SQLite

void sqlite3Fts5BufferAppendVarint(int*, Fts5Buffer*, i64);
void sqlite3Fts5BufferAppendBlob(int*, Fts5Buffer*, int, const u8*);
void sqlite3Fts5BufferAppendString(int *, Fts5Buffer*, const char*);
void sqlite3Fts5BufferFree(Fts5Buffer*);
void sqlite3Fts5BufferZero(Fts5Buffer*);
void sqlite3Fts5BufferSet(int*, Fts5Buffer*, int, const u8*);
void sqlite3Fts5BufferAppendPrintf(int *, Fts5Buffer*, char *zFmt, ...);
void sqlite3Fts5BufferAppend32(int*, Fts5Buffer*, int);

char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...);

#define fts5BufferZero(x)             sqlite3Fts5BufferZero(x)
#define fts5BufferAppendVarint(a,b,c) sqlite3Fts5BufferAppendVarint(a,b,c)
#define fts5BufferFree(a)             sqlite3Fts5BufferFree(a)
#define fts5BufferAppendBlob(a,b,c,d) sqlite3Fts5BufferAppendBlob(a,b,c,d)
#define fts5BufferSet(a,b,c,d)        sqlite3Fts5BufferSet(a,b,c,d)
#define fts5BufferAppend32(a,b,c)     sqlite3Fts5BufferAppend32(a,b,c)

#define fts5BufferGrow(pRc,pBuf,nn) ( \
  (pBuf)->n + (nn) <= (pBuf)->nSpace ? 0 : \
    sqlite3Fts5BufferSize((pRc),(pBuf),(nn)+(pBuf)->n) \
)

/* Write and decode big-endian 32-bit integer values */

  aBuf[3] = (iVal>> 0) & 0x00FF;
}

int sqlite3Fts5Get32(const u8 *aBuf){
  return (aBuf[0] << 24) + (aBuf[1] << 16) + (aBuf[2] << 8) + aBuf[3];
}

void sqlite3Fts5BufferAppend32(int *pRc, Fts5Buffer *pBuf, int iVal){
  if( fts5BufferGrow(pRc, pBuf, 4) ) return;
  sqlite3Fts5Put32(&pBuf->p[pBuf->n], iVal);
  pBuf->n += 4;
}

/*
** Append buffer nData/pData to buffer pBuf. If an OOM error occurs, set 
** the error code in p. If an error has already occurred when this function
** is called, it is a no-op.
*/
void sqlite3Fts5BufferAppendBlob(
  int *pRc,

      nSegment += pStruct->aLevel[iLvl].nSeg;
    }
  }

  return nSegment;
}
#endif













/*
** Serialize and store the "structure" record.
**
** If an error occurs, leave an error code in the Fts5Index object. If an
** error has already occurred, this function is a no-op.
*/
static void fts5StructureWrite(Fts5Index *p, Fts5Structure *pStruct){
  if( p->rc==SQLITE_OK ){
    Fts5Buffer buf;               /* Buffer to serialize record into */
    int iLvl;                     /* Used to iterate through levels */
    int iCookie;                  /* Cookie value to store */

    assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
    memset(&buf, 0, sizeof(Fts5Buffer));

    /* Append the current configuration cookie */
    iCookie = p->pConfig->iCookie;
    if( iCookie<0 ) iCookie = 0;
    fts5BufferAppend32(&p->rc, &buf, iCookie);




    fts5BufferAppendVarint(&p->rc, &buf, pStruct->nLevel);
    fts5BufferAppendVarint(&p->rc, &buf, pStruct->nSegment);
    fts5BufferAppendVarint(&p->rc, &buf, (i64)pStruct->nWriteCounter);


    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
      int iSeg;                     /* Used to iterate through segments */
      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nMerge);
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nSeg);
      assert( pLvl->nMerge<=pLvl->nSeg );

