Function main

example/cpp11/porthopper/client.cpp:24–188

using boost::asio::ip::udp;

int main(int argc, char* argv[])
{
  try
  {
    if (argc != 3)
    {
      std::cerr << "Usage: client <host> <port>\n";
      return 1;
    }
    using namespace std; // For atoi.
    std::string host_name = argv[1];
    std::string port = argv[2];

    boost::asio::io_context io_context;

    // Determine the location of the server.
    tcp::resolver resolver(io_context);
    tcp::endpoint remote_endpoint = *resolver.resolve(host_name, port).begin();

    // Establish the control connection to the server.
    tcp::socket control_socket(io_context);
    control_socket.connect(remote_endpoint);

    // Create a datagram socket to receive data from the server.
    udp::socket data_socket(io_context, udp::endpoint(udp::v4(), 0));

    // Determine what port we will receive data on.
    udp::endpoint data_endpoint = data_socket.local_endpoint();

    // Ask the server to start sending us data.
    control_request start = control_request::start(data_endpoint.port());
    boost::asio::write(control_socket, start.to_buffers());

    unsigned long last_frame_number = 0;
    for (;;)
    {
      // Receive 50 messages on the current data socket.
      for (int i = 0; i < 50; ++i)
      {
        // Receive a frame from the server.
        frame f;
        data_socket.receive(f.to_buffers(), 0);
        if (f.number() > last_frame_number)
        {
          last_frame_number = f.number();
          std::cout << "\n" << f.payload();
        }
      }

      // Time to switch to a new socket. To ensure seamless handover we will
      // continue to receive packets using the old socket until data arrives on
      // the new one.
      std::cout << " Starting renegotiation";

      // Create the new data socket.
      udp::socket new_data_socket(io_context, udp::endpoint(udp::v4(), 0));

      // Determine the new port we will use to receive data.