Class SnappyFrameDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.compression.SnappyFrameDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:

SnappyFramedDecoder

public class SnappyFrameDecoder
extends ByteToMessageDecoder

Uncompresses a ByteBuf encoded with the Snappy framing format. See Snappy framing format. Note that by default, validation of the checksum header in each chunk is DISABLED for performance improvements. If performance is less of an issue, or if you would prefer the safety that checksum validation brings, please use the SnappyFrameDecoder(boolean) constructor with the argument set to true.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static enum	SnappyFrameDecoder.ChunkType

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 boolean	corrupted
private static final int	MAX_COMPRESSED_CHUNK_SIZE
private static final int	MAX_DECOMPRESSED_DATA_SIZE
private static final int	MAX_UNCOMPRESSED_DATA_SIZE
private int	numBytesToSkip
private final Snappy	snappy
private static final int	SNAPPY_IDENTIFIER_LEN
private boolean	started
private final boolean	validateChecksums

Fields inherited from class ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor	Description
SnappyFrameDecoder()	Creates a new snappy-framed decoder with validation of checksums turned OFF.
SnappyFrameDecoder(boolean validateChecksums)	Creates a new snappy-framed decoder with validation of checksums as specified.

Method Summary

Modifier and Type	Method	Description
private static void	checkByte(byte actual, byte expect)
protected void	decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)	Decode the from one ByteBuf to an other.
private static SnappyFrameDecoder.ChunkType	mapChunkType(byte type)	Decodes the chunk type from the type tag byte.

Methods inherited from class ByteToMessageDecoder

actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, decodeLast, discardSomeReadBytes, handlerRemoved, handlerRemoved0, 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

SNAPPY_IDENTIFIER_LEN

private static final int SNAPPY_IDENTIFIER_LEN

See Also:

• Constant Field Values

MAX_UNCOMPRESSED_DATA_SIZE

private static final int MAX_UNCOMPRESSED_DATA_SIZE

See Also:

• Constant Field Values

MAX_DECOMPRESSED_DATA_SIZE

private static final int MAX_DECOMPRESSED_DATA_SIZE

See Also:

• Constant Field Values

MAX_COMPRESSED_CHUNK_SIZE

private static final int MAX_COMPRESSED_CHUNK_SIZE

See Also:

• Constant Field Values

snappy

private final Snappy snappy

validateChecksums

private final boolean validateChecksums

started

private boolean started

corrupted

private boolean corrupted

numBytesToSkip

private int numBytesToSkip

Constructor Details

SnappyFrameDecoder

public SnappyFrameDecoder()

Creates a new snappy-framed decoder with validation of checksums turned OFF. To turn checksum validation on, please use the alternate SnappyFrameDecoder(boolean) constructor.

SnappyFrameDecoder

public SnappyFrameDecoder(boolean validateChecksums)

Creates a new snappy-framed decoder with validation of checksums as specified.

Parameters:

validateChecksums - If true, the checksum field will be validated against the actual uncompressed data, and if the checksums do not match, a suitable DecompressionException will be thrown

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

checkByte

private static void checkByte(byte actual,
 byte expect)

mapChunkType

private static SnappyFrameDecoder.ChunkType mapChunkType(byte type)

Decodes the chunk type from the type tag byte.

Parameters:

type - The tag byte extracted from the stream

Returns:

The appropriate SnappyFrameDecoder.ChunkType, defaulting to SnappyFrameDecoder.ChunkType.RESERVED_UNSKIPPABLE