diff options
Diffstat (limited to 'pack-bitmap.c')
| -rw-r--r-- | pack-bitmap.c | 2321 |
1 files changed, 2321 insertions, 0 deletions
diff --git a/pack-bitmap.c b/pack-bitmap.c new file mode 100644 index 0000000..440407f --- /dev/null +++ b/pack-bitmap.c @@ -0,0 +1,2321 @@ +#include "cache.h" +#include "commit.h" +#include "strbuf.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" +#include "midx.h" +#include "config.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 { + /* + * The pack or multi-pack index (MIDX) that this bitmap index belongs + * to. + * + * Exactly one of these must be non-NULL; this specifies the object + * order used to interpret this bitmap. + */ + struct packed_git *pack; + struct multi_pack_index *midx; + + /* + * 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; + + /* The checksum of the packfile or MIDX; points into map. */ + const unsigned char *checksum; + + /* + * If not NULL, this point into the commit table extension + * (within the memory mapped region `map`). + */ + unsigned char *table_lookup; + + /* + * 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) + 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 uint32_t bitmap_num_objects(struct bitmap_index *index) +{ + if (index->midx) + return index->midx->num_objects; + return index->pack->num_objects; +} + +static int load_bitmap_header(struct bitmap_index *index) +{ + struct bitmap_disk_header *header = (void *)index->map; + size_t header_size = sizeof(*header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz; + + if (index->map_size < header_size + the_hash_algo->rawsz) + return error(_("corrupted bitmap index (too small)")); + + 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 '%d' for bitmap index file"), index->version); + + /* Parse known bitmap format options */ + { + uint32_t flags = ntohs(header->options); + size_t cache_size = st_mult(bitmap_num_objects(index), sizeof(uint32_t)); + unsigned char *index_end = index->map + index->map_size - the_hash_algo->rawsz; + + if ((flags & BITMAP_OPT_FULL_DAG) == 0) + BUG("unsupported options for bitmap index file " + "(Git requires BITMAP_OPT_FULL_DAG)"); + + if (flags & BITMAP_OPT_HASH_CACHE) { + if (cache_size > index_end - index->map - header_size) + return error(_("corrupted bitmap index file (too short to fit hash cache)")); + index->hashes = (void *)(index_end - cache_size); + index_end -= cache_size; + } + + if (flags & BITMAP_OPT_LOOKUP_TABLE) { + size_t table_size = st_mult(ntohl(header->entry_count), + BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH); + if (table_size > index_end - index->map - header_size) + return error(_("corrupted bitmap index file (too short to fit lookup table)")); + if (git_env_bool("GIT_TEST_READ_COMMIT_TABLE", 1)) + index->table_lookup = (void *)(index_end - table_size); + index_end -= table_size; + } + } + + index->entry_count = ntohl(header->entry_count); + index->checksum = header->checksum; + index->map_pos += header_size; + 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 nth_bitmap_object_oid(struct bitmap_index *index, + struct object_id *oid, + uint32_t n) +{ + if (index->midx) + return nth_midxed_object_oid(oid, index->midx, n) ? 