boost官方文档中聊天程序实例讲解
平台:ubuntu 14.04 g++
安装boost的一些库:
sudo apt-get install libboost-system-dev libboost-thread-dev
编译:chat_client.cpp chat_server.cpp
g++ chat_server.cpp -lboost_system -o chat_server
g++ chat_server.cpp -lboost_system -lboost_thread -lpthread -o chat_client
运行:
1. 首先运行chat_server服务器端,命令:
$ ./chat_server 8080
2. 打开另一个终端,查看本机的ip地址,比如:192.168.1.101,运行chat_client客户端,命令:
$ ./chat_client 192.168.1.101 8080
3. 在chat_client的终端中继续输入想发送的信息,终端会自动再次显示一遍的你输入到的信息:
./chat_client 192.168.1.101 8080你还你还你好你好
数据包格式chat_message.hpp
- <pre name="code" class="cpp"><h3>数据包chat_message.hpp</h3>
- // chat_message.hpp
- // ~~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2013 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)
- //实例源于http://www.boost.org/doc/libs/1_55_0/doc/html/boost_asio/examples/cpp03_examples.html 文档中没有注释,自己在///开始看的时候也走了点弯路,本文对该源码写了详细的注释,希望能让后来者们少走些弯路。
- //首先看看数据包的结构:
- //数据包分为两个部分,首先是报头占4bytes,每一byte表示一个数字,也就是最多能表示的出9999,不足在前填0;
- // 数据包头的数字表示数据部分的长度大小。
- #ifndef CHAT_MESSAGE_HPP
- #define CHAT_MESSAGE_HPP
- #include <cstdio>
- #include <cstdlib>
- #include <cstring>
- class chat_message
- {
- public:
- enum { header_length = 4 };
- enum { max_body_length = 512 };
- chat_message()
- : body_length_(0)
- {
- }
- const char* data() const
- {
- return data_;
- }
- char* data()
- {
- return data_;
- }
- size_t length() const
- {
- return header_length + body_length_;
- }
- const char* body() const
- {
- return data_ + header_length;
- }
- char* body()
- {
- return data_ + header_length;
- }
- size_t body_length() const
- {
- return body_length_;
- }
- void body_length(size_t new_length)
- {
- body_length_ = new_length;
- if (body_length_ > max_body_length)
- body_length_ = max_body_length;
- }
- bool decode_header()//将报头的4字节字符串转换成数字
- {
- using namespace std; // For strncat and atoi.
- char header[header_length + 1] = "";
- strncat(header, data_, header_length);
- body_length_ = atoi(header);
- if (body_length_ > max_body_length)
- {
- body_length_ = 0;
- return false;
- }
- return true;
- }
- void encode_header()//把数据部分大小编码成字符串
- {
- using namespace std; // For sprintf and memcpy.
- char header[header_length + 1] = "";
- sprintf(header, "%4d", body_length_);
- memcpy(data_, header, header_length);
- }
- private:
- char data_[header_length + max_body_length];
- size_t body_length_;
- };
- #endif // CHAT_MESSAGE_HPP
聊天客户端chat_client.cpp
///////////////////////////////////////////////////////////////////////////////////////////////////////- <h3>
- </h3><h3>
- <span style="white-space:pre-wrap">聊天客户端chat_client.cpp</span>
- </h3>
- <pre>
- ///////////////////////////////////////////////////////////////////////////////////////////////////////
- //
- // chat_client.cpp
- // ~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2013 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)
- //
- //boost开发文档中实时聊天程序的客户端
- //实现的大致思路是:在创建的客户端实例中初始化socket、连接服务器端,并且不断的进行着异步读操作(从服务器端读数据)
- //在主线程中,从console中不断读取要被发送的消息,并且把这些消息post至io_service,然后进行异步写操作
- //读写socket都是用异步操作
- //这种方法不同于分别开一个读线程,一个写线程, 它的优势是线程不会一直等待读写数据,在并发数大的情况下通过异步读写能提高资源利用率
- #include <cstdlib>
- #include <deque>
- #include <iostream>
- #include <boost/bind.hpp>
- #include <boost/asio.hpp>
- #include <boost/thread/thread.hpp>
- #include "chat_message.hpp"
- using boost::asio::ip::tcp;
- typedef std::deque<chat_message> chat_message_queue;
- class chat_client
- {
- public:
- chat_client(boost::asio::io_service& io_service,
- tcp::resolver::iterator endpoint_iterator)
- : io_service_(io_service),
- socket_(io_service) //使得成员函数能直接使用这些变量
- {
- boost::asio::async_connect(socket_, endpoint_iterator,
- boost::bind(&chat_client::handle_connect, this,
- boost::asio::placeholders::error)); //所有的操作都采用异步的方式
- }
- void write(const chat_message& msg)
- {
- io_service_.post(boost::bind(&chat_client::do_write, this, msg)); //将消息主动投递给io_service
- }
- void close()
- {
- io_service_.post(boost::bind(&chat_client::do_close, this)); //这个close函数是客户端要主动终止时调用 do_close函数是从服务器端
- //读数据失败时调用
- }
- private:
- void handle_connect(const boost::system::error_code& error)
- {
- if (!error)
- {
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length), //读取数据报头
- boost::bind(&chat_client::handle_read_header, this,
- boost::asio::placeholders::error));
- }
- }
- void handle_read_header(const boost::system::error_code& error)
- {
