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

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** This file is part of the QtCore module of the Qt Toolkit.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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

#ifndef QENDIAN_H

#define QENDIAN_H

#include <QtCore/qglobal.h>

#ifdef Q_OS_LINUX

# include <features.h>

#endif

#ifdef __GLIBC__

#include <byteswap.h>

#endif

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Core)

/*

 * ENDIAN FUNCTIONS

*/

inline void qbswap_helper(const uchar *src, uchar *dest, int size)

{

    for (int i = 0; i < size ; ++i) dest[i] = src[size - 1 - i];

}

/*

 * qbswap(const T src, const uchar *dest);

 * Changes the byte order of \a src from big endian to little endian or vice versa

 * and stores the result in \a dest.

 * There is no alignment requirements for \a dest.

*/

template <typename T> inline void qbswap(const T src, uchar *dest)

{

    qbswap_helper(reinterpret_cast<const uchar *>(&src), dest, sizeof(T));

}

// Used to implement a type-safe and alignment-safe copy operation

// If you want to avoid the memcopy, you must write specializations for this function

template <typename T> inline void qToUnaligned(const T src, uchar *dest)

{

    qMemCopy(dest, &src, sizeof(T));

}

/* T qFromLittleEndian(const uchar *src)

 * This function will read a little-endian encoded value from \a src

 * and return the value in host-endian encoding.

 * There is no requirement that \a src must be aligned.

*/

#if defined Q_CC_MSVC && _MSC_VER < 1300 || defined Q_CC_SUN

inline quint64 qFromLittleEndian_helper(const uchar *src, quint64 *dest)

{

    return 0

        | src[0]

        | src[1] * Q_UINT64_C(0x0000000000000100)

        | src[2] * Q_UINT64_C(0x0000000000010000)

        | src[3] * Q_UINT64_C(0x0000000001000000)

        | src[4] * Q_UINT64_C(0x0000000100000000)

        | src[5] * Q_UINT64_C(0x0000010000000000)

        | src[6] * Q_UINT64_C(0x0001000000000000)

        | src[7] * Q_UINT64_C(0x0100000000000000);

}

inline quint32 qFromLittleEndian_helper(const uchar *src, quint32 *dest)

{

    return 0

        | src[0]

        | src[1] * quint32(0x00000100)

        | src[2] * quint32(0x00010000)

        | src[3] * quint32(0x01000000);

}

inline quint16 qFromLittleEndian_helper(const uchar *src, quint16 *dest)

{

    return 0

        | src[0]

        | src[1] * 0x0100;

}

inline qint64 qFromLittleEndian_helper(const uchar *src, qint64 * dest)

{ return static_cast<qint64>(qFromLittleEndian_helper(src, reinterpret_cast<quint64*>(0))); }

inline qint32 qFromLittleEndian_helper(const uchar *src, qint32 * dest)

{ return static_cast<qint32>(qFromLittleEndian_helper(src, reinterpret_cast<quint32*>(0))); }

inline qint16 qFromLittleEndian_helper(const uchar *src, qint16 * dest)

{ return static_cast<qint16>(qFromLittleEndian_helper(src, reinterpret_cast<quint16*>(0))); }

template <class T> inline T qFromLittleEndian(const uchar *src)

{

    return qFromLittleEndian_helper(src, reinterpret_cast<T*>(0));

}

#else

template <typename T> inline T qFromLittleEndian(const uchar *src);

template <> inline quint64 qFromLittleEndian<quint64>(const uchar *src)

{

    return 0

        | src[0]

        | src[1] * Q_UINT64_C(0x0000000000000100)

        | src[2] * Q_UINT64_C(0x0000000000010000)

        | src[3] * Q_UINT64_C(0x0000000001000000)

        | src[4] * Q_UINT64_C(0x0000000100000000)

        | src[5] * Q_UINT64_C(0x0000010000000000)

        | src[6] * Q_UINT64_C(0x0001000000000000)

        | src[7] * Q_UINT64_C(0x0100000000000000);

}

template <> inline quint32 qFromLittleEndian<quint32>(const uchar *src)

