Boost asio: Is it possible to include the accepted tcp socket in basic_socket_iostream (or somehow get it from it)?

Question

So here is my problem: we already have an accepted boost asio tcp socket. And all of our APIs use it. And we just need to do this “read timeout” in one function.

Here you can make such a "read wait time", as shown here . But I get the asio tcp socket extension from my APIs, so I wonder if it was possible to turn Boost :: asio socket into basic_socket_iostream , How do I do this?

Answer 1

I wonder how it is possible to turn Boost :: asio socket into basic_socket_iostream. How to do it?

you can use tcp::iostream::rdbuf() to get a pointer to socket::basic_socket_streambuf , then assign() descriptor.

 #include <boost/asio.hpp> int main() { boost::asio::io_service io_service; boost::asio::ip::tcp::socket socket( io_service ); boost::asio::ip::tcp::iostream stream; stream.rdbuf()->assign( boost::asio::ip::tcp::v4(), socket.native_handle() ); } 

Although it is very minimized, and I highly recommend not to go along this route. As pointed out by Ralf's answer , and my answer to your related question, you really should use deadline_timer for this.

Answer 2

You do not indicate whether there is a requirement not to use asynchronous APIs, so maybe this will help you and maybe not:

If I do not understand you, I think SO answer that you are referring to another use case, i.e. timeout using tcp :: iostream. If you just want to add a timeout to reading, have you looked at timeouts in the asio documentation ? This is the standard approach to timeout a socket operation.

Answer 3

For anyone who runs into this problem, after I try to do this for hours, I decided to write a simple wrapper class using Boost "Devices": http://www.boost.org/doc/libs/1_64_0 /libs/iostreams/doc/tutorial/container_source.html

 #include <iostream> #include <boost/smart_ptr.hpp> #include <boost/asio.hpp> #include <boost/iostreams/stream.hpp> #include <boost/iostreams/concepts.hpp> using boost::asio::ip::tcp; typedef boost::shared_ptr<tcp::socket> socket_ptr; class my_source : public boost::iostreams::source { public: my_source(socket_ptr sock) : _sock(sock) { } std::streamsize read(char* s, std::streamsize n) { return _sock->read_some(boost::asio::buffer(s, n)); } private: socket_ptr _sock; }; 

Usage example

:

 boost::iostreams::stream<my_source> in(sock); for (;;) { std::getline(in, line); if (line.length() > 0) std::cout << line << std::endl; else break; }