handle method

Implementation

@override
Future<void> handle(P2PStream<dynamic> stream) async {
  late final ProtocolID proto;
  late final HandlerFunc handler;
  try {
    final result = await negotiate(stream);
    proto = result.$1;
    handler = result.$2;
  } catch (e) {
    // Clean up any leftover bytes on negotiation failure
    _leftoverMap.remove(stream.id());
    rethrow;
  }

  // After negotiation, inject any leftover bytes back into the stream.
  // This handles the case where Go sends protocol negotiation + application data
  // in the same TCP segment.
  _injectLeftover(stream);

  // Ensure the stream is valid before proceeding
  if (stream.isClosed) {
    _log.warning(
        '[multistreamMuxer - handle] Stream for protocol $proto was closed during or immediately after negotiation. Aborting handler call.');
    return;
  }

  try {
    _log.fine(
        '[multistreamMuxer - handle] Protocol $proto negotiated. Attempting to set protocol on stream scope and stream itself.');
    await stream.scope().setProtocol(proto);
    await stream.setProtocol(proto);
    _log.fine(
        '[multistreamMuxer - handle] Successfully set protocol $proto on stream scope and stream. Proceeding to call handler.');
  } catch (e, s) {
    _log.severe(
        '[multistreamMuxer - handle] CRITICAL: Error occurred while setting protocol $proto on stream scope/stream: $e\n$s. Resetting stream and not calling handler.');
    await stream.reset();
    rethrow;
  }

  // Only call the handler if setProtocol was successful
  return handler(proto, stream);
}