From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Derrick Stolee <derrickstolee@github.com>,
Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>,
git@vger.kernel.org, me@ttaylorr.com, vdye@github.com
Subject: Re: [PATCH v2 0/8] ref-filter: ahead/behind counting, faster --merged option
Date: Wed, 15 Mar 2023 12:34:10 -0700 [thread overview]
Message-ID: <xmqqilf1oll9.fsf@gitster.g> (raw)
In-Reply-To: <ZBIA7+85Lld+lpUS@coredump.intra.peff.net> (Jeff King's message of "Wed, 15 Mar 2023 13:31:27 -0400")
Jeff King <peff@peff.net> writes:
> E.g., imagine resolving "main" to 1234abcd in step one, then somebody
> updates it to 5678cdef, then you run "for-each-ref" to compute
> ahead/behind, and now you show an inconsistent result: you say that
> "main" points to 1234abcd, but show the wrong ahead/behind information.
>
> Showing 1234abcd at all is out-of-date, of course, but the real problem
> is the lack of atomicity. Most porcelain scripts deal with this by
> resolving the refs immediately, assuming object ids are immutable (which
> they are modulo games like refs/replace), and then working with them.
A really paranoid caller can use %(ahead-behind-detail:refs/heads/main)
and get a report on refs/heads/topic, something that conveys
refs/heads/topic (at 67f9f40d) is ahead by 2 commits and behind
by 4 commits relative to refs/heads/main (at d7c3a768).
in a machine readable form. And when the "ahead by 2 commits"
disappears, we know 67f9f40d is merged to main sometime before
d7c3a768. Then it can say "update-ref -d refs/heads/topic 67f9f40d"
to avoid racing with simultanous updaters.
next prev parent reply other threads:[~2023-03-15 19:34 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-06 14:06 [PATCH 0/8] ahead-behind: new builtin for counting multiple commit ranges Derrick Stolee via GitGitGadget
2023-03-06 14:06 ` [PATCH 1/8] ahead-behind: create empty builtin Derrick Stolee via GitGitGadget
2023-03-06 18:48 ` Junio C Hamano
2023-03-07 0:40 ` Taylor Blau
2023-03-08 22:14 ` Derrick Stolee
2023-03-08 22:56 ` Junio C Hamano
2023-03-06 14:06 ` [PATCH 2/8] ahead-behind: parse tip references Derrick Stolee via GitGitGadget
2023-03-07 0:43 ` Taylor Blau
2023-03-06 14:06 ` [PATCH 3/8] ahead-behind: implement --ignore-missing option Derrick Stolee via GitGitGadget
2023-03-07 0:46 ` Taylor Blau
2023-03-06 14:06 ` [PATCH 4/8] commit-graph: combine generation computations Derrick Stolee via GitGitGadget
2023-03-06 14:06 ` [PATCH 5/8] commit-graph: return generation from memory Derrick Stolee via GitGitGadget
2023-03-06 14:06 ` [PATCH 6/8] commit-graph: introduce `ensure_generations_valid()` Taylor Blau via GitGitGadget
2023-03-06 18:52 ` Junio C Hamano
2023-03-07 0:50 ` Taylor Blau
2023-03-06 14:06 ` [PATCH 7/8] ahead-behind: implement ahead_behind() logic Derrick Stolee via GitGitGadget
2023-03-07 1:05 ` Taylor Blau
2023-03-09 17:32 ` Derrick Stolee
2023-03-06 14:06 ` [PATCH 8/8] ahead-behind: add --contains mode Derrick Stolee via GitGitGadget
2023-03-06 18:26 ` [PATCH 0/8] ahead-behind: new builtin for counting multiple commit ranges Junio C Hamano
2023-03-06 20:18 ` Derrick Stolee
2023-03-06 22:24 ` Junio C Hamano
2023-03-07 0:36 ` Taylor Blau
2023-03-09 9:20 ` Jeff King
2023-03-09 21:51 ` Junio C Hamano
2023-03-07 0:33 ` Taylor Blau
2023-03-10 17:20 ` [PATCH v2 0/8] ref-filter: ahead/behind counting, faster --merged option Derrick Stolee via GitGitGadget
2023-03-10 17:20 ` [PATCH v2 1/8] for-each-ref: add --stdin option Derrick Stolee via GitGitGadget
2023-03-10 18:08 ` Junio C Hamano
2023-03-13 10:31 ` Phillip Wood
2023-03-13 13:33 ` Derrick Stolee
2023-03-13 21:10 ` Taylor Blau
2023-03-15 13:37 ` Ævar Arnfjörð Bjarmason
2023-03-15 17:17 ` Jeff King
2023-03-15 17:49 ` Jeff King
2023-03-15 19:24 ` Junio C Hamano
2023-03-15 19:44 ` Jeff King
2023-03-10 17:20 ` [PATCH v2 2/8] for-each-ref: explicitly test no matches Derrick Stolee via GitGitGadget
