scalar: add --no-tags option

From: Derrick Stolee <[email protected]>

Some large repositories use tags to track a huge list of release versions. While this is choice is costly on the ref advertisement, it is further wasteful for clients who do not need those tags. Allow clients to optionally skip the tag advertisement.

This behavior is similar to that of 'git clone --no-tags' implemented in 0dab2468ee5 (clone: add a --no-tags option to clone without tags, 2017-04-26), including the modification of the remote.origin.tagOpt config value to include "--no-tags".

One thing that is opposite of the 'git clone' implementation is that this allows '--tags' as an assumed option, which can be naturally negated with '--no-tags'. The clone command does not accept '--tags' but allows "--no-no-tags" as the negation of its '--no-tags' option.

While testing this option, combine the test with the previously untested '--no-src' option introduced in 4527db8ff8c (scalar: add --[no-]src option, 2023-08-28).

---
scalar: add --no-tags option

The need for this was discovered due to the release behavior of an internal monorepo. The use of Azure DevOps' limited refs feature does not apply to tags, so the number of tags was causing some pain for users.

Thanks, -Stolee

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1780%2Fderrickstolee%2Fscalar-no-tags-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1780/derrickstolee/scalar-no-tags-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1780

 Documentation/scalar.txt |  6 ++++++
 scalar.c                 | 15 ++++++++++++---
 t/t9210-scalar.sh        | 18 ++++++++++++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)

index 361f51a6473..507ed2ae669 100644
@@ -86,6 +86,12 @@ cloning. If the HEAD at the remote did not point at any branch when
 	`<entlistment>/src` directory. Use `--no-src` to place the cloned
 	repository directly in the `<enlistment>` directory.
 
+--[no-]tags::
+	By default, `scalar clone` will fetch the tag objects advertised by
+	the remote and future `git fetch` commands will do the same. Use
+	`--no-tags` to avoid fetching tags in `scalar clone` and to configure
+	the repository to avoid fetching tags in the future.
+
 --[no-]full-clone::
 	A sparse-checkout is initialized by default. This behavior can be
 	turned off via `--full-clone`.

index 6166a8dd4c8..c6dd746b5b2 100644
@@ -410,7 +410,7 @@ static int cmd_clone(int argc, const char **argv)
 {
 	const char *branch = NULL;
 	int full_clone = 0, single_branch = 0, show_progress = isatty(2);
-	int src = 1;
+	int src = 1, tags = 1;
 	struct option clone_options[] = {
 		OPT_STRING('b', "branch", &branch, N_("<branch>"),
 			   N_("branch to checkout after clone")),

@@ -421,11 +421,13 @@ static int cmd_clone(int argc, const char **argv)
 			    "be checked out")),
 		OPT_BOOL(0, "src", &src,
 			 N_("create repository within 'src' directory")),
+		OPT_BOOL(0, "tags", &tags,
+			 N_("specify if tags should be fetched during clone")),
 		OPT_END(),
 	};
 	const char * const clone_usage[] = {
 		N_("scalar clone [--single-branch] [--branch <main-branch>] [--full-clone]\n"
-		   "\t[--[no-]src] <url> [<enlistment>]"),
+		   "\t[--[no-]src] [--[no-]tags] <url> [<enlistment>]"),
 		NULL
 	};
 	const char *url;

@@ -504,6 +506,11 @@ static int cmd_clone(int argc, const char **argv)
 		goto cleanup;
 	}
 
+	if (!tags && set_config("remote.origin.tagOpt=--no-tags")) {
+		res = error(_("could not disable tags in '%s'"), dir);
+		goto cleanup;
+	}
+
 	if (!full_clone &&
 	    (res = run_git("sparse-checkout", "init", "--cone", NULL)))
 		goto cleanup;

@@ -513,7 +520,9 @@ static int cmd_clone(int argc, const char **argv)
 
 	if ((res = run_git("fetch", "--quiet",
 				show_progress ? "--progress" : "--no-progress",
-				"origin", NULL))) {
+				"origin",
+				(!tags ? "--no-tags" : NULL),
+				NULL))) {
 		warning(_("partial clone failed; attempting full clone"));
 
 		if (set_config("remote.origin.promisor") ||

index a41b4fcc085..e8613990e13 100755
@@ -169,6 +169,24 @@ test_expect_success 'scalar clone' '
 	)
 '
 
