Re: [RFC PATCH] git log: support "auto" decorations

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Thu, May 29, 2014 at 09:54:10PM -0700, Linus Torvalds wrote:
>
>> That said, part of it is just that show-signature is so suboptimal
>> performance-wise, re-parsing the commit buffer for each commit when
>> "show_signature" is set. That's just crazy, we've already parsed the
>> commit text, we already *could* know if it has a signature or not, and
>> skip it if it doesn't. That would require one of the flag bits in the
>> object, though, or something, so it's probably not worth doing.
>
> Wow, it's really quite bad. Not only do we spend time on commits that we
> could otherwise know do not have signatures, but we actually pull the
> buffer from disk, even though we generally have it saved as
> commit->buffer.

The one for the signature on the commit itself is me being lazy and
defensive; I did not want to have to worry about people mucking with
what is in commit->buffer for whatever reason (e.g. re-encode in
different charset, etc.) and then asking the signature validated.

The other one for the merge-tag is me just being lazy, as it is
unlikely to be corrupt by any reasonable kinds of mucking with
commit->buffer on a merge.