edu.pdx.cs399J
Class AbstractLRUMap<K,V>

java.lang.Object
  java.util.AbstractMap<K,V>
      edu.pdx.cs399J.AbstractLRUMap<K,V>

All Implemented Interfaces:

Map<K,V>

public abstract class AbstractLRUMap<K,V>
extends AbstractMap<K,V>

This is the abstract superclass of an "LRU Map". An LRU Map is a Java Map that has a bounded number of mappings. If a new mapping is added to an LRU Map that already has the maximum number of mappings, then the least recently used mapping is removed. An element is used when it is added to or gotten from the Map.

Nested Class Summary

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

Map.Entry<K,V>

Field Summary

protected int

capacity The maximum number of mappings that this map can hold

Constructor Summary

protected

AbstractLRUMap(int capacity) Creates a new LRU Map that will hold a given number of mappings

Method Summary

abstract void	clear()
abstract V	get(Object key) Getting an element from a map marks the mapping as "used".
abstract List<String>	getStudentNames() Returns the names of the students who implemented this LRU Map.
abstract V	put(K key, V value) When a mapping is made in an LRU that already contains the maximum number of mappings, the Least Recently Used element is removed.
void	putAll(Map<? extends K,? extends V> map)
abstract V	remove(Object key) Removes the given key from this map.

Methods inherited from class java.util.AbstractMap

clone, containsKey, containsValue, entrySet, equals, hashCode, isEmpty, keySet, size, toString, values

Methods inherited from class java.lang.Object

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

Field Detail

capacity

protected int capacity

The maximum number of mappings that this map can hold

Constructor Detail

AbstractLRUMap

protected AbstractLRUMap(int capacity)

Creates a new LRU Map that will hold a given number of mappings

Parameters:

capacity - The maximum number of mappings in this map

Throws:

IllegalArgumentException - capacity is negative

Method Detail

getStudentNames

public abstract List<String> getStudentNames()

Returns the names of the students who implemented this LRU Map.

put

public abstract V put(K key,
                      V value)

When a mapping is made in an LRU that already contains the maximum number of mappings, the Least Recently Used element is removed.

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

get

public abstract V get(Object key)

Getting an element from a map marks the mapping as "used". Note that the type of key must be Object so that, after type erasure, it will be compatible with the pre-generic API.

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

remove

public abstract V remove(Object key)

Removes the given key from this map. Note that the type of key must be Object so that, after type erasure, it will be compatible with the pre-generic API.

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

putAll

public void putAll(Map<? extends K,? extends V> map)

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class AbstractMap<K,V>

clear

public abstract void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>