lzo/src/lzo_crc.c

   1 /* lzo_crc.c -- crc checksum for the the LZO library
   2
   3    This file is part of the LZO real-time data compression library.
   4
   5    Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
   6    Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
   7    Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
   8    Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
   9    Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
  10    Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
  11    Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
  12    Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
  13    Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
  14    Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
  15    Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
  16    Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
  17    Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
  18    All Rights Reserved.
  19
  20    The LZO library is free software; you can redistribute it and/or
  21    modify it under the terms of the GNU General Public License as
  22    published by the Free Software Foundation; either version 2 of
  23    the License, or (at your option) any later version.
  24
  25    The LZO library is distributed in the hope that it will be useful,
  26    but WITHOUT ANY WARRANTY; without even the implied warranty of
  27    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28    GNU General Public License for more details.
  29
  30    You should have received a copy of the GNU General Public License
  31    along with the LZO library; see the file COPYING.
  32    If not, write to the Free Software Foundation, Inc.,
  33    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  34
  35    Markus F.X.J. Oberhumer
  36    <markus@oberhumer.com>
  37    http://www.oberhumer.com/opensource/lzo/
  38  */
  39
  40
  41 #include "lzo_conf.h"
  42
  43
  44 /***********************************************************************
  45 // crc32 checksum
  46 // adapted from free code by Mark Adler <madler@alumni.caltech.edu>
  47 // see http://www.zlib.org/
  48 ************************************************************************/
  49
  50 static const lzo_uint32 lzo_crc32_table[256] = {
  51   0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  52   0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  53   0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  54   0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  55   0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  56   0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  57   0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  58   0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  59   0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  60   0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  61   0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  62   0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  63   0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  64   0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  65   0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  66   0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  67   0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  68   0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
  69   0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
  70   0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
  71   0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
  72   0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
  73   0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
  74   0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
  75   0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
  76   0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
  77   0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
  78   0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
  79   0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
  80   0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
  81   0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
  82   0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
  83   0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
  84   0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
  85   0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
  86   0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
  87   0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
  88   0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
  89   0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
  90   0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
  91   0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
  92   0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
  93   0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
  94   0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
  95   0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
  96   0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
  97   0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
  98   0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
  99   0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
 100   0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
 101   0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
 102   0x2d02ef8dL
 103 };
 104
 105
 106 LZO_PUBLIC(const lzo_uint32p)
 107 lzo_get_crc32_table(void)
 108 {
 109     return lzo_crc32_table;
 110 }
 111
 112
 113 #if 1
 114 #define LZO_DO1(buf,i) \
 115     crc = table[((int)crc ^ buf[i]) & 0xff] ^ (crc >> 8)
 116 #else
 117 #define LZO_DO1(buf,i) \
 118     crc = table[(unsigned char)((unsigned char)crc ^ buf[i])] ^ (crc >> 8)
 119 #endif
 120 #define LZO_DO2(buf,i)  LZO_DO1(buf,i); LZO_DO1(buf,i+1);
 121 #define LZO_DO4(buf,i)  LZO_DO2(buf,i); LZO_DO2(buf,i+2);
 122 #define LZO_DO8(buf,i)  LZO_DO4(buf,i); LZO_DO4(buf,i+4);
 123 #define LZO_DO16(buf,i) LZO_DO8(buf,i); LZO_DO8(buf,i+8);
 124
 125
 126 LZO_PUBLIC(lzo_uint32)
 127 lzo_crc32(lzo_uint32 c, const lzo_bytep buf, lzo_uint len)
 128 {
 129     lzo_uint32 crc;
 130 #undef table
 131 #if 1
 132 #  define table lzo_crc32_table
 133 #else
 134    const lzo_uint32 * table = lzo_crc32_table;
 135 #endif
 136
 137     if (buf == NULL)
 138         return 0;
 139
 140     crc = (c & LZO_UINT32_C(0xffffffff)) ^ LZO_UINT32_C(0xffffffff);
 141     if (len >= 16) do
 142     {
 143         LZO_DO16(buf,0);
 144         buf += 16;
 145         len -= 16;
 146     } while (len >= 16);
 147     if (len != 0) do
 148     {
 149         LZO_DO1(buf,0);
 150         buf += 1;
 151         len -= 1;
 152     } while (len > 0);
 153
 154     return crc ^ LZO_UINT32_C(0xffffffff);
 155 #undef table
 156 }
 157
 158 #undef LZO_DO1
 159 #undef LZO_DO2
 160 #undef LZO_DO4
 161 #undef LZO_DO8
 162 #undef LZO_DO16
 163
 164
 165 /*
 166 vi:ts=4:et
 167 */