Migrate dart2js stubs for dart:io

tool/input_sdk/lib/io/http_impl.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of dart.io;
+
+const int _OUTGOING_BUFFER_SIZE = 8 * 1024;
+
+class _HttpIncoming extends Stream<List<int>> {
+  final int _transferLength;
+  final Completer _dataCompleter = new Completer();
+  Stream<List<int>> _stream;
+
+  bool fullBodyRead = false;
+
+  // Common properties.
+  final _HttpHeaders headers;
+  bool upgraded = false;
+
+  // ClientResponse properties.
+  int statusCode;
+  String reasonPhrase;
+
+  // Request properties.
+  String method;
+  Uri uri;
+
+  bool hasSubscriber = false;
+
+  // The transfer length if the length of the message body as it
+  // appears in the message (RFC 2616 section 4.4). This can be -1 if
+  // the length of the massage body is not known due to transfer
+  // codings.
+  int get transferLength => _transferLength;
+
+  _HttpIncoming(this.headers, this._transferLength, this._stream);
+
+  StreamSubscription<List<int>> listen(void onData(List<int> event),
+                                       {Function onError,
+                                        void onDone(),
+                                        bool cancelOnError}) {
+    hasSubscriber = true;
+    return _stream
+        .handleError((error) {
+          throw new HttpException(error.message, uri: uri);
+        })
+        .listen(onData,
+                onError: onError,
+                onDone: onDone,
+                cancelOnError: cancelOnError);
+  }
+
+  // Is completed once all data have been received.
+  Future get dataDone => _dataCompleter.future;
+
+  void close(bool closing) {
+    fullBodyRead = true;
+    hasSubscriber = true;
+    _dataCompleter.complete(closing);
+  }
+}
+
+abstract class _HttpInboundMessage extends Stream<List<int>> {
+  final _HttpIncoming _incoming;
+  List<Cookie> _cookies;
+
+  _HttpInboundMessage(this._incoming);
+
+  List<Cookie> get cookies {
+    if (_cookies != null) return _cookies;
+    return _cookies = headers._parseCookies();
+  }
+
+  _HttpHeaders get headers => _incoming.headers;
+  String get protocolVersion => headers.protocolVersion;
+  int get contentLength => headers.contentLength;
+  bool get persistentConnection => headers.persistentConnection;
+}
+
+
+class _HttpRequest extends _HttpInboundMessage implements HttpRequest {
+  final HttpResponse response;
+
+  final _HttpServer _httpServer;
+
+  final _HttpConnection _httpConnection;
+
+  _HttpSession _session;
+
+  Uri _requestedUri;
+
+  _HttpRequest(this.response, _HttpIncoming _incoming, this._httpServer,
+               this._httpConnection) : super(_incoming) {
+    if (headers.protocolVersion == "1.1") {
+      response.headers
+          ..chunkedTransferEncoding = true
+          ..persistentConnection = headers.persistentConnection;
+    }
+
+    if (_httpServer._sessionManagerInstance != null) {
+      // Map to session if exists.
+      var sessionIds = cookies
+          .where((cookie) => cookie.name.toUpperCase() == _DART_SESSION_ID)
+          .map((cookie) => cookie.value);
+      for (var sessionId in sessionIds) {
+        _session = _httpServer._sessionManager.getSession(sessionId);
+        if (_session != null) {
+          _session._markSeen();
+          break;
+        }
+      }
+    }
+  }
+
+  StreamSubscription<List<int>> listen(void onData(List<int> event),
+                                       {Function onError,
+                                        void onDone(),
+                                        bool cancelOnError}) {
+    return _incoming.listen(onData,
+                            onError: onError,
+                            onDone: onDone,
+                            cancelOnError: cancelOnError);
+  }
+
+  Uri get uri => _incoming.uri;
+
+  Uri get requestedUri {
+    if (_requestedUri == null) {
+      var proto = headers['x-forwarded-proto'];
+      var scheme = proto != null ? proto.first :
+          _httpConnection._socket is SecureSocket ? "https" : "http";
+      var hostList = headers['x-forwarded-host'];
+      String host;
+      if (hostList != null) {
+        host = hostList.first;
+      } else {
+        hostList = headers['host'];
+        if (hostList != null) {
+          host = hostList.first;
+        } else {
+          host = "${_httpServer.address.host}:${_httpServer.port}";
+        }
+      }
+      _requestedUri = Uri.parse("$scheme://$host$uri");
+    }
+    return _requestedUri;
+  }
+
+  String get method => _incoming.method;
+
+  HttpSession get session {
+    if (_session != null) {
+      if (_session._destroyed) {
+        // It's destroyed, clear it.
+        _session = null;
+        // Create new session object by calling recursive.
+        return session;
+      }
+      // It's already mapped, use it.
+      return _session;
+    }
+    // Create session, store it in connection, and return.
+    return _session = _httpServer._sessionManager.createSession();
+  }
+
+  HttpConnectionInfo get connectionInfo => _httpConnection.connectionInfo;
+
+  X509Certificate get certificate {
+    var socket = _httpConnection._socket;
+    if (socket is SecureSocket) return socket.peerCertificate;
+    return null;
+  }
+}
+
+
+class _HttpClientResponse
+    extends _HttpInboundMessage implements HttpClientResponse {
+  List<RedirectInfo> get redirects => _httpRequest._responseRedirects;
+
+  // The HttpClient this response belongs to.
+  final _HttpClient _httpClient;
+
+  // The HttpClientRequest of this response.
+  final _HttpClientRequest _httpRequest;
+
+  _HttpClientResponse(_HttpIncoming _incoming, this._httpRequest,
+                      this._httpClient) : super(_incoming) {
+    // Set uri for potential exceptions.
+    _incoming.uri = _httpRequest.uri;
+  }
+
+  int get statusCode => _incoming.statusCode;
+  String get reasonPhrase => _incoming.reasonPhrase;
+
+  X509Certificate get certificate {
+    var socket = _httpRequest._httpClientConnection._socket;
+    if (socket is SecureSocket) return socket.peerCertificate;
+    throw new UnsupportedError("Socket is not a SecureSocket");
+  }
+
+  List<Cookie> get cookies {
+    if (_cookies != null) return _cookies;
+    _cookies = new List<Cookie>();
+    List<String> values = headers[HttpHeaders.SET_COOKIE];
+    if (values != null) {
+      values.forEach((value) {
+        _cookies.add(new Cookie.fromSetCookieValue(value));
+      });
+    }
+    return _cookies;
+  }
+
+  bool get isRedirect {
+    if (_httpRequest.method == "GET" || _httpRequest.method == "HEAD") {
+      return statusCode == HttpStatus.MOVED_PERMANENTLY ||
+             statusCode == HttpStatus.FOUND ||
+             statusCode == HttpStatus.SEE_OTHER ||
+             statusCode == HttpStatus.TEMPORARY_REDIRECT;
+    } else if (_httpRequest.method == "POST") {
+      return statusCode == HttpStatus.SEE_OTHER;
+    }
+    return false;
+  }
+
+  Future<HttpClientResponse> redirect([String method,
+                                       Uri url,
+                                       bool followLoops]) {
+    if (method == null) {
+      // Set method as defined by RFC 2616 section 10.3.4.
+      if (statusCode == HttpStatus.SEE_OTHER && _httpRequest.method == "POST") {
+        method = "GET";
+      } else {
+        method = _httpRequest.method;
+      }
+    }
+    if (url == null) {
+      String location = headers.value(HttpHeaders.LOCATION);
+      if (location == null) {
+        throw new StateError("Response has no Location header for redirect");
+      }
+      url = Uri.parse(location);
+    }
+    if (followLoops != true) {
+      for (var redirect in redirects) {
+        if (redirect.location == url) {
+          return new Future.error(
+              new RedirectException("Redirect loop detected", redirects));
+        }
+      }
+    }
+    return _httpClient._openUrlFromRequest(method, url, _httpRequest)
+        .then((request) {
+          request._responseRedirects
+              ..addAll(this.redirects)
+              ..add(new _RedirectInfo(statusCode, method, url));
+          return request.close();
+        });
+  }
+
+  StreamSubscription<List<int>> listen(void onData(List<int> event),
+                                       {Function onError,
+                                        void onDone(),
+                                        bool cancelOnError}) {
+    if (_incoming.upgraded) {
+      // If upgraded, the connection is already 'removed' form the client.
+      // Since listening to upgraded data is 'bogus', simply close and
+      // return empty stream subscription.
+      _httpRequest._httpClientConnection.destroy();
+      return new Stream.fromIterable([]).listen(null, onDone: onDone);
+    }
+    var stream = _incoming;
+    if (_httpClient.autoUncompress &&
+        headers.value(HttpHeaders.CONTENT_ENCODING) == "gzip") {
+      stream = stream.transform(GZIP.decoder);
+    }
+    return stream.listen(onData,
+                         onError: onError,
+                         onDone: onDone,
+                         cancelOnError: cancelOnError);
+  }
+
+  Future<Socket> detachSocket() {
+    _httpClient._connectionClosed(_httpRequest._httpClientConnection);
+    return _httpRequest._httpClientConnection.detachSocket();
+  }
+
+  HttpConnectionInfo get connectionInfo => _httpRequest.connectionInfo;
+
+  bool get _shouldAuthenticateProxy {
+    // Only try to authenticate if there is a challenge in the response.
+    List<String> challenge = headers[HttpHeaders.PROXY_AUTHENTICATE];
+    return statusCode == HttpStatus.PROXY_AUTHENTICATION_REQUIRED &&
+        challenge != null && challenge.length == 1;
+  }
+
+  bool get _shouldAuthenticate {
+    // Only try to authenticate if there is a challenge in the response.
+    List<String> challenge = headers[HttpHeaders.WWW_AUTHENTICATE];
+    return statusCode == HttpStatus.UNAUTHORIZED &&
+        challenge != null && challenge.length == 1;
+  }
+
+  Future<HttpClientResponse> _authenticate(bool proxyAuth) {
+    Future<HttpClientResponse> retry() {
+      // Drain body and retry.
+      return drain().then((_) {
+          return _httpClient._openUrlFromRequest(_httpRequest.method,
+                                                 _httpRequest.uri,
+                                                 _httpRequest)
+              .then((request) => request.close());
+          });
+    }
+
+    List<String> authChallenge() {
+      return proxyAuth ? headers[HttpHeaders.PROXY_AUTHENTICATE]
+                       : headers[HttpHeaders.WWW_AUTHENTICATE];
+    }
+
+    _Credentials findCredentials(_AuthenticationScheme scheme) {
+      return proxyAuth ? _httpClient._findProxyCredentials(_httpRequest._proxy,
+                                                           scheme)
+                       : _httpClient._findCredentials(_httpRequest.uri, scheme);
+    }
+
+    void removeCredentials(_Credentials cr) {
+      if (proxyAuth) {
+        _httpClient._removeProxyCredentials(cr);
+      } else {
+        _httpClient._removeCredentials(cr);
+      }
+    }
+
+    Future requestAuthentication(_AuthenticationScheme scheme, String realm) {
+      if (proxyAuth) {
+        if (_httpClient._authenticateProxy == null) {
+          return new Future.value(false);
+        }
+        var proxy = _httpRequest._proxy;
+        return _httpClient._authenticateProxy(proxy.host,
+                                              proxy.port,
+                                              scheme.toString(),
+                                              realm);
+      } else {
+        if (_httpClient._authenticate == null) {
+          return new Future.value(false);
+        }
+        return _httpClient._authenticate(_httpRequest.uri,
+                                         scheme.toString(),
+                                         realm);
+      }
+    }
+
+    List<String> challenge = authChallenge();
+    assert(challenge != null || challenge.length == 1);
+    _HeaderValue header =
+        _HeaderValue.parse(challenge[0], parameterSeparator: ",");
+    _AuthenticationScheme scheme =
+        new _AuthenticationScheme.fromString(header.value);
+    String realm = header.parameters["realm"];
+
+    // See if any matching credentials are available.
+    _Credentials cr = findCredentials(scheme);
+    if (cr != null) {
+      // For basic authentication don't retry already used credentials
+      // as they must have already been added to the request causing
+      // this authenticate response.
