[PATCH 00/10] repack: support repacking into a geometric sequence

@@ -856,6 +856,13 @@ ifdef::git-rev-list[]
 	Only useful with `--objects`; print the object IDs that are not
 	in packs.
 
+--no-kept-objects[=<kind>]::
+	Halts the traversal as soon as an object in a kept pack is
+	found. If `<kind>` is `on-disk`, only packs with a corresponding
+	`*.keep` file are ignored. If `<kind>` is `in-core`, only packs
+	with their in-core kept state set are ignored. Otherwise, both
+	kinds of kept packs are ignored.
+
 --object-names::
 	Only useful with `--objects`; print the names of the object IDs
 	that are found. This is the default behavior.

@@ -338,6 +338,13 @@ static void traverse_trees_and_blobs(struct traversal_context *ctx,
 			ctx->show_object(obj, name, ctx->show_data);
 			continue;
 		}
+		if (ctx->revs->no_kept_objects) {
+			struct pack_entry e;
+			if (find_kept_pack_entry(ctx->revs->repo, &obj->oid,
+						 ctx->revs->keep_pack_cache_flags,
+						 &e))
+				continue;
+		}
 		if (!path)
 			path = "";
 		if (obj->type == OBJ_TREE) {

@@ -2334,6 +2334,16 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->unpacked = 1;
 	} else if (starts_with(arg, "--unpacked=")) {
 		die(_("--unpacked=<packfile> no longer supported"));
+	} else if (!strcmp(arg, "--no-kept-objects")) {
+		revs->no_kept_objects = 1;
+		revs->keep_pack_cache_flags |= IN_CORE_KEEP_PACKS;
+		revs->keep_pack_cache_flags |= ON_DISK_KEEP_PACKS;
+	} else if (skip_prefix(arg, "--no-kept-objects=", &optarg)) {
+		revs->no_kept_objects = 1;
+		if (!strcmp(optarg, "in-core"))
+			revs->keep_pack_cache_flags |= IN_CORE_KEEP_PACKS;
+		if (!strcmp(optarg, "on-disk"))
+			revs->keep_pack_cache_flags |= ON_DISK_KEEP_PACKS;
 	} else if (!strcmp(arg, "-r")) {
 		revs->diff = 1;
 		revs->diffopt.flags.recursive = 1;

@@ -3822,6 +3832,11 @@ enum commit_action get_commit_action(struct rev_info *revs, struct commit *commi
 		return commit_ignore;
 	if (revs->unpacked && has_object_pack(&commit->object.oid))
 		return commit_ignore;
+	if (revs->no_kept_objects) {
+		if (has_object_kept_pack(&commit->object.oid,
+					 revs->keep_pack_cache_flags))
+			return commit_ignore;
+	}
 	if (commit->object.flags & UNINTERESTING)
 		return commit_ignore;
 	if (revs->line_level_traverse && !want_ancestry(revs)) {

@@ -148,6 +148,7 @@ struct rev_info {
 			edge_hint_aggressive:1,
 			limited:1,
 			unpacked:1,
+			no_kept_objects:1,
 			boundary:2,
 			count:1,
 			left_right:1,

@@ -312,6 +313,9 @@ struct rev_info {
 	 * This is loaded from the commit-graph being used.
 	 */
 	struct bloom_filter_settings *bloom_filter_settings;
+
+	/* misc. flags related to '--no-kept-objects' */
+	unsigned keep_pack_cache_flags;
 };
 
 int ref_excluded(struct string_list *, const char *path);

