Phase 3 of read-only-plans project: ExecInitExpr now builds expression

execution state trees, and ExecEvalExpr takes an expression state tree
not an expression plan tree.  The plan tree is now read-only as far as
the executor is concerned.  Next step is to begin actually exploiting
this property.

src/backend/utils/adt/sets.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.54 2002/09/04 20:31:29 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.55 2002/12/13 19:45:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,7 +24,6 @@
 #include "catalog/pg_namespace.h"
 #include "catalog/pg_proc.h"
 #include "executor/executor.h"
-#include "utils/fcache.h"
 #include "utils/fmgroids.h"
 #include "utils/sets.h"
 #include "utils/syscache.h"
@@ -143,7 +142,7 @@ Datum
 seteval(PG_FUNCTION_ARGS)
 {
 	Oid			funcoid = PG_GETARG_OID(0);
-	FunctionCachePtr fcache;
+	FuncExprState *fcache;
 	Datum		result;
 	bool		isNull;
 	ExprDoneCond isDone;
@@ -152,10 +151,27 @@ seteval(PG_FUNCTION_ARGS)
 	 * If this is the first call, we need to set up the fcache for the
 	 * target set's function.
 	 */
-	fcache = (FunctionCachePtr) fcinfo->flinfo->fn_extra;
+	fcache = (FuncExprState *) fcinfo->flinfo->fn_extra;
 	if (fcache == NULL)
 	{
-		fcache = init_fcache(funcoid, 0, fcinfo->flinfo->fn_mcxt);
+		MemoryContext	oldcontext;
+		FuncExpr   *func;
+
+		oldcontext = MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
+
+		func = makeNode(FuncExpr);
+		func->funcid = funcoid;
+		func->funcresulttype = InvalidOid; /* nothing will look at this */
+		func->funcretset = true;
+		func->funcformat = COERCE_EXPLICIT_CALL;
+		func->args = NIL;		/* there are no arguments */
+
+		fcache = (FuncExprState *) ExecInitExpr((Expr *) func, NULL);
+
+		MemoryContextSwitchTo(oldcontext);
+
+		init_fcache(funcoid, fcache, fcinfo->flinfo->fn_mcxt);
+
 		fcinfo->flinfo->fn_extra = (void *) fcache;
 	}
 
@@ -169,22 +185,10 @@ seteval(PG_FUNCTION_ARGS)
 	isDone = ExprSingleResult;
 
 	result = ExecMakeFunctionResult(fcache,
-									NIL,
 									NULL,		/* no econtext, see above */
 									&isNull,
 									&isDone);
 
-	/*
-	 * If we're done with the results of this set function, get rid of its
-	 * func cache so that we will start from the top next time. (Can you
-	 * say "memory leak"?  This feature is a crock anyway...)
-	 */
-	if (isDone != ExprMultipleResult)
-	{
-		pfree(fcache);
-		fcinfo->flinfo->fn_extra = NULL;
-	}
-
 	/*
 	 * Return isNull/isDone status.
 	 */

src/backend/utils/cache/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for utils/cache
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/utils/cache/Makefile,v 1.16 2002/03/31 06:26:31 tgl Exp $
+#    $Header: /cvsroot/pgsql/src/backend/utils/cache/Makefile,v 1.17 2002/12/13 19:45:56 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -12,8 +12,7 @@ subdir = src/backend/utils/cache
 top_builddir = ../../../..
 include $(top_builddir)/src/Makefile.global
 
-OBJS = catcache.o inval.o relcache.o syscache.o lsyscache.o \
-	fcache.o
+OBJS = catcache.o inval.o relcache.o syscache.o lsyscache.o
 
 all: SUBSYS.o
 

src/backend/utils/cache/fcache.c

@@ -1,53 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * fcache.c
- *	  Code for the 'function cache' used in Oper and Func nodes.
- *
- *
- * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/Attic/fcache.c,v 1.45 2002/06/20 20:29:39 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "miscadmin.h"
-#include "utils/acl.h"
-#include "utils/fcache.h"
-#include "utils/lsyscache.h"
-
-
-/*
- * Build a 'FunctionCache' struct given the PG_PROC oid.
- */
-FunctionCachePtr
-init_fcache(Oid foid, int nargs, MemoryContext fcacheCxt)
-{
-	FunctionCachePtr retval;
-	AclResult	aclresult;
-
-	/* Check permission to call function */
-	aclresult = pg_proc_aclcheck(foid, GetUserId(), ACL_EXECUTE);
-	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, get_func_name(foid));
-
-	/* Safety check (should never fail, as parser should check sooner) */
-	if (nargs > FUNC_MAX_ARGS)
-		elog(ERROR, "init_fcache: too many arguments");
-
-	/* Create fcache entry in the desired context */
-	retval = (FunctionCachePtr) MemoryContextAlloc(fcacheCxt,
-												   sizeof(FunctionCache));
-	MemSet(retval, 0, sizeof(FunctionCache));
-
-	/* Set up the primary fmgr lookup information */
-	fmgr_info_cxt(foid, &(retval->func), fcacheCxt);
-
-	/* Initialize additional info */
-	retval->setArgsValid = false;
-
-	return retval;
-}