** The commands implemented by this function are documented in the "Special
** INSERT Directives" section of the documentation. It should be updated if
** more commands are added to this function.
*/
static int fts5SpecialInsert(
  Fts5Table *pTab,                /* Fts5 table object */
  sqlite3_value *pCmd,            /* Value inserted into special column */
  sqlite3_value *pVal             /* Value inserted into rowid column */
){
  Fts5Config *pConfig = pTab->pConfig;
  const char *z = (const char*)sqlite3_value_text(pCmd);
  int rc = SQLITE_OK;
  int bError = 0;

  if( 0==sqlite3_stricmp("delete-all", z) ){
................................................................................
      );
      rc = SQLITE_ERROR;
    }else{
      rc = sqlite3Fts5StorageRebuild(pTab->pStorage);
    }
  }else if( 0==sqlite3_stricmp("optimize", z) ){
    rc = sqlite3Fts5StorageOptimize(pTab->pStorage);



  }else if( 0==sqlite3_stricmp("integrity-check", z) ){
    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);
  }else{
    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5ConfigSetValue(pTab->pConfig, z, pVal, &bError);
    }

** The commands implemented by this function are documented in the "Special
** INSERT Directives" section of the documentation. It should be updated if
** more commands are added to this function.
*/
static int fts5SpecialInsert(
  Fts5Table *pTab,                /* Fts5 table object */
  sqlite3_value *pCmd,            /* Value inserted into special column */
  sqlite3_value *pVal             /* Value inserted into rank column */
){
  Fts5Config *pConfig = pTab->pConfig;
  const char *z = (const char*)sqlite3_value_text(pCmd);
  int rc = SQLITE_OK;
  int bError = 0;

  if( 0==sqlite3_stricmp("delete-all", z) ){
................................................................................
      );
      rc = SQLITE_ERROR;
    }else{
      rc = sqlite3Fts5StorageRebuild(pTab->pStorage);
    }
  }else if( 0==sqlite3_stricmp("optimize", z) ){
    rc = sqlite3Fts5StorageOptimize(pTab->pStorage);
  }else if( 0==sqlite3_stricmp("merge", z) ){
    int nMerge = sqlite3_value_int(pVal);
    rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);
  }else if( 0==sqlite3_stricmp("integrity-check", z) ){
    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);
  }else{
    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5ConfigSetValue(pTab->pConfig, z, pVal, &bError);
    }

** Return the total number of entries read from the %_data table by 
** this connection since it was created.
*/
int sqlite3Fts5IndexReads(Fts5Index *p);

int sqlite3Fts5IndexReinit(Fts5Index *p);
int sqlite3Fts5IndexOptimize(Fts5Index *p);


int sqlite3Fts5IndexLoadConfig(Fts5Index *p);

int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v);
#define fts5GetVarint32(a,b) sqlite3Fts5GetVarint32(a,(u32*)&b)

int sqlite3Fts5GetVarintLen(u32 iVal);
................................................................................
int sqlite3Fts5StorageConfigValue(Fts5Storage *p, const char*, sqlite3_value*);

int sqlite3Fts5StorageSpecialDelete(Fts5Storage *p, i64 iDel, sqlite3_value**);

int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);
int sqlite3Fts5StorageRebuild(Fts5Storage *p);
int sqlite3Fts5StorageOptimize(Fts5Storage *p);


/*
** End of interface to code in fts5_storage.c.
**************************************************************************/


/**************************************************************************

** Return the total number of entries read from the %_data table by 
** this connection since it was created.
*/
int sqlite3Fts5IndexReads(Fts5Index *p);

int sqlite3Fts5IndexReinit(Fts5Index *p);
int sqlite3Fts5IndexOptimize(Fts5Index *p);
int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge);

int sqlite3Fts5IndexLoadConfig(Fts5Index *p);

int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v);
#define fts5GetVarint32(a,b) sqlite3Fts5GetVarint32(a,(u32*)&b)

int sqlite3Fts5GetVarintLen(u32 iVal);
................................................................................
int sqlite3Fts5StorageConfigValue(Fts5Storage *p, const char*, sqlite3_value*);

int sqlite3Fts5StorageSpecialDelete(Fts5Storage *p, i64 iDel, sqlite3_value**);

int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);
int sqlite3Fts5StorageRebuild(Fts5Storage *p);
int sqlite3Fts5StorageOptimize(Fts5Storage *p);
int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge);

