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SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference

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Overview
Comment:Performance optimizations in the VDBE and especially to the OP_Next and related opcodes and in the sqlite3BtreeNext() and sqlite3BtreePrevious() routines. This is a cherrypick of [6f99b54aedeb], [d2efea1682a7], and [d78c5d89de4b].
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 7f72fc4f47445a2c01910b268335873de9f75059
User & Date: drh 2013-08-20 03:13:51
Context
2013-08-20
16:08
Test script changes to support testing sqlite3_interrupt(). check-in: 0cede9f8 user: dan tags: trunk
13:02
Merge performance enhancements and compiler warning fixes from trunk. check-in: 3e403328 user: drh tags: sessions
03:13
Performance optimizations in the VDBE and especially to the OP_Next and related opcodes and in the sqlite3BtreeNext() and sqlite3BtreePrevious() routines. This is a cherrypick of [6f99b54aedeb], [d2efea1682a7], and [d78c5d89de4b]. check-in: 7f72fc4f user: drh tags: trunk
00:42
Performance optimizations in the VDBE and especially to the OP_Next and related opcodes. check-in: d78c5d89 user: drh tags: toTypeFuncs
2013-08-19
23:18
Performance improvement to SQL function calls in the VDBE. check-in: d2efea16 user: drh tags: toTypeFuncs
22:22
Additional performance improvements in sqlite3BtreeNext() and sqlite3BtreePrevious(). check-in: 6f99b54a user: drh tags: toTypeFuncs
20:04
Performance improvement in sqlite3BtreeNext() and sqlite3BtreePrevious() for the common case of a valid cursor. check-in: dc65ad8c user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/btree.c.

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  }
  pCur->eState = CURSOR_INVALID;
  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
  if( rc==SQLITE_OK ){
    sqlite3_free(pCur->pKey);
    pCur->pKey = 0;
    assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );



  }
  return rc;
}

#define restoreCursorPosition(p) \
  (p->eState>=CURSOR_REQUIRESEEK ? \
         btreeRestoreCursorPosition(p) : \
................................................................................
  int rc;

  rc = restoreCursorPosition(pCur);
  if( rc ){
    *pHasMoved = 1;
    return rc;
  }
  if( pCur->eState!=CURSOR_VALID || pCur->skipNext!=0 ){
    *pHasMoved = 1;
  }else{
    *pHasMoved = 0;
  }
  return SQLITE_OK;
}

................................................................................
int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
  int rc;
  int idx;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );

  if( pCur->eState!=CURSOR_VALID ){
    rc = restoreCursorPosition(pCur);
    if( rc!=SQLITE_OK ){

      return rc;
    }
    if( CURSOR_INVALID==pCur->eState ){
      *pRes = 1;
      return SQLITE_OK;
    }
  }
  if( pCur->skipNext ){


    if( pCur->skipNext>0 ){
      pCur->skipNext = 0;
      *pRes = 0;
      return SQLITE_OK;
    }
    pCur->skipNext = 0;

  }

  pPage = pCur->apPage[pCur->iPage];
  idx = ++pCur->aiIdx[pCur->iPage];
  assert( pPage->isInit );

  /* If the database file is corrupt, it is possible for the value of idx 
................................................................................
  testcase( idx>pPage->nCell );

  pCur->info.nSize = 0;
  pCur->validNKey = 0;
  if( idx>=pPage->nCell ){
    if( !pPage->leaf ){
      rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));


      if( rc ) return rc;

      rc = moveToLeftmost(pCur);
      *pRes = 0;
      return rc;
    }
    do{
      if( pCur->iPage==0 ){
        *pRes = 1;
................................................................................
** this routine was called, then set *pRes=1.
*/
int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
  int rc;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );


  pCur->atLast = 0;
  if( pCur->eState!=CURSOR_VALID ){
    if( ALWAYS(pCur->eState>=CURSOR_REQUIRESEEK) ){
      rc = btreeRestoreCursorPosition(pCur);
      if( rc!=SQLITE_OK ) return rc;



    }
    if( CURSOR_INVALID==pCur->eState ){
      *pRes = 1;
      return SQLITE_OK;
    }
  }
  if( pCur->skipNext ){


    if( pCur->skipNext<0 ){
      pCur->skipNext = 0;
      *pRes = 0;
      return SQLITE_OK;
    }
    pCur->skipNext = 0;