@@ -0,0 +1,69 @@
+#!/bin/sh
+
+test_description='rev-list with .keep packs'
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit loose &&
+	test_commit packed &&
+	test_commit kept &&
+
+	KEPT_PACK=$(git pack-objects --revs .git/objects/pack/pack <<-EOF
+	refs/tags/kept
+	^refs/tags/packed
+	EOF
+	) &&
+	MISC_PACK=$(git pack-objects --revs .git/objects/pack/pack <<-EOF
+	refs/tags/packed
+	^refs/tags/loose
+	EOF
+	) &&
+
+	touch .git/objects/pack/pack-$KEPT_PACK.keep
+'
+
+rev_list_objects () {
+	git rev-list "$@" >out &&
+	sort out
+}
+
+idx_objects () {
+	git show-index <$1 >expect-idx &&
+	cut -d" " -f2 <expect-idx | sort
+}
+
+test_expect_success '--no-kept-objects excludes trees and blobs in .keep packs' '
+	rev_list_objects --objects --all --no-object-names >kept &&
+	rev_list_objects --objects --all --no-object-names --no-kept-objects >no-kept &&
+
+	idx_objects .git/objects/pack/pack-$KEPT_PACK.idx >expect &&
+	comm -3 kept no-kept >actual &&
+
+	test_cmp expect actual
+'
+
+test_expect_success '--no-kept-objects excludes kept non-MIDX object' '
+	test_config core.multiPackIndex true &&
+
+	# Create a pack with just the commit object in pack, and do not mark it
+	# as kept (even though it appears in $KEPT_PACK, which does have a .keep
+	# file).
+	MIDX_PACK=$(git pack-objects .git/objects/pack/pack <<-EOF
+	$(git rev-parse kept)
+	EOF
+	) &&
+
+	# Write a MIDX containing all packs, but use the version of the commit
+	# at "kept" in a non-kept pack by touching $MIDX_PACK.
+	touch .git/objects/pack/pack-$MIDX_PACK.pack &&
+	git multi-pack-index write &&
+
+	rev_list_objects --objects --no-object-names --no-kept-objects HEAD >actual &&
+	(
+		idx_objects .git/objects/pack/pack-$MISC_PACK.idx &&
+		git rev-list --objects --no-object-names refs/tags/loose
+	) | sort >expect &&
+	test_cmp expect actual
+'
+
+test_done

@@ -2015,7 +2015,10 @@ static int fill_pack_entry(const struct object_id *oid,
 	return 1;
 }
 
-int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
+static int find_one_pack_entry(struct repository *r,
+			       const struct object_id *oid,
+			       struct pack_entry *e,
+			       int kept_only)
 {
 	struct list_head *pos;
 	struct multi_pack_index *m;

@@ -2025,26 +2028,77 @@ int find_pack_entry(struct repository *r, const struct object_id *oid, struct pa
 		return 0;
 
 	for (m = r->objects->multi_pack_index; m; m = m->next) {
-		if (fill_midx_entry(r, oid, e, m))
+		if (!(fill_midx_entry(r, oid, e, m)))
+			continue;
+
+		if (!kept_only)
+			return 1;
+
+		if (((kept_only & ON_DISK_KEEP_PACKS) && e->p->pack_keep) ||
+		    ((kept_only & IN_CORE_KEEP_PACKS) && e->p->pack_keep_in_core))
 			return 1;
 	}
 
 	list_for_each(pos, &r->objects->packed_git_mru) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
-		if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
-			list_move(&p->mru, &r->objects->packed_git_mru);
-			return 1;
+		if (p->multi_pack_index && !kept_only) {
+			/*
+			 * If this pack is covered by the MIDX, we'd have found
+			 * the object already in the loop above if it was here,
+			 * so don't bother looking.
+			 *
+			 * The exception is if we are looking only at kept
+			 * packs. An object can be present in two packs covered
+			 * by the MIDX, one kept and one not-kept. And as the
+			 * MIDX points to only one copy of each object, it might
+			 * have returned only the non-kept version above. We
+			 * have to check again to be thorough.
+			 */
+			continue;
+		}
+		if (!kept_only ||
+		    (((kept_only & ON_DISK_KEEP_PACKS) && p->pack_keep) ||
+		     ((kept_only & IN_CORE_KEEP_PACKS) && p->pack_keep_in_core))) {
+			if (fill_pack_entry(oid, e, p)) {
+				list_move(&p->mru, &r->objects->packed_git_mru);
+				return 1;
+			}
 		}
 	}
 	return 0;
 }
 
