Boost.Asio翻译（五）

Boost.Asio翻译（五）

Daytime.7 - A combined TCP/UDP asynchronous server

This tutorial program shows how to combine the two asynchronous servers that we have just written, into a single server application.

本例示范了我们如何将已经实现的两种异步服务器整合为一个服务器应用程序。

The main() function

 
    
   
   
   
 
    
 
     int 
      main()
{
   
     try 
     
  {
    boost::asio::io_service io_service; 
    
 
   
 

We will begin by creating a server object to accept a TCP client connection.

 我们首先创建一个用于接收TCP客户端连接的服务器对象。

   
  
  
  
 
    
   
   
   
 
     
       tcp_server server1(io_service); 
   
 
   
  
  
  

We also need a server object to accept a UDP client request.

我们也需要一个用于接收UDP客户端请求的服务器对象。

 
    
   
   
   
 
    
 
      
     udp_server server2(io_service); 
    
 
   
 

We have created two lots of work for the boost::asio::io_service object to do.

这样我们就已经创建了两个需要完成很多工作的服务器，而这些工作都由boost::asio::io_service对象完成。

   
  
  
  
 
    
   
   
   
 
       io_service.run();
  }
   
    catch 
     (std::exception 
    & 
     e)
  {
    std::cerr  
    << 
     e.what()  
    << 
     std::endl;
  }

   
    return 
      
    0 
    ;
} 
   
 
   
  
  
  

The tcp_connection and tcp_server classes

TCP连接和TCP服务器类

The following two classes are taken from Daytime.3 .

下面的两个类实例来自例子Daytime.3。

 
    
   
   
   
 
    
 
     class 
      tcp_connection
  :  
     public 
      boost::enable_shared_from_this 
     < 
     tcp_connection 
     > 
     
{
 
     public 
     :
  typedef boost::shared_ptr 
     < 
     tcp_connection 
     > 
      pointer;

   
     static 
      pointer create(boost::asio::io_service 
     & 
      io_service)
  {
     
     return 
      pointer( 
     new 
      tcp_connection(io_service));
  }

  tcp::socket 
     & 
      socket()
  {
     
     return 
      socket_;
  }

   
     void 
      start()
  {
    message_  
     = 
      make_daytime_string();

    boost::asio::async_write(socket_, boost::asio::buffer(message_),
        boost::bind( 
     & 
     tcp_connection::handle_write, shared_from_this()));
  }

 
     private 
     :
  tcp_connection(boost::asio::io_service 
     & 
      io_service)
    : socket_(io_service)
  {
  }

   
     void 
      handle_write()
  {
  }

  tcp::socket socket_;
  std:: 
     string 
      message_;
};

 
     class 
      tcp_server
{
 
     public 
     :
  tcp_server(boost::asio::io_service 
     & 
      io_service)
    : acceptor_(io_service, tcp::endpoint(tcp::v4(),  
     13 
     ))
  {
    start_accept();
  }

 
     private 
     :
   
     void 
      start_accept()
  {
    tcp_connection::pointer new_connection  
     = 
     
      tcp_connection::create(acceptor_.io_service());

    acceptor_.async_accept(new_connection 
     -> 
     socket(),
        boost::bind( 
     & 
     tcp_server::handle_accept,  
     this 
     , new_connection,
          boost::asio::placeholders::error));
  }

   
     void 
      handle_accept(tcp_connection::pointer new_connection,
       
     const 
      boost::system::error_code 
     & 
      error)
  {
     
     if 
      ( 
     ! 
     error)
    {
      new_connection 
     -> 
     start();
      start_accept();
    }
  }

  tcp::acceptor acceptor_;
}; 
    
 
   
 

The udp_server class

UDP服务器类

Similarly, this next class is taken from the previous tutorial step .

同样，下面的这个类实例也是来自以前的示例程序。

 
    
   
   
   
 
    
 
     class 
      udp_server
{
 
     public 
     :
  udp_server(boost::asio::io_service 
     & 
      io_service)
    : socket_(io_service, udp::endpoint(udp::v4(),  
     13 
     ))
  {
    start_receive();
  }

 
     private 
     :
   
     void 
      start_receive()
  {
    socket_.async_receive_from(
        boost::asio::buffer(recv_buffer_), remote_endpoint_,
        boost::bind( 
     & 
     udp_server::handle_receive,  
     this 
     ,
          boost::asio::placeholders::error));
  }

   
     void 
      handle_receive( 
     const 
      boost::system::error_code 
     & 
      error)
  {
     
     if 
      ( 
     ! 
     error  
     || 
      error  
     == 
      boost::asio::error::message_size)
    {
      boost::shared_ptr 
     < 
     std:: 
     string 
     > 
      message(
           
     new 
      std:: 
     string 
     (make_daytime_string()));

      socket_.async_send_to(boost::asio::buffer( 
     * 
     message), remote_endpoint_,
          boost::bind( 
     & 
     udp_server::handle_send,  
     this 
     , message));

      start_receive();
    }
  }

   
     void 
      handle_send(boost::shared_ptr 
     < 
     std:: 
     string 
     > 
       
