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

[Elijah Newren <newren@gmail.com>]

On Wed, May 27, 2020 at 6:14 PM Matheus Tavares
<matheus.bernardino@usp.br> wrote:
>
> When sparse checkout is enabled, some users expect the output of certain
> commands (such as grep, diff, and log) to be also restricted within the
> sparsity patterns. This would allow them to effectively work only on the
> subset of files in which they are interested; and allow some commands to
> possibly perform better, by not considering uninteresting paths. For
> this reason, we taught grep to honor the sparsity patterns, in the
> previous patch. But, on the other hand, allowing grep and the other
> commands mentioned to optionally ignore the patterns also make for some
> interesting use cases. E.g. using grep to search for a function
> documentation that resides outside the sparse checkout.
>
> In any case, there is no current way for users to configure the behavior
> they want for these commands. Aiming to provide this flexibility, let's
> introduce the sparse.restrictCmds setting (and the analogous
> --[no]-restrict-to-sparse-paths global option). The default value is
> true. For now, grep is the only one affected by this setting, but the
> goal is to have support for more commands, in the future.
>
> Helped-by: Elijah Newren <newren@gmail.com>
> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
> ---
>  Documentation/config.txt               |   2 +
>  Documentation/config/sparse.txt        |  24 +++++
>  Documentation/git-grep.txt             |   3 +
>  Documentation/git.txt                  |   4 +
>  Makefile                               |   1 +
>  builtin/grep.c                         |  13 ++-
>  contrib/completion/git-completion.bash |   2 +
>  git.c                                  |   6 ++
>  sparse-checkout.c                      |  16 +++
>  sparse-checkout.h                      |  11 +++
>  t/t7817-grep-sparse-checkout.sh        | 132 ++++++++++++++++++++++++-
>  t/t9902-completion.sh                  |   4 +-
>  12 files changed, 212 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/config/sparse.txt
>  create mode 100644 sparse-checkout.c
>  create mode 100644 sparse-checkout.h
>
> diff --git a/Documentation/config.txt b/Documentation/config.txt
> index ef0768b91a..fd74b80302 100644
> --- a/Documentation/config.txt
> +++ b/Documentation/config.txt
> @@ -436,6 +436,8 @@ include::config/sequencer.txt[]
>
>  include::config/showbranch.txt[]
>
> +include::config/sparse.txt[]
> +
>  include::config/splitindex.txt[]
>
>  include::config/ssh.txt[]
> 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.

> ++
> +Note: commands which export, integrity check, or create history will always
> +operate on full trees (e.g. fast-export, format-patch, fsck, commit, etc.),
> +unaffected by any sparsity patterns. Also, writting commands such as
> +sparse-checkout and read-tree will not be affected by this configuration.

