Avoid unnecessary fetch from pg_shadow in the normal case in

pg_class_aclmask().  We only need to do this when we have to check
pg_shadow.usecatupd, and that's not relevant unless the target table
is a system catalog.  So we can usually avoid one syscache lookup.
This commit is contained in:
Tom Lane 2005-05-29 23:38:05 +00:00
parent 140b078d2a
commit 03a542ba63
1 changed files with 27 additions and 23 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/catalog/aclchk.c,v 1.111 2005/04/14 20:03:23 tgl Exp $
* $PostgreSQL: pgsql/src/backend/catalog/aclchk.c,v 1.112 2005/05/29 23:38:05 tgl Exp $
*
* NOTES
* See acl.h.
@ -1310,6 +1310,29 @@ aclcheck_error(AclResult aclerr, AclObjectKind objectkind,
}
/* Check if given userid has usecatupd privilege according to pg_shadow */
static bool
has_usecatupd(AclId userid)
{
bool usecatupd;
HeapTuple tuple;
tuple = SearchSysCache(SHADOWSYSID,
ObjectIdGetDatum(userid),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("user with ID %u does not exist", userid)));
usecatupd = ((Form_pg_shadow) GETSTRUCT(tuple))->usecatupd;
ReleaseSysCache(tuple);
return usecatupd;
}
/*
* Exported routine for examining a user's privileges for a table
*
@ -1325,8 +1348,6 @@ pg_class_aclmask(Oid table_oid, AclId userid,
AclMode mask, AclMaskHow how)
{
AclMode result;
bool usesuper,
usecatupd;
HeapTuple tuple;
Form_pg_class classForm;
Datum aclDatum;
@ -1335,24 +1356,7 @@ pg_class_aclmask(Oid table_oid, AclId userid,
AclId ownerId;
/*
* Validate userid, find out if he is superuser, also get usecatupd
*/
tuple = SearchSysCache(SHADOWSYSID,
ObjectIdGetDatum(userid),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("user with ID %u does not exist", userid)));
usecatupd = ((Form_pg_shadow) GETSTRUCT(tuple))->usecatupd;
ReleaseSysCache(tuple);
usesuper = superuser_arg(userid);
/*
* Now get the relation's tuple from pg_class
* Must get the relation's tuple from pg_class
*/
tuple = SearchSysCache(RELOID,
ObjectIdGetDatum(table_oid),
@ -1377,7 +1381,7 @@ pg_class_aclmask(Oid table_oid, AclId userid,
if ((mask & (ACL_INSERT | ACL_UPDATE | ACL_DELETE)) &&
IsSystemClass(classForm) &&
classForm->relkind != RELKIND_VIEW &&
!usecatupd &&
!has_usecatupd(userid) &&
!allowSystemTableMods)
{
#ifdef ACLDEBUG
@ -1389,7 +1393,7 @@ pg_class_aclmask(Oid table_oid, AclId userid,
/*
* Otherwise, superusers bypass all permission-checking.
*/
if (usesuper)
if (superuser_arg(userid))
{
#ifdef ACLDEBUG
elog(DEBUG2, "%u is superuser, home free", userid);