returned. If only one argument is passed, a pointer to the tokenizer
  implementation currently registered as <tokenizer-name> is returned,
  encoded as a blob. Or, if no such tokenizer exists, an SQL exception
  (error) is raised.

  SECURITY: If the fts3 extension is used in an environment where potentially
    malicious users may execute arbitrary SQL (i.e. gears), they should be
    prevented from invoking the fts3_tokenizer() function, possibly using the
    authorisation callback.
    prevented from invoking the fts3_tokenizer() function.  The
    fts3_tokenizer() function is disabled by default. It is only enabled
    by SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER. Do not enable it in
    security sensitive environments.

  See "Sample code" below for an example of calling the fts3_tokenizer()
  function from C code.

3. ICU Library Tokenizers

  If this extension is compiled with the SQLITE_ENABLE_ICU pre-processor 

#ifndef SQLITE_AMALGAMATION
# if defined(SQLITE_DEBUG)
int sqlite3Fts3Always(int b) { assert( b ); return b; }
int sqlite3Fts3Never(int b)  { assert( !b ); return b; }
# endif
#endif

/*
** This variable is set to false when running tests for which the on disk
** structures should not be corrupt. Otherwise, true. If it is false, extra
** assert() conditions in the fts3 code are activated - conditions that are
** only true if it is guaranteed that the fts3 database is not corrupt.
*/
int sqlite3_fts3_may_be_corrupt = 1;

/* 
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
** The number of bytes written is returned.
*/
int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
  unsigned char *q = (unsigned char *) p;
  sqlite_uint64 vu = v;
  do{
    *q++ = (unsigned char) ((vu & 0x7f) | 0x80);
    vu >>= 7;
  }while( vu!=0 );
  q[-1] &= 0x7f;  /* turn off high bit in final byte */
  assert( q - (unsigned char *)p <= FTS3_VARINT_MAX );
  return (int) (q - (unsigned char *)p);
}

#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
  v = (v & mask1) | ( (*ptr++) << shift );                    \
  v = (v & mask1) | ( (*(const unsigned char*)(ptr++)) << shift );  \
  if( (v & mask2)==0 ){ var = v; return ret; }
#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
  v = (*ptr++);                                               \
  if( (v & mask2)==0 ){ var = v; return ret; }

/* 
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read, or 0 on error.
** The value is stored in *v.
*/
int sqlite3Fts3GetVarint(const char *pBuf, sqlite_int64 *v){
int sqlite3Fts3GetVarintU(const char *pBuf, sqlite_uint64 *v){
  const unsigned char *p = (const unsigned char*)pBuf;
  const unsigned char *pStart = p;
  u32 a;
  u64 b;
  int shift;

  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
  b = (a & 0x0FFFFFFF );

  for(shift=28; shift<=63; shift+=7){
    u64 c = *p++;
    b += (c&0x7F) << shift;
    if( (c & 0x80)==0 ) break;
  }
  *v = b;
  return (int)(p - pStart);
}

/* 
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read, or 0 on error.
** The value is stored in *v.
*/
int sqlite3Fts3GetVarint(const char *pBuf, sqlite_int64 *v){
  return sqlite3Fts3GetVarintU(pBuf, (sqlite3_uint64*)v);
}

/* 
** Read a 64-bit variable-length integer from memory starting at p[0] and
** not extending past pEnd[-1].
** Return the number of bytes read, or 0 on error.
** The value is stored in *v.
*/
int sqlite3Fts3GetVarintBounded(
  const char *pBuf,
  const char *pEnd,
  sqlite_int64 *v
){
  const unsigned char *p = (const unsigned char*)pBuf;
  const unsigned char *pStart = p;
  const unsigned char *pX = (const unsigned char*)pEnd;
  u64 b = 0;
  int shift;
  for(shift=0; shift<=63; shift+=7){
    u64 c = p<pX ? *p : 0;
    p++;
    b += (c&0x7F) << shift;
    if( (c & 0x80)==0 ) break;
  }
  *v = b;
  return (int)(p - pStart);
}

/*
** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to 
** a non-negative 32-bit integer before it is returned.
*/
int sqlite3Fts3GetVarint32(const char *p, int *pi){
  const unsigned char *ptr = (const unsigned char*)p;
  u32 a;

#ifndef fts3GetVarint32
  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
  GETVARINT_INIT(a, ptr, 0,  0x00,     0x80, *pi, 1);
#else
  a = (*p++);
  a = (*ptr++);
  assert( a & 0x80 );
#endif

  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *pi, 2);
  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *pi, 3);
  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *pi, 4);
  GETVARINT_STEP(a, ptr, 7,  0x7F,     0x4000, *pi, 2);
  GETVARINT_STEP(a, ptr, 14, 0x3FFF,   0x200000, *pi, 3);
  GETVARINT_STEP(a, ptr, 21, 0x1FFFFF, 0x10000000, *pi, 4);
  a = (a & 0x0FFFFFFF );
  *pi = (int)(a | ((u32)(*p & 0x07) << 28));
  *pi = (int)(a | ((u32)(*ptr & 0x07) << 28));
  assert( 0==(a & 0x80000000) );
  assert( *pi>=0 );
  return 5;
}

/*
** Return the number of bytes required to encode v as a varint

static int fts3DestroyMethod(sqlite3_vtab *pVtab){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;              /* Return code */
  const char *zDb = p->zDb;        /* Name of database (e.g. "main", "temp") */
  sqlite3 *db = p->db;             /* Database handle */

  /* Drop the shadow tables */
  if( p->zContentTbl==0 ){
    fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_content'", zDb, p->zName);
  fts3DbExec(&rc, db, 
  }
  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segments'", zDb,p->zName);
  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segdir'", zDb, p->zName);
  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_docsize'", zDb, p->zName);
  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_stat'", zDb, p->zName);
    "DROP TABLE IF EXISTS %Q.'%q_segments';"
    "DROP TABLE IF EXISTS %Q.'%q_segdir';"
    "DROP TABLE IF EXISTS %Q.'%q_docsize';"
    "DROP TABLE IF EXISTS %Q.'%q_stat';"
    "%s DROP TABLE IF EXISTS %Q.'%q_content';",
    zDb, p->zName,
    zDb, p->zName,
    zDb, p->zName,
    zDb, p->zName,
    (p->zContentTbl ? "--" : ""), zDb,p->zName
  );

  /* If everything has worked, invoke fts3DisconnectMethod() to free the
  ** memory associated with the Fts3Table structure and return SQLITE_OK.
  ** Otherwise, return an SQLite error code.
  */
  return (rc==SQLITE_OK ? fts3DisconnectMethod(pVtab) : rc);
}

**     fts3QuoteId("un \"zip\"")   ->    "un \"\"zip\"\""
**
** The pointer returned points to memory obtained from sqlite3_malloc(). It
** is the callers responsibility to call sqlite3_free() to release this
** memory.
*/
static char *fts3QuoteId(char const *zInput){
  int nRet;
  sqlite3_int64 nRet;
  char *zRet;
  nRet = 2 + (int)strlen(zInput)*2 + 1;
  zRet = sqlite3_malloc(nRet);
  zRet = sqlite3_malloc64(nRet);
  if( zRet ){
    int i;
    char *z = zRet;
    *(z++) = '"';
    for(i=0; zInput[i]; i++){
      if( zInput[i]=='"' ) *(z++) = '"';
      *(z++) = zInput[i];

    const char *p;
    nIndex++;
    for(p=zParam; *p; p++){
      if( *p==',' ) nIndex++;
    }
  }

  aIndex = sqlite3_malloc(sizeof(struct Fts3Index) * nIndex);
  aIndex = sqlite3_malloc64(sizeof(struct Fts3Index) * nIndex);
  *apIndex = aIndex;
  if( !aIndex ){
    return SQLITE_NOMEM;
  }

  memset(aIndex, 0, sizeof(struct Fts3Index) * nIndex);
  if( zParam ){

      sqlite3Fts3ErrMsg(pzErr, "%s", sqlite3_errmsg(db));
    }
  }
  sqlite3_free(zSql);

  if( rc==SQLITE_OK ){
    const char **azCol;           /* Output array */
    int nStr = 0;                 /* Size of all column names (incl. 0x00) */
    sqlite3_int64 nStr = 0;       /* Size of all column names (incl. 0x00) */
    int nCol;                     /* Number of table columns */
    int i;                        /* Used to iterate through columns */

    /* Loop through the returned columns. Set nStr to the number of bytes of
    ** space required to store a copy of each column name, including the
    ** nul-terminator byte.  */
    nCol = sqlite3_column_count(pStmt);
    for(i=0; i<nCol; i++){
      const char *zCol = sqlite3_column_name(pStmt, i);
      nStr += (int)strlen(zCol) + 1;
      nStr += strlen(zCol) + 1;
    }

    /* Allocate and populate the array to return. */
    azCol = (const char **)sqlite3_malloc(sizeof(char *) * nCol + nStr);
    azCol = (const char **)sqlite3_malloc64(sizeof(char *) * nCol + nStr);
    if( azCol==0 ){
      rc = SQLITE_NOMEM;
    }else{
      char *p = (char *)&azCol[nCol];
      for(i=0; i<nCol; i++){
        const char *zCol = sqlite3_column_name(pStmt, i);
        int n = (int)strlen(zCol)+1;

  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 */
  sqlite3_int64 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 */

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

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

  nByte = sizeof(const char *) * (argc-2);
  aCol = (const char **)sqlite3_malloc(nByte);
  aCol = (const char **)sqlite3_malloc64(nByte);
  if( aCol ){
    memset((void*)aCol, 0, nByte);
    azNotindexed = (char **)sqlite3_malloc(nByte);
    azNotindexed = (char **)sqlite3_malloc64(nByte);
  }
  if( azNotindexed ){
    memset(azNotindexed, 0, nByte);
  }
  if( !aCol || !azNotindexed ){
    rc = SQLITE_NOMEM;
    goto fts3_init_out;

  nByte = sizeof(Fts3Table) +                  /* Fts3Table */
          nCol * sizeof(char *) +              /* azColumn */
          nIndex * sizeof(struct Fts3Index) +  /* aIndex */
          nCol * sizeof(u8) +                  /* abNotindexed */
          nName +                              /* zName */
          nDb +                                /* zDb */
          nString;                             /* Space for azColumn strings */
  p = (Fts3Table*)sqlite3_malloc(nByte);
  p = (Fts3Table*)sqlite3_malloc64(nByte);
  if( p==0 ){
    rc = SQLITE_NOMEM;
    goto fts3_init_out;
  }
  memset(p, 0, nByte);
  p->db = db;
  p->nColumn = nCol;

    p->bHasStat = 2;
  }

  /* Figure out the page-size for the database. This is required in order to
  ** estimate the cost of loading large doclists from the database.  */
  fts3DatabasePageSize(&rc, p);
  p->nNodeSize = p->nPgsz-35;

#if defined(SQLITE_DEBUG)||defined(SQLITE_TEST)
  p->nMergeCount = FTS3_MERGE_COUNT;
#endif

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

fts3_init_out:
  sqlite3_free(zPrefix);
  sqlite3_free(aIndex);

  int i;                          /* Iterator variable */
  int iCons = -1;                 /* Index of constraint to use */

  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
  int iIdx;

  if( p->bLock ){
    return SQLITE_ERROR;
  }

  /* By default use a full table scan. This is an expensive option,
  ** so search through the constraints to see if a more efficient 
  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 5000000;

    char *zSql;
    if( p->pSeekStmt ){
      pCsr->pStmt = p->pSeekStmt;
      p->pSeekStmt = 0;
    }else{
      zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);
      if( !zSql ) return SQLITE_NOMEM;
      p->bLock++;
      rc = sqlite3_prepare_v3(
      rc = sqlite3_prepare_v3(p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);
          p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
      );
      p->bLock--;
      sqlite3_free(zSql);
    }
    if( rc==SQLITE_OK ) pCsr->bSeekStmt = 1;
  }
  return rc;
}

/*
** Position the pCsr->pStmt statement so that it is on the row
** of the %_content table that contains the last match.  Return
** SQLITE_OK on success.  
*/
static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
  int rc = SQLITE_OK;
  if( pCsr->isRequireSeek ){
    rc = fts3CursorSeekStmt(pCsr);
    if( rc==SQLITE_OK ){
      Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
      pTab->bLock++;
      sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
      pCsr->isRequireSeek = 0;
      if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
        pTab->bLock--;
        return SQLITE_OK;
      }else{
        pTab->bLock--;
        rc = sqlite3_reset(pCsr->pStmt);
        if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
          /* If no row was found and no error has occurred, then the %_content
          ** table is missing a row that is present in the full-text index.
          ** The data structures are corrupt.  */
          rc = FTS_CORRUPT_VTAB;
          pCsr->isEof = 1;

  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 */
  i64 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.  
  **

    if( !isFirstTerm ){
      zCsr += fts3GetVarint32(zCsr, &nPrefix);
    }
    isFirstTerm = 0;
    zCsr += fts3GetVarint32(zCsr, &nSuffix);
    
    assert( nPrefix>=0 && nSuffix>=0 );
    if( &zCsr[nSuffix]>zEnd ){
    if( nPrefix>zCsr-zNode || nSuffix>zEnd-zCsr || nSuffix==0 ){
      rc = FTS_CORRUPT_VTAB;
      goto finish_scan;
    }
    if( nPrefix+nSuffix>nAlloc ){
    if( (i64)nPrefix+nSuffix>nAlloc ){
      char *zNew;
      nAlloc = (nPrefix+nSuffix) * 2;
      zNew = (char *)sqlite3_realloc(zBuffer, nAlloc);
      nAlloc = ((i64)nPrefix+nSuffix) * 2;
      zNew = (char *)sqlite3_realloc64(zBuffer, nAlloc);
      if( !zNew ){
        rc = SQLITE_NOMEM;
        goto finish_scan;
      }
      zBuffer = zNew;
    }
    assert( zBuffer );

  int rc = SQLITE_OK;             /* Return code */
  int iHeight;                    /* Height of this node in tree */

  assert( piLeaf || piLeaf2 );

  fts3GetVarint32(zNode, &iHeight);
  rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
  assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
  assert_fts3_nc( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );

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

    if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
      rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);
      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, 0);
    }
    if( rc==SQLITE_OK ){
      int iNewHeight = 0;
      fts3GetVarint32(zBlob, &iNewHeight);
      if( iNewHeight>=iHeight ){
        rc = FTS_CORRUPT_VTAB;
      }else{
      rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
        rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
      }
    }
    sqlite3_free(zBlob);
  }

  return rc;
}

    p += n;
    *pp = p;
  }
  *ppPoslist = pEnd;
}

/*
** Value used to signify the end of an position-list. This is safe because
** it is not possible to have a document with 2^31 terms.
** Value used to signify the end of an position-list. This must be
** as large or larger than any value that might appear on the
** position-list, even a position list that has been corrupted.
*/
#define POSITION_LIST_END 0x7fffffff
#define POSITION_LIST_END LARGEST_INT64

/*
** This function is used to help parse position-lists. When this function is
** called, *pp may point to the start of the next varint in the position-list
** being parsed, or it may point to 1 byte past the end of the position-list
** (in which case **pp will be a terminator bytes POS_END (0) or
** (1)).

/*
** Compute the union of two position lists.  The output written
** into *pp contains all positions of both *pp1 and *pp2 in sorted
** order and with any duplicates removed.  All pointers are
** updated appropriately.   The caller is responsible for insuring
** that there is enough space in *pp to hold the complete output.
*/
static void fts3PoslistMerge(
static int fts3PoslistMerge(
  char **pp,                      /* Output buffer */
  char **pp1,                     /* Left input list */
  char **pp2                      /* Right input list */
){
  char *p = *pp;
  char *p1 = *pp1;
  char *p2 = *pp2;

  while( *p1 || *p2 ){
    int iCol1;         /* The current column index in pp1 */
    int iCol2;         /* The current column index in pp2 */

    if( *p1==POS_COLUMN ) fts3GetVarint32(&p1[1], &iCol1);
    else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;
    if( *p1==POS_COLUMN ){ 
      fts3GetVarint32(&p1[1], &iCol1);
      if( iCol1==0 ) return FTS_CORRUPT_VTAB;
    }
    else if( *p1==POS_END ) iCol1 = 0x7fffffff;
    else iCol1 = 0;

    if( *p2==POS_COLUMN ) fts3GetVarint32(&p2[1], &iCol2);
    else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;
    if( *p2==POS_COLUMN ){
      fts3GetVarint32(&p2[1], &iCol2);
      if( iCol2==0 ) return FTS_CORRUPT_VTAB;
    }
    else if( *p2==POS_END ) iCol2 = 0x7fffffff;
    else iCol2 = 0;

    if( iCol1==iCol2 ){
      sqlite3_int64 i1 = 0;       /* Last position from pp1 */
      sqlite3_int64 i2 = 0;       /* Last position from pp2 */
      sqlite3_int64 iPrev = 0;
      int n = fts3PutColNumber(&p, iCol1);

    }
  }

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

/*
** 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:

      sqlite3_int64 iPos2 = 0;

      if( iCol1 ){
        *p++ = POS_COLUMN;
        p += sqlite3Fts3PutVarint(p, iCol1);
      }

      assert( *p1!=POS_END && *p1!=POS_COLUMN );
      assert( *p2!=POS_END && *p2!=POS_COLUMN );
      fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
      fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
      if( iPos1<0 || iPos2<0 ) break;

      while( 1 ){
        if( iPos2==iPos1+nToken 
         || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken) 
        ){
          sqlite3_int64 iSave;
          iSave = isSaveLeft ? iPos1 : iPos2;

  char *pEnd,                     /* End of buffer */
  int bDescIdx,                   /* True if docids are descending */
  sqlite3_int64 *pVal             /* IN/OUT: Integer value */
){
  if( *pp>=pEnd ){
    *pp = 0;
  }else{
    sqlite3_int64 iVal;
    *pp += sqlite3Fts3GetVarint(*pp, &iVal);
    u64 iVal;
    *pp += sqlite3Fts3GetVarintU(*pp, &iVal);
    if( bDescIdx ){
      *pVal -= iVal;
      *pVal = (i64)((u64)*pVal - iVal);
    }else{
      *pVal += iVal;
      *pVal = (i64)((u64)*pVal + iVal);
    }
  }
}

/*
** This function is used to write a single varint to a buffer. The varint
** is written to *pp. Before returning, *pp is set to point 1 byte past the

static void fts3PutDeltaVarint3(
  char **pp,                      /* IN/OUT: Output pointer */
  int bDescIdx,                   /* True for descending docids */
  sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */
  int *pbFirst,                   /* IN/OUT: True after first int written */
  sqlite3_int64 iVal              /* Write this value to the list */
){
  sqlite3_int64 iWrite;
  sqlite3_uint64 iWrite;
  if( bDescIdx==0 || *pbFirst==0 ){
    assert_fts3_nc( *pbFirst==0 || iVal>=*piPrev );
    iWrite = iVal - *piPrev;
    iWrite = (u64)iVal - (u64)*piPrev;
  }else{
    assert_fts3_nc( *piPrev>=iVal );
    iWrite = *piPrev - iVal;
    iWrite = (u64)*piPrev - (u64)iVal;
  }
  assert( *pbFirst || *piPrev==0 );
  assert( *pbFirst==0 || iWrite>0 );
  assert_fts3_nc( *pbFirst==0 || iWrite>0 );
  *pp += sqlite3Fts3PutVarint(*pp, iWrite);
  *piPrev = iVal;
  *pbFirst = 1;
}


/*
** This macro is used by various functions that merge doclists. The two
** arguments are 64-bit docid values. If the value of the stack variable
** bDescDoclist is 0 when this macro is invoked, then it returns (i1-i2). 
** Otherwise, (i2-i1).
**
** Using this makes it easier to write code that can merge doclists that are
** sorted in either ascending or descending order.
*/
/* #define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i64)((u64)i1-i2)) */
#define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i1-i2))
#define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i1>i2?1:((i1==i2)?0:-1)))

/*
** This function does an "OR" merge of two doclists (output contains all
** positions contained in either argument doclist). If the docids in the 
** input doclists are sorted in ascending order, parameter bDescDoclist
** should be false. If they are sorted in ascending order, it should be
** passed a non-zero value.