0 : -1; + return nth_packed_object_id(oid, index->pack, n); +} + +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; + + if (index->map_size - index->map_pos < 6) + return error(_("corrupt ewah bitmap: truncated header for entry %d"), i); + + 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); + + if (nth_bitmap_object_oid(index, &oid, commit_idx_pos) < 0) + return error(_("corrupt ewah bitmap: commit index %u out of range"), + (unsigned)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) + 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; +} + +char *midx_bitmap_filename(struct multi_pack_index *midx) +{ + struct strbuf buf = STRBUF_INIT; + + get_midx_filename(&buf, midx->object_dir); + strbuf_addf(&buf, "-%s.bitmap", hash_to_hex(get_midx_checksum(midx))); + + return strbuf_detach(&buf, NULL); +} + +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_midx_bitmap_1(struct bitmap_index *bitmap_git, + struct multi_pack_index *midx) +{ + struct stat st; + char *bitmap_name = midx_bitmap_filename(midx); + int fd = git_open(bitmap_name); + uint32_t i; + struct packed_git *preferred; + + if (fd < 0) { + if (errno != ENOENT) + warning_errno("cannot open '%s'", bitmap_name); + free(bitmap_name); + return -1; + } + free(bitmap_name); + + if (fstat(fd, &st)) { + error_errno(_("cannot fstat bitmap file")); + close(fd); + return -1; + } + + if (bitmap_git->pack || bitmap_git->midx) { + struct strbuf buf = STRBUF_INIT; + get_midx_filename(&buf, midx->object_dir); + /* ignore extra bitmap file; we can only handle one */ + warning(_("ignoring extra bitmap file: '%s'"), buf.buf); + close(fd); + strbuf_release(&buf); + return -1; + } + + bitmap_git->midx = midx; + bitmap_git->map_size = xsize_t(st.st_size); + bitmap_git->map_pos = 0; + bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, + MAP_PRIVATE, fd, 0); + close(fd); + + if (load_bitmap_header(bitmap_git) < 0) + goto cleanup; + + if (!hasheq(get_midx_checksum(bitmap_git->midx), bitmap_git->checksum)) { + error(_("checksum doesn't match in MIDX and bitmap")); + goto cleanup; + } + + if (load_midx_revindex(bitmap_git->midx) < 0) { + warning(_("multi-pack bitmap is missing required reverse index")); + goto cleanup; + } + + for (i = 0; i < bitmap_git->midx->num_packs; i++) { + if (prepare_midx_pack(the_repository, bitmap_git->midx, i)) + die(_("could not open pack %s"), + bitmap_git->midx->pack_names[i]); + } + + preferred = bitmap_git->midx->packs[midx_preferred_pack(bitmap_git)]; + if (!is_pack_valid(preferred)) { + warning(_("preferred pack (%s) is invalid"), + preferred->pack_name); + goto cleanup; + } + + return 0; + +cleanup: + munmap(bitmap_git->map, bitmap_git->map_size); + bitmap_git->map_size = 0; + bitmap_git->map_pos = 0; + bitmap_git->map = NULL; + bitmap_git->midx = NULL; + return -1; +} + +static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile) +{ + int fd; + struct stat st; + char *bitmap_name; + + if (open_pack_index(packfile)) + return -1; + + bitmap_name = pack_bitmap_filename(packfile); + fd = git_open(bitmap_name); + + if (fd < 0) { + if (errno != ENOENT) + warning_errno("cannot open '%s'", bitmap_name); + free(bitmap_name); + return -1; + } + free(bitmap_name); + + if (fstat(fd, &st)) { + error_errno(_("cannot fstat bitmap file")); + close(fd); + return -1; + } + + if (bitmap_git->pack || bitmap_git->midx) { + /* ignore extra bitmap file; we can only handle one */ + warning(_("ignoring extra bitmap file: '%s'"), packfile->pack_name); + close(fd); + return -1; + } + + if (!is_pack_valid(packfile)) { + 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; + bitmap_git->map_pos = 0; + bitmap_git->pack = NULL; + return -1; + } + + return 0; +} + +static int load_reverse_index(struct bitmap_index *bitmap_git) +{ + if (bitmap_is_midx(bitmap_git)) { + uint32_t i; + int ret; + + /* + * The multi-pack-index's .rev file is already loaded via + * open_pack_bitmap_1(). + * + * But we still need to open the individual pack .rev files, + * since we will need to make use of them in pack-objects. + */ + for (i = 0; i < bitmap_git->midx->num_packs; i++) { + ret = load_pack_revindex(bitmap_git->midx->packs[i]); + if (ret) + return ret; + } + return 0; + } + return load_pack_revindex(bitmap_git->pack); +} + +static int