Class DeflateEncoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<WebSocketFrame>

io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionEncoder

io.netty.handler.codec.http.websocketx.extensions.compression.DeflateEncoder

All Implemented Interfaces:

ChannelHandler, ChannelOutboundHandler

Direct Known Subclasses:

PerFrameDeflateEncoder, PerMessageDeflateEncoder

abstract class DeflateEncoder
extends WebSocketExtensionEncoder

Deflate implementation of a payload compressor for io.netty.handler.codec.http.websocketx.WebSocketFrame.

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private final int	compressionLevel
(package private) static final int	DEFAULT_MEM_LEVEL
private EmbeddedChannel	encoder
private final WebSocketExtensionFilter	extensionEncoderFilter
private final int	memLevel
private final boolean	noContext
private final int	windowSize

Constructor Summary

Constructors

Constructor	Description
DeflateEncoder(int compressionLevel, int windowSize, boolean noContext, WebSocketExtensionFilter extensionEncoderFilter)	Constructor
DeflateEncoder(int compressionLevel, int windowSize, int memLevel, boolean noContext, WebSocketExtensionFilter extensionEncoderFilter)	Constructor

Method Summary

Modifier and Type	Method	Description
private void	cleanup()
private ByteBuf	compressContent(ChannelHandlerContext ctx, WebSocketFrame msg)
protected void	encode(ChannelHandlerContext ctx, WebSocketFrame msg, List<Object> out)	Encode from one message to an other.
protected WebSocketExtensionFilter	extensionEncoderFilter()	Returns the extension encoder filter.
void	handlerRemoved(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
protected abstract boolean	removeFrameTail(WebSocketFrame msg)
protected abstract int	rsv(WebSocketFrame msg)

Methods inherited from class MessageToMessageEncoder

acceptOutboundMessage, write

Methods inherited from class ChannelOutboundHandlerAdapter

bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, exceptionCaught, handlerAdded, isSharable

Methods inherited from class Object

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

Methods inherited from interface ChannelHandler

exceptionCaught, handlerAdded

Field Details

DEFAULT_MEM_LEVEL

static final int DEFAULT_MEM_LEVEL

See Also:

• Constant Field Values

compressionLevel

private final int compressionLevel

windowSize

private final int windowSize

memLevel

private final int memLevel

noContext

private final boolean noContext

extensionEncoderFilter

private final WebSocketExtensionFilter extensionEncoderFilter

encoder

private EmbeddedChannel encoder

Constructor Details

DeflateEncoder

DeflateEncoder(int compressionLevel,
 int windowSize,
 boolean noContext,
 WebSocketExtensionFilter extensionEncoderFilter)

Constructor

Parameters:

compressionLevel - compression level of the compressor.

windowSize - maximum size of the window compressor buffer.

noContext - true to disable context takeover.

extensionEncoderFilter - extension encoder filter.

DeflateEncoder

DeflateEncoder(int compressionLevel,
 int windowSize,
 int memLevel,
 boolean noContext,
 WebSocketExtensionFilter extensionEncoderFilter)

Constructor

Parameters:

compressionLevel - compression level of the compressor.

windowSize - maximum size of the window compressor buffer.

memLevel - internal compression state memory level (1..9).

noContext - true to disable context takeover.

extensionEncoderFilter - extension encoder filter.

Method Details

extensionEncoderFilter

protected WebSocketExtensionFilter extensionEncoderFilter()

Returns the extension encoder filter.

rsv

protected abstract int rsv(WebSocketFrame msg)

Parameters:

msg - the current frame.

Returns:

the rsv bits to set in the compressed frame.

removeFrameTail

protected abstract boolean removeFrameTail(WebSocketFrame msg)

Parameters:

msg - the current frame.

Returns:

true if compressed payload tail needs to be removed.

encode

protected void encode(ChannelHandlerContext ctx,
 WebSocketFrame msg,
 List<Object> out)
               throws Exception

Description copied from class: MessageToMessageEncoder

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

Specified by:

encode in class MessageToMessageEncoder<WebSocketFrame>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

Throws:

Exception - is thrown if an error occurs

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerRemoved in interface ChannelHandler

Overrides:

handlerRemoved in class ChannelHandlerAdapter

Throws:

Exception

compressContent

private ByteBuf compressContent(ChannelHandlerContext ctx,
 WebSocketFrame msg)

cleanup

private void cleanup()