}
/*
-** Return true if the entire partition should be cached in the temp
-** table before processing.
+** Return true if the entire partition should be cached in the ephemeral
+** table before processing any rows.
*/
static int windowCachePartition(Window *pMWin){
Window *pWin;
return 0;
}
+typedef struct WindowCodeArg WindowCodeArg;
+struct WindowCodeArg {
+ Parse *pParse;
+ Window *pMWin;
+ Vdbe *pVdbe;
+ int regGosub;
+ int addrGosub;
+ int regArg;
+};
+
+#define WINDOW_RETURN_ROW 1
+#define WINDOW_AGGINVERSE 2
+#define WINDOW_AGGSTEP 3
+
+static int windowCodeOp(
+ WindowCodeArg *p,
+ int op,
+ int csr,
+ int regCountdown,
+ int jumpOnEof
+){
+ int ret = 0;
+ Vdbe *v = p->pVdbe;
+ int addrIf = 0;
+
+ if( regCountdown>0 ){
+ addrIf = sqlite3VdbeAddOp3(v, OP_IfPos, regCountdown, 0, 1);
+ }
+
+ if( jumpOnEof ){
+ sqlite3VdbeAddOp2(v, OP_Next, csr, sqlite3VdbeCurrentAddr(v)+2);
+ ret = sqlite3VdbeAddOp0(v, OP_Goto);
+ }else{
+ sqlite3VdbeAddOp2(v, OP_Next, csr, sqlite3VdbeCurrentAddr(v)+1);
+ }
+
+ switch( op ){
+ case WINDOW_RETURN_ROW:
+ windowAggFinal(p->pParse, p->pMWin, 0);
+ windowReturnOneRow(p->pParse, p->pMWin, p->regGosub, p->addrGosub);
+ break;
+
+ case WINDOW_AGGINVERSE:
+ windowAggStep(p->pParse, p->pMWin, csr, 1, p->regArg, p->pMWin->regSize);
+ break;
+
+ case WINDOW_AGGSTEP:
+ windowAggStep(p->pParse, p->pMWin, csr, 0, p->regArg, p->pMWin->regSize);
+ break;
+ }
+
+ if( ret ){
+ sqlite3VdbeJumpHere(v, ret);
+ }
+ if( regCountdown>0 ){
+ sqlite3VdbeJumpHere(v, addrIf);
+ }
+ return ret;
+}
+
+
+
+/*
+** This function - windowCodeStep() - generates the VM code that reads data
+** from the sub-select and returns rows to the consumer. For the simplest
+** case:
+**
+** ROWS BETWEEN <expr1> PRECEDING AND <expr2> FOLLOWING
+**
+** The VM code generated is equivalent in spirit to the following:
+**
+** while( !eof ){
+** if( new partition ){
+** Gosub flush
+** }
+** Insert new row into eph table.
+**
+** if( first row of partition ){
+** Rewind(csrEnd, skipNext=1)
+** Rewind(csrStart, skipNext=1)
+** Rewind(csrCurrent, skipNext=1)
+**
+** regEnd = <expr2> // FOLLOWING expression
+** regStart = <expr1> // PRECEDING expression
+** }else{
+** if( (regEnd--)<=0 ){
+** Next(csrCurrent)
+** Return one row.
+** if( (regStart--)<0 ){
+** Next(csrStart)
+** AggInverse(csrStart)
+** }
+** }
+** }
+**
+** Next(csrEnd)
+** AggStep(csrEnd)
+** }
+** flush:
+** while( 1 ){
+** Next(csrCurrent)
+** if( eof ) break
+** Return one row.
+** if( (regStart--)<0 ){
+** Next(csrStart)
+** AggInverse(csrStart)
+** }
+** }
+** Empty eph table.
+**
+** More generally, the pattern used for all window types is:
+**
+** while( !eof ){
+** if( new partition ){
+** Gosub flush
+** }
+** Insert new row into eph table.
+** if( first row of partition ){
+** FIRST_ROW_CODE
+** }else{
+** SECOND_ROW_CODE
+** }
+** ALL_ROW_CODE
+** }
+** flush:
+** FLUSH_CODE
+** Empty eph table.
