From: Junio C Hamano <gitster@pobox.com>
To: Patrick Steinhardt <ps@pks.im>
Cc: Karthik Nayak <karthik.188@gmail.com>,
Chris Torek <chris.torek@gmail.com>,
git@vger.kernel.org
Subject: Re: [PATCH 7/8] refs: add 'update-symref' command to 'update-ref'
Date: Wed, 10 Apr 2024 09:06:45 -0700 [thread overview]
Message-ID: <xmqqzfu1w6ay.fsf@gitster.g> (raw)
In-Reply-To: <ZhYTe2zpJyHJ8iIT@tanuki> (Patrick Steinhardt's message of "Wed, 10 Apr 2024 06:20:11 +0200")
Patrick Steinhardt <ps@pks.im> writes:
>> > I might have missed it while scanning through this thread, but why
>> > exactly is the zero OID not a good enough placeholder here to say that
>> > the ref must not exist? A symref cannot point to a ref named after the
>> > zero OID anyway.
>
>> > In my opinion, "update-symref" with an old-value must be able to accept
>> > both object IDs and symrefs as old value. Like this it would be possible
>> > to update a proper ref to a symref in a race-free way. So you can say:
>> >
>> > git update-ref SYMREF refs/heads/main 19981daefd7c147444462739375462b49412ce33
>
>> > To update "SYRMEF" to "refs/heads/main", but only in case it currently
>> > is a proper ref that points to 19981daefd7c147444462739375462b49412ce33.
>> > Similarly...
>> >
>> > git update-ref SYMREF refs/heads/main refs/heads/master
>
>> > would update "SYMREF" to "refs/heads/main", but only if it currently
>> > points to the symref "refs/heads/master".
I think that would work well. We need to explicitly forbid a file
$GIT_DIR/[0-9a-f]{40} to be used as a pseudoref, which I think that
is an improvement. I do not know how the transition to move to a
world with a stricter rule would look like, though.
>> > And by extension I think that
>> > the zero OID should retain its established meaning of "This ref must not
>> > exist":
>> >
>> > git update-ref SYMREF refs/heads/main 0000000000000000000000000000000000000000
>> >
>> > This would only update "SYMREF" to "refs/heads/main" if it does not yet
>> > exist.
We express "SYMREF must currently be a symref" by naming an old-ref,
and we say "SYMREF can currently be either a ref or symref, but it
must point at this object" by naming an old-oid. The looseness of
the latter (i.e. we cannot express "Before making HEAD point at ref
X, ensure that it is detached at OID") looks a bit disturbing, but
otherwise looks good. I offhand do not know how expressive we would
want the "old" requirement to be.
>> On a side-note: This would also mean that we should somehow support
>> moving from symrefs to a regular ref via a transaction, so that means we
>> should allow
>>
>> update SP <ref> SP <new-oid> [SP (<old-oid> | <old-rev>)] LF
>>
>> too, but I'm not going to tackle that in my patches.
>
> Yes, I think that would be a sensible idea, even though we have to be
> careful with backwards compatibility here. In any case, I think it makes
> sense to not extend the scope of your patch series and leave this for
> the future.
Likewise, we may want to be able to express "Before making HEAD
detached at commit X, ensure that HEAD points at ref Y that points
at commit Z". IOW, the "old" part might have to be not
[SP (<old-oid> | <old-ref>)]
but
[SP <old-oid> SP <old-ref>]
to specify both, perhaps?
