JBoss API: Class LRUEnterpriseContextCachePolicy

org.jboss.ejb.plugins
Class LRUEnterpriseContextCachePolicy

java.lang.Object
  |
  +--org.jboss.util.LRUCachePolicy
        |
        +--org.jboss.ejb.plugins.LRUEnterpriseContextCachePolicy

All Implemented Interfaces:

CachePolicy, Monitorable, Service, XmlLoadable

Direct Known Subclasses:

LRUStatefulContextCachePolicy

public class LRUEnterpriseContextCachePolicy

extends LRUCachePolicy

implements XmlLoadable, Monitorable

Least Recently Used cache policy for EnterpriseContexts.

Version:

$Revision: 1.7.4.8 $

Author:

Simone Bordet

See Also:

AbstractInstanceCache

Inner Class Summary

protected class	LRUEnterpriseContextCachePolicy.ContextLRUList Subclass that logs list activity events.
protected class	LRUEnterpriseContextCachePolicy.OveragerTask This TimerTask passivates cached beans that have not been called for a while.
protected class	LRUEnterpriseContextCachePolicy.ResizerTask This TimerTask resizes the cache capacity using the cache miss frequency algorithm, that is the more cache misses we have, the more the cache size is enlarged, and viceversa.

Inner classes inherited from class org.jboss.util.LRUCachePolicy

LRUCachePolicy.LRUCacheEntry, LRUCachePolicy.LRUList

Field Summary

protected static Logger	log
protected static java.util.Timer	tasksTimer

Fields inherited from class org.jboss.util.LRUCachePolicy

m_list, m_map, m_maxCapacity, m_minCapacity

Constructor Summary

LRUEnterpriseContextCachePolicy(AbstractInstanceCache eic)
Creates a LRU cache policy object given the instance cache that use this policy object.

Method Summary

protected void	ageOut(LRUCachePolicy.LRUCacheEntry entry) Callback method called when the cache algorithm ages out of the cache the given entry.
protected void	cacheMiss() Callback method called when a cache miss happens.
protected LRUCachePolicy.LRUList	createList() Factory method for the linked list used by this cache implementation.
void	destroy() Destroys the cache that is now unusable.
void	importXml(org.w3c.dom.Element element) Reads from the configuration the parameters for this cache policy, that are all optionals.
void	sample(java.lang.Object s) Samples the status of the implementor object and register the status into the snapshot argument.
void	start() Starts this cache that is now ready to be used.
void	stop() Stops this cache thus LRUCachePolicy.flush()ing all cached objects.

Methods inherited from class org.jboss.util.LRUCachePolicy

createCacheEntry, flush, get, init, insert, peek, remove

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static Logger log

tasksTimer

protected static java.util.Timer tasksTimer

Constructor Detail

LRUEnterpriseContextCachePolicy

public LRUEnterpriseContextCachePolicy(AbstractInstanceCache eic)

Creates a LRU cache policy object given the instance cache that use this policy object.

Method Detail

sample

public void sample(java.lang.Object s)

Description copied from interface: Monitorable

Samples the status of the implementor object and register the status into the snapshot argument.

Specified by:

sample in interface Monitorable

start

public void start()
           throws java.lang.Exception

Description copied from class: LRUCachePolicy

Starts this cache that is now ready to be used.

Overrides:

start in class LRUCachePolicy

Following copied from class: org.jboss.util.LRUCachePolicy

See Also:

LRUCachePolicy.init(), LRUCachePolicy.stop()

stop

public void stop()

Description copied from class: LRUCachePolicy

Stops this cache thus LRUCachePolicy.flush()ing all cached objects.
After this method is called, a call to LRUCachePolicy.start() will restart the cache.

Overrides:

stop in class LRUCachePolicy

Following copied from class: org.jboss.util.LRUCachePolicy

See Also:

LRUCachePolicy.start(), LRUCachePolicy.destroy()

destroy

public void destroy()

Description copied from class: LRUCachePolicy

Destroys the cache that is now unusable.
To have it working again it must be re-LRUCachePolicy.init()ialized and re-LRUCachePolicy.start()ed.

Overrides:

destroy in class LRUCachePolicy

Following copied from class: org.jboss.util.LRUCachePolicy

See Also:

LRUCachePolicy.init()

importXml

public void importXml(org.w3c.dom.Element element)
               throws DeploymentException

Reads from the configuration the parameters for this cache policy, that are all optionals. FIXME 20010626 marcf: Simone seriously arent' all the options overkill? give it another 6 month . Remember you are exposing the guts of this to the end user, also provide defaults so that if an entry is not specified you can still work and it looks _much_ better in the configuration files.

Specified by:

importXml in interface XmlLoadable

createList

protected LRUCachePolicy.LRUList createList()

Description copied from class: LRUCachePolicy

Factory method for the linked list used by this cache implementation.

Overrides:

createList in class LRUCachePolicy

ageOut

protected void ageOut(LRUCachePolicy.LRUCacheEntry entry)

Description copied from class: LRUCachePolicy

Callback method called when the cache algorithm ages out of the cache the given entry.
The implementation here is removing the given entry from the cache.

Overrides:

ageOut in class LRUCachePolicy

cacheMiss

protected void cacheMiss()

Description copied from class: LRUCachePolicy

Callback method called when a cache miss happens.

Overrides:

cacheMiss in class LRUCachePolicy