Module org.eclipse.jetty.io

Package org.eclipse.jetty.io

Interface RetainableByteBuffer

All Superinterfaces:

Retainable

All Known Implementing Classes:

AbstractRetainableByteBuffer, ArrayByteBufferPool.Tracking.Buffer, RetainableByteBuffer.Wrapper

public interface RetainableByteBuffer
extends Retainable

A pooled ByteBuffer which maintains a reference count that is incremented with Retainable.retain() and decremented with Retainable.release().

The ByteBuffer is released to a ByteBufferPool when Retainable.release() is called one more time than Retainable.retain(); in such case, the call to Retainable.release() returns true.

A RetainableByteBuffer can either be:

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

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	RetainableByteBuffer.Wrapper	A wrapper for RetainableByteBuffer instances

Nested classes/interfaces inherited from interface org.eclipse.jetty.io.Retainable

Retainable.ReferenceCounter

Field Summary

Fields

Modifier and Type	Field	Description
static final RetainableByteBuffer	EMPTY	A Zero-capacity, non-retainable RetainableByteBuffer.

Method Summary

Modifier and Type	Method	Description
default int	capacity()
default void	clear()
ByteBuffer	getByteBuffer()	Get the wrapped, not null, ByteBuffer.
default boolean	hasRemaining()
default boolean	isDirect()
boolean	isRetained()
default int	remaining()
static RetainableByteBuffer	wrap(ByteBuffer byteBuffer)	Returns a non-retainable RetainableByteBuffer that wraps the given ByteBuffer.
static RetainableByteBuffer	wrap(ByteBuffer byteBuffer, Retainable retainable)	Returns a RetainableByteBuffer that wraps the given ByteBuffer and Retainable.

Methods inherited from interface org.eclipse.jetty.io.Retainable

canRetain, release, retain

Field Details

EMPTY

static final RetainableByteBuffer EMPTY

A Zero-capacity, non-retainable RetainableByteBuffer.

Method Details

wrap

static RetainableByteBuffer wrap(ByteBuffer byteBuffer)

Returns a non-retainable RetainableByteBuffer that wraps the given ByteBuffer.

Use this method to wrap user-provided ByteBuffers, or ByteBuffers that hold constant bytes, to make them look like RetainableByteBuffers.

The returned RetainableByteBuffer Retainable.canRetain() method always returns false.

RetainableByteBuffers returned by this method are not suitable to be wrapped in other Retainable implementations that may delegate calls to Retainable.retain().

Parameters:

byteBuffer - the ByteBuffer to wrap

Returns:

a non-retainable RetainableByteBuffer

See Also:

• ByteBufferPool.NonPooling

wrap

static RetainableByteBuffer wrap(ByteBuffer byteBuffer,
 Retainable retainable)

Returns a RetainableByteBuffer that wraps the given ByteBuffer and Retainable.

Parameters:

byteBuffer - the ByteBuffer to wrap

retainable - the associated Retainable.

Returns:

a RetainableByteBuffer

See Also:

• ByteBufferPool.NonPooling

isRetained

boolean isRetained()

Returns:

whether this instance is retained

See Also:

• Retainable.ReferenceCounter.isRetained()

getByteBuffer

ByteBuffer getByteBuffer()

Get the wrapped, not null, ByteBuffer.

Returns:

the wrapped, not null, ByteBuffer

isDirect

default boolean isDirect()

Returns:

whether the ByteBuffer is direct

remaining

default int remaining()

Returns:

the number of remaining bytes in the ByteBuffer

hasRemaining

default boolean hasRemaining()

Returns:

whether the ByteBuffer has remaining bytes

capacity

default int capacity()

Returns:

the ByteBuffer capacity

clear

default void clear()

See Also:

• BufferUtil.clear(ByteBuffer)