private function readLines($fp) {
        $buffer = '';
        $timeout = time() + $this->timeout;

        while (is_resource($fp) && !feof($fp)) {
            $str = @fgets($fp, 515);
            $buffer .= $str;

            // If 4th character is a space, we are done reading, break the loop, micro-optimisation over strlen
            // Thanks to https://github.com/PHPMailer/PHPMailer/blob/master/class.smtp.php#L1035
            if ((isset($str[3]) and $str[3] == ' ')) {
                break;
            }

            // Timed-out? Log and break
            $info = stream_get_meta_data($fp);
            if ($info['timed_out']) {
                break;
            }
            // Now check if reads took too long
            if ($endtime and time() > $endtime) {
                break;
            }
        }

        return $buffer;
    }