1 files changed, 562 insertions, 155 deletions

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 13cde5896a..1a3dd445f8 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -37,6 +37,134 @@
 #include "shallow.h"
 #include "promisor-remote.h"
 
+/*
+ * Objects we are going to pack are collected in the `to_pack` structure.
+ * It contains an array (dynamically expanded) of the object data, and a map
+ * that can resolve SHA1s to their position in the array.
+ */
+static struct packing_data to_pack;
+
+static inline struct object_entry *oe_delta(
+		const struct packing_data *pack,
+		const struct object_entry *e)
+{
+	if (!e->delta_idx)
+		return NULL;
+	if (e->ext_base)
+		return &pack->ext_bases[e->delta_idx - 1];
+	else
+		return &pack->objects[e->delta_idx - 1];
+}
+
+static inline unsigned long oe_delta_size(struct packing_data *pack,
+					  const struct object_entry *e)
+{
+	if (e->delta_size_valid)
+		return e->delta_size_;
+
+	/*
+	 * pack->delta_size[] can't be NULL because oe_set_delta_size()
+	 * must have been called when a new delta is saved with
+	 * oe_set_delta().
+	 * If oe_delta() returns NULL (i.e. default state, which means
+	 * delta_size_valid is also false), then the caller must never
+	 * call oe_delta_size().
+	 */
+	return pack->delta_size[e - pack->objects];
+}
+
+unsigned long oe_get_size_slow(struct packing_data *pack,
+			       const struct object_entry *e);
+
+static inline unsigned long oe_size(struct packing_data *pack,
+				    const struct object_entry *e)
+{
+	if (e->size_valid)
+		return e->size_;
+
+	return oe_get_size_slow(pack, e);
+}
+
+static inline void oe_set_delta(struct packing_data *pack,
+				struct object_entry *e,
+				struct object_entry *delta)
+{
+	if (delta)
+		e->delta_idx = (delta - pack->objects) + 1;
+	else
+		e->delta_idx = 0;
+}
+
+static inline struct object_entry *oe_delta_sibling(
+		const struct packing_data *pack,
+		const struct object_entry *e)
+{
+	if (e->delta_sibling_idx)
+		return &pack->objects[e->delta_sibling_idx - 1];
+	return NULL;
+}
+
+static inline struct object_entry *oe_delta_child(
+		const struct packing_data *pack,
+		const struct object_entry *e)
+{
+	if (e->delta_child_idx)
+		return &pack->objects[e->delta_child_idx - 1];
+	return NULL;
+}
+
+static inline void oe_set_delta_child(struct packing_data *pack,
+				      struct object_entry *e,
+				      struct object_entry *delta)
+{
+	if (delta)
+		e->delta_child_idx = (delta - pack->objects) + 1;
+	else
+		e->delta_child_idx = 0;
+}
+
+static inline void oe_set_delta_sibling(struct packing_data *pack,
+					struct object_entry *e,
+					struct object_entry *delta)
+{
+	if (delta)
+		e->delta_sibling_idx = (delta - pack->objects) + 1;
+	else
+		e->delta_sibling_idx = 0;
+}
+
+static inline void oe_set_size(struct packing_data *pack,
+			       struct object_entry *e,
+			       unsigned long size)
+{
+	if (size < pack->oe_size_limit) {
+		e->size_ = size;
+		e->size_valid = 1;
+	} else {
+		e->size_valid = 0;
+		if (oe_get_size_slow(pack, e) != size)
+			BUG("'size' is supposed to be the object size!");
+	}
+}
+
+static inline void oe_set_delta_size(struct packing_data *pack,
+				     struct object_entry *e,
+				     unsigned long size)
+{
+	if (size < pack->oe_delta_size_limit) {
+		e->delta_size_ = size;
+		e->delta_size_valid = 1;
+	} else {
+		packing_data_lock(pack);
+		if (!pack->delta_size)
+			ALLOC_ARRAY(pack->delta_size, pack->nr_alloc);
+		packing_data_unlock(pack);
+
+		pack->delta_size[e - pack->objects] = size;
+		e->delta_size_valid = 0;
+	}
+}
+
 #define IN_PACK(obj) oe_in_pack(&to_pack, obj)
 #define SIZE(obj) oe_size(&to_pack, obj)
 #define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
@@ -56,13 +184,6 @@ static const char *pack_usage[] = {
 	NULL
 };
 
