From: Jeff King <peff@peff.net>
Date: Mon, 10 Jul 2017 00:06:38 GMT
Subject: Re: [PATCH] sha1_file: add slash once in for_each_file_in_obj_subdir()
Message-ID: <20170710000638.p7foedomfmdakyww@sigill.intra.peff.net>
In-Reply-To: <xmqqy3rx8svk.fsf@gitster.mtv.corp.google.com>

On Sun, Jul 09, 2017 at 09:41:51AM -0700, Junio C Hamano wrote:

> > On the plus side, this moves an invariant out of the loop. On the minus
> > side, it has to introduce an extra variable for "length we add on to"
> > versus "dir length to pass to the subdir_cb". That's not rocket science,
> > but it does slightly complicate things (though I note we already have
> > "origlen", so this is bumping us from 2 to 3 length variables, not 1 to
> > 2).
> >
> > So I dunno. It's fine with me if we take it, and fine if we leave it.
> 
> Unlike origlen, base vs dir lengths are not strictly needed; we
> prepare the base including '/', and we know we always have just one
> '/' at the end, so anybody that uses dirlen to truncate it back to
> the original before passing it down can truncate to (baselen-1), no?
> 
> In other words, something like this (not an incremental but a
> replacement) to keep calling "baselen" the length of the leading
> constant part we append to?

Yeah, I think that is correct. And you could even drop origlen by
replacing it with "baselen - 3" at the end. But somehow doing the
computation on the fly actually seems more complicated to me (from the
perspective of a reader who is trying to make sure all is correct).

-Peff