The Tor Browser: testing/xpcshell/node-http2/lib/http.js@6474c204b198 (annotated)

testing/xpcshell/node-http2/lib/http.js@6474c204b198 (annotated)

testing/xpcshell/node-http2/lib/http.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // Public API
 // ==========
 // The main governing power behind the http2 API design is that it should look very similar to the
 // existing node.js [HTTPS API][1] (which is, in turn, almost identical to the [HTTP API][2]). The
 // additional features of HTTP/2 are exposed as extensions to this API. Furthermore, node-http2
 // should fall back to using HTTP/1.1 if needed. Compatibility with undocumented or deprecated
 // elements of the node.js HTTP/HTTPS API is a non-goal.
 //
 // Additional and modified API elements
 // ------------------------------------
 //
 // - **Class: http2.Endpoint**: an API for using the raw HTTP/2 framing layer. For documentation
 //   see the [lib/endpoint.js](endpoint.html) file.
 //
 // - **Class: http2.Server**
 //   - **Event: 'connection' (socket, [endpoint])**: there's a second argument if the negotiation of
 //     HTTP/2 was successful: the reference to the [Endpoint](endpoint.html) object tied to the
 //     socket.
 //
 // - **http2.createServer(options, [requestListener])**: additional option:
 //   - **log**: an optional [bunyan](https://github.com/trentm/node-bunyan) logger object
 //   - **plain**: if `true`, the server will accept HTTP/2 connections over plain TCP instead of
 //     TLS
 //
 // - **Class: http2.ServerResponse**
 //   - **response.push(options)**: initiates a server push. `options` describes the 'imaginary'
 //     request to which the push stream is a response; the possible options are identical to the
 //     ones accepted by `http2.request`. Returns a ServerResponse object that can be used to send
 //     the response headers and content.
 //
 // - **Class: http2.Agent**
 //   - **new Agent(options)**: additional option:
 //     - **log**: an optional [bunyan](https://github.com/trentm/node-bunyan) logger object
 //   - **agent.sockets**: only contains TCP sockets that corresponds to HTTP/1 requests.
 //   - **agent.endpoints**: contains [Endpoint](endpoint.html) objects for HTTP/2 connections.
 //
 // - **http2.request(options, [callback])**: additional option:
 //   - **plain**: if `true`, the client will not try to build a TLS tunnel, instead it will use
 //     the raw TCP stream for HTTP/2
 //
 // - **Class: http2.ClientRequest**
 //   - **Event: 'socket' (socket)**: in case of an HTTP/2 incoming message, `socket` is a reference
 //     to the associated [HTTP/2 Stream](stream.html) object (and not to the TCP socket).
 //   - **Event: 'push' (promise)**: signals the intention of a server push associated to this
 //     request. `promise` is an IncomingPromise. If there's no listener for this event, the server
 //     push is cancelled.
 //   - **request.setPriority(priority)**: assign a priority to this request. `priority` is a number
 //     between 0 (highest priority) and 2^31-1 (lowest priority). Default value is 2^30.
 //
 // - **Class: http2.IncomingMessage**
 //   - has two subclasses for easier interface description: **IncomingRequest** and
 //     **IncomingResponse**
 //   - **message.socket**: in case of an HTTP/2 incoming message, it's a reference to the associated
 //     [HTTP/2 Stream](stream.html) object (and not to the TCP socket).
 //
 // - **Class: http2.IncomingRequest (IncomingMessage)**
 //   - **message.url**: in case of an HTTP/2 incoming request, the `url` field always contains the
 //     path, and never a full url (it contains the path in most cases in the HTTPS api as well).
 //   - **message.scheme**: additional field. Mandatory HTTP/2 request metadata.
 //   - **message.host**: additional field. Mandatory HTTP/2 request metadata. Note that this
 //     replaces the old Host header field, but node-http2 will add Host to the `message.headers` for
 //     backwards compatibility.
 //
 // - **Class: http2.IncomingPromise (IncomingRequest)**
 //   - contains the metadata of the 'imaginary' request to which the server push is an answer.
 //   - **Event: 'response' (response)**: signals the arrival of the actual push stream. `response`
 //     is an IncomingResponse.
 //   - **Event: 'push' (promise)**: signals the intention of a server push associated to this
 //     request. `promise` is an IncomingPromise. If there's no listener for this event, the server
 //     push is cancelled.
