用 Service Workers 为网站加速

其实 Service Workers 是 Google 爸爸推出很久的一个黑科技，它可以在浏览器层面动态缓存一些请求，从而使网站的二次加载速度大幅提高。

二次刷新我的博客，只重载了 16.0KB 的资源，甚至可以剪断网线访问 ∠( ᐛ 」∠)＿

需要注意的是，Service Workers 只有在 HTTPS 的前提下才能发挥作用

添加 sw-toolbox 核心

下载 sw-toolbox.js 并且放置到主题目录下的 assets/js 目录

*如果你是默认主题，应该是在path_to_ghost/content/themes/casper/assets/js

创建缓存规则

在主题根目录下创建 serviceworker.js，并且写入下面内容

'use strict';

(function () {
  'use strict';
    /**
    * Service Worker Toolbox caching
    */

    var cacheVersion = '-toolbox-v1';
    var dynamicVendorCacheName = 'dynamic-vendor' + cacheVersion;
    var staticVendorCacheName = 'static-vendor' + cacheVersion;
    var staticAssetsCacheName = 'static-assets' + cacheVersion;
    var contentCacheName = 'content' + cacheVersion;
    var maxEntries = 50;

    self.importScripts('assets/js/sw-toolbox.js');

    self.toolbox.options.debug = false;

    // 缓存本站静态文件
    self.toolbox.router.get('/assets/(.*)', self.toolbox.cacheFirst, {
        cache: {
          name: staticAssetsCacheName,
          maxEntries: maxEntries
        }
    });

    // 缓存 googleapis
    self.toolbox.router.get('/css', self.toolbox.fastest, {
        origin: /fonts.googleapis.com/,
            cache: {
              name: dynamicVendorCacheName,
              maxEntries: maxEntries
            }
    });

    // 不缓存 DISQUS 评论
    self.toolbox.router.get('/(.*)', self.toolbox.networkOnly, {
        origin: /disqus.com/
    });
    self.toolbox.router.get('/(.*)', self.toolbox.networkOnly, {
        origin: /disquscdn.com/
    });


    // 缓存所有 Google 字体
    self.toolbox.router.get('/(.*)', self.toolbox.cacheFirst, {
        origin: /(fonts.gstatic.com|www.google-analytics.com)/,
        cache: {
          name: staticVendorCacheName,
          maxEntries: maxEntries
        }
    });

    self.toolbox.router.get('/content/(.*)', self.toolbox.fastest, {
        cache: {
          name: contentCacheName,
          maxEntries: maxEntries
        }
    });

    self.toolbox.router.get('/*', function (request, values, options) {
        if (!request.url.match(/(/ghost/|/page/)/) && request.headers.get('accept').includes('text/html')) {
            return self.toolbox.fastest(request, values, options);
        } else {
            return self.toolbox.networkOnly(request, values, options);
        }
        }, {
        cache: {
            name: contentCacheName,
            maxEntries: maxEntries
        }
    });

    // immediately activate this serviceworker
    self.addEventListener('install', function (event) {
        return event.waitUntil(self.skipWaiting());
    });

    self.addEventListener('activate', function (event) {
        return event.waitUntil(self.clients.claim());
    }); 

})();

启用 Service Workers

在主题下的 default.hbs 文件 </body> 标签前加入下面代码

 <script>
    var serviceWorkerUri = '/serviceworker.js';

    if ('serviceWorker' in navigator) {  
        navigator.serviceWorker.register(serviceWorkerUri).then(function() {
          if (navigator.serviceWorker.controller) {
            console.log('Assets cached by the controlling service worker.');
          } else {
            console.log('Please reload this page to allow the service worker to handle network operations.');
          }
        }).catch(function(error) {
          console.log('ERROR: ' + error);
        });
    } else {
        console.log('Service workers are not supported in the current browser.');
    }
    </script>

搞定！刷新一遍，剪断网线试试吧 ୧(๑•̀⌄•́๑)૭