From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Taylor Blau <me@ttaylorr.com>,
git@vger.kernel.org, dstolee@microsoft.com
Subject: Re: [PATCH 03/10] builtin/pack-objects.c: learn '--assume-kept-packs-closed'
Date: Fri, 29 Jan 2021 12:30:38 -0800 [thread overview]
Message-ID: <xmqq35yjtrip.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <YBRfvZh86Z8wAnxZ@coredump.intra.peff.net> (Jeff King's message of "Fri, 29 Jan 2021 14:19:25 -0500")
Jeff King <peff@peff.net> writes:
>> If there is an out-of-band guarantee that .kept packs won't refer to
>> outside world, then we can obtain identical results to what existing
>> --honor-pack-keep (which traverses everything and then filteres out
>> what is in .keep pack) does by just stopping traversal when we see
>> an object that is found in a .keep pack. OK, I guess that it
>> answers the correctness question I asked about [02/10].
>>
>> It still is curious how we can safely "assume", but presumably we
>> will see how in a patch that appears later in the series.
>
> I think this would generally happen if the .keep packs are generated
> using something like "git repack -a", which packs everything reachable
> together. So if you do:
>
> git repack -ad
> touch .git/objects/pack/pack-whatever.keep
> ... some more packs come in, perhaps via pushes ...
> # imagine repack knew how to pass this along...
> git repack -a --assume-kept-packs-closed
>
> then you'd repack just the objects that aren't in the big pack.
Yeah. As a tool to help the above workflow, where you are only
creating another .keep out of youngest objects (i.e. those that are
either loose or in non-kept packs), because by definition anything
in .keep cannot be pointing back at these younger objects, it does
make sense to take advantage of "the set of packs with .keep as a
whole is closed".
It may become tricky once we start talking about creating a new
.keep out of youngest objects PLUS a few young keep packs, though.
Starting from all on-disk .keep packs, you'd mark them as in-core
keep bit, then drop in-core keep bit from the few young keep packs
that you intend to coalesce with the youngest objects---that is how
I would imagine your repacking strategy would go. The set of all
the on-disk .keep packs may give us "closed" guarantee, but if we
exclude a few latest packs from that set, would the remainder still
give us the "closed" guarantee we can take advantage of, in order to
pack these youngest objects (including the ones in the kept packs
that we are coalescing)?
next prev parent reply other threads:[~2021-01-29 20:35 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 23:23 [PATCH 00/10] repack: support repacking into a geometric sequence Taylor Blau
2021-01-19 23:24 ` [PATCH 01/10] packfile: introduce 'find_kept_pack_entry()' Taylor Blau
2021-01-20 13:40 ` Derrick Stolee
2021-01-20 14:38 ` Taylor Blau
2021-01-29 2:33 ` Junio C Hamano
2021-01-29 18:38 ` Taylor Blau
