Re: [PATCH RESEND] Avoid a useless prefix lookup in strbuf_expand()

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

Marco Costalba <mcostalba@gmail.com> writes:

> Currently the --prett=format prefix is looked up in a
> ...
> diff --git a/pretty.c b/pretty.c
> index b987ff2..64ead65 100644
> --- a/pretty.c
> +++ b/pretty.c
> @@ -282,16 +282,18 @@ static char *logmsg_reencode(const struct commit *commit,
>  	return out;
>  }
>  
> -static void format_person_part(struct strbuf *sb, char part,
> +/* returns placeholder length or 0 if placeholder is not known */
> +static size_t format_person_part(struct strbuf *sb, char part,
>                                 const char *msg, int len)
>  {
> -	int start, end, tz = 0;
> -	unsigned long date;
> +	int start, end, tz = 0, end_of_data;
> +	unsigned long date = 0;
>  	char *ep;
>  
> -	/* parse name */
> +	/* advance 'end' to point to email start delimiter */
>  	for (end = 0; end < len && msg[end] != '<'; end++)
>  		; /* do nothing */
> +

Another thing I noticed is that --pretty='format:%an %ae %at'
would end up running this function three times.  Perhaps it is
worth memoizing the result in format_commit_context while you
are at it?