// SevenZip/CRC.java
|
|
package SevenZip;
|
|
public class CRC
|
{
|
static public int[] Table = new int[256];
|
|
static
|
{
|
for (int i = 0; i < 256; i++)
|
{
|
int r = i;
|
for (int j = 0; j < 8; j++)
|
if ((r & 1) != 0)
|
r = (r >>> 1) ^ 0xEDB88320;
|
else
|
r >>>= 1;
|
Table[i] = r;
|
}
|
}
|
|
int _value = -1;
|
|
public void Init()
|
{
|
_value = -1;
|
}
|
|
public void Update(byte[] data, int offset, int size)
|
{
|
for (int i = 0; i < size; i++)
|
_value = Table[(_value ^ data[offset + i]) & 0xFF] ^ (_value >>> 8);
|
}
|
|
public void Update(byte[] data)
|
{
|
int size = data.length;
|
for (int i = 0; i < size; i++)
|
_value = Table[(_value ^ data[i]) & 0xFF] ^ (_value >>> 8);
|
}
|
|
public void UpdateByte(int b)
|
{
|
_value = Table[(_value ^ b) & 0xFF] ^ (_value >>> 8);
|
}
|
|
public int GetDigest()
|
{
|
return _value ^ (-1);
|
}
|
}
|
