[v3,02/17] sparse-checkout: create 'init' subcommand

Commit Message

Linus Arver via GitGitGadget Oct. 7, 2019, 8:08 p.m. UTC

From: Derrick Stolee <[e-mail]>

Getting started with a sparse-checkout file can be daunting. Help
users start their sparse enlistment using 'git sparse-checkout init'.
This will set 'core.sparseCheckout=true' in their config, write
an initial set of patterns to the sparse-checkout file, and update
their working directory.

Make sure to use the `extensions.worktreeConfig` setting and write
the sparse checkout config to the worktree-specific config file.
This avoids confusing interactions with other worktrees.

The use of running another process for 'git read-tree' is sub-
optimal. This will be removed in a later change.

Signed-off-by: Derrick Stolee <[e-mail]>
---
 Documentation/git-sparse-checkout.txt | 12 ++++
 builtin/sparse-checkout.c             | 79 ++++++++++++++++++++++++++-
 t/t1091-sparse-checkout-builtin.sh    | 41 ++++++++++++++
 3 files changed, 131 insertions(+), 1 deletion(-)

Comments

Elijah Newren Oct. 11, 2019, 10:14 p.m. UTC | #1

On Mon, Oct 7, 2019 at 1:08 PM Derrick Stolee via GitGitGadget
<[e-mail]> wrote:
> ++
> +The init subcommand also enables the 'extensions.worktreeConfig' setting
> +and sets the `core.sparseCheckout` setting in the worktree-specific config
> +file. This prevents the sparse-checkout feature from interfering with other
> +worktrees.

I'm afraid that might be mis-parsed by future readers.  Perhaps something like:

The init subcommand also enables the `core.sparseCheckout` setting.
To avoid interfering with other worktrees, it first enables the
`extensions.worktreeConfig` setting and makes sure to set the
`core.sparseCheckout` setting in the worktree-specific config file.

> +enum sparse_checkout_mode {
> +       MODE_NONE = 0,
> +       MODE_FULL = 1,
> +};

So MODE_FULL is "true" and MODE_NONE is "false".  MODE_NONE seems
confusing to me, but let's keep reading...

> +
> +static int sc_set_config(enum sparse_checkout_mode mode)
> +{
> +       struct argv_array argv = ARGV_ARRAY_INIT;
> +
> +       if (git_config_set_gently("extensions.worktreeConfig", "true")) {
> +               error(_("failed to set extensions.worktreeConfig setting"));
> +               return 1;
> +       }
> +
> +       argv_array_pushl(&argv, "config", "--worktree", "core.sparseCheckout", NULL);
> +
> +       if (mode)
> +               argv_array_pushl(&argv, "true", NULL);
> +       else
> +               argv_array_pushl(&argv, "false", NULL);

Wait, what?  MODE_FULL is used to specify that you want a sparse
checkout, and MODE_NONE is used to denote that you want a full (i.e.
non-sparse) checkout?  These are *very* confusing names.


> +static int sparse_checkout_init(int argc, const char **argv)
> +{
> +       struct pattern_list pl;
> +       char *sparse_filename;
> +       FILE *fp;
> +       int res;
> +
> +       if (sc_set_config(MODE_FULL))
> +               return 1;

Seems confusing here too.


Everything else in the patch looks good, though.

Derrick Stolee Oct. 14, 2019, 8:22 p.m. UTC | #2

On 10/11/2019 6:14 PM, Elijah Newren wrote:
> On Mon, Oct 7, 2019 at 1:08 PM Derrick Stolee via GitGitGadget
> <[e-mail]> wrote:
>> ++
>> +The init subcommand also enables the 'extensions.worktreeConfig' setting
>> +and sets the `core.sparseCheckout` setting in the worktree-specific config
>> +file. This prevents the sparse-checkout feature from interfering with other
>> +worktrees.
> 
> I'm afraid that might be mis-parsed by future readers.  Perhaps something like:
> 
> The init subcommand also enables the `core.sparseCheckout` setting.

I like the paragraph below, but the sentence above is repeated from
the earlier paragraph.

> To avoid interfering with other worktrees, it first enables the
> `extensions.worktreeConfig` setting and makes sure to set the
> `core.sparseCheckout` setting in the worktree-specific config file.
> 
>> +enum sparse_checkout_mode {
>> +       MODE_NONE = 0,
>> +       MODE_FULL = 1,
>> +};
> 
> So MODE_FULL is "true" and MODE_NONE is "false".  MODE_NONE seems
> confusing to me, but let's keep reading...
> 
>> +
>> +static int sc_set_config(enum sparse_checkout_mode mode)
>> +{
>> +       struct argv_array argv = ARGV_ARRAY_INIT;
>> +
>> +       if (git_config_set_gently("extensions.worktreeConfig", "true")) {
>> +               error(_("failed to set extensions.worktreeConfig setting"));
>> +               return 1;
>> +       }
>> +
>> +       argv_array_pushl(&argv, "config", "--worktree", "core.sparseCheckout", NULL);
>> +
>> +       if (mode)
>> +               argv_array_pushl(&argv, "true", NULL);
>> +       else
>> +               argv_array_pushl(&argv, "false", NULL);
> 
> Wait, what?  MODE_FULL is used to specify that you want a sparse
> checkout, and MODE_NONE is used to denote that you want a full (i.e.
> non-sparse) checkout?  These are *very* confusing names.

I understand they are confusing, hopefully it makes more sense with
the cone mode later.

