com.helger.commons.collection.lru

Class LRUSet<ELEMENTTYPE>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractSet<ELEMENTTYPE>

com.helger.commons.collection.lru.LRUSet<ELEMENTTYPE>

Type Parameters:

ELEMENTTYPE - Element type

All Implemented Interfaces:

Serializable, Iterable<ELEMENTTYPE>, Collection<ELEMENTTYPE>, Set<ELEMENTTYPE>

@NotThreadSafe
 @UseDirectEqualsAndHashCode
public class LRUSet<ELEMENTTYPE>
extends AbstractSet<ELEMENTTYPE>
implements Serializable

A special ordered set, that has an upper limit of contained elements. It is therefore a "Last Recently Used" cache.
The underlying data structure is a LRUMap map.

Author:

Philip Helger

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LRUSet(int nMaxSize)

Method Summary

Modifier and Type	Method and Description
boolean	add(ELEMENTTYPE aItem)
boolean	equals(Object o)
int	getMaxSize()
int	hashCode()
Iterator<ELEMENTTYPE>	iterator()
protected void	onRemoveEldestEntry(int nSize, ELEMENTTYPE aEldest) Protected method that is invoked every time an element is removed from the cache, because the maximum size is exceeded.
int	size()
String	toString()

Methods inherited from class java.util.AbstractSet

removeAll

Methods inherited from class java.util.AbstractCollection

addAll, clear, contains, containsAll, isEmpty, remove, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

addAll, clear, contains, containsAll, isEmpty, remove, retainAll, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

LRUSet

public LRUSet(@Nonnegative
              int nMaxSize)

Method Detail

onRemoveEldestEntry

@OverrideOnDemand
protected void onRemoveEldestEntry(@Nonnegative
                                                      int nSize,
                                                      @Nonnull
                                                      ELEMENTTYPE aEldest)

Protected method that is invoked every time an element is removed from the cache, because the maximum size is exceeded.

Parameters:

nSize - Current size of the map. Always ≥ 0.

aEldest - The entry that is to be removed. Never null.

getMaxSize

@Nonnegative
public final int getMaxSize()

Returns:

The maximum number of elements that can reside in this cache.

add

public boolean add(@Nullable
                   ELEMENTTYPE aItem)

Specified by:

add in interface Collection<ELEMENTTYPE>

Specified by:

add in interface Set<ELEMENTTYPE>

Overrides:

add in class AbstractCollection<ELEMENTTYPE>

iterator

@Nonnull
public Iterator<ELEMENTTYPE> iterator()

Specified by:

iterator in interface Iterable<ELEMENTTYPE>

Specified by:

iterator in interface Collection<ELEMENTTYPE>

Specified by:

iterator in interface Set<ELEMENTTYPE>

Specified by:

iterator in class AbstractCollection<ELEMENTTYPE>

size

@Nonnegative
public int size()

Specified by:

size in interface Collection<ELEMENTTYPE>

Specified by:

size in interface Set<ELEMENTTYPE>

Specified by:

size in class AbstractCollection<ELEMENTTYPE>

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection<ELEMENTTYPE>

Specified by:

equals in interface Set<ELEMENTTYPE>

Overrides:

equals in class AbstractSet<ELEMENTTYPE>

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<ELEMENTTYPE>

Specified by:

hashCode in interface Set<ELEMENTTYPE>

Overrides:

hashCode in class AbstractSet<ELEMENTTYPE>

toString

public String toString()

Overrides:

toString in class AbstractCollection<ELEMENTTYPE>