CacheStorage | Web API

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CacheStorage interface represents the storage for 缓存 对象。

接口：

Provides a master directory of all the named caches that can be accessed by a ServiceWorker or other type of worker or window scope (you’re not limited to only using it with service workers, even though the 服务工作者 spec defines it). 注意 : Chrome and Safari only expose `CacheStorage` to the windowed context over HTTPS . window.caches will be undefined unless an SSL certificate is configured.
Maintains a mapping of string names to corresponding 缓存 对象。

使用 CacheStorage.open() to obtain a 缓存 实例。

使用 CacheStorage.match() to check if a given Request is a key in any of the 缓存 objects that the CacheStorage object tracks.

You can access CacheStorage through the global caches 特性。

注意 : CacheStorage always rejects with a


							SecurityError

on untrusted origins (i.e. those that aren't using HTTPS, although this definition will likely become more complex in the future.) When testing, you can get around this by checking the "Enable Service Workers over HTTP (when toolbox is open)" option in the Firefox Devtools options/gear menu. 注意 :


								CacheStorage.match()

is a convenience method. Equivalent functionality to match a cache entry can be implemented by returning an array of cache names from


								CacheStorage.keys()

, opening each cache with


								CacheStorage.open()

, and matching the one you want with


								Cache.match()

方法

CacheStorage.match(): Checks if a given Request is a key in any of the 缓存 objects that the CacheStorage object tracks, and returns a Promise that resolves to that match.
CacheStorage.has(): 返回 Promise that resolves to true 若 缓存 object matching the cacheName exists.
CacheStorage.open(): 返回 Promise that resolves to the 缓存 object matching the cacheName (a new cache is created if it doesn't already exist.)
CacheStorage.delete(): Finds the 缓存 object matching the cacheName , and if found, deletes the 缓存 object and returns a Promise that resolves to true . If no 缓存 object is found, it resolves to false .
CacheStorage.keys(): 返回 Promise that will resolve with an array containing strings corresponding to all of the named 缓存 objects tracked by the CacheStorage . Use this method to iterate over a list of all the 缓存 对象。

范例

This code snippet is from the MDN sw-test example (见 sw-test running live .) This service worker script waits for an InstallEvent to fire, then runs waitUntil to handle the install process for the app. This consists of calling CacheStorage.open to create a new cache, then using Cache.addAll to add a series of assets to it.

In the second code block, we wait for a FetchEvent to fire. We construct a custom response like so:

Check whether a match for the request is found in the CacheStorage. If so, serve that.
If not, fetch the request from the network, then also open the cache created in the first block and add a clone of the request to it using Cache.put ( cache.put(event.request, response.clone()) )。
If this fails (e.g. because the network is down), return a fallback response.

Finally, return whatever the custom response ended up being equal to, using FetchEvent.respondWith .

self.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open('v1').then(function(cache) {
      return cache.addAll([
        '/sw-test/',
        '/sw-test/index.html',
        '/sw-test/style.css',
        '/sw-test/app.js',
        '/sw-test/image-list.js',
        '/sw-test/star-wars-logo.jpg',
        '/sw-test/gallery/bountyHunters.jpg',
        '/sw-test/gallery/myLittleVader.jpg',
        '/sw-test/gallery/snowTroopers.jpg'
      ]);
    })
  );
});
self.addEventListener('fetch', function(event) {
  event.respondWith(caches.match(event.request).then(function(response) {
    // caches.match() always resolves
    // but in case of success response will have value
    if (response !== undefined) {
      return response;
    } else {
      return fetch(event.request).then(function (response) {
        // response may be used only once
        // we need to save clone to put one copy in cache
        // and serve second one
        let responseClone = response.clone();
        caches.open('v1').then(function (cache) {
          cache.put(event.request, responseClone);
        });
        return response;
      }).catch(function () {
        return caches.match('/sw-test/gallery/myLittleVader.jpg');
      });
    }
  }));
});

This snippet shows how the API can be used outside of a service worker context, and uses the await operator for much more readable code.

