ceph/src/boost/libs/asio/example/cpp03/services/daytime_client.cpp

   1 //
   2 // daytime_client.cpp
   3 // ~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #include <boost/asio.hpp>
  12 #include <boost/bind/bind.hpp>
  13 #include <iostream>
  14 #include "logger.hpp"
  15
  16 using boost::asio::ip::tcp;
  17
  18 char read_buffer[1024];
  19
  20 void read_handler(const boost::system::error_code& e,
  21     std::size_t bytes_transferred, tcp::socket* s)
  22 {
  23   if (!e)
  24   {
  25     std::cout.write(read_buffer, bytes_transferred);
  26
  27     s->async_read_some(boost::asio::buffer(read_buffer),
  28         boost::bind(read_handler, boost::asio::placeholders::error,
  29           boost::asio::placeholders::bytes_transferred, s));
  30   }
  31   else
  32   {
  33     boost::asio::execution_context& context = boost::asio::query(
  34         s->get_executor(), boost::asio::execution::context);
  35     services::logger logger(context, "read_handler");
  36
  37     std::string msg = "Read error: ";
  38     msg += e.message();
  39     logger.log(msg);
  40   }
  41 }
  42
  43 void connect_handler(const boost::system::error_code& e, tcp::socket* s)
  44 {
  45   boost::asio::execution_context& context = boost::asio::query(
  46       s->get_executor(), boost::asio::execution::context);
  47   services::logger logger(context, "connect_handler");
  48
  49   if (!e)
  50   {
  51     logger.log("Connection established");
  52
  53     s->async_read_some(boost::asio::buffer(read_buffer),
  54         boost::bind(read_handler, boost::asio::placeholders::error,
  55           boost::asio::placeholders::bytes_transferred, s));
  56   }
  57   else
  58   {
  59     std::string msg = "Unable to establish connection: ";
  60     msg += e.message();
  61     logger.log(msg);
  62   }
  63 }
  64
  65 int main(int argc, char* argv[])
  66 {
  67   try
  68   {
  69     if (argc != 2)
  70     {
  71       std::cerr << "Usage: daytime_client <host>" << std::endl;
  72       return 1;
  73     }
  74
  75     boost::asio::io_context io_context;
  76
  77     // Set the name of the file that all logger instances will use.
  78     services::logger logger(io_context, "");
  79     logger.use_file("log.txt");
  80
  81     // Resolve the address corresponding to the given host.
  82     tcp::resolver resolver(io_context);
  83     tcp::resolver::results_type endpoints =
  84       resolver.resolve(argv[1], "daytime");
  85
  86     // Start an asynchronous connect.
  87     tcp::socket socket(io_context);
  88     boost::asio::async_connect(socket, endpoints,
  89         boost::bind(connect_handler,
  90           boost::asio::placeholders::error, &socket));
  91
  92     // Run the io_context until all operations have finished.
  93     io_context.run();
  94   }
  95   catch (std::exception& e)
  96   {
  97     std::cerr << e.what() << std::endl;
  98   }
  99
 100   return 0;
 101 }