  }

  pPage = pCur->apPage[pCur->iPage];
  assert( pPage->isInit );
  if( !pPage->leaf ){
    int idx = pCur->aiIdx[pCur->iPage];
    rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
    if( rc ){

      return rc;
    }
    rc = moveToRightmost(pCur);
  }else{
    while( pCur->aiIdx[pCur->iPage]==0 ){
      if( pCur->iPage==0 ){
        pCur->eState = CURSOR_INVALID;







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  }
  pCur->eState = CURSOR_INVALID;
  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
  if( rc==SQLITE_OK ){
    sqlite3_free(pCur->pKey);
    pCur->pKey = 0;
    assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
    if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
      pCur->eState = CURSOR_SKIPNEXT;
    }
  }
  return rc;
}

#define restoreCursorPosition(p) \
  (p->eState>=CURSOR_REQUIRESEEK ? \
         btreeRestoreCursorPosition(p) : \
................................................................................
  int rc;

  rc = restoreCursorPosition(pCur);
  if( rc ){
    *pHasMoved = 1;
    return rc;
  }
  if( pCur->eState!=CURSOR_VALID || NEVER(pCur->skipNext!=0) ){
    *pHasMoved = 1;
  }else{
    *pHasMoved = 0;
  }
  return SQLITE_OK;
}

................................................................................
int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
  int rc;
  int idx;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  if( pCur->eState!=CURSOR_VALID ){
    rc = restoreCursorPosition(pCur);
    if( rc!=SQLITE_OK ){
      *pRes = 0;
      return rc;
    }
    if( CURSOR_INVALID==pCur->eState ){
      *pRes = 1;
      return SQLITE_OK;
    }

    if( pCur->skipNext ){
      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
      pCur->eState = CURSOR_VALID;
      if( pCur->skipNext>0 ){
        pCur->skipNext = 0;
        *pRes = 0;
        return SQLITE_OK;
      }
      pCur->skipNext = 0;
    }
  }

  pPage = pCur->apPage[pCur->iPage];
  idx = ++pCur->aiIdx[pCur->iPage];
  assert( pPage->isInit );

  /* If the database file is corrupt, it is possible for the value of idx 
................................................................................
  testcase( idx>pPage->nCell );

  pCur->info.nSize = 0;
  pCur->validNKey = 0;
  if( idx>=pPage->nCell ){
    if( !pPage->leaf ){
      rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
      if( rc ){
        *pRes = 0;
        return rc;
      }
      rc = moveToLeftmost(pCur);
      *pRes = 0;
      return rc;
    }
    do{
      if( pCur->iPage==0 ){
        *pRes = 1;
................................................................................
** this routine was called, then set *pRes=1.
*/
int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
  int rc;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pRes!=0 );
  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
  pCur->atLast = 0;
  if( pCur->eState!=CURSOR_VALID ){
    if( ALWAYS(pCur->eState>=CURSOR_REQUIRESEEK) ){
      rc = btreeRestoreCursorPosition(pCur);
      if( rc!=SQLITE_OK ){
        *pRes = 0;
        return rc;
      }
    }
    if( CURSOR_INVALID==pCur->eState ){
      *pRes = 1;
      return SQLITE_OK;
    }

    if( pCur->skipNext ){
      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
      pCur->eState = CURSOR_VALID;
      if( pCur->skipNext<0 ){
        pCur->skipNext = 0;
        *pRes = 0;
        return SQLITE_OK;
      }
      pCur->skipNext = 0;
    }
  }

  pPage = pCur->apPage[pCur->iPage];
  assert( pPage->isInit );
  if( !pPage->leaf ){
    int idx = pCur->aiIdx[pCur->iPage];
    rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
    if( rc ){
      *pRes = 0;
      return rc;
    }
    rc = moveToRightmost(pCur);
  }else{
    while( pCur->aiIdx[pCur->iPage]==0 ){
      if( pCur->iPage==0 ){
        pCur->eState = CURSOR_INVALID;

Changes to src/btreeInt.h.

