builtin/maintenance: introduce "rerere-gc" task

While git-gc(1) knows to garbage collect the rerere cache,
git-maintenance(1) does not yet have a task for this cleanup. Introduce
a new "rerere-gc" task to plug this gap.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config/maintenance.adoc b/Documentation/config/maintenance.adoc
index b36b62c1c47e4ab619c4740264c05d5272fc975f..2f71934218332215b5a0a39180aaf53b17abfecd 100644 (file)
--- a/Documentation/config/maintenance.adoc
+++ b/Documentation/config/maintenance.adoc
@@ -84,6 +84,15 @@ maintenance.reflog-expire.auto::
        expired reflog entries in the "HEAD" reflog is at least the value of
        `maintenance.loose-objects.auto`. The default value is 100.
 
+maintenance.rerere-gc.auto::
+       This integer config option controls how often the `rerere-gc` task
+       should be run as part of `git maintenance run --auto`. If zero, then
+       the `rerere-gc` task will not run with the `--auto` option. A negative
+       value will force the task to run every time. Otherwise, any positive
+       value implies the command will run when the "rr-cache" directory exists
+       and has at least one entry, regardless of whether it is stale or not.
+       This heuristic may be refined in the future. The default value is 1.
+
 maintenance.worktree-prune.auto::
        This integer config option controls how often the `worktree-prune` task
        should be run as part of `git maintenance run --auto`. If zero, then

diff --git a/Documentation/git-maintenance.adoc b/Documentation/git-maintenance.adoc
index 6f085a9cf8c92add5c32323be64959266571b4c6..931f3e02e85fe4ec4fa5859b3106694a894e0737 100644 (file)
--- 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 03b4e32bb5e8fb43e11f04c864a198c2574780c5..3393d2535d47c734379b2b400b95167fb2e15c32 100644 (file)
--- 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"
@@ -33,6 +34,7 @@
 #include "pack-objects.h"
 #include "path.h"
 #include "reflog.h"
+#include "rerere.h"
 #include "blob.h"
 #include "tree.h"
 #include "promisor-remote.h"
@@ -393,6 +395,35 @@ 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, limit = 1;
+       DIR *dir = NULL;
+
+       git_config_get_int("maintenance.rerere-gc.auto", &limit);
+       if (limit <= 0) {
+               should_gc = limit < 0;
+               goto out;
+       }
+
+       /*
+        * We skip garbage collection in case we either have no "rr-cache"
+        * directory or when it doesn't contain at least one entry.
+        */
+       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);
+       if (dir)
+               closedir(dir);
+       return should_gc;
+}
+
 static int too_many_loose_objects(struct gc_config *cfg)
 {
        /*
@@ -1511,6 +1542,7 @@ enum maintenance_task_label {
        TASK_PACK_REFS,
        TASK_REFLOG_EXPIRE,
        TASK_WORKTREE_PRUNE,
+       TASK_RERERE_GC,
 
        /* Leave as final value */
        TASK__COUNT
@@ -1557,6 +1589,11 @@ 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 8f4120a0351e2e495f3f00203730ece258ee9058..8cf89e285f49e5d2f891636d39b089f03e571156 100755 (executable)
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -564,6 +564,50 @@ test_expect_success 'worktree-prune task honors gc.worktreePruneExpire' '
        test_path_is_missing .git/worktrees/worktree
 '
 
+test_expect_rerere_gc () {
+       negate=
+       if test "$1" = "!"
+       then
+               negate="!"
+               shift
+       fi
+
+       rm -f "rerere-gc.txt" &&
+       GIT_TRACE2_EVENT="$(pwd)/rerere-gc.txt" "$@" &&
+       test_subcommand $negate git rerere gc <rerere-gc.txt
+}
+
+test_expect_success 'rerere-gc task without --auto always collects garbage' '
+       test_expect_rerere_gc git maintenance run --task=rerere-gc
+'
+
+test_expect_success 'rerere-gc task with --auto only prunes with prunable entries' '
+       test_when_finished "rm -rf .git/rr-cache" &&
+       test_expect_rerere_gc ! git maintenance run --auto --task=rerere-gc &&
+       mkdir .git/rr-cache &&
+       test_expect_rerere_gc ! git maintenance run --auto --task=rerere-gc &&
+       : >.git/rr-cache/entry &&
+       test_expect_rerere_gc git maintenance run --auto --task=rerere-gc
+'
+
+test_expect_success 'rerere-gc task with --auto honors maintenance.rerere-gc.auto' '
+       test_when_finished "rm -rf .git/rr-cache" &&
+
+       # A negative value should always prune.
+       test_expect_rerere_gc git -c maintenance.rerere-gc.auto=-1 maintenance run --auto --task=rerere-gc &&
+
+       # A positive value prunes when there is at least one entry.
+       test_expect_rerere_gc ! git -c maintenance.rerere-gc.auto=9000 maintenance run --auto --task=rerere-gc &&
+       mkdir .git/rr-cache &&
+       test_expect_rerere_gc ! git -c maintenance.rerere-gc.auto=9000 maintenance run --auto --task=rerere-gc &&
+       : >.git/rr-cache/entry-1 &&
+       test_expect_rerere_gc git -c maintenance.rerere-gc.auto=9000 maintenance run --auto --task=rerere-gc &&
+
+       # Zero should never prune.
+       : >.git/rr-cache/entry-1 &&
+       test_expect_rerere_gc ! git -c maintenance.rerere-gc.auto=0 maintenance run --auto --task=rerere-gc
+'
+
 test_expect_success '--auto and --schedule incompatible' '
        test_must_fail git maintenance run --auto --schedule=daily 2>err &&
        test_grep "at most one" err