Package org.apache.hadoop.io

Class ElasticByteBufferPool

java.lang.Object

org.apache.hadoop.io.ElasticByteBufferPool

All Implemented Interfaces:

ByteBufferPool

Direct Known Subclasses:

WeakReferencedElasticByteBufferPool

@Public
@Stable
public class ElasticByteBufferPool
extends Object
implements ByteBufferPool

This is a simple ByteBufferPool which just creates ByteBuffers as needed. It also caches ByteBuffers after they're released. It will always return the smallest cached buffer with at least the capacity you request. We don't try to do anything clever here like try to limit the maximum cache size.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static final class	ElasticByteBufferPool.Key

Constructor Summary

Constructors

Constructor	Description
ElasticByteBufferPool()

Method Summary

Modifier and Type	Method	Description
ByteBuffer	getBuffer(boolean direct, int length)	Get a new direct ByteBuffer.
void	putBuffer(ByteBuffer buffer)	Release a buffer back to the pool.
int	size(boolean direct)	Get the size of the buffer pool, for the specified buffer type.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.io.ByteBufferPool

release

Constructor Details

ElasticByteBufferPool

public ElasticByteBufferPool()

Method Details

getBuffer

public ByteBuffer getBuffer(boolean direct,
 int length)

Description copied from interface: ByteBufferPool

Get a new direct ByteBuffer. The pool can provide this from removing a buffer from its internal cache, or by allocating a new buffer.

Specified by:

getBuffer in interface ByteBufferPool

Parameters:

direct - Whether the buffer should be direct.

length - The minimum length the buffer will have.

Returns:

A new ByteBuffer. This ByteBuffer must be direct. Its capacity can be less than what was requested, but must be at least 1 byte.

putBuffer

public void putBuffer(ByteBuffer buffer)

Description copied from interface: ByteBufferPool

Release a buffer back to the pool. The pool may choose to put this buffer into its cache.

Specified by:

putBuffer in interface ByteBufferPool

Parameters:

buffer - a direct bytebuffer

size

@Private
@Unstable
public int size(boolean direct)

Get the size of the buffer pool, for the specified buffer type.

Parameters:

direct - Whether the size is returned for direct buffers

Returns:

The size