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-rw-r--r--third_party/git/pack-bitmap.c1445
1 files changed, 0 insertions, 1445 deletions
diff --git a/third_party/git/pack-bitmap.c b/third_party/git/pack-bitmap.c
deleted file mode 100644
index 4077e731e800..000000000000
--- a/third_party/git/pack-bitmap.c
+++ /dev/null
@@ -1,1445 +0,0 @@
-#include "cache.h"
-#include "commit.h"
-#include "tag.h"
-#include "diff.h"
-#include "revision.h"
-#include "progress.h"
-#include "list-objects.h"
-#include "pack.h"
-#include "pack-bitmap.h"
-#include "pack-revindex.h"
-#include "pack-objects.h"
-#include "packfile.h"
-#include "repository.h"
-#include "object-store.h"
-#include "list-objects-filter-options.h"
-
-/*
- * An entry on the bitmap index, representing the bitmap for a given
- * commit.
- */
-struct stored_bitmap {
-	struct object_id oid;
-	struct ewah_bitmap *root;
-	struct stored_bitmap *xor;
-	int flags;
-};
-
-/*
- * The active bitmap index for a repository. By design, repositories only have
- * a single bitmap index available (the index for the biggest packfile in
- * the repository), since bitmap indexes need full closure.
- *
- * If there is more than one bitmap index available (e.g. because of alternates),
- * the active bitmap index is the largest one.
- */
-struct bitmap_index {
-	/* Packfile to which this bitmap index belongs to */
-	struct packed_git *pack;
-
-	/*
-	 * Mark the first `reuse_objects` in the packfile as reused:
-	 * they will be sent as-is without using them for repacking
-	 * calculations
-	 */
-	uint32_t reuse_objects;
-
-	/* mmapped buffer of the whole bitmap index */
-	unsigned char *map;
-	size_t map_size; /* size of the mmaped buffer */
-	size_t map_pos; /* current position when loading the index */
-
-	/*
-	 * Type indexes.
-	 *
-	 * Each bitmap marks which objects in the packfile  are of the given
-	 * type. This provides type information when yielding the objects from
-	 * the packfile during a walk, which allows for better delta bases.
-	 */
-	struct ewah_bitmap *commits;
-	struct ewah_bitmap *trees;
-	struct ewah_bitmap *blobs;
-	struct ewah_bitmap *tags;
-
-	/* Map from object ID -> `stored_bitmap` for all the bitmapped commits */
-	kh_oid_map_t *bitmaps;
-
-	/* Number of bitmapped commits */
-	uint32_t entry_count;
-
-	/* If not NULL, this is a name-hash cache pointing into map. */
-	uint32_t *hashes;
-
-	/*
-	 * Extended index.
-	 *
-	 * When trying to perform bitmap operations with objects that are not
-	 * packed in `pack`, these objects are added to this "fake index" and
-	 * are assumed to appear at the end of the packfile for all operations
-	 */
-	struct eindex {
-		struct object **objects;
-		uint32_t *hashes;
-		uint32_t count, alloc;
-		kh_oid_pos_t *positions;
-	} ext_index;
-
-	/* Bitmap result of the last performed walk */
-	struct bitmap *result;
-
-	/* "have" bitmap from the last performed walk */
-	struct bitmap *haves;
-
-	/* Version of the bitmap index */
-	unsigned int version;
-};
-
-static struct ewah_bitmap *lookup_stored_bitmap(struct stored_bitmap *st)
-{
-	struct ewah_bitmap *parent;
-	struct ewah_bitmap *composed;
-
-	if (st->xor == NULL)
-		return st->root;
-
-	composed = ewah_pool_new();
-	parent = lookup_stored_bitmap(st->xor);
-	ewah_xor(st->root, parent, composed);
-
-	ewah_pool_free(st->root);
-	st->root = composed;
-	st->xor = NULL;
-
-	return composed;
-}
-
-/*
- * Read a bitmap from the current read position on the mmaped
- * index, and increase the read position accordingly
- */
-static struct ewah_bitmap *read_bitmap_1(struct bitmap_index *index)
-{
-	struct ewah_bitmap *b = ewah_pool_new();
-
-	ssize_t bitmap_size = ewah_read_mmap(b,
-		index->map + index->map_pos,
-		index->map_size - index->map_pos);
-
-	if (bitmap_size < 0) {
-		error("Failed to load bitmap index (corrupted?)");
-		ewah_pool_free(b);
-		return NULL;
-	}
-
-	index->map_pos += bitmap_size;
-	return b;
-}
-
-static int load_bitmap_header(struct bitmap_index *index)
-{
-	struct bitmap_disk_header *header = (void *)index->map;
-
-	if (index->map_size < sizeof(*header) + the_hash_algo->rawsz)
-		return error("Corrupted bitmap index (missing header data)");
-
-	if (memcmp(header->magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE)) != 0)
-		return error("Corrupted bitmap index file (wrong header)");
-
-	index->version = ntohs(header->version);
-	if (index->version != 1)
-		return error("Unsupported version for bitmap index file (%d)", index->version);
-
-	/* Parse known bitmap format options */
-	{
-		uint32_t flags = ntohs(header->options);
-
-		if ((flags & BITMAP_OPT_FULL_DAG) == 0)
-			return error("Unsupported options for bitmap index file "
