cz.cuni.amis.utils.maps
Class WeakHashTriMap<PRIMARY_KEY,SECONDARY_KEY,TERTIARY_KEY,ITEM>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>
          cz.cuni.amis.utils.maps.WeakHashTriMap<PRIMARY_KEY,SECONDARY_KEY,TERTIARY_KEY,ITEM>

Type Parameters:

PRIMARY_KEY -

SECONDARY_KEY -

TERTIARY_KEY -

ITEM -

All Implemented Interfaces:

Map<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

public class WeakHashTriMap<PRIMARY_KEY,SECONDARY_KEY,TERTIARY_KEY,ITEM>
extends WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

Three-level hash map, where the PRIMARY_KEY maps are implemented using WeakHashMap. This means, that the PRIMARY_KEY maps, may be garbage collected unless there is a direct reference to the PRIMARY_KEY.

Author:

srlok

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

WeakHashTriMap()
Creates a WeakHashTriMap with default loadFactor(0.75) and default starting capacities (16,16,16)

WeakHashTriMap(int primaryCapacity, int secondaryCapacity, int tertiaryCapacity)
Creates a new WeakHashTriMap with the default loadFactor (0.75) for all levels and the provided starting capacties for different levels.

Method Summary

Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>	get(Object primaryKey) Returns a HashMap> Never returns null, if the map under primary key doesn't exist, an empty one is added and returned.
Map<TERTIARY_KEY,ITEM>	get(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey) Returns the requested map, never returns null.
ITEM	get(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey, TERTIARY_KEY tertiaryKey) Returns item specified, returns null if item does not appear in the map.
void	put(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey, TERTIARY_KEY tertiaryKey, ITEM item) Puts the item into the map.
Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>	remove(Object primaryKey) Removes the requested map.
Map<TERTIARY_KEY,ITEM>	remove(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey) removes the map under primary and secondary key, if the map does not exist, the data structure is not changed and a new map is returned.
ITEM	remove(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey, TERTIARY_KEY tertiaryKey) Returns the item under specified keys and removes it from the map, returns null if item is not present in the map.

Methods inherited from class java.util.WeakHashMap

clear, containsKey, containsValue, entrySet, isEmpty, keySet, put, putAll, size, values

Methods inherited from class java.util.AbstractMap

clone, equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

WeakHashTriMap

public WeakHashTriMap()

Creates a WeakHashTriMap with default loadFactor(0.75) and default starting capacities (16,16,16)

WeakHashTriMap

public WeakHashTriMap(int primaryCapacity,
                      int secondaryCapacity,
                      int tertiaryCapacity)

Creates a new WeakHashTriMap with the default loadFactor (0.75) for all levels and the provided starting capacties for different levels.

Parameters:

primaryCapacity -

secondaryCapacity -

tertiaryCapacity -

Method Detail

get

public Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>> get(Object primaryKey)

Returns a HashMap> Never returns null, if the map under primary key doesn't exist, an empty one is added and returned.

Specified by:

get in interface Map<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

Overrides:

get in class WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

Parameters:

primaryKey -

Returns:

get

public Map<TERTIARY_KEY,ITEM> get(PRIMARY_KEY primaryKey,
                                  SECONDARY_KEY secondaryKey)

Returns the requested map, never returns null. If the map does not exist an empty map is created and returned.

Parameters:

primaryKey -

secondaryKey -

Returns:

get

public ITEM get(PRIMARY_KEY primaryKey,
                SECONDARY_KEY secondaryKey,
                TERTIARY_KEY tertiaryKey)

Returns item specified, returns null if item does not appear in the map.

Parameters:

primaryKey -

secondaryKey -

tertiaryKey -

Returns:

put

public void put(PRIMARY_KEY primaryKey,
                SECONDARY_KEY secondaryKey,
                TERTIARY_KEY tertiaryKey,
                ITEM item)

Puts the item into the map.

Parameters:

primaryKey -

secondaryKey -

tertiaryKey -

item -

remove

public Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>> remove(Object primaryKey)

Removes the requested map. If the map doesn't exist, returns an empty map.

Specified by:

remove in interface Map<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

Overrides:

remove in class WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,Map<TERTIARY_KEY,ITEM>>>

remove

public Map<TERTIARY_KEY,ITEM> remove(PRIMARY_KEY primaryKey,
                                     SECONDARY_KEY secondaryKey)

removes the map under primary and secondary key, if the map does not exist, the data structure is not changed and a new map is returned.

Parameters:

primaryKey -

secondaryKey -

Returns:

remove

public ITEM remove(PRIMARY_KEY primaryKey,
                   SECONDARY_KEY secondaryKey,
                   TERTIARY_KEY tertiaryKey)

Returns the item under specified keys and removes it from the map, returns null if item is not present in the map.

Parameters:

primaryKey -

secondaryKey -

tertiaryKey -

Returns: