Support the Rack hijack API

[halorgium]

Rack now supports a "hijack" API which allows high-level frameworks built on top of Rack (e.g. Rails) to access the underlying socket:

rack/rack#481

It would be great if Reel supported this feature, as it would expose its end-to-end streaming support (along with Celluloid::IO-based sockets) to frameworks wishing to utilize the hijack API.

[digitalextremist]

@halorgium if you feel like jumping on this, please go ahead. You might get to it before me and will know better than I would. As mentioned in IRC, I am not going to use Rack's hijack support in my own applications. I am seeing I need to regain some ground. It will likely take me several days to get back to this.

[halorgium]

@digitalextremist sure. i hope you learnt some things while giving this a go!

[halorgium]

@tarcieri needs a more sane approach for telling the Connection to not close the socket.

[tarcieri]

@halorgium Connection#detach, see: https://github.com/celluloid/reel/blob/master/lib/reel/connection.rb#L36

[halorgium]

For some reason, all Connections are detached with the Rack handler. see:

reel/lib/rack/handler/reel.rb

Line 44 in a273967

Celluloid::Actor[:reel_rack_pool].handle(connection.detach)

[halorgium]

@tarcieri this seems to work, and both the example apps behave.
@raggi would you mind having a look at this too?

[coveralls]

Coverage increased (+14.04%) when pulling 2e88d19 on halorgium:hijacking into a273967 on celluloid:master.

[digitalextremist]

@halorgium nice work! Using your branch, I am able to verify full Rack-WebSocket compatibility using the pre-header hijack approach. Once the socket is taken over by my application, I complete the handshake myself and have a full-duplex connection ( which works very nicely with faye/websocket-protocol-ruby )

[digitalextremist]

As mentioned, I am using your branch in my development environment --

At times it seems requests for static files are not closing. Trying to isolate //

[halorgium]

@digitalextremist probably best to file a new issue, but static files should not be hijacked... are you using a middleware like Rack::File?

EDIT: should not

[digitalextremist]

No middleware that might affect static files. Brought this up here because it might also extend to ordinary Requests not coming in through ws:// ...I've been seeing it enough to where I thought you might want to surf around in your branch in a browser that loads images, css, js, etc.

[tarcieri]

@halorgium closing this for now. I'm changing the internal hijacking API in #77. I think we need to redo the Rack adapter completely before we consider supporting Rack's hijack