/* 32-bit CRC table and calculation macro */

/****************************************************************************
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 * Copyright Rob Swindell - http://www.synchro.net/copyright.html			*
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 * This library is free software; you can redistribute it and/or			*
 * modify it under the terms of the GNU Lesser General Public License		*
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 * See the GNU Lesser General Public License for more details: lgpl.txt or	*
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#ifndef _CRC32_H_
#define _CRC32_H_

#include <stdio.h>  /* FILE */
#include "gen_defs.h"   /* uint32_t */

#ifdef __cplusplus
extern "C" {
#endif

extern int32_t crc32tbl[];
extern const uint32_t crc32tbl_slicing[3][256];

uint32_t crc32_update(uint32_t crc, const void* buf, size_t);
uint32_t crc32i(uint32_t crc, const char* buf, size_t);
uint32_t fcrc32(FILE* fp, size_t);

#ifdef __cplusplus
}
#endif

#define ucrc32(ch, crc) (crc32tbl[(crc ^ (ch)) & 0xff] ^ (crc >> 8))
static inline uint32_t ucrc32_4(const unsigned char* p, uint32_t crc)
{
	crc ^= (uint32_t)p[0]
	    | ((uint32_t)p[1] << 8)
	    | ((uint32_t)p[2] << 16)
	    | ((uint32_t)p[3] << 24);
	return crc32tbl_slicing[2][crc & 0xff]
	    ^ crc32tbl_slicing[1][(crc >> 8) & 0xff]
	    ^ crc32tbl_slicing[0][(crc >> 16) & 0xff]
	    ^ (uint32_t)crc32tbl[crc >> 24];
}

#define crc32(x, y) crc32i(0xffffffff, x, y)

#endif  /* Don't add anything after this line */