load_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_reverse_index(bitmap_git)) + 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 (!bitmap_git->table_lookup && 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; +} + +static int open_midx_bitmap(struct repository *r, + struct bitmap_index *bitmap_git) +{ + int ret = -1; + struct multi_pack_index *midx; + + assert(!bitmap_git->map); + + for (midx = get_multi_pack_index(r); midx; midx = midx->next) { + if (!open_midx_bitmap_1(bitmap_git, midx)) + ret = 0; + } + return ret; +} + +static int open_bitmap(struct repository *r, + struct bitmap_index *bitmap_git) +{ + assert(!bitmap_git->map); + + if (!open_midx_bitmap(r, bitmap_git)) + return 0; + return open_pack_bitmap(r, bitmap_git); +} + +struct bitmap_index *prepare_bitmap_git(struct repository *r) +{ + struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git)); + + if (!open_bitmap(r, bitmap_git) && !load_bitmap(bitmap_git)) + return bitmap_git; + + free_bitmap_index(bitmap_git); + return NULL; +} + +struct bitmap_index *prepare_midx_bitmap_git(struct multi_pack_index *midx) +{ + struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git)); + + if (!open_midx_bitmap_1(bitmap_git, midx) && !load_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; +}; + +struct bitmap_lookup_table_triplet { + uint32_t commit_pos; + uint64_t offset; + uint32_t xor_row; +}; + +struct bitmap_lookup_table_xor_item { + struct object_id oid; + uint64_t offset; +}; + +/* + * Given a `triplet` struct pointer and pointer `p`, this + * function reads the triplet beginning at `p` into the struct. + * Note that this function assumes that there is enough memory + * left for filling the `triplet` struct from `p`. + */ +static int bitmap_lookup_table_get_triplet_by_pointer(struct bitmap_lookup_table_triplet *triplet, + const unsigned char *p) +{ + if (!triplet) + return -1; + + triplet->commit_pos = get_be32(p); + p += sizeof(uint32_t); + triplet->offset = get_be64(p); + p += sizeof(uint64_t); + triplet->xor_row = get_be32(p); + return 0; +} + +/* + * This function gets the raw triplet from `row`'th row in the + * lookup table and fills that data to the `triplet`. + */ +static int bitmap_lookup_table_get_triplet(struct bitmap_index *bitmap_git, + uint32_t pos, + struct bitmap_lookup_table_triplet *triplet) +{ + unsigned char *p = NULL; + if (pos >= bitmap_git->entry_count) + return error(_("corrupt bitmap lookup table: triplet position out of index")); + + p = bitmap_git->table_lookup + st_mult(pos, BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH); + + return bitmap_lookup_table_get_triplet_by_pointer(triplet, p); +} + +/* + * Searches for a matching triplet. `commit_pos` is a pointer + * to the wanted commit position value. `table_entry` points to + * a triplet in lookup table. The first 4 bytes of each + * triplet (pointed by `table_entry`) are compared with `*commit_pos`. + */ +static int triplet_cmp(const void *commit_pos, const void *table_entry) +{ + + uint32_t a = *(uint32_t *)commit_pos; + uint32_t b = get_be32(table_entry); + if (a > b) + return 1; + else if (a < b) + return -1; + + return 0; +} + +static uint32_t bitmap_bsearch_pos(struct bitmap_index *bitmap_git, + struct object_id *oid, + uint32_t *result) +{ + int found; + + if (bitmap_is_midx(bitmap_git)) + found = bsearch_midx(oid, bitmap_git->midx, result); + else + found = bsearch_pack(oid, bitmap_git->pack, result); + + return found; +} + +/* + * `bsearch_triplet_by_pos` function searches for the raw triplet + * having commit position same as `commit_pos` and fills `triplet` + * object from the raw triplet. Returns 1 on success and 0 on + * failure. + */ +static int bitmap_bsearch_triplet_by_pos(uint32_t