Class JdkZlibDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.compression.ZlibDecoder

io.netty.handler.codec.compression.JdkZlibDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

public class JdkZlibDecoder
extends ZlibDecoder

Decompress a ByteBuf using the inflate algorithm.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static enum	JdkZlibDecoder.GzipState

Nested classes/interfaces inherited from class ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private final ByteBufChecksum	crc
private boolean	decideZlibOrNone
private final boolean	decompressConcatenated
private static final int	DEFAULT_MAX_FORWARD_BYTES
private final byte[]	dictionary
private static final int	FCOMMENT
private static final int	FEXTRA
private static final int	FHCRC
private boolean	finished
private int	flags
private static final int	FNAME
private static final int	FRESERVED
private JdkZlibDecoder.GzipState	gzipState
private Inflater	inflater
private final int	maxForwardBytes
private boolean	needsRead
private int	xlen

Fields inherited from class ZlibDecoder

maxAllocation

Fields inherited from class ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Modifier	Constructor	Description
	JdkZlibDecoder()	Deprecated. Use JdkZlibDecoder(int).
	JdkZlibDecoder(boolean decompressConcatenated)	Deprecated. Use JdkZlibDecoder(boolean, int).
	JdkZlibDecoder(boolean decompressConcatenated, int maxAllocation)
	JdkZlibDecoder(byte[] dictionary)	Deprecated. Use JdkZlibDecoder(byte[], int).
	JdkZlibDecoder(byte[] dictionary, int maxAllocation)	Creates a new instance with the specified preset dictionary and maximum buffer allocation.
	JdkZlibDecoder(int maxAllocation)	Creates a new instance with the default wrapper (ZlibWrapper.ZLIB) and the specified maximum buffer allocation.
	JdkZlibDecoder(ZlibWrapper wrapper)	Deprecated. Use JdkZlibDecoder(ZlibWrapper, int).
	JdkZlibDecoder(ZlibWrapper wrapper, boolean decompressConcatenated)	Deprecated. Use JdkZlibDecoder(ZlibWrapper, boolean, int).
	JdkZlibDecoder(ZlibWrapper wrapper, boolean decompressConcatenated, int maxAllocation)
private	JdkZlibDecoder(ZlibWrapper wrapper, byte[] dictionary, boolean decompressConcatenated, int maxAllocation)
	JdkZlibDecoder(ZlibWrapper wrapper, int maxAllocation)	Creates a new instance with the specified wrapper and maximum buffer allocation.

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.
protected void	decompressionBufferExhausted(ByteBuf buffer)	Called when the decompression buffer cannot be expanded further.
private boolean	handleGzipFooter(ByteBuf in)
protected void	handlerRemoved0(ChannelHandlerContext ctx)	Gets called after the ByteToMessageDecoder was removed from the actual context and it doesn't handle events anymore.
boolean	isClosed()	Returns true if and only if the end of the compressed stream has been reached.
private static boolean	looksLikeZlib(short cmf_flg)
private boolean	readGZIPFooter(ByteBuf in)	Read the GZIP footer.
private boolean	readGZIPHeader(ByteBuf in)
private boolean	skipIfNeeded(ByteBuf in, int flagMask)	Skip bytes in the input if needed until we find the end marker 0x00.
private boolean	verifyCrc(ByteBuf in)	Verifies CRC.
private boolean	verifyCrc16(ByteBuf in)

Methods inherited from class ZlibDecoder

prepareDecompressBuffer

Methods inherited from class ByteToMessageDecoder

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

Methods inherited from class ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, handlerAdded, isSharable

Methods inherited from class Object

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

Methods inherited from interface ChannelHandler

handlerAdded

Field Details

FHCRC

private static final int FHCRC

See Also:

• Constant Field Values

FEXTRA

private static final int FEXTRA

See Also:

• Constant Field Values

FNAME

private static final int FNAME

See Also:

• Constant Field Values

FCOMMENT

private static final int FCOMMENT

See Also:

• Constant Field Values

FRESERVED

private static final int FRESERVED

See Also:

• Constant Field Values

inflater

private Inflater inflater

dictionary

private final byte[] dictionary

crc

private final ByteBufChecksum crc

decompressConcatenated

private final boolean decompressConcatenated

gzipState

private JdkZlibDecoder.GzipState gzipState

flags

private int flags

xlen

private int xlen

needsRead

private boolean needsRead

DEFAULT_MAX_FORWARD_BYTES

private static final int DEFAULT_MAX_FORWARD_BYTES

maxForwardBytes

private final int maxForwardBytes

finished

private volatile boolean finished

decideZlibOrNone

private boolean decideZlibOrNone

Constructor Details

JdkZlibDecoder

@Deprecated
public JdkZlibDecoder()

Deprecated.