}

static void fts5MultiIterNext2(
  Fts5Index *p, 
  Fts5IndexIter *pIter,
  int *pbNewTerm                  /* OUT: True if *might* be new term */
){

  if( p->rc==SQLITE_OK ){
    do {
      int iFirst = pIter->aFirst[1].iFirst;
      Fts5SegIter *pSeg = &pIter->aSeg[iFirst];
      int bNewTerm = 0;

      fts5SegIterNext(p, pSeg, &bNewTerm);
      if( pSeg->pLeaf==0 || bNewTerm 
       || fts5MultiIterAdvanceRowid(p, pIter, iFirst)
      ){
        fts5MultiIterAdvanced(p, pIter, iFirst, 1);
        fts5MultiIterSetEof(pIter);
        *pbNewTerm = 1;
      }else{
        *pbNewTerm = 0;
      }
      fts5AssertMultiIterSetup(p, pIter);

    }while( pIter->bSkipEmpty && fts5MultiIterIsEmpty(p, pIter) );
  }
}


static Fts5IndexIter *fts5MultiIterAlloc(
  Fts5Index *p,                   /* FTS5 backend to iterate within */
  int nSeg

  pWriter->iSegid = iSegid;

  fts5WriteDlidxGrow(p, pWriter, 1);
  pWriter->writer.pgno = 1;
  pWriter->bFirstTermInPage = 1;
  pWriter->iBtPage = 1;




  /* Grow the two buffers to pgsz + padding bytes in size. */
  fts5BufferGrow(&p->rc, &pWriter->writer.pgidx, nBuffer);
  fts5BufferGrow(&p->rc, &pWriter->writer.buf, nBuffer);

  if( p->pIdxWriter==0 ){
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pIdxWriter, sqlite3_mprintf(
          "INSERT INTO '%q'.'%q_idx'(segid,term,pgno) VALUES(?,?,?)", 
          pConfig->zDb, pConfig->zName
    ));

      if( (ret + i) > nMax ) break;
      ret += i;
    }
  }
  return ret;
}

#define fts5BufferSafeAppendBlob(pBuf, pBlob, nBlob) {     \
  assert( (pBuf)->nSpace>=((pBuf)->n+nBlob) );             \
  memcpy(&(pBuf)->p[(pBuf)->n], pBlob, nBlob);             \
  (pBuf)->n += nBlob;                                      \
}

#define fts5BufferSafeAppendVarint(pBuf, iVal) {                \
  (pBuf)->n += sqlite3Fts5PutVarint(&(pBuf)->p[(pBuf)->n], (iVal));  \
  assert( (pBuf)->nSpace>=(pBuf)->n );                          \
}

/*
** Flush the contents of in-memory hash table iHash to a new level-0 
** segment on disk. Also update the corresponding structure record.
**
** If an error occurs, set the Fts5Index.rc error code. If an error has 
** already occurred, this function is a no-op.
*/

    Fts5DoclistIter i1;
    Fts5DoclistIter i2;
    Fts5Buffer out;
    Fts5Buffer tmp;
    memset(&out, 0, sizeof(out));
    memset(&tmp, 0, sizeof(tmp));

    fts5BufferGrow(&p->rc, &out, p1->n + p2->n);
    fts5DoclistIterInit(p1, &i1);
    fts5DoclistIterInit(p2, &i2);
    while( p->rc==SQLITE_OK && (i1.aPoslist!=0 || i2.aPoslist!=0) ){
      if( i2.aPoslist==0 || (i1.aPoslist && i1.iRowid<i2.iRowid) ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
        fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);

  Fts5IndexIter *pRet = 0;
  int iIdx = 0;
  Fts5Buffer buf = {0, 0, 0};

  /* If the QUERY_SCAN flag is set, all other flags must be clear. */
  assert( (flags & FTS5INDEX_QUERY_SCAN)==0 || flags==FTS5INDEX_QUERY_SCAN );

  if( fts5BufferGrow(&p->rc, &buf, nToken+1)==0 ){
    memcpy(&buf.p[1], pToken, nToken);

#ifdef SQLITE_DEBUG
    /* If the QUERY_TEST_NOIDX flag was specified, then this must be a
    ** prefix-query. Instead of using a prefix-index (if one exists), 
    ** evaluate the prefix query using the main FTS index. This is used
    ** for internal sanity checking by the integrity-check in debug