*/
static int fts3DoclistOrMerge(
  int bDescDoclist,               /* True if arguments are desc */
  char *a1, int n1,               /* First doclist */
  char *a2, int n2,               /* Second doclist */
  char **paOut, int *pnOut        /* OUT: Malloc'd doclist */
){
  int rc = SQLITE_OK;
  sqlite3_int64 i1 = 0;
  sqlite3_int64 i2 = 0;
  sqlite3_int64 iPrev = 0;
  char *pEnd1 = &a1[n1];
  char *pEnd2 = &a2[n2];
  char *p1 = a1;
  char *p2 = a2;

  ** The space required to store the output is therefore the sum of the
  ** sizes of the two inputs, plus enough space for exactly one of the input
  ** docids to grow. 
  **
  ** A symetric argument may be made if the doclists are in descending 
  ** order.
  */
  aOut = sqlite3_malloc(n1+n2+FTS3_VARINT_MAX-1);
  aOut = sqlite3_malloc64((i64)n1+n2+FTS3_VARINT_MAX-1+FTS3_BUFFER_PADDING);
  if( !aOut ) return SQLITE_NOMEM;

  p = aOut;
  fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
  fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
  while( p1 || p2 ){
    sqlite3_int64 iDiff = DOCID_CMP(i1, i2);

    if( p2 && p1 && iDiff==0 ){
      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
      fts3PoslistMerge(&p, &p1, &p2);
      rc = fts3PoslistMerge(&p, &p1, &p2);
      if( rc ) break;
      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
    }else if( !p2 || (p1 && iDiff<0) ){
      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
      fts3PoslistCopy(&p, &p1);
      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
    }else{
      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i2);
      fts3PoslistCopy(&p, &p2);
      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
    }
  }

    
    assert( (p-aOut)<=((p1?(p1-a1):n1)+(p2?(p2-a2):n2)+FTS3_VARINT_MAX-1) );
  }

  if( rc!=SQLITE_OK ){
    sqlite3_free(aOut);
    p = aOut = 0;
  }else{
    assert( (p-aOut)<=n1+n2+FTS3_VARINT_MAX-1 );
    memset(&aOut[(p-aOut)], 0, FTS3_BUFFER_PADDING);
  }
  *paOut = aOut;
  *pnOut = (int)(p-aOut);
  assert( *pnOut<=n1+n2+FTS3_VARINT_MAX-1 );
  return SQLITE_OK;
  return rc;
}

/*
** This function does a "phrase" merge of two doclists. In a phrase merge,
** the output contains a copy of each position from the right-hand input
** doclist for which there is a position in the left-hand input doclist
** exactly nDist tokens before it.

  char *p2 = aRight;
  char *p;
  int bFirstOut = 0;
  char *aOut;

  assert( nDist>0 );
  if( bDescDoclist ){
    aOut = sqlite3_malloc(*pnRight + FTS3_VARINT_MAX);
    aOut = sqlite3_malloc64((sqlite3_int64)*pnRight + FTS3_VARINT_MAX);
    if( aOut==0 ) return SQLITE_NOMEM;
  }else{
    aOut = aRight;
  }
  p = aOut;

  fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);

    **
    ** Similar padding is added in the fts3DoclistOrMerge() function.
    */
    pTS->aaOutput[0] = sqlite3_malloc(nDoclist + FTS3_VARINT_MAX + 1);
    pTS->anOutput[0] = nDoclist;
    if( pTS->aaOutput[0] ){
      memcpy(pTS->aaOutput[0], aDoclist, nDoclist);
      memset(&pTS->aaOutput[0][nDoclist], 0, FTS3_VARINT_MAX);
    }else{
      return SQLITE_NOMEM;
    }
  }else{
    char *aMerge = aDoclist;
    int nMerge = nDoclist;
    int iOut;

*/
static int fts3SegReaderCursorAppend(
  Fts3MultiSegReader *pCsr, 
  Fts3SegReader *pNew
){
  if( (pCsr->nSegment%16)==0 ){
    Fts3SegReader **apNew;
    int nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);
    apNew = (Fts3SegReader **)sqlite3_realloc(pCsr->apSegment, nByte);
    sqlite3_int64 nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);
    apNew = (Fts3SegReader **)sqlite3_realloc64(pCsr->apSegment, nByte);
    if( !apNew ){
      sqlite3Fts3SegReaderFree(pNew);
      return SQLITE_NOMEM;
    }
    pCsr->apSegment = apNew;
  }
  pCsr->apSegment[pCsr->nSegment++] = pNew;

  /* If iLevel is less than 0 and this is not a scan, include a seg-reader 
  ** for the pending-terms. If this is a scan, then this call must be being
  ** made by an fts4aux module, not an FTS table. In this case calling
  ** Fts3SegReaderPending might segfault, as the data structures used by 
  ** fts4aux are not completely populated. So it's easiest to filter these
  ** calls out here.  */
  if( iLevel<0 && p->aIndex ){
  if( iLevel<0 && p->aIndex && p->iPrevLangid==iLangid ){
    Fts3SegReader *pSeg = 0;
    rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix||isScan, &pSeg);
    if( rc==SQLITE_OK && pSeg ){
      rc = fts3SegReaderCursorAppend(pCsr, pSeg);
    }
  }

      sqlite3_int64 iLeavesEndBlock = sqlite3_column_int64(pStmt, 2);
      sqlite3_int64 iEndBlock = sqlite3_column_int64(pStmt, 3);
      int nRoot = sqlite3_column_bytes(pStmt, 4);
      char const *zRoot = sqlite3_column_blob(pStmt, 4);

      /* If zTerm is not NULL, and this segment is not stored entirely on its
      ** root node, the range of leaves scanned can be reduced. Do this. */
      if( iStartBlock && zTerm ){
      if( iStartBlock && zTerm && zRoot ){
        sqlite3_int64 *pi = (isPrefix ? &iLeavesEndBlock : 0);
        rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &iStartBlock, pi);
        if( rc!=SQLITE_OK ) goto finished;
        if( isPrefix==0 && isScan==0 ) iLeavesEndBlock = iStartBlock;
      }
 
      rc = sqlite3Fts3SegReaderNew(pCsr->nSegment+1, 

** 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 rc;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
  if( pCsr->eSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){
    Fts3Table *pTab = (Fts3Table*)pCursor->pVtab;
    pTab->bLock++;
    if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
      pCsr->isEof = 1;
      rc = sqlite3_reset(pCsr->pStmt);
    }else{
      pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
      rc = SQLITE_OK;
    }
    pTab->bLock--;
  }else{
    rc = fts3EvalNext((Fts3Cursor *)pCursor);
  }
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  return rc;
}

/*
** The following are copied from sqliteInt.h.
**
** Constants for the largest and smallest possible 64-bit signed integers.
** These macros are designed to work correctly on both 32-bit and 64-bit
** compilers.
*/
#ifndef SQLITE_AMALGAMATION
# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** If the numeric type of argument pVal is "integer", then return it
** converted to a 64-bit signed integer. Otherwise, return a copy of
** the second parameter, iDefault.
*/
static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
  if( pVal ){

  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
  int iIdx;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  if( p->bLock ){
    return SQLITE_ERROR;
  }

  eSearch = (idxNum & 0x0000FFFF);
  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( p->pSegments==0 );

  /* Collect arguments into local variables */
  iIdx = 0;

      );
    }else{
      zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s", 
          p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
      );
    }
    if( zSql ){
      p->bLock++;
      rc = sqlite3_prepare_v3(
      rc = sqlite3_prepare_v3(p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);
          p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
      );
      p->bLock--;
      sqlite3_free(zSql);
    }else{
      rc = SQLITE_NOMEM;
    }
  }else if( eSearch==FTS3_DOCID_SEARCH ){
    rc = fts3CursorSeekStmt(pCsr);
    if( rc==SQLITE_OK ){

**
** Flush the contents of the pending-terms table to disk.
*/
static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
  int rc = SQLITE_OK;
  UNUSED_PARAMETER(iSavepoint);
  assert( ((Fts3Table *)pVtab)->inTransaction );
  assert( ((Fts3Table *)pVtab)->mxSavepoint < iSavepoint );
  assert( ((Fts3Table *)pVtab)->mxSavepoint <= iSavepoint );
  TESTONLY( ((Fts3Table *)pVtab)->mxSavepoint = iSavepoint );
  if( ((Fts3Table *)pVtab)->bIgnoreSavepoint==0 ){
    rc = fts3SyncMethod(pVtab);
  }
  return rc;
}

**
** Discard the contents of the pending terms table.
*/
static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
  Fts3Table *p = (Fts3Table*)pVtab;
  UNUSED_PARAMETER(iSavepoint);
  assert( p->inTransaction );
  assert( p->mxSavepoint >= iSavepoint );
  TESTONLY( p->mxSavepoint = iSavepoint );
  sqlite3Fts3PendingTermsClear(p);
  return SQLITE_OK;
}

static const sqlite3_module fts3Module = {
  /* iVersion      */ 2,
  /* iVersion      */ 3,
  /* xCreate       */ fts3CreateMethod,
  /* xConnect      */ fts3ConnectMethod,
  /* xBestIndex    */ fts3BestIndexMethod,
  /* xDisconnect   */ fts3DisconnectMethod,
  /* xDestroy      */ fts3DestroyMethod,
  /* xOpen         */ fts3OpenMethod,
  /* xClose        */ fts3CloseMethod,

    ){
      rc = SQLITE_NOMEM;
    }
  }

#ifdef SQLITE_TEST
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3ExprInitTestInterface(db);
    rc = sqlite3Fts3ExprInitTestInterface(db, pHash);
  }
#endif

  /* Create the virtual table wrapper around the hash-table and overload 
  ** the four scalar functions. If this is successful, register the
  ** module with sqlite.
  */

    }
    assert( pToken->pSegcsr==0 );
  }

  return rc;
}

#ifndef SQLITE_DISABLE_FTS4_DEFERRED
/*
** This function is called on each phrase after the position lists for
** any deferred tokens have been loaded into memory. It updates the phrases
** current position list to include only those positions that are really
** instances of the phrase (after considering deferred tokens). If this
** means that the phrase does not appear in the current row, doclist.pList
** and doclist.nList are both zeroed.

      }
      sqlite3_free(aPoslist);
    }
  }

  return SQLITE_OK;
}
#endif /* SQLITE_DISABLE_FTS4_DEFERRED */

/*
** Maximum number of tokens a phrase may have to be considered for the
** incremental doclists strategy.
*/
#define MAX_INCR_PHRASE_TOKENS 4

  ** scanned in forward order, and the phrase consists of 
  ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
  ** tokens or prefix tokens that cannot use a prefix-index.  */
  int bHaveIncr = 0;
  int bIncrOk = (bOptOk 
   && pCsr->bDesc==pTab->bDescIdx 
   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
#ifdef SQLITE_TEST
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   && pTab->bNoIncrDoclist==0
#endif
  );
  for(i=0; bIncrOk==1 && i<p->nToken; i++){
    Fts3PhraseToken *pToken = &p->aToken[i];
    if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
      bIncrOk = 0;

*/
static void fts3EvalDlPhraseNext(
  Fts3Table *pTab,
  Fts3Doclist *pDL,
  u8 *pbEof
){
  char *pIter;                            /* Used to iterate through aAll */
  char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
  char *pEnd;                             /* 1 byte past end of aAll */
 
  if( pDL->pNextDocid ){
    pIter = pDL->pNextDocid;
    assert( pDL->aAll!=0 || pIter==0 );
  }else{
    pIter = pDL->aAll;
  }

  if( pIter>=pEnd ){
  if( pIter==0 || pIter>=(pEnd = pDL->aAll + pDL->nAll) ){
    /* We have already reached the end of this doclist. EOF. */
    *pbEof = 1;
  }else{
    sqlite3_int64 iDelta;
    pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
    if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
      pDL->iDocid += iDelta;

        }
      }

      /* Check if the current entries really are a phrase match */
      if( bEof==0 ){
        int nList = 0;
        int nByte = a[p->nToken-1].nList;
        char *aDoclist = sqlite3_malloc(nByte+1);
        char *aDoclist = sqlite3_malloc(nByte+FTS3_BUFFER_PADDING);
        if( !aDoclist ) return SQLITE_NOMEM;
        memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);
        memset(&aDoclist[nByte], 0, FTS3_BUFFER_PADDING);

        for(i=0; i<(p->nToken-1); i++){
          if( a[i].bIgnore==0 ){
            char *pL = a[i].pList;
            char *pR = aDoclist;
            char *pOut = aDoclist;
            int nDist = p->nToken-1-i;

    sqlite3_int64 nByte = 0;
    const char *pEnd;
    const char *a;

    rc = sqlite3Fts3SelectDoctotal(p, &pStmt);
    if( rc!=SQLITE_OK ) return rc;
    a = sqlite3_column_blob(pStmt, 0);
    testcase( a==0 );  /* If %_stat.value set to X'' */
    assert( a );
    if( a ){

    pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
    a += sqlite3Fts3GetVarint(a, &nDoc);
    while( a<pEnd ){
      a += sqlite3Fts3GetVarint(a, &nByte);
      pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
      a += sqlite3Fts3GetVarintBounded(a, pEnd, &nDoc);
      while( a<pEnd ){
        a += sqlite3Fts3GetVarintBounded(a, pEnd, &nByte);
      }
    }
    if( nDoc==0 || nByte==0 ){
      sqlite3_reset(pStmt);
      return FTS_CORRUPT_VTAB;
    }

    pCsr->nDoc = nDoc;

  fts3EvalAllocateReaders(pCsr, pCsr->pExpr, &nToken, &nOr, &rc);

  /* Determine which, if any, tokens in the expression should be deferred. */
#ifndef SQLITE_DISABLE_FTS4_DEFERRED
  if( rc==SQLITE_OK && nToken>1 && pTab->bFts4 ){
    Fts3TokenAndCost *aTC;
    Fts3Expr **apOr;
    aTC = (Fts3TokenAndCost *)sqlite3_malloc(
    aTC = (Fts3TokenAndCost *)sqlite3_malloc64(
        sizeof(Fts3TokenAndCost) * nToken
      + sizeof(Fts3Expr *) * nOr * 2
    );
    apOr = (Fts3Expr **)&aTC[nToken];

    if( !aTC ){
      rc = SQLITE_NOMEM;

  ** no exceptions to this - it's the way the parser in fts3_expr.c works.
  */
  if( *pRc==SQLITE_OK 
   && pExpr->eType==FTSQUERY_NEAR 
   && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
  ){
    Fts3Expr *p; 
    int nTmp = 0;                 /* Bytes of temp space */
    sqlite3_int64 nTmp = 0;       /* Bytes of temp space */
    char *aTmp;                   /* Temp space for PoslistNearMerge() */

    /* Allocate temporary working space. */
    for(p=pExpr; p->pLeft; p=p->pLeft){
      assert( p->pRight->pPhrase->doclist.nList>0 );
      nTmp += p->pRight->pPhrase->doclist.nList;
    }
    nTmp += p->pPhrase->doclist.nList;
    aTmp = sqlite3_malloc(nTmp*2);
    aTmp = sqlite3_malloc64(nTmp*2);
    if( !aTmp ){
      *pRc = SQLITE_NOMEM;
      res = 0;
    }else{
      char *aPoslist = p->pPhrase->doclist.pList;
      int nToken = p->pPhrase->nToken;

** After allocating the Fts3Expr.aMI[] array for each phrase in the 
** expression rooted at pExpr, the cursor iterates through all rows matched
** by pExpr, calling this function for each row. This function increments
** the values in Fts3Expr.aMI[] according to the position-list currently
** found in Fts3Expr.pPhrase->doclist.pList for each of the phrase 
** expression nodes.
*/
static void fts3EvalUpdateCounts(Fts3Expr *pExpr){
static void fts3EvalUpdateCounts(Fts3Expr *pExpr, int nCol){
  if( pExpr ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    if( pPhrase && pPhrase->doclist.pList ){
      int iCol = 0;
      char *p = pPhrase->doclist.pList;

      assert( *p );
      while( 1 ){
      do{
        u8 c = 0;
        int iCnt = 0;
        while( 0xFE & (*p | c) ){
          if( (c&0x80)==0 ) iCnt++;
          c = *p++ & 0x80;
        }

        /* aMI[iCol*3 + 1] = Number of occurrences
        ** aMI[iCol*3 + 2] = Number of rows containing at least one instance
        */
        pExpr->aMI[iCol*3 + 1] += iCnt;
        pExpr->aMI[iCol*3 + 2] += (iCnt>0);
        if( *p==0x00 ) break;
        p++;
        p += fts3GetVarint32(p, &iCol);
      }
      }while( iCol<nCol );
    }

    fts3EvalUpdateCounts(pExpr->pLeft);
    fts3EvalUpdateCounts(pExpr->pRight);
    fts3EvalUpdateCounts(pExpr->pLeft, nCol);
    fts3EvalUpdateCounts(pExpr->pRight, nCol);
  }
}

/*
** Expression pExpr must be of type FTSQUERY_PHRASE.
**
** If it is not already allocated and populated, this function allocates and

    bEof = pRoot->bEof;
    assert( pRoot->bStart );

    /* Allocate space for the aMSI[] array of each FTSQUERY_PHRASE node */
    for(p=pRoot; p; p=p->pLeft){
      Fts3Expr *pE = (p->eType==FTSQUERY_PHRASE?p:p->pRight);
      assert( pE->aMI==0 );
      pE->aMI = (u32 *)sqlite3_malloc(pTab->nColumn * 3 * sizeof(u32));
      pE->aMI = (u32 *)sqlite3_malloc64(pTab->nColumn * 3 * sizeof(u32));
      if( !pE->aMI ) return SQLITE_NOMEM;
      memset(pE->aMI, 0, pTab->nColumn * 3 * sizeof(u32));
    }

    fts3EvalRestart(pCsr, pRoot, &rc);

    while( pCsr->isEof==0 && rc==SQLITE_OK ){

        pCsr->iPrevId = pRoot->iDocid;
      }while( pCsr->isEof==0 
           && pRoot->eType==FTSQUERY_NEAR 
           && sqlite3Fts3EvalTestDeferred(pCsr, &rc) 
      );

      if( rc==SQLITE_OK && pCsr->isEof==0 ){
        fts3EvalUpdateCounts(pRoot);
        fts3EvalUpdateCounts(pRoot, pTab->nColumn);
      }
    }

    pCsr->isEof = 0;
    pCsr->iPrevId = iPrevId;

    if( bEof ){

/*
** Maximum length of a varint encoded integer. The varint format is different
** from that used by SQLite, so the maximum length is 10, not 9.
*/
#define FTS3_VARINT_MAX 10

#define FTS3_BUFFER_PADDING 8

/*
** FTS4 virtual tables may maintain multiple indexes - one index of all terms
** in the document set and zero or more prefix indexes. All indexes are stored
** as one or more b+-trees in the %_segments and %_segdir tables. 
**
** It is possible to determine which index a b+-tree belongs to based on the
** value stored in the "%_segdir.level" column. Given this value L, the index

/*
** Terminator values for position-lists and column-lists.
*/
#define POS_COLUMN  (1)     /* Column-list terminator */
#define POS_END     (0)     /* Position-list terminator */ 

/*
** The assert_fts3_nc() macro is similar to the assert() macro, except that it
** is used for assert() conditions that are true only if it can be 
** guranteed that the database is not corrupt.
*/
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
extern int sqlite3_fts3_may_be_corrupt;
# define assert_fts3_nc(x) assert(sqlite3_fts3_may_be_corrupt || (x))
#else
# define assert_fts3_nc(x) assert(x)
#endif

/*
** This section provides definitions to allow the
** FTS3 extension to be compiled outside of the 
** amalgamation.
*/
#ifndef SQLITE_AMALGAMATION
/*

*/
#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
# define TESTONLY(X)  X
#else
# define TESTONLY(X)
#endif

#define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
#define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)

#endif /* SQLITE_AMALGAMATION */

#ifdef SQLITE_DEBUG
int sqlite3Fts3Corrupt(void);
# define FTS_CORRUPT_VTAB sqlite3Fts3Corrupt()
#else
# define FTS_CORRUPT_VTAB SQLITE_CORRUPT_VTAB

  char **azColumn;                /* column names.  malloced */
  u8 *abNotindexed;               /* True for 'notindexed' columns */
  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
  char *zContentTbl;              /* content=xxx option, or NULL */
  char *zLanguageid;              /* languageid=xxx option, or NULL */
  int nAutoincrmerge;             /* Value configured by 'automerge' */
  u32 nLeafAdd;                   /* Number of leaf blocks added this trans */
  int bLock;                      /* Used to prevent recursive content= tbls */

  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[40];
  sqlite3_stmt *pSeekStmt;        /* Cache for fts3CursorSeekStmt() */

  ** values do not contribute to FTS functionality; they are used for
  ** verifying the operation of the SQLite core.
  */
  int inTransaction;     /* True after xBegin but before xCommit/xRollback */
  int mxSavepoint;       /* Largest valid xSavepoint integer */
#endif

#ifdef SQLITE_TEST
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /* True to disable the incremental doclist optimization. This is controled
  ** by special insert command 'test-no-incr-doclist'.  */
  int bNoIncrDoclist;

  /* Number of segments in a level */
  int nMergeCount;
#endif
};

/* Macro to find the number of segments to merge */
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
# define MergeCount(P) ((P)->nMergeCount)
#else
# define MergeCount(P) FTS3_MERGE_COUNT
#endif

/*
** When the core wants to read from the virtual table, it creates a
** virtual table cursor (an instance of the following structure) using
** the xOpen method. Cursors are destroyed using the xClose method.
*/
struct Fts3Cursor {

  (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \
)

/* fts3.c */
void sqlite3Fts3ErrMsg(char**,const char*,...);
int sqlite3Fts3PutVarint(char *, sqlite3_int64);
int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
int sqlite3Fts3GetVarintU(const char *, sqlite_uint64 *);
int sqlite3Fts3GetVarintBounded(const char*,const char*,sqlite3_int64*);
int sqlite3Fts3GetVarint32(const char *, int *);
int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);
void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
void sqlite3Fts3CreateStatTable(int*, Fts3Table*);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
  char **, int, int, int, const char *, int, Fts3Expr **, char **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db, Fts3Hash*);
int sqlite3Fts3InitTerm(sqlite3 *db);
#endif

int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
  sqlite3_tokenizer_cursor **
);

  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
){
  char const *zDb;                /* Name of database (e.g. "main") */
  char const *zFts3;              /* Name of fts3 table */
  int nDb;                        /* Result of strlen(zDb) */
  int nFts3;                      /* Result of strlen(zFts3) */
  int nByte;                      /* Bytes of space to allocate here */
  sqlite3_int64 nByte;            /* Bytes of space to allocate here */
  int rc;                         /* value returned by declare_vtab() */
  Fts3auxTable *p;                /* Virtual table object to return */

  UNUSED_PARAMETER(pUnused);

  /* The user should invoke this in one of two forms:
  **

  }
  nFts3 = (int)strlen(zFts3);

  rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA);
  if( rc!=SQLITE_OK ) return rc;

  nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
  p = (Fts3auxTable *)sqlite3_malloc(nByte);
  p = (Fts3auxTable *)sqlite3_malloc64(nByte);
  if( !p ) return SQLITE_NOMEM;
  memset(p, 0, nByte);

  p->pFts3Tab = (Fts3Table *)&p[1];
  p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1];
  p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1];
  p->pFts3Tab->db = db;

  sqlite3_free(pCsr);
  return SQLITE_OK;
}

static int fts3auxGrowStatArray(Fts3auxCursor *pCsr, int nSize){
  if( nSize>pCsr->nStat ){
    struct Fts3auxColstats *aNew;
    aNew = (struct Fts3auxColstats *)sqlite3_realloc(pCsr->aStat, 
    aNew = (struct Fts3auxColstats *)sqlite3_realloc64(pCsr->aStat, 
        sizeof(struct Fts3auxColstats) * nSize
    );
    if( aNew==0 ) return SQLITE_NOMEM;
    memset(&aNew[pCsr->nStat], 0, 
        sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat)
    );
    pCsr->aStat = aNew;

  if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;

  if( iEq>=0 || iGe>=0 ){
    const unsigned char *zStr = sqlite3_value_text(apVal[0]);
    assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) );
    if( zStr ){
      pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);
      pCsr->filter.nTerm = sqlite3_value_bytes(apVal[0]);
      if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;
      pCsr->filter.nTerm = (int)strlen(pCsr->filter.zTerm);
    }
  }

  if( iLe>=0 ){
    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe]));
    pCsr->nStop = sqlite3_value_bytes(apVal[iLe]);
    if( pCsr->zStop==0 ) return SQLITE_NOMEM;
    pCsr->nStop = (int)strlen(pCsr->zStop);
  }
  
  if( iLangid>=0 ){
    iLangVal = sqlite3_value_int(apVal[iLangid]);

    /* If the user specified a negative value for the languageid, use zero
    ** instead. This works, as the "languageid=?" constraint will also

     0,                           /* xSync         */
     0,                           /* xCommit       */
     0,                           /* xRollback     */
     0,                           /* xFindFunction */
     0,                           /* xRename       */
     0,                           /* xSavepoint    */
     0,                           /* xRelease      */
     0                            /* xRollbackTo   */
     0,                           /* xRollbackTo   */
  };
  int rc;                         /* Return code */

  rc = sqlite3_create_module(db, "fts4aux", &fts3aux_module, 0);
  return rc;
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