-				"(Git requires BITMAP_OPT_FULL_DAG)");
-
-		if (flags & BITMAP_OPT_HASH_CACHE) {
-			unsigned char *end = index->map + index->map_size - the_hash_algo->rawsz;
-			index->hashes = ((uint32_t *)end) - index->pack->num_objects;
-		}
-	}
-
-	index->entry_count = ntohl(header->entry_count);
-	index->map_pos += sizeof(*header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz;
-	return 0;
-}
-
-static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
-					  struct ewah_bitmap *root,
-					  const struct object_id *oid,
-					  struct stored_bitmap *xor_with,
-					  int flags)
-{
-	struct stored_bitmap *stored;
-	khiter_t hash_pos;
-	int ret;
-
-	stored = xmalloc(sizeof(struct stored_bitmap));
-	stored->root = root;
-	stored->xor = xor_with;
-	stored->flags = flags;
-	oidcpy(&stored->oid, oid);
-
-	hash_pos = kh_put_oid_map(index->bitmaps, stored->oid, &ret);
-
-	/* a 0 return code means the insertion succeeded with no changes,
-	 * because the SHA1 already existed on the map. this is bad, there
-	 * shouldn't be duplicated commits in the index */
-	if (ret == 0) {
-		error("Duplicate entry in bitmap index: %s", oid_to_hex(oid));
-		return NULL;
-	}
-
-	kh_value(index->bitmaps, hash_pos) = stored;
-	return stored;
-}
-
-static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
-{
-	uint32_t result = get_be32(buffer + *pos);
-	(*pos) += sizeof(result);
-	return result;
-}
-
-static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
-{
-	return buffer[(*pos)++];
-}
-
-#define MAX_XOR_OFFSET 160
-
-static int load_bitmap_entries_v1(struct bitmap_index *index)
-{
-	uint32_t i;
-	struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
-
-	for (i = 0; i < index->entry_count; ++i) {
-		int xor_offset, flags;
-		struct ewah_bitmap *bitmap = NULL;
-		struct stored_bitmap *xor_bitmap = NULL;
-		uint32_t commit_idx_pos;
-		struct object_id oid;
-
-		commit_idx_pos = read_be32(index->map, &index->map_pos);
-		xor_offset = read_u8(index->map, &index->map_pos);
-		flags = read_u8(index->map, &index->map_pos);
-
-		nth_packed_object_id(&oid, index->pack, commit_idx_pos);
-
-		bitmap = read_bitmap_1(index);
-		if (!bitmap)
-			return -1;
-
-		if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
-			return error("Corrupted bitmap pack index");
-
-		if (xor_offset > 0) {
-			xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
-
-			if (xor_bitmap == NULL)
-				return error("Invalid XOR offset in bitmap pack index");
-		}
-
-		recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
-			index, bitmap, &oid, xor_bitmap, flags);
-	}
-
-	return 0;
-}
-
-static char *pack_bitmap_filename(struct packed_git *p)
-{
-	size_t len;
-
-	if (!strip_suffix(p->pack_name, ".pack", &len))
-		BUG("pack_name does not end in .pack");
-	return xstrfmt("%.*s.bitmap", (int)len, p->pack_name);
-}
-
-static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
-{
-	int fd;
-	struct stat st;
-	char *idx_name;
-
-	if (open_pack_index(packfile))
-		return -1;
-
-	idx_name = pack_bitmap_filename(packfile);
-	fd = git_open(idx_name);
-	free(idx_name);
-
-	if (fd < 0)
-		return -1;
-
-	if (fstat(fd, &st)) {
-		close(fd);
-		return -1;
-	}
-
-	if (bitmap_git->pack) {
-		warning("ignoring extra bitmap file: %s", packfile->pack_name);
-		close(fd);
-		return -1;
-	}
-
-	bitmap_git->pack = packfile;
-	bitmap_git->map_size = xsize_t(st.st_size);
-	bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	bitmap_git->map_pos = 0;
-	close(fd);
-
-	if (load_bitmap_header(bitmap_git) < 0) {
-		munmap(bitmap_git->map, bitmap_git->map_size);
-		bitmap_git->map = NULL;
-		bitmap_git->map_size = 0;
-		return -1;
-	}
-
-	return 0;
-}
-
-static int load_pack_bitmap(struct bitmap_index *bitmap_git)
-{
-	assert(bitmap_git->map);
-
-	bitmap_git->bitmaps = kh_init_oid_map();
-	bitmap_git->ext_index.positions = kh_init_oid_pos();
-	if (load_pack_revindex(bitmap_git->pack))
-		goto failed;
-
-	if (!(bitmap_git->commits = read_bitmap_1(bitmap_git)) ||
-		!(bitmap_git->trees = read_bitmap_1(bitmap_git)) ||
-		!(bitmap_git->blobs = read_bitmap_1(bitmap_git)) ||
-		!(bitmap_git->tags = read_bitmap_1(bitmap_git)))
-		goto failed;
-
-	if (load_bitmap_entries_v1(bitmap_git) < 0)
-		goto failed;
-
-	return 0;
-
-failed:
-	munmap(bitmap_git->map, bitmap_git->map_size);
-	bitmap_git->map = NULL;
-	bitmap_git->map_size = 0;
-
-	kh_destroy_oid_map(bitmap_git->bitmaps);
-	bitmap_git->bitmaps = NULL;
-
-	kh_destroy_oid_pos(bitmap_git->ext_index.positions);
-	bitmap_git->ext_index.positions = NULL;
-
-	return -1;
-}
-
-static int open_pack_bitmap(struct repository *r,
-			    struct bitmap_index *bitmap_git)
