Boost Asioserver使用

今天主要想说道说道boost里面的网络通信库怎样设计和使用，由于近期一直在和网络一起工作，大数据处理和机器学习都离不开最后使用网络进行上线部署。先看看所有的源码吧。

#include <cstdlib>
#include <iostream>
#include <memory>
#include <utility>
#include <boost/asio.hpp>
#include <stdint.h>
#include "data.h"
#include <ostream>
#include <boost/archive/binary_iarchive.hpp>
#include <boost/archive/binary_oarchive.hpp>

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

class session
	: public std::enable_shared_from_this < session >
{
public:
	session(boost::asio::ip::tcp::socket socket)
		: socket_(std::move(socket))
	{
	}

	void start()
	{
		do_read();
	}

private:
	void do_read()
	{
		auto self(shared_from_this());

		//int32_t data_length;
		boost::asio::async_read(socket_, 
			boost::asio::buffer(&data_length, 4),
			[this, self](boost::system::error_code ec, std::size_t length)
		{
			if (!ec)
			{
				do_read_body();
			}
		});
	}
	void do_read_body()
	{
		
		auto self(shared_from_this());
		boost::asio::async_read(socket_,
			buf_, boost::asio::transfer_exactly(data_length),
			[this, self](boost::system::error_code ec, std::size_t length)
		{
			std::cout << length<<std::endl;
			if (!ec)
			{
				ProcessMessage();
				do_read();
			}
			else
			{
				std::cout << "error" << std::endl;
			}
		});
	};

	void ProcessMessage()
	{
		boost::archive::binary_iarchive ia(buf_);
		translate_data message;
		ia >> message;
		std::cout << message.width<<std::endl;
	};


	int32_t data_length;

	boost::asio::ip::tcp::socket socket_;

	boost::asio::streambuf buf_;
};

class server
{
public:
	server(boost::asio::io_service& io_service, short port)
		: acceptor_(io_service, boost::asio::ip::tcp::endpoint(tcp::v4(), port)),
		socket_(io_service)
	{
		do_accept();
	}

private:
	void do_accept()
	{
		acceptor_.async_accept(socket_,
			[this](boost::system::error_code ec)
		{
			if (!ec)
			{
				std::make_shared<session>(std::move(socket_))->start();
			}

			do_accept();
		});
	}

	boost::asio::ip::tcp::acceptor acceptor_;
	boost::asio::ip::tcp::socket socket_;
};

int main(int argc, char* argv[])
{
	try
	{
		/*if (argc != 2)
		{
			std::cerr << "Usage: async_tcp_echo_server <port>\n";
			return 1;
		}*/

		boost::asio::io_service io_service;

		server s(io_service, 8888);

		io_service.run();
	}
	catch (std::exception& e)
	{
		std::cerr << "Exception: " << e.what() << "\n";
	}

	return 0;
}

data是消息的数据格式，translate_data 这个类的定义，该类能够使用boost进行序列化。整个消息处理起来很的流畅，能够使得我们仅仅关心数据流，而忽略server怎样异步接收消息。当然我的演示样例代码中的数据格式很之简单，数据包开头的int表示数据有多少个字节。索性连我的消息代码一起放出来：

#include <boost/serialization/array.hpp>
#include <boost/serialization/vector.hpp>

struct MeasurementZ
{
	double m_a[3];
	double m_w[3];
	double m_t;
	friend class boost::serialization::access;

	template<class Archive>
	void serialize(Archive& ar, const unsigned int version)
	{
		ar & boost::serialization::make_array(m_a, 3 * sizeof(double));
		ar & boost::serialization::make_array(m_w, 3 * sizeof(double));
		ar & m_t;
	}
};

struct translate_data
{
	int width;
	int height;
	double mt;
	int N;
	unsigned char* buffer;//640*480;
	
	std::vector<MeasurementZ> z;
	std::vector<double> Quaterniond;//4
	std::vector<double> Vector3d;//3
	double M_rM_t;
};
BOOST_SERIALIZATION_SPLIT_FREE(translate_data)
namespace boost
{
	namespace serialization
	{
		/** Serialization support for cv::Mat */
		template<class Archive>
		void save(Archive & ar, const translate_data& m, const unsigned int version)
		{
			ar & m.width;
			ar & m.height;
			ar & m.mt;
			ar & m.N;
			
			const size_t data_size = m.width * m.height*sizeof(unsigned char);
			ar & boost::serialization::make_array(m.buffer, data_size);
			ar & m.z;
			ar & m.Quaterniond;
			ar & m.Vector3d;
			ar & m.M_rM_t;
		}    /** Serialization support for cv::Mat */
		template <class Archive>
		void load(Archive & ar, translate_data& m, const unsigned int version)
		{
			ar & m.width;
			ar & m.height;
			ar & m.mt;
			ar & m.N;

			const size_t data_size = m.width * m.height*sizeof(unsigned char);
			m.buffer = new unsigned char[m.width*m.height];
			ar & boost::serialization::make_array(m.buffer, data_size);
			ar & m.z;
			ar & m.Quaterniond;
			ar & m.Vector3d;
			ar & m.M_rM_t;
		}
	}
};

整个project很easy，请有用c++11标准来完毕。