/*
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
*/
#include "sqliteInt.h"
void sqlite3WindowDelete(sqlite3 *db, Window *p){
if( p ){
sqlite3ExprDelete(db, p->pFilter);
sqlite3ExprListDelete(db, p->pPartition);
sqlite3ExprListDelete(db, p->pOrderBy);
sqlite3ExprDelete(db, p->pEnd);
sqlite3ExprDelete(db, p->pStart);
sqlite3DbFree(db, p);
}
}
Window *sqlite3WindowAlloc(
Parse *pParse,
int eType,
int eStart, Expr *pStart,
int eEnd, Expr *pEnd
){
Window *pWin = (Window*)sqlite3DbMallocZero(pParse->db, sizeof(Window));
if( pWin ){
pWin->eType = eType;
pWin->eStart = eStart;
pWin->eEnd = eEnd;
pWin->pEnd = pEnd;
pWin->pStart = pStart;
}else{
sqlite3ExprDelete(pParse->db, pEnd);
sqlite3ExprDelete(pParse->db, pStart);
}
return pWin;
}
void sqlite3WindowAttach(Parse *pParse, Expr *p, Window *pWin){
if( p ){
p->pWin = pWin;
}else{
sqlite3WindowDelete(pParse->db, pWin);
}
}
/*
** Return 0 if the two window objects are identical, or non-zero otherwise.
*/
int sqlite3WindowCompare(Parse *pParse, Window *p1, Window *p2){
if( p1->eType!=p2->eType ) return 1;
if( p1->eStart!=p2->eStart ) return 1;
if( p1->eEnd!=p2->eEnd ) return 1;
if( sqlite3ExprCompare(pParse, p1->pStart, p2->pStart, -1) ) return 1;
if( sqlite3ExprCompare(pParse, p1->pEnd, p2->pEnd, -1) ) return 1;
if( sqlite3ExprListCompare(p1->pPartition, p2->pPartition, -1) ) return 1;
if( sqlite3ExprListCompare(p1->pOrderBy, p2->pOrderBy, -1) ) return 1;
return 0;
}
static void windowAggInit(Parse *pParse, Window *pMWin){
Window *pWin;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
int funcFlags = pWin->pFunc->funcFlags;
if( (funcFlags & SQLITE_FUNC_MINMAX) && pWin->eStart!=TK_UNBOUNDED ){
ExprList *pList = pWin->pOwner->x.pList;
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pList, 0, 0);
Vdbe *v = sqlite3GetVdbe(pParse);
pWin->csrApp = pParse->nTab++;
pWin->regApp = pParse->nMem+1;
pParse->nMem += 3;
if( pKeyInfo && pWin->pFunc->zName[1]=='i' ){
assert( pKeyInfo->aSortOrder[0]==0 );
pKeyInfo->aSortOrder[0] = 1;
}
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pWin->csrApp, 2);
sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);
}
}
}
void sqlite3WindowCodeInit(Parse *pParse, Window *pWin){
Vdbe *v = sqlite3GetVdbe(pParse);
int nPart = (pWin->pPartition ? pWin->pPartition->nExpr : 0);
nPart += (pWin->pOrderBy ? pWin->pOrderBy->nExpr : 0);
if( nPart ){
pWin->regPart = pParse->nMem+1;
pParse->nMem += nPart;
sqlite3VdbeAddOp3(v, OP_Null, 0, pWin->regPart, pWin->regPart+nPart-1);
}
windowAggInit(pParse, pWin);
}
static void windowCheckFrameValue(Parse *pParse, int reg, int bEnd){
static const char *azErr[] = {
"frame starting offset must be a non-negative integer",
"frame ending offset must be a non-negative integer"
};
Vdbe *v = sqlite3GetVdbe(pParse);
int regZero = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regZero);
sqlite3VdbeAddOp2(v, OP_MustBeInt, reg, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp3(v, OP_Ge, regZero, sqlite3VdbeCurrentAddr(v)+2, reg);
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_ERROR, OE_Abort);
sqlite3VdbeAppendP4(v, (void*)azErr[bEnd], P4_STATIC);
