| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254 | /*  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 { dontWaitFor } from 'workbox-core/_private/dontWaitFor.js';import { getFriendlyURL } from 'workbox-core/_private/getFriendlyURL.js';import { logger } from 'workbox-core/_private/logger.js';import { registerQuotaErrorCallback } from 'workbox-core/registerQuotaErrorCallback.js';import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';import { CacheExpiration } from './CacheExpiration.js';import './_version.js';/** * This plugin can be used in a `workbox-strategy` to regularly enforce a * limit on the age and / or the number of cached requests. * * It can only be used with `workbox-strategy` instances that have a * [custom `cacheName` property set](/web/tools/workbox/guides/configure-workbox#custom_cache_names_in_strategies). * In other words, it can't be used to expire entries in strategy that uses the * default runtime cache name. * * Whenever a cached response is used or updated, this plugin will look * at the associated cache and remove any old or extra responses. * * When using `maxAgeSeconds`, responses may be used *once* after expiring * because the expiration clean up will not have occurred until *after* the * cached response has been used. If the response has a "Date" header, then * a light weight expiration check is performed and the response will not be * used immediately. * * When using `maxEntries`, the entry least-recently requested will be removed * from the cache first. * * @memberof workbox-expiration */class ExpirationPlugin {    /**     * @param {ExpirationPluginOptions} config     * @param {number} [config.maxEntries] The maximum number of entries to cache.     * Entries used the least will be removed as the maximum is reached.     * @param {number} [config.maxAgeSeconds] The maximum age of an entry before     * it's treated as stale and removed.     * @param {Object} [config.matchOptions] The [`CacheQueryOptions`](https://developer.mozilla.org/en-US/docs/Web/API/Cache/delete#Parameters)     * that will be used when calling `delete()` on the cache.     * @param {boolean} [config.purgeOnQuotaError] Whether to opt this cache in to     * automatic deletion if the available storage quota has been exceeded.     */    constructor(config = {}) {        /**         * A "lifecycle" callback that will be triggered automatically by the         * `workbox-strategies` handlers when a `Response` is about to be returned         * from a [Cache](https://developer.mozilla.org/en-US/docs/Web/API/Cache) to         * the handler. It allows the `Response` to be inspected for freshness and         * prevents it from being used if the `Response`'s `Date` header value is         * older than the configured `maxAgeSeconds`.         *         * @param {Object} options         * @param {string} options.cacheName Name of the cache the response is in.         * @param {Response} options.cachedResponse The `Response` object that's been         *     read from a cache and whose freshness should be checked.         * @return {Response} Either the `cachedResponse`, if it's         *     fresh, or `null` if the `Response` is older than `maxAgeSeconds`.         *         * @private         */        this.cachedResponseWillBeUsed = async ({ event, request, cacheName, cachedResponse, }) => {            if (!cachedResponse) {                return null;            }            const isFresh = this._isResponseDateFresh(cachedResponse);            // Expire entries to ensure that even if the expiration date has            // expired, it'll only be used once.            const cacheExpiration = this._getCacheExpiration(cacheName);            dontWaitFor(cacheExpiration.expireEntries());            // Update the metadata for the request URL to the current timestamp,            // but don't `await` it as we don't want to block the response.            const updateTimestampDone = cacheExpiration.updateTimestamp(request.url);            if (event) {                try {                    event.waitUntil(updateTimestampDone);                }                catch (error) {                    if (process.env.NODE_ENV !== 'production') {                        // The event may not be a fetch event; only log the URL if it is.                        if ('request' in event) {                            logger.warn(`Unable to ensure service worker stays alive when ` +                                `updating cache entry for ` +                                `'${getFriendlyURL(event.request.url)}'.`);                        }                    }                }            }            return isFresh ? cachedResponse : null;        };        /**         * A "lifecycle" callback that will be triggered automatically by the         * `workbox-strategies` handlers when an entry is added to a cache.         *         * @param {Object} options         * @param {string} options.cacheName Name of the cache that was updated.         * @param {string} options.request The Request for the cached entry.         *         * @private         */        this.cacheDidUpdate = async ({ cacheName, request, }) => {            if (process.env.NODE_ENV !