org.apache.cocoon.components.store.impl
Class MRUMemoryStore

java.lang.Object
  org.apache.cocoon.components.store.impl.MRUMemoryStore

All Implemented Interfaces:

Store

Direct Known Subclasses:

DefaultStore, DefaultTransientStore

public class MRUMemoryStore

extends Object

implements Store

This class provides a cache algorithm for the requested documents. It combines a HashMap and a LinkedList to create a so called MRU (Most Recently Used) cache. Adapted from org.apache.excalibur.store.impl.MRUMemoryStore

Version:

$Id: MRUMemoryStore.html 1304280 2012-03-23 11:18:01Z ilgrosso $

Field Summary

protected boolean

persistent

Fields inherited from interface org.apache.excalibur.store.Store

PERSISTENT_STORE, ROLE, TRANSIENT_STORE

Constructor Summary

MRUMemoryStore()

Method Summary

void	clear() Clear the Store of all elements
boolean	containsKey(Object key) Indicates if the given key is associated to a contained object.
void	destroy() Dispose the component
void	free() Frees some of the fast memory used by this store.
Object	get(Object key) Get the object associated to the given unique key.
Log	getLogger()
void	hold(Object key, Object value) This method holds the requested object in a HashMap combined with a LinkedList to create the MRU.
void	init() Initialize the MRUMemoryStore.
Enumeration	keys() Returns the list of used keys as an Enumeration.
void	remove(Object key) Remove the object associated to the given key.
void	setLogger(Log l)
void	setMaxObjects(int maxobjects) Indicates how many objects will be held in the cache.
void	setPersistentStore(Store persistentStore) Set to keep objects persisted after container shutdown
void	setStoreJanitor(StoreJanitor storeJanitor)
void	setUsePersistentStore(boolean persistent)
int	size() Returns count of the objects in the store, or -1 if could not be obtained.
void	store(Object key, Object value) Store the given object in a persistent state.

Methods inherited from class java.lang.Object

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

Field Detail

persistent

protected boolean persistent

Constructor Detail

MRUMemoryStore

public MRUMemoryStore()

Method Detail

getLogger

public Log getLogger()

setLogger

public void setLogger(Log l)

setMaxObjects

public void setMaxObjects(int maxobjects)

Indicates how many objects will be held in the cache. When the number of maxobjects has been reached. The last object in the cache will be thrown out. (Default: 100 objects)

Parameters:

maxobjects -

setUsePersistentStore

public void setUsePersistentStore(boolean persistent)

Parameters:

persistent -

setPersistentStore

public void setPersistentStore(Store persistentStore)

Set to keep objects persisted after container shutdown

Parameters:

persistentStore -

setStoreJanitor

public void setStoreJanitor(StoreJanitor storeJanitor)

Parameters:

storeJanitor -

init

public void init()
          throws Exception

Initialize the MRUMemoryStore.

Throws:

Exception

ParameterException

destroy

public void destroy()

Dispose the component

store

public void store(Object key,
                  Object value)

Store the given object in a persistent state. It is up to the caller to ensure that the key has a persistent state across different JVM executions.

Specified by:

store in interface Store

Parameters:

key - The key for the object to store

value - The object to store

hold

public void hold(Object key,
                 Object value)

This method holds the requested object in a HashMap combined with a LinkedList to create the MRU. It also stores objects onto the filesystem if configured.

Parameters:

key - The key of the object to be stored

value - The object to be stored

get

public Object get(Object key)

Get the object associated to the given unique key.

Specified by:

get in interface Store

Parameters:

key - The key of the requested object

Returns:

the requested object

remove

public void remove(Object key)

Remove the object associated to the given key.

Specified by:

remove in interface Store

Parameters:

key - The key of to be removed object

clear

public void clear()

Clear the Store of all elements

Specified by:

clear in interface Store

containsKey

public boolean containsKey(Object key)

Indicates if the given key is associated to a contained object.

Specified by:

containsKey in interface Store

Parameters:

key - The key of the object

Returns:

true if the key exists

keys

public Enumeration keys()

Returns the list of used keys as an Enumeration.

Specified by:

keys in interface Store

Returns:

the enumeration of the cache

size

public int size()

Returns count of the objects in the store, or -1 if could not be obtained.

Specified by:

size in interface Store

free

public void free()

Frees some of the fast memory used by this store. It removes the last element in the store.

Specified by:

free in interface Store