Package org.jboss.as.naming.util

Class FastCopyHashMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.jboss.as.naming.util.FastCopyHashMap<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>

public class FastCopyHashMap<K,V>
extends AbstractMap<K,V>
implements Map<K,V>, Cloneable, Serializable

A HashMap that is optimized for fast shallow copies. If the copy-ctor is passed another FastCopyHashMap, or clone is called on this map, the shallow copy can be performed using little more than a single array copy. In order to accomplish this, immutable objects must be used internally, so update operations result in slightly more object churn than HashMap.

Note: It is very important to use a smaller load factor than you normally would for HashMap, since the implementation is open-addressed with linear probing. With a 50% load-factor a get is expected to return in only 2 probes. However, a 90% load-factor is expected to return in around 50 probes.

Author:

Jason T. Greene

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	FastCopyHashMap.SimpleEntry<K,V>

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

AbstractMap.SimpleImmutableEntry<K extends Object,V extends Object>

Constructor Summary

Constructors

Constructor	Description
FastCopyHashMap()
FastCopyHashMap(int initialCapacity)
FastCopyHashMap(int initialCapacity, float loadFactor)
FastCopyHashMap(Map<? extends K,? extends V> map)

Method Summary

Modifier and Type	Method	Description
void	clear()
FastCopyHashMap<K,V>	clone()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
boolean	isEmpty()
Set<K>	keySet()
void	printDebugStats()
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> map)
V	remove(Object key)
int	size()
Collection<V>	values()

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Constructor Details

FastCopyHashMap

public FastCopyHashMap(int initialCapacity,
 float loadFactor)

FastCopyHashMap

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

FastCopyHashMap

public FastCopyHashMap(int initialCapacity)

FastCopyHashMap

public FastCopyHashMap()

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>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get 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>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue 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>

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>

remove

public V remove(Object key)

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

clear

public void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

clone

public FastCopyHashMap<K,V> clone()

Overrides:

clone in class AbstractMap<K,V>

printDebugStats

public void printDebugStats()

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet 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>

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

Overrides:

values in class AbstractMap<K,V>