commit_pos, + struct bitmap_index *bitmap_git, + struct bitmap_lookup_table_triplet *triplet) +{ + unsigned char *p = bsearch(&commit_pos, bitmap_git->table_lookup, bitmap_git->entry_count, + BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH, triplet_cmp); + + if (!p) + return -1; + + return bitmap_lookup_table_get_triplet_by_pointer(triplet, p); +} + +static struct stored_bitmap *lazy_bitmap_for_commit(struct bitmap_index *bitmap_git, + struct commit *commit) +{ + uint32_t commit_pos, xor_row; + uint64_t offset; + int flags; + struct bitmap_lookup_table_triplet triplet; + struct object_id *oid = &commit->object.oid; + struct ewah_bitmap *bitmap; + struct stored_bitmap *xor_bitmap = NULL; + const int bitmap_header_size = 6; + static struct bitmap_lookup_table_xor_item *xor_items = NULL; + static size_t xor_items_nr = 0, xor_items_alloc = 0; + static int is_corrupt = 0; + int xor_flags; + khiter_t hash_pos; + struct bitmap_lookup_table_xor_item *xor_item; + + if (is_corrupt) + return NULL; + + if (!bitmap_bsearch_pos(bitmap_git, oid, &commit_pos)) + return NULL; + + if (bitmap_bsearch_triplet_by_pos(commit_pos, bitmap_git, &triplet) < 0) + return NULL; + + xor_items_nr = 0; + offset = triplet.offset; + xor_row = triplet.xor_row; + + while (xor_row != 0xffffffff) { + ALLOC_GROW(xor_items, xor_items_nr + 1, xor_items_alloc); + + if (xor_items_nr + 1 >= bitmap_git->entry_count) { + error(_("corrupt bitmap lookup table: xor chain exceeds entry count")); + goto corrupt; + } + + if (bitmap_lookup_table_get_triplet(bitmap_git, xor_row, &triplet) < 0) + goto corrupt; + + xor_item = &xor_items[xor_items_nr]; + xor_item->offset = triplet.offset; + + if (nth_bitmap_object_oid(bitmap_git, &xor_item->oid, triplet.commit_pos) < 0) { + error(_("corrupt bitmap lookup table: commit index %u out of range"), + triplet.commit_pos); + goto corrupt; + } + + hash_pos = kh_get_oid_map(bitmap_git->bitmaps, xor_item->oid); + + /* + * If desired bitmap is already stored, we don't need + * to iterate further. Because we know that bitmaps + * that are needed to be parsed to parse this bitmap + * has already been stored. So, assign this stored bitmap + * to the xor_bitmap. + */ + if (hash_pos < kh_end(bitmap_git->bitmaps) && + (xor_bitmap = kh_value(bitmap_git->bitmaps, hash_pos))) + break; + xor_items_nr++; + xor_row = triplet.xor_row; + } + + while (xor_items_nr) { + xor_item = &xor_items[xor_items_nr - 1]; + bitmap_git->map_pos = xor_item->offset; + if (bitmap_git->map_size - bitmap_git->map_pos < bitmap_header_size) { + error(_("corrupt ewah bitmap: truncated header for bitmap of commit \"%s\""), + oid_to_hex(&xor_item->oid)); + goto corrupt; + } + + bitmap_git->map_pos += sizeof(uint32_t) + sizeof(uint8_t); + xor_flags = read_u8(bitmap_git->map, &bitmap_git->map_pos); + bitmap = read_bitmap_1(bitmap_git); + + if (!bitmap) + goto corrupt; + + xor_bitmap = store_bitmap(bitmap_git, bitmap, &xor_item->oid, xor_bitmap, xor_flags); + xor_items_nr--; + } + + bitmap_git->map_pos = offset; + if (bitmap_git->map_size - bitmap_git->map_pos < bitmap_header_size) { + error(_("corrupt ewah bitmap: truncated header for bitmap of commit \"%s\""), + oid_to_hex(oid)); + goto corrupt; + } + + /* + * Don't bother reading the commit's index position or its xor + * offset: + * + * - The commit's index position is irrelevant to us, since + * load_bitmap_entries_v1 only uses it to learn the object + * id which is used to compute the hashmap's key. We already + * have an object id, so no need to look it up again. + * + * - The xor_offset is unusable for us, since it specifies how + * many entries previous to ours we should look at. This + * makes sense when reading the bitmaps sequentially (as in + * load_bitmap_entries_v1()), since