-/*
- * Objects we are going to pack are collected in the `to_pack` structure.
- * It contains an array (dynamically expanded) of the object data, and a map
- * that can resolve SHA1s to their position in the array.
- */
-static struct packing_data to_pack;
-
 static struct pack_idx_entry **written_list;
 static uint32_t nr_result, nr_written, nr_seen;
 static struct bitmap_index *bitmap_git;
@@ -301,6 +422,17 @@ static void copy_pack_data(struct hashfile *f,
 	}
 }
 
+static inline int oe_size_greater_than(struct packing_data *pack,
+				       const struct object_entry *lhs,
+				       unsigned long rhs)
+{
+	if (lhs->size_valid)
+		return lhs->size_ > rhs;
+	if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
+		return 1;
+	return oe_get_size_slow(pack, lhs) > rhs;
+}
+
 /* Return 0 if we will bust the pack-size limit */
 static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 					   unsigned long limit, int usable_delta)
@@ -642,6 +774,14 @@ static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 	return 0;
 }
 
+static inline unsigned char oe_layer(struct packing_data *pack,
+				     struct object_entry *e)
+{
+	if (!pack->layer)
+		return 0;
+	return pack->layer[e - pack->objects];
+}
+
 static inline void add_to_write_order(struct object_entry **wo,
 			       unsigned int *endp,
 			       struct object_entry *e)
@@ -815,8 +955,8 @@ static struct reused_chunk {
 	/* The offset of the first object of this chunk in the original
 	 * packfile. */
 	off_t original;
-	/* The offset of the first object of this chunk in the generated
-	 * packfile minus "original". */
+	/* The difference for "original" minus the offset of the first object of
+	 * this chunk in the generated packfile. */
 	off_t difference;
 } *reused_chunks;
 static int reused_chunks_nr;
@@ -984,6 +1124,11 @@ static void write_reused_pack(struct hashfile *f)
 				break;
 
 			offset += ewah_bit_ctz64(word >> offset);
+			/*
+			 * Can use bit positions directly, even for MIDX
+			 * bitmaps. See comment in try_partial_reuse()
+			 * for why.
+			 */
 			write_reused_pack_one(pos + offset, f, &w_curs);
 			display_progress(progress_state, ++written);
 		}
@@ -1030,7 +1175,7 @@ static void write_pack_file(void)
 	write_order = compute_write_order();
 
 	do {
-		struct object_id oid;
+		unsigned char hash[GIT_MAX_RAWSZ];
 		char *pack_tmp_name = NULL;
 
 		if (pack_to_stdout)
@@ -1059,13 +1204,13 @@ static void write_pack_file(void)
 		 * If so, rewrite it like in fast-import
 		 */
 		if (pack_to_stdout) {
-			finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
+			finalize_hashfile(f, hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 		} else if (nr_written == nr_remaining) {
-			finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
+			finalize_hashfile(f, hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 		} else {
-			int fd = finalize_hashfile(f, oid.hash, 0);
-			fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
-						 nr_written, oid.hash, offset);
+			int fd = finalize_hashfile(f, hash, 0);
+			fixup_pack_header_footer(fd, hash, pack_tmp_name,
+						 nr_written, hash, offset);
 			close(fd);
 			if (write_bitmap_index) {
 				if (write_bitmap_index != WRITE_BITMAP_QUIET)
@@ -1077,6 +1222,7 @@ static void write_pack_file(void)
 		if (!pack_to_stdout) {
 			struct stat st;
 			struct strbuf tmpname = STRBUF_INIT;
+			char *idx_tmp_name = NULL;
 
