From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 13 Jan 2012 00:14:16 GMT
Subject: Re: thin packs ending up fat
Message-ID: <7vboq81msn.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20120112223234.GA4949@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Hmm. It turns out this is really easy, because we have already marked
> such objects as preferred bases.
>
> So with this patch:
>
> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index 96c1680..d05e228 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -1439,6 +1439,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
>  	 */
>  	if (reuse_delta && trg_entry->in_pack &&
>  	    trg_entry->in_pack == src_entry->in_pack &&
> +	    !src_entry->preferred_base &&
>  	    trg_entry->in_pack_type != OBJ_REF_DELTA &&
>  	    trg_entry->in_pack_type != OBJ_OFS_DELTA)
>  		return 0;

Yeah, I was wondering why this one-liner was not in the original message
;-)

> here are the numbers I get:
>
>                   dataset
>             | fetches | tags
> ---------------------------------
>      before | 53358   | 2750977
> size  after | 32398   | 2668479
>      change |   -39%  |      -3%
> ---------------------------------
>      before |  0.18   | 1.12
> CPU   after |  0.18   | 1.15
>      change |    +0%  |      +3%

Looks good.