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-rw-r--r--third_party/git/builtin/pack-objects.c3663
1 files changed, 3663 insertions, 0 deletions
diff --git a/third_party/git/builtin/pack-objects.c b/third_party/git/builtin/pack-objects.c
new file mode 100644
index 000000000000..02aa6ee4808a
--- /dev/null
+++ b/third_party/git/builtin/pack-objects.c
@@ -0,0 +1,3663 @@
+#include "builtin.h"
+#include "cache.h"
+#include "repository.h"
+#include "config.h"
+#include "attr.h"
+#include "object.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree.h"
+#include "delta.h"
+#include "pack.h"
+#include "pack-revindex.h"
+#include "csum-file.h"
+#include "tree-walk.h"
+#include "diff.h"
+#include "revision.h"
+#include "list-objects.h"
+#include "list-objects-filter.h"
+#include "list-objects-filter-options.h"
+#include "pack-objects.h"
+#include "progress.h"
+#include "refs.h"
+#include "streaming.h"
+#include "thread-utils.h"
+#include "pack-bitmap.h"
+#include "delta-islands.h"
+#include "reachable.h"
+#include "sha1-array.h"
+#include "argv-array.h"
+#include "list.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "dir.h"
+#include "midx.h"
+#include "trace2.h"
+
+#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)
+#define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
+#define DELTA(obj) oe_delta(&to_pack, obj)
+#define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
+#define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
+#define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
+#define SET_DELTA_EXT(obj, oid) oe_set_delta_ext(&to_pack, obj, oid)
+#define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
+#define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
+#define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
+
+static const char *pack_usage[] = {
+	N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
+	N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
+	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;
+static uint32_t write_layer;
+
+static int non_empty;
+static int reuse_delta = 1, reuse_object = 1;
+static int keep_unreachable, unpack_unreachable, include_tag;
+static timestamp_t unpack_unreachable_expiration;
+static int pack_loose_unreachable;
+static int local;
+static int have_non_local_packs;
+static int incremental;
+static int ignore_packed_keep_on_disk;
+static int ignore_packed_keep_in_core;
+static int allow_ofs_delta;
+static struct pack_idx_option pack_idx_opts;
+static const char *base_name;
+static int progress = 1;
+static int window = 10;
+static unsigned long pack_size_limit;
+static int depth = 50;
+static int delta_search_threads;
+static int pack_to_stdout;
+static int sparse;
+static int thin;
+static int num_preferred_base;
+static struct progress *progress_state;
+
+static struct packed_git *reuse_packfile;
+static uint32_t reuse_packfile_objects;
+static struct bitmap *reuse_packfile_bitmap;
+
+static int use_bitmap_index_default = 1;
+static int use_bitmap_index = -1;
+static int allow_pack_reuse = 1;
+static enum {
+	WRITE_BITMAP_FALSE = 0,
+	WRITE_BITMAP_QUIET,
+	WRITE_BITMAP_TRUE,
+} write_bitmap_index;
+static uint16_t write_bitmap_options = BITMAP_OPT_HASH_CACHE;
+
+static int exclude_promisor_objects;
+
+static int use_delta_islands;
+
+static unsigned long delta_cache_size = 0;
+static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
+static unsigned long cache_max_small_delta_size = 1000;
+
+static unsigned long window_memory_limit = 0;
+
+static struct list_objects_filter_options filter_options;
+
+enum missing_action {
+	MA_ERROR = 0,      /* fail if any missing objects are encountered */
+	MA_ALLOW_ANY,      /* silently allow ALL missing objects */
+	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
+};
+static enum missing_action arg_missing_action;
+static show_object_fn fn_show_object;
+
+/*
+ * stats
+ */
+static uint32_t written, written_delta;
+static uint32_t reused, reused_delta;
+
+/*
+ * Indexed commits
+ */
+static struct commit **indexed_commits;
+static unsigned int indexed_commits_nr;
+static unsigned int indexed_commits_alloc;
+
+static void index_commit_for_bitmap(struct commit *commit)
+{
+	if (indexed_commits_nr >= indexed_commits_alloc) {
+		indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
+		REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
+	}
+
+	indexed_commits[indexed_commits_nr++] = commit;
+}
+
+static void *get_delta(struct object_entry *entry)
+{
+	unsigned long size, base_size, delta_size;
+	void *buf, *base_buf, *delta_buf;
+	enum object_type type;
+
+	buf = read_object_file(&entry->idx.oid, &type, &size);
+	if (!buf)
+		die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
+	base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
+				    &base_size);
+	if (!base_buf)
+		die("unable to read %s",
+		    oid_to_hex(&DELTA(entry)->idx.oid));
+	delta_buf = diff_delta(base_buf, base_size,
+			       buf, size, &delta_size, 0);
+	/*
+	 * We successfully computed this delta once but dropped it for
+	 * memory reasons. Something is very wrong if this time we
+	 * recompute and create a different delta.
+	 */
+	if (!delta_buf || delta_size != DELTA_SIZE(entry))
+		BUG("delta size changed");
+	free(buf);
+	free(base_buf);
+	return delta_buf;
+}
+
+static unsigned long do_compress(void **pptr, unsigned long size)
+{
+	git_zstream stream;
+	void *in, *out;
+	unsigned long maxsize;
+
+	git_deflate_init(&stream, pack_compression_level);
+	maxsize = git_deflate_bound(&stream, size);
+
+	in = *pptr;
+	out = xmalloc(maxsize);
+	*pptr = out;
+
+	stream.next_in = in;
+	stream.avail_in = size;
+	stream.next_out = out;
+	stream.avail_out = maxsize;
+	while (git_deflate(&stream, Z_FINISH) == Z_OK)
+		; /* nothing */
+	git_deflate_end(&stream);
+
+	free(in);
+	return stream.total_out;
+}
+
+static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
+					   const struct object_id *oid)
+{
+	git_zstream stream;
+	unsigned char ibuf[1024 * 16];
+	unsigned char obuf[1024 * 16];
+	unsigned long olen = 0;
+
+	git_deflate_init(&stream, pack_compression_level);
+
+	for (;;) {
+		ssize_t readlen;
+		int zret = Z_OK;
+		readlen = read_istream(st, ibuf, sizeof(ibuf));
+		if (readlen == -1)
+			die(_("unable to read %s"), oid_to_hex(oid));
+
+		stream.next_in = ibuf;
+		stream.avail_in = readlen;
+		while ((stream.avail_in || readlen == 0) &&
+		       (zret == Z_OK || zret == Z_BUF_ERROR)) {
+			stream.next_out = obuf;
+			stream.avail_out = sizeof(obuf);
+			zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
+			hashwrite(f, obuf, stream.next_out - obuf);
+			olen += stream.next_out - obuf;
+		}
+		if (stream.avail_in)
+			die(_("deflate error (%d)"), zret);
+		if (readlen == 0) {
+			if (zret != Z_STREAM_END)
+				die(_("deflate error (%d)"), zret);
+			break;
+		}
+	}
+	git_deflate_end(&stream);
+	return olen;
+}
+
+/*
+ * we are going to reuse the existing object data as is.  make
+ * sure it is not corrupt.
+ */
+static int check_pack_inflate(struct packed_git *p,
+		struct pack_window **w_curs,
+		off_t offset,
+		off_t len,
+		unsigned long expect)
+{
+	git_zstream stream;
+	unsigned char fakebuf[4096], *in;
+	int st;
+
+	memset(&stream, 0, sizeof(stream));
+	git_inflate_init(&stream);
+	do {
+		in = use_pack(p, w_curs, offset, &stream.avail_in);
+		stream.next_in = in;
+		stream.next_out = fakebuf;
+		stream.avail_out = sizeof(fakebuf);
+		st = git_inflate(&stream, Z_FINISH);
+		offset += stream.next_in - in;
+	} while (st == Z_OK || st == Z_BUF_ERROR);
+	git_inflate_end(&stream);
+	return (st == Z_STREAM_END &&
+		stream.total_out == expect &&
+		stream.total_in == len) ? 0 : -1;
+}
+
+static void copy_pack_data(struct hashfile *f,
+		struct packed_git *p,
+		struct pack_window **w_curs,
+		off_t offset,
+		off_t len)
+{
+	unsigned char *in;
+	unsigned long avail;
+
+	while (len) {
+		in = use_pack(p, w_curs, offset, &avail);
+		if (avail > len)
+			avail = (unsigned long)len;
+		hashwrite(f, in, avail);
+		offset += avail;
+		len -= avail;
+	}
+}
+
+/* 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)
+{
+	unsigned long size, datalen;
+	unsigned char header[MAX_PACK_OBJECT_HEADER],
+		      dheader[MAX_PACK_OBJECT_HEADER];
+	unsigned hdrlen;
+	enum object_type type;
+	void *buf;
+	struct git_istream *st = NULL;
+	const unsigned hashsz = the_hash_algo->rawsz;
+
+	if (!usable_delta) {
+		if (oe_type(entry) == OBJ_BLOB &&
+		    oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
+		    (st = open_istream(the_repository, &entry->idx.oid, &type,
+				       &size, NULL)) != NULL)
+			buf = NULL;
+		else {
+			buf = read_object_file(&entry->idx.oid, &type, &size);
+			if (!buf)
+				die(_("unable to read %s"),
+				    oid_to_hex(&entry->idx.oid));
+		}
+		/*
+		 * make sure no cached delta data remains from a
+		 * previous attempt before a pack split occurred.
+		 */
+		FREE_AND_NULL(entry->delta_data);
+		entry->z_delta_size = 0;
+	} else if (entry->delta_data) {
+		size = DELTA_SIZE(entry);
+		buf = entry->delta_data;
+		entry->delta_data = NULL;
+		type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
+			OBJ_OFS_DELTA : OBJ_REF_DELTA;
+	} else {
+		buf = get_delta(entry);
+		size = DELTA_SIZE(entry);
+		type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
+			OBJ_OFS_DELTA : OBJ_REF_DELTA;
+	}
+
+	if (st)	/* large blob case, just assume we don't compress well */
+		datalen = size;
+	else if (entry->z_delta_size)
+		datalen = entry->z_delta_size;
+	else
+		datalen = do_compress(&buf, size);
+
+	/*
+	 * The object header is a byte of 'type' followed by zero or
+	 * more bytes of length.
+	 */
+	hdrlen = encode_in_pack_object_header(header, sizeof(header),
+					      type, size);
+
+	if (type == OBJ_OFS_DELTA) {
+		/*
+		 * Deltas with relative base contain an additional
+		 * encoding of the relative offset for the delta
+		 * base from this object's position in the pack.
+		 */
+		off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
+		unsigned pos = sizeof(dheader) - 1;
+		dheader[pos] = ofs & 127;
+		while (ofs >>= 7)
+			dheader[--pos] = 128 | (--ofs & 127);
+		if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
+			if (st)
+				close_istream(st);
+			free(buf);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, dheader + pos, sizeof(dheader) - pos);
+		hdrlen += sizeof(dheader) - pos;
+	} else if (type == OBJ_REF_DELTA) {
+		/*
+		 * Deltas with a base reference contain
+		 * additional bytes for the base object ID.
+		 */
+		if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
+			if (st)
+				close_istream(st);
+			free(buf);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
+		hdrlen += hashsz;
+	} else {
+		if (limit && hdrlen + datalen + hashsz >= limit) {
+			if (st)
+				close_istream(st);
+			free(buf);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+	}
+	if (st) {
+		datalen = write_large_blob_data(st, f, &entry->idx.oid);
+		close_istream(st);
+	} else {
+		hashwrite(f, buf, datalen);
+		free(buf);
+	}
+
+	return hdrlen + datalen;
+}
+
+/* Return 0 if we will bust the pack-size limit */
+static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
+				unsigned long limit, int usable_delta)
+{
+	struct packed_git *p = IN_PACK(entry);
+	struct pack_window *w_curs = NULL;
+	struct revindex_entry *revidx;
+	off_t offset;
+	enum object_type type = oe_type(entry);
+	off_t datalen;
+	unsigned char header[MAX_PACK_OBJECT_HEADER],
+		      dheader[MAX_PACK_OBJECT_HEADER];
+	unsigned hdrlen;
+	const unsigned hashsz = the_hash_algo->rawsz;
+	unsigned long entry_size = SIZE(entry);
+
+	if (DELTA(entry))
+		type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
+			OBJ_OFS_DELTA : OBJ_REF_DELTA;
+	hdrlen = encode_in_pack_object_header(header, sizeof(header),
+					      type, entry_size);
+
+	offset = entry->in_pack_offset;
+	revidx = find_pack_revindex(p, offset);
+	datalen = revidx[1].offset - offset;
+	if (!pack_to_stdout && p->index_version > 1 &&
+	    check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
+		error(_("bad packed object CRC for %s"),
+		      oid_to_hex(&entry->idx.oid));
+		unuse_pack(&w_curs);
+		return write_no_reuse_object(f, entry, limit, usable_delta);
+	}
+
+	offset += entry->in_pack_header_size;
+	datalen -= entry->in_pack_header_size;
+
+	if (!pack_to_stdout && p->index_version == 1 &&
+	    check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
+		error(_("corrupt packed object for %s"),
+		      oid_to_hex(&entry->idx.oid));
+		unuse_pack(&w_curs);
+		return write_no_reuse_object(f, entry, limit, usable_delta);
+	}
+
+	if (type == OBJ_OFS_DELTA) {
+		off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
+		unsigned pos = sizeof(dheader) - 1;
+		dheader[pos] = ofs & 127;
+		while (ofs >>= 7)
+			dheader[--pos] = 128 | (--ofs & 127);
+		if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
+			unuse_pack(&w_curs);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, dheader + pos, sizeof(dheader) - pos);
+		hdrlen += sizeof(dheader) - pos;
+		reused_delta++;
+	} else if (type == OBJ_REF_DELTA) {
+		if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
+			unuse_pack(&w_curs);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
+		hdrlen += hashsz;
+		reused_delta++;
+	} else {
+		if (limit && hdrlen + datalen + hashsz >= limit) {
+			unuse_pack(&w_curs);
+			return 0;
+		}
+		hashwrite(f, header, hdrlen);
+	}
+	copy_pack_data(f, p, &w_curs, offset, datalen);
+	unuse_pack(&w_curs);
+	reused++;
+	return hdrlen + datalen;
+}
+
+/* Return 0 if we will bust the pack-size limit */
+static off_t write_object(struct hashfile *f,
+			  struct object_entry *entry,
+			  off_t write_offset)
+{
+	unsigned long limit;
+	off_t len;
+	int usable_delta, to_reuse;
+
+	if (!pack_to_stdout)
+		crc32_begin(f);
+
+	/* apply size limit if limited packsize and not first object */
+	if (!pack_size_limit || !nr_written)
+		limit = 0;
+	else if (pack_size_limit <= write_offset)
+		/*
+		 * the earlier object did not fit the limit; avoid
+		 * mistaking this with unlimited (i.e. limit = 0).