-{
-	struct packed_git *p;
-	int ret = -1;
-
-	assert(!bitmap_git->map);
-
-	for (p = get_all_packs(r); p; p = p->next) {
-		if (open_pack_bitmap_1(bitmap_git, p) == 0)
-			ret = 0;
-	}
-
-	return ret;
-}
-
-struct bitmap_index *prepare_bitmap_git(struct repository *r)
-{
-	struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
-
-	if (!open_pack_bitmap(r, bitmap_git) && !load_pack_bitmap(bitmap_git))
-		return bitmap_git;
-
-	free_bitmap_index(bitmap_git);
-	return NULL;
-}
-
-struct include_data {
-	struct bitmap_index *bitmap_git;
-	struct bitmap *base;
-	struct bitmap *seen;
-};
-
-static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
-					   const struct object_id *oid)
-{
-	kh_oid_pos_t *positions = bitmap_git->ext_index.positions;
-	khiter_t pos = kh_get_oid_pos(positions, *oid);
-
-	if (pos < kh_end(positions)) {
-		int bitmap_pos = kh_value(positions, pos);
-		return bitmap_pos + bitmap_git->pack->num_objects;
-	}
-
-	return -1;
-}
-
-static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
-					   const struct object_id *oid)
-{
-	off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
-	if (!offset)
-		return -1;
-
-	return find_revindex_position(bitmap_git->pack, offset);
-}
-
-static int bitmap_position(struct bitmap_index *bitmap_git,
-			   const struct object_id *oid)
-{
-	int pos = bitmap_position_packfile(bitmap_git, oid);
-	return (pos >= 0) ? pos : bitmap_position_extended(bitmap_git, oid);
-}
-
-static int ext_index_add_object(struct bitmap_index *bitmap_git,
-				struct object *object, const char *name)
-{
-	struct eindex *eindex = &bitmap_git->ext_index;
-
-	khiter_t hash_pos;
-	int hash_ret;
-	int bitmap_pos;
-
-	hash_pos = kh_put_oid_pos(eindex->positions, object->oid, &hash_ret);
-	if (hash_ret > 0) {
-		if (eindex->count >= eindex->alloc) {
-			eindex->alloc = (eindex->alloc + 16) * 3 / 2;
-			REALLOC_ARRAY(eindex->objects, eindex->alloc);
-			REALLOC_ARRAY(eindex->hashes, eindex->alloc);
-		}
-
-		bitmap_pos = eindex->count;
-		eindex->objects[eindex->count] = object;
-		eindex->hashes[eindex->count] = pack_name_hash(name);
-		kh_value(eindex->positions, hash_pos) = bitmap_pos;
-		eindex->count++;
-	} else {
-		bitmap_pos = kh_value(eindex->positions, hash_pos);
-	}
-
-	return bitmap_pos + bitmap_git->pack->num_objects;
-}
-
-struct bitmap_show_data {
-	struct bitmap_index *bitmap_git;
-	struct bitmap *base;
-};
-
-static void show_object(struct object *object, const char *name, void *data_)
-{
-	struct bitmap_show_data *data = data_;
-	int bitmap_pos;
-
-	bitmap_pos = bitmap_position(data->bitmap_git, &object->oid);
-
-	if (bitmap_pos < 0)
-		bitmap_pos = ext_index_add_object(data->bitmap_git, object,
-						  name);
-
-	bitmap_set(data->base, bitmap_pos);
-}
-
-static void show_commit(struct commit *commit, void *data)
-{
-}
-
-static int add_to_include_set(struct bitmap_index *bitmap_git,
-			      struct include_data *data,
-			      const struct object_id *oid,
-			      int bitmap_pos)
-{
-	khiter_t hash_pos;
-
-	if (data->seen && bitmap_get(data->seen, bitmap_pos))
-		return 0;
-
-	if (bitmap_get(data->base, bitmap_pos))
-		return 0;
-
-	hash_pos = kh_get_oid_map(bitmap_git->bitmaps, *oid);
-	if (hash_pos < kh_end(bitmap_git->bitmaps)) {
-		struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, hash_pos);
-		bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
-		return 0;
-	}
-
-	bitmap_set(data->base, bitmap_pos);
-	return 1;
-}
-
-static int should_include(struct commit *commit, void *_data)
-{
-	struct include_data *data = _data;
-	int bitmap_pos;
-
-	bitmap_pos = bitmap_position(data->bitmap_git, &commit->object.oid);
-	if (bitmap_pos < 0)
-		bitmap_pos = ext_index_add_object(data->bitmap_git,
-						  (struct object *)commit,
-						  NULL);
-
-	if (!add_to_include_set(data->bitmap_git, data, &commit->object.oid,
-				bitmap_pos)) {
-		struct commit_list *parent = commit->parents;
-
-		while (parent) {
-			parent->item->object.flags |= SEEN;
-			parent = parent->next;
-		}
-
-		return 0;
-	}
-
-	return 1;
-}
-
-static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
-				   struct rev_info *revs,
-				   struct object_list *roots,
-				   struct bitmap *seen,
-				   struct list_objects_filter_options *filter)
-{
-	struct bitmap *base = NULL;
-	int needs_walk = 0;
-
-	struct object_list *not_mapped = NULL;
-
-	/*
-	 * Go through all the roots for the walk. The ones that have bitmaps
-	 * on the bitmap index will be `or`ed together to form an initial
-	 * global reachability analysis.
-	 *
-	 * The ones without bitmaps in the index will be stored in the
-	 * `not_mapped_list` for further processing.
