de.bb.util

Class TinyIdentitySet<T>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractSet<T>

de.bb.util.TinyIdentitySet<T>

Type Parameters:

T -

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<T>, java.util.Collection<T>, java.util.Set<T>

public class TinyIdentitySet<T>
extends java.util.AbstractSet<T>
implements java.io.Serializable

A set with as few as possible memory usage. Preferred usage: If you need many sets which are close to empty or are read (iterated) way more than written (add/remove). Benefits:

• iterator is 4-5 times faster than hash set iterator
• contains with 2 elements 50% faster, 7-8 elements the speed is similar

Drawbacks:

• add/remove is slower, 5-25% (total size 2-10)

So use it only if it fits.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TinyIdentitySet()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(T added)
void	clear()
boolean	contains(java.lang.Object o)
boolean	isEmpty()
java.util.Iterator<T>	iterator()
boolean	remove(java.lang.Object o)
int	size()
java.lang.Object[]	toArray()
<T> T[]	toArray(T[] array)

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, retainAll, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

addAll, containsAll, retainAll

Constructor Detail

TinyIdentitySet

public TinyIdentitySet()

Method Detail

size

public int size()

Specified by:

size in interface java.util.Collection<T>

Specified by:

size in interface java.util.Set<T>

Specified by:

size in class java.util.AbstractCollection<T>

See Also:

Set.size()

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<T>

Specified by:

isEmpty in interface java.util.Set<T>

Overrides:

isEmpty in class java.util.AbstractCollection<T>

See Also:

Set.isEmpty()

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection<T>

Specified by:

contains in interface java.util.Set<T>

Overrides:

contains in class java.util.AbstractCollection<T>

See Also:

Set.contains(Object)

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<T>

Specified by:

toArray in interface java.util.Set<T>

Overrides:

toArray in class java.util.AbstractCollection<T>

See Also:

Set.toArray()

toArray

public <T> T[] toArray(T[] array)

Specified by:

toArray in interface java.util.Collection<T>

Specified by:

toArray in interface java.util.Set<T>

Overrides:

toArray in class java.util.AbstractCollection<T>

See Also:

Set.toArray(Object[])

add

public boolean add(T added)

Specified by:

add in interface java.util.Collection<T>

Specified by:

add in interface java.util.Set<T>

Overrides:

add in class java.util.AbstractCollection<T>

See Also:

Set.add(Object)

remove

public boolean remove(java.lang.Object o)

Specified by:

remove in interface java.util.Collection<T>

Specified by:

remove in interface java.util.Set<T>

Overrides:

remove in class java.util.AbstractCollection<T>

See Also:

Set.remove(Object)

clear

public void clear()

Specified by:

clear in interface java.util.Collection<T>

Specified by:

clear in interface java.util.Set<T>

Overrides:

clear in class java.util.AbstractCollection<T>

See Also:

Set.clear()

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T>

Specified by:

iterator in interface java.util.Collection<T>

Specified by:

iterator in interface java.util.Set<T>

Specified by:

iterator in class java.util.AbstractCollection<T>

See Also:

Set.iterator()