public function display($id)
    {
        if (!$this->locking) {
            readfile($this->path . '/' . $id);

            return;
        }

        $fp = fopen($this->path . '/' . $id, 'rb');
        flock($fp, LOCK_SH);
        fpassthru($fp);
        flock($fp, LOCK_UN);
        fclose($fp);
    }