+      if (cr.scheme == _AuthenticationScheme.BASIC && !cr.used) {
+        // Credentials where found, prepare for retrying the request.
+        return retry();
+      }
+
+      // Digest authentication only supports the MD5 algorithm.
+      if (cr.scheme == _AuthenticationScheme.DIGEST &&
+          (header.parameters["algorithm"] == null ||
+           header.parameters["algorithm"].toLowerCase() == "md5")) {
+        if (cr.nonce == null || cr.nonce == header.parameters["nonce"]) {
+          // If the nonce is not set then this is the first authenticate
+          // response for these credentials. Set up authentication state.
+          if (cr.nonce == null) {
+            cr..nonce = header.parameters["nonce"]
+              ..algorithm = "MD5"
+              ..qop = header.parameters["qop"]
+              ..nonceCount = 0;
+          }
+          // Credentials where found, prepare for retrying the request.
+          return retry();
+        } else if (header.parameters["stale"] != null &&
+                   header.parameters["stale"].toLowerCase() == "true") {
+          // If stale is true retry with new nonce.
+          cr.nonce = header.parameters["nonce"];
+          // Credentials where found, prepare for retrying the request.
+          return retry();
+        }
+      }
+    }
+
+    // Ask for more credentials if none found or the one found has
+    // already been used. If it has already been used it must now be
+    // invalid and is removed.
+    if (cr != null) {
+      removeCredentials(cr);
+      cr = null;
+    }
+    return requestAuthentication(scheme, realm).then((credsAvailable) {
+      if (credsAvailable) {
+        cr = _httpClient._findCredentials(_httpRequest.uri, scheme);
+        return retry();
+      } else {
+        // No credentials available, complete with original response.
+        return this;
+      }
+    });
+  }
+}
+
+
+abstract class _HttpOutboundMessage<T> extends _IOSinkImpl {
+  // Used to mark when the body should be written. This is used for HEAD
+  // requests and in error handling.
+  bool _encodingSet = false;
+
+  bool _bufferOutput = true;
+
+  final Uri _uri;
+  final _HttpOutgoing _outgoing;
+
+  final _HttpHeaders headers;
+
+  _HttpOutboundMessage(Uri uri,
+                       String protocolVersion,
+                       _HttpOutgoing outgoing,
+                       {_HttpHeaders initialHeaders})
+      : _uri = uri,
+        headers = new _HttpHeaders(
+            protocolVersion,
+            defaultPortForScheme: uri.scheme == 'https' ?
+                HttpClient.DEFAULT_HTTPS_PORT :
+                HttpClient.DEFAULT_HTTP_PORT,
+            initialHeaders: initialHeaders),
+        _outgoing = outgoing,
+        super(outgoing, null) {
+    _outgoing.outbound = this;
+    _encodingMutable = false;
+  }
+
+  int get contentLength => headers.contentLength;
+  void set contentLength(int contentLength) {
+    headers.contentLength = contentLength;
+  }
+
+  bool get persistentConnection => headers.persistentConnection;
+  void set persistentConnection(bool p) {
+    headers.persistentConnection = p;
+  }
+
+  bool get bufferOutput => _bufferOutput;
+  void set bufferOutput(bool bufferOutput) {
+    if (_outgoing.headersWritten) throw new StateError("Header already sent");
+    _bufferOutput = bufferOutput;
+  }
+
+
+  Encoding get encoding {
+    if (_encodingSet && _outgoing.headersWritten) {
+      return _encoding;
+    }
+    var charset;
+    if (headers.contentType != null && headers.contentType.charset != null) {
+      charset = headers.contentType.charset;
+    } else {
+      charset = "iso-8859-1";
+    }
+    return Encoding.getByName(charset);
+  }
+
+  void add(List<int> data) {
+    if (data.length == 0) return;
+    super.add(data);
+  }
+
+  void write(Object obj) {
+    if (!_encodingSet) {
+      _encoding = encoding;
+      _encodingSet = true;
+    }
+    super.write(obj);
+  }
+
+  void _writeHeader();
+
+  bool get _isConnectionClosed => false;
+}
+
+
+class _HttpResponse extends _HttpOutboundMessage<HttpResponse>
+    implements HttpResponse {
+  int _statusCode = 200;
+  String _reasonPhrase;
+  List<Cookie> _cookies;
+  _HttpRequest _httpRequest;
+  Duration _deadline;
+  Timer _deadlineTimer;
+
+  _HttpResponse(Uri uri,
+                String protocolVersion,
+                _HttpOutgoing outgoing,
+                HttpHeaders defaultHeaders,
+                String serverHeader)
+      : super(uri, protocolVersion, outgoing, initialHeaders: defaultHeaders) {
+    if (serverHeader != null) headers.set('server', serverHeader);
+  }
+
+  bool get _isConnectionClosed => _httpRequest._httpConnection._isClosing;
+
+  List<Cookie> get cookies {
+    if (_cookies == null) _cookies = new List<Cookie>();
+    return _cookies;
+  }
+
+  int get statusCode => _statusCode;
+  void set statusCode(int statusCode) {
+    if (_outgoing.headersWritten) throw new StateError("Header already sent");
+    _statusCode = statusCode;
+  }
+
+  String get reasonPhrase => _findReasonPhrase(statusCode);
+  void set reasonPhrase(String reasonPhrase) {
+    if (_outgoing.headersWritten) throw new StateError("Header already sent");
+    _reasonPhrase = reasonPhrase;
+  }
+
+  Future redirect(Uri location, {int status: HttpStatus.MOVED_TEMPORARILY}) {
+    if (_outgoing.headersWritten) throw new StateError("Header already sent");
+    statusCode = status;
+    headers.set("location", location.toString());
+    return close();
+  }
+
+  Future<Socket> detachSocket({bool writeHeaders: true}) {
+    if (_outgoing.headersWritten) throw new StateError("Headers already sent");
+    deadline = null;  // Be sure to stop any deadline.
+    var future = _httpRequest._httpConnection.detachSocket();
+    if (writeHeaders) {
+      var headersFuture = _outgoing.writeHeaders(drainRequest: false,
+                                                 setOutgoing: false);
+      assert(headersFuture == null);
+    } else {
+      // Imitate having written the headers.
+      _outgoing.headersWritten = true;
+    }
+    // Close connection so the socket is 'free'.
+    close();
+    done.catchError((_) {
+      // Catch any error on done, as they automatically will be
+      // propagated to the websocket.
+    });
+    return future;
+  }
+
+  HttpConnectionInfo get connectionInfo => _httpRequest.connectionInfo;
+
+  Duration get deadline => _deadline;
+
+  void set deadline(Duration d) {
+    if (_deadlineTimer != null) _deadlineTimer.cancel();
+    _deadline = d;
+
+    if (_deadline == null) return;
+    _deadlineTimer = new Timer(_deadline, () {
+      _httpRequest._httpConnection.destroy();
+    });
+  }
+
+  void _writeHeader() {
+    Uint8List buffer = new Uint8List(_OUTGOING_BUFFER_SIZE);
+    int offset = 0;
+
+    void write(List<int> bytes) {
+      int len = bytes.length;
+      for (int i = 0; i < len; i++) {
+        buffer[offset + i] = bytes[i];
+      }
+      offset += len;
+    }
+
+    // Write status line.
+    if (headers.protocolVersion == "1.1") {
+      write(_Const.HTTP11);
+    } else {
+      write(_Const.HTTP10);
+    }
+    buffer[offset++] = _CharCode.SP;
+    write(statusCode.toString().codeUnits);
+    buffer[offset++] = _CharCode.SP;
+    write(reasonPhrase.codeUnits);
+    buffer[offset++] = _CharCode.CR;
+    buffer[offset++] = _CharCode.LF;
+
+    var session = _httpRequest._session;
+    if (session != null && !session._destroyed) {
+      // Mark as not new.
+      session._isNew = false;
+      // Make sure we only send the current session id.
+      bool found = false;
+      for (int i = 0; i < cookies.length; i++) {
+        if (cookies[i].name.toUpperCase() == _DART_SESSION_ID) {
+          cookies[i]
+              ..value = session.id
+              ..httpOnly = true
+              ..path = "/";
+          found = true;
+        }
+      }
+      if (!found) {
+        var cookie = new Cookie(_DART_SESSION_ID, session.id);
+        cookies.add(cookie
+            ..httpOnly = true
+            ..path = "/");
+      }
+    }
+    // Add all the cookies set to the headers.
+    if (_cookies != null) {
+      _cookies.forEach((cookie) {
+        headers.add(HttpHeaders.SET_COOKIE, cookie);
+      });
+    }
+
+    headers._finalize();
+
+    // Write headers.
+    offset = headers._write(buffer, offset);
+    buffer[offset++] = _CharCode.CR;
+    buffer[offset++] = _CharCode.LF;
+    _outgoing.setHeader(buffer, offset);
+  }
+
+  String _findReasonPhrase(int statusCode) {
+    if (_reasonPhrase != null) {
+      return _reasonPhrase;
+    }
+
+    switch (statusCode) {
+      case HttpStatus.CONTINUE: return "Continue";
+      case HttpStatus.SWITCHING_PROTOCOLS: return "Switching Protocols";
+      case HttpStatus.OK: return "OK";
+      case HttpStatus.CREATED: return "Created";
+      case HttpStatus.ACCEPTED: return "Accepted";
+      case HttpStatus.NON_AUTHORITATIVE_INFORMATION:
+        return "Non-Authoritative Information";
+      case HttpStatus.NO_CONTENT: return "No Content";
+      case HttpStatus.RESET_CONTENT: return "Reset Content";
+      case HttpStatus.PARTIAL_CONTENT: return "Partial Content";
+      case HttpStatus.MULTIPLE_CHOICES: return "Multiple Choices";
+      case HttpStatus.MOVED_PERMANENTLY: return "Moved Permanently";
+      case HttpStatus.FOUND: return "Found";
+      case HttpStatus.SEE_OTHER: return "See Other";
+      case HttpStatus.NOT_MODIFIED: return "Not Modified";
+      case HttpStatus.USE_PROXY: return "Use Proxy";
+      case HttpStatus.TEMPORARY_REDIRECT: return "Temporary Redirect";
+      case HttpStatus.BAD_REQUEST: return "Bad Request";
+      case HttpStatus.UNAUTHORIZED: return "Unauthorized";
+      case HttpStatus.PAYMENT_REQUIRED: return "Payment Required";
+      case HttpStatus.FORBIDDEN: return "Forbidden";
+      case HttpStatus.NOT_FOUND: return "Not Found";
+      case HttpStatus.METHOD_NOT_ALLOWED: return "Method Not Allowed";
+      case HttpStatus.NOT_ACCEPTABLE: return "Not Acceptable";
+      case HttpStatus.PROXY_AUTHENTICATION_REQUIRED:
+        return "Proxy Authentication Required";
+      case HttpStatus.REQUEST_TIMEOUT: return "Request Time-out";
+      case HttpStatus.CONFLICT: return "Conflict";
+      case HttpStatus.GONE: return "Gone";
+      case HttpStatus.LENGTH_REQUIRED: return "Length Required";
+      case HttpStatus.PRECONDITION_FAILED: return "Precondition Failed";
+      case HttpStatus.REQUEST_ENTITY_TOO_LARGE:
+        return "Request Entity Too Large";
+      case HttpStatus.REQUEST_URI_TOO_LONG: return "Request-URI Too Large";
+      case HttpStatus.UNSUPPORTED_MEDIA_TYPE: return "Unsupported Media Type";
+      case HttpStatus.REQUESTED_RANGE_NOT_SATISFIABLE:
+        return "Requested range not satisfiable";
+      case HttpStatus.EXPECTATION_FAILED: return "Expectation Failed";
+      case HttpStatus.INTERNAL_SERVER_ERROR: return "Internal Server Error";
+      case HttpStatus.NOT_IMPLEMENTED: return "Not Implemented";
+      case HttpStatus.BAD_GATEWAY: return "Bad Gateway";
+      case HttpStatus.SERVICE_UNAVAILABLE: return "Service Unavailable";
+      case HttpStatus.GATEWAY_TIMEOUT: return "Gateway Time-out";
+      case HttpStatus.HTTP_VERSION_NOT_SUPPORTED:
+        return "Http Version not supported";
+      default: return "Status $statusCode";
+    }
+  }
+}
+
+
+class _HttpClientRequest extends _HttpOutboundMessage<HttpClientResponse>
+    implements HttpClientRequest {
+  final String method;
+  final Uri uri;
+  final List<Cookie> cookies = new List<Cookie>();
+
+  // The HttpClient this request belongs to.
