Use non-throttled timeouts for websockets

ts/context/Timers.ts

@@ -0,0 +1,43 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { setTimeout, clearTimeout } from 'timers';
+
+export type Timeout = {
+  id: number;
+  __signalContext: never;
+};
+
+export class Timers {
+  private counter = 0;
+
+  private readonly timers = new Map<number, NodeJS.Timeout>();
+
+  public setTimeout(callback: () => void, delay: number): Timeout {
+    let id: number;
+    do {
+      id = this.counter;
+      // eslint-disable-next-line no-bitwise
+      this.counter = (this.counter + 1) >>> 0;
+    } while (this.timers.has(id));
+
+    const timer = setTimeout(() => {
+      this.timers.delete(id);
+      callback();
+    }, delay);
+
+    this.timers.set(id, timer);
+
+    return ({ id } as unknown) as Timeout;
+  }
+
+  public clearTimeout({ id }: Timeout): ReturnType<typeof clearTimeout> {
+    const timer = this.timers.get(id);
+    if (timer === undefined) {
+      return;
+    }
+
+    this.timers.delete(id);
+    return clearTimeout(timer);
+  }
+}