 			/*
 			 * Packs are runtime accessed in their mtime
@@ -1097,34 +1243,41 @@ static void write_pack_file(void)
 					warning_errno(_("failed utime() on %s"), pack_tmp_name);
 			}
 
-			strbuf_addf(&tmpname, "%s-", base_name);
+			strbuf_addf(&tmpname, "%s-%s.", base_name,
+				    hash_to_hex(hash));
 
 			if (write_bitmap_index) {
-				bitmap_writer_set_checksum(oid.hash);
+				bitmap_writer_set_checksum(hash);
 				bitmap_writer_build_type_index(
 					&to_pack, written_list, nr_written);
 			}
 
-			finish_tmp_packfile(&tmpname, pack_tmp_name,
+			stage_tmp_packfiles(&tmpname, pack_tmp_name,
 					    written_list, nr_written,
-					    &pack_idx_opts, oid.hash);
+					    &pack_idx_opts, hash, &idx_tmp_name);
 
 			if (write_bitmap_index) {
-				strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
+				size_t tmpname_len = tmpname.len;
 
+				strbuf_addstr(&tmpname, "bitmap");
 				stop_progress(&progress_state);
 
 				bitmap_writer_show_progress(progress);
 				bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
-				bitmap_writer_build(&to_pack);
+				if (bitmap_writer_build(&to_pack) < 0)
+					die(_("failed to write bitmap index"));
 				bitmap_writer_finish(written_list, nr_written,
 						     tmpname.buf, write_bitmap_options);
 				write_bitmap_index = 0;
+				strbuf_setlen(&tmpname, tmpname_len);
 			}
 
+			rename_tmp_packfile_idx(&tmpname, &idx_tmp_name);
+
+			free(idx_tmp_name);
 			strbuf_release(&tmpname);
 			free(pack_tmp_name);
-			puts(oid_to_hex(&oid));
+			puts(hash_to_hex(hash));
 		}
 
 		/* mark written objects as written to previous pack */
@@ -1188,7 +1341,8 @@ 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;
@@ -1204,27 +1358,82 @@ static int want_found_object(int exclude, struct packed_git *p)
 	 * make sure no copy of this object appears in _any_ pack that makes us
 	 * to omit the object, so we need to check all the packs.
 	 *
-	 * We can however first check whether these options can possible matter;
+	 * We can however first check whether these options can possibly matter;
 	 * if they do not matter we know we want the object in generated pack.
 	 * 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))
-		return 1;
 
+	/*
+	 * Objects in packs borrowed from elsewhere are discarded regardless of
+	 * if they appear in other packs that weren't borrowed.
+	 */
 	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;
+
+	/*
+	 * Then 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;
 
 	/* 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).
@@ -1252,7 +1461,7 @@ 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;
 	}
@@ -1260,51 +1469,20 @@ 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;
-			}
+			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);
-		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));
-			if (want != -1)
-				return want;
-		}
+		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) {
@@ -1635,7 +1813,7 @@ static void add_preferred_base(struct object_id *oid)
 		}
 	}
 
-	it = xcalloc(1, sizeof(*it));
+	CALLOC_ARRAY(it, 1);
 	it->next = pbase_tree;
 	pbase_tree = it;
 
@@ -2096,7 +2274,7 @@ static void get_object_details(void)
 		progress_state = start_progress(_("Counting objects"),
 						to_pack.nr_objects);
 
-	sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
+	CALLOC_ARRAY(sorted_by_offset, to_pack.nr_objects);
 	for (i = 0; i < to_pack.nr_objects; i++)
 		sorted_by_offset[i] = to_pack.objects + i;
 	QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
@@ -2206,6 +2384,26 @@ static pthread_mutex_t progress_mutex;
  * progress_mutex for protection.
  */
 