+  final _HttpClient _httpClient;
+  final _HttpClientConnection _httpClientConnection;
+
+  final Completer<HttpClientResponse> _responseCompleter
+      = new Completer<HttpClientResponse>();
+
+  final _Proxy _proxy;
+
+  Future<HttpClientResponse> _response;
+
+  // TODO(ajohnsen): Get default value from client?
+  bool _followRedirects = true;
+
+  int _maxRedirects = 5;
+
+  List<RedirectInfo> _responseRedirects = [];
+
+  _HttpClientRequest(_HttpOutgoing outgoing, Uri uri, this.method, this._proxy,
+                     this._httpClient, this._httpClientConnection)
+      : uri = uri,
+        super(uri, "1.1", outgoing) {
+    // GET and HEAD have 'content-length: 0' by default.
+    if (method == "GET" || method == "HEAD") {
+      contentLength = 0;
+    } else {
+      headers.chunkedTransferEncoding = true;
+    }
+  }
+
+  Future<HttpClientResponse> get done {
+    if (_response == null) {
+      _response = Future.wait([_responseCompleter.future, super.done],
+                              eagerError: true)
+        .then((list) => list[0]);
+    }
+    return _response;
+  }
+
+  Future<HttpClientResponse> close() {
+    super.close();
+    return done;
+  }
+
+  int get maxRedirects => _maxRedirects;
+  void set maxRedirects(int maxRedirects) {
+    if (_outgoing.headersWritten) throw new StateError("Request already sent");
+    _maxRedirects = maxRedirects;
+  }
+
+  bool get followRedirects => _followRedirects;
+  void set followRedirects(bool followRedirects) {
+    if (_outgoing.headersWritten) throw new StateError("Request already sent");
+    _followRedirects = followRedirects;
+  }
+
+  HttpConnectionInfo get connectionInfo => _httpClientConnection.connectionInfo;
+
+  void _onIncoming(_HttpIncoming incoming) {
+    var response = new _HttpClientResponse(incoming, this, _httpClient);
+    Future<HttpClientResponse> future;
+    if (followRedirects && response.isRedirect) {
+      if (response.redirects.length < maxRedirects) {
+        // Redirect and drain response.
+        future = response.drain().then((_) => response.redirect());
+      } else {
+        // End with exception, too many redirects.
+        future = response.drain()
+            .then((_) => new Future.error(
+                new RedirectException("Redirect limit exceeded",
+                                      response.redirects)));
+      }
+    } else if (response._shouldAuthenticateProxy) {
+      future = response._authenticate(true);
+    } else if (response._shouldAuthenticate) {
+      future = response._authenticate(false);
+    } else {
+      future = new Future<HttpClientResponse>.value(response);
+    }
+    future.then(
+        (v) => _responseCompleter.complete(v),
+        onError: _responseCompleter.completeError);
+  }
+
+  void _onError(error, StackTrace stackTrace) {
+    _responseCompleter.completeError(error, stackTrace);
+  }
+
+  // Generate the request URI based on the method and proxy.
+  String _requestUri() {
+    // Generate the request URI starting from the path component.
+    String uriStartingFromPath() {
+      String result = uri.path;
+      if (result.isEmpty) result = "/";
+      if (uri.hasQuery) {
+        result = "${result}?${uri.query}";
+      }
+      return result;
+    }
+
+    if (_proxy.isDirect) {
+      return uriStartingFromPath();
+    } else {
+      if (method == "CONNECT") {
+        // For the connect method the request URI is the host:port of
+        // the requested destination of the tunnel (see RFC 2817
+        // section 5.2)
+        return "${uri.host}:${uri.port}";
+      } else {
+        if (_httpClientConnection._proxyTunnel) {
+          return uriStartingFromPath();
+        } else {
+          return uri.removeFragment().toString();
+        }
+      }
+    }
+  }
+
+  void _writeHeader() {
+    Uint8List buffer = new Uint8List(_OUTGOING_BUFFER_SIZE);
+    int offset = 0;
+
+    void write(List<int> bytes) {
+      int len = bytes.length;
+      for (int i = 0; i < len; i++) {
+        buffer[offset + i] = bytes[i];
+      }
+      offset += len;
+    }
+
+    // Write the request method.
+    write(method.codeUnits);
+    buffer[offset++] = _CharCode.SP;
+    // Write the request URI.
+    write(_requestUri().codeUnits);
+    buffer[offset++] = _CharCode.SP;
+    // Write HTTP/1.1.
+    write(_Const.HTTP11);
+    buffer[offset++] = _CharCode.CR;
+    buffer[offset++] = _CharCode.LF;
+
+    // Add the cookies to the headers.
+    if (!cookies.isEmpty) {
+      StringBuffer sb = new StringBuffer();
+      for (int i = 0; i < cookies.length; i++) {
+        if (i > 0) sb.write("; ");
+        sb..write(cookies[i].name)..write("=")..write(cookies[i].value);
+      }
+      headers.add(HttpHeaders.COOKIE, sb.toString());
+    }
+
+    headers._finalize();
+
+    // Write headers.
+    offset = headers._write(buffer, offset);
+    buffer[offset++] = _CharCode.CR;
+    buffer[offset++] = _CharCode.LF;
+    _outgoing.setHeader(buffer, offset);
+  }
+}
+
+// Used by _HttpOutgoing as a target of a chunked converter for gzip
+// compression.
+class _HttpGZipSink extends ByteConversionSink {
+  final Function _consume;
+  _HttpGZipSink(this._consume);
+
+  void add(List<int> chunk) {
+    _consume(chunk);
+  }
+
+  void addSlice(List<int> chunk, int start, int end, bool isLast) {
+    if (chunk is Uint8List) {
+      _consume(new Uint8List.view(chunk.buffer, start, end - start));
+    } else {
+      _consume(chunk.sublist(start, end - start));
+    }
+  }
+
+  void close() {}
+}
+
+
+// The _HttpOutgoing handles all of the following:
+//  - Buffering
+//  - GZip compressionm
+//  - Content-Length validation.
+//  - Errors.
+//
+// Most notable is the GZip compression, that uses a double-buffering system,
+// one before gzip (_gzipBuffer) and one after (_buffer).
+class _HttpOutgoing implements StreamConsumer<List<int>> {
+  static const List<int> _footerAndChunk0Length =
+      const [_CharCode.CR, _CharCode.LF, 0x30, _CharCode.CR, _CharCode.LF,
+             _CharCode.CR, _CharCode.LF];
+
+  static const List<int> _chunk0Length =
+      const [0x30, _CharCode.CR, _CharCode.LF, _CharCode.CR, _CharCode.LF];
+
+  final Completer _doneCompleter = new Completer();
+  final Socket socket;
+
+  bool ignoreBody = false;
+  bool headersWritten = false;
+
+  Uint8List _buffer;
+  int _length = 0;
+
+  Future _closeFuture;
+
+  bool chunked = false;
+  int _pendingChunkedFooter = 0;
+
+  int contentLength;
+  int _bytesWritten = 0;
+
+  bool _gzip = false;
+  ByteConversionSink _gzipSink;
+  // _gzipAdd is set iff the sink is being added to. It's used to specify where
+  // gzipped data should be taken (sometimes a controller, sometimes a socket).
+  Function _gzipAdd;
+  Uint8List _gzipBuffer;
+  int _gzipBufferLength = 0;
+
+  bool _socketError = false;
+
+  _HttpOutboundMessage outbound;
+
+  _HttpOutgoing(this.socket);
+
+  // Returns either a future or 'null', if it was able to write headers
+  // immediately.
+  Future writeHeaders({bool drainRequest: true, bool setOutgoing: true}) {
+    Future write() {
+      try {
+        outbound._writeHeader();
+      } catch (_) {
+        // Headers too large.
+        return new Future.error(new HttpException(
+            "Headers size exceeded the of '$_OUTGOING_BUFFER_SIZE'"
+            " bytes"));
+      }
+      return null;
+    }
+
+    if (headersWritten) return null;
+    headersWritten = true;
+    Future drainFuture;
+    bool gzip = false;
+    if (outbound is _HttpResponse) {
+      // Server side.
+      _HttpResponse response = outbound;
+      if (response._httpRequest._httpServer.autoCompress &&
+          outbound.bufferOutput &&
+          outbound.headers.chunkedTransferEncoding) {
+        List acceptEncodings =
+            response._httpRequest.headers[HttpHeaders.ACCEPT_ENCODING];
+        List contentEncoding = outbound.headers[HttpHeaders.CONTENT_ENCODING];
+        if (acceptEncodings != null &&
+            acceptEncodings
+                .expand((list) => list.split(","))
+                .any((encoding) => encoding.trim().toLowerCase() == "gzip") &&
+            contentEncoding == null) {
+          outbound.headers.set(HttpHeaders.CONTENT_ENCODING, "gzip");
+          gzip = true;
+        }
+      }
+      if (drainRequest && !response._httpRequest._incoming.hasSubscriber) {
+        drainFuture = response._httpRequest.drain().catchError((_) {});
+      }
+    } else {
+      drainRequest = false;
+    }
+    if (ignoreBody) {
+      return write();
+    }
+    if (setOutgoing) {
+      int contentLength = outbound.headers.contentLength;
+      if (outbound.headers.chunkedTransferEncoding) {
+        chunked = true;
+        if (gzip) this.gzip = true;
+      } else if (contentLength >= 0) {
+        this.contentLength = contentLength;
+      }
+    }
+    if (drainFuture != null) {
+      return drainFuture.then((_) => write());
+    }
+    return write();
+  }
+
+
+  Future addStream(Stream<List<int>> stream) {
+    if (_socketError) {
+      stream.listen(null).cancel();
+      return new Future.value(outbound);
+    }
+    if (ignoreBody) {
+      stream.drain().catchError((_) {});
+      var future = writeHeaders();
+      if (future != null) {
+        return future.then((_) => close());
+      }
+      return close();
+    }
+    var sub;
+    // Use new stream so we are able to pause (see below listen). The
+    // alternative is to use stream.extand, but that won't give us a way of
+    // pausing.
+    var controller = new StreamController(
+        onPause: () => sub.pause(),
+        onResume: () => sub.resume(),
+        sync: true);
+
+    void onData(data) {
+      if (_socketError) return;
+      if (data.length == 0) return;
+      if (chunked) {
+        if (_gzip) {
+          _gzipAdd = controller.add;
+          _addGZipChunk(data, _gzipSink.add);
+          _gzipAdd = null;
+          return;
+        }
+        _addChunk(_chunkHeader(data.length), controller.add);
+        _pendingChunkedFooter = 2;
+      } else {
+        if (contentLength != null) {
+          _bytesWritten += data.length;
+          if (_bytesWritten > contentLength) {
+            controller.addError(new HttpException(
+                "Content size exceeds specified contentLength. "
+                "$_bytesWritten bytes written while expected "
+                "$contentLength. "
+                "[${new String.fromCharCodes(data)}]"));
+            return;
+          }
+        }
+      }
+      _addChunk(data, controller.add);
+    }
+
+    sub = stream.listen(
+        onData,
+        onError: controller.addError,
+        onDone: controller.close,
+        cancelOnError: true);
+    // Write headers now that we are listening to the stream.
+    if (!headersWritten) {
+      var future = writeHeaders();
+      if (future != null) {
+        // While incoming is being drained, the pauseFuture is non-null. Pause
+        // output until it's drained.
+        sub.pause(future);
+      }
+    }
+    return socket.addStream(controller.stream)
+        .then((_) {
+          return outbound;
+        }, onError: (error, stackTrace) {
+          // Be sure to close it in case of an error.
