org.iq80.leveldb.util

Class PureJavaCrc32C

java.lang.Object

org.iq80.leveldb.util.PureJavaCrc32C

All Implemented Interfaces:

Checksum

public class PureJavaCrc32C
extends Object
implements Checksum

A pure-java implementation of the CRC32 checksum that uses the CRC32-C polynomial, the same polynomial used by iSCSI and implemented on many Intel chipsets supporting SSE4.2.

Constructor Summary

Constructors

Constructor and Description
PureJavaCrc32C() Create a new PureJavaCrc32 object.

Method Summary

Modifier and Type	Method and Description
int	getIntValue()
int	getMaskedValue()
long	getValue()
static int	mask(int crc) Return a masked representation of crc.
void	reset()
static int	unmask(int maskedCrc) Return the crc whose masked representation is masked_crc.
void	update(byte[] b, int off, int len)
void	update(int b)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PureJavaCrc32C

public PureJavaCrc32C()

Create a new PureJavaCrc32 object.

Method Detail

mask

public static int mask(int crc)

Return a masked representation of crc.

Motivation: it is problematic to compute the CRC of a string that contains embedded CRCs. Therefore we recommend that CRCs stored somewhere (e.g., in files) should be masked before being stored.

unmask

public static int unmask(int maskedCrc)

Return the crc whose masked representation is masked_crc.

getMaskedValue

public int getMaskedValue()

getIntValue

public int getIntValue()

getValue

public long getValue()

Specified by:

getValue in interface Checksum

reset

public final void reset()

Specified by:

reset in interface Checksum

update

public void update(byte[] b,
                   int off,
                   int len)

Specified by:

update in interface Checksum

update

public void update(int b)

Specified by:

update in interface Checksum