}
/*
** Generate VM code to invoke either xStep() (if bInverse is 0) or
** xInverse (if bInverse is non-zero) for each window function in the
** linked list starting at pMWin.
*/
static void windowAggStep(
Parse *pParse,
Window *pMWin,
int csr,
int bInverse,
int reg
){
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
int regArg;
if( csr>=0 ){
int i;
for(i=0; i<pWin->nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+i, reg+i);
}
regArg = reg;
}else{
regArg = reg + pWin->iArgCol;
}
if( pWin->csrApp ){
if( bInverse==0 ){
sqlite3VdbeAddOp2(v, OP_AddImm, pWin->regApp+1, 1);
sqlite3VdbeAddOp2(v, OP_SCopy, regArg, pWin->regApp);
sqlite3VdbeAddOp3(v, OP_MakeRecord, pWin->regApp, 2, pWin->regApp+2);
sqlite3VdbeAddOp2(v, OP_IdxInsert, pWin->csrApp, pWin->regApp+2);
}else{
sqlite3VdbeAddOp4Int(v, OP_SeekGE, pWin->csrApp, 0, regArg, 1);
sqlite3VdbeAddOp1(v, OP_Delete, pWin->csrApp);
sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
}
}else{
if( pWin->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
CollSeq *pColl;
pColl = sqlite3ExprCollSeq(pParse, pWin->pOwner->x.pList->a[0].pExpr);
sqlite3VdbeAddOp4(v, OP_CollSeq, 0,0,0, (const char*)pColl, P4_COLLSEQ);
}
sqlite3VdbeAddOp3(v, OP_AggStep0, bInverse, regArg, pWin->regAccum);
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
}
}
}
static void windowAggFinal(Parse *pParse, Window *pMWin, int bFinal){
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
if( pWin->csrApp ){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
sqlite3VdbeAddOp1(v, OP_Last, pWin->csrApp);
sqlite3VdbeAddOp3(v, OP_Column, pWin->csrApp, 0, pWin->regResult);
sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
if( bFinal ){
sqlite3VdbeAddOp1(v, OP_ResetSorter, pWin->csrApp);
}
}else{
if( bFinal==0 ){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
}
sqlite3VdbeAddOp2(v, OP_AggFinal, pWin->regAccum, pWin->nArg);
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
if( bFinal ){
sqlite3VdbeAddOp2(v, OP_Copy, pWin->regAccum, pWin->regResult);
}else{
sqlite3VdbeChangeP3(v, -1, pWin->regResult);
}
}
}
}
static void windowPartitionCache(
Parse *pParse,
Select *p,
WhereInfo *pWInfo,
int regFlushPart,
int lblFlushPart
){
Window *pMWin = p->pWin;
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
int iSubCsr = p->pSrc->a[0].iCursor;
int nSub = p->pSrc->a[0].pTab->nCol;
int k;
int reg = pParse->nMem+1;
int regRecord = reg+nSub;
int regRowid = regRecord+1;
pParse->nMem += nSub + 2;
/* Martial the row returned by the sub-select into an array of
** registers. */
for(k=0; k<nSub; k++){
sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, k, reg+k);
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, reg, nSub, regRecord);
/* Check if this is the start of a new partition. If so, call the
** flush_partition sub-routine. */
if( pMWin->pPartition ){
int addr;
ExprList *pPart = pMWin->pPartition;
int nPart = (pPart ? pPart->nExpr : 0);
int regNewPart = reg + pMWin->nBufferCol;
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pPart, 0, 0);
addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPart, pMWin->regPart,nPart);
sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
sqlite3VdbeAddOp3(v, OP_Jump, addr+2, addr+4, addr+2);
sqlite3VdbeAddOp3(v, OP_Copy, regNewPart, pMWin->regPart, nPart-1);
sqlite3VdbeAddOp2(v, OP_Gosub, regFlushPart, lblFlushPart);
}
/* Buffer the current row in the ephemeral table. */
sqlite3VdbeAddOp2(v, OP_NewRowid, pMWin->iEphCsr, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, pMWin->iEphCsr, regRecord, regRowid);
/* End of the input loop */
sqlite3WhereEnd(pWInfo);
/* Invoke "flush_partition" to deal with the final (or only) partition */
sqlite3VdbeAddOp2(v, OP_Gosub, regFlushPart, lblFlushPart);
