Package org.apache.commons.codec.digest

Class PureJavaCrc32C

java.lang.Object

org.apache.commons.codec.digest.PureJavaCrc32C

All Implemented Interfaces:

java.util.zip.Checksum

public class PureJavaCrc32C
extends java.lang.Object
implements java.util.zip.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. Copied from Hadoop 2.3.6: https://git-wip-us.apache.org/repos/asf?p=hadoop.git;a=blob_plain; f=hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PureJavaCrc32C.java; hb=2120de588b92b9f22b1cc4188761d6a8c61aa778

This class is Not ThreadSafe

Since:

1.11

Field Summary

Fields

Modifier and Type	Field	Description
private int	crc	the current CRC value, bit-flipped
private static int[]	T
private static int	T8_0_start
private static int	T8_1_start
private static int	T8_2_start
private static int	T8_3_start
private static int	T8_4_start
private static int	T8_5_start
private static int	T8_6_start
private static int	T8_7_start

Constructor Summary

Constructors

Constructor	Description
PureJavaCrc32C()	Create a new PureJavaCrc32 object.

Method Summary

Modifier and Type	Method	Description
long	getValue()
void	reset()
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

Methods inherited from interface java.util.zip.Checksum

update, update

Field Detail

crc

private int crc

the current CRC value, bit-flipped

T8_0_start

private static final int T8_0_start

See Also:

Constant Field Values

T8_1_start

private static final int T8_1_start

See Also:

Constant Field Values

T8_2_start

private static final int T8_2_start

See Also:

Constant Field Values

T8_3_start

private static final int T8_3_start

See Also:

Constant Field Values

T8_4_start

private static final int T8_4_start

See Also:

Constant Field Values

T8_5_start

private static final int T8_5_start

See Also:

Constant Field Values

T8_6_start

private static final int T8_6_start

See Also:

Constant Field Values

T8_7_start

private static final int T8_7_start

See Also:

Constant Field Values

T

private static final int[] T

Constructor Detail

PureJavaCrc32C

public PureJavaCrc32C()

Create a new PureJavaCrc32 object.

Method Detail

getValue

public long getValue()

Specified by:

getValue in interface java.util.zip.Checksum

reset

public void reset()

Specified by:

reset in interface java.util.zip.Checksum

update

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

Specified by:

update in interface java.util.zip.Checksum

update

public final void update(int b)

Specified by:

update in interface java.util.zip.Checksum