+		 */
+		limit = 1;
+	else
+		limit = pack_size_limit - write_offset;
+
+	if (!DELTA(entry))
+		usable_delta = 0;	/* no delta */
+	else if (!pack_size_limit)
+	       usable_delta = 1;	/* unlimited packfile */
+	else if (DELTA(entry)->idx.offset == (off_t)-1)
+		usable_delta = 0;	/* base was written to another pack */
+	else if (DELTA(entry)->idx.offset)
+		usable_delta = 1;	/* base already exists in this pack */
+	else
+		usable_delta = 0;	/* base could end up in another pack */
+
+	if (!reuse_object)
+		to_reuse = 0;	/* explicit */
+	else if (!IN_PACK(entry))
+		to_reuse = 0;	/* can't reuse what we don't have */
+	else if (oe_type(entry) == OBJ_REF_DELTA ||
+		 oe_type(entry) == OBJ_OFS_DELTA)
+				/* check_object() decided it for us ... */
+		to_reuse = usable_delta;
+				/* ... but pack split may override that */
+	else if (oe_type(entry) != entry->in_pack_type)
+		to_reuse = 0;	/* pack has delta which is unusable */
+	else if (DELTA(entry))
+		to_reuse = 0;	/* we want to pack afresh */
+	else
+		to_reuse = 1;	/* we have it in-pack undeltified,
+				 * and we do not need to deltify it.
+				 */
+
+	if (!to_reuse)
+		len = write_no_reuse_object(f, entry, limit, usable_delta);
+	else
+		len = write_reuse_object(f, entry, limit, usable_delta);
+	if (!len)
+		return 0;
+
+	if (usable_delta)
+		written_delta++;
+	written++;
+	if (!pack_to_stdout)
+		entry->idx.crc32 = crc32_end(f);
+	return len;
+}
+
+enum write_one_status {
+	WRITE_ONE_SKIP = -1, /* already written */
+	WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
+	WRITE_ONE_WRITTEN = 1, /* normal */
+	WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
+};
+
+static enum write_one_status write_one(struct hashfile *f,
+				       struct object_entry *e,
+				       off_t *offset)
+{
+	off_t size;
+	int recursing;
+
+	/*
+	 * we set offset to 1 (which is an impossible value) to mark
+	 * the fact that this object is involved in "write its base
+	 * first before writing a deltified object" recursion.
+	 */
+	recursing = (e->idx.offset == 1);
+	if (recursing) {
+		warning(_("recursive delta detected for object %s"),
+			oid_to_hex(&e->idx.oid));
+		return WRITE_ONE_RECURSIVE;
+	} else if (e->idx.offset || e->preferred_base) {
+		/* offset is non zero if object is written already. */
+		return WRITE_ONE_SKIP;
+	}
+
+	/* if we are deltified, write out base object first. */
+	if (DELTA(e)) {
+		e->idx.offset = 1; /* now recurse */
+		switch (write_one(f, DELTA(e), offset)) {
+		case WRITE_ONE_RECURSIVE:
+			/* we cannot depend on this one */
+			SET_DELTA(e, NULL);
+			break;
+		default:
+			break;
+		case WRITE_ONE_BREAK:
+			e->idx.offset = recursing;
+			return WRITE_ONE_BREAK;
+		}
+	}
+
+	e->idx.offset = *offset;
+	size = write_object(f, e, *offset);
+	if (!size) {
+		e->idx.offset = recursing;
+		return WRITE_ONE_BREAK;
+	}
+	written_list[nr_written++] = &e->idx;
+
+	/* make sure off_t is sufficiently large not to wrap */
+	if (signed_add_overflows(*offset, size))
+		die(_("pack too large for current definition of off_t"));
+	*offset += size;
+	return WRITE_ONE_WRITTEN;
+}
+
+static int mark_tagged(const char *path, const struct object_id *oid, int flag,
+		       void *cb_data)
+{
+	struct object_id peeled;
+	struct object_entry *entry = packlist_find(&to_pack, oid);
+
+	if (entry)
+		entry->tagged = 1;
+	if (!peel_ref(path, &peeled)) {
+		entry = packlist_find(&to_pack, &peeled);
+		if (entry)
+			entry->tagged = 1;
+	}
+	return 0;
+}
+
+static inline void add_to_write_order(struct object_entry **wo,
+			       unsigned int *endp,
+			       struct object_entry *e)
+{
+	if (e->filled || oe_layer(&to_pack, e) != write_layer)
+		return;
+	wo[(*endp)++] = e;
+	e->filled = 1;
+}
+
+static void add_descendants_to_write_order(struct object_entry **wo,
+					   unsigned int *endp,
+					   struct object_entry *e)
+{
+	int add_to_order = 1;
+	while (e) {
+		if (add_to_order) {
+			struct object_entry *s;
+			/* add this node... */
+			add_to_write_order(wo, endp, e);
+			/* all its siblings... */
+			for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
+				add_to_write_order(wo, endp, s);
+			}
+		}
+		/* drop down a level to add left subtree nodes if possible */
+		if (DELTA_CHILD(e)) {
+			add_to_order = 1;
+			e = DELTA_CHILD(e);
+		} else {
+			add_to_order = 0;
+			/* our sibling might have some children, it is next */
+			if (DELTA_SIBLING(e)) {
+				e = DELTA_SIBLING(e);
+				continue;
+			}
+			/* go back to our parent node */
+			e = DELTA(e);
+			while (e && !DELTA_SIBLING(e)) {
+				/* we're on the right side of a subtree, keep
+				 * going up until we can go right again */
+				e = DELTA(e);
+			}
+			if (!e) {
+				/* done- we hit our original root node */
+				return;
+			}
+			/* pass it off to sibling at this level */
+			e = DELTA_SIBLING(e);
+		}
+	};
+}
+
+static void add_family_to_write_order(struct object_entry **wo,
+				      unsigned int *endp,
+				      struct object_entry *e)
+{
+	struct object_entry *root;
+
+	for (root = e; DELTA(root); root = DELTA(root))
+		; /* nothing */
+	add_descendants_to_write_order(wo, endp, root);
+}
+
+static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
+{
+	unsigned int i, last_untagged;
+	struct object_entry *objects = to_pack.objects;
+
+	for (i = 0; i < to_pack.nr_objects; i++) {
+		if (objects[i].tagged)
+			break;
+		add_to_write_order(wo, wo_end, &objects[i]);
+	}
+	last_untagged = i;
+
+	/*
+	 * Then fill all the tagged tips.
+	 */
+	for (; i < to_pack.nr_objects; i++) {
+		if (objects[i].tagged)
+			add_to_write_order(wo, wo_end, &objects[i]);
+	}
+
+	/*
+	 * And then all remaining commits and tags.
+	 */
+	for (i = last_untagged; i < to_pack.nr_objects; i++) {
+		if (oe_type(&objects[i]) != OBJ_COMMIT &&
+		    oe_type(&objects[i]) != OBJ_TAG)
+			continue;
+		add_to_write_order(wo, wo_end, &objects[i]);
+	}
+
+	/*
+	 * And then all the trees.
+	 */
+	for (i = last_untagged; i < to_pack.nr_objects; i++) {
+		if (oe_type(&objects[i]) != OBJ_TREE)
+			continue;
+		add_to_write_order(wo, wo_end, &objects[i]);
+	}
+
+	/*
+	 * Finally all the rest in really tight order
+	 */
+	for (i = last_untagged; i < to_pack.nr_objects; i++) {
+		if (!objects[i].filled && oe_layer(&to_pack, &objects[i]) == write_layer)
+			add_family_to_write_order(wo, wo_end, &objects[i]);
+	}
+}
+
+static struct object_entry **compute_write_order(void)
+{
+	uint32_t max_layers = 1;
+	unsigned int i, wo_end;
+
+	struct object_entry **wo;
+	struct object_entry *objects = to_pack.objects;
+
+	for (i = 0; i < to_pack.nr_objects; i++) {
+		objects[i].tagged = 0;
+		objects[i].filled = 0;
+		SET_DELTA_CHILD(&objects[i], NULL);
+		SET_DELTA_SIBLING(&objects[i], NULL);
+	}
+
+	/*
+	 * Fully connect delta_child/delta_sibling network.
+	 * Make sure delta_sibling is sorted in the original
+	 * recency order.
+	 */
+	for (i = to_pack.nr_objects; i > 0;) {
+		struct object_entry *e = &objects[--i];
+		if (!DELTA(e))
+			continue;
+		/* Mark me as the first child */
+		e->delta_sibling_idx = DELTA(e)->delta_child_idx;
+		SET_DELTA_CHILD(DELTA(e), e);
+	}
+
+	/*
+	 * Mark objects that are at the tip of tags.
+	 */
+	for_each_tag_ref(mark_tagged, NULL);
+
+	if (use_delta_islands)
+		max_layers = compute_pack_layers(&to_pack);
+
+	ALLOC_ARRAY(wo, to_pack.nr_objects);
+	wo_end = 0;
+
+	for (; write_layer < max_layers; ++write_layer)
+		compute_layer_order(wo, &wo_end);
+
+	if (wo_end != to_pack.nr_objects)
+		die(_("ordered %u objects, expected %"PRIu32),
+		    wo_end, to_pack.nr_objects);
+
+	return wo;
+}
+
+
+/*
+ * A reused set of objects. All objects in a chunk have the same
+ * relative position in the original packfile and the generated
+ * packfile.
+ */
+
+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". */
+	off_t difference;
+} *reused_chunks;
+static int reused_chunks_nr;
+static int reused_chunks_alloc;
+
+static void record_reused_object(off_t where, off_t offset)
+{
+	if (reused_chunks_nr && reused_chunks[reused_chunks_nr-1].difference == offset)
+		return;
+
+	ALLOC_GROW(reused_chunks, reused_chunks_nr + 1,
+		   reused_chunks_alloc);
+	reused_chunks[reused_chunks_nr].original = where;
+	reused_chunks[reused_chunks_nr].difference = offset;
+	reused_chunks_nr++;
+}
+
+/*
+ * Binary search to find the chunk that "where" is in. Note
+ * that we're not looking for an exact match, just the first
+ * chunk that contains it (which implicitly ends at the start
+ * of the next chunk.
+ */
+static off_t find_reused_offset(off_t where)
+{
+	int lo = 0, hi = reused_chunks_nr;
+	while (lo < hi) {
+		int mi = lo + ((hi - lo) / 2);
+		if (where == reused_chunks[mi].original)
+			return reused_chunks[mi].difference;
+		if (where < reused_chunks[mi].original)
+			hi = mi;
+		else
+			lo = mi + 1;
+	}
+
+	/*
+	 * The first chunk starts at zero, so we can't have gone below
+	 * there.
