Re: [PATCH 4/3] sha1_name: use bsearch_pack() in unique_in_pack()

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

René Scharfe <l.s.r@web.de> writes:

> Replace the custom binary search in unique_in_pack() with a call to
> bsearch_pack().  This reduces code duplication and makes use of the
> fan-out table of packs.
>
> Signed-off-by: Rene Scharfe <l.s.r@web.de>
> ---
> This is basically the same replacement as done by patch 3.  Speed is
> less of a concern here -- at least I don't know a commonly used
> command that needs to resolve lots of short hashes.

Looks correct.  Did you find this by eyeballing, or do you have some
interesting tool you use?

>
>  sha1_name.c | 21 ++-------------------
>  1 file changed, 2 insertions(+), 19 deletions(-)
>
> diff --git a/sha1_name.c b/sha1_name.c
> index 24894b3dbe..0185c6081a 100644
> --- a/sha1_name.c
> +++ b/sha1_name.c
> @@ -150,31 +150,14 @@ static int match_sha(unsigned len, const unsigned char *a, const unsigned char *
>  static void unique_in_pack(struct packed_git *p,
>  			   struct disambiguate_state *ds)
>  {
> -	uint32_t num, last, i, first = 0;
> +	uint32_t num, i, first = 0;
>  	const struct object_id *current = NULL;
>  
>  	if (open_pack_index(p) || !p->num_objects)
>  		return;
>  
>  	num = p->num_objects;
> -	last = num;
> -	while (first < last) {
> -		uint32_t mid = first + (last - first) / 2;
> -		const unsigned char *current;
> -		int cmp;
> -
> -		current = nth_packed_object_sha1(p, mid);
> -		cmp = hashcmp(ds->bin_pfx.hash, current);
> -		if (!cmp) {
> -			first = mid;
> -			break;
> -		}
> -		if (cmp > 0) {
> -			first = mid+1;
> -			continue;
> -		}
> -		last = mid;
> -	}
> +	bsearch_pack(&ds->bin_pfx, p, &first);
>  
>  	/*
>  	 * At this point, "first" is the location of the lowest object