}

/*
** 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);
static void *fts3MallocZero(sqlite3_int64 nByte){
  void *pRet = sqlite3_malloc64(nByte);
  if( pRet ) memset(pRet, 0, nByte);
  return pRet;
}

int sqlite3Fts3OpenTokenizer(
  sqlite3_tokenizer *pTokenizer,
  int iLangid,

  }

  *pnConsumed = i;
  rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, i, &pCursor);
  if( rc==SQLITE_OK ){
    const char *zToken;
    int nToken = 0, iStart = 0, iEnd = 0, iPosition = 0;
    int nByte;                               /* total space to allocate */
    sqlite3_int64 nByte;                    /* total space to allocate */

    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;

}


/*
** Enlarge a memory allocation.  If an out-of-memory allocation occurs,
** then free the old allocation.
*/
static void *fts3ReallocOrFree(void *pOrig, int nNew){
  void *pRet = sqlite3_realloc(pOrig, nNew);
static void *fts3ReallocOrFree(void *pOrig, sqlite3_int64 nNew){
  void *pRet = sqlite3_realloc64(pOrig, nNew);
  if( !pRet ){
    sqlite3_free(pOrig);
  }
  return pRet;
}

/*

  }

  if( sqlite3_fts3_enable_parentheses ){
    if( *zInput=='(' ){
      int nConsumed = 0;
      pParse->nNest++;
      rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);
      if( rc==SQLITE_OK && !*ppExpr ){ rc = SQLITE_DONE; }
      *pnConsumed = (int)(zInput - z) + 1 + nConsumed;
      return rc;
    }else if( *zInput==')' ){
      pParse->nNest--;
      *pnConsumed = (int)((zInput - z) + 1);
      *ppExpr = 0;
      return SQLITE_DONE;

  if( nMaxDepth==0 ){
    rc = SQLITE_ERROR;
  }

  if( rc==SQLITE_OK ){
    if( (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
      Fts3Expr **apLeaf;
      apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
      apLeaf = (Fts3Expr **)sqlite3_malloc64(sizeof(Fts3Expr *) * nMaxDepth);
      if( 0==apLeaf ){
        rc = SQLITE_NOMEM;
      }else{
        memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
      }

      if( rc==SQLITE_OK ){

** Everything after this point is just test code.
*/

#ifdef SQLITE_TEST

#include <stdio.h>

/*
** Function to query the hash-table of tokenizers (see README.tokenizers).
*/
static int queryTestTokenizer(
  sqlite3 *db, 
  const char *zName,  
  const sqlite3_tokenizer_module **pp
){
  int rc;
  sqlite3_stmt *pStmt;
  const char zSql[] = "SELECT fts3_tokenizer(?)";

  *pp = 0;
  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
      memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
    }
  }

  return sqlite3_finalize(pStmt);
}

/*
** Return a pointer to a buffer containing a text representation of the
** expression passed as the first argument. The buffer is obtained from
** sqlite3_malloc(). It is the responsibility of the caller to use 
** sqlite3_free() to release the memory. If an OOM condition is encountered,
** NULL is returned.
**

** to parse the query expression (see README.tokenizers). The second argument
** is the query expression to parse. Each subsequent argument is the name
** of a column of the fts3 table that the query expression may refer to.
** For example:
**
**   SELECT fts3_exprtest('simple', 'Bill col2:Bloggs', 'col1', 'col2');
*/
static void fts3ExprTest(
static void fts3ExprTestCommon(
  int bRebalance,
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_tokenizer_module const *pModule = 0;
  sqlite3_tokenizer *pTokenizer = 0;
  int rc;
  char **azCol = 0;
  const char *zExpr;
  int nExpr;
  int nCol;
  int ii;
  Fts3Expr *pExpr;
  char *zBuf = 0;
  sqlite3 *db = sqlite3_context_db_handle(context);
  Fts3Hash *pHash = (Fts3Hash*)sqlite3_user_data(context);
  const char *zTokenizer = 0;
  char *zErr = 0;

  if( argc<3 ){
    sqlite3_result_error(context, 
        "Usage: fts3_exprtest(tokenizer, expr, col1, ...", -1
    );
    return;
  }

  rc = queryTestTokenizer(db,
                          (const char *)sqlite3_value_text(argv[0]), &pModule);
  if( rc==SQLITE_NOMEM ){
    sqlite3_result_error_nomem(context);
  zTokenizer = (const char*)sqlite3_value_text(argv[0]);
  rc = sqlite3Fts3InitTokenizer(pHash, zTokenizer, &pTokenizer, &zErr);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ){
      sqlite3_result_error_nomem(context);
    goto exprtest_out;
  }else if( !pModule ){
    sqlite3_result_error(context, "No such tokenizer module", -1);
    }else{
      sqlite3_result_error(context, zErr, -1);
    goto exprtest_out;
  }

    }
    sqlite3_free(zErr);
  rc = pModule->xCreate(0, 0, &pTokenizer);
  assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
  if( rc==SQLITE_NOMEM ){
    sqlite3_result_error_nomem(context);
    return;
    goto exprtest_out;
  }
  pTokenizer->pModule = pModule;

  zExpr = (const char *)sqlite3_value_text(argv[1]);
  nExpr = sqlite3_value_bytes(argv[1]);
  nCol = argc-2;
  azCol = (char **)sqlite3_malloc(nCol*sizeof(char *));
  azCol = (char **)sqlite3_malloc64(nCol*sizeof(char *));
  if( !azCol ){
    sqlite3_result_error_nomem(context);
    goto exprtest_out;
  }
  for(ii=0; ii<nCol; ii++){
    azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
  }

  if( sqlite3_user_data(context) ){
  if( bRebalance ){
    char *zDummy = 0;
    rc = sqlite3Fts3ExprParse(
        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr, &zDummy
    );
    assert( rc==SQLITE_OK || pExpr==0 );
    sqlite3_free(zDummy);
  }else{

    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
    sqlite3_free(zBuf);
  }

  sqlite3Fts3ExprFree(pExpr);

exprtest_out:
  if( pModule && pTokenizer ){
    rc = pModule->xDestroy(pTokenizer);
  if( pTokenizer ){
    rc = pTokenizer->pModule->xDestroy(pTokenizer);
  }
  sqlite3_free(azCol);
}

static void fts3ExprTest(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  fts3ExprTestCommon(0, context, argc, argv);
}
static void fts3ExprTestRebalance(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  fts3ExprTestCommon(1, context, argc, argv);
}

/*
** Register the query expression parser test function fts3_exprtest() 
** with database connection db. 
*/
int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db, Fts3Hash *pHash){
  int rc = sqlite3_create_function(
      db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
      db, "fts3_exprtest", -1, SQLITE_UTF8, (void*)pHash, fts3ExprTest, 0, 0
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 
        -1, SQLITE_UTF8, (void *)1, fts3ExprTest, 0, 0
        -1, SQLITE_UTF8, (void*)pHash, fts3ExprTestRebalance, 0, 0
    );
  }
  return rc;
}

#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

#include <string.h>

#include "fts3_hash.h"

/*
** Malloc and Free functions
*/
static void *fts3HashMalloc(int n){
  void *p = sqlite3_malloc(n);
static void *fts3HashMalloc(sqlite3_int64 n){
  void *p = sqlite3_malloc64(n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}
static void fts3HashFree(void *p){
  sqlite3_free(p);

){
  IcuTokenizer *p;
  int n = 0;

  if( argc>0 ){
    n = strlen(argv[0])+1;
  }
  p = (IcuTokenizer *)sqlite3_malloc(sizeof(IcuTokenizer)+n);
  p = (IcuTokenizer *)sqlite3_malloc64(sizeof(IcuTokenizer)+n);
  if( !p ){
    return SQLITE_NOMEM;
  }
  memset(p, 0, sizeof(IcuTokenizer));

  if( n ){
    p->zLocale = (char *)&p[1];

  if( zInput==0 ){
    nInput = 0;
    zInput = "";
  }else if( nInput<0 ){
    nInput = strlen(zInput);
  }
  nChar = nInput+1;
  pCsr = (IcuCursor *)sqlite3_malloc(
  pCsr = (IcuCursor *)sqlite3_malloc64(
      sizeof(IcuCursor) +                /* IcuCursor */
      ((nChar+3)&~3) * sizeof(UChar) +   /* IcuCursor.aChar[] */
      (nChar+1) * sizeof(int)            /* IcuCursor.aOffset[] */
  );
  if( !pCsr ){
    return SQLITE_NOMEM;
  }

/*************************************************************************
** Start of MatchinfoBuffer code.
*/

/*
** Allocate a two-slot MatchinfoBuffer object.
*/
static MatchinfoBuffer *fts3MIBufferNew(int nElem, const char *zMatchinfo){
static MatchinfoBuffer *fts3MIBufferNew(size_t nElem, const char *zMatchinfo){
  MatchinfoBuffer *pRet;
  sqlite3_int64 nByte = sizeof(u32) * (2*(sqlite3_int64)nElem + 1)
  int nByte = sizeof(u32) * (2*nElem + 1) + sizeof(MatchinfoBuffer);
  int nStr = (int)strlen(zMatchinfo);
                           + sizeof(MatchinfoBuffer);
  sqlite3_int64 nStr = strlen(zMatchinfo);

  pRet = sqlite3_malloc(nByte + nStr+1);
  pRet = sqlite3_malloc64(nByte + nStr+1);
  if( pRet ){
    memset(pRet, 0, nByte);
    pRet->aMatchinfo[0] = (u8*)(&pRet->aMatchinfo[1]) - (u8*)pRet;
    pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0] + sizeof(u32)*(nElem+1);
    pRet->nElem = nElem;
    pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0]
                                      + sizeof(u32)*((int)nElem+1);
    pRet->nElem = (int)nElem;
    pRet->zMatchinfo = ((char*)pRet) + nByte;
    memcpy(pRet->zMatchinfo, zMatchinfo, nStr+1);
    pRet->aRef[0] = 1;
  }

  return pRet;
}

    xRet = fts3MIBufferFree;
  }
  else if( p->aRef[2]==0 ){
    p->aRef[2] = 1;
    aOut = &p->aMatchinfo[p->nElem+2];
    xRet = fts3MIBufferFree;
  }else{
    aOut = (u32*)sqlite3_malloc(p->nElem * sizeof(u32));
    aOut = (u32*)sqlite3_malloc64(p->nElem * sizeof(u32));
    if( aOut ){
      xRet = sqlite3_free;
      if( p->bGlobal ) memcpy(aOut, &p->aMatchinfo[1], p->nElem*sizeof(u32));
    }
  }

  *paOut = aOut;

  for(i=0; i<pIter->nPhrase; i++){
    SnippetPhrase *pPhrase = &pIter->aPhrase[i];
    if( pPhrase->pTail ){
      char *pCsr = pPhrase->pTail;
      int iCsr = pPhrase->iTail;

      while( iCsr<(iStart+pIter->nSnippet) ){
      while( iCsr<(iStart+pIter->nSnippet) && iCsr>=iStart ){
        int j;
        u64 mPhrase = (u64)1 << i;
        u64 mPhrase = (u64)1 << (i%64);
        u64 mPos = (u64)1 << (iCsr - iStart);
        assert( iCsr>=iStart );
        assert( iCsr>=iStart && (iCsr - iStart)<=64 );
        assert( i>=0 );
        if( (mCover|mCovered)&mPhrase ){
          iScore++;
        }else{
          iScore += 1000;
        }
        mCover |= mPhrase;

  pPhrase->nToken = pExpr->pPhrase->nToken;
  rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pCsr);
  assert( rc==SQLITE_OK || pCsr==0 );
  if( pCsr ){
    int iFirst = 0;
    pPhrase->pList = pCsr;
    fts3GetDeltaPosition(&pCsr, &iFirst);
    assert( iFirst>=0 );
    pPhrase->pHead = pCsr;
    pPhrase->pTail = pCsr;
    pPhrase->iHead = iFirst;
    pPhrase->iTail = iFirst;
    if( iFirst<0 ){
      rc = FTS_CORRUPT_VTAB;
    }else{
      pPhrase->pHead = pCsr;
      pPhrase->pTail = pCsr;
      pPhrase->iHead = iFirst;
      pPhrase->iTail = iFirst;
    }
  }else{
    assert( rc!=SQLITE_OK || (
       pPhrase->pList==0 && pPhrase->pHead==0 && pPhrase->pTail==0 
    ));
  }

  return rc;

  u64 *pmSeen,                    /* IN/OUT: Mask of phrases seen */
  SnippetFragment *pFragment,     /* OUT: Best snippet found */
  int *piScore                    /* OUT: Score of snippet pFragment */
){
  int rc;                         /* Return Code */
  int nList;                      /* Number of phrases in expression */
  SnippetIter sIter;              /* Iterates through snippet candidates */
  int nByte;                      /* Number of bytes of space to allocate */
  sqlite3_int64 nByte;            /* Number of bytes of space to allocate */
  int iBestScore = -1;            /* Best snippet score found so far */
  int i;                          /* Loop counter */

  memset(&sIter, 0, sizeof(sIter));

  /* Iterate through the phrases in the expression to count them. The same
  ** callback makes sure the doclists are loaded for each phrase.
  */
  rc = fts3ExprLoadDoclists(pCsr, &nList, 0);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  /* Now that it is known how many phrases there are, allocate and zero
  ** the required space using malloc().
  */
  nByte = sizeof(SnippetPhrase) * nList;
  sIter.aPhrase = (SnippetPhrase *)sqlite3_malloc(nByte);
  sIter.aPhrase = (SnippetPhrase *)sqlite3_malloc64(nByte);
  if( !sIter.aPhrase ){
    return SQLITE_NOMEM;
  }
  memset(sIter.aPhrase, 0, nByte);

  /* Initialize the contents of the SnippetIter object. Then iterate through
  ** the set of phrases in the expression to populate the aPhrase[] array.
  */
  sIter.pCsr = pCsr;
  sIter.iCol = iCol;
  sIter.nSnippet = nSnippet;
  sIter.nPhrase = nList;
  sIter.iCurrent = -1;
  rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void*)&sIter);
  if( rc==SQLITE_OK ){

    /* Set the *pmSeen output variable. */
    for(i=0; i<nList; i++){
      if( sIter.aPhrase[i].pHead ){
        *pmSeen |= (u64)1 << i;
        *pmSeen |= (u64)1 << (i%64);
      }
    }

    /* Loop through all candidate snippets. Store the best snippet in 
     ** *pFragment. Store its associated 'score' in iBestScore.
     */
    pFragment->iCol = iCol;

  }

  /* If there is insufficient space allocated at StrBuffer.z, use realloc()
  ** to grow the buffer until so that it is big enough to accomadate the
  ** appended data.
  */
  if( pStr->n+nAppend+1>=pStr->nAlloc ){
    int nAlloc = pStr->nAlloc+nAppend+100;
    char *zNew = sqlite3_realloc(pStr->z, nAlloc);
    sqlite3_int64 nAlloc = pStr->nAlloc+(sqlite3_int64)nAppend+100;
    char *zNew = sqlite3_realloc64(pStr->z, nAlloc);
    if( !zNew ){
      return SQLITE_NOMEM;
    }
    pStr->z = zNew;
    pStr->nAlloc = nAlloc;
  }
  assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );

  if( hlmask ){
    int nLeft;                    /* Tokens to the left of first highlight */
    int nRight;                   /* Tokens to the right of last highlight */
    int nDesired;                 /* Ideal number of tokens to shift forward */

    for(nLeft=0; !(hlmask & ((u64)1 << nLeft)); nLeft++);
    for(nRight=0; !(hlmask & ((u64)1 << (nSnippet-1-nRight))); nRight++);
    assert( (nSnippet-1-nRight)<=63 && (nSnippet-1-nRight)>=0 );
    nDesired = (nLeft-nRight)/2;

    /* Ideally, the start of the snippet should be pushed forward in the
    ** document nDesired tokens. This block checks if there are actually
    ** nDesired tokens to the right of the snippet. If so, *piPos and
    ** *pHlMask are updated to shift the snippet nDesired tokens to the
    ** right. Otherwise, the snippet is shifted by the number of tokens

  *ppCollist = pEnd;
  return nEntry;
}

/*
** This function gathers 'y' or 'b' data for a single phrase.
*/
static void fts3ExprLHits(
static int fts3ExprLHits(
  Fts3Expr *pExpr,                /* Phrase expression node */
  MatchInfo *p                    /* Matchinfo context */
){
  Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;
  int iStart;
  Fts3Phrase *pPhrase = pExpr->pPhrase;
  char *pIter = pPhrase->doclist.pList;

        p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));
      }
    }
    assert( *pIter==0x00 || *pIter==0x01 );
    if( *pIter!=0x01 ) break;
    pIter++;
    pIter += fts3GetVarint32(pIter, &iCol);
    if( iCol>=p->nCol ) return FTS_CORRUPT_VTAB;
  }
  return SQLITE_OK;
}

/*
** Gather the results for matchinfo directives 'y' and 'b'.
*/
static void fts3ExprLHitGather(
static int fts3ExprLHitGather(
  Fts3Expr *pExpr,
  MatchInfo *p
){
  int rc = SQLITE_OK;
  assert( (pExpr->pLeft==0)==(pExpr->pRight==0) );
  if( pExpr->bEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){
    if( pExpr->pLeft ){
      fts3ExprLHitGather(pExpr->pLeft, p);
      fts3ExprLHitGather(pExpr->pRight, p);
      rc = fts3ExprLHitGather(pExpr->pLeft, p);
      if( rc==SQLITE_OK ) rc = fts3ExprLHitGather(pExpr->pRight, p);
    }else{
      fts3ExprLHits(pExpr, p);
      rc = fts3ExprLHits(pExpr, p);
    }
  }
  return rc;
}

/*
** fts3ExprIterate() callback used to collect the "global" matchinfo stats
** for a single query. 
**
** fts3ExprIterate() callback to load the 'global' elements of a

  ){
    return SQLITE_OK;
  }
  sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);
  return SQLITE_ERROR;
}

static int fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
  int nVal;                       /* Number of integers output by cArg */
static size_t fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
  size_t nVal;                      /* Number of integers output by cArg */

  switch( cArg ){
    case FTS3_MATCHINFO_NDOC:
    case FTS3_MATCHINFO_NPHRASE: 
    case FTS3_MATCHINFO_NCOL: 
      nVal = 1;
      break;

  return nVal;
}

static int fts3MatchinfoSelectDoctotal(
  Fts3Table *pTab,
  sqlite3_stmt **ppStmt,
  sqlite3_int64 *pnDoc,
  const char **paLen
  const char **paLen,
  const char **ppEnd
){
  sqlite3_stmt *pStmt;
  const char *a;
  const char *pEnd;
  sqlite3_int64 nDoc;
  int n;


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

  n = sqlite3_column_bytes(pStmt, 0);
  a = sqlite3_column_blob(pStmt, 0);
  if( a==0 ){
    return FTS_CORRUPT_VTAB;
  }
  pEnd = a + n;
  a += sqlite3Fts3GetVarint(a, &nDoc);
  if( nDoc==0 ) return FTS_CORRUPT_VTAB;
  *pnDoc = (u32)nDoc;
  a += sqlite3Fts3GetVarintBounded(a, pEnd, &nDoc);
  if( nDoc<=0 || a>pEnd ){
    return FTS_CORRUPT_VTAB;
  }
  *pnDoc = nDoc;

  if( paLen ) *paLen = a;
  if( ppEnd ) *ppEnd = pEnd;
  return SQLITE_OK;
}

/*
** An instance of the following structure is used to store state while 
** iterating through a multi-column position-list corresponding to the
** hits for a single phrase on a single row in order to calculate the

** undefined.
*/
static int fts3MatchinfoLcs(Fts3Cursor *pCsr, MatchInfo *pInfo){
  LcsIterator *aIter;
  int i;
  int iCol;
  int nToken = 0;
  int rc = SQLITE_OK;

  /* Allocate and populate the array of LcsIterator objects. The array
  ** contains one element for each matchable phrase in the query.
  **/
  aIter = sqlite3_malloc(sizeof(LcsIterator) * pCsr->nPhrase);
  aIter = sqlite3_malloc64(sizeof(LcsIterator) * pCsr->nPhrase);
  if( !aIter ) return SQLITE_NOMEM;
  memset(aIter, 0, sizeof(LcsIterator) * pCsr->nPhrase);
  (void)fts3ExprIterate(pCsr->pExpr, fts3MatchinfoLcsCb, (void*)aIter);

  for(i=0; i<pInfo->nPhrase; i++){
    LcsIterator *pIter = &aIter[i];
    nToken -= pIter->pExpr->pPhrase->nToken;
    pIter->iPosOffset = nToken;
  }

  for(iCol=0; iCol<pInfo->nCol; iCol++){
    int nLcs = 0;                 /* LCS value for this column */
    int nLive = 0;                /* Number of iterators in aIter not at EOF */

    for(i=0; i<pInfo->nPhrase; i++){
      int rc;
      LcsIterator *pIt = &aIter[i];
      rc = sqlite3Fts3EvalPhrasePoslist(pCsr, pIt->pExpr, iCol, &pIt->pRead);
      if( rc!=SQLITE_OK ) return rc;
      if( rc!=SQLITE_OK ) goto matchinfo_lcs_out;
      if( pIt->pRead ){
        pIt->iPos = pIt->iPosOffset;
        fts3LcsIteratorAdvance(&aIter[i]);
        fts3LcsIteratorAdvance(pIt);
        if( pIt->pRead==0 ){
          rc = FTS_CORRUPT_VTAB;
          goto matchinfo_lcs_out;
        }
        nLive++;
      }
    }

    while( nLive>0 ){
      LcsIterator *pAdv = 0;      /* The iterator to advance by one position */
      int nThisLcs = 0;           /* LCS for the current iterator positions */

      }
      if( fts3LcsIteratorAdvance(pAdv) ) nLive--;
    }

    pInfo->aMatchinfo[iCol] = nLcs;
  }

 matchinfo_lcs_out:
  sqlite3_free(aIter);
  return SQLITE_OK;
  return rc;
}

/*
** Populate the buffer pInfo->aMatchinfo[] with an array of integers to
** be returned by the matchinfo() function. Argument zArg contains the 
** format string passed as the second argument to matchinfo (or the
** default value "pcx" if no second argument was specified). The format

      case FTS3_MATCHINFO_NCOL:
        if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nCol;
        break;
        
      case FTS3_MATCHINFO_NDOC:
        if( bGlobal ){
          sqlite3_int64 nDoc = 0;
          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0);
          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0, 0);
          pInfo->aMatchinfo[0] = (u32)nDoc;
        }
        break;

      case FTS3_MATCHINFO_AVGLENGTH: 
        if( bGlobal ){
          sqlite3_int64 nDoc;     /* Number of rows in table */
          const char *a;          /* Aggregate column length array */
          const char *pEnd;       /* First byte past end of length array */

