fb25e53b4f
Strip out Sort Transform from Libbsc copy. Reduce Libbsc memory use. Avoid redundant adler32 of data block in Libbsc.
85 lines
2.4 KiB
C++
85 lines
2.4 KiB
C++
/*-----------------------------------------------------------*/
|
|
/* Block Sorting, Lossless Data Compression Library. */
|
|
/* Adler-32 checksum functions */
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*--
|
|
|
|
This file is a part of bsc and/or libbsc, a program and a library for
|
|
lossless, block-sorting data compression.
|
|
|
|
Copyright (c) 2009-2012 Ilya Grebnov <ilya.grebnov@gmail.com>
|
|
|
|
See file AUTHORS for a full list of contributors.
|
|
|
|
The bsc and libbsc is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The bsc and libbsc 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 Lesser General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with the bsc and libbsc. If not, see http://www.gnu.org/licenses/.
|
|
|
|
Please see the files COPYING and COPYING.LIB for full copyright information.
|
|
|
|
See also the bsc and libbsc web site:
|
|
http://libbsc.com/ for more information.
|
|
|
|
--*/
|
|
|
|
#include <stdlib.h>
|
|
#include <memory.h>
|
|
#include <string.h>
|
|
|
|
#include "adler32.h"
|
|
|
|
#include "../platform/platform.h"
|
|
#include "../libbsc.h"
|
|
|
|
#define BASE 65521UL
|
|
#define NMAX 5552
|
|
|
|
#define DO1(buf, i) { sum1 += (buf)[i]; sum2 += sum1; }
|
|
#define DO2(buf, i) DO1(buf, i); DO1(buf, i + 1);
|
|
#define DO4(buf, i) DO2(buf, i); DO2(buf, i + 2);
|
|
#define DO8(buf, i) DO4(buf, i); DO4(buf, i + 4);
|
|
#define DO16(buf) DO8(buf, 0); DO8(buf, 8);
|
|
#define MOD(a) a %= BASE
|
|
|
|
unsigned int bsc_adler32(const unsigned char * T, int n, int features)
|
|
{
|
|
unsigned int sum1 = 1;
|
|
unsigned int sum2 = 0;
|
|
|
|
while (n >= NMAX)
|
|
{
|
|
for (int i = 0; i < NMAX / 16; ++i)
|
|
{
|
|
DO16(T); T += 16;
|
|
}
|
|
MOD(sum1); MOD(sum2); n -= NMAX;
|
|
}
|
|
|
|
while (n >= 16)
|
|
{
|
|
DO16(T); T += 16; n -= 16;
|
|
}
|
|
|
|
while (n > 0)
|
|
{
|
|
DO1(T, 0); T += 1; n -= 1;
|
|
}
|
|
|
|
MOD(sum1); MOD(sum2);
|
|
|
|
return sum1 | (sum2 << 16);
|
|
}
|
|
|
|
/*-----------------------------------------------------------*/
|
|
/* End adler32.cpp */
|
|
/*-----------------------------------------------------------*/
|