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function waitForState(worker, state, context) {
return new Promise(resolve => {
function onStateChange() {
if (worker.state === state) {
worker.removeEventListener("statechange", onStateChange);
resolve(context);
}
}
// First add an event listener, so we won't miss any change that happens
// before we check the current state.
worker.addEventListener("statechange", onStateChange);
// Now check if the worker is already in the desired state.
onStateChange();
});
}
/**
* Helper for browser tests to issue register calls from the content global and
* wait for the SW to progress to the active state, as most tests desire.
* From the ContentTask.spawn, use via
* `content.wrappedJSObject.registerAndWaitForActive`.
*/
async function registerAndWaitForActive(script, maybeScope) {
console.log("...calling register");
let opts = undefined;
if (maybeScope) {
opts = { scope: maybeScope };
}
const reg = await navigator.serviceWorker.register(script, opts);
// Unless registration resurrection happens, the SW should be in the
// installing slot.
console.log("...waiting for activation");
await waitForState(reg.installing, "activated", reg);
console.log("...activated!");
return reg;
}
/**
* Helper to create an iframe with the given URL and return the first
* postMessage payload received. This is intended to be used when creating
* cross-origin iframes.
*
* A promise will be returned that resolves with the payload of the postMessage
* call.
*/
function createIframeAndWaitForMessage(url) {
const iframe = document.createElement("iframe");
document.body.appendChild(iframe);
return new Promise(resolve => {
window.addEventListener(
"message",
event => {
resolve(event.data);
},
{ once: true }
);
iframe.src = url;
});
}
/**
* Helper to create a nested iframe into the iframe created by
* createIframeAndWaitForMessage().
*
* A promise will be returned that resolves with the payload of the postMessage
* call.
*/
function createNestedIframeAndWaitForMessage(url) {
const iframe = document.getElementsByTagName("iframe")[0];
iframe.contentWindow.postMessage("create nested iframe", "*");
return new Promise(resolve => {
window.addEventListener(
"message",
event => {
resolve(event.data);
},
{ once: true }
);
});
}
async function unregisterAll() {
const registrations = await navigator.serviceWorker.getRegistrations();
for (const reg of registrations) {
await reg.unregister();
}
}
/**
* Make a blob that contains random data and therefore shouldn't compress all
* that well.
*/
function makeRandomBlob(size) {
const arr = new Uint8Array(size);
let offset = 0;
/**
* getRandomValues will only provide a maximum of 64k of data at a time and
* will error if we ask for more, so using a while loop for get a random value
* which much larger than 64k.
*/
while (offset < size) {
const nextSize = Math.min(size - offset, 65536);
window.crypto.getRandomValues(new Uint8Array(arr.buffer, offset, nextSize));
offset += nextSize;
}
return new Blob([arr], { type: "application/octet-stream" });
}
async function fillStorage(cacheBytes, idbBytes) {
// ## Fill Cache API Storage
const cache = await caches.open("filler");
await cache.put("fill", new Response(makeRandomBlob(cacheBytes)));
// ## Fill IDB
const storeName = "filler";
let db = await new Promise((resolve, reject) => {
let openReq = indexedDB.open("filler", 1);
openReq.onerror = event => {
reject(event.target.error);
};
openReq.onsuccess = event => {
resolve(event.target.result);
};
openReq.onupgradeneeded = event => {
const useDB = event.target.result;
useDB.onerror = error => {
reject(error);
};
const store = useDB.createObjectStore(storeName);
store.put({ blob: makeRandomBlob(idbBytes) }, "filler-blob");
};
});
}