使用Google Proto缓冲区发送/接收数据

Question

I need to design a socket which will listen to a port for incoming requests and send reply in response to these requests. These sockets will also be responsible for sending data to port on some events ( which has nothing to do with data received mentioned above).

All this I have to do with google proto buffer.

Can anyone please suggest me with some good articles on these OR provide me help with this.

Answer 1

You can use proto buffers with any networking library for C++. To send proto buffer just call SerializeToArray on your proto buffer object and send that array via network. If you receive object, use ParseFromArray function to deserialize your array back to proto buffer object.

boost asio could be used for that, see examples of servers and client here

example (just for showing the concept):

class connection {
public:
    connection(const std::string& server, const std::string& port) 
        try 
            : is_ok_(false)
            , resolver_(ioservice_)
            , query_   (server, port)
            , socket_  (ioservice_)
        {
            GOOGLE_PROTOBUF_VERIFY_VERSION;
            asio::connect(socket_, resolver_.resolve(query_));
        } catch (...) { throw exception("Couldn't connect"); }

    ~connection() {
        socket_.close();
    }

    bool send_receive(Query* q, Response* r) {
        if (0 == q) return false;

        int query_length = q->ByteSize();
        std::vector<uint8_t> buf(query_length);

        if (false == q->SerializeToArray(&(buf[0]), query_length)) {
            std::cerr << "Couldn't serialize protobuf" << std::endl;
            return false;
        }
        socket_.write_some(asio::buffer(buf));
        if (0 == r) return false;

        size_t s = socket_.read_some(asio::buffer(buf));
        r->ParseFromArray(&(buf[0]), (int)buf.size());
    }
private:
    boost::asio::io_service ioservice_;
    tcp::resolver           resolver_;
    tcp::resolver::query    query_;
    tcp::socket             socket_;
    bool                    is_ok_;
}