- if (!error && read_msg_.decode_header()) //分别处理数据报头和数据部分
- {
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.body(), read_msg_.body_length()),//读取数据包数据部分
- boost::bind(&chat_client::handle_read_body, this,
- boost::asio::placeholders::error));
- }
- else
- {
- do_close();
- }
- }
- void handle_read_body(const boost::system::error_code& error)
- {
- if (!error)
- {
- std::cout.write(read_msg_.body(), read_msg_.body_length()); //输出消息
- std::cout << "\n";
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length), //在这里读取下一个数据包头
- boost::bind(&chat_client::handle_read_header, this,
- boost::asio::placeholders::error)); //完成一次读操作(处理完一个数据包) 进行下一次读操作
- }
- else
- {
- do_close();
- }
- }
- void do_write(chat_message msg)
- {
- bool write_in_progress = !write_msgs_.empty(); //空的话变量为false
- write_msgs_.push_back(msg); //把要写的数据push至写队列
- if (!write_in_progress)//队列初始为空 push一个msg后就有一个元素了
- {
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msgs_.front().data(),
- write_msgs_.front().length()),
- boost::bind(&chat_client::handle_write, this,
- boost::asio::placeholders::error));
- }
- }
- void handle_write(const boost::system::error_code& error)//第一个消息单独处理,剩下的才更好操作
- {
- if (!error)
- {
- write_msgs_.pop_front();//刚才处理完一个数据 所以要pop一个
- if (!write_msgs_.empty())
- {
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msgs_.front().data(),
- write_msgs_.front().length()),
- boost::bind(&chat_client::handle_write, this,
- boost::asio::placeholders::error)); //循环处理剩余的消息
- }
- }
- else
- {
- do_close();
- }
- }
- void do_close()
- {
- socket_.close();
- }
- private:
- boost::asio::io_service& io_service_;
- tcp::socket socket_;
- chat_message read_msg_;
- chat_message_queue write_msgs_;
- };
- int main(int argc, char* argv[])
- {
- try
- {
- if (argc != 3)
- {
- std::cerr << "Usage: chat_client <host> <port>\n";
- return 1;
- }
- boost::asio::io_service io_service;
- tcp::resolver resolver(io_service);
- tcp::resolver::query query(argv[1], argv[2]); //输入ip(或域名)和端口号
- tcp::resolver::iterator iterator = resolver.resolve(query);
- chat_client c(io_service, iterator);
- boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service));
- char line[chat_message::max_body_length + 1];
- while (std::cin.getline(line, chat_message::max_body_length + 1))
- {
- using namespace std; // For strlen and memcpy.
- chat_message msg;
- msg.body_length(strlen(line));
- memcpy(msg.body(), line, msg.body_length());
- msg.encode_header();
- c.write(msg);
- }
- c.close();
- t.join();
- }
- catch (std::exception& e)
- {
- std::cerr << "Exception: " << e.what() << "\n";
- }
- return 0;
- }
聊天服务器端chat_server.cpp
- //
- // chat_server.cpp
- // ~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2013 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)
- //
- //服务器端程序,首先开启一个chat_server,用来初始话io_service和chat_room; 服务器每次只开启一个chat_room,chat_room的作用是 1//.保存用户信息 2.实现用户的join和leave 3.保存从每个客户端接收到的信息 4.将接收到的消息挂到每一个客户端write_msgs队尾
- //每连接上一个客户端(socket)就开启一个新的chat_session 并加入唯一的chat_room chat_session中实现分别对每一个客户端的异步读写//操作
- #include <algorithm>
- #include <cstdlib>
- #include <deque>
- #include <iostream>
- #include <list>
- #include <set>
- #include <boost/bind.hpp>
- #include <boost/shared_ptr.hpp>
- #include <boost/enable_shared_from_this.hpp>
- #include <boost/asio.hpp>
- #include "chat_message.hpp"
- using boost::asio::ip::tcp;
- //----------------------------------------------------------------------
- typedef std::deque<chat_message> chat_message_queue;
- //----------------------------------------------------------------------
- class chat_participant
- {
- public:
- virtual ~chat_participant() {}
- virtual void deliver(const chat_message& msg) = 0; //后面需要重载
- };
- typedef boost::shared_ptr<chat_participant> chat_participant_ptr;
- //----------------------------------------------------------------------
- class chat_room
- {
- public:
- void join(chat_participant_ptr participant)
- {
- participants_.insert(participant);
- std::for_each(recent_msgs_.begin(), recent_msgs_.end(),
- boost::bind(&chat_participant::deliver, participant, _1));
- }
- void leave(chat_participant_ptr participant)
- {
- participants_.erase(participant);
- }
- //将从某个客户端收到的消息挂到 每一个客户端的write_msgs队尾 具体见chat_participant::deliver
- void deliver(const chat_message& msg)
- {
- recent_msgs_.push_back(msg);
- while (recent_msgs_.size() > max_recent_msgs)
