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) 2011 Markus Franz Xaver Johannes Oberhumer
6   Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer
7   Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer
8   Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
9   Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
10   Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
11   Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
12   Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
13   Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
14   Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
15   Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
16   Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
17   Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
18   Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
19   Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
20   Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
21   All Rights Reserved.
22
23   The LZO library is free software; you can redistribute it and/or
24   modify it under the terms of the GNU General Public License as
25   published by the Free Software Foundation; either version 2 of
26   the License, or (at your option) any later version.
27
28   The LZO library is distributed in the hope that it will be useful,
29   but WITHOUT ANY WARRANTY; without even the implied warranty of
30   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
31   GNU General Public License for more details.
32
33   You should have received a copy of the GNU General Public License
34   along with the LZO library; see the file COPYING.
35   If not, write to the Free Software Foundation, Inc.,
36   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
37
38   Markus F.X.J. Oberhumer
39   <markus@oberhumer.com>
40   http://www.oberhumer.com/opensource/lzo/
41 */
42
43
44#include "lzo_conf.h"
45
46
47/***********************************************************************
48// crc32 checksum
49// adapted from free code by Mark Adler <madler@alumni.caltech.edu>
50// see http://www.zlib.org/
51************************************************************************/
52
53static const lzo_uint32 lzo_crc32_table[256] = {
54  0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
55  0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
56  0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
57  0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
58  0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
59  0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
60  0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
61  0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
62  0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
63  0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
64  0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
65  0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
66  0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
67  0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
68  0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
69  0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
70  0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
71  0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
72  0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
73  0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
74  0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
75  0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
76  0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
77  0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
78  0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
79  0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
80  0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
81  0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
82  0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
83  0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
84  0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
85  0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
86  0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
87  0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
88  0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
89  0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
90  0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
91  0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
92  0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
93  0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
94  0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
95  0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
96  0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
97  0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
98  0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
99  0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
100  0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
101  0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
102  0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
103  0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
104  0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
105  0x2d02ef8dL
106};
107
108
109LZO_PUBLIC(const lzo_uint32p)
110lzo_get_crc32_table(void)
111{
112    return lzo_crc32_table;
113}
114
115
116#if 1
117#define LZO_DO1(buf,i) \
118    crc = table[((unsigned)crc ^ buf[i]) & 0xff] ^ (crc >> 8)
119#else
120#define LZO_DO1(buf,i) \
121    crc = table[(unsigned char)((unsigned char)crc ^ buf[i])] ^ (crc >> 8)
122#endif
123#define LZO_DO2(buf,i)  LZO_DO1(buf,i); LZO_DO1(buf,i+1);
124#define LZO_DO4(buf,i)  LZO_DO2(buf,i); LZO_DO2(buf,i+2);
125#define LZO_DO8(buf,i)  LZO_DO4(buf,i); LZO_DO4(buf,i+4);
126#define LZO_DO16(buf,i) LZO_DO8(buf,i); LZO_DO8(buf,i+8);
127
128
129LZO_PUBLIC(lzo_uint32)
130lzo_crc32(lzo_uint32 c, const lzo_bytep buf, lzo_uint len)
131{
132    lzo_uint32 crc;
133#undef table
134#if 1
135#  define table lzo_crc32_table
136#else
137   const lzo_uint32 * table = lzo_crc32_table;
138#endif
139
140    if (buf == NULL)
141        return 0;
142
143    crc = (c & LZO_UINT32_C(0xffffffff)) ^ LZO_UINT32_C(0xffffffff);
144    if (len >= 16) do
145    {
146        LZO_DO16(buf,0);
147        buf += 16;
148        len -= 16;
149    } while (len >= 16);
150    if (len != 0) do
151    {
152        LZO_DO1(buf,0);
153        buf += 1;
154        len -= 1;
155    } while (len > 0);
156
157    return crc ^ LZO_UINT32_C(0xffffffff);
158#undef table
159}
160
161#undef LZO_DO1
162#undef LZO_DO2
163#undef LZO_DO4
164#undef LZO_DO8
165#undef LZO_DO16
166
167
168/*
169vi:ts=4:et
170*/
171