+          if (_gzip) _gzipSink.close();
+          _socketError = true;
+          _doneCompleter.completeError(error, stackTrace);
+          if (_ignoreError(error)) {
+            return outbound;
+          } else {
+            throw error;
+          }
+        });
+  }
+
+  Future close() {
+    // If we are already closed, return that future.
+    if (_closeFuture != null) return _closeFuture;
+    // If we earlier saw an error, return immediate. The notification to
+    // _Http*Connection is already done.
+    if (_socketError) return new Future.value(outbound);
+    if (outbound._isConnectionClosed) return new Future.value(outbound);
+    if (!headersWritten && !ignoreBody) {
+      if (outbound.headers.contentLength == -1) {
+        // If no body was written, ignoreBody is false (it's not a HEAD
+        // request) and the content-length is unspecified, set contentLength to
+        // 0.
+        outbound.headers.chunkedTransferEncoding = false;
+        outbound.headers.contentLength = 0;
+      } else if (outbound.headers.contentLength > 0) {
+        var error = new HttpException(
+              "No content even though contentLength was specified to be "
+              "greater than 0: ${outbound.headers.contentLength}.",
+              uri: outbound._uri);
+        _doneCompleter.completeError(error);
+        return _closeFuture = new Future.error(error);
+      }
+    }
+    // If contentLength was specified, validate it.
+    if (contentLength != null) {
+      if (_bytesWritten < contentLength) {
+        var error = new HttpException(
+            "Content size below specified contentLength. "
+            " $_bytesWritten bytes written but expected "
+            "$contentLength.",
+            uri: outbound._uri);
+        _doneCompleter.completeError(error);
+        return _closeFuture = new Future.error(error);
+      }
+    }
+
+    Future finalize() {
+      // In case of chunked encoding (and gzip), handle remaining gzip data and
+      // append the 'footer' for chunked encoding.
+      if (chunked) {
+        if (_gzip) {
+          _gzipAdd = socket.add;
+          if (_gzipBufferLength > 0) {
+            _gzipSink.add(new Uint8List.view(
+                _gzipBuffer.buffer, 0, _gzipBufferLength));
+          }
+          _gzipBuffer = null;
+          _gzipSink.close();
+          _gzipAdd = null;
+        }
+        _addChunk(_chunkHeader(0), socket.add);
+      }
+      // Add any remaining data in the buffer.
+      if (_length > 0) {
+        socket.add(new Uint8List.view(_buffer.buffer, 0, _length));
+      }
+      // Clear references, for better GC.
+      _buffer = null;
+      // And finally flush it. As we support keep-alive, never close it from
+      // here. Once the socket is flushed, we'll be able to reuse it (signaled
+      // by the 'done' future).
+      return socket.flush()
+        .then((_) {
+          _doneCompleter.complete(socket);
+          return outbound;
+        }, onError: (error, stackTrace) {
+          _doneCompleter.completeError(error, stackTrace);
+          if (_ignoreError(error)) {
+            return outbound;
+          } else {
+            throw error;
+          }
+        });
+    }
+
+    var future = writeHeaders();
+    if (future != null) {
+      return _closeFuture = future.whenComplete(finalize);
+    }
+    return _closeFuture = finalize();
+  }
+
+  Future get done => _doneCompleter.future;
+
+  void setHeader(List<int> data, int length) {
+    assert(_length == 0);
+    assert(data.length == _OUTGOING_BUFFER_SIZE);
+    _buffer = data;
+    _length = length;
+  }
+
+  void set gzip(bool value) {
+    _gzip = value;
+    if (_gzip) {
+      _gzipBuffer = new Uint8List(_OUTGOING_BUFFER_SIZE);
+      assert(_gzipSink == null);
+      _gzipSink = new ZLibEncoder(gzip: true)
+          .startChunkedConversion(
+              new _HttpGZipSink((data) {
+                // We are closing down prematurely, due to an error. Discard.
+                if (_gzipAdd == null) return;
+                _addChunk(_chunkHeader(data.length), _gzipAdd);
+                _pendingChunkedFooter = 2;
+                _addChunk(data, _gzipAdd);
+              }));
+    }
+  }
+
+  bool _ignoreError(error)
+    => (error is SocketException || error is TlsException) &&
+       outbound is HttpResponse;
+
+  void _addGZipChunk(chunk, void add(List<int> data)) {
+    if (!outbound.bufferOutput) {
+      add(chunk);
+      return;
+    }
+    if (chunk.length > _gzipBuffer.length - _gzipBufferLength) {
+      add(new Uint8List.view(
+          _gzipBuffer.buffer, 0, _gzipBufferLength));
+      _gzipBuffer = new Uint8List(_OUTGOING_BUFFER_SIZE);
+      _gzipBufferLength = 0;
+    }
+    if (chunk.length > _OUTGOING_BUFFER_SIZE) {
+      add(chunk);
+    } else {
+      _gzipBuffer.setRange(_gzipBufferLength,
+                           _gzipBufferLength + chunk.length,
+                           chunk);
+      _gzipBufferLength += chunk.length;
+    }
+  }
+
+  void _addChunk(chunk, void add(List<int> data)) {
+    if (!outbound.bufferOutput) {
+      if (_buffer != null) {
+        // If _buffer is not null, we have not written the header yet. Write
+        // it now.
+        add(new Uint8List.view(_buffer.buffer, 0, _length));
+        _buffer = null;
+        _length = 0;
+      }
+      add(chunk);
+      return;
+    }
+    if (chunk.length > _buffer.length - _length) {
+      add(new Uint8List.view(_buffer.buffer, 0, _length));
+      _buffer = new Uint8List(_OUTGOING_BUFFER_SIZE);
+      _length = 0;
+    }
+    if (chunk.length > _OUTGOING_BUFFER_SIZE) {
+      add(chunk);
+    } else {
+      _buffer.setRange(_length, _length + chunk.length, chunk);
+      _length += chunk.length;
+    }
+  }
+
+  List<int> _chunkHeader(int length) {
+    const hexDigits = const [0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+                             0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46];
+    if (length == 0) {
+      if (_pendingChunkedFooter == 2) return _footerAndChunk0Length;
+      return _chunk0Length;
+    }
+    int size = _pendingChunkedFooter;
+    int len = length;
+    // Compute a fast integer version of (log(length + 1) / log(16)).ceil().
+    while (len > 0) {
+      size++;
+      len >>= 4;
+    }
+    var footerAndHeader = new Uint8List(size + 2);
+    if (_pendingChunkedFooter == 2) {
+      footerAndHeader[0] = _CharCode.CR;
+      footerAndHeader[1] = _CharCode.LF;
+    }
+    int index = size;
+    while (index > _pendingChunkedFooter) {
+      footerAndHeader[--index] = hexDigits[length & 15];
+      length = length >> 4;
+    }
+    footerAndHeader[size + 0] = _CharCode.CR;
+    footerAndHeader[size + 1] = _CharCode.LF;
+    return footerAndHeader;
+  }
+}
+
+class _HttpClientConnection {
+  final String key;
+  final Socket _socket;
+  final bool _proxyTunnel;
+  final SecurityContext _context;
+  final _HttpParser _httpParser;
+  StreamSubscription _subscription;
+  final _HttpClient _httpClient;
+  bool _dispose = false;
+  Timer _idleTimer;
+  bool closed = false;
+  Uri _currentUri;
+
+  Completer<_HttpIncoming> _nextResponseCompleter;
+  Future _streamFuture;
+
+  _HttpClientConnection(this.key, this._socket, this._httpClient,
+                        [this._proxyTunnel = false, this._context])
+      : _httpParser = new _HttpParser.responseParser() {
+    _httpParser.listenToStream(_socket);
+
+    // Set up handlers on the parser here, so we are sure to get 'onDone' from
+    // the parser.
+    _subscription = _httpParser.listen(
+        (incoming) {
+          // Only handle one incoming response at the time. Keep the
+          // stream paused until the response have been processed.
+          _subscription.pause();
+          // We assume the response is not here, until we have send the request.
+          if (_nextResponseCompleter == null) {
+            throw new HttpException(
+                "Unexpected response (unsolicited response without request).",
+                uri: _currentUri);
+          }
+
+          // Check for status code '100 Continue'. In that case just
+          // consume that response as the final response will follow
+          // it. There is currently no API for the client to wait for
+          // the '100 Continue' response.
+          if (incoming.statusCode == 100) {
+            incoming.drain().then((_) {
+              _subscription.resume();
+            }).catchError((error, [StackTrace stackTrace]) {
+              _nextResponseCompleter.completeError(
+                  new HttpException(error.message, uri: _currentUri),
+                  stackTrace);
+              _nextResponseCompleter = null;
+            });
+          } else {
+            _nextResponseCompleter.complete(incoming);
+            _nextResponseCompleter = null;
+          }
+        },
+        onError: (error, [StackTrace stackTrace]) {
+          if (_nextResponseCompleter != null) {
+            _nextResponseCompleter.completeError(
+                new HttpException(error.message, uri: _currentUri),
+                stackTrace);
+            _nextResponseCompleter = null;
+          }
+        },
+        onDone: () {
+          if (_nextResponseCompleter != null) {
+            _nextResponseCompleter.completeError(new HttpException(
+                "Connection closed before response was received",
+                uri: _currentUri));
+            _nextResponseCompleter = null;
+          }
+          close();
+        });
+  }
+
+  _HttpClientRequest send(Uri uri, int port, String method, _Proxy proxy) {
+    if (closed) {
+      throw new HttpException(
+          "Socket closed before request was sent", uri: uri);
+    }
+    _currentUri = uri;
+    // Start with pausing the parser.
+    _subscription.pause();
+    _ProxyCredentials proxyCreds;  // Credentials used to authorize proxy.
+    _SiteCredentials creds;  // Credentials used to authorize this request.
+    var outgoing = new _HttpOutgoing(_socket);
+    // Create new request object, wrapping the outgoing connection.
+    var request = new _HttpClientRequest(outgoing,
+                                         uri,
+                                         method,
+                                         proxy,
+                                         _httpClient,
+                                         this);
+    // For the Host header an IPv6 address must be enclosed in []'s.
+    var host = uri.host;
+    if (host.contains(':')) host = "[$host]";
+    request.headers
+        ..host = host
+        ..port = port
+        .._add(HttpHeaders.ACCEPT_ENCODING, "gzip");
+    if (_httpClient.userAgent != null) {
+      request.headers._add('user-agent', _httpClient.userAgent);
+    }
+    if (proxy.isAuthenticated) {
+      // If the proxy configuration contains user information use that
+      // for proxy basic authorization.
+      String auth = _CryptoUtils.bytesToBase64(
+          UTF8.encode("${proxy.username}:${proxy.password}"));
+      request.headers.set(HttpHeaders.PROXY_AUTHORIZATION, "Basic $auth");
+    } else if (!proxy.isDirect && _httpClient._proxyCredentials.length > 0) {
+      proxyCreds = _httpClient._findProxyCredentials(proxy);
+      if (proxyCreds != null) {
+        proxyCreds.authorize(request);
+      }
+    }
+    if (uri.userInfo != null && !uri.userInfo.isEmpty) {
+      // If the URL contains user information use that for basic
+      // authorization.
+      String auth =
+          _CryptoUtils.bytesToBase64(UTF8.encode(uri.userInfo));
+      request.headers.set(HttpHeaders.AUTHORIZATION, "Basic $auth");
+    } else {
+      // Look for credentials.
+      creds = _httpClient._findCredentials(uri);
+      if (creds != null) {
+        creds.authorize(request);
+      }
+    }
+    // Start sending the request (lazy, delayed until the user provides
+    // data).
+    _httpParser.isHead = method == "HEAD";
+    _streamFuture = outgoing.done
+        .then((s) {
+          // Request sent, set up response completer.
+          _nextResponseCompleter = new Completer();
+
+          // Listen for response.
+          _nextResponseCompleter.future
+              .then((incoming) {
+                _currentUri = null;
+                incoming.dataDone.then((closing) {
+                  if (incoming.upgraded) {
+                    _httpClient._connectionClosed(this);
+                    startTimer();
+                    return;
+                  }
+                  if (closed) return;
+                  if (!closing &&
+                      !_dispose &&
+                      incoming.headers.persistentConnection &&
+                      request.persistentConnection) {
+                    // Return connection, now we are done.
