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Diffstat (limited to 'src/corelib/global/qendian.h')
| -rw-r--r-- | src/corelib/global/qendian.h | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/src/corelib/global/qendian.h b/src/corelib/global/qendian.h new file mode 100644 index 0000000000..566307b311 --- /dev/null +++ b/src/corelib/global/qendian.h @@ -0,0 +1,370 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** 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 +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QENDIAN_H +#define QENDIAN_H + +#include <QtCore/qglobal.h> + +// include stdlib.h and hope that it defines __GLIBC__ for glibc-based systems +#include <stdlib.h> + +#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_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_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 |