Add EventListener to HiveConnector

[s2lomon]

opens up the possibility to add external event listeners
that live in hive plugin ecosystem

[kokosing]

Few minor comments. Otherwise looks good.

[kokosing]

Why not to toImmutableSet()?

[findepi]

there is not point to even attempt any deduplication

[kokosing]

I had two points, none of them serious:

• injector.getInstance(Key.get(new TypeLiteral<Set<EventListener>>() {})) returns a set, so why do we change this?
• Using list here could make a false impression that this could contain duplicates (set still can, but it is less obvious). I don't see a reason why one would need even thing about it.

Any way, I will it leave up to author.

[findepi]

Since ClassLoaderSafeEventListener doesn't (and shouldn't) implement equals, using set is pointless.

[kokosing]

Just add newSetBinder(binder, EventListener.class); here. I don't see a need for defaultEventListenerModule() method.

[s2lomon]

better reading experience along with expressing the intention of it, so that the reader doesn't have to guess that it's a necessary default Event Listener.

[kokosing]

It is a matter of taste. I would prefer not to over-optimize reading experience, but rather follow the current layout.

[electrum]

Agreed, we should just bind an empty set here.

[s2lomon]

ok

[kokosing]

Suggested change

	public ClassLoaderSafeEventListener(EventListener delegate, ClassLoader classLoader)
	public ClassLoaderSafeEventListener(@ForClassLoaderSafe EventListener delegate, ClassLoader classLoader)

[s2lomon]

What would that annotation do? This class is used as a decorator inside a stream/for-loop operation. Nothing will be injected into it through guice, as there are potentially many EventListeners etc. For me adding it there would be misleading, but maybe I don't get the full purpose.

[kokosing]

ClassLoaderSafe* classes are also designed to be used with guice. I wanted to add this annotation to make sure it follows the convention and behaves like any other ClassLoaderSafe* class.

[kokosing]

Please don't get me wrong. I don't want you to use it ;)

[s2lomon]

ok I get it :)

[kokosing]

static import

[electrum]

Agreed, we should just bind an empty set here.

[electrum]

There's no need to create a no-op listener. The default implementation of Connector.getEventListeners() returns an empty set, so empty iterable is legal. We just need to create the set binder.

[s2lomon]

fair point

[kokosing]

Merged, thanks!