+test_expect_success 'scalar clone --no-... opts' '
+	# Note: redirect stderr always to avoid having a verbose test
+	# run result in a difference in the --[no-]progress option.
+	GIT_TRACE2_EVENT="$(pwd)/no-opt-trace" scalar clone \
+		--no-tags --no-src \
+		"file://$(pwd)" no-opts --single-branch 2>/dev/null &&
+
+	test_subcommand git fetch --quiet --no-progress \
+			origin --no-tags <no-opt-trace &&
+	(
+		cd no-opts &&
+
+		test_cmp_config --no-tags remote.origin.tagopt &&
+		git for-each-ref --format="%(refname)" refs/tags/ >tags &&
+		test_line_count = 0 tags
+	)
+'
+
 test_expect_success 'scalar reconfigure' '
 	git init one/src &&
 	scalar register one &&

base-commit: 2e7b89e038c0c888acf61f1b4ee5a43d4dd5e94c

gitgitgadget

Yuck. The loophole may be something we may want to close later, though (and replaced with a proper "--tags" support).

Makes sense.

This is a tangent, but the "--[no-]tags" option in "git fetch" is misdesigned; the default is to auto-follow tags that would annotate objects that are being fetched, and "--no-tags" is a way to decline the auto-following. But "--tags" is to say that all tags must be fetched. There is no obvious way to say "I want the auto-following behaviour" (e.g., to override an earlier "--no-tags" or "--tags").

Micronit. Shouldn't we make it clear that this is about the clone subcommand? E.g.

Subject: scalar: add --no-tags option to "scalar clone"

or something?

Hi Stolee,

the patch makes sense to me. The commit message is delightfully thorough. I'll just offer minor suggestions below:

	s/is \(choice is\)/\1/

				tags ? NULL : "--no-tags",

	test_cmp_config -C no-opts --no-tags remote.origin.tagopt &&
	git -C no-opts for-each-ref --format="%(refname)" refs/tags/ >tags &&
	test_line_count = 0 tags

Everything other than "prefer repeated use of -C instead of a single subshell in there" (which I think worsens readability, even though it may save one process), I agree with your suggestions.

Thanks.

Thanks, both, for your review comments. v2 is on the way with these suggestions.

-Stolee

From: Derrick Stolee <[email protected]>

Some large repositories use tags to track a huge list of release versions. While this choice is costly on the ref advertisement, it is further wasteful for clients who do not need those tags. Allow clients to optionally skip the tag advertisement.

This behavior is similar to that of 'git clone --no-tags' implemented in 0dab2468ee5 (clone: add a --no-tags option to clone without tags, 2017-04-26), including the modification of the remote.origin.tagOpt config value to include "--no-tags".

One thing that is opposite of the 'git clone' implementation is that this allows '--tags' as an assumed option, which can be naturally negated with '--no-tags'. The clone command does not accept '--tags' but allows "--no-no-tags" as the negation of its '--no-tags' option.

While testing this option, combine the test with the previously untested '--no-src' option introduced in 4527db8ff8c (scalar: add --[no-]src option, 2023-08-28).

---
scalar: add --no-tags option

The need for this was discovered due to the release behavior of an internal monorepo. The use of Azure DevOps' limited refs feature does not apply to tags, so the number of tags was causing some pain for users.

Thanks, -Stolee

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1780%2Fderrickstolee%2Fscalar-no-tags-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1780/derrickstolee/scalar-no-tags-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1780

Range-diff vs v1:

1: f0e8217869a ! 1: 3378b4f728a scalar: add --no-tags option
@@ Metadata
Author: Derrick Stolee <[email protected]>

## Commit message ##
- scalar: add --no-tags option
+ scalar: add --no-tags option to 'scalar clone'

Some large repositories use tags to track a huge list of release
- versions. While this is choice is costly on the ref advertisement, it is
+ versions. While this choice is costly on the ref advertisement, it is
further wasteful for clients who do not need those tags. Allow clients to optionally skip the tag advertisement.