+static inline int oe_size_less_than(struct packing_data *pack,
+				    const struct object_entry *lhs,
+				    unsigned long rhs)
+{
+	if (lhs->size_valid)
+		return lhs->size_ < rhs;
+	if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */
+		return 0;
+	return oe_get_size_slow(pack, lhs) < rhs;
+}
+
+static inline void oe_set_tree_depth(struct packing_data *pack,
+				     struct object_entry *e,
+				     unsigned int tree_depth)
+{
+	if (!pack->tree_depth)
+		CALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
+	pack->tree_depth[e - pack->objects] = tree_depth;
+}
+
 /*
  * Return the size of the object without doing any delta
  * reconstruction (so non-deltas are true object sizes, but deltas
@@ -2428,7 +2626,7 @@ static void find_deltas(struct object_entry **list, unsigned *list_size,
 	struct unpacked *array;
 	unsigned long mem_usage = 0;
 
-	array = xcalloc(window, sizeof(struct unpacked));
+	CALLOC_ARRAY(array, window);
 
 	for (;;) {
 		struct object_entry *entry;
@@ -2665,7 +2863,7 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
 	if (progress > pack_to_stdout)
 		fprintf_ln(stderr, _("Delta compression using up to %d threads"),
 			   delta_search_threads);
-	p = xcalloc(delta_search_threads, sizeof(*p));
+	CALLOC_ARRAY(p, delta_search_threads);
 
 	/* Partition the work amongst work threads. */
 	for (i = 0; i < delta_search_threads; i++) {
@@ -2953,6 +3151,13 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 			    pack_idx_opts.version);
 		return 0;
 	}
+	if (!strcmp(k, "pack.writereverseindex")) {
+		if (git_config_bool(k, v))
+			pack_idx_opts.flags |= WRITE_REV;
+		else
+			pack_idx_opts.flags &= ~WRITE_REV;
+		return 0;
+	}
 	if (!strcmp(k, "uploadpack.blobpackfileuri")) {
 		struct configured_exclusion *ex = xmalloc(sizeof(*ex));
 		const char *oid_end, *pack_end;
@@ -2979,6 +3184,208 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 	return git_default_config(k, v, cb);
 }
 
