io.undertow.server.handlers.cache

Class LRUCache<K,V>

java.lang.Object

io.undertow.server.handlers.cache.LRUCache<K,V>

public class LRUCache<K,V>
extends Object

A non-blocking cache where entries are indexed by a key.

To reduce contention, entry allocation and eviction execute in a sampling fashion (entry hits modulo N). Eviction follows an LRU approach (oldest sampled entries are removed first) when the cache is out of capacity.

This cache can also be configured to run in FIFO mode, rather than LRU.

Author:

Jason T. Greene, Stuart Douglas

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LRUCache.CacheEntry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
static int	MAX_AGE_NO_CACHING	Max age 0, indicating that entries expire upon creation and are not retained;
static int	MAX_AGE_NO_EXPIRY	Mage age -1, entries dont expire

Constructor Summary

Constructors

Constructor	Description
LRUCache(int maxEntries, int maxAge)
LRUCache(int maxEntries, int maxAge, boolean fifo)

Method Summary

Modifier and Type	Method	Description
void	add(K key, V newValue)
void	clear()
V	get(K key)
Set<K>	keySet()
V	remove(K key)

Methods inherited from class java.lang.Object

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

Field Detail

MAX_AGE_NO_CACHING

public static final int MAX_AGE_NO_CACHING

Max age 0, indicating that entries expire upon creation and are not retained;

See Also:

Constant Field Values

MAX_AGE_NO_EXPIRY

public static final int MAX_AGE_NO_EXPIRY

Mage age -1, entries dont expire

See Also:

Constant Field Values

Constructor Detail

LRUCache

public LRUCache(int maxEntries,
                int maxAge)

LRUCache

public LRUCache(int maxEntries,
                int maxAge,
                boolean fifo)

Method Detail

add

public void add(K key,
                V newValue)

get

public V get(K key)

keySet

public Set<K> keySet()

remove

public V remove(K key)

clear

public void clear()