prevent cached thumbnails from being opaque responses

fixes https://github.com/vector-im/hydrogen-web/issues/169
This commit is contained in:
Bruno Windels 2020-10-20 17:28:42 +02:00
parent 13f1620d88
commit 545a2e481a

View file

@ -22,7 +22,7 @@ const HASHED_PRECACHED_ASSETS = "%%HASHED_PRECACHED_ASSETS%%";
const HASHED_CACHED_ON_REQUEST_ASSETS = "%%HASHED_CACHED_ON_REQUEST_ASSETS%%";
const unhashedCacheName = `hydrogen-assets-${GLOBAL_HASH}`;
const hashedCacheName = `hydrogen-assets`;
const mediaThumbnailCacheName = `hydrogen-media-thumbnails`;
const mediaThumbnailCacheName = `hydrogen-media-thumbnails-v2`;
self.addEventListener('install', function(e) {
e.waitUntil((async () => {
@ -73,6 +73,17 @@ self.addEventListener('fetch', (event) => {
event.respondWith(handleRequest(event.request));
});
function isCacheableThumbnail(url) {
if (url.pathname.startsWith("/_matrix/media/r0/thumbnail/")) {
const width = parseInt(url.searchParams.get("width"), 10);
const height = parseInt(url.searchParams.get("height"), 10);
if (width <= 50 && height <= 50) {
return true;
}
}
return false;
}
async function handleRequest(request) {
const baseURL = self.registration.scope;
if (request.url === baseURL) {
@ -80,7 +91,13 @@ async function handleRequest(request) {
}
let response = await readCache(request);
if (!response) {
// use cors so the resource in the cache isn't opaque and uses up to 7mb
// https://developers.google.com/web/tools/chrome-devtools/progressive-web-apps?utm_source=devtools#opaque-responses
if (isCacheableThumbnail(new URL(request.url))) {
response = await fetch(request, {mode: "cors", credentials: "omit"});
} else {
response = await fetch(request);
}
await updateCache(request, response);
}
return response;
@ -89,13 +106,9 @@ async function handleRequest(request) {
async function updateCache(request, response) {
const url = new URL(request.url);
const baseURL = self.registration.scope;
if (url.pathname.startsWith("/_matrix/media/r0/thumbnail/")) {
const width = parseInt(url.searchParams.get("width"), 10);
const height = parseInt(url.searchParams.get("height"), 10);
if (width <= 50 && height <= 50) {
if (isCacheableThumbnail(url)) {
const cache = await caches.open(mediaThumbnailCacheName);
cache.put(request, response.clone());
}
} else if (request.url.startsWith(baseURL)) {
let assetName = request.url.substr(baseURL.length);
if (HASHED_CACHED_ON_REQUEST_ASSETS.includes(assetName)) {
@ -118,7 +131,7 @@ async function readCache(request) {
}
const url = new URL(request.url);
if (url.pathname.startsWith("/_matrix/media/r0/thumbnail/")) {
if (isCacheableThumbnail(url)) {
const mediaThumbnailCache = await caches.open(mediaThumbnailCacheName);
response = await mediaThumbnailCache.match(request);
}