+/* Counters for trace2 output when in --stdin-packs mode. */
+static int stdin_packs_found_nr;
+static int stdin_packs_hints_nr;
+
+static int add_object_entry_from_pack(const struct object_id *oid,
+				      struct packed_git *p,
+				      uint32_t pos,
+				      void *_data)
+{
+	struct rev_info *revs = _data;
+	struct object_info oi = OBJECT_INFO_INIT;
+	off_t ofs;
+	enum object_type type;
+
+	display_progress(progress_state, ++nr_seen);
+
+	if (have_duplicate_entry(oid, 0))
+		return 0;
+
+	ofs = nth_packed_object_offset(p, pos);
+	if (!want_object_in_pack(oid, 0, &p, &ofs))
+		return 0;
+
+	oi.typep = &type;
+	if (packed_object_info(the_repository, p, ofs, &oi) < 0)
+		die(_("could not get type of object %s in pack %s"),
+		    oid_to_hex(oid), p->pack_name);
+	else if (type == OBJ_COMMIT) {
+		/*
+		 * commits in included packs are used as starting points for the
+		 * subsequent revision walk
+		 */
+		add_pending_oid(revs, NULL, oid, 0);
+	}
+
+	stdin_packs_found_nr++;
+
+	create_object_entry(oid, type, 0, 0, 0, p, ofs);
+
+	return 0;
+}
+
+static void show_commit_pack_hint(struct commit *commit, void *_data)
+{
+	/* nothing to do; commits don't have a namehash */
+}
+
+static void show_object_pack_hint(struct object *object, const char *name,
+				  void *_data)
+{
+	struct object_entry *oe = packlist_find(&to_pack, &object->oid);
+	if (!oe)
+		return;
+
+	/*
+	 * Our 'to_pack' list was constructed by iterating all objects packed in
+	 * included packs, and so doesn't have a non-zero hash field that you
+	 * would typically pick up during a reachability traversal.
+	 *
+	 * Make a best-effort attempt to fill in the ->hash and ->no_try_delta
+	 * here using a now in order to perhaps improve the delta selection
+	 * process.
+	 */
+	oe->hash = pack_name_hash(name);
+	oe->no_try_delta = name && no_try_delta(name);
+
+	stdin_packs_hints_nr++;
+}
+
+static int pack_mtime_cmp(const void *_a, const void *_b)
+{
+	struct packed_git *a = ((const struct string_list_item*)_a)->util;
+	struct packed_git *b = ((const struct string_list_item*)_b)->util;
+
+	/*
+	 * order packs by descending mtime so that objects are laid out
+	 * roughly as newest-to-oldest
+	 */
+	if (a->mtime < b->mtime)
+		return 1;
+	else if (b->mtime < a->mtime)
+		return -1;
+	else
+		return 0;
+}
+
+static void read_packs_list_from_stdin(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list include_packs = STRING_LIST_INIT_DUP;
+	struct string_list exclude_packs = STRING_LIST_INIT_DUP;
+	struct string_list_item *item = NULL;
+
+	struct packed_git *p;
+	struct rev_info revs;
+
+	repo_init_revisions(the_repository, &revs, NULL);
+	/*
+	 * Use a revision walk to fill in the namehash of objects in the include
+	 * packs. To save time, we'll avoid traversing through objects that are
+	 * in excluded packs.
+	 *
+	 * That may cause us to avoid populating all of the namehash fields of
+	 * all included objects, but our goal is best-effort, since this is only
+	 * an optimization during delta selection.
+	 */
+	revs.no_kept_objects = 1;
+	revs.keep_pack_cache_flags |= IN_CORE_KEEP_PACKS;
+	revs.blob_objects = 1;
+	revs.tree_objects = 1;
+	revs.tag_objects = 1;
+	revs.ignore_missing_links = 1;
+
+	while (strbuf_getline(&buf, stdin) != EOF) {
+		if (!buf.len)
+			continue;
+
+		if (*buf.buf == '^')
+			string_list_append(&exclude_packs, buf.buf + 1);
+		else
+			string_list_append(&include_packs, buf.buf);
+
+		strbuf_reset(&buf);
+	}
+
+	string_list_sort(&include_packs);
+	string_list_sort(&exclude_packs);
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		const char *pack_name = pack_basename(p);
+
+		item = string_list_lookup(&include_packs, pack_name);
+		if (!item)
+			item = string_list_lookup(&exclude_packs, pack_name);
+
+		if (item)
+			item->util = p;
+	}
+
+	/*
+	 * Arguments we got on stdin may not even be packs. First
+	 * check that to avoid segfaulting later on in
+	 * e.g. pack_mtime_cmp(), excluded packs are handled below.
+	 *
+	 * Since we first parsed our STDIN and then sorted the input
+	 * lines the pack we error on will be whatever line happens to
+	 * sort first. This is lazy, it's enough that we report one
+	 * bad case here, we don't need to report the first/last one,
+	 * or all of them.
+	 */
+	for_each_string_list_item(item, &include_packs) {
+		struct packed_git *p = item->util;
+		if (!p)
+			die(_("could not find pack '%s'"), item->string);
+	}
+
+	/*
+	 * Then, handle all of the excluded packs, marking them as
+	 * kept in-core so that later calls to add_object_entry()
+	 * discards any objects that are also found in excluded packs.
+	 */
+	for_each_string_list_item(item, &exclude_packs) {
+		struct packed_git *p = item->util;
+		if (!p)
+			die(_("could not find pack '%s'"), item->string);
+		p->pack_keep_in_core = 1;
+	}
+
+	/*
+	 * Order packs by ascending mtime; use QSORT directly to access the
+	 * string_list_item's ->util pointer, which string_list_sort() does not
+	 * provide.
+	 */
+	QSORT(include_packs.items, include_packs.nr, pack_mtime_cmp);
+
+	for_each_string_list_item(item, &include_packs) {
+		struct packed_git *p = item->util;
+		if (!p)
+			die(_("could not find pack '%s'"), item->string);
+		for_each_object_in_pack(p,
+					add_object_entry_from_pack,
+					&revs,
+					FOR_EACH_OBJECT_PACK_ORDER);
+	}
+
+	if (prepare_revision_walk(&revs))
+		die(_("revision walk setup failed"));
+	traverse_commit_list(&revs,
+			     show_commit_pack_hint,
+			     show_object_pack_hint,
+			     NULL);
+
+	trace2_data_intmax("pack-objects", the_repository, "stdin_packs_found",
+			   stdin_packs_found_nr);
+	trace2_data_intmax("pack-objects", the_repository, "stdin_packs_hints",
+			   stdin_packs_hints_nr);
+
+	strbuf_release(&buf);
+	string_list_clear(&include_packs, 0);
+	string_list_clear(&exclude_packs, 0);
+}
+
 static void read_object_list_from_stdin(void)
 {
 	char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
@@ -3011,13 +3418,9 @@ static void read_object_list_from_stdin(void)
 	}
 }
 