 //   - **promise.cancel()**: cancels the promised server push.
 //   - **promise.setPriority(priority)**: assign a priority to this push stream. `priority` is a
 //     number between 0 (highest priority) and 2^31-1 (lowest priority). Default value is 2^30.
 //
 // API elements not yet implemented
 // --------------------------------
 //
 // - **Class: http2.Server**
 //   - **server.maxHeadersCount**
 //
 // API elements that are not applicable to HTTP/2
 // ----------------------------------------------
 //
 // The reason may be deprecation of certain HTTP/1.1 features, or that some API elements simply
 // don't make sense when using HTTP/2. These will not be present when a request is done with HTTP/2,
 // but will function normally when falling back to using HTTP/1.1.
 //
 // - **Class: http2.Server**
 //   - **Event: 'checkContinue'**: not in the spec, yet (see [http-spec#18][expect-continue])
 //   - **Event: 'upgrade'**: upgrade is deprecated in HTTP/2
 //   - **Event: 'timeout'**: HTTP/2 sockets won't timeout because of application level keepalive
 //     (PING frames)
 //   - **Event: 'connect'**: not in the spec, yet (see [http-spec#230][connect])
 //   - **server.setTimeout(msecs, [callback])**
 //   - **server.timeout**
 //
 // - **Class: http2.ServerResponse**
 //   - **Event: 'close'**
 //   - **Event: 'timeout'**
 //   - **response.writeContinue()**
 //   - **response.writeHead(statusCode, [reasonPhrase], [headers])**: reasonPhrase will always be
 //     ignored since [it's not supported in HTTP/2][3]
 //   - **response.setTimeout(timeout, [callback])**
 //
 // - **Class: http2.Agent**
 //   - **agent.maxSockets**: only affects HTTP/1 connection pool. When using HTTP/2, there's always
 //     one connection per host.
 //
 // - **Class: http2.ClientRequest**
 //   - **Event: 'upgrade'**
 //   - **Event: 'connect'**
 //   - **Event: 'continue'**
 //   - **request.setTimeout(timeout, [callback])**
 //   - **request.setNoDelay([noDelay])**
 //   - **request.setSocketKeepAlive([enable], [initialDelay])**
 //
 // - **Class: http2.IncomingMessage**
 //   - **Event: 'close'**
 //   - **message.setTimeout(timeout, [callback])**
 //
 // [1]: http://nodejs.org/api/https.html
 // [2]: http://nodejs.org/api/http.html
 // [3]: http://tools.ietf.org/html/draft-ietf-httpbis-http2-10#section-8.1.3.2
 // [expect-continue]: https://github.com/http2/http2-spec/issues/18
 // [connect]: https://github.com/http2/http2-spec/issues/230
 // Common server and client side code
 // ==================================
 var net = require('net');
 var url = require('url');
 var util = require('util');
 var EventEmitter = require('events').EventEmitter;
 var PassThrough = require('stream').PassThrough;
 var Readable = require('stream').Readable;
 var Writable = require('stream').Writable;
 var Endpoint = require('http2-protocol').Endpoint;
 var implementedVersion = require('http2-protocol').ImplementedVersion;
 var http = require('http');
 var https = require('https');
 exports.STATUS_CODES = http.STATUS_CODES;
 exports.IncomingMessage = IncomingMessage;
 exports.OutgoingMessage = OutgoingMessage;
 var deprecatedHeaders = [
   'connection',
   'host',
   'keep-alive',
   'proxy-connection',
   'te',
   'transfer-encoding',
   'upgrade'
 ];
 // When doing NPN/ALPN negotiation, HTTP/1.1 is used as fallback
 var supportedProtocols = [implementedVersion, 'http/1.1', 'http/1.0'];
 // Logging
 // -------
 // Logger shim, used when no logger is provided by the user.
 function noop() {}
 var defaultLogger = {
   fatal: noop,
   error: noop,
   warn : noop,
   info : noop,
   debug: noop,
   trace: noop,
   child: function() { return this; }
 };
 // Bunyan serializers exported by submodules that are worth adding when creating a logger.
 exports.serializers = require('http2-protocol').serializers;
 // IncomingMessage class
 // ---------------------
 function IncomingMessage(stream) {
   // * This is basically a read-only wrapper for the [Stream](stream.html) class.