+	 */
+	assert(lo);
+	return reused_chunks[lo-1].difference;
+}
+
+static void write_reused_pack_one(size_t pos, struct hashfile *out,
+				  struct pack_window **w_curs)
+{
+	off_t offset, next, cur;
+	enum object_type type;
+	unsigned long size;
+
+	offset = reuse_packfile->revindex[pos].offset;
+	next = reuse_packfile->revindex[pos + 1].offset;
+
+	record_reused_object(offset, offset - hashfile_total(out));
+
+	cur = offset;
+	type = unpack_object_header(reuse_packfile, w_curs, &cur, &size);
+	assert(type >= 0);
+
+	if (type == OBJ_OFS_DELTA) {
+		off_t base_offset;
+		off_t fixup;
+
+		unsigned char header[MAX_PACK_OBJECT_HEADER];
+		unsigned len;
+
+		base_offset = get_delta_base(reuse_packfile, w_curs, &cur, type, offset);
+		assert(base_offset != 0);
+
+		/* Convert to REF_DELTA if we must... */
+		if (!allow_ofs_delta) {
+			int base_pos = find_revindex_position(reuse_packfile, base_offset);
+			struct object_id base_oid;
+
+			nth_packed_object_id(&base_oid, reuse_packfile,
+					     reuse_packfile->revindex[base_pos].nr);
+
+			len = encode_in_pack_object_header(header, sizeof(header),
+							   OBJ_REF_DELTA, size);
+			hashwrite(out, header, len);
+			hashwrite(out, base_oid.hash, 20);
+			copy_pack_data(out, reuse_packfile, w_curs, cur, next - cur);
+			return;
+		}
+
+		/* Otherwise see if we need to rewrite the offset... */
+		fixup = find_reused_offset(offset) -
+			find_reused_offset(base_offset);
+		if (fixup) {
+			unsigned char ofs_header[10];
+			unsigned i, ofs_len;
+			off_t ofs = offset - base_offset - fixup;
+
+			len = encode_in_pack_object_header(header, sizeof(header),
+							   OBJ_OFS_DELTA, size);
+
+			i = sizeof(ofs_header) - 1;
+			ofs_header[i] = ofs & 127;
+			while (ofs >>= 7)
+				ofs_header[--i] = 128 | (--ofs & 127);
+
+			ofs_len = sizeof(ofs_header) - i;
+
+			hashwrite(out, header, len);
+			hashwrite(out, ofs_header + sizeof(ofs_header) - ofs_len, ofs_len);
+			copy_pack_data(out, reuse_packfile, w_curs, cur, next - cur);
+			return;
+		}
+
+		/* ...otherwise we have no fixup, and can write it verbatim */
+	}
+
+	copy_pack_data(out, reuse_packfile, w_curs, offset, next - offset);
+}
+
+static size_t write_reused_pack_verbatim(struct hashfile *out,
+					 struct pack_window **w_curs)
+{
+	size_t pos = 0;
+
+	while (pos < reuse_packfile_bitmap->word_alloc &&
+			reuse_packfile_bitmap->words[pos] == (eword_t)~0)
+		pos++;
+
+	if (pos) {
+		off_t to_write;
+
+		written = (pos * BITS_IN_EWORD);
+		to_write = reuse_packfile->revindex[written].offset
+			- sizeof(struct pack_header);
+
+		/* We're recording one chunk, not one object. */
+		record_reused_object(sizeof(struct pack_header), 0);
+		hashflush(out);
+		copy_pack_data(out, reuse_packfile, w_curs,
+			sizeof(struct pack_header), to_write);
+
+		display_progress(progress_state, written);
+	}
+	return pos;
+}
+
+static void write_reused_pack(struct hashfile *f)
+{
+	size_t i = 0;
+	uint32_t offset;
+	struct pack_window *w_curs = NULL;
+
+	if (allow_ofs_delta)
+		i = write_reused_pack_verbatim(f, &w_curs);
+
+	for (; i < reuse_packfile_bitmap->word_alloc; ++i) {
+		eword_t word = reuse_packfile_bitmap->words[i];
+		size_t pos = (i * BITS_IN_EWORD);
+
+		for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
+			if ((word >> offset) == 0)
+				break;
+
+			offset += ewah_bit_ctz64(word >> offset);
+			write_reused_pack_one(pos + offset, f, &w_curs);
+			display_progress(progress_state, ++written);
+		}
+	}
+
+	unuse_pack(&w_curs);
+}
+
+static const char no_split_warning[] = N_(
+"disabling bitmap writing, packs are split due to pack.packSizeLimit"
+);
+
+static void write_pack_file(void)
+{
+	uint32_t i = 0, j;
+	struct hashfile *f;
+	off_t offset;
+	uint32_t nr_remaining = nr_result;
+	time_t last_mtime = 0;
+	struct object_entry **write_order;
+
+	if (progress > pack_to_stdout)
+		progress_state = start_progress(_("Writing objects"), nr_result);
+	ALLOC_ARRAY(written_list, to_pack.nr_objects);
+	write_order = compute_write_order();
+
+	do {
+		struct object_id oid;
+		char *pack_tmp_name = NULL;
+
+		if (pack_to_stdout)
+			f = hashfd_throughput(1, "<stdout>", progress_state);
+		else
+			f = create_tmp_packfile(&pack_tmp_name);
+
+		offset = write_pack_header(f, nr_remaining);
+
+		if (reuse_packfile) {
+			assert(pack_to_stdout);
+			write_reused_pack(f);
+			offset = hashfile_total(f);
+		}
+
+		nr_written = 0;
+		for (; i < to_pack.nr_objects; i++) {
+			struct object_entry *e = write_order[i];
+			if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
+				break;
+			display_progress(progress_state, written);
+		}
+
+		/*
+		 * Did we write the wrong # entries in the header?
+		 * If so, rewrite it like in fast-import
+		 */
+		if (pack_to_stdout) {
+			finalize_hashfile(f, oid.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);
+		} else {
+			int fd = finalize_hashfile(f, oid.hash, 0);
+			fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
+						 nr_written, oid.hash, offset);
+			close(fd);
+			if (write_bitmap_index) {
+				if (write_bitmap_index != WRITE_BITMAP_QUIET)
+					warning(_(no_split_warning));
+				write_bitmap_index = 0;
+			}
+		}
+
+		if (!pack_to_stdout) {
+			struct stat st;
+			struct strbuf tmpname = STRBUF_INIT;
+
+			/*
+			 * Packs are runtime accessed in their mtime
+			 * order since newer packs are more likely to contain
+			 * younger objects.  So if we are creating multiple
+			 * packs then we should modify the mtime of later ones
+			 * to preserve this property.
+			 */
+			if (stat(pack_tmp_name, &st) < 0) {
+				warning_errno(_("failed to stat %s"), pack_tmp_name);
+			} else if (!last_mtime) {
+				last_mtime = st.st_mtime;
+			} else {
+				struct utimbuf utb;
+				utb.actime = st.st_atime;
+				utb.modtime = --last_mtime;
+				if (utime(pack_tmp_name, &utb) < 0)
+					warning_errno(_("failed utime() on %s"), pack_tmp_name);
+			}
+
+			strbuf_addf(&tmpname, "%s-", base_name);
+
+			if (write_bitmap_index) {
+				bitmap_writer_set_checksum(oid.hash);
+				bitmap_writer_build_type_index(
+					&to_pack, written_list, nr_written);
+			}
+
+			finish_tmp_packfile(&tmpname, pack_tmp_name,
+					    written_list, nr_written,
+					    &pack_idx_opts, oid.hash);
+
+			if (write_bitmap_index) {
+				strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
+
+				stop_progress(&progress_state);
+
+				bitmap_writer_show_progress(progress);
+				bitmap_writer_reuse_bitmaps(&to_pack);
+				bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
+				bitmap_writer_build(&to_pack);
+				bitmap_writer_finish(written_list, nr_written,
+						     tmpname.buf, write_bitmap_options);
+				write_bitmap_index = 0;
+			}
+
+			strbuf_release(&tmpname);
+			free(pack_tmp_name);
+			puts(oid_to_hex(&oid));
+		}
+
+		/* mark written objects as written to previous pack */
+		for (j = 0; j < nr_written; j++) {
+			written_list[j]->offset = (off_t)-1;
+		}
+		nr_remaining -= nr_written;
+	} while (nr_remaining && i < to_pack.nr_objects);
+
+	free(written_list);
+	free(write_order);
+	stop_progress(&progress_state);
+	if (written != nr_result)
+		die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
+		    written, nr_result);
+	trace2_data_intmax("pack-objects", the_repository,
+			   "write_pack_file/wrote", nr_result);
+}
+
+static int no_try_delta(const char *path)
+{
+	static struct attr_check *check;
+
+	if (!check)
+		check = attr_check_initl("delta", NULL);
+	git_check_attr(the_repository->index, path, check);
+	if (ATTR_FALSE(check->items[0].value))
+		return 1;
+	return 0;
+}
+
+/*
+ * When adding an object, check whether we have already added it
+ * to our packing list. If so, we can skip. However, if we are
+ * being asked to excludei t, but the previous mention was to include
+ * it, make sure to adjust its flags and tweak our numbers accordingly.
+ *
+ * As an optimization, we pass out the index position where we would have
+ * found the item, since that saves us from having to look it up again a
+ * few lines later when we want to add the new entry.
+ */
+static int have_duplicate_entry(const struct object_id *oid,
+				int exclude)
+{
+	struct object_entry *entry;
+
+	if (reuse_packfile_bitmap &&
+	    bitmap_walk_contains(bitmap_git, reuse_packfile_bitmap, oid))
+		return 1;
+
+	entry = packlist_find(&to_pack, oid);
+	if (!entry)
+		return 0;
+
+	if (exclude) {
+		if (!entry->preferred_base)
+			nr_result--;
+		entry->preferred_base = 1;
+	}
+
+	return 1;
+}
+
+static int want_found_object(int exclude, struct packed_git *p)
+{
+	if (exclude)
+		return 1;
+	if (incremental)
+		return 0;
+
+	/*
+	 * When asked to do --local (do not include an object that appears in a
+	 * pack we borrow from elsewhere) or --honor-pack-keep (do not include
+	 * an object that appears in a pack marked with .keep), finding a pack
+	 * that matches the criteria is sufficient for us to decide to omit it.
+	 * However, even if this pack does not satisfy the criteria, we need to
+	 * 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;
+	 * 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;
+
+	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;
+}
+
+/*
+ * 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).
+ *
+ * If the caller already knows an existing pack it wants to take the object
+ * from, that is passed in *found_pack and *found_offset; otherwise this
+ * function finds if there is any pack that has the object and returns the pack
+ * and its offset in these variables.
+ */
+static int want_object_in_pack(const struct object_id *oid,
+			       int exclude,
+			       struct packed_git **found_pack,
+			       off_t *found_offset)
+{
+	int want;
+	struct list_head *pos;
+	struct multi_pack_index *m;
+
+	if (!exclude && local && has_loose_object_nonlocal(oid))
+		return 0;
+
+	/*
+	 * If we already know the pack object lives in, start checks from that
+	 * pack - in the usual case when neither --local was given nor .keep files
+	 * are present we will determine the answer right now.
+	 */
+	if (*found_pack) {
+		want = want_found_object(exclude, *found_pack);
+		if (want != -1)
+			return want;
+	}
+
+	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));
+			if (want != -1)
+				return want;
+		}
+	}
+
+	return 1;
+}
+
+static void create_object_entry(const struct object_id *oid,
+				enum object_type type,
+				uint32_t hash,
+				int exclude,
+				int no_try_delta,
+				struct packed_git *found_pack,
+				off_t found_offset)
+{
+	struct object_entry *entry;
+
+	entry = packlist_alloc(&to_pack, oid);
+	entry->hash = hash;
+	oe_set_type(entry, type);
+	if (exclude)
+		entry->preferred_base = 1;
+	else
+		nr_result++;
+	if (found_pack) {
+		oe_set_in_pack(&to_pack, entry, found_pack);
+		entry->in_pack_offset = found_offset;
+	}
+
+	entry->no_try_delta = no_try_delta;
+}
+
+static const char no_closure_warning[] = N_(
+"disabling bitmap writing, as some objects are not being packed"
+);
+
+static int add_object_entry(const struct object_id *oid, enum object_type type,
+			    const char *name, int exclude)
+{
+	struct packed_git *found_pack = NULL;
+	off_t found_offset = 0;
+
+	display_progress(progress_state, ++nr_seen);
+
+	if (have_duplicate_entry(oid, exclude))
+		return 0;
+
+	if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
+		/* The pack is missing an object, so it will not have closure */
+		if (write_bitmap_index) {
+			if (write_bitmap_index != WRITE_BITMAP_QUIET)
+				warning(_(no_closure_warning));
+			write_bitmap_index = 0;
+		}
+		return 0;
+	}
+
+	create_object_entry(oid, type, pack_name_hash(name),
+			    exclude, name && no_try_delta(name),
+			    found_pack, found_offset);
+	return 1;
+}
+
+static int add_object_entry_from_bitmap(const struct object_id *oid,
+					enum object_type type,
+					int flags, uint32_t name_hash,
+					struct packed_git *pack, off_t offset)
+{
+	display_progress(progress_state, ++nr_seen);
+
+	if (have_duplicate_entry(oid, 0))
+		return 0;
+
+	if (!want_object_in_pack(oid, 0, &pack, &offset))
+		return 0;
+
+	create_object_entry(oid, type, name_hash, 0, 0, pack, offset);
+	return 1;
+}
+
+struct pbase_tree_cache {
+	struct object_id oid;
+	int ref;
+	int temporary;
+	void *tree_data;
+	unsigned long tree_size;
+};
+
+static struct pbase_tree_cache *(pbase_tree_cache[256]);
+static int pbase_tree_cache_ix(const struct object_id *oid)
+{
+	return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
+}
+static int pbase_tree_cache_ix_incr(int ix)
+{
+	return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
+}
+
+static struct pbase_tree {
+	struct pbase_tree *next;
+	/* This is a phony "cache" entry; we are not
+	 * going to evict it or find it through _get()
+	 * mechanism -- this is for the toplevel node that
+	 * would almost always change with any commit.
+	 */
+	struct pbase_tree_cache pcache;
+} *pbase_tree;
+
+static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
+{
+	struct pbase_tree_cache *ent, *nent;
+	void *data;
+	unsigned long size;
+	enum object_type type;
+	int neigh;
+	int my_ix = pbase_tree_cache_ix(oid);
+	int available_ix = -1;
+
+	/* pbase-tree-cache acts as a limited hashtable.
+	 * your object will be found at your index or within a few
+	 * slots after that slot if it is cached.
