com.sun.labs.minion.util
Class LRACache<K,V>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<K,V>
          java.util.LinkedHashMap<K,V>
              com.sun.labs.minion.util.LRACache<K,V>

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<K,V>

Direct Known Subclasses:

DocCache

public class LRACache<K,V>
extends java.util.LinkedHashMap<K,V>

A least-recently-accessed cache.

See Also:

Serialized Form

Nested Class Summary

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

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

Field Summary

protected static int	DEFAULT_SIZE The default cache size.
protected int	lraSize The number of items to be held in the cache.

Constructor Summary

LRACache()
Creates a cache of the default size.

LRACache(int size)
Creates a cache that will hold the given number of items.

Method Summary

protected boolean

removeEldestEntry(java.util.Map.Entry<K,V> eldest) Removes the oldest entry in the map.

Methods inherited from class java.util.LinkedHashMap

clear, containsValue, get

Methods inherited from class java.util.HashMap

clone, containsKey, entrySet, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

containsKey, entrySet, equals, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Field Detail

lraSize

protected int lraSize

The number of items to be held in the cache. If the size is less than 0, no elements will ever be removed.

DEFAULT_SIZE

protected static final int DEFAULT_SIZE

The default cache size.

See Also:

Constant Field Values

Constructor Detail

LRACache

public LRACache()

Creates a cache of the default size.

LRACache

public LRACache(int size)

Creates a cache that will hold the given number of items.

Parameters:

size - The number of elements to cache. If the size is less than 0, then the cache can grow unboundedly.

Method Detail

removeEldestEntry

protected boolean removeEldestEntry(java.util.Map.Entry<K,V> eldest)

Removes the oldest entry in the map.

Overrides:

removeEldestEntry in class java.util.LinkedHashMap<K,V>

Parameters:

eldest - The oldest entry.

Returns:

true if this entry should be removed, which will happen when the size of the map exceeds our cache size.