   PassThrough.call(this);
   stream.pipe(this);
   this.socket = this.stream = stream;
   this._log = stream._log.child({ component: 'http' });
   // * HTTP/2.0 does not define a way to carry the version identifier that is included in the
   //   HTTP/1.1 request/status line. Version is always 2.0.
   this.httpVersion = '2.0';
   this.httpVersionMajor = 2;
   this.httpVersionMinor = 0;
   // * `this.headers` will store the regular headers (and none of the special colon headers)
   this.headers = {};
   this.trailers = undefined;
   this._lastHeadersSeen = undefined;
   // * Other metadata is filled in when the headers arrive.
   stream.once('headers', this._onHeaders.bind(this));
   stream.once('end', this._onEnd.bind(this));
 }
 IncomingMessage.prototype = Object.create(PassThrough.prototype, { constructor: { value: IncomingMessage } });
 // [Request Header Fields](http://tools.ietf.org/html/draft-ietf-httpbis-http2-10#section-8.1.3.1)
 // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
 //   of key-value pairs. This includes the target URI for the request, the status code for the
 //   response, as well as HTTP header fields.
 IncomingMessage.prototype._onHeaders = function _onHeaders(headers) {
   // * An HTTP/2.0 request or response MUST NOT include any of the following header fields:
   //   Connection, Host, Keep-Alive, Proxy-Connection, TE, Transfer-Encoding, and Upgrade. A server
   //   MUST treat the presence of any of these header fields as a stream error of type
   //   PROTOCOL_ERROR.
   for (var i = 0; i < deprecatedHeaders.length; i++) {
     var key = deprecatedHeaders[i];
     if (key in headers) {
       this._log.error({ key: key, value: headers[key] }, 'Deprecated header found');
       this.stream.emit('error', 'PROTOCOL_ERROR');
       return;
     }
   }
   // * Store the _regular_ headers in `this.headers`
   for (var name in headers) {
     if (name[0] !== ':') {
       this.headers[name] = headers[name];
     }
   }
   // * The last header block, if it's not the first, will represent the trailers
   var self = this;
   this.stream.on('headers', function(headers) {
     self._lastHeadersSeen = headers;
   });
 };
 IncomingMessage.prototype._onEnd = function _onEnd() {
   this.trailers = this._lastHeadersSeen;
 };
 IncomingMessage.prototype.setTimeout = noop;
 IncomingMessage.prototype._checkSpecialHeader = function _checkSpecialHeader(key, value) {
   if ((typeof value !== 'string') || (value.length === 0)) {
     this._log.error({ key: key, value: value }, 'Invalid or missing special header field');
     this.stream.emit('error', 'PROTOCOL_ERROR');
   }
   return value;
 }
 ;
 // OutgoingMessage class
 // ---------------------
 function OutgoingMessage() {
   // * This is basically a read-only wrapper for the [Stream](stream.html) class.
   Writable.call(this);
   this._headers = {};
   this._trailers = undefined;
   this.headersSent = false;
   this.on('finish', this._finish);
 }
 OutgoingMessage.prototype = Object.create(Writable.prototype, { constructor: { value: OutgoingMessage } });
 OutgoingMessage.prototype._write = function _write(chunk, encoding, callback) {
   if (this.stream) {
     this.stream.write(chunk, encoding, callback);
   } else {
     this.once('socket', this._write.bind(this, chunk, encoding, callback));
   }
 };
 OutgoingMessage.prototype._finish = function _finish() {
   if (this.stream) {
     if (this._trailers) {
       if (this.request) {
         this.request.addTrailers(this._trailers);
       } else {
         this.stream.headers(this._trailers);
       }
     }
     this.stream.end();
   } else {
     this.once('socket', this._finish.bind(this));
   }
 };
 OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
   if (this.headersSent) {
     throw new Error('Can\'t set headers after they are sent.');
   } else {
     name = name.toLowerCase();
     if (deprecatedHeaders.indexOf(name) !== -1) {
       throw new Error('Cannot set deprecated header: ' + name);
     }
     this._headers[name] = value;
   }
 };
 OutgoingMessage.prototype.removeHeader = function removeHeader(name) {
   if (this.headersSent) {
     throw new Error('Can\'t remove headers after they are sent.');
   } else {
     delete this._headers[name.toLowerCase()];
   }
 };
 OutgoingMessage.prototype.getHeader = function getHeader(name) {
   return this._headers[name.toLowerCase()];
 };
 OutgoingMessage.prototype.addTrailers = function addTrailers(trailers) {
   this._trailers = trailers;
 };
 OutgoingMessage.prototype.setTimeout = noop;
 OutgoingMessage.prototype._checkSpecialHeader = IncomingMessage.prototype._checkSpecialHeader;
 // Server side
 // ===========
 exports.createServer = createServer;