-	 */
-	while (roots) {
-		struct object *object = roots->item;
-		roots = roots->next;
-
-		if (object->type == OBJ_COMMIT) {
-			khiter_t pos = kh_get_oid_map(bitmap_git->bitmaps, object->oid);
-
-			if (pos < kh_end(bitmap_git->bitmaps)) {
-				struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
-				struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
-
-				if (base == NULL)
-					base = ewah_to_bitmap(or_with);
-				else
-					bitmap_or_ewah(base, or_with);
-
-				object->flags |= SEEN;
-				continue;
-			}
-		}
-
-		object_list_insert(object, &not_mapped);
-	}
-
-	/*
-	 * Best case scenario: We found bitmaps for all the roots,
-	 * so the resulting `or` bitmap has the full reachability analysis
-	 */
-	if (not_mapped == NULL)
-		return base;
-
-	roots = not_mapped;
-
-	/*
-	 * Let's iterate through all the roots that don't have bitmaps to
-	 * check if we can determine them to be reachable from the existing
-	 * global bitmap.
-	 *
-	 * If we cannot find them in the existing global bitmap, we'll need
-	 * to push them to an actual walk and run it until we can confirm
-	 * they are reachable
-	 */
-	while (roots) {
-		struct object *object = roots->item;
-		int pos;
-
-		roots = roots->next;
-		pos = bitmap_position(bitmap_git, &object->oid);
-
-		if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
-			object->flags &= ~UNINTERESTING;
-			add_pending_object(revs, object, "");
-			needs_walk = 1;
-		} else {
-			object->flags |= SEEN;
-		}
-	}
-
-	if (needs_walk) {
-		struct include_data incdata;
-		struct bitmap_show_data show_data;
-
-		if (base == NULL)
-			base = bitmap_new();
-
-		incdata.bitmap_git = bitmap_git;
-		incdata.base = base;
-		incdata.seen = seen;
-
-		revs->include_check = should_include;
-		revs->include_check_data = &incdata;
-
-		if (prepare_revision_walk(revs))
-			die("revision walk setup failed");
-
-		show_data.bitmap_git = bitmap_git;
-		show_data.base = base;
-
-		traverse_commit_list_filtered(filter, revs,
-					      show_commit, show_object,
-					      &show_data, NULL);
-	}
-
-	return base;
-}
-
-static void show_extended_objects(struct bitmap_index *bitmap_git,
-				  struct rev_info *revs,
-				  show_reachable_fn show_reach)
-{
-	struct bitmap *objects = bitmap_git->result;
-	struct eindex *eindex = &bitmap_git->ext_index;
-	uint32_t i;
-
-	for (i = 0; i < eindex->count; ++i) {
-		struct object *obj;
-
-		if (!bitmap_get(objects, bitmap_git->pack->num_objects + i))
-			continue;
-
-		obj = eindex->objects[i];
-		if ((obj->type == OBJ_BLOB && !revs->blob_objects) ||
-		    (obj->type == OBJ_TREE && !revs->tree_objects) ||
-		    (obj->type == OBJ_TAG && !revs->tag_objects))
-			continue;
-
-		show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
-	}
-}
-
-static void init_type_iterator(struct ewah_iterator *it,
-			       struct bitmap_index *bitmap_git,
-			       enum object_type type)
-{
-	switch (type) {
-	case OBJ_COMMIT:
-		ewah_iterator_init(it, bitmap_git->commits);
-		break;
-
-	case OBJ_TREE:
-		ewah_iterator_init(it, bitmap_git->trees);
-		break;
-
-	case OBJ_BLOB:
-		ewah_iterator_init(it, bitmap_git->blobs);
-		break;
-
-	case OBJ_TAG:
-		ewah_iterator_init(it, bitmap_git->tags);
-		break;
-
-	default:
-		BUG("object type %d not stored by bitmap type index", type);
-		break;
-	}
-}
-
-static void show_objects_for_type(
-	struct bitmap_index *bitmap_git,
-	enum object_type object_type,
-	show_reachable_fn show_reach)
-{
-	size_t i = 0;
-	uint32_t offset;
-
-	struct ewah_iterator it;
-	eword_t filter;
-
-	struct bitmap *objects = bitmap_git->result;
-
-	init_type_iterator(&it, bitmap_git, object_type);
-
-	for (i = 0; i < objects->word_alloc &&
-			ewah_iterator_next(&filter, &it); i++) {
-		eword_t word = objects->words[i] & filter;
-		size_t pos = (i * BITS_IN_EWORD);
-
-		if (!word)
-			continue;
-
-		for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
-			struct object_id oid;
-			struct revindex_entry *entry;
-			uint32_t hash = 0;
-
-			if ((word >> offset) == 0)
-				break;
-
-			offset += ewah_bit_ctz64(word >> offset);
-
-			entry = &bitmap_git->pack->revindex[pos + offset];
-			nth_packed_object_id(&oid, bitmap_git->pack, entry->nr);
-
-			if (bitmap_git->hashes)
-				hash = get_be32(bitmap_git->hashes + entry->nr);
-
-			show_reach(&oid, object_type, 0, hash, bitmap_git->pack, entry->offset);
-		}
-	}
-}
-
-static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
-			     struct object_list *roots)
-{
-	while (roots) {
-		struct object *object = roots->item;
-		roots = roots->next;
-
-		if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
-			return 1;
-	}
-
-	return 0;
-}
-
-static struct bitmap *find_tip_objects(struct bitmap_index *bitmap_git,
-				       struct object_list *tip_objects,
-				       enum object_type type)
-{
-	struct bitmap *result = bitmap_new();
-	struct object_list *p;
-
-	for (p = tip_objects; p; p = p->next) {
-		int pos;
-
-		if (p->item->type != type)
-			continue;
-
-		pos = bitmap_position(bitmap_git, &p->item->oid);
-		if (pos < 0)
-			continue;
-
-		bitmap_set(result, pos);
-	}
-
-	return result;
-}
-
-static void filter_bitmap_exclude_type(struct bitmap_index *bitmap_git,
-				       struct object_list *tip_objects,
-				       struct bitmap *to_filter,
-				       enum object_type type)
-{
-	struct eindex *eindex = &bitmap_git->ext_index;
-	struct bitmap *tips;
-	struct ewah_iterator it;
-	eword_t mask;
-	uint32_t i;
-
-	if (type != OBJ_BLOB && type != OBJ_TREE)
-		BUG("filter_bitmap_exclude_type: unsupported type '%d'", type);
-
-	/*
-	 * The non-bitmap version of this filter never removes
-	 * objects which the other side specifically asked for,
-	 * so we must match that behavior.
