doc/html/boost_asio/example/cpp03/chat/chat_client.cpp

   1 //
   2 // chat_client.cpp
   3 // ~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2014 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 <cstdlib>
  12 #include <deque>
  13 #include <iostream>
  14 #include <boost/bind.hpp>
  15 #include <boost/asio.hpp>
  16 #include <boost/thread/thread.hpp>
  17 #include "chat_message.hpp"
  18
  19 using boost::asio::ip::tcp;
  20
  21 typedef std::deque<chat_message> chat_message_queue;
  22
  23 class chat_client
  24 {
  25 public:
  26   chat_client(boost::asio::io_service& io_service,
  27       tcp::resolver::iterator endpoint_iterator)
  28     : io_service_(io_service),
  29       socket_(io_service)
  30   {
  31     boost::asio::async_connect(socket_, endpoint_iterator,
  32         boost::bind(&chat_client::handle_connect, this,
  33           boost::asio::placeholders::error));
  34   }
  35
  36   void write(const chat_message& msg)
  37   {
  38     io_service_.post(boost::bind(&chat_client::do_write, this, msg));
  39   }
  40
  41   void close()
  42   {
  43     io_service_.post(boost::bind(&chat_client::do_close, this));
  44   }
  45
  46 private:
  47
  48   void handle_connect(const boost::system::error_code& error)
  49   {
  50     if (!error)
  51     {
  52       boost::asio::async_read(socket_,
  53           boost::asio::buffer(read_msg_.data(), chat_message::header_length),
  54           boost::bind(&chat_client::handle_read_header, this,
  55             boost::asio::placeholders::error));
  56     }
  57   }
  58
  59   void handle_read_header(const boost::system::error_code& error)
  60   {
  61     if (!error && read_msg_.decode_header())
  62     {
  63       boost::asio::async_read(socket_,
  64           boost::asio::buffer(read_msg_.body(), read_msg_.body_length()),
  65           boost::bind(&chat_client::handle_read_body, this,
  66             boost::asio::placeholders::error));
  67     }
  68     else
  69     {
  70       do_close();
  71     }
  72   }
  73
  74   void handle_read_body(const boost::system::error_code& error)
  75   {
  76     if (!error)
  77     {
  78       std::cout.write(read_msg_.body(), read_msg_.body_length());
  79       std::cout << "\n";
  80       boost::asio::async_read(socket_,
  81           boost::asio::buffer(read_msg_.data(), chat_message::header_length),
  82           boost::bind(&chat_client::handle_read_header, this,
  83             boost::asio::placeholders::error));
  84     }
  85     else
  86     {
  87       do_close();
  88     }
  89   }
  90
  91   void do_write(chat_message msg)
  92   {
  93     bool write_in_progress = !write_msgs_.empty();
  94     write_msgs_.push_back(msg);
  95     if (!write_in_progress)
  96     {
  97       boost::asio::async_write(socket_,
  98           boost::asio::buffer(write_msgs_.front().data(),
  99             write_msgs_.front().length()),
 100           boost::bind(&chat_client::handle_write, this,
 101             boost::asio::placeholders::error));
 102     }
 103   }
 104
 105   void handle_write(const boost::system::error_code& error)
 106   {
 107     if (!error)
 108     {
 109       write_msgs_.pop_front();
 110       if (!write_msgs_.empty())
 111       {
 112         boost::asio::async_write(socket_,
 113             boost::asio::buffer(write_msgs_.front().data(),
 114               write_msgs_.front().length()),
 115             boost::bind(&chat_client::handle_write, this,
 116               boost::asio::placeholders::error));
 117       }
 118     }
 119     else
 120     {
 121       do_close();
 122     }
 123   }
 124
 125   void do_close()
 126   {
 127     socket_.close();
 128   }
 129
 130 private:
 131   boost::asio::io_service& io_service_;
 132   tcp::socket socket_;
 133   chat_message read_msg_;
 134   chat_message_queue write_msgs_;
 135 };
 136
 137 int main(int argc, char* argv[])
 138 {
 139   try
 140   {
 141     if (argc != 3)
 142     {
 143       std::cerr << "Usage: chat_client <host> <port>\n";
 144       return 1;
 145     }
 146
 147     boost::asio::io_service io_service;
 148
 149     tcp::resolver resolver(io_service);
 150     tcp::resolver::query query(argv[1], argv[2]);
 151     tcp::resolver::iterator iterator = resolver.resolve(query);
 152
 153     chat_client c(io_service, iterator);
 154
 155     boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service));
 156
 157     char line[chat_message::max_body_length + 1];
 158     while (std::cin.getline(line, chat_message::max_body_length + 1))
 159     {
 160       using namespace std; // For strlen and memcpy.
 161       chat_message msg;
 162       msg.body_length(strlen(line));
 163       memcpy(msg.body(), line, msg.body_length());
 164       msg.encode_header();
 165       c.write(msg);
 166     }
 167
 168     c.close();
 169     t.join();
 170   }
 171   catch (std::exception& e)
 172   {
 173     std::cerr << "Exception: " << e.what() << "\n";
 174   }
 175
 176   return 0;
 177 }