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    16 ** GNU Lesser General Public License Usage

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    38 ** $QT_END_LICENSE$

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    40 ****************************************************************************/

    41 

    42 #ifndef QENDIAN_H

    43 #define QENDIAN_H

    44 

    45 #include <QtCore/qglobal.h>

    46 

    47 QT_BEGIN_HEADER

    48 

    49 QT_BEGIN_NAMESPACE

    50 

    51 QT_MODULE(Core)

    52 

    53 /*

    54  * ENDIAN FUNCTIONS

    55 */

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

    57 {

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

    59 }

    60 

    61 /*

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

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

    64  * and stores the result in \a dest.

    65  * There is no alignment requirements for \a dest.

    66 */

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

    68 {

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

    70 }

    71 

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

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

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

    75 {

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

    77 }

    78 

    79 /* T qFromLittleEndian(const uchar *src)

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

    81  * and return the value in host-endian encoding.

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

    83 */

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

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

    86 {

    87     return 0

    88         | src[0]

    89         | src[1] * Q_UINT64_C(0x0000000000000100)

    90         | src[2] * Q_UINT64_C(0x0000000000010000)

    91         | src[3] * Q_UINT64_C(0x0000000001000000)

    92         | src[4] * Q_UINT64_C(0x0000000100000000)

    93         | src[5] * Q_UINT64_C(0x0000010000000000)

    94         | src[6] * Q_UINT64_C(0x0001000000000000)

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

    96 }

    97 

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

    99 {

   100     return 0

   101         | src[0]

   102         | src[1] * quint32(0x00000100)

   103         | src[2] * quint32(0x00010000)

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

   105 }

   106 

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

   108 {

   109     return 0

   110         | src[0]

   111         | src[1] * 0x0100;

   112 }

   113 

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

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

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

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

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

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

   120 

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

   122 {

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

   124 }

   125 

   126 #else

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

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

   129 {

   130     return 0

   131         | src[0]

   132         | src[1] * Q_UINT64_C(0x0000000000000100)

   133         | src[2] * Q_UINT64_C(0x0000000000010000)

   134         | src[3] * Q_UINT64_C(0x0000000001000000)

   135         | src[4] * Q_UINT64_C(0x0000000100000000)

   136         | src[5] * Q_UINT64_C(0x0000010000000000)

   137         | src[6] * Q_UINT64_C(0x0001000000000000)

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

   139 }

   140 

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

   142 {

   143     return 0

   144         | src[0]

   145         | src[1] * quint32(0x00000100)

   146         | src[2] * quint32(0x00010000)

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

   148 }

   149 

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

   151 {

   152     return quint16(0

   153                    | src[0]

   154                    | src[1] * 0x0100);

   155 }

   156 

   157 // signed specializations

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

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

   160 

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

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

   163 

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

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

   166 #endif

   167 

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

   169  * and return the value in host-endian encoding.

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

   171 */

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

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

   174 {

   175     return 0

   176         | src[7]

   177         | src[6] * Q_UINT64_C(0x0000000000000100)

   178         | src[5] * Q_UINT64_C(0x0000000000010000)

   179         | src[4] * Q_UINT64_C(0x0000000001000000)

   180         | src[3] * Q_UINT64_C(0x0000000100000000)

   181         | src[2] * Q_UINT64_C(0x0000010000000000)

   182         | src[1] * Q_UINT64_C(0x0001000000000000)

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

   184 }

   185 

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

   187 {

   188     return 0

   189         | src[3]

   190         | src[2] * quint32(0x00000100)

   191         | src[1] * quint32(0x00010000)

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

   193 }

   194 

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

   196 {

   197     return 0

   198         | src[1]

   199         | src[0] * 0x0100;

   200 }

   201 

   202 

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

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

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

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

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

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

   209 

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

   211 {

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

   213 }

   214 

   215 #else

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

   217 template<>

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

   219 {

   220     return 0

   221         | src[7]

   222         | src[6] * Q_UINT64_C(0x0000000000000100)

   223         | src[5] * Q_UINT64_C(0x0000000000010000)

   224         | src[4] * Q_UINT64_C(0x0000000001000000)

   225         | src[3] * Q_UINT64_C(0x0000000100000000)

   226         | src[2] * Q_UINT64_C(0x0000010000000000)

   227         | src[1] * Q_UINT64_C(0x0001000000000000)

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

   229 }

   230 

   231 template<>

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

   233 {

   234     return 0

   235         | src[3]

   236         | src[2] * quint32(0x00000100)

   237         | src[1] * quint32(0x00010000)

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

   239 }

   240 

   241 template<>

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

   243 {

   244     return quint16( 0

   245                     | src[1]

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

   247 }

   248 

   249 

   250 // signed specializations

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

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

   253 

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

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

   256 

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

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

   259 #endif

   260 /*

   261  * T qbswap(T source).

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

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

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

   265 */

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

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

   268 {

   269     return 0

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

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

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

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

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

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

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

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

   278 }

   279 

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

   281 {

   282     return 0

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

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

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

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

   287 }

   288 

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

   290 {

   291     return quint16( 0

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

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

   294 }

   295 

   296 // signed specializations

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

   298 {

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

   300 }

   301 

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

   303 {

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

   305 }

   306 

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

   308 {

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

   310 }

   311 

   312 #if Q_BYTE_ORDER == Q_BIG_ENDIAN

   313 

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

   315 { return source; }

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

   317 { return source; }

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

   319 { return qbswap<T>(source); }

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

   321 { return qbswap<T>(source); }

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

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

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

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

   326 #else // Q_LITTLE_ENDIAN

   327 

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

   329 { return qbswap<T>(source); }

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

   331 { return qbswap<T>(source); }

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

   333 { return source; }

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

   335 { return source; }

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

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

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

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

   340 

   341 #endif // Q_BYTE_ORDER == Q_BIG_ENDIAN

   342 

   343 QT_END_NAMESPACE

   344 

   345 QT_END_HEADER

   346 

   347 #endif // QENDIAN_H