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Remove an unnecessary parameter from selectInnerLoop(). Clean up comments.

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FossilOrigin-Name: 5e6c4a55f6df30da9dbaa8170f3223613cc86f65
This commit is contained in:
drh
2014-01-22 00:23:49 +00:00
parent e73f059093
commit 340309fd69
5 changed files with 93 additions and 94 deletions
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110
src/select.c
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@@ -543,17 +543,16 @@ struct DistinctCtx {
** This routine generates the code for the inside of the inner loop
** of a SELECT.
**
** If srcTab and nColumn are both zero, then the pEList expressions
** are evaluated in order to get the data for this row. If nColumn>0
** then data is pulled from srcTab and pEList is used only to get the
** datatypes for each column.
** If srcTab is negative, then the pEList expressions
** are evaluated in order to get the data for this row. If srcTab is
** zero or more, then data is pulled from srcTab and pEList is used only
** to get number columns and the datatype for each column.
*/
static void selectInnerLoop(
Parse *pParse, /* The parser context */
Select *p, /* The complete select statement being coded */
ExprList *pEList, /* List of values being extracted */
int srcTab, /* Pull data from this table */
int nColumn, /* Number of columns in the source table */
ExprList *pOrderBy, /* If not NULL, sort results using this key */
DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */
SelectDest *pDest, /* How to dispose of the results */
@@ -569,7 +568,6 @@ static void selectInnerLoop(
int nResultCol; /* Number of result columns */
assert( v );
if( NEVER(v==0) ) return;
assert( pEList!=0 );
hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
if( pOrderBy==0 && !hasDistinct ){
@@ -578,11 +576,7 @@ static void selectInnerLoop(
/* Pull the requested columns.
*/
if( nColumn>0 ){
nResultCol = nColumn;
}else{
nResultCol = pEList->nExpr;
}
nResultCol = pEList->nExpr;
if( pDest->iSdst==0 ){
pDest->iSdst = pParse->nMem+1;
pDest->nSdst = nResultCol;
@@ -591,9 +585,10 @@ static void selectInnerLoop(
assert( pDest->nSdst==nResultCol );
}
regResult = pDest->iSdst;
if( nColumn>0 ){
for(i=0; i<nColumn; i++){
if( srcTab>=0 ){
for(i=0; i<nResultCol; i++){
sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
VdbeComment((v, "%s", pEList->a[i].zName));
}
}else if( eDest!=SRT_Exists ){
/* If the destination is an EXISTS(...) expression, the actual
@@ -602,15 +597,12 @@ static void selectInnerLoop(
sqlite3ExprCodeExprList(pParse, pEList, regResult,
(eDest==SRT_Output)?SQLITE_ECEL_DUP:0);
}
nColumn = nResultCol;
/* If the DISTINCT keyword was present on the SELECT statement
** and this row has been seen before, then do not make this row
** part of the result.
*/
if( hasDistinct ){
assert( pEList!=0 );
assert( pEList->nExpr==nColumn );
switch( pDistinct->eTnctType ){
case WHERE_DISTINCT_ORDERED: {
VdbeOp *pOp; /* No longer required OpenEphemeral instr. */
@@ -619,7 +611,7 @@ static void selectInnerLoop(
/* Allocate space for the previous row */
regPrev = pParse->nMem+1;
pParse->nMem += nColumn;
pParse->nMem += nResultCol;
/* Change the OP_OpenEphemeral coded earlier to an OP_Null
** sets the MEM_Cleared bit on the first register of the
@@ -633,10 +625,10 @@ static void selectInnerLoop(
pOp->p1 = 1;
pOp->p2 = regPrev;
iJump = sqlite3VdbeCurrentAddr(v) + nColumn;
for(i=0; i<nColumn; i++){
iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;
for(i=0; i<nResultCol; i++){
CollSeq *pColl = sqlite3ExprCollSeq(pParse, pEList->a[i].pExpr);
if( i<nColumn-1 ){
if( i<nResultCol-1 ){
sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);
}else{
sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);
@@ -645,7 +637,7 @@ static void selectInnerLoop(
sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
}
assert( sqlite3VdbeCurrentAddr(v)==iJump );
sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nColumn-1);
sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);
break;
}
@@ -656,7 +648,7 @@ static void selectInnerLoop(
default: {
assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
codeDistinct(pParse, pDistinct->tabTnct, iContinue, nColumn, regResult);
codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol, regResult);
break;
}
}
@@ -673,7 +665,7 @@ static void selectInnerLoop(
case SRT_Union: {
int r1;
r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
sqlite3ReleaseTempReg(pParse, r1);
break;
@@ -684,7 +676,7 @@ static void selectInnerLoop(
** the temporary table iParm.
*/
case SRT_Except: {
sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nColumn);
sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);
break;
}
#endif
@@ -697,7 +689,7 @@ static void selectInnerLoop(
int r1 = sqlite3GetTempReg(pParse);
testcase( eDest==SRT_Table );
testcase( eDest==SRT_EphemTab );
