[1617] Add ConstnativeHistogram

[shivanthzen]

Fixes: #1617 Add exported ConstNativeHistogram - this can be used to build native histograms if one already has the relevant data without calling the observe function. A viable use case is while converting exponential histograms to nativehistograms.

[shivanthzen]

@ArthurSens Maybe you can take a look at this PR.

[beorn7]

Will have a look ASAP (which won't be before next week, sorry).

[shivanthzen]

Thanks for the comments. I'll resolve them this weekend

[ArthurSens]

Oh, looks like some commits weren't signed and there's one test failing 🤔

The test seems to be flaky, it's also failing in other PRs

[shivanthzen]

I can sign the commits once the PR is approved, It seems signing will need a force push

[beorn7]

I can sign the commits once the PR is approved, It seems signing will need a force push

Yes, it changes the commits and therefore needs a force-push. However, it is essential to sign before approval. That's kind of the point.

[shivanthzen]

Force pushed with signed commits.

[ArthurSens]

@shivanthzen, looks like you accidentally added unrelated commits to your PR, could you keep only the ones that you've authored here?

[shivanthzen]

@ArthurSens Removed other commits from the branch

[kakkoyun]

@beorn7 could you have another look at it?

[beorn7]

This is very close to the top of my review queue now. Will have a look soon, hopefully today.

[beorn7]

Looks good to me, but there are lint warnings now. (They are coming from a recently added check, but they are still relevant.) Also, DCO signing is missing. @shivanthzen could you address the lint warnings and sign the commits? (Feel free to squash commits into fewer or just one before doing that.)

[shivanthzen]

@beorn7 Done

[beorn7]

Follow-up here would be to tackle the addition of exemplars!

To clarify: This means making withExemplarsMetric.Write aware of native histogram exemplars. Then, we only need to update the doc comment of NewMetricWithExemplar and everything should work fine.