private function clean_old_tokens()
{
$tokens = AuthModel::find_all();
$to_remove = array();
foreach ($tokens as $token) {
if ($token->timeexpires < time()) {
$to_remove[] = $token->id;
}
}
$sql = "DELETE FROM presence_auth\n\t\tWHERE id IN(" . implode(',', $to_remove) . ")";
DB::runSQL($sql, array());
}
