org.glassfish.hk2.utilities.cache.internal

Class LRUCacheCheapRead<K,V>

java.lang.Object

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

org.glassfish.hk2.utilities.cache.internal.LRUCacheCheapRead<K,V>

public class LRUCacheCheapRead<K,V>
extends LRUCache<K,V>

LRU Cache implementation that relies on entries that keep last hit (get/put) timestamp in order to be able to remove least recently accessed items when running out of cache capacity. Item order is not being maintained during regular cache usage (mainly reads). This makes pruning operation expensive in exchange for making reads quite cheap in a multi-threaded environment.

Author:

Jakub Podlesak (jakub.podlesak at oracle.com)

Constructor Summary

Constructors

Constructor and Description
LRUCacheCheapRead(int maxCacheSize) Create new cache with given maximum capacity.

Method Summary

Methods

Modifier and Type	Method and Description
V	get(K key) Returns the value associated with the given key.
int	getMaxCacheSize() Returns the maximum number of entries that will be stored in this cache
CacheEntry	put(K key, V value) Adds the given key and value pair into the cache
void	releaseCache() Clears all entries in the cache, for use when a known event makes the cache incorrect

Methods inherited from class org.glassfish.hk2.utilities.cache.LRUCache

createCache

Methods inherited from class java.lang.Object

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

Constructor Detail

LRUCacheCheapRead

public LRUCacheCheapRead(int maxCacheSize)

Create new cache with given maximum capacity.

Parameters:

maxCacheSize - Maximum number of items to keep.

Method Detail

get

public V get(K key)

Description copied from class: LRUCache

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

Specified by:

get in class LRUCache<K,V>

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 CacheEntry put(K key,
             V value)

Description copied from class: LRUCache

Adds the given key and value pair into the cache

Specified by:

put in class LRUCache<K,V>

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 void releaseCache()

Description copied from class: LRUCache

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

Specified by:

releaseCache in class LRUCache<K,V>

getMaxCacheSize

public int getMaxCacheSize()

Description copied from class: LRUCache

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

Specified by:

getMaxCacheSize in class LRUCache<K,V>

Returns:

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