Package nl.tue.storage.hashing.impl

Class AdHashHashCodeProvider

java.lang.Object

nl.tue.storage.hashing.impl.AdHashHashCodeProvider

All Implemented Interfaces:

HashCodeProvider, IncrementalHashCodeProvider

public class AdHashHashCodeProvider
extends java.lang.Object
implements IncrementalHashCodeProvider

The AdHashHashCodeProvider is an incremental hash function, loosely based on the MurMur3 hash function. The idea comes from "M. Bellare, and D. Micciancio, "A new paradigm for collision-free hashing: Incrementality at reduced cost, Advances in Cryptology - EUROCRYPT'97, Lecture Notes in Computer Science, 1233, pp.163- 192, Springer-Verlag, 1997."

Author:

bfvdonge

Field Summary

Fields

Modifier and Type	Field	Description
static int	C1
static int	C2
static int	INIT

Constructor Summary

Constructors

Constructor	Description
AdHashHashCodeProvider()

Method Summary

Modifier and Type	Method	Description
protected int	h(int idx, int s)
protected int	h(int idx, short s)
int	hash(int[]... sets)
int	hash(short[]... sets)
int	hash(ShortShortMultiset... sets)
java.lang.String	toString()
int	updateHash(int oldHash, int idx, int oldVal, int newVal)	Updates the old hash value and returns the new one, assuming that the value at index idx was changed from oldVal to newVal.
int	updateHash(int oldHash, int idx, short oldVal, short newVal)	Updates the old hash value and returns the new one, assuming that the value at index idx was changed from oldVal to newVal.

Methods inherited from class java.lang.Object

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

Field Detail

INIT

public static final int INIT

See Also:

Constant Field Values

C1

public static final int C1

See Also:

Constant Field Values

C2

public static final int C2

See Also:

Constant Field Values

Constructor Detail

AdHashHashCodeProvider

public AdHashHashCodeProvider()

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

hash

public int hash(ShortShortMultiset... sets)

Specified by:

hash in interface HashCodeProvider

hash

public int hash(short[]... sets)

Specified by:

hash in interface HashCodeProvider

h

protected int h(int idx,
                short s)

h

protected int h(int idx,
                int s)

hash

public int hash(int[]... sets)

Specified by:

hash in interface HashCodeProvider

updateHash

public int updateHash(int oldHash,
                      int idx,
                      short oldVal,
                      short newVal)

Description copied from interface: IncrementalHashCodeProvider

Updates the old hash value and returns the new one, assuming that the value at index idx was changed from oldVal to newVal. Note that idx should be an index into the concatenation of the arrays previously provided in the call to hash().

Specified by:

updateHash in interface IncrementalHashCodeProvider

Returns:

updateHash

public int updateHash(int oldHash,
                      int idx,
                      int oldVal,
                      int newVal)

Description copied from interface: IncrementalHashCodeProvider

Updates the old hash value and returns the new one, assuming that the value at index idx was changed from oldVal to newVal. Note that idx should be an index into the concatenation of the arrays previously provided in the call to hash().

Specified by:

updateHash in interface IncrementalHashCodeProvider

Returns: