diff options
Diffstat (limited to 'src/backend/utils/cache/catcache.c')
| -rw-r--r-- | src/backend/utils/cache/catcache.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 3e1c428a532..d8e31f3967b 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.73 2000/11/24 04:16:12 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.74 2001/01/05 22:54:37 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1047,17 +1047,36 @@ ReleaseCatCache(HeapTuple tuple) } /* -------------------------------- - * RelationInvalidateCatalogCacheTuple() + * PrepareToInvalidateCacheTuple() * - * Invalidate a tuple from a specific relation. This call determines the - * cache in question and calls CatalogCacheIdInvalidate(). It is -ok- - * if the relation cannot be found, it simply means this backend has yet - * to open it. + * This is part of a rather subtle chain of events, so pay attention: + * + * When a tuple is updated or deleted, it cannot be flushed from the + * catcaches immediately, for reasons explained at the top of inval.c. + * Instead we have to add entry(s) for the tuple to a list of pending tuple + * invalidations that will be done at the end of the command or transaction. + * + * The lists of tuples that need to be flushed are kept by inval.c. This + * routine is a helper routine for inval.c. Given a tuple belonging to + * the specified relation, find all catcaches it could be in, compute the + * correct hashindex for each such catcache, and call the specified function + * to record the cache id, hashindex, and tuple ItemPointer in inval.c's + * lists. CatalogCacheIdInvalidate will be called later, if appropriate, + * using the recorded information. + * + * Note that it is irrelevant whether the given tuple is actually loaded + * into the catcache at the moment. Even if it's not there now, it might + * be by the end of the command, so we have to be prepared to flush it. + * + * Also note that it's not an error if there are no catcaches for the + * specified relation. inval.c doesn't know exactly which rels have + * catcaches --- it will call this routine for any tuple that's in a + * system relation. * -------------------------------- */ void -RelationInvalidateCatalogCacheTuple(Relation relation, - HeapTuple tuple, +PrepareToInvalidateCacheTuple(Relation relation, + HeapTuple tuple, void (*function) (int, Index, ItemPointer)) { CatCache *ccp; @@ -1069,13 +1088,13 @@ RelationInvalidateCatalogCacheTuple(Relation relation, Assert(RelationIsValid(relation)); Assert(HeapTupleIsValid(tuple)); Assert(PointerIsValid(function)); - CACHE1_elog(DEBUG, "RelationInvalidateCatalogCacheTuple: called"); + CACHE1_elog(DEBUG, "PrepareToInvalidateCacheTuple: called"); /* ---------------- * for each cache * if the cache contains tuples from the specified relation - * call the invalidation function on the tuples - * in the proper hash bucket + * compute the tuple's hash index in this cache, + * and call the passed function to register the information. * ---------------- */ |