+                    _httpClient._returnConnection(this);
+                    _subscription.resume();
+                  } else {
+                    destroy();
+                  }
+                });
+                // For digest authentication if proxy check if the proxy
+                // requests the client to start using a new nonce for proxy
+                // authentication.
+                if (proxyCreds != null &&
+                    proxyCreds.scheme == _AuthenticationScheme.DIGEST) {
+                  var authInfo = incoming.headers["proxy-authentication-info"];
+                  if (authInfo != null && authInfo.length == 1) {
+                    var header =
+                        _HeaderValue.parse(
+                            authInfo[0], parameterSeparator: ',');
+                    var nextnonce = header.parameters["nextnonce"];
+                    if (nextnonce != null) proxyCreds.nonce = nextnonce;
+                  }
+                }
+                // For digest authentication check if the server requests the
+                // client to start using a new nonce.
+                if (creds != null &&
+                    creds.scheme == _AuthenticationScheme.DIGEST) {
+                  var authInfo = incoming.headers["authentication-info"];
+                  if (authInfo != null && authInfo.length == 1) {
+                    var header =
+                        _HeaderValue.parse(
+                            authInfo[0], parameterSeparator: ',');
+                    var nextnonce = header.parameters["nextnonce"];
+                    if (nextnonce != null) creds.nonce = nextnonce;
+                  }
+                }
+                request._onIncoming(incoming);
+              })
+              // If we see a state error, we failed to get the 'first'
+              // element.
+              .catchError((error) {
+                throw new HttpException(
+                    "Connection closed before data was received", uri: uri);
+              }, test: (error) => error is StateError)
+              .catchError((error, stackTrace) {
+                // We are done with the socket.
+                destroy();
+                request._onError(error, stackTrace);
+              });
+
+          // Resume the parser now we have a handler.
+          _subscription.resume();
+          return s;
+        }, onError: (e) {
+          destroy();
+        });
+    return request;
+  }
+
+  Future<Socket> detachSocket() {
+    return _streamFuture.then(
+        (_) => new _DetachedSocket(_socket, _httpParser.detachIncoming()));
+  }
+
+  void destroy() {
+    closed = true;
+    _httpClient._connectionClosed(this);
+    _socket.destroy();
+  }
+
+  void close() {
+    closed = true;
+    _httpClient._connectionClosed(this);
+    _streamFuture
+          // TODO(ajohnsen): Add timeout.
+        .then((_) => _socket.destroy());
+  }
+
+  Future<_HttpClientConnection> createProxyTunnel(host, port, proxy, callback) {
+    _HttpClientRequest request =
+        send(new Uri(host: host, port: port),
+             port,
+             "CONNECT",
+             proxy);
+    if (proxy.isAuthenticated) {
+      // If the proxy configuration contains user information use that
+      // for proxy basic authorization.
+      String auth = _CryptoUtils.bytesToBase64(
+          UTF8.encode("${proxy.username}:${proxy.password}"));
+      request.headers.set(HttpHeaders.PROXY_AUTHORIZATION, "Basic $auth");
+    }
+    return request.close()
+        .then((response) {
+          if (response.statusCode != HttpStatus.OK) {
+            throw "Proxy failed to establish tunnel "
+                  "(${response.statusCode} ${response.reasonPhrase})";
+          }
+          var socket = (response as _HttpClientResponse)._httpRequest
+              ._httpClientConnection._socket;
+          return SecureSocket.secure(
+              socket,
+              host: host,
+              context: _context,
+              onBadCertificate: callback);
+        })
+        .then((secureSocket) {
+          String key = _HttpClientConnection.makeKey(true, host, port);
+          return new _HttpClientConnection(
+              key, secureSocket, request._httpClient, true);
+        });
+  }
+
+  HttpConnectionInfo get connectionInfo => _HttpConnectionInfo.create(_socket);
+
+  static makeKey(bool isSecure, String host, int port) {
+    return isSecure ? "ssh:$host:$port" : "$host:$port";
+  }
+
+  void stopTimer() {
+    if (_idleTimer != null) {
+      _idleTimer.cancel();
+      _idleTimer = null;
+    }
+  }
+
+  void startTimer() {
+    assert(_idleTimer == null);
+    _idleTimer = new Timer(
+        _httpClient.idleTimeout,
+        () {
+          _idleTimer = null;
+          close();
+        });
+  }
+}
+
+class _ConnectionInfo {
+  final _HttpClientConnection connection;
+  final _Proxy proxy;
+
+  _ConnectionInfo(this.connection, this.proxy);
+}
+
+
+class _ConnectionTarget {
+  // Unique key for this connection target.
+  final String key;
+  final String host;
+  final int port;
+  final bool isSecure;
+  final SecurityContext context;
+  final Set<_HttpClientConnection> _idle = new HashSet();
+  final Set<_HttpClientConnection> _active = new HashSet();
+  final Queue _pending = new ListQueue();
+  int _connecting = 0;
+
+  _ConnectionTarget(this.key,
+                    this.host,
+                    this.port,
+                    this.isSecure,
+                    this.context);
+
+  bool get isEmpty => _idle.isEmpty && _active.isEmpty && _connecting == 0;
+
+  bool get hasIdle => _idle.isNotEmpty;
+
+  bool get hasActive => _active.isNotEmpty || _connecting > 0;
+
+  _HttpClientConnection takeIdle() {
+    assert(hasIdle);
+    _HttpClientConnection connection = _idle.first;
+    _idle.remove(connection);
+    connection.stopTimer();
+    _active.add(connection);
+    return connection;
+  }
+
+  _checkPending() {
+    if (_pending.isNotEmpty) {
+      _pending.removeFirst()();
+    }
+  }
+
+  void addNewActive(_HttpClientConnection connection) {
+    _active.add(connection);
+  }
+
+  void returnConnection(_HttpClientConnection connection) {
+    assert(_active.contains(connection));
+    _active.remove(connection);
+    _idle.add(connection);
+    connection.startTimer();
+    _checkPending();
+  }
+
+  void connectionClosed(_HttpClientConnection connection) {
+    assert(!_active.contains(connection) || !_idle.contains(connection));
+    _active.remove(connection);
+    _idle.remove(connection);
+    _checkPending();
+  }
+
+  void close(bool force) {
+    for (var c in _idle.toList()) {
+      c.close();
+    }
+    if (force) {
+      for (var c in _active.toList()) {
+        c.destroy();
+      }
+    }
+  }
+
+  Future<_ConnectionInfo> connect(String uriHost,
+                                  int uriPort,
+                                  _Proxy proxy,
+                                  _HttpClient client) {
+    if (hasIdle) {
+      var connection = takeIdle();
+      client._connectionsChanged();
+      return new Future.value(new _ConnectionInfo(connection, proxy));
+    }
+    if (client.maxConnectionsPerHost != null &&
+        _active.length + _connecting >= client.maxConnectionsPerHost) {
+      var completer = new Completer();
+      _pending.add(() {
+        connect(uriHost, uriPort, proxy, client)
+            .then(completer.complete, onError: completer.completeError);
+      });
+      return completer.future;
+    }
+    var currentBadCertificateCallback = client._badCertificateCallback;
+
+    bool callback(X509Certificate certificate) {
+      if (currentBadCertificateCallback == null) return false;
+      return currentBadCertificateCallback(certificate, uriHost, uriPort);
+    }
+
+    Future socketFuture = (isSecure && proxy.isDirect
+        ? SecureSocket.connect(host,
+                               port,
+                               context: context,
+                               onBadCertificate: callback)
+        : Socket.connect(host, port));
+    _connecting++;
+    return socketFuture.then((socket) {
+        _connecting--;
+        socket.setOption(SocketOption.TCP_NODELAY, true);
+        var connection =
+            new _HttpClientConnection(key, socket, client, false, context);
+        if (isSecure && !proxy.isDirect) {
+          connection._dispose = true;
+          return connection.createProxyTunnel(uriHost, uriPort, proxy, callback)
+              .then((tunnel) {
+                client._getConnectionTarget(uriHost, uriPort, true)
+                    .addNewActive(tunnel);
+                return new _ConnectionInfo(tunnel, proxy);
+              });
+        } else {
+          addNewActive(connection);
+          return new _ConnectionInfo(connection, proxy);
+        }
+      }, onError: (error) {
+        _connecting--;
+        _checkPending();
+        throw error;
+      });
+  }
+}
+
+typedef bool BadCertificateCallback(X509Certificate cr, String host, int port);
+
+class _HttpClient implements HttpClient {
+  bool _closing = false;
+  bool _closingForcefully = false;
+  final Map<String, _ConnectionTarget> _connectionTargets
+      = new HashMap<String, _ConnectionTarget>();
+  final List<_Credentials> _credentials = [];
+  final List<_ProxyCredentials> _proxyCredentials = [];
+  final SecurityContext _context;
+  Function _authenticate;
+  Function _authenticateProxy;
+  Function _findProxy = HttpClient.findProxyFromEnvironment;
+  Duration _idleTimeout = const Duration(seconds: 15);
+  BadCertificateCallback _badCertificateCallback;
+
+  Duration get idleTimeout => _idleTimeout;
+
+  int maxConnectionsPerHost;
+
+  bool autoUncompress = true;
+
+  String userAgent = _getHttpVersion();
+
+  _HttpClient(SecurityContext this._context);
+
+  void set idleTimeout(Duration timeout) {
+    _idleTimeout = timeout;
+    for (var c in _connectionTargets.values) {
+      for (var idle in c._idle) {
+        // Reset timer. This is fine, as it's not happening often.
+        idle.stopTimer();
+        idle.startTimer();
+      }
+    }
+  }
+
+  set badCertificateCallback(bool callback(X509Certificate cert,
+                                           String host,
+                                           int port)) {
+    _badCertificateCallback = callback;
+  }
+
+
+  Future<HttpClientRequest> open(String method,
+                                 String host,
+                                 int port,
+                                 String path) {
+    const int hashMark = 0x23;
+    const int questionMark = 0x3f;
+    int fragmentStart = path.length;
+    int queryStart = path.length;
+    for (int i = path.length - 1; i >= 0; i--) {
+      var char = path.codeUnitAt(i);
+      if (char == hashMark) {
+        fragmentStart = i;
+        queryStart = i;
+      } else if (char == questionMark) {
+        queryStart = i;
+      }
+    }
+    String query = null;
+    if (queryStart < fragmentStart) {
+      query = path.substring(queryStart + 1, fragmentStart);
+      path = path.substring(0, queryStart);
+    }
+    Uri uri = new Uri(scheme: "http", host: host, port: port,
+                      path: path, query: query);
+    return _openUrl(method, uri);
+  }
+
+  Future<HttpClientRequest> openUrl(String method, Uri url)
+      => _openUrl(method, url);
+
+  Future<HttpClientRequest> get(String host, int port, String path)
+      => open("get", host, port, path);
+
+  Future<HttpClientRequest> getUrl(Uri url) => _openUrl("get", url);
+
+  Future<HttpClientRequest> post(String host, int port, String path)
+      => open("post", host, port, path);
+
+  Future<HttpClientRequest> postUrl(Uri url) => _openUrl("post", url);
+
+  Future<HttpClientRequest> put(String host, int port, String path)
+      => open("put", host, port, path);
+
+  Future<HttpClientRequest> putUrl(Uri url) => _openUrl("put", url);
+
+  Future<HttpClientRequest> delete(String host, int port, String path)
+      => open("delete", host, port, path);
+
+  Future<HttpClientRequest> deleteUrl(Uri url) => _openUrl("delete", url);
+
+  Future<HttpClientRequest> head(String host, int port, String path)
+      => open("head", host, port, path);
+
+  Future<HttpClientRequest> headUrl(Uri url) => _openUrl("head", url);
+
+  Future<HttpClientRequest> patch(String host, int port, String path)
+      => open("patch", host, port, path);
+
+  Future<HttpClientRequest> patchUrl(Uri url) => _openUrl("patch", url);
+
+  void close({bool force: false}) {
+    _closing = true;
+    _closingForcefully = force;
+    _closeConnections(_closingForcefully);
+    assert(!_connectionTargets.values.any((s) => s.hasIdle));
+    assert(!force ||
+        !_connectionTargets.values.any((s) => s._active.isNotEmpty));
+  }
+
+  set authenticate(Future<bool> f(Uri url, String scheme, String realm)) {
+    _authenticate = f;
+  }
+
+  void addCredentials(Uri url, String realm, HttpClientCredentials cr) {
+    _credentials.add(new _SiteCredentials(url, realm, cr));
+  }
+
+  set authenticateProxy(
+      Future<bool> f(String host, int port, String scheme, String realm)) {
+    _authenticateProxy = f;
+  }
+
+  void addProxyCredentials(String host,
+                           int port,
+                           String realm,
+                           HttpClientCredentials cr) {
+    _proxyCredentials.add(new _ProxyCredentials(host, port, realm, cr));
+  }
+
+  set findProxy(String f(Uri uri)) => _findProxy = f;
+
+  Future<_HttpClientRequest> _openUrl(String method, Uri uri) {
+    // Ignore any fragments on the request URI.
