Package org.apache.commons.compress.compressors.snappy

Class PureJavaCrc32C

java.lang.Object

org.apache.commons.compress.compressors.snappy.PureJavaCrc32C

All Implemented Interfaces:

Checksum

final 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.

This file is a copy of the implementation at the Apache Hadoop project.

Since:

1.7

See Also:

• "https://svn.apache.org/repos/asf/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PureJavaCrc32C.java"

Field Summary

Fields

Modifier and Type	Field	Description
private int	crc	the current CRC value, bit-flipped
private static final int[]	T
private static final int	T8_0_START
private static final int	T8_1_START
private static final int	T8_2_START
private static final int	T8_3_START
private static final int	T8_4_START
private static final int	T8_5_START
private static final int	T8_6_START
private static final 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()	Called by ctor but the class is final so this is safe.
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

Field Details

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

crc

private int crc

the current CRC value, bit-flipped

Constructor Details

PureJavaCrc32C

public PureJavaCrc32C()

Create a new PureJavaCrc32 object.

Method Details

getValue

public long getValue()

Specified by:

getValue in interface Checksum

reset

public void reset()

Called by ctor but the class is final so this is safe.

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