Add special handling for parsing websocket data

[sacovo]

Library users can specify when they want to use websocket connections, by setting allow_upgrade to true. If so the parser will send received data to the handler, even when no content-length was specified for the request.

[mfelsche]

Hi @sacovo nice job! Though I would handle the websocket case differently. The protocol itself is not trivial to implement: See for example: https://www.rfc-editor.org/rfc/rfc6455#section-5 And it shouldn't go through the http-parser.

Instead it should be possible to somehow call Session.upgrade(<NEW_HANDLER>) and then this new handler will receive data and will be able to send data to the given connection, including doing websockety stuff. I just need to figure out the details of how this should look.

[sacovo]

Sounds reasonable. I'm working on implementing websocket parsing, I'll let you know, as soon as I finish.

[sacovo]

I've implemented a parser here: https://github.com/sacovo/flying_pace/blob/main/flying_pace/websocket.pony

[mfelsche]

Sorry for the late reply.

I am in the process of adding a behaviour called upgrade to the Session that takes a TCPConnectionNotify iso and basically just forwards to: TcpConnection.set_notify.

This way one can manually upgrade to whatever protocol is desired. I want to test this with a websocket library that already exists for pony and use its TCPConnectionNotify implementation: https://github.com/oraoto/pony-websocket/blob/master/websocket/listener.pony#L60

Give me another week to finish the tests, but i think it looks promising.

[jemc]

Adding the "do not merge" label because this is waiting for the related work from @mfelsche

[mfelsche]

@sacovo I finally got around to finish the session upgrade handling I was talking about in #75 I hope the provided example makes the intent clearer and it works for your websocket needs.

[sacovo]

Yes, this works (with some small changes).