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refactor ALTER some-obj SET OWNER implementation

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Remove duplicate implementation of catalog munging and miscellaneous
privilege and consistency checks.  Instead rely on already existing data
in objectaddress.c to do the work.

Author: KaiGai Kohei
Tweaked by me
Reviewed by Robert Haas
This commit is contained in:
Alvaro Herrera
2012-10-03 18:02:38 -03:00
parent 1f91c8ca1d
commit 994c36e01d
24 changed files with 270 additions and 1338 deletions
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102
src/backend/catalog/pg_largeobject.c
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@@ -139,108 +139,6 @@ LargeObjectDrop(Oid loid)
heap_close(pg_lo_meta, RowExclusiveLock);
}
/*
* LargeObjectAlterOwner
*
* Implementation of ALTER LARGE OBJECT statement
*/
void
LargeObjectAlterOwner(Oid loid, Oid newOwnerId)
{
Form_pg_largeobject_metadata form_lo_meta;
Relation pg_lo_meta;
ScanKeyData skey[1];
SysScanDesc scan;
HeapTuple oldtup;
HeapTuple newtup;
pg_lo_meta = heap_open(LargeObjectMetadataRelationId,
RowExclusiveLock);
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(loid));
scan = systable_beginscan(pg_lo_meta,
LargeObjectMetadataOidIndexId, true,
SnapshotNow, 1, skey);
oldtup = systable_getnext(scan);
if (!HeapTupleIsValid(oldtup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("large object %u does not exist", loid)));
form_lo_meta = (Form_pg_largeobject_metadata) GETSTRUCT(oldtup);
if (form_lo_meta->lomowner != newOwnerId)
{
Datum values[Natts_pg_largeobject_metadata];
bool nulls[Natts_pg_largeobject_metadata];
bool replaces[Natts_pg_largeobject_metadata];
Acl *newAcl;
Datum aclDatum;
bool isnull;
/* Superusers can always do it */
if (!superuser())
{
/*
* lo_compat_privileges is not checked here, because ALTER LARGE
* OBJECT ... OWNER did not exist at all prior to PostgreSQL 9.0.
*
* We must be the owner of the existing object.
*/
if (!pg_largeobject_ownercheck(loid, GetUserId()))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be owner of large object %u", loid)));
/* Must be able to become new owner */
check_is_member_of_role(GetUserId(), newOwnerId);
}
memset(values, 0, sizeof(values));
memset(nulls, false, sizeof(nulls));
memset(replaces, false, sizeof(nulls));
values[Anum_pg_largeobject_metadata_lomowner - 1]
= ObjectIdGetDatum(newOwnerId);
replaces[Anum_pg_largeobject_metadata_lomowner - 1] = true;
/*
* Determine the modified ACL for the new owner. This is only
* necessary when the ACL is non-null.
*/
aclDatum = heap_getattr(oldtup,
Anum_pg_largeobject_metadata_lomacl,
RelationGetDescr(pg_lo_meta), &isnull);
if (!isnull)
{
newAcl = aclnewowner(DatumGetAclP(aclDatum),
form_lo_meta->lomowner, newOwnerId);
values[Anum_pg_largeobject_metadata_lomacl - 1]
= PointerGetDatum(newAcl);
replaces[Anum_pg_largeobject_metadata_lomacl - 1] = true;
}
newtup = heap_modify_tuple(oldtup, RelationGetDescr(pg_lo_meta),
values, nulls, replaces);
simple_heap_update(pg_lo_meta, &newtup->t_self, newtup);
CatalogUpdateIndexes(pg_lo_meta, newtup);
heap_freetuple(newtup);
/* Update owner dependency reference */
changeDependencyOnOwner(LargeObjectRelationId,
loid, newOwnerId);
}
systable_endscan(scan);
heap_close(pg_lo_meta, RowExclusiveLock);
}
/*
* LargeObjectExists
*