org.glassfish.hk2.utilities.general.internal

Class WeakHashLRUImpl<K>

java.lang.Object

org.glassfish.hk2.utilities.general.internal.WeakHashLRUImpl<K>

All Implemented Interfaces:

WeakHashLRU<K>

public class WeakHashLRUImpl<K>
extends Object
implements WeakHashLRU<K>

An implementation of the WeakHashLRU as needed by the CAR algorithm

Author:

jwells

Constructor Summary

Constructors

Constructor and Description
WeakHashLRUImpl(boolean isWeak)

Method Summary

Methods

Modifier and Type	Method and Description
void	add(K key) Adds the given key to the LRU.
void	clear() Removes all entries from this LRU
void	clearStaleReferences() Causes stale references to be cleared from the data structures.
boolean	contains(K key) Tells if the given key is in the LRU
void	releaseMatching(CacheKeyFilter<K> filter) Releases all keys that match the filter
K	remove() Removes the key that was Least Recently Used
boolean	remove(K key) Removes the given key from the LRU, if found
int	size() Returns the number of elements currently in the clock.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

WeakHashLRUImpl

public WeakHashLRUImpl(boolean isWeak)

Method Detail

add

public void add(K key)

Description copied from interface: WeakHashLRU

Adds the given key to the LRU. It will be placed at the MRU of the LRU. If this key already exists in the LRU it will be moved to the MRU

Specified by:

add in interface WeakHashLRU<K>

Parameters:

key - Must not be null

contains

public boolean contains(K key)

Description copied from interface: WeakHashLRU

Tells if the given key is in the LRU

Specified by:

contains in interface WeakHashLRU<K>

Parameters:

key - The key to search for, may not be null

Returns:

true if found, false otherwise

remove

public boolean remove(K key)

Description copied from interface: WeakHashLRU

Removes the given key from the LRU, if found

Specified by:

remove in interface WeakHashLRU<K>

Parameters:

key - The key to remove, may not be null

Returns:

true if removed, false otherwise

size

public int size()

Description copied from interface: WeakHashLRU

Returns the number of elements currently in the clock. References that have gone away because they were weakly referenced will not be counted in the size

Specified by:

size in interface WeakHashLRU<K>

Returns:

The number of entries currently in the LRU

remove

public K remove()

Description copied from interface: WeakHashLRU

Removes the key that was Least Recently Used

Specified by:

remove in interface WeakHashLRU<K>

Returns:

The key that was removed, or null if the list is empty

releaseMatching

public void releaseMatching(CacheKeyFilter<K> filter)

Description copied from interface: WeakHashLRU

Releases all keys that match the filter

Specified by:

releaseMatching in interface WeakHashLRU<K>

Parameters:

filter - A non-null filter that can be used to delete every key that matches the filter

clear

public void clear()

Description copied from interface: WeakHashLRU

Removes all entries from this LRU

Specified by:

clear in interface WeakHashLRU<K>

clearStaleReferences

public void clearStaleReferences()

Description copied from interface: WeakHashLRU

Causes stale references to be cleared from the data structures. Since this is a weak clock the references can go away at any time, which happens whenever any operation has been performed. However, it may be the case that no operation will be performed for a while and so this method is provided to have a no-op operation to call in order to clear out any stale references

Specified by:

clearStaleReferences in interface WeakHashLRU<K>

toString

public String toString()

Overrides:

toString in class Object