Package org.broadleafcommerce.common.util

Class EfficientLRUMap<K,V>

java.lang.Object

org.broadleafcommerce.common.util.EfficientLRUMap<K,V>

All Implemented Interfaces:

Map<K,V>

public class EfficientLRUMap<K,V>
extends Object
implements Map<K,V>

This class provides an LRUMap structure that defaults to a more efficient ConcurrentHashMap if the size has not yet been reached.

In Broadleaf, there are many instances where an LRUMap could be used to guard against implementations where Map sizes grow in unexpected ways. However, the large majority of cases would fit well within the max bounds of the LRUMap.

This class provides an approach that provides the benefits of a LRUMap for memory protection while allowing concurrent access under normal circumstances.

For the first [n] entries, the underlying implementation will be a ConcurrentHashMap. On the "n+1"th entry, this implementation will switch its underlying implementation to a synchronized LRUMap.

Author:

bpolster

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
EfficientLRUMap(int maxEntries)

Method Summary

Modifier and Type	Method	Description
void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
protected Class	getUnderlyingMapClass()
boolean	isEmpty()
Set<K>	keySet()
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> m)
V	remove(Object key)
protected void	resetInternalMap()	We are clearing the map, so we can switch back to a ConcurrentHashMap
int	size()
protected boolean	switchToLRUMap()
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.Map

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

Constructor Details

EfficientLRUMap

public EfficientLRUMap(int maxEntries)

Method Details

size

public int size()

Specified by:

size in interface Map<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

put

public V put(K key,
 V value)

Specified by:

put in interface Map<K,V>

switchToLRUMap

protected boolean switchToLRUMap()

remove

public V remove(Object key)

Specified by:

remove in interface Map<K,V>

putAll

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

Specified by:

putAll in interface Map<K,V>

clear

public void clear()

Specified by:

clear in interface Map<K,V>

resetInternalMap

protected void resetInternalMap()

We are clearing the map, so we can switch back to a ConcurrentHashMap

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

entrySet

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

Specified by:

entrySet in interface Map<K,V>

getUnderlyingMapClass

protected Class getUnderlyingMapClass()