Clarify the relationship between a Window object and its associated Expr.
FossilOrigin-Name: 0cd55e98a478740032f5569ddc00fa5b0e063e90db6e00ac7598c9b7c2fffeee
diff --git a/src/expr.c b/src/expr.c
index 819a14b..9431c4c 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1271,7 +1271,7 @@
if( ExprHasProperty(p, EP_Reduced|EP_TokenOnly) ){
pNew->pWin = 0;
}else{
- pNew->pWin = sqlite3WindowDup(db, p->pWin);
+ pNew->pWin = sqlite3WindowDup(db, pNew, p->pWin);
}
if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
if( pNew->op==TK_SELECT_COLUMN ){
diff --git a/src/resolve.c b/src/resolve.c
index 0d94668..221564f 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -800,8 +800,6 @@
pExpr->pWin->pNextWin = pSel->pWin;
pSel->pWin = pExpr->pWin;
}
- pExpr->pWin->pFunc = pDef;
- pExpr->pWin->nArg = (pExpr->x.pList ? pExpr->x.pList->nExpr : 0);
}else{
NameContext *pNC2 = pNC;
pExpr->op = TK_AGG_FUNCTION;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 7d4c3ea..cd702ce 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3488,7 +3488,6 @@
Expr *pFilter;
FuncDef *pFunc;
- int nArg;
int iEphCsr; /* Temp table used by this window */
int regAccum;
@@ -3513,7 +3512,7 @@
int sqlite3WindowRewrite(Parse*, Select*);
int sqlite3ExpandSubquery(Parse*, struct SrcList_item*);
void sqlite3WindowUpdate(Parse*, Window*, Window*, FuncDef*);
-Window *sqlite3WindowDup(sqlite3 *db, Window *p);
+Window *sqlite3WindowDup(sqlite3 *db, Expr *pOwner, Window *p);
/*
** Assuming zIn points to the first byte of a UTF-8 character,
diff --git a/src/window.c b/src/window.c
index 9c63362..a627be1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -26,7 +26,7 @@
i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
if( p ) (*p)++;
}
-static void row_numberInverseFunc(
+static void row_numberInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -38,7 +38,8 @@
}
/*
-** Context object type used by rank() and dense_rank().
+** Context object type used by rank(), dense_rank(), percent_rank() and
+** cume_dist().
*/
struct CallCount {
i64 nValue;
@@ -58,7 +59,7 @@
p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
if( p ) p->nStep = 1;
}
-static void dense_rankInverseFunc(
+static void dense_rankInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -93,7 +94,7 @@
}
}
}
-static void rankInverseFunc(
+static void rankInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -130,7 +131,7 @@
}
}
}
-static void percent_rankInverseFunc(
+static void percent_rankInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -166,7 +167,7 @@
p->nStep++;
}
}
-static void cume_distInverseFunc(
+static void cume_distInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -181,6 +182,9 @@
}
}
+/*
+** Context object for ntile() window function.
+*/
struct NtileCtx {
i64 nTotal; /* Total rows in partition */
i64 nParam; /* Parameter passed to ntile(N) */
@@ -214,7 +218,7 @@
p->iRow++;
}
}
-static void ntileInverseFunc(
+static void ntileInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -243,6 +247,9 @@
}
}
+/*
+** Context object for last_value() window function.
+*/
struct LastValueCtx {
sqlite3_value *pVal;
int nVal;
@@ -264,7 +271,7 @@
p->nVal++;
}
}
-static void last_valueInverseFunc(
+static void last_valueInvFunc(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **apArg
@@ -296,76 +303,33 @@
}
}
-static void nth_valueStepFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void nth_valueInverseFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void nth_valueValueFunc(sqlite3_context *pCtx){
-}
-
-static void first_valueStepFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void first_valueInverseFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void first_valueValueFunc(sqlite3_context *pCtx){
-}
-
-static void leadStepFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void leadInverseFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void leadValueFunc(sqlite3_context *pCtx){
-}
-
-static void lagStepFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void lagInverseFunc(
- sqlite3_context *pCtx,
- int nArg,
- sqlite3_value **apArg
-){
-}
-static void lagValueFunc(sqlite3_context *pCtx){
-}
+/*
+** No-op implementations of nth_value(), first_value(), lead() and lag().
