net.eduvax.util

Class WeakHashtable<K,V>

java.lang.Object

net.eduvax.util.WeakHashtable<K,V>

All Implemented Interfaces:

DataSource<K,V>

public class WeakHashtable<K,V>
extends java.lang.Object
implements DataSource<K,V>

A Weak Hashtable stores objects while letting garbage collector collect them. Permits to use automatic memory management as a transparent cache.

Field Summary

Fields

Modifier and Type	Field and Description
private DataSource<K,V>	_dataSource Data source to retrieve garbage collected objects
private int	_kcCount key clean count
private java.util.Hashtable<K,java.lang.ref.WeakReference<V>>	_weakRefs weak reference table
private static int	DEF_KCCOUNT null return count to reach to trigger key clean.

Constructor Summary

Constructors

Constructor and Description
WeakHashtable(DataSource<K,V> source) Create new WeakHashtable.

Method Summary

Methods

Modifier and Type	Method and Description
private void	cleanKey() Remove obsolete keys.
V	get(K key)

Methods inherited from class java.lang.Object

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

Field Detail

_weakRefs

private java.util.Hashtable<K,java.lang.ref.WeakReference<V>> _weakRefs

weak reference table

_dataSource

private DataSource<K,V> _dataSource

Data source to retrieve garbage collected objects

_kcCount

private int _kcCount

key clean count

DEF_KCCOUNT

private static int DEF_KCCOUNT

null return count to reach to trigger key clean.

Constructor Detail

WeakHashtable

public WeakHashtable(DataSource<K,V> source)

Create new WeakHashtable.

Parameters:

source - source where to search for uncached objects.

Method Detail

get

public V get(K key)

Specified by:

get in interface DataSource<K,V>

cleanKey

private void cleanKey()

Remove obsolete keys. To avoid key collection overload, remove keys related to already collected objects.