Merge branch 'ds/maintenance-part-2'

"git maintenance", an extended big brother of "git gc", continues
to evolve.

* ds/maintenance-part-2:
  maintenance: add incremental-repack auto condition
  maintenance: auto-size incremental-repack batch
  maintenance: add incremental-repack task
  midx: use start_delayed_progress()
  midx: enable core.multiPackIndex by default
  maintenance: create auto condition for loose-objects
  maintenance: add loose-objects task
  maintenance: add prefetch task

Documentation/config/core.txt

@@ -606,8 +606,8 @@ core.useReplaceRefs::
 
 core.multiPackIndex::
 	Use the multi-pack-index file to track multiple packfiles using a
-	single index. See link:technical/multi-pack-index.html[the
-	multi-pack-index design document].
+	single index. See linkgit:git-multi-pack-index[1] for more
+	information. Defaults to true.
 
 core.sparseCheckout::
 	Enable "sparse checkout" feature. See linkgit:git-sparse-checkout[1]

Documentation/config/maintenance.txt

@@ -14,3 +14,21 @@ maintenance.commit-graph.auto::
 	reachable commits that are not in the commit-graph file is at least
 	the value of `maintenance.commit-graph.auto`. The default value is
 	100.
+
+maintenance.loose-objects.auto::
+	This integer config option controls how often the `loose-objects` task
+	should be run as part of `git maintenance run --auto`. If zero, then
+	the `loose-objects` task will not run with the `--auto` option. A
+	negative value will force the task to run every time. Otherwise, a
+	positive value implies the command should run when the number of
+	loose objects is at least the value of `maintenance.loose-objects.auto`.
+	The default value is 100.
+
+maintenance.incremental-repack.auto::
+	This integer config option controls how often the `incremental-repack`
+	task should be run as part of `git maintenance run --auto`. If zero,
+	then the `incremental-repack` task will not run with the `--auto`
+	option. A negative value will force the task to run every time.
+	Otherwise, a positive value implies the command should run when the
+	number of pack-files not in the multi-pack-index is at least the value
+	of `maintenance.incremental-repack.auto`. The default value is 10.

Documentation/git-maintenance.txt

@@ -47,6 +47,21 @@ commit-graph::
 	`commit-graph-chain` file. They will be deleted by a later run based
 	on the expiration delay.
 
+prefetch::
+	The `prefetch` task updates the object directory with the latest
+	objects from all registered remotes. For each remote, a `git fetch`
+	command is run. The refmap is custom to avoid updating local or remote
+	branches (those in `refs/heads` or `refs/remotes`). Instead, the
+	remote refs are stored in `refs/prefetch/<remote>/`. Also, tags are
+	not updated.
++
+This is done to avoid disrupting the remote-tracking branches. The end users
+expect these refs to stay unmoved unless they initiate a fetch.  With prefetch
+task, however, the objects necessary to complete a later real fetch would
+already be obtained, so the real fetch would go faster.  In the ideal case,
+it will just become an update to bunch of remote-tracking branches without
+any object transfer.
+
 gc::
 	Clean up unnecessary files and optimize the local repository. "GC"
 	stands for "garbage collection," but this task performs many
@@ -55,6 +70,39 @@ gc::
 	be disruptive in some situations, as it deletes stale data. See
 	linkgit:git-gc[1] for more details on garbage collection in Git.
 