+** These are all implemented inline using VDBE instructions.
+*/
+static void nth_valueStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **a){}
+static void nth_valueInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
+static void nth_valueValueFunc(sqlite3_context *pCtx){}
+static void first_valueStepFunc(sqlite3_context *p, int n, sqlite3_value **ap){}
+static void first_valueInvFunc(sqlite3_context *p, int n, sqlite3_value **ap){}
+static void first_valueValueFunc(sqlite3_context *pCtx){}
+static void leadStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
+static void leadInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
+static void leadValueFunc(sqlite3_context *pCtx){}
+static void lagStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
+static void lagInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
+static void lagValueFunc(sqlite3_context *pCtx){}
#define WINDOWFUNC(name,nArg,extra) { \
nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0, \
name ## StepFunc, name ## ValueFunc, name ## ValueFunc, \
- name ## InverseFunc, #name \
+ name ## InvFunc, #name \
}
#define WINDOWFUNCF(name,nArg,extra) { \
nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0, \
name ## StepFunc, name ## FinalizeFunc, name ## ValueFunc, \
- name ## InverseFunc, #name \
+ name ## InvFunc, #name \
}
/*
@@ -437,6 +401,7 @@
pWin->eEnd = TK_CURRENT;
}
}
+ pWin->pFunc = pFunc;
}
typedef struct WindowRewrite WindowRewrite;
@@ -462,7 +427,7 @@
Window *pWin;
for(pWin=p->pWin; pWin; pWin=pWin->pNextWin){
if( pExpr->pWin==pWin ){
- pExpr->pWin->pOwner = pExpr;
+ assert( pWin->pOwner==pExpr );
return WRC_Prune;
}
}
@@ -684,6 +649,7 @@
void sqlite3WindowAttach(Parse *pParse, Expr *p, Window *pWin){
if( p ){
p->pWin = pWin;
+ if( pWin ) pWin->pOwner = p;
}else{
sqlite3WindowDelete(pParse->db, pWin);
}
@@ -766,6 +732,11 @@
sqlite3VdbeAppendP4(v, (void*)azErr[bEnd], P4_STATIC);
}
+static int windowArgCount(Window *pWin){
+ ExprList *pList = pWin->pOwner->x.pList;
+ return (pList ? pList->nExpr : 0);
+}
+
/*
** Generate VM code to invoke either xStep() (if bInverse is 0) or
** xInverse (if bInverse is non-zero) for each window function in the
@@ -784,11 +755,11 @@
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
int flags = pWin->pFunc->funcFlags;
int regArg;
- int nArg = pWin->nArg;
+ int nArg = windowArgCount(pWin);
if( csr>=0 ){
int i;
- for(i=0; i<pWin->nArg; i++){
+ for(i=0; i<nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+i, reg+i);
}
regArg = reg;
@@ -832,11 +803,12 @@
int addrIf = 0;
if( pWin->pFilter ){
int regTmp;
+ assert( nArg==pWin->pOwner->x.pList->nExpr );
if( csr>0 ){
regTmp = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+pWin->nArg,regTmp);
+ sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+nArg,regTmp);
}else{
- regTmp = regArg + pWin->nArg;
+ regTmp = regArg + nArg;
}
addrIf = sqlite3VdbeAddOp3(v, OP_IfNot, regTmp, 0, 1);
if( csr>0 ){
@@ -876,7 +848,7 @@
if( bFinal==0 ){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
}
- sqlite3VdbeAddOp2(v, OP_AggFinal, pWin->regAccum, pWin->nArg);
+ sqlite3VdbeAddOp2(v, OP_AggFinal, pWin->regAccum, windowArgCount(pWin));