-/* Remember to update object flag allocation in object.h */
-#define OBJECT_ADDED (1u<<20)
-
 static void show_commit(struct commit *commit, void *data)
 {
 	add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
-	commit->object.flags |= OBJECT_ADDED;
 
 	if (write_bitmap_index)
 		index_commit_for_bitmap(commit);
@@ -3030,7 +3433,6 @@ static void show_object(struct object *obj, const char *name, void *data)
 {
 	add_preferred_base_object(name);
 	add_object_entry(&obj->oid, obj->type, name, 0);
-	obj->flags |= OBJECT_ADDED;
 
 	if (use_delta_islands) {
 		const char *p;
@@ -3111,79 +3513,23 @@ static void show_edge(struct commit *commit)
 	add_preferred_base(&commit->object.oid);
 }
 
-struct in_pack_object {
-	off_t offset;
-	struct object *object;
-};
-
-struct in_pack {
-	unsigned int alloc;
-	unsigned int nr;
-	struct in_pack_object *array;
-};
-
-static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
+static int add_object_in_unpacked_pack(const struct object_id *oid,
+				       struct packed_git *pack,
+				       uint32_t pos,
+				       void *_data)
 {
-	in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
-	in_pack->array[in_pack->nr].object = object;
-	in_pack->nr++;
-}
-
-/*
- * Compare the objects in the offset order, in order to emulate the
- * "git rev-list --objects" output that produced the pack originally.
- */
-static int ofscmp(const void *a_, const void *b_)
-{
-	struct in_pack_object *a = (struct in_pack_object *)a_;
-	struct in_pack_object *b = (struct in_pack_object *)b_;
-
-	if (a->offset < b->offset)
-		return -1;
-	else if (a->offset > b->offset)
-		return 1;
-	else
-		return oidcmp(&a->object->oid, &b->object->oid);
+	add_object_entry(oid, OBJ_NONE, "", 0);
+	return 0;
 }
 
