From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 14 Sep 2021 02:05:32 GMT
Subject: Re: [PATCH 4/4] t5326: test propagating hashcache values
Message-ID: <xmqqpmtbc3o3.fsf@gitster.g>
In-Reply-To: <YT/3BuDa7KfUN/38@nand.local>

Taylor Blau <me@ttaylorr.com> writes:

> Alas, there they are. They are basically no different than having the
> name-hash for single pack bitmaps, it's just now we don't throw them
> away when generating a MIDX bitmap from a state where the repository
> already has a single-pack bitmap.

I actually wasn't expecting any CPU/time difference.

I hope that we are talking about the same name-hash, which is used
to sort the blobs so that when pack-objects try to find a good delta
base, the blobs from the same path will sit close to each other and
hopefully fit in the pack window.

The effect I was hoping to see by not discarding the information was
that we find better delta base hence smaller deltas in the resulting
packfiles.

Thanks.