From: Brandon Williams <bmwill@google.com>
To: Stefan Beller <sbeller@google.com>
Cc: "git@vger.kernel.org" <git@vger.kernel.org>,
Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH v2 5/6] submodule: improve submodule_has_commits
Date: Tue, 2 May 2017 10:25:55 -0700 [thread overview]
Message-ID: <20170502172555.GA181268@google.com> (raw)
In-Reply-To: <CAGZ79kbbz3AAjbg_dV9RVS8kgLs-zWZxt5tsFbQczCm78LcTVw@mail.gmail.com>
On 05/01, Stefan Beller wrote:
> On Mon, May 1, 2017 at 6:02 PM, Brandon Williams <bmwill@google.com> wrote:
> > +
> > + if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
>
> eh, I gave too much and self-contradicting feedback here earlier,
> ideally I'd like to review this to be similar as:
>
> if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1)
> die("cannot capture git-rev-list in submodule '%s', sub->path);
This wouldn't really work because if you provide a SHA1 to rev-list
which it isn't able to find then it returns a non-zero exit code which
would cause this to die, which isn't the desired behavior.
>
> if (out.len)
> has_commit = 0;
>
> instead as that does not have a silent error. (though it errs
> on the safe side, so maybe it is not to bad.)
>
> I could understand if the callers do not want to have
> `submodule_has_commits` die()-ing on them, so maybe
>
> if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) {
> warning("cannot capture git-rev-list in submodule '%s', sub->path);
> has_commit = -1;
> /* this would require auditing all callers and handling -1 though */
> }
>
> if (out.len)
> has_commit = 0;
>
> As the comment eludes, we'd then have
> 0 -> has no commits
> 1 -> has commits
> -1 -> error
>
> So to group (error || has_no_commits), we could write
>
> if (submodule_has_commits(..) <= 0)
>
> which is awkward. So maybe we can rename the function
> to misses_submodule_commits instead, as then we could
> flip the return value as well and have
>
> 0 -> has commits
> 1 -> has no commits
> -1 -> error
>
> and the lazy invoker could just go with
>
> if (!misses_submodule_commits(..))
> proceed();
> else
> die("missing submodule commits or errors; I don't care");
>
> whereas the careful invoker could go with
>
> switch (misses_submodule_commits(..)) {
> case 0:
> proceed(); break;
> case 1:
> pull_magic_trick(); break;
> case -1:
> make_errors_go_away_and_retry(); break;
> }
I feel like you're making this a little too complicated, as all I'm
doing is shuffling around already existing logic. I understand the want
to make things more robust but this seems unnecessarily complex.
> ---
> On the longer term plan:
> As you wrote about costs. Maybe instead of invoking rev-list,
> we could try to have this in-core as a first try-out for
> "classified-repos", looking at refs.h there is e.g.
>
> int for_each_ref_submodule(const char *submodule_path,
> each_ref_fn fn, void *cb_data);
>
> which we could use to obtain all submodule refs and then
> use the revision walking machinery to find out ourselves if
> we have or do not have the commits. (As we loaded the
> odb of the submodule, this would *just work*, building one
> kludgy hack upon the next.)
>
> Thanks,
> Stefan
--
Brandon Williams
next prev parent reply other threads:[~2017-05-02 17:26 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-28 23:53 [PATCH 0/6] changed submodules Brandon Williams
2017-04-28 23:53 ` [PATCH 1/6] submodule: rename add_sha1_to_array Brandon Williams
2017-05-01 3:18 ` Junio C Hamano
2017-04-28 23:53 ` [PATCH 2/6] submodule: rename free_submodules_sha1s Brandon Williams
2017-04-28 23:53 ` [PATCH 3/6] submodule: remove add_oid_to_argv Brandon Williams
2017-04-28 23:54 ` [PATCH 4/6] submodule: change string_list changed_submodule_paths Brandon Williams
2017-05-01 3:28 ` Junio C Hamano
2017-05-01 16:35 ` Brandon Williams
2017-04-28 23:54 ` [PATCH 5/6] submodule: improve submodule_has_commits Brandon Williams
2017-04-29 0:28 ` Stefan Beller
2017-04-30 23:14 ` Brandon Williams
2017-05-01 16:52 ` Stefan Beller
2017-05-01 16:55 ` Brandon Williams
2017-05-01 3:37 ` Junio C Hamano
2017-05-01 16:46 ` Brandon Williams
2017-04-28 23:54 ` [PATCH 6/6] submodule: refactor logic to determine changed submodules Brandon Williams
2017-04-29 0:53 ` Stefan Beller
2017-05-01 16:49 ` Brandon Williams
2017-05-01 1:42 ` [PATCH 0/6] " Junio C Hamano
2017-05-02 1:02 ` [PATCH v2 " Brandon Williams
2017-05-02 1:02 ` [PATCH v2 1/6] submodule: rename add_sha1_to_array Brandon Williams
2017-05-02 1:05 ` Stefan Beller
2017-05-02 1:09 ` Brandon Williams
2017-05-02 1:02 ` [PATCH v2 2/6] submodule: rename free_submodules_sha1s Brandon Williams
2017-05-02 1:02 ` [PATCH v2 3/6] submodule: remove add_oid_to_argv Brandon Williams
2017-05-02 1:02 ` [PATCH v2 4/6] submodule: change string_list changed_submodule_paths Brandon Williams
2017-05-02 1:02 ` [PATCH v2 5/6] submodule: improve submodule_has_commits Brandon Williams
2017-05-02 1:34 ` Stefan Beller
2017-05-02 17:25 ` Brandon Williams [this message]
2017-05-02 17:55 ` Stefan Beller
2017-05-02 19:14 ` Brandon Williams
2017-05-02 19:30 ` Brandon Williams
2017-05-02 1:02 ` [PATCH v2 6/6] submodule: refactor logic to determine changed submodules Brandon Williams
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