diff options
Diffstat (limited to 'src/backend/access/transam/xid.c')
| -rw-r--r-- | src/backend/access/transam/xid.c | 47 |
1 files changed, 26 insertions, 21 deletions
diff --git a/src/backend/access/transam/xid.c b/src/backend/access/transam/xid.c index 689fc33ceaf..babe7c9a48b 100644 --- a/src/backend/access/transam/xid.c +++ b/src/backend/access/transam/xid.c @@ -6,23 +6,18 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: xid.c,v 1.32 2001/08/23 23:06:37 tgl Exp $ - * - * OLD COMMENTS - * XXX WARNING - * Much of this file will change when we change our representation - * of transaction ids -cim 3/23/90 - * - * It is time to make the switch from 5 byte to 4 byte transaction ids - * This file was totally reworked. -mer 5/22/92 + * $Id: xid.c,v 1.33 2001/08/26 16:55:59 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" +#include <limits.h> + #include "access/xact.h" + #define PG_GETARG_TRANSACTIONID(n) DatumGetTransactionId(PG_GETARG_DATUM(n)) #define PG_RETURN_TRANSACTIONID(x) return TransactionIdGetDatum(x) @@ -30,9 +25,9 @@ Datum xidin(PG_FUNCTION_ARGS) { - char *representation = PG_GETARG_CSTRING(0); + char *str = PG_GETARG_CSTRING(0); - PG_RETURN_TRANSACTIONID((TransactionId) atol(representation)); + PG_RETURN_TRANSACTIONID((TransactionId) strtoul(str, NULL, 0)); } Datum @@ -40,21 +35,15 @@ xidout(PG_FUNCTION_ARGS) { TransactionId transactionId = PG_GETARG_TRANSACTIONID(0); /* maximum 32 bit unsigned integer representation takes 10 chars */ - char *representation = palloc(11); + char *str = palloc(11); - snprintf(representation, 11, "%lu", (unsigned long) transactionId); + snprintf(str, 11, "%lu", (unsigned long) transactionId); - PG_RETURN_CSTRING(representation); + PG_RETURN_CSTRING(str); } -/* ---------------------------------------------------------------- - * xideq - * ---------------------------------------------------------------- - */ - /* - * xideq - returns 1, iff xid1 == xid2 - * 0 else; + * xideq - are two xids equal? */ Datum xideq(PG_FUNCTION_ARGS) @@ -64,3 +53,19 @@ xideq(PG_FUNCTION_ARGS) 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)); +} |