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/* crc32.c -- compute the CRC-32 of a data stream
* Copyright (C) 1995-1998 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "zlib.h"
#define local static
extern unsigned long crc32tab[];
#define DO1(buf) crc = crc32tab[((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8);
#define DO2(buf) DO1(buf); DO1(buf);
#define DO4(buf) DO2(buf); DO2(buf);
#define DO8(buf) DO4(buf); DO4(buf);
/* ========================================================================= */
uLong ZEXPORT zcrc32(crc, buf, len)
uLong crc;
const Bytef *buf;
uInt len;
{
if (buf == Z_NULL)
return 0L;
crc = crc ^ 0xffffffffL;
while (len >= 8) {
DO8(buf);
len -= 8;
}
if (len) do {
DO1(buf);
} while (--len);
return crc ^ 0xffffffffL;
}
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