org.graylog2.inputs.transports.netty

Class LenientDelimiterBasedFrameDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

org.graylog2.inputs.transports.netty.LenientDelimiterBasedFrameDecoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler

public class LenientDelimiterBasedFrameDecoder
extends io.netty.handler.codec.ByteToMessageDecoder

A decoder that splits the received ByteBufs by one or more delimiters. It is particularly useful for decoding the frames which ends with a delimiter such as NUL or newline characters.

Predefined delimiters

Delimiters defines frequently used delimiters for convenience' sake.

Specifying more than one delimiter

LenientDelimiterBasedFrameDecoder allows you to specify more than one delimiter. If more than one delimiter is found in the buffer, it chooses the delimiter which produces the shortest frame. For example, if you have the following data in the buffer:

 +--------------+
 | ABC\nDEF\r\n |
 +--------------+
 

a LenientDelimiterBasedFrameDecoder(Delimiters.lineDelimiter()) will choose '\n' as the first delimiter and produce two frames:

 +-----+-----+
 | ABC | DEF |
 +-----+-----+
 

rather than incorrectly choosing '\r\n' as the first delimiter:

 +----------+
 | ABC\nDEF |
 +----------+
 

Nested Class Summary

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

io.netty.handler.codec.ByteToMessageDecoder.Cumulator

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

io.netty.channel.ChannelHandler.Sharable

Field Summary

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

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor and Description
LenientDelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, boolean emitLastLineWithoutDelimiter, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
LenientDelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, io.netty.buffer.ByteBuf delimiter) Creates a new instance.
LenientDelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
LenientDelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, io.netty.buffer.ByteBuf delimiter) Creates a new instance.
LenientDelimiterBasedFrameDecoder(int maxFrameLength, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
LenientDelimiterBasedFrameDecoder(int maxFrameLength, io.netty.buffer.ByteBuf delimiter) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
protected Object	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf buffer) Create a frame out of the ByteBuf and return it.
protected void	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf in, List<Object> out)

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

actualReadableBytes, callDecode, channelInactive, 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

Constructor Detail

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

delimiter - the delimiter

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         boolean stripDelimiter,
                                         io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

delimiter - the delimiter

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         boolean stripDelimiter,
                                         boolean failFast,
                                         io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

failFast - If true, a TooLongFrameException is thrown as soon as the decoder notices the length of the frame will exceed maxFrameLength regardless of whether the entire frame has been read. If false, a TooLongFrameException is thrown after the entire frame that exceeds maxFrameLength has been read.

delimiter - the delimiter

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

delimiters - the delimiters

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         boolean stripDelimiter,
                                         io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

delimiters - the delimiters

LenientDelimiterBasedFrameDecoder

public LenientDelimiterBasedFrameDecoder(int maxFrameLength,
                                         boolean stripDelimiter,
                                         boolean failFast,
                                         boolean emitLastLineWithoutDelimiter,
                                         io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

failFast - If true, a TooLongFrameException is thrown as soon as the decoder notices the length of the frame will exceed maxFrameLength regardless of whether the entire frame has been read. If false, a TooLongFrameException is thrown after the entire frame that exceeds maxFrameLength has been read.

emitLastLineWithoutDelimiter - emit the last line even if it doesn't end with the delimiter

delimiters - the delimiters

Method Detail

decode

protected final void decode(io.netty.channel.ChannelHandlerContext ctx,
                            io.netty.buffer.ByteBuf in,
                            List<Object> out)
                     throws Exception

Specified by:

decode in class io.netty.handler.codec.ByteToMessageDecoder

Throws:

Exception

decode

protected Object decode(io.netty.channel.ChannelHandlerContext ctx,
                        io.netty.buffer.ByteBuf buffer)
                 throws Exception

Create a frame out of the ByteBuf and return it.

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

buffer - the ByteBuf from which to read data

Returns:

frame the ByteBuf which represent the frame or null if no frame could be created.

Throws:

Exception