org.shiftone.cache.policy
Class AbstractPolicyCache

java.lang.Object
  org.shiftone.cache.policy.AbstractPolicyCache

All Implemented Interfaces:

Cache, ReapableCache

Direct Known Subclasses:

FifoCache, LfuCache, LruCache

public abstract class AbstractPolicyCache

extends java.lang.Object

implements ReapableCache

Class AbstractPolicyCache

Version:

$Revision: 1.1 $

Author:

Jeff Drost

Field Summary

static int

SHRINK_DIV

Constructor Summary

protected

AbstractPolicyCache(java.lang.String name, long timeoutMilliSeconds, int maxSize, EvictionListener evictionListener)

Method Summary

void	addObject(java.lang.Object key, java.lang.Object cacheObject) adds an object to the cache
void	clear() This method calls shrinkToSize(0) which will loop through each element, removing them one by one (in order of lease valued to most valued).
protected abstract CacheNode	createNode(java.lang.Object key, java.lang.Object cacheObject) Create a new node.
protected abstract void	delete(CacheNode node) Remove a node from the cache.
protected abstract CacheNode	findNodeByKey(java.lang.Object key) Method findNodeByKey
protected abstract CacheNode	getLeastValuableNode() This method will execute the cache's onEviction strategy.
protected int	getMaxSize()
protected java.lang.String	getName()
java.lang.Object	getObject(java.lang.Object key) gets the value stored in the cache by it's key, or null if the key is not found.
protected long	getTimeoutMilliSeconds()
void	remove(java.lang.Object key) remove a specific key/value pair from the cache
abstract void	removeExpiredElements() Purge the cache of expired elements.
protected abstract void	revalueNode(CacheNode node) Update the node's value.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.shiftone.cache.Cache

size

Field Detail

SHRINK_DIV

public static final int SHRINK_DIV

See Also:

Constant Field Values

Constructor Detail

AbstractPolicyCache

protected AbstractPolicyCache(java.lang.String name,
                              long timeoutMilliSeconds,
                              int maxSize,
                              EvictionListener evictionListener)

Method Detail

addObject

public final void addObject(java.lang.Object key,
                            java.lang.Object cacheObject)

Description copied from interface: Cache

adds an object to the cache

Specified by:

addObject in interface Cache

getObject

public final java.lang.Object getObject(java.lang.Object key)

Description copied from interface: Cache

gets the value stored in the cache by it's key, or null if the key is not found.

Specified by:

getObject in interface Cache

remove

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

Description copied from interface: Cache

remove a specific key/value pair from the cache

Specified by:

remove in interface Cache

getName

protected java.lang.String getName()

getMaxSize

protected final int getMaxSize()

getTimeoutMilliSeconds

protected final long getTimeoutMilliSeconds()

clear

public void clear()

This method calls shrinkToSize(0) which will loop through each element, removing them one by one (in order of lease valued to most valued). Derived classes may wish to implement this in a more efficient way (by just reinitalizing itself).

Specified by:

clear in interface Cache

findNodeByKey

protected abstract CacheNode findNodeByKey(java.lang.Object key)

Method findNodeByKey

revalueNode

protected abstract void revalueNode(CacheNode node)

Update the node's value. This is done immediately after the node is retrieved.

delete

protected abstract void delete(CacheNode node)

Remove a node from the cache.

getLeastValuableNode

protected abstract CacheNode getLeastValuableNode()

This method will execute the cache's onEviction strategy. If this method is called, there will be at least one element in the cache to remove. The method itself does not need to check for the existance of a element.

This method is only called by shrinkToSize();

removeExpiredElements

public abstract void removeExpiredElements()

Purge the cache of expired elements.

Specified by:

removeExpiredElements in interface ReapableCache

createNode

protected abstract CacheNode createNode(java.lang.Object key,
                                        java.lang.Object cacheObject)

Create a new node.

toString

public java.lang.String toString()