research.m1stereo.tv/gitweb/ - melted/blob - src/modules/kino/endian_types.h

   1 /* <endian_types.h>
   2  *
   3  * Quick hack to handle endianness and word length issues.
   4  * Defines _le, _be, and _ne variants to standard ISO types
   5  * like int32_t, that are stored in little-endian, big-endian,
   6  * and native-endian byteorder in memory, respectively.
   7  * Caveat: int32_le_t and friends cannot be used in vararg
   8  * functions like printf() without an explicit cast.
   9  *
  10  * Copyright (c) 2003-2005 Daniel Kobras <kobras@debian.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #ifndef _ENDIAN_TYPES_H
  28 #define _ENDIAN_TYPES_H
  29
  30 /* Needed for BYTE_ORDER and BIG/LITTLE_ENDIAN macros. */
  31 #ifndef _BSD_SOURCE
  32 # define _BSD_SOURCE
  33 # include <endian.h>
  34 # undef  _BSD_SOURCE
  35 #else
  36 # include <endian.h>
  37 #endif
  38
  39 #include <sys/types.h>
  40 #include <byteswap.h>
  41
  42 static inline int8_t bswap(const int8_t& x)
  43 {
  44         return x;
  45 }
  46
  47 static inline u_int8_t bswap(const u_int8_t& x)
  48 {
  49         return x;
  50 }
  51
  52 static inline int16_t bswap(const int16_t& x)
  53 {
  54         return bswap_16(x);
  55 }
  56
  57 static inline u_int16_t bswap(const u_int16_t& x)
  58 {
  59         return bswap_16(x);
  60 }
  61
  62 static inline int32_t bswap(const int32_t& x)
  63 {
  64         return bswap_32(x);
  65 }
  66
  67 static inline u_int32_t bswap(const u_int32_t& x)
  68 {
  69         return bswap_32(x);
  70 }
  71
  72 static inline int64_t bswap(const int64_t& x)
  73 {
  74         return bswap_64(x);
  75 }
  76
  77 static inline u_int64_t bswap(const u_int64_t& x)
  78 {
  79         return bswap_64(x);
  80 }
  81
  82 #define le_to_cpu       cpu_to_le
  83 #define be_to_cpu       cpu_to_be
  84
  85 template <class T> static inline T cpu_to_le(const T& x)
  86 {
  87 #if BYTE_ORDER == LITTLE_ENDIAN
  88         return x;
  89 #else
  90         return bswap(x);
  91 #endif
  92 }
  93
  94 template <class T> static inline T cpu_to_be(const T& x)
  95 {
  96 #if BYTE_ORDER == LITTLE_ENDIAN
  97         return bswap(x);
  98 #else
  99         return x;
 100 #endif
 101 }
 102
 103 template <class T> class le_t {
 104         T       m;
 105         T       read() const {
 106                 return le_to_cpu(m);
 107         };
 108         void    write(const T& n) {
 109                 m = cpu_to_le(n);
 110         };
 111 public:
 112         le_t(void) {
 113                 m = 0;
 114         };
 115         le_t(const T& o) {
 116                 write(o);
 117         };
 118         operator T() const {
 119                 return read();
 120         };
 121         le_t<T> operator++() {
 122                 write(read() + 1);
 123                 return *this;
 124         };
 125         le_t<T> operator++(int) {
 126                 write(read() + 1);
 127                 return *this;
 128         };
 129         le_t<T> operator--() {
 130                 write(read() - 1);
 131                 return *this;
 132         };
 133         le_t<T> operator--(int) {
 134                 write(read() - 1);
 135                 return *this;
 136         };
 137         le_t<T>& operator+=(const T& t) {
 138                 write(read() + t);
 139                 return *this;
 140         };
 141         le_t<T>& operator-=(const T& t) {
 142                 write(read() - t);
 143                 return *this;
 144         };
 145         le_t<T>& operator&=(const le_t<T>& t) {
 146                 m &= t.m;
 147                 return *this;
 148         };
 149         le_t<T>& operator|=(const le_t<T>& t) {
 150                 m |= t.m;
 151                 return *this;
 152         };
 153 } __attribute__((packed));
 154