+loose-objects::
+	The `loose-objects` job cleans up loose objects and places them into
+	pack-files. In order to prevent race conditions with concurrent Git
+	commands, it follows a two-step process. First, it deletes any loose
+	objects that already exist in a pack-file; concurrent Git processes
+	will examine the pack-file for the object data instead of the loose
+	object. Second, it creates a new pack-file (starting with "loose-")
+	containing a batch of loose objects. The batch size is limited to 50
+	thousand objects to prevent the job from taking too long on a
+	repository with many loose objects. The `gc` task writes unreachable
+	objects as loose objects to be cleaned up by a later step only if
+	they are not re-added to a pack-file; for this reason it is not
+	advisable to enable both the `loose-objects` and `gc` tasks at the
+	same time.
+
+incremental-repack::
+	The `incremental-repack` job repacks the object directory
+	using the `multi-pack-index` feature. In order to prevent race
+	conditions with concurrent Git commands, it follows a two-step
+	process. First, it calls `git multi-pack-index expire` to delete
+	pack-files unreferenced by the `multi-pack-index` file. Second, it
+	calls `git multi-pack-index repack` to select several small
+	pack-files and repack them into a bigger one, and then update the
+	`multi-pack-index` entries that refer to the small pack-files to
+	refer to the new pack-file. This prepares those small pack-files
+	for deletion upon the next run of `git multi-pack-index expire`.
+	The selection of the small pack-files is such that the expected
+	size of the big pack-file is at least the batch size; see the
+	`--batch-size` option for the `repack` subcommand in
+	linkgit:git-multi-pack-index[1]. The default batch-size is zero,
+	which is a special case that attempts to repack all pack-files
+	into a single pack-file.
+
 OPTIONS
 -------
 --auto::

builtin/gc.c

@@ -29,6 +29,8 @@
 #include "tree.h"
 #include "promisor-remote.h"
 #include "refs.h"
+#include "remote.h"
+#include "object-store.h"
 
 #define FAILED_RUN "failed to run %s"
 
@@ -816,6 +818,51 @@ static int maintenance_task_commit_graph(struct maintenance_run_opts *opts)
 	return 0;
 }
 
+static int fetch_remote(const char *remote, struct maintenance_run_opts *opts)
+{
+	struct child_process child = CHILD_PROCESS_INIT;
+
+	child.git_cmd = 1;
+	strvec_pushl(&child.args, "fetch", remote, "--prune", "--no-tags",
+		     "--no-write-fetch-head", "--recurse-submodules=no",
+		     "--refmap=", NULL);
+
+	if (opts->quiet)
+		strvec_push(&child.args, "--quiet");
+
+	strvec_pushf(&child.args, "+refs/heads/*:refs/prefetch/%s/*", remote);
+
+	return !!run_command(&child);
+}
+
+static int append_remote(struct remote *remote, void *cbdata)
+{
+	struct string_list *remotes = (struct string_list *)cbdata;
+
+	string_list_append(remotes, remote->name);
+	return 0;
+}
+
+static int maintenance_task_prefetch(struct maintenance_run_opts *opts)
+{
+	int result = 0;
+	struct string_list_item *item;
+	struct string_list remotes = STRING_LIST_INIT_DUP;
+
+	if (for_each_remote(append_remote, &remotes)) {
+		error(_("failed to fill remotes"));
+		result = 1;
+		goto cleanup;
+	}
+
+	for_each_string_list_item(item, &remotes)
+		result |= fetch_remote(item->string, opts);
+
+cleanup:
+	string_list_clear(&remotes, 0);
+	return result;
+}
+
 static int maintenance_task_gc(struct maintenance_run_opts *opts)
 {
 	struct child_process child = CHILD_PROCESS_INIT;
@@ -834,6 +881,268 @@ static int maintenance_task_gc(struct maintenance_run_opts *opts)
 	return run_command(&child);
 }
 
