基于WebSocket火拼俄罗斯方块

# Engine.IO: the realtime engine [](http://travis-ci.org/socketio/engine.io) [](http://badge.fury.io/js/engine.io) `Engine.IO` is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for [Socket.IO](http://github.com/socketio/socket.io). ## How to use ### Server #### (A) Listening on a port ```js var engine = require('engine.io'); var server = engine.listen(80); server.on('connection', function(socket){ socket.send('utf 8 string'); socket.send(new Buffer([0, 1, 2, 3, 4, 5])); // binary data }); ``` #### (B) Intercepting requests for a http.Server ```js var engine = require('engine.io'); var http = require('http').createServer().listen(3000); var server = engine.attach(http); server.on('connection', function (socket) { socket.on('message', function(data){ }); socket.on('close', function(){ }); }); ``` #### (C) Passing in requests ```js var engine = require('engine.io'); var server = new engine.Server(); server.on('connection', function(socket){ socket.send('hi'); }); // … httpServer.on('upgrade', function(req, socket, head){ server.handleUpgrade(req, socket, head); }); httpServer.on('request', function(req, res){ server.handleRequest(req, res); }); ``` ### Client ```html <script src="/path/to/engine.io.js"></script> <script> var socket = new eio.Socket('ws://localhost/'); socket.on('open', function(){ socket.on('message', function(data){}); socket.on('close', function(){}); }); </script> ``` For more information on the client refer to the [engine-client](http://github.com/learnboost/engine.io-client) repository. ## What features does it have? - **Maximum reliability**. Connections are established even in the presence of: - proxies and load balancers. - personal firewall and antivirus software. - for more information refer to **Goals** and **Architecture** sections - **Minimal client size** aided by: - lazy loading of flash transports. - lack of redundant transports. - **Scalable** - load balancer friendly - **Future proof** - **100% Node.JS core style** - No API sugar (left for higher level projects) - Written in readable vanilla JavaScript ## API ### Server <hr><br> #### Top-level These are exposed by `require('engine.io')`: ##### Events - `flush` - Called when a socket buffer is being flushed. - **Arguments** - `Socket`: socket being flushed - `Array`: write buffer - `drain` - Called when a socket buffer is drained - **Arguments** - `Socket`: socket being flushed ##### Properties - `protocol` _(Number)_: protocol revision number - `Server`: Server class constructor - `Socket`: Socket class constructor - `Transport` _(Function)_: transport constructor - `transports` _(Object)_: map of available transports ##### Methods - `()` - Returns a new `Server` instance. If the first argument is an `http.Server` then the new `Server` instance will be attached to it. Otherwise, the arguments are passed directly to the `Server` constructor. - **Parameters** - `http.Server`: optional, server to attach to. - `Object`: optional, options object (see `Server#constructor` api docs below) The following are identical ways to instantiate a server and then attach it. ```js var httpServer; // previously created with `http.createServer();` from node.js api. // create a server first, and then attach var eioServer = require('engine.io').Server(); eioServer.attach(httpServer); // or call the module as a function to get `Server` var eioServer = require('engine.io')(); eioServer.attach(httpServer); // immediately attach var eioServer = require('engine.io')(httpServer); ``` - `listen` - Creates an `http.Server` which listens on the given port and attaches WS to it. It returns `501 Not Implemented` for regular http requests. - **Parameters** - `Number`: port to listen on. - `Object`: optional, options object - `Function`: callback for `listen`. - **Options** - All options from `Server.attach` method, documented below. - **Additionally** See Server `constructor` below for options you can pass for creating the new Server - **Returns** `Server` - `attach` - Captures `upgrade` requests for a `http.Server`. In other words, makes a regular http.Server WebSocket-compatible. - **Parameters** - `http.Server`: server to attach to. - `Object`: optional, options object - **Options** - All options from `Server.attach` method, documented below. - **Additionally** See Server `constructor` below for options you can pass for creating the new Server - **Returns** `Server` a new Server instance. <hr><br> #### Server The main server/manager. _Inherits from EventEmitter_. ##### Events - `connection` - Fired when a new connection is established. - **Arguments** - `Socket`: a Socket object ##### Properties **Important**: if you plan to use Engine.IO in a scalable way, please keep in mind the properties below will only reflect the clients connected to a single process. - `clients` _(Object)_: hash of connected clients by id. - `clientsCount` _(Number)_: number of connected clients. ##### Methods - **constructor** - Initializes the server - **Parameters** - `Object`: optional, options object - **Options** - `pingTimeout` (`Number`): how many ms without a pong packet to consider the connection closed (`60000`) - `pingInterval` (`Number`): how many ms before sending a new ping packet (`25000`) - `upgradeTimeout` (`Number`): how many ms before an uncompleted transport upgrade is cancelled (`10000`) - `maxHttpBufferSize` (`Number`): how many bytes or characters a message can be, before closing the session (to avoid DoS). Default value is `10E7`. - `allowRequest` (`Function`): A function that receives a given handshake or upgrade request as its first parameter, and can decide whether to continue or not. The second argument is a function that needs to be called with the decided information: `fn(err, success)`, where `success` is a boolean value where false means that the request is rejected, and err is an error code. - `transports` (`<Array> String`): transports to allow connections to (`['polling', 'websocket']`) - `allowUpgrades` (`Boolean`): whether to allow transport upgrades (`true`) - `perMessageDeflate` (`Object|Boolean`): parameters of the WebSocket permessage-deflate extension (see [ws module](https://github.com/einaros/ws) api docs). Set to `false` to disable. (`true`) - `threshold` (`Number`): data is compressed only if the byte size is above this value (`1024`) - `httpCompression` (`Object|Boolean`): parameters of the http compression for the polling transports (see [zlib](http://nodejs.org/api/zlib.html#zlib_options) api docs). Set to `false` to disable. (`true`) - `threshold` (`Number`): data is compressed only if the byte size is above this value (`1024`) - `cookie` (`String|Boolean`): name of the HTTP cookie that contains the client sid to send as part of handshake response headers. Set to `false` to not send one. (`io`) - `cookiePath` (`String|Boolean`): path of the above `cookie` option. If false, no path will be sent, which means browsers will only send the cookie on the engine.io attached path (`/engine.io`). Set false to not save io cookie on all requests. (`/`) - `cookieHttpOnly` (`Boolean`): If `true` HttpOnly io cookie cannot be accessed by client-side APIs, such as JavaScript. (`true`) _This option has no effect if `cookie` or `cookiePath` is set to `false`._ - `wsEngine` (`String`)