libt2n: (gerd) some refactoring, documentation improvement

[libt2n] / src / connection.hxx

/***************************************************************************
 *   Copyright (C) 2006 by Gerd v. Egidy                                   *
 *   gve@intra2net.com                                                     *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Lesser General Public License version   *
 *   2.1 as published by the Free Software Foundation.                     *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU Lesser General Public License for more details.                   *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this program; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifndef __LIBT2N_CONNECTION
#define __LIBT2N_CONNECTION

#include <string>
#include <vector>
#include <list>
#include <iostream>

#include <boost/function.hpp>

#include <netinet/in.h>

#include "types.hxx"

namespace libt2n
{

/** @brief a connection between client and server. abstact.
*/
class connection
{
    private:
        bool closed;

        /// vector initialized for all callback-types, all elements in each list will be called
        std::vector<std::list<boost::function<void ()> > > callbacks;

    protected:
        connection()
            : callbacks(__events_end), closed(false)
            { }

        std::string buffer;

        typedef uint32_t packet_size_indicator;

        packet_size_indicator bytes_available();

        virtual void real_write(const std::string& data)=0;

        virtual std::ostream* get_logstream(log_level_values level)=0;

        void do_callbacks(callback_event_type event);

    public:
        virtual ~connection();

        /// is this connection closed or not
        bool is_closed()
            { return closed; }

        /// close this connection
        virtual void close();

        /** @brief look for new data and store it in the local buffer
            @param usec_timeout wait until new data is found, max timeout usecs.
                  -1: wait endless
                   0: return instantly
            @param usec_timeout_remaining if non-NULL the function will write the
                  not used time to the given target
            @retval true if new data was found (does not mean that the received data 
                    is a complete packet though)
        */
        virtual bool fill_buffer(long long usec_timeout=-1,long long* usec_timeout_remaining=NULL)=0;

        bool get_packet(std::string& data);

        unsigned int peek_packet(std::string& data);

        /// returns true if a complete data packet is in the buffer. retrieve it with get_packet().
        bool packet_available()
            { return bytes_available(); }

        void write(const std::string& data);

        void add_callback(callback_event_type event, const boost::function<void ()>& func);

        std::list<boost::function<void ()> > get_callback_list(callback_event_type event);
};

}

#endif