we can keep track of + * each bitmap as we read them. + * + * But it can't work for us, since the bitmap's don't have a + * fixed size. So we learn the position of the xor'd bitmap + * from the commit table (and resolve it to a bitmap in the + * above if-statement). + * + * Instead, we can skip ahead and immediately read the flags and + * ewah bitmap. + */ + bitmap_git->map_pos += sizeof(uint32_t) + sizeof(uint8_t); + flags = read_u8(bitmap_git->map, &bitmap_git->map_pos); + bitmap = read_bitmap_1(bitmap_git); + + if (!bitmap) + goto corrupt; + + return store_bitmap(bitmap_git, bitmap, oid, xor_bitmap, flags); + +corrupt: + free(xor_items); + is_corrupt = 1; + return NULL; +} + +struct ewah_bitmap *bitmap_for_commit(struct bitmap_index *bitmap_git, + struct commit *commit) +{ + khiter_t hash_pos = kh_get_oid_map(bitmap_git->bitmaps, + commit->object.oid); + if (hash_pos >= kh_end(bitmap_git->bitmaps)) { + struct stored_bitmap *bitmap = NULL; + if (!bitmap_git->table_lookup) + return NULL; + + /* this is a fairly hot codepath - no trace2_region please */ + /* NEEDSWORK: cache misses aren't recorded */ + bitmap = lazy_bitmap_for_commit(bitmap_git, commit); + if (!bitmap) + return NULL; + return lookup_stored_bitmap(bitmap); + } + return lookup_stored_bitmap(kh_value(bitmap_git->bitmaps, hash_pos)); +} + +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_num_objects(bitmap_git); + } + + return -1; +} + +static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git, + const struct object_id *oid) +{ + uint32_t pos; + off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack); + if (!offset) + return -1; + + if (offset_to_pack_pos(bitmap_git->pack, offset, &pos) < 0) + return -1; + return pos; +} + +static int bitmap_position_midx(struct bitmap_index *bitmap_git, + const struct object_id *oid) +{ + uint32_t want, got; + if (!bsearch_midx(oid, bitmap_git->midx, &want)) + return -1; + + if (midx_to_pack_pos(bitmap_git->midx, want, &got) < 0) + return -1; + return got; +} + +static int bitmap_position(struct bitmap_index *bitmap_git, + const struct object_id *oid) +{ + int pos; + if (bitmap_is_midx(bitmap_git)) + pos = bitmap_position_midx(bitmap_git, oid); + else + 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_num_objects(bitmap_git); +} + +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, + struct commit *commit, + int bitmap_pos) +{ + struct ewah_bitmap *partial; + + if (data->seen && bitmap_get(data->seen, bitmap_pos)) + return 0; + + if (bitmap_get(data->base, bitmap_pos)) + return 0; + + partial = bitmap_for_commit(bitmap_git, commit); + if (partial) { + bitmap_or_ewah(data->base, partial); + 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, bitmap_pos)) { + struct commit_list *parent = commit->parents; + + while (parent) { + parent->item->object.flags |= SEEN; + parent = parent->next; + } + + return 0; + } + + return 1; +} + +static int should_include_obj(struct object *obj, void *_data) +{ + struct include_data *data = _data; + int bitmap_pos; + + bitmap_pos = bitmap_position(data->bitmap_git, &obj->oid); + if (bitmap_pos < 0) + return 1; + if ((data->seen && bitmap_get(data->seen, bitmap_pos)) || + bitmap_get(data->base, bitmap_pos)) { + obj->flags |= SEEN; + return 0; + } + return 1; +} + +static int add_commit_to_bitmap(struct bitmap_index *bitmap_git, + struct bitmap **base, + struct commit *commit) +{ + struct ewah_bitmap *or_with = bitmap_for_commit(bitmap_git, commit); + + if (!or_with) + return 0; + + if (!