Move to websocket for requests to signal server

ts/util/AbortableProcess.ts

@@ -0,0 +1,38 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+/* eslint-disable no-restricted-syntax */
+
+import { explodePromise } from './explodePromise';
+
+export interface IController {
+  abort(): void;
+}
+
+export class AbortableProcess<Result> implements IController {
+  private abortReject: (error: Error) => void;
+
+  public readonly resultPromise: Promise<Result>;
+
+  constructor(
+    private readonly name: string,
+    private readonly controller: IController,
+    resultPromise: Promise<Result>
+  ) {
+    const {
+      promise: abortPromise,
+      reject: abortReject,
+    } = explodePromise<Result>();
+
+    this.abortReject = abortReject;
+    this.resultPromise = Promise.race([abortPromise, resultPromise]);
+  }
+
+  public abort(): void {
+    this.controller.abort();
+    this.abortReject(new Error(`Process "${this.name}" was aborted`));
+  }
+
+  public getResult(): Promise<Result> {
+    return this.resultPromise;
+  }
+}