Postgres95 1.01 Distribution - Virgin SourcesPG95-1_01

1 files changed, 61 insertions, 0 deletions

diff --git a/src/backend/access/attnum.h b/src/backend/access/attnum.h
new file mode 100644
index 00000000000..7c999e58e9d
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+++ b/src/backend/access/attnum.h
@@ -0,0 +1,61 @@
+/*-------------------------------------------------------------------------
+ *
+ * attnum.h--
+ *    POSTGRES attribute number definitions.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: attnum.h,v 1.1.1.1 1996/07/09 06:21:08 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef	ATTNUM_H
+#define ATTNUM_H
+
+#include "c.h"
+
+/*
+ * user defined attribute numbers start at 1.	-ay 2/95
+ */
+typedef int16		AttrNumber;
+
+#define InvalidAttrNumber	0
+
+/* ----------------
+ *	support macros
+ * ----------------
+ */
+/*
+ * AttributeNumberIsValid --
+ *	True iff the attribute number is valid.
+ */
+#define AttributeNumberIsValid(attributeNumber) \
+    ((bool) ((attributeNumber) != InvalidAttrNumber))
+
+/*
+ * AttrNumberIsForUserDefinedAttr --
+ *	True iff the attribute number corresponds to an user defined attribute.
+ */
+#define AttrNumberIsForUserDefinedAttr(attributeNumber) \
+    ((bool) ((attributeNumber) > 0))
+
+/*
+ * AttrNumberGetAttrOffset --
+ *	Returns the attribute offset for an attribute number.
+ *
+ * Note:
+ *	Assumes the attribute number is for an user defined attribute.
+ */
+#define AttrNumberGetAttrOffset(attNum) \
+     (AssertMacro(AttrNumberIsForUserDefinedAttr(attNum)) ? \
+      ((attNum - 1)) : 0)
+
+/*
+ * AttributeOffsetGetAttributeNumber --
+ *	Returns the attribute number for an attribute offset.
+ */
+#define AttrOffsetGetAttrNumber(attributeOffset) \
+     ((AttrNumber) (1 + attributeOffset))
+
+#endif /* ATTNUM_H */