Re: [PATCH v3 5/5] config: add setting to ignore sparsity patterns in some cmds

[Elijah Newren <newren@gmail.com>]

On Sun, May 31, 2020 at 9:46 PM Matheus Tavares Bernardino
<matheus.bernardino@usp.br> wrote:
>
> On Sat, May 30, 2020 at 1:18 PM Elijah Newren <newren@gmail.com> wrote:
> >
> > On Wed, May 27, 2020 at 6:14 PM Matheus Tavares
> > <matheus.bernardino@usp.br> wrote:
> > > diff --git a/Documentation/config/sparse.txt b/Documentation/config/sparse.txt
> > > new file mode 100644
> > > index 0000000000..2a25b4b8ef
> > > --- /dev/null
> > > +++ b/Documentation/config/sparse.txt
> > > @@ -0,0 +1,24 @@
> > > +sparse.restrictCmds::
> > > +       Only meaningful in conjunction with core.sparseCheckout. This option
> > > +       extends sparse checkouts (which limit which paths are written to the
> > > +       working tree), so that output and operations are also limited to the
> > > +       sparsity paths where possible and implemented. The purpose of this
> > > +       option is to (1) focus output for the user on the portion of the
> > > +       repository that is of interest to them, and (2) enable potentially
> > > +       dramatic performance improvements, especially in conjunction with
> > > +       partial clones.
> > > ++
> > > +When this option is true (default), some git commands may limit their behavior
> > > +to the paths specified by the sparsity patterns, or to the intersection of
> > > +those paths and any (like `*.c`) that the user might also specify on the
> > > +command line. When false, the affected commands will work on full trees,
> > > +ignoring the sparsity patterns. For now, only git-grep honors this setting. In
> > > +this command, the restriction takes effect in three cases: with --cached; when
> > > +a commit-ish is given; when searching a working tree where some paths excluded
> > > +by the sparsity patterns are present (e.g. manually created paths or not
> > > +removed submodules).
> >
> > I think "In this command, the restriction takes effect..." to the end
> > of the paragraph should be removed.  I don't want every subcommand's
> > behavior to be specified here; it'll grow unreadably long and be more
> > likely to eventually go stale.
>
> Yeah, I was also concerned about that. But wouldn't it be important to
> inform the users how the setting takes place in grep (specially with
> the corner cases)? And maybe others, in the future?
>
> What if we move the information that is only relevant to a single
> command into its own man page? I.e. git-grep.txt would have something
> like:

Moving it to grep's manpage seems ideal to me.  grep's behavior should
be defined in grep's manual.

> sparse.restrictCmds::
> See complete definition in linkgit:git-config[1]. In grep, the
> restriction takes effect in three cases: with --cached; when a
> commit-ish is given; when searching a working tree where some paths
> excluded by the sparsity patterns are present (e.g. manually created
> paths or not removed submodules).

That looks more than a little confusing.  Could this definition be
something more like "See base definition in linkgit:git-config[1].
grep honors sparse.restrictCmds by limiting searches to the sparsity
paths in three cases: when searching the working tree, when searching
the index with --cached, or when searching a specified commit"

> The only problem then is that the information would be a little
> scattered... But I think it shouldn't be a big deal, as a person
> interested in knowing how foo behaves with sparse.restrictCmds would
> only need to look into foo's man page, anyway.
>
> > > diff --git a/git.c b/git.c
> > > index a2d337eed7..6db1382ae4 100644
> > > --- a/git.c
> > > +++ b/git.c
> > > @@ -319,6 +324,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> > >                 (*argv)++;
> > >                 (*argc)--;
> > >         }
> > > +
> > >         return (*argv) - orig_argv;
> > >  }
> > >
> >
> > Why the stray whitespace change?
>
> Oops, that shouldn't be there. Thanks!
>
> >
> > > diff --git a/sparse-checkout.c b/sparse-checkout.c
> > > new file mode 100644
> > > index 0000000000..9a9e50fd29
> > > --- /dev/null
> > > +++ b/sparse-checkout.c
> > > @@ -0,0 +1,16 @@
> > > +#include "cache.h"
> > > +#include "config.h"
> > > +#include "sparse-checkout.h"
> > > +
> > > +int restrict_to_sparse_paths(struct repository *repo)
> > > +{
> > > +       int ret;
> > > +
> > > +       if (opt_restrict_to_sparse_paths >= 0)
> > > +               return opt_restrict_to_sparse_paths;
> > > +
> > > +       if (repo_config_get_bool(repo, "sparse.restrictcmds", &ret))
> > > +               ret = 1;
> > > +
> > > +       return ret;
> > > +}
> >
> > Do we want to considering renaming this file to sparse.c, since it's
> > for sparse grep and sparse diff and etc., not just for the checkout
> > piece?  It would also go along well with our toplevel related config
> > being in the "sparse" namespace.
>
> Makes sense. But since Stolee is already working on
> "sparse-checkout.c" [1], if we use "sparse.c" in this series we will
> end up with two extra files. And as "sparse.c" is quite small, I think
> we could unify into the "sparse-checkout.c".
>
> [1]: https://lore.kernel.org/git/0181a134bfb6986dc0e54ae624c478446a1324a9.1588857462.git.gitgitgadget@gmail.com/

Or we could just suggest he use sparse.c too.  :-)

Stolee?


> > > diff --git a/t/t7817-grep-sparse-checkout.sh b/t/t7817-grep-sparse-checkout.sh
> > > index ce080cf572..1aef084186 100755
> > > --- a/t/t7817-grep-sparse-checkout.sh
> > > +++ b/t/t7817-grep-sparse-checkout.sh
> >
> > All these testcases look great (modulo the small typo I pointed out
> > earlier); I kept thinking "but what about case <x>?" and then I kept
> > reading and saw you covered it.  You even added some I wasn't thinking
> > about and might have overlooked but seem important.
>
> Thanks :)