p7zip-rar/CPP/7zip/Compress/BZip2Crc.h
2017-10-11 12:40:22 +02:00

32 lines
756 B
C++

// BZip2Crc.h
#ifndef __BZIP2_CRC_H
#define __BZIP2_CRC_H
#include "../../Common/MyTypes.h"
class CBZip2Crc
{
UInt32 _value;
static UInt32 Table[256];
public:
static void InitTable();
CBZip2Crc(): _value(0xFFFFFFFF) {};
void Init() { _value = 0xFFFFFFFF; }
void UpdateByte(Byte b) { _value = Table[(_value >> 24) ^ b] ^ (_value << 8); }
void UpdateByte(unsigned int b) { _value = Table[(_value >> 24) ^ b] ^ (_value << 8); }
UInt32 GetDigest() const { return _value ^ 0xFFFFFFFF; }
};
class CBZip2CombinedCrc
{
UInt32 _value;
public:
CBZip2CombinedCrc(): _value(0){};
void Init() { _value = 0; }
void Update(UInt32 v) { _value = ((_value << 1) | (_value >> 31)) ^ v; }
UInt32 GetDigest() const { return _value ; }
};
#endif