Package io.netty.handler.codec.memcache.binary

Class AbstractBinaryMemcacheDecoder<M extends BinaryMemcacheMessage>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.memcache.AbstractMemcacheObjectDecoder

io.netty.handler.codec.memcache.binary.AbstractBinaryMemcacheDecoder<M>

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:

BinaryMemcacheRequestDecoder, BinaryMemcacheResponseDecoder

@UnstableApi
public abstract class AbstractBinaryMemcacheDecoder<M extends BinaryMemcacheMessage>
extends AbstractMemcacheObjectDecoder

Decoder for both BinaryMemcacheRequest and BinaryMemcacheResponse.

The difference in the protocols (header) is implemented by the subclasses.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	AbstractBinaryMemcacheDecoder.State	Contains all states this decoder can possibly be in.

Nested classes/interfaces inherited from class io.netty.handler.codec.ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private int	alreadyReadChunkSize
private int	chunkSize
private M	currentMessage
static int	DEFAULT_MAX_CHUNK_SIZE
private AbstractBinaryMemcacheDecoder.State	state

Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractBinaryMemcacheDecoder()	Create a new AbstractBinaryMemcacheDecoder with default settings.
protected	AbstractBinaryMemcacheDecoder(int chunkSize)	Create a new AbstractBinaryMemcacheDecoder with custom settings.

Method Summary

Modifier and Type	Method	Description
protected abstract M	buildInvalidMessage()	Helper method to create a upstream message when the incoming parsing did fail.
void	channelInactive(ChannelHandlerContext ctx)	When the channel goes inactive, release all frames to prevent data leaks.
protected void	decode(ChannelHandlerContext ctx, ByteBuf in, java.util.List<java.lang.Object> out)	Decode the from one ByteBuf to an other.
protected abstract M	decodeHeader(ByteBuf in)	Decode and return the parsed BinaryMemcacheMessage.
private MemcacheContent	invalidChunk(java.lang.Exception cause)	Helper method to create a content chunk indicating a invalid decoding result.
private M	invalidMessage(java.lang.Exception cause)	Helper method to create a message indicating a invalid decoding result.
protected void	resetDecoder()	Prepare for next decoding iteration.
private static void	validateHeader(BinaryMemcacheMessage header)	Validates the length fields of a decoded header against each other.

Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder

actualReadableBytes, callDecode, channelRead, channelReadComplete, decodeLast, discardSomeReadBytes, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggered

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded

Field Detail

DEFAULT_MAX_CHUNK_SIZE

public static final int DEFAULT_MAX_CHUNK_SIZE

See Also:

Constant Field Values

chunkSize

private final int chunkSize

currentMessage

private M extends BinaryMemcacheMessage currentMessage

alreadyReadChunkSize

private int alreadyReadChunkSize

state

private AbstractBinaryMemcacheDecoder.State state

Constructor Detail

AbstractBinaryMemcacheDecoder

protected AbstractBinaryMemcacheDecoder()

Create a new AbstractBinaryMemcacheDecoder with default settings.

AbstractBinaryMemcacheDecoder

protected AbstractBinaryMemcacheDecoder(int chunkSize)

Create a new AbstractBinaryMemcacheDecoder with custom settings.

Parameters:

chunkSize - the maximum chunk size of the payload.

Method Detail

decode

protected void decode(ChannelHandlerContext ctx,
                      ByteBuf in,
                      java.util.List<java.lang.Object> out)
               throws java.lang.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:

java.lang.Exception - is thrown if an error occurs

validateHeader

private static void validateHeader(BinaryMemcacheMessage header)

Validates the length fields of a decoded header against each other.

A header that fails this check can not be framed, so decoding stops permanently rather than attempting to resynchronize, see the class documentation.

Note that keyLength and extrasLength are unsigned in the protocol and are interpreted as such here, see BinaryMemcacheMessage.keyLength() and BinaryMemcacheMessage.extrasLength().

Parameters:

header - the decoded header to validate.

Throws:

CorruptedFrameException - if the lengths in the header are inconsistent.

invalidMessage

private M invalidMessage(java.lang.Exception cause)

Helper method to create a message indicating a invalid decoding result.

Parameters:

cause - the cause of the decoding failure.

Returns:

a valid message indicating failure.

invalidChunk

private MemcacheContent invalidChunk(java.lang.Exception cause)

Helper method to create a content chunk indicating a invalid decoding result.

Parameters:

cause - the cause of the decoding failure.

Returns:

a valid content chunk indicating failure.

channelInactive

public void channelInactive(ChannelHandlerContext ctx)
                     throws java.lang.Exception

When the channel goes inactive, release all frames to prevent data leaks.

Specified by:

channelInactive in interface ChannelInboundHandler

Overrides:

channelInactive in class ByteToMessageDecoder

Parameters:

ctx - handler context

Throws:

java.lang.Exception

resetDecoder

protected void resetDecoder()

Prepare for next decoding iteration.

decodeHeader

protected abstract M decodeHeader(ByteBuf in)

Decode and return the parsed BinaryMemcacheMessage.

Parameters:

in - the incoming buffer.

Returns:

the decoded header.

buildInvalidMessage

protected abstract M buildInvalidMessage()

Helper method to create a upstream message when the incoming parsing did fail.

Returns:

a message indicating a decoding failure.