}
/*
** ROWS BETWEEN <expr1> PRECEDING AND <expr2> FOLLOWING
** ----------------------------------------------------
**
** Pseudo-code for the implementation of this window frame type is as
** follows. sqlite3WhereBegin() has already been called to generate the
** top of the main loop when this function is called.
**
** Each time the sub-routine at addrGosub is invoked, a single output
** row is generated based on the current row indicated by Window.iEphCsr.
**
** ...
** if( new partition ){
** Gosub flush_partition
** }
** Insert (record in eph-table)
** sqlite3WhereEnd()
** Gosub flush_partition
**
** flush_partition:
** Once {
** OpenDup (iEphCsr -> csrStart)
** OpenDup (iEphCsr -> csrEnd)
** }
** regStart = <expr1> // PRECEDING expression
** regEnd = <expr2> // FOLLOWING expression
** if( regStart<0 || regEnd<0 ){ error! }
** Rewind (csr,csrStart,csrEnd) // if EOF goto flush_partition_done
** Next(csrEnd) // if EOF skip Aggstep
** Aggstep (csrEnd)
** if( (regEnd--)<=0 ){
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( (regStart--)<=0 ){
** AggStep (csrStart, xInverse)
** Next(csrStart)
** }
** }
** flush_partition_done:
** ResetSorter (csr)
** Return
**
** ROWS BETWEEN <expr> PRECEDING AND CURRENT ROW
** ROWS BETWEEN CURRENT ROW AND <expr> FOLLOWING
** ROWS BETWEEN UNBOUNDED PRECEDING AND <expr> FOLLOWING
**
** These are similar to the above. For "CURRENT ROW", intialize the
** register to 0. For "UNBOUNDED PRECEDING" to infinity.
**
** ROWS BETWEEN <expr> PRECEDING AND UNBOUNDED FOLLOWING
** ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
**
** Rewind (csr,csrStart,csrEnd) // if EOF goto flush_partition_done
** while( 1 ){
** Next(csrEnd) // Exit while(1) at EOF
** Aggstep (csrEnd)
** }
** while( 1 ){
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( (regStart--)<=0 ){
** AggStep (csrStart, xInverse)
** Next(csrStart)
** }
** }
**
** For the "CURRENT ROW AND UNBOUNDED FOLLOWING" case, the final if()
** condition is always true (as if regStart were initialized to 0).
**
** RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
**
** This is the only RANGE case handled by this routine. It modifies the
** second while( 1 ) loop in "ROWS BETWEEN CURRENT ... UNBOUNDED..." to
** be:
**
** while( 1 ){
** AggFinal (xValue)
** while( 1 ){
** regPeer++
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( new peer ) break;
** }
** while( (regPeer--)>0 ){
** AggStep (csrStart, xInverse)
** Next(csrStart)
** }
** }
**
** ROWS BETWEEN <expr> FOLLOWING AND <expr> FOLLOWING
**
** regEnd = regEnd - regStart
** Rewind (csr,csrStart,csrEnd) // if EOF goto flush_partition_done
** Aggstep (csrEnd)
** Next(csrEnd) // if EOF fall-through
** if( (regEnd--)<=0 ){
** if( (regStart--)<=0 ){
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** }
** AggStep (csrStart, xInverse)
** Next (csrStart)
** }
**
** ROWS BETWEEN <expr> PRECEDING AND <expr> PRECEDING
**
** Replace the bit after "Rewind" in the above with:
**
** if( (regEnd--)<=0 ){
** AggStep (csrEnd)
** Next (csrEnd)
** }
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( (regStart--)<=0 ){
** AggStep (csr2, xInverse)
** Next (csr2)
** }
**
*/
static void windowCodeRowExprStep(
Parse *pParse,