s/writting/writing/

> diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
> index 9bdf807584..abbf100109 100644
> --- a/Documentation/git-grep.txt
> +++ b/Documentation/git-grep.txt
> @@ -41,6 +41,9 @@ characters.  An empty string as search expression matches all lines.
>  CONFIGURATION
>  -------------
>
> +git-grep honors the sparse.restrictCmds setting. See its definition in
> +linkgit:git-config[1].
> +
>  :git-grep: 1
>  include::config/grep.txt[]
>
> diff --git a/Documentation/git.txt b/Documentation/git.txt
> index 9d6769e95a..5e107c6246 100644
> --- a/Documentation/git.txt
> +++ b/Documentation/git.txt
> @@ -180,6 +180,10 @@ If you just want to run git as if it was started in `<path>` then use
>         Do not perform optional operations that require locks. This is
>         equivalent to setting the `GIT_OPTIONAL_LOCKS` to `0`.
>
> +--[no-]restrict-to-sparse-paths::
> +       Overrides the sparse.restrictCmds configuration (see
> +       linkgit:git-config[1]) for this execution.
> +
>  --list-cmds=group[,group...]::
>         List commands by group. This is an internal/experimental
>         option and may change or be removed in the future. Supported
> diff --git a/Makefile b/Makefile
> index 90aa329eb7..0c0013b32c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -983,6 +983,7 @@ LIB_OBJS += sha1-name.o
>  LIB_OBJS += shallow.o
>  LIB_OBJS += sideband.o
>  LIB_OBJS += sigchain.o
> +LIB_OBJS += sparse-checkout.o
>  LIB_OBJS += split-index.o
>  LIB_OBJS += stable-qsort.o
>  LIB_OBJS += strbuf.o
> diff --git a/builtin/grep.c b/builtin/grep.c
> index 11e33b8aee..cc696dab4a 100644
> --- a/builtin/grep.c
> +++ b/builtin/grep.c
> @@ -25,6 +25,7 @@
>  #include "submodule-config.h"
>  #include "object-store.h"
>  #include "packfile.h"
> +#include "sparse-checkout.h"
>
>  static char const * const grep_usage[] = {
>         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
> @@ -498,6 +499,7 @@ static int grep_cache(struct grep_opt *opt,
>         int nr;
>         struct strbuf name = STRBUF_INIT;
>         int name_base_len = 0;
> +       int sparse_paths_only = restrict_to_sparse_paths(repo);
>         if (repo->submodule_prefix) {
>                 name_base_len = strlen(repo->submodule_prefix);
>                 strbuf_addstr(&name, repo->submodule_prefix);
> @@ -509,7 +511,7 @@ static int grep_cache(struct grep_opt *opt,
>         for (nr = 0; nr < repo->index->cache_nr; nr++) {
>                 const struct cache_entry *ce = repo->index->cache[nr];
>
> -               if (ce_skip_worktree(ce))
> +               if (sparse_paths_only && ce_skip_worktree(ce))
>                         continue;
>
>                 strbuf_setlen(&name, name_base_len);
> @@ -715,9 +717,10 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
>                      int is_root_tree)
>  {
>         struct pattern_list *patterns = NULL;
> +       int sparse_paths_only = restrict_to_sparse_paths(opt->repo);
>         int ret;
>
> -       if (is_root_tree)
> +       if (is_root_tree && sparse_paths_only)
>                 patterns = get_sparsity_patterns(opt->repo);
>
>         ret = do_grep_tree(opt, pathspec, tree, base, tn_len, is_root_tree,

It's kinda nice how clean and easy it is to insert this new option
after the previous patch.

> @@ -1257,6 +1260,12 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
>
>         if (!use_index || untracked) {
>                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
> +
> +               if (opt_restrict_to_sparse_paths >= 0) {
> +                       die(_("--[no-]restrict-to-sparse-paths is incompatible"
> +                                 " with --no-index and --untracked"));
> +               }
> +
>                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
>         } else if (0 <= opt_exclude) {
>                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
> diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
> index 70ad04e1b2..71956f7313 100644
> --- a/contrib/completion/git-completion.bash
> +++ b/contrib/completion/git-completion.bash
> @@ -3208,6 +3208,8 @@ __git_main ()
>                         --namespace=
>                         --no-replace-objects
>                         --help
> +                       --restrict-to-sparse-paths
> +                       --no-restrict-to-sparse-paths
>                         "
>                         ;;
>                 *)
> diff --git a/git.c b/git.c
> index a2d337eed7..6db1382ae4 100644
> --- a/git.c
> +++ b/git.c
> @@ -38,6 +38,7 @@ const char git_more_info_string[] =
>            "See 'git help git' for an overview of the system.");
>
>  static int use_pager = -1;
> +int opt_restrict_to_sparse_paths = -1;
>
>  static void list_builtins(struct string_list *list, unsigned int exclude_option);
>
> @@ -311,6 +312,10 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
>                         } else {
>                                 exit(list_cmds(cmd));
>                         }
> +               } else if (!strcmp(cmd, "--restrict-to-sparse-paths")) {
> +                       opt_restrict_to_sparse_paths = 1;
> +               } else if (!strcmp(cmd, "--no-restrict-to-sparse-paths")) {
> +                       opt_restrict_to_sparse_paths = 0;
>                 } else {
>                         fprintf(stderr, _("unknown option: %s\n"), cmd);
>                         usage(git_usage_string);
> @@ -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?

> 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.