     /* 
     message 
     */ 
     )
  {
  }

  udp::socket socket_;
  udp::endpoint remote_endpoint_;
  boost::array 
     < 
     char 
     ,  
     1 
     > 
      recv_buffer_;
}; 
    
 
   
 

See the full source listing

全部源码：

//
//  server.cpp
//  ~~~~~~~~~~
//
//  Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
//  Distributed under the Boost Software License, Version 1.0. (See accompanying  //  file LICENSE_1_0.txt or copy at  http://www.boost.org/LICENSE_1_0.txt )
//

#include  < ctime >
#include  < iostream >
#include  < string >
#include  < boost / array.hpp >
#include  < boost / bind.hpp >
#include  < boost / shared_ptr.hpp >
#include  < boost / enable_shared_from_this.hpp >
#include  < boost / asio.hpp >

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

std:: string  make_daytime_string()
{
   using   namespace  std;  //  For time_t, time and ctime;
  time_t now  =  time( 0 );
   return  ctime( & now);
}

class  tcp_connection
  :  public  boost::enable_shared_from_this < tcp_connection >
{
public :
  typedef boost::shared_ptr < tcp_connection >  pointer;

   static  pointer create(boost::asio::io_service &  io_service)
  {
     return  pointer( new  tcp_connection(io_service));
  }

  tcp::socket &  socket()
  {
     return  socket_;
  }

   void  start()
  {
    message_  =  make_daytime_string();

    boost::asio::async_write(socket_, boost::asio::buffer(message_),
        boost::bind( & tcp_connection::handle_write, shared_from_this()));
  }

private :
  tcp_connection(boost::asio::io_service &  io_service)
    : socket_(io_service)
  {
  }

   void  handle_write()
  {
  }

  tcp::socket socket_;
  std:: string  message_;
};

class  tcp_server
{
public :
  tcp_server(boost::asio::io_service &  io_service)
    : acceptor_(io_service, tcp::endpoint(tcp::v4(),  13 ))
  {
    start_accept();
  }

private :
   void  start_accept()
  {
    tcp_connection::pointer new_connection  =
      tcp_connection::create(acceptor_.io_service());

    acceptor_.async_accept(new_connection -> socket(),
        boost::bind( & tcp_server::handle_accept,  this , new_connection,
          boost::asio::placeholders::error));
  }

   void  handle_accept(tcp_connection::pointer new_connection,
       const  boost::system::error_code &  error)
  {
     if  ( ! error)
    {
      new_connection -> start();
      start_accept();
    }
  }

  tcp::acceptor acceptor_;
};

class  udp_server
{
public :
  udp_server(boost::asio::io_service &  io_service)
    : socket_(io_service, udp::endpoint(udp::v4(),  13 ))
  {
    start_receive();
  }

private :
   void  start_receive()
  {
    socket_.async_receive_from(
        boost::asio::buffer(recv_buffer_), remote_endpoint_,
        boost::bind( & udp_server::handle_receive,  this ,
          boost::asio::placeholders::error));
  }

   void  handle_receive( const  boost::system::error_code &  error)
  {
     if  ( ! error  ||  error  ==  boost::asio::error::message_size)
    {
      boost::shared_ptr < std:: string >  message(
           new  std:: string (make_daytime_string()));

      socket_.async_send_to(boost::asio::buffer( * message), remote_endpoint_,
          boost::bind( & udp_server::handle_send,  this , message));

      start_receive();
    }
  }

   void  handle_send(boost::shared_ptr < std:: string >   /* message */ )
  {
  }

  udp::socket socket_;
  udp::endpoint remote_endpoint_;
  boost::array < char ,  1 >  recv_buffer_;
};

int  main()
{
   try
  {
    boost::asio::io_service io_service;
    tcp_server server1(io_service);
    udp_server server2(io_service);
    io_service.run();
  }
   catch  (std::exception &  e)
  {
    std::cerr  <<  e.what()  <<  std::endl;
  }

   return   0 ;
}