* NONE == "No patterns at all"
* FULL == "all patterns allowed"
* CONE == "only cone patterns" (appears later)

Since this is just an internal detail, what if I switched it to

* MODE_NO_PATTERNS
* MODE_ALL_PATTERNS
* MODE_CONE_PATTERNS

Would that make more sense?

>> +static int sparse_checkout_init(int argc, const char **argv)
>> +{
>> +       struct pattern_list pl;
>> +       char *sparse_filename;
>> +       FILE *fp;
>> +       int res;
>> +
>> +       if (sc_set_config(MODE_FULL))
>> +               return 1;
> 
> Seems confusing here too.
> 
> 
> Everything else in the patch looks good, though.

Thanks,
-Stolee

Patch

diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt
index 81676b1d33..e095c4a98b 100644
--- a/Documentation/git-sparse-checkout.txt
+++ b/Documentation/git-sparse-checkout.txt
@@ -26,6 +26,18 @@  COMMANDS
 'list'::
 	Provide a list of the contents in the sparse-checkout file.
 
+'init'::
+	Enable the `core.sparseCheckout` setting. If the
+	sparse-checkout file does not exist, then populate it with
+	patterns that match every file in the root directory and
+	no other directories, then will remove all directories tracked
+	by Git. Add patterns to the sparse-checkout file to
+	repopulate the working directory.
++
+The init subcommand also enables the 'extensions.worktreeConfig' setting
+and sets the `core.sparseCheckout` setting in the worktree-specific config
+file. This prevents the sparse-checkout feature from interfering with other
+worktrees.
 
 SPARSE CHECKOUT
 ----------------
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index eed9625a05..64b2bb2b8c 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -8,7 +8,7 @@ 
 #include "strbuf.h"
 
 static char const * const builtin_sparse_checkout_usage[] = {
-	N_("git sparse-checkout [list]"),
+	N_("git sparse-checkout [init|list]"),
 	NULL
 };
 
@@ -59,6 +59,81 @@  static int sparse_checkout_list(int argc, const char **argv)
 	return 0;
 }
 
+static int update_working_directory(void)
+{
+	struct argv_array argv = ARGV_ARRAY_INIT;
+	int result = 0;
+	argv_array_pushl(&argv, "read-tree", "-m", "-u", "HEAD", NULL);
+
+	if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+		error(_("failed to update index with new sparse-checkout paths"));
+		result = 1;
+	}
+
+	argv_array_clear(&argv);
+	return result;
+}
+
+enum sparse_checkout_mode {
+	MODE_NONE = 0,
+	MODE_FULL = 1,
+};
+
+static int sc_set_config(enum sparse_checkout_mode mode)
+{
+	struct argv_array argv = ARGV_ARRAY_INIT;
+
+	if (git_config_set_gently("extensions.worktreeConfig", "true")) {
+		error(_("failed to set extensions.worktreeConfig setting"));
+		return 1;
+	}
+
+	argv_array_pushl(&argv, "config", "--worktree", "core.sparseCheckout", NULL);
+
+	if (mode)
+		argv_array_pushl(&argv, "true", NULL);
+	else
+		argv_array_pushl(&argv, "false", NULL);
+
+	if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+		error(_("failed to enable core.sparseCheckout"));
+		return 1;
+	}
+
+	return 0;
+}
+
+static int sparse_checkout_init(int argc, const char **argv)
+{
+	struct pattern_list pl;
+	char *sparse_filename;
+	FILE *fp;
+	int res;
+
+	if (sc_set_config(MODE_FULL))
+		return 1;
+
+	memset(&pl, 0, sizeof(pl));
+
+	sparse_filename = get_sparse_checkout_filename();
+	res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL);
+
+	/* If we already have a sparse-checkout file, use it. */
+	if (res >= 0) {
+		free(sparse_filename);
+		goto reset_dir;
+	}
+
+	/* initial mode: all blobs at root */
+	fp = fopen(sparse_filename, "w");
+	free(sparse_filename);
+	fprintf(fp, "/*\n!/*/\n");
+	fclose(fp);
+
+reset_dir:
+	return update_working_directory();
+}
+
 int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
 {
 	static struct option builtin_sparse_checkout_options[] = {
@@ -79,6 +154,8 @@  int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
 	if (argc > 0) {
 		if (!strcmp(argv[0], "list"))
 			return sparse_checkout_list(argc, argv);
+		if (!strcmp(argv[0], "init"))
+			return sparse_checkout_init(argc, argv);
 	}
 
 	usage_with_options(builtin_sparse_checkout_usage,
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index a9b04b1a88..c70085a759 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -47,4 +47,45 @@  test_expect_success 'git sparse-checkout list (populated)' '
 	test_cmp expect list
 '
 
+test_expect_success 'git sparse-checkout init' '
+	git -C repo sparse-checkout init &&
+	cat >expect <<-EOF &&
+		/*
+		!/*/
+	EOF
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	git -C repo config --list >config &&
+	test_i18ngrep "core.sparsecheckout=true" config &&
+	ls repo >dir  &&
+	echo a >expect &&
+	test_cmp expect dir
+'
+
+test_expect_success 'git sparse-checkout list after init' '
+	git -C repo sparse-checkout list >actual &&
+	cat >expect <<-EOF &&
+		/*
+		!/*/
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'init with existing sparse-checkout' '
+	echo "*folder*" >> repo/.git/info/sparse-checkout &&
+	git -C repo sparse-checkout init &&
+	cat >expect <<-EOF &&
+		/*
+		!/*/
+		*folder*
+	EOF
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	ls repo >dir  &&
+	cat >expect <<-EOF &&
+		a
+		folder1
+		folder2
+	EOF
+	test_cmp expect dir
+'
+
 test_done