uk.co.strangeskies.collection.computingmap

Class LRUCacheComputingMap<K,V>

java.lang.Object

uk.co.strangeskies.collection.computingmap.ComputingEntryHashMap<K,V>

uk.co.strangeskies.collection.computingmap.CacheComputingMap<K,V>

uk.co.strangeskies.collection.computingmap.LRUCacheComputingMap<K,V>

All Implemented Interfaces:

ComputingMap<K,V>, ReadOnlyMap<K,V>

public class LRUCacheComputingMap<K,V>
extends CacheComputingMap<K,V>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	LRUCacheComputingMap.LinkedEntry

Nested classes/interfaces inherited from class uk.co.strangeskies.collection.computingmap.CacheComputingMap

CacheComputingMap.KeyedReference, CacheComputingMap.ReferenceEntry

Nested classes/interfaces inherited from class uk.co.strangeskies.collection.computingmap.ComputingEntryHashMap

ComputingEntryHashMap.ComputingEntry, ComputingEntryHashMap.DeferredEntry, ComputingEntryHashMap.Entry<K,V>

Constructor Summary

Constructors

Modifier	Constructor and Description
	LRUCacheComputingMap(java.util.function.Function<K,V> computation, int maximumSize, boolean softReferences)
protected	LRUCacheComputingMap(LRUCacheComputingMap<K,V> other)

Method Summary

Modifier and Type	Method and Description
int	cacheSize()
boolean	clear() Remove all keys and values from the map.
protected ComputingEntryHashMap.Entry<K,V>	createEntry(K key)
V	get(K key) For the given key, this method should return the value which has been computed.
boolean	isEmpty()
boolean	put(K key) Enters the key into the map such that a value of type V will at some point be computed which will be then returned by any subsequent calls to ComputingMap.get(K).
boolean	putAll(java.util.Collection<? extends K> keys)
V	putGet(K key, java.util.function.Consumer<V> wasPresent, java.util.function.Consumer<V> wasMissing)
boolean	removeAll(java.util.Set<K> keys)

Methods inherited from class uk.co.strangeskies.collection.computingmap.CacheComputingMap

clean, removeGet

Methods inherited from class uk.co.strangeskies.collection.computingmap.ComputingEntryHashMap

computation, keySet, putGetImpl, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.co.strangeskies.collection.computingmap.ComputingMap

putGet, remove, removeAll

Methods inherited from interface uk.co.strangeskies.collection.computingmap.ReadOnlyMap

size

Constructor Detail

LRUCacheComputingMap

public LRUCacheComputingMap(java.util.function.Function<K,V> computation,
                            int maximumSize,
                            boolean softReferences)

LRUCacheComputingMap

protected LRUCacheComputingMap(LRUCacheComputingMap<K,V> other)

Method Detail

createEntry

protected ComputingEntryHashMap.Entry<K,V> createEntry(K key)

Overrides:

createEntry in class CacheComputingMap<K,V>

cacheSize

public int cacheSize()

get

public V get(K key)

Description copied from interface: ComputingMap

For the given key, this method should return the value which has been computed. This interface, by contract, provides no guarantees that the value for a previously entered key will still be contained within the map. Despite this, for keys which have not yet been entered into the map, an invocation of this method should simply return null, rather than attempting to compute the given value and then return it. Implementations are, of course, free to provide this guarantee.

Specified by:

get in interface ComputingMap<K,V>

Specified by:

get in interface ReadOnlyMap<K,V>

Overrides:

get in class CacheComputingMap<K,V>

Parameters:

key - The key object for which to return the mapped computed value

Returns:

The computed value associated with a given key

put

public boolean put(K key)

Description copied from interface: ComputingMap

Enters the key into the map such that a value of type V will at some point be computed which will be then returned by any subsequent calls to ComputingMap.get(K). Generally keys should be immutable, and the computation associated with the map will be expected to produce identical results each time, so in the case that the key has already been added to the map most implementations should just return instantly and do no work. Because of this it also makes little sense to return the previous value for a key entered more than once.

Specified by:

put in interface ComputingMap<K,V>

Overrides:

put in class CacheComputingMap<K,V>

Parameters:

key - The key object to be mapped to a new value

Returns:

True if the associated value was not already contained in the map, false otherwise

putAll

public boolean putAll(java.util.Collection<? extends K> keys)

putGet

public V putGet(K key,
                java.util.function.Consumer<V> wasPresent,
                java.util.function.Consumer<V> wasMissing)

Specified by:

putGet in interface ComputingMap<K,V>

Overrides:

putGet in class CacheComputingMap<K,V>

removeAll

public boolean removeAll(java.util.Set<K> keys)

clear

public boolean clear()

Description copied from interface: ComputingMap

Remove all keys and values from the map.

Specified by:

clear in interface ComputingMap<K,V>

Overrides:

clear in class ComputingEntryHashMap<K,V>

Returns:

True if the map contained keys, false if it was empty.

isEmpty

public boolean isEmpty()