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Date:   Thu, 9 Mar 2023 09:06:08 +0000
From:   Eric Wong <e@80x24.org>
To:     Jeff King <peff@peff.net>
Cc:     Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>,
        git@vger.kernel.org, gitster@pobox.com, me@ttaylorr.com,
        =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>,
        Derrick Stolee <derrickstolee@github.com>,
        Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Subject: Re: [PATCH v2] object-file: reprepare alternates when necessary
Message-ID: <20230309090608.M92573@dcvr>
References: <pull.1490.git.1678136369387.gitgitgadget@gmail.com>
 <pull.1490.v2.git.1678301252360.gitgitgadget@gmail.com>
 <ZAmJtnLgwimRBGTb@coredump.intra.peff.net>
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Jeff King <peff@peff.net> wrote:
> The only downside might be performance. For sane cases, I think scanning
> the new alternates is OK. I know Eric (cc'd) has some crazy
> 100k-alternate setup (from 407532f82d, etc), but I'd expect a reprepare
> there is already expensive (we already have to re-scan every one of
> those directories for packfiles, and throw out any loose object caches).

I'm not sure if that 100k alternate thing is happening, yet...
(initial specs called for ~30k, but I figured it might grow)

If it does, I'm thinking about enhancing --batch-command, to support
`add-alternate' to dynamically add alternates while running cat-file.

Right now, my biggest use case is only 250 alternates or so.