 exports.Server = Server;
 exports.IncomingRequest = IncomingRequest;
 exports.OutgoingResponse = OutgoingResponse;
 exports.ServerResponse = OutgoingResponse; // for API compatibility
 // Server class
 // ------------
 function Server(options) {
   options = util._extend({}, options);
   this._log = (options.log || defaultLogger).child({ component: 'http' });
   this._settings = options.settings;
   var start = this._start.bind(this);
   var fallback = this._fallback.bind(this);
   // HTTP2 over TLS (using NPN or ALPN)
   if ((options.key && options.cert) || options.pfx) {
     this._log.info('Creating HTTP/2 server over TLS');
     this._mode = 'tls';
     options.ALPNProtocols = supportedProtocols;
     options.NPNProtocols = supportedProtocols;
     this._server = https.createServer(options);
     this._originalSocketListeners = this._server.listeners('secureConnection');
     this._server.removeAllListeners('secureConnection');
     this._server.on('secureConnection', function(socket) {
       var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;
       if ((negotiatedProtocol === implementedVersion) && socket.servername) {
         start(socket);
       } else {
         fallback(socket);
       }
     });
     this._server.on('request', this.emit.bind(this, 'request'));
   }
   // HTTP2 over plain TCP
   else if (options.plain) {
     this._log.info('Creating HTTP/2 server over plain TCP');
     this._mode = 'plain';
     this._server = net.createServer(start);
   }
   // HTTP/2 with HTTP/1.1 upgrade
   else {
     this._log.error('Trying to create HTTP/2 server with Upgrade from HTTP/1.1');
     throw new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported. Please provide TLS keys.');
   }
   this._server.on('close', this.emit.bind(this, 'close'));
 }
 Server.prototype = Object.create(EventEmitter.prototype, { constructor: { value: Server } });
 // Starting HTTP/2
 Server.prototype._start = function _start(socket) {
   var endpoint = new Endpoint(this._log, 'SERVER', this._settings);
   this._log.info({ e: endpoint,
                    client: socket.remoteAddress + ':' + socket.remotePort,
                    SNI: socket.servername
                  }, 'New incoming HTTP/2 connection');
   endpoint.pipe(socket).pipe(endpoint);
   var self = this;
   endpoint.on('stream', function _onStream(stream) {
     var response = new OutgoingResponse(stream);
     var request = new IncomingRequest(stream);
     request.once('ready', self.emit.bind(self, 'request', request, response));
   });
   endpoint.on('error', this.emit.bind(this, 'clientError'));
   socket.on('error', this.emit.bind(this, 'clientError'));
   this.emit('connection', socket, endpoint);
 };
 Server.prototype._fallback = function _fallback(socket) {
   var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;
   this._log.info({ client: socket.remoteAddress + ':' + socket.remotePort,
                    protocol: negotiatedProtocol,
                    SNI: socket.servername
                  }, 'Falling back to simple HTTPS');
   for (var i = 0; i < this._originalSocketListeners.length; i++) {
     this._originalSocketListeners[i].call(this._server, socket);
   }
   this.emit('connection', socket);
 };
 // There are [3 possible signatures][1] of the `listen` function. Every arguments is forwarded to
 // the backing TCP or HTTPS server.
 // [1]: http://nodejs.org/api/http.html#http_server_listen_port_hostname_backlog_callback
 Server.prototype.listen = function listen(port, hostname) {
   this._log.info({ on: ((typeof hostname === 'string') ? (hostname + ':' + port) : port) },
                  'Listening for incoming connections');
   this._server.listen.apply(this._server, arguments);
 };
 Server.prototype.close = function close(callback) {
   this._log.info('Closing server');
   this._server.close(callback);
 };
 Server.prototype.setTimeout = function setTimeout(timeout, callback) {
   if (this._mode === 'tls') {
     this._server.setTimeout(timeout, callback);
   }
 };
 Object.defineProperty(Server.prototype, 'timeout', {
   get: function getTimeout() {
     if (this._mode === 'tls') {
       return this._server.timeout;
     } else {
       return undefined;
     }
   },
   set: function setTimeout(timeout) {
     if (this._mode === 'tls') {
       this._server.timeout = timeout;
     }
   }
 });
 // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
 // `server`.There are events on the `http.Server` class where it makes difference whether someone is
 // listening on the event or not. In these cases, we can not simply forward the events from the
 // `server` to `this` since that means a listener. Instead, we forward the subscriptions.
