Wikibase is going to use PSR-16-compliant simple CacheInterface as a generic cache interface in PHP code.
We are going to use psr/simple-cache library that defines the interface, and relevant extensions.
As the library is not part of the mediawiki vendor component yet, it would need to go through the security review, so it could be used in Wikibase extension.
Source code of the library is at: https://github.com/php-fig/simple-cache.
We are intending to use the most recent version 1.0.1 of the library.
The library does not have dependencies.
The library only defines interfaces. Implementations of particular cache services (e.g. decorated BagOStuff implementations) will be provided in Wikibase code base.
Should any further information needed to be provided, Wikidata developers (WMDE) should be able to do it.