SQLite

 ((i64)(height) << (FTS5_DATA_PAGE_B)) +                                       \
 ((i64)(pgno))                                                                 \
)

#define FTS5_SEGMENT_ROWID(segid, height, pgno) fts5_dri(segid, 0, height, pgno)
#define FTS5_DLIDX_ROWID(segid, height, pgno)   fts5_dri(segid, 1, height, pgno)

#if 0
/*
** The height of segment b-trees is actually limited to one less than 
** (1<<HEIGHT_BITS). This is because the rowid address space for nodes
** with such a height is used by doclist indexes.
*/
#define FTS5_SEGMENT_MAX_HEIGHT ((1 << FTS5_DATA_HEIGHT_B)-1)
#endif

/*
** Maximum segments permitted in a single index 
*/
#define FTS5_MAX_SEGMENT 2000

#if 0
/*
** The rowid for the doclist index associated with leaf page pgno of segment
** segid in index idx.
*/
#define FTS5_DOCLIST_IDX_ROWID(segid, height, pgno) \
        FTS5_SEGMENT_ROWID(segid, FTS5_SEGMENT_MAX_HEIGHT, pgno)
#endif

#ifdef SQLITE_DEBUG
int sqlite3Fts5Corrupt() { return SQLITE_CORRUPT_VTAB; }
#endif


/*
** Each time a blob is read from the %_data table, it is padded with this

  if( p->pReader ){
    sqlite3_blob *pReader = p->pReader;
    p->pReader = 0;
    sqlite3_blob_close(pReader);
  }
}

/*
** Check if row iRowid exists in the %_data table, and that it contains
** a blob value. If so, return SQLITE_ERROR (yes - SQLITE_ERROR, not 
** SQLITE_OK). If not, return SQLITE_CORRUPT_VTAB.
**
** If an error occurs (e.g. OOM or IOERR), return the relevant error code.
**
** This function does not need to be efficient. It is part of vary rarely
** invoked error handling code only.
*/
#if 0
static int fts5CheckMissingRowid(Fts5Index *p, i64 iRowid){
  const char *zFmt = "SELECT typeof(block)=='blob' FROM '%q'.%Q WHERE id=%lld";
  int bOk = 0;
  int rc;
  char *zSql;

  zSql = sqlite3_mprintf(zFmt, p->pConfig->zDb, p->zDataTbl, iRowid);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3_stmt *pStmt;
    rc = sqlite3_prepare_v2(p->pConfig->db, zSql, -1, &pStmt, 0);
    if( rc==SQLITE_OK ){
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        bOk = sqlite3_column_int(pStmt, 0);
      }
      rc = sqlite3_finalize(pStmt);
    }
    sqlite3_free(zSql);
  }

  if( rc==SQLITE_OK ){
    rc = bOk ? SQLITE_ERROR : FTS5_CORRUPT;
  }

  return rc;
}
#endif

static Fts5Data *fts5DataReadOrBuffer(
  Fts5Index *p, 
  Fts5Buffer *pBuf, 
  i64 iRowid
){
  Fts5Data *pRet = 0;
  if( p->rc==SQLITE_OK ){

  sqlite3_bind_int64(p->pDeleter, 1, iFirst);
  sqlite3_bind_int64(p->pDeleter, 2, iLast);
  sqlite3_step(p->pDeleter);
  p->rc = sqlite3_reset(p->pDeleter);
}

/*
** Close the sqlite3_blob handle used to read records from the %_data table.
** And discard any cached reads. This function is called at the end of
** a read transaction or when any sub-transaction is rolled back.
*/
#if 0
static void fts5DataReset(Fts5Index *p){
  if( p->pReader ){
    sqlite3_blob_close(p->pReader);
    p->pReader = 0;
  }
}
#endif

/*
** Remove all records associated with segment iSegid.
*/
static void fts5DataRemoveSegment(Fts5Index *p, int iSegid){
  i64 iFirst = FTS5_SEGMENT_ROWID(iSegid, 0, 0);
  i64 iLast = FTS5_SEGMENT_ROWID(iSegid+1, 0, 0)-1;
  fts5DataDelete(p, iFirst, iLast);

    if( pPage->buf.n>=p->pConfig->pgsz ){
      fts5WriteFlushLeaf(p, pWriter);
    }
  }
}

#if 0
static void fts5WriteAppendPoslistInt(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  int iVal
){
  if( p->rc==SQLITE_OK ){
    Fts5PageWriter *pPage = &pWriter->aWriter[0];
    fts5BufferAppendVarint(&p->rc, &pPage->buf, iVal);
    if( pPage->buf.n>=p->pConfig->pgsz ){
      fts5WriteFlushLeaf(p, pWriter);
    }
  }
}
#endif

static void fts5WriteAppendPoslistData(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  const u8 *aData, 
  int nData
){
  Fts5PageWriter *pPage = &pWriter->aWriter[0];

    pStruct->nSegment++;

    /* Read input from all segments in the input level */
    nInput = pLvl->nSeg;
  }
  bOldest = (pLvlOut->nSeg==1 && pStruct->nLevel==iLvl+2);

#if 0
fprintf(stdout, "merging %d segments from level %d!", nInput, iLvl);
fflush(stdout);
#endif

  assert( iLvl>=0 );
  for(fts5MultiIterNew(p, pStruct, 0, 0, 0, 0, iLvl, nInput, &pIter);
      fts5MultiIterEof(p, pIter)==0;
      fts5MultiIterNext(p, pIter, 0, 0)
  ){
    Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
    int nPos;                     /* position-list size field value */

  SELECT 
    my_phrasesize(t1, -1),
    my_phrasesize(t1, 0),
    my_phrasesize(t1, 1),
    my_phrasesize(t1, 2)
  FROM t1 WHERE t1 MATCH 'a OR b+c'
} {0 1 2 0}

#-------------------------------------------------------------------------
#
do_execsql_test 8.0 {
  CREATE VIRTUAL TABLE x1 USING fts5(a);
}

foreach {tn lRow res} {
  4  {"a a a" "b" "a d"} {"[a] [a] [a]" "[a] d"}
  1  {"b d" "a b"}       {"[b] [d]" "[a] b"}
  2  {"d b" "a d"}       {"[d] [b]" "[a] d"}
  3  {"a a d"}           {"[a] [a] d"}
} {
  execsql { DELETE FROM x1 }
  foreach row $lRow { execsql { INSERT INTO x1 VALUES($row) } }
  breakpoint
  do_execsql_test 8.$tn {
    SELECT highlight(x1, 0, '[', ']') FROM x1 WHERE x1 MATCH 'a OR (b AND d)';
  } $res
}

finish_test

  execsql {
    CREATE VIRTUAL TABLE tt USING fts5(x);
    CREATE VIRTUAL TABLE tv USING fts5vocab(tt, 'row');
    INSERT INTO tt(tt, rank) VALUES('pgsz', 32);
    BEGIN;
  }
  for {set i 0} {$i < 20} {incr i} {
    set str [string repeat "$i " 20]
    set str [string repeat "$i " 50]
    execsql { INSERT INTO tt VALUES($str) }
  }
  execsql COMMIT
} {}

do_faultsim_test 2.1 -faults oom-t* -body {
do_faultsim_test 3.1 -faults oom-t* -body {
  db eval {
    SELECT term FROM tv;
  }
} -test {
  faultsim_test_result {0 {0 1 10 11 12 13 14 15 16 17 18 19 2 3 4 5 6 7 8 9}}
}