Asserts write buffer seeking behaviour, including:
* Seeking past already persisted data correctly
* Skipping to next available op in non-contiguous offset stream
* Skipping to next available op for dropped ops due to retention
* Panics when seeking beyond available data (into the future)
Removes a pair of tests that covered some of the above due to their
tight coupling with ingester internals.
This commit adds a new test that exercises all major external APIs of
the ingester:
* Writing data via the write buffer
* Waiting for data to be readable via the progress API
* Querying data and and asserting the contents
This should provide basic integration coverage for the Ingester
internals. This commit also removes a similar test (though with less
coverage) that was tightly coupled to the existing buffering structures.
Adds a test helper type that maintains the in-memory state for a single
ingester integration test, and provides easy-to-use methods to
manipulate and inspect the ingester instance.
Dom Dwyer