/*
** End of interface to code in fts5_storage.c.
**************************************************************************/


/**************************************************************************

  if( p->rc==SQLITE_OK ){
    int rc = SQLITE_OK;

    if( p->pReader ){
      /* This call may return SQLITE_ABORT if there has been a savepoint
      ** rollback since it was last used. In this case a new blob handle
      ** is required.  */


      rc = sqlite3_blob_reopen(p->pReader, iRowid);


      if( rc==SQLITE_ABORT ){
        fts5CloseReader(p);
        rc = SQLITE_OK;
      }

    }

    /* If the blob handle is not yet open, open and seek it. Otherwise, use
    ** the blob_reopen() API to reseek the existing blob handle.  */
    if( p->pReader==0 ){
      Fts5Config *pConfig = p->pConfig;
      rc = sqlite3_blob_open(pConfig->db, 
          pConfig->zDb, p->zDataTbl, "block", iRowid, 0, &p->pReader
      );
    }

    /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls
................................................................................
** any currently existing segment. If a free segment id cannot be found,
** SQLITE_FULL is returned.
**
** If an error has already occurred, this function is a no-op. 0 is 
** returned in this case.
*/
static int fts5AllocateSegid(Fts5Index *p, Fts5Structure *pStruct){
  int i;
  u32 iSegid = 0;

  if( p->rc==SQLITE_OK ){
    if( pStruct->nSegment>=FTS5_MAX_SEGMENT ){
      p->rc = SQLITE_FULL;
    }else{
      while( iSegid==0 ){
................................................................................
  Fts5StructureSegment *pSeg      /* Segment object to append to */
){
  int nByte = pSeg->nHeight * sizeof(Fts5PageWriter);
  memset(pWriter, 0, sizeof(Fts5SegWriter));
  pWriter->iIdx = iIdx;
  pWriter->iSegid = pSeg->iSegid;
  pWriter->aWriter = (Fts5PageWriter*)fts5IdxMalloc(p, nByte);
  pWriter->nWriter = pSeg->nHeight;

  if( p->rc==SQLITE_OK ){
    int pgno = 1;
    int i;

    pWriter->aWriter[0].pgno = pSeg->pgnoLast+1;
    for(i=pSeg->nHeight-1; i>0; i--){
      i64 iRowid = FTS5_SEGMENT_ROWID(pWriter->iIdx, pWriter->iSegid, i, pgno);
      Fts5PageWriter *pPg = &pWriter->aWriter[i];
      pPg->pgno = pgno;
      fts5DataBuffer(p, &pPg->buf, iRowid);
      if( p->rc==SQLITE_OK ){
................................................................................
        pgno = ss.iChild;
        fts5NodeIterFree(&ss);
      }
    }
    if( pSeg->nHeight==1 ){
      pWriter->nEmpty = pSeg->pgnoLast-1;
    }
    assert( (pgno+pWriter->nEmpty)==pSeg->pgnoLast );
    pWriter->bFirstTermInPage = 1;
    assert( pWriter->aWriter[0].term.n==0 );
  }
}

/*
** Iterator pIter was used to iterate through the input segments of on an
................................................................................
    if( p->rc ) return;
    pLvl = &pStruct->aLevel[iLvl];
    pLvlOut = &pStruct->aLevel[iLvl+1];

    fts5WriteInit(p, &writer, iIdx, iSegid);

    /* Add the new segment to the output level */
    if( iLvl+1==pStruct->nLevel ) pStruct->nLevel++;
    pSeg = &pLvlOut->aSeg[pLvlOut->nSeg];
    pLvlOut->nSeg++;
    pSeg->pgnoFirst = 1;
    pSeg->iSegid = iSegid;
    pStruct->nSegment++;

    /* Read input from all segments in the input level */
................................................................................
    pLvl->nMerge = nInput;
  }

  fts5MultiIterFree(p, pIter);
  fts5BufferFree(&term);
  if( pnRem ) *pnRem -= writer.nLeafWritten;
}






















































