Module org.arakhne.afc.core.references

Package org.arakhne.afc.references

Class AbstractReferencedValueMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.arakhne.afc.references.AbstractReferencedValueMap<K,V>

Type Parameters:

K - is the type of the keys.

V - is the type of the values.

All Implemented Interfaces:

Map<K,V>

Direct Known Subclasses:

AbstractPhantomValueMap, AbstractSoftValueMap, AbstractWeakValueMap

public abstract class AbstractReferencedValueMap<K,V>
extends AbstractMap<K,V>

A Map implementation with weak/soft values. An entry in a AbstractReferencedValueMap will automatically be removed when its value is no longer in ordinary use or null.

This abstract implementation does not decide if the map is based on a tree or on a hashtable; it does not impose soft or weak references.

Since:

5.8

Version:

17.0 2020-01-04 14:41:38

Author:

Stéphane GALLAND

Maven Group Id:

org.arakhne.afc.core

Maven Artifact Id:

references

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	AbstractReferencedValueMap.PhantomReferencedValue<VKT,VVT>	Value stored in a AbstractReferencedValueMap inside a PhantomReference.
protected static interface	AbstractReferencedValueMap.ReferencableValue<K,V>	This interface provides information about the pairs inside a map with weak/soft reference values.
protected static class	AbstractReferencedValueMap.SoftReferencedValue<VKT,VVT>	Value stored in a AbstractReferencedValueMap inside a SoftReference.
protected static class	AbstractReferencedValueMap.WeakReferencedValue<VKT,VVT>	Value stored in a AbstractReferencedValueMap inside a WeakReference.

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
protected Map<K,AbstractReferencedValueMap.ReferencableValue<K,V>>	map	Internal map.
protected static Object	NULL_VALUE	Defines the NULL object inside a WeakValueMap.

Constructor Summary

Constructors

Constructor	Description
AbstractReferencedValueMap(Map<K,AbstractReferencedValueMap.ReferencableValue<K,V>> map)	Constructs an empty Map.

Method Summary

Modifier and Type	Method	Description
Set<Map.Entry<K,V>>	entrySet()
boolean	equals(Object obj)
void	expurge()	Clean the references that was released.
protected void	expurgeNow()	Clean the references that was marked as released inside the queue.
void	expurgeQueuedReferences()	Clean the references that was marked as released inside the queue.
(package private) static <T> T[]	finishToArray(T[] array, Iterator<?> it)	Reallocates the array being used within toArray when the iterator returned more elements than expected, and finishes filling it from the iterator.
int	hashCode()
boolean	isDeeplyExpurge()	Replies if this map expurge all the released references even if they are not enqueued by the virtual machine.
protected AbstractReferencedValueMap.ReferencableValue<K,V>	makeValue(K key, V value)	Create a storage object that permits to put the specified elements inside this map.
protected abstract AbstractReferencedValueMap.ReferencableValue<K,V>	makeValue(K key, V value, ReferenceQueue<V> refQueue)	Create a storage object that permits to put the specified elements inside this map.
protected static <VALUET> VALUET	maskNull(VALUET value)	Mask the null values given by the used of this map.
V	put(K key, V value)
boolean	setDeeplyExpurge(boolean deeplyExpurge)	Set if this map expurge all the released references even if they are not enqueued by the virtual machine.
protected static <VALUET> VALUET	unmaskNull(VALUET value)	Unmask the null values given by the used of this map.

Methods inherited from class java.util.AbstractMap

clear, clone, containsKey, containsValue, get, isEmpty, keySet, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Detail

NULL_VALUE

protected static final Object NULL_VALUE

Defines the NULL object inside a WeakValueMap.

See Also:

maskNull(Object)

map

protected final Map<K,AbstractReferencedValueMap.ReferencableValue<K,V>> map

Internal map.

Constructor Detail

AbstractReferencedValueMap

public AbstractReferencedValueMap(Map<K,AbstractReferencedValueMap.ReferencableValue<K,V>> map)

Constructs an empty Map.

Parameters:

map - is the map instance to use to store the entries.

Throws:

IllegalArgumentException - if the initial capacity is negative or the load factor is nonpositive

Method Detail

maskNull

@Pure
protected static <VALUET> VALUET maskNull(VALUET value)

Mask the null values given by the used of this map.

This method replaces the null value by the internal representation NULL_VALUE.

Type Parameters:

VALUET - is the type of the value.

Parameters:

value - is the value given by the user of this map.

Returns:

the internal representation of the value.

See Also:

unmaskNull(Object)

unmaskNull

@Pure
protected static <VALUET> VALUET unmaskNull(VALUET value)

Unmask the null values given by the used of this map.

This method replaces the internal representation NULL_VALUE of null values by its user representation null.

Type Parameters:

VALUET - is the type of the value.

Parameters:

value - is the value given by the user of this map.

Returns:

the internal representation of the value.

See Also:

maskNull(Object)

finishToArray

static <T> T[] finishToArray(T[] array,
                             Iterator<?> it)

Reallocates the array being used within toArray when the iterator returned more elements than expected, and finishes filling it from the iterator.

Type Parameters:

T - the type of the elements in the array.

Parameters:

array - the array, replete with previously stored elements

it - the in-progress iterator over this collection

Returns:

array containing the elements in the given array, plus any further elements returned by the iterator, trimmed to size

expurgeNow

protected final void expurgeNow()

Clean the references that was marked as released inside the queue.

isDeeplyExpurge

@Pure
public final boolean isDeeplyExpurge()

Replies if this map expurge all the released references even if they are not enqueued by the virtual machine.

Returns:

true is the values are deeply expurged when they are released from the moemory, otherwise false.

setDeeplyExpurge

public final boolean setDeeplyExpurge(boolean deeplyExpurge)

Set if this map expurge all the released references even if they are not enqueued by the virtual machine.

Parameters:

deeplyExpurge - must be true to expurge all the released values, otherwise false to expurge only the enqueued values.

Returns:

the old value of this flag

expurgeQueuedReferences

public final void expurgeQueuedReferences()

Clean the references that was marked as released inside the queue.

expurge

public final void expurge()

Clean the references that was released.

makeValue

protected abstract AbstractReferencedValueMap.ReferencableValue<K,V> makeValue(K key,
                                                                                     V value,
                                                                                     ReferenceQueue<V> refQueue)

Create a storage object that permits to put the specified elements inside this map.

Parameters:

key - is the key associated to the value

value - is the value

refQueue - is the reference queue to use

Returns:

the new storage object

makeValue

protected final AbstractReferencedValueMap.ReferencableValue<K,V> makeValue(K key,
                                                                                  V value)

Create a storage object that permits to put the specified elements inside this map.

Parameters:

key - is the key associated to the value

value - is the value

Returns:

the new storage object

put

public final V put(K key,
                   V value)

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

entrySet

@Pure
public final Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

equals

@Pure
public final boolean equals(Object obj)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class AbstractMap<K,V>

hashCode

@Pure
public final int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class AbstractMap<K,V>