 Server.prototype.on = function on(event, listener) {
   if ((event === 'upgrade') || (event === 'timeout')) {
     this._server.on(event, listener && listener.bind(this));
   } else {
     EventEmitter.prototype.on.call(this, event, listener);
   }
 };
 // `addContext` is used to add Server Name Indication contexts
 Server.prototype.addContext = function addContext(hostname, credentials) {
   if (this._mode === 'tls') {
     this._server.addContext(hostname, credentials);
   }
 };
 function createServer(options, requestListener) {
   if (typeof options === 'function') {
     requestListener = options;
     options = undefined;
   }
   var server = new Server(options);
   if (requestListener) {
     server.on('request', requestListener);
   }
   return server;
 }
 // IncomingRequest class
 // ---------------------
 function IncomingRequest(stream) {
   IncomingMessage.call(this, stream);
 }
 IncomingRequest.prototype = Object.create(IncomingMessage.prototype, { constructor: { value: IncomingRequest } });
 // [Request Header Fields](http://tools.ietf.org/html/draft-ietf-httpbis-http2-10#section-8.1.3.1)
 // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
 //   of key-value pairs. This includes the target URI for the request, the status code for the
 //   response, as well as HTTP header fields.
 IncomingRequest.prototype._onHeaders = function _onHeaders(headers) {
   // * The ":method" header field includes the HTTP method
   // * The ":scheme" header field includes the scheme portion of the target URI
   // * The ":authority" header field includes the authority portion of the target URI
   // * The ":path" header field includes the path and query parts of the target URI.
   //   This field MUST NOT be empty; URIs that do not contain a path component MUST include a value
   //   of '/', unless the request is an OPTIONS request for '*', in which case the ":path" header
   //   field MUST include '*'.
   // * All HTTP/2.0 requests MUST include exactly one valid value for all of these header fields. A
   //   server MUST treat the absence of any of these header fields, presence of multiple values, or
   //   an invalid value as a stream error of type PROTOCOL_ERROR.
   this.method = this._checkSpecialHeader(':method'   , headers[':method']);
   this.scheme = this._checkSpecialHeader(':scheme'   , headers[':scheme']);
   this.host   = this._checkSpecialHeader(':authority', headers[':authority']  );
   this.url    = this._checkSpecialHeader(':path'     , headers[':path']  );
   // * Host header is included in the headers object for backwards compatibility.
   this.headers.host = this.host;
   // * Handling regular headers.
   IncomingMessage.prototype._onHeaders.call(this, headers);
   // * Signaling that the headers arrived.
   this._log.info({ method: this.method, scheme: this.scheme, host: this.host,
                    path: this.url, headers: this.headers }, 'Incoming request');
   this.emit('ready');
 };
 // OutgoingResponse class
 // ----------------------
 function OutgoingResponse(stream) {
   OutgoingMessage.call(this);
   this._log = stream._log.child({ component: 'http' });
   this.stream = stream;
   this.statusCode = 200;
   this.sendDate = true;
   this.stream.once('headers', this._onRequestHeaders.bind(this));
 }
 OutgoingResponse.prototype = Object.create(OutgoingMessage.prototype, { constructor: { value: OutgoingResponse } });
 OutgoingResponse.prototype.writeHead = function writeHead(statusCode, reasonPhrase, headers) {
   if (typeof reasonPhrase === 'string') {
     this._log.warn('Reason phrase argument was present but ignored by the writeHead method');
   } else {
     headers = reasonPhrase;
   }
   for (var name in headers) {
     this.setHeader(name, headers[name]);
   }
   headers = this._headers;
   if (this.sendDate && !('date' in this._headers)) {
     headers.date = (new Date()).toUTCString();
   }
   this._log.info({ status: statusCode, headers: this._headers }, 'Sending server response');
   headers[':status'] = this.statusCode = statusCode;
   this.stream.headers(headers);
   this.headersSent = true;
 };
 OutgoingResponse.prototype._implicitHeaders = function _implicitHeaders() {
   if (!this.headersSent) {
     this.writeHead(this.statusCode);
   }
 };
 OutgoingResponse.prototype.write = function write() {
   this._implicitHeaders();
   return OutgoingMessage.prototype.write.apply(this, arguments);
 };
 OutgoingResponse.prototype.end = function end() {
