Package org.apache.commons.codec.digest

Class PureJavaCrc32

java.lang.Object

org.apache.commons.codec.digest.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 Copied from Hadoop 2.6.3. The code agrees with the following file in the 2.6.3 tag: 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/PureJavaCrc32.java; hb=2120de588b92b9f22b1cc4188761d6a8c61aa778

This class is Not ThreadSafe

Since:

1.11

See Also:

CRC32

Constructor Summary

Constructors

Constructor	Description
PureJavaCrc32()	Create a new PureJavaCrc32 object.

Method Summary

Modifier and Type	Method	Description
long	getValue()
void	reset()
void	update(byte[] b, int offset, int len)
void	update(int b)

Methods inherited from interface java.util.zip.Checksum

update, update

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

reset

public void reset()

Specified by:

reset in interface java.util.zip.Checksum

update

public void update(byte[] b,
                   int offset,
                   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