/*
** A total of nLeaf leaf pages of data has just been flushed to a level-0
** segments in index iIdx with structure pStruct. This function updates the
** write-counter accordingly and, if necessary, performs incremental merge
** work.
**
** If an error occurs, set the Fts5Index.rc error code. If an error has 
** already occurred, this function is a no-op.
*/
static void fts5IndexWork(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index to work on */
  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
  int nLeaf                       /* Number of output leaves just written */
){
  if( p->rc==SQLITE_OK ){
    Fts5Structure *pStruct = *ppStruct;
    i64 nWrite;                   /* Initial value of write-counter */
    int nWork;                    /* Number of work-quanta to perform */
    int nRem;                     /* Number of leaf pages left to write */

    /* Update the write-counter. While doing so, set nWork. */
    nWrite = pStruct->nWriteCounter;
    nWork = ((nWrite + nLeaf) / p->nWorkUnit) - (nWrite / p->nWorkUnit);
    pStruct->nWriteCounter += nLeaf;
    nRem = p->nWorkUnit * nWork * pStruct->nLevel;

    while( nRem>0 ){
      int iLvl;                   /* To iterate through levels */
      int iBestLvl = 0;           /* Level offering the most input segments */
      int nBest = 0;              /* Number of input segments on best level */

      /* Set iBestLvl to the level to read input segments from. */
      assert( pStruct->nLevel>0 );
      for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
        Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
        if( pLvl->nMerge ){
          if( pLvl->nMerge>nBest ){
            iBestLvl = iLvl;
            nBest = pLvl->nMerge;
          }
          break;
        }
        if( pLvl->nSeg>nBest ){
          nBest = pLvl->nSeg;
          iBestLvl = iLvl;
        }
      }

      /* If nBest is still 0, then the index must be empty. */
#ifdef SQLITE_DEBUG
      for(iLvl=0; nBest==0 && iLvl<pStruct->nLevel; iLvl++){
        assert( pStruct->aLevel[iLvl].nSeg==0 );
      }
#endif

      if( nBest<p->pConfig->nAutomerge 
       && pStruct->aLevel[iBestLvl].nMerge==0 
      ){
        break;
      }
      fts5IndexMergeLevel(p, iIdx, &pStruct, iBestLvl, &nRem);
      assert( nRem==0 || p->rc==SQLITE_OK );
      if( p->rc==SQLITE_OK && pStruct->aLevel[iBestLvl].nMerge==0 ){
        fts5StructurePromote(p, iBestLvl+1, pStruct);
      }
      *ppStruct = pStruct;
    }

  }
}

static void fts5IndexCrisisMerge(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index to work on */
  Fts5Structure **ppStruct        /* IN/OUT: Current structure of index */
){
  Fts5Structure *pStruct = *ppStruct;
  int iLvl = 0;
  while( p->rc==SQLITE_OK 
      && iLvl<pStruct->nLevel
      && pStruct->aLevel[iLvl].nSeg>=p->pConfig->nCrisisMerge 
  ){
    fts5IndexMergeLevel(p, iIdx, &pStruct, iLvl, 0);
    fts5StructurePromote(p, iLvl+1, pStruct);
    iLvl++;
  }
  *ppStruct = pStruct;
}

................................................................................
      pSeg->pgnoLast = pgnoLast;
      pStruct->nSegment++;
    }
    fts5StructurePromote(p, 0, pStruct);
  }


  if( p->pConfig->nAutomerge>0 ) fts5IndexWork(p, iHash, &pStruct, pgnoLast);
  fts5IndexCrisisMerge(p, iHash, &pStruct);
  fts5StructureWrite(p, iHash, pStruct);
  fts5StructureRelease(pStruct);
}

/*
** Flush any data stored in the in-memory hash tables to the database.
*/
static void fts5IndexFlush(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  int i;                          /* Used to iterate through indexes */
  int nLeaf = 0;                  /* Number of leaves written */

  /* If an error has already occured this call is a no-op. */
  if( p->rc!=SQLITE_OK || p->nPendingData==0 ) return;
  assert( p->apHash );

