Package io.undertow.util

Class ReferenceCountedPooled

java.lang.Object

io.undertow.util.ReferenceCountedPooled

All Implemented Interfaces:

PooledByteBuffer, java.io.Closeable, java.lang.AutoCloseable

public class ReferenceCountedPooled
extends java.lang.Object
implements PooledByteBuffer

A reference counted pooled implementation, that basically consists of a main buffer, that can be sliced off into smaller buffers, and the underlying buffer will not be freed until all the slices and the main buffer itself have also been freed. This also supports the notion of un-freeing the main buffer. Basically this allows the buffer be re-used, so if only a small slice of the buffer was used for read operations the main buffer can potentially be re-used. This prevents buffer exhaustion attacks where content is sent in many small packets, and you end up allocating a large number of buffers to hold a small amount of data.

Author:

Stuart Douglas

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ReferenceCountedPooled.FreeNotifier

Constructor Summary

Constructors

Constructor	Description
ReferenceCountedPooled(PooledByteBuffer underlying, int referenceCount)
ReferenceCountedPooled(PooledByteBuffer underlying, int referenceCount, ReferenceCountedPooled.FreeNotifier freeNotifier)

Method Summary

Modifier and Type	Method	Description
void	close()
PooledByteBuffer	createView(java.nio.ByteBuffer newValue)
java.nio.ByteBuffer	getBuffer()
void	increaseReferenceCount()
boolean	isFreed()
boolean	isOpen()
java.lang.String	toString()
boolean	tryUnfree()

Methods inherited from class java.lang.Object

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

Constructor Detail

ReferenceCountedPooled

public ReferenceCountedPooled(PooledByteBuffer underlying,
                              int referenceCount)

ReferenceCountedPooled

public ReferenceCountedPooled(PooledByteBuffer underlying,
                              int referenceCount,
                              ReferenceCountedPooled.FreeNotifier freeNotifier)

Method Detail

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface PooledByteBuffer

isOpen

public boolean isOpen()

Specified by:

isOpen in interface PooledByteBuffer

isFreed

public boolean isFreed()

tryUnfree

public boolean tryUnfree()

getBuffer

public java.nio.ByteBuffer getBuffer()
                              throws java.lang.IllegalStateException

Specified by:

getBuffer in interface PooledByteBuffer

Throws:

java.lang.IllegalStateException

createView

public PooledByteBuffer createView(java.nio.ByteBuffer newValue)

increaseReferenceCount

public void increaseReferenceCount()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object