+	 */
+	for (neigh = 0; neigh < 8; neigh++) {
+		ent = pbase_tree_cache[my_ix];
+		if (ent && oideq(&ent->oid, oid)) {
+			ent->ref++;
+			return ent;
+		}
+		else if (((available_ix < 0) && (!ent || !ent->ref)) ||
+			 ((0 <= available_ix) &&
+			  (!ent && pbase_tree_cache[available_ix])))
+			available_ix = my_ix;
+		if (!ent)
+			break;
+		my_ix = pbase_tree_cache_ix_incr(my_ix);
+	}
+
+	/* Did not find one.  Either we got a bogus request or
+	 * we need to read and perhaps cache.
+	 */
+	data = read_object_file(oid, &type, &size);
+	if (!data)
+		return NULL;
+	if (type != OBJ_TREE) {
+		free(data);
+		return NULL;
+	}
+
+	/* We need to either cache or return a throwaway copy */
+
+	if (available_ix < 0)
+		ent = NULL;
+	else {
+		ent = pbase_tree_cache[available_ix];
+		my_ix = available_ix;
+	}
+
+	if (!ent) {
+		nent = xmalloc(sizeof(*nent));
+		nent->temporary = (available_ix < 0);
+	}
+	else {
+		/* evict and reuse */
+		free(ent->tree_data);
+		nent = ent;
+	}
+	oidcpy(&nent->oid, oid);
+	nent->tree_data = data;
+	nent->tree_size = size;
+	nent->ref = 1;
+	if (!nent->temporary)
+		pbase_tree_cache[my_ix] = nent;
+	return nent;
+}
+
+static void pbase_tree_put(struct pbase_tree_cache *cache)
+{
+	if (!cache->temporary) {
+		cache->ref--;
+		return;
+	}
+	free(cache->tree_data);
+	free(cache);
+}
+
+static int name_cmp_len(const char *name)
+{
+	int i;
+	for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
+		;
+	return i;
+}
+
+static void add_pbase_object(struct tree_desc *tree,
+			     const char *name,
+			     int cmplen,
+			     const char *fullname)
+{
+	struct name_entry entry;
+	int cmp;
+
+	while (tree_entry(tree,&entry)) {
+		if (S_ISGITLINK(entry.mode))
+			continue;
+		cmp = tree_entry_len(&entry) != cmplen ? 1 :
+		      memcmp(name, entry.path, cmplen);
+		if (cmp > 0)
+			continue;
+		if (cmp < 0)
+			return;
+		if (name[cmplen] != '/') {
+			add_object_entry(&entry.oid,
+					 object_type(entry.mode),
+					 fullname, 1);
+			return;
+		}
+		if (S_ISDIR(entry.mode)) {
+			struct tree_desc sub;
+			struct pbase_tree_cache *tree;
+			const char *down = name+cmplen+1;
+			int downlen = name_cmp_len(down);
+
+			tree = pbase_tree_get(&entry.oid);
+			if (!tree)
+				return;
+			init_tree_desc(&sub, tree->tree_data, tree->tree_size);
+
+			add_pbase_object(&sub, down, downlen, fullname);
+			pbase_tree_put(tree);
+		}
+	}
+}
+
+static unsigned *done_pbase_paths;
+static int done_pbase_paths_num;
+static int done_pbase_paths_alloc;
+static int done_pbase_path_pos(unsigned hash)
+{
+	int lo = 0;
+	int hi = done_pbase_paths_num;
+	while (lo < hi) {
+		int mi = lo + (hi - lo) / 2;
+		if (done_pbase_paths[mi] == hash)
+			return mi;
+		if (done_pbase_paths[mi] < hash)
+			hi = mi;
+		else
+			lo = mi + 1;
+	}
+	return -lo-1;
+}
+
+static int check_pbase_path(unsigned hash)
+{
+	int pos = done_pbase_path_pos(hash);
+	if (0 <= pos)
+		return 1;
+	pos = -pos - 1;
+	ALLOC_GROW(done_pbase_paths,
+		   done_pbase_paths_num + 1,
+		   done_pbase_paths_alloc);
+	done_pbase_paths_num++;
+	if (pos < done_pbase_paths_num)
+		MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
+			   done_pbase_paths_num - pos - 1);
+	done_pbase_paths[pos] = hash;
+	return 0;
+}
+
+static void add_preferred_base_object(const char *name)
+{
+	struct pbase_tree *it;
+	int cmplen;
+	unsigned hash = pack_name_hash(name);
+
+	if (!num_preferred_base || check_pbase_path(hash))
+		return;
+
+	cmplen = name_cmp_len(name);
+	for (it = pbase_tree; it; it = it->next) {
+		if (cmplen == 0) {
+			add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
+		}
+		else {
+			struct tree_desc tree;
+			init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
+			add_pbase_object(&tree, name, cmplen, name);
+		}
+	}
+}
+
+static void add_preferred_base(struct object_id *oid)
+{
+	struct pbase_tree *it;
+	void *data;
+	unsigned long size;
+	struct object_id tree_oid;
+
+	if (window <= num_preferred_base++)
+		return;
+
+	data = read_object_with_reference(the_repository, oid,
+					  tree_type, &size, &tree_oid);
+	if (!data)
+		return;
+
+	for (it = pbase_tree; it; it = it->next) {
+		if (oideq(&it->pcache.oid, &tree_oid)) {
+			free(data);
+			return;
+		}
+	}
+
+	it = xcalloc(1, sizeof(*it));
+	it->next = pbase_tree;
+	pbase_tree = it;
+
+	oidcpy(&it->pcache.oid, &tree_oid);
+	it->pcache.tree_data = data;
+	it->pcache.tree_size = size;
+}
+
+static void cleanup_preferred_base(void)
+{
+	struct pbase_tree *it;
+	unsigned i;
+
+	it = pbase_tree;
+	pbase_tree = NULL;
+	while (it) {
+		struct pbase_tree *tmp = it;
+		it = tmp->next;
+		free(tmp->pcache.tree_data);
+		free(tmp);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
+		if (!pbase_tree_cache[i])
+			continue;
+		free(pbase_tree_cache[i]->tree_data);
+		FREE_AND_NULL(pbase_tree_cache[i]);
+	}
+
+	FREE_AND_NULL(done_pbase_paths);
+	done_pbase_paths_num = done_pbase_paths_alloc = 0;
+}
+
+/*
+ * Return 1 iff the object specified by "delta" can be sent
+ * literally as a delta against the base in "base_sha1". If
+ * so, then *base_out will point to the entry in our packing
+ * list, or NULL if we must use the external-base list.
+ *
+ * Depth value does not matter - find_deltas() will
+ * never consider reused delta as the base object to
+ * deltify other objects against, in order to avoid
+ * circular deltas.
+ */
+static int can_reuse_delta(const struct object_id *base_oid,
+			   struct object_entry *delta,
+			   struct object_entry **base_out)
+{
+	struct object_entry *base;
+
+	/*
+	 * First see if we're already sending the base (or it's explicitly in
+	 * our "excluded" list).
+	 */
+	base = packlist_find(&to_pack, base_oid);
+	if (base) {
+		if (!in_same_island(&delta->idx.oid, &base->idx.oid))
+			return 0;
+		*base_out = base;
+		return 1;
+	}
+
+	/*
+	 * Otherwise, reachability bitmaps may tell us if the receiver has it,
+	 * even if it was buried too deep in history to make it into the
+	 * packing list.
+	 */
+	if (thin && bitmap_has_oid_in_uninteresting(bitmap_git, base_oid)) {
+		if (use_delta_islands) {
+			if (!in_same_island(&delta->idx.oid, base_oid))
+				return 0;
+		}
+		*base_out = NULL;
+		return 1;
+	}
+
+	return 0;
+}
+
+static void check_object(struct object_entry *entry)
+{
+	unsigned long canonical_size;
+
+	if (IN_PACK(entry)) {
+		struct packed_git *p = IN_PACK(entry);
+		struct pack_window *w_curs = NULL;
+		int have_base = 0;
+		struct object_id base_ref;
+		struct object_entry *base_entry;
+		unsigned long used, used_0;
+		unsigned long avail;
+		off_t ofs;
+		unsigned char *buf, c;
+		enum object_type type;
+		unsigned long in_pack_size;
+
+		buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
+
+		/*
+		 * We want in_pack_type even if we do not reuse delta
+		 * since non-delta representations could still be reused.
+		 */
+		used = unpack_object_header_buffer(buf, avail,
+						   &type,
+						   &in_pack_size);
+		if (used == 0)
+			goto give_up;
+
+		if (type < 0)
+			BUG("invalid type %d", type);
+		entry->in_pack_type = type;
+
+		/*
+		 * Determine if this is a delta and if so whether we can
+		 * reuse it or not.  Otherwise let's find out as cheaply as
+		 * possible what the actual type and size for this object is.
+		 */
+		switch (entry->in_pack_type) {
+		default:
+			/* Not a delta hence we've already got all we need. */
+			oe_set_type(entry, entry->in_pack_type);
+			SET_SIZE(entry, in_pack_size);
+			entry->in_pack_header_size = used;
+			if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
+				goto give_up;
+			unuse_pack(&w_curs);
+			return;
+		case OBJ_REF_DELTA:
+			if (reuse_delta && !entry->preferred_base) {
+				oidread(&base_ref,
+					use_pack(p, &w_curs,
+						 entry->in_pack_offset + used,
+						 NULL));
+				have_base = 1;
+			}
+			entry->in_pack_header_size = used + the_hash_algo->rawsz;
+			break;
+		case OBJ_OFS_DELTA:
+			buf = use_pack(p, &w_curs,
+				       entry->in_pack_offset + used, NULL);
+			used_0 = 0;
+			c = buf[used_0++];
+			ofs = c & 127;
+			while (c & 128) {
+				ofs += 1;
+				if (!ofs || MSB(ofs, 7)) {
+					error(_("delta base offset overflow in pack for %s"),
+					      oid_to_hex(&entry->idx.oid));
+					goto give_up;
+				}
+				c = buf[used_0++];
+				ofs = (ofs << 7) + (c & 127);
+			}
+			ofs = entry->in_pack_offset - ofs;
+			if (ofs <= 0 || ofs >= entry->in_pack_offset) {
+				error(_("delta base offset out of bound for %s"),
+				      oid_to_hex(&entry->idx.oid));
+				goto give_up;
+			}
+			if (reuse_delta && !entry->preferred_base) {
+				struct revindex_entry *revidx;
+				revidx = find_pack_revindex(p, ofs);
+				if (!revidx)
+					goto give_up;
+				if (!nth_packed_object_id(&base_ref, p, revidx->nr))
+					have_base = 1;
+			}
+			entry->in_pack_header_size = used + used_0;
+			break;
+		}
+
+		if (have_base &&
+		    can_reuse_delta(&base_ref, entry, &base_entry)) {
+			oe_set_type(entry, entry->in_pack_type);
+			SET_SIZE(entry, in_pack_size); /* delta size */
+			SET_DELTA_SIZE(entry, in_pack_size);
+
+			if (base_entry) {
+				SET_DELTA(entry, base_entry);
+				entry->delta_sibling_idx = base_entry->delta_child_idx;
+				SET_DELTA_CHILD(base_entry, entry);
+			} else {
+				SET_DELTA_EXT(entry, &base_ref);
+			}
+
+			unuse_pack(&w_curs);
+			return;
+		}
+
+		if (oe_type(entry)) {
+			off_t delta_pos;
+
+			/*
+			 * This must be a delta and we already know what the
+			 * final object type is.  Let's extract the actual
+			 * object size from the delta header.
+			 */
+			delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
+			canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
+			if (canonical_size == 0)
+				goto give_up;
+			SET_SIZE(entry, canonical_size);
+			unuse_pack(&w_curs);
+			return;
+		}
+
+		/*
+		 * No choice but to fall back to the recursive delta walk
+		 * with oid_object_info() to find about the object type
+		 * at this point...
+		 */
+		give_up:
+		unuse_pack(&w_curs);
+	}
+
+	oe_set_type(entry,
+		    oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
+	if (entry->type_valid) {
+		SET_SIZE(entry, canonical_size);
+	} else {
+		/*
+		 * Bad object type is checked in prepare_pack().  This is
+		 * to permit a missing preferred base object to be ignored
+		 * as a preferred base.  Doing so can result in a larger
+		 * pack file, but the transfer will still take place.
+		 */
+	}
+}
+
+static int pack_offset_sort(const void *_a, const void *_b)
+{
+	const struct object_entry *a = *(struct object_entry **)_a;
+	const struct object_entry *b = *(struct object_entry **)_b;
+	const struct packed_git *a_in_pack = IN_PACK(a);
+	const struct packed_git *b_in_pack = IN_PACK(b);
+
+	/* avoid filesystem trashing with loose objects */
+	if (!a_in_pack && !b_in_pack)
+		return oidcmp(&a->idx.oid, &b->idx.oid);
+
+	if (a_in_pack < b_in_pack)
+		return -1;
+	if (a_in_pack > b_in_pack)
+		return 1;
+	return a->in_pack_offset < b->in_pack_offset ? -1 :
+			(a->in_pack_offset > b->in_pack_offset);
+}
+
+/*
+ * Drop an on-disk delta we were planning to reuse. Naively, this would
+ * just involve blanking out the "delta" field, but we have to deal
+ * with some extra book-keeping:
+ *
+ *   1. Removing ourselves from the delta_sibling linked list.
+ *
+ *   2. Updating our size/type to the non-delta representation. These were
+ *      either not recorded initially (size) or overwritten with the delta type
+ *      (type) when check_object() decided to reuse the delta.