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  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
};

/*
** Potential values for BtCursor.eState.
**
** CURSOR_VALID:
**   Cursor points to a valid entry. getPayload() etc. may be called.
**
** CURSOR_INVALID:
**   Cursor does not point to a valid entry. This can happen (for example) 
**   because the table is empty or because BtreeCursorFirst() has not been
**   called.
**








** CURSOR_REQUIRESEEK:
**   The table that this cursor was opened on still exists, but has been 
**   modified since the cursor was last used. The cursor position is saved
**   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 
**   this state, restoreCursorPosition() can be called to attempt to
**   seek the cursor to the saved position.
**
................................................................................
**   on a different connection that shares the BtShared cache with this
**   cursor.  The error has left the cache in an inconsistent state.
**   Do nothing else with this cursor.  Any attempt to use the cursor
**   should return the error code stored in BtCursor.skip
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1

#define CURSOR_REQUIRESEEK       2
#define CURSOR_FAULT             3

/* 
** The database page the PENDING_BYTE occupies. This page is never used.
*/
# define PENDING_BYTE_PAGE(pBt) PAGER_MJ_PGNO(pBt)

/*







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  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
};

/*
** Potential values for BtCursor.eState.
**



** CURSOR_INVALID:
**   Cursor does not point to a valid entry. This can happen (for example) 
**   because the table is empty or because BtreeCursorFirst() has not been
**   called.
**
** CURSOR_VALID:
**   Cursor points to a valid entry. getPayload() etc. may be called.
**
** CURSOR_SKIPNEXT:
**   Cursor is valid except that the Cursor.skipNext field is non-zero
**   indicating that the next sqlite3BtreeNext() or sqlite3BtreePrevious()
**   operation should be a no-op.
**
** CURSOR_REQUIRESEEK:
**   The table that this cursor was opened on still exists, but has been 
**   modified since the cursor was last used. The cursor position is saved
**   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 
**   this state, restoreCursorPosition() can be called to attempt to
**   seek the cursor to the saved position.
**
................................................................................
**   on a different connection that shares the BtShared cache with this
**   cursor.  The error has left the cache in an inconsistent state.
**   Do nothing else with this cursor.  Any attempt to use the cursor
**   should return the error code stored in BtCursor.skip
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1
#define CURSOR_SKIPNEXT          2
#define CURSOR_REQUIRESEEK       3
#define CURSOR_FAULT             4

/* 
** The database page the PENDING_BYTE occupies. This page is never used.
*/
# define PENDING_BYTE_PAGE(pBt) PAGER_MJ_PGNO(pBt)

/*

Changes to src/vdbe.c.

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  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  if( db->xProgress ){
    assert( 0 < db->nProgressOps );
    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP-1];
    if( nProgressLimit==0 ){
      nProgressLimit = db->nProgressOps;
    }else{
      nProgressLimit %= (unsigned)db->nProgressOps;
    }
  }
#endif
................................................................................
  /* The output cell may already have a buffer allocated. Move
  ** the pointer to ctx.s so in case the user-function can use
  ** the already allocated buffer instead of allocating a new one.
  */
  sqlite3VdbeMemMove(&ctx.s, pOut);
  MemSetTypeFlag(&ctx.s, MEM_Null);

  ctx.isError = 0;
  if( ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
    assert( pOp>aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = pOp[-1].p4.pColl;
  }
  db->lastRowid = lastRowid;
  (*ctx.pFunc->xFunc)(&ctx, n, apVal); /* IMP: R-24505-23230 */
  lastRowid = db->lastRowid;

  /* If any auxiliary data functions have been called by this user function,
  ** immediately call the destructor for any non-static values.
  */
  sqlite3VdbeDeleteAuxData(p, pc, pOp->p1);

  if( db->mallocFailed ){
    /* Even though a malloc() has failed, the implementation of the
    ** user function may have called an sqlite3_result_XXX() function
    ** to return a value. The following call releases any resources
    ** associated with such a value.
    */
    sqlite3VdbeMemRelease(&ctx.s);
    goto no_mem;
  }

  /* If the function returned an error, throw an exception */

  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
    rc = ctx.isError;


