SQLite

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

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;

        if( rc==SQLITE_OK ){
          rc = fts3MatchinfoLcs(pCsr, pInfo);
        }
        break;

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

      default: {
        Fts3Expr *pExpr;

  if( p->rc==SQLITE_OK && nLvl>=pWriter->nDlidx ){
    Fts5DlidxWriter *aDlidx = (Fts5DlidxWriter*)sqlite3_realloc64(
        pWriter->aDlidx, sizeof(Fts5DlidxWriter) * nLvl
    );
    if( aDlidx==0 ){
      p->rc = SQLITE_NOMEM;
    }else{
      size_t nByte = sizeof(Fts5DlidxWriter) * (nLvl - pWriter->nDlidx);
      memset(&aDlidx[pWriter->nDlidx], 0, nByte);
      pWriter->aDlidx = aDlidx;
      pWriter->nDlidx = nLvl;
    }
  }
  return p->rc;
}

  fts5_extension_function xFunc,  /* Aux. function implementation */
  void(*xDestroy)(void*)          /* Destructor for pUserData */
){
  Fts5Global *pGlobal = (Fts5Global*)pApi;
  int rc = sqlite3_overload_function(pGlobal->db, zName, -1);
  if( rc==SQLITE_OK ){
    Fts5Auxiliary *pAux;
    sqlite3_int64 nName;            /* Size of zName in bytes, including \0 */
    sqlite3_int64 nByte;            /* Bytes of space to allocate */

    nName = strlen(zName) + 1;
    nByte = sizeof(Fts5Auxiliary) + nName;
    pAux = (Fts5Auxiliary*)sqlite3_malloc64(nByte);
    if( pAux ){
      memset(pAux, 0, (size_t)nByte);
      pAux->zFunc = (char*)&pAux[1];
      memcpy(pAux->zFunc, zName, nName);
      pAux->pGlobal = pGlobal;
      pAux->pUserData = pUserData;
      pAux->xFunc = xFunc;
      pAux->xDestroy = xDestroy;
      pAux->pNext = pGlobal->pAux;

  const char *zName,              /* Name of new function */
  void *pUserData,                /* User data for aux. function */
  fts5_tokenizer *pTokenizer,     /* Tokenizer implementation */
  void(*xDestroy)(void*)          /* Destructor for pUserData */
){
  Fts5Global *pGlobal = (Fts5Global*)pApi;
  Fts5TokenizerModule *pNew;
  sqlite3_int64 nName;            /* Size of zName and its \0 terminator */
  sqlite3_int64 nByte;            /* Bytes of space to allocate */
  int rc = SQLITE_OK;

  nName = strlen(zName) + 1;
  nByte = sizeof(Fts5TokenizerModule) + nName;
  pNew = (Fts5TokenizerModule*)sqlite3_malloc64(nByte);
  if( pNew ){
    memset(pNew, 0, (size_t)nByte);
    pNew->zName = (char*)&pNew[1];
    memcpy(pNew->zName, zName, nName);
    pNew->pUserData = pUserData;
    pNew->x = *pTokenizer;
    pNew->xDestroy = xDestroy;
    pNew->pNext = pGlobal->pTok;
    pGlobal->pTok = pNew;

**
** If an error (i.e. an OOM condition) occurs, return NULL and leave an 
** error code in the rbu handle passed as the first argument. Or, if an 
** error has already occurred when this function is called, return NULL 
** immediately without attempting the allocation or modifying the stored
** error code.
*/
static void *rbuMalloc(sqlite3rbu *p, sqlite3_int64 nByte){
  void *pRet = 0;
  if( p->rc==SQLITE_OK ){
    assert( nByte>0 );
    pRet = sqlite3_malloc64(nByte);
    if( pRet==0 ){
      p->rc = SQLITE_NOMEM;
    }else{
      memset(pRet, 0, nByte);
    }
  }
  return pRet;
}


/*
** Allocate and zero the pIter->azTblCol[] and abTblPk[] arrays so that
** there is room for at least nCol elements. If an OOM occurs, store an
** error code in the RBU handle passed as the first argument.
*/
static void rbuAllocateIterArrays(sqlite3rbu *p, RbuObjIter *pIter, int nCol){
  sqlite3_int64 nByte = (2*sizeof(char*) + sizeof(int) + 3*sizeof(u8)) * nCol;
  char **azNew;

  azNew = (char**)rbuMalloc(p, nByte);
  if( azNew ){
    pIter->azTblCol = azNew;
    pIter->azTblType = &azNew[nCol];
    pIter->aiSrcOrder = (int*)&pIter->azTblType[nCol];

** string, an error code is left in the rbu handle passed as the first
** argument and NULL is returned. Or, if an error has already occurred
** when this function is called, NULL is returned immediately, without
** attempting the allocation or modifying the stored error code.
*/
static char *rbuObjIterGetBindlist(sqlite3rbu *p, int nBind){
  char *zRet = 0;
  sqlite3_int64 nByte = 2*(sqlite3_int64)nBind + 1;

  zRet = (char*)rbuMalloc(p, nByte);
  if( zRet ){
    int i;
    for(i=0; i<nBind; i++){
      zRet[i*2] = '?';
      zRet[i*2+1] = (i+1==nBind) ? '\0' : ',';

