Add binary I/O routines for a bunch more datatypes. Still a few to go,

but that was enough tedium for one day.  Along the way, move the few
support routines for types xid and cid into a more logical place.

src/backend/utils/adt/xid.c

@@ -0,0 +1,169 @@
+/*-------------------------------------------------------------------------
+ *
+ * xid.c
+ *	  POSTGRES transaction identifier and command identifier datatypes.
+ *
+ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/xid.c,v 1.1 2003/05/12 23:08:50 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <limits.h>
+
+#include "access/xact.h"
+#include "libpq/pqformat.h"
+#include "utils/builtins.h"
+
+
+#define PG_GETARG_TRANSACTIONID(n)	DatumGetTransactionId(PG_GETARG_DATUM(n))
+#define PG_RETURN_TRANSACTIONID(x)	return TransactionIdGetDatum(x)
+
+#define PG_GETARG_COMMANDID(n)		DatumGetCommandId(PG_GETARG_DATUM(n))
+#define PG_RETURN_COMMANDID(x)		return CommandIdGetDatum(x)
+
+
+Datum
+xidin(PG_FUNCTION_ARGS)
+{
+	char	   *str = PG_GETARG_CSTRING(0);
+
+	PG_RETURN_TRANSACTIONID((TransactionId) strtoul(str, NULL, 0));
+}
+
+Datum
+xidout(PG_FUNCTION_ARGS)
+{
+	TransactionId transactionId = PG_GETARG_TRANSACTIONID(0);
+
+	/* maximum 32 bit unsigned integer representation takes 10 chars */
+	char	   *str = palloc(11);
+
+	snprintf(str, 11, "%lu", (unsigned long) transactionId);
+
+	PG_RETURN_CSTRING(str);
+}
+
+/*
+ *		xidrecv			- converts external binary format to xid
+ */
+Datum
+xidrecv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+
+	PG_RETURN_TRANSACTIONID((TransactionId) pq_getmsgint(buf, sizeof(TransactionId)));
+}
+
+/*
+ *		xidsend			- converts xid to binary format
+ */
+Datum
+xidsend(PG_FUNCTION_ARGS)
+{
+	TransactionId arg1 = PG_GETARG_TRANSACTIONID(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint(&buf, arg1, sizeof(arg1));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*
+ *		xideq			- are two xids equal?
+ */
+Datum
+xideq(PG_FUNCTION_ARGS)
+{
+	TransactionId xid1 = PG_GETARG_TRANSACTIONID(0);
+	TransactionId xid2 = PG_GETARG_TRANSACTIONID(1);
+
+	PG_RETURN_BOOL(TransactionIdEquals(xid1, xid2));
+}
+
+/*
+ *		xid_age			- compute age of an XID (relative to current xact)
+ */
+Datum
+xid_age(PG_FUNCTION_ARGS)
+{
+	TransactionId xid = PG_GETARG_TRANSACTIONID(0);
+	TransactionId now = GetCurrentTransactionId();
+
+	/* Permanent XIDs are always infinitely old */
+	if (!TransactionIdIsNormal(xid))
+		PG_RETURN_INT32(INT_MAX);
+
+	PG_RETURN_INT32((int32) (now - xid));
+}
+
+
+/*****************************************************************************
+ *	 COMMAND IDENTIFIER ROUTINES											 *
+ *****************************************************************************/
+
+/*
+ *		cidin	- converts CommandId to internal representation.
+ */
+Datum
+cidin(PG_FUNCTION_ARGS)
+{
+	char	   *s = PG_GETARG_CSTRING(0);
+	CommandId	c;
+
+	c = atoi(s);
+
+	PG_RETURN_COMMANDID(c);
+}
+
+/*
+ *		cidout	- converts a cid to external representation.
+ */
+Datum
+cidout(PG_FUNCTION_ARGS)
+{
+	CommandId	c = PG_GETARG_COMMANDID(0);
+	char	   *result = (char *) palloc(16);
+
+	snprintf(result, 16, "%u", (unsigned int) c);
+	PG_RETURN_CSTRING(result);
+}
+
+/*
+ *		cidrecv			- converts external binary format to cid
+ */
+Datum
+cidrecv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+
+	PG_RETURN_COMMANDID((CommandId) pq_getmsgint(buf, sizeof(CommandId)));
+}
+
+/*
+ *		cidsend			- converts cid to binary format
+ */
+Datum
+cidsend(PG_FUNCTION_ARGS)
+{
+	CommandId arg1 = PG_GETARG_COMMANDID(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint(&buf, arg1, sizeof(arg1));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+Datum
+cideq(PG_FUNCTION_ARGS)
+{
+	CommandId	arg1 = PG_GETARG_COMMANDID(0);
+	CommandId	arg2 = PG_GETARG_COMMANDID(1);
+
+	PG_RETURN_BOOL(arg1 == arg2);
+}