org.terracotta.collections.chm
Class SelectableConcurrentHashMap<K,V>

java.lang.Object
  java.util.AbstractMap<K,V>
      org.terracotta.collections.chm.ConcurrentHashMap<K,V>
          org.terracotta.collections.chm.SelectableConcurrentHashMap<K,V>

All Implemented Interfaces:

Serializable, ConcurrentMap<K,V>, Map<K,V>

public class SelectableConcurrentHashMap<K,V>
extends ConcurrentHashMap<K,V>

SelectableConcurrentHashMap subclasses a repackaged version of ConcurrentHashMap ito allow efficient random sampling of the map values.

The random sampling technique involves randomly selecting a map Segment, and then selecting a number of random entry chains from that segment.

Author:

Chris Dennis

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.terracotta.collections.chm.ConcurrentHashMap

ConcurrentHashMap.HashEntry<K,V>

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

AbstractMap.SimpleImmutableEntry<K,V>

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

Map.Entry<K,V>

Constructor Summary

SelectableConcurrentHashMap()

SelectableConcurrentHashMap(int initialCapacity, float loadFactor, int concurrency)

Method Summary

Map.Entry<K,V>	getRandomEntry()
Map.Entry<K,V>	getRandomLocalEntry()
ConcurrentHashMap.HashEntry<K,V>	putReturnHashEntry(K key, V newValue)
ConcurrentHashMap.HashEntry<K,V>	removeReturnHashEntry(Object key)
ConcurrentHashMap.HashEntry<K,V>	removeReturnHashEntry(Object key, Object value)
ConcurrentHashMap.HashEntry<K,V>	replaceReturnHashEntry(K key, V newValue)
ConcurrentHashMap.HashEntry<K,V>	replaceReturnHashEntry(K key, V oldValue, V newValue)
boolean	replaceUsingReferenceEquality(K key, V oldValue, V newValue) Similar to ConcurrentHashMap.replace(Object, Object, Object), only difference is that it uses reference equality instead of object equality when comparing the oldValue and newValue

Methods inherited from class org.terracotta.collections.chm.ConcurrentHashMap

clear, contains, containsKey, containsValue, elements, entrySet, get, hash, isEmpty, keys, keySet, put, putAll, putIfAbsent, remove, remove, replace, replace, 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

SelectableConcurrentHashMap

public SelectableConcurrentHashMap()

SelectableConcurrentHashMap

public SelectableConcurrentHashMap(int initialCapacity,
                                   float loadFactor,
                                   int concurrency)

Method Detail

getRandomEntry

public Map.Entry<K,V> getRandomEntry()

getRandomLocalEntry

public Map.Entry<K,V> getRandomLocalEntry()

replaceUsingReferenceEquality

public boolean replaceUsingReferenceEquality(K key,
                                             V oldValue,
                                             V newValue)

Similar to ConcurrentHashMap.replace(Object, Object, Object), only difference is that it uses reference equality instead of object equality when comparing the oldValue and newValue

Throws:

NullPointerException - if any of the arguments are null

removeReturnHashEntry

public ConcurrentHashMap.HashEntry<K,V> removeReturnHashEntry(Object key)

removeReturnHashEntry

public ConcurrentHashMap.HashEntry<K,V> removeReturnHashEntry(Object key,
                                                              Object value)

replaceReturnHashEntry

public ConcurrentHashMap.HashEntry<K,V> replaceReturnHashEntry(K key,
                                                               V oldValue,
                                                               V newValue)

putReturnHashEntry

public ConcurrentHashMap.HashEntry<K,V> putReturnHashEntry(K key,
                                                           V newValue)

replaceReturnHashEntry

public ConcurrentHashMap.HashEntry<K,V> replaceReturnHashEntry(K key,
                                                               V newValue)