Upgrade to Netty 4

[joelgwebber]

I'm entering this primarily to make sure that I'm not duplicating work. I need sockjs support for Netty 4 in my own work, and this appears to be the most complete sockjs library I've found for Netty (there are a number of reasons we can't use Vert.x).

I've begun the upgrade process in a fork, and it doesn't look like it's going to be too much work, but I obviously don't want to do duplicate work if you're already working on it.

[cgbystrom]

Interesting idea.

Without having looked at Netty 4 much, supporting both version 3 and 4 would require two separate implementations, right?

Our push server at Battlelog, Beaconpush, has been the main driver in the API design for sockjs-netty. In Beaconpush, we haven't yet migrated to Netty 4 as it was just recently released.
We are of course intending to do so but it likely won't happen before December.

But if more people are willing to help port sockjs-netty over to Netty 4 I am of course grateful. That is the version to support moving forward for sure.

[joelgwebber]

There's definitely no reasonable way to support both APIs in one version of the library. It would probably make the most sense keep Netty 3 support in a branch so it can continue to be fixed/updated/etc. The Netty 4 APIs are significantly different in some aspects, so the conversion cannot be entirely rote, but it's not too difficult either -- it's mostly a matter of understanding which events in the new ChannelHandler interface map to the old ones, and where their semantics differ. There's a pretty good writeup on the whole process here: http://netty.io/wiki/new-and-noteworthy.html

I'll keep plugging away at it in my spare time, and let you know when I have something worth reviewing. And if you or anyone else decides to take this on before I finish, please let me know so we don't duplicate too much work.

Thanks!

[cgbystrom]

Cool, keep going :)