Re: Typesafer git hash patch

[Jeff King <peff@peff.net>]

On Tue, Feb 28, 2017 at 08:33:13PM +0000, brian m. carlson wrote:

> On Tue, Feb 28, 2017 at 03:26:34PM -0500, Jeff King wrote:
> > Yeah, a lot of brian's patches have been focused around the fixing the
> > related size assumptions. We've got GIT_SHA1_HEXSZ which doesn't solve
> > the problem, but at least makes it easy to find. And a big improvement
> > in the most recent series is a parse_oid() function that lets you parse
> > object-ids left-to-right without knowing the size up front. So things
> > like:
> > 
> >   if (len > 82 &&
> >       !get_sha1_hex(buf, sha1_a) &&
> >       get_sha1_hex(buf + 41, sha1_b))
> > 
> > becomes more like:
> > 
> >   if (parse_oid(p, oid_a, &p) && *p++ == ' ' &&
> >       parse_oid(p, oid_b, &p) && *p++ == '\n')
> 
> What I could do instead of using GIT_SHA1_HEXSZ is use GIT_MAX_HEXSZ for
> things that are about allocating enough memory and create a global (or
> function) for things that only care about what the current hash size is.
> That might be a desirable approach.  If other people agree, I can make a
> patch to do that.

I was going to say "don't worry about it, and focus on converting to
constants at all for now". But I guess while you are doing that, it does
not hurt to split the MAX_HEXSZ cases out. It will save work in sorting
them later.

-Peff