1 files changed, 101 insertions, 0 deletions
diff --git a/src/backend/nodes/memnodes.h b/src/backend/nodes/memnodes.h
new file mode 100644
index 00000000000..35adee0d9c3
--- /dev/null
+++ b/src/backend/nodes/memnodes.h
@@ -0,0 +1,101 @@
+/*-------------------------------------------------------------------------
+ *
+ * memnodes.h--
+ *    POSTGRES memory context node definitions.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: memnodes.h,v 1.1.1.1 1996/07/09 06:21:32 scrappy Exp $
+ *
+ * XXX the typedefs in this file are different from the other ???nodes.h;
+ *    they are pointers to structures instead of the structures themselves.
+ *    If you're wondering, this is plain laziness. I don't want to touch
+ *    the memory context code which should be revamped altogether some day.
+ *							- ay 10/94
+ *-------------------------------------------------------------------------
+ */
+#ifndef	MEMNODES_H
+#define MEMNODES_H
+
+#include "c.h"
+
+#include "utils/memutils.h"
+#include "lib/fstack.h"
+
+#include "nodes/nodes.h"
+
+/*
+ * MemoryContext --
+ *	A logical context in which memory allocations occur.
+ *
+ * The types of memory contexts can be thought of as members of the
+ * following inheritance hierarchy with properties summarized below.
+ *
+ *			Node
+ *			|
+ *		MemoryContext___
+ *		/		\
+ *	GlobalMemory	PortalMemoryContext
+ *			/		\
+ *	PortalVariableMemory	PortalHeapMemory
+ *
+ *			Flushed at	Flushed at	Checkpoints
+ *			Transaction	Portal
+ *			Commit		Close
+ *
+ * GlobalMemory			n		n		n
+ * PortalVariableMemory		n		y		n
+ * PortalHeapMemory		y		y		y
+ */
+
+typedef struct MemoryContextMethodsData {
+    Pointer	(*alloc)();
+    void	(*free_p)(); /* need to use free as a #define,
+				so can't use free */
+    Pointer	(*realloc)();
+    char*	(*getName)();
+    void	(*dump)();
+} *MemoryContextMethods;
+
+typedef struct MemoryContext {
+    NodeTag			type;
+    MemoryContextMethods	method;
+} *MemoryContext;
+
+/* think about doing this right some time but we'll have explicit fields
+   for now -ay 10/94 */
+typedef struct GlobalMemory {
+    NodeTag			type;
+    MemoryContextMethods	method;
+    AllocSetData	setData;
+    char		*name;
+    OrderedElemData	elemData;
+} *GlobalMemory;
+
+typedef MemoryContext *PortalMemoryContext;
+
+typedef struct PortalVariableMemory {
+    NodeTag			type;
+    MemoryContextMethods	method;
+    AllocSetData	setData;
+} *PortalVariableMemory;
+
+typedef struct PortalHeapMemory {
+    NodeTag			type;
+    MemoryContextMethods	method;
+    Pointer		block;
+    FixedStackData	stackData;
+} *PortalHeapMemory;
+
+/*
+ * MemoryContextIsValid --
+ *	True iff memory context is valid.
+ */
+#define MemoryContextIsValid(context) \
+    (IsA(context,MemoryContext) || IsA(context,GlobalMemory) || \
+     IsA(context,PortalVariableMemory) || IsA(context,PortalHeapMemory))
+
+#endif	/* MEMNODES_H */
+
+