+int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
+{
+	return find_one_pack_entry(r, oid, e, 0);
+}
+
+int find_kept_pack_entry(struct repository *r,
+			 const struct object_id *oid,
+			 unsigned flags,
+			 struct pack_entry *e)
+{
+	/*
+	 * Load all packs, including midx packs, since our "kept" strategy
+	 * relies on that. We're relying on the side effect of it setting up
+	 * r->objects->packed_git, which is a little ugly.
+	 */
+	get_all_packs(r);
+	return find_one_pack_entry(r, oid, e, flags);
+}
+
 int has_object_pack(const struct object_id *oid)
 {
 	struct pack_entry e;
 	return find_pack_entry(the_repository, oid, &e);
 }
 
+int has_object_kept_pack(const struct object_id *oid, unsigned flags)
+{
+	struct pack_entry e;
+	return find_kept_pack_entry(the_repository, oid, flags, &e);
+}
+
 int has_pack_index(const unsigned char *sha1)
 {
 	struct stat st;

@@ -161,13 +161,19 @@ int packed_object_info(struct repository *r,
 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1);
 const struct packed_git *has_packed_and_bad(struct repository *r, const unsigned char *sha1);
 
+#define ON_DISK_KEEP_PACKS 1
+#define IN_CORE_KEEP_PACKS 2
+#define ALL_KEEP_PACKS (ON_DISK_KEEP_PACKS | IN_CORE_KEEP_PACKS)
+
 /*
  * Iff a pack file in the given repository contains the object named by sha1,
  * return true and store its location to e.
  */
 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e);
+int find_kept_pack_entry(struct repository *r, const struct object_id *oid, unsigned flags, struct pack_entry *e);
 
 int has_object_pack(const struct object_id *oid);
+int has_object_kept_pack(const struct object_id *oid, unsigned flags);
 
 int has_pack_index(const unsigned char *sha1);
 

@@ -1215,9 +1215,9 @@ static int want_found_object(const struct object_id *oid, int exclude,
 		 */
 		unsigned flags = 0;
 		if (ignore_packed_keep_on_disk)
-			flags |= ON_DISK_KEEP_PACKS;
+			flags |= CACHE_ON_DISK_KEEP_PACKS;
 		if (ignore_packed_keep_in_core)
-			flags |= IN_CORE_KEEP_PACKS;
+			flags |= CACHE_IN_CORE_KEEP_PACKS;
 
 		if (ignore_packed_keep_on_disk && p->pack_keep)
 			return 0;

@@ -105,6 +105,14 @@ static inline int pack_map_entry_cmp(const void *unused_cmp_data,
 	return strcmp(pg1->pack_name, key ? key : pg2->pack_name);
 }
 
+#define CACHE_ON_DISK_KEEP_PACKS 1
+#define CACHE_IN_CORE_KEEP_PACKS 2
+
+struct kept_pack_cache {
+	struct packed_git **packs;
+	unsigned flags;
+};
+
 struct raw_object_store {
 	/*
 	 * Set of all object directories; the main directory is first (and

@@ -150,6 +158,8 @@ struct raw_object_store {
 	/* A most-recently-used ordered version of the packed_git list. */
 	struct list_head packed_git_mru;
 
+	struct kept_pack_cache *kept_pack_cache;
+
 	/*
 	 * A map of packfiles to packed_git structs for tracking which
 	 * packs have been loaded already.

@@ -2015,10 +2015,7 @@ static int fill_pack_entry(const struct object_id *oid,
 	return 1;
 }
 
-static int find_one_pack_entry(struct repository *r,
-			       const struct object_id *oid,
-			       struct pack_entry *e,
-			       int kept_only)
+int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
 {
 	struct list_head *pos;
 	struct multi_pack_index *m;

@@ -2028,49 +2025,64 @@ static int find_one_pack_entry(struct repository *r,
 		return 0;
 
 	for (m = r->objects->multi_pack_index; m; m = m->next) {
-		if (!(fill_midx_entry(r, oid, e, m)))
-			continue;
-
-		if (!kept_only)
-			return 1;
-
-		if (((kept_only & ON_DISK_KEEP_PACKS) && e->p->pack_keep) ||
-		    ((kept_only & IN_CORE_KEEP_PACKS) && e->p->pack_keep_in_core))
+		if (fill_midx_entry(r, oid, e, m))
 			return 1;
 	}
 
