On Thu, Mar 14, 2019 at 12:54:36AM +0100, Ævar Arnfjörð Bjarmason wrote: > There's been a lot of changing of the hardcoded "40" values to > the_hash_algo->hexsz, but we've so far missed this one where we > hardcoded 38 for the loose object file length. > > This is because a SHA-1 like abcde[...] gets turned into > objects/ab/cde[...]. There's no reason to suppose the same won't be > the case for SHA-256, and reading between the lines in > hash-function-transition.txt the format is planned to be the same. Yep, makes sense. > However, we may want to modify this code for the hash function > transition. There's a potential pathological case here where we'll > only consider the loose objects for the currently active hash, but > objects for that hash will share a directory storage with the other > hash. > > Thus we could theoretically have 1k SHA-1 loose objects, and say 1 > million SHA-256 objects, and not notice because we're currently using > SHA-1. I agree that we may end up needing to touch this, but I think this patch doesn't make anything worse in that respect (and likely makes it better, since we at least know this "38" is supposed to be a hash). > diff --git a/builtin/gc.c b/builtin/gc.c > index 8c2312681c..9c2c63276d 100644 > --- a/builtin/gc.c > +++ b/builtin/gc.c > @@ -156,6 +156,8 @@ static int too_many_loose_objects(void) > int auto_threshold; > int num_loose = 0; > int needed = 0; > + const unsigned hexsz = the_hash_algo->hexsz; > + const unsigned hexsz_loose = hexsz - 2; It doesn't look like hexsz gets used anywhere else; is it worth having the extra variable? (Admittedly this quite a nit). -Peff
