Package org.apache.hadoop.hbase.util

Class PoolMap<K,V>

java.lang.Object

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

Type Parameters:

K - the type of the key to the resource

V - the type of the resource being pooled

@Private
public class PoolMap<K,V>
extends Object

The PoolMap maps a key to a collection of values, the elements of which are managed by a pool. In effect, that collection acts as a shared pool of resources, access to which is closely controlled as per the semantics of the pool.

In case the size of the pool is set to a non-zero positive number, that is used to cap the number of resources that a pool may contain for any given key. A size of Integer.MAX_VALUE is interpreted as an unbounded pool.

PoolMap is thread-safe. It does not remove elements automatically. Unused resources must be closed and removed explicitly.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	PoolMap.Pool<R>
static interface	PoolMap.PoolResourceSupplier<R>
static enum	PoolMap.PoolType
(package private) static class	PoolMap.RoundRobinPool<R>	The RoundRobinPool represents a PoolMap.Pool, which stores its resources in an ArrayList.
(package private) static class	PoolMap.ThreadLocalPool<R>	The ThreadLocalPool represents a PoolMap.Pool that works similarly to ThreadLocal class.

Field Summary

Fields

Modifier and Type	Field	Description
private final int	poolMaxSize
private final Map<K,PoolMap.Pool<V>>	pools
private final PoolMap.PoolType	poolType

Constructor Summary

Constructors

Constructor	Description
PoolMap(PoolMap.PoolType poolType, int poolMaxSize)

Method Summary

Modifier and Type	Method	Description
void	clear()
protected PoolMap.Pool<V>	createPool()
protected static <V> V	createResource(PoolMap.PoolResourceSupplier<V> supplier)
V	getOrCreate(K key, PoolMap.PoolResourceSupplier<V> supplier)
boolean	remove(K key, V value)
List<V>	values()

Methods inherited from class java.lang.Object

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

Field Details

pools

private final Map<K,PoolMap.Pool<V>> pools

poolType

private final PoolMap.PoolType poolType

poolMaxSize

private final int poolMaxSize

Constructor Details

PoolMap

public PoolMap(PoolMap.PoolType poolType,
 int poolMaxSize)

Method Details

getOrCreate

public V getOrCreate(K key,
 PoolMap.PoolResourceSupplier<V> supplier)
              throws IOException

Throws:

IOException

remove

public boolean remove(K key,
 V value)

values

public List<V> values()

clear

public void clear()

createResource

protected static <V> V createResource(PoolMap.PoolResourceSupplier<V> supplier)
                               throws IOException

Throws:

IOException

createPool

protected PoolMap.Pool<V> createPool()