Offer direct span creation API for use within explicit tracers.

[raphw]

Adds a DirectTracer abstraction that allows for recording data explicitly, for example when using tracer APIs such as OpenTelementry.

[github-actions]

👋 @raphw Thanks a lot for your contribution!

It may take some time before we review a PR, so even if you don’t see activity for some time, it does not mean that we have forgotten about it.

Every once in a while we go through a process of prioritization, after which we are focussing on the tasks that were planned for the upcoming milestone. The prioritization status is typically reflected through the PR labels. It could be pending triage, a candidate for a future milestone, or have a target milestone set to it.

[SylvainJuge]

Hi @raphw , if I am not mistaken most of the changes here are also included in #3340 , is that correct ?

For now the only concern that I have is the exact meaning we want to give to direct implementations, as it's not straightforward to know which one to pick apart from relying on what is available in the classpath, do you have a few other naming strategies that would be less abstract ?

[raphw]

Direct is maybe not the best term. Maybe explicit is a better prefix?

[botelastic]

Hi! We just realized that we haven't looked into this issue in a while. We're sorry! We're labeling this issue as stalled to make it hit our filters and make sure we get back to it in as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1. Thank you for your contribution!

[botelastic]

Hi! This issue has been stale for a while and we're going to close it as part of our cleanup procedure. We appreciate your contribution and would like to apologize if we have not been able to review it, due to the current heavy load of the team. Feel free to re-open this issue if you think it should stay open. Thank you for your contribution!

[raphw]

I am creating a new, independant PR.