On Tue, Dec 1, 2020 at 6:00 AM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > "Han-Wen Nienhuys via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > > > From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> > > > > The reftable backend needs to know the hash algorithm for writing the > > initialization hash table. > > > > The initial reftable contains a symref HEAD => "main" (or "master"), which is > > agnostic to the size of hash value, but this is an exceptional circumstance, and > > the reftable library does not cater for this exception. It insists that all > > tables in the stack have a consistent format ID for the hash algorithm. > > > > Call set_repo_hash_algo directly after reading out GIT_DEFAULT_HASH. > > Seeing that there is no mention of the_repository in the entire > init-db.c file, it's not because it's hidden in the call to refs_init_db(). refs_init_db accesses the_repository global variable, because get_main_ref_store() takes a repository (and not repository_format) argument. > Isn't it the matter of passing the hash > taken from repo_fmt to the refs API to initialize that part of the > repository, instead of relying on half-initialized state in > the_repository? The refstore is created in get_main_ref_store(). I can't add a repository_format argument there, because it has a lot of call sites where the repository_format isn't available. If the_repository is only half-initialized at this point in init_db(), then why are we passing it in refs_init_db() just a couple of lines further? At what point the_repository considered initialized? > It's not like only the hash_algo member is yet to > be prepared in the_repository instance at that point in the code. > Most of the members are, except for a very few fields initialized by > initialize_the_repository(), not filled in the codepath, no? > > So, this might have been the most convenient way to pass hash_algo > down but the patch does not convince me that it is the best way. I'm a bit at a loss here; I never learned how to cleanly work with so many global variables, so I'm happy to take your suggestion. -- Han-Wen Nienhuys - Google Munich I work 80%. Don't expect answers from me on Fridays. -- Google Germany GmbH, Erika-Mann-Strasse 33, 80636 Munich Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
