tneotia
commented
2 years ago I just tried the same behavior with Isolate.spawn on Flutter 2.8 beta, and this time it gives a different error:
Invalid argument(s): Illegal argument in isolate message: (object is aPointer)
_SendPortImpl._sendInternal (dart:isolate-patch/isolate_patch.dart:249:43)
_SendPortImpl.send (dart:isolate-patch/isolate_patch.dart:230:5)
getChatsIsolate (package:bluebubbles/repository/models/io/chat.dart:242:17)
_delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:300:17)
_RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)I'm guessing this is because ToMany and ToOne have references to the box and store inside of them using Pointer, which is explicitly not able to be sent through SendPort.send. I don't know if this can be changed / fixed on the ObjectBox side in any way, but if there's a workaround I can use, it would be great!
Edit: I did some experimenting & research and found the async_task package. That has allowed me to "convert" the synchronous ObjectBox methods into an asynchronous task, which is also fine from a performance perspective, it only feels slightly worse than using isolates (but then again, it is also slightly faster).
Here's what the code looks like now:
/// Async method to get chats from objectbox
class GetChats extends AsyncTask<List<dynamic>, List<Chat>> {
final List<dynamic> stuff;
GetChats(this.stuff);
@override
AsyncTask<List<dynamic>, List<Chat>> instantiate(List<dynamic> parameters, [Map<String, SharedData>? sharedData]) {
return GetChats(parameters);
}
@override
List<dynamic> parameters() {
return stuff;
}
@override
FutureOr<List<Chat>> run() {
return store.runInTransaction(TxMode.read, () {
/// Query the [chatBox] for chats with limit and offset, prioritize pinned
/// chats and order by latest message date
final query = (chatBox.query()
..order(Chat_.isPinned, flags: Order.descending)
..order(Chat_.latestMessageDate, flags: Order.descending))
.build();
query
..limit = stuff[0]
..offset = stuff[1];
final chats = query.find();
query.close();
/// Assign the handles to the chats, deduplicate, and get fake participants
/// for redacted mode
for (Chat c in chats) {
c.participants = List<Handle>.from(c.handles);
c._deduplicateParticipants();
c.fakeParticipants = c.participants.map((p) => (stuff[3][p.address] ?? "Unknown") as String).toList();
}
return chats;
});
}
}Future<List<Attachment>> getAttachmentsAsync() async {
if (kIsWeb || id == null) return [];
final task = GetChatAttachments([id!, prefs.getString("objectbox-reference")]);
return (await createAsyncTask<List<Attachment>>(task)) ?? [];
}/// Create a "fake" asynchronous task from a traditionally synchronous task
///
/// Used for heavy ObjectBox read/writes to avoid causing jank
Future<T?> createAsyncTask<T>(AsyncTask<List<dynamic>, T> task) async {
final executor = AsyncExecutor(parallelism: 0, taskTypeRegister: () => [task]);
executor.logger.enabled = true;
executor.logger.enabledExecution = true;
await executor.execute(task);
return task.result;
}ObjectBox devs, if fixing the Pointer issue feels out of scope, feel free to close this issue. The AsyncTask workaround is enough for me :). And finally, thanks for such an excellent DB - it has really revolutionized the performance and speed of our app compared to sqflite!
greenrobot-team
Basic info
Steps to reproduce
compute)Expected behavior
Dart should be able to send the class item back to the main thread.
Code
Logs, stack traces
Additional context
We are trying to improve the performance of our already performance-heavy app, so isolate access is a must for us. Prior to trying to use Relations, we were using the SQL concept of join tables in ObjectBox, basically we had created a few separate classes to link 2 separate class IDs together, for example:
Relations seem like a much better way of accomplishing this, and greatly reduces some of the code we need on functions that deal with lists of these entities. However, this issue where the isolate cannot return a class with relations is deal breaking, is there any solution or workaround to get this behavior to work properly?