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
#ifndef SQLITE_OMIT_CTE
if( eDest==SRT_DistTable ){
/* If the destination is DistTable, then cursor (iParm+1) is open
@@ -730,7 +722,7 @@ static void selectInnerLoop(
** item into the set table with bogus data.
*/
case SRT_Set: {
assert( nColumn==1 );
assert( nResultCol==1 );
pDest->affSdst =
sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst);
if( pOrderBy ){
@@ -762,7 +754,7 @@ static void selectInnerLoop(
** of the scan loop.
*/
case SRT_Mem: {
assert( nColumn==1 );
assert( nResultCol==1 );
if( pOrderBy ){
pushOntoSorter(pParse, pOrderBy, p, regResult);
}else{
@@ -783,14 +775,14 @@ static void selectInnerLoop(
testcase( eDest==SRT_Output );
if( pOrderBy ){
int r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
pushOntoSorter(pParse, pOrderBy, p, r1);
sqlite3ReleaseTempReg(pParse, r1);
}else if( eDest==SRT_Coroutine ){
sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
}else{
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn);
sqlite3ExprCacheAffinityChange(pParse, regResult, nColumn);
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
}
break;
}
@@ -1857,7 +1849,7 @@ static int multiSelect(
/* Find the next row in the Queue and output that row */
addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak);
selectInnerLoop(pParse, p, p->pEList, iQueue, p->pEList->nExpr,
selectInnerLoop(pParse, p, p->pEList, iQueue,
0, 0, &dest, addrCont, addrBreak);
sqlite3VdbeResolveLabel(v, addrCont);
@@ -2020,7 +2012,7 @@ static int multiSelect(
computeLimitRegisters(pParse, p, iBreak);
sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak);
iStart = sqlite3VdbeCurrentAddr(v);
selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
selectInnerLoop(pParse, p, p->pEList, unionTab,
0, 0, &dest, iCont, iBreak);
sqlite3VdbeResolveLabel(v, iCont);
sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart);
@@ -2098,7 +2090,7 @@ static int multiSelect(
iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);
sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);
sqlite3ReleaseTempReg(pParse, r1);
selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
selectInnerLoop(pParse, p, p->pEList, tab1,
0, 0, &dest, iCont, iBreak);
sqlite3VdbeResolveLabel(v, iCont);
sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart);
@@ -4299,50 +4291,8 @@ static void explainSimpleCount(
/*
** Generate code for the SELECT statement given in the p argument.
**
** The results are distributed in various ways depending on the
** contents of the SelectDest structure pointed to by argument pDest
** as follows:
**
** pDest->eDest Result
** ------------ -------------------------------------------
** SRT_Output Generate a row of output (using the OP_ResultRow
** opcode) for each row in the result set.
**
** SRT_Mem Only valid if the result is a single column.
** Store the first column of the first result row
** in register pDest->iSDParm then abandon the rest
** of the query. This destination implies "LIMIT 1".
**
** SRT_Set The result must be a single column. Store each
** row of result as the key in table pDest->iSDParm.
** Apply the affinity pDest->affSdst before storing
** results. Used to implement "IN (SELECT ...)".
**
** SRT_Union Store results as a key in a temporary table
** identified by pDest->iSDParm.
**
** SRT_Except Remove results from the temporary table pDest->iSDParm.
**
** SRT_Table Store results in temporary table pDest->iSDParm.
** This is like SRT_EphemTab except that the table
** is assumed to already be open.
**
** SRT_EphemTab Create an temporary table pDest->iSDParm and store
** the result there. The cursor is left open after
** returning. This is like SRT_Table except that
** this destination uses OP_OpenEphemeral to create
** the table first.
**
** SRT_Coroutine Generate a co-routine that returns a new row of
** results each time it is invoked. The entry point
** of the co-routine is stored in register pDest->iSDParm.
**
** SRT_Exists Store a 1 in memory cell pDest->iSDParm if the result
** set is not empty.
**
** SRT_Discard Throw the results away. This is used by SELECT
** statements within triggers whose only purpose is
** the side-effects of functions.
** The results are returned according to the SelectDest structure.
** See comments in sqliteInt.h for further information.
**
** This routine returns the number of errors. If any errors are
** encountered, then an appropriate error message is left in
@@ -4683,7 +4633,7 @@ int sqlite3Select(
}
/* Use the standard inner loop. */
selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, &sDistinct, pDest,
selectInnerLoop(pParse, p, pEList, -1, pOrderBy, &sDistinct, pDest,
sqlite3WhereContinueLabel(pWInfo),
sqlite3WhereBreakLabel(pWInfo));
@@ -4955,7 +4905,7 @@ int sqlite3Select(
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
finalizeAggFunctions(pParse, &sAggInfo);
sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
selectInnerLoop(pParse, p, p->pEList, -1, pOrderBy,
&sDistinct, pDest,
addrOutputRow+1, addrSetAbort);
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
@@ -5098,7 +5048,7 @@ int sqlite3Select(
pOrderBy = 0;
sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, 0,
selectInnerLoop(pParse, p, p->pEList, -1, 0, 0,
pDest, addrEnd, addrEnd);
sqlite3ExprListDelete(db, pDel);
}