Improving performance of ProtobufDecoder

[Shay Banon]

It would be interesting to understand where the performance improvement is
coming from. I assume its because protobuf parses a byte[] faster then
InputStream (god knows why...) and not because readBytes and then working on
it is faster than ChannelBufferInputStream?

By the way, with the new ChannelBuffer#array method, you can dispence with
the array copy (readBytes) and pass the array itself (with the correct
postion and length, of course) if its available.

-shay.banon

On Wed, Jul 14, 2010 at 8:16 PM, IanS <iswett at yahoo.com> wrote:

>
> I found the performance of protocol buffers to be somewhat slow for small
> messages, and discovered that it was much faster and produced less garbage
> to read into a byte[] and parse from that for messages less than 4k.
>
> Here is the new version of decode, which almost doubles the network
> performance for me when using relatively small(ie: 100 byte) messages:
>
>
> protected Object decode(ChannelHandlerContext ctx, Channel channel, Object
> msg) throws Exception {
>                if (!(msg instanceof ChannelBuffer)) {
>                        return msg;
>                }
>
>                ChannelBuffer buf = (ChannelBuffer) msg;
>                if(buf.readableBytes() <= 4096) {
>                        byte[] bytes = new byte[buf.readableBytes()];
>                        buf.readBytes(bytes);
>
>                        if(extensionRegistry == null)
>                        {
>                                return
> prototype.newBuilderForType().mergeFrom(bytes).build();
>                        }
>                        else
>                        {
>                                return
> prototype.newBuilderForType().mergeFrom(bytes,
> extensionRegistry).build();
>                        }
>                }
>                else
>                {
>                        if (extensionRegistry == null) {
>                                return
> prototype.newBuilderForType().mergeFrom(
>                                                new
> ChannelBufferInputStream((ChannelBuffer) msg)).build();
>                        } else {
>                                return
> prototype.newBuilderForType().mergeFrom(
>                                                new
> ChannelBufferInputStream((ChannelBuffer) msg),
>                                                extensionRegistry).build();
>                        }
>                }
>        }
>
>
> I would be happy to have this integrated into the next release.  Is the
> most
> appropriate way to go about that to file a JIRA request?
>
> Thanks, Ian
> --
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