next prev parent reply other threads:[~2024-04-10 16:06 UTC|newest]
Thread overview: 194+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-30 22:46 [PATCH 0/8] update-ref: add support for update-symref option Karthik Nayak
2024-03-30 22:46 ` [PATCH 1/8] files-backend: extract out `create_symref_lock` Karthik Nayak
2024-04-02 12:20 ` Patrick Steinhardt
2024-04-03 14:52 ` Karthik Nayak
2024-03-30 22:46 ` [PATCH 2/8] reftable-backend: extract out `write_symref_with_log` Karthik Nayak
2024-04-02 12:20 ` Patrick Steinhardt
2024-03-30 22:46 ` [PATCH 3/8] reftable-backend: move `write_symref_with_log` up Karthik Nayak
2024-03-30 22:46 ` [PATCH 4/8] refs: accept symref in `ref_transaction_add_update` Karthik Nayak
2024-03-30 22:46 ` [PATCH 5/8] refs/files-backend: add support for symref updates Karthik Nayak
2024-04-02 12:20 ` Patrick Steinhardt
2024-03-30 22:46 ` [PATCH 6/8] refs/reftable-backend: " Karthik Nayak
2024-04-02 12:20 ` Patrick Steinhardt
2024-03-30 22:46 ` [PATCH 7/8] refs: add 'update-symref' command to 'update-ref' Karthik Nayak
2024-03-31 22:08 ` Junio C Hamano
2024-03-31 22:27 ` Chris Torek
2024-03-31 23:14 ` Junio C Hamano
2024-04-01 1:31 ` Junio C Hamano
2024-04-02 12:20 ` Patrick Steinhardt
2024-04-02 16:40 ` Junio C Hamano
2024-04-09 11:55 ` Patrick Steinhardt
2024-04-09 16:15 ` Karthik Nayak
2024-04-10 4:20 ` Patrick Steinhardt
2024-04-10 16:06 ` Junio C Hamano [this message]
2024-04-10 17:31 ` Patrick Steinhardt
2024-04-01 10:38 ` Karthik Nayak
2024-04-01 11:48 ` Karthik Nayak
2024-04-01 16:17 ` Junio C Hamano
2024-04-01 20:40 ` Junio C Hamano
2024-04-01 22:37 ` Karthik Nayak
2024-03-30 22:46 ` [PATCH 8/8] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-04-02 12:20 ` Patrick Steinhardt
2024-04-12 9:59 ` [PATCH v2 0/7] update-ref: add symref oriented commands Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 1/7] refs: accept symref values in `ref_transaction[_add]_update` Karthik Nayak
2024-04-18 14:25 ` Christian Couder
2024-04-19 10:28 ` Karthik Nayak
2024-04-18 15:08 ` Phillip Wood
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-19 15:47 ` Karthik Nayak
2024-05-04 15:15 ` phillip.wood123
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-19 18:09 ` Karthik Nayak
2024-04-23 6:31 ` Patrick Steinhardt
2024-04-23 10:48 ` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 2/7] update-ref: add support for symref-verify Karthik Nayak
2024-04-18 14:26 ` Christian Couder
2024-04-19 21:21 ` Karthik Nayak
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-19 21:53 ` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 3/7] update-ref: add support for symref-delete Karthik Nayak
2024-04-18 14:52 ` Christian Couder
2024-04-21 10:43 ` Karthik Nayak
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-21 10:45 ` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 4/7] files-backend: extract out `create_symref_lock` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 5/7] update-ref: add support for symref-create Karthik Nayak
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-19 15:48 ` Junio C Hamano
2024-04-21 12:50 ` Karthik Nayak
2024-04-21 15:57 ` Karthik Nayak
2024-04-23 6:39 ` Patrick Steinhardt
2024-04-23 10:52 ` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 6/7] update-ref: add support for symref-update Karthik Nayak
2024-04-19 9:40 ` Patrick Steinhardt
2024-04-21 19:00 ` Karthik Nayak
2024-04-23 6:49 ` Patrick Steinhardt
2024-04-23 11:30 ` Karthik Nayak
2024-04-12 9:59 ` [PATCH v2 7/7] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-04-12 18:01 ` [PATCH v2 0/7] update-ref: add symref oriented commands Junio C Hamano
2024-04-12 18:49 ` Karthik Nayak
2024-04-18 15:05 ` Christian Couder
2024-04-21 19:06 ` Karthik Nayak
2024-04-20 6:16 ` Patrick Steinhardt