  }

  /* Copy the result of the function into register P3 */
  sqlite3VdbeChangeEncoding(&ctx.s, encoding);
  sqlite3VdbeMemMove(pOut, &ctx.s);
  if( sqlite3VdbeMemTooBig(pOut) ){
    goto too_big;
................................................................................
        res = 1;  /* Results are not equal */
      }
    }else{
      /* SQLITE_NULLEQ is clear and at least one operand is NULL,
      ** then the result is always NULL.
      ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
      */


      if( pOp->p5 & SQLITE_STOREP2 ){
        pOut = &aMem[pOp->p2];
        MemSetTypeFlag(pOut, MEM_Null);
        REGISTER_TRACE(pOp->p2, pOut);
      }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
        pc = pOp->p2-1;
      }
      break;
    }
  }else{
    /* Neither operand is NULL.  Do a comparison. */
    affinity = pOp->p5 & SQLITE_AFF_MASK;
    if( affinity ){
................................................................................
*/
case OP_SorterSort:    /* jump */
case OP_Sort: {        /* jump */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
................................................................................
case OP_SorterNext:    /* jump */
case OP_Prev:          /* jump */
case OP_Next: {        /* jump */
  VdbeCursor *pC;
  int res;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p5<=ArraySize(p->aCounter) );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
    break;  /* See ticket #2273 */
  }
  assert( pC->isSorter==(pOp->opcode==OP_SorterNext) );
  if( isSorter(pC) ){
    assert( pOp->opcode==OP_SorterNext );
    rc = sqlite3VdbeSorterNext(db, pC, &res);
  }else{
    res = 1;
    assert( pC->deferredMoveto==0 );
    assert( pC->pCursor );
    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
    rc = pOp->p4.xAdvance(pC->pCursor, &res);
  }
  pC->nullRow = (u8)res;
  pC->cacheStatus = CACHE_STALE;
  if( res==0 ){
    pc = pOp->p2 - 1;
    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
  }
  pC->rowidIsValid = 0;
  goto check_for_interrupt;
}
................................................................................

  /* This is the only way out of this procedure.  We have to
  ** release the mutexes on btrees that were acquired at the
  ** top. */
vdbe_return:
  db->lastRowid = lastRowid;
  testcase( nVmStep>0 );
  p->aCounter[SQLITE_STMTSTATUS_VM_STEP-1] += (int)nVmStep;
  sqlite3VdbeLeave(p);
  return rc;

  /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
  ** is encountered.
  */
too_big:







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584
585
586
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590
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592
593
594
595
596
597
598
....
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462





1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
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1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
....
1844
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1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856


1857
1858
1859
1860
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1862
1863
....
4434
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4444
4445
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4448
....
4513
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4545
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....
6237
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6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  if( db->xProgress ){
    assert( 0 < db->nProgressOps );
    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
    if( nProgressLimit==0 ){
      nProgressLimit = db->nProgressOps;
    }else{
      nProgressLimit %= (unsigned)db->nProgressOps;
    }
  }
#endif
................................................................................
  /* The output cell may already have a buffer allocated. Move
  ** the pointer to ctx.s so in case the user-function can use
  ** the already allocated buffer instead of allocating a new one.
  */
  sqlite3VdbeMemMove(&ctx.s, pOut);
  MemSetTypeFlag(&ctx.s, MEM_Null);

  ctx.fErrorOrAux = 0;
  if( ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
    assert( pOp>aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = pOp[-1].p4.pColl;
  }
  db->lastRowid = lastRowid;
  (*ctx.pFunc->xFunc)(&ctx, n, apVal); /* IMP: R-24505-23230 */
  lastRowid = db->lastRowid;






  if( db->mallocFailed ){
    /* Even though a malloc() has failed, the implementation of the
    ** user function may have called an sqlite3_result_XXX() function
    ** to return a value. The following call releases any resources
    ** associated with such a value.
    */
    sqlite3VdbeMemRelease(&ctx.s);
    goto no_mem;
  }

  /* If the function returned an error, throw an exception */
  if( ctx.fErrorOrAux ){
    if( ctx.isError ){
      sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
      rc = ctx.isError;
    }
    sqlite3VdbeDeleteAuxData(p, pc, pOp->p1);
  }