          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);
          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a, &pEnd);
          if( rc==SQLITE_OK ){
            int iCol;
            for(iCol=0; iCol<pInfo->nCol; iCol++){
              u32 iVal;
              sqlite3_int64 nToken;
              a += sqlite3Fts3GetVarint(a, &nToken);
              if( a>pEnd ){
                rc = SQLITE_CORRUPT_VTAB;
                break;
              }
              iVal = (u32)(((u32)(nToken&0xffffffff)+nDoc/2)/nDoc);
              pInfo->aMatchinfo[iCol] = iVal;
            }
          }
        }
        break;

      case FTS3_MATCHINFO_LENGTH: {
        sqlite3_stmt *pSelectDocsize = 0;
        rc = sqlite3Fts3SelectDocsize(pTab, pCsr->iPrevId, &pSelectDocsize);
        if( rc==SQLITE_OK ){
          int iCol;
          const char *a = sqlite3_column_blob(pSelectDocsize, 0);
          const char *pEnd = a + sqlite3_column_bytes(pSelectDocsize, 0);
          for(iCol=0; iCol<pInfo->nCol; iCol++){
            sqlite3_int64 nToken;
            a += sqlite3Fts3GetVarint(a, &nToken);
            a += sqlite3Fts3GetVarintBounded(a, pEnd, &nToken);
            if( a>pEnd ){
              rc = SQLITE_CORRUPT_VTAB;
              break;
            }
            pInfo->aMatchinfo[iCol] = (u32)nToken;
          }
        }
        sqlite3_reset(pSelectDocsize);
        break;
      }

      case FTS3_MATCHINFO_LCS:
        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
        if( rc==SQLITE_OK ){
          rc = fts3MatchinfoLcs(pCsr, pInfo);
        }
        break;

      case FTS3_MATCHINFO_LHITS_BM:
      case FTS3_MATCHINFO_LHITS: {
        int nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);
        size_t nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);
        memset(pInfo->aMatchinfo, 0, nZero);
        fts3ExprLHitGather(pCsr->pExpr, pInfo);
        rc = fts3ExprLHitGather(pCsr->pExpr, pInfo);
        break;
      }

      default: {
        Fts3Expr *pExpr;
        assert( zArg[i]==FTS3_MATCHINFO_HITS );
        pExpr = pCsr->pExpr;
        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
        if( rc!=SQLITE_OK ) break;
        if( bGlobal ){
          if( pCsr->pDeferred ){
            rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);
            rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc,0,0);
            if( rc!=SQLITE_OK ) break;
          }
          rc = fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
          sqlite3Fts3EvalTestDeferred(pCsr, &rc);
          if( rc!=SQLITE_OK ) break;
        }
        (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);

  /* If Fts3Cursor.pMIBuffer is NULL, then this is the first time the
  ** matchinfo function has been called for this query. In this case 
  ** allocate the array used to accumulate the matchinfo data and
  ** initialize those elements that are constant for every row.
  */
  if( pCsr->pMIBuffer==0 ){
    int nMatchinfo = 0;           /* Number of u32 elements in match-info */
    size_t nMatchinfo = 0;        /* Number of u32 elements in match-info */
    int i;                        /* Used to iterate through zArg */

    /* Determine the number of phrases in the query */
    pCsr->nPhrase = fts3ExprPhraseCount(pCsr->pExpr);
    sInfo.nPhrase = pCsr->nPhrase;

    /* Determine the number of integers in the buffer returned by this call. */

  SnippetFragment aSnippet[4];    /* Maximum of 4 fragments per snippet */
  int nFToken = -1;               /* Number of tokens in each fragment */

  if( !pCsr->pExpr ){
    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
    return;
  }

  /* Limit the snippet length to 64 tokens. */
  if( nToken<-64 ) nToken = -64;
  if( nToken>+64 ) nToken = +64;

  for(nSnippet=1; 1; nSnippet++){

    int iSnip;                    /* Loop counter 0..nSnippet-1 */
    u64 mCovered = 0;             /* Bitmask of phrases covered by snippet */
    u64 mSeen = 0;                /* Bitmask of phrases seen by BestSnippet() */

  int rc;

  UNUSED_PARAMETER(iPhrase);
  rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pList);
  nTerm = pExpr->pPhrase->nToken;
  if( pList ){
    fts3GetDeltaPosition(&pList, &iPos);
    assert( iPos>=0 );
    assert_fts3_nc( iPos>=0 );
  }

  for(iTerm=0; iTerm<nTerm; iTerm++){
    TermOffset *pT = &p->aTerm[p->iTerm++];
    pT->iOff = nTerm-iTerm-1;
    pT->pList = pList;
    pT->iPos = iPos;

  assert( pCsr->isRequireSeek==0 );

  /* Count the number of terms in the query */
  rc = fts3ExprLoadDoclists(pCsr, 0, &nToken);
  if( rc!=SQLITE_OK ) goto offsets_out;

  /* Allocate the array of TermOffset iterators. */
  sCtx.aTerm = (TermOffset *)sqlite3_malloc(sizeof(TermOffset)*nToken);
  sCtx.aTerm = (TermOffset *)sqlite3_malloc64(sizeof(TermOffset)*nToken);
  if( 0==sCtx.aTerm ){
    rc = SQLITE_NOMEM;
    goto offsets_out;
  }
  sCtx.iDocid = pCsr->iPrevId;
  sCtx.pCsr = pCsr;

        }
      }

      if( !pTerm ){
        /* All offsets for this column have been gathered. */
        rc = SQLITE_DONE;
      }else{
        assert( iCurrent<=iMinPos );
        assert_fts3_nc( iCurrent<=iMinPos );
        if( 0==(0xFE&*pTerm->pList) ){
          pTerm->pList = 0;
        }else{
          fts3GetDeltaPosition(&pTerm->pList, &pTerm->iPos);
        }
        while( rc==SQLITE_OK && iCurrent<iMinPos ){
          rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);

  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
){
  char const *zDb;                /* Name of database (e.g. "main") */
  char const *zFts3;              /* Name of fts3 table */
  int nDb;                        /* Result of strlen(zDb) */
  int nFts3;                      /* Result of strlen(zFts3) */
  int nByte;                      /* Bytes of space to allocate here */
  sqlite3_int64 nByte;            /* Bytes of space to allocate here */
  int rc;                         /* value returned by declare_vtab() */
  Fts3termTable *p;                /* Virtual table object to return */
  Fts3termTable *p;               /* Virtual table object to return */
  int iIndex = 0;

  UNUSED_PARAMETER(pCtx);
  if( argc==5 ){
    iIndex = atoi(argv[4]);
    argc--;
  }

  zFts3 = argv[3];
  nFts3 = (int)strlen(zFts3);

  rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA);
  if( rc!=SQLITE_OK ) return rc;

  nByte = sizeof(Fts3termTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
  p = (Fts3termTable *)sqlite3_malloc(nByte);
  p = (Fts3termTable *)sqlite3_malloc64(nByte);
  if( !p ) return SQLITE_NOMEM;
  memset(p, 0, nByte);
  memset(p, 0, (size_t)nByte);

  p->pFts3Tab = (Fts3Table *)&p[1];
  p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1];
  p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1];
  p->pFts3Tab->db = db;
  p->pFts3Tab->nIndex = iIndex+1;
  p->iIndex = iIndex;

     0,                           /* xSync         */
     0,                           /* xCommit       */
     0,                           /* xRollback     */
     0,                           /* xFindFunction */
     0,                           /* xRename       */
     0,                           /* xSavepoint    */
     0,                           /* xRelease      */
     0                            /* xRollbackTo   */
     0,                           /* xRollbackTo   */
  };
  int rc;                         /* Return code */

  rc = sqlite3_create_module(db, "fts4term", &fts3term_module, 0);
  return rc;
}

#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  while( p<pEnd && testIsTokenChar(*p)==0 ) p++;

  if( p==pEnd ){
    rc = SQLITE_DONE;
  }else{
    /* Advance to the end of the token */
    const char *pToken = p;
    int nToken;
    sqlite3_int64 nToken;
    while( p<pEnd && testIsTokenChar(*p) ) p++;
    nToken = (int)(p-pToken);
    nToken = (sqlite3_int64)(p-pToken);

    /* Copy the token into the buffer */
    if( nToken>pCsr->nBuffer ){
      sqlite3_free(pCsr->aBuffer);
      pCsr->aBuffer = sqlite3_malloc(nToken);
      pCsr->aBuffer = sqlite3_malloc64(nToken);
    }
    if( pCsr->aBuffer==0 ){
      rc = SQLITE_NOMEM;
    }else{
      int i;

      if( pCsr->iLangid & 0x00000001 ){
        for(i=0; i<nToken; i++) pCsr->aBuffer[i] = pToken[i];
      }else{
        for(i=0; i<nToken; i++) pCsr->aBuffer[i] = (char)testTolower(pToken[i]);
      }
      pCsr->iToken++;
      pCsr->iInput = (int)(p - pCsr->aInput);

      *ppToken = pCsr->aBuffer;
      *pnBytes = nToken;
      *pnBytes = (int)nToken;
      *piStartOffset = (int)(pToken - pCsr->aInput);
      *piEndOffset = (int)(p - pCsr->aInput);
      *piPosition = pCsr->iToken;
    }
  }

  return rc;

  UNUSED_PARAMETER(clientData);
  return TCL_OK;
}

/* 
** End of tokenizer code.
**************************************************************************/ 

/*
**      sqlite3_fts3_may_be_corrupt BOOLEAN
**
** Set or clear the global "may-be-corrupt" flag. Return the old value.
*/
static int SQLITE_TCLAPI fts3_may_be_corrupt(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int bOld = sqlite3_fts3_may_be_corrupt;

  if( objc!=2 && objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?BOOLEAN?");
    return TCL_ERROR;
  }
  if( objc==2 ){
    int bNew;
    if( Tcl_GetBooleanFromObj(interp, objv[1], &bNew) ) return TCL_ERROR;
    sqlite3_fts3_may_be_corrupt = bNew;
  }

  Tcl_SetObjResult(interp, Tcl_NewIntObj(bOld));
  return TCL_OK;
}

int Sqlitetestfts3_Init(Tcl_Interp *interp){
  Tcl_CreateObjCommand(interp, "fts3_near_match", fts3_near_match_cmd, 0, 0);
  Tcl_CreateObjCommand(interp, 
      "fts3_configure_incr_load", fts3_configure_incr_load_cmd, 0, 0
  );
  Tcl_CreateObjCommand(
      interp, "fts3_test_tokenizer", fts3_test_tokenizer_cmd, 0, 0
  );

  Tcl_CreateObjCommand(
      interp, "fts3_test_varint", fts3_test_varint_cmd, 0, 0
  );
  Tcl_CreateObjCommand(
      interp, "sqlite3_fts3_may_be_corrupt", fts3_may_be_corrupt, 0, 0
  );
  return TCL_OK;
}
#endif                  /* SQLITE_ENABLE_FTS3 || SQLITE_ENABLE_FTS4 */
#endif                  /* ifdef SQLITE_TEST */

    int nByte = 0;
    char **azDequote;

    for(i=0; i<argc; i++){
      nByte += (int)(strlen(argv[i]) + 1);
    }

    *pazDequote = azDequote = sqlite3_malloc(sizeof(char *)*argc + nByte);
    *pazDequote = azDequote = sqlite3_malloc64(sizeof(char *)*argc + nByte);
    if( azDequote==0 ){
      rc = SQLITE_NOMEM;
    }else{
      char *pSpace = (char *)&azDequote[argc];
      for(i=0; i<argc; i++){
        int n = (int)strlen(argv[i]);
        azDequote[i] = pSpace;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  fts3tokResetCursor(pCsr);
  if( idxNum==1 ){
    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
    int nByte = sqlite3_value_bytes(apVal[0]);
    pCsr->zInput = sqlite3_malloc(nByte+1);
    pCsr->zInput = sqlite3_malloc64(nByte+1);
    if( pCsr->zInput==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memcpy(pCsr->zInput, zByte, nByte);
      pCsr->zInput[nByte] = 0;
      rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);
      if( rc==SQLITE_OK ){

     0,                           /* xSync         */
     0,                           /* xCommit       */
     0,                           /* xRollback     */
     0,                           /* xFindFunction */
     0,                           /* xRename       */
     0,                           /* xSavepoint    */
     0,                           /* xRelease      */
     0                            /* xRollbackTo   */
     0,                           /* xRollbackTo   */
  };
  int rc;                         /* Return code */

  rc = sqlite3_create_module(db, "fts3tokenize", &fts3tok_module, (void*)pHash);
  return rc;
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

*/
static int fts3TokenizerEnabled(sqlite3_context *context){
  sqlite3 *db = sqlite3_context_db_handle(context);
  int isEnabled = 0;
  sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled);
  return isEnabled;
}

/*
** The real sqlite3_value_frombind() implementation was not added
** until version 3.28.0 of the SQLite core.  This fake version facilitates
** testing.
*/
static int bFrombindTrue = 0;
static int sqlite3_value_frombind(sqlite3_value *NotUsed){
  (void)NotUsed;
  return bFrombindTrue;
}

/*
** Implementation of the SQL scalar function for accessing the underlying 
** hash table. This function may be called as follows:
**
**   SELECT <function-name>(<key-name>);
**   SELECT <function-name>(<key-name>, <pointer>);

  pHash = (Fts3Hash *)sqlite3_user_data(context);

  zName = sqlite3_value_text(argv[0]);
  nName = sqlite3_value_bytes(argv[0])+1;

  if( argc==2 ){
    if( fts3TokenizerEnabled(context) ){
    if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[1]) ){
      void *pOld;
      int n = sqlite3_value_bytes(argv[1]);
      if( zName==0 || n!=sizeof(pPtr) ){
        sqlite3_result_error(context, "argument type mismatch", -1);
        return;
      }
      pPtr = *(void **)sqlite3_value_blob(argv[1]);

    if( !pPtr ){
      char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
      sqlite3_result_error(context, zErr, -1);
      sqlite3_free(zErr);
      return;
    }
  }
  if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[0]) ){
  sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
    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 */

    sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", z);
    rc = SQLITE_ERROR;
  }else{
    char const **aArg = 0;
    int iArg = 0;
    z = &z[n+1];
    while( z<zEnd && (NULL!=(z = (char *)sqlite3Fts3NextToken(z, &n))) ){
      int nNew = sizeof(char *)*(iArg+1);
      char const **aNew = (const char **)sqlite3_realloc((void *)aArg, nNew);
      sqlite3_int64 nNew = sizeof(char *)*(iArg+1);
      char const **aNew = (const char **)sqlite3_realloc64((void *)aArg, nNew);
      if( !aNew ){
        sqlite3_free(zCopy);
        sqlite3_free((void *)aArg);
        return SQLITE_NOMEM;
      }
      aArg = aNew;
      aArg[iArg++] = z;

  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
    if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB
     && sqlite3_column_bytes(pStmt, 0)==sizeof(*pp)
    ){
      memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
    }
  }

  return sqlite3_finalize(pStmt);
}

  const sqlite3_tokenizer_module *p2;
  sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);

  UNUSED_PARAMETER(argc);
  UNUSED_PARAMETER(argv);

  /* Test the query function */
  bFrombindTrue = 1;
  sqlite3Fts3SimpleTokenizerModule(&p1);
  rc = queryTokenizer(db, "simple", &p2);
  assert( rc==SQLITE_OK );
  assert( p1==p2 );
  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
  assert( rc==SQLITE_ERROR );
  assert( p2==0 );
  assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );

  /* Test the storage function */
  if( fts3TokenizerEnabled(context) ){
    rc = registerTokenizer(db, "nosuchtokenizer", p1);
    assert( rc==SQLITE_OK );
    rc = queryTokenizer(db, "nosuchtokenizer", &p2);
    assert( rc==SQLITE_OK );
    assert( p2==p1 );
  }
  bFrombindTrue = 0;

  sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
}

#endif

/*

int sqlite3Fts3InitHashTable(
  sqlite3 *db, 
  Fts3Hash *pHash, 
  const char *zName
){
  int rc = SQLITE_OK;
  void *p = (void *)pHash;
  const int any = SQLITE_ANY;
  const int any = SQLITE_UTF8|SQLITE_DIRECTONLY;

#ifdef SQLITE_TEST
  char *zTest = 0;
  char *zTest2 = 0;
  void *pdb = (void *)db;
  zTest = sqlite3_mprintf("%s_test", zName);
  zTest2 = sqlite3_mprintf("%s_internal_test", zName);

#endif /* ifndef SQLITE_AMALGAMATION */

typedef struct unicode_tokenizer unicode_tokenizer;
typedef struct unicode_cursor unicode_cursor;

struct unicode_tokenizer {
  sqlite3_tokenizer base;
  int bRemoveDiacritic;
  int eRemoveDiacritic;
  int nException;
  int *aiException;
};

struct unicode_cursor {
  sqlite3_tokenizer_cursor base;
  const unsigned char *aInput;    /* Input text being tokenized */

    }
  }

  if( nEntry ){
    int *aNew;                    /* New aiException[] array */
    int nNew;                     /* Number of valid entries in array aNew[] */

    aNew = sqlite3_realloc(p->aiException, (p->nException+nEntry)*sizeof(int));
    aNew = sqlite3_realloc64(p->aiException,(p->nException+nEntry)*sizeof(int));
    if( aNew==0 ) return SQLITE_NOMEM;
    nNew = p->nException;

    z = (const unsigned char *)zIn;
    while( z<zTerm ){
      READ_UTF8(z, zTerm, iCode);
      if( sqlite3FtsUnicodeIsalnum((int)iCode)!=bAlnum 

  unicode_tokenizer *pNew;        /* New tokenizer object */
  int i;
  int rc = SQLITE_OK;

  pNew = (unicode_tokenizer *) sqlite3_malloc(sizeof(unicode_tokenizer));
  if( pNew==NULL ) return SQLITE_NOMEM;
  memset(pNew, 0, sizeof(unicode_tokenizer));
  pNew->bRemoveDiacritic = 1;
  pNew->eRemoveDiacritic = 1;

  for(i=0; rc==SQLITE_OK && i<nArg; i++){
    const char *z = azArg[i];
    int n = (int)strlen(z);

    if( n==19 && memcmp("remove_diacritics=1", z, 19)==0 ){
      pNew->bRemoveDiacritic = 1;
      pNew->eRemoveDiacritic = 1;
    }
    else if( n==19 && memcmp("remove_diacritics=0", z, 19)==0 ){
      pNew->bRemoveDiacritic = 0;
      pNew->eRemoveDiacritic = 0;
    }
    else if( n==19 && memcmp("remove_diacritics=2", z, 19)==0 ){
      pNew->eRemoveDiacritic = 2;
    }
    else if( n>=11 && memcmp("tokenchars=", z, 11)==0 ){
      rc = unicodeAddExceptions(pNew, 1, &z[11], n-11);
    }
    else if( n>=11 && memcmp("separators=", z, 11)==0 ){
      rc = unicodeAddExceptions(pNew, 0, &z[11], n-11);
    }

  zOut = pCsr->zToken;
  do {
    int iOut;

    /* Grow the output buffer if required. */
    if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){
      char *zNew = sqlite3_realloc(pCsr->zToken, pCsr->nAlloc+64);
      char *zNew = sqlite3_realloc64(pCsr->zToken, pCsr->nAlloc+64);
      if( !zNew ) return SQLITE_NOMEM;
      zOut = &zNew[zOut - pCsr->zToken];
      pCsr->zToken = zNew;
      pCsr->nAlloc += 64;
    }

    /* Write the folded case of the last character read to the output */
    zEnd = z;
    iOut = sqlite3FtsUnicodeFold((int)iCode, p->bRemoveDiacritic);
    iOut = sqlite3FtsUnicodeFold((int)iCode, p->eRemoveDiacritic);
    if( iOut ){
      WRITE_UTF8(zOut, iOut);
    }

    /* If the cursor is not at EOF, read the next character */
    if( z>=zTerm ) break;
    READ_UTF8(z, zTerm, iCode);

/*
** 2012 May 25
** 2012-05-25
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.

