Package tools.refinery.store.model

Class TupleHashProvider

java.lang.Object

tools.refinery.store.model.TupleHashProvider

All Implemented Interfaces:

ContinuousHashProvider<Tuple>

public class TupleHashProvider
extends Object
implements ContinuousHashProvider<Tuple>

Field Summary

Fields

Modifier and Type	Field	Description
static final TupleHashProvider	INSTANCE
protected static final int	LARGEST_BINARY_INDEX_1
protected static final int	LARGEST_PRIME_30_BITS_INTEGER
protected static final long	LARGEST_PRIME_30_BITS_LONG
static final int	MAX_MODEL_SIZE
protected static final int[]	primes

Fields inherited from interface tools.refinery.store.map.ContinuousHashProvider

EFFECTIVE_BIT_MASK, EFFECTIVE_BITS, MAX_PRACTICAL_DEPTH

Constructor Summary

Constructors

Constructor	Description
TupleHashProvider()

Method Summary

Modifier and Type	Method	Description
int	getHash(Tuple key, int index)	Provides a hash code for a object key with a given index.

Methods inherited from class java.lang.Object

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

Methods inherited from interface tools.refinery.store.map.ContinuousHashProvider

compare, getEffectiveHash

Field Details

primes

protected static final int[] primes

LARGEST_PRIME_30_BITS_LONG

protected static final long LARGEST_PRIME_30_BITS_LONG

See Also:

• Constant Field Values

LARGEST_PRIME_30_BITS_INTEGER

protected static final int LARGEST_PRIME_30_BITS_INTEGER

See Also:

• Constant Field Values

LARGEST_BINARY_INDEX_1

protected static final int LARGEST_BINARY_INDEX_1

See Also:

• Constant Field Values

MAX_MODEL_SIZE

public static final int MAX_MODEL_SIZE

See Also:

• Constant Field Values

INSTANCE

public static final TupleHashProvider INSTANCE

Constructor Details

TupleHashProvider

public TupleHashProvider()

Method Details

getHash

public int getHash(Tuple key,
 int index)

Description copied from interface: ContinuousHashProvider

Provides a hash code for a object key with a given index. It has the following contracts:

• If equals(key1, key2), then getHash(key1, index) == getHash(key2, index) for all values of index.
• If getHash(key1,index) == getHash(key2, index) for all values of index, then equals(key1, key2)
• In current implementation, we use only the least significant ContinuousHashProvider.EFFECTIVE_BITS

Check Object.equals(Object) for further details.

Specified by:

getHash in interface ContinuousHashProvider<Tuple>

Parameters:

key - The target data object.

index - The depth of the hash code. Needs to be non-negative.

Returns:

A hash code.