diff options
Diffstat (limited to 'src/backend/access/transam/transam.c')
| -rw-r--r-- | src/backend/access/transam/transam.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c index 3466b50ef24..e53b05e04d5 100644 --- a/src/backend/access/transam/transam.c +++ b/src/backend/access/transam/transam.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/transam/transam.c,v 1.70 2007/08/01 22:45:07 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/transam/transam.c,v 1.71 2007/09/08 20:31:14 tgl Exp $ * * NOTES * This file contains the high level access-method interface to the @@ -432,6 +432,33 @@ TransactionIdFollowsOrEquals(TransactionId id1, TransactionId id2) return (diff >= 0); } + +/* + * TransactionIdLatest --- get latest XID among a main xact and its children + */ +TransactionId +TransactionIdLatest(TransactionId mainxid, + int nxids, const TransactionId *xids) +{ + TransactionId result; + + /* + * In practice it is highly likely that the xids[] array is sorted, and + * so we could save some cycles by just taking the last child XID, but + * this probably isn't so performance-critical that it's worth depending + * on that assumption. But just to show we're not totally stupid, scan + * the array back-to-front to avoid useless assignments. + */ + result = mainxid; + while (--nxids >= 0) + { + if (TransactionIdPrecedes(result, xids[nxids])) + result = xids[nxids]; + } + return result; +} + + /* * TransactionIdGetCommitLSN * |