+    uri = uri.removeFragment();
+
+    if (method == null) {
+      throw new ArgumentError(method);
+    }
+    if (method != "CONNECT") {
+      if (uri.host.isEmpty) {
+        throw new ArgumentError("No host specified in URI $uri");
+      } else if (uri.scheme != "http" && uri.scheme != "https") {
+        throw new ArgumentError(
+            "Unsupported scheme '${uri.scheme}' in URI $uri");
+      }
+    }
+
+    bool isSecure = (uri.scheme == "https");
+    int port = uri.port;
+    if (port == 0) {
+      port = isSecure ?
+          HttpClient.DEFAULT_HTTPS_PORT :
+          HttpClient.DEFAULT_HTTP_PORT;
+    }
+    // Check to see if a proxy server should be used for this connection.
+    var proxyConf = const _ProxyConfiguration.direct();
+    if (_findProxy != null) {
+      // TODO(sgjesse): Keep a map of these as normally only a few
+      // configuration strings will be used.
+      try {
+        proxyConf = new _ProxyConfiguration(_findProxy(uri));
+      } catch (error, stackTrace) {
+        return new Future.error(error, stackTrace);
+      }
+    }
+    return _getConnection(uri.host, port, proxyConf, isSecure)
+        .then((_ConnectionInfo info) {
+
+          _HttpClientRequest send(_ConnectionInfo info) {
+            return info.connection.send(uri,
+                                        port,
+                                        method.toUpperCase(),
+                                        info.proxy);
+          }
+
+          // If the connection was closed before the request was sent, create
+          // and use another connection.
+          if (info.connection.closed) {
+            return _getConnection(uri.host, port, proxyConf, isSecure)
+                .then(send);
+          }
+          return send(info);
+        });
+  }
+
+  Future<_HttpClientRequest> _openUrlFromRequest(String method,
+                                                Uri uri,
+                                                _HttpClientRequest previous) {
+    // If the new URI is relative (to either '/' or some sub-path),
+    // construct a full URI from the previous one.
+    Uri resolved = previous.uri.resolveUri(uri);
+    return _openUrl(method, resolved).then((_HttpClientRequest request) {
+
+          request
+              // Only follow redirects if initial request did.
+              ..followRedirects = previous.followRedirects
+              // Allow same number of redirects.
+              ..maxRedirects = previous.maxRedirects;
+          // Copy headers.
+          for (var header in previous.headers._headers.keys) {
+            if (request.headers[header] == null) {
+              request.headers.set(header, previous.headers[header]);
+            }
+          }
+          return request
+              ..headers.chunkedTransferEncoding = false
+              ..contentLength = 0;
+        });
+  }
+
+  // Return a live connection to the idle pool.
+  void _returnConnection(_HttpClientConnection connection) {
+    _connectionTargets[connection.key].returnConnection(connection);
+    _connectionsChanged();
+  }
+
+  // Remove a closed connnection from the active set.
+  void _connectionClosed(_HttpClientConnection connection) {
+    connection.stopTimer();
+    var connectionTarget = _connectionTargets[connection.key];
+    if (connectionTarget != null) {
+      connectionTarget.connectionClosed(connection);
+      if (connectionTarget.isEmpty) {
+        _connectionTargets.remove(connection.key);
+      }
+      _connectionsChanged();
+    }
+  }
+
+  void _connectionsChanged() {
+    if (_closing) {
+      _closeConnections(_closingForcefully);
+    }
+  }
+
+  void _closeConnections(bool force) {
+    for (var connectionTarget in _connectionTargets.values.toList()) {
+      connectionTarget.close(force);
+    }
+  }
+
+  _ConnectionTarget _getConnectionTarget(String host, int port, bool isSecure) {
+    String key = _HttpClientConnection.makeKey(isSecure, host, port);
+    return _connectionTargets.putIfAbsent(key, () {
+      return new _ConnectionTarget(key, host, port, isSecure, _context);
+    });
+  }
+
+  // Get a new _HttpClientConnection, from the matching _ConnectionTarget.
+  Future<_ConnectionInfo> _getConnection(String uriHost,
+                                          int uriPort,
+                                          _ProxyConfiguration proxyConf,
+                                          bool isSecure) {
+    Iterator<_Proxy> proxies = proxyConf.proxies.iterator;
+
+    Future<_ConnectionInfo> connect(error) {
+      if (!proxies.moveNext()) return new Future.error(error);
+      _Proxy proxy = proxies.current;
+      String host = proxy.isDirect ? uriHost: proxy.host;
+      int port = proxy.isDirect ? uriPort: proxy.port;
+      return _getConnectionTarget(host, port, isSecure)
+          .connect(uriHost, uriPort, proxy, this)
+          // On error, continue with next proxy.
+          .catchError(connect);
+    }
+    // Make sure we go through the event loop before taking a
+    // connection from the pool. For long-running synchronous code the
+    // server might have closed the connection, so this lowers the
+    // probability of getting a connection that was already closed.
+    return new Future(() => connect(new HttpException("No proxies given")));
+  }
+
+  _SiteCredentials _findCredentials(Uri url, [_AuthenticationScheme scheme]) {
+    // Look for credentials.
+    _SiteCredentials cr =
+        _credentials.fold(null, (_SiteCredentials prev, value) {
+          var siteCredentials = value as _SiteCredentials;
+          if (siteCredentials.applies(url, scheme)) {
+            if (prev == null) return value;
+            return siteCredentials.uri.path.length > prev.uri.path.length
+                ? siteCredentials
+                : prev;
+          } else {
+            return prev;
+          }
+        });
+    return cr;
+  }
+
+  _ProxyCredentials _findProxyCredentials(_Proxy proxy,
+                                          [_AuthenticationScheme scheme]) {
+    // Look for credentials.
+    var it = _proxyCredentials.iterator;
+    while (it.moveNext()) {
+      if (it.current.applies(proxy, scheme)) {
+        return it.current;
+      }
+    }
+    return null;
+  }
+
+  void _removeCredentials(_Credentials cr) {
+    int index = _credentials.indexOf(cr);
+    if (index != -1) {
+      _credentials.removeAt(index);
+    }
+  }
+
+  void _removeProxyCredentials(_Credentials cr) {
+    int index = _proxyCredentials.indexOf(cr);
+    if (index != -1) {
+      _proxyCredentials.removeAt(index);
+    }
+  }
+
+  static String _findProxyFromEnvironment(Uri url,
+                                          Map<String, String> environment) {
+    checkNoProxy(String option) {
+      if (option == null) return null;
+      Iterator<String> names = option.split(",").map((s) => s.trim()).iterator;
+      while (names.moveNext()) {
+        var name = names.current;
+        if ((name.startsWith("[") &&
+             name.endsWith("]") &&
+             "[${url.host}]" == name) ||
+            (name.isNotEmpty &&
+             url.host.endsWith(name))) {
+          return "DIRECT";
+        }
+      }
+      return null;
+    }
+
+    checkProxy(String option) {
+      if (option == null) return null;
+      option = option.trim();
+      if (option.isEmpty) return null;
+      int pos = option.indexOf("://");
+      if (pos >= 0) {
+        option = option.substring(pos + 3);
+      }
+      pos = option.indexOf("/");
+      if (pos >= 0) {
+        option = option.substring(0, pos);
+      }
+      // Add default port if no port configured.
+      if (option.indexOf("[") == 0) {
+        var pos = option.lastIndexOf(":");
+        if (option.indexOf("]") > pos) option = "$option:1080";
+      } else {
+        if (option.indexOf(":") == -1) option = "$option:1080";
+      }
+      return "PROXY $option";
+    }
+
+    // Default to using the process current environment.
+    if (environment == null) environment = _platformEnvironmentCache;
+
+    String proxyCfg;
+
+    String noProxy = environment["no_proxy"];
+    if (noProxy == null) noProxy = environment["NO_PROXY"];
+    if ((proxyCfg = checkNoProxy(noProxy)) != null) {
+      return proxyCfg;
+    }
+
+    if (url.scheme == "http") {
+      String proxy = environment["http_proxy"];
+      if (proxy == null) proxy = environment["HTTP_PROXY"];
+      if ((proxyCfg = checkProxy(proxy)) != null) {
+        return proxyCfg;
+      }
+    } else if (url.scheme == "https") {
+      String proxy = environment["https_proxy"];
+      if (proxy == null) proxy = environment["HTTPS_PROXY"];
+      if ((proxyCfg = checkProxy(proxy)) != null) {
+        return proxyCfg;
+      }
+    }
+    return "DIRECT";
+  }
+
+  static Map<String, String> _platformEnvironmentCache = Platform.environment;
+}
+
+
+class _HttpConnection
+    extends LinkedListEntry<_HttpConnection> with _ServiceObject {
+  static const _ACTIVE = 0;
+  static const _IDLE = 1;
+  static const _CLOSING = 2;
+  static const _DETACHED = 3;
+
+  // Use HashMap, as we don't need to keep order.
+  static Map<int, _HttpConnection> _connections =
+      new HashMap<int, _HttpConnection>();
+
+  final _socket;
+  final _HttpServer _httpServer;
+  final _HttpParser _httpParser;
+  int _state = _IDLE;
+  StreamSubscription _subscription;
+  bool _idleMark = false;
+  Future _streamFuture;
+
+  _HttpConnection(this._socket, this._httpServer)
+      : _httpParser = new _HttpParser.requestParser() {
+    try { _socket._owner = this; } catch (_) { print(_); }
+    _connections[_serviceId] = this;
+    _httpParser.listenToStream(_socket);
+    _subscription = _httpParser.listen(
+        (incoming) {
+          _httpServer._markActive(this);
+          // If the incoming was closed, close the connection.
+          incoming.dataDone.then((closing) {
+            if (closing) destroy();
+          });
+          // Only handle one incoming request at the time. Keep the
+          // stream paused until the request has been send.
+          _subscription.pause();
+          _state = _ACTIVE;
+          var outgoing = new _HttpOutgoing(_socket);
+          var response = new _HttpResponse(incoming.uri,
+                                           incoming.headers.protocolVersion,
+                                           outgoing,
+                                           _httpServer.defaultResponseHeaders,
+                                           _httpServer.serverHeader);
+          var request = new _HttpRequest(response, incoming, _httpServer, this);
+          _streamFuture = outgoing.done
+              .then((_) {
+                response.deadline = null;
+                if (_state == _DETACHED) return;
+                if (response.persistentConnection &&
+                    request.persistentConnection &&
+                    incoming.fullBodyRead &&
+                    !_httpParser.upgrade &&
+                    !_httpServer.closed) {
+                  _state = _IDLE;
+                  _idleMark = false;
+                  _httpServer._markIdle(this);
+                  // Resume the subscription for incoming requests as the
+                  // request is now processed.
+                  _subscription.resume();
+                } else {
+                  // Close socket, keep-alive not used or body sent before
+                  // received data was handled.
+                  destroy();
+                }
+              }, onError: (_) {
+                destroy();
+              });
+          outgoing.ignoreBody = request.method == "HEAD";
+          response._httpRequest = request;
+          _httpServer._handleRequest(request);
+        },
+        onDone: () {
+          destroy();
+        },
+        onError: (error) {
+          // Ignore failed requests that was closed before headers was received.
