/*
* ResetCatalogCaches
*
* Reset all caches when a shared cache inval event forces it
*/
void
ResetCatalogCaches(void)
{
CatCache *cache;
CACHE1_elog(DEBUG2, "ResetCatalogCaches called");
for (cache = CacheHdr->ch_caches; cache; cache = cache->cc_next)
ResetCatalogCache(cache);
CACHE1_elog(DEBUG2, "end of ResetCatalogCaches call");
}
/*
* CatalogCacheFlushCatalog
*
* Flush all catcache entries that came from the specified system catalog.
* This is needed after VACUUM FULL/CLUSTER on the catalog, since the
* tuples very likely now have different TIDs than before. (At one point
* we also tried to force re-execution of CatalogCacheInitializeCache for
* the cache(s) on that catalog. This is a bad idea since it leads to all
* kinds of trouble if a cache flush occurs while loading cache entries.
* We now avoid the need to do it by copying cc_tupdesc out of the relcache,
* rather than relying on the relcache to keep a tupdesc for us. Of course
* this assumes the tupdesc of a cachable system table will not change...)
*/
void
CatalogCacheFlushCatalog(Oid catId)
{
CatCache *cache;
CACHE2_elog(DEBUG2, "CatalogCacheFlushCatalog called for %u", catId);
for (cache = CacheHdr->ch_caches; cache; cache = cache->cc_next)
{
/* We can ignore uninitialized caches, since they must be empty */
if (cache->cc_tupdesc == NULL)
continue;
/* Does this cache store tuples of the target catalog? */
if (cache->cc_tupdesc->attrs[0]->attrelid == catId)
{
/* Yes, so flush all its contents */
ResetCatalogCache(cache);
/* Tell inval.c to call syscache callbacks for this cache */
CallSyscacheCallbacks(cache->id, NULL);
}
}
CACHE1_elog(DEBUG2, "end of CatalogCacheFlushCatalog call");
}
/*
* PrepareToInvalidateCacheTuple()
*
* This is part of a rather subtle chain of events, so pay attention:
*
* When a tuple is inserted or deleted, it cannot be flushed from the
* catcaches immediately, for reasons explained at the top of cache/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 hash value for each such catcache, and call the specified function
* to record the cache id, hash value, 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, or there might be a matching negative entry
* to flush --- or other backends' caches might have such entries --- so
* we have to make list entries to flush it later.
*
* 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
PrepareToInvalidateCacheTuple(Relation relation,
HeapTuple tuple,
void (*function) (int, uint32, ItemPointer, Oid))
{
CatCache *ccp;
Oid reloid;
CACHE1_elog(DEBUG2, "PrepareToInvalidateCacheTuple: called");
/*
* sanity checks
*/
Assert(RelationIsValid(relation));
Assert(HeapTupleIsValid(tuple));
Assert(PointerIsValid(function));
Assert(CacheHdr != NULL);
reloid = RelationGetRelid(relation);
/* ----------------
* for each cache
* if the cache contains tuples from the specified relation
* compute the tuple's hash value in this cache,
* and call the passed function to register the information.
* ----------------
*/
for (ccp = CacheHdr->ch_caches; ccp; ccp = ccp->cc_next)
{
/* Just in case cache hasn't finished initialization yet... */
if (ccp->cc_tupdesc == NULL)
CatalogCacheInitializeCache(ccp);
if (ccp->cc_reloid != reloid)
continue;
(*function) (ccp->id,
CatalogCacheComputeTupleHashValue(ccp, tuple),
&tuple->t_self,
ccp->cc_relisshared ? (Oid) 0 : MyDatabaseId);
}
}
/*
* CatalogCacheFlushCatalog
*
* Flush all catcache entries that came from the specified system catalog.
* This is needed after VACUUM FULL/CLUSTER on the catalog, since the
* tuples very likely now have different TIDs than before. (At one point
* we also tried to force re-execution of CatalogCacheInitializeCache for
* the cache(s) on that catalog. This is a bad idea since it leads to all
* kinds of trouble if a cache flush occurs while loading cache entries.
* We now avoid the need to do it by copying cc_tupdesc out of the relcache,
* rather than relying on the relcache to keep a tupdesc for us. Of course
* this assumes the tupdesc of a cachable system table will not change...)
*/
void
CatalogCacheFlushCatalog(Oid catId)
{
CatCache *cache;
CACHE2_elog(DEBUG2, "CatalogCacheFlushCatalog called for %u", catId);
for (cache = CacheHdr->ch_caches; cache; cache = cache->cc_next)
{
/* Does this cache store tuples of the target catalog? */
if (cache->cc_reloid == catId)
{
/* Yes, so flush all its contents */
ResetCatalogCache(cache);
/* Tell inval.c to call syscache callbacks for this cache */
CallSyscacheCallbacks(cache->id, 0);
}
}
CACHE1_elog(DEBUG2, "end of CatalogCacheFlushCatalog call");
}
/*
* CatalogCacheIdInvalidate
*
* Invalidate entries in the specified cache, given a hash value.
