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From: Duy Nguyen <pclouds@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: khanzf@gmail.com, Git Mailing List <git@vger.kernel.org>
Subject: Re: Understanding pack format
Date: Fri, 2 Nov 2018 17:00:21 +0100	[thread overview]
Message-ID: <CACsJy8DFUeEddSa2z4VTSqhaUBJ4+SUf8xvjh6iWY2Phhh96iQ@mail.gmail.com> (raw)
In-Reply-To: <xmqqlg6covi6.fsf@gitster-ct.c.googlers.com>

On Fri, Nov 2, 2018 at 7:19 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> Farhan Khan <khanzf@gmail.com> writes:
>
> > ...Where is this in the git code? That might
> > serve as a good guide.
>
> There are two major codepaths.  One is used at runtime, giving us
> random access into the packfile with the help with .idx file.  The
> other is used when receiving a new packstream to create an .idx
> file.

The third path is copying/reusing objects in
builtin/pack-objects.c::write_reuse_object(). Since it's mostly
encoding the header of new objects in pack, it could also be a good
starting point. Then you can move to write_no_reuse_object() and get
how the data is encoded, deltified or not (yeah not parsed, but I
think it's more or less the same thing conceptually).
-- 
Duy

  reply	other threads:[~2018-11-02 16:00 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-02  5:23 Understanding pack format Farhan Khan
2018-11-02  6:15 ` Junio C Hamano
2018-11-02 16:00   ` Duy Nguyen [this message]
2018-11-06  2:23     ` Farhan Khan
2018-11-06  6:09       ` Jeff King
2018-11-06 16:06       ` Duy Nguyen
2018-11-02 15:54 ` Duy Nguyen

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