  /* If not in RBU_STAGE_OAL, allow this call to pass through. Or, if this
  ** rbu is in the RBU_STAGE_OAL state, use heap memory for *-shm space 
  ** instead of a file on disk.  */
  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
  if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){
    if( iRegion<=p->nShm ){
      sqlite3_int64 nByte = (iRegion+1) * sizeof(char*);
      char **apNew = (char**)sqlite3_realloc64(p->apShm, nByte);
      if( apNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(&apNew[p->nShm], 0, sizeof(char*) * (1 + iRegion - p->nShm));
        p->apShm = apNew;
        p->nShm = iRegion+1;

** Growing the hash table in this case is a performance optimization only,
** it is not required for correct operation.
*/
static int sessionGrowHash(int bPatchset, SessionTable *pTab){
  if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){
    int i;
    SessionChange **apNew;
    sqlite3_int64 nNew = 2*(sqlite3_int64)(pTab->nChange ? pTab->nChange : 128);

    apNew = (SessionChange **)sqlite3_malloc64(sizeof(SessionChange *) * nNew);
    if( apNew==0 ){
      if( pTab->nChange==0 ){
        return SQLITE_ERROR;
      }
      return SQLITE_OK;

/*
** Ensure that there is room in the buffer to append nByte bytes of data.
** If not, use sqlite3_realloc() to grow the buffer so that there is.
**
** If successful, return zero. Otherwise, if an OOM condition is encountered,
** set *pRc to SQLITE_NOMEM and return non-zero.
*/
static int sessionBufferGrow(SessionBuffer *p, size_t nByte, int *pRc){
  if( *pRc==SQLITE_OK && p->nAlloc-p->nBuf<nByte ){
    u8 *aNew;
    i64 nNew = p->nAlloc ? p->nAlloc : 128;
    do {
      nNew = nNew*2;
    }while( (nNew-p->nBuf)<nByte );

      sessionBufferGrow(&p->tblhdr, nByte, &rc);
    }else{
      rc = SQLITE_CORRUPT_BKPT;
    }
  }

  if( rc==SQLITE_OK ){
    size_t iPK = sizeof(sqlite3_value*)*p->nCol*2;
    memset(p->tblhdr.aBuf, 0, iPK);
    memcpy(&p->tblhdr.aBuf[iPK], &p->in.aData[p->in.iNext], nCopy);
    p->in.iNext += nCopy;
  }

  p->apValue = (sqlite3_value**)p->tblhdr.aBuf;
  p->abPK = (u8*)&p->apValue[p->nCol*2];

  while( pApply->constraints.nBuf ){
    sqlite3_changeset_iter *pIter2 = 0;
    SessionBuffer cons = pApply->constraints;
    memset(&pApply->constraints, 0, sizeof(SessionBuffer));

    rc = sessionChangesetStart(&pIter2, 0, 0, cons.nBuf, cons.aBuf, 0);
    if( rc==SQLITE_OK ){
      size_t nByte = 2*pApply->nCol*sizeof(sqlite3_value*);
      int rc2;
      pIter2->bPatchset = bPatchset;
      pIter2->zTab = (char*)zTab;
      pIter2->nCol = pApply->nCol;
      pIter2->abPK = pApply->abPK;
      sessionBufferGrow(&pIter2->tblhdr, nByte, &rc);
      pIter2->apValue = (sqlite3_value**)pIter2->tblhdr.aBuf;

  sqlite3 *db,      /* Connection to notify of malloc failures */
  void *pArray,     /* Array of objects.  Might be reallocated */
  int szEntry,      /* Size of each object in the array */
  int *pnEntry,     /* Number of objects currently in use */
  int *pIdx         /* Write the index of a new slot here */
){
  char *z;
  sqlite3_int64 n = *pIdx = *pnEntry;
  if( (n & (n-1))==0 ){
    sqlite3_int64 sz = (n==0) ? 1 : 2*n;
    void *pNew = sqlite3DbRealloc(db, pArray, sz*szEntry);
    if( pNew==0 ){
      *pIdx = -1;
      return pArray;
    }
    pArray = pNew;
  }
  z = (char*)pArray;
  memset(&z[n * szEntry], 0, szEntry);

  ++*pnEntry;
  return pArray;
}

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.

