org.jboss.netty.handler.codec.protobuf
Class ProtobufVarint32FrameDecoder

java.lang.Object
  org.jboss.netty.channel.SimpleChannelUpstreamHandler
      org.jboss.netty.handler.codec.frame.FrameDecoder
          org.jboss.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder

All Implemented Interfaces:

ChannelHandler, ChannelUpstreamHandler

public class ProtobufVarint32FrameDecoder
extends FrameDecoder

A decoder that splits the received ChannelBuffers dynamically by the value of the Google Protocol Buffers Base 128 Varints integer length field in the message. For example:

 BEFORE DECODE (302 bytes)       AFTER DECODE (300 bytes)
 +--------+---------------+      +---------------+
 | Length | Protobuf Data |----->| Protobuf Data |
 | 0xAC02 |  (300 bytes)  |      |  (300 bytes)  |
 +--------+---------------+      +---------------+
 

Version:

$Rev: 2323 $, $Date: 2010-06-24 11:13:12 +0900 (Thu, 24 Jun 2010) $

Author:

The Netty Project, Tomasz Blachowicz (tblachowicz@gmail.com), Trustin Lee

See Also:

CodedInputStream

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

ProtobufVarint32FrameDecoder()
Creates a new instance.

Method Summary

protected Object

decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) Decodes the received packets so far into a frame.

Methods inherited from class org.jboss.netty.handler.codec.frame.FrameDecoder

channelClosed, channelDisconnected, decodeLast, exceptionCaught, messageReceived

Methods inherited from class org.jboss.netty.channel.SimpleChannelUpstreamHandler

channelBound, channelConnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, handleUpstream, writeComplete

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtobufVarint32FrameDecoder

public ProtobufVarint32FrameDecoder()

Creates a new instance.

Method Detail

decode

protected Object decode(ChannelHandlerContext ctx,
                        Channel channel,
                        ChannelBuffer buffer)
                 throws Exception

Description copied from class: FrameDecoder

Decodes the received packets so far into a frame.

Specified by:

decode in class FrameDecoder

Parameters:

ctx - the context of this handler

channel - the current channel

buffer - the cumulative buffer of received packets so far. Note that the buffer might be empty, which means you should not make an assumption that the buffer contains at least one byte in your decoder implementation.

Returns:

the decoded frame if a full frame was received and decoded. null if there's not enough data in the buffer to decode a frame.

Throws:

Exception