/****************************************************************************

** libebml : parse EBML files, see http://embl.sourceforge.net/

**

** <file/class description>

**

** Copyright (C) 2002-2010 Steve Lhomme.  All rights reserved.

**

** This file is part of libebml.

**

** 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.

**

** 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

**

** See http://www.gnu.org/licenses/lgpl-2.1.html for LGPL licensing information.

**

** Contact license@matroska.org if any conditions of this licensing are

** not clear to you.

**

**********************************************************************/

/*!

    \file

    \version \$Id: EbmlEndian.h 1298 2008-02-21 22:14:18Z mosu $

    \author Ingo Ralf Blum   <ingoralfblum @ users.sf.net>

    \author Lasse Kärkkäinen <tronic @ users.sf.net>

    \author Steve Lhomme     <robux4 @ users.sf.net>

*/

#ifndef LIBEBML_ENDIAN_H

#define LIBEBML_ENDIAN_H

#include <algorithm>

#include <cstring>

#include "EbmlConfig.h" // contains _ENDIANESS_

namespace libebml {

enum endianess {

    big_endian,   ///< PowerPC, Alpha, 68000

    little_endian ///< Intel x86 platforms

};

/*!

    \class Endian

    \brief general class to handle endian-specific buffers

    \note don't forget to define/undefine _ENDIANESS_ to BIG_ENDIAN depending on your machine

*/

template<class TYPE, endianess ENDIAN> class Endian

{

    public:

      Endian() = default;

      Endian(const TYPE value)

      {

        memcpy(&platform_value, &value, sizeof(TYPE));

        process_endian();

      }

      inline Endian & Eval(const binary *endian_buffer)

      {

          //endian_value = *(TYPE *)(endian_buffer);

          memcpy(&endian_value, endian_buffer, sizeof(TYPE));  // Some (all?) RISC processors do not allow reading objects bigger than 1 byte from non-aligned addresses, and endian_buffer may point to a non-aligned address.

          process_platform();

          return *this;

      }

      inline void Fill(binary *endian_buffer) const

      {

          //*(TYPE*)endian_buffer = endian_value;

          memcpy(endian_buffer, &endian_value, sizeof(TYPE)); // See above.

      }

      inline operator const TYPE&() const { return platform_value; }

    //  inline TYPE endian() const   { return endian_value; }

      inline const TYPE &endian() const       { return endian_value; }

      inline size_t size() const   { return sizeof(TYPE); }

      inline bool operator!=(const binary *buffer) const {return *(reinterpret_cast<TYPE*>(buffer)) == platform_value;}

#if defined(EBML_STRICT_API)

    private:

#else

    protected:

#endif

      TYPE platform_value;

      TYPE endian_value;

      inline void process_endian()

      {

          endian_value = platform_value;

#ifdef WORDS_BIGENDIAN

          if (ENDIAN == little_endian)

#else  // _ENDIANESS_

          if (ENDIAN == big_endian)

#endif // _ENDIANESS_

            std::reverse(reinterpret_cast<uint8*>(&endian_value),reinterpret_cast<uint8*>(&endian_value+1));

      }

      inline void process_platform()

      {

          platform_value = endian_value;

#ifdef WORDS_BIGENDIAN

          if (ENDIAN == little_endian)

#else  // _ENDIANESS_

          if (ENDIAN == big_endian)

#endif // _ENDIANESS_

            std::reverse(reinterpret_cast<uint8*>(&platform_value),reinterpret_cast<uint8*>(&platform_value+1));

      }

};

} // namespace libebml

#endif // LIBEBML_ENDIAN_H