diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 106 |
1 files changed, 80 insertions, 26 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 379d0ecc552..1e22c030462 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -8,13 +8,14 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.82 2000/07/22 11:18:46 wieck Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.83 2000/08/03 19:18:54 tgl Exp $ * * * INTERFACE ROUTINES * heapgettup - fetch next heap tuple from a scan * heap_open - open a heap relation by relationId * heap_openr - open a heap relation by name + * heap_open[r]_nofail - same, but return NULL on failure instead of elog * heap_close - close a heap relation * heap_beginscan - begin relation scan * heap_rescan - restart a relation scan @@ -560,19 +561,17 @@ fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, #endif /* defined(DISABLE_COMPLEX_MACRO)*/ - /* ---------------------------------------------------------------- * heap access method interface * ---------------------------------------------------------------- */ + /* ---------------- * heap_open - open a heap relation by relationId * - * If lockmode is "NoLock", no lock is obtained on the relation, - * and the caller must check for a NULL return value indicating - * that no such relation exists. - * Otherwise, an error is raised if the relation does not exist, - * and the specified kind of lock is obtained on the relation. + * If lockmode is not "NoLock", the specified kind of lock is + * obtained on the relation. + * An error is raised if the relation does not exist. * ---------------- */ Relation @@ -592,17 +591,15 @@ heap_open(Oid relationId, LOCKMODE lockmode) /* The relcache does all the real work... */ r = RelationIdGetRelation(relationId); - /* Under no circumstances will we return an index as a relation. */ - if (RelationIsValid(r) && r->rd_rel->relkind == RELKIND_INDEX) - elog(ERROR, "%s is an index relation", RelationGetRelationName(r)); - - if (lockmode == NoLock) - return r; /* caller must check RelationIsValid! */ - if (!RelationIsValid(r)) elog(ERROR, "Relation %u does not exist", relationId); - LockRelation(r, lockmode); + /* Under no circumstances will we return an index as a relation. */ + if (r->rd_rel->relkind == RELKIND_INDEX) + elog(ERROR, "%s is an index relation", RelationGetRelationName(r)); + + if (lockmode != NoLock) + LockRelation(r, lockmode); return r; } @@ -610,11 +607,9 @@ heap_open(Oid relationId, LOCKMODE lockmode) /* ---------------- * heap_openr - open a heap relation by name * - * If lockmode is "NoLock", no lock is obtained on the relation, - * and the caller must check for a NULL return value indicating - * that no such relation exists. - * Otherwise, an error is raised if the relation does not exist, - * and the specified kind of lock is obtained on the relation. + * If lockmode is not "NoLock", the specified kind of lock is + * obtained on the relation. + * An error is raised if the relation does not exist. * ---------------- */ Relation @@ -624,7 +619,6 @@ heap_openr(const char *relationName, LOCKMODE lockmode) Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES); - /* ---------------- * increment access statistics * ---------------- @@ -635,17 +629,77 @@ heap_openr(const char *relationName, LOCKMODE lockmode) /* The relcache does all the real work... */ r = RelationNameGetRelation(relationName); + if (!RelationIsValid(r)) + elog(ERROR, "Relation '%s' does not exist", relationName); + + /* Under no circumstances will we return an index as a relation. */ + if (r->rd_rel->relkind == RELKIND_INDEX) + elog(ERROR, "%s is an index relation", RelationGetRelationName(r)); + + if (lockmode != NoLock) + LockRelation(r, lockmode); + + return r; +} + +/* ---------------- + * heap_open_nofail - open a heap relation by relationId, + * do not raise error on failure + * + * The caller must check for a NULL return value indicating + * that no such relation exists. + * No lock is obtained on the relation, either. + * ---------------- + */ +Relation +heap_open_nofail(Oid relationId) +{ + Relation r; + + /* ---------------- + * increment access statistics + * ---------------- + */ + IncrHeapAccessStat(local_open); + IncrHeapAccessStat(global_open); + + /* The relcache does all the real work... */ + r = RelationIdGetRelation(relationId); + /* Under no circumstances will we return an index as a relation. */ if (RelationIsValid(r) && r->rd_rel->relkind == RELKIND_INDEX) elog(ERROR, "%s is an index relation", RelationGetRelationName(r)); - if (lockmode == NoLock) - return r; /* caller must check RelationIsValid! */ + return r; +} - if (!RelationIsValid(r)) - elog(ERROR, "Relation '%s' does not exist", relationName); +/* ---------------- + * heap_openr_nofail - open a heap relation by name, + * do not raise error on failure + * + * The caller must check for a NULL return value indicating + * that no such relation exists. + * No lock is obtained on the relation, either. + * ---------------- + */ +Relation +heap_openr_nofail(const char *relationName) +{ + Relation r; - LockRelation(r, lockmode); + /* ---------------- + * increment access statistics + * ---------------- + */ + IncrHeapAccessStat(local_openr); + IncrHeapAccessStat(global_openr); + + /* The relcache does all the real work... */ + r = RelationNameGetRelation(relationName); + + /* Under no circumstances will we return an index as a relation. */ + if (RelationIsValid(r) && r->rd_rel->relkind == RELKIND_INDEX) + elog(ERROR, "%s is an index relation", RelationGetRelationName(r)); return r; } |