From d0b4399d81f39decccb23fa38f772b71b51bf96a Mon Sep 17 00:00:00 2001 From: Neil Conway Date: Wed, 26 May 2004 04:41:50 +0000 Subject: Reimplement the linked list data structure used throughout the backend. In the past, we used a 'Lispy' linked list implementation: a "list" was merely a pointer to the head node of the list. The problem with that design is that it makes lappend() and length() linear time. This patch fixes that problem (and others) by maintaining a count of the list length and a pointer to the tail node along with each head node pointer. A "list" is now a pointer to a structure containing some meta-data about the list; the head and tail pointers in that structure refer to ListCell structures that maintain the actual linked list of nodes. The function names of the list API have also been changed to, I hope, be more logically consistent. By default, the old function names are still available; they will be disabled-by-default once the rest of the tree has been updated to use the new API names. --- src/backend/executor/nodeSubplan.c | 60 ++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 31 deletions(-) (limited to 'src/backend/executor/nodeSubplan.c') diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index 8c667b70e78..d7db23b2c3e 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.61 2004/03/17 01:02:23 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.62 2004/05/26 04:41:16 neilc Exp $ * *------------------------------------------------------------------------- */ @@ -212,8 +212,8 @@ ExecScanSubPlan(SubPlanState *node, TupleTableSlot *slot; Datum result; bool found = false; /* TRUE if got at least one subplan tuple */ - List *pvar; - List *lst; + ListCell *pvar; + ListCell *l; ArrayBuildState *astate = NULL; /* @@ -228,21 +228,19 @@ ExecScanSubPlan(SubPlanState *node, * calculation we have to do is done in the parent econtext, since the * Param values don't need to have per-query lifetime.) */ - pvar = node->args; - foreach(lst, subplan->parParam) + Assert(length(subplan->parParam) == length(node->args)); + + forboth(l, subplan->parParam, pvar, node->args) { - int paramid = lfirsti(lst); + int paramid = lfirst_int(l); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); - Assert(pvar != NIL); prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar), econtext, &(prm->isnull), NULL); - pvar = lnext(pvar); planstate->chgParam = bms_add_member(planstate->chgParam, paramid); } - Assert(pvar == NIL); ExecReScan(planstate, NULL); @@ -278,7 +276,7 @@ ExecScanSubPlan(SubPlanState *node, Datum rowresult = BoolGetDatum(!useOr); bool rownull = false; int col = 1; - List *plst; + ListCell *plst; if (subLinkType == EXISTS_SUBLINK) { @@ -343,11 +341,12 @@ ExecScanSubPlan(SubPlanState *node, * For ALL, ANY, and MULTIEXPR sublinks, iterate over combining * operators for columns of tuple. */ - plst = subplan->paramIds; - foreach(lst, node->exprs) + Assert(length(node->exprs) == length(subplan->paramIds)); + + forboth(l, node->exprs, plst, subplan->paramIds) { - ExprState *exprstate = (ExprState *) lfirst(lst); - int paramid = lfirsti(plst); + ExprState *exprstate = (ExprState *) lfirst(l); + int paramid = lfirst_int(plst); ParamExecData *prmdata; Datum expresult; bool expnull; @@ -400,7 +399,6 @@ ExecScanSubPlan(SubPlanState *node, } } - plst = lnext(plst); col++; } @@ -559,7 +557,7 @@ buildSubPlanHash(SubPlanState *node) HeapTuple tup = slot->val; TupleDesc tdesc = slot->ttc_tupleDescriptor; int col = 1; - List *plst; + ListCell *plst; bool isnew; /* @@ -737,7 +735,7 @@ ExecInitSubPlan(SubPlanState *node, EState *estate) */ if (subplan->setParam != NIL) { - List *lst; + ListCell *lst; foreach(lst, subplan->setParam) { @@ -762,8 +760,8 @@ ExecInitSubPlan(SubPlanState *node, EState *estate) List *lefttlist, *righttlist, *leftptlist, - *rightptlist, - *lexpr; + *rightptlist; + ListCell *lexpr; /* We need a memory context to hold the hash table(s) */ node->tablecxt = @@ -815,7 +813,7 @@ ExecInitSubPlan(SubPlanState *node, EState *estate) Assert(length(fstate->args) == 2); /* Process lefthand argument */ - exstate = (ExprState *) lfirst(fstate->args); + exstate = (ExprState *) linitial(fstate->args); expr = exstate->expr; tle = makeTargetEntry(makeResdom(i, exprType((Node *) expr), @@ -914,7 +912,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) SubLinkType subLinkType = subplan->subLinkType; MemoryContext oldcontext; TupleTableSlot *slot; - List *lst; + ListCell *l; bool found = false; ArrayBuildState *astate = NULL; @@ -941,7 +939,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) if (subLinkType == EXISTS_SUBLINK) { /* There can be only one param... */ - int paramid = lfirsti(subplan->setParam); + int paramid = linitial_int(subplan->setParam); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); prm->execPlan = NULL; @@ -992,9 +990,9 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) /* * Now set all the setParam params from the columns of the tuple */ - foreach(lst, subplan->setParam) + foreach(l, subplan->setParam) { - int paramid = lfirsti(lst); + int paramid = lfirsti(l); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); prm->execPlan = NULL; @@ -1008,7 +1006,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) if (subLinkType == EXISTS_SUBLINK) { /* There can be only one param... */ - int paramid = lfirsti(subplan->setParam); + int paramid = linitial_int(subplan->setParam); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); prm->execPlan = NULL; @@ -1017,9 +1015,9 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) } else { - foreach(lst, subplan->setParam) + foreach(l, subplan->setParam) { - int paramid = lfirsti(lst); + int paramid = lfirsti(l); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); prm->execPlan = NULL; @@ -1031,7 +1029,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) else if (subLinkType == ARRAY_SUBLINK) { /* There can be only one param... */ - int paramid = lfirsti(subplan->setParam); + int paramid = linitial_int(subplan->setParam); ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); Assert(astate != NULL); @@ -1074,7 +1072,7 @@ ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent) PlanState *planstate = node->planstate; SubPlan *subplan = (SubPlan *) node->xprstate.expr; EState *estate = parent->state; - List *lst; + ListCell *l; /* sanity checks */ if (subplan->parParam != NIL) @@ -1091,9 +1089,9 @@ ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent) /* * Mark this subplan's output parameters as needing recalculation */ - foreach(lst, subplan->setParam) + foreach(l, subplan->setParam) { - int paramid = lfirsti(lst); + int paramid = lfirsti(l); ParamExecData *prm = &(estate->es_param_exec_vals[paramid]); prm->execPlan = node; -- cgit v1.2.3