n} { nested_select [expr $n+1] }
  }
  return $::max
}
do_test rtree8-1.2.1 { populate_t1 50  } {}
do_test rtree8-1.2.2 { nested_select 1 } {51}

# This test runs many SELECT queries simultaneously against a large 
# table, causing a collision in the hash-table used to store r-tree 
# nodes internally.
#
populate_t1 1500
do_execsql_test rtree8-1.3.1 { SELECT max(nodeno) FROM t1_node } {164}
do_test rtree8-1.3.2 {
  set rowids [execsql {SELECT min(rowid) FROM t1_rowid GROUP BY nodeno}]
  set stmt_list [list]
  foreach row $rowids {
    set stmt [sqlite3_prepare db "SELECT * FROM t1 WHERE id = $row" -1 tail]
    sqlite3_step $stmt
    lappend res_list [sqlite3_column_int $stmt 0]
    lappend stmt_list $stmt 
  }
} {}
do_test rtree8-1.3.3 { set res_list } $rowids
do_execsql_test rtree8-1.3.4 { SELECT count(*) FROM t1 } {1500}
do_test rtree8-1.3.5 { 
  foreach stmt $stmt_list { sqlite3_finalize $stmt }
} {}


#-------------------------------------------------------------------------
# The following block of tests - rtree8-2.* - test a couple of database
# corruption cases. In this case things are not corrupted at the b-tree
# level, but the contents of the various tables used internally by an
# r-tree table are inconsistent.
#
populate_t1 50
do_execsql_test rtree8-2.1.1 { SELECT max(nodeno) FROM t1_node } {5}
do_execsql_test rtree8-2.1.2 { DELETE FROM t1_node } {}
for {set i 1} {$i <= 50} {incr i} {
  do_catchsql_test rtree8-2.1.3.$i { 
    SELECT * FROM t1 WHERE id = $i 
  } {1 {database disk image is malformed}}
}
do_catchsql_test rtree8-2.1.4 { 
  SELECT * FROM t1
} {1 {database disk image is malformed}}
do_catchsql_test rtree8-2.1.5 { 
  DELETE FROM t1
} {1 {database disk image is malformed}}

do_execsql_test rtree8-2.1.6 { 
  DROP TABLE t1;
  CREATE VIRTUAL TABLE t1 USING rtree_i32(id, x1, x2);
} {}


populate_t1 50
do_execsql_test rtree8-2.2.1 {
  DELETE FROM t1_parent
} {}
do_catchsql_test rtree8-2.2.2 {
  DELETE FROM t1 WHERE id=25
} {1 {database disk image is malformed}}
do_execsql_test rtree8-2.2.3 { 
  DROP TABLE t1;
  CREATE VIRTUAL TABLE t1 USING rtree_i32(id, x1, x2);
} {}


#-------------------------------------------------------------------------
# Test that trying to use the MATCH operator with the r-tree module does
# not confuse it. 
#
populate_t1 10
do_catchsql_test rtree8-3.1 { 
  SELECT * FROM t1 WHERE x1 MATCH '1234'
} {1 {SQL logic error or missing database}}

#-------------------------------------------------------------------------
# Test a couple of invalid arguments to rtreedepth().
#
do_catchsql_test rtree8-4.1 {
  SELECT rtreedepth('hello world')
} {1 {Invalid argument to rtreedepth()}}
do_catchsql_test rtree8-4.2 {
  SELECT rtreedepth(X'00')
} {1 {Invalid argument to rtreedepth()}}


#-------------------------------------------------------------------------
# Delete half of a lopsided tree.
#
do_execsql_test rtree8-5.1 { 
  CREATE VIRTUAL TABLE t2 USING rtree_i32(id, x1, x2) 
} {}
do_test rtree8-5.2 {
  execsql BEGIN
  for {set i 0} {$i < 100} {incr i} {
    execsql { INSERT INTO t2 VALUES($i, 100, 101) }
  }
  for {set i 100} {$i < 200} {incr i} {
    execsql { INSERT INTO t2 VALUES($i, 1000, 1001) }
  }
  execsql COMMIT
} {}
do_test rtree8-5.3 {
  execsql BEGIN
  for {set i 0} {$i < 200} {incr i} {
    execsql { DELETE FROM t2 WHERE id = $i }
  }
  execsql COMMIT
} {}


finish_test