** If the argument is a codepoint corresponding to a lowercase letter
** in the ASCII range with a diacritic added, return the codepoint
** of the ASCII letter only. For example, if passed 235 - "LATIN
** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER
** E"). The resuls of passing a codepoint that corresponds to an
** uppercase letter are undefined.
*/
static int remove_diacritic(int c){
static int remove_diacritic(int c, int bComplex){
  unsigned short aDia[] = {
        0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 
     2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 
     2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 
     2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 
     3456,  3696,  3712,  3728,  3744,  3896,  3912,  3928, 
     3968,  4008,  4040,  4106,  4138,  4170,  4202,  4234, 
     4266,  4296,  4312,  4344,  4408,  4424,  4472,  4504, 
     6148,  6198,  6264,  6280,  6360,  6429,  6505,  6529, 
    61448, 61468, 61534, 61592, 61642, 61688, 61704, 61726, 
    61784, 61800, 61836, 61880, 61914, 61948, 61998, 62122, 
    62154, 62200, 62218, 62302, 62364, 62442, 62478, 62536, 
    62554, 62584, 62604, 62640, 62648, 62656, 62664, 62730, 
    62924, 63050, 63082, 63274, 63390, 
     3456,  3696,  3712,  3728,  3744,  3766,  3832,  3896, 
     3912,  3928,  3944,  3968,  4008,  4040,  4056,  4106, 
     4138,  4170,  4202,  4234,  4266,  4296,  4312,  4344, 
     4408,  4424,  4442,  4472,  4488,  4504,  6148,  6198, 
     6264,  6280,  6360,  6429,  6505,  6529, 61448, 61468, 
    61512, 61534, 61592, 61610, 61642, 61672, 61688, 61704, 
    61726, 61784, 61800, 61816, 61836, 61880, 61896, 61914, 
    61948, 61998, 62062, 62122, 62154, 62184, 62200, 62218, 
    62252, 62302, 62364, 62410, 62442, 62478, 62536, 62554, 
    62584, 62604, 62640, 62648, 62656, 62664, 62730, 62766, 
    62830, 62890, 62924, 62974, 63032, 63050, 63082, 63118, 
    63182, 63242, 63274, 63310, 63368, 63390, 
  };
#define HIBIT ((unsigned char)0x80)
  char aChar[] = {
  unsigned char aChar[] = {
    '\0', 'a',  'c',  'e',  'i',  'n',  'o',  'u',  'y',  'y',  'a',  'c',  
    'd',  'e',  'e',  'g',  'h',  'i',  'j',  'k',  'l',  'n',  'o',  'r',  
    's',  't',  'u',  'u',  'w',  'y',  'z',  'o',  'u',  'a',  'i',  'o',  
    '\0',      'a',       'c',       'e',       'i',       'n',       
    'o',       'u',       'y',       'y',       'a',       'c',       
    'd',       'e',       'e',       'g',       'h',       'i',       
    'j',       'k',       'l',       'n',       'o',       'r',       
    's',       't',       'u',       'u',       'w',       'y',       
    'z',       'o',       'u',       'a',       'i',       'o',       
    'u',       'u'|HIBIT, 'a'|HIBIT, 'g',       'k',       'o',       
    'o'|HIBIT, 'j',       'g',       'n',       'a'|HIBIT, 'a',       
    'e',       'i',       'o',       'r',       'u',       's',       
    't',       'h',       'a',       'e',       'o'|HIBIT, 'o',       
    'o'|HIBIT, 'y',       '\0',      '\0',      '\0',      '\0',      
    'u',  'g',  'k',  'o',  'j',  'g',  'n',  'a',  'e',  'i',  'o',  'r',  
    'u',  's',  't',  'h',  'a',  'e',  'o',  'y',  '\0', '\0', '\0', '\0', 
    '\0', '\0', '\0', '\0', 'a',  'b',  'd',  'd',  'e',  'f',  'g',  'h',  
    'h',  'i',  'k',  'l',  'l',  'm',  'n',  'p',  'r',  'r',  's',  't',  
    'u',  'v',  'w',  'w',  'x',  'y',  'z',  'h',  't',  'w',  'y',  'a',  
    'e',  'i',  'o',  'u',  'y',  
    '\0',      '\0',      '\0',      '\0',      'a',       'b',       
    'c'|HIBIT, 'd',       'd',       'e'|HIBIT, 'e',       'e'|HIBIT, 
    'f',       'g',       'h',       'h',       'i',       'i'|HIBIT, 
    'k',       'l',       'l'|HIBIT, 'l',       'm',       'n',       
    'o'|HIBIT, 'p',       'r',       'r'|HIBIT, 'r',       's',       
    's'|HIBIT, 't',       'u',       'u'|HIBIT, 'v',       'w',       
    'w',       'x',       'y',       'z',       'h',       't',       
    'w',       'y',       'a',       'a'|HIBIT, 'a'|HIBIT, 'a'|HIBIT, 
    'e',       'e'|HIBIT, 'e'|HIBIT, 'i',       'o',       'o'|HIBIT, 
    'o'|HIBIT, 'o'|HIBIT, 'u',       'u'|HIBIT, 'u'|HIBIT, 'y',       
  };

  unsigned int key = (((unsigned int)c)<<3) | 0x00000007;
  int iRes = 0;
  int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;
  int iLo = 0;
  while( iHi>=iLo ){
    int iTest = (iHi + iLo) / 2;
    if( key >= aDia[iTest] ){
      iRes = iTest;
      iLo = iTest+1;
    }else{
      iHi = iTest-1;
    }
  }
  assert( key>=aDia[iRes] );
  if( bComplex==0 && (aChar[iRes] & 0x80) ) return c;
  return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);
  return (c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : ((int)aChar[iRes] & 0x7F);
}


/*
** Return true if the argument interpreted as a unicode codepoint
** is a diacritical modifier character.
*/
int sqlite3FtsUnicodeIsdiacritic(int c){
  unsigned int mask0 = 0x08029FDF;
  unsigned int mask1 = 0x000361F8;
  if( c<768 || c>817 ) return 0;
  return (c < 768+32) ?
      (mask0 & (1 << (c-768))) :
      (mask1 & (1 << (c-768-32)));
      (mask0 & ((unsigned int)1 << (c-768))) :
      (mask1 & ((unsigned int)1 << (c-768-32)));
}


/*
** Interpret the argument as a unicode codepoint. If the codepoint
** is an upper case character that has a lower case equivalent,
** return the codepoint corresponding to the lower case version.
** Otherwise, return a copy of the argument.
**
** The results are undefined if the value passed to this function
** is less than zero.
*/
int sqlite3FtsUnicodeFold(int c, int bRemoveDiacritic){
int sqlite3FtsUnicodeFold(int c, int eRemoveDiacritic){
  /* Each entry in the following array defines a rule for folding a range
  ** of codepoints to lower case. The rule applies to a range of nRange
  ** codepoints starting at codepoint iCode.
  **
  ** If the least significant bit in flags is clear, then the rule applies
  ** to all nRange codepoints (i.e. all nRange codepoints are upper case and
  ** need to be folded). Or, if it is set, then the rule only applies to

    assert( iRes>=0 && c>=aEntry[iRes].iCode );
    p = &aEntry[iRes];
    if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){
      ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;
      assert( ret>0 );
    }

    if( eRemoveDiacritic ){
    if( bRemoveDiacritic ) ret = remove_diacritic(ret);
      ret = remove_diacritic(ret, eRemoveDiacritic==2);
    }
  }
  
  else if( c>=66560 && c<66600 ){
    ret = c + 40;
  }

  return ret;
}
#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */
#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */

#include "fts3Int.h"
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

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

#include <stdio.h>

#define FTS_MAX_APPENDABLE_HEIGHT 16

/*
** 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

# define FTS3_NODE_CHUNK_THRESHOLD test_fts3_node_chunk_threshold
#else
# define FTS3_NODE_CHUNKSIZE (4*1024) 
# define FTS3_NODE_CHUNK_THRESHOLD (FTS3_NODE_CHUNKSIZE*4)
#endif

/*
** The two values that may be meaningfully bound to the :1 parameter in
** The values that may be meaningfully bound to the :1 parameter in
** statements SQL_REPLACE_STAT and SQL_SELECT_STAT.
*/
#define FTS_STAT_DOCTOTAL      0
#define FTS_STAT_INCRMERGEHINT 1
#define FTS_STAT_AUTOINCRMERGE 2

/*

/* This statement is used to determine which level to read the input from
** when performing an incremental merge. It returns the absolute level number
** of the oldest level in the db that contains at least ? segments. Or,
** if no level in the FTS index contains more than ? segments, the statement
** returns zero rows.  */
/* 28 */ "SELECT level, count(*) AS cnt FROM %Q.'%q_segdir' "
         "  GROUP BY level HAVING cnt>=?"
         "  ORDER BY (level %% 1024) ASC LIMIT 1",
         "  ORDER BY (level %% 1024) ASC, 2 DESC LIMIT 1",

/* Estimate the upper limit on the number of leaf nodes in a new segment
** created by merging the oldest :2 segments from absolute level :1. See 
** function sqlite3Fts3Incrmerge() for details.  */
/* 29 */ "SELECT 2 * total(1 + leaves_end_block - start_block) "
         "  FROM %Q.'%q_segdir' WHERE level = ? AND idx < ?",

  sqlite3_stmt *pStmt;

  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
  assert( eStmt<SizeofArray(azSql) && eStmt>=0 );
  
  pStmt = p->aStmt[eStmt];
  if( !pStmt ){
    int f = SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_NO_VTAB;
    char *zSql;
    if( eStmt==SQL_CONTENT_INSERT ){
      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist);
    }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){
      f &= ~SQLITE_PREPARE_NO_VTAB;
      zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist);
    }else{
      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName);
    }
    if( !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v3(p->db, zSql, -1, SQLITE_PREPARE_PERSISTENT,
      rc = sqlite3_prepare_v3(p->db, zSql, -1, f, &pStmt, NULL);
                              &pStmt, NULL);
      sqlite3_free(zSql);
      assert( rc==SQLITE_OK || pStmt==0 );
      p->aStmt[eStmt] = pStmt;
    }
  }
  if( apVal ){
    int i;

static sqlite3_int64 getAbsoluteLevel(
  Fts3Table *p,                   /* FTS3 table handle */
  int iLangid,                    /* Language id */
  int iIndex,                     /* Index in p->aIndex[] */
  int iLevel                      /* Level of segments */
){
  sqlite3_int64 iBase;            /* First absolute level for iLangid/iIndex */
  assert( iLangid>=0 );
  assert_fts3_nc( iLangid>=0 );
  assert( p->nIndex>0 );
  assert( iIndex>=0 && iIndex<p->nIndex );

  iBase = ((sqlite3_int64)iLangid * p->nIndex + iIndex) * FTS3_SEGDIR_MAXLEVEL;
  return iBase + iLevel;
}

){
  PendingList *p = *pp;
  int rc = SQLITE_OK;

  assert( !p || p->iLastDocid<=iDocid );

  if( !p || p->iLastDocid!=iDocid ){
    sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0);
    u64 iDelta = (u64)iDocid - (u64)(p ? p->iLastDocid : 0);
    if( p ){
      assert( p->nData<p->nSpace );
      assert( p->aData[p->nData]==0 );
      p->nData++;
    }
    if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iDelta)) ){
      goto pendinglistappend_out;

  if( rc==SQLITE_OK ){
    /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already
    ** full, merge all segments in level iLevel into a single iLevel+1
    ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise,
    ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.
    */
    if( iNext>=FTS3_MERGE_COUNT ){
    if( iNext>=MergeCount(p) ){
      fts3LogMerge(16, getAbsoluteLevel(p, iLangid, iIndex, iLevel));
      rc = fts3SegmentMerge(p, iLangid, iIndex, iLevel);
      *piIdx = 0;
    }else{
      *piIdx = iNext;
    }
  }

        if( rc!=SQLITE_OK ){
          sqlite3_free(aByte);
          aByte = 0;
        }
      }
      *paBlob = aByte;
    }
  }else if( rc==SQLITE_ERROR ){
    rc = FTS_CORRUPT_VTAB;
  }

  return rc;
}

/*
** Close the blob handle at p->pSegments, if it is open. See comments above

      return SQLITE_OK;
    }

    fts3SegReaderSetEof(pReader);

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

    rc = sqlite3Fts3ReadBlock(
        p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode, 
        (bIncr ? &pReader->nPopulate : 0)

  rc = fts3SegReaderRequire(pReader, pNext, FTS3_VARINT_MAX*2);
  if( rc!=SQLITE_OK ) return rc;
  
  /* 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 += fts3GetVarint32(pNext, &nPrefix);
  pNext += fts3GetVarint32(pNext, &nSuffix);
  if( nPrefix<0 || nSuffix<=0 
   || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] 
  if( nSuffix<=0 
   || (&pReader->aNode[pReader->nNode] - pNext)<nSuffix
   || nPrefix>pReader->nTerm
  ){
    return FTS_CORRUPT_VTAB;
  }

  /* Both nPrefix and nSuffix were read by fts3GetVarint32() and so are
  ** between 0 and 0x7FFFFFFF. But the sum of the two may cause integer
  ** overflow - hence the (i64) casts.  */
  if( nPrefix+nSuffix>pReader->nTermAlloc ){
    int nNew = (nPrefix+nSuffix)*2;
    char *zNew = sqlite3_realloc(pReader->zTerm, nNew);
  if( (i64)nPrefix+nSuffix>(i64)pReader->nTermAlloc ){
    i64 nNew = ((i64)nPrefix+nSuffix)*2;
    char *zNew = sqlite3_realloc64(pReader->zTerm, nNew);
    if( !zNew ){
      return SQLITE_NOMEM;
    }
    pReader->zTerm = zNew;
    pReader->nTermAlloc = nNew;
  }

  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] 
  if( pReader->nDoclist > pReader->nNode-(pReader->aDoclist-pReader->aNode)
   || (pReader->nPopulate==0 && pReader->aDoclist[pReader->nDoclist-1])
  ){
    return FTS_CORRUPT_VTAB;
  }
  return SQLITE_OK;
}

    ** returning.
    */
    if( p>=pEnd ){
      pReader->pOffsetList = 0;
    }else{
      rc = fts3SegReaderRequire(pReader, p, FTS3_VARINT_MAX);
      if( rc==SQLITE_OK ){
        sqlite3_int64 iDelta;
        pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta);
        u64 iDelta;
        pReader->pOffsetList = p + sqlite3Fts3GetVarintU(p, &iDelta);
        if( pTab->bDescIdx ){
          pReader->iDocid -= iDelta;
          pReader->iDocid = (i64)((u64)pReader->iDocid - iDelta);
        }else{
          pReader->iDocid += iDelta;
          pReader->iDocid = (i64)((u64)pReader->iDocid + iDelta);
        }
      }
    }
  }

  return SQLITE_OK;
  return rc;
}


int sqlite3Fts3MsrOvfl(
  Fts3Cursor *pCsr, 
  Fts3MultiSegReader *pMsr,
  int *pnOvfl

  const char *zRoot,              /* Buffer containing root node */
  int nRoot,                      /* Size of buffer containing root node */
  Fts3SegReader **ppReader        /* OUT: Allocated Fts3SegReader */
){
  Fts3SegReader *pReader;         /* Newly allocated SegReader object */
  int nExtra = 0;                 /* Bytes to allocate segment root node */

  assert( zRoot!=0 || nRoot==0 );
#ifdef CORRUPT_DB
  assert( zRoot!=0 || CORRUPT_DB );
#endif
  assert( iStartLeaf<=iEndLeaf );

  if( iStartLeaf==0 ){
    if( iEndLeaf!=0 ) return FTS_CORRUPT_VTAB;
    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->bLookup = bLookup!=0;
  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->rootOnly = 1;
    pReader->nNode = nRoot;
    memcpy(pReader->aNode, zRoot, nRoot);
    if( nRoot ) memcpy(pReader->aNode, zRoot, nRoot);
    memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING);
  }else{
    pReader->iCurrentBlock = iStartLeaf-1;
  }
  *ppReader = pReader;
  return SQLITE_OK;
}

    if( pE ){
      aElem = &pE;
      nElem = 1;
    }
  }

  if( nElem>0 ){
    sqlite3_int64 nByte;
    int nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *);
    pReader = (Fts3SegReader *)sqlite3_malloc(nByte);
    nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *);
    pReader = (Fts3SegReader *)sqlite3_malloc64(nByte);
    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 *));

  sqlite3_stmt *pStmt;
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);
    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);
    sqlite3_bind_null(pStmt, 2);
  }
  return rc;
}

/*
** Find the largest relative level number in the table. If successful, set
** *pnMax to this value and return SQLITE_OK. Otherwise, if an error occurs,

      char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);
      if( !zEnd ) return SQLITE_NOMEM;
      sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);
    }
    sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);
    sqlite3_bind_null(pStmt, 6);
  }
  return rc;
}

/*
** Return the size of the common prefix (if any) shared by zPrev and
** zNext, in bytes. For example, 

    int nData = pTree->nData;     /* Current size of node in bytes */
    int nReq = nData;             /* Required space after adding zTerm */
    int nPrefix;                  /* Number of bytes of prefix compression */
    int nSuffix;                  /* Suffix length */

    nPrefix = fts3PrefixCompress(pTree->zTerm, pTree->nTerm, zTerm, nTerm);
    nSuffix = nTerm-nPrefix;

    /* If nSuffix is zero or less, then zTerm/nTerm must be a prefix of 
    ** pWriter->zTerm/pWriter->nTerm. i.e. must be equal to or less than when
    ** compared with BINARY collation. This indicates corruption.  */
    if( nSuffix<=0 ) return FTS_CORRUPT_VTAB;

    nReq += sqlite3Fts3VarintLen(nPrefix)+sqlite3Fts3VarintLen(nSuffix)+nSuffix;
    if( nReq<=p->nNodeSize || !pTree->zTerm ){

      if( nReq>p->nNodeSize ){
        /* An unusual case: this is the first term to be added to the node
        ** and the static node buffer (p->nNodeSize bytes) is not large

    rc = sqlite3_reset(pStmt);
    if( rc!=SQLITE_OK ) return rc;
  }
  nData = pWriter->nData;

  nPrefix = fts3PrefixCompress(pWriter->zTerm, pWriter->nTerm, zTerm, nTerm);
  nSuffix = nTerm-nPrefix;

  /* If nSuffix is zero or less, then zTerm/nTerm must be a prefix of 
  ** pWriter->zTerm/pWriter->nTerm. i.e. must be equal to or less than when
  ** compared with BINARY collation. This indicates corruption.  */
  if( nSuffix<=0 ) return FTS_CORRUPT_VTAB;

  /* Figure out how many bytes are required by this new entry */
  nReq = sqlite3Fts3VarintLen(nPrefix) +    /* varint containing prefix size */
    sqlite3Fts3VarintLen(nSuffix) +         /* varint containing suffix size */
    nSuffix +                               /* Term suffix */
    sqlite3Fts3VarintLen(nDoclist) +        /* Size of doclist */
    nDoclist;                               /* Doclist data */

  if( nData>0 && nData+nReq>p->nNodeSize ){
    int rc;

    /* The current leaf node is full. Write it out to the database. */
    if( pWriter->iFree==LARGEST_INT64 ) return FTS_CORRUPT_VTAB;
    rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData);
    if( rc!=SQLITE_OK ) return rc;
    p->nLeafAdd++;

    /* Add the current term to the interior node tree. The term added to
    ** the interior tree must:
    **

    pWriter->nSize = nReq;
  }
  assert( nData+nReq<=pWriter->nSize );

  /* Append the prefix-compressed term and doclist to the buffer. */
  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nPrefix);
  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nSuffix);
  assert( nSuffix>0 );
  memcpy(&pWriter->aData[nData], &zTerm[nPrefix], nSuffix);
  nData += nSuffix;
  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nDoclist);
  assert( nDoclist>0 );
  memcpy(&pWriter->aData[nData], aDoclist, nDoclist);
  pWriter->nData = nData + nDoclist;

  /* Save the current term so that it can be used to prefix-compress the next.
  ** If the isCopyTerm parameter is true, then the buffer pointed to by
  ** zTerm is transient, so take a copy of the term data. Otherwise, just
  ** store a copy of the pointer.
  */
  if( isCopyTerm ){
    if( nTerm>pWriter->nMalloc ){
      char *zNew = sqlite3_realloc(pWriter->zMalloc, nTerm*2);
      if( !zNew ){
        return SQLITE_NOMEM;
      }
      pWriter->nMalloc = nTerm*2;
      pWriter->zMalloc = zNew;
      pWriter->zTerm = zNew;
    }
    assert( pWriter->zTerm==pWriter->zMalloc );
    assert( nTerm>0 );
    memcpy(pWriter->zTerm, zTerm, nTerm);
  }else{
    pWriter->zTerm = (char *)zTerm;
  }
  pWriter->nTerm = nTerm;

  return SQLITE_OK;

    if( iCol==iCurrent ){
      nList = (int)(p - pList);
      break;
    }

    nList -= (int)(p - pList);
    pList = p;
    if( nList==0 ){
    if( nList<=0 ){
      break;
    }
    p = &pList[1];
    p += fts3GetVarint32(p, &iCurrent);
  }

  if( bZero && &pList[nList]!=pEnd ){
  if( bZero && (pEnd - &pList[nList])>0){
    memset(&pList[nList], 0, pEnd - &pList[nList]);
  }
  *ppList = pList;
  *pnList = nList;
}

/*

    char *pNew;
    pMsr->nBuffer = nList*2;
    pNew = (char *)sqlite3_realloc(pMsr->aBuffer, pMsr->nBuffer);
    if( !pNew ) return SQLITE_NOMEM;
    pMsr->aBuffer = pNew;
  }

  assert( nList>0 );
  memcpy(pMsr->aBuffer, pList, nList);
  return SQLITE_OK;
}

int sqlite3Fts3MsrIncrNext(
  Fts3Table *p,                   /* Virtual table handle */
  Fts3MultiSegReader *pMsr,       /* Multi-segment-reader handle */

        if( !isIgnoreEmpty || nList>0 ){

          /* Calculate the 'docid' delta value to write into the merged 
          ** doclist. */
          sqlite3_int64 iDelta;
          if( p->bDescIdx && nDoclist>0 ){
            if( iPrev<=iDocid ) return FTS_CORRUPT_VTAB;
            iDelta = iPrev - iDocid;
            iDelta = (i64)((u64)iPrev - (u64)iDocid);
          }else{
            if( nDoclist>0 && iPrev>=iDocid ) return FTS_CORRUPT_VTAB;
            iDelta = iDocid - iPrev;
            iDelta = (i64)((u64)iDocid - (u64)iPrev);
          }
          assert( iDelta>0 || (nDoclist==0 && iDelta==iDocid) );
          assert( nDoclist>0 || iDelta==iDocid );

          nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0);
          if( nDoclist+nByte>pCsr->nBuffer ){
            char *aNew;
            pCsr->nBuffer = (nDoclist+nByte)*2;
            aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);
            if( !aNew ){

    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);
    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
    bIgnoreEmpty = (iLevel!=FTS3_SEGCURSOR_PENDING) && (iNewLevel>iMaxLevel);
  }
  if( rc!=SQLITE_OK ) goto finished;

  assert( csr.nSegment>0 );
  assert( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
  assert( iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) );
  assert_fts3_nc( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
  assert_fts3_nc( 
    iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) 
  );

  memset(&filter, 0, sizeof(Fts3SegFilter));
  filter.flags = FTS3_SEGMENT_REQUIRE_POS;
  filter.flags |= (bIgnoreEmpty ? FTS3_SEGMENT_IGNORE_EMPTY : 0);

  rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);
  while( SQLITE_OK==rc ){
    rc = sqlite3Fts3SegReaderStep(p, &csr);
    if( rc!=SQLITE_ROW ) break;
    rc = fts3SegWriterAdd(p, &pWriter, 1, 
        csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
  }
  if( rc!=SQLITE_OK ) goto finished;
  assert( pWriter || bIgnoreEmpty );
  assert_fts3_nc( pWriter || bIgnoreEmpty );

  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
    rc = fts3DeleteSegdir(
        p, iLangid, iIndex, iLevel, csr.apSegment, csr.nSegment
    );
    if( rc!=SQLITE_OK ) goto finished;
  }

*/
static void fts3DecodeIntArray(
  int N,             /* The number of integers to decode */
  u32 *a,            /* Write the integer values */
  const char *zBuf,  /* The BLOB containing the varints */
  int nBuf           /* size of the BLOB */
){
  int i, j;
  UNUSED_PARAMETER(nBuf);
  for(i=j=0; i<N; i++){
    sqlite3_int64 x;
    j += sqlite3Fts3GetVarint(&zBuf[j], &x);
  int i = 0;
  if( nBuf && (zBuf[nBuf-1]&0x80)==0 ){
    int j;
    for(i=j=0; i<N && j<nBuf; i++){
      sqlite3_int64 x;
      j += sqlite3Fts3GetVarint(&zBuf[j], &x);
    assert(j<=nBuf);
    a[i] = (u32)(x & 0xffffffff);
  }
      a[i] = (u32)(x & 0xffffffff);
    }
  }
  while( i<N ) a[i++] = 0;
}

/*
** Insert the sizes (in tokens) for each column of the document
** with docid equal to p->iPrevDocid.  The sizes are encoded as
** a blob of varints.
*/
static void fts3InsertDocsize(
  int *pRC,                       /* Result code */
  Fts3Table *p,                   /* Table into which to insert */
  u32 *aSz                        /* Sizes of each column, in tokens */
){
  char *pBlob;             /* The BLOB encoding of the document size */
  int nBlob;               /* Number of bytes in the BLOB */
  sqlite3_stmt *pStmt;     /* Statement used to insert the encoding */
  int rc;                  /* Result code from subfunctions */

  if( *pRC ) return;
  pBlob = sqlite3_malloc( 10*p->nColumn );
  pBlob = sqlite3_malloc64( 10*(sqlite3_int64)p->nColumn );
  if( pBlob==0 ){
    *pRC = SQLITE_NOMEM;
    return;
  }
  fts3EncodeIntArray(p->nColumn, aSz, pBlob, &nBlob);
  rc = fts3SqlStmt(p, SQL_REPLACE_DOCSIZE, &pStmt, 0);
  if( rc ){

