[Feature] Add wildcard handlers for events

[grahamjenson]

This feature lets a server or client handle events with wildcards, e.g.

server.OnEvent("/", "*", func(s socketio.Conn, e socketio.EventRequest, msg interface{}) interface{} {

would handle all events in the namespace if no other handler was specified.

It uses a radix structure to find the closest wildcard match, so if an event called "clients" came in then "clie*" will handle it over "c*"

This will always return an exact match before looking for wildcard matches, so performance should not be impacted if you use exact matches. This would also be a workaround if an event ended with a wildcard, e.g. an event called "star*".

This PR also:

1. Expands the possible receiving functions for an event handler, because we need to pass along the event name to the handler. (I am not happy with this solution, though not sure how to make it better, suggestions?)
2. splits out the Ack and Event Call functions as they are now dissimilar enough
3. Only looks up (locks) the event once per call by refactoring to the method GetEventHandler
4. Adds an example for a proxy (my ultimate goal) using the client and wildcard server to intercept and pass along messages. This is not a perfect proxy, but does the basic work.

[grahamjenson]

@erkie @sshaplygin I think this is ready to merge. Tests are running locally for me, not sure why there are failures (flaky?).

[sshaplygin]

Hey, @grahamjenson. Thanks for you great job! Is this feature comparable with source socket.io into ts implementation? From which version is the functionality supported in the original version?

[sshaplygin]

Use camel case instead of snake case for const FN_TYPE_ERROR

[sshaplygin]

we don't need overwrite vars hasConn and hasEventRequest , because by default it is false too

[sshaplygin]

it is required params for start your app. We must check with args

[sshaplygin]

pls, separate logs rows code lines with backspaces

[sshaplygin]

pls, separate code worked with mutex with backspace.

i suggest next style:

nh.eventsLock.Lock()
defer nh.eventsLock.Unlock()

ef := newEventFunc(f)

[sshaplygin]

pls, separate code worked with mutex with backspace

[sshaplygin]

Pls, rewrite this part to if ok we will return eventHandler, else we make magic :)

[sshaplygin]

i suggest to rewrite this part by method. for example:

// getArgsStart finding the number of remaining arguments
func getArgsStart(ft reflect.Type) int {
	hasConn := false
	hasEventRequest := false

	if ft.NumIn() == 1 {
		if implementsEventRequest(ft.In(0)) {
			panic("Cannot have EventRequest as first argument" + FN_TYPE_ERROR)
		}

		hasConn = implementsConn(ft.In(0))
	}

	if ft.NumIn() > 1 {
		if implementsEventRequest(ft.In(0)) {
			panic("Cannot have EventRequest as first argument" + FN_TYPE_ERROR)
		}

		if implementsConn(ft.In(1)) {
			panic("Cannot have Conn as second argument" + FN_TYPE_ERROR)
		}

		hasConn = implementsConn(ft.In(0))
		hasEventRequest = implementsEventRequest(ft.In(1))
	}

	if hasEventRequest && !hasConn {
		panic("Must have Conn if has EventRequest" + FN_TYPE_ERROR)
	}

	// Finding the number of remaining arguments
	argsStart := 0
	if hasConn {
		argsStart += 1
	}
	if hasEventRequest {
		argsStart += 1
	}
	
	return argsStart
}

[sshaplygin]

findOrCreateClient it is bad method, because witch made double thinks on once method: create or find. Please, create client on server obviously

[googollee]

archived.