  /* Flush the terms and each prefix index to disk */
  for(i=0; i<=pConfig->nPrefix; i++){
    fts5FlushOneHash(p, i, &nLeaf);
  }
  p->nPendingData = 0;
................................................................................
}


int sqlite3Fts5IndexOptimize(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  int i;


  fts5IndexFlush(p);
  for(i=0; i<=pConfig->nPrefix; i++){
    Fts5Structure *pStruct = fts5StructureRead(p, i);
    Fts5Structure *pNew = 0;
    int nSeg = 0;
    if( pStruct ){
      assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
................................................................................

    fts5StructureRelease(pStruct);
  }

  return fts5IndexReturn(p); 
}













/*
** Iterator pMulti currently points to a valid entry (not EOF). This
** function appends a copy of the position-list of the entry pMulti 
** currently points to to buffer pBuf.
**
................................................................................
        sqlite3_free(apNew);
      }
      return rc;
    }
  }

  if( iRowid<=p->iWriteRowid || (p->nPendingData > p->nMaxPendingData) ){

    fts5IndexFlush(p);
  }
  p->iWriteRowid = iRowid;
  return fts5IndexReturn(p);
}

/*
................................................................................

static void fts5IndexIntegrityCheckSegment(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index that pSeg is a part of */
  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
){
  Fts5BtreeIter iter;             /* Used to iterate through b-tree hierarchy */



  /* Iterate through the b-tree hierarchy.  */
  for(fts5BtreeIterInit(p, iIdx, pSeg, &iter);
      p->rc==SQLITE_OK && iter.bEof==0;
      fts5BtreeIterNext(&iter)
  ){
    i64 iRow;                     /* Rowid for this leaf */

  if( p->rc==SQLITE_OK ){
    int rc = SQLITE_OK;

    if( p->pReader ){
      /* This call may return SQLITE_ABORT if there has been a savepoint
      ** rollback since it was last used. In this case a new blob handle
      ** is required.  */
      sqlite3_blob *pBlob = p->pReader;
      p->pReader = 0;
      rc = sqlite3_blob_reopen(pBlob, iRowid);
      assert( p->pReader==0 );
      p->pReader = pBlob;
      if( rc!=SQLITE_OK ){
        fts5CloseReader(p);

      }
      if( rc==SQLITE_ABORT ) rc = SQLITE_OK;
    }

    /* If the blob handle is not yet open, open and seek it. Otherwise, use
    ** the blob_reopen() API to reseek the existing blob handle.  */
    if( p->pReader==0 && rc==SQLITE_OK ){
      Fts5Config *pConfig = p->pConfig;
      rc = sqlite3_blob_open(pConfig->db, 
          pConfig->zDb, p->zDataTbl, "block", iRowid, 0, &p->pReader
      );
    }

    /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls
................................................................................
** any currently existing segment. If a free segment id cannot be found,
** SQLITE_FULL is returned.
**
** If an error has already occurred, this function is a no-op. 0 is 
** returned in this case.
*/
static int fts5AllocateSegid(Fts5Index *p, Fts5Structure *pStruct){

  u32 iSegid = 0;

  if( p->rc==SQLITE_OK ){
    if( pStruct->nSegment>=FTS5_MAX_SEGMENT ){
      p->rc = SQLITE_FULL;
    }else{
      while( iSegid==0 ){
................................................................................
  Fts5StructureSegment *pSeg      /* Segment object to append to */
){
  int nByte = pSeg->nHeight * sizeof(Fts5PageWriter);
  memset(pWriter, 0, sizeof(Fts5SegWriter));
  pWriter->iIdx = iIdx;
  pWriter->iSegid = pSeg->iSegid;
  pWriter->aWriter = (Fts5PageWriter*)fts5IdxMalloc(p, nByte);


  if( p->rc==SQLITE_OK ){
    int pgno = 1;
    int i;
    pWriter->nWriter = pSeg->nHeight;
    pWriter->aWriter[0].pgno = pSeg->pgnoLast+1;
    for(i=pSeg->nHeight-1; i>0; i--){
      i64 iRowid = FTS5_SEGMENT_ROWID(pWriter->iIdx, pWriter->iSegid, i, pgno);
      Fts5PageWriter *pPg = &pWriter->aWriter[i];
      pPg->pgno = pgno;
      fts5DataBuffer(p, &pPg->buf, iRowid);
      if( p->rc==SQLITE_OK ){
................................................................................
        pgno = ss.iChild;
        fts5NodeIterFree(&ss);
      }
    }
    if( pSeg->nHeight==1 ){
      pWriter->nEmpty = pSeg->pgnoLast-1;
    }
    assert( p->rc!=SQLITE_OK || (pgno+pWriter->nEmpty)==pSeg->pgnoLast );
    pWriter->bFirstTermInPage = 1;
    assert( pWriter->aWriter[0].term.n==0 );
  }
}