  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 );
  a = sqlite3_malloc64( (sizeof(u32)+10)*(sqlite3_int64)nStat );
  if( a==0 ){
    *pRC = SQLITE_NOMEM;
    return;
  }
  pBlob = (char*)&a[nStat];
  rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
  if( rc ){

    *pRC = rc;
    return;
  }
  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, SQLITE_STATIC);
  sqlite3_step(pStmt);
  *pRC = sqlite3_reset(pStmt);
  sqlite3_bind_null(pStmt, 2);
  sqlite3_free(a);
}

/*
** Merge the entire database so that there is one segment for each 
** iIndex/iLangid combination.
*/
static int fts3DoOptimize(Fts3Table *p, int bReturnDone){
  int bSeenDone = 0;
  int rc;
  sqlite3_stmt *pAllLangid = 0;

  rc = sqlite3Fts3PendingTermsFlush(p);
  if( rc==SQLITE_OK ){
  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
    rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
  }
  if( rc==SQLITE_OK ){
    int rc2;
    sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);
    sqlite3_bind_int(pAllLangid, 2, p->nIndex);
    while( sqlite3_step(pAllLangid)==SQLITE_ROW ){
      int i;
      int iLangid = sqlite3_column_int(pAllLangid, 0);
      for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
        rc = fts3SegmentMerge(p, iLangid, i, FTS3_SEGCURSOR_ALL);
        if( rc==SQLITE_DONE ){
          bSeenDone = 1;
          rc = SQLITE_OK;
        }
      }
    }
    rc2 = sqlite3_reset(pAllLangid);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  sqlite3Fts3SegmentsClose(p);
  sqlite3Fts3PendingTermsClear(p);

  return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc;
}

/*
** This function is called when the user executes the following statement:
**

      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
      sqlite3_free(zSql);
    }

    if( rc==SQLITE_OK ){
      int nByte = sizeof(u32) * (p->nColumn+1)*3;
      aSz = (u32 *)sqlite3_malloc(nByte);
      sqlite3_int64 nByte = sizeof(u32) * ((sqlite3_int64)p->nColumn+1)*3;
      aSz = (u32 *)sqlite3_malloc64(nByte);
      if( aSz==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(aSz, 0, nByte);
        aSzIns = &aSz[p->nColumn+1];
        aSzDel = &aSzIns[p->nColumn+1];
      }

  Fts3Table *p,                   /* FTS3 table handle */
  sqlite3_int64 iAbsLevel,        /* Absolute level to open */
  int nSeg,                       /* Number of segments to merge */
  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
){
  int rc;                         /* Return Code */
  sqlite3_stmt *pStmt = 0;        /* Statement used to read %_segdir entry */  
  int nByte;                      /* Bytes allocated at pCsr->apSegment[] */
  sqlite3_int64 nByte;            /* Bytes allocated at pCsr->apSegment[] */

  /* Allocate space for the Fts3MultiSegReader.aCsr[] array */
  memset(pCsr, 0, sizeof(*pCsr));
  nByte = sizeof(Fts3SegReader *) * nSeg;
  pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc(nByte);
  pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc64(nByte);

  if( pCsr->apSegment==0 ){
    rc = SQLITE_NOMEM;
  }else{
    memset(pCsr->apSegment, 0, nByte);
    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
  }

    p->aNode = 0;
  }else{
    if( bFirst==0 ){
      p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);
    }
    p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);

    if( nPrefix>p->term.n || nSuffix>p->nNode-p->iOff || nSuffix==0 ){
      return FTS_CORRUPT_VTAB;
    }
    blobGrowBuffer(&p->term, nPrefix+nSuffix, &rc);
    if( rc==SQLITE_OK ){
      memcpy(&p->term.a[nPrefix], &p->aNode[p->iOff], nSuffix);
      p->term.n = nPrefix+nSuffix;
      p->iOff += nSuffix;
      if( p->iChild==0 ){
        p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);
        if( (p->nNode-p->iOff)<p->nDoclist ){
          return FTS_CORRUPT_VTAB;
        }
        p->aDoclist = &p->aNode[p->iOff];
        p->iOff += p->nDoclist;
      }
    }
  }

  assert( p->iOff<=p->nNode );
  assert_fts3_nc( p->iOff<=p->nNode );

  return rc;
}

/*
** Release all dynamic resources held by node-reader object *p.
*/
static void nodeReaderRelease(NodeReader *p){

*/
static int nodeReaderInit(NodeReader *p, const char *aNode, int nNode){
  memset(p, 0, sizeof(NodeReader));
  p->aNode = aNode;
  p->nNode = nNode;

  /* Figure out if this is a leaf or an internal node. */
  if( p->aNode[0] ){
  if( aNode && aNode[0] ){
    /* An internal node. */
    p->iOff = 1 + sqlite3Fts3GetVarint(&p->aNode[1], &p->iChild);
  }else{
    p->iOff = 1;
  }

  return nodeReaderNext(p);
  return aNode ? nodeReaderNext(p) : SQLITE_OK;
}

/*
** This function is called while writing an FTS segment each time a leaf o
** node is finished and written to disk. The key (zTerm/nTerm) is guaranteed
** to be greater than the largest key on the node just written, but smaller
** than or equal to the first key that will be written to the next leaf

    /* Figure out how much space the key will consume if it is written to
    ** the current node of layer iLayer. Due to the prefix compression, 
    ** the space required changes depending on which node the key is to
    ** be added to.  */
    nPrefix = fts3PrefixCompress(pNode->key.a, pNode->key.n, zTerm, nTerm);
    nSuffix = nTerm - nPrefix;
    if(nSuffix<=0 ) return FTS_CORRUPT_VTAB;
    nSpace  = sqlite3Fts3VarintLen(nPrefix);
    nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;

    if( pNode->key.n==0 || (pNode->block.n + nSpace)<=p->nNodeSize ){ 
      /* If the current node of layer iLayer contains zero keys, or if adding
      ** the key to it will not cause it to grow to larger than nNodeSize 
      ** bytes in size, write the key here.  */

  int bFirst = (pPrev->n==0);     /* True if this is the first term written */
  int nPrefix;                    /* Size of term prefix in bytes */
  int nSuffix;                    /* Size of term suffix in bytes */

  /* Node must have already been started. There must be a doclist for a
  ** leaf node, and there must not be a doclist for an internal node.  */
  assert( pNode->n>0 );
  assert( (pNode->a[0]=='\0')==(aDoclist!=0) );
  assert_fts3_nc( (pNode->a[0]=='\0')==(aDoclist!=0) );

  blobGrowBuffer(pPrev, nTerm, &rc);
  if( rc!=SQLITE_OK ) return rc;

  nPrefix = fts3PrefixCompress(pPrev->a, pPrev->n, zTerm, nTerm);
  nSuffix = nTerm - nPrefix;
  if( nSuffix<=0 ) return FTS_CORRUPT_VTAB;
  memcpy(pPrev->a, zTerm, nTerm);
  pPrev->n = nTerm;

  if( bFirst==0 ){
    pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nPrefix);
  }
  pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nSuffix);

static int fts3TermCmp(
  const char *zLhs, int nLhs,     /* LHS of comparison */
  const char *zRhs, int nRhs      /* RHS of comparison */
){
  int nCmp = MIN(nLhs, nRhs);
  int res;

  res = memcmp(zLhs, zRhs, nCmp);
  res = (nCmp ? memcmp(zLhs, zRhs, nCmp) : 0);
  if( res==0 ) res = nLhs - nRhs;

  return res;
}


/*

      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
      if( pWriter->nLeafData<0 ){
        pWriter->nLeafData = pWriter->nLeafData * -1;
      }
      pWriter->bNoLeafData = (pWriter->nLeafData==0);
      nRoot = sqlite3_column_bytes(pSelect, 4);
      aRoot = sqlite3_column_blob(pSelect, 4);
      if( aRoot==0 ){
        sqlite3_reset(pSelect);
        return nRoot ? SQLITE_NOMEM : FTS_CORRUPT_VTAB;
      }
    }else{
      return sqlite3_reset(pSelect);
    }

    /* Check for the zero-length marker in the %_segments table */
    rc = fts3IsAppendable(p, iEnd, &bAppendable);

    if( rc==SQLITE_OK && bAppendable ){
      /* It is possible to append to this segment. Set up the IncrmergeWriter
      ** object to do so.  */
      int i;
      int nHeight = (int)aRoot[0];
      NodeWriter *pNode;
      if( nHeight<1 || nHeight>FTS_MAX_APPENDABLE_HEIGHT ){
        sqlite3_reset(pSelect);
        return FTS_CORRUPT_VTAB;
      }

      pWriter->nLeafEst = (int)((iEnd - iStart) + 1)/FTS_MAX_APPENDABLE_HEIGHT;
      pWriter->iStart = iStart;
      pWriter->iEnd = iEnd;
      pWriter->iAbsLevel = iAbsLevel;
      pWriter->iIdx = iIdx;

      for(i=nHeight+1; i<FTS_MAX_APPENDABLE_HEIGHT; i++){
        pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
      }

      pNode = &pWriter->aNodeWriter[nHeight];
      pNode->iBlock = pWriter->iStart + pWriter->nLeafEst*nHeight;
      blobGrowBuffer(&pNode->block, MAX(nRoot, p->nNodeSize), &rc);
      blobGrowBuffer(&pNode->block, 
          MAX(nRoot, p->nNodeSize)+FTS3_NODE_PADDING, &rc
      );
      if( rc==SQLITE_OK ){
        memcpy(pNode->block.a, aRoot, nRoot);
        pNode->block.n = nRoot;
        memset(&pNode->block.a[nRoot], 0, FTS3_NODE_PADDING);
      }

      for(i=nHeight; i>=0 && rc==SQLITE_OK; i--){
        NodeReader reader;
        pNode = &pWriter->aNodeWriter[i];

        if( pNode->block.a){
        rc = nodeReaderInit(&reader, pNode->block.a, pNode->block.n);
        while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);
        blobGrowBuffer(&pNode->key, reader.term.n, &rc);
        if( rc==SQLITE_OK ){
          memcpy(pNode->key.a, reader.term.a, reader.term.n);
          pNode->key.n = reader.term.n;
          if( i>0 ){
            char *aBlock = 0;
            int nBlock = 0;
            pNode = &pWriter->aNodeWriter[i-1];
            pNode->iBlock = reader.iChild;
            rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
            blobGrowBuffer(&pNode->block, MAX(nBlock, p->nNodeSize), &rc);
            if( rc==SQLITE_OK ){
              memcpy(pNode->block.a, aBlock, nBlock);
              pNode->block.n = nBlock;
            }
            sqlite3_free(aBlock);
          rc = nodeReaderInit(&reader, pNode->block.a, pNode->block.n);
          while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);
          blobGrowBuffer(&pNode->key, reader.term.n, &rc);
          if( rc==SQLITE_OK ){
            memcpy(pNode->key.a, reader.term.a, reader.term.n);
            pNode->key.n = reader.term.n;
            if( i>0 ){
              char *aBlock = 0;
              int nBlock = 0;
              pNode = &pWriter->aNodeWriter[i-1];
              pNode->iBlock = reader.iChild;
              rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
              blobGrowBuffer(&pNode->block, 
                  MAX(nBlock, p->nNodeSize)+FTS3_NODE_PADDING, &rc
              );
              if( rc==SQLITE_OK ){
                memcpy(pNode->block.a, aBlock, nBlock);
                pNode->block.n = nBlock;
                memset(&pNode->block.a[nBlock], 0, FTS3_NODE_PADDING);
              }
              sqlite3_free(aBlock);
            }
          }
        }
        nodeReaderRelease(&reader);
      }
    }

    rc2 = sqlite3_reset(pSelect);

  const char *zTerm,              /* Omit all terms smaller than this */
  int nTerm,                      /* Size of zTerm in bytes */
  sqlite3_int64 *piBlock          /* OUT: Block number in next layer down */
){
  NodeReader reader;              /* Reader object */
  Blob prev = {0, 0, 0};          /* Previous term written to new node */
  int rc = SQLITE_OK;             /* Return code */
  int bLeaf;                       /* True for a leaf node */

  if( nNode<1 ) return FTS_CORRUPT_VTAB;
  int bLeaf = aNode[0]=='\0';     /* True for a leaf node */
  bLeaf = aNode[0]=='\0';

  /* Allocate required output space */
  blobGrowBuffer(pNew, nNode, &rc);
  if( rc!=SQLITE_OK ) return rc;
  pNew->n = 0;

  /* Populate new node buffer */

    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pChomp, 1, iNewStart);
      sqlite3_bind_blob(pChomp, 2, root.a, root.n, SQLITE_STATIC);
      sqlite3_bind_int64(pChomp, 3, iAbsLevel);
      sqlite3_bind_int(pChomp, 4, iIdx);
      sqlite3_step(pChomp);
      rc = sqlite3_reset(pChomp);
      sqlite3_bind_null(pChomp, 2);
    }
  }

  sqlite3_free(root.a);
  sqlite3_free(block.a);
  return rc;
}

  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pReplace, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pReplace, 1, FTS_STAT_INCRMERGEHINT);
    sqlite3_bind_blob(pReplace, 2, pHint->a, pHint->n, SQLITE_STATIC);
    sqlite3_step(pReplace);
    rc = sqlite3_reset(pReplace);
    sqlite3_bind_null(pReplace, 2);
  }

  return rc;
}

/*
** Load an incr-merge hint from the database. The incr-merge hint, if one 

** If no error occurs, return SQLITE_OK. If the hint blob in *pHint does
** not contain at least two valid varints, return SQLITE_CORRUPT_VTAB.
*/
static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){
  const int nHint = pHint->n;
  int i;

  i = pHint->n-2;
  i = pHint->n-1;
  if( (pHint->a[i] & 0x80) ) return FTS_CORRUPT_VTAB;
  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;
  if( i==0 ) return FTS_CORRUPT_VTAB;
  i--;
  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;

  pHint->n = i;
  i += sqlite3Fts3GetVarint(&pHint->a[i], piAbsLevel);
  i += fts3GetVarint32(&pHint->a[i], pnInput);
  assert( i<=nHint );
  if( i!=nHint ) return FTS_CORRUPT_VTAB;

  return SQLITE_OK;
}


/*

    if( rc==SQLITE_OK && hint.n ){
      int nHint = hint.n;
      sqlite3_int64 iHintAbsLevel = 0;      /* Hint level */
      int nHintSeg = 0;                     /* Hint number of segments */

      rc = fts3IncrmergeHintPop(&hint, &iHintAbsLevel, &nHintSeg);
      if( nSeg<0 || (iAbsLevel % nMod) >= (iHintAbsLevel % nMod) ){
        /* Based on the scan in the block above, it is known that there
        ** are no levels with a relative level smaller than that of
        ** iAbsLevel with more than nSeg segments, or if nSeg is -1, 
        ** no levels with more than nMin segments. Use this to limit the
        ** value of nHintSeg to avoid a large memory allocation in case the 
        ** merge-hint is corrupt*/
        iAbsLevel = iHintAbsLevel;
        nSeg = nHintSeg;
        nSeg = MIN(MAX(nMin,nSeg), nHintSeg);
        bUseHint = 1;
        bDirtyHint = 1;
      }else{
        /* This undoes the effect of the HintPop() above - so that no entry
        ** is removed from the hint blob.  */
        hint.n = nHint;
      }
    }

    /* If nSeg is less that zero, then there is no level with at least
    ** nMin segments and no hint in the %_stat table. No work to do.
    ** Exit early in this case.  */
    if( nSeg<0 ) break;
    if( nSeg<=0 ) break;

    /* Open a cursor to iterate through the contents of the oldest nSeg 
    ** indexes of absolute level iAbsLevel. If this cursor is opened using 
    ** the 'hint' parameters, it is possible that there are less than nSeg
    ** segments available in level iAbsLevel. In this case, no work is
    ** done on iAbsLevel - fall through to the next iteration of the loop 
    ** to start work on some other level.  */

    }

    if( rc==SQLITE_OK ){
      rc = fts3IncrmergeCsr(p, iAbsLevel, nSeg, pCsr);
    }
    if( SQLITE_OK==rc && pCsr->nSegment==nSeg
     && SQLITE_OK==(rc = sqlite3Fts3SegReaderStart(p, pCsr, pFilter))
     && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pCsr))
    ){
      int bEmpty = 0;
      rc = sqlite3Fts3SegReaderStep(p, pCsr);
      if( rc==SQLITE_OK ){
        bEmpty = 1;
      }else if( rc!=SQLITE_ROW ){
        sqlite3Fts3SegReaderFinish(pCsr);
        break;
      }
      if( bUseHint && iIdx>0 ){
        const char *zKey = pCsr->zTerm;
        int nKey = pCsr->nTerm;
        rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);
      }else{
        rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);
      }

      if( rc==SQLITE_OK && pWriter->nLeafEst ){
        fts3LogMerge(nSeg, iAbsLevel);
        if( bEmpty==0 ){
        do {
          rc = fts3IncrmergeAppend(p, pWriter, pCsr);
          if( rc==SQLITE_OK ) rc = sqlite3Fts3SegReaderStep(p, pCsr);
          if( pWriter->nWork>=nRem && rc==SQLITE_ROW ) rc = SQLITE_OK;
        }while( rc==SQLITE_ROW );
          do {
            rc = fts3IncrmergeAppend(p, pWriter, pCsr);
            if( rc==SQLITE_OK ) rc = sqlite3Fts3SegReaderStep(p, pCsr);
            if( pWriter->nWork>=nRem && rc==SQLITE_ROW ) rc = SQLITE_OK;
          }while( rc==SQLITE_ROW );
        }

        /* Update or delete the input segments */
        if( rc==SQLITE_OK ){
          nRem -= (1 + pWriter->nWork);
          rc = fts3IncrmergeChomp(p, iAbsLevel, pCsr, &nSeg);
          if( nSeg!=0 ){
            bDirtyHint = 1;

** before it will be selected for a merge, respectively.
*/
static int fts3DoIncrmerge(
  Fts3Table *p,                   /* FTS3 table handle */
  const char *zParam              /* Nul-terminated string containing "A,B" */
){
  int rc;
  int nMin = (FTS3_MERGE_COUNT / 2);
  int nMin = (MergeCount(p) / 2);
  int nMerge = 0;
  const char *z = zParam;

  /* Read the first integer value */
  nMerge = fts3Getint(&z);

  /* If the first integer value is followed by a ',',  read the second

static int fts3DoAutoincrmerge(
  Fts3Table *p,                   /* FTS3 table handle */
  const char *zParam              /* Nul-terminated string containing boolean */
){
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = 0;
  p->nAutoincrmerge = fts3Getint(&zParam);
  if( p->nAutoincrmerge==1 || p->nAutoincrmerge>FTS3_MERGE_COUNT ){
  if( p->nAutoincrmerge==1 || p->nAutoincrmerge>MergeCount(p) ){
    p->nAutoincrmerge = 8;
  }
  if( !p->bHasStat ){
    assert( p->bFts4==0 );
    sqlite3Fts3CreateStatTable(&rc, p);
    if( rc ) return rc;
  }

  if( rc==SQLITE_OK ){
    while( SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, &csr)) ){
      char *pCsr = csr.aDoclist;
      char *pEnd = &pCsr[csr.nDoclist];

      i64 iDocid = 0;
      i64 iCol = 0;
      i64 iPos = 0;
      u64 iPos = 0;

      pCsr += sqlite3Fts3GetVarint(pCsr, &iDocid);
      while( pCsr<pEnd ){
        i64 iVal = 0;
        pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
        u64 iVal = 0;
        pCsr += sqlite3Fts3GetVarintU(pCsr, &iVal);
        if( pCsr<pEnd ){
          if( iVal==0 || iVal==1 ){
            iCol = 0;
            iPos = 0;
            if( iVal ){
              pCsr += sqlite3Fts3GetVarint(pCsr, &iCol);
            }else{
              pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
              iDocid += iVal;
              pCsr += sqlite3Fts3GetVarintU(pCsr, &iVal);
              if( p->bDescIdx ){
                iDocid = (i64)((u64)iDocid - iVal);
              }else{
                iDocid = (i64)((u64)iDocid + iVal);
              }
            }
          }else{
            iPos += (iVal - 2);
            cksum = cksum ^ fts3ChecksumEntry(
                csr.zTerm, csr.nTerm, iLangid, iIndex, iDocid,
                (int)iCol, (int)iPos
            );

      i64 iDocid = sqlite3_column_int64(pStmt, 0);
      int iLang = langidFromSelect(p, pStmt);
      int iCol;

      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
        if( p->abNotindexed[iCol]==0 ){
          const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
          int nText = sqlite3_column_bytes(pStmt, iCol+1);
          sqlite3_tokenizer_cursor *pT = 0;

          rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);
          rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, -1, &pT);
          while( rc==SQLITE_OK ){
            char const *zToken;       /* Buffer containing token */
            int nToken = 0;           /* Number of bytes in token */
            int iDum1 = 0, iDum2 = 0; /* Dummy variables */
            int iPos = 0;             /* Position of token in zText */

            rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);

**
**   "INSERT INTO tbl(tbl) VALUES(<expr>)"
**
** Argument pVal contains the result of <expr>. Currently the only 
** meaningful value to insert is the text 'optimize'.
*/
static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
  int rc;                         /* Return Code */
  int rc = SQLITE_ERROR;           /* Return Code */
  const char *zVal = (const char *)sqlite3_value_text(pVal);
  int nVal = sqlite3_value_bytes(pVal);

  if( !zVal ){
    return SQLITE_NOMEM;
  }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){
    rc = fts3DoOptimize(p, 0);
  }else if( nVal==7 && 0==sqlite3_strnicmp(zVal, "rebuild", 7) ){
    rc = fts3DoRebuild(p);
  }else if( nVal==15 && 0==sqlite3_strnicmp(zVal, "integrity-check", 15) ){
    rc = fts3DoIntegrityCheck(p);
  }else if( nVal>6 && 0==sqlite3_strnicmp(zVal, "merge=", 6) ){
    rc = fts3DoIncrmerge(p, &zVal[6]);
  }else if( nVal>10 && 0==sqlite3_strnicmp(zVal, "automerge=", 10) ){
    rc = fts3DoAutoincrmerge(p, &zVal[10]);
#ifdef SQLITE_TEST
  }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
    p->nNodeSize = atoi(&zVal[9]);
    rc = SQLITE_OK;
  }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
    p->nMaxPendingData = atoi(&zVal[11]);
    rc = SQLITE_OK;
  }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){
    p->bNoIncrDoclist = atoi(&zVal[21]);
    rc = SQLITE_OK;
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  }else{
    int v;
    if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
      v = atoi(&zVal[9]);
      if( v>=24 && v<=p->nPgsz-35 ) p->nNodeSize = v;
      rc = SQLITE_OK;
    }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
      v = atoi(&zVal[11]);
      if( v>=64 && v<=FTS3_MAX_PENDING_DATA ) p->nMaxPendingData = v;
      rc = SQLITE_OK;
    }else if( nVal>21 && 0==sqlite3_strnicmp(zVal,"test-no-incr-doclist=",21) ){
      p->bNoIncrDoclist = atoi(&zVal[21]);
      rc = SQLITE_OK;
#endif
  }else{
    rc = SQLITE_ERROR;
  }

    }else if( nVal>11 && 0==sqlite3_strnicmp(zVal,"mergecount=",11) ){
      v = atoi(&zVal[11]);
      if( v>=4 && v<=FTS3_MERGE_COUNT && (v&1)==0 ) p->nMergeCount = v;
      rc = SQLITE_OK;
    }
#endif
  }
  return rc;
}

#ifndef SQLITE_DISABLE_FTS4_DEFERRED
/*
** Delete all cached deferred doclists. Deferred doclists are cached
** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function.

