boost :: asio :: async_read_until读取分隔符问题

时间:2012-02-02 10:32:25

标签: c++ asynchronous network-programming boost-asio

我正在调整here中的asio聊天客户端示例,以便与发布基于行的数据的现有客户端应用程序进行通信。这是我的代码:

#include <cstdlib>
#include <deque>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>

boost::mutex global_stream_lock;
using boost::asio::ip::tcp;
typedef std::deque<std::string> simple_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)
    {
        if(DEBUGGING) std::cout << "[" << __FUNCTION__ << "]" << std::endl;
        boost::asio::async_connect(socket_, endpoint_iterator,
                                   boost::bind(&chat_client::handle_connect, this,
                                               boost::asio::placeholders::error));
    }

    void write(const std::string& i_msg)
    {
        io_service_.post(boost::bind(&chat_client::do_write, this, i_msg));
    }

    void close()
    {
        io_service_.post(boost::bind(&chat_client::do_close, this));
    }

private:

    void handle_connect(const boost::system::error_code& error)
    {
        if (!error)
        {
            boost::asio::async_read_until(socket_, simple_msg_buf_, "\n",
                                          boost::bind(&chat_client::handle_read_message, this,
                                                      boost::asio::placeholders::error,
                                                      boost::asio::placeholders::bytes_transferred));
        }
    }

    void handle_read_message(const boost::system::error_code& error, std::size_t bytes_transferred)
    {
        if (!error && bytes_transferred) 
        {
            // Remove newline from input.
            simple_msg_buf_.commit(bytes_transferred);

            std::istream is(&simple_msg_buf_);
            std::string s;
            is >> s;

            std::cout << s << std::endl;

            boost::asio::async_read_until(socket_, simple_msg_buf_, "\n",
                                        boost::bind(&chat_client::handle_read_message, this,
                                                    boost::asio::placeholders::error,
                                                    boost::asio::placeholders::bytes_transferred));
        }
        else
        {
            do_close();
        }
    }

    void do_close()
    {
        socket_.close();
    }

private:
    boost::asio::io_service& io_service_;
    tcp::socket socket_;
    boost::asio::streambuf simple_msg_buf_;
    simple_message_queue write_simple_msgs;
};

int main(int argc, char* argv[])
{
    try
    {
        boost::asio::io_service io_service;
        tcp::resolver resolver(io_service);
        tcp::resolver::query query("127.0.0.1", "20001");
        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));

        std::string input;
        while(std::cin)
        {
            std::getline(std::cin,input);

            // do something with input...
        }

        c.close();
        t.join();
    }
    catch (std::exception& e)
    {
        std::cerr << "Exception: " << e.what() << "\n";
    }

    return 0;
}

我与服务器通信没有问题,但我收到的数据格式不是应该的。我想逐行解析数据,所以我在Mac OS X(intel)上使用"\n"分隔符。例如,假设我希望格式的数据:This:(IS SOME) data;我通过上面的代码实际收到的格式是:

This:(IS
SOME)
data

因此看起来"\n"字符的处理方式与空格(" ")相同。 实际上,如果我用"\n"替换" "分隔符,则行为是相同的。 我也尝试了"\r""\r\n",但两种模式都没有被选中。

有谁知道可能导致这种情况的原因?

0 个答案:

没有答案