+ *
+ *   3. Resetting our delta depth, as we are now a base object.
+ */
+static void drop_reused_delta(struct object_entry *entry)
+{
+	unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
+	struct object_info oi = OBJECT_INFO_INIT;
+	enum object_type type;
+	unsigned long size;
+
+	while (*idx) {
+		struct object_entry *oe = &to_pack.objects[*idx - 1];
+
+		if (oe == entry)
+			*idx = oe->delta_sibling_idx;
+		else
+			idx = &oe->delta_sibling_idx;
+	}
+	SET_DELTA(entry, NULL);
+	entry->depth = 0;
+
+	oi.sizep = &size;
+	oi.typep = &type;
+	if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
+		/*
+		 * We failed to get the info from this pack for some reason;
+		 * fall back to oid_object_info, which may find another copy.
+		 * And if that fails, the error will be recorded in oe_type(entry)
+		 * and dealt with in prepare_pack().
+		 */
+		oe_set_type(entry,
+			    oid_object_info(the_repository, &entry->idx.oid, &size));
+	} else {
+		oe_set_type(entry, type);
+	}
+	SET_SIZE(entry, size);
+}
+
+/*
+ * Follow the chain of deltas from this entry onward, throwing away any links
+ * that cause us to hit a cycle (as determined by the DFS state flags in
+ * the entries).
+ *
+ * We also detect too-long reused chains that would violate our --depth
+ * limit.
+ */
+static void break_delta_chains(struct object_entry *entry)
+{
+	/*
+	 * The actual depth of each object we will write is stored as an int,
+	 * as it cannot exceed our int "depth" limit. But before we break
+	 * changes based no that limit, we may potentially go as deep as the
+	 * number of objects, which is elsewhere bounded to a uint32_t.
+	 */
+	uint32_t total_depth;
+	struct object_entry *cur, *next;
+
+	for (cur = entry, total_depth = 0;
+	     cur;
+	     cur = DELTA(cur), total_depth++) {
+		if (cur->dfs_state == DFS_DONE) {
+			/*
+			 * We've already seen this object and know it isn't
+			 * part of a cycle. We do need to append its depth
+			 * to our count.
+			 */
+			total_depth += cur->depth;
+			break;
+		}
+
+		/*
+		 * We break cycles before looping, so an ACTIVE state (or any
+		 * other cruft which made its way into the state variable)
+		 * is a bug.
+		 */
+		if (cur->dfs_state != DFS_NONE)
+			BUG("confusing delta dfs state in first pass: %d",
+			    cur->dfs_state);
+
+		/*
+		 * Now we know this is the first time we've seen the object. If
+		 * it's not a delta, we're done traversing, but we'll mark it
+		 * done to save time on future traversals.
+		 */
+		if (!DELTA(cur)) {
+			cur->dfs_state = DFS_DONE;
+			break;
+		}
+
+		/*
+		 * Mark ourselves as active and see if the next step causes
+		 * us to cycle to another active object. It's important to do
+		 * this _before_ we loop, because it impacts where we make the
+		 * cut, and thus how our total_depth counter works.
+		 * E.g., We may see a partial loop like:
+		 *
+		 *   A -> B -> C -> D -> B
+		 *
+		 * Cutting B->C breaks the cycle. But now the depth of A is
+		 * only 1, and our total_depth counter is at 3. The size of the
+		 * error is always one less than the size of the cycle we
+		 * broke. Commits C and D were "lost" from A's chain.
+		 *
+		 * If we instead cut D->B, then the depth of A is correct at 3.
+		 * We keep all commits in the chain that we examined.
+		 */
+		cur->dfs_state = DFS_ACTIVE;
+		if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
+			drop_reused_delta(cur);
+			cur->dfs_state = DFS_DONE;
+			break;
+		}
+	}
+
+	/*
+	 * And now that we've gone all the way to the bottom of the chain, we
+	 * need to clear the active flags and set the depth fields as
+	 * appropriate. Unlike the loop above, which can quit when it drops a
+	 * delta, we need to keep going to look for more depth cuts. So we need
+	 * an extra "next" pointer to keep going after we reset cur->delta.
+	 */
+	for (cur = entry; cur; cur = next) {
+		next = DELTA(cur);
+
+		/*
+		 * We should have a chain of zero or more ACTIVE states down to
+		 * a final DONE. We can quit after the DONE, because either it
+		 * has no bases, or we've already handled them in a previous
+		 * call.
+		 */
+		if (cur->dfs_state == DFS_DONE)
+			break;
+		else if (cur->dfs_state != DFS_ACTIVE)
+			BUG("confusing delta dfs state in second pass: %d",
+			    cur->dfs_state);
+
+		/*
+		 * If the total_depth is more than depth, then we need to snip
+		 * the chain into two or more smaller chains that don't exceed
+		 * the maximum depth. Most of the resulting chains will contain
+		 * (depth + 1) entries (i.e., depth deltas plus one base), and
+		 * the last chain (i.e., the one containing entry) will contain
+		 * whatever entries are left over, namely
+		 * (total_depth % (depth + 1)) of them.
+		 *
+		 * Since we are iterating towards decreasing depth, we need to
+		 * decrement total_depth as we go, and we need to write to the
+		 * entry what its final depth will be after all of the
+		 * snipping. Since we're snipping into chains of length (depth
+		 * + 1) entries, the final depth of an entry will be its
+		 * original depth modulo (depth + 1). Any time we encounter an
+		 * entry whose final depth is supposed to be zero, we snip it
+		 * from its delta base, thereby making it so.
+		 */
+		cur->depth = (total_depth--) % (depth + 1);
+		if (!cur->depth)
+			drop_reused_delta(cur);
+
+		cur->dfs_state = DFS_DONE;
+	}
+}
+
+static void get_object_details(void)
+{
+	uint32_t i;
+	struct object_entry **sorted_by_offset;
+
+	if (progress)
+		progress_state = start_progress(_("Counting objects"),
+						to_pack.nr_objects);
+
+	sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
+	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);
+
+	for (i = 0; i < to_pack.nr_objects; i++) {
+		struct object_entry *entry = sorted_by_offset[i];
+		check_object(entry);
+		if (entry->type_valid &&
+		    oe_size_greater_than(&to_pack, entry, big_file_threshold))
+			entry->no_try_delta = 1;
+		display_progress(progress_state, i + 1);
+	}
+	stop_progress(&progress_state);
+
+	/*
+	 * This must happen in a second pass, since we rely on the delta
+	 * information for the whole list being completed.
+	 */
+	for (i = 0; i < to_pack.nr_objects; i++)
+		break_delta_chains(&to_pack.objects[i]);
+
+	free(sorted_by_offset);
+}
+
+/*
+ * We search for deltas in a list sorted by type, by filename hash, and then
+ * by size, so that we see progressively smaller and smaller files.
+ * That's because we prefer deltas to be from the bigger file
+ * to the smaller -- deletes are potentially cheaper, but perhaps
+ * more importantly, the bigger file is likely the more recent
+ * one.  The deepest deltas are therefore the oldest objects which are
+ * less susceptible to be accessed often.
+ */
+static int type_size_sort(const void *_a, const void *_b)
+{
+	const struct object_entry *a = *(struct object_entry **)_a;
+	const struct object_entry *b = *(struct object_entry **)_b;
+	const enum object_type a_type = oe_type(a);
+	const enum object_type b_type = oe_type(b);
+	const unsigned long a_size = SIZE(a);
+	const unsigned long b_size = SIZE(b);
+
+	if (a_type > b_type)
+		return -1;
+	if (a_type < b_type)
+		return 1;
+	if (a->hash > b->hash)
+		return -1;
+	if (a->hash < b->hash)
+		return 1;
+	if (a->preferred_base > b->preferred_base)
+		return -1;
+	if (a->preferred_base < b->preferred_base)
+		return 1;
+	if (use_delta_islands) {
+		const int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
+		if (island_cmp)
+			return island_cmp;
+	}
+	if (a_size > b_size)
+		return -1;
+	if (a_size < b_size)
+		return 1;
+	return a < b ? -1 : (a > b);  /* newest first */
+}
+
+struct unpacked {
+	struct object_entry *entry;
+	void *data;
+	struct delta_index *index;
+	unsigned depth;
+};
+
+static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
+			   unsigned long delta_size)
+{
+	if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
+		return 0;
+
+	if (delta_size < cache_max_small_delta_size)
+		return 1;
+
+	/* cache delta, if objects are large enough compared to delta size */
+	if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
+		return 1;
+
+	return 0;
+}
+
+/* Protect delta_cache_size */
+static pthread_mutex_t cache_mutex;
+#define cache_lock()		pthread_mutex_lock(&cache_mutex)
+#define cache_unlock()		pthread_mutex_unlock(&cache_mutex)
+
+/*
+ * Protect object list partitioning (e.g. struct thread_param) and
+ * progress_state
+ */
+static pthread_mutex_t progress_mutex;
+#define progress_lock()		pthread_mutex_lock(&progress_mutex)
+#define progress_unlock()	pthread_mutex_unlock(&progress_mutex)
+
+/*
+ * Access to struct object_entry is unprotected since each thread owns
+ * a portion of the main object list. Just don't access object entries
+ * ahead in the list because they can be stolen and would need
+ * progress_mutex for protection.
+ */
+
+/*
+ * Return the size of the object without doing any delta
+ * reconstruction (so non-deltas are true object sizes, but deltas
+ * return the size of the delta data).
+ */
+unsigned long oe_get_size_slow(struct packing_data *pack,
+			       const struct object_entry *e)
+{
+	struct packed_git *p;
+	struct pack_window *w_curs;
+	unsigned char *buf;
+	enum object_type type;
+	unsigned long used, avail, size;
+
+	if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
+		packing_data_lock(&to_pack);
+		if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
+			die(_("unable to get size of %s"),
+			    oid_to_hex(&e->idx.oid));
+		packing_data_unlock(&to_pack);
+		return size;
+	}
+
+	p = oe_in_pack(pack, e);
+	if (!p)
+		BUG("when e->type is a delta, it must belong to a pack");
+
+	packing_data_lock(&to_pack);
+	w_curs = NULL;
+	buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
+	used = unpack_object_header_buffer(buf, avail, &type, &size);
+	if (used == 0)
+		die(_("unable to parse object header of %s"),
+		    oid_to_hex(&e->idx.oid));
+
+	unuse_pack(&w_curs);
+	packing_data_unlock(&to_pack);
+	return size;
+}
+
+static int try_delta(struct unpacked *trg, struct unpacked *src,
+		     unsigned max_depth, unsigned long *mem_usage)
+{
+	struct object_entry *trg_entry = trg->entry;
+	struct object_entry *src_entry = src->entry;
+	unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
+	unsigned ref_depth;
+	enum object_type type;
+	void *delta_buf;
+
+	/* Don't bother doing diffs between different types */
+	if (oe_type(trg_entry) != oe_type(src_entry))
+		return -1;
+
+	/*
+	 * We do not bother to try a delta that we discarded on an
+	 * earlier try, but only when reusing delta data.  Note that
+	 * src_entry that is marked as the preferred_base should always
+	 * be considered, as even if we produce a suboptimal delta against
+	 * it, we will still save the transfer cost, as we already know
+	 * the other side has it and we won't send src_entry at all.
+	 */
+	if (reuse_delta && IN_PACK(trg_entry) &&
+	    IN_PACK(trg_entry) == IN_PACK(src_entry) &&
+	    !src_entry->preferred_base &&
+	    trg_entry->in_pack_type != OBJ_REF_DELTA &&
+	    trg_entry->in_pack_type != OBJ_OFS_DELTA)
+		return 0;
+
+	/* Let's not bust the allowed depth. */
+	if (src->depth >= max_depth)
+		return 0;
+
+	/* Now some size filtering heuristics. */
+	trg_size = SIZE(trg_entry);
+	if (!DELTA(trg_entry)) {
+		max_size = trg_size/2 - the_hash_algo->rawsz;
+		ref_depth = 1;
+	} else {
+		max_size = DELTA_SIZE(trg_entry);
+		ref_depth = trg->depth;
+	}
+	max_size = (uint64_t)max_size * (max_depth - src->depth) /
+						(max_depth - ref_depth + 1);
+	if (max_size == 0)
+		return 0;
+	src_size = SIZE(src_entry);
+	sizediff = src_size < trg_size ? trg_size - src_size : 0;
+	if (sizediff >= max_size)
+		return 0;
+	if (trg_size < src_size / 32)
+		return 0;
+
+	if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
+		return 0;
+
+	/* Load data if not already done */
+	if (!trg->data) {
+		packing_data_lock(&to_pack);
+		trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
+		packing_data_unlock(&to_pack);
+		if (!trg->data)
+			die(_("object %s cannot be read"),
+			    oid_to_hex(&trg_entry->idx.oid));
+		if (sz != trg_size)
+			die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
+			    oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
+			    (uintmax_t)trg_size);
+		*mem_usage += sz;
+	}
+	if (!src->data) {
+		packing_data_lock(&to_pack);
+		src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
+		packing_data_unlock(&to_pack);
+		if (!src->data) {
+			if (src_entry->preferred_base) {
+				static int warned = 0;
+				if (!warned++)
+					warning(_("object %s cannot be read"),
+						oid_to_hex(&src_entry->idx.oid));
+				/*
+				 * Those objects are not included in the
+				 * resulting pack.  Be resilient and ignore
+				 * them if they can't be read, in case the
+				 * pack could be created nevertheless.
