uk.ac.starlink.ttools.server

Class SoftCache<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

uk.ac.starlink.ttools.server.SoftCache<K,V>

All Implemented Interfaces:

Map<K,V>

public class SoftCache<K,V>
extends AbstractMap<K,V>

Map implementation that stores values using SoftReference objects. This is therefore supposed to act like a memory-limited LRU cache. However, it's at the mercy of the JVM SoftReference implementation, so it's not guaranteed that it's going to do a good job of it.

Note: I read a comment somewhere that the Sun/Oracle JVM will drop these cache entries less aggressively if it's running in -server rather than -client mode.

Since:

14 Jan 2020

Author:

Mark Taylor

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

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

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
SoftCache() Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	containsKey(Object key)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
void	purge() Deletes any entries that have been garbage collected.
V	put(K key, V value)
V	remove(Object key)

Methods inherited from class java.util.AbstractMap

clear, clone, containsValue, equals, hashCode, isEmpty, keySet, putAll, 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

Constructor Detail

SoftCache

public SoftCache()

Constructor.

Method Detail

purge

public void purge()

Deletes any entries that have been garbage collected.

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

put

public V put(K key,
             V value)

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

remove

public V remove(Object key)

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>