org.jasig.portal.utils
Class SoftHashMap

java.lang.Object
  java.util.AbstractMap
      org.jasig.portal.utils.SoftHashMap

All Implemented Interfaces:

java.util.Map

public class SoftHashMap
extends java.util.AbstractMap

A HashMap implementation that uses soft references, leaving memory management up to the gc.

Version:

$Revision: 1.4.4.3 $

Author:

Peter Kharchenko (thanks to Dr. Kabutz on whose article the code is based)

Nested Class Summary

private static class

SoftHashMap.KeyReferencePair An extension of a SoftReference that contains a key by which it was mapped.

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry

Field Summary

private java.util.LinkedList	fifo
private edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap	map
private int	minSize
private java.lang.ref.ReferenceQueue	removeQueue

Constructor Summary

SoftHashMap()

SoftHashMap(int minSize)
Construct a SoftHashMap

Method Summary

private void	addToFIFO(java.lang.Object o)
private void	cleanMap()
void	clear()
java.util.Set	entrySet()
java.lang.Object	get(java.lang.Object key)
java.lang.Object	put(java.lang.Object key, java.lang.Object value)
java.lang.Object	remove(java.lang.Object key)
int	size()

Methods inherited from class java.util.AbstractMap

clone, containsKey, containsValue, equals, hashCode, isEmpty, keySet, putAll, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

map

private final edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap map

fifo

private final java.util.LinkedList fifo

removeQueue

private final java.lang.ref.ReferenceQueue removeQueue

minSize

private int minSize

Constructor Detail

SoftHashMap

public SoftHashMap(int minSize)

Construct a SoftHashMap

Parameters:

minSize - minimum number of objects to keep (approximate)

SoftHashMap

public SoftHashMap()

Method Detail

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Specified by:

put in interface java.util.Map

Overrides:

put in class java.util.AbstractMap

get

public java.lang.Object get(java.lang.Object key)

Specified by:

get in interface java.util.Map

Overrides:

get in class java.util.AbstractMap

remove

public java.lang.Object remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map

Overrides:

remove in class java.util.AbstractMap

size

public int size()

Specified by:

size in interface java.util.Map

Overrides:

size in class java.util.AbstractMap

clear

public void clear()

Specified by:

clear in interface java.util.Map

Overrides:

clear in class java.util.AbstractMap

entrySet

public java.util.Set entrySet()

Specified by:

entrySet in interface java.util.Map

Specified by:

entrySet in class java.util.AbstractMap

addToFIFO

private void addToFIFO(java.lang.Object o)

cleanMap

private void cleanMap()