net.sf.saxon.expr.sort

Class LRUCache<K,V>

java.lang.Object

net.sf.saxon.expr.sort.LRUCache<K,V>

public class LRUCache<K,V>
extends Object

An LRU cache, based on LinkedHashMap. Synthesized and simplified from various published examples of the genre. The methods are not synchronized.

Constructor Summary

Constructors

Constructor and Description
LRUCache(int cacheSize) Creates a new LRU cache.
LRUCache(int cacheSize, boolean concurrent) Creates a new LRU cache, with the option of making it thread-safe

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clear the cache
V	get(K key) Retrieves an entry from the cache. The retrieved entry becomes the most recently used entry.
void	put(K key, V value) Adds an entry to this cache.
int	size() Get the number of entries in the cache

Methods inherited from class java.lang.Object

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

Constructor Detail

LRUCache

public LRUCache(int cacheSize)

Creates a new LRU cache.

Parameters:

cacheSize - the maximum number of entries that will be kept in this cache.

LRUCache

public LRUCache(int cacheSize,
        boolean concurrent)

Creates a new LRU cache, with the option of making it thread-safe

Parameters:

cacheSize - the maximum number of entries that will be kept in this cache.

concurrent - set to true if concurrent access is required, so that access will be synchronized

Method Detail

get

public V get(K key)

Retrieves an entry from the cache.
The retrieved entry becomes the most recently used entry.

Parameters:

key - the key whose associated value is to be returned.

Returns:

the value associated to this key, or null if no value with this key exists in the cache.

put

public void put(K key,
       V value)

Adds an entry to this cache. If the cache is full, the LRU (least recently used) entry is dropped.

Parameters:

key - the key with which the specified value is to be associated.

value - a value to be associated with the specified key.

clear

public void clear()

Clear the cache

size

public int size()

Get the number of entries in the cache

Returns:

the number of entries