Send BufferProtocol message in Qt

gistfile1.cpp

Protocol::Request request;
request.mutable_island()->mutable_binoms()->set_id(99999);
request.mutable_island()->mutable_heigthmap()->set_id(1111);

std::ostringstream messageStream;
request.SerializeToOstream(&messageStream);

QByteArray block;
QDataStream out(&block, QIODevice::WriteOnly);
out.setVersion(QDataStream::Qt_4_8);
out << (quint16)0;
out << messageStream.str().c_str();
out.device()->seek(0);
out << (quint16)(block.size() - sizeof(quint16));

socket->write(block);