  /* Copy the result of the function into register P3 */
  sqlite3VdbeChangeEncoding(&ctx.s, encoding);
  sqlite3VdbeMemMove(pOut, &ctx.s);
  if( sqlite3VdbeMemTooBig(pOut) ){
    goto too_big;
................................................................................
        res = 1;  /* Results are not equal */
      }
    }else{
      /* SQLITE_NULLEQ is clear and at least one operand is NULL,
      ** then the result is always NULL.
      ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
      */
      if( pOp->p5 & SQLITE_JUMPIFNULL ){
        pc = pOp->p2-1;
      }else if( pOp->p5 & SQLITE_STOREP2 ){
        pOut = &aMem[pOp->p2];
        MemSetTypeFlag(pOut, MEM_Null);
        REGISTER_TRACE(pOp->p2, pOut);


      }
      break;
    }
  }else{
    /* Neither operand is NULL.  Do a comparison. */
    affinity = pOp->p5 & SQLITE_AFF_MASK;
    if( affinity ){
................................................................................
*/
case OP_SorterSort:    /* jump */
case OP_Sort: {        /* jump */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
................................................................................
case OP_SorterNext:    /* jump */
case OP_Prev:          /* jump */
case OP_Next: {        /* jump */
  VdbeCursor *pC;
  int res;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p5<ArraySize(p->aCounter) );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
    break;  /* See ticket #2273 */
  }
  assert( pC->isSorter==(pOp->opcode==OP_SorterNext) );
  if( isSorter(pC) ){
    assert( pOp->opcode==OP_SorterNext );
    rc = sqlite3VdbeSorterNext(db, pC, &res);
  }else{
    /* res = 1; // Always initialized by the xAdvance() call */
    assert( pC->deferredMoveto==0 );
    assert( pC->pCursor );
    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
    rc = pOp->p4.xAdvance(pC->pCursor, &res);
  }
  pC->nullRow = (u8)res;
  pC->cacheStatus = CACHE_STALE;
  if( res==0 ){
    pc = pOp->p2 - 1;
    p->aCounter[pOp->p5]++;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
  }
  pC->rowidIsValid = 0;
  goto check_for_interrupt;
}
................................................................................

  /* This is the only way out of this procedure.  We have to
  ** release the mutexes on btrees that were acquired at the
  ** top. */
vdbe_return:
  db->lastRowid = lastRowid;
  testcase( nVmStep>0 );
  p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
  sqlite3VdbeLeave(p);
  return rc;

  /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
  ** is encountered.
  */
too_big:

Changes to src/vdbeInt.h.

262
263
264
265
266
267
268
269
270
271
272

273
274
275
276
277
278
279
...
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
** (Mem) which are only defined there.
*/
struct sqlite3_context {
  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
  Mem s;                /* The return value is stored here */
  Mem *pMem;            /* Memory cell used to store aggregate context */
  CollSeq *pColl;       /* Collating sequence */
  int isError;          /* Error code returned by the function. */
  int skipFlag;         /* Skip skip accumulator loading if true */
  int iOp;              /* Instruction number of OP_Function */
  Vdbe *pVdbe;          /* The VM that owns this context */

};

/*
** An Explain object accumulates indented output which is helpful
** in describing recursive data structures.
*/
struct Explain {
................................................................................
  bft bIsReader:1;        /* True for statements that read */
  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
  int nChange;            /* Number of db changes made since last reset */
  yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
  yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  int aCounter[4];        /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  char *zSql;             /* Text of the SQL statement that generated this */







|
|
|
|
>







 







|







262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
...
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
** (Mem) which are only defined there.
*/
struct sqlite3_context {
  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
  Mem s;                /* The return value is stored here */
  Mem *pMem;            /* Memory cell used to store aggregate context */
  CollSeq *pColl;       /* Collating sequence */
  Vdbe *pVdbe;          /* The VM that owns this context */
  int iOp;              /* Instruction number of OP_Function */
  int isError;          /* Error code returned by the function. */
  u8 skipFlag;          /* Skip skip accumulator loading if true */
  u8 fErrorOrAux;       /* isError!=0 or pVdbe->pAuxData modified */
};

/*
** An Explain object accumulates indented output which is helpful
** in describing recursive data structures.
*/
struct Explain {
................................................................................
  bft bIsReader:1;        /* True for statements that read */
  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
  int nChange;            /* Number of db changes made since last reset */
  yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
  yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  char *zSql;             /* Text of the SQL statement that generated this */

Changes to src/vdbeapi.c.