{

    return 0

        | src[0]

        | src[1] * quint32(0x00000100)

        | src[2] * quint32(0x00010000)

        | src[3] * quint32(0x01000000);

}

template <> inline quint16 qFromLittleEndian<quint16>(const uchar *src)

{

    return quint16(0

                   | src[0]

                   | src[1] * 0x0100);

}

// signed specializations

template <> inline qint64 qFromLittleEndian<qint64>(const uchar *src)

{ return static_cast<qint64>(qFromLittleEndian<quint64>(src)); }

template <> inline qint32 qFromLittleEndian<qint32>(const uchar *src)

{ return static_cast<qint32>(qFromLittleEndian<quint32>(src)); }

template <> inline qint16 qFromLittleEndian<qint16>(const uchar *src)

{ return static_cast<qint16>(qFromLittleEndian<quint16>(src)); }

#endif

/* This function will read a big-endian (also known as network order) encoded value from \a src

 * and return the value in host-endian encoding.

 * There is no requirement that \a src must be aligned.

*/

#if defined Q_CC_MSVC && _MSC_VER < 1300 || defined Q_CC_SUN

inline quint64 qFromBigEndian_helper(const uchar *src, quint64 *dest)

{

    return 0

        | src[7]

        | src[6] * Q_UINT64_C(0x0000000000000100)

        | src[5] * Q_UINT64_C(0x0000000000010000)

        | src[4] * Q_UINT64_C(0x0000000001000000)

        | src[3] * Q_UINT64_C(0x0000000100000000)

        | src[2] * Q_UINT64_C(0x0000010000000000)

        | src[1] * Q_UINT64_C(0x0001000000000000)

        | src[0] * Q_UINT64_C(0x0100000000000000);

}

inline quint32 qFromBigEndian_helper(const uchar *src, quint32 * dest)

{

    return 0

        | src[3]

        | src[2] * quint32(0x00000100)

        | src[1] * quint32(0x00010000)

        | src[0] * quint32(0x01000000);

}

inline quint16 qFromBigEndian_helper(const uchar *src, quint16 * des)

{

    return 0

        | src[1]

        | src[0] * 0x0100;

}

inline qint64 qFromBigEndian_helper(const uchar *src, qint64 * dest)

{ return static_cast<qint64>(qFromBigEndian_helper(src, reinterpret_cast<quint64*>(0))); }

inline qint32 qFromBigEndian_helper(const uchar *src, qint32 * dest)

{ return static_cast<qint32>(qFromBigEndian_helper(src, reinterpret_cast<quint32*>(0))); }

inline qint16 qFromBigEndian_helper(const uchar *src, qint16 * dest)

{ return static_cast<qint16>(qFromBigEndian_helper(src, reinterpret_cast<quint16*>(0))); }

template <class T> inline T qFromBigEndian(const uchar *src)

{

    return qFromBigEndian_helper(src, reinterpret_cast<T*>(0));

}

#else

template <class T> inline T qFromBigEndian(const uchar *src);

template<>

inline quint64 qFromBigEndian<quint64>(const uchar *src)

{

    return 0

        | src[7]

        | src[6] * Q_UINT64_C(0x0000000000000100)

        | src[5] * Q_UINT64_C(0x0000000000010000)

        | src[4] * Q_UINT64_C(0x0000000001000000)

        | src[3] * Q_UINT64_C(0x0000000100000000)

        | src[2] * Q_UINT64_C(0x0000010000000000)

        | src[1] * Q_UINT64_C(0x0001000000000000)

        | src[0] * Q_UINT64_C(0x0100000000000000);

}

template<>

inline quint32 qFromBigEndian<quint32>(const uchar *src)

{

    return 0

        | src[3]

        | src[2] * quint32(0x00000100)

        | src[1] * quint32(0x00010000)

        | src[0] * quint32(0x01000000);

}

template<>

inline quint16 qFromBigEndian<quint16>(const uchar *src)

{

    return quint16( 0

                    | src[1]

                    | src[0] * quint16(0x0100));

}

// signed specializations

template <> inline qint64 qFromBigEndian<qint64>(const uchar *src)

{ return static_cast<qint64>(qFromBigEndian<quint64>(src)); }

template <> inline qint32 qFromBigEndian<qint32>(const uchar *src)

{ return static_cast<qint32>(qFromBigEndian<quint32>(src)); }

template <> inline qint16 qFromBigEndian<qint16>(const uchar *src)

{ return static_cast<qint16>(qFromBigEndian<quint16>(src)); }

#endif

/*

 * T qbswap(T source).

