Files
moxxy_native/lib/src/service/foreground/isolate.dart

99 lines
2.7 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'dart:isolate';
import 'dart:ui';
import 'package:logging/logging.dart';
import 'package:moxxy_native/src/service/config.dart';
import 'package:moxxy_native/src/service/datasender/isolate.dart';
import 'package:moxxy_native/src/service/datasender/types.dart';
import 'package:moxxy_native/src/service/entrypoints/isolate.dart';
import 'package:moxxy_native/src/service/foreground/base.dart';
class IsolateForegroundService extends ForegroundService {
/// The port on which we receive data from the isolate.
final ReceivePort _receivePort = ReceivePort();
/// The port on which we send data to the isolate.
late final SendPort _sendPort;
/// A completer that indicates when _sendPort has been set.
/// For more notes, see the comment in [start].
Completer<void>? _sendPortCompleter = Completer<void>();
/// The data sender backing this class.
late final IsolateForegroundServiceDataSender _dataSender;
/// A logger.
final Logger _log = Logger('IsolateForegroundService');
@override
Future<void> attach(
HandleEventCallback handleData,
) async {
_receivePort.asBroadcastStream().listen((data) async {
if (data is SendPort) {
// Set the send port.
_sendPort = data;
// Resolve the waiting future.
assert(
_sendPortCompleter != null,
'_sendPort should only be received once!',
);
_sendPortCompleter?.complete();
return;
}
await handleData(
jsonDecode(data! as String) as Map<String, dynamic>,
);
});
}
@override
Future<void> start(
ServiceConfig config,
HandleEventCallback uiHandleData,
) async {
// Listen for events
await attach(uiHandleData);
await Isolate.spawn(
isolateEntrypoint,
[
_receivePort.sendPort,
config.toString(),
RootIsolateToken.instance!,
],
);
// Wait for [_sendPort] to get set.
// The issue is that [_receivePort] provides a stream that only one listener can listen to.
// This means that we cannot do `await _receivePort.first`. To work around this, we just cram
// an approximation of `_receivePort.first` into the actual listener.
await _sendPortCompleter!.future;
_sendPortCompleter = null;
// Create the data sender
_dataSender = IsolateForegroundServiceDataSender(_sendPort);
_log.finest('Background service started...');
}
@override
Future<bool> isRunning() async => false;
@override
ForegroundServiceDataSender getDataSender() => _dataSender;
@override
Future<BackgroundEvent?> send(
BackgroundCommand command, {
bool awaitable = true,
}) {
return _dataSender.sendData(
command,
awaitable: awaitable,
);
}
}