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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-21 20:56:19 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-21 20:56:19 +0000
commit0b6210cd37b68b94252cb798598b12974a20e1c1 (patch)
treee371686554a877842d95aa94f100bee552ff2a8e /test/wpt/tests/common/dispatcher/dispatcher.js
parentInitial commit. (diff)
downloadnode-undici-upstream.tar.xz
node-undici-upstream.zip
Adding upstream version 5.28.2+dfsg1+~cs23.11.12.3.upstream/5.28.2+dfsg1+_cs23.11.12.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// Define a universal message passing API. It works cross-origin and across
+// browsing context groups.
+const dispatcher_path = "/common/dispatcher/dispatcher.py";
+const dispatcher_url = new URL(dispatcher_path, location.href).href;
+
+// Return a promise, limiting the number of concurrent accesses to a shared
+// resources to |max_concurrent_access|.
+const concurrencyLimiter = (max_concurrency) => {
+ let pending = 0;
+ let waiting = [];
+ return async (task) => {
+ pending++;
+ if (pending > max_concurrency)
+ await new Promise(resolve => waiting.push(resolve));
+ let result = await task();
+ pending--;
+ waiting.shift()?.();
+ return result;
+ };
+}
+
+// Wait for a random amount of time in the range [10ms,100ms].
+const randomDelay = () => {
+ return new Promise(resolve => setTimeout(resolve, 10 + 90*Math.random()));
+}
+
+// Sending too many requests in parallel causes congestion. Limiting it improves
+// throughput.
+//
+// Note: The following table has been determined on the test:
+// ../cache-storage.tentative.https.html
+// using Chrome with a 64 core CPU / 64GB ram, in release mode:
+// ┌───────────┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬────┐
+// │concurrency│ 1 │ 2 │ 3 │ 4 │ 5 │ 6 │ 10│ 15│ 20│ 30│ 50│ 100│
+// ├───────────┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼────┤
+// │time (s) │ 54│ 38│ 31│ 29│ 26│ 24│ 22│ 22│ 22│ 22│ 34│ 36 │
+// └───────────┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴────┘
+const limiter = concurrencyLimiter(6);
+
+// While requests to different remote contexts can go in parallel, we need to
+// ensure that requests to each remote context are done in order. This maps a
+// uuid to a queue of requests to send. A queue is processed until it is empty
+// and then is deleted from the map.
+const sendQueues = new Map();
+
+// Sends a single item (with rate-limiting) and calls the associated resolver
+// when it is successfully sent.
+const sendItem = async function (uuid, resolver, message) {
+ await limiter(async () => {
+ // Requests might be dropped. Retry until getting a confirmation it has been
+ // processed.
+ while(1) {
+ try {
+ let response = await fetch(dispatcher_url + `?uuid=${uuid}`, {
+ method: 'POST',
+ body: message
+ })
+ if (await response.text() == "done") {
+ resolver();
+ return;
+ }
+ } catch (fetch_error) {}
+ await randomDelay();
+ };
+ });
+}
+
+// While the queue is non-empty, send the next item. This is async and new items
+// may be added to the queue while others are being sent.
+const processQueue = async function (uuid, queue) {
+ while (queue.length) {
+ const [resolver, message] = queue.shift();
+ await sendItem(uuid, resolver, message);
+ }
+ // The queue is empty, delete it.
+ sendQueues.delete(uuid);
+}
+
+const send = async function (uuid, message) {
+ const itemSentPromise = new Promise((resolve) => {
+ const item = [resolve, message];
+ if (sendQueues.has(uuid)) {
+ // There is already a queue for `uuid`, just add to it and it will be processed.
+ sendQueues.get(uuid).push(item);
+ } else {
+ // There is no queue for `uuid`, create it and start processing.
+ const queue = [item];
+ sendQueues.set(uuid, queue);
+ processQueue(uuid, queue);
+ }
+ });
+ // Wait until the item has been successfully sent.
+ await itemSentPromise;
+}
+
+const receive = async function (uuid) {
+ while(1) {
+ let data = "not ready";
+ try {
+ data = await limiter(async () => {
+ let response = await fetch(dispatcher_url + `?uuid=${uuid}`);
+ return await response.text();
+ });
+ } catch (fetch_error) {}
+
+ if (data == "not ready") {
+ await randomDelay();
+ continue;
+ }
+
+ return data;
+ }
+}
+
+// Returns an URL. When called, the server sends toward the `uuid` queue the
+// request headers. Useful for determining if something was requested with
+// Cookies.
