org.makumba.db.makumba
Class ResourcePool

java.lang.Object
  org.makumba.db.makumba.ResourcePool

public abstract class ResourcePool
extends Object

Keeps a number of identical creation-expensive resources. Avoids resource re-creation/deletion TODO: this class should be replaced by one more generic pool that exists out there

Author:

Cristian Bogdan

Field Summary

(package private) Vector<Object>	all
(package private) WeakReference<ResourcePool>	poolRef a weak reference to ourselves, for usage by foreign objects
(package private) long	sleeping
(package private) Stack<Object>	stack
(package private) long	stale
(package private) Thread	stalePreventionThread
(package private) Stack<Date>	timeStack

Constructor Summary

ResourcePool()

Method Summary

void	close() clear all resource containers. if we have a stale prevention thread, we interrupt it
void	close(Object o) close a resource
abstract Object	create() re-define this method to express how to create a resource
(package private) Object	createAndCount() create a new resource
protected void	finalize()
Object	get() get one resource
int	getSize()
void	init(int n) initialize the pool with n resources
void	put(Object o) put back one resource
void	renew(Object o) refresh a resource that was unused for a long time to prevent it from staling
protected void	renewAll() check for stale resources and renew the rotten ones
void	startStalePreventionThread(long sleepingTime, long staleTime) start a stale prevention thread

Methods inherited from class java.lang.Object

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

Field Detail

stack

Stack<Object> stack

timeStack

Stack<Date> timeStack

all

Vector<Object> all

poolRef

WeakReference<ResourcePool> poolRef

a weak reference to ourselves, for usage by foreign objects

sleeping

long sleeping

stale

long stale

stalePreventionThread

Thread stalePreventionThread

Constructor Detail

ResourcePool

public ResourcePool()

Method Detail

create

public abstract Object create()
                       throws Exception

re-define this method to express how to create a resource

Throws:

Exception

createAndCount

Object createAndCount()
                throws Exception

create a new resource

Throws:

Exception

init

public void init(int n)
          throws Exception

initialize the pool with n resources

Throws:

Exception

get

public Object get()
           throws Exception

get one resource

Throws:

Exception

put

public void put(Object o)

put back one resource

close

public void close()

clear all resource containers. if we have a stale prevention thread, we interrupt it

finalize

protected void finalize()

Overrides:

finalize in class Object

renew

public void renew(Object o)

refresh a resource that was unused for a long time to prevent it from staling

close

public void close(Object o)

close a resource

startStalePreventionThread

public void startStalePreventionThread(long sleepingTime,
                                       long staleTime)

start a stale prevention thread

renewAll

protected void renewAll()

check for stale resources and renew the rotten ones

getSize

public int getSize()