Select *p,
WhereInfo *pWInfo,
int regGosub,
int addrGosub
){
Window *pMWin = p->pWin;
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
int k;
int nSub = p->pSrc->a[0].pTab->nCol;
int regFlushPart; /* Register for "Gosub flush_partition" */
int lblFlushPart; /* Label for "Gosub flush_partition" */
int lblFlushDone; /* Label for "Gosub flush_partition_done" */
int regArg;
int nArg;
int addr;
int csrStart = pParse->nTab++;
int csrEnd = pParse->nTab++;
int regStart; /* Value of <expr> PRECEDING */
int regEnd; /* Value of <expr> FOLLOWING */
int addrNext;
int addrGoto;
int addrTop;
int addrIfPos1;
int addrIfPos2;
int regPeer = 0; /* Number of peers in current group */
int regPeerVal = 0; /* Array of values identifying peer group */
int iPeer = 0; /* Column offset in eph-table of peer vals */
int nPeerVal; /* Number of peer values */
int bRange = 0;
assert( pMWin->eStart==TK_PRECEDING
|| pMWin->eStart==TK_CURRENT
|| pMWin->eStart==TK_FOLLOWING
|| pMWin->eStart==TK_UNBOUNDED
);
assert( pMWin->eEnd==TK_FOLLOWING
|| pMWin->eEnd==TK_CURRENT
|| pMWin->eEnd==TK_UNBOUNDED
|| pMWin->eEnd==TK_PRECEDING
);
if( pMWin->eType==TK_RANGE
&& pMWin->eStart==TK_CURRENT
&& pMWin->eEnd==TK_UNBOUNDED
){
bRange = 1;
}
/* Allocate register and label for the "flush_partition" sub-routine. */
regFlushPart = ++pParse->nMem;
lblFlushPart = sqlite3VdbeMakeLabel(v);
lblFlushDone = sqlite3VdbeMakeLabel(v);
regStart = ++pParse->nMem;
regEnd = ++pParse->nMem;
windowPartitionCache(pParse, p, pWInfo, regFlushPart, lblFlushPart);
addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);
/* Start of "flush_partition" */
sqlite3VdbeResolveLabel(v, lblFlushPart);
sqlite3VdbeAddOp2(v, OP_Once, 0, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp2(v, OP_OpenDup, csrStart, pMWin->iEphCsr);
sqlite3VdbeAddOp2(v, OP_OpenDup, csrEnd, pMWin->iEphCsr);
/* If either regStart or regEnd are not non-negative integers, throw
** an exception. */
if( pMWin->pStart ){
sqlite3ExprCode(pParse, pMWin->pStart, regStart);
windowCheckFrameValue(pParse, regStart, 0);
}
if( pMWin->pEnd ){
sqlite3ExprCode(pParse, pMWin->pEnd, regEnd);
windowCheckFrameValue(pParse, regEnd, 1);
}
/* If this is "ROWS <expr1> FOLLOWING AND ROWS <expr2> FOLLOWING", do:
**
** regEnd = regEnd - regStart;
*/
if( pMWin->pEnd && pMWin->pStart && pMWin->eStart==TK_FOLLOWING ){
assert( pMWin->eEnd==TK_FOLLOWING );
sqlite3VdbeAddOp3(v, OP_Subtract, regStart, regEnd, regEnd);
}
/* Initialize the accumulator register for each window function to NULL */
nArg = 0;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
nArg = MAX(nArg, pWin->nArg);
}
regArg = pParse->nMem+1;
pParse->nMem += nArg;
sqlite3VdbeAddOp2(v, OP_Rewind, pMWin->iEphCsr, lblFlushDone);
sqlite3VdbeAddOp2(v, OP_Rewind, csrStart, lblFlushDone);
sqlite3VdbeChangeP5(v, 1);
sqlite3VdbeAddOp2(v, OP_Rewind, csrEnd, lblFlushDone);
sqlite3VdbeChangeP5(v, 1);
/* Invoke AggStep function for each window function using the row that
** csrEnd currently points to. Or, if csrEnd is already at EOF,
** do nothing. */
addrTop = sqlite3VdbeCurrentAddr(v);
if( pMWin->eEnd==TK_PRECEDING ){
addrIfPos1 = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0 , 1);
}
sqlite3VdbeAddOp2(v, OP_Next, csrEnd, sqlite3VdbeCurrentAddr(v)+2);
addr = sqlite3VdbeAddOp0(v, OP_Goto);
windowAggStep(pParse, pMWin, csrEnd, 0, regArg);
if( pMWin->eEnd==TK_UNBOUNDED ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
sqlite3VdbeJumpHere(v, addr);
addrTop = sqlite3VdbeCurrentAddr(v);
}else{
sqlite3VdbeJumpHere(v, addr);
if( pMWin->eEnd==TK_PRECEDING ){
sqlite3VdbeJumpHere(v, addrIfPos1);
}
}
if( pMWin->eEnd==TK_FOLLOWING ){
addrIfPos1 = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0 , 1);
}
if( pMWin->eStart==TK_FOLLOWING ){
addrIfPos2 = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0 , 1);
}
if( bRange ){
assert( pMWin->eStart==TK_CURRENT && pMWin->pOrderBy );
regPeer = ++pParse->nMem;
regPeerVal = pParse->nMem+1;
iPeer = pMWin->nBufferCol + (pMWin->pPartition?pMWin->pPartition->nExpr:0);
nPeerVal = pMWin->pOrderBy->nExpr;
pParse->nMem += (2 * nPeerVal);
for(k=0; k<nPeerVal; k++){
sqlite3VdbeAddOp3(v, OP_Column, pMWin->iEphCsr, iPeer+k, regPeerVal+k);
}
sqlite3VdbeAddOp2(v, OP_Integer, 0, regPeer);
}
windowAggFinal(pParse, pMWin, 0);
if( bRange ){
sqlite3VdbeAddOp2(v, OP_AddImm, regPeer, 1);
}
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp2(v, OP_Goto, 0, lblFlushDone);
if( bRange ){
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pMWin->pOrderBy,0,0);
int addrJump = sqlite3VdbeCurrentAddr(v)-4;
for(k=0; k<nPeerVal; k++){
int iOut = regPeerVal + nPeerVal + k;
sqlite3VdbeAddOp3(v, OP_Column, pMWin->iEphCsr, iPeer+k, iOut);
}
sqlite3VdbeAddOp3(v, OP_Compare, regPeerVal, regPeerVal+nPeerVal, nPeerVal);
sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
addr = sqlite3VdbeCurrentAddr(v)+1;
sqlite3VdbeAddOp3(v, OP_Jump, addr, addrJump, addr);
}
if( pMWin->eStart==TK_FOLLOWING ){
sqlite3VdbeJumpHere(v, addrIfPos2);
}
if( pMWin->eStart==TK_CURRENT
|| pMWin->eStart==TK_PRECEDING
|| pMWin->eStart==TK_FOLLOWING
){
int addrJumpHere = 0;
if( pMWin->eStart==TK_PRECEDING ){
addrJumpHere = sqlite3VdbeAddOp3(v, OP_IfPos, regStart, 0 , 1);
}
if( bRange ){
sqlite3VdbeAddOp3(v, OP_IfPos, regPeer, sqlite3VdbeCurrentAddr(v)+2, 1);
addrJumpHere = sqlite3VdbeAddOp0(v, OP_Goto);
}
sqlite3VdbeAddOp2(v, OP_Next, csrStart, sqlite3VdbeCurrentAddr(v)+1);
windowAggStep(pParse, pMWin, csrStart, 1, regArg);
if( bRange ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrJumpHere-1);
}
if( addrJumpHere ){
sqlite3VdbeJumpHere(v, addrJumpHere);
}
}
if( pMWin->eEnd==TK_FOLLOWING ){
sqlite3VdbeJumpHere(v, addrIfPos1);
}
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
/* flush_partition_done: */
sqlite3VdbeResolveLabel(v, lblFlushDone);
sqlite3VdbeAddOp1(v, OP_ResetSorter, pMWin->iEphCsr);
sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);
/* Jump to here to skip over flush_partition */
sqlite3VdbeJumpHere(v, addrGoto);
}
/*
** RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
**
** flush_partition:
** Once {
** OpenDup (iEphCsr -> csrLead)
** }
** Integer ctr 0
** foreach row (csrLead){
** if( new peer ){
** AggFinal (xValue)
** for(i=0; i<ctr; i++){
** Gosub addrGosub
** Next iEphCsr
** }
** Integer ctr 0
** }
** AggStep (csrLead)
** Incr ctr
** }
**
** AggFinal (xFinalize)
** for(i=0; i<ctr; i++){
** Gosub addrGosub
** Next iEphCsr
** }
**
** ResetSorter (csr)
** Return
**
** ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
** RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
** RANGE BETWEEN CURRENT ROW AND CURRENT ROW
**
** TODO.
*/
