Adding upstream version 16.2.upstream/16.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 207 insertions, 0 deletions

diff --git a/src/include/access/tupmacs.h b/src/include/access/tupmacs.h
new file mode 100644
index 0000000..3414446
--- /dev/null
+++ b/src/include/access/tupmacs.h
@@ -0,0 +1,207 @@
+/*-------------------------------------------------------------------------
+ *
+ * tupmacs.h
+ *	  Tuple macros used by both index tuples and heap tuples.
+ *
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/tupmacs.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef TUPMACS_H
+#define TUPMACS_H
+
+#include "catalog/pg_type_d.h"	/* for TYPALIGN macros */
+
+
+/*
+ * Check a tuple's null bitmap to determine whether the attribute is null.
+ * Note that a 0 in the null bitmap indicates a null, while 1 indicates
+ * non-null.
+ */
+static inline bool
+att_isnull(int ATT, const bits8 *BITS)
+{
+	return !(BITS[ATT >> 3] & (1 << (ATT & 0x07)));
+}
+
+#ifndef FRONTEND
+/*
+ * Given a Form_pg_attribute and a pointer into a tuple's data area,
+ * return the correct value or pointer.
+ *
+ * We return a Datum value in all cases.  If the attribute has "byval" false,
+ * we return the same pointer into the tuple data area that we're passed.
+ * Otherwise, we return the correct number of bytes fetched from the data
+ * area and extended to Datum form.
+ *
+ * On machines where Datum is 8 bytes, we support fetching 8-byte byval
+ * attributes; otherwise, only 1, 2, and 4-byte values are supported.
+ *
+ * Note that T must already be properly aligned for this to work correctly.
+ */
+#define fetchatt(A,T) fetch_att(T, (A)->attbyval, (A)->attlen)
+
+/*
+ * Same, but work from byval/len parameters rather than Form_pg_attribute.
+ */
+static inline Datum
+fetch_att(const void *T, bool attbyval, int attlen)
+{
+	if (attbyval)
+	{
+		switch (attlen)
+		{
+			case sizeof(char):
+				return CharGetDatum(*((const char *) T));
+			case sizeof(int16):
+				return Int16GetDatum(*((const int16 *) T));
+			case sizeof(int32):
+				return Int32GetDatum(*((const int32 *) T));
+#if SIZEOF_DATUM == 8
+			case sizeof(Datum):
+				return *((const Datum *) T);
+#endif
+			default:
+				elog(ERROR, "unsupported byval length: %d", attlen);
+				return 0;
+		}
+	}
+	else
+		return PointerGetDatum(T);
+}
+#endif							/* FRONTEND */
+
+/*
+ * att_align_datum aligns the given offset as needed for a datum of alignment
+ * requirement attalign and typlen attlen.  attdatum is the Datum variable
+ * we intend to pack into a tuple (it's only accessed if we are dealing with
+ * a varlena type).  Note that this assumes the Datum will be stored as-is;
+ * callers that are intending to convert non-short varlena datums to short
+ * format have to account for that themselves.
+ */
+#define att_align_datum(cur_offset, attalign, attlen, attdatum) \
+( \
+	((attlen) == -1 && VARATT_IS_SHORT(DatumGetPointer(attdatum))) ? \
+	(uintptr_t) (cur_offset) : \
+	att_align_nominal(cur_offset, attalign) \
+)
+
+/*
+ * att_align_pointer performs the same calculation as att_align_datum,
+ * but is used when walking a tuple.  attptr is the current actual data
+ * pointer; when accessing a varlena field we have to "peek" to see if we
+ * are looking at a pad byte or the first byte of a 1-byte-header datum.
+ * (A zero byte must be either a pad byte, or the first byte of a correctly
+ * aligned 4-byte length word; in either case we can align safely.  A non-zero
+ * byte must be either a 1-byte length word, or the first byte of a correctly
+ * aligned 4-byte length word; in either case we need not align.)
+ *
+ * Note: some callers pass a "char *" pointer for cur_offset.  This is
+ * a bit of a hack but should work all right as long as uintptr_t is the
+ * correct width.
