summaryrefslogtreecommitdiffstatshomepage
path: root/src/lib/lib7z/XzCrc64.c
blob: 41f5e00756374c8716cc0ee8891ddd0ecc5c93b1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
/* XzCrc64.c -- CRC64 calculation
2010-04-16 : Igor Pavlov : Public domain */

#include "XzCrc64.h"

#define kCrc64Poly UINT64_CONST(0xC96C5795D7870F42)
UInt64 g_Crc64Table[256];

void MY_FAST_CALL Crc64GenerateTable(void)
{
	UInt32 i;
	for (i = 0; i < 256; i++)
	{
	UInt64 r = i;
	int j;
	for (j = 0; j < 8; j++)
		r = (r >> 1) ^ ((UInt64)kCrc64Poly & ~((r & 1) - 1));
	g_Crc64Table[i] = r;
	}
}

UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size)
{
	const Byte *p = (const Byte *)data;
	for (; size > 0 ; size--, p++)
	v = CRC64_UPDATE_BYTE(v, *p);
	return v;
}

UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size)
{
	return CRC64_GET_DIGEST(Crc64Update(CRC64_INIT_VAL, data, size));
}