+static int prune_packed(struct maintenance_run_opts *opts)
+{
+	struct child_process child = CHILD_PROCESS_INIT;
+
+	child.git_cmd = 1;
+	strvec_push(&child.args, "prune-packed");
+
+	if (opts->quiet)
+		strvec_push(&child.args, "--quiet");
+
+	return !!run_command(&child);
+}
+
+struct write_loose_object_data {
+	FILE *in;
+	int count;
+	int batch_size;
+};
+
+static int loose_object_auto_limit = 100;
+
+static int loose_object_count(const struct object_id *oid,
+			       const char *path,
+			       void *data)
+{
+	int *count = (int*)data;
+	if (++(*count) >= loose_object_auto_limit)
+		return 1;
+	return 0;
+}
+
+static int loose_object_auto_condition(void)
+{
+	int count = 0;
+
+	git_config_get_int("maintenance.loose-objects.auto",
+			   &loose_object_auto_limit);
+
+	if (!loose_object_auto_limit)
+		return 0;
+	if (loose_object_auto_limit < 0)
+		return 1;
+
+	return for_each_loose_file_in_objdir(the_repository->objects->odb->path,
+					     loose_object_count,
+					     NULL, NULL, &count);
+}
+
+static int bail_on_loose(const struct object_id *oid,
+			 const char *path,
+			 void *data)
+{
+	return 1;
+}
+
+static int write_loose_object_to_stdin(const struct object_id *oid,
+				       const char *path,
+				       void *data)
+{
+	struct write_loose_object_data *d = (struct write_loose_object_data *)data;
+
+	fprintf(d->in, "%s\n", oid_to_hex(oid));
+
+	return ++(d->count) > d->batch_size;
+}
+
+static int pack_loose(struct maintenance_run_opts *opts)
+{
+	struct repository *r = the_repository;
+	int result = 0;
+	struct write_loose_object_data data;
+	struct child_process pack_proc = CHILD_PROCESS_INIT;
+
+	/*
+	 * Do not start pack-objects process
+	 * if there are no loose objects.
+	 */
+	if (!for_each_loose_file_in_objdir(r->objects->odb->path,
+					   bail_on_loose,
+					   NULL, NULL, NULL))
+		return 0;
+
+	pack_proc.git_cmd = 1;
+
+	strvec_push(&pack_proc.args, "pack-objects");
+	if (opts->quiet)
+		strvec_push(&pack_proc.args, "--quiet");
+	strvec_pushf(&pack_proc.args, "%s/pack/loose", r->objects->odb->path);
+
+	pack_proc.in = -1;
+
+	if (start_command(&pack_proc)) {
+		error(_("failed to start 'git pack-objects' process"));
+		return 1;
+	}
+
+	data.in = xfdopen(pack_proc.in, "w");
+	data.count = 0;
+	data.batch_size = 50000;
+
+	for_each_loose_file_in_objdir(r->objects->odb->path,
+				      write_loose_object_to_stdin,
+				      NULL,
+				      NULL,
+				      &data);
+
+	fclose(data.in);
+
+	if (finish_command(&pack_proc)) {
+		error(_("failed to finish 'git pack-objects' process"));
+		result = 1;
+	}
+
+	return result;
+}
+
+static int maintenance_task_loose_objects(struct maintenance_run_opts *opts)
+{
+	return prune_packed(opts) || pack_loose(opts);
+}
+
+static int incremental_repack_auto_condition(void)
+{
+	struct packed_git *p;
+	int enabled;
+	int incremental_repack_auto_limit = 10;
+	int count = 0;
+
+	if (git_config_get_bool("core.multiPackIndex", &enabled) ||
+	    !enabled)
+		return 0;
+
+	git_config_get_int("maintenance.incremental-repack.auto",
+			   &incremental_repack_auto_limit);
+
+	if (!incremental_repack_auto_limit)
+		return 0;
+	if (incremental_repack_auto_limit < 0)
