FFmpeg/libavutil/adler32.c
Reimar Döffinger d086c1203c Add coverage exclusions for test code.
For some of the code e.g. doing timing measurements there is no
real point in running regression testing on it, thus it should
not be counted against coverage.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
2011-12-05 20:05:44 +01:00

90 lines
2.5 KiB
C

/*
* Compute the Adler-32 checksum of a data stream.
* This is a modified version based on adler32.c from the zlib library.
*
* Copyright (C) 1995 Mark Adler
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#include "config.h"
#include "adler32.h"
#define BASE 65521L /* largest prime smaller than 65536 */
#define DO1(buf) { s1 += *buf++; s2 += s1; }
#define DO4(buf) DO1(buf); DO1(buf); DO1(buf); DO1(buf);
#define DO16(buf) DO4(buf); DO4(buf); DO4(buf); DO4(buf);
unsigned long av_adler32_update(unsigned long adler, const uint8_t * buf,
unsigned int len)
{
unsigned long s1 = adler & 0xffff;
unsigned long s2 = adler >> 16;
while (len > 0) {
#if CONFIG_SMALL
while (len > 4 && s2 < (1U << 31)) {
DO4(buf);
len -= 4;
}
#else
while (len > 16 && s2 < (1U << 31)) {
DO16(buf);
len -= 16;
}
#endif
DO1(buf); len--;
s1 %= BASE;
s2 %= BASE;
}
return (s2 << 16) | s1;
}
#ifdef TEST
// LCOV_EXCL_START
#include <string.h>
#include "log.h"
#include "timer.h"
#define LEN 7001
volatile int checksum;
int main(int argc, char **argv)
{
int i;
char data[LEN];
av_log_set_level(AV_LOG_DEBUG);
for (i = 0; i < LEN; i++)
data[i] = ((i * i) >> 3) + 123 * i;
if (argc > 1 && !strcmp(argv[1], "-t")) {
for (i = 0; i < 1000; i++) {
START_TIMER;
checksum = av_adler32_update(1, data, LEN);
STOP_TIMER("adler");
}
} else {
checksum = av_adler32_update(1, data, LEN);
}
av_log(NULL, AV_LOG_DEBUG, "%X (expected 50E6E508)\n", checksum);
return checksum == 0x50e6e508 ? 0 : 1;
}
// LCOV_EXCL_STOP
#endif