 	list_for_each(pos, &r->objects->packed_git_mru) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
-		if (p->multi_pack_index && !kept_only) {
-			/*
-			 * If this pack is covered by the MIDX, we'd have found
-			 * the object already in the loop above if it was here,
-			 * so don't bother looking.
-			 *
-			 * The exception is if we are looking only at kept
-			 * packs. An object can be present in two packs covered
-			 * by the MIDX, one kept and one not-kept. And as the
-			 * MIDX points to only one copy of each object, it might
-			 * have returned only the non-kept version above. We
-			 * have to check again to be thorough.
-			 */
-			continue;
-		}
-		if (!kept_only ||
-		    (((kept_only & ON_DISK_KEEP_PACKS) && p->pack_keep) ||
-		     ((kept_only & IN_CORE_KEEP_PACKS) && p->pack_keep_in_core))) {
-			if (fill_pack_entry(oid, e, p)) {
-				list_move(&p->mru, &r->objects->packed_git_mru);
-				return 1;
-			}
+		if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
+			list_move(&p->mru, &r->objects->packed_git_mru);
+			return 1;
 		}
 	}
 	return 0;
 }
 
-int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
+static void maybe_invalidate_kept_pack_cache(struct repository *r,
+					     unsigned flags)
 {
-	return find_one_pack_entry(r, oid, e, 0);
+	if (!r->objects->kept_pack_cache)
+		return;
+	if (r->objects->kept_pack_cache->flags == flags)
+		return;
+	free(r->objects->kept_pack_cache->packs);
+	FREE_AND_NULL(r->objects->kept_pack_cache);
+}
+
+static struct packed_git **kept_pack_cache(struct repository *r, unsigned flags)
+{
+	maybe_invalidate_kept_pack_cache(r, flags);
+
+	if (!r->objects->kept_pack_cache) {
+		struct packed_git **packs = NULL;
+		size_t nr = 0, alloc = 0;
+		struct packed_git *p;
+
+		/*
+		 * We want "all" packs here, because we need to cover ones that
+		 * are used by a midx, as well. We need to look in every one of
+		 * them (instead of the midx itself) to cover duplicates. It's
+		 * possible that an object is found in two packs that the midx
+		 * covers, one kept and one not kept, but the midx returns only
+		 * the non-kept version.
+		 */
+		for (p = get_all_packs(r); p; p = p->next) {
+			if ((p->pack_keep && (flags & CACHE_ON_DISK_KEEP_PACKS)) ||
+			    (p->pack_keep_in_core && (flags & CACHE_IN_CORE_KEEP_PACKS))) {
+				ALLOC_GROW(packs, nr + 1, alloc);
+				packs[nr++] = p;
+			}
+		}
+		ALLOC_GROW(packs, nr + 1, alloc);
+		packs[nr] = NULL;
+
+		r->objects->kept_pack_cache = xmalloc(sizeof(*r->objects->kept_pack_cache));
+		r->objects->kept_pack_cache->packs = packs;
+		r->objects->kept_pack_cache->flags = flags;
+	}
+
+	return r->objects->kept_pack_cache->packs;
 }
 
 int find_kept_pack_entry(struct repository *r,

@@ -2078,13 +2090,15 @@ int find_kept_pack_entry(struct repository *r,
 			 unsigned flags,
 			 struct pack_entry *e)
 {
-	/*
-	 * Load all packs, including midx packs, since our "kept" strategy
-	 * relies on that. We're relying on the side effect of it setting up
-	 * r->objects->packed_git, which is a little ugly.
-	 */
-	get_all_packs(r);
-	return find_one_pack_entry(r, oid, e, flags);
+	struct packed_git **cache;
+
+	for (cache = kept_pack_cache(r, flags); *cache; cache++) {
+		struct packed_git *p = *cache;
+		if (fill_pack_entry(oid, e, p))
+			return 1;
+	}
+
+	return 0;
 }
 
 int has_object_pack(const struct object_id *oid)

@@ -2093,7 +2107,8 @@ int has_object_pack(const struct object_id *oid)
 	return find_pack_entry(the_repository, oid, &e);
 }
 