+		return 1;
+
+	for (p = get_packed_git(the_repository);
+	     count < incremental_repack_auto_limit && p;
+	     p = p->next) {
+		if (!p->multi_pack_index)
+			count++;
+	}
+
+	return count >= incremental_repack_auto_limit;
+}
+
+static int multi_pack_index_write(struct maintenance_run_opts *opts)
+{
+	struct child_process child = CHILD_PROCESS_INIT;
+
+	child.git_cmd = 1;
+	strvec_pushl(&child.args, "multi-pack-index", "write", NULL);
+
+	if (opts->quiet)
+		strvec_push(&child.args, "--no-progress");
+
+	if (run_command(&child))
+		return error(_("failed to write multi-pack-index"));
+
+	return 0;
+}
+
+static int multi_pack_index_expire(struct maintenance_run_opts *opts)
+{
+	struct child_process child = CHILD_PROCESS_INIT;
+
+	child.git_cmd = 1;
+	strvec_pushl(&child.args, "multi-pack-index", "expire", NULL);
+
+	if (opts->quiet)
+		strvec_push(&child.args, "--no-progress");
+
+	close_object_store(the_repository->objects);
+
+	if (run_command(&child))
+		return error(_("'git multi-pack-index expire' failed"));
+
+	return 0;
+}
+
+#define TWO_GIGABYTES (INT32_MAX)
+
+static off_t get_auto_pack_size(void)
+{
+	/*
+	 * The "auto" value is special: we optimize for
+	 * one large pack-file (i.e. from a clone) and
+	 * expect the rest to be small and they can be
+	 * repacked quickly.
+	 *
+	 * The strategy we select here is to select a
+	 * size that is one more than the second largest
+	 * pack-file. This ensures that we will repack
+	 * at least two packs if there are three or more
+	 * packs.
+	 */
+	off_t max_size = 0;
+	off_t second_largest_size = 0;
+	off_t result_size;
+	struct packed_git *p;
+	struct repository *r = the_repository;
+
+	reprepare_packed_git(r);
+	for (p = get_all_packs(r); p; p = p->next) {
+		if (p->pack_size > max_size) {
+			second_largest_size = max_size;
+			max_size = p->pack_size;
+		} else if (p->pack_size > second_largest_size)
+			second_largest_size = p->pack_size;
+	}
+
+	result_size = second_largest_size + 1;
+
+	/* But limit ourselves to a batch size of 2g */
+	if (result_size > TWO_GIGABYTES)
+		result_size = TWO_GIGABYTES;
+
+	return result_size;
+}
+
+static int multi_pack_index_repack(struct maintenance_run_opts *opts)
+{
+	struct child_process child = CHILD_PROCESS_INIT;
+
+	child.git_cmd = 1;
+	strvec_pushl(&child.args, "multi-pack-index", "repack", NULL);
+
+	if (opts->quiet)
+		strvec_push(&child.args, "--no-progress");
+
+	strvec_pushf(&child.args, "--batch-size=%"PRIuMAX,
+				  (uintmax_t)get_auto_pack_size());
+
+	close_object_store(the_repository->objects);
+
+	if (run_command(&child))
+		return error(_("'git multi-pack-index repack' failed"));
+
+	return 0;
+}
+
+static int maintenance_task_incremental_repack(struct maintenance_run_opts *opts)
+{
+	prepare_repo_settings(the_repository);
+	if (!the_repository->settings.core_multi_pack_index) {
+		warning(_("skipping incremental-repack task because core.multiPackIndex is disabled"));
+		return 0;
+	}
+
+	if (multi_pack_index_write(opts))
+		return 1;
+	if (multi_pack_index_expire(opts))
+		return 1;
+	if (multi_pack_index_repack(opts))
+		return 1;
+	return 0;
+}
+
 typedef int maintenance_task_fn(struct maintenance_run_opts *opts);
 