-	 */
-	tips = find_tip_objects(bitmap_git, tip_objects, type);
-
-	/*
-	 * We can use the blob type-bitmap to work in whole words
-	 * for the objects that are actually in the bitmapped packfile.
-	 */
-	for (i = 0, init_type_iterator(&it, bitmap_git, type);
-	     i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);
-	     i++) {
-		if (i < tips->word_alloc)
-			mask &= ~tips->words[i];
-		to_filter->words[i] &= ~mask;
-	}
-
-	/*
-	 * Clear any blobs that weren't in the packfile (and so would not have
-	 * been caught by the loop above. We'll have to check them
-	 * individually.
-	 */
-	for (i = 0; i < eindex->count; i++) {
-		uint32_t pos = i + bitmap_git->pack->num_objects;
-		if (eindex->objects[i]->type == type &&
-		    bitmap_get(to_filter, pos) &&
-		    !bitmap_get(tips, pos))
-			bitmap_unset(to_filter, pos);
-	}
-
-	bitmap_free(tips);
-}
-
-static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
-				    struct object_list *tip_objects,
-				    struct bitmap *to_filter)
-{
-	filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
-				   OBJ_BLOB);
-}
-
-static unsigned long get_size_by_pos(struct bitmap_index *bitmap_git,
-				     uint32_t pos)
-{
-	struct packed_git *pack = bitmap_git->pack;
-	unsigned long size;
-	struct object_info oi = OBJECT_INFO_INIT;
-
-	oi.sizep = &size;
-
-	if (pos < pack->num_objects) {
-		struct revindex_entry *entry = &pack->revindex[pos];
-		if (packed_object_info(the_repository, pack,
-				       entry->offset, &oi) < 0) {
-			struct object_id oid;
-			nth_packed_object_id(&oid, pack, entry->nr);
-			die(_("unable to get size of %s"), oid_to_hex(&oid));
-		}
-	} else {
-		struct eindex *eindex = &bitmap_git->ext_index;
-		struct object *obj = eindex->objects[pos - pack->num_objects];
-		if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0)
-			die(_("unable to get size of %s"), oid_to_hex(&obj->oid));
-	}
-
-	return size;
-}
-
-static void filter_bitmap_blob_limit(struct bitmap_index *bitmap_git,
-				     struct object_list *tip_objects,
-				     struct bitmap *to_filter,
-				     unsigned long limit)
-{
-	struct eindex *eindex = &bitmap_git->ext_index;
-	struct bitmap *tips;
-	struct ewah_iterator it;
-	eword_t mask;
-	uint32_t i;
-
-	tips = find_tip_objects(bitmap_git, tip_objects, OBJ_BLOB);
-
-	for (i = 0, init_type_iterator(&it, bitmap_git, OBJ_BLOB);
-	     i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);
-	     i++) {
-		eword_t word = to_filter->words[i] & mask;
-		unsigned offset;
-
-		for (offset = 0; offset < BITS_IN_EWORD; offset++) {
-			uint32_t pos;
-
-			if ((word >> offset) == 0)
-				break;
-			offset += ewah_bit_ctz64(word >> offset);
-			pos = i * BITS_IN_EWORD + offset;
-
-			if (!bitmap_get(tips, pos) &&
-			    get_size_by_pos(bitmap_git, pos) >= limit)
-				bitmap_unset(to_filter, pos);
-		}
-	}
-
-	for (i = 0; i < eindex->count; i++) {
-		uint32_t pos = i + bitmap_git->pack->num_objects;
-		if (eindex->objects[i]->type == OBJ_BLOB &&
-		    bitmap_get(to_filter, pos) &&
-		    !bitmap_get(tips, pos) &&
-		    get_size_by_pos(bitmap_git, pos) >= limit)
-			bitmap_unset(to_filter, pos);
-	}
-
-	bitmap_free(tips);
-}
-
-static void filter_bitmap_tree_depth(struct bitmap_index *bitmap_git,
-				     struct object_list *tip_objects,
-				     struct bitmap *to_filter,
-				     unsigned long limit)
-{
-	if (limit)
-		BUG("filter_bitmap_tree_depth given non-zero limit");
-
-	filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
-				   OBJ_TREE);
-	filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
-				   OBJ_BLOB);
-}
-
-static int filter_bitmap(struct bitmap_index *bitmap_git,
-			 struct object_list *tip_objects,
-			 struct bitmap *to_filter,
-			 struct list_objects_filter_options *filter)
-{
-	if (!filter || filter->choice == LOFC_DISABLED)
-		return 0;
-
-	if (filter->choice == LOFC_BLOB_NONE) {
-		if (bitmap_git)
-			filter_bitmap_blob_none(bitmap_git, tip_objects,
-						to_filter);
-		return 0;
-	}
-
-	if (filter->choice == LOFC_BLOB_LIMIT) {
-		if (bitmap_git)
-			filter_bitmap_blob_limit(bitmap_git, tip_objects,
-						 to_filter,
-						 filter->blob_limit_value);
-		return 0;
-	}
-
-	if (filter->choice == LOFC_TREE_DEPTH &&
-	    filter->tree_exclude_depth == 0) {
-		if (bitmap_git)
-			filter_bitmap_tree_depth(bitmap_git, tip_objects,
-						 to_filter,
-						 filter->tree_exclude_depth);
-		return 0;
-	}
-
-	/* filter choice not handled */
-	return -1;
-}
-
-static int can_filter_bitmap(struct list_objects_filter_options *filter)
-{
-	return !filter_bitmap(NULL, NULL, NULL, filter);
-}
-
-struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs,
-					 struct list_objects_filter_options *filter)
-{
-	unsigned int i;
-
-	struct object_list *wants = NULL;
-	struct object_list *haves = NULL;
-
-	struct bitmap *wants_bitmap = NULL;
-	struct bitmap *haves_bitmap = NULL;
-
-	struct bitmap_index *bitmap_git;
-
-	/*
-	 * We can't do pathspec limiting with bitmaps, because we don't know
-	 * which commits are associated with which object changes (let alone
-	 * even which objects are associated with which paths).
