To support the `_recovery` API, the recovery process keeps track of current progress in a class called RecoveryState. This class currently have some issues, mostly around concurrency (see #6644 ). This PR cleans it up as well as other issues around it:
- Make the Index subsection API cleaner:
- remove redundant information - all calculation is done based on the underlying file map
- clearer definition of what is what: total files, vs reused files (local files that match the source) vs recovered files (copied over). % based progress is reported based on recovered files only.
- cleaned up json response to match other API (sadly this breaks the structure). We now properly report human values for dates and other units.
- Add more robust unit testing
- Detail flag was passed along as state (it's now a ToXContent param)
- State lookup during reporting is now always done via the IndexShard , no more fall backs to many other classes.
- Cleanup APIs around time and move the little computations to the state class as opposed to doing them out of the API
I also improved error messages out of the REST testing infra for things I run into.
Closes#6644Closes#9811