Package tools.refinery.store.map

Interface ContinuousHashProvider<K>

Type Parameters:

K - Target java type.

All Known Implementing Classes:

TupleHashProvider

public interface ContinuousHashProvider<K>

A class representing an equivalence relation for a type K with a continuous hash function.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	EFFECTIVE_BIT_MASK
static final int	EFFECTIVE_BITS
static final int	MAX_PRACTICAL_DEPTH	Maximal practical depth for differentiating keys.

Method Summary

Modifier and Type	Method	Description
default int	compare(K key1, K key2)
default int	getEffectiveHash(K key, int index)
int	getHash(K key, int index)	Provides a hash code for a object key with a given index.

Field Details

EFFECTIVE_BITS

static final int EFFECTIVE_BITS

See Also:

• Constant Field Values

EFFECTIVE_BIT_MASK

static final int EFFECTIVE_BIT_MASK

See Also:

• Constant Field Values

MAX_PRACTICAL_DEPTH

static final int MAX_PRACTICAL_DEPTH

Maximal practical depth for differentiating keys. If two keys have the same hash code until that depth, the algorithm can stop.

See Also:

• Constant Field Values

Method Details

getHash

int getHash(K key,
 int index)

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 EFFECTIVE_BITS

Check Object.equals(Object) for further details.

Parameters:

key - The target data object.

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

Returns:

A hash code.

getEffectiveHash

default int getEffectiveHash(K key,
 int index)

compare

default int compare(K key1,
 K key2)