-	 */
-	if (revs->prune)
-		return NULL;
-
-	if (!can_filter_bitmap(filter))
-		return NULL;
-
-	/* try to open a bitmapped pack, but don't parse it yet
-	 * because we may not need to use it */
-	bitmap_git = xcalloc(1, sizeof(*bitmap_git));
-	if (open_pack_bitmap(revs->repo, bitmap_git) < 0)
-		goto cleanup;
-
-	for (i = 0; i < revs->pending.nr; ++i) {
-		struct object *object = revs->pending.objects[i].item;
-
-		if (object->type == OBJ_NONE)
-			parse_object_or_die(&object->oid, NULL);
-
-		while (object->type == OBJ_TAG) {
-			struct tag *tag = (struct tag *) object;
-
-			if (object->flags & UNINTERESTING)
-				object_list_insert(object, &haves);
-			else
-				object_list_insert(object, &wants);
-
-			object = parse_object_or_die(get_tagged_oid(tag), NULL);
-		}
-
-		if (object->flags & UNINTERESTING)
-			object_list_insert(object, &haves);
-		else
-			object_list_insert(object, &wants);
-	}
-
-	/*
-	 * if we have a HAVES list, but none of those haves is contained
-	 * in the packfile that has a bitmap, we don't have anything to
-	 * optimize here
-	 */
-	if (haves && !in_bitmapped_pack(bitmap_git, haves))
-		goto cleanup;
-
-	/* if we don't want anything, we're done here */
-	if (!wants)
-		goto cleanup;
-
-	/*
-	 * now we're going to use bitmaps, so load the actual bitmap entries
-	 * from disk. this is the point of no return; after this the rev_list
-	 * becomes invalidated and we must perform the revwalk through bitmaps
-	 */
-	if (load_pack_bitmap(bitmap_git) < 0)
-		goto cleanup;
-
-	object_array_clear(&revs->pending);
-
-	if (haves) {
-		revs->ignore_missing_links = 1;
-		haves_bitmap = find_objects(bitmap_git, revs, haves, NULL,
-					    filter);
-		reset_revision_walk();
-		revs->ignore_missing_links = 0;
-
-		if (haves_bitmap == NULL)
-			BUG("failed to perform bitmap walk");
-	}
-
-	wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap,
-				    filter);
-
-	if (!wants_bitmap)
-		BUG("failed to perform bitmap walk");
-
-	if (haves_bitmap)
-		bitmap_and_not(wants_bitmap, haves_bitmap);
-
-	filter_bitmap(bitmap_git, wants, wants_bitmap, filter);
-
-	bitmap_git->result = wants_bitmap;
-	bitmap_git->haves = haves_bitmap;
-
-	object_list_free(&wants);
-	object_list_free(&haves);
-
-	return bitmap_git;
-
-cleanup:
-	free_bitmap_index(bitmap_git);
-	object_list_free(&wants);
-	object_list_free(&haves);
-	return NULL;
-}
-
-static void try_partial_reuse(struct bitmap_index *bitmap_git,
-			      size_t pos,
-			      struct bitmap *reuse,
-			      struct pack_window **w_curs)
-{
-	struct revindex_entry *revidx;
-	off_t offset;
-	enum object_type type;
-	unsigned long size;
-
-	if (pos >= bitmap_git->pack->num_objects)
-		return; /* not actually in the pack */
-
-	revidx = &bitmap_git->pack->revindex[pos];
-	offset = revidx->offset;
-	type = unpack_object_header(bitmap_git->pack, w_curs, &offset, &size);
-	if (type < 0)
-		return; /* broken packfile, punt */
-
-	if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA) {
-		off_t base_offset;
-		int base_pos;
-
-		/*
-		 * Find the position of the base object so we can look it up
-		 * in our bitmaps. If we can't come up with an offset, or if
-		 * that offset is not in the revidx, the pack is corrupt.
-		 * There's nothing we can do, so just punt on this object,
-		 * and the normal slow path will complain about it in
-		 * more detail.
-		 */
-		base_offset = get_delta_base(bitmap_git->pack, w_curs,
-					     &offset, type, revidx->offset);
-		if (!base_offset)
-			return;
-		base_pos = find_revindex_position(bitmap_git->pack, base_offset);
-		if (base_pos < 0)
-			return;
-
-		/*
-		 * We assume delta dependencies always point backwards. This
-		 * lets us do a single pass, and is basically always true
-		 * due to the way OFS_DELTAs work. You would not typically
-		 * find REF_DELTA in a bitmapped pack, since we only bitmap
-		 * packs we write fresh, and OFS_DELTA is the default). But
-		 * let's double check to make sure the pack wasn't written with
-		 * odd parameters.
