engine.io

实现跨浏览器、跨设备双向通信层

通信:Emitter

class Emitter {_subs: {};construtor (params?: object) {return(params && this.mixin(params));}mixin (params) {for (let key in Emitter.prototype) {params[key] = Emitter.prototype[key];}return params;     }on (event, fn) {(this._subs[event] = this._subs[event] || []).push(fn);return this;}once (event, fn) {function on () {this.off(event, fn);fn.apply(this, arguments);}on.fn = fn;this.on(event, on);return this;}off (event, fn) {if (0 === arguments.length) {this._subs = {};return this;}let callbacks = this._subs[event];if (!callbacks || !callbacks.length === 0) return this;if (1 === arguments.length) {delete this._subs[event];return this;}let cb;for (let i = 0; i < callbacks.length; i++) {cb = callbacks[i];if (cb === fn || cb.fn === fn) {callbacks.splice(i, 1);break;}}return this;}emit (event, ...args?: any) {callbacks = this._subs[event];callbacks.forEach((item)=>{item.apply(this.args);});return this;}}

transports

base class [Transport]

websocket

class WS extends Transport {name: string = 'websocket';supportsBinary: boolean = true;constructor (params) {super(params);}doOpen () {const uri = this.uri();const protocols = this.protocols;let opts = {agent: this.agent}// SSL options for Node.js clientopts.pfx = this.pfx;opts.key = this.key;opts.passphrase = this.passphrase;opts.cert = this.cert;opts.ca = this.ca;opts.ciphers = this.ciphers;opts.rejectUnauthorized = this.rejectUnauthorized;if (this.extraHeaders) {opts.headers = this.extraHeaders;}if (this.localAddress) {opts.localAddress = this.localAddress;}try {this.ws = this.usingBrowserWebSocket ? (protocols ? new WebSocket(uri, protocols) : new WebSocket(uri)) : new WebSocket(uri, protocols, opts);} catch (err) {return this.emit('error', err);}this.addEventListeners();}doClose () {if (typeof this.ws !== 'undefined') {this.ws.close();}}write () {}addEventListener () {this.ws.onopen = () => {this.onOpen();}this.ws.onclose = () => {this.onClose();}this.ws.onmessage = (ev) => {this.onData(ev.data);}this.ws.onerror = () => {this.onError('websocket error', e);}}
}