org.jboss.cache.eviction
Class LRUAlgorithm

java.lang.Object
  org.jboss.cache.eviction.BaseEvictionAlgorithm
      org.jboss.cache.eviction.LRUAlgorithm

All Implemented Interfaces:

EvictionAlgorithm

Direct Known Subclasses:

AopLRUAlgorithm

public class LRUAlgorithm

extends BaseEvictionAlgorithm

implements EvictionAlgorithm

Least recently Used algorithm to purge old data. Note that this algorithm is not thread-safe.

Author:

Ben Wang 02-2004, Daniel Huang - dhuang@jboss.org

Field Summary

Fields inherited from class org.jboss.cache.eviction.BaseEvictionAlgorithm

evictionQueue, recycleQueue, region

Constructor Summary

LRUAlgorithm()

Method Summary

protected void	prune()
protected EvictionQueue	setupEvictionQueue(Region region) This method will create an EvictionQueue implementation and prepare it for use.
protected boolean	shouldEvictNode(NodeEntry entry) This method will check whether the given node should be evicted or not.

Methods inherited from class org.jboss.cache.eviction.BaseEvictionAlgorithm

emptyRecycleQueue, evict, evictCacheNode, getEvictionQueue, initialize, process, processAddedNodes, processQueues, processRemovedNodes, processVisitedNodes, resetEvictionQueue

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.cache.eviction.EvictionAlgorithm

getEvictionQueue, process, resetEvictionQueue

Constructor Detail

LRUAlgorithm

public LRUAlgorithm()

Method Detail

setupEvictionQueue

protected EvictionQueue setupEvictionQueue(Region region)
                                    throws EvictionException

Description copied from class: BaseEvictionAlgorithm

This method will create an EvictionQueue implementation and prepare it for use.

Specified by:

setupEvictionQueue in class BaseEvictionAlgorithm

Parameters:

region - Region to setup an eviction queue for.

Returns:

The created EvictionQueue to be used as the eviction queue for this algorithm.

Throws:

EvictionException

See Also:

EvictionQueue

shouldEvictNode

protected boolean shouldEvictNode(NodeEntry entry)

Description copied from class: BaseEvictionAlgorithm

This method will check whether the given node should be evicted or not.

Specified by:

shouldEvictNode in class BaseEvictionAlgorithm

Parameters:

entry - NodeEntry to test eviction for.

Returns:

True if the given node should be evicted. False if the given node should not be evicted.

prune

protected void prune()
              throws EvictionException

Overrides:

prune in class BaseEvictionAlgorithm

Throws:

EvictionException