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 *

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 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef LIBJIMAGE_ENDIAN_HPP

#define LIBJIMAGE_ENDIAN_HPP

#include "inttypes.hpp"

// Selectable endian handling. Endian handlers are used when accessing values

// that are of unknown (until runtime) endian.  The only requirement of the values

// accessed are that they are aligned to proper size boundaries (no misalignment.)

// To select an endian handler, one should call Endian::get_handler(big_endian);

// Where big_endian is true if big endian is required and false otherwise.  The

// native endian handler can be fetched with Endian::get_native_handler();

// To retrieve a value using the approprate endian, use one of the overloaded

// calls to get. To set a value, then use one of the overloaded set calls.

// Ex.

//          s4 value; // Imported value;

//          ...

//          Endian* endian = Endian::get_handler(true);  // Use big endian

//          s4 corrected = endian->get(value);

//          endian->set(value, 1);

//

class Endian {

public:

    virtual u2 get(u2 x) = 0;

    virtual u4 get(u4 x) = 0;

    virtual u8 get(u8 x) = 0;

    virtual s2 get(s2 x) = 0;

    virtual s4 get(s4 x) = 0;

    virtual s8 get(s8 x) = 0;

    virtual void set(u2& x, u2 y) = 0;

    virtual void set(u4& x, u4 y) = 0;

    virtual void set(u8& x, u8 y) = 0;

    virtual void set(s2& x, s2 y) = 0;

    virtual void set(s4& x, s4 y) = 0;

    virtual void set(s8& x, s8 y) = 0;

    // Quick little endian test.

    static bool is_little_endian() { u4 x = 1; return *(u1 *)&x != 0; }

    // Quick big endian test.

    static bool is_big_endian() { return !is_little_endian(); }

    // Select an appropriate endian handler.

    static Endian* get_handler(bool big_endian);

    // Return the native endian handler.

    static Endian* get_native_handler();

    // get platform u2 from Java Big endian

    static u2 get_java(u1* x);

    // set platform u2 to Java Big endian

    static void set_java(u1* p, u2 x);

};

// Normal endian handling.

class NativeEndian : public Endian {

private:

    static NativeEndian _native;

public:

    u2 get(u2 x);

    u4 get(u4 x);

    u8 get(u8 x);

    s2 get(s2 x);

    s4 get(s4 x);

    s8 get(s8 x);

    void set(u2& x, u2 y);

    void set(u4& x, u4 y);

    void set(u8& x, u8 y);

    void set(s2& x, s2 y);

    void set(s4& x, s4 y);

    void set(s8& x, s8 y);

    static Endian* get_native() { return &_native; }

};

// Swapping endian handling.

class SwappingEndian : public Endian {

private:

    static SwappingEndian _swapping;

public:

    u2 get(u2 x);

    u4 get(u4 x);

    u8 get(u8 x);

    s2 get(s2 x);

    s4 get(s4 x);

    s8 get(s8 x);

    void set(u2& x, u2 y);

    void set(u4& x, u4 y);

    void set(u8& x, u8 y);

    void set(s2& x, s2 y);

    void set(s4& x, s4 y);

    void set(s8& x, s8 y);

    static Endian* get_swapping() { return &_swapping; }

};

#endif // LIBJIMAGE_ENDIAN_HPP