chore(3p/git): Unvendor git and track patches instead r/2903

This was vendored a long time ago under the expectation that keeping
it in sync with cgit would be easier this way, but it has proven not
to be a big issue.

On the other hand, a vendored copy of git is an annoying maintenance
burden. It is much easier to rebase the single (dottime) patch that we
have.

This removes the vendored copy of git and instead passes the git
source code to cgit via `pkgs.srcOnly`, which includes the applied
patch so that cgit can continue rendering dottime.

Change-Id: If31f62dea7ce688fd1b9050204e9378019775f2b

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);
-}