nl.knowledgeplaza.util.pool
Class FastestFirstObjectPool<T>

java.lang.Object
  nl.knowledgeplaza.util.pool.BaseObjectPool<T>
      nl.knowledgeplaza.util.pool.PriorityObjectPool<T>
          nl.knowledgeplaza.util.pool.FastestFirstObjectPool<T>

All Implemented Interfaces:

ObjectPool<T>

public class FastestFirstObjectPool<T>
extends PriorityObjectPool<T>
implements ObjectPool<T>

This class implements a priority pool based on the assumption that all pooled objects are the same but not identical. This means they can all do the same work, but maybe not equally fast. It is assumed that all pooled objects on average get to process identical tasks, or workload. Because of this unequality, some pooled objects will perform the workload faster than others. This object pool will hand out the faster pooled objects before the slower. Faster is determine by keeping statistical data on how long it takes to perform the workload. Over time this should flatten out into a correct representation. The implementation tries to do its work with as less objects as possible (stack alike), unused objects have a very high average which puts them at the end of the priority queue.

Version:

$Revision: 1.3 $

Author:

$Author: toeukpap $

See Also:

Nested Class Summary

Nested classes/interfaces inherited from class nl.knowledgeplaza.util.pool.BaseObjectPool

BaseObjectPool.NotFromThisPoolException, BaseObjectPool.TimeOutException

Field Summary

protected Map<T,nl.knowledgeplaza.util.pool.FastestFirstObjectPool.AverageData>	iAverageData
static String	SOURCECODE_VERSION Standard variable for determining version of a class file.

Fields inherited from class nl.knowledgeplaza.util.pool.PriorityObjectPool

iListOfPooledObjects, iSortedListOfPooledObjects

Fields inherited from class nl.knowledgeplaza.util.pool.BaseObjectPool

iClose, iListOfHandedOutObjects, iListOfHandedOutObjectsSync, iShuttingDown, iSynchronized, itestOnBorrow, WHEN_EXHAUSTED_BLOCK, WHEN_EXHAUSTED_FAIL

Constructor Summary

FastestFirstObjectPool()
Initialize Assume that the pooled objects are Comparable

FastestFirstObjectPool(Collection<T> collection, Comparator<T> comparator)
Initialize

FastestFirstObjectPool(PoolableObjectFactory<T> poolableObjectFactory)
Initialize

Method Summary

void	factoryDestroyObject(T object) Clean up the statistical data
int	getMinimumNumberOfMeasurements() MinimumNumberOfMeasurements
protected T	obtainPooledObjectImpl() this method obtains a pooled object, the implementation determines the behaviour (LIFO, FIFO, etc)
protected void	returnPooledObjectImpl(T o) this method returns a pooled object, the implementation determines the behaviour (LIFO, FIFO, etc)
void	setMinimumNumberOfMeasurements(int value)

Methods inherited from class nl.knowledgeplaza.util.pool.PriorityObjectPool

getPooledObjectsImpl

Methods inherited from class nl.knowledgeplaza.util.pool.BaseObjectPool

addObject, borrowObject, clear, close, factoryActivateObject, factoryMakeObject, factoryPassivateObject, factoryValidateObject, fill, getFactory, getMaxActive, getMaxIdle, getMaxWait, getName, getNameDescription, getNumActive, getNumberOfObjectsScheduledForDestruction, getNumIdle, getPooledObjects, getTestOnBorrow, getWhenExhaustedAction, invalidateObject, isClosed, isShuttingDown, isSynchronized, maintenance, obtainPooledObject, returnObject, returnPooledObject, setFactory, setMaxActive, setMaxIdle, setMaxWait, setName, setSynchronized, setTestOnBorrow, setWhenExhaustedAction, shutdown

Methods inherited from class java.lang.Object

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

Methods inherited from interface nl.knowledgeplaza.util.pool.ObjectPool

addObject, borrowObject, clear, close, getNumActive, getNumIdle, invalidateObject, isSynchronized, returnObject, setFactory, setSynchronized, shutdown

Field Detail

SOURCECODE_VERSION

public static final String SOURCECODE_VERSION

Standard variable for determining version of a class file.

See Also:

Constant Field Values

iAverageData

protected Map<T,nl.knowledgeplaza.util.pool.FastestFirstObjectPool.AverageData> iAverageData

Constructor Detail

FastestFirstObjectPool

public FastestFirstObjectPool()

Initialize Assume that the pooled objects are Comparable

FastestFirstObjectPool

public FastestFirstObjectPool(PoolableObjectFactory<T> poolableObjectFactory)

Initialize

FastestFirstObjectPool

public FastestFirstObjectPool(Collection<T> collection,
                              Comparator<T> comparator)

Initialize

Method Detail

getMinimumNumberOfMeasurements

public int getMinimumNumberOfMeasurements()

MinimumNumberOfMeasurements

setMinimumNumberOfMeasurements

public void setMinimumNumberOfMeasurements(int value)

obtainPooledObjectImpl

protected T obtainPooledObjectImpl()

Description copied from class: BaseObjectPool

this method obtains a pooled object, the implementation determines the behaviour (LIFO, FIFO, etc)

Overrides:

obtainPooledObjectImpl in class PriorityObjectPool<T>

returnPooledObjectImpl

protected void returnPooledObjectImpl(T o)

Description copied from class: BaseObjectPool

this method returns a pooled object, the implementation determines the behaviour (LIFO, FIFO, etc)

Overrides:

returnPooledObjectImpl in class PriorityObjectPool<T>

factoryDestroyObject

public void factoryDestroyObject(T object)

Clean up the statistical data

Overrides:

factoryDestroyObject in class BaseObjectPool<T>