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Date:   Wed, 24 Jan 2018 22:25:18 +0000
From:   Eric Wong <e@80x24.org>
To:     =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>
Cc:     git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>,
        Jeff King <peff@peff.net>
Subject: Re: Git packs friendly to block-level deduplication
Message-ID: <20180124222518.GA24157@whir>
References: <87bmhiykvw.fsf@evledraar.gmail.com>
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Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
> If you have a bunch of git repositories cloned of the same project on
> the same filesystem, it would be nice of the packs that are produced
> would be friendly to block-level deduplication.

Fwiw, I currently get around this when mirroring by having all
the remotes I care about mirrored to a "hidden" root repo, and
having other repos point to the hidden root objects via
object/info/alternates.  Not that great for usability and
probably potentially racy...

> Has anyone here barked up this tree before? Suggestions? Tips on where
> to start hacking the repack code to accomplish this would be most
> welcome.

The Debian version of gzip(1) has an --rsyncable patch which
might be of help.