net.siefkes.nlstego.util
Class ExtendedLRUMap

java.lang.Object
  java.util.AbstractMap
      org.apache.commons.collections.map.AbstractHashedMap
          org.apache.commons.collections.map.AbstractLinkedMap
              org.apache.commons.collections.map.LRUMap
                  net.siefkes.nlstego.util.ExtendedLRUMap

All Implemented Interfaces:

Serializable, Cloneable, Map, BoundedMap, IterableMap, OrderedMap

public class ExtendedLRUMap
extends LRUMap

An extension of the LRUMap that also allows transparent (invisible) read operations which do not modify the access order of the map entries.

Version:

$Revision: 1.2 $, $Date: 2005/07/12 17:02:22 $, $Author: siefkes $

Author:

Christian Siefkes

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractLinkedMap

AbstractLinkedMap.EntrySetIterator, AbstractLinkedMap.KeySetIterator, AbstractLinkedMap.LinkEntry, AbstractLinkedMap.LinkIterator, AbstractLinkedMap.LinkMapIterator, AbstractLinkedMap.ValuesIterator

Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractHashedMap

AbstractHashedMap.EntrySet, AbstractHashedMap.HashEntry, AbstractHashedMap.HashIterator, AbstractHashedMap.HashMapIterator, AbstractHashedMap.KeySet, AbstractHashedMap.Values

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields inherited from class org.apache.commons.collections.map.LRUMap

DEFAULT_MAX_SIZE

Fields inherited from class org.apache.commons.collections.map.AbstractLinkedMap

header

Fields inherited from class org.apache.commons.collections.map.AbstractHashedMap

data, DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, entrySet, GETKEY_INVALID, GETVALUE_INVALID, keySet, loadFactor, MAXIMUM_CAPACITY, modCount, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID, size, threshold, values

Constructor Summary

ExtendedLRUMap()
Creates a new instance.

ExtendedLRUMap(int maxSize)
Creates a new instance.

ExtendedLRUMap(int maxSize, boolean scanUntilRemovable)
Creates a new instance.

ExtendedLRUMap(int maxSize, float loadFactor)
Creates a new instance.

ExtendedLRUMap(int maxSize, float loadFactor, boolean scanUntilRemovable)
Creates a new instance.

ExtendedLRUMap(Map map)
Constructor copying elements from another map.

ExtendedLRUMap(Map map, boolean scanUntilRemovable)
Constructor copying elements from another map.

Method Summary

Object

transparentGet(Object key) Returns the value to the specified key, without changing the LRU structure.

Methods inherited from class org.apache.commons.collections.map.LRUMap

addMapping, clone, doReadObject, doWriteObject, get, isFull, isScanUntilRemovable, maxSize, moveToMRU, removeLRU, reuseMapping, updateEntry

Methods inherited from class org.apache.commons.collections.map.AbstractLinkedMap

addEntry, clear, containsValue, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, entryAfter, entryBefore, firstKey, getEntry, init, lastKey, mapIterator, nextKey, orderedMapIterator, previousKey, removeEntry

Methods inherited from class org.apache.commons.collections.map.AbstractHashedMap

calculateNewCapacity, calculateThreshold, checkCapacity, containsKey, convertKey, destroyEntry, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, getEntry, hash, hashCode, hashIndex, isEmpty, isEqualKey, isEqualValue, keySet, put, putAll, remove, removeMapping, reuseEntry, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Constructor Detail

ExtendedLRUMap

public ExtendedLRUMap()

Creates a new instance.

ExtendedLRUMap

public ExtendedLRUMap(int maxSize)

Creates a new instance.

Parameters:

maxSize - the maximum size of the map

ExtendedLRUMap

public ExtendedLRUMap(int maxSize,
                      boolean scanUntilRemovable)

Creates a new instance.

Parameters:

maxSize - the maximum size of the map

scanUntilRemovable - scan until a removeable entry is found, default false

ExtendedLRUMap

public ExtendedLRUMap(int maxSize,
                      float loadFactor)

Creates a new instance.

Parameters:

maxSize - the maximum size of the map

loadFactor - the load factor

ExtendedLRUMap

public ExtendedLRUMap(int maxSize,
                      float loadFactor,
                      boolean scanUntilRemovable)

Creates a new instance.

Parameters:

maxSize - the maximum size of the map

loadFactor - the load factor

scanUntilRemovable - scan until a removeable entry is found, default false

ExtendedLRUMap

public ExtendedLRUMap(Map map)

Constructor copying elements from another map. The maximum size is set from the map's size.

Parameters:

map - the map to copy

ExtendedLRUMap

public ExtendedLRUMap(Map map,
                      boolean scanUntilRemovable)

Constructor copying elements from another map. The maximum size is set from the map's size.

Parameters:

map - the map to copy

scanUntilRemovable - scan until a removeable entry is found, default false

Method Detail

transparentGet

public Object transparentGet(Object key)

Returns the value to the specified key, without changing the LRU structure. Use this instead of get, if you want to make an "invisible" request that is ignored by the replacement algorithm.

Parameters:

key - the key to look up

Returns:

the mapped value, null if no match