static void windowCodeCacheStep(
Parse *pParse,
Select *p,
WhereInfo *pWInfo,
int regGosub,
int addrGosub
){
Window *pMWin = p->pWin;
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
int k;
int addr;
ExprList *pPart = pMWin->pPartition;
ExprList *pOrderBy = pMWin->pOrderBy;
int nPeer = pOrderBy->nExpr;
int regNewPeer;
int addrGoto; /* Address of Goto used to jump flush_par.. */
int addrRewind; /* Address of Rewind that starts loop */
int regFlushPart;
int lblFlushPart;
int csrLead;
int regCtr;
int regArg; /* Register array to martial function args */
int nArg;
assert( (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_CURRENT)
);
regNewPeer = pParse->nMem+1;
pParse->nMem += nPeer;
/* Allocate register and label for the "flush_partition" sub-routine. */
regFlushPart = ++pParse->nMem;
lblFlushPart = sqlite3VdbeMakeLabel(v);
csrLead = pParse->nTab++;
regCtr = ++pParse->nMem;
windowPartitionCache(pParse, p, pWInfo, regFlushPart, lblFlushPart);
addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);
/* Start of "flush_partition" */
sqlite3VdbeResolveLabel(v, lblFlushPart);
sqlite3VdbeAddOp2(v, OP_Once, 0, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp2(v, OP_OpenDup, csrLead, pMWin->iEphCsr);
/* Initialize the accumulator register for each window function to NULL */
nArg = 0;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
nArg = MAX(nArg, pWin->nArg);
}
regArg = pParse->nMem+1;
pParse->nMem += nArg;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regCtr);
addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, csrLead);
sqlite3VdbeAddOp1(v, OP_Rewind, pMWin->iEphCsr);
if( pOrderBy ){
int addrJump; /* Address of OP_Jump below */
int iOff = pMWin->nBufferCol + (pPart ? pPart->nExpr : 0);
int regPeer = pMWin->regPart + (pPart ? pPart->nExpr : 0);
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pOrderBy, 0, 0);
for(k=0; k<nPeer; k++){
sqlite3VdbeAddOp3(v, OP_Column, csrLead, iOff+k, regNewPeer+k);
}
addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPeer, regPeer, nPeer);
sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
addrJump = sqlite3VdbeAddOp3(v, OP_Jump, addr+2, 0, addr+2);
sqlite3VdbeAddOp3(v, OP_Copy, regNewPeer, regPeer, nPeer-1);
windowAggFinal(pParse, pMWin, 0);
sqlite3VdbeAddOp3(v, OP_IfPos, regCtr, sqlite3VdbeCurrentAddr(v)+2 , 1);
sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)-3);
sqlite3VdbeJumpHere(v, addrJump);
}
windowAggStep(pParse, pMWin, csrLead, 0, regArg);
sqlite3VdbeAddOp2(v, OP_AddImm, regCtr, 1);
sqlite3VdbeAddOp2(v, OP_Next, csrLead, addrRewind+2);
windowAggFinal(pParse, pMWin, 1);
sqlite3VdbeAddOp3(v, OP_IfPos, regCtr, sqlite3VdbeCurrentAddr(v)+2 , 1);
sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)-3);
sqlite3VdbeJumpHere(v, addrRewind);
sqlite3VdbeJumpHere(v, addrRewind+1);
sqlite3VdbeAddOp1(v, OP_ResetSorter, pMWin->iEphCsr);
sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);
/* Jump to here to skip over flush_partition */
sqlite3VdbeJumpHere(v, addrGoto);
