From: "Samo Pogačnik" <samo_pogacnik@t-2•net>
To: "Patrick Steinhardt" <ps@pks•im>,
"Samo Pogačnik via GitGitGadget" <gitgitgadget@gmail•com>
Cc: git@vger•kernel.org
Subject: Re: [PATCH 2/2] shallow: handling fetch relative-deepen
Date: Fri, 09 Jan 2026 17:48:19 +0100 [thread overview]
Message-ID: <d2cb7351419002ec3be6423f39091e9d0d0e3877.camel@t-2.net> (raw)
In-Reply-To: <aVy9a9f1AZzTbBQa@pks.im>
[-- Attachment #1: Type: text/plain, Size: 5621 bytes --]
On Tue, 2026-01-06 at 08:44 +0100, Patrick Steinhardt wrote:
> On Tue, Dec 09, 2025 at 06:11:20PM +0000, Samo Pogačnik via GitGitGadget
> wrote:
> > From: =?UTF-8?q?Samo=20Poga=C4=8Dnik?= <samo_pogacnik@t-2•net>
> >
> > When a shallowed repository gets deepened beyond the beginning of a
> > merged branch, we may endup with some shallows, that are behind the
>
> s/endup/end up/
> s/shallows, that/shallows that/
>
> > reachable ones.
>
> Hm, which reachable ones? Sorry, I can't quite follow, it would help the
> reviewer to add a bit more context.
>
> > Added test 'fetching deepen beyond merged branch' exposes that
> > behaviour.
> >
> > On the other hand, it seems that equivalent absolute depth driven
> > fetches result in all the correct shallows. That led to this proposal,
> > which unifies absolute and relative deepening in a way that the same
> > get_shallow_commits() call is used in both cases. The difference is
> > only that depth is adapted for relative deepening by measuring
> > equivalent depth of current local shallow commits in the current remote
> > repo. Thus a new function get_shallows_depth() has been added and the
> > function get_reachable_list() became redundant / removed.
> >
> > The get_shallows_depth() function also shares the logic of the
> > get_shallow_commits() function, but it focuses on counting depth of
> > each existing shallow commit. The minimum result is stored as
> > 'data->deepen_relative', which is set not to be zero for relative
> > deepening anyway. That way we can allways summ 'data->deepen_relative'
> > and 'depth' values, because 'data->deepen_relative' is always 0 in
> > absolute deepening.
>
> I think the commit message needs some polishing. I myself am not that
> familiar with our shallow logic, so I'm a bit lost here to be honest.
>
> Typically, a commit message should be self-explanatory and guide the
> reader through the problem space as well as the solution. It should, in
> the following order:
>
> - Explain what the actual issue is as observed by the user. I'm not
> really sure about this part, only that it's something related to
> shallow clones, deepening and merge commits.
>
> - Explain what the root cause of the issue is.
>
> - Explain how the root cause is being fixed. Ideally, it should also
> explain why that is the correct fix, potentially referencing other
> code like you do.
>
> Your commit message on the other hand explains more of the "what" and
> less of the "why", which makes it hard to follow. Also, an ASCII commit
> graph would probably go a long way in explaining the issue :)
>
> > diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
> > index 2677cd5faa..d05c45e32b 100755
> > --- a/t/t5500-fetch-pack.sh
> > +++ b/t/t5500-fetch-pack.sh
> > @@ -955,6 +955,30 @@ test_expect_success 'fetching deepen' '
> > )
> > '
> >
> > +test_expect_success 'fetching deepen beyond merged branch' '
> > + test_create_repo shallow-deepen-merged &&
> > + (
> > + cd shallow-deepen-merged &&
> > + git commit --allow-empty -m one &&
> > + git commit --allow-empty -m two &&
> > + git commit --allow-empty -m three &&
> > + git switch -c branch &&
> > + git commit --allow-empty -m four &&
> > + git commit --allow-empty -m five &&
> > + git switch main &&
> > + git merge --no-ff branch &&
> > + cd - &&
> > + git clone --bare --depth 3 "file://$(pwd)/shallow-deepen-
> > merged" deepen.git &&
> > + git -C deepen.git fetch origin --deepen=1 &&
> > + echo "Shallow:" && cat deepen.git/shallow &&
> > + git -C deepen.git rev-list --all >actual &&
> > + echo "All rev-lis:" && cat actual &&
>
> This statement and the one two lines further up look like debug code to
> me.
>
> > + for commit in $(sed "/^$/d" deepen.git/shallow); do
>
> Nit: loops should be formatted like this:
>
> for commit in ...
