Package com.globalmentor.collections

Class PurgeOnWriteWeakValueHashMap<K,V>

java.lang.Object

com.globalmentor.collections.AbstractPurgeOnWriteReferenceValueMap<K,V,PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>>

com.globalmentor.collections.PurgeOnWriteWeakValueHashMap<K,V>

Type Parameters:

K - The type of key.

V - The type of value.

All Implemented Interfaces:

java.util.Map<K,V>

public class PurgeOnWriteWeakValueHashMap<K,V>
extends AbstractPurgeOnWriteReferenceValueMap<K,V,PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>>

A map that uses weak references to store map values. Values are only purged when map write operations occur. null values are not supported.

Author:

Garret Wilson

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>	A weak reference that keeps track of the key with which a value was associated.

Nested classes/interfaces inherited from class com.globalmentor.collections.AbstractPurgeOnWriteReferenceValueMap

AbstractPurgeOnWriteReferenceValueMap.Keyed<K>

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

java.util.Map.Entry<K extends java.lang.Object,V extends java.lang.Object>

Constructor Summary

Constructors

Modifier	Constructor	Description
	PurgeOnWriteWeakValueHashMap()	Default constructor with a default initial capacity and load factor.
	PurgeOnWriteWeakValueHashMap(int initialCapacity)	Empty map constructor with the specified initial capacity and a default load factor.
	PurgeOnWriteWeakValueHashMap(int initialCapacity, float loadFactor)	Empty map constructor with the specified initial capacity and load factor.
protected	PurgeOnWriteWeakValueHashMap(java.util.Map<K,PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>> map)	Decorated map constructor.

Method Summary

Modifier and Type	Method	Description
protected PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>	createReference(K key, V value, java.lang.ref.ReferenceQueue<V> referenceQueue)	Creates the appropriate reference for associating the given value with the given key.

Methods inherited from class com.globalmentor.collections.AbstractPurgeOnWriteReferenceValueMap

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, purge, purgeExcept, put, putAll, remove, size, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Constructor Detail

PurgeOnWriteWeakValueHashMap

public PurgeOnWriteWeakValueHashMap(int initialCapacity,
                                    float loadFactor)

Empty map constructor with the specified initial capacity and load factor.

Parameters:

initialCapacity - The initial capacity.

loadFactor - The load factor.

Throws:

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

PurgeOnWriteWeakValueHashMap

public PurgeOnWriteWeakValueHashMap(int initialCapacity)

Empty map constructor with the specified initial capacity and a default load factor.

Parameters:

initialCapacity - The initial capacity.

Throws:

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

PurgeOnWriteWeakValueHashMap

public PurgeOnWriteWeakValueHashMap()

Default constructor with a default initial capacity and load factor.

PurgeOnWriteWeakValueHashMap

protected PurgeOnWriteWeakValueHashMap(java.util.Map<K,PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>> map)

Decorated map constructor.

Parameters:

map - The map to decorate.

Throws:

java.lang.NullPointerException - If the map is null.

Method Detail

createReference

protected PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V> createReference(K key,
                                                                                     V value,
                                                                                     java.lang.ref.ReferenceQueue<V> referenceQueue)

Creates the appropriate reference for associating the given value with the given key. The reference will be registered with the given queue.

Specified by:

createReference in class AbstractPurgeOnWriteReferenceValueMap<K,V,PurgeOnWriteWeakValueHashMap.WeakValueReference<K,V>>

Parameters:

key - The key with which the value is being associated.

value - The value to be stored.

referenceQueue - The queue with which the reference will be registered.

Returns:

A reference to the given value that also indicates the key being used.