Use streams to download attachments directly to disk

Co-authored-by: trevor-signal <131492920+trevor-signal@users.noreply.github.com>

ts/util/getStreamWithTimeout.ts

@@ -1,6 +1,7 @@
 // Copyright 2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
+import { Transform } from 'stream';
 import type { Readable } from 'stream';
 
 import * as Bytes from '../Bytes';
@@ -59,3 +60,46 @@ export function getStreamWithTimeout(
 
   return promise;
 }
+
+export function getTimeoutStream({
+  name,
+  timeout,
+  abortController,
+}: OptionsType): Transform {
+  const timeoutStream = new Transform();
+
+  let timer: NodeJS.Timeout | undefined;
+  const clearTimer = () => {
+    clearTimeoutIfNecessary(timer);
+    timer = undefined;
+  };
+
+  const reset = () => {
+    clearTimer();
+
+    timer = setTimeout(() => {
+      abortController.abort();
+      timeoutStream.emit(
+        'error',
+        new StreamTimeoutError(`getStreamWithTimeout(${name}) timed out`)
+      );
+      clearTimer();
+    }, timeout);
+  };
+
+  timeoutStream._transform = function transform(chunk, _encoding, done) {
+    try {
+      reset();
+    } catch (error) {
+      return done(error);
+    }
+
+    this.push(chunk);
+
+    done();
+  };
+
+  reset();
+
+  return timeoutStream;
+}