  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 */
  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel = 0;                /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  /* At this point it must be known if the %_stat table exists or not.
  ** So bHasStat may not be 2.  */

  if( nArg>1 && sqlite3_value_int(apVal[2 + p->nColumn + 2])<0 ){
    rc = SQLITE_CONSTRAINT;
    goto update_out;
  }

  /* Allocate space to hold the change in document sizes */
  aSzDel = sqlite3_malloc( sizeof(aSzDel[0])*(p->nColumn+1)*2 );
  aSzDel = sqlite3_malloc64(sizeof(aSzDel[0])*((sqlite3_int64)p->nColumn+1)*2);
  if( aSzDel==0 ){
    rc = SQLITE_NOMEM;
    goto update_out;
  }
  aSzIns = &aSzDel[p->nColumn+1];
  memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);

    goto update_out;
  }

  /* If this is a DELETE or UPDATE operation, remove the old record. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );
    rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);
    isRemove = 1;
  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);
    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
    if( rc==SQLITE_OK ){
      rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
    }
    if( p->bHasDocsize ){

source [file join [file dirname [info script]] parseunicode.tcl]

proc print_rd {map} {
  global tl_lookup_table
  set aChar [list]
  set lRange [list]

  set nRange 1
  set iFirst  [lindex $map 0 0]
  set cPrev   [lindex $map 0 1]
  set fPrev   [lindex $map 0 2]

  foreach m [lrange $map 1 end] {
    foreach {i c} $m {}
    foreach {i c f} $m {}

    if {$cPrev == $c} {
    if {$cPrev == $c && $fPrev==$f} {
      for {set j [expr $iFirst+$nRange]} {$j<$i} {incr j} {
        if {[info exists tl_lookup_table($j)]==0} break
      }

      if {$j==$i} {
        set nNew [expr {(1 + $i - $iFirst)}]
        if {$nNew<=8} {
          set nRange $nNew
          continue
        }
      }
    }

    lappend lRange [list $iFirst $nRange]
    lappend aChar  $cPrev
    lappend aFlag  $fPrev

    set iFirst $i
    set cPrev  $c
    set fPrev  $f
    set nRange 1
  }
  lappend lRange [list $iFirst $nRange]
  lappend aChar $cPrev
  lappend aFlag $fPrev

  puts "/*"
  puts "** If the argument is a codepoint corresponding to a lowercase letter"
  puts "** in the ASCII range with a diacritic added, return the codepoint"
  puts "** of the ASCII letter only. For example, if passed 235 - \"LATIN"
  puts "** SMALL LETTER E WITH DIAERESIS\" - return 65 (\"LATIN SMALL LETTER"
  puts "** E\"). The resuls of passing a codepoint that corresponds to an"
  puts "** uppercase letter are undefined."
  puts "*/"
  puts "static int ${::remove_diacritic}(int c)\{"
  puts "static int ${::remove_diacritic}(int c, int bComplex)\{"
  puts "  unsigned short aDia\[\] = \{"
  puts -nonewline "        0, "
  set i 1
  foreach r $lRange {
    foreach {iCode nRange} $r {}
    if {($i % 8)==0} {puts "" ; puts -nonewline "    " }
    incr i

    puts -nonewline [format "%5d" [expr ($iCode<<3) + $nRange-1]]
    puts -nonewline ", "
  }
  puts ""
  puts "  \};"
  puts "#define HIBIT ((unsigned char)0x80)"
  puts "  char aChar\[\] = \{"
  puts -nonewline "    '\\0', "
  puts "  unsigned char aChar\[\] = \{"
  puts -nonewline "    '\\0',      "
  set i 1
  foreach c $aChar {
    set str "'$c',  "
    if {$c == ""} { set str "'\\0', " }
  foreach c $aChar f $aFlag {
    if { $f } {
      set str "'$c'|HIBIT, "
    } else {
      set str "'$c',       "
    }
    if {$c == ""} { set str "'\\0',      " }

    if {($i % 12)==0} {puts "" ; puts -nonewline "    " }
    if {($i % 6)==0} {puts "" ; puts -nonewline "    " }
    incr i
    puts -nonewline "$str"
  }
  puts ""
  puts "  \};"
  puts {
  unsigned int key = (((unsigned int)c)<<3) | 0x00000007;
  int iRes = 0;
  int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;
  int iLo = 0;
  while( iHi>=iLo ){
    int iTest = (iHi + iLo) / 2;
    if( key >= aDia[iTest] ){
      iRes = iTest;
      iLo = iTest+1;
    }else{
      iHi = iTest-1;
    }
  }
  assert( key>=aDia[iRes] );
  if( bComplex==0 && (aChar[iRes] & 0x80) ) return c;
  return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);}
  return (c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : ((int)aChar[iRes] & 0x7F);}
  puts "\}"
}

proc print_isdiacritic {zFunc map} {

  set lCode [list]
  foreach m $map {
    foreach {code char} $m {}
    foreach {code char flag} $m {}
    if {$flag} continue
    if {$code && $char == ""} { lappend lCode $code }
  }
  set lCode [lsort -integer $lCode]
  set iFirst [lindex $lCode 0]
  set iLast [lindex $lCode end]

  set i1 0

  puts "*/"
  puts "int ${zFunc}\(int c)\{"
  puts "  unsigned int mask0 = [format "0x%08X" $i1];"
  puts "  unsigned int mask1 = [format "0x%08X" $i2];"

  puts "  if( c<$iFirst || c>$iLast ) return 0;"
  puts "  return (c < $iFirst+32) ?"
  puts "      (mask0 & (1 << (c-$iFirst))) :"
  puts "      (mask1 & (1 << (c-$iFirst-32)));"
  puts "      (mask0 & ((unsigned int)1 << (c-$iFirst))) :"
  puts "      (mask1 & ((unsigned int)1 << (c-$iFirst-32)));"
  puts "\}"
}


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

proc an_load_separator_ranges {} {

  puts "** is an upper case character that has a lower case equivalent,"
  puts "** return the codepoint corresponding to the lower case version."
  puts "** Otherwise, return a copy of the argument."
  puts "**"
  puts "** The results are undefined if the value passed to this function"
  puts "** is less than zero."
  puts "*/"
  puts "int ${zFunc}\(int c, int bRemoveDiacritic)\{"
  puts "int ${zFunc}\(int c, int eRemoveDiacritic)\{"

  set liOff [tl_generate_ioff_table $lRecord]
  tl_print_table_header
  foreach entry $lRecord { 
    if {[tl_print_table_entry toggle $entry $liOff]} { 
      lappend lHigh $entry 
    } 

    assert( iRes>=0 && c>=aEntry[iRes].iCode );
    p = &aEntry[iRes];
    if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){
      ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;
      assert( ret>0 );
    }

    if( eRemoveDiacritic ){
    if( bRemoveDiacritic ) ret = ${::remove_diacritic}(ret);
      ret = ${::remove_diacritic}(ret, eRemoveDiacritic==2);
    }
  }
  }]

  foreach entry $lHigh {
    tl_print_if_entry $entry
  }

  puts ""
  puts "  return ret;"
  puts "\}"
}

proc code {txt} {
  set txt [string trimright $txt]
  set txt [string trimleft $txt "\n"]
  set n [expr {[string length $txt] - [string length [string trim $txt]]}]
  set ret ""
  foreach L [split $txt "\n"] {
    append ret "[string range $L $n end]\n"
  }
  return [uplevel "subst -nocommands {$ret}"]
}

proc intarray {lInt} {
  set ret ""
  set n [llength $lInt]
  for {set i 0} {$i < $n} {incr i 10} {
    append ret "\n    "
    foreach int [lrange $lInt $i [expr $i+9]] {
      append ret [format "%-7s" "$int, "]
    }
  }
  append ret "\n  "
  set ret
}

proc categories_switch {Cvar first lSecond} {
  upvar $Cvar C
  set ret ""
  append ret "case '$first':\n"
  append ret "          switch( zCat\[1\] ){\n"
  foreach s $lSecond {
    append ret "            case '$s': aArray\[$C($first$s)\] = 1; break;\n"
  }
  append ret "            case '*': \n"
  foreach s $lSecond {
    append ret "              aArray\[$C($first$s)\] = 1;\n"
  }
  append ret "              break;\n"
  append ret "            default: return 1;"
  append ret "          }\n"
  append ret "          break;\n"
}

# Argument is a list. Each element of which is itself a list of two elements:
#
#   * the codepoint
#   * the category
#
# List elements are sorted in order of codepoint.
#
proc print_categories {lMap} {
  set categories {
    Cc Cf Cn Cs
    Ll Lm Lo Lt Lu
    Mc Me Mn
    Nd Nl No
    Pc Pd Pe Pf Pi Po Ps
    Sc Sk Sm So
    Zl Zp Zs

    LC Co
  }

  for {set i 0} {$i < [llength $categories]} {incr i} {
    set C([lindex $categories $i]) [expr 1+$i]
  }

  set caseC [categories_switch C C {c f n s o}]
  set caseL [categories_switch C L {l m o t u C}]
  set caseM [categories_switch C M {c e n}]
  set caseN [categories_switch C N {d l o}]
  set caseP [categories_switch C P {c d e f i o s}]
  set caseS [categories_switch C S {c k m o}]
  set caseZ [categories_switch C Z {l p s}]

  set nCat [expr [llength [array names C]] + 1]
  puts [code {
    int sqlite3Fts5UnicodeCatParse(const char *zCat, u8 *aArray){ 
      aArray[0] = 1;
      switch( zCat[0] ){
        $caseC
        $caseL
        $caseM
        $caseN
        $caseP
        $caseS
        $caseZ
      }
      return 0;
    }
  }]

  set nRepeat 0
  set first   [lindex $lMap 0 0]
  set class   [lindex $lMap 0 1]
  set prev -1

  set CASE(0) "Lu"
  set CASE(1) "Ll"

  foreach m $lMap {
    foreach {codepoint cl} $m {}
    set codepoint [expr "0x$codepoint"]
    if {$codepoint>=(1<<20)} continue

    set bNew 0
    if {$codepoint!=($prev+1)} {
      set bNew 1
    } elseif {
      $cl==$class || ($class=="LC" && $cl==$CASE([expr $nRepeat & 0x01]))
    } {
      incr nRepeat
    } elseif {$class=="Lu" && $nRepeat==1 && $cl=="Ll"} {
      set class LC
      incr nRepeat
    } else {
      set bNew 1
    }
    if {$bNew} {
      lappend lEntries [list $first $class $nRepeat]
      set nRepeat 1
      set first $codepoint
      set class $cl
    }
    set prev $codepoint
  }
  if {$nRepeat>0} {
    lappend lEntries [list $first $class $nRepeat]
  }

  set aBlock [list 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
  set aMap [list]
  foreach e $lEntries {
    foreach {cp class nRepeat} $e {}
    set block [expr ($cp>>16)]
    if {$block>0 && [lindex $aBlock $block]==0} {
      for {set i 1} {$i<=$block} {incr i} {
        if {[lindex $aBlock $i]==0} {
          lset aBlock $i [llength $aMap]
        }
      }
    }
    lappend aMap [expr {$cp & 0xFFFF}]
    lappend aData [expr {($nRepeat << 5) + $C($class)}]
  }
  for {set i 1} {$i<[llength $aBlock]} {incr i} {
    if {[lindex $aBlock $i]==0} {
      lset aBlock $i [llength $aMap]
    }
  }

  set aBlockArray [intarray $aBlock]
  set aMapArray [intarray $aMap]
  set aDataArray [intarray $aData]
  puts [code {
    static u16 aFts5UnicodeBlock[] = {$aBlockArray};
    static u16 aFts5UnicodeMap[] = {$aMapArray};
    static u16 aFts5UnicodeData[] = {$aDataArray};

    int sqlite3Fts5UnicodeCategory(u32 iCode) { 
      int iRes = -1;
      int iHi;
      int iLo;
      int ret;
      u16 iKey;

      if( iCode>=(1<<20) ){
        return 0;
      }
      iLo = aFts5UnicodeBlock[(iCode>>16)];
      iHi = aFts5UnicodeBlock[1+(iCode>>16)];
      iKey = (iCode & 0xFFFF);
      while( iHi>iLo ){
        int iTest = (iHi + iLo) / 2;
        assert( iTest>=iLo && iTest<iHi );
        if( iKey>=aFts5UnicodeMap[iTest] ){
          iRes = iTest;
          iLo = iTest+1;
        }else{
          iHi = iTest;
        }
      }

      if( iRes<0 ) return 0;
      if( iKey>=(aFts5UnicodeMap[iRes]+(aFts5UnicodeData[iRes]>>5)) ) return 0;
      ret = aFts5UnicodeData[iRes] & 0x1F;
      if( ret!=$C(LC) ) return ret;
      return ((iKey - aFts5UnicodeMap[iRes]) & 0x01) ? $C(Ll) : $C(Lu);
    }

    void sqlite3Fts5UnicodeAscii(u8 *aArray, u8 *aAscii){
      int i = 0;
      int iTbl = 0;
      while( i<128 ){
        int bToken = aArray[ aFts5UnicodeData[iTbl] & 0x1F ];
        int n = (aFts5UnicodeData[iTbl] >> 5) + i;
        for(; i<128 && i<n; i++){
          aAscii[i] = (u8)bToken;
        }
        iTbl++;
      }
    }
  }]
}

proc print_test_categories {lMap} {

  set lCP [list]
  foreach e $lMap {
    foreach {cp cat} $e {}
    if {[expr 0x$cp] < (1<<20)} {
      lappend lCP "{0x$cp, \"$cat\"}, "
    }
  }

  set aCP "\n"
  for {set i 0} {$i < [llength $lCP]} {incr i 4} {
    append aCP "    [join [lrange $lCP $i $i+3]]\n"
  }


  puts [code {
    static int categories_test (int *piCode){
      struct Codepoint {
        int iCode;
        const char *zCat;
      } aCP[] = {$aCP};
      int i;
      int iCP = 0;

      for(i=0; i<1000000; i++){
        u8 aArray[40];
        int cat = 0;
        int c = 0;
        memset(aArray, 0, sizeof(aArray));
        if( aCP[iCP].iCode==i ){
          sqlite3Fts5UnicodeCatParse(aCP[iCP].zCat, aArray);
          iCP++;
        }else{
          aArray[0] = 1;
        }

        c = sqlite3Fts5UnicodeCategory((u32)i);
        if( aArray[c]==0 ){
          *piCode = i;
          return 1;
        }
      }

      return 0;
    }
  }]
}

proc print_fold_test {zFunc mappings} {
  global tl_lookup_table

  foreach m $mappings {
    set c [lindex $m 1]
    if {$c == ""} {

  puts "\}"
}


proc print_fileheader {} {
  puts [string trim {
/*
** 2012 May 25
** 2012-05-25
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.

}

proc print_test_main {} {
  puts ""
  puts "#include <stdio.h>"
  puts ""
  puts "int main(int argc, char **argv)\{"
  puts "  int r1, r2;"
  puts "  int r1, r2, r3;"
  puts "  int code;"
  puts "  r3 = 0;"
  puts "  r1 = isalnum_test(&code);"
  puts "  if( r1 ) printf(\"isalnum(): Problem with code %d\\n\",code);"
  puts "  else printf(\"isalnum(): test passed\\n\");"
  puts "  r2 = fold_test(&code);"
  puts "  if( r2 ) printf(\"fold(): Problem with code %d\\n\",code);"
  puts "  else printf(\"fold(): test passed\\n\");"
  if {$::generate_fts5_code} {
    puts "  r3 = categories_test(&code);"
    puts "  if( r3 ) printf(\"categories(): Problem with code %d\\n\",code);"
    puts "  else printf(\"categories(): test passed\\n\");"
  }
  puts "  return (r1 || r2);"
  puts "  return (r1 || r2 || r3);"
  puts "\}"
}

# Proces the command line arguments. Exit early if they are not to
# our liking.
#
proc usage {} {

    default {
      usage
    }
  }
}

print_fileheader

if {$::generate_test_code} {
  puts "typedef unsigned short int u16;"
  puts "typedef unsigned char u8;"
  puts "#include <string.h>"
}

# Print the isalnum() function to stdout.
#
set lRange [an_load_separator_ranges]
if {$generate_fts5_code==0} {
print_isalnum ${function_prefix}UnicodeIsalnum $lRange
  print_isalnum ${function_prefix}UnicodeIsalnum $lRange
}

# Leave a gap between the two generated C functions.
#
puts ""
puts ""

# Load the fold data. This is used by the [rd_XXX] commands

print_isdiacritic ${function_prefix}UnicodeIsdiacritic $mappings
puts ""
puts ""

# Print the fold() function to stdout.
#
print_fold ${function_prefix}UnicodeFold

if {$generate_fts5_code} {
  puts ""
  puts ""
  print_categories [cc_load_unicodedata_text ${unicodedata.txt}]
}

# Print the test routines and main() function to stdout, if -test 
# was specified.
#
if {$::generate_test_code} {
  if {$generate_fts5_code==0} {
  print_test_isalnum ${function_prefix}UnicodeIsalnum $lRange
    print_test_isalnum ${function_prefix}UnicodeIsalnum $lRange
  }
  print_fold_test ${function_prefix}UnicodeFold $mappings
  print_test_categories [cc_load_unicodedata_text ${unicodedata.txt}]
  print_test_main 
}

if {$generate_fts5_code} {
  # no-op
} else {
  puts "#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */"
  puts "#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */"
}

#--------------------------------------------------------------------------
# Parameter $zName must be a path to the file UnicodeData.txt. This command
# reads the file and returns a list of mappings required to remove all
# diacritical marks from a unicode string. Each mapping is itself a list
# consisting of two elements - the unicode codepoint and the single ASCII
# character that it should be replaced with, or an empty string if the 
# codepoint should simply be removed from the input. Examples:
#
#   { 224 a  }     (replace codepoint 224 to "a")
#   { 769 "" }     (remove codepoint 769 from input)
#   { 224 a  0 }     (replace codepoint 224 to "a")
#   { 769 "" 0 }     (remove codepoint 769 from input)
#
# Mappings are only returned for non-upper case codepoints. It is assumed
# that the input has already been folded to lower case.
#
# The third value in the list is always either 0 or 1. 0 if the 
# UnicodeData.txt file maps the codepoint to a single ASCII character and
# a diacritic, or 1 if the mapping is indirect. For example, consider the 
# two entries:
#
# 1ECD;LATIN SMALL LETTER O WITH DOT BELOW;Ll;0;L;006F 0323;;;;N;;;1ECC;;1ECC
# 1ED9;LATIN SMALL LETTER O WITH CIRCUMFLEX AND DOT BELOW;Ll;0;L;1ECD 0302;;;;N;;;1ED8;;1ED8
#
# The first codepoint is a direct mapping (as 006F is ASCII and 0323 is a 
# diacritic). The second is an indirect mapping, as it maps to the
# first codepoint plus 0302 (a diacritic).
#
proc rd_load_unicodedata_text {zName} {
  global tl_lookup_table

  set fd [open $zName]
  set lField {
    code

      continue
    }

    set iCode  [expr "0x$code"]
    set iAscii [expr "0x[lindex $character_decomposition_mapping 0]"]
    set iDia   [expr "0x[lindex $character_decomposition_mapping 1]"]

    # Filter out upper-case characters, as they will be mapped to their
    # lower-case equivalents before this data is used.
    if {[info exists tl_lookup_table($iCode)]} continue

    # Check if this is an indirect mapping. If so, set bIndirect to true
    # and change $iAscii to the indirectly mappped ASCII character.
    set bIndirect 0
    if {[info exists dia($iDia)] && [info exists mapping($iAscii)]} {
      set iAscii $mapping($iAscii)
      set bIndirect 1
    }

    if { ($iAscii >= 97 && $iAscii <= 122)
      || ($iAscii >= 65 && $iAscii <= 90)
    } {
      lappend lRet [list $iCode [string tolower [format %c $iAscii]]]
      lappend lRet [list $iCode [string tolower [format %c $iAscii]] $bIndirect]
      set mapping($iCode) $iAscii
      set dia($iDia) 1
    }
  }

  foreach d [array names dia] {
    lappend lRet [list $d ""]
    lappend lRet [list $d "" 0]
  }
  set lRet [lsort -integer -index 0 $lRet]

  close $fd
  set lRet
}

    foreach elem $c { lappend c2 [expr "0x[string trim $elem]"] }
    set b [string trim $b]
    set d [string trim $d]

    if {$b=="C" || $b=="S"} { set tl_lookup_table($a2) $c2 }
  }
}

proc cc_load_unicodedata_text {zName} {
  set fd [open $zName]
  set lField {
    code
    character_name
    general_category
    canonical_combining_classes
    bidirectional_category
    character_decomposition_mapping
    decimal_digit_value
    digit_value
    numeric_value
    mirrored
    unicode_1_name
    iso10646_comment_field
    uppercase_mapping
    lowercase_mapping
    titlecase_mapping

