dlib C++ Library - iosockstream.h

    // Copyright (C) 2012  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_IOSOCKSTrEAM_Hh_
    #define DLIB_IOSOCKSTrEAM_Hh_

    #include "iosockstream_abstract.h"

    #include <iostream>
    #include <memory>

    #include "../sockstreambuf.h"
    #include "../timeout.h"

    #ifdef _MSC_VER
    // Disable the warning about inheriting from std::iostream 'via dominance' since this warning is a warning about
    // visual studio conforming to the standard and is ignorable.
    // See http://connect.microsoft.com/VisualStudio/feedback/details/733720/inheriting-from-std-fstream-produces-c4250-warning
    // for further details if interested.
    #pragma warning(disable : 4250)
    #endif // _MSC_VER

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        class iosockstream : public std::iostream
        {
        public:

            iosockstream(
            ) :
                std::iostream(0)
            {
            }

            iosockstream(
                const network_address& addr
            ) :
                std::iostream(0)
            {
                open(addr);
            }

            iosockstream(
                const network_address& addr,
                unsigned long timeout
            ) :
                std::iostream(0)
            {
                open(addr, timeout);
            }

            ~iosockstream()
            {
                close();
            }

            void open (
                const network_address& addr
            )
            {
                auto_mutex lock(class_mutex);
                close();
                con.reset(connect(addr));
                buf.reset(new sockstreambuf(con.get()));
                // Note that we use the sockstreambuf's ability to autoflush instead of
                // telling the iostream::tie() function to tie the stream to itself even though
                // that should work fine.  The reason we do it this way is because there is a
                // bug in visual studio 2012 that causes a program to crash when a stream is
                // tied to itself and then used.  See
                // http://connect.microsoft.com/VisualStudio/feedback/details/772293/tying-a-c-iostream-object-to-itself-causes-a-stack-overflow-in-visual-studio-2012
                // for further details.
                buf->flush_output_on_read();
                rdbuf(buf.get());
                clear();
            }

            void open (
                const network_address& addr,
                unsigned long timeout
            )
            {
                auto_mutex lock(class_mutex);
                close(timeout);
                con.reset(connect(addr.host_address, addr.port, timeout));
                buf.reset(new sockstreambuf(con.get()));
                buf->flush_output_on_read();
                rdbuf(buf.get());
                clear();
            }

            void close(
                unsigned long timeout = 10000
            )
            {
                auto_mutex lock(class_mutex);
                rdbuf(0);
                try
                {
                    if (buf)
                    {
                        dlib::timeout t(*con,&connection::shutdown,timeout);

                        // This will flush the sockstreambuf and also destroy it.
                        buf.reset();

                        if(con->shutdown_outgoing())
                        {
                            // there was an error so just close it now and return
                            con->shutdown();
                        }
                        else
                        {
                            char junk[100];
                            // wait for the other end to close their side
                            while (con->read(junk,sizeof(junk)) > 0);
                        }
                    }
                }
                catch (...)
                {
                    con.reset();
                    throw;
                }
                con.reset();
            }

            void terminate_connection_after_timeout (
                unsigned long timeout
            )
            {
                auto_mutex lock(class_mutex);
                if (con)
                {
                    con_timeout.reset(new dlib::timeout(*this,&iosockstream::terminate_connection,timeout,con));
                }
            }

            void shutdown (
            )
            {
                auto_mutex lock(class_mutex);
                if (con)
                    con->shutdown();
            }

        private:

            void terminate_connection(
                std::shared_ptr<connection> thecon
            )
            {
                thecon->shutdown();
            }

            std::unique_ptr<timeout> con_timeout;
            rmutex class_mutex;
            std::shared_ptr<connection> con;
            std::unique_ptr<sockstreambuf> buf;

        };

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_IOSOCKSTrEAM_Hh_