com.tangosol.util

Class CopyOnWriteMap<K,V>

java.lang.Object

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

All Implemented Interfaces:

Map<K,V>

public class CopyOnWriteMap<K,V>
extends Object
implements Map<K,V>

A thread-safe variant of Map in which all mutating operations (e.g. put, putAll) are implemented by making a fresh copy of the underlying map.

Iterators over this map are guaranteed to produce a safe-iteration and not to throw ConcurrentModificationException. The iterator will not reflect concurrent additions, removals, or changes to this map.

Note: mutations on this map are costly, but may be more efficient than alternatives when "get" operations vastly outnumber mutations. All mutating operations are synchronized, so concurrent mutation can be prevented by holding synchronization on this object.

Since:

Coherence 3.7.2

Author:

pp 2011.09.17, rhl 2010.09.09 (from CopyOnWriteLongArray)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	CopyOnWriteMap.EntrySet A set of entries backed by this map.
protected class	CopyOnWriteMap.KeySet A set of keys backed by this map.

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

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
CopyOnWriteMap(Class clazz)
CopyOnWriteMap(Map<K,V> map) Construct a CopyOnWriteMap, initialized with the contents of the specified map.

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object oKey)
boolean	containsValue(Object oValue)
protected Map<K,V>	copyMap(Map<K,V> map) Create an instance of Map based on the contents of the provided map.
Set<Map.Entry<K,V>>	entrySet() Return a set view of the underlying map.
boolean	equals(Object o)
V	get(Object oKey)
protected Map<K,V>	getInternalMap() Return the internal map.
int	hashCode()
protected Map<K,V>	instantiateMap(Class clazz) Create a new instance of Map based on the provided Class.
boolean	isEmpty()
Set<K>	keySet() Returns a Set view of the keys contained in the underlying map.
V	put(K oKey, V oValue)
void	putAll(Map<? extends K,? extends V> map)
V	remove(Object oKey)
protected void	setInternalMap(Map<K,V> map) Set the internal map.
int	size()
String	toString()
Collection<V>	values()

Methods inherited from class java.lang.Object

clone, 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

Constructor Detail

CopyOnWriteMap

public CopyOnWriteMap(Class clazz)

CopyOnWriteMap

public CopyOnWriteMap(Map<K,V> map)

Construct a CopyOnWriteMap, initialized with the contents of the specified map.

Parameters:

map - the initial map

Method Detail

getInternalMap

protected Map<K,V> getInternalMap()

Return the internal map.

Returns:

the internal map

setInternalMap

protected void setInternalMap(Map<K,V> map)

Set the internal map.

Parameters:

map - the new internal map

instantiateMap

protected Map<K,V> instantiateMap(Class clazz)

Create a new instance of Map based on the provided Class.

Parameters:

clazz - the type of Map to instantiate

Returns:

a new empty instance of Map

Throws:

IllegalArgumentException - if the provided Class does not implement Map.

copyMap

protected Map<K,V> copyMap(Map<K,V> map)

Create an instance of Map based on the contents of the provided map.

Parameters:

map - the map to copy

Returns:

an instance of Map populated with the contents of the provided map

size

public int size()

Specified by:

size in interface Map<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

containsKey

public boolean containsKey(Object oKey)

Specified by:

containsKey in interface Map<K,V>

containsValue

public boolean containsValue(Object oValue)

Specified by:

containsValue in interface Map<K,V>

get

public V get(Object oKey)

Specified by:

get in interface Map<K,V>

put

public V put(K oKey,
             V oValue)

Specified by:

put in interface Map<K,V>

remove

public V remove(Object oKey)

Specified by:

remove in interface Map<K,V>

putAll

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

Specified by:

putAll in interface Map<K,V>

clear

public void clear()

Specified by:

clear in interface Map<K,V>

keySet

public Set<K> keySet()

Returns a Set view of the keys contained in the underlying map.

Specified by:

keySet in interface Map<K,V>

Returns:

a Set view of the keys contained in the underlying map

entrySet

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

Return a set view of the underlying map.

Specified by:

entrySet in interface Map<K,V>

Returns:

a set view of the underlying map

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

equals

public boolean equals(Object o)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object