}
/*
** RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
**
** ...
** if( new partition ){
** AggFinal (xFinalize)
** Gosub addrGosub
** ResetSorter eph-table
** }
** else if( new peer ){
** AggFinal (xValue)
** Gosub addrGosub
** ResetSorter eph-table
** }
** AggStep
** Insert (record into eph-table)
** sqlite3WhereEnd()
** AggFinal (xFinalize)
** Gosub addrGosub
**
** RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
**
** As above, except take no action for a "new peer". Invoke
** the sub-routine once only for each partition.
**
** RANGE BETWEEN CURRENT ROW AND CURRENT ROW
**
** As above, except that the "new peer" condition is handled in the
** same way as "new partition" (so there is no "else if" block).
**
** ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
**
** As above, except assume every row is a "new peer".
*/
static void windowCodeDefaultStep(
Parse *pParse,
Select *p,
WhereInfo *pWInfo,
int regGosub,
int addrGosub
){
Window *pMWin = p->pWin;
Vdbe *v = sqlite3GetVdbe(pParse);
Window *pWin;
int k;
int iSubCsr = p->pSrc->a[0].iCursor;
int nSub = p->pSrc->a[0].pTab->nCol;
int reg = pParse->nMem+1;
int regRecord = reg+nSub;
int regRowid = regRecord+1;
int addr;
ExprList *pPart = pMWin->pPartition;
ExprList *pOrderBy = pMWin->pOrderBy;
assert( pMWin->eType==TK_RANGE
|| (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_CURRENT)
);
assert( (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_CURRENT)
|| (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_UNBOUNDED)
|| (pMWin->eStart==TK_CURRENT && pMWin->eEnd==TK_CURRENT)
|| (pMWin->eStart==TK_CURRENT && pMWin->eEnd==TK_UNBOUNDED && !pOrderBy)
);
if( pMWin->eEnd==TK_UNBOUNDED ){
pOrderBy = 0;
}
pParse->nMem += nSub + 2;
/* Martial the row returned by the sub-select into an array of
** registers. */
for(k=0; k<nSub; k++){
sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, k, reg+k);
}
/* Check if this is the start of a new partition or peer group. */
if( pPart || pOrderBy ){
int nPart = (pPart ? pPart->nExpr : 0);
int addrGoto = 0;
int addrJump = 0;
int nPeer = (pOrderBy ? pOrderBy->nExpr : 0);
if( pPart ){
int regNewPart = reg + pMWin->nBufferCol;
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pPart, 0, 0);
addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPart, pMWin->regPart,nPart);
sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
addrJump = sqlite3VdbeAddOp3(v, OP_Jump, addr+2, 0, addr+2);
windowAggFinal(pParse, pMWin, 1);
if( pOrderBy ){
addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);
}
}
if( pOrderBy ){
int regNewPeer = reg + pMWin->nBufferCol + nPart;
int regPeer = pMWin->regPart + nPart;
if( addrJump ) sqlite3VdbeJumpHere(v, addrJump);
if( pMWin->eType==TK_RANGE ){
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pOrderBy, 0, 0);
addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPeer, regPeer, nPeer);
sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
addrJump = sqlite3VdbeAddOp3(v, OP_Jump, addr+2, 0, addr+2);
