Using drift from multiple isolates and databases with watch

[notcancername]

Hello,

I'm using the Drift feature of running in a separate Isolate to be accessed via IsolateNameServer:

Future<DriftIsolate> createIsolate() async {
  final token = RootIsolateToken.instance;
  return await DriftIsolate.spawn(() {
    BackgroundIsolateBinaryMessenger.ensureInitialized(token!);
    return LazyDatabase(() async {
      final dbFolder = await getApplicationDocumentsDirectory();
      final path = p.join(dbFolder.path, 'app_database.db');

      return NativeDatabase(File(path), logStatements: true);
    });
  });
}

//...

@DriftDatabase(tables: [SomeTable])
class AppDatabase extends _$AppDatabase {
  AppDatabase() : super(_openConnection());

  @override
  int get schemaVersion => 1;
}

LazyDatabase _openConnection() {
  driftRuntimeOptions.dontWarnAboutMultipleDatabases = true; // different queryexecutor used for each database
  return LazyDatabase(() async {
      final di = DriftIsolate.fromConnectPort(
      IsolateNameServer.lookupPortByName('drift_isolate')!);
    final conn = await di.connect();
    return conn.executor;
  });
}


//... main
  var di = await createIsolate();
  IsolateNameServer.registerPortWithName(di.connectPort, "drift_isolate");

//... some widget
  late AppDatabase db;
  late Stream<List<SomeTableData>> someStream;
  
  @override
  void initState() {
    super.initState();
    db = AppDatabase();
    someStream = db.select(db.someTable).watch();
  }
  
  @override
  void dispose() {
    super.dispose();
    db.close();
  }
  
  //... build
    StreamBuilder(
      stream: someStream,
      builder: ...,
    )
    
    //... some code in a different isolate with a different instance of AppDatabase
    await db.into(db.someTable).insert(...);

The initial SELECT from the watch function is logged, as is the INSERT, but the stream is never updated with the inserted entry. I must be misusing the API somehow. If anyone could point me in the right direction, it would be much appreciated.

[kuhnroyal]

If everything is correctly setup, you don't need driftRuntimeOptions.dontWarnAboutMultipleDatabases = true;. Are you calling createIsolate() somewhere else? You should only have one open database instance, and that is the single DriftIsolate.
Your code looks okish but the problem may be in your insert code. Don't create a second isolate, connect with the same port from IsolateNameServer.lookupPortByName('drift_isolate').

[notcancername]

If everything is correctly setup, you don't need driftRuntimeOptions.dontWarnAboutMultipleDatabases = true;. Are you calling createIsolate() somewhere else?

No, I am only calling it once in main. I am opening multiple databases each connecting to the DriftIsolate because I need to use it from different isolates, as shown in the code.

You should only have one open database instance, and that is the single DriftIsolate.

Yes, as far as I am aware, there is only one DriftIsolate created, and that is in main.

Don't create a second isolate, connect with the same port from IsolateNameServer.lookupPortByName('drift_isolate').

I am not, the AppDatabase creation code is as shown, it connects to the DriftIsolate. I create an AppDatabase when I need it and close it properly on disposal.

[notcancername]

Right. I am creating another AppDatabase in the same Isolate. I will move that to one AppDatabase.

[kuhnroyal]

Are you using hot reload/restart?
Try to set .connect(isolateDebugLog: true).

[notcancername]

No, I'm rebuilding every time. Will do, thanks.

[notcancername]

Thank you, using one AppDatabase per isolate resolved it For Some Reason™.