boost::asio 与 C++0x

看到C++0x的lambda特性，随想到boost::asio，于是拿来练练手，的确很方便。但总有***的感觉。

以下代码的编译环境还是满苛刻的。
本人的编译环境为gcc 4.5.2 + boost 1.46。C++0x lambda则需要gcc 4.5以上版本

程序功能
命令：http-get 域名
功能：输出域名的首页，接收所有数据。因为是所有数据。所以有的数据会包含Chunked信息。

代码比较简单，都是最基本的应用，所以没啥注释。由于asio的handler全使用了lambda，代码整洁了许多，没有了长长的bind。

    #include <string>
    #include <iostream>
    #include <algorithm>
    #include <boost/asio.hpp>
    using namespace std;
    using namespace boost;
    using boost::asio::ip::tcp;

    #define CHECK_ERROR_CODE(code) if (code) { cerr << code.message() << endl; return; }
    class HttpClient
    {
        asio::io_service &io_service_;
        asio::streambuf  buffer_;
        tcp::socket      socket_;
        tcp::resolver    resolver_;
        string           domain_;

        public:
        HttpClient(asio::io_service &io_service) : io_service_(io_service), socket_(io_service), resolver_(io_service)
        {

        }

        void get(const string &domain)
        {
            resolve(domain);
        }

        void resolve(const string &domain)
        {
            domain_ = domain;
            tcp::resolver::query query(domain, "http");
            resolver_.async_resolve(query,
                [this](const system::error_code &code, tcp::resolver::iterator iterator) {
                    CHECK_ERROR_CODE(code);
                    connect( iterator->endpoint() );
                }
            );
        }


        void connect(tcp::endpoint remote_endpoint)
        {
            socket_.async_connect(remote_endpoint,
                [this](const system::error_code &code) {
                    CHECK_ERROR_CODE(code);
                    send_header();
                }
            );
        }


        void send_header()
        {
            string request_header("GET / HTTP/1.1\r\nHost: "+domain_+"\r\nConnection: close\r\n\r\n");
            async_write(socket_, asio::buffer(request_header), asio::transfer_all(),
                [this](const system::error_code &code, size_t n) {
                    CHECK_ERROR_CODE(code);
                    recv_any();
                }
            );
        }


        void recv_any()
        {
            async_read(socket_, buffer_, asio::transfer_at_least(1),
                [this](const system::error_code &code, size_t n) {
                    size_t size = asio::buffer_size(buffer_.data());
                    if (size>0) {
                        const char *data = asio::buffer_cast<const char*>(buffer_.data());
                        cout.write(data, size);
                        buffer_.consume(size);
                    }

                    CHECK_ERROR_CODE(code);
                    recv_any();
                }
            );
        }
    };

    int main(int argc, char *argv[])
    {
        if (argc<2) {
            cerr << "http-get domain" << endl;
            return 1;
        }
        asio::io_service io_service;
        HttpClient       client(io_service);
        client.get(argv[1]);

        io_service.run();
        return 0;
    }

另存为http-get.cc，编译并运行

$ g++ -std=c++0x -lboost_system -lboost_thread http-get.cc -o http-get
$ ./http-get
HTTP/1.1 200 OK
Date: Sun, 27 Mar 2011 20:36:51 GMT
Server: BWS/1.0
Content-Length: 6759
Content-Type: text/html;charset=gb2312
Cache-Control: private
Expires: Sun, 27 Mar 2011 20:36:51 GMT
Set-Cookie: BAIDUID=83C77B5AA4FFE997F526519A3612F959:FG=1; expires=Sun, 27-Mar-41 20:36:51 GMT; path=/; domain=.baidu.com
P3P: CP=" OTI DSP COR IVA OUR IND COM "
Connection: Close

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