Re: [PATCH v2 4/7] maintenance: add [un]register subcommands

> From: Derrick Stolee <dstolee@microsoft.com>
> 
> In preparation for launching background maintenance from the 'git
> maintenance' builtin, create register/unregister subcommands. These
> commands update the new 'maintenance.repos' config option in the global

> config so the background maintenance job knows which repositories to
> maintain.
> 
> These commands allow users to add a repository to the background
> maintenance list without disrupting the actual maintenance mechanism.
> 
> For example, a user can run 'git maintenance register' when no
> background maintenance is running and it will not start the background
> maintenance. A later update to start running background maintenance will
> then pick up this repository automatically.
> 
> The opposite example is that a user can run 'git maintenance unregister'
> to remove the current repository from background maintenance without
> halting maintenance for other repositories.
> 
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
>  Documentation/git-maintenance.txt | 14 ++++++++
>  builtin/gc.c                      | 55 ++++++++++++++++++++++++++++++-
>  t/t7900-maintenance.sh            | 17 +++++++++-
>  3 files changed, 84 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/git-maintenance.txt b/Documentation/git-maintenance.txt
> index 3af5907b01..78d0d8df91 100644
> --- a/Documentation/git-maintenance.txt
> +++ b/Documentation/git-maintenance.txt
> @@ -29,6 +29,15 @@ Git repository.
>  SUBCOMMANDS
>  -----------
>  
> +register::
> +	Initialize Git config values so any scheduled maintenance will
> +	start running on this repository. This adds the repository to the
> +	`maintenance.repo` config variable in the current user's global
> +	config and enables some recommended configuration values for
> +	`maintenance.<task>.schedule`. The tasks that are enabled are safe
> +	for running in the background without disrupting foreground
> +	processes.
> +
>  run::
>  	Run one or more maintenance tasks. If one or more `--task` options
>  	are specified, then those tasks are run in that order. Otherwise,
> @@ -36,6 +45,11 @@ run::
>  	config options are true. By default, only `maintenance.gc.enabled`
>  	is true.
>  
> +unregister::
> +	Remove the current repository from background maintenance. This
> +	only removes the repository from the configured list. It does not
> +	stop the background maintenance processes from running.
> +
>  TASKS
>  -----
>  
> diff --git a/builtin/gc.c b/builtin/gc.c
> index e28561b6c5..0290b249c9 100644
> --- a/builtin/gc.c
> +++ b/builtin/gc.c
> @@ -1408,7 +1408,56 @@ static int maintenance_run(int argc, const char **argv, const char *prefix)
>  	return maintenance_run_tasks(&opts);
>  }
>  
> -static const char builtin_maintenance_usage[] = N_("git maintenance run [<options>]");
> +static int maintenance_register(void)
> +{
> +	struct child_process config_set = CHILD_PROCESS_INIT;
> +	struct child_process config_get = CHILD_PROCESS_INIT;
> +
> +	/* There is no current repository, so skip registering it */
> +	if (!the_repository || !the_repository->gitdir)
> +		return 0;
> +
> +	config_get.git_cmd = 1;
> +	strvec_pushl(&config_get.args, "config", "--global", "--get", "maintenance.repo",
> +		     the_repository->worktree ? the_repository->worktree
> +					      : the_repository->gitdir,
> +			 NULL);
> +	config_get.out = -1;
> +
> +	if (start_command(&config_get))
> +		return error(_("failed to run 'git config'"));
> +
> +	/* We already have this value in our config! */
> +	if (!finish_command(&config_get))
> +		return 0;
> +
> +	config_set.git_cmd = 1;
> +	strvec_pushl(&config_set.args, "config", "--add", "--global", "maintenance.repo",
> +		     the_repository->worktree ? the_repository->worktree
> +					      : the_repository->gitdir,
> +		     NULL);
> +
> +	return run_command(&config_set);
> +}
> +
> +static int maintenance_unregister(void)
> +{
> +	struct child_process config_unset = CHILD_PROCESS_INIT;
> +
> +	if (!the_repository || !the_repository->gitdir)
> +		return error(_("no current repository to unregister"));
> +
> +	config_unset.git_cmd = 1;
> +	strvec_pushl(&config_unset.args, "config", "--global", "--unset",
> +		     "maintenance.repo",
> +		     the_repository->worktree ? the_repository->worktree
> +					      : the_repository->gitdir,
> +		     NULL);
> +
> +	return run_command(&config_unset);
> +}
> +
> +static const char builtin_maintenance_usage[] =	N_("git maintenance <subcommand> [<options>]");
>  
>  int cmd_maintenance(int argc, const char **argv, const char *prefix)
>  {
> @@ -1417,6 +1466,10 @@ int cmd_maintenance(int argc, const char **argv, const char *prefix)
>  
>  	if (!strcmp(argv[1], "run"))
>  		return maintenance_run(argc - 1, argv + 1, prefix);
> +	if (!strcmp(argv[1], "register"))
> +		return maintenance_register();
> +	if (!strcmp(argv[1], "unregister"))
> +		return maintenance_unregister();
>  
>  	die(_("invalid subcommand: %s"), argv[1]);
>  }
> diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
> index 328bbaa830..272d1605d2 100755
> --- a/t/t7900-maintenance.sh
> +++ b/t/t7900-maintenance.sh
> @@ -9,7 +9,7 @@ GIT_TEST_MULTI_PACK_INDEX=0
>  
>  test_expect_success 'help text' '
>  	test_expect_code 129 git maintenance -h 2>err &&
> -	test_i18ngrep "usage: git maintenance run" err &&
> +	test_i18ngrep "usage: git maintenance <subcommand>" err &&
>  	test_expect_code 128 git maintenance barf 2>err &&
>  	test_i18ngrep "invalid subcommand: barf" err
>  '
> @@ -304,4 +304,19 @@ test_expect_success '--schedule inheritance weekly -> daily -> hourly' '
>  	test_subcommand git multi-pack-index write --no-progress <weekly.txt
>  '
>  
> +test_expect_success 'register and unregister' '
> +	test_when_finished git config --global --unset-all maintenance.repo &&
> +	git config --global --add maintenance.repo /existing1 &&
> +	git config --global --add maintenance.repo /existing2 &&
> +	git config --global --get-all maintenance.repo >before &&
> +	git maintenance register &&
> +	git config --global --get-all maintenance.repo >actual &&
> +	cp before after &&
> +	pwd >>after &&
> +	test_cmp after actual &&
> +	git maintenance unregister &&
> +	git config --global --get-all maintenance.repo >actual &&
> +	test_cmp before actual
> +'
> +
>  test_done
> -- 
> gitgitgadget
>