// Try to get data from the cache, but fall back to fetching it live.
async function getData() {
   const cacheVersion = 1;
   const cacheName    = `myapp-${ cacheVersion }`;
   const url          = 'https://jsonplaceholder.typicode.com/todos/1';
   let cachedData     = await getCachedData( cacheName, url );
   if ( cachedData ) {
      console.log( 'Retrieved cached data' );
      return cachedData;
   }
   console.log( 'Fetching fresh data' );
   const cacheStorage = await caches.open( cacheName );
   await cacheStorage.add( url );
   cachedData = await getCachedData( cacheName, url );
   await deleteOldCaches( cacheName );
   return cachedData;
}
// Get data from the cache.
async function getCachedData( cacheName, url ) {
   const cacheStorage   = await caches.open( cacheName );
   const cachedResponse = await cacheStorage.match( url );
   if ( ! cachedResponse || ! cachedResponse.ok ) {
      return false;
   }
   return await cachedResponse.json();
}
// Delete any old caches to respect user's disk space.
async function deleteOldCaches( currentCache ) {
   const keys = await caches.keys();
   for ( const key of keys ) {
      const isOurCache = 'myapp-' === key.substr( 0, 6 );
      if ( currentCache === key || ! isOurCache ) {
         continue;
      }
      caches.delete( key );
   }
}
try {
   const data = await getData();
   console.log( { data } );
} catch ( error ) {
   console.error( { error } );
}

规范

规范	状态	注释
服务工作者 The definition of 'CacheStorage' in that specification.	工作草案	初始定义。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`CacheStorage`	Chrome 40 40 Accessible from `Window` from version 43. Accessible from `WorkerGlobalScope` from version 43.	Edge ≤18	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 27	Safari 11.1	WebView Android 40 40 Accessible from `Window` from version 43. Accessible from `WorkerGlobalScope` from version 43.	Chrome Android 40 40 Accessible from `Window` from version 43. Accessible from `WorkerGlobalScope` from version 43.	Firefox Android 44	Opera Android 27	Safari iOS 11.3	Samsung Internet Android 4.0 4.0 Accessible from `Window` from Samsung Internet 4.0. Accessible from `WorkerGlobalScope` from Samsung Internet 4.0.
`delete`	Chrome 40	Edge 16	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 27	Safari 11.1	WebView Android 40	Chrome Android 40	Firefox Android 44	Opera Android 27	Safari iOS Yes	Samsung Internet Android 4.0
`has`	Chrome 40	Edge 16	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 27	Safari 11.1	WebView Android 40	Chrome Android 40	Firefox Android 44	Opera Android 27	Safari iOS Yes	Samsung Internet Android 4.0
`keys`	Chrome 40	Edge 16	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 27	Safari 11.1	WebView Android 40	Chrome Android 40	Firefox Android 44	Opera Android 27	Safari iOS Yes	Samsung Internet Android 4.0
`match`	Chrome 54 54 部分支持 40 The options parameter only supports `ignoreSearch` ，和 `cacheName` .	Edge 16	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 41 41 部分支持 27 The options parameter only supports `ignoreSearch` ，和 `cacheName` .	Safari 11.1	WebView Android 54 54 部分支持 40 The options parameter only supports `ignoreSearch` ，和 `cacheName` .	Chrome Android 54 54 部分支持 40 The options parameter only supports `ignoreSearch` ，和 `cacheName` .	Firefox Android 44	Opera Android 41 41 部分支持 27 The options parameter only supports `ignoreSearch` ，和 `cacheName` .	Safari iOS Yes	Samsung Internet Android 6.0 6.0 部分支持 4.0 The options parameter only supports `ignoreSearch` ，和 `cacheName` .
`open`	Chrome 40	Edge 16	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 27	Safari 11.1	WebView Android 40	Chrome Android 40	Firefox Android 44	Opera Android 27	Safari iOS Yes	Samsung Internet Android 4.0
Secure context required	Chrome 65	Edge ≤79	Firefox 44	IE No	Opera 52	Safari Yes	WebView Android 65	Chrome Android 65	Firefox Android 44	Opera Android 47	Safari iOS Yes	Samsung Internet Android 9.0

图例

完整支持
不支持
实验。期望将来行为有所改变。

另请参阅

元数据

最后修改： May 12, 2020

服务工作者 API
CacheStorage
方法
1. delete()
2. has()
3. keys()
4. match()
5. open()
Related pages for Service Workers API

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