+				 */
+				return 0;
+			}
+			die(_("object %s cannot be read"),
+			    oid_to_hex(&src_entry->idx.oid));
+		}
+		if (sz != src_size)
+			die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
+			    oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
+			    (uintmax_t)src_size);
+		*mem_usage += sz;
+	}
+	if (!src->index) {
+		src->index = create_delta_index(src->data, src_size);
+		if (!src->index) {
+			static int warned = 0;
+			if (!warned++)
+				warning(_("suboptimal pack - out of memory"));
+			return 0;
+		}
+		*mem_usage += sizeof_delta_index(src->index);
+	}
+
+	delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
+	if (!delta_buf)
+		return 0;
+
+	if (DELTA(trg_entry)) {
+		/* Prefer only shallower same-sized deltas. */
+		if (delta_size == DELTA_SIZE(trg_entry) &&
+		    src->depth + 1 >= trg->depth) {
+			free(delta_buf);
+			return 0;
+		}
+	}
+
+	/*
+	 * Handle memory allocation outside of the cache
+	 * accounting lock.  Compiler will optimize the strangeness
+	 * away when NO_PTHREADS is defined.
+	 */
+	free(trg_entry->delta_data);
+	cache_lock();
+	if (trg_entry->delta_data) {
+		delta_cache_size -= DELTA_SIZE(trg_entry);
+		trg_entry->delta_data = NULL;
+	}
+	if (delta_cacheable(src_size, trg_size, delta_size)) {
+		delta_cache_size += delta_size;
+		cache_unlock();
+		trg_entry->delta_data = xrealloc(delta_buf, delta_size);
+	} else {
+		cache_unlock();
+		free(delta_buf);
+	}
+
+	SET_DELTA(trg_entry, src_entry);
+	SET_DELTA_SIZE(trg_entry, delta_size);
+	trg->depth = src->depth + 1;
+
+	return 1;
+}
+
+static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
+{
+	struct object_entry *child = DELTA_CHILD(me);
+	unsigned int m = n;
+	while (child) {
+		const unsigned int c = check_delta_limit(child, n + 1);
+		if (m < c)
+			m = c;
+		child = DELTA_SIBLING(child);
+	}
+	return m;
+}
+
+static unsigned long free_unpacked(struct unpacked *n)
+{
+	unsigned long freed_mem = sizeof_delta_index(n->index);
+	free_delta_index(n->index);
+	n->index = NULL;
+	if (n->data) {
+		freed_mem += SIZE(n->entry);
+		FREE_AND_NULL(n->data);
+	}
+	n->entry = NULL;
+	n->depth = 0;
+	return freed_mem;
+}
+
+static void find_deltas(struct object_entry **list, unsigned *list_size,
+			int window, int depth, unsigned *processed)
+{
+	uint32_t i, idx = 0, count = 0;
+	struct unpacked *array;
+	unsigned long mem_usage = 0;
+
+	array = xcalloc(window, sizeof(struct unpacked));
+
+	for (;;) {
+		struct object_entry *entry;
+		struct unpacked *n = array + idx;
+		int j, max_depth, best_base = -1;
+
+		progress_lock();
+		if (!*list_size) {
+			progress_unlock();
+			break;
+		}
+		entry = *list++;
+		(*list_size)--;
+		if (!entry->preferred_base) {
+			(*processed)++;
+			display_progress(progress_state, *processed);
+		}
+		progress_unlock();
+
+		mem_usage -= free_unpacked(n);
+		n->entry = entry;
+
+		while (window_memory_limit &&
+		       mem_usage > window_memory_limit &&
+		       count > 1) {
+			const uint32_t tail = (idx + window - count) % window;
+			mem_usage -= free_unpacked(array + tail);
+			count--;
+		}
+
+		/* We do not compute delta to *create* objects we are not
+		 * going to pack.
+		 */
+		if (entry->preferred_base)
+			goto next;
+
+		/*
+		 * If the current object is at pack edge, take the depth the
+		 * objects that depend on the current object into account
+		 * otherwise they would become too deep.
+		 */
+		max_depth = depth;
+		if (DELTA_CHILD(entry)) {
+			max_depth -= check_delta_limit(entry, 0);
+			if (max_depth <= 0)
+				goto next;
+		}
+
+		j = window;
+		while (--j > 0) {
+			int ret;
+			uint32_t other_idx = idx + j;
+			struct unpacked *m;
+			if (other_idx >= window)
+				other_idx -= window;
+			m = array + other_idx;
+			if (!m->entry)
+				break;
+			ret = try_delta(n, m, max_depth, &mem_usage);
+			if (ret < 0)
+				break;
+			else if (ret > 0)
+				best_base = other_idx;
+		}
+
+		/*
+		 * If we decided to cache the delta data, then it is best
+		 * to compress it right away.  First because we have to do
+		 * it anyway, and doing it here while we're threaded will
+		 * save a lot of time in the non threaded write phase,
+		 * as well as allow for caching more deltas within
+		 * the same cache size limit.
+		 * ...
+		 * But only if not writing to stdout, since in that case
+		 * the network is most likely throttling writes anyway,
+		 * and therefore it is best to go to the write phase ASAP
+		 * instead, as we can afford spending more time compressing
+		 * between writes at that moment.
+		 */
+		if (entry->delta_data && !pack_to_stdout) {
+			unsigned long size;
+
+			size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
+			if (size < (1U << OE_Z_DELTA_BITS)) {
+				entry->z_delta_size = size;
+				cache_lock();
+				delta_cache_size -= DELTA_SIZE(entry);
+				delta_cache_size += entry->z_delta_size;
+				cache_unlock();
+			} else {
+				FREE_AND_NULL(entry->delta_data);
+				entry->z_delta_size = 0;
+			}
+		}
+
+		/* if we made n a delta, and if n is already at max
+		 * depth, leaving it in the window is pointless.  we
+		 * should evict it first.
+		 */
+		if (DELTA(entry) && max_depth <= n->depth)
+			continue;
+
+		/*
+		 * Move the best delta base up in the window, after the
+		 * currently deltified object, to keep it longer.  It will
+		 * be the first base object to be attempted next.
+		 */
+		if (DELTA(entry)) {
+			struct unpacked swap = array[best_base];
+			int dist = (window + idx - best_base) % window;
+			int dst = best_base;
+			while (dist--) {
+				int src = (dst + 1) % window;
+				array[dst] = array[src];
+				dst = src;
+			}
+			array[dst] = swap;
+		}
+
+		next:
+		idx++;
+		if (count + 1 < window)
+			count++;
+		if (idx >= window)
+			idx = 0;
+	}
+
+	for (i = 0; i < window; ++i) {
+		free_delta_index(array[i].index);
+		free(array[i].data);
+	}
+	free(array);
+}
+
+/*
+ * The main object list is split into smaller lists, each is handed to
+ * one worker.
+ *
+ * The main thread waits on the condition that (at least) one of the workers
+ * has stopped working (which is indicated in the .working member of
+ * struct thread_params).
+ *
+ * When a work thread has completed its work, it sets .working to 0 and
+ * signals the main thread and waits on the condition that .data_ready
+ * becomes 1.
+ *
+ * The main thread steals half of the work from the worker that has
+ * most work left to hand it to the idle worker.
+ */
+
+struct thread_params {
+	pthread_t thread;
+	struct object_entry **list;
+	unsigned list_size;
+	unsigned remaining;
+	int window;
+	int depth;
+	int working;
+	int data_ready;
+	pthread_mutex_t mutex;
+	pthread_cond_t cond;
+	unsigned *processed;
+};
+
+static pthread_cond_t progress_cond;
+
+/*
+ * Mutex and conditional variable can't be statically-initialized on Windows.
+ */
+static void init_threaded_search(void)
+{
+	pthread_mutex_init(&cache_mutex, NULL);
+	pthread_mutex_init(&progress_mutex, NULL);
+	pthread_cond_init(&progress_cond, NULL);
+}
+
+static void cleanup_threaded_search(void)
+{
+	pthread_cond_destroy(&progress_cond);
+	pthread_mutex_destroy(&cache_mutex);
+	pthread_mutex_destroy(&progress_mutex);
+}
+
+static void *threaded_find_deltas(void *arg)
+{
+	struct thread_params *me = arg;
+
+	progress_lock();
+	while (me->remaining) {
+		progress_unlock();
+
+		find_deltas(me->list, &me->remaining,
+			    me->window, me->depth, me->processed);
+
+		progress_lock();
+		me->working = 0;
+		pthread_cond_signal(&progress_cond);
+		progress_unlock();
+
+		/*
+		 * We must not set ->data_ready before we wait on the
+		 * condition because the main thread may have set it to 1
+		 * before we get here. In order to be sure that new
+		 * work is available if we see 1 in ->data_ready, it
+		 * was initialized to 0 before this thread was spawned
+		 * and we reset it to 0 right away.
+		 */
+		pthread_mutex_lock(&me->mutex);
+		while (!me->data_ready)
+			pthread_cond_wait(&me->cond, &me->mutex);
+		me->data_ready = 0;
+		pthread_mutex_unlock(&me->mutex);
+
+		progress_lock();
+	}
+	progress_unlock();
+	/* leave ->working 1 so that this doesn't get more work assigned */
+	return NULL;
+}
+
+static void ll_find_deltas(struct object_entry **list, unsigned list_size,
+			   int window, int depth, unsigned *processed)
+{
+	struct thread_params *p;
+	int i, ret, active_threads = 0;
+
+	init_threaded_search();
+
+	if (delta_search_threads <= 1) {
+		find_deltas(list, &list_size, window, depth, processed);
+		cleanup_threaded_search();
+		return;
+	}
+	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));
+
+	/* Partition the work amongst work threads. */
+	for (i = 0; i < delta_search_threads; i++) {
+		unsigned sub_size = list_size / (delta_search_threads - i);
+
+		/* don't use too small segments or no deltas will be found */
+		if (sub_size < 2*window && i+1 < delta_search_threads)
+			sub_size = 0;
+
+		p[i].window = window;
+		p[i].depth = depth;
+		p[i].processed = processed;
+		p[i].working = 1;
+		p[i].data_ready = 0;
+
+		/* try to split chunks on "path" boundaries */
+		while (sub_size && sub_size < list_size &&
+		       list[sub_size]->hash &&
+		       list[sub_size]->hash == list[sub_size-1]->hash)
+			sub_size++;
+
+		p[i].list = list;
+		p[i].list_size = sub_size;
+		p[i].remaining = sub_size;
+
+		list += sub_size;
+		list_size -= sub_size;
+	}
+
+	/* Start work threads. */
+	for (i = 0; i < delta_search_threads; i++) {
+		if (!p[i].list_size)
+			continue;
+		pthread_mutex_init(&p[i].mutex, NULL);
+		pthread_cond_init(&p[i].cond, NULL);
+		ret = pthread_create(&p[i].thread, NULL,
+				     threaded_find_deltas, &p[i]);
+		if (ret)
+			die(_("unable to create thread: %s"), strerror(ret));
+		active_threads++;
+	}
+
+	/*
+	 * Now let's wait for work completion.  Each time a thread is done
+	 * with its work, we steal half of the remaining work from the
+	 * thread with the largest number of unprocessed objects and give
+	 * it to that newly idle thread.  This ensure good load balancing
+	 * until the remaining object list segments are simply too short
+	 * to be worth splitting anymore.
+	 */
+	while (active_threads) {
+		struct thread_params *target = NULL;
+		struct thread_params *victim = NULL;
+		unsigned sub_size = 0;
+
+		progress_lock();
+		for (;;) {
+			for (i = 0; !target && i < delta_search_threads; i++)
+				if (!p[i].working)
+					target = &p[i];
+			if (target)
+				break;
+			pthread_cond_wait(&progress_cond, &progress_mutex);
+		}
+
+		for (i = 0; i < delta_search_threads; i++)
+			if (p[i].remaining > 2*window &&
+			    (!victim || victim->remaining < p[i].remaining))
+				victim = &p[i];
+		if (victim) {
+			sub_size = victim->remaining / 2;
+			list = victim->list + victim->list_size - sub_size;
+			while (sub_size && list[0]->hash &&
+			       list[0]->hash == list[-1]->hash) {
+				list++;
+				sub_size--;
+			}
+			if (!sub_size) {
+				/*
+				 * It is possible for some "paths" to have
+				 * so many objects that no hash boundary
+				 * might be found.  Let's just steal the
+				 * exact half in that case.
+				 */
+				sub_size = victim->remaining / 2;
+				list -= sub_size;
+			}
+			target->list = list;
+			victim->list_size -= sub_size;
+			victim->remaining -= sub_size;
+		}
+		target->list_size = sub_size;
+		target->remaining = sub_size;
+		target->working = 1;
+		progress_unlock();
+
+		pthread_mutex_lock(&target->mutex);
+		target->data_ready = 1;
+		pthread_cond_signal(&target->cond);
+		pthread_mutex_unlock(&target->mutex);
+
+		if (!sub_size) {
+			pthread_join(target->thread, NULL);
+			pthread_cond_destroy(&target->cond);
+			pthread_mutex_destroy(&target->mutex);
+			active_threads--;
+		}
+	}
+	cleanup_threaded_search();
+	free(p);
+}
+
+static int obj_is_packed(const struct object_id *oid)
+{
+	return packlist_find(&to_pack, oid) ||
+		(reuse_packfile_bitmap &&
+		 bitmap_walk_contains(bitmap_git, reuse_packfile_bitmap, oid));
+}
+
+static void add_tag_chain(const struct object_id *oid)
+{
+	struct tag *tag;
+
+	/*
+	 * We catch duplicates already in add_object_entry(), but we'd
+	 * prefer to do this extra check to avoid having to parse the
+	 * tag at all if we already know that it's being packed (e.g., if
+	 * it was included via bitmaps, we would not have parsed it
+	 * previously).
