1 files changed, 47 insertions, 0 deletions
diff --git a/src/backend/storage/buf.h b/src/backend/storage/buf.h
new file mode 100644
index 00000000000..73582e8a61c
--- /dev/null
+++ b/src/backend/storage/buf.h
@@ -0,0 +1,47 @@
+/*-------------------------------------------------------------------------
+ *
+ * buf.h--
+ *    Basic buffer manager data types.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: buf.h,v 1.1.1.1 1996/07/09 06:21:52 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef	BUF_H
+#define BUF_H
+
+#define InvalidBuffer	(0)
+#define UnknownBuffer	(-99999)
+
+typedef long	Buffer;
+
+/*
+ * BufferIsInvalid --
+ *	True iff the buffer is invalid.
+ */
+#define BufferIsInvalid(buffer)	((buffer) == InvalidBuffer)
+
+/*
+ * BufferIsUnknown --
+ *	True iff the buffer is unknown.
+ */
+#define BufferIsUnknown(buffer)	((buffer) == UnknownBuffer)
+
+/*
+ * BufferIsLocal --
+ *	True iff the buffer is local (not visible to other servers).
+ */
+#define BufferIsLocal(buffer)	((buffer) < 0)
+
+/*
+ * If NO_BUFFERISVALID is defined, all error checking using BufferIsValid()
+ * are suppressed.  Decision-making using BufferIsValid is not affected.
+ * This should be set only if one is sure there will be no errors.
+ * - plai 9/10/90
+ */
+#undef NO_BUFFERISVALID
+
+#endif	/* BUF_H */