org.cache2k.core

Class AbstractEviction

java.lang.Object

org.cache2k.core.AbstractEviction

All Implemented Interfaces:

Eviction, EvictionMetrics

Direct Known Subclasses:

ClockProPlusEviction, RandomEviction

public abstract class AbstractEviction
extends Object
implements Eviction, EvictionMetrics

Basic eviction functionality.

Author:

Jens Wilke

Field Summary

Fields

Modifier and Type	Field and Description
protected long	correctedMaxSize
protected HeapCache	heapCache
static int	MAXIMAL_CHUNK_SIZE
protected long	maxSize
static int	MINIMAL_CHUNK_SIZE
static long	MINIMUM_CAPACITY_FOR_CHUNKING

Constructor Summary

Constructors

Constructor and Description
AbstractEviction(HeapCache _heapCache, HeapCacheListener _listener, long _maxSize)

Method Summary

Modifier and Type	Method and Description
void	close() Free resources, for example thread pool or queue.
boolean	drain() Drain eviction queue and do updates in the eviction data structures.
void	evictEventually() Evict if needed, checks all segments.
void	evictEventually(int hc) Evict if needed, focused on the segment addressed by the hash code.
protected abstract Entry	findEvictionCandidate(Entry e) Find a candidate for eviction.
long	getEvictedCount() Number of entries evicted
int	getEvictionRunningCount() Number of eviction currently going on
long	getExpiredRemovedCount() Removed entries, because expired
String	getExtraStatistics() Fragment that the eviction wants to add to the Cache.toString() output.
long	getMaxSize() Size limit after eviction kicks in
EvictionMetrics	getMetrics()
long	getNewEntryCount()
long	getRemovedCount()
long	getVirginRemovedCount() Removal of an entry that was never used
protected abstract void	insertIntoReplacementList(Entry e)
protected abstract void	removeFromReplacementList(Entry e)
protected void	removeFromReplacementListOnEvict(Entry e)
<T> T	runLocked(Job<T> j) Runs job making sure concurrent evictions operations pause.
void	start() Start concurrent eviction threads.
void	stop() Stop concurrent threads that may access the eviction data structures.
boolean	submitWithoutEviction(Entry e) Submit to eviction for inserting or removing from the replacement list.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cache2k.core.Eviction

checkIntegrity, removeAll

Methods inherited from interface org.cache2k.core.EvictionMetrics

getHitCount, getSize

Field Detail

MINIMAL_CHUNK_SIZE

public static final int MINIMAL_CHUNK_SIZE

See Also:

Constant Field Values

MAXIMAL_CHUNK_SIZE

public static final int MAXIMAL_CHUNK_SIZE

See Also:

Constant Field Values

MINIMUM_CAPACITY_FOR_CHUNKING

public static final long MINIMUM_CAPACITY_FOR_CHUNKING

See Also:

Constant Field Values

maxSize

protected final long maxSize

correctedMaxSize

protected final long correctedMaxSize

heapCache

protected final HeapCache heapCache

Constructor Detail

AbstractEviction

public AbstractEviction(HeapCache _heapCache,
                        HeapCacheListener _listener,
                        long _maxSize)

Method Detail

submitWithoutEviction

public boolean submitWithoutEviction(Entry e)

Description copied from interface: Eviction

Submit to eviction for inserting or removing from the replacement list. However, eviction should not be triggered (which in turn triggers a hash table update) since the hash segment lock is hold at the moment.

Specified by:

submitWithoutEviction in interface Eviction

evictEventually

public void evictEventually()

Description copied from interface: Eviction

Evict if needed, checks all segments.

Specified by:

evictEventually in interface Eviction

evictEventually

public void evictEventually(int hc)

Description copied from interface: Eviction

Evict if needed, focused on the segment addressed by the hash code. Called when eviction is might be needed after a new entry was inserted.

Specified by:

evictEventually in interface Eviction

getNewEntryCount

public long getNewEntryCount()

Specified by:

getNewEntryCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getNewEntryCount()

getRemovedCount

public long getRemovedCount()

Specified by:

getRemovedCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getRemoveCount()

getVirginRemovedCount

public long getVirginRemovedCount()

Description copied from interface: EvictionMetrics

Removal of an entry that was never used

Specified by:

getVirginRemovedCount in interface EvictionMetrics

getExpiredRemovedCount

public long getExpiredRemovedCount()

Description copied from interface: EvictionMetrics

Removed entries, because expired

Specified by:

getExpiredRemovedCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getExpiredCount()

getEvictedCount

public long getEvictedCount()

Description copied from interface: EvictionMetrics

Number of entries evicted

Specified by:

getEvictedCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getEvictedCount()

getMaxSize

public long getMaxSize()

Description copied from interface: EvictionMetrics

Size limit after eviction kicks in

Specified by:

getMaxSize in interface EvictionMetrics

getEvictionRunningCount

public int getEvictionRunningCount()

Description copied from interface: EvictionMetrics

Number of eviction currently going on

Specified by:

getEvictionRunningCount in interface EvictionMetrics

getMetrics

public EvictionMetrics getMetrics()

Specified by:

getMetrics in interface Eviction

start

public void start()

Description copied from interface: Eviction

Start concurrent eviction threads.

Specified by:

start in interface Eviction

stop

public void stop()

Description copied from interface: Eviction

Stop concurrent threads that may access the eviction data structures. Needs to be called before checkIntegrity or accessing the counter values.

Specified by:

stop in interface Eviction

drain

public boolean drain()

Description copied from interface: Eviction

Drain eviction queue and do updates in the eviction data structures. Does no eviction when size limit is reached.

Specified by:

drain in interface Eviction

Returns:

true, if eviction is needed

close

public void close()

Description copied from interface: Eviction

Free resources, for example thread pool or queue.

Specified by:

close in interface Eviction

runLocked

public <T> T runLocked(Job<T> j)

Description copied from interface: Eviction

Runs job making sure concurrent evictions operations pause.

Specified by:

runLocked in interface Eviction

removeFromReplacementListOnEvict

protected void removeFromReplacementListOnEvict(Entry e)

findEvictionCandidate

protected abstract Entry findEvictionCandidate(Entry e)

Find a candidate for eviction. The caller needs to provide the previous eviction candidate if this method is called multiple times until a fit is found.

Parameters:

e - null or previous found eviction candidate returned by this method. This is currently not used by the implemented eviction methods but might be in the future.

removeFromReplacementList

protected abstract void removeFromReplacementList(Entry e)

insertIntoReplacementList

protected abstract void insertIntoReplacementList(Entry e)

getExtraStatistics

public String getExtraStatistics()

Description copied from interface: EvictionMetrics

Fragment that the eviction wants to add to the Cache.toString() output.

Specified by:

getExtraStatistics in interface EvictionMetrics