org.apache.cassandra.utils

Class PureJavaCrc32

java.lang.Object

org.apache.cassandra.utils.PureJavaCrc32

All Implemented Interfaces:

java.util.zip.Checksum

public class PureJavaCrc32
extends java.lang.Object
implements java.util.zip.Checksum

A pure-java implementation of the CRC32 checksum that uses the same polynomial as the built-in native CRC32. This is to avoid the JNI overhead for certain uses of Checksumming where many small pieces of data are checksummed in succession. The current version is ~10x to 1.8x as fast as Sun's native java.util.zip.CRC32 in Java 1.6

See Also:

This class is copied from hadoop-commons project and retains that formatting. (The initial patch added PureJavaCrc32 was HADOOP-6148)

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
int	getCrc()
long	getValue()
void	reset()
void	update(byte[] b, int off, int len)
void	update(java.nio.ByteBuffer b, int off, int len)
void	update(int b)
void	updateInt(int v)

Methods inherited from class java.lang.Object

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

Constructor Detail

PureJavaCrc32

public PureJavaCrc32()

Create a new PureJavaCrc32 object.

Method Detail

getValue

public long getValue()

Specified by:

getValue in interface java.util.zip.Checksum

getCrc

public int getCrc()

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 void update(java.nio.ByteBuffer b,
                   int off,
                   int len)

update

public final void update(int b)

Specified by:

update in interface java.util.zip.Checksum

updateInt

public final void updateInt(int v)