org.glassfish.hk2.utilities.cache
Class LRUCache<K,V>

java.lang.Object
  org.glassfish.hk2.utilities.cache.LRUCache<K,V>

Direct Known Subclasses:

LRUCacheImpl

public abstract class LRUCache<K,V>
extends java.lang.Object

A cache that contains a certain number of entries, and whose oldest accessed entries are removed when removal is necessary.

Author:

jwells

Constructor Summary

LRUCache()

Method Summary

static <K,V> LRUCache<K,V>	createCache(int maxCacheSize) Creates a cache with the given maximum cache size
abstract V	get(K key) Returns the value associated with the given key.
abstract int	getMaxCacheSize() Returns the maximum number of entries that will be stored in this cache
abstract CacheEntry	put(K key, V value) Adds the given key and value pair into the cache
abstract void	releaseCache() Clears all entries in the cache, for use when a known event makes the cache incorrect

Methods inherited from class java.lang.Object

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

Constructor Detail

LRUCache

public LRUCache()

Method Detail

createCache

public static <K,V> LRUCache<K,V> createCache(int maxCacheSize)

Creates a cache with the given maximum cache size

Parameters:

maxCacheSize - The maximum number of entries in the cache, must be greater than 2

Returns:

An LRUCache that can be used to quickly retrieve objects

get

public abstract V get(K key)

Returns the value associated with the given key. If there is no value, returns null

Parameters:

key - Must be a non-null key, appropriate for use as the key to a hash map

Returns:

The value associated with the key, or null if there is no such value

put

public abstract CacheEntry put(K key,
                               V value)

Adds the given key and value pair into the cache

Parameters:

key - Must be a non-null key, appropriate for use as the key to a hash map

value - Must be a non-null value

Returns:

A cache entry that can be used to remove this entry from the cache. Will not return null

releaseCache

public abstract void releaseCache()

Clears all entries in the cache, for use when a known event makes the cache incorrect

getMaxCacheSize

public abstract int getMaxCacheSize()

Returns the maximum number of entries that will be stored in this cache

Returns:

The maximum number of entries that will be stored in this cache