org.jboss.ejb.plugins
Class AbstractInstanceCache

java.lang.Object
  org.jboss.ejb.plugins.AbstractInstanceCache

All Implemented Interfaces:

AbstractInstanceCacheMBean, AllowedOperationsFlags, ContainerPlugin, InstanceCache, MetricsConstants, Monitorable, org.jboss.system.Service, XmlLoadable

Direct Known Subclasses:

EntityInstanceCache, StatefulSessionInstanceCache

public abstract class AbstractInstanceCache

extends Object

implements InstanceCache, XmlLoadable, Monitorable, MetricsConstants, AbstractInstanceCacheMBean

Base class for caches of entity and stateful beans.

It manages the cache entries through a CachePolicy object; the implementation of the cache policy object must respect the following requirements:

• Have a public constructor that takes a single argument of type AbstractInstanceCache.class or a subclass

Version:

$Revision: 1.42.2.1 $

Author:

Simone Bordet, Bill Burke, Marc Fleury, Scott.Stark@jboss.org

Field Summary

protected static org.jboss.logging.Logger

log

Fields inherited from interface org.jboss.ejb.AllowedOperationsFlags

IN_AFTER_BEGIN, IN_AFTER_COMPLETION, IN_BEFORE_COMPLETION, IN_BUSINESS_METHOD, IN_EJB_ACTIVATE, IN_EJB_CREATE, IN_EJB_FIND, IN_EJB_HOME, IN_EJB_LOAD, IN_EJB_PASSIVATE, IN_EJB_POST_CREATE, IN_EJB_REMOVE, IN_EJB_STORE, IN_EJB_TIMEOUT, IN_INTERCEPTOR_METHOD, IN_SERVICE_ENDPOINT_METHOD, IN_SET_ENTITY_CONTEXT, IN_SET_MESSAGE_DRIVEN_CONTEXT, IN_SET_SESSION_CONTEXT, IN_UNSET_ENTITY_CONTEXT, NOT_ALLOWED

Fields inherited from interface org.jboss.monitor.MetricsConstants

ACTIVITY, APPLICATION, BEAN, BEANCACHE_METRICS, CHECKPOINT, INVOCATION_METRICS, MEMORY_MONITOR, METHOD, PRIMARY_KEY, SYSTEM_METRICS, THREAD_MONITOR, TIME, TYPE

Constructor Summary

AbstractInstanceCache()

Method Summary

protected abstract EnterpriseContext	acquireContext() Acquires an EnterpriseContext from the pool
protected abstract void	activate(EnterpriseContext ctx) Activates the given EnterpriseContext
protected abstract boolean	canPassivate(EnterpriseContext ctx) Returns whether the given context can be passivated or not
void	create()
void	destroy()
protected boolean	doActivate(EnterpriseContext ctx) Activate the given EnterpriseContext
void	flush() Flush the cache.
protected abstract void	freeContext(EnterpriseContext ctx) Frees the given EnterpriseContext to the pool
EnterpriseContext	get(Object id) Gets a bean instance from this cache given the identity.
protected org.jboss.util.CachePolicy	getCache() Returns the cache policy used for this cache.
Object	getCacheLock() Returns the mutex used to sync access to the cache policy object
String	getCachePolicyString() Display the cache policy.
long	getCacheSize() Get the current cache size
protected abstract Container	getContainer() Returns the container for this cache.
protected abstract Object	getKey(EnterpriseContext ctx) Returns the key used by the cache to map the given context
long	getPassivatedCount() Get the passivated count.
void	importXml(Element element)
void	insert(EnterpriseContext ctx) Inserts an active bean instance after creation or activation.
boolean	isActive(Object id) Checks whether an instance corresponding to a particular id is active.
protected void	logActivation(Object id)
protected void	logPassivation(Object id)
protected abstract void	passivate(EnterpriseContext ctx) Passivates the given EnterpriseContext
void	release(EnterpriseContext ctx) Releases the given bean instance from this cache.
void	remove(Object id) From InstanceCache interface
void	resetStatistic()
Map	retrieveStatistic()
void	sample(Object s) Samples the status of the implementor object and register the status into the snapshot argument.
protected abstract void	setKey(Object id, EnterpriseContext ctx) Sets the given id as key for the given context
void	start()
void	stop()
protected void	tryToPassivate(EnterpriseContext ctx)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.ejb.ContainerPlugin

setContainer

Field Detail

log

protected static org.jboss.logging.Logger log

Constructor Detail

AbstractInstanceCache

public AbstractInstanceCache()

Method Detail

sample

public void sample(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

retrieveStatistic

public Map retrieveStatistic()

resetStatistic

public void resetStatistic()

get

public EnterpriseContext get(Object id)
                      throws RemoteException,
                             NoSuchObjectException

Description copied from interface: InstanceCache

Gets a bean instance from this cache given the identity. This method may involve activation if the instance is not in the cache.