 * Changes the byte order of a value from big endian to little endian or vice versa.

 * This function can be used if you are not concerned about alignment issues,

 * and it is therefore a bit more convenient and in most cases more efficient.

*/

template <typename T> T qbswap(T source);

#ifdef __GLIBC__

template <> inline quint64 qbswap<quint64>(quint64 source)

{

    return bswap_64(source);

}

template <> inline quint32 qbswap<quint32>(quint32 source)

{

    return bswap_32(source);

}

template <> inline quint16 qbswap<quint16>(quint16 source)

{

    return bswap_16(source);

}

#else

template <> inline quint64 qbswap<quint64>(quint64 source)

{

    return 0

        | ((source & Q_UINT64_C(0x00000000000000ff)) << 56)

        | ((source & Q_UINT64_C(0x000000000000ff00)) << 40)

        | ((source & Q_UINT64_C(0x0000000000ff0000)) << 24)

        | ((source & Q_UINT64_C(0x00000000ff000000)) << 8)

        | ((source & Q_UINT64_C(0x000000ff00000000)) >> 8)

        | ((source & Q_UINT64_C(0x0000ff0000000000)) >> 24)

        | ((source & Q_UINT64_C(0x00ff000000000000)) >> 40)

        | ((source & Q_UINT64_C(0xff00000000000000)) >> 56);

}

template <> inline quint32 qbswap<quint32>(quint32 source)

{

    return 0

        | ((source & 0x000000ff) << 24)

        | ((source & 0x0000ff00) << 8)

        | ((source & 0x00ff0000) >> 8)

        | ((source & 0xff000000) >> 24);

}

template <> inline quint16 qbswap<quint16>(quint16 source)

{

    return quint16( 0

                    | ((source & 0x00ff) << 8)

                    | ((source & 0xff00) >> 8) );

}

#endif // __GLIBC__

// signed specializations

template <> inline qint64 qbswap<qint64>(qint64 source)

{

    return qbswap<quint64>(quint64(source));

}

template <> inline qint32 qbswap<qint32>(qint32 source)

{

    return qbswap<quint32>(quint32(source));

}

template <> inline qint16 qbswap<qint16>(qint16 source)

{

    return qbswap<quint16>(quint16(source));

}

#if Q_BYTE_ORDER == Q_BIG_ENDIAN

template <typename T> inline T qToBigEndian(T source)

{ return source; }

template <typename T> inline T qFromBigEndian(T source)

{ return source; }

template <typename T> inline T qToLittleEndian(T source)

{ return qbswap<T>(source); }

template <typename T> inline T qFromLittleEndian(T source)

{ return qbswap<T>(source); }

template <typename T> inline void qToBigEndian(T src, uchar *dest)

{ qToUnaligned<T>(src, dest); }

template <typename T> inline void qToLittleEndian(T src, uchar *dest)

{ qbswap<T>(src, dest); }

#else // Q_LITTLE_ENDIAN

template <typename T> inline T qToBigEndian(T source)

{ return qbswap<T>(source); }

template <typename T> inline T qFromBigEndian(T source)

{ return qbswap<T>(source); }

template <typename T> inline T qToLittleEndian(T source)

{ return source; }

template <typename T> inline T qFromLittleEndian(T source)

{ return source; }

template <typename T> inline void qToBigEndian(T src, uchar *dest)

{ qbswap<T>(src, dest); }

template <typename T> inline void qToLittleEndian(T src, uchar *dest)

{ qToUnaligned<T>(src, dest); }

#endif // Q_BYTE_ORDER == Q_BIG_ENDIAN

QT_END_NAMESPACE

QT_END_HEADER

#endif // QENDIAN_H