207
208
209
210
211
212
213

214
215
216
217
218
219

220
221
222
223
224
225
226
...
276
277
278
279
280
281
282

283
284
285
286
287
288
289
290
291
292

293
294
295
296
297
298
299
300
301

302
303
304
305
306
307
308
...
617
618
619
620
621
622
623




624
625
626
627
628
629
630
....
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_ERROR;

  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_ERROR;

  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
}
#endif
void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
}
................................................................................
}
void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
}
void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
  pCtx->isError = errCode;

  if( pCtx->s.flags & MEM_Null ){
    sqlite3VdbeMemSetStr(&pCtx->s, sqlite3ErrStr(errCode), -1, 
                         SQLITE_UTF8, SQLITE_STATIC);
  }
}

/* Force an SQLITE_TOOBIG error. */
void sqlite3_result_error_toobig(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_TOOBIG;

  sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1, 
                       SQLITE_UTF8, SQLITE_STATIC);
}

/* An SQLITE_NOMEM error. */
void sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
  pCtx->isError = SQLITE_NOMEM;

  pCtx->s.db->mallocFailed = 1;
}

/*
** This function is called after a transaction has been committed. It 
** invokes callbacks registered with sqlite3_wal_hook() as required.
*/
................................................................................
  if( pAuxData==0 ){
    pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
    if( !pAuxData ) goto failed;
    pAuxData->iOp = pCtx->iOp;
    pAuxData->iArg = iArg;
    pAuxData->pNext = pVdbe->pAuxData;
    pVdbe->pAuxData = pAuxData;




  }else if( pAuxData->xDelete ){
    pAuxData->xDelete(pAuxData->pAux);
  }

  pAuxData->pAux = pAux;
  pAuxData->xDelete = xDelete;
  return;
................................................................................
}

/*
** Return the value of a status counter for a prepared statement
*/
int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
  Vdbe *pVdbe = (Vdbe*)pStmt;
  int v = pVdbe->aCounter[op-1];
  if( resetFlag ) pVdbe->aCounter[op-1] = 0;
  return v;
}







>






>







 







>










>









>







 







>
>
>
>







 







|
|
|

207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
...
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
...
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
....
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_ERROR;
  pCtx->fErrorOrAux = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_ERROR;
  pCtx->fErrorOrAux = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
}
#endif
void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
}
................................................................................
}
void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
}
void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
  pCtx->isError = errCode;
  pCtx->fErrorOrAux = 1;
  if( pCtx->s.flags & MEM_Null ){
    sqlite3VdbeMemSetStr(&pCtx->s, sqlite3ErrStr(errCode), -1, 
                         SQLITE_UTF8, SQLITE_STATIC);
  }
}

/* Force an SQLITE_TOOBIG error. */
void sqlite3_result_error_toobig(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = SQLITE_TOOBIG;
  pCtx->fErrorOrAux = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1, 
                       SQLITE_UTF8, SQLITE_STATIC);
}

/* An SQLITE_NOMEM error. */
void sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
  pCtx->isError = SQLITE_NOMEM;
  pCtx->fErrorOrAux = 1;
  pCtx->s.db->mallocFailed = 1;
}

/*
** This function is called after a transaction has been committed. It 
** invokes callbacks registered with sqlite3_wal_hook() as required.
*/
................................................................................
  if( pAuxData==0 ){
    pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
    if( !pAuxData ) goto failed;
    pAuxData->iOp = pCtx->iOp;
    pAuxData->iArg = iArg;
    pAuxData->pNext = pVdbe->pAuxData;
    pVdbe->pAuxData = pAuxData;
    if( pCtx->fErrorOrAux==0 ){
      pCtx->isError = 0;
      pCtx->fErrorOrAux = 1;
    }
  }else if( pAuxData->xDelete ){
    pAuxData->xDelete(pAuxData->pAux);
  }

  pAuxData->pAux = pAux;
  pAuxData->xDelete = xDelete;
  return;
................................................................................
}

/*
** Return the value of a status counter for a prepared statement
*/
int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
  Vdbe *pVdbe = (Vdbe*)pStmt;
  u32 v = pVdbe->aCounter[op];
  if( resetFlag ) pVdbe->aCounter[op] = 0;
  return (int)v;
}