- recent_msgs_.pop_front(); //room中保存的消息数有限
- std::for_each(participants_.begin(), participants_.end(),
- boost::bind(&chat_participant::deliver, _1, boost::ref(msg)));
- }
- private:
- std::set<chat_participant_ptr> participants_;//用set来保存用户信息
- enum { max_recent_msgs = 100 };
- chat_message_queue recent_msgs_;//用来保存从某个客户端接收到的信息
- };
- //----------------------------------------------------------------------
- class chat_session
- : public chat_participant,
- public boost::enable_shared_from_this<chat_session>
- {
- public:
- chat_session(boost::asio::io_service& io_service, chat_room& room)
- : socket_(io_service),
- room_(room)
- {
- }
- tcp::socket& socket()
- {
- return socket_;
- }
- void start()//每生成一个新的chat_session都会调用
- {
- room_.join(shared_from_this());
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length),
- boost::bind(
- &chat_session::handle_read_header, shared_from_this(),
- boost::asio::placeholders::error)); //异步读客户端发来的消息
- }
- void deliver(const chat_message& msg)
- {
- bool write_in_progress = !write_msgs_.empty();
- write_msgs_.push_back(msg); //把room中保存的消息挂到write_msgs队尾
- if (!write_in_progress)
- {
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msgs_.front().data(),
- write_msgs_.front().length()),
- boost::bind(&chat_session::handle_write, shared_from_this(),
- boost::asio::placeholders::error));
- }
- }
- void handle_read_header(const boost::system::error_code& error)
- {
- if (!error && read_msg_.decode_header())
- {
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.body(), read_msg_.body_length()),
- boost::bind(&chat_session::handle_read_body, shared_from_this(),
- boost::asio::placeholders::error));
- }
- else
- {
- room_.leave(shared_from_this());
- }
- }
- void handle_read_body(const boost::system::error_code& error)
- {
- if (!error)
- {
- room_.deliver(read_msg_);
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length),
- boost::bind(&chat_session::handle_read_header, shared_from_this(),
- boost::asio::placeholders::error));
- }
- else
- {
- room_.leave(shared_from_this());
- }
- }
- void handle_write(const boost::system::error_code& error)
- {
- if (!error)
- {
- write_msgs_.pop_front();
- if (!write_msgs_.empty())
- {
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msgs_.front().data(),
- write_msgs_.front().length()),
- boost::bind(&chat_session::handle_write, shared_from_this(),
- boost::asio::placeholders::error)); //服务器端将收到的消息送给所有的客户端(广播的方式)
- }
- }
- else
- {
- room_.leave(shared_from_this());
- }
- }
- private:
- tcp::socket socket_;
- chat_room& room_;
- chat_message read_msg_;
- chat_message_queue write_msgs_;
- };
- typedef boost::shared_ptr<chat_session> chat_session_ptr;
- //----------------------------------------------------------------------
- class chat_server
- {
- public:
- chat_server(boost::asio::io_service& io_service,
- const tcp::endpoint& endpoint)
- : io_service_(io_service),
- acceptor_(io_service, endpoint) //全局只有一个io_service和一个acceptor
- {
- start_accept();
- }
- void start_accept()
- {
- chat_session_ptr new_session(new chat_session(io_service_, room_));
- acceptor_.async_accept(new_session->socket(),
- boost::bind(&chat_server::handle_accept, this, new_session,
- boost::asio::placeholders::error));
- }
- void handle_accept(chat_session_ptr session,
- const boost::system::error_code& error)
- {
- if (!error)
- {
- session->start();
- }
- start_accept(); //每连接上一个socket都会调用
- }
- private:
- boost::asio::io_service& io_service_;
- tcp::acceptor acceptor_;
- chat_room room_; //chat_room中没有重载构造函数 所以会直接调用默认构造函数
- };
- typedef boost::shared_ptr<chat_server> chat_server_ptr;
- typedef std::list<chat_server_ptr> chat_server_list;
- //----------------------------------------------------------------------
- int main(int argc, char* argv[])
- {
- try
- {
- if (argc < 2)
- {
- std::cerr << "Usage: chat_server <port> [<port> ...]\n";
- return 1;
- }
- boost::asio::io_service io_service;
- chat_server_list servers;
- for (int i = 1; i < argc; ++i)
- {
- using namespace std; // For atoi.
- tcp::endpoint endpoint(tcp::v4(), atoi(argv[i]));
- chat_server_ptr server(new chat_server(io_service, endpoint));
- servers.push_back(server);
- }
- io_service.run();
- }
- catch (std::exception& e)
- {
- std::cerr << "Exception: " << e.what() << "\n";
- }
- return 0;
- }
-
- 转载自:blog.csdn.net/cyg0810/article/details/36179195