We currently have a bit of conflation in api/ between those APIs that are provided a platform abstraction layer (mostly for the benefit of core Envoy, but also extensions) and the APIs that will one day act as a stable interface for extensions. For example:

is clearly in the second category, and

is in the first. This becomes even stranger when we have the ApiImpl require access to a stats object in

This is because the filesystem code is both a platform abstraction API and also providing higher level functionality like stats tracking.

Ideally, we split out the API into a api/platform and api/export, where we clearly delineate these two concerns. New platform ports of Envoy populate the interfaces in api/platform, extensions take dependencies on api/export.

CC @jmarantz @eziskind @mattklein123