1 files changed, 407 insertions, 0 deletions
diff --git a/node_modules/engine.io/lib/transports/polling.js b/node_modules/engine.io/lib/transports/polling.js
new file mode 100644
index 0000000..6c5c0cc
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+++ b/node_modules/engine.io/lib/transports/polling.js
@@ -0,0 +1,407 @@
+
+/**
+ * Module requirements.
+ */
+
+var Transport = require('../transport');
+var parser = require('engine.io-parser');
+var zlib = require('zlib');
+var accepts = require('accepts');
+var util = require('util');
+var debug = require('debug')('engine:polling');
+
+var compressionMethods = {
+  gzip: zlib.createGzip,
+  deflate: zlib.createDeflate
+};
+
+/**
+ * Exports the constructor.
+ */
+
+module.exports = Polling;
+
+/**
+ * HTTP polling constructor.
+ *
+ * @api public.
+ */
+
+function Polling (req) {
+  Transport.call(this, req);
+
+  this.closeTimeout = 30 * 1000;
+  this.maxHttpBufferSize = null;
+  this.httpCompression = null;
+}
+
+/**
+ * Inherits from Transport.
+ *
+ * @api public.
+ */
+
+util.inherits(Polling, Transport);
+
+/**
+ * Transport name
+ *
+ * @api public
+ */
+
+Polling.prototype.name = 'polling';
+
+/**
+ * Overrides onRequest.
+ *
+ * @param {http.IncomingMessage}
+ * @api private
+ */
+
+Polling.prototype.onRequest = function (req) {
+  var res = req.res;
+
+  if ('GET' === req.method) {
+    this.onPollRequest(req, res);
+  } else if ('POST' === req.method) {
+    this.onDataRequest(req, res);
+  } else {
+    res.writeHead(500);
+    res.end();
+  }
+};
+
+/**
+ * The client sends a request awaiting for us to send data.
+ *
+ * @api private
+ */
+
+Polling.prototype.onPollRequest = function (req, res) {
+  if (this.req) {
+    debug('request overlap');
+    // assert: this.res, '.req and .res should be (un)set together'
+    this.onError('overlap from client');
+    res.writeHead(500);
+    res.end();
+    return;
+  }
+
+  debug('setting request');
+
+  this.req = req;
+  this.res = res;
+
+  var self = this;
+
+  function onClose () {
+    self.onError('poll connection closed prematurely');
+  }
+
+  function cleanup () {
+    req.removeListener('close', onClose);
+    self.req = self.res = null;
+  }
+
+  req.cleanup = cleanup;
+  req.on('close', onClose);
+
+  this.writable = true;
+  this.emit('drain');
+
+  // if we're still writable but had a pending close, trigger an empty send
+  if (this.writable && this.shouldClose) {
+    debug('triggering empty send to append close packet');
+    this.send([{ type: 'noop' }]);
+  }
+};
+
+/**
+ * The client sends a request with data.
+ *
+ * @api private
+ */
+
+Polling.prototype.onDataRequest = function (req, res) {
+  if (this.dataReq) {
+    // assert: this.dataRes, '.dataReq and .dataRes should be (un)set together'
+    this.onError('data request overlap from client');
+    res.writeHead(500);
+    res.end();
+    return;
+  }
+
+  var isBinary = 'application/octet-stream' === req.headers['content-type'];
+
+  this.dataReq = req;
+  this.dataRes = res;
+
+  var chunks = isBinary ? new Buffer(0) : ''; // eslint-disable-line node/no-deprecated-api
+  var self = this;
+
+  function cleanup () {
+    req.removeListener('data', onData);
+    req.removeListener('end', onEnd);
+    req.removeListener('close', onClose);
+    self.dataReq = self.dataRes = chunks = null;
+  }
+
+  function onClose () {
+    cleanup();
+    self.onError('data request connection closed prematurely');
+  }
+
+  function onData (data) {
+    var contentLength;
+    if (isBinary) {
+      chunks = Buffer.concat([chunks, data]);
+      contentLength = chunks.length;
+    } else {
+      chunks += data;
+      contentLength = Buffer.byteLength(chunks);
+    }
+
+    if (contentLength > self.maxHttpBufferSize) {
+      chunks = isBinary ? new Buffer(0) : ''; // eslint-disable-line node/no-deprecated-api
+      req.connection.destroy();
+    }
+  }
+
+  function onEnd () {
+    self.onData(chunks);
+
+    var headers = {
+      // text/html is required instead of text/plain to avoid an
+      // unwanted download dialog on certain user-agents (GH-43)
+      'Content-Type': 'text/html',
+      'Content-Length': 2
+    };
+
+    res.writeHead(200, self.headers(req, headers));
+    res.end('ok');
+    cleanup();
+  }
+
+  req.on('close', onClose);
+  if (!isBinary) req.setEncoding('utf8');
+  req.on('data', onData);
+  req.on('end', onEnd);
+};
+
+/**
+ * Processes the incoming data payload.
