org.jasig.portal.concurrency.caching
Class ReferenceEntityCache

java.lang.Object
  org.jasig.portal.concurrency.caching.ReferenceEntityCache

All Implemented Interfaces:

IEntityCache

Direct Known Subclasses:

ReferenceInvalidatingEntityCache

public class ReferenceEntityCache
extends java.lang.Object
implements IEntityCache

Reference implementation of IEntityCache. Each cache holds entities of a single type in an LRUCache, a kind of HashMap. Synchronization for get(), add() and remove() is handled by the LRUCache. At intervals, the cleanupThread kicks off a sweep of the cache to trim it down to its maximum size.

Version:

$Revision: 1.16.2.2 $

Author:

Dan Ellentuck

See Also:

LRUCache

Nested Class Summary

protected class

ReferenceEntityCache.CacheSweeper

Field Summary

protected java.util.Map	cache
protected java.lang.Thread	cleanupThread
protected java.lang.Class	entityType
protected org.apache.commons.logging.Log	log Commons Logging instance configured to log as the runtime class.
protected java.lang.String	simpleTypeName
protected int	sweepIntervalMillis
protected static int	threadID

Constructor Summary

ReferenceEntityCache(java.lang.Class type, int maxSize, int maxUnusedTime, int sweepInterval)
ReferenceEntityCache constructor comment.

Method Summary

void	add(IBasicEntity entity) Checks that entity is the same type as, i.e., could be cast to, the cache type.
void	cleanupCache() Remove stale entries from the cache.
void	clearCache() Remove all entries from the cache.
(package private) void	debug(java.lang.String msg) Deprecated. Use Commons Logging directly.
IBasicEntity	get(java.lang.String key)
protected java.util.Map	getCache()
java.lang.Class	getEntityType()
private java.lang.String	getSimpleTypeName()
private void	initializeEntityType(java.lang.Class type)
void	remove(java.lang.String key)
protected void	setCache(java.util.Map newCache)
int	size() Answers the number of entries in the cache.
java.lang.String	toString() Returns a String that represents the value of this object.
void	update(IBasicEntity entity)

Methods inherited from class java.lang.Object

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

Field Detail

log

protected final org.apache.commons.logging.Log log

Commons Logging instance configured to log as the runtime class. Available to subclasses for logging, and used in the implementation of debug() so that debug messages will log as the runtime class.

cache

protected java.util.Map cache

entityType

protected java.lang.Class entityType

simpleTypeName

protected java.lang.String simpleTypeName

threadID

protected static int threadID

sweepIntervalMillis

protected int sweepIntervalMillis

cleanupThread

protected java.lang.Thread cleanupThread

Constructor Detail

ReferenceEntityCache

public ReferenceEntityCache(java.lang.Class type,
                            int maxSize,
                            int maxUnusedTime,
                            int sweepInterval)
                     throws CachingException

ReferenceEntityCache constructor comment.

Throws:

CachingException

Method Detail

add

public void add(IBasicEntity entity)
         throws CachingException

Checks that entity is the same type as, i.e., could be cast to, the cache type.

Specified by:

add in interface IEntityCache

Parameters:

entity - the entity to be added to the cache.

Throws:

CachingException

initializeEntityType

private void initializeEntityType(java.lang.Class type)
                           throws CachingException

Throws:

CachingException

cleanupCache

public void cleanupCache()

Remove stale entries from the cache.

Specified by:

cleanupCache in interface IEntityCache

clearCache

public void clearCache()

Remove all entries from the cache.

Specified by:

clearCache in interface IEntityCache

debug

void debug(java.lang.String msg)

Deprecated. Use Commons Logging directly.

Print a debug message prepended with the current time.

This method is deprecated. Instead use Commons Logging directly. Backing logging implementations such as log4j have capabilities for including (and formatting) the timestamps of log entries without that timestamp being explicitly generated here in the logging client.

While this method internally guards against needless additional object creation, code calling this method should itself use the isDebugEnabled() guard in order to avoid generating intermediary Strings as the msg argument to this method.

get

public IBasicEntity get(java.lang.String key)

Specified by:

get in interface IEntityCache

Parameters:

key - the key of the entity.

Returns:

org.jasig.portal.concurrency.IBasicEntity

getCache

protected java.util.Map getCache()

Returns:

java.util.Map

getEntityType

public final java.lang.Class getEntityType()

Specified by:

getEntityType in interface IEntityCache

Returns:

java.lang.Class

See Also:

for known types.

remove

public void remove(java.lang.String key)
            throws CachingException

Specified by:

remove in interface IEntityCache

Parameters:

key - the key of the entity to be un-cached.

Throws:

CachingException

setCache

protected void setCache(java.util.Map newCache)

Parameters:

newCache - java.util.Map

size

public int size()

Description copied from interface: IEntityCache

Answers the number of entries in the cache.

Specified by:

size in interface IEntityCache

Returns:

int

toString

public java.lang.String toString()

Returns a String that represents the value of this object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the receiver

getSimpleTypeName

private java.lang.String getSimpleTypeName()

update

public void update(IBasicEntity entity)
            throws CachingException

Specified by:

update in interface IEntityCache

Parameters:

entity - the entity to be updated in the cache.

Throws:

CachingException