 155 /* Just copy-and-pasted from le_t. Too lazy to do it right. */
 156
 157 template <class T> class be_t {
 158         T       m;
 159         T       read() const {
 160                 return be_to_cpu(m);
 161         };
 162         void    write(const T& n) {
 163                 m = cpu_to_be(n);
 164         };
 165 public:
 166         be_t(void) {
 167                 m = 0;
 168         };
 169         be_t(const T& o) {
 170                 write(o);
 171         };
 172         operator T() const {
 173                 return read();
 174         };
 175         be_t<T> operator++() {
 176                 write(read() + 1);
 177                 return *this;
 178         };
 179         be_t<T> operator++(int) {
 180                 write(read() + 1);
 181                 return *this;
 182         };
 183         be_t<T> operator--() {
 184                 write(read() - 1);
 185                 return *this;
 186         };
 187         be_t<T> operator--(int) {
 188                 write(read() - 1);
 189                 return *this;
 190         };
 191         be_t<T>& operator+=(const T& t) {
 192                 write(read() + t);
 193                 return *this;
 194         };
 195         be_t<T>& operator-=(const T& t) {
 196                 write(read() - t);
 197                 return *this;
 198         };
 199         be_t<T>& operator&=(const be_t<T>& t) {
 200                 m &= t.m;
 201                 return *this;
 202         };
 203         be_t<T>& operator|=(const be_t<T>& t) {
 204                 m |= t.m;
 205                 return *this;
 206         };
 207 } __attribute__((packed));
 208
 209 /* Define types of native endianness similar to the little and big endian
 210  * versions below. Not really necessary but useful occasionally to emphasize
 211  * endianness of data.
 212  */
 213
 214 typedef int8_t          int8_ne_t;
 215 typedef int16_t         int16_ne_t;
 216 typedef int32_t         int32_ne_t;
 217 typedef int64_t         int64_ne_t;
 218 typedef u_int8_t        u_int8_ne_t;
 219 typedef u_int16_t       u_int16_ne_t;
 220 typedef u_int32_t       u_int32_ne_t;
 221 typedef u_int64_t       u_int64_ne_t;
 222
 223
 224 /* The classes work on their native endianness as well, but obviously
 225  * introduce some overhead.  Use the faster typedefs to native types
 226  * therefore, unless you're debugging.
 227  */
 228
 229 #if BYTE_ORDER == LITTLE_ENDIAN
 230 typedef int8_ne_t       int8_le_t;
 231 typedef int16_ne_t      int16_le_t;
 232 typedef int32_ne_t      int32_le_t;
 233 typedef int64_ne_t      int64_le_t;
 234 typedef u_int8_ne_t     u_int8_le_t;
 235 typedef u_int16_ne_t    u_int16_le_t;
 236 typedef u_int32_ne_t    u_int32_le_t;
 237 typedef u_int64_ne_t    u_int64_le_t;
 238 typedef int8_t          int8_be_t;
 239 typedef be_t<int16_t>   int16_be_t;
 240 typedef be_t<int32_t>   int32_be_t;
 241 typedef be_t<int64_t>   int64_be_t;
 242 typedef u_int8_t        u_int8_be_t;
 243 typedef be_t<u_int16_t> u_int16_be_t;
 244 typedef be_t<u_int32_t> u_int32_be_t;
 245 typedef be_t<u_int64_t> u_int64_be_t;
 246 #else
 247 typedef int8_ne_t       int8_be_t;
 248 typedef int16_ne_t      int16_be_t;
 249 typedef int32_ne_t      int32_be_t;
 250 typedef int64_ne_t      int64_be_t;
 251 typedef u_int8_ne_t     u_int8_be_t;
 252 typedef u_int16_ne_t    u_int16_be_t;
 253 typedef u_int32_ne_t    u_int32_be_t;
 254 typedef u_int64_ne_t    u_int64_be_t;
 255 typedef int8_t          int8_le_t;
 256 typedef le_t<int16_t>   int16_le_t;
 257 typedef le_t<int32_t>   int32_le_t;
 258 typedef le_t<int64_t>   int64_le_t;
 259 typedef u_int8_t        u_int8_le_t;
 260 typedef le_t<u_int16_t> u_int16_le_t;
 261 typedef le_t<u_int32_t> u_int32_le_t;
 262 typedef le_t<u_int64_t> u_int64_le_t;
 263 #endif
 264
 265 #endif