-int has_object_kept_pack(const struct object_id *oid, unsigned flags)
+int has_object_kept_pack(const struct object_id *oid,
+			 unsigned flags)
 {
 	struct pack_entry e;
 	return find_kept_pack_entry(the_repository, oid, flags, &e);

@@ -161,10 +161,6 @@ int packed_object_info(struct repository *r,
 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1);
 const struct packed_git *has_packed_and_bad(struct repository *r, const unsigned char *sha1);
 
-#define ON_DISK_KEEP_PACKS 1
-#define IN_CORE_KEEP_PACKS 2
-#define ALL_KEEP_PACKS (ON_DISK_KEEP_PACKS | IN_CORE_KEEP_PACKS)
-
 /*
  * Iff a pack file in the given repository contains the object named by sha1,
  * return true and store its location to e.

@@ -2336,14 +2336,14 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		die(_("--unpacked=<packfile> no longer supported"));
 	} else if (!strcmp(arg, "--no-kept-objects")) {
 		revs->no_kept_objects = 1;
-		revs->keep_pack_cache_flags |= IN_CORE_KEEP_PACKS;
-		revs->keep_pack_cache_flags |= ON_DISK_KEEP_PACKS;
+		revs->keep_pack_cache_flags |= CACHE_IN_CORE_KEEP_PACKS;
+		revs->keep_pack_cache_flags |= CACHE_ON_DISK_KEEP_PACKS;
 	} else if (skip_prefix(arg, "--no-kept-objects=", &optarg)) {
 		revs->no_kept_objects = 1;
 		if (!strcmp(optarg, "in-core"))
-			revs->keep_pack_cache_flags |= IN_CORE_KEEP_PACKS;
+			revs->keep_pack_cache_flags |= CACHE_IN_CORE_KEEP_PACKS;
 		if (!strcmp(optarg, "on-disk"))
-			revs->keep_pack_cache_flags |= ON_DISK_KEEP_PACKS;
+			revs->keep_pack_cache_flags |= CACHE_ON_DISK_KEEP_PACKS;
 	} else if (!strcmp(arg, "-r")) {
 		revs->diff = 1;
 		revs->diffopt.flags.recursive = 1;

@@ -1178,7 +1178,8 @@ static int have_duplicate_entry(const struct object_id *oid,
 	return 1;
 }
 
-static int want_found_object(int exclude, struct packed_git *p)
+static int want_found_object(const struct object_id *oid, int exclude,
+			     struct packed_git *p)
 {
 	if (exclude)
 		return 1;

@@ -1199,22 +1200,73 @@ static int want_found_object(int exclude, struct packed_git *p)
 	 * Otherwise, we signal "-1" at the end to tell the caller that we do
 	 * not know either way, and it needs to check more packs.
 	 */
-	if (!ignore_packed_keep_on_disk &&
-	    !ignore_packed_keep_in_core &&
-	    (!local || !have_non_local_packs))
+
+	/*
+	 * Handle .keep first, as we have a fast(er) path there.
+	 */
+	if (ignore_packed_keep_on_disk || ignore_packed_keep_in_core) {
+		/*
+		 * Set the flags for the kept-pack cache to be the ones we want
+		 * to ignore.
+		 *
+		 * That is, if we are ignoring objects in on-disk keep packs,
+		 * then we want to search through the on-disk keep and ignore
+		 * the in-core ones.
+		 */
+		unsigned flags = 0;
+		if (ignore_packed_keep_on_disk)
+			flags |= ON_DISK_KEEP_PACKS;
+		if (ignore_packed_keep_in_core)
+			flags |= IN_CORE_KEEP_PACKS;
+
+		if (ignore_packed_keep_on_disk && p->pack_keep)
+			return 0;
+		if (ignore_packed_keep_in_core && p->pack_keep_in_core)
+			return 0;
+		if (has_object_kept_pack(oid, flags))
+			return 0;
+	}
+
+	/*
+	 * At this point we know definitively that either we don't care about
+	 * keep-packs, or the object is not in one. Keep checking other
+	 * conditions...
+	 */
+
+	if (!local || !have_non_local_packs)
 		return 1;
-
 	if (local && !p->pack_local)
 		return 0;
-	if (p->pack_local &&
-	    ((ignore_packed_keep_on_disk && p->pack_keep) ||
-	     (ignore_packed_keep_in_core && p->pack_keep_in_core)))
-		return 0;
 
