Patrick Steinhardt <ps@xxxxxx> writes: > diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c > index 3c6107c7ce5..7d86d920970 100644 > --- a/refs/reftable-backend.c > +++ b/refs/reftable-backend.c > @@ -15,6 +15,7 @@ > #include "../object.h" > #include "../path.h" > #include "../refs.h" > +#include "../reftable/reftable-basics.h" > #include "../reftable/reftable-stack.h" > #include "../reftable/reftable-record.h" > #include "../reftable/reftable-error.h" > @@ -289,7 +290,16 @@ static struct ref_store *reftable_be_init(struct repository *repo, > refs->store_flags = store_flags; > refs->log_all_ref_updates = repo_settings_get_log_all_ref_updates(repo); > > - refs->write_options.hash_id = repo->hash_algo->format_id; > + switch (repo->hash_algo->format_id) { > + case GIT_SHA1_FORMAT_ID: > + refs->write_options.hash_id = REFTABLE_HASH_SHA1; > + break; > + case GIT_SHA256_FORMAT_ID: > + refs->write_options.hash_id = REFTABLE_HASH_SHA256; > + break; > + default: > + BUG("unknown hash algorithm %d", repo->hash_algo->format_id); > + } > refs->write_options.default_permissions = calc_shared_perm(0666 & ~mask); > refs->write_options.disable_auto_compact = > !git_env_bool("GIT_TEST_REFTABLE_AUTOCOMPACTION", 1); OK. With this step, together with the previous one, we let Git side to use GIT_SHA{1,256}_FORMAT_ID to specify what algorithm is in use in the repository, and reftable-backend.c layer is responsible for translating them into REFTABLE_HASH_SHA{1,256}, which is internally used in reftable library to convey the same thing. Which makes sense. > diff --git a/reftable/reftable-basics.h b/reftable/reftable-basics.h > index 6e8e636b716..e0397ed5836 100644 > --- a/reftable/reftable-basics.h > +++ b/reftable/reftable-basics.h > @@ -11,6 +11,19 @@ > > #include <stddef.h> > > +/* > + * Hash functions understood by the reftable library. Note that the values are > + * arbitrary and somewhat random such that we can easily detect cases where the > + * hash hasn't been properly set up. > + */ > +enum reftable_hash { > + REFTABLE_HASH_SHA1 = 89, > + REFTABLE_HASH_SHA256 = 247, > +}; ;-). > +#define REFTABLE_HASH_SIZE_SHA1 20 > +#define REFTABLE_HASH_SIZE_SHA256 32 > +#define REFTABLE_HASH_SIZE_MAX REFTABLE_HASH_SIZE_SHA256 > + > /* Overrides the functions to use for memory management. */ > void reftable_set_alloc(void *(*malloc)(size_t), > void *(*realloc)(void *, size_t), void (*free)(void *)); OK.