Package io.debezium.util

Class BoundedConcurrentHashMap.LRU<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

java.util.LinkedHashMap<BoundedConcurrentHashMap.HashEntry<K,V>,V>

io.debezium.util.BoundedConcurrentHashMap.LRU<K,V>

All Implemented Interfaces:

BoundedConcurrentHashMap.EvictionPolicy<K,V>, Serializable, Cloneable, Map<BoundedConcurrentHashMap.HashEntry<K,V>,V>

Enclosing class:

BoundedConcurrentHashMap<K,V>

static final class BoundedConcurrentHashMap.LRU<K,V>
extends LinkedHashMap<BoundedConcurrentHashMap.HashEntry<K,V>,V>
implements BoundedConcurrentHashMap.EvictionPolicy<K,V>

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K extends Object,V extends Object>, AbstractMap.SimpleImmutableEntry<K extends Object,V extends Object>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K extends Object,V extends Object>

Field Summary

Fields

Modifier and Type	Field	Description
private final ConcurrentLinkedQueue<BoundedConcurrentHashMap.HashEntry<K,V>>	accessQueue
private final float	batchThresholdFactor
private final Set<BoundedConcurrentHashMap.HashEntry<K,V>>	evicted
private final int	maxBatchQueueSize
private final BoundedConcurrentHashMap.Segment<K,V>	segment
private static final long	serialVersionUID	The serialVersionUID
private final int	trimDownSize

Fields inherited from interface io.debezium.util.BoundedConcurrentHashMap.EvictionPolicy

MAX_BATCH_SIZE

Constructor Summary

Constructors

Constructor	Description
LRU(BoundedConcurrentHashMap.Segment<K,V> s, int capacity, float lf, int maxBatchSize, float batchThresholdFactor)

Method Summary

Modifier and Type	Method	Description
void	clear()	Invoked to notify EvictionPolicy implementation that all Segment entries have been cleared.
BoundedConcurrentHashMap.HashEntry<K,V>	createNewEntry(K key, int hash, BoundedConcurrentHashMap.HashEntry<K,V> next, V value)
Set<BoundedConcurrentHashMap.HashEntry<K,V>>	execute()	Invokes eviction policy algorithm and returns set of evicted entries.
protected boolean	isAboveThreshold()
boolean	onEntryHit(BoundedConcurrentHashMap.HashEntry<K,V> e)	Invoked to notify EvictionPolicy implementation that an entry in Segment has been accessed.
Set<BoundedConcurrentHashMap.HashEntry<K,V>>	onEntryMiss(BoundedConcurrentHashMap.HashEntry<K,V> e)	Invoked to notify EvictionPolicy implementation that there has been an attempt to access an entry in Segment, however that entry was not present in Segment.
void	onEntryRemove(BoundedConcurrentHashMap.HashEntry<K,V> e)	Invoked to notify EvictionPolicy implementation that an entry e has been removed from Segment.
protected boolean	removeEldestEntry(Map.Entry<BoundedConcurrentHashMap.HashEntry<K,V>,V> eldest)
BoundedConcurrentHashMap.Eviction	strategy()	Returns type of eviction algorithm (strategy).
boolean	thresholdExpired()	Returns true if batching threshold has expired, false otherwise.

Methods inherited from class java.util.LinkedHashMap

containsValue, entrySet, forEach, get, getOrDefault, keySet, replaceAll, values

Methods inherited from class java.util.HashMap

clone, compute, computeIfAbsent, computeIfPresent, containsKey, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, containsKey, equals, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Field Details

serialVersionUID

private static final long serialVersionUID

The serialVersionUID

See Also:

• Constant Field Values

accessQueue

private final ConcurrentLinkedQueue<BoundedConcurrentHashMap.HashEntry<K,V>> accessQueue

segment

private final BoundedConcurrentHashMap.Segment<K,V> segment

maxBatchQueueSize

private final int maxBatchQueueSize

trimDownSize

private final int trimDownSize

batchThresholdFactor

private final float batchThresholdFactor

evicted

private final Set<BoundedConcurrentHashMap.HashEntry<K,V>> evicted

Constructor Details

LRU

public LRU(BoundedConcurrentHashMap.Segment<K,V> s,
 int capacity,
 float lf,
 int maxBatchSize,
 float batchThresholdFactor)

Method Details

execute

public Set<BoundedConcurrentHashMap.HashEntry<K,V>> execute()

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Invokes eviction policy algorithm and returns set of evicted entries.

Set cannot be null but could possibly be an empty set.

Specified by:

execute in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Returns:

set of evicted entries.

onEntryMiss

public Set<BoundedConcurrentHashMap.HashEntry<K,V>> onEntryMiss(BoundedConcurrentHashMap.HashEntry<K,V> e)

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Invoked to notify EvictionPolicy implementation that there has been an attempt to access an entry in Segment, however that entry was not present in Segment.

Specified by:

onEntryMiss in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Parameters:

e - accessed entry in Segment

Returns:

non null set of evicted entries.

onEntryHit

public boolean onEntryHit(BoundedConcurrentHashMap.HashEntry<K,V> e)

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Invoked to notify EvictionPolicy implementation that an entry in Segment has been accessed. Returns true if batching threshold has been reached, false otherwise.

Note that this method is potentially invoked without holding a lock on Segment.

Specified by:

onEntryHit in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Parameters:

e - accessed entry in Segment

Returns:

true if batching threshold has been reached, false otherwise.

thresholdExpired

public boolean thresholdExpired()

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Returns true if batching threshold has expired, false otherwise.

Note that this method is potentially invoked without holding a lock on Segment.

Specified by:

thresholdExpired in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Returns:

true if batching threshold has expired, false otherwise.

onEntryRemove

public void onEntryRemove(BoundedConcurrentHashMap.HashEntry<K,V> e)

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Invoked to notify EvictionPolicy implementation that an entry e has been removed from Segment.

Specified by:

onEntryRemove in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Parameters:

e - removed entry in Segment

clear

public void clear()

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Invoked to notify EvictionPolicy implementation that all Segment entries have been cleared.

Specified by:

clear in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class LinkedHashMap<BoundedConcurrentHashMap.HashEntry<K,V>,V>

strategy

public BoundedConcurrentHashMap.Eviction strategy()

Description copied from interface: BoundedConcurrentHashMap.EvictionPolicy

Returns type of eviction algorithm (strategy).

Specified by:

strategy in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>

Returns:

type of eviction algorithm

isAboveThreshold

protected boolean isAboveThreshold()

removeEldestEntry

protected boolean removeEldestEntry(Map.Entry<BoundedConcurrentHashMap.HashEntry<K,V>,V> eldest)

Overrides:

removeEldestEntry in class LinkedHashMap<BoundedConcurrentHashMap.HashEntry<K,V>,V>

createNewEntry

public BoundedConcurrentHashMap.HashEntry<K,V> createNewEntry(K key,
 int hash,
 BoundedConcurrentHashMap.HashEntry<K,V> next,
 V value)

Specified by:

createNewEntry in interface BoundedConcurrentHashMap.EvictionPolicy<K,V>