[PATCH 7/7] builtin/maintenance: introduce "rerere-gc" task

From

Patrick Steinhardt <ps@pks.im>

Date

Apr 25, 2025, 07:29 UTC

Message-ID

<20250425-pks-maintenance-missing-tasks-v1-7-972ed6ab2c0d@pks.im>

In-Reply-To

<20250425-pks-maintenance-missing-tasks-v1-0-972ed6ab2c0d@pks.im>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 Documentation/git-maintenance.adoc |  4 ++++
 builtin/gc.c                       | 27 +++++++++++++++++++++++++++
 t/t7900-maintenance.sh             | 17 +++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/Documentation/git-maintenance.adoc b/Documentation/git-maintenance.adoc
index 6f085a9cf8c..931f3e02e85 100644
--- a/Documentation/git-maintenance.adoc
+++ b/Documentation/git-maintenance.adoc
@@ -166,6 +166,10 @@ reflog-expire::
 	The `reflog-expire` task deletes any entries in the reflog older than the
 	expiry threshold. See linkgit:git-reflog[1] for more information.
 
+rerere-gc::
+	The `rerere-gc` task invokes garbage collection for stale entries in
+	the rerere cache. See linkgit:git-rerere[1] for more information.
+
 worktree-prune::
 	The `worktree-prune` task deletes stale or broken worktrees. See
 	linkit:git-worktree[1] for more information.
diff --git a/builtin/gc.c b/builtin/gc.c
index a0816bcf302..d19449b33d4 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -16,6 +16,7 @@
 #include "builtin.h"
 #include "abspath.h"
 #include "date.h"
+#include "dir.h"
 #include "environment.h"
 #include "hex.h"
 #include "config.h"
@@ -384,6 +385,26 @@ static int maintenance_task_rerere_gc(struct maintenance_run_opts *opts UNUSED,
 	return run_command(&rerere_cmd);
 }
 
+static int rerere_gc_condition(struct gc_config *cfg UNUSED)
+{
+	struct strbuf path = STRBUF_INIT;
+	int should_gc = 0;
+	DIR *dir;
+
+	/* Skip garbage collecting the rerere cache in case rerere is disabled. */
+	repo_git_path_replace(the_repository, &path, "rr-cache");
+
+	dir = opendir(path.buf);
+	if (!dir)
+		goto out;
+	should_gc = !!readdir_skip_dot_and_dotdot(dir);
+
+out:
+	strbuf_release(&path);
+	closedir(dir);
+	return should_gc;
+}
+
 static int too_many_loose_objects(struct gc_config *cfg)
 {
 	/*
@@ -1491,6 +1512,7 @@ enum maintenance_task_label {
 	TASK_PACK_REFS,
 	TASK_REFLOG_EXPIRE,
 	TASK_WORKTREE_PRUNE,
+	TASK_RERERE_GC,
 
 	/* Leave as final value */
 	TASK__COUNT
@@ -1537,6 +1559,11 @@ static struct maintenance_task tasks[] = {
 		maintenance_task_worktree_prune,
 		worktree_prune_condition,
 	},
+	[TASK_RERERE_GC] = {
+		"rerere-gc",
+		maintenance_task_rerere_gc,
+		rerere_gc_condition,
+	},
 };
 
 static int compare_tasks_by_selection(const void *a_, const void *b_)
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index d21feda271f..9cc52f28ca4 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -510,6 +510,23 @@ test_expect_success 'worktree-prune task --auto only prunes with prunable worktr
 	test_subcommand git worktree prune --expire 3.months.ago <worktree-prune-auto.txt
 '
 
+test_expect_success 'rerere-gc task' '
+	GIT_TRACE2_EVENT="$(pwd)/rerere-gc.txt" \
+		git maintenance run --task=rerere-gc &&
+	test_subcommand git rerere gc <rerere-gc.txt
+'
+
+test_expect_success 'rerere-gc task --auto only prunes with existing rr-cache dir' '
+	mkdir .git/rr-cache &&
+	GIT_TRACE2_EVENT="$(pwd)/rerere-gc-auto.txt" \
+		git maintenance run --auto --task=rerere-gc &&
+	test_subcommand ! git rerere gc <rerere-gc-auto.txt &&
+	: >.git/rr-cache/entry &&
+	GIT_TRACE2_EVENT="$(pwd)/rerere-gc-auto.txt" \
+		git maintenance run --auto --task=rerere-gc &&
+	test_subcommand git rerere gc <rerere-gc-auto.txt
+'
+
 test_expect_success '--auto and --schedule incompatible' '
 	test_must_fail git maintenance run --auto --schedule=daily 2>err &&
 	test_grep "at most one" err

-- 
2.49.0.901.g37484f566f.dirty