 /*
@@ -854,6 +1163,9 @@ struct maintenance_task {
 };
 
 enum maintenance_task_label {
+	TASK_PREFETCH,
+	TASK_LOOSE_OBJECTS,
+	TASK_INCREMENTAL_REPACK,
 	TASK_GC,
 	TASK_COMMIT_GRAPH,
 
@@ -862,6 +1174,20 @@ enum maintenance_task_label {
 };
 
 static struct maintenance_task tasks[] = {
+	[TASK_PREFETCH] = {
+		"prefetch",
+		maintenance_task_prefetch,
+	},
+	[TASK_LOOSE_OBJECTS] = {
+		"loose-objects",
+		maintenance_task_loose_objects,
+		loose_object_auto_condition,
+	},
+	[TASK_INCREMENTAL_REPACK] = {
+		"incremental-repack",
+		maintenance_task_incremental_repack,
+		incremental_repack_auto_condition,
+	},
 	[TASK_GC] = {
 		"gc",
 		maintenance_task_gc,

midx.c

@@ -10,6 +10,7 @@
 #include "progress.h"
 #include "trace2.h"
 #include "run-command.h"
+#include "repository.h"
 
 #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
 #define MIDX_VERSION 1
@@ -398,15 +399,9 @@ int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, i
 {
 	struct multi_pack_index *m;
 	struct multi_pack_index *m_search;
-	int config_value;
-	static int env_value = -1;
 
-	if (env_value < 0)
-		env_value = git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0);
-
-	if (!env_value &&
-	    (repo_config_get_bool(r, "core.multipackindex", &config_value) ||
-	    !config_value))
+	prepare_repo_settings(r);
+	if (!r->settings.core_multi_pack_index)
 		return 0;
 
 	for (m_search = r->objects->multi_pack_index; m_search; m_search = m_search->next)
@@ -850,7 +845,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index *
 
 	packs.pack_paths_checked = 0;
 	if (flags & MIDX_PROGRESS)
-		packs.progress = start_progress(_("Adding packfiles to multi-pack-index"), 0);
+		packs.progress = start_delayed_progress(_("Adding packfiles to multi-pack-index"), 0);
 	else
 		packs.progress = NULL;
 
@@ -987,7 +982,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index *
 	}
 
 	if (flags & MIDX_PROGRESS)
-		progress = start_progress(_("Writing chunks to multi-pack-index"),
+		progress = start_delayed_progress(_("Writing chunks to multi-pack-index"),
 					  num_chunks);
 	for (i = 0; i < num_chunks; i++) {
 		if (written != chunk_offsets[i])
@@ -1129,7 +1124,7 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 	}
 
 	if (flags & MIDX_PROGRESS)
-		progress = start_progress(_("Looking for referenced packfiles"),
+		progress = start_delayed_progress(_("Looking for referenced packfiles"),
 					  m->num_packs);
 	for (i = 0; i < m->num_packs; i++) {
 		if (prepare_midx_pack(r, m, i))
@@ -1250,7 +1245,7 @@ int expire_midx_packs(struct repository *r, const char *object_dir, unsigned fla
 	count = xcalloc(m->num_packs, sizeof(uint32_t));
 
 	if (flags & MIDX_PROGRESS)
-		progress = start_progress(_("Counting referenced objects"),
+		progress = start_delayed_progress(_("Counting referenced objects"),
 					  m->num_objects);
 	for (i = 0; i < m->num_objects; i++) {
 		int pack_int_id = nth_midxed_pack_int_id(m, i);
@@ -1260,7 +1255,7 @@ int expire_midx_packs(struct repository *r, const char *object_dir, unsigned fla
 	stop_progress(&progress);
 
 	if (flags & MIDX_PROGRESS)
-		progress = start_progress(_("Finding and deleting unreferenced packfiles"),
+		progress = start_delayed_progress(_("Finding and deleting unreferenced packfiles"),
 					  m->num_packs);
 	for (i = 0; i < m->num_packs; i++) {
 		char *pack_name;

repo-settings.c

@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "config.h"
 #include "repository.h"
+#include "midx.h"
 
 #define UPDATE_DEFAULT_BOOL(s,v) do { if (s == -1) { s = v; } } while(0)
 
@@ -52,6 +53,11 @@ void prepare_repo_settings(struct repository *r)
 		r->settings.pack_use_sparse = value;
 	UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
 
