Add palloc0 function to inline MemSet for newNode call.

Author: bmomjian

src/backend/nodes/nodes.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/nodes.c,v 1.17 2002/10/11 04:16:44 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/nodes.c,v 1.18 2002/11/10 02:17:25 momjian Exp $
  *
  * HISTORY
  *	  Andrew Yu			Oct 20, 1994	file creation
@@ -28,15 +28,5 @@
  *	  macro makeNode. eg. to create a Resdom node, use makeNode(Resdom)
  *
  */
-Node *
-newNode(Size size, NodeTag tag)
-{
-	Node	   *newNode;
+Node *newNodeMacroHolder;
 
-	Assert(size >= sizeof(Node));		/* need the tag, at least */
-
-	newNode = (Node *) palloc(size);
-	MemSet((char *) newNode, 0, size);
-	newNode->type = tag;
-	return newNode;
-}

src/backend/utils/mmgr/mcxt.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/mmgr/mcxt.c,v 1.34 2002/10/11 04:16:44 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/mmgr/mcxt.c,v 1.35 2002/11/10 02:17:25 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -452,6 +452,29 @@ MemoryContextAlloc(MemoryContext context, Size size)
 	return (*context->methods->alloc) (context, size);
 }
 
+/*
+ * MemoryContextAllocZero
+ *		Like MemoryContextAlloc, but clears allocated memory
+ *
+ *	We could just call MemoryContextAlloc then clear the memory, but this
+ *	function is called too many times, so we have a separate version.
+ */
+void *
+MemoryContextAllocZero(MemoryContext context, Size size)
+{
+	void *ret;
+
+	AssertArg(MemoryContextIsValid(context));
+
+	if (!AllocSizeIsValid(size))
+		elog(ERROR, "MemoryContextAllocZero: invalid request size %lu",
+			 (unsigned long) size);
+
+	ret = (*context->methods->alloc) (context, size);
+	MemSet(ret, 0, size);
+	return ret;
+}
+
 /*
  * pfree
  *		Release an allocated chunk.

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.121 2002/11/06 00:00:44 tgl Exp $
+ * $Id: nodes.h,v 1.122 2002/11/10 02:17:25 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -262,6 +262,24 @@ typedef struct Node
 
 #define nodeTag(nodeptr)		(((Node*)(nodeptr))->type)
 
+/*
+ *	There is no way to dereference the palloc'ed pointer to assign the
+ *	tag, and return the pointer itself, so we need a holder variable.
+ *	Fortunately, this function isn't recursive so we just define
+ *	a global variable for this purpose.
+ */
+extern Node *newNodeMacroHolder;
+
+#define newNode(size, tag) \
+( \
+	AssertMacro((size) >= sizeof(Node)),		/* need the tag, at least */ \
+\
+	newNodeMacroHolder = (Node *) palloc0(size), \
+	newNodeMacroHolder->type = (tag), \
+	newNodeMacroHolder \
+)
+
+
 #define makeNode(_type_)		((_type_ *) newNode(sizeof(_type_),T_##_type_))
 #define NodeSetTag(nodeptr,t)	(((Node*)(nodeptr))->type = (t))
 
@@ -283,11 +301,6 @@ typedef struct Node
  * ----------------------------------------------------------------
  */
 
-/*
- * nodes/nodes.c
- */
-extern Node *newNode(Size size, NodeTag tag);
-
 /*
  * nodes/{outfuncs.c,print.c}
  */

src/include/utils/palloc.h

@@ -21,7 +21,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: palloc.h,v 1.21 2002/10/11 04:16:44 momjian Exp $
+ * $Id: palloc.h,v 1.22 2002/11/10 02:17:25 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,9 +46,12 @@ extern DLLIMPORT MemoryContext CurrentMemoryContext;
  * Fundamental memory-allocation operations (more are in utils/memutils.h)
  */
 extern void *MemoryContextAlloc(MemoryContext context, Size size);
+extern void *MemoryContextAllocZero(MemoryContext context, Size size);
 
 #define palloc(sz)	MemoryContextAlloc(CurrentMemoryContext, (sz))
 
+#define palloc0(sz)	MemoryContextAllocZero(CurrentMemoryContext, (sz))
+
 extern void pfree(void *pointer);
 
 extern void *repalloc(void *pointer, Size size);