Deserializer.h

/*
 * Copyright (C) 2008 by Marc Boris Duerner
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * As a special exception, you may use this file as part of a free
 * software library without restriction. Specifically, if other files
 * instantiate templates or use macros or inline functions from this
 * file, or you compile this file and link it with other files to
 * produce an executable, this file does not by itself cause the
 * resulting executable to be covered by the GNU General Public
 * License. This exception does not however invalidate any other
 * reasons why the executable file might be covered by the GNU Library
 * General Public License.
 *
 * 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef Pt_Deserializer_h
#define Pt_Deserializer_h

#include <Pt/Api.h>
#include <Pt/Composer.h>
#include <Pt/Formatter.h>
#include <Pt/NonCopyable.h>
#include <Pt/SerializationContext.h>

namespace Pt {

class PT_API Deserializer : private NonCopyable
{
    public:
        Deserializer();

        virtual ~Deserializer();

        SerializationContext* context();

        void reset(SerializationContext* context);

        Formatter* formatter();

        void setFormatter(Formatter& formatter);

        void clear();

        template <typename T>
        void begin(T& t)
        {
            if( ! _fmt)
                return;

            // allocate() also destructs _current
            void* m = this->allocate( sizeof(BasicComposer<T>) );

            BasicComposer<T>* comp = 0;
            try
            {
                comp = new (m) BasicComposer<T>(_context);
                comp->begin(t);
                _current = comp;
            }
            catch(...)
            {
                if(comp)
                    comp->~BasicComposer<T>();

                this->deallocate(m);
                throw;
            }

            _fmt->beginParse(*_current);
        }

        bool advance();

        void finish();

        void fixup();

    private:
        void* allocate(std::size_t n);

        void deallocate(void* p);

    private:
        SerializationContext* _context;
        Formatter* _fmt;
        Composer* _current;
        void* _mem;
        std::size_t _memsize;
        Pt::varint_t _r0; // allocator
};

} // namespace Pt

#endif