org.apache.jcs.engine

Class CacheEventQueue

java.lang.Object

org.apache.jcs.engine.CacheEventQueue

All Implemented Interfaces:

ICacheEventQueue

public class CacheEventQueue
extends java.lang.Object
implements ICacheEventQueue

An event queue is used to propagate ordered cache events to one and only one target listener.

This is a modified version of the experimental version. It should lazy initilaize the processor thread, and kill the thread if the queue goes emtpy for a specified period, now set to 1 minute. If something comes in after that a new processor thread should be created.

Field Summary

Fields inherited from interface org.apache.jcs.engine.behavior.ICacheEventQueue

POOLED_QUEUE_TYPE, SINGLE_QUEUE_TYPE

Constructor Summary

Constructors

Constructor and Description
CacheEventQueue(ICacheListener listener, long listenerId, java.lang.String cacheName) Constructs with the specified listener and the cache name.
CacheEventQueue(ICacheListener listener, long listenerId, java.lang.String cacheName, int maxFailure, int waitBeforeRetry) Constructor for the CacheEventQueue object

Method Summary

Methods

Modifier and Type	Method and Description
void	addDisposeEvent() Adds a feature to the DisposeEvent attribute of the ICacheEventQueue object
void	addPutEvent(ICacheElement ce) This adds a put event to the queue.
void	addRemoveAllEvent() This adds a remove all event to the queue.
void	addRemoveEvent(java.io.Serializable key) This adds a remove event to the queue.
void	destroy() Event Q is emtpy.
long	getListenerId() Gets the listenerId attribute of the ICacheEventQueue object
java.lang.String	getQueueType() What type of queue is this.
IStats	getStatistics() This method returns semi-structured data on this queue.
int	getWaitToDieMillis() Returns the time to wait for events before killing the background thread.
void	initialize(ICacheListener listener, long listenerId, java.lang.String cacheName, int maxFailure, int waitBeforeRetry, java.lang.String threadPoolName) Initializes the queue.
boolean	isAlive() If they queue has an active thread it is considered alive.
boolean	isEmpty() Are there elements in the queue.
boolean	isWorking() A Queue is working unless it has reached its max failure count.
void	setAlive(boolean aState) Sets whether the queue is actively processing -- if there are working threads.
void	setWaitToDieMillis(int wtdm) Sets the time to wait for events before killing the background thread.
void	setWorking(boolean b) This means that the queue is functional.
int	size() Returns the number of elements in the queue.
void	stopProcessing() Kill the processor thread and indicate that the queue is detroyed and no longer alive, but it can still be working.
java.lang.String	toString() Creates a brief string identifying the listener and the region.

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheEventQueue

public CacheEventQueue(ICacheListener listener,
               long listenerId,
               java.lang.String cacheName)

Constructs with the specified listener and the cache name.

Parameters:

listener -

listenerId -

cacheName -

CacheEventQueue

public CacheEventQueue(ICacheListener listener,
               long listenerId,
               java.lang.String cacheName,
               int maxFailure,
               int waitBeforeRetry)

Constructor for the CacheEventQueue object

Parameters:

listener -

listenerId -

cacheName -

maxFailure -

waitBeforeRetry -

Method Detail

initialize

public void initialize(ICacheListener listener,
              long listenerId,
              java.lang.String cacheName,
              int maxFailure,
              int waitBeforeRetry,
              java.lang.String threadPoolName)

Initializes the queue.

Specified by:

initialize in interface ICacheEventQueue

Parameters:

listener -

listenerId -

cacheName -

maxFailure -

waitBeforeRetry -

threadPoolName -

getQueueType

public java.lang.String getQueueType()

What type of queue is this.

Specified by:

getQueueType in interface ICacheEventQueue

Returns:

queueType

stopProcessing

public void stopProcessing()

Kill the processor thread and indicate that the queue is detroyed and no longer alive, but it can still be working.

getWaitToDieMillis

public int getWaitToDieMillis()

Returns the time to wait for events before killing the background thread.

Returns:

int

setWaitToDieMillis

public void setWaitToDieMillis(int wtdm)

Sets the time to wait for events before killing the background thread.

Parameters:

wtdm - the ms for the q to sit idle.

toString

public java.lang.String toString()

Creates a brief string identifying the listener and the region.

Overrides:

toString in class java.lang.Object

Returns:

String debugging info.

isAlive

public boolean isAlive()

If they queue has an active thread it is considered alive.

Specified by:

isAlive in interface ICacheEventQueue

Returns:

The alive value

setAlive

public void setAlive(boolean aState)

Sets whether the queue is actively processing -- if there are working threads.

Parameters:

aState -

getListenerId

public long getListenerId()

Description copied from interface: ICacheEventQueue

Gets the listenerId attribute of the ICacheEventQueue object

Specified by:

getListenerId in interface ICacheEventQueue

Returns:

The listenerId value

destroy

public void destroy()

Event Q is emtpy.

Calling destroy interupts the processor thread.

Specified by:

destroy in interface ICacheEventQueue

addPutEvent

public void addPutEvent(ICacheElement ce)
                 throws java.io.IOException

This adds a put event to the queue. When it is processed, the element will be put to the listener.

Specified by:

addPutEvent in interface ICacheEventQueue

Parameters:

ce - The feature to be added to the PutEvent attribute

Throws:

java.io.IOException

addRemoveEvent

public void addRemoveEvent(java.io.Serializable key)
                    throws java.io.IOException

This adds a remove event to the queue. When processed the listener's remove method will be called for the key.

Specified by:

addRemoveEvent in interface ICacheEventQueue

Parameters:

key - The feature to be added to the RemoveEvent attribute

Throws:

java.io.IOException

addRemoveAllEvent

public void addRemoveAllEvent()
                       throws java.io.IOException

This adds a remove all event to the queue. When it is processed, all elements will be removed from the cache.

Specified by:

addRemoveAllEvent in interface ICacheEventQueue

Throws:

java.io.IOException

addDisposeEvent

public void addDisposeEvent()
                     throws java.io.IOException

Description copied from interface: ICacheEventQueue

Adds a feature to the DisposeEvent attribute of the ICacheEventQueue object

Specified by:

addDisposeEvent in interface ICacheEventQueue

Throws:

java.io.IOException

getStatistics

public IStats getStatistics()

This method returns semi-structured data on this queue.

Specified by:

getStatistics in interface ICacheEventQueue

Returns:

information on the status and history of the queue

See Also:

ICacheEventQueue.getStatistics()

isWorking

public boolean isWorking()

Description copied from interface: ICacheEventQueue

A Queue is working unless it has reached its max failure count.

Specified by:

isWorking in interface ICacheEventQueue

Returns:

whether the queue is functional.

setWorking

public void setWorking(boolean b)

This means that the queue is functional. If we reached the max number of failures, the queue is marked as non functional and will never work again.

Parameters:

b -

isEmpty

public boolean isEmpty()

Description copied from interface: ICacheEventQueue

Are there elements in the queue.

Specified by:

isEmpty in interface ICacheEventQueue

Returns:

whether there are any items in the queue.

size

public int size()

Returns the number of elements in the queue.

Specified by:

size in interface ICacheEventQueue

Returns:

number of items in the queue.