org.semanticweb.elk.util.collections

Class ArraySlicedSet<E>

java.lang.Object

org.semanticweb.elk.util.collections.ArraySlicedSet<E>

Type Parameters:

E - the type of the elements in the sets

public class ArraySlicedSet<E>
extends Object

A compact representation of several sets (called "slices") that can share many elements. The representation is backed by arrays that store the elements and numerical masks that encode to which sets those elements belong to. The membership is checked using hash values of elements with linear probing to resolve hash collisions: see [1] p.526. Parts of the code are inspired by the implementation of HashMap. [1] Donald E. Knuth, The Art of Computer Programming, Volume 3, Sorting and Searching, Second Edition

Author:

Yevgeny Kazakov

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_SLICES the maximal number of slices that can be stored in a ArraySlicedSet

Constructor Summary

Constructors

Constructor and Description
ArraySlicedSet(int slices)
ArraySlicedSet(int slices, int initialCapacity)

Method Summary

Modifier and Type	Method and Description
boolean	add(int s, E e) Inserts a given element into the given slice
void	clear() Clears all slices of this ArraySlicedSet.
boolean	contains(int s, Object o)
Set<E>	getSlice(int s)
boolean	isEmpty(int s)
boolean	remove(int s, Object o) Removes the given object from the given slice
boolean	removeAll(int s, Collection<?> c) Removes all element of the given Collection from the given slice
int	size(int s)

Methods inherited from class java.lang.Object

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

Field Detail

MAX_SLICES

public static int MAX_SLICES

the maximal number of slices that can be stored in a ArraySlicedSet

Constructor Detail

ArraySlicedSet

public ArraySlicedSet(int slices,
                      int initialCapacity)

ArraySlicedSet

public ArraySlicedSet(int slices)

Method Detail

size

public int size(int s)

Parameters:

s - the slice id

Returns:

the number of elements currently stored in the provided slice

isEmpty

public boolean isEmpty(int s)

Parameters:

s - the slice id

Returns:

true if the given slice does not contain any elements and false otherwise

contains

public boolean contains(int s,
                        Object o)

add

public boolean add(int s,
                   E e)

Inserts a given element into the given slice

Parameters:

s - the slice id

e - the elements to be inserted in to the given slice

Returns:

true if the given element did not occur in the given slice and thus was inserted. Otherwise false is returned and nothing is modified.

remove

public boolean remove(int s,
                      Object o)

Removes the given object from the given slice

Parameters:

s - the slice id

o - the object that should be removed from the given slice

Returns:

true if the given object is equal to some element of the given slice; this element will be removed from the slice. If there is no such an object, false is returned and nothing is modified

removeAll

public boolean removeAll(int s,
                         Collection<?> c)

Removes all element of the given Collection from the given slice

Parameters:

s - the slice id

c - the collection whose elements should be removed

Returns:

true if at least one element is removed from the slice. An element is removed if an equal element is present in the given collection. If no elements are removed, false is returned and nothing is modified.

clear

public void clear()

Clears all slices of this ArraySlicedSet. After calling this methods, all slices are empty.

getSlice

public Set<E> getSlice(int s)

Parameters:

s - the slice id

Returns:

the set corresponding to this slice backed by this ArraySlicedSet; it can be modified