Add centrifuge worker prototype

[FluffyDiscord]

This PR aims to implement support for Centrifuge worker https://roadrunner.dev/docs/plugins-centrifuge using symfony event dispatcher.

As it is, it works, but it should probably receive it's own middleware stack, mainly for doctrine and sentry. I am not sure about it's own kernel_reboots, I guess its also needed?

The centrifugo middleware will need to be separated from http middlewares, probably simply using different namespaces, so we do not touch http middlewares and keep the yaml config. Middlewares would then sort by the interface they implement.

If we do want to add kernel reboots, then we will need to change the yaml config structure, which could be breaking change if we want to make them universal

[Baldinof]

Thank you!

Sorry for the delay, I'll try to have a look this week.

[FluffyDiscord]

Please let me know which things need to be added or adjusted so this PR aligns with this bundle's intentions

[FluffyDiscord]

don't forget also this PR this week so we can have offical support! :]

[Baldinof]

Thank you!

Honestly I never used Centrifuge :D

[Baldinof]

I would prefer it to be like this:

Suggested change

	$eventClass = match (true) {
	$request instanceof Request\Connect => ConnectEvent::class,
	$request instanceof Request\Publish => PublishEvent::class,
	$request instanceof Request\Refresh => RefreshEvent::class,
	$request instanceof Request\SubRefresh => SubRefreshEvent::class,
	$request instanceof Request\Subscribe => SubscribeEvent::class,
	$request instanceof Request\RPC => RPCEvent::class,
	$request instanceof Request\Invalid => InvalidEvent::class,
	default => throw new \RuntimeException(sprintf("Unsupported \$request type '%s'", $request::class)),
	};
	$event = new $eventClass($request);
	$event = match (true) {
	$request instanceof Request\Connect => new ConnectEvent($request),
	$request instanceof Request\Publish => new PublishEvent($request),
	$request instanceof Request\Refresh => new RefreshEvent($request),
	$request instanceof Request\SubRefresh => new SubRefreshEvent($request),
	$request instanceof Request\Subscribe => new SubscribeEvent($request),
	$request instanceof Request\RPC => new RPCEvent($request),
	$request instanceof Request\Invalid => new InvalidEvent($request),
	default => throw new \RuntimeException(sprintf("Unsupported \$request type '%s'", $request::class)),
	};

[Baldinof]

Can we have a dedicated exception?

[Baldinof]

Maybe instead we can set a default response instance in the events? So $processedEvent->getResponse() would never return null? What do you think?

[FluffyDiscord]

Didn't think about it, but it makes sense.

[Baldinof]

Should we do more stuff here?

In the http context, exception are converted into http responses (unles something happen of the Symfony request handling), so we almost never reach this catch in the http worker.

Maybe we should re-use the kernel_reboot.allowed_exceptions list and do not disconnect if it's whitelisted?

[FluffyDiscord]

In the context of websocket I think we should always disconnect on any exception by default. You are expected to send valid payload that the other side can parse without errors, since there is no "default" payload that you can send that will be always processed. It's up to the user to handle his own errors as they can always change the response event to something else. Centrifuge has also auto reconnect feature that handles disconnects for you.

[Baldinof]

This should be in the suggest section

[FluffyDiscord]

Do you have any suggestions about the middleware structure in the context of websockets? There should definitely be a Doctrine and Sentry middleware - Doctrine to reset the EntityManager and Sentry to send all caught events, just like in the context of HTTP.

I am not sure which would be better, if to add event listener (which could be cancelled by user by mistake) or equivalent of the HTTP stack, but modified to run before and after instead of the current Generator approach (since we are dispatching the websocket message as event)

[michaelgracious]

Is this PR is stalled? This is something i'd love to see in the bundle so we can use Centrifuge

[FluffyDiscord]

Is this PR is stalled? This is something i'd love to see in the bundle so we can use Centrifuge

yes, I won't be adding anything here, I have made my own bundle with centrifuge