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Remove the rowhash object from the code. Rowset now fills its role. (CVS 6535)

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FossilOrigin-Name: e963bed0fe3ce5fa32f04b930e5ed0956dc2aa47
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drh
2009-04-22 02:15:47 +00:00
parent 733bf1b1e2
commit 1b26c7ccfa
12 changed files with 61 additions and 472 deletions
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49
src/where.c
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@@ -16,7 +16,7 @@
** so is applicable. Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.384 2009/04/21 17:23:05 danielk1977 Exp $
** $Id: where.c,v 1.385 2009/04/22 02:15:49 drh Exp $
*/
#include "sqliteInt.h"
@@ -2414,14 +2414,11 @@ static Bitmask codeOneLoopStart(
** 1) If pWInfo->regRowSet is non-zero, then the rowid must be inserted
** into the RowSet object stored in register pWInfo->regRowSet.
**
** 2) If pWInfo->regRowHash is non-zero, then the rowid must be inserted
** into the RowHash object stored in register pWInfo->regRowHash.
**
** Extracting a rowid value from a VDBE cursor is not always a cheap
** operation, especially if the rowid is being extracted from an index
** cursor. If the rowid value is available as a by-product of the code
** generated to create the top of the scan loop, then it can be reused
** for either of the two purposes enumerated above without extracting
** without extracting
** it from a cursor. The following two variables are used to communicate
** the availability of the rowid value to the C-code at the end of this
** function that generates the rowid-handling VDBE code.
@@ -2437,7 +2434,7 @@ static Bitmask codeOneLoopStart(
iCur = pTabItem->iCursor;
bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0
&& (wctrlFlags & WHERE_FILL_ROWHASH)==0;
&& (wctrlFlags & WHERE_FILL_ROWTEST)==0;
regRowSet = pWInfo->regRowSet;
codeRowSetEarly = 0;
@@ -2817,22 +2814,22 @@ static Bitmask codeOneLoopStart(
** In the example, there are three indexed terms connected by OR.
** The top of the loop looks like this:
**
** Null 1 # Zero the row-hash in reg 1
** Null 1 # Zero the rowset in reg 1
**
** Then, for each indexed term, the following. The arguments to
** RowHash are such that the rowid of the current row is inserted
** into the row-hash. If it is already present, control skips the
** RowSetTest are such that the rowid of the current row is inserted
** into the RowSet. If it is already present, control skips the
** Gosub opcode and jumps straight to the code generated by WhereEnd().
**
** sqlite3WhereBegin(<term>)
** RowHash # Insert rowid into rowhash
** RowSetTest # Insert rowid into rowset
** Gosub 2 A
** sqlite3WhereEnd()
**
** Following the above, code to terminate the loop. Label A, the target
** of the Gosub above, jumps to the instruction right after the Goto.
**
** Null 1 # Zero the row-hash in reg 1
** Null 1 # Zero the rowset in reg 1
** Goto B # The loop is finished.
**
** A: <loop body> # Return data, whatever.
@@ -2842,14 +2839,14 @@ static Bitmask codeOneLoopStart(
** B: <after the loop>
**
*/
const int f = WHERE_OMIT_OPEN | WHERE_OMIT_CLOSE | WHERE_FILL_ROWHASH;
const int f = WHERE_OMIT_OPEN | WHERE_OMIT_CLOSE | WHERE_FILL_ROWTEST;
WhereClause *pOrWc; /* The OR-clause broken out into subterms */
WhereTerm *pFinal; /* Final subterm within the OR-clause. */
SrcList oneTab; /* Shortened table list */
int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */
int regRowhash = ++pParse->nMem; /* Register for RowHash object */
int regRowset = ++pParse->nMem; /* Register for RowSet object */
int iLoopBody = sqlite3VdbeMakeLabel(v); /* Start of loop body */
int iRetInit; /* Address of regReturn init */
int ii;
@@ -2866,8 +2863,8 @@ static Bitmask codeOneLoopStart(
oneTab.nAlloc = 1;
oneTab.a[0] = *pTabItem;
/* Initialize the row-hash register to contain NULL. An SQL NULL is
** equivalent to an empty row-hash.
/* Initialize the rowset register to contain NULL. An SQL NULL is
** equivalent to an empty rowset.
**
** Also initialize regReturn to contain the address of the instruction
** immediately following the OP_Return at the bottom of the loop. This
@@ -2877,7 +2874,7 @@ static Bitmask codeOneLoopStart(
** fall through to the next instruction, just as an OP_Next does if
** called on an uninitialized cursor.
*/
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowhash);
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
/* iReleaseReg = iRowidReg = sqlite3GetTempReg(pParse); */
@@ -2888,18 +2885,18 @@ static Bitmask codeOneLoopStart(
/* Loop through table entries that match term pOrTerm. */
pSubWInfo = sqlite3WhereBegin(
pParse, &oneTab, pOrTerm->pExpr, 0, f, regRowhash);
pParse, &oneTab, pOrTerm->pExpr, 0, f, regRowset);
if( pSubWInfo ){
int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
/* The call to sqlite3WhereBegin has coded an OP_RowHash
** at instruction iRowHash. Set P2 (the jump target) of this
/* The call to sqlite3WhereBegin has coded an OP_RowSetTest
** at instruction iRowSet. Set P2 (the jump target) of this
** instruction to jump past the OP_Gosub coded below. This way,
** if the rowid is already in the hash-table, the body of the
** loop is not executed.
*/
int iRowHash = pSubWInfo->iRowidHandler;
sqlite3VdbeChangeP2(v, iRowHash, sqlite3VdbeCurrentAddr(v) + 1);
sqlite3VdbeChangeP4(v, iRowHash, (char *)iSet, P4_INT32);
int iRowSet = pSubWInfo->iRowidHandler;
sqlite3VdbeChangeP2(v, iRowSet, sqlite3VdbeCurrentAddr(v) + 1);
sqlite3VdbeChangeP4(v, iRowSet, (char *)iSet, P4_INT32);
sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
/* Finish the loop through table entries that match term pOrTerm. */
@@ -2908,7 +2905,7 @@ static Bitmask codeOneLoopStart(
}
}
sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowhash);
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
sqlite3VdbeResolveLabel(v, iLoopBody);
@@ -2998,8 +2995,8 @@ static Bitmask codeOneLoopStart(
if( pWInfo->wctrlFlags&WHERE_FILL_ROWSET ){
sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, iRowidReg);
}else{
assert( pWInfo->wctrlFlags&WHERE_FILL_ROWHASH );
sqlite3VdbeAddOp3(v, OP_RowHash, regRowSet, 0, iRowidReg);
assert( pWInfo->wctrlFlags&WHERE_FILL_ROWTEST );
sqlite3VdbeAddOp3(v, OP_RowSetTest, regRowSet, 0, iRowidReg);
}
}
sqlite3ReleaseTempReg(pParse, iReleaseReg);
@@ -3189,7 +3186,7 @@ WhereInfo *sqlite3WhereBegin(
pWInfo->pWC = pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
pWInfo->wctrlFlags = wctrlFlags;
pMaskSet = (WhereMaskSet*)&pWC[1];
assert( regRowSet==0 || (wctrlFlags&(WHERE_FILL_ROWSET|WHERE_FILL_ROWHASH)) );
assert( regRowSet==0 || (wctrlFlags&(WHERE_FILL_ROWSET|WHERE_FILL_ROWTEST)) );
/* Split the WHERE clause into separate subexpressions where each
** subexpression is separated by an AND operator.