+const showRequestHeaders = function(origin, uuid) {
+ return origin + dispatcher_path + `?uuid=${uuid}&show-headers`;
+}
+
+// Same as above, except for the response is cacheable.
+const cacheableShowRequestHeaders = function(origin, uuid) {
+ return origin + dispatcher_path + `?uuid=${uuid}&cacheable&show-headers`;
+}
+
+// This script requires
+// - `/common/utils.js` for `token()`.
+
+// Returns the URL of a document that can be used as a `RemoteContext`.
+//
+// `uuid` should be a UUID uniquely identifying the given remote context.
+// `options` has the following shape:
+//
+// {
+// host: (optional) Sets the returned URL's `host` property. Useful for
+// cross-origin executors.
+// protocol: (optional) Sets the returned URL's `protocol` property.
+// }
+function remoteExecutorUrl(uuid, options) {
+ const url = new URL("/common/dispatcher/remote-executor.html", location);
+ url.searchParams.set("uuid", uuid);
+
+ if (options?.host) {
+ url.host = options.host;
+ }
+
+ if (options?.protocol) {
+ url.protocol = options.protocol;
+ }
+
+ return url;
+}
+
+// Represents a remote executor. For more detailed explanation see `README.md`.
+class RemoteContext {
+ // `uuid` is a UUID string that identifies the remote context and should
+ // match with the `uuid` parameter of the URL of the remote context.
+ constructor(uuid) {
+ this.context_id = uuid;
+ }
+
+ // Evaluates the script `expr` on the executor.
+ // - If `expr` is evaluated to a Promise that is resolved with a value:
+ // `execute_script()` returns a Promise resolved with the value.
+ // - If `expr` is evaluated to a non-Promise value:
+ // `execute_script()` returns a Promise resolved with the value.
+ // - If `expr` throws an error or is evaluated to a Promise that is rejected:
+ // `execute_script()` returns a rejected Promise with the error's
+ // `message`.
+ // Note that currently the type of error (e.g. DOMException) is not
+ // preserved, except for `TypeError`.
+ // The values should be able to be serialized by JSON.stringify().
+ async execute_script(fn, args) {
+ const receiver = token();
+ await this.send({receiver: receiver, fn: fn.toString(), args: args});
+ const response = JSON.parse(await receive(receiver));
+ if (response.status === 'success') {
+ return response.value;
+ }
+
+ // exception
+ if (response.name === 'TypeError') {
+ throw new TypeError(response.value);
+ }
+ throw new Error(response.value);
+ }
+
+ async send(msg) {
+ return await send(this.context_id, JSON.stringify(msg));
+ }
+};
+
+class Executor {
+ constructor(uuid) {
+ this.uuid = uuid;
+
+ // If `suspend_callback` is not `null`, the executor should be suspended
+ // when there are no ongoing tasks.
+ this.suspend_callback = null;
+
+ this.execute();
+ }
+
+ // Wait until there are no ongoing tasks nor fetch requests for polling
+ // tasks, and then suspend the executor and call `callback()`.
+ // Navigation from the executor page should be triggered inside `callback()`,
+ // to avoid conflict with in-flight fetch requests.
+ suspend(callback) {
+ this.suspend_callback = callback;
+ }
+
+ resume() {
+ }
+
+ async execute() {
+ while(true) {
+ if (this.suspend_callback !== null) {
+ this.suspend_callback();
+ this.suspend_callback = null;
+ // Wait for `resume()` to be called.
+ await new Promise(resolve => this.resume = resolve);
+
+ // Workaround for https://crbug.com/1244230.
+ // Without this workaround, the executor is resumed and the fetch
+ // request to poll the next task is initiated synchronously from
+ // pageshow event after the page restored from BFCache, and the fetch
+ // request promise is never resolved (and thus the test results in
+ // timeout) due to https://crbug.com/1244230. The root cause is not yet
+ // known, but setTimeout() with 0ms causes the resume triggered on
+ // another task and seems to resolve the issue.
+ await new Promise(resolve => setTimeout(resolve, 0));
+
+ continue;
+ }
+
+ const task = JSON.parse(await receive(this.uuid));
+
+ let response;
+ try {
+ const value = await eval(task.fn).apply(null, task.args);
+ response = JSON.stringify({
+ status: 'success',
+ value: value
+ });
+ } catch(e) {
+ response = JSON.stringify({
+ status: 'exception',
+ name: e.name,
+ value: e.message
+ });
+ }
+ await send(task.receiver, response);
+ }
+ }
+}