From 67fdec20726e48ba3a934cb25bb30d47ec4a4f29 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Yaroslav=20De=20La=20Pe=C3=B1a=20Smirnov?= Date: Wed, 29 Nov 2017 11:44:34 +0300 Subject: Initial commit, version 0.5.3 --- node_modules/engine.io/lib/transports/polling.js | 407 +++++++++++++++++++++++ 1 file changed, 407 insertions(+) create mode 100644 node_modules/engine.io/lib/transports/polling.js (limited to 'node_modules/engine.io/lib/transports/polling.js') 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 --- /dev/null +++ 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; +}; -- cgit v1.2.3