> do
> ...
> done
>
> > diff --git a/upload-pack.c b/upload-pack.c
> > index 2d2b70cbf2..ecd3e7f5ef 100644
> > --- a/upload-pack.c
> > +++ b/upload-pack.c
> > @@ -704,54 +705,82 @@ error:
> > return -1;
> > }
> >
> > -static int get_reachable_list(struct upload_pack_data *data,
> > - struct object_array *reachable)
> > +define_commit_slab(commit_depth, int *);
> > +static void free_depth_in_slab(int **ptr)
> > {
> > - struct child_process cmd = CHILD_PROCESS_INIT;
> > - int i;
> > - struct object *o;
> > - char namebuf[GIT_MAX_HEXSZ + 2]; /* ^ + hash + LF */
> > - const unsigned hexsz = the_hash_algo->hexsz;
> > - int ret;
> > -
> > - if (do_reachable_revlist(&cmd, &data->shallows, reachable,
> > - data->allow_uor) < 0) {
> > - ret = -1;
> > - goto out;
> > - }
> > -
> > - while ((i = read_in_full(cmd.out, namebuf, hexsz + 1)) == hexsz +
> > 1) {
> > - struct object_id oid;
> > - const char *p;
> > -
> > - if (parse_oid_hex(namebuf, &oid, &p) || *p != '\n')
> > - break;
> > -
> > - o = lookup_object(the_repository, &oid);
> > - if (o && o->type == OBJ_COMMIT) {
> > - o->flags &= ~TMP_MARK;
> > + FREE_AND_NULL(*ptr);
> > +}
> > +static void get_shallows_depth(struct upload_pack_data *data)
>
> This function looks very similar to `get_shallow_commits()`. Is it
> possible to deduplicate the logic?
Thank you for the valuable reply. I'll try to address all the raised points
including mentioning in commit 1/2 that added test from 2/2 fail without 1/2 as
quickly as time allows me to.
Thanks!
Samo
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2026-01-09 16:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-09 18:11 [PATCH 0/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2025-12-09 18:11 ` [PATCH 1/2] shallow: free local object_array allocations Samo Pogačnik via GitGitGadget
2026-01-06 7:44 ` Patrick Steinhardt
2026-01-09 16:21 ` Samo Pogačnik
2026-01-09 16:33 ` Patrick Steinhardt
2025-12-09 18:11 ` [PATCH 2/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2026-01-06 7:44 ` Patrick Steinhardt
2026-01-09 16:48 ` Samo Pogačnik [this message]
2026-01-09 22:23 ` [PATCH v2 0/2] " Samo Pogačnik via GitGitGadget
2026-01-09 22:23 ` [PATCH v2 1/2] shallow: free local object_array allocations Samo Pogačnik via GitGitGadget
2026-01-09 22:23 ` [PATCH v2 2/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2026-01-10 4:17 ` Junio C Hamano
2026-01-10 5:13 ` [PATCH v3 0/2] " Samo Pogačnik via GitGitGadget
2026-01-10 5:13 ` [PATCH v3 1/2] shallow: free local object_array allocations Samo Pogačnik via GitGitGadget
2026-01-10 5:13 ` [PATCH v3 2/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2026-01-15 15:50 ` Kristoffer Haugsbakk
2026-01-16 22:30 ` [PATCH v4 0/2] " Samo Pogačnik via GitGitGadget
2026-01-16 22:31 ` [PATCH v4 1/2] shallow: free local object_array allocations Samo Pogačnik via GitGitGadget
2026-01-16 22:31 ` [PATCH v4 2/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2026-02-11 13:38 ` Patrick Steinhardt
2026-02-13 20:48 ` Samo Pogačnik
2026-02-14 9:40 ` Samo Pogačnik
2026-02-15 11:19 ` Samo Pogačnik
2026-02-15 20:11 ` [PATCH v5 0/2] " Samo Pogačnik via GitGitGadget
2026-02-15 20:11 ` [PATCH v5 1/2] shallow: free local object_array allocations Samo Pogačnik via GitGitGadget
2026-02-15 20:11 ` [PATCH v5 2/2] shallow: handling fetch relative-deepen Samo Pogačnik via GitGitGadget
2026-02-20 22:34 ` [PATCH v5 0/2] " 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=d2cb7351419002ec3be6423f39091e9d0d0e3877.camel@t-2.net \
--to=samo_pogacnik@t-2$(echo .)net \
--cc=git@vger$(echo .)kernel.org \
--cc=gitgitgadget@gmail$(echo .)com \
--cc=ps@pks$(echo .)im \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox