listen method

@override Future<Stream<CommunicateData<Socket>>> listen(SocketConnectionPoint bind)

Implementation

@override
Future<Stream<CommunicateData<Socket>>> listen(
    SocketConnectionPoint bind) async {
  final StreamController<CommunicateData<Socket>> controller =
      StreamController();
  _streams.add(controller);
  ServerSocket serverSocket = await _bind(bind.address, bind.port);
  _servers.add(serverSocket);
  // connection
  serverSocket.listen((Socket socket) {
    _connection.add(socket);
    // receive data
    socket.listen((Uint8List data) {
      // if have not received data yet.
      if (_receiveBuffers[socket] == null) {
        int bodyPosition = 0;
        int dataSize = 0;
        // search first LF sign.
        // chars until first LF represent the size of this message.
        for (int i = 0; i < data.length; i++) {
          if (data[i] == utf8.encode("\n").first) {
            bodyPosition = i + 1; // the message after first LF.
            dataSize = int.parse(utf8.decode(data.sublist(0, i)));
            break;
          }
        }

        data = data.sublist(bodyPosition); // change [data] to only the body.

        _receiveBuffers[socket] =
            CommunicateDataTcp(connection: socket, dataSize: dataSize);
      }

      final receiveBuffer = _receiveBuffers[socket];
      if (receiveBuffer == null) return;

      receiveBuffer.receive(data);

      // if received all of messages.
      if (receiveBuffer.isReceivedAll()) {
        controller.sink.add(receiveBuffer.receiveData!); // stream data.
        _receiveBuffers.remove(receiveBuffer.connection); // remove buffer.
      }
    });
  });
  return controller.stream;
}