#4851 ConcurrentHashSet→Utils.concurrentHashSet

[magicprinc]

Issue: #4851

It seems that io.vertx.core.impl.ConcurrentHashSet is a copy of JDK's Collections.newSetFromMap.
The Best Code is No Code At All.
It is probably a good idea to review and replace this class with two utility methods.

[tsegismont]

Thank you @magicprinc

Can you please make a few changes?

[magicprinc]

@tsegismont fixed. Please see.

Changed implementation to

public static <E> Set<E> concurrentHashSet (){
  return ConcurrentHashMap.newKeySet();// we can change implementation
}

or do you mean: replace everywhere Util.concurrentHashSet with its body?

I think this separate method is a more robust and readable solution.

[magicprinc]

@He-Pin Could you fix other Vert.x modules (if any) which are using this - deleted - class

[He-Pin]

@magicprinc Hi, thanks for the ping, I think it would be better for you to do it, and I don't have a write access to this project, then I have to make a PR to yours and that will make the thing a little complicated :)

[magicprinc]

@He-Pin @tsegismont I can't find any other ConcurrentHashSet usages besides the corrected ones, so we probably have managed it :-)

[tsegismont]

@magicprinc before we merge this PR we also need updates for the projects that depend on this class (see #4851 (comment))

[magicprinc]

@tsegismont All your tasks are done! 👍

1. I have replaced method with its body.
2. Fix in vertx-service-discovery: #4851 ConcurrentHashSet is redundant with ConcurrentHashMap#newKeySet() vert-x3/vertx-service-discovery#172
3. Fix in vertx-mqtt: ConcurrentHashSet is redundant with ConcurrentHashMap#newKeySet() #4851 vert-x3/vertx-mqtt#243

[tsegismont]

@magicprinc one last comment, thank you

[magicprinc]

@He-Pin Could you review and approve this too? 🙏

[He-Pin]

Lgtm