org.apache.ignite.internal.processors.cache.persistence.wal.crc

Class PureJavaCrc32

java.lang.Object

org.apache.ignite.internal.processors.cache.persistence.wal.crc.PureJavaCrc32

public class PureJavaCrc32
extends Object

This class was taken from Hadoop org.apache.hadoop.util.PureJavaCrc32 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

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
static int	calcCrc32(ByteBuffer b, int len) Calculates CRC32 checksum.
int	getValue() return crc32 value
void	reset() preparation for further calculations
void	update(ByteBuffer b, 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

PureJavaCrc32

public PureJavaCrc32()

Create a new PureJavaCrc32 object.

Method Detail

getValue

public int getValue()

return crc32 value

reset

public void reset()

preparation for further calculations

update

public void update(ByteBuffer b,
          int len)

Parameters:

b - B.

len - Length.

update

public final void update(int b)

Parameters:

b - B.

calcCrc32

public static int calcCrc32(ByteBuffer b,
            int len)

Calculates CRC32 checksum. This method will move buffer's position to len bytes forward.

Parameters:

b - B.

len - Length.