From: Miles Bader <miles@gnu.org>
Date: Sun, 07 Oct 2007 15:46:39 GMT
Subject: Re: [PATCH] Make strbuf_cmp inline, constify its arguments and optimize it a bit
Message-ID: <87sl4nlyg0.fsf@catnip.gol.com>
In-Reply-To: <20071007143912.GB10024@artemis.corp>

Pierre Habouzit <madcoder@debian.org> writes:
>> strbuf->buf is always non-NULL and NUL-terminated so you could just do
>> 
>> static inline int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
>> {
>> 	int len = a->len < b->len ? a->len : b->len;
>> 	return memcmp(a->buf, b->buf, len + 1);
>> }
>
>   doesn't work, because a buffer can have (in some very specific cases)
> an embeded NUL.

Couldn't you then just do:

   int len = a->len < b->len ? a->len : b->len;
   int cmp = memcmp(a->buf, b->buf, len);
   if (cmp == 0)
      cmp = b->len - a->len;
   return cmp;

[In the case where one string is a prefix of the other, then the longer
one is "greater".]

?

-Miles

-- 
"Suppose He doesn't give a shit?  Suppose there is a God but He
just doesn't give a shit?"  [George Carlin]