public static function parse_socket_options(&$options, $host = null)
    {
        if (empty($host) || empty($options)) {
            return $options;
        }

        // get rid of schema and port from the hostname
        $host_url = parse_url($host);
        if (isset($host_url['host'])) {
            $host = $host_url['host'];
        }

        // find per-host options
        if (array_key_exists($host, $options)) {
            $options = $options[$host];
        }
    }