+          destroy();
+        });
+  }
+
+  void markIdle() {
+    _idleMark = true;
+  }
+
+  bool get isMarkedIdle => _idleMark;
+
+  void destroy() {
+    if (_state == _CLOSING || _state == _DETACHED) return;
+    _state = _CLOSING;
+    _socket.destroy();
+    _httpServer._connectionClosed(this);
+    _connections.remove(_serviceId);
+  }
+
+  Future<Socket> detachSocket() {
+    _state = _DETACHED;
+    // Remove connection from server.
+    _httpServer._connectionClosed(this);
+
+    _HttpDetachedIncoming detachedIncoming = _httpParser.detachIncoming();
+
+    return _streamFuture.then((_) {
+      _connections.remove(_serviceId);
+      return new _DetachedSocket(_socket, detachedIncoming);
+    });
+  }
+
+  HttpConnectionInfo get connectionInfo => _HttpConnectionInfo.create(_socket);
+
+  bool get _isActive => _state == _ACTIVE;
+  bool get _isIdle => _state == _IDLE;
+  bool get _isClosing => _state == _CLOSING;
+  bool get _isDetached => _state == _DETACHED;
+
+  String get _serviceTypePath => 'io/http/serverconnections';
+  String get _serviceTypeName => 'HttpServerConnection';
+
+  Map _toJSON(bool ref) {
+    var name = "${_socket.address.host}:${_socket.port} <-> "
+        "${_socket.remoteAddress.host}:${_socket.remotePort}";
+    var r = <String, dynamic>{
+      'id': _servicePath,
+      'type': _serviceType(ref),
+      'name': name,
+      'user_name': name,
+    };
+    if (ref) {
+      return r;
+    }
+    r['server'] = _httpServer._toJSON(true);
+    try {
+      r['socket'] = _socket._toJSON(true);
+    } catch (_) {
+      r['socket'] = {
+        'id': _servicePath,
+        'type': '@Socket',
+        'name': 'UserSocket',
+        'user_name': 'UserSocket',
+      };
+    }
+    switch (_state) {
+      case _ACTIVE: r['state'] = "Active"; break;
+      case _IDLE: r['state'] = "Idle"; break;
+      case _CLOSING: r['state'] = "Closing"; break;
+      case _DETACHED: r['state'] = "Detached"; break;
+      default: r['state'] = 'Unknown'; break;
+    }
+    return r;
+  }
+}
+
+
+// HTTP server waiting for socket connections.
+class _HttpServer
+    extends Stream<HttpRequest> with _ServiceObject
+    implements HttpServer {
+  // Use default Map so we keep order.
+  static Map<int, _HttpServer> _servers = new Map<int, _HttpServer>();
+
+  String serverHeader;
+  final HttpHeaders defaultResponseHeaders = _initDefaultResponseHeaders();
+  bool autoCompress = false;
+
+  Duration _idleTimeout;
+  Timer _idleTimer;
+
+  static Future<HttpServer> bind(
+      address, int port, int backlog, bool v6Only, bool shared) {
+    return ServerSocket.bind(
+        address, port, backlog: backlog, v6Only: v6Only, shared: shared)
+            .then((socket) {
+              return new _HttpServer._(socket, true);
+            });
+  }
+
+  static Future<HttpServer> bindSecure(address,
+                                       int port,
+                                       SecurityContext context,
+                                       int backlog,
+                                       bool v6Only,
+                                       bool requestClientCertificate,
+                                       bool shared) {
+    return SecureServerSocket.bind(
+        address,
+        port,
+        context,
+        backlog: backlog,
+        v6Only: v6Only,
+        requestClientCertificate: requestClientCertificate,
+        shared: shared)
+            .then((socket) {
+              return new _HttpServer._(socket, true);
+            });
+  }
+
+  _HttpServer._(this._serverSocket, this._closeServer) {
+    _controller = new StreamController<HttpRequest>(sync: true,
+                                                    onCancel: close);
+    idleTimeout = const Duration(seconds: 120);
+    _servers[_serviceId] = this;
+    _serverSocket._owner = this;
+  }
+
+  _HttpServer.listenOn(this._serverSocket) : _closeServer = false {
+    _controller = new StreamController<HttpRequest>(sync: true,
+                                                    onCancel: close);
+    idleTimeout = const Duration(seconds: 120);
+    _servers[_serviceId] = this;
+    try { _serverSocket._owner = this; } catch (_) {}
+  }
+
+  static HttpHeaders _initDefaultResponseHeaders() {
+    var defaultResponseHeaders = new _HttpHeaders('1.1');
+    defaultResponseHeaders.contentType = ContentType.TEXT;
+    defaultResponseHeaders.set('X-Frame-Options', 'SAMEORIGIN');
+    defaultResponseHeaders.set('X-Content-Type-Options', 'nosniff');
+    defaultResponseHeaders.set('X-XSS-Protection', '1; mode=block');
+    return defaultResponseHeaders;
+  }
+
+  Duration get idleTimeout => _idleTimeout;
+
+  void set idleTimeout(Duration duration) {
+    if (_idleTimer != null) {
+      _idleTimer.cancel();
+      _idleTimer = null;
+    }
+    _idleTimeout = duration;
+    if (_idleTimeout != null) {
+      _idleTimer = new Timer.periodic(_idleTimeout, (_) {
+        for (var idle in _idleConnections.toList()) {
+          if (idle.isMarkedIdle) {
+            idle.destroy();
+          } else {
+            idle.markIdle();
+          }
+        }
+      });
+    }
+  }
+
+  StreamSubscription<HttpRequest> listen(void onData(HttpRequest event),
+                                         {Function onError,
+                                         void onDone(),
+                                         bool cancelOnError}) {
+    _serverSocket.listen(
+        (Socket socket) {
+          socket.setOption(SocketOption.TCP_NODELAY, true);
+          // Accept the client connection.
+          _HttpConnection connection = new _HttpConnection(socket, this);
+          _idleConnections.add(connection);
+        },
+        onError: (error, stackTrace) {
+          // Ignore HandshakeExceptions as they are bound to a single request,
+          // and are not fatal for the server.
+          if (error is! HandshakeException) {
+            _controller.addError(error, stackTrace);
+          }
+        },
+        onDone: _controller.close);
+    return _controller.stream.listen(onData,
+                                     onError: onError,
+                                     onDone: onDone,
+                                     cancelOnError: cancelOnError);
+  }
+
+  Future close({bool force: false}) {
+    closed = true;
+    Future result;
+    if (_serverSocket != null && _closeServer) {
+      result = _serverSocket.close();
+    } else {
+      result = new Future.value();
+    }
+    idleTimeout = null;
+    if (force) {
+      for (var c in _activeConnections.toList()) {
+        c.destroy();
+      }
+      assert(_activeConnections.isEmpty);
+    }
+    for (var c in _idleConnections.toList()) {
+      c.destroy();
+    }
+    _maybePerformCleanup();
+    return result;
+  }
+
+  void _maybePerformCleanup() {
+    if (closed &&
+        _idleConnections.isEmpty &&
+        _activeConnections.isEmpty &&
+        _sessionManagerInstance != null) {
+      _sessionManagerInstance.close();
+      _sessionManagerInstance = null;
+      _servers.remove(_serviceId);
+    }
+  }
+
+  int get port {
+    if (closed) throw new HttpException("HttpServer is not bound to a socket");
+    return _serverSocket.port;
+  }
+
+  InternetAddress get address {
+    if (closed) throw new HttpException("HttpServer is not bound to a socket");
+    return _serverSocket.address;
+  }
+
+  set sessionTimeout(int timeout) {
+    _sessionManager.sessionTimeout = timeout;
+  }
+
+  void _handleRequest(_HttpRequest request) {
+    if (!closed) {
+      _controller.add(request);
+    } else {
+      request._httpConnection.destroy();
+    }
+  }
+
+  void _connectionClosed(_HttpConnection connection) {
+    // Remove itself from either idle or active connections.
+    connection.unlink();
+    _maybePerformCleanup();
+  }
+
+  void _markIdle(_HttpConnection connection) {
+    _activeConnections.remove(connection);
+    _idleConnections.add(connection);
+  }
+
+  void _markActive(_HttpConnection connection) {
+    _idleConnections.remove(connection);
+    _activeConnections.add(connection);
+  }
+
+  _HttpSessionManager get _sessionManager {
+    // Lazy init.
+    if (_sessionManagerInstance == null) {
+      _sessionManagerInstance = new _HttpSessionManager();
+    }
+    return _sessionManagerInstance;
+  }
+
+  HttpConnectionsInfo connectionsInfo() {
+    HttpConnectionsInfo result = new HttpConnectionsInfo();
+    result.total = _activeConnections.length + _idleConnections.length;
+    _activeConnections.forEach((_HttpConnection conn) {
+      if (conn._isActive) {
+        result.active++;
+      } else {
+        assert(conn._isClosing);
+        result.closing++;
+      }
+    });
+    _idleConnections.forEach((_HttpConnection conn) {
+      result.idle++;
+      assert(conn._isIdle);
+    });
+    return result;
+  }
+
+  String get _serviceTypePath => 'io/http/servers';
+  String get _serviceTypeName => 'HttpServer';
+
+  Map<String, dynamic> _toJSON(bool ref) {
+    var r = <String, dynamic>{
+      'id': _servicePath,
+      'type': _serviceType(ref),
+      'name': '${address.host}:$port',
+      'user_name': '${address.host}:$port',
+    };
+    if (ref) {
+      return r;
+    }
+    try {
+      r['socket'] = _serverSocket._toJSON(true);
+    } catch (_) {
+      r['socket'] = {
+        'id': _servicePath,
+        'type': '@Socket',
+        'name': 'UserSocket',
+        'user_name': 'UserSocket',
+      };
+    }
+    r['port'] = port;
+    r['address'] = address.host;
+    r['active'] = _activeConnections.map((c) => c._toJSON(true)).toList();
+    r['idle'] = _idleConnections.map((c) => c._toJSON(true)).toList();
+    r['closed'] = closed;
+    return r;
+  }
+
+  _HttpSessionManager _sessionManagerInstance;
+
+  // Indicated if the http server has been closed.
+  bool closed = false;
+
+  // The server listen socket. Untyped as it can be both ServerSocket and
+  // SecureServerSocket.
+  final _serverSocket;
+  final bool _closeServer;
+
+  // Set of currently connected clients.
+  final LinkedList<_HttpConnection> _activeConnections
+      = new LinkedList<_HttpConnection>();
+  final LinkedList<_HttpConnection> _idleConnections
+      = new LinkedList<_HttpConnection>();
+  StreamController<HttpRequest> _controller;
+}
+
+
+class _ProxyConfiguration {
+  static const String PROXY_PREFIX = "PROXY ";
+  static const String DIRECT_PREFIX = "DIRECT";
+
+  _ProxyConfiguration(String configuration) : proxies = new List<_Proxy>() {
+    if (configuration == null) {
+      throw new HttpException("Invalid proxy configuration $configuration");
+    }
+    List<String> list = configuration.split(";");
+    list.forEach((String proxy) {
+      proxy = proxy.trim();
+      if (!proxy.isEmpty) {
+        if (proxy.startsWith(PROXY_PREFIX)) {
+          String username;
+          String password;
+          // Skip the "PROXY " prefix.
+          proxy = proxy.substring(PROXY_PREFIX.length).trim();
+          // Look for proxy authentication.
+          int at = proxy.indexOf("@");
+          if (at != -1) {
+            String userinfo = proxy.substring(0, at).trim();
+            proxy = proxy.substring(at + 1).trim();
+            int colon = userinfo.indexOf(":");
+            if (colon == -1 || colon == 0 || colon == proxy.length - 1) {
+              throw new HttpException(
+                  "Invalid proxy configuration $configuration");
+            }
+            username = userinfo.substring(0, colon).trim();
+            password = userinfo.substring(colon + 1).trim();
+          }
+          // Look for proxy host and port.
