[PATCH v2 12/18] maintenance: create maintenance.<task>.enabled config

["Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>]

From: Derrick Stolee <dstolee@microsoft.com>

Currently, a normal run of "git maintenance run" will only run the 'gc'
task, as it is the only one enabled. This is mostly for backwards-
compatible reasons since "git maintenance run --auto" commands replaced
previous "git gc --auto" commands after some Git processes. Users could
manually run specific maintenance tasks by calling "git maintenance run
--task=<task>" directly.

Allow users to customize which steps are run automatically using config.
The 'maintenance.<task>.enabled' option then can turn on these other
tasks (or turn off the 'gc' task).

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 Documentation/config.txt             |  2 ++
 Documentation/config/maintenance.txt |  4 ++++
 Documentation/git-maintenance.txt    |  6 +++++-
 builtin/gc.c                         | 13 +++++++++++++
 t/t7900-maintenance.sh               | 12 ++++++++++++
 5 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/config/maintenance.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index ef0768b91a..2783b825f9 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -396,6 +396,8 @@ include::config/mailinfo.txt[]
 
 include::config/mailmap.txt[]
 
+include::config/maintenance.txt[]
+
 include::config/man.txt[]
 
 include::config/merge.txt[]
diff --git a/Documentation/config/maintenance.txt b/Documentation/config/maintenance.txt
new file mode 100644
index 0000000000..370cbfb42f
--- /dev/null
+++ b/Documentation/config/maintenance.txt
@@ -0,0 +1,4 @@
+maintenance.<task>.enabled::
+	This boolean config option controls whether the maintenance task
+	with name `<task>` is run when no `--task` option is specified.
+	By default, only `maintenance.gc.enabled` is true.
diff --git a/Documentation/git-maintenance.txt b/Documentation/git-maintenance.txt
index bda8df4aaa..4a61441bbc 100644
--- a/Documentation/git-maintenance.txt
+++ b/Documentation/git-maintenance.txt
@@ -30,7 +30,11 @@ SUBCOMMANDS
 -----------
 
 run::
-	Run one or more maintenance tasks.
+	Run one or more maintenance tasks. If one or more `--task` options
+	are specified, then those tasks are run in that order. Otherwise,
+	the tasks are determined by which `maintenance.<task>.enabled`
+	config options are true. By default, only `maintenance.gc.enabled`
+	is true.
 
 TASKS
 -----
diff --git a/builtin/gc.c b/builtin/gc.c
index 889d97afe7..b6dc4b1832 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1185,6 +1185,7 @@ static int maintenance_run(void)
 static void initialize_tasks(void)
 {
 	int i;
+	struct strbuf config_name = STRBUF_INIT;
 	num_tasks = 0;
 
 	for (i = 0; i < MAX_NUM_TASKS; i++)
@@ -1210,6 +1211,18 @@ static void initialize_tasks(void)
 	tasks[num_tasks]->name = "commit-graph";
 	tasks[num_tasks]->fn = maintenance_task_commit_graph;
 	num_tasks++;
+
+	for (i = 0; i < num_tasks; i++) {
+		int config_value;
+
+		strbuf_setlen(&config_name, 0);
+		strbuf_addf(&config_name, "maintenance.%s.enabled", tasks[i]->name);
+
+		if (!git_config_get_bool(config_name.buf, &config_value))
+			tasks[i]->enabled = config_value;
+	}
+
+	strbuf_release(&config_name);
 }
 
 static int task_option_parse(const struct option *opt,
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index ab5c961eb9..3ee51723e0 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -21,6 +21,18 @@ test_expect_success 'run [--auto|--quiet]' '
 	grep ",\"gc\",\"--quiet\"" run-quiet.txt
 '
 
+test_expect_success 'maintenance.<task>.enabled' '
+	git config maintenance.gc.enabled false &&
+	git config maintenance.commit-graph.enabled true &&
+	git config maintenance.loose-objects.enabled true &&
+	GIT_TRACE2_EVENT="$(pwd)/run-config.txt" git maintenance run &&
+	! grep ",\"fetch\"" run-config.txt &&
+	! grep ",\"gc\"" run-config.txt &&
+	! grep ",\"multi-pack-index\"" run-config.txt &&
+	grep ",\"commit-graph\"" run-config.txt &&
+	grep ",\"prune-packed\"" run-config.txt
+'
+
 test_expect_success 'run --task=<task>' '
 	GIT_TRACE2_EVENT="$(pwd)/run-commit-graph.txt" git maintenance run --task=commit-graph &&
 	GIT_TRACE2_EVENT="$(pwd)/run-gc.txt" git maintenance run --task=gc &&
-- 
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