Use JdkZlibDecoder(int).

Creates a new instance with the default wrapper (ZlibWrapper.ZLIB).

JdkZlibDecoder

public JdkZlibDecoder(int maxAllocation)

Creates a new instance with the default wrapper (ZlibWrapper.ZLIB) and the specified maximum buffer allocation.

Parameters:

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is decided by the ByteBufAllocator.

JdkZlibDecoder

@Deprecated
public JdkZlibDecoder(byte[] dictionary)

Deprecated.

Use JdkZlibDecoder(byte[], int).

Creates a new instance with the specified preset dictionary. The wrapper is always ZlibWrapper.ZLIB because it is the only format that supports the preset dictionary.

JdkZlibDecoder

public JdkZlibDecoder(byte[] dictionary,
 int maxAllocation)

Creates a new instance with the specified preset dictionary and maximum buffer allocation. The wrapper is always ZlibWrapper.ZLIB because it is the only format that supports the preset dictionary.

Parameters:

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is decided by the ByteBufAllocator.

JdkZlibDecoder

@Deprecated
public JdkZlibDecoder(ZlibWrapper wrapper)

Deprecated.

Use JdkZlibDecoder(ZlibWrapper, int).

Creates a new instance with the specified wrapper. Be aware that only ZlibWrapper.GZIP, ZlibWrapper.ZLIB and ZlibWrapper.NONE are supported atm.

JdkZlibDecoder

public JdkZlibDecoder(ZlibWrapper wrapper,
 int maxAllocation)

Creates a new instance with the specified wrapper and maximum buffer allocation. Be aware that only ZlibWrapper.GZIP, ZlibWrapper.ZLIB and ZlibWrapper.NONE are supported atm.

Parameters:

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is decided by the ByteBufAllocator.

JdkZlibDecoder

@Deprecated
public JdkZlibDecoder(ZlibWrapper wrapper,
 boolean decompressConcatenated)

Deprecated.

Use JdkZlibDecoder(ZlibWrapper, boolean, int).

JdkZlibDecoder

public JdkZlibDecoder(ZlibWrapper wrapper,
 boolean decompressConcatenated,
 int maxAllocation)

JdkZlibDecoder

@Deprecated
public JdkZlibDecoder(boolean decompressConcatenated)

Deprecated.

Use JdkZlibDecoder(boolean, int).

JdkZlibDecoder

public JdkZlibDecoder(boolean decompressConcatenated,
 int maxAllocation)

JdkZlibDecoder

private JdkZlibDecoder(ZlibWrapper wrapper,
 byte[] dictionary,
 boolean decompressConcatenated,
 int maxAllocation)

Method Details

isClosed

public boolean isClosed()

Description copied from class: ZlibDecoder

Returns true if and only if the end of the compressed stream has been reached.

Specified by:

isClosed in class ZlibDecoder

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

handleGzipFooter

private boolean handleGzipFooter(ByteBuf in)

decompressionBufferExhausted

protected void decompressionBufferExhausted(ByteBuf buffer)

Description copied from class: ZlibDecoder

Called when the decompression buffer cannot be expanded further. Default implementation is a no-op, but subclasses can override in case they want to do something before the DecompressionException is thrown, such as log the data that was decompressed so far.

Overrides:

decompressionBufferExhausted in class ZlibDecoder

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

readGZIPHeader

private boolean readGZIPHeader(ByteBuf in)

skipIfNeeded

private boolean skipIfNeeded(ByteBuf in,
 int flagMask)

Skip bytes in the input if needed until we find the end marker 0x00.

Parameters:

in - the input

flagMask - the mask that should be present in the flags when we need to skip bytes.

Returns:

true if the operation is complete and we can move to the next state, false if we need the retry again once we have more readable bytes.

readGZIPFooter

private boolean readGZIPFooter(ByteBuf in)

Read the GZIP footer.

Parameters:

in - the input.

Returns:

true if the footer could be read, false if the read could not be performed as the input ByteBuf doesn't have enough readable bytes (8 bytes).

verifyCrc

private boolean verifyCrc(ByteBuf in)

Verifies CRC.

Parameters:

in - the input.

Returns:

true if verification could be performed, false if verification could not be performed as the input ByteBuf doesn't have enough readable bytes (4 bytes).

verifyCrc16

private boolean verifyCrc16(ByteBuf in)

looksLikeZlib

private static boolean looksLikeZlib(short cmf_flg)

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