Package org.eclipse.jetty.io

Class RetainableByteBuffer

java.lang.Object

org.eclipse.jetty.io.RetainableByteBuffer

All Implemented Interfaces:

Retainable

Direct Known Subclasses:

ArrayRetainableByteBufferPool.Tracking.Buffer

public class RetainableByteBuffer
extends Object
implements Retainable

A pooled ByteBuffer which maintains a reference count that is incremented with retain() and decremented with release(). The buffer is released to the pool when release() is called one more time than retain().

A RetainableByteBuffer can either be:

• in pool; in this case isRetained() returns false and calling release() throws IllegalStateException
• out of pool but not retained; in this case isRetained() returns false and calling release() returns true
• out of pool and retained; in this case isRetained() returns true and calling release() returns false

Calling release() on a out of pool and retained instance does not re-pool it while that re-pools it on a out of pool but not retained instance.

Method Summary

Modifier and Type	Method	Description
protected void	acquire()	Increments the retained counter of this buffer.
int	capacity()
void	clear()
ByteBuffer	getBuffer()
long	getLastUpdate()
boolean	hasRemaining()
boolean	isDirect()
boolean	isEmpty()
boolean	isRetained()	Checks if retain() has been called at least one more time than release().
boolean	release()	Decrements the retained counter of this buffer.
int	remaining()
void	retain()	Increments the retained counter of this buffer.
String	toString()

Methods inherited from class java.lang.Object

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

Method Details

capacity

public int capacity()

getBuffer

public ByteBuffer getBuffer()

getLastUpdate

public long getLastUpdate()

isRetained

public boolean isRetained()

Checks if retain() has been called at least one more time than release().

Returns:

true if this buffer is retained, false otherwise.

isDirect

public boolean isDirect()

acquire

protected void acquire()

Increments the retained counter of this buffer. It must be done internally by the pool right after creation and after each un-pooling. The reason why this method exists on top of retain() is to be able to have some safety checks that must know why the ref counter is being incremented.

retain

public void retain()

Increments the retained counter of this buffer.

Specified by:

retain in interface Retainable

release

public boolean release()

Decrements the retained counter of this buffer.

Returns:

true if the buffer was re-pooled, false otherwise.

remaining

public int remaining()

hasRemaining

public boolean hasRemaining()

isEmpty

public boolean isEmpty()

clear

public void clear()

toString

public String toString()

Overrides:

toString in class Object