/*
* PrepareForTupleInvalidation
* Detect whether invalidation of this tuple implies invalidation
* of catalog/relation cache entries; if so, register inval events.
*/
static void
PrepareForTupleInvalidation(Relation relation, HeapTuple tuple)
{
Oid tupleRelId;
Oid databaseId;
Oid relationId;
/* Do nothing during bootstrap */
if (IsBootstrapProcessingMode())
return;
/*
* We only need to worry about invalidation for tuples that are in system
* relations; user-relation tuples are never in catcaches and can't affect
* the relcache either.
*/
if (!IsSystemRelation(relation))
return;
/*
* TOAST tuples can likewise be ignored here. Note that TOAST tables are
* considered system relations so they are not filtered by the above test.
*/
if (IsToastRelation(relation))
return;
/*
* First let the catcache do its thing
*/
PrepareToInvalidateCacheTuple(relation, tuple,
RegisterCatcacheInvalidation);
/*
* Now, is this tuple one of the primary definers of a relcache entry?
*/
tupleRelId = RelationGetRelid(relation);
if (tupleRelId == RelationRelationId)
{
Form_pg_class classtup = (Form_pg_class) GETSTRUCT(tuple);
RelFileNode rnode;
relationId = HeapTupleGetOid(tuple);
if (classtup->relisshared)
databaseId = InvalidOid;
else
databaseId = MyDatabaseId;
/*
* We need to send out an smgr inval as well as a relcache inval. This
* is needed because other backends might possibly possess smgr cache
* but not relcache entries for the target relation.
*
* Note: during a pg_class row update that assigns a new relfilenode
* or reltablespace value, we will be called on both the old and new
* tuples, and thus will broadcast invalidation messages showing both
* the old and new RelFileNode values. This ensures that other
* backends will close smgr references to the old file.
*
* XXX possible future cleanup: it might be better to trigger smgr
* flushes explicitly, rather than indirectly from pg_class updates.
*/
if (classtup->reltablespace)
rnode.spcNode = classtup->reltablespace;
else
rnode.spcNode = MyDatabaseTableSpace;
rnode.dbNode = databaseId;
rnode.relNode = classtup->relfilenode;
RegisterSmgrInvalidation(rnode);
}
else if (tupleRelId == AttributeRelationId)
{
Form_pg_attribute atttup = (Form_pg_attribute) GETSTRUCT(tuple);
relationId = atttup->attrelid;
/*
* KLUGE ALERT: we always send the relcache event with MyDatabaseId,
* even if the rel in question is shared (which we can't easily tell).
* This essentially means that only backends in this same database
* will react to the relcache flush request. This is in fact
* appropriate, since only those backends could see our pg_attribute
* change anyway. It looks a bit ugly though.
*/
databaseId = MyDatabaseId;
}
else
return;
/*
* Yes. We need to register a relcache invalidation event.
*/
RegisterRelcacheInvalidation(databaseId, relationId);
}
/*
* CacheInvalidateHeapTuple
* Register the given tuple for invalidation at end of command
* (ie, current command is creating or outdating this tuple).
* Also, detect whether a relcache invalidation is implied.
*
* For an insert or delete, tuple is the target tuple and newtuple is NULL.
* For an update, we are called just once, with tuple being the old tuple
* version and newtuple the new version. This allows avoidance of duplicate
* effort during an update.
*/
void
CacheInvalidateHeapTuple(Relation relation,
HeapTuple tuple,
HeapTuple newtuple)
{
Oid tupleRelId;
Oid databaseId;
Oid relationId;
/* Do nothing during bootstrap */
if (IsBootstrapProcessingMode())
return;
/*
* We only need to worry about invalidation for tuples that are in system
* relations; user-relation tuples are never in catcaches and can't affect
* the relcache either.
*/
if (!IsSystemRelation(relation))
return;
/*
* TOAST tuples can likewise be ignored here. Note that TOAST tables are
* considered system relations so they are not filtered by the above test.
*/
if (IsToastRelation(relation))
return;
/*
* First let the catcache do its thing
*/
PrepareToInvalidateCacheTuple(relation, tuple, newtuple,
RegisterCatcacheInvalidation);
/*
* Now, is this tuple one of the primary definers of a relcache entry?
*
* Note we ignore newtuple here; we assume an update cannot move a tuple
* from being part of one relcache entry to being part of another.
*/
tupleRelId = RelationGetRelid(relation);
if (tupleRelId == RelationRelationId)
{
Form_pg_class classtup = (Form_pg_class) GETSTRUCT(tuple);
relationId = HeapTupleGetOid(tuple);
if (classtup->relisshared)
databaseId = InvalidOid;
else
databaseId = MyDatabaseId;
}
else if (tupleRelId == AttributeRelationId)
{
Form_pg_attribute atttup = (Form_pg_attribute) GETSTRUCT(tuple);
relationId = atttup->attrelid;
/*
* KLUGE ALERT: we always send the relcache event with MyDatabaseId,
* even if the rel in question is shared (which we can't easily tell).
