Package org.cache2k.core

Class SegmentedEviction

java.lang.Object

org.cache2k.core.SegmentedEviction

All Implemented Interfaces:

Eviction, EvictionMetrics

public class SegmentedEviction
extends Object
implements Eviction, EvictionMetrics

Forwards eviction operations to segments based on the hash code.

Author:

Jens Wilke

Constructor Summary

Constructors

Constructor	Description
SegmentedEviction(Eviction[] segments)

Method Summary

Modifier and Type	Method	Description
void	changeCapacity(long entryCountOrWeight)	Change the capacity.
void	checkIntegrity(IntegrityState integrityState)
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	evictEventuallyBeforeInsert()	Evict if needed, checks all segments.
void	evictEventuallyBeforeInsertOnSegment(int hashCodeHint)	Evict if needed, focused on the segment addressed by the hash code.
long	getEvictedCount()	Number of entries evicted
long	getEvictedWeight()	Accumulated weight of evicted or deleted entries
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	getHitCount()	Number of recorded hits.
long	getMaxSize()	Size limit after eviction kicks in
long	getMaxWeight()
EvictionMetrics	getMetrics()
long	getNewEntryCount()
long	getRemovedCount()
long	getSize()	Number of entries in the eviction data structure
long	getTotalWeight()	Accumulated weight of all entries currently controlled by eviction.
long	getVirginRemovedCount()	Removal of an entry that was never used
boolean	isWeigherPresent()
long	removeAll()	Remove all entries from the eviction data structure.
<T> T	runLocked(Supplier<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	submitWithoutTriggeringEviction(Entry e)	Submit to eviction for inserting or removing from the replacement list.
boolean	updateWeight(Entry e)	Updates the weight on the entry and recalculates the total weight if needed.

Methods inherited from class java.lang.Object

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

Constructor Detail

SegmentedEviction

public SegmentedEviction(Eviction[] segments)

Method Detail

updateWeight

public boolean updateWeight(Entry e)

Description copied from interface: Eviction

Updates the weight on the entry and recalculates the total weight if needed.

Expected not to hold the entry lock, which means, that this does not run in sync with the actual update. That is okay as long as its runs after every update.

Since we need to lock the eviction structure, this could happen async in a separate thread.

Specified by:

updateWeight in interface Eviction

Returns:

hint whether eviction should be run. for bulk operations do eviction once. so not do it within this method

submitWithoutTriggeringEviction

public boolean submitWithoutTriggeringEviction(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:

submitWithoutTriggeringEviction in interface Eviction

evictEventuallyBeforeInsertOnSegment

public void evictEventuallyBeforeInsertOnSegment(int hashCodeHint)

Description copied from interface: Eviction

Evict if needed, focused on the segment addressed by the hash code. Called before a new entry is inserted (changed from after in v1.4)

Specified by:

evictEventuallyBeforeInsertOnSegment in interface Eviction

evictEventuallyBeforeInsert

public void evictEventuallyBeforeInsert()

Description copied from interface: Eviction

Evict if needed, checks all segments. Called before a new entry is inserted (changed from after in v1.4)

Specified by:

evictEventuallyBeforeInsert in interface Eviction

evictEventually

public void evictEventually()

Description copied from interface: Eviction

Evict if needed, checks all segments.

Specified by:

evictEventually in interface Eviction

removeAll

public long removeAll()

Description copied from interface: Eviction

Remove all entries from the eviction data structure.

Specified by:

removeAll in interface Eviction

Returns:

entry count

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

close

public void close()

Description copied from interface: Eviction

Free resources, for example thread pool or queue.

Specified by:

close 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

runLocked

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

Description copied from interface: Eviction

Runs job making sure concurrent evictions operations pause.

Specified by:

runLocked in interface Eviction

checkIntegrity

public void checkIntegrity(IntegrityState integrityState)

Specified by:

checkIntegrity in interface Eviction

getMetrics

public EvictionMetrics getMetrics()

Specified by:

getMetrics in interface Eviction

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

getHitCount

public long getHitCount()

Description copied from interface: EvictionMetrics

Number of recorded hits.

Specified by:

getHitCount in interface EvictionMetrics

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()

getExpiredRemovedCount

public long getExpiredRemovedCount()

Description copied from interface: EvictionMetrics

Removed entries, because expired

Specified by:

getExpiredRemovedCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getExpiredCount()

getVirginRemovedCount

public long getVirginRemovedCount()

Description copied from interface: EvictionMetrics

Removal of an entry that was never used

Specified by:

getVirginRemovedCount in interface EvictionMetrics

getEvictedCount

public long getEvictedCount()

Description copied from interface: EvictionMetrics

Number of entries evicted

Specified by:

getEvictedCount in interface EvictionMetrics

See Also:

InternalCacheInfo.getEvictedCount()

getSize

public long getSize()

Description copied from interface: EvictionMetrics

Number of entries in the eviction data structure

Specified by:

getSize in interface EvictionMetrics

getMaxSize

public long getMaxSize()

Description copied from interface: EvictionMetrics

Size limit after eviction kicks in

Specified by:

getMaxSize in interface EvictionMetrics

getMaxWeight

public long getMaxWeight()

Specified by:

getMaxWeight in interface EvictionMetrics

getTotalWeight

public long getTotalWeight()

Description copied from interface: EvictionMetrics

Accumulated weight of all entries currently controlled by eviction.

Specified by:

getTotalWeight in interface EvictionMetrics

getEvictionRunningCount

public int getEvictionRunningCount()

Description copied from interface: EvictionMetrics

Number of eviction currently going on

Specified by:

getEvictionRunningCount in interface EvictionMetrics

getEvictedWeight

public long getEvictedWeight()

Description copied from interface: EvictionMetrics

Accumulated weight of evicted or deleted entries

Specified by:

getEvictedWeight in interface EvictionMetrics

isWeigherPresent

public boolean isWeigherPresent()

Specified by:

isWeigherPresent in interface Eviction

changeCapacity

public void changeCapacity(long entryCountOrWeight)

Description copied from interface: Eviction

Change the capacity. If capacity is reduced, it will evict entries before returning.

Specified by:

changeCapacity in interface Eviction