*/
static HashElem *findElementWithHash(
  const Hash *pH,     /* The pH to be searched */
  const char *pKey,   /* The key we are searching for */
  unsigned int *pHash /* Write the hash value here */
){
  HashElem *elem;                /* Used to loop thru the element list */
  unsigned int count;            /* Number of elements left to test */
  unsigned int h;                /* The computed hash */
  static HashElem nullElement = { 0, 0, 0, 0 };

  if( pH->ht ){   /*OPTIMIZATION-IF-TRUE*/
    struct _ht *pEntry;
    h = strHash(pKey) % pH->htsize;
    pEntry = &pH->ht[h];

    elem->next->prev = elem->prev;
  }
  if( pH->ht ){
    pEntry = &pH->ht[h];
    if( pEntry->chain==elem ){
      pEntry->chain = elem->next;
    }
    assert( pEntry->count>0 );
    pEntry->count--;
  }
  sqlite3_free( elem );
  pH->count--;
  if( pH->count==0 ){
    assert( pH->first==0 );
    assert( pH->count==0 );
    sqlite3HashClear(pH);

** the hash table.
*/
struct Hash {
  unsigned int htsize;      /* Number of buckets in the hash table */
  unsigned int count;       /* Number of entries in this table */
  HashElem *first;          /* The first element of the array */
  struct _ht {              /* the hash table */
    unsigned int count;        /* Number of entries with this hash */
    HashElem *chain;           /* Pointer to first entry with this hash */
  } *ht;
};

/* Each element in the hash table is an instance of the following 
** structure.  All elements are stored on a single doubly-linked list.
**

  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
  ** size of the op array or add 1KB of space, whichever is smaller. */
#ifdef SQLITE_TEST_REALLOC_STRESS
  sqlite3_int64 nNew = (v->nOpAlloc>=512 ? 2*(sqlite3_int64)v->nOpAlloc
                        : (sqlite3_int64)v->nOpAlloc+nOp);
#else
  sqlite3_int64 nNew = (v->nOpAlloc ? 2*(sqlite3_int64)v->nOpAlloc
                        : (sqlite3_int64)(1024/sizeof(Op)));
  UNUSED_PARAMETER(nOp);
#endif

  /* Ensure that the size of a VDBE does not grow too large */
  if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
    sqlite3OomFault(p->db);
    return SQLITE_NOMEM;

#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */

/* An instance of this object describes bulk memory available for use
** by subcomponents of a prepared statement.  Space is allocated out
** of a ReusableSpace object by the allocSpace() routine below.
*/
struct ReusableSpace {
  u8 *pSpace;            /* Available memory */
  sqlite3_int64 nFree;   /* Bytes of available memory */
  sqlite3_int64 nNeeded; /* Total bytes that could not be allocated */
};

/* Try to allocate nByte bytes of 8-byte aligned bulk memory for pBuf
** from the ReusableSpace object.  Return a pointer to the allocated
** memory on success.  If insufficient memory is available in the
** ReusableSpace object, increase the ReusableSpace.nNeeded
** value by the amount needed and return NULL.
**
** If pBuf is not initially NULL, that means that the memory has already
** been allocated by a prior call to this routine, so just return a copy
** of pBuf and leave ReusableSpace unchanged.
**
** This allocator is employed to repurpose unused slots at the end of the
** opcode array of prepared state for other memory needs of the prepared
** statement.
*/
static void *allocSpace(
  struct ReusableSpace *p,  /* Bulk memory available for allocation */
  void *pBuf,               /* Pointer to a prior allocation */
  sqlite3_int64 nByte       /* Bytes of memory needed */
){
  assert( EIGHT_BYTE_ALIGNMENT(p->pSpace) );
  if( pBuf==0 ){
    nByte = ROUND8(nByte);
    if( nByte <= p->nFree ){
      p->nFree -= nByte;
      pBuf = &p->pSpace[p->nFree];

  int iPage,               /* The page we seek */
  volatile u32 **ppPage    /* Write the page pointer here */
){
  int rc = SQLITE_OK;

  /* Enlarge the pWal->apWiData[] array if required */
  if( pWal->nWiData<=iPage ){
    sqlite3_int64 nByte = sizeof(u32*)*(iPage+1);
    volatile u32 **apNew;
    apNew = (volatile u32 **)sqlite3_realloc64((void *)pWal->apWiData, nByte);
    if( !apNew ){
      *ppPage = 0;
      return SQLITE_NOMEM_BKPT;
    }
    memset((void*)&apNew[pWal->nWiData], 0,

    s2 = aIn[1];
  }else{
    s1 = s2 = 0;
  }

  assert( nByte>=8 );
  assert( (nByte&0x00000007)==0 );
  assert( nByte<=65536 );

  if( nativeCksum ){
    do {
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
    }while( aData<aEnd );
  }else{

** The calling routine should invoke walIteratorFree() to destroy the
** WalIterator object when it has finished with it.
*/
static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
  WalIterator *p;                 /* Return value */
  int nSegment;                   /* Number of segments to merge */
  u32 iLast;                      /* Last frame in log */
  sqlite3_int64 nByte;            /* Number of bytes to allocate */
  int i;                          /* Iterator variable */
  ht_slot *aTmp;                  /* Temp space used by merge-sort */
  int rc = SQLITE_OK;             /* Return Code */

  /* This routine only runs while holding the checkpoint lock. And
  ** it only runs if there is actually content in the log (mxFrame>0).
  */