 	/* we don't know yet; keep looking for more packs */
 	return -1;
 }
 
+static int want_object_in_pack_one(struct packed_git *p,
+				   const struct object_id *oid,
+				   int exclude,
+				   struct packed_git **found_pack,
+				   off_t *found_offset)
+{
+	off_t offset;
+
+	if (p == *found_pack)
+		offset = *found_offset;
+	else
+		offset = find_pack_entry_one(oid->hash, p);
+
+	if (offset) {
+		if (!*found_pack) {
+			if (!is_pack_valid(p))
+				return -1;
+			*found_offset = offset;
+			*found_pack = p;
+		}
+		return want_found_object(oid, exclude, p);
+	}
+	return -1;
+}
+
 /*
  * Check whether we want the object in the pack (e.g., we do not want
  * objects found in non-local stores if the "--local" option was used).

@@ -1242,7 +1294,7 @@ static int want_object_in_pack(const struct object_id *oid,
 	 * are present we will determine the answer right now.
 	 */
 	if (*found_pack) {
-		want = want_found_object(exclude, *found_pack);
+		want = want_found_object(oid, exclude, *found_pack);
 		if (want != -1)
 			return want;
 	}

@@ -1250,53 +1302,22 @@ static int want_object_in_pack(const struct object_id *oid,
 	for (m = get_multi_pack_index(the_repository); m; m = m->next) {
 		struct pack_entry e;
 		if (fill_midx_entry(the_repository, oid, &e, m)) {
-			struct packed_git *p = e.p;
-			off_t offset;
-
-			if (p == *found_pack)
-				offset = *found_offset;
-			else
-				offset = find_pack_entry_one(oid->hash, p);
-
-			if (offset) {
-				if (!*found_pack) {
-					if (!is_pack_valid(p))
-						continue;
-					*found_offset = offset;
-					*found_pack = p;
-				}
-				want = want_found_object(exclude, p);
-				if (want != -1)
-					return want;
-			}
-		}
-	}
-
-	list_for_each(pos, get_packed_git_mru(the_repository)) {
-		struct packed_git *p = list_entry(pos, struct packed_git, mru);
-		off_t offset;
-
-		if (p == *found_pack)
-			offset = *found_offset;
-		else
-			offset = find_pack_entry_one(oid->hash, p);
-
-		if (offset) {
-			if (!*found_pack) {
-				if (!is_pack_valid(p))
-					continue;
-				*found_offset = offset;
-				*found_pack = p;
-			}
-			want = want_found_object(exclude, p);
-			if (!exclude && want > 0)
-				list_move(&p->mru,
-					  get_packed_git_mru(the_repository));
+			want = want_object_in_pack_one(e.p, oid, exclude, found_pack, found_offset);
 			if (want != -1)
 				return want;
 		}
 	}
 
+	list_for_each(pos, get_packed_git_mru(the_repository)) {
+		struct packed_git *p = list_entry(pos, struct packed_git, mru);
+		want = want_object_in_pack_one(p, oid, exclude, found_pack, found_offset);
+		if (!exclude && want > 0)
+			list_move(&p->mru,
+				  get_packed_git_mru(the_repository));
+		if (want != -1)
+			return want;
+	}
+
 	if (uri_protocols.nr) {
 		struct configured_exclusion *ex =
 			oidmap_get(&configured_exclusions, oid);

@@ -27,8 +27,11 @@ repack_into_n () {
 	>pushes &&
 
 	# create base packfile
-	head -n 1 pushes |
-	git pack-objects --delta-base-offset --revs staging/pack &&
+	base_pack=$(
+		head -n 1 pushes |
+		git pack-objects --delta-base-offset --revs staging/pack
+	) &&
+	test_export base_pack &&
 
