Postgres95 1.01 Distribution - Virgin SourcesPG95-1_01

1 files changed, 43 insertions, 0 deletions

diff --git a/src/backend/access/tupmacs.h b/src/backend/access/tupmacs.h
new file mode 100644
index 00000000000..9a9bcce3b41
--- /dev/null
+++ b/src/backend/access/tupmacs.h
@@ -0,0 +1,43 @@
+/*-------------------------------------------------------------------------
+ *
+ * tupmacs.h--
+ *    Tuple macros used by both index tuples and heap tuples.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: tupmacs.h,v 1.1.1.1 1996/07/09 06:21:09 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef TUPMACS_H
+#define TUPMACS_H
+
+/*
+ * check to see if the ATT'th bit of an array of 8-bit bytes is set.
+ */
+#define att_isnull(ATT, BITS) (!((BITS)[(ATT) >> 3] & (1 << ((ATT) & 0x07))))
+
+/*
+ * given a AttributeTupleForm and a pointer into a tuple's data
+ * area, return the correct value or pointer.
+ *
+ * note that T must already be properly LONGALIGN/SHORTALIGN'd for
+ * this to work correctly.
+ *
+ * the double-cast is to stop gcc from (correctly) complaining about 
+ * casting integer types with size < sizeof(char *) to (char *).
+ * sign-extension may get weird if you use an integer type that
+ * isn't the same size as (char *) for the first cast.  (on the other
+ * hand, it's safe to use another type for the (foo *)(T).)
+ */
+#define fetchatt(A, T) \
+ ((*(A))->attbyval \
+  ? ((*(A))->attlen > sizeof(int16) \
+     ? (char *) (long) *((int32 *)(T)) \
+     : ((*(A))->attlen < sizeof(int16) \
+        ? (char *) (long) *((char *)(T)) \
+        : (char *) (long) *((int16 *)(T)))) \
+  : (char *) (T))
+	
+#endif