2021-01-29 19:31 ` Jeff King
2021-01-29 20:20 ` Junio C Hamano
2021-01-19 23:24 ` [PATCH 02/10] revision: learn '--no-kept-objects' Taylor Blau
2021-01-29 3:10 ` Junio C Hamano
2021-01-29 19:13 ` Taylor Blau
2021-01-19 23:24 ` [PATCH 03/10] builtin/pack-objects.c: learn '--assume-kept-packs-closed' Taylor Blau
2021-01-29 3:21 ` Junio C Hamano
2021-01-29 19:19 ` Jeff King
2021-01-29 20:01 ` Taylor Blau
2021-01-29 20:25 ` Jeff King
2021-01-29 22:10 ` Taylor Blau
2021-01-29 22:57 ` Jeff King
2021-01-29 23:03 ` Junio C Hamano
2021-01-29 23:28 ` Taylor Blau
2021-02-02 3:04 ` Taylor Blau
2021-01-29 23:31 ` Jeff King
2021-01-29 22:13 ` Junio C Hamano
2021-01-29 20:30 ` Junio C Hamano [this message]
2021-01-29 22:43 ` Jeff King
2021-01-29 22:53 ` Taylor Blau
2021-01-29 23:00 ` Jeff King
2021-01-29 23:10 ` Junio C Hamano
2021-01-19 23:24 ` [PATCH 04/10] p5303: add missing &&-chains Taylor Blau
2021-01-19 23:24 ` [PATCH 05/10] p5303: measure time to repack with keep Taylor Blau
2021-01-29 3:40 ` Junio C Hamano
2021-01-29 19:32 ` Jeff King
2021-01-29 20:04 ` [PATCH] p5303: avoid sed GNU-ism Jeff King
2021-01-29 20:19 ` Eric Sunshine
2021-01-29 20:27 ` Jeff King
2021-01-29 20:36 ` Eric Sunshine
2021-01-29 22:11 ` Taylor Blau
2021-01-29 20:38 ` [PATCH 05/10] p5303: measure time to repack with keep Junio C Hamano
2021-01-29 22:10 ` Jeff King
2021-01-29 23:12 ` Junio C Hamano
2021-01-19 23:24 ` [PATCH 06/10] pack-objects: rewrite honor-pack-keep logic Taylor Blau
2021-01-19 23:24 ` [PATCH 07/10] packfile: add kept-pack cache for find_kept_pack_entry() Taylor Blau
2021-01-19 23:24 ` [PATCH 08/10] builtin/pack-objects.c: teach '--keep-pack-stdin' Taylor Blau
2021-01-19 23:24 ` [PATCH 09/10] builtin/repack.c: extract loose object handling Taylor Blau
2021-01-20 13:59 ` Derrick Stolee
2021-01-20 14:34 ` Taylor Blau
2021-01-20 15:51 ` Derrick Stolee
2021-01-21 3:45 ` Junio C Hamano
2021-01-19 23:24 ` [PATCH 10/10] builtin/repack.c: add '--geometric' option Taylor Blau
2021-01-20 14:05 ` [PATCH 00/10] repack: support repacking into a geometric sequence Derrick Stolee
2021-02-04 3:58 ` [PATCH v2 0/8] " Taylor Blau
2021-02-04 3:58 ` [PATCH v2 1/8] packfile: introduce 'find_kept_pack_entry()' Taylor Blau
2021-02-16 21:42 ` Jeff King
2021-02-16 21:48 ` Taylor Blau
2021-02-04 3:58 ` [PATCH v2 2/8] revision: learn '--no-kept-objects' Taylor Blau
2021-02-16 23:17 ` Jeff King
2021-02-17 18:35 ` Taylor Blau
2021-02-04 3:59 ` [PATCH v2 3/8] builtin/pack-objects.c: add '--stdin-packs' option Taylor Blau
2021-02-16 23:46 ` Jeff King
2021-02-17 18:59 ` Taylor Blau
2021-02-17 19:21 ` Jeff King
2021-02-04 3:59 ` [PATCH v2 4/8] p5303: add missing &&-chains Taylor Blau
2021-02-04 3:59 ` [PATCH v2 5/8] p5303: measure time to repack with keep Taylor Blau
2021-02-16 23:58 ` Jeff King
2021-02-17 0:02 ` Jeff King
2021-02-17 19:13 ` Taylor Blau
2021-02-17 19:25 ` Jeff King
2021-02-04 3:59 ` [PATCH v2 6/8] builtin/pack-objects.c: rewrite honor-pack-keep logic Taylor Blau
