1/* lzo_util.c -- utilities for 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// 49************************************************************************/ 50 51/* If you use the LZO library in a product, I would appreciate that you 52 * keep this copyright string in the executable of your product. 53.*/ 54 55static const char __lzo_copyright[] = 56#if !defined(__LZO_IN_MINLZO) 57 /* save space as some people want a really small decompressor */ 58 LZO_VERSION_STRING; 59#else 60 "\r\n\n" 61 "LZO data compression library.\n" 62 "$Copyright: LZO Copyright (C) 1996-2011 Markus Franz Xaver Johannes Oberhumer\n" 63 "<markus@oberhumer.com>\n" 64 "http://www.oberhumer.com $\n\n" 65 "$Id: LZO version: v" LZO_VERSION_STRING ", " LZO_VERSION_DATE " $\n" 66 "$Info: " LZO_INFO_STRING " $\n"; 67#endif 68 69 70LZO_PUBLIC(const lzo_bytep) 71lzo_copyright(void) 72{ 73#if (LZO_OS_DOS16 && LZO_CC_TURBOC) 74 return (lzo_voidp) __lzo_copyright; 75#else 76 return (const lzo_bytep) __lzo_copyright; 77#endif 78} 79 80LZO_PUBLIC(unsigned) 81lzo_version(void) 82{ 83 return LZO_VERSION; 84} 85 86LZO_PUBLIC(const char *) 87lzo_version_string(void) 88{ 89 return LZO_VERSION_STRING; 90} 91 92LZO_PUBLIC(const char *) 93lzo_version_date(void) 94{ 95 return LZO_VERSION_DATE; 96} 97 98LZO_PUBLIC(const lzo_charp) 99_lzo_version_string(void) 100{ 101 return LZO_VERSION_STRING; 102} 103 104LZO_PUBLIC(const lzo_charp) 105_lzo_version_date(void) 106{ 107 return LZO_VERSION_DATE; 108} 109 110 111/*********************************************************************** 112// adler32 checksum 113// adapted from free code by Mark Adler <madler@alumni.caltech.edu> 114// see http://www.zlib.org/ 115************************************************************************/ 116 117#define LZO_BASE 65521u /* largest prime smaller than 65536 */ 118#define LZO_NMAX 5552 119/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 120 121#define LZO_DO1(buf,i) s1 += buf[i]; s2 += s1 122#define LZO_DO2(buf,i) LZO_DO1(buf,i); LZO_DO1(buf,i+1); 123#define LZO_DO4(buf,i) LZO_DO2(buf,i); LZO_DO2(buf,i+2); 124#define LZO_DO8(buf,i) LZO_DO4(buf,i); LZO_DO4(buf,i+4); 125#define LZO_DO16(buf,i) LZO_DO8(buf,i); LZO_DO8(buf,i+8); 126 127LZO_PUBLIC(lzo_uint32) 128lzo_adler32(lzo_uint32 adler, const lzo_bytep buf, lzo_uint len) 129{ 130 lzo_uint32 s1 = adler & 0xffff; 131 lzo_uint32 s2 = (adler >> 16) & 0xffff; 132 unsigned k; 133 134 if (buf == NULL) 135 return 1; 136 137 while (len > 0) 138 { 139 k = len < LZO_NMAX ? (unsigned) len : LZO_NMAX; 140 len -= k; 141 if (k >= 16) do 142 { 143 LZO_DO16(buf,0); 144 buf += 16; 145 k -= 16; 146 } while (k >= 16); 147 if (k != 0) do 148 { 149 s1 += *buf++; 150 s2 += s1; 151 } while (--k > 0); 152 s1 %= LZO_BASE; 153 s2 %= LZO_BASE; 154 } 155 return (s2 << 16) | s1; 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/* 166vi:ts=4:et 167*/ 168