 	# and then incrementals between each pair of commits
 	last= &&

@@ -87,6 +90,15 @@ do
 		  --reflog --indexed-objects --delta-base-offset \
 		  --stdout </dev/null >/dev/null
 	'
+
+	test_perf "repack with keep ($nr_packs)" '
+		git pack-objects --keep-true-parents \
+		  --honor-pack-keep --assume-kept-packs-closed \
+		  --keep-pack=pack-$base_pack.pack \
+		  --non-empty --all \
+		  --reflog --indexed-objects --delta-base-offset \
+		  --stdout </dev/null >/dev/null
+	'
 done
 
 # Measure pack loading with 10,000 packs.

@@ -135,6 +135,14 @@ depth is 4095.
 	leading directory (e.g. `pack-123.pack`). The option could be
 	specified multiple times to keep multiple packs.
 
+--keep-pack-stdin::
+	Take a list of line-delimited `<pack-name>` arguments, treating
+	them as if they were each passed as `--keep-pack=<pack-name>`.
+	Useful for when many packs are being kept to avoid argument
+	length limitations. Requires that `--revs` be passed or implied,
+	but does not allow the caller to pass additional traversal
+	arguments over standard input.
+
 --assume-kept-packs-closed::
 	This flag causes `git rev-list` to halt the object traversal
 	when it encounters an object found in a kept pack. This is

@@ -3343,7 +3343,7 @@ static void record_recent_commit(struct commit *commit, void *data)
 	oid_array_append(&recent_objects, &commit->object.oid);
 }
 
-static void get_object_list(int ac, const char **av)
+static void get_object_list(int ac, const char **av, int read_from_stdin)
 {
 	struct rev_info revs;
 	struct setup_revision_opt s_r_opt = {

@@ -3363,7 +3363,7 @@ static void get_object_list(int ac, const char **av)
 	save_warning = warn_on_object_refname_ambiguity;
 	warn_on_object_refname_ambiguity = 0;
 
-	while (fgets(line, sizeof(line), stdin) != NULL) {
+	while (read_from_stdin && fgets(line, sizeof(line), stdin) != NULL) {
 		int len = strlen(line);
 		if (len && line[len - 1] == '\n')
 			line[--len] = 0;

@@ -3487,6 +3487,15 @@ static int option_parse_unpack_unreachable(const struct option *opt,
 	return 0;
 }
 
+static void collect_kept_packs(struct string_list *keep_pack_list)
+{
+	struct strbuf buf = STRBUF_INIT;
+	while (strbuf_getline(&buf, stdin) != EOF)
+		string_list_append(keep_pack_list,
+				   strbuf_detach(&buf, NULL));
+	strbuf_release(&buf);
+}
+
 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 {
 	int use_internal_rev_list = 0;

@@ -3496,6 +3505,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
 	int rev_list_index = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
+	int keep_pack_stdin = 0;
 	struct option pack_objects_options[] = {
 		OPT_SET_INT('q', "quiet", &progress,
 			    N_("do not show progress meter"), 0),

@@ -3568,6 +3578,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			 N_("assume the union of kept packs is closed under reachability")),
 		OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
 				N_("ignore this pack")),
+		OPT_BOOL(0, "keep-pack-stdin", &keep_pack_stdin,
+			 N_("read the list of kept packs from stdin")),
 		OPT_INTEGER(0, "compression", &pack_compression_level,
 			    N_("pack compression level")),
 		OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,

@@ -3728,6 +3740,11 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (progress && all_progress_implied)
 		progress = 2;
 
+	if (keep_pack_stdin) {
+		if (!use_internal_rev_list)
+			die(_("--keep-pack-stdin requires --revs"));
+		collect_kept_packs(&keep_pack_list);
+	}
 	add_extra_kept_packs(&keep_pack_list);
 	if (ignore_packed_keep_on_disk) {
 		struct packed_git *p;

@@ -3769,7 +3786,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (!use_internal_rev_list)
 		read_object_list_from_stdin();
 	else {
-		get_object_list(rp.nr, rp.v);
+		get_object_list(rp.nr, rp.v, !keep_pack_stdin);
 		strvec_clear(&rp);
 	}
 	cleanup_preferred_base();

@@ -165,6 +165,17 @@ depth is 4095.
 	Pass the `--delta-islands` option to `git-pack-objects`, see
 	linkgit:git-pack-objects[1].
 
