SQLite

    }
  }

  fts3EvalStartReaders(pCsr, pExpr, bOptOk, &rc);
  return rc;
}

static void fts3EvalZeroPoslist(Fts3Phrase *pPhrase){
  if( pPhrase->doclist.bFreeList ){
    sqlite3_free(pPhrase->doclist.pList);
  }
  pPhrase->doclist.pList = 0;
  pPhrase->doclist.nList = 0;
  pPhrase->doclist.bFreeList = 0;

}

static int fts3EvalNearTrim2(
  int nNear,
  char *aTmp,                     /* Temporary space to use */
  char **paPoslist,               /* IN/OUT: Position list */
  int *pnToken,                   /* IN/OUT: Tokens in phrase of *paPoslist */
  Fts3Phrase *pPhrase             /* The phrase object to trim the doclist of */
){
  int nParam1 = nNear + pPhrase->nToken;
  int nParam2 = nNear + *pnToken;
  int nNew;
  char *p2; 
  char *pOut; 
  int res;

  assert( pPhrase->doclist.pList );

  p2 = pOut = pPhrase->doclist.pList;
  res = fts3PoslistNearMerge(
    &pOut, aTmp, nParam1, nParam2, paPoslist, &p2
  );
  if( res ){
    nNew = (pOut - pPhrase->doclist.pList) - 1;

        Fts3Expr *pLeft = pExpr->pLeft;
        Fts3Expr *pRight = pExpr->pRight;

        if( pRight->bStart==0 ){
          fts3EvalNext(pCsr, pRight, pRc);
          assert( *pRc!=SQLITE_OK || pRight->bStart );
        }

        fts3EvalNext(pCsr, pLeft, pRc);
        if( pLeft->bEof==0 ){
          while( !*pRc 
              && !pRight->bEof 
              && DOCID_CMP(pLeft->iDocid, pRight->iDocid)>0 
          ){
            fts3EvalNext(pCsr, pRight, pRc);
          }

        }
        pExpr->iDocid = pLeft->iDocid;
        pExpr->bEof = pLeft->bEof;
        break;
      }

      default: {
        Fts3Phrase *pPhrase = pExpr->pPhrase;
        fts3EvalZeroPoslist(pPhrase);
        *pRc = fts3EvalPhraseNext(pCsr, pPhrase, &pExpr->bEof);
        pExpr->iDocid = pPhrase->doclist.iDocid;
        break;
      }
    }
  }
}

static int fts3EvalDeferredTest(Fts3Cursor *pCsr, Fts3Expr *pExpr, int *pRc){
  int bHit = 1;
  if( *pRc==SQLITE_OK ){
    switch( pExpr->eType ){
      case FTSQUERY_NEAR:
      case FTSQUERY_AND:
        bHit = (
            fts3EvalDeferredTest(pCsr, pExpr->pLeft, pRc)
         && fts3EvalDeferredTest(pCsr, pExpr->pRight, pRc)
         && fts3EvalNearTest(pExpr, pRc)
        );

        /* If the NEAR expression does not match any rows, zero the doclist for 
        ** all phrases involved in the NEAR. This is because the snippet(),
        ** offsets() and matchinfo() functions are not supposed to recognize 
        ** any instances of phrases that are part of unmatched NEAR queries. 
        ** For example if this expression:
        **
        **    ... MATCH 'a OR (b NEAR c)'
        **
        ** is matched against a row containing:
        **
        **        'a b d e'
        **
        ** then any snippet() should ony highlight the "a" term, not the "b"
        ** (as "b" is part of a non-matching NEAR clause).
        */
        if( bHit==0 
         && pExpr->eType==FTSQUERY_NEAR 
         && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
        ){
          Fts3Expr *p;
          for(p=pExpr; p->pPhrase==0; p=p->pLeft){
            if( p->pRight->iDocid==pCsr->iPrevId ){
              fts3EvalZeroPoslist(p->pRight->pPhrase);
            }
          }
          if( p->iDocid==pCsr->iPrevId ){
            fts3EvalZeroPoslist(p->pPhrase);
          }
        }

        break;

      case FTSQUERY_OR: {
        int bHit1 = fts3EvalDeferredTest(pCsr, pExpr->pLeft, pRc);
        int bHit2 = fts3EvalDeferredTest(pCsr, pExpr->pRight, pRc);
        bHit = bHit1 || bHit2;
        break;
      }

      case FTSQUERY_NOT:
        bHit = (
            fts3EvalDeferredTest(pCsr, pExpr->pLeft, pRc)
         && !fts3EvalDeferredTest(pCsr, pExpr->pRight, pRc)
        );
        break;

      default: {
        if( pCsr->pDeferred 
         && (pExpr->iDocid==pCsr->iPrevId || pExpr->bDeferred)
        ){
          Fts3Phrase *pPhrase = pExpr->pPhrase;
          assert( pExpr->bDeferred || pPhrase->doclist.bFreeList==0 );
          if( pExpr->bDeferred ){
            fts3EvalZeroPoslist(pPhrase);
          }
          *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);
          bHit = (pPhrase->doclist.pList!=0);
          pExpr->iDocid = pCsr->iPrevId;
        }else{
          bHit = (pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId);
        }
        break;

  Fts3Expr *pExpr,
  int *pRc
){
  if( pExpr && *pRc==SQLITE_OK ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;

    if( pPhrase ){
      fts3EvalZeroPoslist(pPhrase);
      if( pPhrase->bIncr ){
        sqlite3Fts3EvalPhraseCleanup(pPhrase);
        memset(&pPhrase->doclist, 0, sizeof(Fts3Doclist));
        *pRc = sqlite3Fts3EvalStart(pCsr, pExpr, 0);
      }else{
        pPhrase->doclist.pNextDocid = 0;
        pPhrase->doclist.iDocid = 0;