+	value = git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0);
+	if (value || !repo_config_get_bool(r, "core.multipackindex", &value))
+		r->settings.core_multi_pack_index = value;
+	UPDATE_DEFAULT_BOOL(r->settings.core_multi_pack_index, 1);
+
 	if (!repo_config_get_bool(r, "feature.manyfiles", &value) && value) {
 		UPDATE_DEFAULT_BOOL(r->settings.index_version, 4);
 		UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache, UNTRACKED_CACHE_WRITE);

repository.h

@@ -39,6 +39,8 @@ struct repo_settings {
 
 	int pack_use_sparse;
 	enum fetch_negotiation_setting fetch_negotiation_algorithm;
+
+	int core_multi_pack_index;
 };
 
 struct repository {

t/t5319-multi-pack-index.sh

@@ -3,6 +3,7 @@
 test_description='multi-pack-indexes'
 . ./test-lib.sh
 
+GIT_TEST_MULTI_PACK_INDEX=0
 objdir=.git/objects
 
 HASH_LEN=$(test_oid rawsz)
@@ -173,12 +174,12 @@ test_expect_success 'write progress off for redirected stderr' '
 '
 
 test_expect_success 'write force progress on for stderr' '
-	git multi-pack-index --object-dir=$objdir --progress write 2>err &&
+	GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --progress write 2>err &&
 	test_file_not_empty err
 '
 
 test_expect_success 'write with the --no-progress option' '
-	git multi-pack-index --object-dir=$objdir --no-progress write 2>err &&
+	GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --no-progress write 2>err &&
 	test_line_count = 0 err
 '
 
@@ -368,17 +369,17 @@ test_expect_success 'git-fsck incorrect offset' '
 '
 
 test_expect_success 'repack progress off for redirected stderr' '
-	git multi-pack-index --object-dir=$objdir repack 2>err &&
+	GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir repack 2>err &&
 	test_line_count = 0 err
 '
 
 test_expect_success 'repack force progress on for stderr' '
-	git multi-pack-index --object-dir=$objdir --progress repack 2>err &&
+	GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --progress repack 2>err &&
 	test_file_not_empty err
 '
 
 test_expect_success 'repack with the --no-progress option' '
-	git multi-pack-index --object-dir=$objdir --no-progress repack 2>err &&
+	GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --no-progress repack 2>err &&
 	test_line_count = 0 err
 '
 
@@ -562,7 +563,7 @@ test_expect_success 'expire progress off for redirected stderr' '
 test_expect_success 'expire force progress on for stderr' '
 	(
 		cd dup &&
-		git multi-pack-index --progress expire 2>err &&
+		GIT_PROGRESS_DELAY=0 git multi-pack-index --progress expire 2>err &&
 		test_file_not_empty err
 	)
 '
@@ -570,7 +571,7 @@ test_expect_success 'expire force progress on for stderr' '
 test_expect_success 'expire with the --no-progress option' '
 	(
 		cd dup &&
-		git multi-pack-index --no-progress expire 2>err &&
+		GIT_PROGRESS_DELAY=0 git multi-pack-index --no-progress expire 2>err &&
 		test_line_count = 0 err
 	)
 '

t/t7900-maintenance.sh

@@ -5,6 +5,7 @@ test_description='git maintenance builtin'
 . ./test-lib.sh
 
 GIT_TEST_COMMIT_GRAPH=0
+GIT_TEST_MULTI_PACK_INDEX=0
 
 test_expect_success 'help text' '
 	test_expect_code 129 git maintenance -h 2>err &&
@@ -62,4 +63,188 @@ test_expect_success 'run --task duplicate' '
 	test_i18ngrep "cannot be selected multiple times" err
 '
 
