From: Jeff King <peff@peff.net>
Date: Fri, 03 Jan 2014 15:44:26 GMT
Subject: Re: [PATCH v2 3/4] Speed up is_git_command() by checking early for internal commands
Message-ID: <20140103154426.GA23534@sigill.intra.peff.net>
In-Reply-To: <xmqq38l6qii6.fsf@gitster.dls.corp.google.com>

On Thu, Jan 02, 2014 at 11:41:05AM -0800, Junio C Hamano wrote:

>  - builtin/merge.c is the same, but it is conceptually even worse.
>    It has the end-user supplied string and wants to see if it is a
>    valid strategy.  If the user wants to use a custom strategy, a
>    single stat() to make sure if it exists should suffice, and the
>    error codepath should load the command list to present the names
>    of available ones in the error message.

Is it a single stat()? I think we would need to check each element of
$PATH. Though in practice, the exec-dir would be the first thing we
check, and where we would find the majority of hits. So it would still
be a win, as we would avoid touching anything but the exec-dir in the
common case.

-Peff