-		 */
-		if (base_pos >= pos)
-			return;
-
-		/*
-		 * And finally, if we're not sending the base as part of our
-		 * reuse chunk, then don't send this object either. The base
-		 * would come after us, along with other objects not
-		 * necessarily in the pack, which means we'd need to convert
-		 * to REF_DELTA on the fly. Better to just let the normal
-		 * object_entry code path handle it.
-		 */
-		if (!bitmap_get(reuse, base_pos))
-			return;
-	}
-
-	/*
-	 * If we got here, then the object is OK to reuse. Mark it.
-	 */
-	bitmap_set(reuse, pos);
-}
-
-int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
-				       struct packed_git **packfile_out,
-				       uint32_t *entries,
-				       struct bitmap **reuse_out)
-{
-	struct bitmap *result = bitmap_git->result;
-	struct bitmap *reuse;
-	struct pack_window *w_curs = NULL;
-	size_t i = 0;
-	uint32_t offset;
-
-	assert(result);
-
-	while (i < result->word_alloc && result->words[i] == (eword_t)~0)
-		i++;
-
-	/* Don't mark objects not in the packfile */
-	if (i > bitmap_git->pack->num_objects / BITS_IN_EWORD)
-		i = bitmap_git->pack->num_objects / BITS_IN_EWORD;
-
-	reuse = bitmap_word_alloc(i);
-	memset(reuse->words, 0xFF, i * sizeof(eword_t));
-
-	for (; i < result->word_alloc; ++i) {
-		eword_t word = result->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);
-			try_partial_reuse(bitmap_git, pos + offset, reuse, &w_curs);
-		}
-	}
-
-	unuse_pack(&w_curs);
-
-	*entries = bitmap_popcount(reuse);
-	if (!*entries) {
-		bitmap_free(reuse);
-		return -1;
-	}
-
-	/*
-	 * Drop any reused objects from the result, since they will not
-	 * need to be handled separately.
-	 */
-	bitmap_and_not(result, reuse);
-	*packfile_out = bitmap_git->pack;
-	*reuse_out = reuse;
-	return 0;
-}
-
-int bitmap_walk_contains(struct bitmap_index *bitmap_git,
-			 struct bitmap *bitmap, const struct object_id *oid)
-{
-	int idx;
-
-	if (!bitmap)
-		return 0;
-
-	idx = bitmap_position(bitmap_git, oid);
-	return idx >= 0 && bitmap_get(bitmap, idx);
-}
-
-void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
-				 struct rev_info *revs,
-				 show_reachable_fn show_reachable)
-{
-	assert(bitmap_git->result);
-
-	show_objects_for_type(bitmap_git, OBJ_COMMIT, show_reachable);
-	if (revs->tree_objects)
-		show_objects_for_type(bitmap_git, OBJ_TREE, show_reachable);
-	if (revs->blob_objects)
-		show_objects_for_type(bitmap_git, OBJ_BLOB, show_reachable);
-	if (revs->tag_objects)
-		show_objects_for_type(bitmap_git, OBJ_TAG, show_reachable);
-
-	show_extended_objects(bitmap_git, revs, show_reachable);
-}
-
-static uint32_t count_object_type(struct bitmap_index *bitmap_git,
-				  enum object_type type)
-{
-	struct bitmap *objects = bitmap_git->result;
-	struct eindex *eindex = &bitmap_git->ext_index;
-
-	uint32_t i = 0, count = 0;
-	struct ewah_iterator it;
-	eword_t filter;
-
-	init_type_iterator(&it, bitmap_git, type);
-
-	while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
-		eword_t word = objects->words[i++] & filter;
-		count += ewah_bit_popcount64(word);
-	}
-
-	for (i = 0; i < eindex->count; ++i) {
-		if (eindex->objects[i]->type == type &&
-			bitmap_get(objects, bitmap_git->pack->num_objects + i))
-			count++;
-	}
-
-	return count;
-}
-
-void count_bitmap_commit_list(struct bitmap_index *bitmap_git,
-			      uint32_t *commits, uint32_t *trees,
-			      uint32_t *blobs, uint32_t *tags)
-{
-	assert(bitmap_git->result);
-
-	if (commits)
-		*commits = count_object_type(bitmap_git, OBJ_COMMIT);
-
-	if (trees)
-		*trees = count_object_type(bitmap_git, OBJ_TREE);
-
-	if (blobs)
-		*blobs = count_object_type(bitmap_git, OBJ_BLOB);
-
-	if (tags)
-		*tags = count_object_type(bitmap_git, OBJ_TAG);
-}
-
-struct bitmap_test_data {
-	struct bitmap_index *bitmap_git;
-	struct bitmap *base;
-	struct progress *prg;
-	size_t seen;
-};
-
-static void test_show_object(struct object *object, const char *name,
-			     void *data)
-{
-	struct bitmap_test_data *tdata = data;
-	int bitmap_pos;
-
-	bitmap_pos = bitmap_position(tdata->bitmap_git, &object->oid);
-	if (bitmap_pos < 0)
-		die("Object not in bitmap: %s\n", oid_to_hex(&object->oid));
-
-	bitmap_set(tdata->base, bitmap_pos);
-	display_progress(tdata->prg, ++tdata->seen);
-}
-
-static void test_show_commit(struct commit *commit, void *data)
-{
-	struct bitmap_test_data *tdata = data;
-	int bitmap_pos;
-
-	bitmap_pos = bitmap_position(tdata->bitmap_git,
-				     &commit->object.oid);
-	if (bitmap_pos < 0)