2021-02-17 16:05 ` Jeff King
2021-02-17 19:23 ` Taylor Blau
2021-02-17 19:29 ` Jeff King
2021-02-04 3:59 ` [PATCH v2 7/8] packfile: add kept-pack cache for find_kept_pack_entry() Taylor Blau
2021-02-17 17:11 ` Jeff King
2021-02-17 19:54 ` Taylor Blau
2021-02-17 20:25 ` Jeff King
2021-02-17 20:29 ` Taylor Blau
2021-02-17 21:43 ` Jeff King
2021-02-04 3:59 ` [PATCH v2 8/8] builtin/repack.c: add '--geometric' option Taylor Blau
2021-02-17 18:17 ` Jeff King
2021-02-17 20:01 ` Taylor Blau
2021-02-17 0:01 ` [PATCH v2 0/8] repack: support repacking into a geometric sequence Jeff King
2021-02-17 18:18 ` Jeff King
2021-02-18 3:14 ` [PATCH v3 " Taylor Blau
2021-02-18 3:14 ` [PATCH v3 1/8] packfile: introduce 'find_kept_pack_entry()' Taylor Blau
2021-02-18 3:14 ` [PATCH v3 2/8] revision: learn '--no-kept-objects' Taylor Blau
2021-02-18 3:14 ` [PATCH v3 3/8] builtin/pack-objects.c: add '--stdin-packs' option Taylor Blau
2021-02-18 3:14 ` [PATCH v3 4/8] p5303: add missing &&-chains Taylor Blau
2021-02-18 3:14 ` [PATCH v3 5/8] p5303: measure time to repack with keep Taylor Blau
2021-02-18 3:14 ` [PATCH v3 6/8] builtin/pack-objects.c: rewrite honor-pack-keep logic Taylor Blau
2021-02-18 3:14 ` [PATCH v3 7/8] packfile: add kept-pack cache for find_kept_pack_entry() Taylor Blau
2021-02-18 3:14 ` [PATCH v3 8/8] builtin/repack.c: add '--geometric' option Taylor Blau
2021-02-23 0:31 ` [PATCH v3 0/8] repack: support repacking into a geometric sequence Jeff King
2021-02-23 1:06 ` Taylor Blau
2021-02-23 1:42 ` Jeff King
2021-02-23 2:24 ` [PATCH v4 " Taylor Blau
2021-02-23 2:25 ` [PATCH v4 1/8] packfile: introduce 'find_kept_pack_entry()' Taylor Blau
2021-02-23 2:25 ` [PATCH v4 2/8] revision: learn '--no-kept-objects' Taylor Blau
2021-02-23 2:25 ` [PATCH v4 3/8] builtin/pack-objects.c: add '--stdin-packs' option Taylor Blau
2021-02-23 8:07 ` Junio C Hamano
2021-02-23 18:51 ` Jeff King
2021-02-23 2:25 ` [PATCH v4 4/8] p5303: add missing &&-chains Taylor Blau
2021-02-23 2:25 ` [PATCH v4 5/8] p5303: measure time to repack with keep Taylor Blau
2021-02-23 2:25 ` [PATCH v4 6/8] builtin/pack-objects.c: rewrite honor-pack-keep logic Taylor Blau
2021-02-23 2:25 ` [PATCH v4 7/8] packfile: add kept-pack cache for find_kept_pack_entry() Taylor Blau
2021-02-23 2:25 ` [PATCH v4 8/8] builtin/repack.c: add '--geometric' option Taylor Blau
2021-02-24 23:19 ` Junio C Hamano
2021-02-24 23:43 ` Junio C Hamano
2021-03-04 21:40 ` Taylor Blau
2021-03-04 21:55 ` Taylor Blau
2021-02-23 3:39 ` [PATCH v4 0/8] repack: support repacking into a geometric sequence Jeff King
2021-02-23 7:43 ` Junio C Hamano
2021-02-23 18:44 ` Jeff King
2021-02-23 19:54 ` Martin Fick
2021-02-23 20:06 ` Taylor Blau
2021-02-23 21:57 ` Martin Fick
2021-02-23 20:15 ` Jeff King
2021-02-23 21:41 ` Martin Fick
2021-02-23 21:53 ` Jeff King
2021-02-24 18:13 ` Martin Fick
2021-02-26 6:23 ` Jeff King
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