 static void add_objects_in_unpacked_packs(void)
 {
-	struct packed_git *p;
-	struct in_pack in_pack;
-	uint32_t i;
-
-	memset(&in_pack, 0, sizeof(in_pack));
-
-	for (p = get_all_packs(the_repository); p; p = p->next) {
-		struct object_id oid;
-		struct object *o;
-
-		if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
-			continue;
-		if (open_pack_index(p))
-			die(_("cannot open pack index"));
-
-		ALLOC_GROW(in_pack.array,
-			   in_pack.nr + p->num_objects,
-			   in_pack.alloc);
-
-		for (i = 0; i < p->num_objects; i++) {
-			nth_packed_object_id(&oid, p, i);
-			o = lookup_unknown_object(&oid);
-			if (!(o->flags & OBJECT_ADDED))
-				mark_in_pack_object(o, p, &in_pack);
-			o->flags |= OBJECT_ADDED;
-		}
-	}
-
-	if (in_pack.nr) {
-		QSORT(in_pack.array, in_pack.nr, ofscmp);
-		for (i = 0; i < in_pack.nr; i++) {
-			struct object *o = in_pack.array[i].object;
-			add_object_entry(&o->oid, o->type, "", 0);
-		}
-	}
-	free(in_pack.array);
+	if (for_each_packed_object(add_object_in_unpacked_pack, NULL,
+				   FOR_EACH_OBJECT_PACK_ORDER |
+				   FOR_EACH_OBJECT_LOCAL_ONLY |
+				   FOR_EACH_OBJECT_SKIP_IN_CORE_KEPT_PACKS |
+				   FOR_EACH_OBJECT_SKIP_ON_DISK_KEPT_PACKS))
+		die(_("cannot open pack index"));
 }
 
 static int add_loose_object(const struct object_id *oid, const char *path,
@@ -3262,6 +3608,7 @@ static void loosen_unused_packed_objects(void)
 {
 	struct packed_git *p;
 	uint32_t i;
+	uint32_t loosened_objects_nr = 0;
 	struct object_id oid;
 
 	for (p = get_all_packs(the_repository); p; p = p->next) {
@@ -3275,11 +3622,16 @@ static void loosen_unused_packed_objects(void)
 			nth_packed_object_id(&oid, p, i);
 			if (!packlist_find(&to_pack, &oid) &&
 			    !has_sha1_pack_kept_or_nonlocal(&oid) &&
-			    !loosened_object_can_be_discarded(&oid, p->mtime))
+			    !loosened_object_can_be_discarded(&oid, p->mtime)) {
 				if (force_object_loose(&oid, p->mtime))
 					die(_("unable to force loose object"));
+				loosened_objects_nr++;
+			}
 		}
 	}
+
+	trace2_data_intmax("pack-objects", the_repository,
+			   "loosen_unused_packed_objects/loosened", loosened_objects_nr);
 }
 
 /*
@@ -3299,7 +3651,7 @@ static int pack_options_allow_reuse(void)
 
 static int get_object_list_from_bitmap(struct rev_info *revs)
 {
-	if (!(bitmap_git = prepare_bitmap_walk(revs, &filter_options)))
+	if (!(bitmap_git = prepare_bitmap_walk(revs, &filter_options, 0)))
 		return -1;
 
 	if (pack_options_allow_reuse() &&
@@ -3310,7 +3662,8 @@ static int get_object_list_from_bitmap(struct rev_info *revs)
 			&reuse_packfile_bitmap)) {
 		assert(reuse_packfile_objects);
 		nr_result += reuse_packfile_objects;
-		display_progress(progress_state, nr_result);
+		nr_seen += reuse_packfile_objects;
+		display_progress(progress_state, nr_seen);
 	}
 
 	traverse_bitmap_commit_list(bitmap_git, revs,
@@ -3330,6 +3683,37 @@ static void record_recent_commit(struct commit *commit, void *data)
 	oid_array_append(&recent_objects, &commit->object.oid);
 }
 
+static int mark_bitmap_preferred_tip(const char *refname,
+				     const struct object_id *oid, int flags,
+				     void *_data)
+{
+	struct object_id peeled;
+	struct object *object;
+
+	if (!peel_iterated_oid(oid, &peeled))
+		oid = &peeled;
+
+	object = parse_object_or_die(oid, refname);
+	if (object->type == OBJ_COMMIT)
+		object->flags |= NEEDS_BITMAP;
+
+	return 0;
+}
+
+static void mark_bitmap_preferred_tips(void)
+{
+	struct string_list_item *item;
+	const struct string_list *preferred_tips;
+
+	preferred_tips = bitmap_preferred_tips(the_repository);
+	if (!preferred_tips)
+		return;
+
+	for_each_string_list_item(item, preferred_tips) {
+		for_each_ref_in(item->string, mark_bitmap_preferred_tip, NULL);
+	}
+}
+
 static void get_object_list(int ac, const char **av)
 {
 	struct rev_info revs;
@@ -3384,6 +3768,9 @@ static void get_object_list(int ac, const char **av)
 	if (use_delta_islands)
 		load_delta_islands(the_repository, progress);
 