+test_expect_success 'run --task=prefetch with no remotes' '
+	git maintenance run --task=prefetch 2>err &&
+	test_must_be_empty err
+'
+
+test_expect_success 'prefetch multiple remotes' '
+	git clone . clone1 &&
+	git clone . clone2 &&
+	git remote add remote1 "file://$(pwd)/clone1" &&
+	git remote add remote2 "file://$(pwd)/clone2" &&
+	git -C clone1 switch -c one &&
+	git -C clone2 switch -c two &&
+	test_commit -C clone1 one &&
+	test_commit -C clone2 two &&
+	GIT_TRACE2_EVENT="$(pwd)/run-prefetch.txt" git maintenance run --task=prefetch 2>/dev/null &&
+	fetchargs="--prune --no-tags --no-write-fetch-head --recurse-submodules=no --refmap= --quiet" &&
+	test_subcommand git fetch remote1 $fetchargs +refs/heads/\\*:refs/prefetch/remote1/\\* <run-prefetch.txt &&
+	test_subcommand git fetch remote2 $fetchargs +refs/heads/\\*:refs/prefetch/remote2/\\* <run-prefetch.txt &&
+	test_path_is_missing .git/refs/remotes &&
+	git log prefetch/remote1/one &&
+	git log prefetch/remote2/two &&
+	git fetch --all &&
+	test_cmp_rev refs/remotes/remote1/one refs/prefetch/remote1/one &&
+	test_cmp_rev refs/remotes/remote2/two refs/prefetch/remote2/two
+'
+
+test_expect_success 'loose-objects task' '
+	# Repack everything so we know the state of the object dir
+	git repack -adk &&
+
+	# Hack to stop maintenance from running during "git commit"
+	echo in use >.git/objects/maintenance.lock &&
+
+	# Assuming that "git commit" creates at least one loose object
+	test_commit create-loose-object &&
+	rm .git/objects/maintenance.lock &&
+
+	ls .git/objects >obj-dir-before &&
+	test_file_not_empty obj-dir-before &&
+	ls .git/objects/pack/*.pack >packs-before &&
+	test_line_count = 1 packs-before &&
+
+	# The first run creates a pack-file
+	# but does not delete loose objects.
+	git maintenance run --task=loose-objects &&
+	ls .git/objects >obj-dir-between &&
+	test_cmp obj-dir-before obj-dir-between &&
+	ls .git/objects/pack/*.pack >packs-between &&
+	test_line_count = 2 packs-between &&
+	ls .git/objects/pack/loose-*.pack >loose-packs &&
+	test_line_count = 1 loose-packs &&
+
+	# The second run deletes loose objects
+	# but does not create a pack-file.
+	git maintenance run --task=loose-objects &&
+	ls .git/objects >obj-dir-after &&
+	cat >expect <<-\EOF &&
+	info
+	pack
+	EOF
+	test_cmp expect obj-dir-after &&
+	ls .git/objects/pack/*.pack >packs-after &&
+	test_cmp packs-between packs-after
+'
+
+test_expect_success 'maintenance.loose-objects.auto' '
+	git repack -adk &&
+	GIT_TRACE2_EVENT="$(pwd)/trace-lo1.txt" \
+		git -c maintenance.loose-objects.auto=1 maintenance \
+		run --auto --task=loose-objects 2>/dev/null &&
+	test_subcommand ! git prune-packed --quiet <trace-lo1.txt &&
+	printf data-A | git hash-object -t blob --stdin -w &&
+	GIT_TRACE2_EVENT="$(pwd)/trace-loA" \
+		git -c maintenance.loose-objects.auto=2 \
+		maintenance run --auto --task=loose-objects 2>/dev/null &&
+	test_subcommand ! git prune-packed --quiet <trace-loA &&
+	printf data-B | git hash-object -t blob --stdin -w &&
+	GIT_TRACE2_EVENT="$(pwd)/trace-loB" \
+		git -c maintenance.loose-objects.auto=2 \
+		maintenance run --auto --task=loose-objects 2>/dev/null &&
+	test_subcommand git prune-packed --quiet <trace-loB &&
+	GIT_TRACE2_EVENT="$(pwd)/trace-loC" \