Implementation should have O(1) complexity.

This method is never called for stateless session beans.

Specified by:

get in interface InstanceCache

Parameters:

id - The primary key of the bean .

Returns:

The EnterpriseContext related to the given id.

Throws:

NoSuchObjectException - if the bean cannot be found.

RemoteException - In case of illegal calls (concurrent / reentrant)

See Also:

InstanceCache.release(org.jboss.ejb.EnterpriseContext)

insert

public void insert(EnterpriseContext ctx)

Description copied from interface: InstanceCache

Inserts an active bean instance after creation or activation.

Implementation should guarantee proper locking and O(1) complexity.

Specified by:

insert in interface InstanceCache

Parameters:

ctx - The EnterpriseContext to insert in the cache

See Also:

InstanceCache.remove(java.lang.Object)

tryToPassivate

protected void tryToPassivate(EnterpriseContext ctx)

release

public void release(EnterpriseContext ctx)

Description copied from interface: InstanceCache

Releases the given bean instance from this cache. This method may passivate the bean to get it out of the cache. Implementation should return almost immediately leaving the passivation to be executed by another thread.

Specified by:

release in interface InstanceCache

Parameters:

ctx - The EnterpriseContext to release

See Also:

InstanceCache.get(java.lang.Object)

remove

public void remove(Object id)

From InstanceCache interface

Specified by:

remove in interface InstanceCache

Parameters:

id - The pimary key of the bean.

See Also:

InstanceCache.insert(org.jboss.ejb.EnterpriseContext)

isActive

public boolean isActive(Object id)

Description copied from interface: InstanceCache

Checks whether an instance corresponding to a particular id is active.

Specified by:

isActive in interface InstanceCache

Parameters:

id - The pimary key of the bean.

See Also:

InstanceCache.insert(org.jboss.ejb.EnterpriseContext)

getCacheSize

public long getCacheSize()

Get the current cache size

Specified by:

getCacheSize in interface InstanceCache

Returns:

the size of the cache

flush

public void flush()

Flush the cache.

Specified by:

flush in interface InstanceCache

getPassivatedCount

public long getPassivatedCount()

Get the passivated count.

Specified by:

getPassivatedCount in interface AbstractInstanceCacheMBean

Returns:

the number of passivated instances.

getCachePolicyString

public String getCachePolicyString()

Display the cache policy.

Specified by:

getCachePolicyString in interface AbstractInstanceCacheMBean

Returns:

the cache policy as a string.

importXml

public void importXml(Element element)
               throws org.jboss.deployment.DeploymentException

Specified by:

importXml in interface XmlLoadable

Throws:

org.jboss.deployment.DeploymentException

create

public void create()
            throws Exception

Specified by:

create in interface org.jboss.system.Service

Throws:

Exception

start

public void start()
           throws Exception

Specified by:

start in interface org.jboss.system.Service

Throws:

Exception

stop

public void stop()

Specified by:

stop in interface org.jboss.system.Service

destroy

public void destroy()

Specified by:

destroy in interface org.jboss.system.Service

logActivation

protected void logActivation(Object id)

logPassivation

protected void logPassivation(Object id)

getContainer

protected abstract Container getContainer()

Returns the container for this cache.

getCache

protected org.jboss.util.CachePolicy getCache()

Returns the cache policy used for this cache.

getCacheLock

public Object getCacheLock()

Returns the mutex used to sync access to the cache policy object

passivate

protected abstract void passivate(EnterpriseContext ctx)
                           throws RemoteException

Passivates the given EnterpriseContext

Throws:

RemoteException

activate

protected abstract void activate(EnterpriseContext ctx)
                          throws RemoteException

Activates the given EnterpriseContext

Throws:

RemoteException

doActivate

protected boolean doActivate(EnterpriseContext ctx)
                      throws RemoteException

Activate the given EnterpriseContext

Parameters:

ctx - the context

Returns:

false if we recursively activating

Throws:

RemoteException - for any error

acquireContext

protected abstract EnterpriseContext acquireContext()
                                             throws Exception

Acquires an EnterpriseContext from the pool

Throws:

Exception

freeContext

protected abstract void freeContext(EnterpriseContext ctx)

Frees the given EnterpriseContext to the pool

getKey

protected abstract Object getKey(EnterpriseContext ctx)

Returns the key used by the cache to map the given context

setKey

protected abstract void setKey(Object id,
                               EnterpriseContext ctx)

Sets the given id as key for the given context

canPassivate

protected abstract boolean canPassivate(EnterpriseContext ctx)

Returns whether the given context can be passivated or not