    }

    fts3EvalUpdateCounts(pCsr, pExpr->pLeft, pRc);
    fts3EvalUpdateCounts(pCsr, pExpr->pRight, pRc);
  }
}

static int fts3EvalGatherStats(
  Fts3Cursor *pCsr,
  Fts3Expr *pExpr
){
  int rc = SQLITE_OK;             /* Return code */

  assert( pExpr->eType==FTSQUERY_PHRASE );
  if( pExpr->aMI==0 ){

    /* Find the root of the NEAR expression */
    pRoot = pExpr;
    while( pRoot->pParent && pRoot->pParent->eType==FTSQUERY_NEAR ){
      pRoot = pRoot->pParent;
    }
    iDocid = pRoot->iDocid;
    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));
      if( !pE->aMI ) return SQLITE_NOMEM;

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

    if( bEof ){
      pRoot->bEof = bEof;
    }else{
      /* Caution: pRoot may iterate through docids in ascending or descending
      ** order. For this reason, even though it seems more defensive, the 
      ** do loop can not be written:
      **
      **   do {...} while( pRoot->iDocid<iDocid && rc==SQLITE_OK );
      */
      fts3EvalRestart(pCsr, pRoot, &rc);

      do {
        fts3EvalNext(pCsr, pRoot, &rc);
        assert( pRoot->bEof==0 );

      }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
      fts3EvalLoadDeferred(pCsr, &rc);
    }
  }
  return rc;
}

/*

  if( pExpr->bDeferred ){
    assert( pCsr->nDoc>0 );
    for(iCol=0; iCol<pTab->nColumn; iCol++){
      aiOut[iCol*3 + 1] = pCsr->nDoc;
      aiOut[iCol*3 + 2] = pCsr->nDoc;
    }
  }else{
    rc = fts3EvalGatherStats(pCsr, pExpr);
    if( rc==SQLITE_OK ){
      assert( pExpr->aMI );
      for(iCol=0; iCol<pTab->nColumn; iCol++){
        aiOut[iCol*3 + 1] = pExpr->aMI[iCol*3 + 1];
        aiOut[iCol*3 + 2] = pExpr->aMI[iCol*3 + 2];
      }
    }

**   * the contents of pPhrase->doclist, and
**   * any Fts3MultiSegReader objects held by phrase tokens.
*/
void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *pPhrase){
  if( pPhrase ){
    int i;
    sqlite3_free(pPhrase->doclist.aAll);
    fts3EvalZeroPoslist(pPhrase);
    memset(&pPhrase->doclist, 0, sizeof(Fts3Doclist));
    for(i=0; i<pPhrase->nToken; i++){
      fts3SegReaderCursorFree(pPhrase->aToken[i].pSegcsr);
      pPhrase->aToken[i].pSegcsr = 0;
    }
  }
}

#endif

proc do_orderbydocid_test {tn sql res} {
  uplevel [list do_select_test $tn.asc "$sql ORDER BY docid ASC" $res]
  uplevel [list do_select_test $tn.desc "$sql ORDER BY docid DESC" \
    [lsort -int -dec $res]
  ]
}

set NUM_TRIALS 100

foreach {nodesize order} {
  50    DESC
  50    ASC
  500   ASC
  1000  DESC
  2000  ASC
} {
  catch { array unset ::t1 }
  set testname "$nodesize/$order"

  # Create the FTS3 table. Populate it (and the Tcl array) with 100 rows.
  #
  db transaction {
    catchsql { DROP TABLE t1 }
    execsql "CREATE VIRTUAL TABLE t1 USING fts4(a, b, c, order=$order)"
    execsql "INSERT INTO t1(t1) VALUES('nodesize=$nodesize')"
    for {set i 0} {$i < 100} {incr i} { insert_row $i }
  }
  
  for {set iTest 1} {$iTest <= $NUM_TRIALS} {incr iTest} {
    catchsql COMMIT

    set DO_MALLOC_TEST 0
    set nRep 10
    if {$iTest==100 && $nodesize==50} { 
      set DO_MALLOC_TEST 1 
      set nRep 2

    # Pick 10 terms from the vocabulary. Check that the results of querying
    # the database for the set of documents containing each of these terms
    # is the same as the result obtained by scanning the contents of the Tcl 
    # array for each term.
    #
    for {set i 0} {$i < 10} {incr i} {
      set term [random_term]
      do_select_test 1.$i.asc {
        SELECT docid, mit(matchinfo(t1)) FROM t1 WHERE t1 MATCH $term
        ORDER BY docid ASC
      } [simple_token_matchinfo $term 0]
      do_select_test 1.$i.desc {
        SELECT docid, mit(matchinfo(t1)) FROM t1 WHERE t1 MATCH $term
        ORDER BY docid DESC
      } [simple_token_matchinfo $term 1]
    }

    # This time, use the first two characters of each term as a term prefix
    # to query for. Test that querying the Tcl array produces the same results

        } [$proc [simple_phrase $term1] [simple_phrase $term2]]
      }
    }
 
    # Set operations on NEAR queries.
    #
    foreach {tn op proc} {
      11 OR  setop_or
      12 NOT setop_not
      13 AND setop_and
    } {
      for {set i 0} {$i < $nRep} {incr i} {
        set term1 [random_term]
        set term2 [random_term]
        set term3 [random_term]
        set term4 [random_term]
        set match "$term1 NEAR $term2 $op $term3 NEAR $term4"