/*
** Iterator pIter was used to iterate through the input segments of on an
................................................................................
    if( p->rc ) return;
    pLvl = &pStruct->aLevel[iLvl];
    pLvlOut = &pStruct->aLevel[iLvl+1];

    fts5WriteInit(p, &writer, iIdx, iSegid);

    /* Add the new segment to the output level */

    pSeg = &pLvlOut->aSeg[pLvlOut->nSeg];
    pLvlOut->nSeg++;
    pSeg->pgnoFirst = 1;
    pSeg->iSegid = iSegid;
    pStruct->nSegment++;

    /* Read input from all segments in the input level */
................................................................................
    pLvl->nMerge = nInput;
  }

  fts5MultiIterFree(p, pIter);
  fts5BufferFree(&term);
  if( pnRem ) *pnRem -= writer.nLeafWritten;
}

/*
** Do up to nPg pages of automerge work on index iIdx.
*/
static void fts5IndexMerge(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index to work on */
  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
  int nPg                         /* Pages of work to do */
){
  int nRem = nPg;
  Fts5Structure *pStruct = *ppStruct;
  while( nRem>0 && p->rc==SQLITE_OK ){
    int iLvl;                   /* To iterate through levels */
    int iBestLvl = 0;           /* Level offering the most input segments */
    int nBest = 0;              /* Number of input segments on best level */

    /* Set iBestLvl to the level to read input segments from. */
    assert( pStruct->nLevel>0 );
    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
      if( pLvl->nMerge ){
        if( pLvl->nMerge>nBest ){
          iBestLvl = iLvl;
          nBest = pLvl->nMerge;
        }
        break;
      }
      if( pLvl->nSeg>nBest ){
        nBest = pLvl->nSeg;
        iBestLvl = iLvl;
      }
    }

    /* If nBest is still 0, then the index must be empty. */
#ifdef SQLITE_DEBUG
    for(iLvl=0; nBest==0 && iLvl<pStruct->nLevel; iLvl++){
      assert( pStruct->aLevel[iLvl].nSeg==0 );
    }
#endif

    if( nBest<p->pConfig->nAutomerge 
        && pStruct->aLevel[iBestLvl].nMerge==0 
      ){
      break;
    }
    fts5IndexMergeLevel(p, iIdx, &pStruct, iBestLvl, &nRem);
    if( p->rc==SQLITE_OK && pStruct->aLevel[iBestLvl].nMerge==0 ){
      fts5StructurePromote(p, iBestLvl+1, pStruct);
    }
  }
  *ppStruct = pStruct;
}

/*
** A total of nLeaf leaf pages of data has just been flushed to a level-0
** segments in index iIdx with structure pStruct. This function updates the
** write-counter accordingly and, if necessary, performs incremental merge
** work.
**
** If an error occurs, set the Fts5Index.rc error code. If an error has 
** already occurred, this function is a no-op.
*/
static void fts5IndexAutomerge(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index to work on */
  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
  int nLeaf                       /* Number of output leaves just written */
){
  if( p->rc==SQLITE_OK && p->pConfig->nAutomerge>0 ){
    Fts5Structure *pStruct = *ppStruct;
    i64 nWrite;                   /* Initial value of write-counter */
    int nWork;                    /* Number of work-quanta to perform */
    int nRem;                     /* Number of leaf pages left to write */

    /* Update the write-counter. While doing so, set nWork. */
    nWrite = pStruct->nWriteCounter;
    nWork = ((nWrite + nLeaf) / p->nWorkUnit) - (nWrite / p->nWorkUnit);
    pStruct->nWriteCounter += nLeaf;
    nRem = p->nWorkUnit * nWork * pStruct->nLevel;

    fts5IndexMerge(p, iIdx, ppStruct, nRem);