+ */
+#define att_align_pointer(cur_offset, attalign, attlen, attptr) \
+( \
+	((attlen) == -1 && VARATT_NOT_PAD_BYTE(attptr)) ? \
+	(uintptr_t) (cur_offset) : \
+	att_align_nominal(cur_offset, attalign) \
+)
+
+/*
+ * att_align_nominal aligns the given offset as needed for a datum of alignment
+ * requirement attalign, ignoring any consideration of packed varlena datums.
+ * There are three main use cases for using this macro directly:
+ *	* we know that the att in question is not varlena (attlen != -1);
+ *	  in this case it is cheaper than the above macros and just as good.
+ *	* we need to estimate alignment padding cost abstractly, ie without
+ *	  reference to a real tuple.  We must assume the worst case that
+ *	  all varlenas are aligned.
+ *	* within arrays and multiranges, we unconditionally align varlenas (XXX this
+ *	  should be revisited, probably).
+ *
+ * The attalign cases are tested in what is hopefully something like their
+ * frequency of occurrence.
+ */
+#define att_align_nominal(cur_offset, attalign) \
+( \
+	((attalign) == TYPALIGN_INT) ? INTALIGN(cur_offset) : \
+	 (((attalign) == TYPALIGN_CHAR) ? (uintptr_t) (cur_offset) : \
+	  (((attalign) == TYPALIGN_DOUBLE) ? DOUBLEALIGN(cur_offset) : \
+	   ( \
+			AssertMacro((attalign) == TYPALIGN_SHORT), \
+			SHORTALIGN(cur_offset) \
+	   ))) \
+)
+
+/*
+ * att_addlength_datum increments the given offset by the space needed for
+ * the given Datum variable.  attdatum is only accessed if we are dealing
+ * with a variable-length attribute.
+ */
+#define att_addlength_datum(cur_offset, attlen, attdatum) \
+	att_addlength_pointer(cur_offset, attlen, DatumGetPointer(attdatum))
+
+/*
+ * att_addlength_pointer performs the same calculation as att_addlength_datum,
+ * but is used when walking a tuple --- attptr is the pointer to the field
+ * within the tuple.
+ *
+ * Note: some callers pass a "char *" pointer for cur_offset.  This is
+ * actually perfectly OK, but probably should be cleaned up along with
+ * the same practice for att_align_pointer.
+ */
+#define att_addlength_pointer(cur_offset, attlen, attptr) \
+( \
+	((attlen) > 0) ? \
+	( \
+		(cur_offset) + (attlen) \
+	) \
+	: (((attlen) == -1) ? \
+	( \
+		(cur_offset) + VARSIZE_ANY(attptr) \
+	) \
+	: \
+	( \
+		AssertMacro((attlen) == -2), \
+		(cur_offset) + (strlen((char *) (attptr)) + 1) \
+	)) \
+)
+
+#ifndef FRONTEND
+/*
+ * store_att_byval is a partial inverse of fetch_att: store a given Datum
+ * value into a tuple data area at the specified address.  However, it only
+ * handles the byval case, because in typical usage the caller needs to
+ * distinguish by-val and by-ref cases anyway, and so a do-it-all function
+ * wouldn't be convenient.
+ */
+static inline void
+store_att_byval(void *T, Datum newdatum, int attlen)
+{
+	switch (attlen)
+	{
+		case sizeof(char):
+			*(char *) T = DatumGetChar(newdatum);
+			break;
+		case sizeof(int16):
+			*(int16 *) T = DatumGetInt16(newdatum);
+			break;
+		case sizeof(int32):
+			*(int32 *) T = DatumGetInt32(newdatum);
+			break;
+#if SIZEOF_DATUM == 8
+		case sizeof(Datum):
+			*(Datum *) T = newdatum;
+			break;
+#endif
+		default:
+			elog(ERROR, "unsupported byval length: %d", attlen);
+	}
+}
+#endif							/* FRONTEND */
+
+#endif							/* TUPMACS_H */