it.cnr.isti.hpc.hash

Class MurmurHash3

java.lang.Object

it.cnr.isti.hpc.hash.MurmurHash3

All Implemented Interfaces:

Hash

public class MurmurHash3
extends Object
implements Hash

MurmurHash3 implementation in Java, based on Austin Appleby's original in C Only implementing x64 version, because this should always be faster on 64 bit native processors, even 64 bit being ran with a 32 bit OS; this should also be as fast or faster than the x86 version on some modern 32 bit processors.

Since:

5.0

Author:

Patrick McFarland

See Also:

MurmurHash website, MurmurHash entry on Wikipedia

Constructor Summary

Constructors

Constructor and Description
MurmurHash3()

Method Summary

Methods

Modifier and Type	Method and Description
int	hash(byte[] payload)
int	hash(int hashcode)
int	hash(long[] payload) Hashes a byte array efficiently.
int	hash(Object o)
long	hashLong(byte[] payload)
long	hashLong(long hashcode)
long	hashLong(long[] payload)
long	hashLong(Object o)
static long[]	MurmurHash3_x64_128(byte[] key, int seed) Hash a value using the x64 128 bit variant of MurmurHash3
static long[]	MurmurHash3_x64_128(long[] key, int seed) Hash a value using the x64 128 bit variant of MurmurHash3
static int	MurmurHash3_x64_32(byte[] key, int seed) Hash a value using the x64 32 bit variant of MurmurHash3
static int	MurmurHash3_x64_32(long[] key, int seed) Hash a value using the x64 32 bit variant of MurmurHash3
static long	MurmurHash3_x64_64(byte[] key, int seed) Hash a value using the x64 64 bit variant of MurmurHash3
static long	MurmurHash3_x64_64(long[] key, int seed) Hash a value using the x64 64 bit variant of MurmurHash3

Methods inherited from class java.lang.Object

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

Constructor Detail

MurmurHash3

public MurmurHash3()

Method Detail

MurmurHash3_x64_128

public static long[] MurmurHash3_x64_128(byte[] key,
                         int seed)

Hash a value using the x64 128 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

128 bit hashed key, in an array containing two longs

MurmurHash3_x64_64

public static long MurmurHash3_x64_64(byte[] key,
                      int seed)

Hash a value using the x64 64 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

64 bit hashed key

MurmurHash3_x64_32

public static int MurmurHash3_x64_32(byte[] key,
                     int seed)

Hash a value using the x64 32 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

32 bit hashed key

MurmurHash3_x64_128

public static long[] MurmurHash3_x64_128(long[] key,
                         int seed)

Hash a value using the x64 128 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

128 bit hashed key, in an array containing two longs

MurmurHash3_x64_64

public static long MurmurHash3_x64_64(long[] key,
                      int seed)

Hash a value using the x64 64 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

64 bit hashed key

MurmurHash3_x64_32

public static int MurmurHash3_x64_32(long[] key,
                     int seed)

Hash a value using the x64 32 bit variant of MurmurHash3

Parameters:

key - value to hash

seed - random value

Returns:

32 bit hashed key

hash

public int hash(byte[] payload)

hashLong

public long hashLong(byte[] payload)

hash

public int hash(long[] payload)

Hashes a byte array efficiently.

Parameters:

payload - a byte array to hash

Returns:

a hash code for the byte array

hashLong

public long hashLong(long[] payload)

hash

public int hash(int hashcode)

hashLong

public long hashLong(long hashcode)

hash

public int hash(Object o)

Specified by:

hash in interface Hash

hashLong

public long hashLong(Object o)

Specified by:

hashLong in interface Hash