org.apache.hive.common.util

Class Murmur3

java.lang.Object

org.apache.hive.common.util.Murmur3

public class Murmur3
extends Object

Murmur3 is successor to Murmur2 fast non-crytographic hash algorithms. Murmur3 32 and 128 bit variants. 32-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#94 128-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#255 This is a public domain code with no copyrights. From homepage of MurmurHash (https://code.google.com/p/smhasher/), "All MurmurHash versions are public domain software, and the author disclaims all copyright to their code."

Field Summary

Fields

Modifier and Type	Field and Description
static long	NULL_HASHCODE

Constructor Summary

Constructors

Constructor and Description
Murmur3()

Method Summary

Methods

Modifier and Type	Method and Description
static long[]	hash128(byte[] data) Murmur3 128-bit variant.
static long[]	hash128(byte[] data, int length, int seed) Murmur3 128-bit variant.
static int	hash32(byte[] data) Murmur3 32-bit variant.
static int	hash32(byte[] data, int length, int seed) Murmur3 32-bit variant.
static long	hash64(byte[] data) Murmur3 64-bit variant.
static long	hash64(byte[] data, int length)
static long	hash64(byte[] data, int length, int seed) Murmur3 64-bit variant.

Methods inherited from class java.lang.Object

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

Field Detail

NULL_HASHCODE

public static final long NULL_HASHCODE

See Also:

Constant Field Values

Constructor Detail

Murmur3

public Murmur3()

Method Detail

hash32

public static int hash32(byte[] data)

Murmur3 32-bit variant.

Parameters:

data - - input byte array

Returns:

- hashcode

hash32

public static int hash32(byte[] data,
         int length,
         int seed)

Murmur3 32-bit variant.

Parameters:

data - - input byte array

length - - length of array

seed - - seed. (default 0)

Returns:

- hashcode

hash64

public static long hash64(byte[] data)

Murmur3 64-bit variant. This is essentially MSB 8 bytes of Murmur3 128-bit variant.

Parameters:

data - - input byte array

Returns:

- hashcode

hash64

public static long hash64(byte[] data,
          int length)

hash64

public static long hash64(byte[] data,
          int length,
          int seed)

Murmur3 64-bit variant. This is essentially MSB 8 bytes of Murmur3 128-bit variant.

Parameters:

data - - input byte array

length - - length of array

seed - - seed. (default is 0)

Returns:

- hashcode

hash128

public static long[] hash128(byte[] data)

Murmur3 128-bit variant.

Parameters:

data - - input byte array

Returns:

- hashcode (2 longs)

hash128

public static long[] hash128(byte[] data,
             int length,
             int seed)

Murmur3 128-bit variant.

Parameters:

data - - input byte array

length - - length of array

seed - - seed. (default is 0)

Returns:

- hashcode (2 longs)