athena/extern/lzo/src/lzo_util.c

155 lines
3.9 KiB
C

/* lzo_util.c -- utilities for the LZO library
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The LZO library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The LZO library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the LZO library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
http://www.oberhumer.com/opensource/lzo/
*/
#include "lzo_conf.h"
/***********************************************************************
//
************************************************************************/
/* If you use the LZO library in a product, I would appreciate that you
* keep this copyright string in the executable of your product.
.*/
static const char lzo_copyright_[] =
#if !defined(__LZO_IN_MINLZO)
/* save space as some people want a really small decompressor */
LZO_VERSION_STRING;
#else
"\r\n\n"
"LZO data compression library.\n"
"$Copyright: LZO Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer\n"
"<markus@oberhumer.com>\n"
"http://www.oberhumer.com $\n\n"
"$Id: LZO version: v" LZO_VERSION_STRING ", " LZO_VERSION_DATE " $\n"
"$Info: " LZO_INFO_STRING " $\n";
#endif
static const char lzo_version_string_[] = LZO_VERSION_STRING;
static const char lzo_version_date_[] = LZO_VERSION_DATE;
LZO_PUBLIC(const lzo_bytep)
lzo_copyright(void)
{
return (const lzo_bytep) lzo_copyright_;
}
LZO_PUBLIC(unsigned)
lzo_version(void)
{
return LZO_VERSION;
}
LZO_PUBLIC(const char*)
lzo_version_string(void)
{
return lzo_version_string_;
}
LZO_PUBLIC(const char*)
lzo_version_date(void)
{
return lzo_version_date_;
}
LZO_PUBLIC(const lzo_charp)
_lzo_version_string(void)
{
return lzo_version_string_;
}
LZO_PUBLIC(const lzo_charp)
_lzo_version_date(void)
{
return lzo_version_date_;
}
/***********************************************************************
// adler32 checksum
// adapted from free code by Mark Adler <madler@alumni.caltech.edu>
// see http://www.zlib.org/
************************************************************************/
#define LZO_BASE 65521u /* largest prime smaller than 65536 */
#define LZO_NMAX 5552
/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
#define LZO_DO1(buf,i) s1 += buf[i]; s2 += s1
#define LZO_DO2(buf,i) LZO_DO1(buf,i); LZO_DO1(buf,i+1)
#define LZO_DO4(buf,i) LZO_DO2(buf,i); LZO_DO2(buf,i+2)
#define LZO_DO8(buf,i) LZO_DO4(buf,i); LZO_DO4(buf,i+4)
#define LZO_DO16(buf,i) LZO_DO8(buf,i); LZO_DO8(buf,i+8)
LZO_PUBLIC(lzo_uint32_t)
lzo_adler32(lzo_uint32_t adler, const lzo_bytep buf, lzo_uint len)
{
lzo_uint32_t s1 = adler & 0xffff;
lzo_uint32_t s2 = (adler >> 16) & 0xffff;
unsigned k;
if (buf == NULL)
return 1;
while (len > 0)
{
k = len < LZO_NMAX ? (unsigned) len : LZO_NMAX;
len -= k;
if (k >= 16) do
{
LZO_DO16(buf, 0);
buf += 16;
k -= 16;
}
while (k >= 16);
if (k != 0) do
{
s1 += *buf++;
s2 += s1;
}
while (--k > 0);
s1 %= LZO_BASE;
s2 %= LZO_BASE;
}
return (s2 << 16) | s1;
}
#undef LZO_DO1
#undef LZO_DO2
#undef LZO_DO4
#undef LZO_DO8
#undef LZO_DO16
/* vim:set ts=4 sw=4 et: */