== 'production') {                assert.isType(cacheName, 'string', {                    moduleName: 'workbox-expiration',                    className: 'Plugin',                    funcName: 'cacheDidUpdate',                    paramName: 'cacheName',                });                assert.isInstance(request, Request, {                    moduleName: 'workbox-expiration',                    className: 'Plugin',                    funcName: 'cacheDidUpdate',                    paramName: 'request',                });            }            const cacheExpiration = this._getCacheExpiration(cacheName);            await cacheExpiration.updateTimestamp(request.url);            await cacheExpiration.expireEntries();        };        if (process.env.NODE_ENV !== 'production') {            if (!(config.maxEntries || config.maxAgeSeconds)) {                throw new WorkboxError('max-entries-or-age-required', {                    moduleName: 'workbox-expiration',                    className: 'Plugin',                    funcName: 'constructor',                });            }            if (config.maxEntries) {                assert.isType(config.maxEntries, 'number', {                    moduleName: 'workbox-expiration',                    className: 'Plugin',                    funcName: 'constructor',                    paramName: 'config.maxEntries',                });            }            if (config.maxAgeSeconds) {                assert.isType(config.maxAgeSeconds, 'number', {                    moduleName: 'workbox-expiration',                    className: 'Plugin',                    funcName: 'constructor',                    paramName: 'config.maxAgeSeconds',                });            }        }        this._config = config;        this._maxAgeSeconds = config.maxAgeSeconds;        this._cacheExpirations = new Map();        if (config.purgeOnQuotaError) {            registerQuotaErrorCallback(() => this.deleteCacheAndMetadata());        }    }    /**     * A simple helper method to return a CacheExpiration instance for a given     * cache name.     *     * @param {string} cacheName     * @return {CacheExpiration}     *     * @private     */    _getCacheExpiration(cacheName) {        if (cacheName === cacheNames.getRuntimeName()) {            throw new WorkboxError('expire-custom-caches-only');        }        let cacheExpiration = this._cacheExpirations.get(cacheName);        if (!cacheExpiration) {            cacheExpiration = new CacheExpiration(cacheName, this._config);            this._cacheExpirations.set(cacheName, cacheExpiration);        }        return cacheExpiration;    }    /**     * @param {Response} cachedResponse     * @return {boolean}     *     * @private     */    _isResponseDateFresh(cachedResponse) {        if (!this._maxAgeSeconds) {            // We aren't expiring by age, so return true, it's fresh            return true;        }        // Check if the 'date' header will suffice a quick expiration check.        // See https://github.com/GoogleChromeLabs/sw-toolbox/issues/164 for        // discussion.        const dateHeaderTimestamp = this._getDateHeaderTimestamp(cachedResponse);        if (dateHeaderTimestamp === null) {            // Unable to parse date, so assume it's fresh.            return true;        }        // If we have a valid headerTime, then our response is fresh iff the        // headerTime plus maxAgeSeconds is greater than the current time.        const now = Date.now();        return dateHeaderTimestamp >= now - this._maxAgeSeconds * 1000;    }    /**     * This method will extract the data header and parse it into a useful     * value.     *     * @param {Response} cachedResponse     * @return {number|null}     *     * @private     */    _getDateHeaderTimestamp(cachedResponse) {        if (!cachedResponse.headers.has('date')) {            return null;        }        const dateHeader = cachedResponse.headers.get('date');        const parsedDate = new Date(dateHeader);        const headerTime = parsedDate.getTime();        // If the Date header was invalid for some reason, parsedDate.getTime()        // will return NaN.        if (isNaN(headerTime)) {            return null;        }        return headerTime;    }    /**     * This is a helper method that performs two operations:     *     * - Deletes *all* the underlying Cache instances associated with this plugin     * instance, by calling caches.delete() on your behalf.     * - Deletes the metadata from IndexedDB used to keep track of expiration     * details for each Cache instance.     *     * When using cache expiration, calling this method is preferable to calling     * `caches.delete()` directly, since this will ensure that the IndexedDB     * metadata is also cleanly removed and open IndexedDB instances are deleted.     *     * Note that if you're *not* using cache expiration for a given cache, calling     * `caches.delete()` and passing in the cache's name should be sufficient.     * There is no Workbox-specific method needed for cleanup in that case.     */    async deleteCacheAndMetadata() {        // Do this one at a time instead of all at once via `Promise.all()` to        // reduce the chance of inconsistency if a promise rejects.        for (const [cacheName, cacheExpiration] of this._cacheExpirations) {            await self.caches.delete(cacheName);            await cacheExpiration.delete();        }        // Reset this._cacheExpirations to its initial state.        this._cacheExpirations = new Map();    }}export { ExpirationPlugin };
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