  }








}































static void fts5IndexCrisismerge(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index to work on */
  Fts5Structure **ppStruct        /* IN/OUT: Current structure of index */
){
  const int nCrisis = p->pConfig->nCrisisMerge;
  Fts5Structure *pStruct = *ppStruct;
  int iLvl = 0;

  assert( p->rc!=SQLITE_OK || pStruct->nLevel>0 );
  while( p->rc==SQLITE_OK && pStruct->aLevel[iLvl].nSeg>=nCrisis ){
    fts5IndexMergeLevel(p, iIdx, &pStruct, iLvl, 0);
    fts5StructurePromote(p, iLvl+1, pStruct);
    iLvl++;
  }
  *ppStruct = pStruct;
}

................................................................................
      pSeg->pgnoLast = pgnoLast;
      pStruct->nSegment++;
    }
    fts5StructurePromote(p, 0, pStruct);
  }


  fts5IndexAutomerge(p, iHash, &pStruct, pgnoLast);
  fts5IndexCrisismerge(p, iHash, &pStruct);
  fts5StructureWrite(p, iHash, pStruct);
  fts5StructureRelease(pStruct);
}

/*
** Flush any data stored in the in-memory hash tables to the database.
*/
static void fts5IndexFlush(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  int i;                          /* Used to iterate through indexes */
  int nLeaf = 0;                  /* Number of leaves written */

  /* If an error has already occured this call is a no-op. */
  if( p->nPendingData==0 ) return;
  assert( p->apHash );

  /* Flush the terms and each prefix index to disk */
  for(i=0; i<=pConfig->nPrefix; i++){
    fts5FlushOneHash(p, i, &nLeaf);
  }
  p->nPendingData = 0;
................................................................................
}


int sqlite3Fts5IndexOptimize(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  int i;

  assert( p->rc==SQLITE_OK );
  fts5IndexFlush(p);
  for(i=0; i<=pConfig->nPrefix; i++){
    Fts5Structure *pStruct = fts5StructureRead(p, i);
    Fts5Structure *pNew = 0;
    int nSeg = 0;
    if( pStruct ){
      assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
................................................................................

    fts5StructureRelease(pStruct);
  }

  return fts5IndexReturn(p); 
}

int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge){
  Fts5Structure *pStruct;

  pStruct = fts5StructureRead(p, 0);
  fts5IndexMerge(p, 0, &pStruct, nMerge);
  fts5StructureWrite(p, 0, pStruct);
  fts5StructureRelease(pStruct);

  return fts5IndexReturn(p);
}


/*
** Iterator pMulti currently points to a valid entry (not EOF). This
** function appends a copy of the position-list of the entry pMulti 
** currently points to to buffer pBuf.
**
................................................................................
        sqlite3_free(apNew);
      }
      return rc;
    }
  }

  if( iRowid<=p->iWriteRowid || (p->nPendingData > p->nMaxPendingData) ){
    assert( p->rc==SQLITE_OK );
    fts5IndexFlush(p);
  }
  p->iWriteRowid = iRowid;
  return fts5IndexReturn(p);
}

/*
................................................................................

static void fts5IndexIntegrityCheckSegment(
  Fts5Index *p,                   /* FTS5 backend object */
  int iIdx,                       /* Index that pSeg is a part of */
  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
){
  Fts5BtreeIter iter;             /* Used to iterate through b-tree hierarchy */

  if( pSeg->pgnoFirst==0 && pSeg->pgnoLast==0 ) return;

  /* Iterate through the b-tree hierarchy.  */
  for(fts5BtreeIterInit(p, iIdx, pSeg, &iter);
      p->rc==SQLITE_OK && iter.bEof==0;
      fts5BtreeIterNext(&iter)
  ){
    i64 iRow;                     /* Rowid for this leaf */

  }
  return rc;
}

int sqlite3Fts5StorageOptimize(Fts5Storage *p){
  return sqlite3Fts5IndexOptimize(p->pIndex);
}





/*
** Allocate a new rowid. This is used for "external content" tables when
** a NULL value is inserted into the rowid column. The new rowid is allocated
** by inserting a dummy row into the %_docsize table. The dummy will be
** overwritten later.
*/

  }
  return rc;
}

int sqlite3Fts5StorageOptimize(Fts5Storage *p){
  return sqlite3Fts5IndexOptimize(p->pIndex);
}

int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge){
  return sqlite3Fts5IndexMerge(p->pIndex, nMerge);
}

