Add SQL type xid8 to expose FullTransactionId to users.

Similar to xid, but 64 bits wide.  This new type is suitable for use in
various system views and administration functions.

Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Takao Fujii <btfujiitkp@oss.nttdata.com>
Reviewed-by: Yoshikazu Imai <imai.yoshikazu@fujitsu.com>
Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/20190725000636.666m5mad25wfbrri%40alap3.anarazel.de

2 files changed, 119 insertions, 0 deletions

diff --git a/src/backend/access/hash/hashvalidate.c b/src/backend/access/hash/hashvalidate.c
index 7b08ed53543..b3d1367fecb 100644
--- a/src/backend/access/hash/hashvalidate.c
+++ b/src/backend/access/hash/hashvalidate.c
@@ -317,6 +317,9 @@ check_hash_func_signature(Oid funcid, int16 amprocnum, Oid argtype)
 			(argtype == DATEOID ||
 			 argtype == XIDOID || argtype == CIDOID))
 			 /* okay, allowed use of hashint4() */ ;
+		else if ((funcid == F_HASHINT8 || funcid == F_HASHINT8EXTENDED) &&
+			(argtype == XID8OID))
+			 /* okay, allowed use of hashint8() */ ;
 		else if ((funcid == F_TIMESTAMP_HASH ||
 				  funcid == F_TIMESTAMP_HASH_EXTENDED) &&
 				 argtype == TIMESTAMPTZOID)
diff --git a/src/backend/utils/adt/xid.c b/src/backend/utils/adt/xid.c
index db6fc9dd6b8..20389aff1d1 100644
--- a/src/backend/utils/adt/xid.c
+++ b/src/backend/utils/adt/xid.c
@@ -21,6 +21,7 @@
 #include "access/xact.h"
 #include "libpq/pqformat.h"
 #include "utils/builtins.h"
+#include "utils/xid8.h"
 
 #define PG_GETARG_TRANSACTIONID(n)	DatumGetTransactionId(PG_GETARG_DATUM(n))
 #define PG_RETURN_TRANSACTIONID(x)	return TransactionIdGetDatum(x)
@@ -147,6 +148,121 @@ xidComparator(const void *arg1, const void *arg2)
 	return 0;
 }
 
+Datum
+xid8toxid(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid = PG_GETARG_FULLTRANSACTIONID(0);
+
+	PG_RETURN_TRANSACTIONID(XidFromFullTransactionId(fxid));
+}
+
+Datum
+xid8in(PG_FUNCTION_ARGS)
+{
+	char	   *str = PG_GETARG_CSTRING(0);
+
+	PG_RETURN_FULLTRANSACTIONID(FullTransactionIdFromU64(pg_strtouint64(str, NULL, 0)));
+}
+
+Datum
+xid8out(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid = PG_GETARG_FULLTRANSACTIONID(0);
+	char	   *result = (char *) palloc(21);
+
+	snprintf(result, 21, UINT64_FORMAT, U64FromFullTransactionId(fxid));
+	PG_RETURN_CSTRING(result);
+}
+
+Datum
+xid8recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	uint64		value;
+
+	value = (uint64) pq_getmsgint64(buf);
+	PG_RETURN_FULLTRANSACTIONID(FullTransactionIdFromU64(value));
+}
+
+Datum
+xid8send(PG_FUNCTION_ARGS)
+{
+	FullTransactionId arg1 = PG_GETARG_FULLTRANSACTIONID(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint64(&buf, (uint64) U64FromFullTransactionId(arg1));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+Datum
+xid8eq(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(FullTransactionIdEquals(fxid1, fxid2));
+}
+
+Datum
+xid8ne(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(!FullTransactionIdEquals(fxid1, fxid2));
+}
+
+Datum
+xid8lt(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(FullTransactionIdPrecedes(fxid1, fxid2));
+}
+
+Datum
+xid8gt(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(FullTransactionIdFollows(fxid1, fxid2));
+}
+
+Datum
+xid8le(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(FullTransactionIdPrecedesOrEquals(fxid1, fxid2));
+}
+
+Datum
+xid8ge(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	PG_RETURN_BOOL(FullTransactionIdFollowsOrEquals(fxid1, fxid2));
+}
+
+Datum
+xid8cmp(PG_FUNCTION_ARGS)
+{
+	FullTransactionId fxid1 = PG_GETARG_FULLTRANSACTIONID(0);
+	FullTransactionId fxid2 = PG_GETARG_FULLTRANSACTIONID(1);
+
+	if (FullTransactionIdFollows(fxid1, fxid2))
+		PG_RETURN_INT32(1);
+	else if (FullTransactionIdEquals(fxid1, fxid2))
+		PG_RETURN_INT32(0);
+	else
+		PG_RETURN_INT32(-1);
+}
+
 /*****************************************************************************
  *	 COMMAND IDENTIFIER ROUTINES											 *
  *****************************************************************************/