*
* We delete cache entries that match the hash value, whether positive
* or negative. We don't care whether the invalidation is the result
* of a tuple insertion or a deletion.
*
* We used to try to match positive cache entries by TID, but that is
* unsafe after a VACUUM FULL on a system catalog: an inval event could
* be queued before VACUUM FULL, and then processed afterwards, when the
* target tuple that has to be invalidated has a different TID than it
* did when the event was created. So now we just compare hash values and
* accept the small risk of unnecessary invalidations due to false matches.
*
* This routine is only quasi-public: it should only be used by inval.c.
*/
void
CatalogCacheIdInvalidate(int cacheId, uint32 hashValue)
{
CatCache *ccp;
CACHE1_elog(DEBUG2, "CatalogCacheIdInvalidate: called");
/*
* inspect caches to find the proper cache
*/
for (ccp = CacheHdr->ch_caches; ccp; ccp = ccp->cc_next)
{
Index hashIndex;
Dlelem *elt,
*nextelt;
if (cacheId != ccp->id)
continue;
/*
* We don't bother to check whether the cache has finished
* initialization yet; if not, there will be no entries in it so no
* problem.
*/
/*
* Invalidate *all* CatCLists in this cache; it's too hard to tell
* which searches might still be correct, so just zap 'em all.
*/
for (elt = DLGetHead(&ccp->cc_lists); elt; elt = nextelt)
{
CatCList *cl = (CatCList *) DLE_VAL(elt);
nextelt = DLGetSucc(elt);
if (cl->refcount > 0)
cl->dead = true;
else
CatCacheRemoveCList(ccp, cl);
}
/*
* inspect the proper hash bucket for tuple matches
*/
hashIndex = HASH_INDEX(hashValue, ccp->cc_nbuckets);
for (elt = DLGetHead(&ccp->cc_bucket[hashIndex]); elt; elt = nextelt)
{
CatCTup *ct = (CatCTup *) DLE_VAL(elt);
nextelt = DLGetSucc(elt);
if (hashValue == ct->hash_value)
{
if (ct->refcount > 0 ||
(ct->c_list && ct->c_list->refcount > 0))
{
ct->dead = true;
/* list, if any, was marked dead above */
Assert(ct->c_list == NULL || ct->c_list->dead);
}
else
CatCacheRemoveCTup(ccp, ct);
CACHE1_elog(DEBUG2, "CatalogCacheIdInvalidate: invalidated");
#ifdef CATCACHE_STATS
ccp->cc_invals++;
#endif
/* could be multiple matches, so keep looking! */
}
}
break; /* need only search this one cache */
}
}
/*
* CatalogCacheIdInvalidate
*
* Invalidate entries in the specified cache, given a hash value and
* item pointer. Positive entries are deleted if they match the item
* pointer. Negative entries must be deleted if they match the hash
* value (since we do not have the exact key of the tuple that's being
* inserted). But this should only rarely result in loss of a cache
* entry that could have been kept.
*
* Note that it's not very relevant whether the tuple identified by
* the item pointer is being inserted or deleted. We don't expect to
* find matching positive entries in the one case, and we don't expect
* to find matching negative entries in the other; but we will do the
* right things in any case.
*
* This routine is only quasi-public: it should only be used by inval.c.
*/
void
CatalogCacheIdInvalidate(int cacheId,
uint32 hashValue,
ItemPointer pointer)
{
CatCache *ccp;
/*
* sanity checks
*/
#ifdef USE_ASSERT_CHECKING
/* Add some debug info for MPP-5739 */
if (!ItemPointerIsValid(pointer))
{
elog(LOG, "CatalogCacheIdInvalidate: cacheId %d, hash %u IP %p", cacheId, hashValue, pointer);
if (pointer != NULL)
{
elog(LOG, "CatalogCacheIdInvalidate: bogus item (?): (blkid.hi %d blkid.lo %d posid %d)",
pointer->ip_blkid.bi_hi, pointer->ip_blkid.bi_lo, pointer->ip_posid);
}
}
#endif
Assert(ItemPointerIsValid(pointer));
CACHE1_elog(DEBUG2, "CatalogCacheIdInvalidate: called");
/*
* inspect caches to find the proper cache
*/
for (ccp = CacheHdr->ch_caches; ccp; ccp = ccp->cc_next)
{
Index hashIndex;
Dlelem *elt,
*nextelt;
if (cacheId != ccp->id)
continue;
/*
* We don't bother to check whether the cache has finished
* initialization yet; if not, there will be no entries in it so no
* problem.