/*
** Allocate a new rowid. This is used for "external content" tables when
** a NULL value is inserted into the rowid column. The new rowid is allocated
** by inserting a dummy row into the %_docsize table. The dummy will be
** overwritten later.
*/

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}

if 0 {

set doc [string trim [string repeat "x y z " 200]]
do_execsql_test 1.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, x);
  CREATE VIRTUAL TABLE x1 USING fts5(x, content='t1', content_rowid='a');
  INSERT INTO x1(x1, rank) VALUES('pgsz', 32);
  WITH input(a,b) AS (
    SELECT 1, $doc UNION ALL
................................................................................
      INSERT INTO "a b c" VALUES('one one', 'z z z', 'nine ten');
  }
} -body {
  execsql { SELECT rowid FROM "a b c" WHERE "a b c" MATCH 'one' }
} -test {
  faultsim_test_result {0 {1 3}}
  catchsql { ROLLBACK }
}

}

#-------------------------------------------------------------------------
# OOM within an 'optimize' operation that writes multiple pages to disk.
#
reset_db 
do_execsql_test 3.0 {

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}



set doc [string trim [string repeat "x y z " 200]]
do_execsql_test 1.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, x);
  CREATE VIRTUAL TABLE x1 USING fts5(x, content='t1', content_rowid='a');
  INSERT INTO x1(x1, rank) VALUES('pgsz', 32);
  WITH input(a,b) AS (
    SELECT 1, $doc UNION ALL
................................................................................
      INSERT INTO "a b c" VALUES('one one', 'z z z', 'nine ten');
  }
} -body {
  execsql { SELECT rowid FROM "a b c" WHERE "a b c" MATCH 'one' }
} -test {
  faultsim_test_result {0 {1 3}}
  catchsql { ROLLBACK }


}

#-------------------------------------------------------------------------
# OOM within an 'optimize' operation that writes multiple pages to disk.
#
reset_db 
do_execsql_test 3.0 {

# 2014 June 17
#
# 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 is focused on OOM errors.
#

source [file join [file dirname [info script]] fts5_common.tcl]
source $testdir/malloc_common.tcl
set testprefix fts5fault3

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}

#-------------------------------------------------------------------------
# An OOM while resuming a partially completed segment merge.
#
db func rnddoc fts5_rnddoc 
do_test 1.0 {
  expr srand(0)
  execsql {
    CREATE VIRTUAL TABLE xx USING fts5(x);
    INSERT INTO xx(xx, rank) VALUES('pgsz', 32);
    INSERT INTO xx(xx, rank) VALUES('automerge', 16);
  }
  for {set i 0} {$i < 10} {incr i} {
    execsql {
      BEGIN;
        INSERT INTO xx(x) VALUES(rnddoc(20));
        INSERT INTO xx(x) VALUES(rnddoc(20));
        INSERT INTO xx(x) VALUES(rnddoc(20));
      COMMIT
    }
  }

  execsql {
    INSERT INTO xx(xx, rank) VALUES('automerge', 2);
    INSERT INTO xx(xx, rank) VALUES('merge', 50);
  }
} {}
faultsim_save_and_close

do_faultsim_test 1 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql { INSERT INTO xx(xx, rank) VALUES('merge', 1) }
} -test {
  faultsim_test_result [list 0 {}]
}

#-------------------------------------------------------------------------
# An OOM while flushing an unusually large term to disk.
#
reset_db
do_execsql_test 2.0 {
  CREATE VIRTUAL TABLE xx USING fts5(x);
  INSERT INTO xx(xx, rank) VALUES('pgsz', 32);
}
faultsim_save_and_close

set    doc "a long term abcdefghijklmnopqrstuvwxyz "
append doc "and then abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz "
append doc [string repeat "abcdefghijklmnopqrstuvwxyz" 10]

do_faultsim_test 2 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql { INSERT INTO xx(x) VALUES ($::doc) }
} -test {
  faultsim_test_result [list 0 {}]
}




finish_test

# 2014 Dec 20
#
# 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.
#
#***********************************************************************
#
# Test that focus on incremental merges of segments.
#

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5merge

db func repeat [list string repeat]