   this._implicitHeaders();
   return OutgoingMessage.prototype.end.apply(this, arguments);
 };
 OutgoingResponse.prototype._onRequestHeaders = function _onRequestHeaders(headers) {
   this._requestHeaders = headers;
 };
 OutgoingResponse.prototype.push = function push(options) {
   if (typeof options === 'string') {
     options = url.parse(options);
   }
   if (!options.path) {
     throw new Error('`path` option is mandatory.');
   }
   var promise = util._extend({
     ':method': (options.method || 'GET').toUpperCase(),
     ':scheme': (options.protocol && options.protocol.slice(0, -1)) || this._requestHeaders[':scheme'],
     ':authority': options.hostname || options.host || this._requestHeaders[':authority'],
     ':path': options.path
   }, options.headers);
   this._log.info({ method: promise[':method'], scheme: promise[':scheme'],
                    authority: promise[':authority'], path: promise[':path'],
                    headers: options.headers }, 'Promising push stream');
   var pushStream = this.stream.promise(promise);
   return new OutgoingResponse(pushStream);
 };
 // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
 // `request`. See `Server.prototype.on` for explanation.
 OutgoingResponse.prototype.on = function on(event, listener) {
   if (this.request && (event === 'timeout')) {
     this.request.on(event, listener && listener.bind(this));
   } else {
     OutgoingMessage.prototype.on.call(this, event, listener);
   }
 };
 // Client side
 // ===========
 exports.ClientRequest = OutgoingRequest; // for API compatibility
 exports.OutgoingRequest = OutgoingRequest;
 exports.IncomingResponse = IncomingResponse;
 exports.Agent = Agent;
 exports.globalAgent = undefined;
 exports.request = function request(options, callback) {
   return (options.agent || exports.globalAgent).request(options, callback);
 };
 exports.get = function get(options, callback) {
   return (options.agent || exports.globalAgent).get(options, callback);
 };
 // Agent class
 // -----------
 function Agent(options) {
   EventEmitter.call(this);
   options = util._extend({}, options);
   this._settings = options.settings;
   this._log = (options.log || defaultLogger).child({ component: 'http' });
   this.endpoints = {};
   // * Using an own HTTPS agent, because the global agent does not look at `NPN/ALPNProtocols` when
   //   generating the key identifying the connection, so we may get useless non-negotiated TLS
   //   channels even if we ask for a negotiated one. This agent will contain only negotiated
   //   channels.
   var agentOptions = {};
   agentOptions.ALPNProtocols = supportedProtocols;
   agentOptions.NPNProtocols = supportedProtocols;
   this._httpsAgent = new https.Agent(agentOptions);
   this.sockets = this._httpsAgent.sockets;
   this.requests = this._httpsAgent.requests;
 }
 Agent.prototype = Object.create(EventEmitter.prototype, { constructor: { value: Agent } });
 Agent.prototype.request = function request(options, callback) {
   if (typeof options === 'string') {
     options = url.parse(options);
   } else {
     options = util._extend({}, options);
   }
   options.method = (options.method || 'GET').toUpperCase();
   options.protocol = options.protocol || 'https:';
   options.host = options.hostname || options.host || 'localhost';
   options.port = options.port || 443;
   options.path = options.path || '/';
   if (!options.plain && options.protocol === 'http:') {
     this._log.error('Trying to negotiate client request with Upgrade from HTTP/1.1');
     throw new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported.');
   }
   var request = new OutgoingRequest(this._log);
   if (callback) {
     request.on('response', callback);
   }
   var key = [
     !!options.plain,
     options.host,
     options.port
   ].join(':');
   // * There's an existing HTTP/2 connection to this host
   if (key in this.endpoints) {
     var endpoint = this.endpoints[key];
     request._start(endpoint.createStream(), options);
   }
   // * HTTP/2 over plain TCP
   else if (options.plain) {
     endpoint = new Endpoint(this._log, 'CLIENT', this._settings);
     endpoint.socket = net.connect({
       host: options.host,
       port: options.port,
       localAddress: options.localAddress
     });
     endpoint.pipe(endpoint.socket).pipe(endpoint);
     request._start(endpoint.createStream(), options);
   }
   // * HTTP/2 over TLS negotiated using NPN or ALPN
