org.apache.jcs.engine.memory
Class AbstractMemoryCache

java.lang.Object
  org.apache.jcs.engine.memory.AbstractMemoryCache

All Implemented Interfaces:

MemoryCache, java.io.Serializable

Direct Known Subclasses:

LRUMemoryCache, MRUMemoryCache

public abstract class AbstractMemoryCache

extends java.lang.Object

implements MemoryCache, java.io.Serializable

Some common code for the LRU and MRU caches.

Version:

$Id: AbstractMemoryCache.java,v 1.5 2003/08/22 11:57:18 mpoeschl Exp $

Author:

Aaron Smuts, James Taylor, John McNally

See Also:

Serialized Form

Field Summary

IElementAttributes	attr Region Elemental Attributes, used as a default.
protected CompositeCache	cache The cache region this store is associated with
protected java.lang.String	cacheName
ICompositeCacheAttributes	cattr Cache Attributes
protected int	chunkSize
private static org.apache.commons.logging.Log	log
protected java.util.Map	map Map where items are stored by key
private ShrinkerThread	shrinker The background memory shrinker
protected int	status

Constructor Summary

AbstractMemoryCache()
Constructor for the LRUMemoryCache object

Method Summary

void	dispose() Prepares for shutdown.
abstract ICacheElement	get(java.io.Serializable key) Get an item from the cache
ICompositeCacheAttributes	getCacheAttributes() Returns the CacheAttributes.
java.lang.String	getCacheName() Returns the cache name.
CompositeCache	getCompositeCache() Gets the cache hub / region taht the MemoryCache is used by
java.util.Set	getGroupKeys(java.lang.String groupName) Gets the set of keys of objects currently in the group
java.util.Iterator	getIterator() Gets the iterator attribute of the LRUMemoryCache object
abstract java.lang.Object[]	getKeyArray() Get an Array of the keys for all elements in the memory cache
abstract ICacheElement	getQuiet(java.io.Serializable key) Get an item from the cache without effecting its order or last access time
int	getSize() Returns the current cache size.
java.lang.String	getStats() Returns the cache statistics.
int	getStatus() Returns the cache status.
void	initialize(CompositeCache hub) For post reflection creation initialization
abstract boolean	remove(java.io.Serializable key) Removes an item from the cache
void	removeAll() Removes all cached items from the cache.
void	setCacheAttributes(ICompositeCacheAttributes cattr) Sets the CacheAttributes.
abstract void	update(ICacheElement ce) Puts an item to the cache.
void	waterfal(ICacheElement ce) Puts an item to the cache.

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final org.apache.commons.logging.Log log

cacheName

protected java.lang.String cacheName

map

protected java.util.Map map

Map where items are stored by key

attr

public IElementAttributes attr

Region Elemental Attributes, used as a default.

cattr

public ICompositeCacheAttributes cattr

Cache Attributes

cache

protected CompositeCache cache

The cache region this store is associated with

status

protected int status

chunkSize

protected int chunkSize

shrinker

private ShrinkerThread shrinker

The background memory shrinker

Constructor Detail

AbstractMemoryCache

public AbstractMemoryCache()

Constructor for the LRUMemoryCache object

Method Detail

initialize

public void initialize(CompositeCache hub)

For post reflection creation initialization

Specified by:

initialize in interface MemoryCache

Parameters:

hub -

remove

public abstract boolean remove(java.io.Serializable key)
                        throws java.io.IOException

Removes an item from the cache

Specified by:

remove in interface MemoryCache

Parameters:

key - Identifies item to be removed

Returns:

Description of the Return Value

Throws:

java.io.IOException - Description of the Exception

get

public abstract ICacheElement get(java.io.Serializable key)
                           throws java.io.IOException

Get an item from the cache

Specified by:

get in interface MemoryCache

Parameters:

key - Description of the Parameter

Returns:

Description of the Return Value

Throws:

java.io.IOException - Description of the Exception

getQuiet

public abstract ICacheElement getQuiet(java.io.Serializable key)
                                throws java.io.IOException

Get an item from the cache without effecting its order or last access time

Specified by:

getQuiet in interface MemoryCache

Parameters:

key - Description of the Parameter

Returns:

The quiet value

Throws:

java.io.IOException - Description of the Exception

update

public abstract void update(ICacheElement ce)
                     throws java.io.IOException

Puts an item to the cache.

Specified by:

update in interface MemoryCache

Parameters:

ce - Description of the Parameter

Throws:

java.io.IOException - Description of the Exception

getKeyArray

public abstract java.lang.Object[] getKeyArray()

Get an Array of the keys for all elements in the memory cache

Specified by:

getKeyArray in interface MemoryCache

Returns:

An Object[]

removeAll

public void removeAll()
               throws java.io.IOException

Removes all cached items from the cache.

Specified by:

removeAll in interface MemoryCache

Throws:

java.io.IOException

dispose

public void dispose()
             throws java.io.IOException

Prepares for shutdown.

Throws:

java.io.IOException

getStats

public java.lang.String getStats()

Returns the cache statistics.

Returns:

The stats value

getSize

public int getSize()

Returns the current cache size.

Specified by:

getSize in interface MemoryCache

Returns:

The size value

getStatus

public int getStatus()

Returns the cache status.

Returns:

The status value

getCacheName

public java.lang.String getCacheName()

Returns the cache name.

Returns:

The cacheName value

waterfal

public void waterfal(ICacheElement ce)
              throws java.io.IOException

Puts an item to the cache.

Specified by:

waterfal in interface MemoryCache

Parameters:

ce - Description of the Parameter

Throws:

java.io.IOException

getIterator

public java.util.Iterator getIterator()

Gets the iterator attribute of the LRUMemoryCache object

Specified by:

getIterator in interface MemoryCache

Returns:

The iterator value

getCacheAttributes

public ICompositeCacheAttributes getCacheAttributes()

Returns the CacheAttributes.

Specified by:

getCacheAttributes in interface MemoryCache

Returns:

The CacheAttributes value

setCacheAttributes

public void setCacheAttributes(ICompositeCacheAttributes cattr)

Sets the CacheAttributes.

Specified by:

setCacheAttributes in interface MemoryCache

Parameters:

cattr - The new CacheAttributes value

getCompositeCache

public CompositeCache getCompositeCache()

Gets the cache hub / region taht the MemoryCache is used by

Specified by:

getCompositeCache in interface MemoryCache

Returns:

The cache value

getGroupKeys

public java.util.Set getGroupKeys(java.lang.String groupName)

Description copied from interface: MemoryCache

Gets the set of keys of objects currently in the group

Specified by:

getGroupKeys in interface MemoryCache