+-g=<factor>::
+--geometric=<factor>::
+	Arrange resulting pack structure so that each successive pack
+	contains at least `<factor>` times the number of objects as the
+	next-largest pack.
++
+`git repack` ensures this by determining a "cut" of packfiles that need to be
+repacked into one in order to ensure a geometric progression. It picks the
+smallest set of packfiles such that as many of the larger packfiles (by count of
+objects contained in that pack) may be left intact.
+
 Configuration
 -------------
 

@@ -298,6 +298,116 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 #define ALL_INTO_ONE 1
 #define LOOSEN_UNREACHABLE 2
 
+struct pack_geometry {
+	struct packed_git **pack;
+	uint32_t pack_nr, pack_alloc;
+	uint32_t split;
+};
+
+static uint32_t geometry_pack_weight(struct packed_git *p)
+{
+	if (open_pack_index(p))
+		die(_("cannot open index for %s"), p->pack_name);
+	return p->num_objects;
+}
+
+static int geometry_cmp(const void *va, const void *vb)
+{
+	uint32_t aw = geometry_pack_weight(*(struct packed_git **)va),
+		 bw = geometry_pack_weight(*(struct packed_git **)vb);
+
+	if (aw < bw)
+		return -1;
+	if (aw > bw)
+		return 1;
+	return 0;
+}
+
+static void init_pack_geometry(struct pack_geometry **geometry_p)
+{
+	struct packed_git *p;
+	struct pack_geometry *geometry;
+
+	*geometry_p = xcalloc(1, sizeof(struct pack_geometry));
+	geometry = *geometry_p;
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		ALLOC_GROW(geometry->pack,
+			   geometry->pack_nr + 1,
+			   geometry->pack_alloc);
+
+		geometry->pack[geometry->pack_nr] = p;
+		geometry->pack_nr++;
+	}
+
+	QSORT(geometry->pack, geometry->pack_nr, geometry_cmp);
+}
+
+static void split_pack_geometry(struct pack_geometry *geometry, int factor)
+{
+	uint32_t i;
+	uint32_t split;
+	off_t total_size = 0;
+
+	split = geometry->pack_nr - 1;
+
+	/*
+	 * First, count the number of packs (in descending order of size) which
+	 * already form a geometric progression.
+	 */
+	for (i = geometry->pack_nr - 1; i > 0; i--) {
+		struct packed_git *ours = geometry->pack[i];
+		struct packed_git *prev = geometry->pack[i - 1];
+		if (geometry_pack_weight(ours) >= factor * geometry_pack_weight(prev))
+			split--;
+		else
+			break;
+	}
+
+	if (split) {
+		/*
+		 * Move the split one to the right, since the top element in the
+		 * last-compared pair can't be in the progression. Only do this
+		 * when we split in the middle of the array (otherwise if we got
+		 * to the end, then the split is in the right place).
+		 */
+		split++;
+	}
+
+	/*
+	 * Then, anything to the left of 'split' must be in a new pack. But,
+	 * creating that new pack may cause packs in the heavy half to no longer
+	 * form a geometric progression.
+	 *
+	 * Compute an expected size of the new pack, and then determine how many
+	 * packs in the heavy half need to be joined into it (if any) to restore
+	 * the geometric progression.
+	 */
+	for (i = 0; i < split; i++)
+		total_size += geometry_pack_weight(geometry->pack[i]);
+	for (i = split; i < geometry->pack_nr; i++) {
+		struct packed_git *ours = geometry->pack[i];
+		if (geometry_pack_weight(ours) < factor * total_size) {
+			split++;
+			total_size += geometry_pack_weight(ours);
+		} else
+			break;
+	}
+
+	geometry->split = split;
+}
+
+static void clear_pack_geometry(struct pack_geometry *geometry)
+{
+	if (!geometry)
+		return;
+
+	free(geometry->pack);
+	geometry->pack_nr = 0;
+	geometry->pack_alloc = 0;
+	geometry->split = 0;
+}
+
 static void handle_loose_and_reachable(struct child_process *cmd,
 				       const char *unpack_unreachable,
 				       int pack_everything,