> diff --git a/sparse-checkout.h b/sparse-checkout.h
> new file mode 100644
> index 0000000000..1de3b588d8
> --- /dev/null
> +++ b/sparse-checkout.h
> @@ -0,0 +1,11 @@
> +#ifndef SPARSE_CHECKOUT_H
> +#define SPARSE_CHECKOUT_H
> +
> +struct repository;
> +
> +extern int opt_restrict_to_sparse_paths; /* from git.c */
> +
> +/* Whether or not cmds should restrict behavior on sparse paths, in this repo */
> +int restrict_to_sparse_paths(struct repository *repo);
> +
> +#endif /* SPARSE_CHECKOUT_H */
> 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
> @@ -80,10 +80,10 @@ test_expect_success 'setup' '
>         test_path_is_file sub2/a
>  '
>
> -# The test bellow checks a special case: the sparsity patterns exclude '/b'
> +# The two tests bellow check a special case: the sparsity patterns exclude '/b'
>  # and sparse checkout is enable, but the path exists on the working tree (e.g.
>  # manually created after `git sparse-checkout init`). In this case, grep should
> -# skip it.
> +# skip the file by default, but not with --no-restrict-to-sparse-paths.
>  test_expect_success 'grep in working tree should honor sparse checkout' '
>         cat >expect <<-EOF &&
>         a:text
> @@ -93,6 +93,16 @@ test_expect_success 'grep in working tree should honor sparse checkout' '
>         git grep "text" >actual &&
>         test_cmp expect actual
>  '
> +test_expect_success 'grep w/ --no-restrict-to-sparse-paths for sparsely excluded but present paths' '
> +       cat >expect <<-EOF &&
> +       a:text
> +       b:new-text
> +       EOF
> +       echo "new-text" >b &&
> +       test_when_finished "rm b" &&
> +       git --no-restrict-to-sparse-paths grep "text" >actual &&
> +       test_cmp expect actual
> +'
>
>  test_expect_success 'grep --cached should honor sparse checkout' '
>         cat >expect <<-EOF &&
> @@ -136,7 +146,7 @@ test_expect_success 'grep <tree-ish> should ignore sparsity patterns' '
>  '
>
>  # Note that sub2/ is present in the worktree but it is excluded by the sparsity
> -# patterns, so grep should not recurse into it.
> +# patterns, so grep should only recurse into it with --no-restrict-to-sparse-paths.
>  test_expect_success 'grep --recurse-submodules should honor sparse checkout in submodule' '
>         cat >expect <<-EOF &&
>         a:text
> @@ -145,6 +155,15 @@ test_expect_success 'grep --recurse-submodules should honor sparse checkout in s
>         git grep --recurse-submodules "text" >actual &&
>         test_cmp expect actual
>  '
> +test_expect_success 'grep --recurse-submodules should search in excluded submodules w/ --no-restrict-to-sparse-paths' '
> +       cat >expect <<-EOF &&
> +       a:text
> +       sub/B/b:text
> +       sub2/a:text
> +       EOF
> +       git --no-restrict-to-sparse-paths grep --recurse-submodules "text" >actual &&
> +       test_cmp expect actual
> +'
>
>  test_expect_success 'grep --recurse-submodules --cached should honor sparse checkout in submodule' '
>         cat >expect <<-EOF &&
> @@ -171,4 +190,111 @@ test_expect_success 'grep --recurse-submodules <commit-ish> should honor sparse
>         test_cmp expect_tag-to-commit actual_tag-to-commit
>  '
>
> +for cmd in 'git --no-restrict-to-sparse-paths grep' \
> +          'git -c sparse.restrictCmds=false grep' \
> +          'git -c sparse.restrictCmds=true --no-restrict-to-sparse-paths grep'
> +do
> +
> +       test_expect_success "$cmd --cached should ignore sparsity patterns" '
> +               cat >expect <<-EOF &&
> +               a:text
> +               b:text
> +               dir/c:text
> +               EOF
> +               $cmd --cached "text" >actual &&
> +               test_cmp expect actual
> +       '
> +
> +       test_expect_success "$cmd <commit-ish> should ignore sparsity patterns" '
> +               commit=$(git rev-parse HEAD) &&
> +               cat >expect_commit <<-EOF &&
> +               $commit:a:text
> +               $commit:b:text
> +               $commit:dir/c:text
> +               EOF
> +               cat >expect_tag-to-commit <<-EOF &&
> +               tag-to-commit:a:text
> +               tag-to-commit:b:text
> +               tag-to-commit:dir/c:text
> +               EOF
> +               $cmd "text" $commit >actual_commit &&
> +               test_cmp expect_commit actual_commit &&
> +               $cmd "text" tag-to-commit >actual_tag-to-commit &&
> +               test_cmp expect_tag-to-commit actual_tag-to-commit
> +       '
> +done
> +
> +test_expect_success 'grep --recurse-submodules --cached \w --no-restrict-to-sparse-paths' '

s%\w%w/%, or s%\w%with%?  Same issue below too.