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
if( bFinal ){
sqlite3VdbeAddOp2(v, OP_Copy, pWin->regAccum, pWin->regResult);
@@ -975,18 +947,19 @@
sqlite3ReleaseTempReg(pParse, tmpReg);
}
else if( pFunc->xSFunc==leadStepFunc || pFunc->xSFunc==lagStepFunc ){
+ int nArg = pWin->pOwner->x.pList->nExpr;
int iEph = pWin->iEphCsr;
int csr = pWin->csrApp;
int lbl = sqlite3VdbeMakeLabel(v);
int tmpReg = sqlite3GetTempReg(pParse);
- if( pWin->nArg<3 ){
+ if( nArg<3 ){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
}else{
sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+2, pWin->regResult);
}
sqlite3VdbeAddOp2(v, OP_Rowid, iEph, tmpReg);
- if( pWin->nArg<2 ){
+ if( nArg<2 ){
int val = (pFunc->xSFunc==leadStepFunc ? 1 : -1);
sqlite3VdbeAddOp2(v, OP_AddImm, tmpReg, val);
}else{
@@ -1036,7 +1009,7 @@
Window *pWin;
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
- nArg = MAX(nArg, pWin->nArg);
+ nArg = MAX(nArg, windowArgCount(pWin));
if( pWin->pFunc->xSFunc==nth_valueStepFunc
|| pWin->pFunc->xSFunc==first_valueStepFunc
){
@@ -1663,7 +1636,7 @@
sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)-1);
}
-Window *sqlite3WindowDup(sqlite3 *db, Window *p){
+Window *sqlite3WindowDup(sqlite3 *db, Expr *pOwner, Window *p){
Window *pNew = 0;
if( p ){
pNew = sqlite3DbMallocZero(db, sizeof(Window));
@@ -1676,77 +1649,30 @@
pNew->eStart = p->eStart;
pNew->pStart = sqlite3ExprDup(db, pNew->pStart, 0);
pNew->pEnd = sqlite3ExprDup(db, pNew->pEnd, 0);
+ pNew->pOwner = pOwner;
}
}
return pNew;
}
/*
-** 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()
-**
+** sqlite3WhereBegin() has already been called for the SELECT statement
+** passed as the second argument when this function is invoked. It generates
+** code to populate the Window.regResult register for each window function and
+** invoke the sub-routine at instruction addrGosub once for each row.
+** This function calls sqlite3WhereEnd() before returning.
*/
void sqlite3WindowCodeStep(
- Parse *pParse,
- Select *p,
- WhereInfo *pWInfo,
- int regGosub,
- int addrGosub
+ Parse *pParse, /* Parse context */
+ Select *p, /* Rewritten SELECT statement */
+ WhereInfo *pWInfo, /* Context returned by sqlite3WhereBegin() */
+ int regGosub, /* Register for OP_Gosub */
+ int addrGosub /* OP_Gosub here to return each row */
){
Window *pMWin = p->pWin;
Window *pWin;
- /*
- ** Call windowCodeRowExprStep() for all window modes *except*:
+ /* Call windowCodeRowExprStep() for all window modes *except*:
**
** RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
** RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
@@ -1761,11 +1687,9 @@
return;
}
- /*
- ** Call windowCodeCacheStep() if there is a window function that requires
+ /* Call windowCodeCacheStep() if there is a window function that requires
** that the entire partition be cached in a temp table before any rows
- ** are returned.
- */
+ ** are returned. */
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
FuncDef *pFunc = pWin->pFunc;
if( (pFunc->funcFlags & SQLITE_FUNC_WINDOW_SIZE)
@@ -1779,6 +1703,7 @@
}
}
+ /* Otherwise, call windowCodeDefaultStep(). */
windowCodeDefaultStep(pParse, p, pWInfo, regGosub, addrGosub);
}