* Update License header for all source files
- Add Apache 2.0 header to source files that did not have one.
- Update all existing headers dated to 2019 to be 2020
- Remove comma from License header to comply with the Apache 2.0
guidelines.
* Update Copyright notice
Use the standard Copyright notices outlined by the
[CNCF](https://github.com/cncf/foundation/blob/master/copyright-notices.md#copyright-notices)
* wip: observers
* wip: float observers
* fix copy pasta
* wip: rework observers in sdk
* small fix in global meter
* wip: aggregators and selectors
* wip: monotonicity option for observers
* some refactor
* wip: docs
needs more package docs (especially for api/metric and sdk/metric)
* fix ci
* Fix copy-pasta in docs
Co-Authored-By: Mauricio Vásquez <mauricio@kinvolk.io>
* recycle unused recorders in observers
if a recorder for a labelset is unused for a second collection cycle
in a row, drop it
* unregister
* thread-safe set callback
* Fix docs
* Revert "wip: aggregators and selectors"
This reverts commit 37b7d05aed5dc90f6d5593325b6eb77494e21736.
* update selector
* tests
* Rework number equality
Compare concrete numbers, so we can get actual numbers in the error
message when they are not equal, not some uint64 representation. This
also uses InDelta for comparing floats.
* Ensure that Observers are registered in the same order
* Run observers in fixed order
So the tests can be reproducible - iterating a map made the order of
measurements random.
* Ensure the proper alignment of the delegates
This wasn't checked at all. After adding the checks, the test-386
failed.
* Small tweaks to the global meter test
* Ensure proper alignment of the callback pointer
test-386 was complaining about it
* update docs
* update a TODO
* address review issues
* drop SetCallback
Co-authored-by: Mauricio Vásquez <mauricio@kinvolk.io>
Co-authored-by: Rahul Patel <rghetia@yahoo.com>