  }
  set lRet [list]

  while { ![eof $fd] } {
    set line [gets $fd]
    if {$line == ""} continue

    set fields [split $line ";"]
    if {[llength $fields] != [llength $lField]} { error "parse error: $line" }
    foreach $lField $fields {}

    lappend lRet [list $code $general_category]
  }

  close $fd
  set lRet
}

  ap = sqlite3_malloc(sizeof(Fts5HashEntry*) * nMergeSlot);
  if( !ap ) return SQLITE_NOMEM;
  memset(ap, 0, sizeof(Fts5HashEntry*) * nMergeSlot);

  for(iSlot=0; iSlot<pHash->nSlot; iSlot++){
    Fts5HashEntry *pIter;
    for(pIter=pHash->aSlot[iSlot]; pIter; pIter=pIter->pHashNext){
      if( pTerm==0 
      if( pTerm==0 || 0==memcmp(fts5EntryKey(pIter), pTerm, nTerm) ){
       || (pIter->nKey+1>=nTerm && 0==memcmp(fts5EntryKey(pIter), pTerm, nTerm))
      ){
        Fts5HashEntry *pEntry = pIter;
        pEntry->pScanNext = 0;
        for(i=0; ap[i]; i++){
          pEntry = fts5HashEntryMerge(pEntry, ap[i]);
          ap[i] = 0;
        }
        ap[i] = pEntry;

  COMMIT;
}

do_execsql_test 22.1 {
  SELECT rowid FROM t9('a*')
} {1}

}


#-------------------------------------------------------------------------
do_execsql_test 25.0 {
  CREATE VIRTUAL TABLE t13 USING fts5(x, detail=%DETAIL%);
}
do_execsql_test 25.1 {
  BEGIN;
  INSERT INTO t13 VALUES('AAAA');
SELECT * FROM t13('BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB*');

  END;
}

}

finish_test

# 2018 March 22
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

source [file join [file dirname [info script]] rbu_common.tcl]
set ::testprefix rbucollate

ifcapable !icu_collations {
  finish_test
  return
}

db close
sqlite3_shutdown
sqlite3_config_uri 1
reset_db
 
# Create a simple RBU database. That expects to write to a table:
#
#   CREATE TABLE t1(a PRIMARY KEY, b, c);
#
proc create_rbu1 {filename} {
  forcedelete $filename
  sqlite3 rbu1 $filename  
  rbu1 eval {
    CREATE TABLE data_t1(a, b, c, rbu_control);
    INSERT INTO data_t1 VALUES('a', 'one', 1, 0);
    INSERT INTO data_t1 VALUES('b', 'two', 2, 0);
    INSERT INTO data_t1 VALUES('c', 'three', 3, 0);
  }
  rbu1 close
  return $filename
}

do_execsql_test 1.0 {
  SELECT icu_load_collation('en_US', 'my-collate');
  CREATE TABLE t1(a COLLATE "my-collate" PRIMARY KEY, b, c);
} {{}}

do_test 1.2 {
  create_rbu1 testrbu.db
  sqlite3rbu rbu test.db testrbu.db
  rbu dbMain_eval { SELECT icu_load_collation('en_US', 'my-collate') }
  rbu dbRbu_eval { SELECT icu_load_collation('en_US', 'my-collate') }
  while 1 {
    set rc [rbu step]
    if {$rc!="SQLITE_OK"} break
  }
  rbu close
  db eval { SELECT * FROM t1 }
} {a one 1 b two 2 c three 3}

#forcedelete testrbu.db
finish_test

** space used by the RBU handle.
*/
struct rbu_vfs {
  sqlite3_vfs base;               /* rbu VFS shim methods */
  sqlite3_vfs *pRealVfs;          /* Underlying VFS */
  sqlite3_mutex *mutex;           /* Mutex to protect pMain */
  sqlite3rbu *pRbu;               /* Owner RBU object */
  rbu_file *pMain;                /* Linked list of main db files */
  rbu_file *pMain;                /* List of main db files */
  rbu_file *pMainRbu;             /* List of main db files with pRbu!=0 */
};

/*
** Each file opened by an rbu VFS is represented by an instance of
** the following structure.
**
** If this is a temporary file (pRbu!=0 && flags&DELETE_ON_CLOSE), variable

  int nShm;                       /* Number of entries in apShm[] array */
  char **apShm;                   /* Array of mmap'd *-shm regions */
  char *zDel;                     /* Delete this when closing file */

  const char *zWal;               /* Wal filename for this main db file */
  rbu_file *pWalFd;               /* Wal file descriptor for this main db */
  rbu_file *pMainNext;            /* Next MAIN_DB file */
  rbu_file *pMainRbuNext;         /* Next MAIN_DB file with pRbu!=0 */
};

/*
** True for an RBU vacuum handle, or false otherwise.
*/
#define rbuIsVacuum(p) ((p)->zTarget==0)

    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
      int bKey = sqlite3_column_int(pXInfo, 5);
      if( bKey ){
        int iCid = sqlite3_column_int(pXInfo, 1);
        int bDesc = sqlite3_column_int(pXInfo, 3);
        const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);
        zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %s", zCols, zComma, 
        zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %Q", zCols, zComma, 
            iCid, pIter->azTblType[iCid], zCollate
        );
        zPk = rbuMPrintf(p, "%z%sc%d%s", zPk, zComma, iCid, bDesc?" DESC":"");
        zComma = ", ";
      }
    }
    zCols = rbuMPrintf(p, "%z, id INTEGER", zCols);

      );

      if( pIter->eType==RBU_PK_IPK && pIter->abTblPk[iCol] ){
        /* If the target table column is an "INTEGER PRIMARY KEY", add
        ** "PRIMARY KEY" to the imposter table column declaration. */
        zPk = "PRIMARY KEY ";
      }
      zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %s%s", 
      zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %Q%s", 
          zSql, zComma, zCol, pIter->azTblType[iCol], zPk, zColl,
          (pIter->abNotNull[iCol] ? " NOT NULL" : "")
      );
      zComma = ", ";
    }

    if( pIter->eType==RBU_PK_WITHOUT_ROWID ){

  i64 nDiff = nNew - pFd->sz;
  pRbu->szTemp += nDiff;
  pFd->sz = nNew;
  assert( pRbu->szTemp>=0 );
  if( pRbu->szTempLimit && pRbu->szTemp>pRbu->szTempLimit ) return SQLITE_FULL;
  return SQLITE_OK;
}

/*
** Add an item to the main-db lists, if it is not already present.
**
** There are two main-db lists. One for all file descriptors, and one
** for all file descriptors with rbu_file.pDb!=0. If the argument has
** rbu_file.pDb!=0, then it is assumed to already be present on the
** main list and is only added to the pDb!=0 list.
*/
static void rbuMainlistAdd(rbu_file *p){
  rbu_vfs *pRbuVfs = p->pRbuVfs;
  rbu_file *pIter;
  assert( (p->openFlags & SQLITE_OPEN_MAIN_DB) );
  sqlite3_mutex_enter(pRbuVfs->mutex);
  if( p->pRbu==0 ){
    for(pIter=pRbuVfs->pMain; pIter; pIter=pIter->pMainNext);
    p->pMainNext = pRbuVfs->pMain;
    pRbuVfs->pMain = p;
  }else{
    for(pIter=pRbuVfs->pMainRbu; pIter && pIter!=p; pIter=pIter->pMainRbuNext){}
    if( pIter==0 ){
      p->pMainRbuNext = pRbuVfs->pMainRbu;
      pRbuVfs->pMainRbu = p;
    }
  }
  sqlite3_mutex_leave(pRbuVfs->mutex);
}

/*
** Remove an item from the main-db lists.
*/
static void rbuMainlistRemove(rbu_file *p){
  rbu_file **pp;
  sqlite3_mutex_enter(p->pRbuVfs->mutex);
  for(pp=&p->pRbuVfs->pMain; *pp && *pp!=p; pp=&((*pp)->pMainNext)){}
  if( *pp ) *pp = p->pMainNext;
  p->pMainNext = 0;
  for(pp=&p->pRbuVfs->pMainRbu; *pp && *pp!=p; pp=&((*pp)->pMainRbuNext)){}
  if( *pp ) *pp = p->pMainRbuNext;
  p->pMainRbuNext = 0;
  sqlite3_mutex_leave(p->pRbuVfs->mutex);
}

/*
** Given that zWal points to a buffer containing a wal file name passed to 
** either the xOpen() or xAccess() VFS method, search the main-db list for
** a file-handle opened by the same database connection on the corresponding
** database file.
**
** If parameter bRbu is true, only search for file-descriptors with
** rbu_file.pDb!=0.
*/
static rbu_file *rbuFindMaindb(rbu_vfs *pRbuVfs, const char *zWal, int bRbu){
  rbu_file *pDb;
  sqlite3_mutex_enter(pRbuVfs->mutex);
  if( bRbu ){
    for(pDb=pRbuVfs->pMainRbu; pDb && pDb->zWal!=zWal; pDb=pDb->pMainRbuNext){}
  }else{
    for(pDb=pRbuVfs->pMain; pDb && pDb->zWal!=zWal; pDb=pDb->pMainNext){}
  }
  sqlite3_mutex_leave(pRbuVfs->mutex);
  return pDb;
}

/*
** Close an rbu file.
*/
static int rbuVfsClose(sqlite3_file *pFile){
  rbu_file *p = (rbu_file*)pFile;
  int rc;
  int i;

  /* Free the contents of the apShm[] array. And the array itself. */
  for(i=0; i<p->nShm; i++){
    sqlite3_free(p->apShm[i]);
  }
  sqlite3_free(p->apShm);
  p->apShm = 0;
  sqlite3_free(p->zDel);

  if( p->openFlags & SQLITE_OPEN_MAIN_DB ){
    rbu_file **pp;
    sqlite3_mutex_enter(p->pRbuVfs->mutex);
    for(pp=&p->pRbuVfs->pMain; *pp!=p; pp=&((*pp)->pMainNext));
    *pp = p->pMainNext;
    rbuMainlistRemove(p);
    sqlite3_mutex_leave(p->pRbuVfs->mutex);
    rbuUnlockShm(p);
    p->pReal->pMethods->xShmUnmap(p->pReal, 0);
  }
  else if( (p->openFlags & SQLITE_OPEN_DELETEONCLOSE) && p->pRbu ){
    rbuUpdateTempSize(p, 0);
  }
  assert( p->pMainNext==0 && p->pRbuVfs->pMain!=p );

  /* Close the underlying file handle */
  rc = p->pReal->pMethods->xClose(p->pReal);
  return rc;
}

      rc = xControl(p->pReal, SQLITE_FCNTL_ZIPVFS, &dummy);
      if( rc==SQLITE_OK ){
        rc = SQLITE_ERROR;
        pRbu->zErrmsg = sqlite3_mprintf("rbu/zipvfs setup error");
      }else if( rc==SQLITE_NOTFOUND ){
        pRbu->pTargetFd = p;
        p->pRbu = pRbu;
        if( p->openFlags & SQLITE_OPEN_MAIN_DB ){
          rbuMainlistAdd(p);
        }
        if( p->pWalFd ) p->pWalFd->pRbu = pRbu;
        rc = SQLITE_OK;
      }
    }
    return rc;
  }
  else if( op==SQLITE_FCNTL_RBUCNT ){

    /* Release the checkpointer and writer locks */
    rbuUnlockShm(p);
    rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
  }
  return rc;
}

/*
** Given that zWal points to a buffer containing a wal file name passed to 
** either the xOpen() or xAccess() VFS method, return a pointer to the
** file-handle opened by the same database connection on the corresponding
** database file.
*/
static rbu_file *rbuFindMaindb(rbu_vfs *pRbuVfs, const char *zWal){
  rbu_file *pDb;
  sqlite3_mutex_enter(pRbuVfs->mutex);
  for(pDb=pRbuVfs->pMain; pDb && pDb->zWal!=zWal; pDb=pDb->pMainNext){}
  sqlite3_mutex_leave(pRbuVfs->mutex);
  return pDb;
}

/* 
** A main database named zName has just been opened. The following 
** function returns a pointer to a buffer owned by SQLite that contains
** the name of the *-wal file this db connection will use. SQLite
** happens to pass a pointer to this buffer when using xAccess()
** or xOpen() to operate on the *-wal file.  
*/

      ** (pFd->zWal) to point to a buffer owned by SQLite that contains
      ** the name of the *-wal file this db connection will use. SQLite
      ** happens to pass a pointer to this buffer when using xAccess()
      ** or xOpen() to operate on the *-wal file.  */
      pFd->zWal = rbuMainToWal(zName, flags);
    }
    else if( flags & SQLITE_OPEN_WAL ){
      rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName);
      rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName, 0);
      if( pDb ){
        if( pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
          /* This call is to open a *-wal file. Intead, open the *-oal. This
          ** code ensures that the string passed to xOpen() is terminated by a
          ** pair of '\0' bytes in case the VFS attempts to extract a URI 
          ** parameter from it.  */
          const char *zBase = zName;

  }
  if( pFd->pReal->pMethods ){
    /* The xOpen() operation has succeeded. Set the sqlite3_file.pMethods
    ** pointer and, if the file is a main database file, link it into the
    ** mutex protected linked list of all such files.  */
    pFile->pMethods = &rbuvfs_io_methods;
    if( flags & SQLITE_OPEN_MAIN_DB ){
      sqlite3_mutex_enter(pRbuVfs->mutex);
      pFd->pMainNext = pRbuVfs->pMain;
      pRbuVfs->pMain = pFd;
      rbuMainlistAdd(pFd);
      sqlite3_mutex_leave(pRbuVfs->mutex);
    }
  }else{
    sqlite3_free(pFd->zDel);
  }

  return rc;
}

  **
  **   b) if the *-wal file does not exist, claim that it does anyway,
  **      causing SQLite to call xOpen() to open it. This call will also
  **      be intercepted (see the rbuVfsOpen() function) and the *-oal
  **      file opened instead.
  */
  if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){
    rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath);
    rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath, 1);
    if( pDb && pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
      if( *pResOut ){
        rc = SQLITE_CANTOPEN;
      }else{
        sqlite3_int64 sz = 0;
        rc = rbuVfsFileSize(&pDb->base, &sz);
        *pResOut = (sz>0);

    {"bp_progress", 2, ""},          /* 5 */
    {"db", 3, "RBU"},                /* 6 */
    {"state", 2, ""},                /* 7 */
    {"progress", 2, ""},             /* 8 */
    {"close_no_error", 2, ""},       /* 9 */
    {"temp_size_limit", 3, "LIMIT"}, /* 10 */
    {"temp_size", 2, ""},            /* 11 */
    {"dbRbu_eval", 3, "SQL"},        /* 12 */
    {0,0,0}
  };
  int iCmd;

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "METHOD");
    return TCL_ERROR;

    case 3: /* savestate */ {
      int rc = sqlite3rbu_savestate(pRbu);
      Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
      ret = (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
      break;
    }

    case 12: /* dbRbu_eval */ 
    case 4: /* dbMain_eval */ {
      sqlite3 *db = sqlite3rbu_db(pRbu, 0);
    case 4:  /* dbMain_eval */ {
      sqlite3 *db = sqlite3rbu_db(pRbu, (iCmd==12));
      int rc = sqlite3_exec(db, Tcl_GetString(objv[2]), 0, 0, 0);
      if( rc!=SQLITE_OK ){
        Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3_errmsg(db), -1));
        ret = TCL_ERROR;
      }
      break;
    }

    assert( pRtree->nBusy==1 );
    rtreeRelease(pRtree);
  }
  return rc;
}


#if defined(SQLITE_TEST)
/*
** Implementation of a scalar function that decodes r-tree nodes to
** human readable strings. This can be used for debugging and analysis.
**
** The scalar function takes two arguments: (1) the number of dimensions
** to the rtree (between 1 and 5, inclusive) and (2) a blob of data containing
** an r-tree node.  For a two-dimensional r-tree structure called "rt", to

    }else{
      zText = sqlite3_mprintf("{%s}", zCell);
    }
  }
  
  sqlite3_result_text(ctx, zText, -1, sqlite3_free);
}
#endif

/* This routine implements an SQL function that returns the "depth" parameter
** from the front of a blob that is an r-tree node.  For example:
**
**     SELECT rtreedepth(data) FROM rt_node WHERE nodeno=1;
**
** The depth value is 0 for all nodes other than the root node, and the root

/*
** 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;
  int rc = SQLITE_OK;

#if defined(SQLITE_TEST)
  rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);
#endif
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "rtreecheck", -1, utf8, 0,rtreecheck, 0,0);
  }
  if( rc==SQLITE_OK ){

** [sqlite3_finalize()] relatively soon. The current implementation acts
** on this hint by avoiding the use of [lookaside memory] so as not to
** deplete the limited store of lookaside memory. Future versions of
** SQLite may act on this hint differently.
** </dl>
*/
#define SQLITE_PREPARE_PERSISTENT              0x01
#define SQLITE_PREPARE_NO_VTAB                 0x04

/*
** CAPI3REF: Compiling An SQL Statement
** KEYWORDS: {SQL statement compiler}
** METHOD: sqlite3
** CONSTRUCTOR: sqlite3_stmt
**

** CAPI3REF: Function Flags
**
** These constants may be ORed together with the 
** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
** to [sqlite3_create_function()], [sqlite3_create_function16()], or
** [sqlite3_create_function_v2()].
*/
#define SQLITE_DETERMINISTIC    0x800
#define SQLITE_DETERMINISTIC    0x000000800
#define SQLITE_DIRECTONLY       0x000080000

/*
** CAPI3REF: Deprecated Functions
** DEPRECATED
**
** These functions are [deprecated].  In order to maintain
** backwards compatibility with older code, these functions continue 

# 2006 September 9
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the FTS3 module.
#
# $Id: fts3aa.test,v 1.1 2007/08/20 17:38:42 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix fts3corrupt4

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {
  finish_test
  return
}

do_execsql_test 1.0 {
  BEGIN;
    CREATE VIRTUAL TABLE ft USING fts3;
    INSERT INTO ft VALUES('aback');
    INSERT INTO ft VALUES('abaft');
    INSERT INTO ft VALUES('abandon');
  COMMIT;
}

proc blob {a} { binary decode hex $a }
db func blob blob

do_execsql_test 1.1 {
  SELECT quote(root) FROM ft_segdir;
} {X'0005616261636B03010200030266740302020003046E646F6E03030200'}

do_execsql_test 1.2 {
  UPDATE ft_segdir SET root = blob(
    '0005616261636B03010200 FFFFFFFF0702 66740302020003046E646F6E03030200'
  );
}

do_catchsql_test 1.3 {
  SELECT * FROM ft WHERE ft MATCH 'abandon';
} {1 {database disk image is malformed}}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 2.0.0 {
  CREATE VIRTUAL TABLE ft USING fts3;
  INSERT INTO ft(ft) VALUES('nodesize=32');
}
do_test 2.0.1 {
  for {set i 0} {$i < 12} {incr i} {
    execsql {
      BEGIN;
        INSERT INTO ft VALUES('abc' || $i);
        INSERT INTO ft VALUES('abc' || $i || 'x' );
        INSERT INTO ft VALUES('abc' || $i || 'xx' );
      COMMIT
    }
  }
  execsql {
    SELECT count(*) FROM ft_segdir;
    SELECT count(*) FROM ft_segments;
  }
} {12 0}

do_execsql_test 2.1 {
  INSERT INTO ft(ft) VALUES('merge=1,4');
  SELECT count(*) FROM ft_segdir;
  SELECT count(*) FROM ft_segments;
} {12 3}

do_execsql_test 2.2 {
  SELECT quote(block) FROM ft_segments WHERE blockid=2
} {X'00056162633130031F0200'}

db func blob blob
do_execsql_test 2.3.1 {
  UPDATE ft_segments SET block = 
    blob('00056162633130031F0200 FFFFFFFF07FF55 66740302020003046E646F6E03030200')
    WHERE blockid=2;
} {}
do_catchsql_test 2.3.2 {
  INSERT INTO ft(ft) VALUES('merge=1,4');
} {1 {database disk image is malformed}}

do_execsql_test 2.4.1 {
  UPDATE ft_segments SET block = 
    blob('00056162633130031F0200 02FFFFFFFF07 66740302020003046E646F6E03030200')
    WHERE blockid=2;
} {}
do_catchsql_test 2.4.2 {
  INSERT INTO ft(ft) VALUES('merge=1,4');
} {1 {database disk image is malformed}}

do_execsql_test 2.5.1 {
  UPDATE ft_segments SET block = 
    blob('00056162633130031F0200 0202 6674 FFFFFF070302020003046E646F6E030200')
    WHERE blockid=2;
} {}
do_catchsql_test 2.5.2 {
  INSERT INTO ft(ft) VALUES('merge=1,4');
} {1 {database disk image is malformed}}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 3.0.0 {
  CREATE VIRTUAL TABLE ft USING fts3;
  INSERT INTO ft(ft) VALUES('nodesize=32');
}
do_test 3.0.1 {
  execsql BEGIN
  for {set i 0} {$i < 20} {incr i} {
    execsql { INSERT INTO ft VALUES('abc' || $i) }
  }
  execsql {
    COMMIT;
    SELECT count(*) FROM ft_segdir;
    SELECT count(*) FROM ft_segments;
  }
} {1 5}

do_execsql_test 3.1 {
  SELECT quote(root) FROM ft_segdir
} {X'0101056162633132040136030132030136'}

db func blob blob
do_execsql_test 3.2 {
  UPDATE ft_segdir 
  SET root = blob('0101056162633132FFFFFFFF070236030132030136');
}

do_catchsql_test 3.1 {
  SELECT * FROM ft WHERE ft MATCH 'abc20'
} {1 {database disk image is malformed}}

finish_test

# cases in the test code, which makes test coverage easier to measure.
# 
do_test fts3expr-5.1 {
  catchsql { SELECT fts3_exprtest('simple', 'a b') }
} {1 {Usage: fts3_exprtest(tokenizer, expr, col1, ...}}
do_test fts3expr-5.2 {
  catchsql { SELECT fts3_exprtest('doesnotexist', 'a b', 'c') }
} {1 {No such tokenizer module}}
} {1 {unknown tokenizer: doesnotexist}}
do_test fts3expr-5.3 {
  catchsql { SELECT fts3_exprtest('simple', 'a b OR', 'c') }
} {1 {Error parsing expression}}

#------------------------------------------------------------------------
# The next set of tests verifies that things actually work as they are
# supposed to when using the new syntax.

} -files {
  fts3aa.test fts3ab.test fts3ac.test fts3ad.test
  fts3ae.test fts3af.test fts3ag.test fts3ah.test
  fts3ai.test fts3aj.test fts3ak.test fts3al.test
  fts3am.test fts3an.test fts3ao.test fts3atoken.test
  fts3auto.test fts3aux1.test fts3aux2.test fts3b.test
  fts3comp1.test fts3conf.test fts3corrupt2.test fts3corrupt.test
  fts3corrupt4.test
  fts3cov.test fts3c.test fts3defer2.test fts3defer3.test
  fts3defer.test fts3drop.test fts3d.test fts3e.test
  fts3expr2.test fts3expr3.test fts3expr4.test fts3expr5.test
  fts3expr.test fts3fault2.test fts3fault.test fts3first.test
  fts3join.test fts3malloc.test fts3matchinfo.test fts3near.test
  fts3offsets.test fts3prefix2.test fts3prefix.test fts3query.test
  fts3shared.test fts3snippet.test fts3sort.test fts3tok1.test