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/*
* CRC32 checksum
*
* Copyright (c) 1998-2019 Joergen Ibsen
*
* 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.
*/
/*
* CRC32 algorithm taken from the zlib source, which is
* Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
*/
#include <ext/tinf.h>
static const unsigned int tinf_crc32tab[16] = {
0x00000000, 0x1DB71064, 0x3B6E20C8, 0x26D930AC, 0x76DC4190,
0x6B6B51F4, 0x4DB26158, 0x5005713C, 0xEDB88320, 0xF00F9344,
0xD6D6A3E8, 0xCB61B38C, 0x9B64C2B0, 0x86D3D2D4, 0xA00AE278,
0xBDBDF21C
};
unsigned int tinf_crc32(const void *data, unsigned int length)
{
const unsigned char *buf = (const unsigned char *) data;
unsigned int crc = 0xFFFFFFFF;
unsigned int i;
if (length == 0) {
return 0;
}
for (i = 0; i < length; ++i) {
crc ^= buf[i];
crc = tinf_crc32tab[crc & 0x0F] ^ (crc >> 4);
crc = tinf_crc32tab[crc & 0x0F] ^ (crc >> 4);
}
return crc ^ 0xFFFFFFFF;
}
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