Bug 1790501 - Add count to DistributionData payload

[rosahbruno]

Update DistributionData object to include count so that a dev can easily check how many samples end up in the distribution. This change effects timing, memory, and custom distributions.

[rosahbruno]

Seeing some weirdness that I don't understand with i64 & u64 in the Kotlin tests. If anyone more knowledgeable about Rust or Kotlin has any ideas, it would be much appreciated!

[rosahbruno]

@travis79
No rush on this, but do you have any ideas about the issue I described above? The Rust tests don't seem to care if I use an i64 or a u64, but Kotlin seems to not like the type conversion and throws weird errors when trying to run the tests.

[travis79]

@travis79 No rush on this, but do you have any ideas about the issue I described above? The Rust tests don't seem to care if I use an i64 or a u64, but Kotlin seems to not like the type conversion and throws weird errors when trying to run the tests.

So, for the longest time unsigned types were a "prototype" feature in kotlin, so we used signed types even though we never had a use case to record negative values. So I think any of the values coming across the FFI should be signed types because of this.

What failures were you seeing on the Kotlin side, maybe that will help me to point you in the right direction to get this working with an i64

[rosahbruno]

Talked with @travis79 and looks like my issues were caused (potentially, unconfirmed) by gradle caching. I ran the Kotlin tests via make test-kotlin instead of ./gradlew and everything worked as expected - the CI tests also passed!

So looks like the issue I was seeing was just a local thing, thanks @travis79 !

[travis79]

This is looking great! I had just a couple of non-blocking nits, and I don't see a need to re-review this. 🎉