+	 */
+	if (obj_is_packed(oid))
+		return;
+
+	tag = lookup_tag(the_repository, oid);
+	while (1) {
+		if (!tag || parse_tag(tag) || !tag->tagged)
+			die(_("unable to pack objects reachable from tag %s"),
+			    oid_to_hex(oid));
+
+		add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
+
+		if (tag->tagged->type != OBJ_TAG)
+			return;
+
+		tag = (struct tag *)tag->tagged;
+	}
+}
+
+static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
+{
+	struct object_id peeled;
+
+	if (starts_with(path, "refs/tags/") && /* is a tag? */
+	    !peel_ref(path, &peeled)    && /* peelable? */
+	    obj_is_packed(&peeled)) /* object packed? */
+		add_tag_chain(oid);
+	return 0;
+}
+
+static void prepare_pack(int window, int depth)
+{
+	struct object_entry **delta_list;
+	uint32_t i, nr_deltas;
+	unsigned n;
+
+	if (use_delta_islands)
+		resolve_tree_islands(the_repository, progress, &to_pack);
+
+	get_object_details();
+
+	/*
+	 * If we're locally repacking then we need to be doubly careful
+	 * from now on in order to make sure no stealth corruption gets
+	 * propagated to the new pack.  Clients receiving streamed packs
+	 * should validate everything they get anyway so no need to incur
+	 * the additional cost here in that case.
+	 */
+	if (!pack_to_stdout)
+		do_check_packed_object_crc = 1;
+
+	if (!to_pack.nr_objects || !window || !depth)
+		return;
+
+	ALLOC_ARRAY(delta_list, to_pack.nr_objects);
+	nr_deltas = n = 0;
+
+	for (i = 0; i < to_pack.nr_objects; i++) {
+		struct object_entry *entry = to_pack.objects + i;
+
+		if (DELTA(entry))
+			/* This happens if we decided to reuse existing
+			 * delta from a pack.  "reuse_delta &&" is implied.
+			 */
+			continue;
+
+		if (!entry->type_valid ||
+		    oe_size_less_than(&to_pack, entry, 50))
+			continue;
+
+		if (entry->no_try_delta)
+			continue;
+
+		if (!entry->preferred_base) {
+			nr_deltas++;
+			if (oe_type(entry) < 0)
+				die(_("unable to get type of object %s"),
+				    oid_to_hex(&entry->idx.oid));
+		} else {
+			if (oe_type(entry) < 0) {
+				/*
+				 * This object is not found, but we
+				 * don't have to include it anyway.
+				 */
+				continue;
+			}
+		}
+
+		delta_list[n++] = entry;
+	}
+
+	if (nr_deltas && n > 1) {
+		unsigned nr_done = 0;
+
+		if (progress)
+			progress_state = start_progress(_("Compressing objects"),
+							nr_deltas);
+		QSORT(delta_list, n, type_size_sort);
+		ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
+		stop_progress(&progress_state);
+		if (nr_done != nr_deltas)
+			die(_("inconsistency with delta count"));
+	}
+	free(delta_list);
+}
+
+static int git_pack_config(const char *k, const char *v, void *cb)
+{
+	if (!strcmp(k, "pack.window")) {
+		window = git_config_int(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.windowmemory")) {
+		window_memory_limit = git_config_ulong(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.depth")) {
+		depth = git_config_int(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.deltacachesize")) {
+		max_delta_cache_size = git_config_int(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.deltacachelimit")) {
+		cache_max_small_delta_size = git_config_int(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.writebitmaphashcache")) {
+		if (git_config_bool(k, v))
+			write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
+		else
+			write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
+	}
+	if (!strcmp(k, "pack.usebitmaps")) {
+		use_bitmap_index_default = git_config_bool(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.allowpackreuse")) {
+		allow_pack_reuse = git_config_bool(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "pack.threads")) {
+		delta_search_threads = git_config_int(k, v);
+		if (delta_search_threads < 0)
+			die(_("invalid number of threads specified (%d)"),
+			    delta_search_threads);
+		if (!HAVE_THREADS && delta_search_threads != 1) {
+			warning(_("no threads support, ignoring %s"), k);
+			delta_search_threads = 0;
+		}
+		return 0;
+	}
+	if (!strcmp(k, "pack.indexversion")) {
+		pack_idx_opts.version = git_config_int(k, v);
+		if (pack_idx_opts.version > 2)
+			die(_("bad pack.indexversion=%"PRIu32),
+			    pack_idx_opts.version);
+		return 0;
+	}
+	return git_default_config(k, v, cb);
+}
+
+static void read_object_list_from_stdin(void)
+{
+	char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
+	struct object_id oid;
+	const char *p;
+
+	for (;;) {
+		if (!fgets(line, sizeof(line), stdin)) {
+			if (feof(stdin))
+				break;
+			if (!ferror(stdin))
+				die("BUG: fgets returned NULL, not EOF, not error!");
+			if (errno != EINTR)
+				die_errno("fgets");
+			clearerr(stdin);
+			continue;
+		}
+		if (line[0] == '-') {
+			if (get_oid_hex(line+1, &oid))
+				die(_("expected edge object ID, got garbage:\n %s"),
+				    line);
+			add_preferred_base(&oid);
+			continue;
+		}
+		if (parse_oid_hex(line, &oid, &p))
+			die(_("expected object ID, got garbage:\n %s"), line);
+
+		add_preferred_base_object(p + 1);
+		add_object_entry(&oid, OBJ_NONE, p + 1, 0);
+	}
+}
+
+/* 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);
+
+	if (use_delta_islands)
+		propagate_island_marks(commit);
+}
+
+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;
+		unsigned depth;
+		struct object_entry *ent;
+
+		/* the empty string is a root tree, which is depth 0 */
+		depth = *name ? 1 : 0;
+		for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
+			depth++;
+
+		ent = packlist_find(&to_pack, &obj->oid);
+		if (ent && depth > oe_tree_depth(&to_pack, ent))
+			oe_set_tree_depth(&to_pack, ent, depth);
+	}
+}
+
+static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
+{
+	assert(arg_missing_action == MA_ALLOW_ANY);
+
+	/*
+	 * Quietly ignore ALL missing objects.  This avoids problems with
+	 * staging them now and getting an odd error later.
+	 */
+	if (!has_object_file(&obj->oid))
+		return;
+
+	show_object(obj, name, data);
+}
+
+static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
+{
+	assert(arg_missing_action == MA_ALLOW_PROMISOR);
+
+	/*
+	 * Quietly ignore EXPECTED missing objects.  This avoids problems with
+	 * staging them now and getting an odd error later.
+	 */
+	if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
+		return;
+
+	show_object(obj, name, data);
+}
+
+static int option_parse_missing_action(const struct option *opt,
+				       const char *arg, int unset)
+{
+	assert(arg);
+	assert(!unset);
+
+	if (!strcmp(arg, "error")) {
+		arg_missing_action = MA_ERROR;
+		fn_show_object = show_object;
+		return 0;
+	}
+
+	if (!strcmp(arg, "allow-any")) {
+		arg_missing_action = MA_ALLOW_ANY;
+		fetch_if_missing = 0;
+		fn_show_object = show_object__ma_allow_any;
+		return 0;
+	}
+
+	if (!strcmp(arg, "allow-promisor")) {
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fetch_if_missing = 0;
+		fn_show_object = show_object__ma_allow_promisor;
+		return 0;
+	}
+
+	die(_("invalid value for --missing"));
+	return 0;
+}
+
+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)
+{
+	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);
+}
+
+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);
+}
+
+static int add_loose_object(const struct object_id *oid, const char *path,
+			    void *data)
+{
+	enum object_type type = oid_object_info(the_repository, oid, NULL);
+
+	if (type < 0) {
+		warning(_("loose object at %s could not be examined"), path);
+		return 0;
+	}
+
+	add_object_entry(oid, type, "", 0);
+	return 0;
+}
+
+/*
+ * We actually don't even have to worry about reachability here.
+ * add_object_entry will weed out duplicates, so we just add every
+ * loose object we find.
+ */
+static void add_unreachable_loose_objects(void)
+{
+	for_each_loose_file_in_objdir(get_object_directory(),
+				      add_loose_object,
+				      NULL, NULL, NULL);
+}
+
+static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
+{
+	static struct packed_git *last_found = (void *)1;
+	struct packed_git *p;
+
+	p = (last_found != (void *)1) ? last_found :
+					get_all_packs(the_repository);
+
+	while (p) {
+		if ((!p->pack_local || p->pack_keep ||
+				p->pack_keep_in_core) &&
+			find_pack_entry_one(oid->hash, p)) {
+			last_found = p;
+			return 1;
+		}
+		if (p == last_found)
+			p = get_all_packs(the_repository);
+		else
+			p = p->next;
+		if (p == last_found)
+			p = p->next;
+	}
+	return 0;
+}
+
+/*
+ * Store a list of sha1s that are should not be discarded
+ * because they are either written too recently, or are
+ * reachable from another object that was.
+ *
+ * This is filled by get_object_list.
+ */
+static struct oid_array recent_objects;
+
+static int loosened_object_can_be_discarded(const struct object_id *oid,
+					    timestamp_t mtime)
+{
+	if (!unpack_unreachable_expiration)
+		return 0;
+	if (mtime > unpack_unreachable_expiration)
+		return 0;
+	if (oid_array_lookup(&recent_objects, oid) >= 0)
+		return 0;
+	return 1;
+}
+
+static void loosen_unused_packed_objects(void)
+{
+	struct packed_git *p;
+	uint32_t i;
+	struct object_id oid;
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
+			continue;
+
+		if (open_pack_index(p))
+			die(_("cannot open pack index"));
+
+		for (i = 0; i < p->num_objects; i++) {
+			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))
+				if (force_object_loose(&oid, p->mtime))
+					die(_("unable to force loose object"));
+		}
+	}
+}
+
+/*
+ * This tracks any options which pack-reuse code expects to be on, or which a
+ * reader of the pack might not understand, and which would therefore prevent
+ * blind reuse of what we have on disk.