+		git -c maintenance.loose-objects.auto=2 \
+		maintenance run --auto --task=loose-objects 2>/dev/null &&
+	test_subcommand git prune-packed --quiet <trace-loC
+'
+
+test_expect_success 'incremental-repack task' '
+	packDir=.git/objects/pack &&
+	for i in $(test_seq 1 5)
+	do
+		test_commit $i || return 1
+	done &&
+
+	# Create three disjoint pack-files with size BIG, small, small.
+	echo HEAD~2 | git pack-objects --revs $packDir/test-1 &&
+	test_tick &&
+	git pack-objects --revs $packDir/test-2 <<-\EOF &&
+	HEAD~1
+	^HEAD~2
+	EOF
+	test_tick &&
+	git pack-objects --revs $packDir/test-3 <<-\EOF &&
+	HEAD
+	^HEAD~1
+	EOF
+	rm -f $packDir/pack-* &&
+	rm -f $packDir/loose-* &&
+	ls $packDir/*.pack >packs-before &&
+	test_line_count = 3 packs-before &&
+
+	# the job repacks the two into a new pack, but does not
+	# delete the old ones.
+	git maintenance run --task=incremental-repack &&
+	ls $packDir/*.pack >packs-between &&
+	test_line_count = 4 packs-between &&
+
+	# the job deletes the two old packs, and does not write
+	# a new one because the batch size is not high enough to
+	# pack the largest pack-file.
+	git maintenance run --task=incremental-repack &&
+	ls .git/objects/pack/*.pack >packs-after &&
+	test_line_count = 2 packs-after
+'
+
+test_expect_success EXPENSIVE 'incremental-repack 2g limit' '
+	for i in $(test_seq 1 5)
+	do
+		test-tool genrandom foo$i $((512 * 1024 * 1024 + 1)) >>big ||
+		return 1
+	done &&
+	git add big &&
+	git commit -m "Add big file (1)" &&
+
+	# ensure any possible loose objects are in a pack-file
+	git maintenance run --task=loose-objects &&
+
+	rm big &&
+	for i in $(test_seq 6 10)
+	do
+		test-tool genrandom foo$i $((512 * 1024 * 1024 + 1)) >>big ||
+		return 1
+	done &&
+	git add big &&
+	git commit -m "Add big file (2)" &&
+
+	# ensure any possible loose objects are in a pack-file
+	git maintenance run --task=loose-objects &&
+
+	# Now run the incremental-repack task and check the batch-size
+	GIT_TRACE2_EVENT="$(pwd)/run-2g.txt" git maintenance run \
+		--task=incremental-repack 2>/dev/null &&
+	test_subcommand git multi-pack-index repack \
+		 --no-progress --batch-size=2147483647 <run-2g.txt
+'
+
+test_expect_success 'maintenance.incremental-repack.auto' '
+	git repack -adk &&
+	git config core.multiPackIndex true &&
+	git multi-pack-index write &&
+	GIT_TRACE2_EVENT="$(pwd)/midx-init.txt" git \
+		-c maintenance.incremental-repack.auto=1 \
+		maintenance run --auto --task=incremental-repack 2>/dev/null &&
+	test_subcommand ! git multi-pack-index write --no-progress <midx-init.txt &&
+	test_commit A &&
+	git pack-objects --revs .git/objects/pack/pack <<-\EOF &&
+	HEAD
+	^HEAD~1
+	EOF
+	GIT_TRACE2_EVENT=$(pwd)/trace-A git \
+		-c maintenance.incremental-repack.auto=2 \
+		maintenance run --auto --task=incremental-repack 2>/dev/null &&
+	test_subcommand ! git multi-pack-index write --no-progress <trace-A &&
+	test_commit B &&
+	git pack-objects --revs .git/objects/pack/pack <<-\EOF &&
+	HEAD
+	^HEAD~1
+	EOF
+	GIT_TRACE2_EVENT=$(pwd)/trace-B git \
+		-c maintenance.incremental-repack.auto=2 \
+		maintenance run --auto --task=incremental-repack 2>/dev/null &&
+	test_subcommand git multi-pack-index write --no-progress <trace-B
+'
+
 test_done