2023-03-10 17:20 ` [PATCH v2 3/8] commit-graph: combine generation computations Derrick Stolee via GitGitGadget
2023-03-10 17:20 ` [PATCH v2 4/8] commit-graph: return generation from memory Derrick Stolee via GitGitGadget
2023-03-10 17:21 ` [PATCH v2 5/8] commit-graph: introduce `ensure_generations_valid()` Taylor Blau via GitGitGadget
2023-03-10 17:21 ` [PATCH v2 6/8] commit-reach: implement ahead_behind() logic Derrick Stolee via GitGitGadget
2023-03-15 13:50 ` Ævar Arnfjörð Bjarmason
2023-03-15 16:03 ` Junio C Hamano
2023-03-15 16:13 ` Derrick Stolee
2023-03-10 17:21 ` [PATCH v2 7/8] for-each-ref: add ahead-behind format atom Derrick Stolee via GitGitGadget
2023-03-10 19:09 ` Junio C Hamano
2023-03-15 13:57 ` Ævar Arnfjörð Bjarmason
2023-03-15 16:01 ` Junio C Hamano
2023-03-15 16:12 ` Derrick Stolee
2023-03-15 16:11 ` Derrick Stolee
2023-03-10 17:21 ` [PATCH v2 8/8] commit-reach: add tips_reachable_from_bases() Derrick Stolee via GitGitGadget
2023-03-15 14:13 ` Ævar Arnfjörð Bjarmason
2023-03-15 16:17 ` Derrick Stolee
2023-03-15 16:18 ` Derrick Stolee
2023-03-10 19:16 ` [PATCH v2 0/8] ref-filter: ahead/behind counting, faster --merged option Junio C Hamano
2023-03-10 19:25 ` Derrick Stolee
2023-03-15 17:31 ` Jeff King
2023-03-15 17:44 ` Derrick Stolee
2023-03-15 19:34 ` Junio C Hamano [this message]
2023-03-15 13:22 ` Ævar Arnfjörð Bjarmason
2023-03-15 13:54 ` Derrick Stolee
2023-03-15 17:45 ` [PATCH v3 " Derrick Stolee via GitGitGadget
2023-03-15 17:45 ` [PATCH v3 1/8] for-each-ref: add --stdin option Derrick Stolee via GitGitGadget
2023-03-15 18:06 ` Jeff King
2023-03-15 19:14 ` Junio C Hamano
2023-03-15 22:41 ` Jonathan Tan
2023-03-15 17:45 ` [PATCH v3 2/8] for-each-ref: explicitly test no matches Derrick Stolee via GitGitGadget
2023-03-15 17:45 ` [PATCH v3 3/8] commit-graph: combine generation computations Derrick Stolee via GitGitGadget
2023-03-15 22:49 ` Jonathan Tan
2023-03-17 18:30 ` Derrick Stolee
2023-03-15 17:45 ` [PATCH v3 4/8] commit-graph: return generation from memory Derrick Stolee via GitGitGadget
2023-03-15 22:58 ` Jonathan Tan
2023-03-15 17:45 ` [PATCH v3 5/8] commit-graph: introduce `ensure_generations_valid()` Taylor Blau via GitGitGadget
2023-03-15 17:45 ` [PATCH v3 6/8] commit-reach: implement ahead_behind() logic Derrick Stolee via GitGitGadget
2023-03-15 23:28 ` Jonathan Tan
2023-03-17 18:44 ` Derrick Stolee
2023-03-15 17:45 ` [PATCH v3 7/8] for-each-ref: add ahead-behind format atom Derrick Stolee via GitGitGadget
2023-03-15 17:45 ` [PATCH v3 8/8] commit-reach: add tips_reachable_from_bases() Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 0/9] ref-filter: ahead/behind counting, faster --merged option Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 1/9] for-each-ref: add --stdin option Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 2/9] for-each-ref: explicitly test no matches Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 3/9] commit-graph: refactor compute_topological_levels() Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 4/9] commit-graph: simplify compute_generation_numbers() Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 5/9] commit-graph: return generation from memory Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 6/9] commit-graph: introduce `ensure_generations_valid()` Taylor Blau via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 7/9] commit-reach: implement ahead_behind() logic Derrick Stolee via GitGitGadget
2023-03-20 20:40 ` Jonathan Tan
2023-03-20 11:26 ` [PATCH v4 8/9] for-each-ref: add ahead-behind format atom Derrick Stolee via GitGitGadget
2023-03-20 11:26 ` [PATCH v4 9/9] commit-reach: add tips_reachable_from_bases() Derrick Stolee via GitGitGadget
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqilf1oll9.fsf@gitster.g \
--to=gitster@pobox.com \
--cc=derrickstolee@github.com \
--cc=git@vger.kernel.org \
--cc=gitgitgadget@gmail.com \
--cc=me@ttaylorr.com \
--cc=peff@peff.net \
--cc=vdye@github.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.