> +       cat >expect <<-EOF &&
> +       a:text
> +       b:text
> +       dir/c:text
> +       sub/A/a:text
> +       sub/B/b:text
> +       sub2/a:text
> +       EOF
> +       git --no-restrict-to-sparse-paths grep --recurse-submodules --cached \
> +               "text" >actual &&
> +       test_cmp expect actual
> +'
> +
> +test_expect_success 'grep --recurse-submodules <commit-ish> \w --no-restrict-to-sparse-paths' '
> +       commit=$(git rev-parse HEAD) &&
> +       cat >expect_commit <<-EOF &&
> +       $commit:a:text
> +       $commit:b:text
> +       $commit:dir/c:text
> +       $commit:sub/A/a:text
> +       $commit:sub/B/b:text
> +       $commit:sub2/a:text
> +       EOF
> +       cat >expect_tag-to-commit <<-EOF &&
> +       tag-to-commit:a:text
> +       tag-to-commit:b:text
> +       tag-to-commit:dir/c:text
> +       tag-to-commit:sub/A/a:text
> +       tag-to-commit:sub/B/b:text
> +       tag-to-commit:sub2/a:text
> +       EOF
> +       git --no-restrict-to-sparse-paths grep --recurse-submodules "text" \
> +               $commit >actual_commit &&
> +       test_cmp expect_commit actual_commit &&
> +       git --no-restrict-to-sparse-paths grep --recurse-submodules "text" \
> +               tag-to-commit >actual_tag-to-commit &&
> +       test_cmp expect_tag-to-commit actual_tag-to-commit
> +'
> +
> +test_expect_success 'should respect the sparse.restrictCmds values from submodules' '
> +       cat >expect <<-EOF &&
> +       a:text
> +       sub/A/a:text
> +       sub/B/b:text
> +       EOF
> +       test_config -C sub sparse.restrictCmds false &&
> +       git grep --cached --recurse-submodules "text" >actual &&
> +       test_cmp expect actual
> +'
> +
> +test_expect_success 'should propagate --[no]-restrict-to-sparse-paths to submodules' '
> +       cat >expect <<-EOF &&
> +       a:text
> +       b:text
> +       dir/c:text
> +       sub/A/a:text
> +       sub/B/b:text
> +       sub2/a:text
> +       EOF
> +       test_config -C sub sparse.restrictCmds true &&
> +       git --no-restrict-to-sparse-paths grep --cached --recurse-submodules "text" >actual &&
> +       test_cmp expect actual
> +'
> +
> +for opt in '--untracked' '--no-index'
> +do
> +       test_expect_success "--[no]-restrict-to-sparse-paths and $opt are incompatible" "
> +               test_must_fail git --restrict-to-sparse-paths grep $opt . 2>actual &&
> +               test_i18ngrep 'restrict-to-sparse-paths is incompatible with' actual
> +       "
> +done
> +
>  test_done
> diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
> index 3c44af6940..a4a7767e06 100755
> --- a/t/t9902-completion.sh
> +++ b/t/t9902-completion.sh
> @@ -1473,6 +1473,8 @@ test_expect_success 'double dash "git" itself' '
>         --namespace=
>         --no-replace-objects Z
>         --help Z
> +       --restrict-to-sparse-paths Z
> +       --no-restrict-to-sparse-paths Z
>         EOF
>  '
>
> @@ -1515,7 +1517,7 @@ test_expect_success 'general options' '
>         test_completion "git --nam" "--namespace=" &&
>         test_completion "git --bar" "--bare " &&
>         test_completion "git --inf" "--info-path " &&
> -       test_completion "git --no-r" "--no-replace-objects "
> +       test_completion "git --no-rep" "--no-replace-objects "
>  '

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.