hexo/node_modules/workbox-precaching/PrecacheStrategy.js

/*
  Copyright 2020 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 { copyResponse } from 'workbox-core/copyResponse.js';
import { cacheNames } from 'workbox-core/_private/cacheNames.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 { Strategy } from 'workbox-strategies/Strategy.js';
import './_version.js';
/**
 * A {@link workbox-strategies.Strategy} implementation
 * specifically designed to work with
 * {@link workbox-precaching.PrecacheController}
 * to both cache and fetch precached assets.
 *
 * Note: an instance of this class is created automatically when creating a
 * `PrecacheController`; it's generally not necessary to create this yourself.
 *
 * @extends workbox-strategies.Strategy
 * @memberof workbox-precaching
 */
class PrecacheStrategy extends Strategy {
    /**
     *
     * @param {Object} [options]
     * @param {string} [options.cacheName] Cache name to store and retrieve
     * requests. Defaults to the cache names provided by
     * {@link workbox-core.cacheNames}.
     * @param {Array<Object>} [options.plugins] {@link https://developers.google.com/web/tools/workbox/guides/using-plugins|Plugins}
     * to use in conjunction with this caching strategy.
     * @param {Object} [options.fetchOptions] Values passed along to the
     * {@link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#Parameters|init}
     * of all fetch() requests made by this strategy.
     * @param {Object} [options.matchOptions] The
     * {@link https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions|CacheQueryOptions}
     * for any `cache.match()` or `cache.put()` calls made by this strategy.
     * @param {boolean} [options.fallbackToNetwork=true] Whether to attempt to
     * get the response from the network if there's a precache miss.
     */
    constructor(options = {}) {
        options.cacheName = cacheNames.getPrecacheName(options.cacheName);
        super(options);
        this._fallbackToNetwork =
            options.fallbackToNetwork === false ? false : true;
        // Redirected responses cannot be used to satisfy a navigation request, so
        // any redirected response must be "copied" rather than cloned, so the new
        // response doesn't contain the `redirected` flag. See:
        // https://bugs.chromium.org/p/chromium/issues/detail?id=669363&desc=2#c1
        this.plugins.push(PrecacheStrategy.copyRedirectedCacheableResponsesPlugin);
    }
    /**
     * @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 response = await handler.cacheMatch(request);
        if (response) {
            return response;
        }
        // If this is an `install` event for an entry that isn't already cached,
        // then populate the cache.
        if (handler.event && handler.event.type === 'install') {
            return await this._handleInstall(request, handler);
        }
        // Getting here means something went wrong. An entry that should have been
        // precached wasn't found in the cache.
        return await this._handleFetch(request, handler);
    }
    async _handleFetch(request, handler) {
        let response;
        const params = (handler.params || {});
        // Fall back to the network if we're configured to do so.
        if (this._fallbackToNetwork) {
            if (process.env.NODE_ENV !== 'production') {
                logger.warn(`The precached response for ` +
                    `${getFriendlyURL(request.url)} in ${this.cacheName} was not ` +
                    `found. Falling back to the network.`);
            }
            const integrityInManifest = params.integrity;
            const integrityInRequest = request.integrity;
            const noIntegrityConflict = !integrityInRequest || integrityInRequest === integrityInManifest;
            // Do not add integrity if the original request is no-cors
            // See https://github.com/GoogleChrome/workbox/issues/3096
            response = await handler.fetch(new Request(request, {
                integrity: request.mode !== 'no-cors'
                    ? integrityInRequest || integrityInManifest
                    : undefined,
            }));
            // It's only "safe" to repair the cache if we're using SRI to guarantee
            // that the response matches the precache manifest's expectations,
            // and there's either a) no integrity property in the incoming request
            // or b) there is an integrity, and it matches the precache manifest.
            // See https://github.com/GoogleChrome/workbox/issues/2858
            // Also if the original request users no-cors we don't use integrity.
            // See https://github.com/GoogleChrome/workbox/issues/3096
            if (integrityInManifest &&
                noIntegrityConflict &&
                request.mode !== 'no-cors') {
                this._useDefaultCacheabilityPluginIfNeeded();
                const wasCached = await handler.cachePut(request, response.clone());
                if (process.env.NODE_ENV !== 'production') {
                    if (wasCached) {
                        logger.log(`A response for ${getFriendlyURL(request.url)} ` +
                            `was used to "repair" the precache.`);
                    }
                }
            }
        }
        else {
            // This shouldn't normally happen, but there are edge cases:
            // https://github.com/GoogleChrome/workbox/issues/1441
            throw new WorkboxError('missing-precache-entry', {
                cacheName: this.cacheName,
                url: request.url,
            });
        }
        if (process.env.NODE_ENV !== 'production') {
            const cacheKey = params.cacheKey || (await handler.getCacheKey(request, 'read'));
            // Workbox is going to handle the route.