+**
+*/
static void windowCodeStep(
Parse *pParse,
Select *p,
int regStart; /* Value of <expr> PRECEDING */
int regEnd; /* Value of <expr> FOLLOWING */
- int iSubCsr = p->pSrc->a[0].iCursor;
- int nSub = p->pSrc->a[0].pTab->nCol;
- int k;
+ int iSubCsr = p->pSrc->a[0].iCursor; /* Cursor of sub-select */
+ int nSub = p->pSrc->a[0].pTab->nCol; /* Number of cols returned by sub */
+ int iCol; /* To iterate through sub cols */
int addrGoto;
int addrIf;
- int addrIfEnd;
- int addrIfStart;
int addrGosubFlush;
int addrInteger;
int addrCacheRewind;
int reg = pParse->nMem+1;
int regRecord = reg+nSub;
int regRowid = regRecord+1;
+ WindowCodeArg s;
- bCache = 1;
+ memset(&s, 0, sizeof(WindowCodeArg));
+ s.pParse = pParse;
+ s.pMWin = pMWin;
+ s.pVdbe = v;
+ s.regGosub = regGosub;
+ s.addrGosub = addrGosub;
pParse->nMem += 1 + nSub + 1;
|| pMWin->eEnd==TK_PRECEDING
);
+
/* Load the column values for the row returned by the sub-select
** into an array of registers starting at reg. Assemble them into
** a record in register regRecord. TODO: An optimization here? */
- for(k=0; k<nSub; k++){
- sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, k, reg+k);
+ for(iCol=0; iCol<nSub; iCol++){
+ sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, iCol, reg+iCol);
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, reg, nSub, regRecord);
}
/* This block is run for the first row of each partition */
- regArg = windowInitAccum(pParse, pMWin);
+ s.regArg = regArg = windowInitAccum(pParse, pMWin);
sqlite3ExprCode(pParse, pMWin->pStart, regStart);
windowCheckIntValue(pParse, regStart, 0);
sqlite3ExprCode(pParse, pMWin->pEnd, regEnd);
windowCheckIntValue(pParse, regEnd, 1);
- if( pMWin->eStart==TK_FOLLOWING || pMWin->eEnd==TK_PRECEDING ){
+ if( pMWin->eStart==pMWin->eEnd
+ && pMWin->eStart!=TK_CURRENT && pMWin->eStart!=TK_UNBOUNDED
+ ){
int op = ((pMWin->eStart==TK_FOLLOWING) ? OP_Ge : OP_Le);
int addrGe = sqlite3VdbeAddOp3(v, op, regStart, 0, regEnd);
windowAggFinal(pParse, pMWin, 0);
sqlite3VdbeAddOp2(v, OP_Integer, 0, pMWin->regFirst);
addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);
- /* This block is run for the second and subsequent rows of each partition */
+ /* Begin generating SECOND_ROW_CODE */
+ VdbeModuleComment((pParse->pVdbe, "Begin windowCodeStep.SECOND_ROW_CODE"));
if( bCache ){
addrCacheNext = sqlite3VdbeCurrentAddr(v);
}else{
sqlite3VdbeJumpHere(v, addrIf);
}
-
if( pMWin->eStart==TK_FOLLOWING ){
- addrIfEnd = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
- windowAggFinal(pParse, pMWin, 0);
- sqlite3VdbeAddOp2(v, OP_Next, csrCurrent, sqlite3VdbeCurrentAddr(v)+1);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
- sqlite3VdbeJumpHere(v, addrIfEnd);
-
- addrIfStart = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrStart, 1, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfStart);
+ windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, regEnd, 0);
+ windowCodeOp(&s, WINDOW_AGGINVERSE, csrStart, regStart, 0);
}else
if( pMWin->eEnd==TK_PRECEDING ){
- addrIfEnd = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrEnd, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrEnd, 0, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfEnd);
-
- windowAggFinal(pParse, pMWin, 0);
- sqlite3VdbeAddOp2(v, OP_Next, csrCurrent, sqlite3VdbeCurrentAddr(v)+1);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
-
- addrIfStart = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrStart, 1, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfStart);
+ windowCodeOp(&s, WINDOW_AGGSTEP, csrEnd, regEnd, 0);
+ windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, 0, 0);
+ windowCodeOp(&s, WINDOW_AGGINVERSE, csrStart, regStart, 0);
}else{
- addrIfEnd = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
- windowAggFinal(pParse, pMWin, 0);
- sqlite3VdbeAddOp2(v, OP_Next, csrCurrent, sqlite3VdbeCurrentAddr(v)+1);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
