net.sf.farrago.util
Class FarragoLruVictimPolicy

java.lang.Object
  net.sf.farrago.util.FarragoLruVictimPolicy

All Implemented Interfaces:

FarragoCacheVictimPolicy

public class FarragoLruVictimPolicy
extends Object
implements FarragoCacheVictimPolicy

FarragoLruVictimPolicy implements an LRU caching policy for the FarragoObjectCache.

This class assumes that synchronization is handled by its caller.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/util/FarragoLruVictimPolicy.java#6 $

Author:

Zelaine Fong

Field Summary

private LinkedHashSet<FarragoCacheEntry>

lruCacheOrder LRU ordering of objects in the cache.

Constructor Summary

FarragoLruVictimPolicy()

Method Summary

void	accessEntry(FarragoCacheEntry entry) Receives notification that an existing entry in the cache is being accessed.
void	clearCache() Receives notification that all entries are being removed from the cache
Iterator<FarragoCacheEntry>	getVictimIterator() Returns an iterator corresponding to a list of potential entries for removal from the cache, in the order of precedence.
FarragoCacheEntry	newEntry(FarragoObjectCache parentCache) Creates a new cache entry
void	registerEntry(FarragoCacheEntry entry) Receives notification that a new entry is being added to the cache.
void	unregisterEntry(FarragoCacheEntry entry) Receives notification that an entry is being removed from the cache.
void	unregisterEntry(Iterator victimRange) Unregisters the current entry being accessed from the victim range

Methods inherited from class java.lang.Object

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

Field Detail

lruCacheOrder

private final LinkedHashSet<FarragoCacheEntry> lruCacheOrder

LRU ordering of objects in the cache. The linked list provides the LRU ordering.

Constructor Detail

FarragoLruVictimPolicy

public FarragoLruVictimPolicy()

Method Detail

newEntry

public FarragoCacheEntry newEntry(FarragoObjectCache parentCache)

Description copied from interface: FarragoCacheVictimPolicy

Creates a new cache entry

Specified by:

newEntry in interface FarragoCacheVictimPolicy

Parameters:

parentCache - the cache this entry is associated with

registerEntry

public void registerEntry(FarragoCacheEntry entry)

Description copied from interface: FarragoCacheVictimPolicy

Receives notification that a new entry is being added to the cache.

Specified by:

registerEntry in interface FarragoCacheVictimPolicy

Parameters:

entry - new entry being added to the cache

unregisterEntry

public void unregisterEntry(Iterator victimRange)

Description copied from interface: FarragoCacheVictimPolicy

Unregisters the current entry being accessed from the victim range

Specified by:

unregisterEntry in interface FarragoCacheVictimPolicy

Parameters:

victimRange - iterator corresponding to the victim range

unregisterEntry

public void unregisterEntry(FarragoCacheEntry entry)

Description copied from interface: FarragoCacheVictimPolicy

Receives notification that an entry is being removed from the cache.

Specified by:

unregisterEntry in interface FarragoCacheVictimPolicy

Parameters:

entry - entry to be removed

accessEntry

public void accessEntry(FarragoCacheEntry entry)

Description copied from interface: FarragoCacheVictimPolicy

Receives notification that an existing entry in the cache is being accessed.

Specified by:

accessEntry in interface FarragoCacheVictimPolicy

Parameters:

entry - entry being accessed

getVictimIterator

public Iterator<FarragoCacheEntry> getVictimIterator()

Description copied from interface: FarragoCacheVictimPolicy

Returns an iterator corresponding to a list of potential entries for removal from the cache, in the order of precedence.

Specified by:

getVictimIterator in interface FarragoCacheVictimPolicy

Returns:

iterator corresponding to cache victims

clearCache

public void clearCache()

Description copied from interface: FarragoCacheVictimPolicy

Receives notification that all entries are being removed from the cache

Specified by:

clearCache in interface FarragoCacheVictimPolicy