            // print the routing details to the console.
            logger.groupCollapsed(`Precaching is responding to: ` + getFriendlyURL(request.url));
            logger.log(`Serving the precached url: ${getFriendlyURL(cacheKey instanceof Request ? cacheKey.url : cacheKey)}`);
            logger.groupCollapsed(`View request details here.`);
            logger.log(request);
            logger.groupEnd();
            logger.groupCollapsed(`View response details here.`);
            logger.log(response);
            logger.groupEnd();
            logger.groupEnd();
        }
        return response;
    }
    async _handleInstall(request, handler) {
        this._useDefaultCacheabilityPluginIfNeeded();
        const response = await handler.fetch(request);
        // Make sure we defer cachePut() until after we know the response
        // should be cached; see https://github.com/GoogleChrome/workbox/issues/2737
        const wasCached = await handler.cachePut(request, response.clone());
        if (!wasCached) {
            // Throwing here will lead to the `install` handler failing, which
            // we want to do if *any* of the responses aren't safe to cache.
            throw new WorkboxError('bad-precaching-response', {
                url: request.url,
                status: response.status,
            });
        }
        return response;
    }
    /**
     * This method is complex, as there a number of things to account for:
     *
     * The `plugins` array can be set at construction, and/or it might be added to
     * to at any time before the strategy is used.
     *
     * At the time the strategy is used (i.e. during an `install` event), there
     * needs to be at least one plugin that implements `cacheWillUpdate` in the
     * array, other than `copyRedirectedCacheableResponsesPlugin`.
     *
     * - If this method is called and there are no suitable `cacheWillUpdate`
     * plugins, we need to add `defaultPrecacheCacheabilityPlugin`.
     *
     * - If this method is called and there is exactly one `cacheWillUpdate`, then
     * we don't have to do anything (this might be a previously added
     * `defaultPrecacheCacheabilityPlugin`, or it might be a custom plugin).
     *
     * - If this method is called and there is more than one `cacheWillUpdate`,
     * then we need to check if one is `defaultPrecacheCacheabilityPlugin`. If so,
     * we need to remove it. (This situation is unlikely, but it could happen if
     * the strategy is used multiple times, the first without a `cacheWillUpdate`,
     * and then later on after manually adding a custom `cacheWillUpdate`.)
     *
     * See https://github.com/GoogleChrome/workbox/issues/2737 for more context.
     *
     * @private
     */
    _useDefaultCacheabilityPluginIfNeeded() {
        let defaultPluginIndex = null;
        let cacheWillUpdatePluginCount = 0;
        for (const [index, plugin] of this.plugins.entries()) {
            // Ignore the copy redirected plugin when determining what to do.
            if (plugin === PrecacheStrategy.copyRedirectedCacheableResponsesPlugin) {
                continue;
            }
            // Save the default plugin's index, in case it needs to be removed.
            if (plugin === PrecacheStrategy.defaultPrecacheCacheabilityPlugin) {
                defaultPluginIndex = index;
            }
            if (plugin.cacheWillUpdate) {
                cacheWillUpdatePluginCount++;
            }
        }
        if (cacheWillUpdatePluginCount === 0) {
            this.plugins.push(PrecacheStrategy.defaultPrecacheCacheabilityPlugin);
        }
        else if (cacheWillUpdatePluginCount > 1 && defaultPluginIndex !== null) {
            // Only remove the default plugin; multiple custom plugins are allowed.
            this.plugins.splice(defaultPluginIndex, 1);
        }
        // Nothing needs to be done if cacheWillUpdatePluginCount is 1
    }
}
PrecacheStrategy.defaultPrecacheCacheabilityPlugin = {
    async cacheWillUpdate({ response }) {
        if (!response || response.status >= 400) {
            return null;
        }
        return response;
    },
};
PrecacheStrategy.copyRedirectedCacheableResponsesPlugin = {
    async cacheWillUpdate({ response }) {
        return response.redirected ? await copyResponse(response) : response;
    },
};
export { PrecacheStrategy };