hexo/node_modules/workbox-strategies/StaleWhileRevalidate.js

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2023-10-03 11:14:36 +08:00
/*
Copyright 2018 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
import { assert } from 'workbox-core/_private/assert.js';
import { logger } from 'workbox-core/_private/logger.js';
import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
import { cacheOkAndOpaquePlugin } from './plugins/cacheOkAndOpaquePlugin.js';
import { Strategy } from './Strategy.js';
import { messages } from './utils/messages.js';
import './_version.js';
/**
* An implementation of a
* [stale-while-revalidate](https://developer.chrome.com/docs/workbox/caching-strategies-overview/#stale-while-revalidate)
* request strategy.
*
* Resources are requested from both the cache and the network in parallel.
* The strategy will respond with the cached version if available, otherwise
* wait for the network response. The cache is updated with the network response
* with each successful request.
*
* By default, this strategy will cache responses with a 200 status code as
* well as [opaque responses](https://developer.chrome.com/docs/workbox/caching-resources-during-runtime/#opaque-responses).
* Opaque responses are cross-origin requests where the response doesn't
* support [CORS](https://enable-cors.org/).
*
* If the network request fails, and there is no cache match, this will throw
* a `WorkboxError` exception.
*
* @extends workbox-strategies.Strategy
* @memberof workbox-strategies
*/
class StaleWhileRevalidate extends Strategy {
/**
* @param {Object} [options]
* @param {string} [options.cacheName] Cache name to store and retrieve
* requests. Defaults to cache names provided by
* {@link workbox-core.cacheNames}.
* @param {Array<Object>} [options.plugins] [Plugins]{@link https://developers.google.com/web/tools/workbox/guides/using-plugins}
* to use in conjunction with this caching strategy.
* @param {Object} [options.fetchOptions] Values passed along to the
* [`init`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#Parameters)
* of [non-navigation](https://github.com/GoogleChrome/workbox/issues/1796)
* `fetch()` requests made by this strategy.
* @param {Object} [options.matchOptions] [`CacheQueryOptions`](https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions)
*/
constructor(options = {}) {
super(options);
// If this instance contains no plugins with a 'cacheWillUpdate' callback,
// prepend the `cacheOkAndOpaquePlugin` plugin to the plugins list.
if (!this.plugins.some((p) => 'cacheWillUpdate' in p)) {
this.plugins.unshift(cacheOkAndOpaquePlugin);
}
}
/**
* @private
* @param {Request|string} request A request to run this strategy for.
* @param {workbox-strategies.StrategyHandler} handler The event that
* triggered the request.
* @return {Promise<Response>}
*/
async _handle(request, handler) {
const logs = [];
if (process.env.NODE_ENV !== 'production') {
assert.isInstance(request, Request, {
moduleName: 'workbox-strategies',
className: this.constructor.name,
funcName: 'handle',
paramName: 'request',
});
}
const fetchAndCachePromise = handler.fetchAndCachePut(request).catch(() => {
// Swallow this error because a 'no-response' error will be thrown in
// main handler return flow. This will be in the `waitUntil()` flow.
});
void handler.waitUntil(fetchAndCachePromise);
let response = await handler.cacheMatch(request);
let error;
if (response) {
if (process.env.NODE_ENV !== 'production') {
logs.push(`Found a cached response in the '${this.cacheName}'` +
` cache. Will update with the network response in the background.`);
}
}
else {
if (process.env.NODE_ENV !== 'production') {
logs.push(`No response found in the '${this.cacheName}' cache. ` +
`Will wait for the network response.`);
}
try {
// NOTE(philipwalton): Really annoying that we have to type cast here.
// https://github.com/microsoft/TypeScript/issues/20006
response = (await fetchAndCachePromise);
}
catch (err) {
if (err instanceof Error) {
error = err;
}
}
}
if (process.env.NODE_ENV !== 'production') {
logger.groupCollapsed(messages.strategyStart(this.constructor.name, request));
for (const log of logs) {
logger.log(log);
}
messages.printFinalResponse(response);
logger.groupEnd();
}
if (!response) {
throw new WorkboxError('no-response', { url: request.url, error });
}
return response;
}
}
export { StaleWhileRevalidate };