Re: Fix silly typo in new builtin grep

From: Linus Torvalds <torvalds@osdl.org>
Date: May 16, 2006, 01:07 UTC
Message-ID: <Pine.LNX.4.64.0605151801100.3866@g5.osdl.org>
In-Reply-To: <Pine.LNX.4.64.0605151743360.3866@g5.osdl.org>

On Mon, 15 May 2006, Linus Torvalds wrote:

Show 9 quoted lines

> 
> Me likee the new built-in grep. The ability to say
> 
> 	git grep __make_request v2.6.13 -- '*.c'
> 
> to grep for it in a specific version is well worth the fact that it 
> obviously ends up being slower than grepping in the currently checked-out 
> tree. It's doing a hell of a lot more, but despite that it's not at all 
> that slow.

Side note: it looks like the version generation really isn't much of a cost. Grepping in v2.6.13 isn't really noticeably slower than the "pre-external grep" was for grepping in the checked-out file tree.

So it looks like we _could_ improve the grepping of specific versions noticeably if we were to have a better regex library that was as optimized as what the external GNU grep seems to do. The actual revision data generation doesn't seem to be the biggest cost, and at least in _theory_ we could probably speed things up by a factor of two with a faster regex library.

That's good to keep in mind. It may be that the glibc regexp is just not very good, but quite frankly, I would personally not be surprised if it's better than most (ie windows, for example).

			Linus