@@ Documentation/scalar.txt: cloning. If the HEAD at the remote did not point at an
+ By default, scalar clone will fetch the tag objects advertised by
+ the remote and future git fetch commands will do the same. Use
+ --no-tags to avoid fetching tags in scalar clone and to configure
-+ the repository to avoid fetching tags in the future.
++ the repository to avoid fetching tags in the future. To fetch tags after
++ cloning with --no-tags, run git fetch --tags.
+
--[no-]full-clone::
A sparse-checkout is initialized by default. This behavior can be
@@ scalar.c: static int cmd_clone(int argc, const char **argv)
show_progress ? "--progress" : "--no-progress",
- "origin", NULL))) {
+ "origin",
-+ (!tags ? "--no-tags" : NULL),
++ (tags ? NULL : "--no-tags"),
+ NULL))) {
warning(_("partial clone failed; attempting full clone"));

 Documentation/scalar.txt |  7 +++++++
 scalar.c                 | 15 ++++++++++++---
 t/t9210-scalar.sh        | 18 ++++++++++++++++++
 3 files changed, 37 insertions(+), 3 deletions(-)

index 361f51a6473..7e4259c6743 100644
@@ -86,6 +86,13 @@ cloning. If the HEAD at the remote did not point at any branch when
 	`<entlistment>/src` directory. Use `--no-src` to place the cloned
 	repository directly in the `<enlistment>` directory.
 
+--[no-]tags::
+	By default, `scalar clone` will fetch the tag objects advertised by
+	the remote and future `git fetch` commands will do the same. Use
+	`--no-tags` to avoid fetching tags in `scalar clone` and to configure
+	the repository to avoid fetching tags in the future. To fetch tags after
+	cloning with `--no-tags`, run `git fetch --tags`.
+
 --[no-]full-clone::
 	A sparse-checkout is initialized by default. This behavior can be
 	turned off via `--full-clone`.

index 6166a8dd4c8..09560aeab54 100644
@@ -410,7 +410,7 @@ static int cmd_clone(int argc, const char **argv)
 {
 	const char *branch = NULL;
 	int full_clone = 0, single_branch = 0, show_progress = isatty(2);
-	int src = 1;
+	int src = 1, tags = 1;
 	struct option clone_options[] = {
 		OPT_STRING('b', "branch", &branch, N_("<branch>"),
 			   N_("branch to checkout after clone")),

@@ -421,11 +421,13 @@ static int cmd_clone(int argc, const char **argv)
 			    "be checked out")),
 		OPT_BOOL(0, "src", &src,
 			 N_("create repository within 'src' directory")),
+		OPT_BOOL(0, "tags", &tags,
+			 N_("specify if tags should be fetched during clone")),
 		OPT_END(),
 	};
 	const char * const clone_usage[] = {
 		N_("scalar clone [--single-branch] [--branch <main-branch>] [--full-clone]\n"
-		   "\t[--[no-]src] <url> [<enlistment>]"),
+		   "\t[--[no-]src] [--[no-]tags] <url> [<enlistment>]"),
 		NULL
 	};
 	const char *url;

@@ -504,6 +506,11 @@ static int cmd_clone(int argc, const char **argv)
 		goto cleanup;
 	}
 
+	if (!tags && set_config("remote.origin.tagOpt=--no-tags")) {
+		res = error(_("could not disable tags in '%s'"), dir);
+		goto cleanup;
+	}
+
 	if (!full_clone &&
 	    (res = run_git("sparse-checkout", "init", "--cone", NULL)))
 		goto cleanup;

@@ -513,7 +520,9 @@ static int cmd_clone(int argc, const char **argv)
 
 	if ((res = run_git("fetch", "--quiet",
 				show_progress ? "--progress" : "--no-progress",
-				"origin", NULL))) {
+				"origin",
+				(tags ? NULL : "--no-tags"),
+				NULL))) {
 		warning(_("partial clone failed; attempting full clone"));
 
 		if (set_config("remote.origin.promisor") ||

index a41b4fcc085..e8613990e13 100755
@@ -169,6 +169,24 @@ test_expect_success 'scalar clone' '
 	)
 '
 
+test_expect_success 'scalar clone --no-... opts' '
+	# Note: redirect stderr always to avoid having a verbose test
+	# run result in a difference in the --[no-]progress option.
+	GIT_TRACE2_EVENT="$(pwd)/no-opt-trace" scalar clone \
+		--no-tags --no-src \
+		"file://$(pwd)" no-opts --single-branch 2>/dev/null &&
+
+	test_subcommand git fetch --quiet --no-progress \
+			origin --no-tags <no-opt-trace &&
+	(
+		cd no-opts &&
+
+		test_cmp_config --no-tags remote.origin.tagopt &&
+		git for-each-ref --format="%(refname)" refs/tags/ >tags &&
+		test_line_count = 0 tags
+	)
+'
+
 test_expect_success 'scalar reconfigure' '
 	git init one/src &&
 	scalar register one &&

base-commit: 2e7b89e038c0c888acf61f1b4ee5a43d4dd5e94c

gitgitgadget