org.apache.slide.util
Class HashMapObjectCache

java.lang.Object
  |
  +--org.apache.slide.util.AbstractObjectCache
        |
        +--org.apache.slide.util.HashMapObjectCache

All Implemented Interfaces:

ObjectCache

public class HashMapObjectCache

extends AbstractObjectCache

Object cache implementation using Keith Visco's HashMap structure.

Version:

$Revision: 1.6 $ $Date: 2000/09/26 02:44:28 $

Author:

Remy Maucherat

Field Summary

protected HashMap

cache Cache structure.

Fields inherited from class org.apache.slide.util.AbstractObjectCache

cacheHits, cacheRequests, currentHitRatio, DEFAULT_HIT_RATIO, DEFAULT_SIZE, desiredHitRatio, initialSize, maxSize

Constructor Summary

HashMapObjectCache()
Constructor.

HashMapObjectCache(int initialSize, int maxSize, double desiredHitRatio)
Constructor.

Method Summary

void	clear() Clear object cache.
java.lang.Object	get(java.lang.Object key) Get the object associated with the key.
protected int	getSize() Get cache size.
void	put(java.lang.Object key, java.lang.Object value) Add an object to the cache, or overwrite its value.
void	remove(java.lang.Object key) Remove object associated with the given key.
protected void	removeSomeObjects() Removes some elements from the cache.
protected void	resize() Resize cache.

Methods inherited from class org.apache.slide.util.AbstractObjectCache

shouldResize

Methods inherited from class java.lang.Object

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

Field Detail

cache

protected HashMap cache

Cache structure.

Constructor Detail

HashMapObjectCache

public HashMapObjectCache()

Constructor.

Warning (blinking) : That constructor is to be used really carefully as the cache maximum size is not limited.

HashMapObjectCache

public HashMapObjectCache(int initialSize,
                          int maxSize,
                          double desiredHitRatio)

Constructor.

Parameters:

initialSize - Initial size of the cache

maxSize - Maximum size of the cache

desiredHitRatio - Desired cache hit ratio

Method Detail

get

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

Get the object associated with the key.

Overrides:

get in class AbstractObjectCache

Parameters:

key - Object's key

Returns:

Object null if there is no object associated with that key in the cache, or the object value otherwise

put

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

Add an object to the cache, or overwrite its value.

Overrides:

put in class AbstractObjectCache

Parameters:

key - Object's key

object - Object's value

remove

public void remove(java.lang.Object key)

Remove object associated with the given key. Doesn't do anything if the key wasn't associated with any object.

Overrides:

remove in class AbstractObjectCache

Parameters:

key - Object's key

clear

public void clear()

Clear object cache.

Overrides:

clear in class AbstractObjectCache

removeSomeObjects

protected void removeSomeObjects()

Removes some elements from the cache. The selection of the objects to remove, along with the number are left to the implementation.

Overrides:

removeSomeObjects in class AbstractObjectCache

getSize

protected int getSize()

Get cache size.

Overrides:

getSize in class AbstractObjectCache

Returns:

int Current cache size

resize

protected void resize()

Resize cache.

Overrides:

resize in class AbstractObjectCache