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

Constructors

Constructor and Description
ProtobufVarint32LengthFieldPrepender() Creates a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
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