2024-04-21 19:11 ` Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 0/8] refs: add symref support to 'git-update-ref' Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 1/8] refs: accept symref values in `ref_transaction[_add]_update` Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 2/8] update-ref: support parsing ref targets in `parse_next_oid` Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 3/8] files-backend: extract out `create_symref_lock` Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 4/8] update-ref: support symrefs in the verify command Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 5/8] update-ref: support symrefs in the delete command Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 6/8] update-ref: support symrefs in the create command Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 7/8] update-ref: support symrefs in the update command Karthik Nayak
2024-04-23 21:28 ` [PATCH v3 8/8] ref: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-04-23 22:03 ` [PATCH v3 0/8] refs: add symref support to 'git-update-ref' Jeff King
2024-04-24 1:17 ` Junio C Hamano
2024-04-24 16:25 ` Karthik Nayak
2024-04-25 6:40 ` Patrick Steinhardt
2024-04-25 21:12 ` Karthik Nayak
2024-04-25 18:01 ` Junio C Hamano
2024-04-25 21:14 ` Karthik Nayak
2024-04-25 21:55 ` Junio C Hamano
2024-04-26 12:48 ` Karthik Nayak
2024-04-26 20:41 ` Jeff King
2024-04-25 17:09 ` Junio C Hamano
2024-04-25 21:07 ` Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 0/7] add symref-* commands to 'git-update-ref --stdin' Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 1/7] refs: accept symref values in `ref_transaction[_add]_update` Karthik Nayak
2024-04-26 19:31 ` Junio C Hamano
2024-04-26 21:15 ` Jeff King
2024-04-29 7:02 ` Patrick Steinhardt
2024-04-29 7:55 ` Jeff King
2024-04-29 9:29 ` phillip.wood123
2024-04-29 9:32 ` phillip.wood123
2024-04-29 16:18 ` Junio C Hamano
2024-04-30 10:33 ` Jeff King
2024-04-30 10:30 ` Jeff King
2024-04-28 19:36 ` Karthik Nayak
2024-04-29 13:38 ` Phillip Wood
2024-04-29 14:01 ` Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 2/7] files-backend: extract out `create_symref_lock` Karthik Nayak
2024-04-26 21:39 ` Junio C Hamano
2024-04-28 19:57 ` Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 3/7] update-ref: add support for 'symref-verify' command Karthik Nayak
2024-04-26 22:51 ` Junio C Hamano
2024-04-28 22:28 ` Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 4/7] update-ref: add support for 'symref-delete' command Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 5/7] update-ref: add support for 'symref-create' command Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 6/7] update-ref: add support for 'symref-update' command Karthik Nayak
2024-04-26 15:24 ` [PATCH v4 7/7] ref: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-04-30 10:14 ` [PATCH v4 0/7] add symref-* commands to 'git-update-ref --stdin' Karthik Nayak
2024-05-01 20:22 ` [PATCH v5 0/7] refs: add support for transactional symref updates Karthik Nayak
2024-05-01 20:22 ` [PATCH v5 1/7] refs: accept symref values in `ref_transaction_update()` Karthik Nayak
2024-05-01 20:22 ` [PATCH v5 2/7] files-backend: extract out `create_symref_lock()` Karthik Nayak
2024-05-01 22:06 ` Junio C Hamano
2024-05-02 7:47 ` Patrick Steinhardt
2024-05-02 11:05 ` Karthik Nayak
2024-05-02 16:49 ` Junio C Hamano
2024-05-01 20:22 ` [PATCH v5 3/7] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-05-01 23:05 ` Junio C Hamano
2024-05-02 5:32 ` Karthik Nayak
2024-05-01 20:22 ` [PATCH v5 4/7] refs: add support for transactional symref updates Karthik Nayak
2024-05-01 23:52 ` Junio C Hamano
2024-05-02 5:50 ` Karthik Nayak
2024-05-02 7:47 ` Patrick Steinhardt
2024-05-02 11:10 ` Karthik Nayak
2024-05-02 16:51 ` Junio C Hamano
2024-05-02 16:00 ` Junio C Hamano
2024-05-02 17:53 ` Junio C Hamano
2024-05-01 20:22 ` [PATCH v5 5/7] refs: use transaction in `refs_create_symref()` Karthik Nayak
2024-05-02 7:47 ` Patrick Steinhardt
2024-05-01 20:22 ` [PATCH v5 6/7] refs: rename `refs_create_symref()` to `refs_update_symref()` Karthik Nayak
2024-05-02 7:47 ` Patrick Steinhardt
2024-05-02 11:34 ` Karthik Nayak
