Re: [PATCH v5 8/8] sha1_file: refactor has_sha1_file_with_flags

> On Thu, Jun 22, 2017 at 2:40 AM, Jonathan Tan <jonathantanmy@google.com> wrote:
> 
> > diff --git a/sha1_file.c b/sha1_file.c
> > index bf6b64ec8..778f01d92 100644
> > --- a/sha1_file.c
> > +++ b/sha1_file.c
> > @@ -3494,18 +3494,10 @@ int has_sha1_pack(const unsigned char *sha1)
> >
> >  int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
> >  {
> > -       struct pack_entry e;
> > -
> >         if (!startup_info->have_repository)
> >                 return 0;
> > -       if (find_pack_entry(sha1, &e))
> > -               return 1;
> > -       if (has_loose_object(sha1))
> > -               return 1;
> > -       if (flags & HAS_SHA1_QUICK)
> > -               return 0;
> > -       reprepare_packed_git();
> > -       return find_pack_entry(sha1, &e);
> > +       return sha1_object_info_extended(sha1, NULL,
> > +                                        flags | OBJECT_INFO_SKIP_CACHED) >= 0;
> >  }
> 
> I am not sure if it could affect performance (in one way or another) a
> lot or not but I just wanted to note that has_loose_object() calls
> check_and_freshen() which calls access() on loose object files, while
> sha1_object_info_extended() calls sha1_loose_object_info() which calls
> stat_sha1_file() which calls lstat() on loose object files.
> 
> So depending on the relative performance of access() and lstat() there
> could be a performance impact on repos that have a lot of loose object
> files.