+ */
+static int pack_options_allow_reuse(void)
+{
+	return allow_pack_reuse &&
+	       pack_to_stdout &&
+	       !ignore_packed_keep_on_disk &&
+	       !ignore_packed_keep_in_core &&
+	       (!local || !have_non_local_packs) &&
+	       !incremental;
+}
+
+static int get_object_list_from_bitmap(struct rev_info *revs)
+{
+	if (!(bitmap_git = prepare_bitmap_walk(revs, &filter_options)))
+		return -1;
+
+	if (pack_options_allow_reuse() &&
+	    !reuse_partial_packfile_from_bitmap(
+			bitmap_git,
+			&reuse_packfile,
+			&reuse_packfile_objects,
+			&reuse_packfile_bitmap)) {
+		assert(reuse_packfile_objects);
+		nr_result += reuse_packfile_objects;
+		display_progress(progress_state, nr_result);
+	}
+
+	traverse_bitmap_commit_list(bitmap_git, revs,
+				    &add_object_entry_from_bitmap);
+	return 0;
+}
+
+static void record_recent_object(struct object *obj,
+				 const char *name,
+				 void *data)
+{
+	oid_array_append(&recent_objects, &obj->oid);
+}
+
+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)
+{
+	struct rev_info revs;
+	struct setup_revision_opt s_r_opt = {
+		.allow_exclude_promisor_objects = 1,
+	};
+	char line[1000];
+	int flags = 0;
+	int save_warning;
+
+	repo_init_revisions(the_repository, &revs, NULL);
+	save_commit_buffer = 0;
+	setup_revisions(ac, av, &revs, &s_r_opt);
+
+	/* make sure shallows are read */
+	is_repository_shallow(the_repository);
+
+	save_warning = warn_on_object_refname_ambiguity;
+	warn_on_object_refname_ambiguity = 0;
+
+	while (fgets(line, sizeof(line), stdin) != NULL) {
+		int len = strlen(line);
+		if (len && line[len - 1] == '\n')
+			line[--len] = 0;
+		if (!len)
+			break;
+		if (*line == '-') {
+			if (!strcmp(line, "--not")) {
+				flags ^= UNINTERESTING;
+				write_bitmap_index = 0;
+				continue;
+			}
+			if (starts_with(line, "--shallow ")) {
+				struct object_id oid;
+				if (get_oid_hex(line + 10, &oid))
+					die("not an SHA-1 '%s'", line + 10);
+				register_shallow(the_repository, &oid);
+				use_bitmap_index = 0;
+				continue;
+			}
+			die(_("not a rev '%s'"), line);
+		}
+		if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
+			die(_("bad revision '%s'"), line);
+	}
+
+	warn_on_object_refname_ambiguity = save_warning;
+
+	if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
+		return;
+
+	if (use_delta_islands)
+		load_delta_islands(the_repository, progress);
+
+	if (prepare_revision_walk(&revs))
+		die(_("revision walk setup failed"));
+	mark_edges_uninteresting(&revs, show_edge, sparse);
+
+	if (!fn_show_object)
+		fn_show_object = show_object;
+	traverse_commit_list_filtered(&filter_options, &revs,
+				      show_commit, fn_show_object, NULL,
+				      NULL);
+
+	if (unpack_unreachable_expiration) {
+		revs.ignore_missing_links = 1;
+		if (add_unseen_recent_objects_to_traversal(&revs,
+				unpack_unreachable_expiration))
+			die(_("unable to add recent objects"));
+		if (prepare_revision_walk(&revs))
+			die(_("revision walk setup failed"));
+		traverse_commit_list(&revs, record_recent_commit,
+				     record_recent_object, NULL);
+	}
+
+	if (keep_unreachable)
+		add_objects_in_unpacked_packs();
+	if (pack_loose_unreachable)
+		add_unreachable_loose_objects();
+	if (unpack_unreachable)
+		loosen_unused_packed_objects();
+
+	oid_array_clear(&recent_objects);
+}
+
+static void add_extra_kept_packs(const struct string_list *names)
+{
+	struct packed_git *p;
+
+	if (!names->nr)
+		return;
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		const char *name = basename(p->pack_name);
+		int i;
+
+		if (!p->pack_local)
+			continue;
+
+		for (i = 0; i < names->nr; i++)
+			if (!fspathcmp(name, names->items[i].string))
+				break;
+
+		if (i < names->nr) {
+			p->pack_keep_in_core = 1;
+			ignore_packed_keep_in_core = 1;
+			continue;
+		}
+	}
+}
+
+static int option_parse_index_version(const struct option *opt,
+				      const char *arg, int unset)
+{
+	char *c;
+	const char *val = arg;
+
+	BUG_ON_OPT_NEG(unset);
+
+	pack_idx_opts.version = strtoul(val, &c, 10);
+	if (pack_idx_opts.version > 2)
+		die(_("unsupported index version %s"), val);
+	if (*c == ',' && c[1])
+		pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
+	if (*c || pack_idx_opts.off32_limit & 0x80000000)
+		die(_("bad index version '%s'"), val);
+	return 0;
+}
+
+static int option_parse_unpack_unreachable(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		unpack_unreachable = 0;
+		unpack_unreachable_expiration = 0;
+	}
+	else {
+		unpack_unreachable = 1;
+		if (arg)
+			unpack_unreachable_expiration = approxidate(arg);
+	}
+	return 0;
+}
+
+int cmd_pack_objects(int argc, const char **argv, const char *prefix)
+{
+	int use_internal_rev_list = 0;
+	int shallow = 0;
+	int all_progress_implied = 0;
+	struct argv_array rp = ARGV_ARRAY_INIT;
+	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;
+	struct option pack_objects_options[] = {
+		OPT_SET_INT('q', "quiet", &progress,
+			    N_("do not show progress meter"), 0),
+		OPT_SET_INT(0, "progress", &progress,
+			    N_("show progress meter"), 1),
+		OPT_SET_INT(0, "all-progress", &progress,
+			    N_("show progress meter during object writing phase"), 2),
+		OPT_BOOL(0, "all-progress-implied",
+			 &all_progress_implied,
+			 N_("similar to --all-progress when progress meter is shown")),
+		{ OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
+		  N_("write the pack index file in the specified idx format version"),
+		  PARSE_OPT_NONEG, option_parse_index_version },
+		OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
+			      N_("maximum size of each output pack file")),
+		OPT_BOOL(0, "local", &local,
+			 N_("ignore borrowed objects from alternate object store")),
+		OPT_BOOL(0, "incremental", &incremental,
+			 N_("ignore packed objects")),
+		OPT_INTEGER(0, "window", &window,
+			    N_("limit pack window by objects")),
+		OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
+			      N_("limit pack window by memory in addition to object limit")),
+		OPT_INTEGER(0, "depth", &depth,
+			    N_("maximum length of delta chain allowed in the resulting pack")),
+		OPT_BOOL(0, "reuse-delta", &reuse_delta,
+			 N_("reuse existing deltas")),
+		OPT_BOOL(0, "reuse-object", &reuse_object,
+			 N_("reuse existing objects")),
+		OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
+			 N_("use OFS_DELTA objects")),
+		OPT_INTEGER(0, "threads", &delta_search_threads,
+			    N_("use threads when searching for best delta matches")),
+		OPT_BOOL(0, "non-empty", &non_empty,
+			 N_("do not create an empty pack output")),
+		OPT_BOOL(0, "revs", &use_internal_rev_list,
+			 N_("read revision arguments from standard input")),
+		OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
+			      N_("limit the objects to those that are not yet packed"),
+			      1, PARSE_OPT_NONEG),
+		OPT_SET_INT_F(0, "all", &rev_list_all,
+			      N_("include objects reachable from any reference"),
+			      1, PARSE_OPT_NONEG),
+		OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
+			      N_("include objects referred by reflog entries"),
+			      1, PARSE_OPT_NONEG),
+		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, "stdout", &pack_to_stdout,
+			 N_("output pack to stdout")),
+		OPT_BOOL(0, "include-tag", &include_tag,
+			 N_("include tag objects that refer to objects to be packed")),
+		OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
+			 N_("keep unreachable objects")),
+		OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
+			 N_("pack loose unreachable objects")),
+		{ OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
+		  N_("unpack unreachable objects newer than <time>"),
+		  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
+		OPT_BOOL(0, "sparse", &sparse,
+			 N_("use the sparse reachability algorithm")),
+		OPT_BOOL(0, "thin", &thin,
+			 N_("create thin packs")),
+		OPT_BOOL(0, "shallow", &shallow,
+			 N_("create packs suitable for shallow fetches")),
+		OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
+			 N_("ignore packs that have companion .keep file")),
+		OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
+				N_("ignore this pack")),
+		OPT_INTEGER(0, "compression", &pack_compression_level,
+			    N_("pack compression level")),
+		OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
+			    N_("do not hide commits by grafts"), 0),
+		OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
+			 N_("use a bitmap index if available to speed up counting objects")),
+		OPT_SET_INT(0, "write-bitmap-index", &write_bitmap_index,
+			    N_("write a bitmap index together with the pack index"),
+			    WRITE_BITMAP_TRUE),
+		OPT_SET_INT_F(0, "write-bitmap-index-quiet",
+			      &write_bitmap_index,
+			      N_("write a bitmap index if possible"),
+			      WRITE_BITMAP_QUIET, PARSE_OPT_HIDDEN),
+		OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
+		{ OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
+		  N_("handling for missing objects"), PARSE_OPT_NONEG,
+		  option_parse_missing_action },
+		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+			 N_("do not pack objects in promisor packfiles")),
+		OPT_BOOL(0, "delta-islands", &use_delta_islands,
+			 N_("respect islands during delta compression")),
+		OPT_END(),
+	};
+
+	if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
+		BUG("too many dfs states, increase OE_DFS_STATE_BITS");
+
+	read_replace_refs = 0;
+
+	sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
+	prepare_repo_settings(the_repository);
+	if (!sparse && the_repository->settings.pack_use_sparse != -1)
+		sparse = the_repository->settings.pack_use_sparse;
+
+	reset_pack_idx_option(&pack_idx_opts);
+	git_config(git_pack_config, NULL);
+
+	progress = isatty(2);
+	argc = parse_options(argc, argv, prefix, pack_objects_options,
+			     pack_usage, 0);
+
+	if (argc) {
+		base_name = argv[0];
+		argc--;
+	}
+	if (pack_to_stdout != !base_name || argc)
+		usage_with_options(pack_usage, pack_objects_options);
+
+	if (depth >= (1 << OE_DEPTH_BITS)) {
+		warning(_("delta chain depth %d is too deep, forcing %d"),
+			depth, (1 << OE_DEPTH_BITS) - 1);
+		depth = (1 << OE_DEPTH_BITS) - 1;
+	}
+	if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
+		warning(_("pack.deltaCacheLimit is too high, forcing %d"),
+			(1U << OE_Z_DELTA_BITS) - 1);
+		cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
+	}
+
+	argv_array_push(&rp, "pack-objects");
+	if (thin) {
+		use_internal_rev_list = 1;
+		argv_array_push(&rp, shallow
+				? "--objects-edge-aggressive"
+				: "--objects-edge");
+	} else
+		argv_array_push(&rp, "--objects");
+
+	if (rev_list_all) {
+		use_internal_rev_list = 1;
+		argv_array_push(&rp, "--all");
+	}
+	if (rev_list_reflog) {
+		use_internal_rev_list = 1;
+		argv_array_push(&rp, "--reflog");
+	}
+	if (rev_list_index) {
+		use_internal_rev_list = 1;
+		argv_array_push(&rp, "--indexed-objects");
+	}
+	if (rev_list_unpacked) {
+		use_internal_rev_list = 1;
+		argv_array_push(&rp, "--unpacked");
+	}
+
+	if (exclude_promisor_objects) {
+		use_internal_rev_list = 1;
+		fetch_if_missing = 0;
+		argv_array_push(&rp, "--exclude-promisor-objects");
+	}
+	if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
+		use_internal_rev_list = 1;
+
+	if (!reuse_object)
+		reuse_delta = 0;
+	if (pack_compression_level == -1)
+		pack_compression_level = Z_DEFAULT_COMPRESSION;
+	else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
+		die(_("bad pack compression level %d"), pack_compression_level);
+
+	if (!delta_search_threads)	/* --threads=0 means autodetect */
+		delta_search_threads = online_cpus();
+
+	if (!HAVE_THREADS && delta_search_threads != 1)
+		warning(_("no threads support, ignoring --threads"));
+	if (!pack_to_stdout && !pack_size_limit)
+		pack_size_limit = pack_size_limit_cfg;
+	if (pack_to_stdout && pack_size_limit)
+		die(_("--max-pack-size cannot be used to build a pack for transfer"));
+	if (pack_size_limit && pack_size_limit < 1024*1024) {
+		warning(_("minimum pack size limit is 1 MiB"));
+		pack_size_limit = 1024*1024;
+	}
+
+	if (!pack_to_stdout && thin)
+		die(_("--thin cannot be used to build an indexable pack"));
+
+	if (keep_unreachable && unpack_unreachable)
+		die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
+	if (!rev_list_all || !rev_list_reflog || !rev_list_index)
+		unpack_unreachable_expiration = 0;
+
+	if (filter_options.choice) {
+		if (!pack_to_stdout)
+			die(_("cannot use --filter without --stdout"));
+	}
+
+	/*
+	 * "soft" reasons not to use bitmaps - for on-disk repack by default we want
+	 *
+	 * - to produce good pack (with bitmap index not-yet-packed objects are
+	 *   packed in suboptimal order).
+	 *
+	 * - to use more robust pack-generation codepath (avoiding possible
+	 *   bugs in bitmap code and possible bitmap index corruption).
+	 */
+	if (!pack_to_stdout)
+		use_bitmap_index_default = 0;
+
+	if (use_bitmap_index < 0)
+		use_bitmap_index = use_bitmap_index_default;
+
+	/* "hard" reasons not to use bitmaps; these just won't work at all */
+	if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
+		use_bitmap_index = 0;
+
+	if (pack_to_stdout || !rev_list_all)
+		write_bitmap_index = 0;
+
+	if (use_delta_islands)
+		argv_array_push(&rp, "--topo-order");
+
+	if (progress && all_progress_implied)
+		progress = 2;
+
+	add_extra_kept_packs(&keep_pack_list);
+	if (ignore_packed_keep_on_disk) {
+		struct packed_git *p;
+		for (p = get_all_packs(the_repository); p; p = p->next)
+			if (p->pack_local && p->pack_keep)
+				break;
+		if (!p) /* no keep-able packs found */
+			ignore_packed_keep_on_disk = 0;
+	}
+	if (local) {
+		/*
+		 * unlike ignore_packed_keep_on_disk above, we do not
+		 * want to unset "local" based on looking at packs, as
+		 * it also covers non-local objects
+		 */
+		struct packed_git *p;
+		for (p = get_all_packs(the_repository); p; p = p->next) {
+			if (!p->pack_local) {
+				have_non_local_packs = 1;
+				break;
+			}
+		}
+	}
+
+	trace2_region_enter("pack-objects", "enumerate-objects",
+			    the_repository);
+	prepare_packing_data(the_repository, &to_pack);
+
+	if (progress)
+		progress_state = start_progress(_("Enumerating objects"), 0);
+	if (!use_internal_rev_list)
+		read_object_list_from_stdin();
+	else {
+		get_object_list(rp.argc, rp.argv);
+		argv_array_clear(&rp);
+	}
+	cleanup_preferred_base();
+	if (include_tag && nr_result)
+		for_each_ref(add_ref_tag, NULL);
+	stop_progress(&progress_state);
+	trace2_region_leave("pack-objects", "enumerate-objects",
+			    the_repository);
+
+	if (non_empty && !nr_result)
+		return 0;
+	if (nr_result) {
+		trace2_region_enter("pack-objects", "prepare-pack",
+				    the_repository);
+		prepare_pack(window, depth);
+		trace2_region_leave("pack-objects", "prepare-pack",
+				    the_repository);
+	}
+
+	trace2_region_enter("pack-objects", "write-pack-file", the_repository);
+	write_pack_file();
+	trace2_region_leave("pack-objects", "write-pack-file", the_repository);
+
+	if (progress)
+		fprintf_ln(stderr,
+			   _("Total %"PRIu32" (delta %"PRIu32"),"
+			     " reused %"PRIu32" (delta %"PRIu32"),"
+			     " pack-reused %"PRIu32),
+			   written, written_delta, reused, reused_delta,
+			   reuse_packfile_objects);
+	return 0;
+}