Package org.apache.hive.common.util

Class Murmur3

java.lang.Object

org.apache.hive.common.util.Murmur3

public class Murmur3
extends java.lang.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."

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Murmur3.IncrementalHash32

Field Summary

Fields

Modifier and Type	Field	Description
private static long	C1
private static int	C1_32
private static long	C2
private static int	C2_32
static int	DEFAULT_SEED
private static int	M
private static int	M_32
private static int	N_32
private static int	N1
private static int	N2
static long	NULL_HASHCODE
private static int	R1
private static int	R1_32
private static int	R2
private static int	R2_32
private static int	R3

Constructor Summary

Constructors

Constructor	Description
Murmur3()

Method Summary

Modifier and Type	Method	Description
private static int	fmix32(int length, int hash)
private static long	fmix64(long h)
static long[]	hash128(byte[] data)	Murmur3 128-bit variant.
static long[]	hash128(byte[] data, int offset, int length, int seed)	Murmur3 128-bit variant.
static int	hash32(byte[] data)	Murmur3 32-bit variant.
static int	hash32(byte[] data, int length)	Murmur3 32-bit variant.
static int	hash32(byte[] data, int length, int seed)	Murmur3 32-bit variant.
static int	hash32(byte[] data, int offset, int length, int seed)	Murmur3 32-bit variant.
static int	hash32(long l0)
static int	hash32(long l0, int seed)	Murmur3 32-bit variant.
static int	hash32(long l0, long l1)
static int	hash32(long l0, long l1, int seed)	Murmur3 32-bit variant.
static long	hash64(byte[] data)	Murmur3 64-bit variant.
static long	hash64(byte[] data, int offset, int length)
static long	hash64(byte[] data, int offset, int length, int seed)	Murmur3 64-bit variant.
static long	hash64(int data)
static long	hash64(long data)
static long	hash64(short data)
private static int	mix32(int k, int hash)
private static int	orBytes(byte b1, byte b2, byte b3, byte b4)

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

C1_32

private static final int C1_32

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Constant Field Values

C2_32

private static final int C2_32

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Constant Field Values

R1_32

private static final int R1_32

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Constant Field Values

R2_32

private static final int R2_32

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Constant Field Values

M_32

private static final int M_32

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Constant Field Values

N_32

private static final int N_32

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Constant Field Values

C1

private static final long C1

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Constant Field Values

C2

private static final long C2

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Constant Field Values

R1

private static final int R1

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Constant Field Values

R2

private static final int R2

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Constant Field Values

R3

private static final int R3

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Constant Field Values

M

private static final int M

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Constant Field Values

N1

private static final int N1

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Constant Field Values

N2

private static final int N2

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Constant Field Values

DEFAULT_SEED

public static final int DEFAULT_SEED

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Constant Field Values

Constructor Detail

Murmur3

public Murmur3()

Method Detail

hash32

public static int hash32(long l0,
                         long l1)

hash32

public static int hash32(long l0)

hash32

public static int hash32(long l0,
                         int seed)

Murmur3 32-bit variant.

hash32

public static int hash32(long l0,
                         long l1,
                         int seed)

Murmur3 32-bit variant.

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)

Murmur3 32-bit variant.

Parameters:

data - - input byte array

length - - length of 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

hash32

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

Murmur3 32-bit variant.

Parameters:

data - - input byte array

offset - - offset of data

length - - length of array

seed - - seed. (default 0)

Returns:

- hashcode

mix32

private static int mix32(int k,
                         int hash)

fmix32

private static int fmix32(int length,
                          int hash)

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(long data)

hash64

public static long hash64(int data)

hash64

public static long hash64(short data)

hash64

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

hash64

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

Murmur3 128-bit variant.

Parameters:

data - - input byte array

offset - - the first element of array

length - - length of array

seed - - seed. (default is 0)

Returns:

- hashcode (2 longs)

fmix64

private static long fmix64(long h)

orBytes

private static int orBytes(byte b1,
                           byte b2,
                           byte b3,
                           byte b4)