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Overview
Comment:Update some stale comments in delete.c. No changes to code.
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Timelines: family | ancestors | onepass-delete-or
Files: files | file ages | folders
SHA1: f59a33260cc853bb35f4259b05fd05bbbeb13945
User & Date: dan 2015-12-12 19:23:41.225
Context
2015-12-12
19:23
Update some stale comments in delete.c. No changes to code. (Leaf check-in: f59a33260c user: dan tags: onepass-delete-or)
17:31
Add further tests for the changes on this branch. Also fix a memory-leak that could follow a malloc failure. (check-in: 21526012c2 user: dan tags: onepass-delete-or)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/delete.c.
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  }else{
    iKey = pParse->nMem + 1;
    iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
    if( iKey>pParse->nMem ) pParse->nMem = iKey;
  }

  if( eOnePass!=ONEPASS_OFF ){
    /* For ONEPASS, no need to store the rowid/primary-key. There is only
    ** one, so just keep it in its register(s) and fall through to the
    ** delete code.  */
    nKey = nPk; /* OP_Found will use an unpacked key */
    aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
    if( aToOpen==0 ){
      sqlite3WhereEnd(pWInfo);
      return SQLITE_NOMEM;
    }
    memset(aToOpen, 1, nIdx+1);








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  }else{
    iKey = pParse->nMem + 1;
    iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
    if( iKey>pParse->nMem ) pParse->nMem = iKey;
  }

  if( eOnePass!=ONEPASS_OFF ){
    /* For a one-pass strategy, no need to store the rowid/primary-key in
    ** a RowSet or temporary table. It is read directly from its register(s) 
    ** by the delete code below. */
    nKey = nPk; /* OP_Found will use an unpacked key */
    aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
    if( aToOpen==0 ){
      sqlite3WhereEnd(pWInfo);
      return SQLITE_NOMEM;
    }
    memset(aToOpen, 1, nIdx+1);
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    }else{
      /* Add the rowid of the row to be deleted to the RowSet */
      nKey = 1;  /* OP_Seek always uses a single rowid */
      sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
    }
  }

  /* If this DELETE cannot use the ONEPASS strategy, this is the 
  ** end of the WHERE loop */

  if( eOnePass!=ONEPASS_OFF ){
    addrBypass = sqlite3VdbeMakeLabel(v);
  }else{
    sqlite3WhereEnd(pWInfo);
  }

  /* Unless this is a view, open cursors for the table we are 
  ** deleting from and all its indices. If this is a view, then the
  ** only effect this statement has is to fire the INSTEAD OF 
  ** triggers.
  */
  if( !isView ){
    int iAddrOnce = 0;
    u8 p5 = (eOnePass==ONEPASS_OFF ? 0 : OPFLAG_FORDELETE);
    if( eOnePass==ONEPASS_MULTI ){
      iAddrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
    }
    testcase( IsVirtual(pTab) );
    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, p5, iTabCur, 
        aToOpen, &iDataCur, &iIdxCur);
    assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
    assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
    if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
  }

  /* Set up a loop over the rowids/primary-keys that were found in the
  ** where-clause loop above.
  */


  if( eOnePass!=ONEPASS_OFF ){
    assert( nKey==nPk );  /* OP_Found will use an unpacked key */
    if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
      assert( pPk!=0 || pTab->pSelect!=0 );
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
      VdbeCoverage(v);
    }








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    }else{
      /* Add the rowid of the row to be deleted to the RowSet */
      nKey = 1;  /* OP_Seek always uses a single rowid */
      sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
    }
  }

  /* If not using a one-pass strategy, this is the end of the first loop.
  ** A second loop, to iterate through the contents of the RowSet or
  ** temporary table populated above, is opened below. */
  if( eOnePass!=ONEPASS_OFF ){
    addrBypass = sqlite3VdbeMakeLabel(v);
  }else{
    sqlite3WhereEnd(pWInfo);
  }

  /* Unless this is a view, open cursors for the table we are 
  ** deleting from and all its indices. If this is a view, then the
  ** only effect this statement has is to fire the INSTEAD OF 
  ** triggers.  */

  if( !isView ){
    int iAddrOnce = 0;
    u8 p5 = (eOnePass==ONEPASS_OFF ? 0 : OPFLAG_FORDELETE);
    if( eOnePass==ONEPASS_MULTI ){
      iAddrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
    }
    testcase( IsVirtual(pTab) );
    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, p5, iTabCur, 
        aToOpen, &iDataCur, &iIdxCur);
    assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
    assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
    if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
  }

  /* If using a one-pass strategy, seek the data-cursor to the entry
  ** in the main table b-tree if where.c has not already done so.
  **
  ** If using the two-pass strategy, start a loop over the contents
  ** of the RowSet or temporary table populated by the first loop.  */
  if( eOnePass!=ONEPASS_OFF ){
    assert( nKey==nPk );  /* OP_Found will use an unpacked key */
    if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
      assert( pPk!=0 || pTab->pSelect!=0 );
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
      VdbeCoverage(v);
    }
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    if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
      iIdxNoSeek = aiCurOnePass[1];
    }
    sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
        iKey, nKey, count, OE_Default, eOnePass, iIdxNoSeek);
  }


  /* End of the loop over all rowids/primary-keys. */

  if( eOnePass!=ONEPASS_OFF ){
    sqlite3VdbeResolveLabel(v, addrBypass);
    sqlite3WhereEnd(pWInfo);
  }else if( pPk ){
    sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addrLoop);
  }else{








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    if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
      iIdxNoSeek = aiCurOnePass[1];
    }
    sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
        iKey, nKey, count, OE_Default, eOnePass, iIdxNoSeek);
  }

  /* For a one-pass strategy, this is the end of the single loop. For a 
  ** two-pass strategy, the end of the loop over the rowids/primary-keys
  ** stored in the RowSet/temporary table.  */
  if( eOnePass!=ONEPASS_OFF ){
    sqlite3VdbeResolveLabel(v, addrBypass);
    sqlite3WhereEnd(pWInfo);
  }else if( pPk ){
    sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addrLoop);
  }else{
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