https://github.com/MetaMask/sw-controller
Service Worker Controller
Used to register a service worker and listen for a ready event. Can be used with sw-stream for easy plumbing.
这个模块是用来登录一个service worker并监听准备好的事件。可以与sw-stream结合使用
Usage
const SwController = require(‘sw-controller‘)const createSwStream = require(‘sw-stream‘)const controller = new SwController({ ?fileName: ‘/service-worker.js‘, ?// optional, scope used when registering service worker ?scope: ‘/‘, ?// default: true, pings the service worker to keep it alive ?keepAlive: true,})controller.once(‘ready‘, () => { ?const swStream = createSwStream({ ???serviceWorker: controller.getWorker(), ?}) ?// talk to the service worker})controller.startWorker()sw-controller/lib/index.js
const EventEmitter = require(‘events‘)module.exports = class ClientSideServiceWorker extends EventEmitter { ???constructor (opts) { ???super() ???// opts ???this.fileName = opts.fileName ???this.scope = opts.scope ???this.keepAlive = opts.keepAlive === undefined ? true : opts.keepAlive ???// service worker refs ???this.serviceWorkerApi = navigator.serviceWorker ???this.activeServiceWorker = null ???// ready status ???this.ready = false ???this.once(‘ready‘, () => this.ready = true) ???????// keep alive ???this.keepAliveActive = false ???this.keepAliveInterval = opts.keepAliveInterval || 60000 ???this.keepAliveIntervalRef = null ???this.keepAliveDelay = opts.keepAliveDelay || 0 ???if (this.keepAlive) { ?????this.once(‘ready‘, () => this.startKeepAlive()) ???} ???// start ???if (opts.autoStart) this.startWorker() ?} ?getWorker() { ???return this.activeServiceWorker || this.serviceWorkerApi.controller ?} ?async startWorker () { ???const registeredWorker = await this.registerWorker() ???// forward messages and errors ???this.serviceWorkerApi.addEventListener(‘message‘, (messageEvent) => this.emit(‘message‘, messageEvent)) ???this.serviceWorkerApi.addEventListener(‘error‘, (err) => this.emit(‘error‘, err)) ???const swReady = await this.serviceWorkerApi.ready ???this.activeServiceWorker = swReady.active ???this.activeServiceWorker.onerror = (err) => this.emit(‘error‘, err) ???this.emit(‘ready‘, this.activeServiceWorker) ?} ?async registerWorker () { ???const registeredWorker = await this.serviceWorkerApi.register(this.fileName, { scope: this.scope }) ???registeredWorker.onupdatefound = (event) => { ?????this.emit(‘updatefound‘) ?????registeredWorker.update() ???} ???return registeredWorker ?} ?sendMessage (message) { ???return new Promise((resolve, reject) => { ?????const messageChannel = new MessageChannel() ?????messageChannel.port1.onmessage = (event) => { ???????if (event.data.err) { ?????????reject(event.data.error) ???????} else { ?????????resolve(event.data.data) ???????} ?????} ?????this.getWorker().postMessage(message, [messageChannel.port2]) ???}) ?} ?startKeepAlive () { ???if (this.keepAliveActive) return ???this.keepAliveActive = true ???setTimeout(() => { ?????this.keepAliveIntervalRef = setInterval(() => { ???????this.emit(‘sendingWakeUp‘) ???????this.sendMessage(‘wakeup‘) ?????}, this.keepAliveInterval) ???}, this.keepAliveDelay) ?} ?stopKeepAlive () { ???if (!this.keepAliveActive) return ???clearInterval(this.keepAliveIntervalRef) ???this.keepAliveIntervalRef = null ???this.keepAliveActive = false ?}} MetaMask/sw-controller
原文地址：https://www.cnblogs.com/wanghui-garcia/p/9915567.html