2024-05-01 20:22 ` [PATCH v5 7/7] refs: remove `create_symref` and associated dead code Karthik Nayak
2024-05-02 7:47 ` Patrick Steinhardt
2024-05-02 16:53 ` Junio C Hamano
2024-05-02 0:20 ` [PATCH v5 0/7] refs: add support for transactional symref updates Junio C Hamano
2024-05-02 5:53 ` Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 " Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 1/7] refs: accept symref values in `ref_transaction_update()` Karthik Nayak
2024-05-04 15:18 ` Phillip Wood
2024-05-05 15:10 ` Karthik Nayak
2024-05-05 15:19 ` phillip.wood123
2024-05-03 12:41 ` [PATCH v6 2/7] files-backend: extract out `create_symref_lock()` Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 3/7] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 4/7] refs: add support for transactional symref updates Karthik Nayak
2024-05-05 14:09 ` Phillip Wood
2024-05-05 16:09 ` Karthik Nayak
2024-05-06 9:35 ` Phillip Wood
2024-05-06 11:19 ` Karthik Nayak
2024-05-06 13:19 ` Phillip Wood
2024-05-06 9:54 ` Phillip Wood
2024-05-06 11:22 ` Karthik Nayak
2024-05-06 13:17 ` Phillip Wood
2024-05-03 12:41 ` [PATCH v6 5/7] refs: use transaction in `refs_create_symref()` Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 6/7] refs: rename `refs_create_symref()` to `refs_update_symref()` Karthik Nayak
2024-05-03 12:41 ` [PATCH v6 7/7] refs: remove `create_symref` and associated dead code Karthik Nayak
2024-05-03 23:09 ` Junio C Hamano
2024-05-04 9:30 ` Karthik Nayak
2024-05-03 16:45 ` [PATCH v6 0/7] refs: add support for transactional symref updates Junio C Hamano
2024-05-06 7:36 ` Patrick Steinhardt
2024-05-07 6:00 ` [PATCH v7 0/8] " Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 1/8] refs: accept symref values in `ref_transaction_update()` Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 2/8] files-backend: extract out `create_symref_lock()` Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 3/8] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 4/8] refs: move `original_update_refname` to 'refs.c' Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 5/8] refs: add support for transactional symref updates Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 6/8] refs: use transaction in `refs_create_symref()` Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 7/8] refs: rename `refs_create_symref()` to `refs_update_symref()` Karthik Nayak
2024-05-07 6:00 ` [PATCH v7 8/8] refs: remove `create_symref` and associated dead code Karthik Nayak
2024-05-07 6:25 ` [PATCH v7 0/8] refs: add support for transactional symref updates Junio C Hamano
2024-05-07 6:31 ` Junio C Hamano
2024-05-07 12:58 ` [PATCH v8 " Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 1/8] refs: accept symref values in `ref_transaction_update()` Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 2/8] files-backend: extract out `create_symref_lock()` Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 3/8] refs: support symrefs in 'reference-transaction' hook Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 4/8] refs: move `original_update_refname` to 'refs.c' Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 5/8] refs: add support for transactional symref updates Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 6/8] refs: use transaction in `refs_create_symref()` Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 7/8] refs: rename `refs_create_symref()` to `refs_update_symref()` Karthik Nayak
2024-05-07 12:58 ` [PATCH v8 8/8] refs: remove `create_symref` and associated dead code Karthik Nayak
2024-05-07 15:50 ` [PATCH v8 0/8] refs: add support for transactional symref updates phillip.wood123
2024-05-07 16:32 ` Junio C Hamano
2024-05-12 17:17 ` Karthik Nayak
2024-05-13 17:15 ` Junio C Hamano
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=xmqqzfu1w6ay.fsf@gitster.g \
--to=gitster@pobox.com \
--cc=chris.torek@gmail.com \
--cc=git@vger.kernel.org \
--cc=karthik.188@gmail.com \
--cc=ps@pks.im \
/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.