   else {
     var started = false;
     options.ALPNProtocols = supportedProtocols;
     options.NPNProtocols = supportedProtocols;
     options.servername = options.host; // Server Name Indication
     options.agent = this._httpsAgent;
     var httpsRequest = https.request(options);
     httpsRequest.on('socket', function(socket) {
       var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;
       if (negotiatedProtocol !== undefined) {
         negotiated();
       } else {
         socket.on('secureConnect', negotiated);
       }
     });
     var self = this;
     function negotiated() {
       var endpoint;
       var negotiatedProtocol = httpsRequest.socket.alpnProtocol || httpsRequest.socket.npnProtocol;
       if (negotiatedProtocol === implementedVersion) {
         httpsRequest.socket.emit('agentRemove');
         unbundleSocket(httpsRequest.socket);
         endpoint = new Endpoint(self._log, 'CLIENT', self._settings);
         endpoint.socket = httpsRequest.socket;
         endpoint.pipe(endpoint.socket).pipe(endpoint);
       }
       if (started) {
         if (endpoint) {
           endpoint.close();
         } else {
           httpsRequest.abort();
         }
       } else {
         if (endpoint) {
           self._log.info({ e: endpoint, server: options.host + ':' + options.port },
                          'New outgoing HTTP/2 connection');
           self.endpoints[key] = endpoint;
           self.emit(key, endpoint);
         } else {
           self.emit(key, undefined);
         }
       }
     }
     this.once(key, function(endpoint) {
       started = true;
       if (endpoint) {
         request._start(endpoint.createStream(), options);
       } else {
         request._fallback(httpsRequest);
       }
     });
   }
   return request;
 };
 Agent.prototype.get = function get(options, callback) {
   var request = this.request(options, callback);
   request.end();
   return request;
 };
 function unbundleSocket(socket) {
   socket.removeAllListeners('data');
   socket.removeAllListeners('end');
   socket.removeAllListeners('readable');
   socket.removeAllListeners('close');
   socket.removeAllListeners('error');
   socket.unpipe();
   delete socket.ondata;
   delete socket.onend;
 }
 Object.defineProperty(Agent.prototype, 'maxSockets', {
   get: function getMaxSockets() {
     return this._httpsAgent.maxSockets;
   },
   set: function setMaxSockets(value) {
     this._httpsAgent.maxSockets = value;
   }
 });
 exports.globalAgent = new Agent();
 // OutgoingRequest class
 // ---------------------
 function OutgoingRequest() {
   OutgoingMessage.call(this);
   this._log = undefined;
   this.stream = undefined;
 }
 OutgoingRequest.prototype = Object.create(OutgoingMessage.prototype, { constructor: { value: OutgoingRequest } });
 OutgoingRequest.prototype._start = function _start(stream, options) {
   this.stream = stream;
   this._log = stream._log.child({ component: 'http' });
   for (var key in options.headers) {
     this.setHeader(key, options.headers[key]);
   }
   var headers = this._headers;
   delete headers.host;
   if (options.auth) {
     headers.authorization = 'Basic ' + new Buffer(options.auth).toString('base64');
   }
   headers[':scheme'] = options.protocol.slice(0, -1);
   headers[':method'] = options.method;
   headers[':authority'] = options.host;
   headers[':path'] = options.path;
   this._log.info({ scheme: headers[':scheme'], method: headers[':method'],
                    authority: headers[':authority'], path: headers[':path'],
                    headers: (options.headers || {}) }, 'Sending request');
   this.stream.headers(headers);
   this.headersSent = true;
   this.emit('socket', this.stream);
   var response = new IncomingResponse(this.stream);
   response.once('ready', this.emit.bind(this, 'response', response));
   this.stream.on('promise', this._onPromise.bind(this));
 };
 OutgoingRequest.prototype._fallback = function _fallback(request) {
   request.on('response', this.emit.bind(this, 'response'));
   this.stream = this.request = request;
   this.emit('socket', this.socket);
 };
 OutgoingRequest.prototype.setPriority = function setPriority(priority) {
   if (this.stream) {
     this.stream.priority(priority);
   } else {
     this.once('socket', this.setPriority.bind(this, priority));
   }
 };
 // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
 // `request`. See `Server.prototype.on` for explanation.
