org.apache.commons.codec.digest

Class XXHash32

java.lang.Object

org.apache.commons.codec.digest.XXHash32

All Implemented Interfaces:

java.util.zip.Checksum

public class XXHash32
extends java.lang.Object
implements java.util.zip.Checksum

Implementation of the xxhash32 hash algorithm.

Copied from Commons Compress 1.14 https://git-wip-us.apache.org/repos/asf?p=commons-compress.git;a=blob;f=src/main/java/org/apache/commons/compress/compressors/lz4/XXHash32.java;h=a406ffc197449be594d46f0d2712b2d4786a1e68;hb=HEAD

NotThreadSafe

Since:

1.11

See Also:

xxHash

Field Summary

Fields

Modifier and Type	Field and Description
private static int	BUF_SIZE
private byte[]	buffer
private byte[]	oneByte
private int	pos
private static int	PRIME1
private static int	PRIME2
private static int	PRIME3
private static int	PRIME4
private static int	PRIME5
private static int	ROTATE_BITS
private int	seed
private int[]	state
private int	totalLen

Constructor Summary

Constructors

Constructor and Description
XXHash32() Creates an XXHash32 instance with a seed of 0.
XXHash32(int seed) Creates an XXHash32 instance.

Method Summary

Modifier and Type	Method and Description
private static long	fromLittleEndian(byte[] bytes, int off, int length) Reads the given byte array as a little endian long.
private static int	getInt(byte[] buffer, int idx)
long	getValue()
private void	initializeState()
private void	process(byte[] b, int offset)
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

Field Detail

BUF_SIZE

private static final int BUF_SIZE

See Also:

Constant Field Values

ROTATE_BITS

private static final int ROTATE_BITS

See Also:

Constant Field Values

PRIME1

private static final int PRIME1

See Also:

Constant Field Values

PRIME2

private static final int PRIME2

See Also:

Constant Field Values

PRIME3

private static final int PRIME3

See Also:

Constant Field Values

PRIME4

private static final int PRIME4

See Also:

Constant Field Values

PRIME5

private static final int PRIME5

See Also:

Constant Field Values

oneByte

private final byte[] oneByte

state

private final int[] state

buffer

private final byte[] buffer

seed

private final int seed

totalLen

private int totalLen

pos

private int pos

Constructor Detail

XXHash32

public XXHash32()

Creates an XXHash32 instance with a seed of 0.

XXHash32

public XXHash32(int seed)

Creates an XXHash32 instance.

Parameters:

seed - the seed to use

Method Detail

reset

public void reset()

Specified by:

reset in interface java.util.zip.Checksum

update

public void update(int b)

Specified by:

update 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

getValue

public long getValue()

Specified by:

getValue in interface java.util.zip.Checksum

getInt

private static int getInt(byte[] buffer,
                          int idx)

initializeState

private void initializeState()

process

private void process(byte[] b,
                     int offset)

fromLittleEndian

private static long fromLittleEndian(byte[] bytes,
                                     int off,
                                     int length)

Reads the given byte array as a little endian long.

Parameters:

bytes - the byte array to convert

off - the offset into the array that starts the value

length - the number of bytes representing the value

Returns:

the number read

Throws:

java.lang.IllegalArgumentException - if len is bigger than eight