52 lines
1.2 KiB
TypeScript
52 lines
1.2 KiB
TypeScript
import { ASSET_CACHE_NAME } from '../config';
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import { pause } from '../util/schedulers';
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declare const self: ServiceWorkerGlobalScope;
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// An attempt to fix freezing UI on iOS
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const CACHE_TIMEOUT = 3000;
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export async function respondWithCache(e: FetchEvent) {
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const cacheResult = await withTimeout(async () => {
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const cache = await self.caches.open(ASSET_CACHE_NAME);
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const cached = await cache.match(e.request);
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return { cache, cached };
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}, CACHE_TIMEOUT);
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const { cache, cached } = cacheResult || {};
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if (cache && cached) {
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if (cached.ok) {
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return cached;
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} else {
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await cache.delete(e.request);
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}
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}
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const remote = await fetch(e.request);
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if (remote.ok && cache) {
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cache.put(e.request, remote.clone());
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}
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return remote;
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}
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async function withTimeout<T>(cb: () => Promise<T>, timeout: number) {
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try {
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return await Promise.race([
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pause(timeout).then(() => Promise.reject(new Error('TIMEOUT'))),
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cb(),
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]);
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} catch (err) {
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// eslint-disable-next-line no-console
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console.error(err);
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return undefined;
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}
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}
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export function clearAssetCache() {
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return self.caches.delete(ASSET_CACHE_NAME);
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}
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