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-rw-r--r--pack-bitmap.c1135
1 files changed, 1135 insertions, 0 deletions
diff --git a/pack-bitmap.c b/pack-bitmap.c
new file mode 100644
index 0000000000..ed2befaac6
--- /dev/null
+++ b/pack-bitmap.c
@@ -0,0 +1,1135 @@
+#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"
+
+/*
+ * 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 unsigned char *hash,
+ 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;
+ oidread(&stored->oid, hash);
+
+ 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", hash_to_hex(hash));
+ 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;
+ const unsigned char *sha1;
+
+ 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);
+
+ sha1 = nth_packed_object_sha1(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, sha1, 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;
+ 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 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(revs, show_commit, show_object,
+ &show_data);
+ }
+
+ return base;
+}
+
+static void show_extended_objects(struct bitmap_index *bitmap_git,
+ 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];
+ show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
+ }
+}
+
+static void show_objects_for_type(
+ struct bitmap_index *bitmap_git,
+ struct ewah_bitmap *type_filter,
+ enum object_type object_type,
+ show_reachable_fn show_reach)
+{
+ size_t pos = 0, i = 0;
+ uint32_t offset;
+
+ struct ewah_iterator it;
+ eword_t filter;
+
+ struct bitmap *objects = bitmap_git->result;
+
+ if (bitmap_git->reuse_objects == bitmap_git->pack->num_objects)
+ return;
+
+ ewah_iterator_init(&it, type_filter);
+
+ while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
+ eword_t word = objects->words[i] & filter;
+
+ 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);
+
+ if (pos + offset < bitmap_git->reuse_objects)
+ continue;
+
+ entry = &bitmap_git->pack->revindex[pos + offset];
+ nth_packed_object_oid(&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);
+ }
+
+ pos += BITS_IN_EWORD;
+ i++;
+ }
+}
+
+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;
+}
+
+struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs)
+{
+ 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 = xcalloc(1, sizeof(*bitmap_git));
+ /* try to open a bitmapped pack, but don't parse it yet
+ * because we may not need to use it */
+ 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);
+
+ if (!tag->tagged)
+ die("bad tag");
+ object = parse_object_or_die(&tag->tagged->oid, 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);
+ 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);
+
+ if (!wants_bitmap)
+ BUG("failed to perform bitmap walk");
+
+ if (haves_bitmap)
+ bitmap_and_not(wants_bitmap, haves_bitmap);
+
+ bitmap_git->result = wants_bitmap;
+ bitmap_git->haves = haves_bitmap;
+
+ return bitmap_git;
+
+cleanup:
+ free_bitmap_index(bitmap_git);
+ return NULL;
+}
+
+int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
+ struct packed_git **packfile,
+ uint32_t *entries,
+ off_t *up_to)
+{
+ /*
+ * Reuse the packfile content if we need more than
+ * 90% of its objects
+ */
+ static const double REUSE_PERCENT = 0.9;
+
+ struct bitmap *result = bitmap_git->result;
+ uint32_t reuse_threshold;
+ uint32_t i, reuse_objects = 0;
+
+ assert(result);
+
+ for (i = 0; i < result->word_alloc; ++i) {
+ if (result->words[i] != (eword_t)~0) {
+ reuse_objects += ewah_bit_ctz64(~result->words[i]);
+ break;
+ }
+
+ reuse_objects += BITS_IN_EWORD;
+ }
+
+#ifdef GIT_BITMAP_DEBUG
+ {
+ const unsigned char *sha1;
+ struct revindex_entry *entry;
+
+ entry = &bitmap_git->reverse_index->revindex[reuse_objects];
+ sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
+
+ fprintf(stderr, "Failed to reuse at %d (%016llx)\n",
+ reuse_objects, result->words[i]);
+ fprintf(stderr, " %s\n", hash_to_hex(sha1));
+ }
+#endif
+
+ if (!reuse_objects)
+ return -1;
+
+ if (reuse_objects >= bitmap_git->pack->num_objects) {
+ bitmap_git->reuse_objects = *entries = bitmap_git->pack->num_objects;
+ *up_to = -1; /* reuse the full pack */
+ *packfile = bitmap_git->pack;
+ return 0;
+ }
+
+ reuse_threshold = bitmap_popcount(bitmap_git->result) * REUSE_PERCENT;
+
+ if (reuse_objects < reuse_threshold)
+ return -1;
+
+ bitmap_git->reuse_objects = *entries = reuse_objects;
+ *up_to = bitmap_git->pack->revindex[reuse_objects].offset;
+ *packfile = bitmap_git->pack;
+
+ return 0;
+}
+
+void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
+ show_reachable_fn show_reachable)
+{
+ assert(bitmap_git->result);
+
+ show_objects_for_type(bitmap_git, bitmap_git->commits,
+ OBJ_COMMIT, show_reachable);
+ show_objects_for_type(bitmap_git, bitmap_git->trees,
+ OBJ_TREE, show_reachable);
+ show_objects_for_type(bitmap_git, bitmap_git->blobs,
+ OBJ_BLOB, show_reachable);
+ show_objects_for_type(bitmap_git, bitmap_git->tags,
+ OBJ_TAG, show_reachable);
+
+ show_extended_objects(bitmap_git, 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;
+
+ 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:
+ return 0;
+ }
+
+ 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_oid(&oid, bitmap_git->pack, entry->nr);
+ oe = packlist_find(mapping, &oid, NULL);
+
+ 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)
+{
+ int pos;
+
+ if (!bitmap_git)
+ return 0; /* no bitmap loaded */
+ if (!bitmap_git->haves)
+ return 0; /* walk had no "haves" */
+
+ pos = bitmap_position_packfile(bitmap_git, oid);
+ if (pos < 0)
+ return 0;
+
+ return bitmap_get(bitmap_git->haves, pos);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-15 06:05:17 +0000