org.apache.hadoop.hbase.util

Class WeakObjectPool<K,V>

java.lang.Object

org.apache.hadoop.hbase.util.ObjectPool<K,V>

org.apache.hadoop.hbase.util.WeakObjectPool<K,V>

@InterfaceAudience.Private
public class WeakObjectPool<K,V>
extends ObjectPool<K,V>

A WeakReference based shared object pool. The objects are kept in weak references and associated with keys which are identified by the equals method. The objects are created by ObjectFactory on demand. The object creation is expected to be lightweight, and the objects may be excessively created and discarded. Thread safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	WeakObjectPool.WeakObjectReference

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.util.ObjectPool

ObjectPool.ObjectFactory<K,V>

Field Summary

Fields inherited from class org.apache.hadoop.hbase.util.ObjectPool

DEFAULT_CONCURRENCY_LEVEL, DEFAULT_INITIAL_CAPACITY, referenceCache, staleRefQueue

Constructor Summary

Constructors

Constructor and Description
WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory)
WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory, int initialCapacity)
WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory, int initialCapacity, int concurrencyLevel)

Method Summary

Modifier and Type	Method and Description
Reference<V>	createReference(K key, V obj) Create a reference associated with the given object
K	getReferenceKey(Reference<V> ref) Get key of the given reference

Methods inherited from class org.apache.hadoop.hbase.util.ObjectPool

get, purge, size

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WeakObjectPool

public WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory)

WeakObjectPool

public WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory,
                      int initialCapacity)

WeakObjectPool

public WeakObjectPool(ObjectPool.ObjectFactory<K,V> objectFactory,
                      int initialCapacity,
                      int concurrencyLevel)

Method Detail

createReference

public Reference<V> createReference(K key,
                                    V obj)

Description copied from class: ObjectPool

Create a reference associated with the given object

Specified by:

createReference in class ObjectPool<K,V>

Parameters:

key - the key to store in the reference

obj - the object to associate with

Returns:

the reference instance

getReferenceKey

public K getReferenceKey(Reference<V> ref)

Description copied from class: ObjectPool

Get key of the given reference

Specified by:

getReferenceKey in class ObjectPool<K,V>

Parameters:

ref - The reference

Returns:

key of the reference