Package org.apache.commons.jcs3.engine.memory.soft

Class SoftReferenceMemoryCache<K,V>

java.lang.Object

org.apache.commons.jcs3.engine.memory.AbstractMemoryCache<K,V>

org.apache.commons.jcs3.engine.memory.soft.SoftReferenceMemoryCache<K,V>

All Implemented Interfaces:

IMemoryCache<K,V>

public class SoftReferenceMemoryCache<K,V>
extends AbstractMemoryCache<K,V>

A JCS IMemoryCache that has SoftReference to all its values. This cache does not respect ICompositeCacheAttributes.getMaxObjects() as overflowing is handled by Java GC.

The cache also has strong references to a maximum number of objects given by the maxObjects parameter

Field Summary

Fields inherited from class org.apache.commons.jcs3.engine.memory.AbstractMemoryCache

chunkSize, hitCnt, lock, map, missCnt, putCnt

Constructor Summary

Constructors

Constructor	Description
SoftReferenceMemoryCache()

Method Summary

Modifier and Type	Method	Description
ConcurrentMap<K,MemoryElementDescriptor<K,V>>	createMap()	Children must implement this method.
int	freeElements(int numberToFree)	This can't be implemented.
Set<K>	getKeySet()	Get an Array of the keys for all elements in the memory cache
int	getSize()	Returns the current cache size.
IStats	getStatistics()	Returns the historical and statistical data for a region's memory cache.
void	initialize(CompositeCache<K,V> hub)	For post reflection creation initialization
protected void	lockedGetElement(MemoryElementDescriptor<K,V> me)	Update control structures after get (guarded by the lock)
protected void	lockedRemoveAll()	Removes all cached items from the cache control structures.
protected void	lockedRemoveElement(MemoryElementDescriptor<K,V> me)	Remove element from control structure (guarded by the lock)
void	update(ICacheElement<K,V> ce)	Puts an item to the cache.

Methods inherited from class org.apache.commons.jcs3.engine.memory.AbstractMemoryCache

dispose, dumpMap, get, getCacheAttributes, getCacheName, getCompositeCache, getMultiple, getQuiet, remove, removeAll, removeByGroup, removeByHierarchy, setCacheAttributes, waterfal

Methods inherited from class java.lang.Object

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

Constructor Details

SoftReferenceMemoryCache

public SoftReferenceMemoryCache()

Method Details

initialize

public void initialize(CompositeCache<K,V> hub)

For post reflection creation initialization

Specified by:

initialize in interface IMemoryCache<K,V>

Overrides:

initialize in class AbstractMemoryCache<K,V>

Parameters:

hub -

createMap

public ConcurrentMap<K,MemoryElementDescriptor<K,V>> createMap()

Description copied from class: AbstractMemoryCache

Children must implement this method. A FIFO implementation may use a tree map. An LRU might use a hashtable. The map returned should be threadsafe.

Specified by:

createMap in class AbstractMemoryCache<K,V>

Returns:

a threadsafe Map

See Also:

• AbstractMemoryCache.createMap()

getKeySet

public Set<K> getKeySet()

Description copied from class: AbstractMemoryCache

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

Specified by:

getKeySet in interface IMemoryCache<K,V>

Overrides:

getKeySet in class AbstractMemoryCache<K,V>

Returns:

An Object[]

See Also:

• IMemoryCache.getKeySet()

getSize

public int getSize()

Returns the current cache size.

Specified by:

getSize in interface IMemoryCache<K,V>

Overrides:

getSize in class AbstractMemoryCache<K,V>

Returns:

The size value

getStatistics

public IStats getStatistics()

Description copied from interface: IMemoryCache

Returns the historical and statistical data for a region's memory cache.

Specified by:

getStatistics in interface IMemoryCache<K,V>

Overrides:

getStatistics in class AbstractMemoryCache<K,V>

Returns:

statistics about the cache

lockedGetElement

protected void lockedGetElement(MemoryElementDescriptor<K,V> me)

Update control structures after get (guarded by the lock)

Specified by:

lockedGetElement in class AbstractMemoryCache<K,V>

Parameters:

me - the memory element descriptor

lockedRemoveElement

protected void lockedRemoveElement(MemoryElementDescriptor<K,V> me)

Remove element from control structure (guarded by the lock)

Specified by:

lockedRemoveElement in class AbstractMemoryCache<K,V>

Parameters:

me - the memory element descriptor

lockedRemoveAll

protected void lockedRemoveAll()

Removes all cached items from the cache control structures. (guarded by the lock)

Specified by:

lockedRemoveAll in class AbstractMemoryCache<K,V>

update

public void update(ICacheElement<K,V> ce)
            throws IOException

Puts an item to the cache.

Specified by:

update in interface IMemoryCache<K,V>

Specified by:

update in class AbstractMemoryCache<K,V>

Parameters:

ce - Description of the Parameter

Throws:

IOException - Description of the Exception

freeElements

public int freeElements(int numberToFree)
                 throws IOException

This can't be implemented.

Parameters:

numberToFree -

Returns:

0

Throws:

IOException