org.jboss.netty.handler.codec.protobuf
Class ProtobufVarint32LengthFieldPrepender

java.lang.Object
  org.jboss.netty.handler.codec.oneone.OneToOneEncoder
      org.jboss.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender

All Implemented Interfaces:

ChannelDownstreamHandler, ChannelHandler

@ChannelHandler.Sharable
public class ProtobufVarint32LengthFieldPrepender
extends OneToOneEncoder

An encoder that prepends the the Google Protocol Buffers Base 128 Varints integer length field. For example:

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

*

Version:

$Rev: 2315 $, $Date: 2010-06-23 14:16:47 +0900 (Wed, 23 Jun 2010) $

Author:

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

See Also:

CodedOutputStream

Nested Class Summary

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

ChannelHandler.Sharable

Constructor Summary

ProtobufVarint32LengthFieldPrepender()
Creates a new instance.

Method Summary

protected Object

encode(ChannelHandlerContext ctx, Channel channel, Object msg) Transforms the specified message into another message and return the transformed message.

Methods inherited from class org.jboss.netty.handler.codec.oneone.OneToOneEncoder

handleDownstream

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtobufVarint32LengthFieldPrepender

public ProtobufVarint32LengthFieldPrepender()

Creates a new instance.

Method Detail

encode

protected Object encode(ChannelHandlerContext ctx,
                        Channel channel,
                        Object msg)
                 throws Exception

Description copied from class: OneToOneEncoder

Transforms the specified message into another message and return the transformed message. Note that you can not return null, unlike you can in OneToOneDecoder.decode(ChannelHandlerContext, Channel, Object); you must return something, at least ChannelBuffers.EMPTY_BUFFER.

Specified by:

encode in class OneToOneEncoder

Throws:

Exception