Class ZstdDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.compression.ZstdDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

public final class ZstdDecoder
extends ByteToMessageDecoder

Decompresses a compressed block ByteBuf using the Zstandard algorithm. See Zstandard.

Nested Class Summary

Nested classes/interfaces inherited from class ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Modifier and Type	Class	Description
static interface	ByteToMessageDecoder.Cumulator	Cumulate ByteBufs.

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Modifier and Type	Interface	Description
static @interface	ChannelHandler.Sharable	Indicates that the same instance of the annotated ChannelHandler can be added to one or more ChannelPipelines multiple times without a race condition.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_MAX_WINDOW_LOG	Default upper bound on the Window_Log accepted by the decoder.
static final int	DEFAULT_MAXIMUM_ALLOCATION_SIZE	Default maximum size of a single output buffer, in bytes (4 MiB).

Fields inherited from class ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Modifier and Type	Field	Description
static final ByteToMessageDecoder.Cumulator	COMPOSITE_CUMULATOR	Cumulate ByteBufs by add them to a CompositeByteBuf and so do no memory copy whenever possible.
static final ByteToMessageDecoder.Cumulator	MERGE_CUMULATOR	Cumulate ByteBufs by merge them into one ByteBuf's, using memory copies.

Constructor Summary

Constructors

Constructor	Description
ZstdDecoder()	Creates a new decoder with the DEFAULT_MAXIMUM_ALLOCATION_SIZE, and the DEFAULT_MAX_WINDOW_LOG window log size.
ZstdDecoder(int maximumAllocationSize)	Creates a new decoder with the given maximum allocation size, and the DEFAULT_MAX_WINDOW_LOG window log size.
ZstdDecoder(int maximumAllocationSize, int maxWindowLog)	Creates a new decoder with an explicit upper bound on the accepted Window_Log.

Method Summary

Modifier and Type	Method	Description
void	channelReadComplete(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected void	decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)	Decode the from one ByteBuf to an other.
void	handlerAdded(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
protected void	handlerRemoved0(ChannelHandlerContext ctx)	Gets called after the ByteToMessageDecoder was removed from the actual context and it doesn't handle events anymore.

Methods inherited from class ByteToMessageDecoder

actualReadableBytes, callDecode, channelInactive, channelRead, decodeLast, discardSomeReadBytes, handlerRemoved, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggered

Modifier and Type	Method	Description
protected int	actualReadableBytes()	Returns the actual number of readable bytes in the internal cumulative buffer of this decoder.
protected void	callDecode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)	Called once data should be decoded from the given ByteBuf.
void	channelInactive(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelInactive() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelRead(ChannelHandlerContext ctx, Object input)	Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected void	decodeLast(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)	Is called one last time when the ChannelHandlerContext goes in-active.
protected final void	discardSomeReadBytes()
final void	handlerRemoved(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
protected ByteBuf	internalBuffer()	Returns the internal cumulative buffer of this decoder.
boolean	isSingleDecode()	If true then only one message is decoded on each ByteToMessageDecoder.channelRead(ChannelHandlerContext, Object) call.
void	setCumulator(ByteToMessageDecoder.Cumulator cumulator)	Set the ByteToMessageDecoder.Cumulator to use for cumulate the received ByteBufs.
void	setDiscardAfterReads(int discardAfterReads)	Set the number of reads after which ByteBuf.discardSomeReadBytes() are called and so free up memory.
void	setSingleDecode(boolean singleDecode)	If set then only one message is decoded on each ByteToMessageDecoder.channelRead(ChannelHandlerContext, Object) call.
void	userEventTriggered(ChannelHandlerContext ctx, Object evt)	Calls ChannelHandlerContext.fireUserEventTriggered(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.

Methods inherited from class ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Modifier and Type	Method	Description
void	channelActive(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelActive() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelRegistered(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelRegistered() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelUnregistered(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelUnregistered() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelWritabilityChanged(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelWritabilityChanged() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	exceptionCaught(ChannelHandlerContext ctx, Throwable cause)	Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline.

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, isSharable

Modifier and Type	Method	Description
protected void	ensureNotSharable()	Throws IllegalStateException if ChannelHandlerAdapter.isSharable() returns true
boolean	isSharable()	Return true if the implementation is ChannelHandler.Sharable and so can be added to different ChannelPipelines.

Methods inherited from class Object

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

Field Details

DEFAULT_MAXIMUM_ALLOCATION_SIZE

public static final int DEFAULT_MAXIMUM_ALLOCATION_SIZE

Default maximum size of a single output buffer, in bytes (4 MiB).

See Also:

• Constant Field Values

DEFAULT_MAX_WINDOW_LOG

public static final int DEFAULT_MAX_WINDOW_LOG

Default upper bound on the Window_Log accepted by the decoder. 27 corresponds to a 128 MiB decompression window.

See Also:

• Constant Field Values

Constructor Details

ZstdDecoder

public ZstdDecoder()

Creates a new decoder with the DEFAULT_MAXIMUM_ALLOCATION_SIZE, and the DEFAULT_MAX_WINDOW_LOG window log size.

The window log size bounds the memory usage of the sliding window for ZSTD frame decompression. Frames declaring a larger window will be rejected to bound the memory the decoder may allocate per stream.

ZstdDecoder

public ZstdDecoder(int maximumAllocationSize)

Creates a new decoder with the given maximum allocation size, and the DEFAULT_MAX_WINDOW_LOG window log size.

The window log size bounds the memory usage of the sliding window for ZSTD frame decompression. Frames declaring a larger window will be rejected to bound the memory the decoder may allocate per stream.

Parameters:

maximumAllocationSize - maximum size of a single output buffer.

ZstdDecoder

public ZstdDecoder(int maximumAllocationSize,
 int maxWindowLog)

Creates a new decoder with an explicit upper bound on the accepted Window_Log.

Parameters:

maximumAllocationSize - maximum size of a single output buffer.

maxWindowLog - upper bound on the Window_Log field of incoming frames; must be in [10, 31]. Frames declaring a larger window will be rejected to bound the memory the decoder may allocate per stream.

Method Details

decode

protected void decode(ChannelHandlerContext ctx,
 ByteBuf in,
 List<Object> out)
               throws Exception

Description copied from class: ByteToMessageDecoder

Decode the from one ByteBuf to an other. This method will be called till either the input ByteBuf has nothing to read when return from this method or till nothing was read from the input ByteBuf.

Specified by:

decode in class ByteToMessageDecoder

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

in - the ByteBuf from which to read data

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error occurs

channelReadComplete

public void channelReadComplete(ChannelHandlerContext ctx)
                         throws Exception

Description copied from class: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelReadComplete in interface ChannelInboundHandler

Overrides:

channelReadComplete in class ByteToMessageDecoder

Throws:

Exception

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws Exception

Description copied from class: ChannelHandlerAdapter

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

Specified by:

handlerAdded in interface ChannelHandler

Overrides:

handlerAdded in class ChannelHandlerAdapter

Throws:

Exception

handlerRemoved0

protected void handlerRemoved0(ChannelHandlerContext ctx)
                        throws Exception

Description copied from class: ByteToMessageDecoder

Gets called after the ByteToMessageDecoder was removed from the actual context and it doesn't handle events anymore.

Overrides:

handlerRemoved0 in class ByteToMessageDecoder

Throws:

Exception