diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 092a23cc0e..4c05492194 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.54 1999/09/18 19:05:58 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.55 1999/09/24 00:23:54 tgl Exp $ * * * INTERFACE ROUTINES @@ -160,7 +160,7 @@ unpinscan(HeapScanDesc scan) ReleaseBuffer(scan->rs_pbuf); /* ------------------------------------ - * Scan will pin buffer one for each non-NULL tuple pointer + * Scan will pin buffer once for each non-NULL tuple pointer * (ptup, ctup, ntup), so they have to be unpinned multiple * times. * ------------------------------------ @@ -170,6 +170,10 @@ unpinscan(HeapScanDesc scan) if (BufferIsValid(scan->rs_nbuf)) ReleaseBuffer(scan->rs_nbuf); + + /* we don't bother to clear rs_pbuf etc --- caller must + * reinitialize them if scan descriptor is not being deleted. + */ } /* ------------------------------------------ @@ -826,6 +830,8 @@ heap_getnext(HeapScanDesc scandesc, int backw) { if (BufferIsValid(scan->rs_nbuf)) ReleaseBuffer(scan->rs_nbuf); + scan->rs_ntup.t_data = NULL; + scan->rs_nbuf = UnknownBuffer; return NULL; } @@ -906,6 +912,8 @@ heap_getnext(HeapScanDesc scandesc, int backw) { if (BufferIsValid(scan->rs_pbuf)) ReleaseBuffer(scan->rs_pbuf); + scan->rs_ptup.t_data = NULL; + scan->rs_pbuf = UnknownBuffer; HEAPDEBUG_3; /* heap_getnext returns NULL at end */ return NULL; } @@ -1014,8 +1022,6 @@ heap_fetch(Relation relation, ItemPointer tid = &(tuple->t_self); OffsetNumber offnum; - AssertMacro(PointerIsValid(userbuf)); /* see comments above */ - /* ---------------- * increment access statistics * ---------------- @@ -1067,21 +1073,17 @@ heap_fetch(Relation relation, if (tuple->t_data == NULL) { + /* Tuple failed time check, so we can release now. */ ReleaseBuffer(buffer); - return; + *userbuf = InvalidBuffer; + } + else + { + /* All checks passed, so return the tuple as valid. + * Caller is now responsible for releasing the buffer. + */ + *userbuf = buffer; } - - /* ---------------- - * all checks passed, now either return a copy of the tuple - * or pin the buffer page and return a pointer, depending on - * whether caller gave us a valid buf. - * ---------------- - */ - - *userbuf = buffer; /* user is required to ReleaseBuffer() - * this */ - - return; } /* ---------------- |