+ *
+ * @param {String} encoded payload
+ * @api private
+ */
+
+Polling.prototype.onData = function (data) {
+  debug('received "%s"', data);
+  var self = this;
+  var callback = function (packet) {
+    if ('close' === packet.type) {
+      debug('got xhr close packet');
+      self.onClose();
+      return false;
+    }
+
+    self.onPacket(packet);
+  };
+
+  parser.decodePayload(data, callback);
+};
+
+/**
+ * Overrides onClose.
+ *
+ * @api private
+ */
+
+Polling.prototype.onClose = function () {
+  if (this.writable) {
+    // close pending poll request
+    this.send([{ type: 'noop' }]);
+  }
+  Transport.prototype.onClose.call(this);
+};
+
+/**
+ * Writes a packet payload.
+ *
+ * @param {Object} packet
+ * @api private
+ */
+
+Polling.prototype.send = function (packets) {
+  this.writable = false;
+
+  if (this.shouldClose) {
+    debug('appending close packet to payload');
+    packets.push({ type: 'close' });
+    this.shouldClose();
+    this.shouldClose = null;
+  }
+
+  var self = this;
+  parser.encodePayload(packets, this.supportsBinary, function (data) {
+    var compress = packets.some(function (packet) {
+      return packet.options && packet.options.compress;
+    });
+    self.write(data, { compress: compress });
+  });
+};
+
+/**
+ * Writes data as response to poll request.
+ *
+ * @param {String} data
+ * @param {Object} options
+ * @api private
+ */
+
+Polling.prototype.write = function (data, options) {
+  debug('writing "%s"', data);
+  var self = this;
+  this.doWrite(data, options, function () {
+    self.req.cleanup();
+  });
+};
+
+/**
+ * Performs the write.
+ *
+ * @api private
+ */
+
+Polling.prototype.doWrite = function (data, options, callback) {
+  var self = this;
+
+  // explicit UTF-8 is required for pages not served under utf
+  var isString = typeof data === 'string';
+  var contentType = isString
+    ? 'text/plain; charset=UTF-8'
+    : 'application/octet-stream';
+
+  var headers = {
+    'Content-Type': contentType
+  };
+
+  if (!this.httpCompression || !options.compress) {
+    respond(data);
+    return;
+  }
+
+  var len = isString ? Buffer.byteLength(data) : data.length;
+  if (len < this.httpCompression.threshold) {
+    respond(data);
+    return;
+  }
+
+  var encoding = accepts(this.req).encodings(['gzip', 'deflate']);
+  if (!encoding) {
+    respond(data);
+    return;
+  }
+
+  this.compress(data, encoding, function (err, data) {
+    if (err) {
+      self.res.writeHead(500);
+      self.res.end();
+      callback(err);
+      return;
+    }
+
+    headers['Content-Encoding'] = encoding;
+    respond(data);
+  });
+
+  function respond (data) {
+    headers['Content-Length'] = 'string' === typeof data ? Buffer.byteLength(data) : data.length;
+    self.res.writeHead(200, self.headers(self.req, headers));
+    self.res.end(data);
+    callback();
+  }
+};
+
+/**
+ * Compresses data.
+ *
+ * @api private
+ */
+
+Polling.prototype.compress = function (data, encoding, callback) {
+  debug('compressing');
+
+  var buffers = [];
+  var nread = 0;
+
+  compressionMethods[encoding](this.httpCompression)
+    .on('error', callback)
+    .on('data', function (chunk) {
+      buffers.push(chunk);
+      nread += chunk.length;
+    })
+    .on('end', function () {
+      callback(null, Buffer.concat(buffers, nread));
+    })
+    .end(data);
+};
+
+/**
+ * Closes the transport.
+ *
+ * @api private
+ */
+
+Polling.prototype.doClose = function (fn) {
+  debug('closing');
+
+  var self = this;
+  var closeTimeoutTimer;
+
+  if (this.dataReq) {
+    debug('aborting ongoing data request');
+    this.dataReq.destroy();
+  }
+
+  if (this.writable) {
+    debug('transport writable - closing right away');
+    this.send([{ type: 'close' }]);
+    onClose();
+  } else if (this.discarded) {
+    debug('transport discarded - closing right away');
+    onClose();
+  } else {
+    debug('transport not writable - buffering orderly close');
+    this.shouldClose = onClose;
+    closeTimeoutTimer = setTimeout(onClose, this.closeTimeout);
+  }
+
+  function onClose () {
+    clearTimeout(closeTimeoutTimer);
+    fn();
+    self.onClose();
+  }
+};
+
+/**
+ * Returns headers for a response.
+ *
+ * @param {http.IncomingMessage} request
+ * @param {Object} extra headers
+ * @api private
+ */
+
+Polling.prototype.headers = function (req, headers) {
+  headers = headers || {};
+
+  // prevent XSS warnings on IE
+  // https://github.com/LearnBoost/socket.io/pull/1333
+  var ua = req.headers['user-agent'];
+  if (ua && (~ua.indexOf(';MSIE') || ~ua.indexOf('Trident/'))) {
+    headers['X-XSS-Protection'] = '0';
+  }
+
+  this.emit('headers', headers);
+  return headers;
+};