com.eibus.util

Class MRUCache<KeyType,ValueType>

java.lang.Object

java.util.Dictionary<KeyType,ValueType>

com.eibus.util.MRUCache<KeyType,ValueType>

public class MRUCache<KeyType,ValueType>
extends java.util.Dictionary<KeyType,ValueType>

This class contains functionality for a Cache, based on a Most Recently Used algorithm. Objects are stored in and retrieved from the cache by key. The default size of the cache is 500. If you retrieve an object from the cache, it will be put at the front. If you put an object in the cache, it will be put at the front. If the cache is full when you put an object in it, the object at the back is removed. The cache retrieves objects by iterating through the list and calling the equals() method on each key.

Constructor Summary

Constructors

Constructor and Description
MRUCache() Creates an MRU Cache with size 500
MRUCache(int maximumSize) Creates an MRU Cache with the specified maximum size

Method Summary

Modifier and Type	Method and Description
protected void	cleanCachedValue(KeyType key, ValueType value) Release all claimed resources.
ValueType	computeIfAbsent(KeyType key, java.util.function.Function<? super KeyType,? extends ValueType> mappingFunction)
java.util.Enumeration<ValueType>	elements() Returns an enumeration of the elements in the cache
ValueType	get(java.lang.Object key) Retrieve the object in the list that has this key
protected int	getMaximumSize()
boolean	isEmpty() Returns true if the number of objects in the cache is 0 or less.
java.util.Enumeration<KeyType>	keys() Returns an enumeration of the keys in the cache
ValueType	put(KeyType key, ValueType element) Puts an object in the cache, by its key.
ValueType	remove(java.lang.Object key) Remove the object with the specified key from the cache.
protected void	setMaximumSize(int maxSize)
int	size() Returns the number of objects in the cache.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MRUCache

public MRUCache(int maximumSize)

Creates an MRU Cache with the specified maximum size

MRUCache

public MRUCache()

Creates an MRU Cache with size 500

Method Detail

isEmpty

public boolean isEmpty()

Returns true if the number of objects in the cache is 0 or less.

Specified by:

isEmpty in class java.util.Dictionary<KeyType,ValueType>

remove

public ValueType remove(java.lang.Object key)

Remove the object with the specified key from the cache.

Specified by:

remove in class java.util.Dictionary<KeyType,ValueType>

Parameters:

key - The key of the object to remove.

size

public int size()

Returns the number of objects in the cache.

Specified by:

size in class java.util.Dictionary<KeyType,ValueType>

get

public ValueType get(java.lang.Object key)

Retrieve the object in the list that has this key

Specified by:

get in class java.util.Dictionary<KeyType,ValueType>

put

public ValueType put(KeyType key,
                     ValueType element)

Puts an object in the cache, by its key. Returns the oldest object in the cache, or null, if the cache is not full.

Specified by:

put in class java.util.Dictionary<KeyType,ValueType>

computeIfAbsent

public ValueType computeIfAbsent(KeyType key,
                                 java.util.function.Function<? super KeyType,? extends ValueType> mappingFunction)

cleanCachedValue

protected void cleanCachedValue(KeyType key,
                                ValueType value)

Release all claimed resources.

Parameters:

key - Cache key

value - Cache Value whose resources needs to be released

elements

public java.util.Enumeration<ValueType> elements()

Returns an enumeration of the elements in the cache

Specified by:

elements in class java.util.Dictionary<KeyType,ValueType>

keys

public java.util.Enumeration<KeyType> keys()

Returns an enumeration of the keys in the cache

Specified by:

keys in class java.util.Dictionary<KeyType,ValueType>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getMaximumSize

protected int getMaximumSize()

setMaximumSize

protected void setMaximumSize(int maxSize)