Don't block message processing on contact syncs

ts/background.ts

@@ -542,7 +542,6 @@ export async function startApp(): Promise<void> {
 
     log.info('Initializing MessageReceiver');
     messageReceiver = new MessageReceiver({
-      server,
       storage: window.storage,
       serverTrustRoot: window.getServerTrustRoot(),
     });

ts/services/contactSync.ts

@@ -5,7 +5,10 @@ import PQueue from 'p-queue';
 
 import { DataWriter } from '../sql/Client';
 import type { ContactSyncEvent } from '../textsecure/messageReceiverEvents';
-import type { ContactDetailsWithAvatar } from '../textsecure/ContactsParser';
+import {
+  parseContactsV2,
+  type ContactDetailsWithAvatar,
+} from '../textsecure/ContactsParser';
 import { normalizeAci } from '../util/normalizeAci';
 import * as Conversation from '../types/Conversation';
 import * as Errors from '../types/errors';
@@ -15,6 +18,11 @@ import { validateConversation } from '../util/validateConversation';
 import { isDirectConversation, isMe } from '../util/whatTypeOfConversation';
 import * as log from '../logging/log';
 import { dropNull } from '../util/dropNull';
+import type { ProcessedAttachment } from '../textsecure/Types';
+import { downloadAttachment } from '../textsecure/downloadAttachment';
+import { strictAssert } from '../util/assert';
+import type { ReencryptedAttachmentV2 } from '../AttachmentCrypto';
+import { SECOND } from '../util/durations';
 
 // When true - we are running the very first storage and contact sync after
 // linking.
@@ -86,8 +94,34 @@ async function updateConversationFromContactSync(
 
 const queue = new PQueue({ concurrency: 1 });
 
+async function downloadAndParseContactAttachment(
+  contactAttachment: ProcessedAttachment
+) {
+  strictAssert(window.textsecure.server, 'server must exist');
+  let downloaded: ReencryptedAttachmentV2 | undefined;
+  try {
+    downloaded = await downloadAttachment(
+      window.textsecure.server,
+      contactAttachment,
+      {
+        disableRetries: true,
+        timeout: 90 * SECOND,
+      }
+    );
+
+    return await parseContactsV2({
+      ...contactAttachment,
+      ...downloaded,
+    });
+  } finally {
+    if (downloaded?.path) {
+      await window.Signal.Migrations.deleteAttachmentData(downloaded.path);
+    }
+  }
+}
+
 async function doContactSync({
-  contacts,
+  contactAttachment,
   complete: isFullSync,
   receivedAtCounter,
   sentAt,
@@ -95,8 +129,11 @@ async function doContactSync({
   const logId =
     `doContactSync(sent=${sentAt}, ` +
     `receivedAt=${receivedAtCounter}, isFullSync=${isFullSync})`;
-  log.info(`${logId}: got ${contacts.length} contacts`);
 
+  log.info(`${logId}: downloading contact attachment`);
+  const contacts = await downloadAndParseContactAttachment(contactAttachment);
+
+  log.info(`${logId}: got ${contacts.length} contacts`);
   const updatedConversations = new Set<ConversationModel>();
 
   let promises = new Array<Promise<void>>();
@@ -195,5 +232,12 @@ export async function onContactSync(ev: ContactSyncEvent): Promise<void> {
   log.info(
     `onContactSync(sent=${ev.sentAt}, receivedAt=${ev.receivedAtCounter}): queueing sync`
   );
-  await queue.add(() => doContactSync(ev));
+
+  const promise = queue.add(() => doContactSync(ev));
+
+  // Returning the promise blocks MessageReceiver.appQueue, which we only want to do on
+  // initial sync
+  if (isInitialSync) {
+    return promise;
+  }
 }

ts/test-electron/MessageReceiver_test.ts

@@ -8,7 +8,6 @@ import Long from 'long';
 
 import MessageReceiver from '../textsecure/MessageReceiver';
 import { IncomingWebSocketRequestLegacy } from '../textsecure/WebsocketResources';
-import type { WebAPIType } from '../textsecure/WebAPI';
 import type { DecryptionErrorEvent } from '../textsecure/messageReceiverEvents';
 import { generateAci } from '../types/ServiceId';
 import type { AciString } from '../types/ServiceId';
@@ -39,7 +38,6 @@ describe('MessageReceiver', () => {
   describe('connecting', () => {
     it('generates decryption-error event when it cannot decrypt', async () => {
       const messageReceiver = new MessageReceiver({
-        server: {} as WebAPIType,
         storage: window.storage,
         serverTrustRoot: 'AAAAAAAA',
       });

ts/textsecure/MessageReceiver.ts

@@ -49,8 +49,7 @@ import { parseIntOrThrow } from '../util/parseIntOrThrow';
 import { clearTimeoutIfNecessary } from '../util/clearTimeoutIfNecessary';
 import { Zone } from '../util/Zone';
 import * as durations from '../util/durations';
-import { DurationInSeconds, SECOND } from '../util/durations';
-import type { AttachmentType } from '../types/Attachment';
+import { DurationInSeconds } from '../util/durations';
 import { Address } from '../types/Address';
 import { QualifiedAddress } from '../types/QualifiedAddress';
 import { normalizeStoryDistributionId } from '../types/StoryDistributionId';
@@ -82,11 +81,8 @@ import {
 import { processSyncMessage } from './processSyncMessage';
 import type { EventHandler } from './EventTarget';
 import EventTarget from './EventTarget';
-import { downloadAttachment } from './downloadAttachment';
 import type { IncomingWebSocketRequest } from './WebsocketResources';
 import { ServerRequestType } from './WebsocketResources';
-import { parseContactsV2 } from './ContactsParser';
-import type { WebAPIType } from './WebAPI';
 import type { Storage } from './Storage';
 import { WarnOnlyError } from './Errors';
 import * as Bytes from '../Bytes';
@@ -215,7 +211,6 @@ enum TaskType {
 }
 
 export type MessageReceiverOptions = {
-  server: WebAPIType;
   storage: Storage;
   serverTrustRoot: string;
 };
@@ -287,8 +282,6 @@ export default class MessageReceiver
 {
   /* eslint-enable @typescript-eslint/brace-style */
 
-  private server: WebAPIType;
-
   private storage: Storage;
 
   private appQueue: PQueue;
@@ -319,10 +312,9 @@ export default class MessageReceiver
 
   private isAppReadyForProcessing: boolean = false;
 
-  constructor({ server, storage, serverTrustRoot }: MessageReceiverOptions) {
+  constructor({ storage, serverTrustRoot }: MessageReceiverOptions) {
     super();
 
-    this.server = server;
     this.storage = storage;
 
     this.count = 0;
@@ -3823,34 +3815,13 @@ export default class MessageReceiver
 
     this.removeFromCache(envelope);
 
-    let attachment: AttachmentType | undefined;
-    try {
-      attachment = await this.handleAttachmentV2(blob, {
-        disableRetries: true,
-        timeout: 90 * SECOND,
-      });
-
-      const { path } = attachment;
-      if (!path) {
-        throw new Error('Failed no path field in returned attachment');
-      }
-
-      const contacts = await parseContactsV2(attachment);
-
-      const contactSync = new ContactSyncEvent(
-        contacts,
-        Boolean(contactSyncProto.complete),
-        envelope.receivedAtCounter,
-        envelope.timestamp
-      );
-      await this.dispatchAndWait(logId, contactSync);
-
-      log.info('handleContacts: finished');
-    } finally {
-      if (attachment?.path) {
-        await window.Signal.Migrations.deleteAttachmentData(attachment.path);
-      }
-    }
+    const contactSync = new ContactSyncEvent(
+      processAttachment(blob),
+      Boolean(contactSyncProto.complete),
+      envelope.receivedAtCounter,
+      envelope.timestamp
+    );
+    await this.dispatchAndWait(logId, contactSync);
   }
 
   private async handleBlocked(
@@ -3937,18 +3908,6 @@ export default class MessageReceiver
     return this.storage.blocked.isGroupBlocked(groupId);
   }
 
-  private async handleAttachmentV2(
-    attachment: Proto.IAttachmentPointer,
-    options?: { timeout?: number; disableRetries?: boolean }
-  ): Promise<AttachmentType> {
-    const cleaned = processAttachment(attachment);
-    const downloaded = await downloadAttachment(this.server, cleaned, options);
-    return {
-      ...cleaned,
-      ...downloaded,
-    };
-  }
-
   private async handleEndSession(
     envelope: ProcessedEnvelope,
     theirServiceId: ServiceIdString

ts/textsecure/messageReceiverEvents.ts

@@ -16,8 +16,8 @@ import type {
   ProcessedEnvelope,
   ProcessedDataMessage,
   ProcessedSent,
+  ProcessedAttachment,
 } from './Types.d';
-import type { ContactDetailsWithAvatar } from './ContactsParser';
 import type {
   CallEventDetails,
   CallLogEventDetails,
@@ -84,7 +84,7 @@ export class ErrorEvent extends Event {
 
 export class ContactSyncEvent extends Event {
   constructor(
-    public readonly contacts: ReadonlyArray<ContactDetailsWithAvatar>,
+    public readonly contactAttachment: ProcessedAttachment,
     public readonly complete: boolean,
     public readonly receivedAtCounter: number,
     public readonly sentAt: number