Module org.omnifaces

Package org.omnifaces.util.cache

Class LruCache<K extends Serializable,V extends Serializable>

java.lang.Object

org.omnifaces.util.cache.LruCache<K,V>

Type Parameters:

K - The generic map key type.

V - The generic map value type.

All Implemented Interfaces:

Serializable, ConcurrentMap<K,V>, Map<K,V>

public class LruCache<K extends Serializable,V extends Serializable>
extends Object
implements ConcurrentMap<K,V>, Serializable

Minimal implementation of thread safe LRU cache with support for eviction listener. Inspired by ConcurrentLinkedHashMap.

The compute methods hold the lock while the function runs, so the function must be short and must not access this cache, else it will block every other caller or deadlock. The eviction listener runs after the lock is released.

Since:

4.4

Author:

Bauke Scholtz

See Also:

• Serialized Form

Nested Class Summary

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

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

Constructor Summary

Constructors

Constructor	Description
LruCache(int maximumCapacity)	Construct LRU cache with given maximum capacity.
LruCache(int maximumCapacity, FunctionalInterfaces.SerializableBiConsumer<K,V> evictionListener)	Construct LRU cache with given maximum capacity and eviction listener.

Method Summary

Modifier and Type	Method	Description
void	clear()
V	compute(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)
V	computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction)
V	computeIfPresent(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
boolean	isEmpty()
Set<K>	keySet()
V	merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction)
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> map)
V	putIfAbsent(K key, V value)
V	remove(Object key)
boolean	remove(Object key, Object value)
V	replace(K key, V value)
boolean	replace(K key, V oldValue, V newValue)
int	size()
Collection<V>	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.concurrent.ConcurrentMap

forEach, getOrDefault, replaceAll

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Details

LruCache

public LruCache(int maximumCapacity)

Construct LRU cache with given maximum capacity.

Parameters:

maximumCapacity - The maximum capacity.

Throws:

IllegalArgumentException - when maximum capacity is less than 2.

LruCache

public LruCache(int maximumCapacity,
 FunctionalInterfaces.SerializableBiConsumer<K,V> evictionListener)

Construct LRU cache with given maximum capacity and eviction listener.

Parameters:

maximumCapacity - The maximum capacity.

evictionListener - The eviction listener.

Throws:

IllegalArgumentException - when maximum capacity is less than 2.

Method Details

get

public V get(Object key)

Specified by:

get in interface Map<K extends Serializable,V extends Serializable>

put

public V put(K key,
 V value)

Specified by:

put in interface Map<K extends Serializable,V extends Serializable>

putIfAbsent

public V putIfAbsent(K key,
 V value)

Specified by:

putIfAbsent in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

putIfAbsent in interface Map<K extends Serializable,V extends Serializable>

computeIfAbsent

public V computeIfAbsent(K key,
 Function<? super K,? extends V> mappingFunction)

Specified by:

computeIfAbsent in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

computeIfAbsent in interface Map<K extends Serializable,V extends Serializable>

computeIfPresent

public V computeIfPresent(K key,
 BiFunction<? super K,? super V,? extends V> remappingFunction)

Specified by:

computeIfPresent in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

computeIfPresent in interface Map<K extends Serializable,V extends Serializable>

compute

public V compute(K key,
 BiFunction<? super K,? super V,? extends V> remappingFunction)

Specified by:

compute in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

compute in interface Map<K extends Serializable,V extends Serializable>

merge

public V merge(K key,
 V value,
 BiFunction<? super V,? super V,? extends V> remappingFunction)

Specified by:

merge in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

merge in interface Map<K extends Serializable,V extends Serializable>

putAll

public void putAll(Map<? extends K,? extends V> map)

Specified by:

putAll in interface Map<K extends Serializable,V extends Serializable>

remove

public V remove(Object key)

Specified by:

remove in interface Map<K extends Serializable,V extends Serializable>

remove

public boolean remove(Object key,
 Object value)

Specified by:

remove in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

remove in interface Map<K extends Serializable,V extends Serializable>

replace

public V replace(K key,
 V value)

Specified by:

replace in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

replace in interface Map<K extends Serializable,V extends Serializable>

replace

public boolean replace(K key,
 V oldValue,
 V newValue)

Specified by:

replace in interface ConcurrentMap<K extends Serializable,V extends Serializable>

Specified by:

replace in interface Map<K extends Serializable,V extends Serializable>

clear

public void clear()

Specified by:

clear in interface Map<K extends Serializable,V extends Serializable>

size

public int size()

Specified by:

size in interface Map<K extends Serializable,V extends Serializable>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K extends Serializable,V extends Serializable>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K extends Serializable,V extends Serializable>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K extends Serializable,V extends Serializable>

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K extends Serializable,V extends Serializable>

values

public Collection<V> values()

Specified by:

values in interface Map<K extends Serializable,V extends Serializable>

entrySet

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

Specified by:

entrySet in interface Map<K extends Serializable,V extends Serializable>