 OutgoingRequest.prototype.on = function on(event, listener) {
   if (this.request && (event === 'upgrade')) {
     this.request.on(event, listener && listener.bind(this));
   } else {
     OutgoingMessage.prototype.on.call(this, event, listener);
   }
 };
 // Methods only in fallback mode
 OutgoingRequest.prototype.setNoDelay = function setNoDelay(noDelay) {
   if (this.request) {
     this.request.setNoDelay(noDelay);
   } else if (!this.stream) {
     this.on('socket', this.setNoDelay.bind(this, noDelay));
   }
 };
 OutgoingRequest.prototype.setSocketKeepAlive = function setSocketKeepAlive(enable, initialDelay) {
   if (this.request) {
     this.request.setSocketKeepAlive(enable, initialDelay);
   } else if (!this.stream) {
     this.on('socket', this.setSocketKeepAlive.bind(this, enable, initialDelay));
   }
 };
 OutgoingRequest.prototype.setTimeout = function setTimeout(timeout, callback) {
   if (this.request) {
     this.request.setTimeout(timeout, callback);
   } else if (!this.stream) {
     this.on('socket', this.setTimeout.bind(this, timeout, callback));
   }
 };
 // Aborting the request
 OutgoingRequest.prototype.abort = function abort() {
   if (this.request) {
     this.request.abort();
   } else if (this.stream) {
     this.stream.reset('CANCEL');
   } else {
     this.on('socket', this.abort.bind(this));
   }
 };
 // Receiving push promises
 OutgoingRequest.prototype._onPromise = function _onPromise(stream, headers) {
   this._log.info({ push_stream: stream.id }, 'Receiving push promise');
   var promise = new IncomingPromise(stream, headers);
   if (this.listeners('push').length > 0) {
     this.emit('push', promise);
   } else {
     promise.cancel();
   }
 };
 // IncomingResponse class
 // ----------------------
 function IncomingResponse(stream) {
   IncomingMessage.call(this, stream);
 }
 IncomingResponse.prototype = Object.create(IncomingMessage.prototype, { constructor: { value: IncomingResponse } });
 // [Response Header Fields](http://tools.ietf.org/html/draft-ietf-httpbis-http2-10#section-8.1.3.2)
 // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
 //   of key-value pairs. This includes the target URI for the request, the status code for the
 //   response, as well as HTTP header fields.
 IncomingResponse.prototype._onHeaders = function _onHeaders(headers) {
   // * A single ":status" header field is defined that carries the HTTP status code field. This
   //   header field MUST be included in all responses.
   // * A client MUST treat the absence of the ":status" header field, the presence of multiple
   //   values, or an invalid value as a stream error of type PROTOCOL_ERROR.
   //   Note: currently, we do not enforce it strictly: we accept any format, and parse it as int
   // * HTTP/2.0 does not define a way to carry the reason phrase that is included in an HTTP/1.1
   //   status line.
   this.statusCode = parseInt(this._checkSpecialHeader(':status', headers[':status']));
   // * Handling regular headers.
   IncomingMessage.prototype._onHeaders.call(this, headers);
   // * Signaling that the headers arrived.
   this._log.info({ status: this.statusCode, headers: this.headers}, 'Incoming response');
   this.emit('ready');
 };
 // IncomingPromise class
 // -------------------------
 function IncomingPromise(responseStream, promiseHeaders) {
   var stream = new Readable();
   stream._read = noop;
   stream.push(null);
   stream._log = responseStream._log;
   IncomingRequest.call(this, stream);
   this._onHeaders(promiseHeaders);
   this._responseStream = responseStream;
   var response = new IncomingResponse(this._responseStream);
   response.once('ready', this.emit.bind(this, 'response', response));
   this.stream.on('promise', this._onPromise.bind(this));
 }
 IncomingPromise.prototype = Object.create(IncomingRequest.prototype, { constructor: { value: IncomingPromise } });
 IncomingPromise.prototype.cancel = function cancel() {
   this._responseStream.reset('CANCEL');
 };
 IncomingPromise.prototype.setPriority = function setPriority(priority) {
   this._responseStream.priority(priority);
 };
 IncomingPromise.prototype._onPromise = OutgoingRequest.prototype._onPromise;