Re: [PATCH v2 00/20] Introduce `USE_THE_REPOSITORY_VARIABLE` macro

Ramsay Jones <ramsay@ramsayjones.plus.com> writes:

I think the goal of the series is to eventually get to the point where nobody uses the_repository variable. If repository.c, which consists of a set of service routines that work on a repository instance, defined it, showing willingness to implicitly rely on the_repository through things like get_oid_hex() (which would rely on the_repository->hash_algo), that would go the opposite direction, so everything, other than the definition of the_repository variable itself that allows other files that still do rely implicitly on the variable to link with it, in repository.c would actively want to refuse to use services only available to those who define USE_THE_* macro.

It is a similar pattern we took when we weaned ourselves off of the_index compatibility macros. The read-cache.c was the central thing that defined the in-core index services, and it was the first thing that lost the_index compatibility macros like read_cache(), add_file_to_cache(), etc. that implicitly worked on the singleton the_index instance, while everybody else still relied on the singleton and services that implicitly worked on the singleton.