LRUCache (Undertow Core 2.3.20.Final API)

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

All Methods Instance Methods Concrete Methods
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()
```