*/
/*
* Invalidate *all* CatCLists in this cache; it's too hard to tell
* which searches might still be correct, so just zap 'em all.
*/
for (elt = DLGetHead(&ccp->cc_lists); elt; elt = nextelt)
{
CatCList *cl = (CatCList *) DLE_VAL(elt);
nextelt = DLGetSucc(elt);
if (cl->refcount > 0)
cl->dead = true;
else
CatCacheRemoveCList(ccp, cl);
}
/*
* inspect the proper hash bucket for tuple matches
*/
hashIndex = HASH_INDEX(hashValue, ccp->cc_nbuckets);
for (elt = DLGetHead(&ccp->cc_bucket[hashIndex]); elt; elt = nextelt)
{
CatCTup *ct = (CatCTup *) DLE_VAL(elt);
nextelt = DLGetSucc(elt);
if (hashValue != ct->hash_value)
continue; /* ignore non-matching hash values */
if (ct->negative ||
ItemPointerEquals(pointer, &ct->tuple.t_self))
{
if (ct->refcount > 0 ||
(ct->c_list && ct->c_list->refcount > 0))
{
ct->dead = true;
/* list, if any, was marked dead above */
Assert(ct->c_list == NULL || ct->c_list->dead);
}
else
CatCacheRemoveCTup(ccp, ct);
CACHE1_elog(DEBUG2, "CatalogCacheIdInvalidate: invalidated");
#ifdef CATCACHE_STATS
ccp->cc_invals++;
#endif
/* could be multiple matches, so keep looking! */
}
}
break; /* need only search this one cache */
}
}
/*
* CatalogCacheFlushRelation
*
* This is called by RelationFlushRelation() to clear out cached information
* about a relation being dropped. (This could be a DROP TABLE command,
* or a temp table being dropped at end of transaction, or a table created
* during the current transaction that is being dropped because of abort.)
* Remove all cache entries relevant to the specified relation OID.
*
* A special case occurs when relId is itself one of the cacheable system
* tables --- although those'll never be dropped, they can get flushed from
* the relcache (VACUUM causes this, for example). In that case we need
* to flush all cache entries that came from that table. (At one point we
* also tried to force re-execution of CatalogCacheInitializeCache for
* the cache(s) on that table. This is a bad idea since it leads to all
* kinds of trouble if a cache flush occurs while loading cache entries.
* We now avoid the need to do it by copying cc_tupdesc out of the relcache,
* rather than relying on the relcache to keep a tupdesc for us. Of course
* this assumes the tupdesc of a cachable system table will not change...)
*/
void
CatalogCacheFlushRelation(Oid relId)
{
CatCache *cache;
CACHE2_elog(DEBUG2, "CatalogCacheFlushRelation called for %u", relId);
for (cache = CacheHdr->ch_caches; cache; cache = cache->cc_next)
{
int i;
/* We can ignore uninitialized caches, since they must be empty */
if (cache->cc_tupdesc == NULL)
continue;
/* Does this cache store tuples of the target relation itself? */
if (cache->cc_tupdesc->attrs[0]->attrelid == relId)
{
/* Yes, so flush all its contents */
ResetCatalogCache(cache);
continue;
}
/* Does this cache store tuples associated with relations at all? */
if (cache->cc_reloidattr == 0)
continue; /* nope, leave it alone */
/* Yes, scan the tuples and remove those related to relId */
for (i = 0; i < cache->cc_nbuckets; i++)
{
Dlelem *elt,
*nextelt;
for (elt = DLGetHead(&cache->cc_bucket[i]); elt; elt = nextelt)
{
CatCTup *ct = (CatCTup *) DLE_VAL(elt);
Oid tupRelid;
nextelt = DLGetSucc(elt);
/*
* Negative entries are never considered related to a rel,
* even if the rel is part of their lookup key.
*/
if (ct->negative)
continue;
if (cache->cc_reloidattr == ObjectIdAttributeNumber)
tupRelid = HeapTupleGetOid(&ct->tuple);
else
{
bool isNull;
tupRelid =
DatumGetObjectId(fastgetattr(&ct->tuple,
cache->cc_reloidattr,
cache->cc_tupdesc,
&isNull));
Assert(!isNull);
}
if (tupRelid == relId)
{
if (ct->refcount > 0)
ct->dead = true;
else
CatCacheRemoveCTup(cache, ct);
#ifdef CATCACHE_STATS
cache->cc_invals++;
#endif
}
}
}
}
CACHE1_elog(DEBUG2, "end of CatalogCacheFlushRelation call");
}
