On 05/01, Stefan Beller wrote:
> On Mon, May 1, 2017 at 6:02 PM, Brandon Williams <bmwill@xxxxxxxxxx> 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