Use streams to download attachments directly to disk

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

ts/types/Conversation.ts

@@ -2,33 +2,87 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import type { ConversationAttributesType } from '../model-types.d';
+import type { ContactAvatarType } from './Avatar';
 import { computeHash } from '../Crypto';
 
 export type BuildAvatarUpdaterOptions = Readonly<{
+  data?: Uint8Array;
+  newAvatar?: ContactAvatarType;
   deleteAttachmentData: (path: string) => Promise<void>;
   doesAttachmentExist: (path: string) => Promise<boolean>;
   writeNewAttachmentData: (data: Uint8Array) => Promise<string>;
 }>;
 
+// This function is ready to handle raw avatar data as well as an avatar which has
+//   already been downloaded to disk.
+// Scenarios that go to disk today:
+//   - During a contact sync (see ContactsParser.ts)
+// Scenarios that stay in memory today:
+//   - models/Conversations/setProfileAvatar
 function buildAvatarUpdater({ field }: { field: 'avatar' | 'profileAvatar' }) {
   return async (
     conversation: Readonly<ConversationAttributesType>,
-    data: Uint8Array,
     {
+      data,
+      newAvatar,
       deleteAttachmentData,
       doesAttachmentExist,
       writeNewAttachmentData,
     }: BuildAvatarUpdaterOptions
   ): Promise<ConversationAttributesType> => {
-    if (!conversation) {
+    if (!conversation || (!data && !newAvatar)) {
       return conversation;
     }
 
-    const avatar = conversation[field];
+    const oldAvatar = conversation[field];
+    const newHash = data ? computeHash(data) : undefined;
 
-    const newHash = computeHash(data);
+    if (!oldAvatar || !oldAvatar.hash) {
+      if (newAvatar) {
+        return {
+          ...conversation,
+          [field]: newAvatar,
+        };
+      }
+      if (data) {
+        return {
+          ...conversation,
+          [field]: {
+            hash: newHash,
+            path: await writeNewAttachmentData(data),
+          },
+        };
+      }
+      throw new Error('buildAvatarUpdater: neither newAvatar or newData');
+    }
 
-    if (!avatar || !avatar.hash) {
+    const { hash, path } = oldAvatar;
+    const exists = await doesAttachmentExist(path);
+    if (!exists) {
+      window.SignalContext.log.warn(
+        `Conversation.buildAvatarUpdater: attachment ${path} did not exist`
+      );
+    }
+
+    if (exists) {
+      if (newAvatar && hash && hash === newAvatar.hash) {
+        await deleteAttachmentData(newAvatar.path);
+        return conversation;
+      }
+      if (data && hash && hash === newHash) {
+        return conversation;
+      }
+    }
+
+    await deleteAttachmentData(path);
+
+    if (newAvatar) {
+      return {
+        ...conversation,
+        [field]: newAvatar,
+      };
+    }
+    if (data) {
       return {
         ...conversation,
         [field]: {
@@ -38,27 +92,7 @@ function buildAvatarUpdater({ field }: { field: 'avatar' | 'profileAvatar' }) {
       };
     }
 
-    const { hash, path } = avatar;
-    const exists = await doesAttachmentExist(path);
-    if (!exists) {
-      window.SignalContext.log.warn(
-        `Conversation.buildAvatarUpdater: attachment ${path} did not exist`
-      );
-    }
-
-    if (exists && hash === newHash) {
-      return conversation;
-    }
-
-    await deleteAttachmentData(path);
-
-    return {
-      ...conversation,
-      [field]: {
-        hash: newHash,
-        path: await writeNewAttachmentData(data),
-      },
-    };
+    throw new Error('buildAvatarUpdater: neither newAvatar or newData');
   };
 }