public function request($url, $headers = array(), $data = array(), $options = array()) {
		$options['hooks']->dispatch('fsockopen.before_request');

		$url_parts = parse_url($url);
		if (empty($url_parts)) {
			throw new Requests_Exception('Invalid URL.', 'invalidurl', $url);
		}
		$host = $url_parts['host'];
		$context = stream_context_create();
		$verifyname = false;
		$case_insensitive_headers = new Requests_Utility_CaseInsensitiveDictionary($headers);

		// HTTPS support
		if (isset($url_parts['scheme']) && strtolower($url_parts['scheme']) === 'https') {
			$remote_socket = 'ssl://' . $host;
			if (!isset($url_parts['port'])) {
				$url_parts['port'] = 443;
			}

			$context_options = array(
				'verify_peer' => true,
				// 'CN_match' => $host,
				'capture_peer_cert' => true
			);
			$verifyname = true;

			// SNI, if enabled (OpenSSL >=0.9.8j)
			if (defined('OPENSSL_TLSEXT_SERVER_NAME') && OPENSSL_TLSEXT_SERVER_NAME) {
				$context_options['SNI_enabled'] = true;
				if (isset($options['verifyname']) && $options['verifyname'] === false) {
					$context_options['SNI_enabled'] = false;
				}
			}

			if (isset($options['verify'])) {
				if ($options['verify'] === false) {
					$context_options['verify_peer'] = false;
				}
				elseif (is_string($options['verify'])) {
					$context_options['cafile'] = $options['verify'];
				}
			}

			if (isset($options['verifyname']) && $options['verifyname'] === false) {
				$context_options['verify_peer_name'] = false;
				$verifyname = false;
			}

			stream_context_set_option($context, array('ssl' => $context_options));
		}
		else {
			$remote_socket = 'tcp://' . $host;
		}

		$this->max_bytes = $options['max_bytes'];

		if (!isset($url_parts['port'])) {
			$url_parts['port'] = 80;
		}
		$remote_socket .= ':' . $url_parts['port'];

		set_error_handler(array($this, 'connect_error_handler'), E_WARNING | E_NOTICE);

		$options['hooks']->dispatch('fsockopen.remote_socket', array(&$remote_socket));

		$socket = stream_socket_client($remote_socket, $errno, $errstr, ceil($options['connect_timeout']), STREAM_CLIENT_CONNECT, $context);

		restore_error_handler();

		if ($verifyname && !$this->verify_certificate_from_context($host, $context)) {
			throw new Requests_Exception('SSL certificate did not match the requested domain name', 'ssl.no_match');
		}

		if (!$socket) {
			if ($errno === 0) {
				// Connection issue
				throw new Requests_Exception(rtrim($this->connect_error), 'fsockopen.connect_error');
			}

			throw new Requests_Exception($errstr, 'fsockopenerror', null, $errno);
		}

		$data_format = $options['data_format'];

		if ($data_format === 'query') {
			$path = self::format_get($url_parts, $data);
			$data = '';
		}
		else {
			$path = self::format_get($url_parts, array());
		}

		$options['hooks']->dispatch('fsockopen.remote_host_path', array(&$path, $url));

		$request_body = '';
		$out = sprintf("%s %s HTTP/%.1F\r\n", $options['type'], $path, $options['protocol_version']);

		if ($options['type'] !== Requests::TRACE) {
			if (is_array($data)) {
				$request_body = http_build_query($data, null, '&');
			}
			else {
				$request_body = $data;
			}

			if (!empty($data)) {
				if (!isset($case_insensitive_headers['Content-Length'])) {
					$headers['Content-Length'] = strlen($request_body);
				}

				if (!isset($case_insensitive_headers['Content-Type'])) {
					$headers['Content-Type'] = 'application/x-www-form-urlencoded; charset=UTF-8';
				}
			}
		}

		if (!isset($case_insensitive_headers['Host'])) {
			$out .= sprintf('Host: %s', $url_parts['host']);

			if (( 'http' === strtolower($url_parts['scheme']) && $url_parts['port'] !== 80 ) || ( 'https' === strtolower($url_parts['scheme']) && $url_parts['port'] !== 443 )) {
				$out .= ':' . $url_parts['port'];
			}
			$out .= "\r\n";
		}

		if (!isset($case_insensitive_headers['User-Agent'])) {
			$out .= sprintf("User-Agent: %s\r\n", $options['useragent']);
		}

		$accept_encoding = $this->accept_encoding();
		if (!isset($case_insensitive_headers['Accept-Encoding']) && !empty($accept_encoding)) {
			$out .= sprintf("Accept-Encoding: %s\r\n", $accept_encoding);
		}

		$headers = Requests::flatten($headers);

		if (!empty($headers)) {
			$out .= implode("\r\n", $headers) . "\r\n";
		}

		$options['hooks']->dispatch('fsockopen.after_headers', array(&$out));

		if (substr($out, -2) !== "\r\n") {
			$out .= "\r\n";
		}

		if (!isset($case_insensitive_headers['Connection'])) {
			$out .= "Connection: Close\r\n";
		}

		$out .= "\r\n" . $request_body;

		$options['hooks']->dispatch('fsockopen.before_send', array(&$out));

		fwrite($socket, $out);
		$options['hooks']->dispatch('fsockopen.after_send', array($out));

		if (!$options['blocking']) {
			fclose($socket);
			$fake_headers = '';
			$options['hooks']->dispatch('fsockopen.after_request', array(&$fake_headers));
			return '';
		}

		$timeout_sec = (int) floor($options['timeout']);
		if ($timeout_sec == $options['timeout']) {
			$timeout_msec = 0;
		}
		else {
			$timeout_msec = self::SECOND_IN_MICROSECONDS * $options['timeout'] % self::SECOND_IN_MICROSECONDS;
		}
		stream_set_timeout($socket, $timeout_sec, $timeout_msec);

		$response = $body = $headers = '';
		$this->info = stream_get_meta_data($socket);
		$size = 0;
		$doingbody = false;
		$download = false;
		if ($options['filename']) {
			$download = fopen($options['filename'], 'wb');
		}

		while (!feof($socket)) {
			$this->info = stream_get_meta_data($socket);
			if ($this->info['timed_out']) {
				throw new Requests_Exception('fsocket timed out', 'timeout');
			}

			$block = fread($socket, Requests::BUFFER_SIZE);
			if (!$doingbody) {
				$response .= $block;
				if (strpos($response, "\r\n\r\n")) {
					list($headers, $block) = explode("\r\n\r\n", $response, 2);
					$doingbody = true;
				}
			}

			// Are we in body mode now?
			if ($doingbody) {
				$options['hooks']->dispatch('request.progress', array($block, $size, $this->max_bytes));
				$data_length = strlen($block);
				if ($this->max_bytes) {
					// Have we already hit a limit?
					if ($size === $this->max_bytes) {
						continue;
					}
					if (($size + $data_length) > $this->max_bytes) {
						// Limit the length
						$limited_length = ($this->max_bytes - $size);
						$block = substr($block, 0, $limited_length);
					}
				}

				$size += strlen($block);
				if ($download) {
					fwrite($download, $block);
				}
				else {
					$body .= $block;
				}
			}
		}
		$this->headers = $headers;

		if ($download) {
			fclose($download);
		}
		else {
			$this->headers .= "\r\n\r\n" . $body;
		}
		fclose($socket);

		$options['hooks']->dispatch('fsockopen.after_request', array(&$this->headers, &$this->info));
		return $this->headers;
	}