#-------------------------------------------------------------------------
# Create an fts index so that:
#
#   * the index consists of two top-level segments
#   * each segment contains records related to $nRowPerSeg rows
#   * all rows consist of tokens "x" and "y" only.
#
# Then run ('merge', 1) until everything is completely merged.
#
proc do_merge1_test {testname nRowPerSeg} {
  set ::nRowPerSeg [expr $nRowPerSeg]
  do_execsql_test $testname.0 {
    DROP TABLE IF EXISTS x8;
    CREATE VIRTUAL TABLE x8 USING fts5(i);
    INSERT INTO x8(x8, rank) VALUES('pgsz', 32);

    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<$::nRowPerSeg)
      INSERT INTO x8 SELECT repeat('x y ', i % 16) FROM ii;

    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<$::nRowPerSeg)
      INSERT INTO x8 SELECT repeat('x y ', i % 16) FROM ii;

    INSERT INTO x8(x8, rank) VALUES('automerge', 2);
  }

  for {set tn 1} {[lindex [fts5_level_segs x8] 0]>0} {incr tn} {
    do_execsql_test $testname.$tn {
      INSERT INTO x8(x8, rank) VALUES('merge', 1);
      INSERT INTO x8(x8) VALUES('integrity-check');
    }
    if {$tn>5} break
  }

  do_test $testname.x [list expr "$tn < 5"] 1
}

do_merge1_test 1.1   1
do_merge1_test 1.2   2
do_merge1_test 1.3   3
do_merge1_test 1.4   4
do_merge1_test 1.5  10
do_merge1_test 1.6  20
do_merge1_test 1.7 100

#-------------------------------------------------------------------------
#
proc do_merge2_test {testname nRow} {
  db func rnddoc fts5_rnddoc

  do_execsql_test $testname.0 {
    DROP TABLE IF EXISTS x8;
    CREATE VIRTUAL TABLE x8 USING fts5(i);
    INSERT INTO x8(x8, rank) VALUES('pgsz', 32);
  }

  set ::nRow $nRow
  do_test $testname.1 {
    for {set i 0} {$i < $::nRow} {incr i} {
      execsql { INSERT INTO x8 VALUES( rnddoc(($i%16) + 5) ) }
      while {[not_merged x8]} {
        execsql {
          INSERT INTO x8(x8, rank) VALUES('automerge', 2);
          INSERT INTO x8(x8, rank) VALUES('merge', 1);
          INSERT INTO x8(x8, rank) VALUES('automerge', 16);
          INSERT INTO x8(x8) VALUES('integrity-check');
        }
      }
    }
  } {}
}
proc not_merged {tbl} {
  set segs [fts5_level_segs $tbl]
  foreach s $segs { if {$s>1} { return 1 } }
  return 0
}

do_merge2_test 2.1    5
do_merge2_test 2.2   10
do_merge2_test 2.3   20

#-------------------------------------------------------------------------
# Test that an auto-merge will complete any merge that has already been
# started, even if the number of input segments is less than the current
# value of the 'automerge' configuration parameter.
#
db func rnddoc fts5_rnddoc

do_execsql_test 3.1 {
  DROP TABLE IF EXISTS x8;
  CREATE VIRTUAL TABLE x8 USING fts5(i);
  INSERT INTO x8(x8, rank) VALUES('pgsz', 32);
  INSERT INTO x8 VALUES(rnddoc(100));
  INSERT INTO x8 VALUES(rnddoc(100));
}
do_test 3.2 {
  execsql {
    INSERT INTO x8(x8, rank) VALUES('automerge', 4);
    INSERT INTO x8(x8, rank) VALUES('merge', 1);
  }
  fts5_level_segs x8
} {2}

do_test 3.3 {
  execsql {
    INSERT INTO x8(x8, rank) VALUES('automerge', 2);
    INSERT INTO x8(x8, rank) VALUES('merge', 1);
  }
  fts5_level_segs x8
} {2 1}

do_test 3.4 {
  execsql { INSERT INTO x8(x8, rank) VALUES('automerge', 4) }
  while {[not_merged x8]} {
    execsql { INSERT INTO x8(x8, rank) VALUES('merge', 1) }
  }
  fts5_level_segs x8
} {0 1}

finish_test