Moved from backend/access to include/access

src/include/access/tupmacs.h

@@ -0,0 +1,55 @@
+/*-------------------------------------------------------------------------
+ *
+ * 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 1996/08/27 21:50:27 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.
+ *
+ * We return a 4 byte (char *) value in all cases.  If the attribute has
+ * "byval" false or has variable length, we return the same pointer
+ * into the tuple data area that we're passed.  Otherwise, we return
+ * the 1, 2, or 4 bytes pointed to by it, properly extended to 4
+ * bytes, depending on the length of the attribute.
+ *
+ * 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).)
+ *
+ * attbyval seems to be fairly redundant.  We have to return a pointer if
+ * the value is longer than 4 bytes or has variable length; returning the
+ * value would be useless.  In fact, for at least the variable length case,
+ * the caller assumes we return a pointer regardless of attbyval.
+ * I would eliminate attbyval altogether, but I don't know how.  -BRYANH.
+ */
+#define fetchatt(A, T) \
+ ((*(A))->attbyval && (*(A))->attlen != -1 \
+  ? ((*(A))->attlen > sizeof(int16) \
+     ? (char *) (long) *((int32 *)(T)) \
+     : ((*(A))->attlen < sizeof(int16) \
+        ? (char *) (long) *((char *)(T)) \
+        : (char *) (long) *((int16 *)(T)))) \
+  : (char *) (T))
+	
+#endif