org.getopt.util.hash
Class FNV1a32

java.lang.Object
  org.getopt.util.hash.FNV1
      org.getopt.util.hash.FNV1a32

public class FNV1a32
extends FNV1

Implementation of FNV1a - a fast hash function. The FNV1a variant provides a slightly better dispersion for short (< 4 bytes) values than plain FNV1.

This implementation uses 32-bit operations, and the values returned from getHash() are limited to the lower 32 bits.

Author:

Andrzej Bialecki <ab@getopt.org>

Field Summary

Fields inherited from class org.getopt.util.hash.FNV1

FNV1_32_INIT, FNV1_64_INIT, hash, INIT

Constructor Summary

FNV1a32()
Create a hash

Method Summary

protected long	fnv(byte[] buf, int offset, int len, long seed) Compute the hash value.
long	getHash() Retrieve the hash value

Methods inherited from class org.getopt.util.hash.FNV1

init, init, update, update

Methods inherited from class java.lang.Object

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

Constructor Detail

FNV1a32

public FNV1a32()

Create a hash

Method Detail

getHash

public long getHash()

Description copied from class: FNV1

Retrieve the hash value

Overrides:

getHash in class FNV1

Returns:

hash value

fnv

protected long fnv(byte[] buf,
                   int offset,
                   int len,
                   long seed)

Description copied from class: FNV1

Compute the hash value.

Specified by:

fnv in class FNV1

Parameters:

buf - byte buffer from which to compute the hash

offset - starting position in the buffer

len - number of bytes after the starting position

seed - initial seed (or previous hash value)

Returns:

the next hash value