Package com.tangosol.util

Class SetMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

com.tangosol.util.SetMap<K,V>

All Implemented Interfaces:

Map<K,V>

public class SetMap<K,V>
extends AbstractMap<K,V>

A Map implementation based on a known set of keys and a Function that when given a key can derive the value. Once a value has been derived for a key the function will not be called again for the same key.

This map can be mutated outside of the original set of keys or within the set of keys. The latter will result in the function not being called for the respective keys.

This implementation is the inverse to a MapSet which can trivially distill a Map of keys and values to a Set of keys. With the use of a Function this implementation allows a Set of keys to be converted lazily to a Map of keys and values.

Since:

12.2.1.4.0

Author:

hr 2016.09.29

Nested Class Summary

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

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

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

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
protected Function<K,V>	f_functionValue	A function to load a value for a provided key.
protected Map<K,Object>	f_map	The underlying map.

Constructor Summary

Constructors

Constructor	Description
SetMap(Set<K> setKeys)	Construct a SetMap.
SetMap(Set<K> setKeys, Function<K,V> functionValue)	Construct a SetMap.
SetMap(Set<K> setKeys, Function<K,V> functionValue, Supplier<Map<K,V>> supplierMap)	Construct a SetMap.

Method Summary

Modifier and Type	Method	Description
void	clear()
boolean	containsKey(Object key)
protected V	ensureValue(Object oKey)	Return a value for the specified key.
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
protected Map<K,V>	getExternalMap()	Return an external map allowing type safe access.
protected Map<K,Object>	getInternalMap()	Return the internal map allowing any object to be stored.
boolean	isEmpty()
Set<K>	keySet()
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> map)
V	remove(Object key)
int	size()

Methods inherited from class java.util.AbstractMap

clone, containsValue, equals, hashCode, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Details

f_map

protected Map<K,Object> f_map

The underlying map.

f_functionValue

protected Function<K,V> f_functionValue

A function to load a value for a provided key.

Constructor Details

SetMap

public SetMap(Set<K> setKeys)

Construct a SetMap.

Parameters:

setKeys - a set of keys to base this Map on

SetMap

public SetMap(Set<K> setKeys,
 Function<K,V> functionValue)

Construct a SetMap.

Parameters:

setKeys - a set of keys to base this Map on

functionValue - a Function to derive the value for a given key

SetMap

public SetMap(Set<K> setKeys,
 Function<K,V> functionValue,
 Supplier<Map<K,V>> supplierMap)

Construct a SetMap.

Parameters:

setKeys - a set of keys to base this Map on

functionValue - a Function to derive the value for a given key

supplierMap - the Map to use to hold keys and values

Method Details

size

public int size()

Specified by:

size in interface Map<K,V>

Overrides:

size in class AbstractMap<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class AbstractMap<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

put

public V put(K key,
 V value)

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

remove

public V remove(Object key)

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 void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class AbstractMap<K,V>

entrySet

public Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

getInternalMap

protected Map<K,Object> getInternalMap()

Return the internal map allowing any object to be stored.

Returns:

the internal map

getExternalMap

protected Map<K,V> getExternalMap()

Return an external map allowing type safe access.

Returns:

an external map

ensureValue

protected V ensureValue(Object oKey)

Return a value for the specified key.

Parameters:

oKey - the key to load a value for

Returns:

a value for the specified key