* This essentially means that only backends in this same database
* will react to the relcache flush request. This is in fact
* appropriate, since only those backends could see our pg_attribute
* change anyway. It looks a bit ugly though. (In practice, shared
* relations can't have schema changes after bootstrap, so we should
* never come here for a shared rel anyway.)
*/
databaseId = MyDatabaseId;
}
else if (tupleRelId == IndexRelationId)
{
Form_pg_index indextup = (Form_pg_index) GETSTRUCT(tuple);
/*
* When a pg_index row is updated, we should send out a relcache inval
* for the index relation. As above, we don't know the shared status
* of the index, but in practice it doesn't matter since indexes of
* shared catalogs can't have such updates.
*/
relationId = indextup->indexrelid;
databaseId = MyDatabaseId;
}
else
return;
/*
* Yes. We need to register a relcache invalidation event.
*/
RegisterRelcacheInvalidation(databaseId, relationId);
}
/*
* CacheInvalidateHeapTuple
* Register the given tuple for invalidation at end of command
* (ie, current command is creating or outdating this tuple).
* Also, detect whether a relcache invalidation is implied.
*
* For an insert or delete, tuple is the target tuple and newtuple is NULL.
* For an update, we are called just once, with tuple being the old tuple
* version and newtuple the new version. This allows avoidance of duplicate
* effort during an update.
*/
void
CacheInvalidateHeapTuple(Relation relation,
HeapTuple tuple,
HeapTuple newtuple)
{
Oid tupleRelId;
Oid databaseId;
Oid relationId;
/* Do nothing during bootstrap */
if (IsBootstrapProcessingMode())
return;
/*
* We only need to worry about invalidation for tuples that are in system
* catalogs; user-relation tuples are never in catcaches and can't affect
* the relcache either.
*/
if (!IsCatalogRelation(relation))
return;
/*
* IsCatalogRelation() will return true for TOAST tables of system
* catalogs, but we don't care about those, either.
*/
if (IsToastRelation(relation))
return;
/*
* If we're not prepared to queue invalidation messages for this
* subtransaction level, get ready now.
*/
PrepareInvalidationState();
/*
* First let the catcache do its thing
*/
tupleRelId = RelationGetRelid(relation);
if (RelationInvalidatesSnapshotsOnly(tupleRelId))
{
databaseId = IsSharedRelation(tupleRelId) ? InvalidOid : MyDatabaseId;
RegisterSnapshotInvalidation(databaseId, tupleRelId);
}
else
PrepareToInvalidateCacheTuple(relation, tuple, newtuple,
RegisterCatcacheInvalidation);
/*
* Now, is this tuple one of the primary definers of a relcache entry? See
* comments in file header for deeper explanation.
*
* Note we ignore newtuple here; we assume an update cannot move a tuple
* from being part of one relcache entry to being part of another.
*/
if (tupleRelId == RelationRelationId)
{
Form_pg_class classtup = (Form_pg_class) GETSTRUCT(tuple);
relationId = classtup->oid;
if (classtup->relisshared)
databaseId = InvalidOid;
else
databaseId = MyDatabaseId;
}
else if (tupleRelId == AttributeRelationId)
{
Form_pg_attribute atttup = (Form_pg_attribute) GETSTRUCT(tuple);
relationId = atttup->attrelid;
/*
* KLUGE ALERT: we always send the relcache event with MyDatabaseId,
* even if the rel in question is shared (which we can't easily tell).
* This essentially means that only backends in this same database
* will react to the relcache flush request. This is in fact
* appropriate, since only those backends could see our pg_attribute
* change anyway. It looks a bit ugly though. (In practice, shared
* relations can't have schema changes after bootstrap, so we should
* never come here for a shared rel anyway.)
*/
databaseId = MyDatabaseId;
}
else if (tupleRelId == IndexRelationId)
{
Form_pg_index indextup = (Form_pg_index) GETSTRUCT(tuple);
/*
* When a pg_index row is updated, we should send out a relcache inval
* for the index relation. As above, we don't know the shared status
* of the index, but in practice it doesn't matter since indexes of
* shared catalogs can't have such updates.
*/
relationId = indextup->indexrelid;
databaseId = MyDatabaseId;
}
else if (tupleRelId == ConstraintRelationId)
{
Form_pg_constraint constrtup = (Form_pg_constraint) GETSTRUCT(tuple);
/*
* Foreign keys are part of relcache entries, too, so send out an
* inval for the table that the FK applies to.
*/
if (constrtup->contype == CONSTRAINT_FOREIGN &&
OidIsValid(constrtup->conrelid))
{
relationId = constrtup->conrelid;
databaseId = MyDatabaseId;
}
else
return;
}
else
return;
/*
* Yes. We need to register a relcache invalidation event.
*/
RegisterRelcacheInvalidation(databaseId, relationId);
}