}else{
addrJump = 0;
}
windowAggFinal(pParse, pMWin, pMWin->eStart==TK_CURRENT);
if( addrGoto ) sqlite3VdbeJumpHere(v, addrGoto);
}
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
sqlite3VdbeAddOp1(v, OP_ResetSorter, pMWin->iEphCsr);
sqlite3VdbeAddOp3(
v, OP_Copy, reg+pMWin->nBufferCol, pMWin->regPart, nPart+nPeer-1
);
if( addrJump ) sqlite3VdbeJumpHere(v, addrJump);
}
/* Invoke step function for window functions */
windowAggStep(pParse, pMWin, -1, 0, reg);
/* Buffer the current row in the ephemeral table. */
if( pMWin->nBufferCol>0 ){
sqlite3VdbeAddOp3(v, OP_MakeRecord, reg, pMWin->nBufferCol, regRecord);
}else{
sqlite3VdbeAddOp2(v, OP_Blob, 0, regRecord);
sqlite3VdbeAppendP4(v, (void*)"", 0);
}
sqlite3VdbeAddOp2(v, OP_NewRowid, pMWin->iEphCsr, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, pMWin->iEphCsr, regRecord, regRowid);
/* End the database scan loop. */
sqlite3WhereEnd(pWInfo);
windowAggFinal(pParse, pMWin, 1);
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
}
/*
** RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
**
** As above, except take no action for a "new peer". Invoke
** the sub-routine once only for each partition.
**
** RANGE BETWEEN CURRENT ROW AND CURRENT ROW
**
** As above, except that the "new peer" condition is handled in the
** same way as "new partition" (so there is no "else if" block).
**
** RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
**
** One way is to just reverse the sort order and do as for BETWEEN
** UNBOUNDED PRECEDING AND CURRENT ROW. But that is not quite the same for
** things like group_concat(). And perhaps other user defined aggregates
** as well.
**
** ...
** if( new partition ){
** Gosub flush_partition;
** ResetSorter eph-table
** }
** AggStep
** Insert (record into eph-table)
** sqlite3WhereEnd()
** Gosub flush_partition
**
** flush_partition:
** OpenDup (csr -> csr2)
** foreach (record in eph-table) {
** if( new peer ){
** while( csr2!=csr ){
** AggStep (xInverse)
** Next (csr2)
** }
** }
** AggFinal (xValue)
** Gosub addrGosub
** }
**
**========================================================================
**
** ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
** ...
** if( new partition ){
** AggFinal (xFinalize)
** }
** AggStep
** AggFinal (xValue)
** Gosub addrGosub
** sqlite3WhereEnd()
**
*/
void sqlite3WindowCodeStep(
Parse *pParse,
Select *p,
WhereInfo *pWInfo,
int regGosub,
int addrGosub,
int *pbLoop
){
Window *pMWin = p->pWin;
*pbLoop = 0;
if( (pMWin->eType==TK_ROWS
&& (pMWin->eStart!=TK_UNBOUNDED||pMWin->eEnd!=TK_CURRENT||!pMWin->pOrderBy))
|| (pMWin->eStart==TK_CURRENT&&pMWin->eEnd==TK_UNBOUNDED&&pMWin->pOrderBy)
){
windowCodeRowExprStep(pParse, p, pWInfo, regGosub, addrGosub);
return;
}
#if 0
if( pMWin->eType==TK_RANGE
&& pMWin->eStart==TK_UNBOUNDED
&& pMWin->eEnd==TK_CURRENT
&& pMWin->pOrderBy
){
windowCodeCacheStep(pParse, p, pWInfo, regGosub, addrGosub);
return;
}
#endif
*pbLoop = 1;
windowCodeDefaultStep(pParse, p, pWInfo, regGosub, addrGosub);
}