libt2n: (gerd) basic command handling (still some todos)

[libt2n] / src / container.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_CONTAINER
#define __LIBT2N_CONTAINER

#include "command.hxx"
#include "t2n_exception.hxx"

namespace libt2n
{

/** @brief contains the result (return value or exception) of a executed command
*/
class result_container
{
    private:
        enum result_type_t { regular, exception } result_type;

        result *res;
        t2n_exception *ex;

        friend class boost::serialization::access;
        // When the class Archive corresponds to an output archive, the
        // & operator is defined similar to <<.  Likewise, when the class Archive
        // is a type of input archive the & operator is defined similar to >>.
        template<class Archive>
        void serialize(Archive & ar, const unsigned int version)
        {
            ar & BOOST_SERIALIZATION_NVP(result_type);
            ar & BOOST_SERIALIZATION_NVP(res);
            ar & BOOST_SERIALIZATION_NVP(ex);
        }

    public:
        result_container()
            { res=0; ex=0; }

        result_container(result *_res)
            { set_result(_res); }
        result_container(t2n_exception *_ex)
            { set_exception(_ex); }

        void set_result(result *_res)
            { res=_res; ex=0; result_type=regular; }
        void set_exception(t2n_exception *_ex)
            { res=0; ex=_ex; result_type=exception; }

        /** @brief returns the result or throw the carried exception.
                   ATTENTION: the result object is deleted in the destructor
        */
        result* get_result(void)
        {
            if (result_type==exception)
                ex->do_throw();
            return res;
        }

        /// deletes the carried result or exception objects
        ~result_container()
        {
            if (res)
                delete res;
            if (ex)
                delete ex;
        }
};

/** @brief contains a command
*/
class command_container
{
    private:
        command *cmd;

        friend class boost::serialization::access;
        template<class Archive>
        void serialize(Archive & ar, const unsigned int version)
        {
            ar & BOOST_SERIALIZATION_NVP(cmd);
        }

    public:
        command_container()
            { cmd=0; }
        command_container(command *_cmd)
            { cmd=_cmd; }

        /// return the contained command
        command* get_command()
            { return cmd; }

        ~command_container()
        {
            if (cmd)
                delete cmd;
        }
};

} // namespace libt2n

BOOST_CLASS_TRACKING(libt2n::result_container, boost::serialization::track_never)
BOOST_CLASS_TRACKING(libt2n::command_container, boost::serialization::track_never)

#endif