+	if (write_bitmap_index)
+		mark_bitmap_preferred_tips();
+
 	if (prepare_revision_walk(&revs))
 		die(_("revision walk setup failed"));
 	mark_edges_uninteresting(&revs, show_edge, sparse);
@@ -3482,6 +3869,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	struct strvec rp = STRVEC_INIT;
 	int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
 	int rev_list_index = 0;
+	int stdin_packs = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
 	struct option pack_objects_options[] = {
 		OPT_SET_INT('q', "quiet", &progress,
@@ -3532,6 +3920,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
 			      N_("include objects referred to by the index"),
 			      1, PARSE_OPT_NONEG),
+		OPT_BOOL(0, "stdin-packs", &stdin_packs,
+			 N_("read packs from stdin")),
 		OPT_BOOL(0, "stdout", &pack_to_stdout,
 			 N_("output pack to stdout")),
 		OPT_BOOL(0, "include-tag", &include_tag,
@@ -3592,6 +3982,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 
 	reset_pack_idx_option(&pack_idx_opts);
 	git_config(git_pack_config, NULL);
+	if (git_env_bool(GIT_TEST_WRITE_REV_INDEX, 0))
+		pack_idx_opts.flags |= WRITE_REV;
 
 	progress = isatty(2);
 	argc = parse_options(argc, argv, prefix, pack_objects_options,
@@ -3604,6 +3996,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (pack_to_stdout != !base_name || argc)
 		usage_with_options(pack_usage, pack_objects_options);
 
+	if (depth < 0)
+		depth = 0;
 	if (depth >= (1 << OE_DEPTH_BITS)) {
 		warning(_("delta chain depth %d is too deep, forcing %d"),
 			depth, (1 << OE_DEPTH_BITS) - 1);
@@ -3614,6 +4008,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			(1U << OE_Z_DELTA_BITS) - 1);
 		cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
 	}
+	if (window < 0)
+		window = 0;
 
 	strvec_push(&rp, "pack-objects");
 	if (thin) {
@@ -3636,7 +4032,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		use_internal_rev_list = 1;
 		strvec_push(&rp, "--indexed-objects");
 	}
-	if (rev_list_unpacked) {
+	if (rev_list_unpacked && !stdin_packs) {
 		use_internal_rev_list = 1;
 		strvec_push(&rp, "--unpacked");
 	}
@@ -3681,8 +4077,13 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (filter_options.choice) {
 		if (!pack_to_stdout)
 			die(_("cannot use --filter without --stdout"));
+		if (stdin_packs)
+			die(_("cannot use --filter with --stdin-packs"));
 	}
 
+	if (stdin_packs && use_internal_rev_list)
+		die(_("cannot use internal rev list with --stdin-packs"));
+
 	/*
 	 * "soft" reasons not to use bitmaps - for on-disk repack by default we want
 	 *
@@ -3741,7 +4142,13 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 
 	if (progress)
 		progress_state = start_progress(_("Enumerating objects"), 0);
-	if (!use_internal_rev_list)
+	if (stdin_packs) {
+		/* avoids adding objects in excluded packs */
+		ignore_packed_keep_in_core = 1;
+		read_packs_list_from_stdin();
+		if (rev_list_unpacked)
+			add_unreachable_loose_objects();
+	} else if (!use_internal_rev_list)
 		read_object_list_from_stdin();
 	else {
 		get_object_list(rp.nr, rp.v);