- addrIfStart = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrStart, 1, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfStart);
- sqlite3VdbeJumpHere(v, addrIfEnd);
+ int addr = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
+ windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, 0, 0);
+ windowCodeOp(&s, WINDOW_AGGINVERSE, csrStart, regStart, 0);
+ sqlite3VdbeJumpHere(v, addr);
}
+ VdbeModuleComment((pParse->pVdbe, "End windowCodeStep.SECOND_ROW_CODE"));
+ VdbeModuleComment((pParse->pVdbe, "Begin windowCodeStep.ALL_ROW_CODE"));
sqlite3VdbeJumpHere(v, addrGoto);
if( pMWin->eEnd!=TK_PRECEDING ){
- sqlite3VdbeAddOp2(v, OP_Next, csrEnd, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrEnd, 0, regArg, pMWin->regSize);
+ windowCodeOp(&s, WINDOW_AGGSTEP, csrEnd, 0, 0);
}
+ VdbeModuleComment((pParse->pVdbe, "End windowCodeStep.ALL_ROW_CODE"));
/* End of the main input loop */
if( bCache ){
/* Fall through */
+ VdbeModuleComment((pParse->pVdbe, "Begin windowCodeStep.FLUSH_CODE"));
if( pMWin->pPartition && bCache==0 ){
addrInteger = sqlite3VdbeAddOp2(v, OP_Integer, 0, regFlushPart);
sqlite3VdbeJumpHere(v, addrGosubFlush);
}
- if( pMWin->eStart==TK_FOLLOWING ){
- int addrBreak;
- addrIfEnd = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrCurrent, sqlite3VdbeCurrentAddr(v)+2);
- addrBreak = sqlite3VdbeAddOp0(v, OP_Goto);
- windowAggFinal(pParse, pMWin, 0);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
- sqlite3VdbeJumpHere(v, addrIfEnd);
-
- addrIfStart = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+2);
- sqlite3VdbeAddOp0(v, OP_Goto);
- windowAggStep(pParse, pMWin, csrStart, 1, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfStart);
- sqlite3VdbeJumpHere(v, addrIfStart+2);
-
- sqlite3VdbeAddOp2(v, OP_Goto, 0, addrIfEnd);
- sqlite3VdbeJumpHere(v, addrBreak);
+ if( pMWin->eEnd==TK_PRECEDING ){
+ windowCodeOp(&s, WINDOW_AGGSTEP, csrEnd, regEnd, 1);
+ windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, 0, 1);
}else{
- sqlite3VdbeAddOp2(v, OP_Next, csrCurrent, sqlite3VdbeCurrentAddr(v)+2);
- addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);
- if( pMWin->eEnd==TK_PRECEDING ){
- addrIfEnd = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrEnd, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrEnd, 0, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfEnd);
- windowAggFinal(pParse, pMWin, 0);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
+ int addrBreak;
+ int addrStart = sqlite3VdbeCurrentAddr(v);
+ if( pMWin->eStart==TK_FOLLOWING ){
+ addrBreak = windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, regEnd, 1);
+ windowCodeOp(&s, WINDOW_AGGINVERSE, csrStart, regStart, 1);
}else{
- windowAggFinal(pParse, pMWin, 0);
- windowReturnOneRow(pParse, pMWin, regGosub, addrGosub);
- addrIfStart = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0, 1);
- sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+1);
- windowAggStep(pParse, pMWin, csrStart, 1, regArg, pMWin->regSize);
- sqlite3VdbeJumpHere(v, addrIfStart);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, addrGoto-1);
+ addrBreak = windowCodeOp(&s, WINDOW_RETURN_ROW, csrCurrent, 0, 1);
+ windowCodeOp(&s, WINDOW_AGGINVERSE, csrStart, regStart, 0);
}
- sqlite3VdbeJumpHere(v, addrGoto);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, addrStart);
+ sqlite3VdbeJumpHere(v, addrBreak);
}
-
if( bCache && addrShortcut>0 ) sqlite3VdbeJumpHere(v, addrShortcut);
sqlite3VdbeAddOp1(v, OP_ResetSorter, csrCurrent);
sqlite3VdbeAddOp2(v, OP_Integer, 0, pMWin->regSize);
if( bCache==0 ) sqlite3VdbeAddOp2(v, OP_Integer, 1, pMWin->regFirst);
+ VdbeModuleComment((pParse->pVdbe, "End windowCodeStep.FLUSH_CODE"));
if( pMWin->pPartition ){
sqlite3VdbeChangeP1(v, addrInteger, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);
projects / thirdparty / sqlite.git / commitdiff
