GoScrobble/web/node_modules/workbox-strategies/NetworkFirst.js

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2022-04-25 02:47:15 +00:00
/*
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 { cacheNames } from 'workbox-core/_private/cacheNames.js';
import { cacheWrapper } from 'workbox-core/_private/cacheWrapper.js';
import { fetchWrapper } from 'workbox-core/_private/fetchWrapper.js';
import { getFriendlyURL } from 'workbox-core/_private/getFriendlyURL.js';
import { logger } from 'workbox-core/_private/logger.js';
import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
import { messages } from './utils/messages.js';
import { cacheOkAndOpaquePlugin } from './plugins/cacheOkAndOpaquePlugin.js';
import './_version.js';
/**
* An implementation of a
* [network first]{@link https://developers.google.com/web/fundamentals/instant-and-offline/offline-cookbook/#network-falling-back-to-cache}
* request strategy.
*
* By default, this strategy will cache responses with a 200 status code as
* well as [opaque responses]{@link https://developers.google.com/web/tools/workbox/guides/handle-third-party-requests}.
* Opaque responses are are cross-origin requests where the response doesn't
* support [CORS]{@link https://enable-cors.org/}.
*
* If the network request fails, and there is no cache match, this will throw
* a `WorkboxError` exception.
*
* @memberof module:workbox-strategies
*/
class NetworkFirst {
/**
* @param {Object} options
* @param {string} options.cacheName Cache name to store and retrieve
* requests. Defaults to cache names provided by
* [workbox-core]{@link module: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 all fetch() requests made by this strategy.
* @param {Object} options.matchOptions [`CacheQueryOptions`](https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions)
* @param {number} options.networkTimeoutSeconds If set, any network requests
* that fail to respond within the timeout will fallback to the cache.
*
* This option can be used to combat
* "[lie-fi]{@link https://developers.google.com/web/fundamentals/performance/poor-connectivity/#lie-fi}"
* scenarios.
*/
constructor(options = {}) {
this._cacheName = cacheNames.getRuntimeName(options.cacheName);
if (options.plugins) {
const isUsingCacheWillUpdate = options.plugins.some((plugin) => !!plugin.cacheWillUpdate);
this._plugins = isUsingCacheWillUpdate ?
options.plugins : [cacheOkAndOpaquePlugin, ...options.plugins];
}
else {
// No plugins passed in, use the default plugin.
this._plugins = [cacheOkAndOpaquePlugin];
}
this._networkTimeoutSeconds = options.networkTimeoutSeconds || 0;
if (process.env.NODE_ENV !== 'production') {
if (this._networkTimeoutSeconds) {
assert.isType(this._networkTimeoutSeconds, 'number', {
moduleName: 'workbox-strategies',
className: 'NetworkFirst',
funcName: 'constructor',
paramName: 'networkTimeoutSeconds',
});
}
}
this._fetchOptions = options.fetchOptions;
this._matchOptions = options.matchOptions;
}
/**
* This method will perform a request strategy and follows an API that
* will work with the
* [Workbox Router]{@link module:workbox-routing.Router}.
*
* @param {Object} options
* @param {Request|string} options.request A request to run this strategy for.
* @param {Event} [options.event] The event that triggered the request.
* @return {Promise<Response>}
*/
async handle({ event, request }) {
const logs = [];
if (typeof request === 'string') {
request = new Request(request);
}
if (process.env.NODE_ENV !== 'production') {
assert.isInstance(request, Request, {
moduleName: 'workbox-strategies',
className: 'NetworkFirst',
funcName: 'handle',
paramName: 'makeRequest',
});
}
const promises = [];
let timeoutId;
if (this._networkTimeoutSeconds) {
const { id, promise } = this._getTimeoutPromise({ request, event, logs });
timeoutId = id;
promises.push(promise);
}
const networkPromise = this._getNetworkPromise({ timeoutId, request, event, logs });
promises.push(networkPromise);
// Promise.race() will resolve as soon as the first promise resolves.
let response = await Promise.race(promises);
// If Promise.race() resolved with null, it might be due to a network
// timeout + a cache miss. If that were to happen, we'd rather wait until
// the networkPromise resolves instead of returning null.
// Note that it's fine to await an already-resolved promise, so we don't
// have to check to see if it's still "in flight".
if (!response) {
response = await networkPromise;
}
if (process.env.NODE_ENV !== 'production') {
logger.groupCollapsed(messages.strategyStart('NetworkFirst', request));
for (const log of logs) {
logger.log(log);
}
messages.printFinalResponse(response);
logger.groupEnd();
}
if (!response) {
throw new WorkboxError('no-response', { url: request.url });
}
return response;
}
/**
* @param {Object} options
* @param {Request} options.request
* @param {Array} options.logs A reference to the logs array
* @param {Event} [options.event]
* @return {Promise<Response>}
*
* @private
*/
_getTimeoutPromise({ request, logs, event }) {
let timeoutId;
const timeoutPromise = new Promise((resolve) => {
const onNetworkTimeout = async () => {
if (process.env.NODE_ENV !== 'production') {
logs.push(`Timing out the network response at ` +
`${this._networkTimeoutSeconds} seconds.`);
}
resolve(await this._respondFromCache({ request, event }));
};
timeoutId = setTimeout(onNetworkTimeout, this._networkTimeoutSeconds * 1000);
});
return {
promise: timeoutPromise,
id: timeoutId,
};
}
/**
* @param {Object} options
* @param {number|undefined} options.timeoutId
* @param {Request} options.request
* @param {Array} options.logs A reference to the logs Array.
* @param {Event} [options.event]
* @return {Promise<Response>}
*
* @private
*/
async _getNetworkPromise({ timeoutId, request, logs, event }) {
let error;
let response;
try {
response = await fetchWrapper.fetch({
request,
event,
fetchOptions: this._fetchOptions,
plugins: this._plugins,
});
}
catch (err) {
error = err;
}
if (timeoutId) {
clearTimeout(timeoutId);
}
if (process.env.NODE_ENV !== 'production') {
if (response) {
logs.push(`Got response from network.`);
}
else {
logs.push(`Unable to get a response from the network. Will respond ` +
`with a cached response.`);
}
}
if (error || !response) {
response = await this._respondFromCache({ request, event });
if (process.env.NODE_ENV !== 'production') {
if (response) {
logs.push(`Found a cached response in the '${this._cacheName}'` +
` cache.`);
}
else {
logs.push(`No response found in the '${this._cacheName}' cache.`);
}
}
}
else {
// Keep the service worker alive while we put the request in the cache
const responseClone = response.clone();
const cachePut = cacheWrapper.put({
cacheName: this._cacheName,
request,
response: responseClone,
event,
plugins: this._plugins,
});
if (event) {
try {
// The event has been responded to so we can keep the SW alive to
// respond to the request
event.waitUntil(cachePut);
}
catch (err) {
if (process.env.NODE_ENV !== 'production') {
logger.warn(`Unable to ensure service worker stays alive when ` +
`updating cache for '${getFriendlyURL(request.url)}'.`);
}
}
}
}
return response;
}
/**
* Used if the network timeouts or fails to make the request.
*
* @param {Object} options
* @param {Request} request The request to match in the cache
* @param {Event} [options.event]
* @return {Promise<Object>}
*
* @private
*/
_respondFromCache({ event, request }) {
return cacheWrapper.match({
cacheName: this._cacheName,
request,
event,
matchOptions: this._matchOptions,
plugins: this._plugins,
});
}
}
export { NetworkFirst };