From: Duy Nguyen <pclouds@gmail.com>
Date: Fri, 04 Oct 2013 12:38:57 GMT
Subject: Re: [PATCH v2] add: add --bulk to index all objects into a pack file
Message-ID: <CACsJy8BLyOtWck1ZidnBZo+KuBiSa5a4mZtbG6LQxTnv3sQXQw@mail.gmail.com>
In-Reply-To: <1380869871-31631-1-git-send-email-pclouds@gmail.com>

On Fri, Oct 4, 2013 at 1:57 PM, Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote:
> It's not an all-win situation though. --bulk is slower than --no-bulk
> because:
>
>  - Triple hashing: we need to calculate both object SHA-1s _and_ pack
>    SHA-1. At the end we have to fix up the pack, which means rehashing
>    the entire pack again. --no-bulk only cares about object SHA-1s.

Oops, it's quadruple hashing: one for object sha-1 (1), one for pack
sha-1 while writing pack (2), two for pack header fixup: one after the
the header fixup (3), and one repeating the same (2) just to verify
that it matches (2) exactly (4). Do we have to be this paranoid? I
think we could drop (2) and (4) in this case.
-- 
Duy