/**
* We have two compound keys with unique constraints:
* (transport, user_id) which is our primary key, and
* (transport, screenname) which is an additional constraint.
*
* Currently there's not a way to represent that second key
* in the general keys list, so we're adding it here to the
* list of keys to use for caching, ensuring that it gets
* cleared as well when we change.
*
* @return array of cache keys
*/
function _allCacheKeys()
{
$ukeys = 'transport,screenname';
$uvals = $this->transport . ',' . $this->screenname;
$ckeys = parent::_allCacheKeys();
$ckeys[] = $this->cacheKey($this->tableName(), $ukeys, $uvals);
return $ckeys;
}