-		die("Object not in bitmap: %s\n", oid_to_hex(&commit->object.oid));
-
-	bitmap_set(tdata->base, bitmap_pos);
-	display_progress(tdata->prg, ++tdata->seen);
-}
-
-void test_bitmap_walk(struct rev_info *revs)
-{
-	struct object *root;
-	struct bitmap *result = NULL;
-	khiter_t pos;
-	size_t result_popcnt;
-	struct bitmap_test_data tdata;
-	struct bitmap_index *bitmap_git;
-
-	if (!(bitmap_git = prepare_bitmap_git(revs->repo)))
-		die("failed to load bitmap indexes");
-
-	if (revs->pending.nr != 1)
-		die("you must specify exactly one commit to test");
-
-	fprintf(stderr, "Bitmap v%d test (%d entries loaded)\n",
-		bitmap_git->version, bitmap_git->entry_count);
-
-	root = revs->pending.objects[0].item;
-	pos = kh_get_oid_map(bitmap_git->bitmaps, root->oid);
-
-	if (pos < kh_end(bitmap_git->bitmaps)) {
-		struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
-		struct ewah_bitmap *bm = lookup_stored_bitmap(st);
-
-		fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
-			oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
-
-		result = ewah_to_bitmap(bm);
-	}
-
-	if (result == NULL)
-		die("Commit %s doesn't have an indexed bitmap", oid_to_hex(&root->oid));
-
-	revs->tag_objects = 1;
-	revs->tree_objects = 1;
-	revs->blob_objects = 1;
-
-	result_popcnt = bitmap_popcount(result);
-
-	if (prepare_revision_walk(revs))
-		die("revision walk setup failed");
-
-	tdata.bitmap_git = bitmap_git;
-	tdata.base = bitmap_new();
-	tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
-	tdata.seen = 0;
-
-	traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
-
-	stop_progress(&tdata.prg);
-
-	if (bitmap_equals(result, tdata.base))
-		fprintf(stderr, "OK!\n");
-	else
-		fprintf(stderr, "Mismatch!\n");
-
-	free_bitmap_index(bitmap_git);
-}
-
-static int rebuild_bitmap(uint32_t *reposition,
-			  struct ewah_bitmap *source,
-			  struct bitmap *dest)
-{
-	uint32_t pos = 0;
-	struct ewah_iterator it;
-	eword_t word;
-
-	ewah_iterator_init(&it, source);
-
-	while (ewah_iterator_next(&word, &it)) {
-		uint32_t offset, bit_pos;
-
-		for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
-			if ((word >> offset) == 0)
-				break;
-
-			offset += ewah_bit_ctz64(word >> offset);
-
-			bit_pos = reposition[pos + offset];
-			if (bit_pos > 0)
-				bitmap_set(dest, bit_pos - 1);
-			else /* can't reuse, we don't have the object */
-				return -1;
-		}
-
-		pos += BITS_IN_EWORD;
-	}
-	return 0;
-}
-
-int rebuild_existing_bitmaps(struct bitmap_index *bitmap_git,
-			     struct packing_data *mapping,
-			     kh_oid_map_t *reused_bitmaps,
-			     int show_progress)
-{
-	uint32_t i, num_objects;
-	uint32_t *reposition;
-	struct bitmap *rebuild;
-	struct stored_bitmap *stored;
-	struct progress *progress = NULL;
-
-	khiter_t hash_pos;
-	int hash_ret;
-
-	num_objects = bitmap_git->pack->num_objects;
-	reposition = xcalloc(num_objects, sizeof(uint32_t));
-
-	for (i = 0; i < num_objects; ++i) {
-		struct object_id oid;
-		struct revindex_entry *entry;
-		struct object_entry *oe;
-
-		entry = &bitmap_git->pack->revindex[i];
-		nth_packed_object_id(&oid, bitmap_git->pack, entry->nr);
-		oe = packlist_find(mapping, &oid);
-
-		if (oe)
-			reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
-	}
-
-	rebuild = bitmap_new();
-	i = 0;
-
-	if (show_progress)
-		progress = start_progress("Reusing bitmaps", 0);
-
-	kh_foreach_value(bitmap_git->bitmaps, stored, {
-		if (stored->flags & BITMAP_FLAG_REUSE) {
-			if (!rebuild_bitmap(reposition,
-					    lookup_stored_bitmap(stored),
-					    rebuild)) {
-				hash_pos = kh_put_oid_map(reused_bitmaps,
-							  stored->oid,
-							  &hash_ret);
-				kh_value(reused_bitmaps, hash_pos) =
-					bitmap_to_ewah(rebuild);
-			}
-			bitmap_reset(rebuild);
-			display_progress(progress, ++i);
-		}
-	});
-
-	stop_progress(&progress);
-
-	free(reposition);
-	bitmap_free(rebuild);
-	return 0;
-}
-
-void free_bitmap_index(struct bitmap_index *b)
-{
-	if (!b)
-		return;
-
-	if (b->map)
-		munmap(b->map, b->map_size);
-	ewah_pool_free(b->commits);
-	ewah_pool_free(b->trees);
-	ewah_pool_free(b->blobs);
-	ewah_pool_free(b->tags);
-	kh_destroy_oid_map(b->bitmaps);
-	free(b->ext_index.objects);
-	free(b->ext_index.hashes);
-	bitmap_free(b->result);
-	bitmap_free(b->haves);
-	free(b);
-}
-
-int bitmap_has_oid_in_uninteresting(struct bitmap_index *bitmap_git,
-				    const struct object_id *oid)
-{
-	return bitmap_git &&
-		bitmap_walk_contains(bitmap_git, bitmap_git->haves, oid);
-}