+          int colon = proxy.lastIndexOf(":");
+          if (colon == -1 || colon == 0 || colon == proxy.length - 1) {
+            throw new HttpException(
+                "Invalid proxy configuration $configuration");
+          }
+          String host = proxy.substring(0, colon).trim();
+          if (host.startsWith("[") && host.endsWith("]")) {
+            host = host.substring(1, host.length - 1);
+          }
+          String portString = proxy.substring(colon + 1).trim();
+          int port;
+          try {
+            port = int.parse(portString);
+          } on FormatException catch (e) {
+            throw new HttpException(
+                "Invalid proxy configuration $configuration, "
+                "invalid port '$portString'");
+          }
+          proxies.add(new _Proxy(host, port, username, password));
+        } else if (proxy.trim() == DIRECT_PREFIX) {
+          proxies.add(new _Proxy.direct());
+        } else {
+          throw new HttpException("Invalid proxy configuration $configuration");
+        }
+      }
+    });
+  }
+
+  const _ProxyConfiguration.direct()
+      : proxies = const [const _Proxy.direct()];
+
+  final List<_Proxy> proxies;
+}
+
+
+class _Proxy {
+  final String host;
+  final int port;
+  final String username;
+  final String password;
+  final bool isDirect;
+
+  const _Proxy(this.host, this.port, this.username, this.password)
+      : isDirect = false;
+  const _Proxy.direct() : host = null, port = null,
+                          username = null, password = null, isDirect = true;
+
+  bool get isAuthenticated => username != null;
+}
+
+
+class _HttpConnectionInfo implements HttpConnectionInfo {
+  InternetAddress remoteAddress;
+  int remotePort;
+  int localPort;
+
+  static _HttpConnectionInfo create(Socket socket) {
+    if (socket == null) return null;
+    try {
+      _HttpConnectionInfo info = new _HttpConnectionInfo();
+      return info
+          ..remoteAddress = socket.remoteAddress
+          ..remotePort = socket.remotePort
+          ..localPort = socket.port;
+    } catch (e) { }
+    return null;
+  }
+}
+
+
+class _DetachedSocket extends Stream<List<int>> implements Socket {
+  final Stream<List<int>> _incoming;
+  final _socket;
+
+  _DetachedSocket(this._socket, this._incoming);
+
+  StreamSubscription<List<int>> listen(void onData(List<int> event),
+                                       {Function onError,
+                                        void onDone(),
+                                        bool cancelOnError}) {
+    return _incoming.listen(onData,
+                            onError: onError,
+                            onDone: onDone,
+                            cancelOnError: cancelOnError);
+  }
+
+  Encoding get encoding => _socket.encoding;
+
+  void set encoding(Encoding value) {
+    _socket.encoding = value;
+  }
+
+  void write(Object obj) { _socket.write(obj); }
+
+  void writeln([Object obj = ""]) { _socket.writeln(obj); }
+
+  void writeCharCode(int charCode) { _socket.writeCharCode(charCode); }
+
+  void writeAll(Iterable objects, [String separator = ""]) {
+    _socket.writeAll(objects, separator);
+  }
+
+  void add(List<int> bytes) { _socket.add(bytes); }
+
+  void addError(error, [StackTrace stackTrace]) =>
+      _socket.addError(error, stackTrace);
+
+  Future<Socket> addStream(Stream<List<int>> stream) {
+    return _socket.addStream(stream);
+  }
+
+  void destroy() { _socket.destroy(); }
+
+  Future flush() => _socket.flush();
+
+  Future close() => _socket.close();
+
+  Future<Socket> get done => _socket.done;
+
+  int get port => _socket.port;
+
+  InternetAddress get address => _socket.address;
+
+  InternetAddress get remoteAddress => _socket.remoteAddress;
+
+  int get remotePort => _socket.remotePort;
+
+  bool setOption(SocketOption option, bool enabled) {
+    return _socket.setOption(option, enabled);
+  }
+
+  Map _toJSON(bool ref) => _socket._toJSON(ref);
+  void set _owner(owner) { _socket._owner = owner; }
+}
+
+
+class _AuthenticationScheme {
+  final int _scheme;
+
+  static const UNKNOWN = const _AuthenticationScheme(-1);
+  static const BASIC = const _AuthenticationScheme(0);
+  static const DIGEST = const _AuthenticationScheme(1);
+
+  const _AuthenticationScheme(this._scheme);
+
+  factory _AuthenticationScheme.fromString(String scheme) {
+    if (scheme.toLowerCase() == "basic") return BASIC;
+    if (scheme.toLowerCase() == "digest") return DIGEST;
+    return UNKNOWN;
+  }
+
+  String toString() {
+    if (this == BASIC) return "Basic";
+    if (this == DIGEST) return "Digest";
+    return "Unknown";
+  }
+}
+
+
+abstract class _Credentials {
+  _HttpClientCredentials credentials;
+  String realm;
+  bool used = false;
+
+  // Digest specific fields.
+  String ha1;
+  String nonce;
+  String algorithm;
+  String qop;
+  int nonceCount;
+
+  _Credentials(this.credentials, this.realm) {
+    if (credentials.scheme == _AuthenticationScheme.DIGEST) {
+      // Calculate the H(A1) value once. There is no mentioning of
+      // username/password encoding in RFC 2617. However there is an
+      // open draft for adding an additional accept-charset parameter to
+      // the WWW-Authenticate and Proxy-Authenticate headers, see
+      // http://tools.ietf.org/html/draft-reschke-basicauth-enc-06. For
+      // now always use UTF-8 encoding.
+      _HttpClientDigestCredentials creds = credentials;
+      var hasher = new _MD5()
+          ..add(UTF8.encode(creds.username))
+          ..add([_CharCode.COLON])
+          ..add(realm.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(UTF8.encode(creds.password));
+      ha1 = _CryptoUtils.bytesToHex(hasher.close());
+    }
+  }
+
+  _AuthenticationScheme get scheme => credentials.scheme;
+
+  void authorize(HttpClientRequest request);
+}
+
+class _SiteCredentials extends _Credentials {
+  Uri uri;
+
+  _SiteCredentials(this.uri, realm, _HttpClientCredentials creds)
+      : super(creds, realm);
+
+  bool applies(Uri uri, _AuthenticationScheme scheme) {
+    if (scheme != null && credentials.scheme != scheme) return false;
+    if (uri.host != this.uri.host) return false;
+    int thisPort =
+        this.uri.port == 0 ? HttpClient.DEFAULT_HTTP_PORT : this.uri.port;
+    int otherPort = uri.port == 0 ? HttpClient.DEFAULT_HTTP_PORT : uri.port;
+    if (otherPort != thisPort) return false;
+    return uri.path.startsWith(this.uri.path);
+  }
+
+  void authorize(HttpClientRequest request) {
+    // Digest credentials cannot be used without a nonce from the
+    // server.
+    if (credentials.scheme == _AuthenticationScheme.DIGEST &&
+        nonce == null) {
+      return;
+    }
+    credentials.authorize(this, request);
+    used = true;
+  }
+}
+
+
+class _ProxyCredentials extends _Credentials {
+  String host;
+  int port;
+
+  _ProxyCredentials(this.host,
+                    this.port,
+                    realm,
+                    _HttpClientCredentials creds)
+      : super(creds, realm);
+
+  bool applies(_Proxy proxy, _AuthenticationScheme scheme) {
+    if (scheme != null && credentials.scheme != scheme) return false;
+    return proxy.host == host && proxy.port == port;
+  }
+
+  void authorize(HttpClientRequest request) {
+    // Digest credentials cannot be used without a nonce from the
+    // server.
+    if (credentials.scheme == _AuthenticationScheme.DIGEST &&
+        nonce == null) {
+      return;
+    }
+    credentials.authorizeProxy(this, request);
+  }
+}
+
+
+abstract class _HttpClientCredentials implements HttpClientCredentials {
+  _AuthenticationScheme get scheme;
+  void authorize(_Credentials credentials, HttpClientRequest request);
+  void authorizeProxy(_ProxyCredentials credentials, HttpClientRequest request);
+}
+
+
+class _HttpClientBasicCredentials
+    extends _HttpClientCredentials
+    implements HttpClientBasicCredentials {
+  String username;
+  String password;
+
+  _HttpClientBasicCredentials(this.username, this.password);
+
+  _AuthenticationScheme get scheme => _AuthenticationScheme.BASIC;
+
+  String authorization() {
+    // There is no mentioning of username/password encoding in RFC
+    // 2617. However there is an open draft for adding an additional
+    // accept-charset parameter to the WWW-Authenticate and
+    // Proxy-Authenticate headers, see
+    // http://tools.ietf.org/html/draft-reschke-basicauth-enc-06. For
+    // now always use UTF-8 encoding.
+    String auth =
+        _CryptoUtils.bytesToBase64(UTF8.encode("$username:$password"));
+    return "Basic $auth";
+  }
+
+  void authorize(_Credentials _, HttpClientRequest request) {
+    request.headers.set(HttpHeaders.AUTHORIZATION, authorization());
+  }
+
+  void authorizeProxy(_ProxyCredentials _, HttpClientRequest request) {
+    request.headers.set(HttpHeaders.PROXY_AUTHORIZATION, authorization());
+  }
+}
+
+
+class _HttpClientDigestCredentials
+    extends _HttpClientCredentials
+    implements HttpClientDigestCredentials {
+  String username;
+  String password;
+
+  _HttpClientDigestCredentials(this.username, this.password);
+
+  _AuthenticationScheme get scheme => _AuthenticationScheme.DIGEST;
+
+  String authorization(_Credentials credentials, _HttpClientRequest request) {
+    String requestUri = request._requestUri();
+    _MD5 hasher = new _MD5()
+        ..add(request.method.codeUnits)
+        ..add([_CharCode.COLON])
+        ..add(requestUri.codeUnits);
+    var ha2 = _CryptoUtils.bytesToHex(hasher.close());
+
+    String qop;
+    String cnonce;
+    String nc;
+    var x;
+    hasher = new _MD5()
+        ..add(credentials.ha1.codeUnits)
+        ..add([_CharCode.COLON]);
+    if (credentials.qop == "auth") {
+      qop = credentials.qop;
+      cnonce = _CryptoUtils.bytesToHex(_IOCrypto.getRandomBytes(4));
+      ++credentials.nonceCount;
+      nc = credentials.nonceCount.toRadixString(16);
+      nc = "00000000".substring(0, 8 - nc.length + 1) + nc;
+      hasher
+          ..add(credentials.nonce.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(nc.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(cnonce.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(credentials.qop.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(ha2.codeUnits);
+    } else {
+      hasher
+          ..add(credentials.nonce.codeUnits)
+          ..add([_CharCode.COLON])
+          ..add(ha2.codeUnits);
+    }
+    var response = _CryptoUtils.bytesToHex(hasher.close());
+
+    StringBuffer buffer = new StringBuffer()
+        ..write('Digest ')
+        ..write('username="$username"')
+        ..write(', realm="${credentials.realm}"')
+        ..write(', nonce="${credentials.nonce}"')
+        ..write(', uri="$requestUri"')
+        ..write(', algorithm="${credentials.algorithm}"');
+    if (qop == "auth") {
+      buffer
+          ..write(', qop="$qop"')
+          ..write(', cnonce="$cnonce"')
+          ..write(', nc="$nc"');
+    }
+    buffer.write(', response="$response"');
+    return buffer.toString();
+  }
+
+  void authorize(_Credentials credentials, HttpClientRequest request) {
+    request.headers.set(HttpHeaders.AUTHORIZATION,
+                        authorization(credentials, request));
+  }
+
+  void authorizeProxy(_ProxyCredentials credentials,
+                      HttpClientRequest request) {
+    request.headers.set(HttpHeaders.PROXY_AUTHORIZATION,
+                        authorization(credentials, request));
+  }
+}
+
+
+class _RedirectInfo implements RedirectInfo {
+  final int statusCode;
+  final String method;
+  final Uri location;
+  const _RedirectInfo(this.statusCode, this.method, this.location);
+}
+
+String _getHttpVersion() {
+  var version = Platform.version;
+  // Only include major and minor version numbers.
+  int index = version.indexOf('.', version.indexOf('.') + 1);
+  version = version.substring(0, index);
+  return 'Dart/$version (dart:io)';
+}