*base) + *base = ewah_to_bitmap(or_with); + else + bitmap_or_ewah(*base, or_with); + + 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 && + add_commit_to_bitmap(bitmap_git, &base, (struct commit *)object)) { + object->flags |= SEEN; + continue; + } + + object_list_insert(object, ¬_mapped); + } + + /* + * Best case scenario: We found bitmaps for all the roots, + * so the resulting `or` bitmap has the full reachability analysis + */ + if (!not_mapped) + 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) + base = bitmap_new(); + + incdata.bitmap_git = bitmap_git; + incdata.base = base; + incdata.seen = seen; + + revs->include_check = should_include; + revs->include_check_obj = should_include_obj; + 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); + + revs->include_check = NULL; + revs->include_check_obj = NULL; + revs->include_check_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_num_objects(bitmap_git) + 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 packed_git *pack; + struct object_id oid; + uint32_t hash = 0, index_pos; + off_t ofs; + + if ((word >> offset) == 0) + break; + + offset += ewah_bit_ctz64(word >> offset); + + if (bitmap_is_midx(bitmap_git)) { + struct multi_pack_index *m = bitmap_git->midx; + uint32_t pack_id; + + index_pos = pack_pos_to_midx(m, pos + offset); + ofs = nth_midxed_offset(m, index_pos); + nth_midxed_object_oid(&oid, m, index_pos); + + pack_id = nth_midxed_pack_int_id(m, index_pos); + pack = bitmap_git->midx->packs[pack_id]; + } else { + index_pos = pack_pos_to_index(bitmap_git->pack, pos + offset); + ofs = pack_pos_to_offset(bitmap_git->pack, pos + offset); + nth_bitmap_object_oid(bitmap_git, &oid, index_pos); + + pack = bitmap_git->pack; + } + + if (bitmap_git->hashes) + hash = get_be32(bitmap_git->hashes + index_pos); + + show_reach(&oid, object_type, 0, hash, pack, ofs); + } + } +} + +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 (bitmap_is_midx(bitmap_git)) { + if (bsearch_midx(&object->oid, bitmap_git->midx, NULL)) + return 1; + } else { + 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; + + /* + * 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 type-level bitmap for 'type' 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 objects 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_num_objects(bitmap_git); + 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) +{ + unsigned long size; + struct object_info oi = OBJECT_INFO_INIT; + + oi.sizep = &size; + + if (pos < bitmap_num_objects(bitmap_git)) { + struct packed_git *pack; + off_t ofs; + + if (bitmap_is_midx(bitmap_git)) { + uint32_t midx_pos = pack_pos_to_midx(bitmap_git->midx, pos); + uint32_t pack_id = nth_midxed_pack_int_id(bitmap_git->midx, midx_pos); + + pack = bitmap_git->midx->packs[pack_id]; + ofs = nth_midxed_offset(bitmap_git->midx, midx_pos); + } else { + pack = bitmap_git->pack; + ofs = pack_pos_to_offset(pack, pos); + } + + if (packed_object_info(the_repository, pack, ofs, &oi) < 0) { + struct object_id oid; + nth_bitmap_object_oid(bitmap_git, &oid, + pack_pos_to_index(pack, pos)); + 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 - bitmap_num_objects(bitmap_git)]; + 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_num_objects(bitmap_git); + 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 void filter_bitmap_object_type(struct bitmap_index *bitmap_git, + struct object_list *tip_objects, + struct bitmap *to_filter, + enum object_type object_type) +{ + if (object_type < OBJ_COMMIT || object_type > OBJ_TAG) + BUG("filter_bitmap_object_type given invalid object"); + + if (object_type != OBJ_TAG) + filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_TAG); + if (object_type != OBJ_COMMIT) + filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_COMMIT); + if (object_type != OBJ_TREE) + filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_TREE); + if (object_type != OBJ_BLOB) + 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; + } + + if (filter->choice == LOFC_OBJECT_TYPE) { + if (bitmap_git) + filter_bitmap_object_type(bitmap_git, tip_objects, + to_filter, + filter->object_type); + return 0; + } + + if (filter->choice == LOFC_COMBINE) { + int i; + for (i = 0; i < filter->sub_nr; i++) { + if (filter_bitmap(bitmap_git, tip_objects, to_filter, + &filter->sub[i]) < 0) + return -1; + } + 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, + int filter_provided_objects) +{ + 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(&revs->filter)) + return NULL; + + /* try to open a bitmapped pack, but don't parse it yet + * because we may not need to use it */ + CALLOC_ARRAY(bitmap_git, 1); + if (open_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); + object->flags |= (tag->object.flags & UNINTERESTING); + } + + 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_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) + 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); + + filter_bitmap(bitmap_git, + (revs->filter.choice && filter_provided_objects) ? NULL : wants, + wants_bitmap, + &revs->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; +} + +/* + * -1 means "stop trying further objects"; 0 means we may or may not have + * reused, but you can keep feeding bits. + */ +static int try_partial_reuse(struct packed_git *pack, + size_t pos, + struct bitmap *reuse, + struct pack_window **w_curs) +{ + off_t offset, delta_obj_offset; + enum object_type type; + unsigned long size; + + /* + * try_partial_reuse() is called either on (a) objects in the + * bitmapped pack (in the case of a single-pack bitmap) or (b) + * objects in the preferred pack of a multi-pack bitmap. + * Importantly, the latter can pretend as if only a single pack + * exists because: + * + * - The first pack->num_objects bits of a MIDX bitmap are + * reserved for the preferred pack, and + * + * - Ties due to duplicate objects are always resolved in + * favor of the preferred pack. + * + * Therefore we do not need to ever ask the MIDX for its copy of + * an object by OID, since it will always select it from the + * preferred pack. Likewise, the selected copy of the base + * object for any deltas will reside in the same pack. + * + * This means that we can reuse pos when looking up the bit in + * the reuse bitmap, too, since bits corresponding to the + * preferred pack precede all bits from other packs. + */ + + if (pos >= pack->num_objects) + return -1; /* not actually in the pack or MIDX preferred pack */ + + offset = delta_obj_offset = pack_pos_to_offset(pack, pos); + type = unpack_object_header(pack, w_curs, &offset, &size); + if (type < 0) + return -1; /* broken packfile, punt */ + + if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA) { + off_t base_offset; + uint32_t 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(pack, w_curs, &offset, type, + delta_obj_offset); + if (!base_offset) + return 0; + if (offset_to_pack_pos(pack, base_offset, &base_pos) < 0) + return 0; + + /* + * 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 0; + + /* + * 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 0; + } + + /* + * If we got here, then the object is OK to reuse. Mark it. + */ + bitmap_set(reuse, pos); + return 0; +} + +uint32_t midx_preferred_pack(struct bitmap_index *bitmap_git) +{ + struct multi_pack_index *m = bitmap_git->midx; + if (!m) + BUG("midx_preferred_pack: requires non-empty MIDX"); + return nth_midxed_pack_int_id(m, pack_pos_to_midx(bitmap_git->midx, 0)); +} + +int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git, + struct packed_git **packfile_out, + uint32_t *entries, + struct bitmap **reuse_out) +{ + struct packed_git *pack; + struct bitmap *result = bitmap_git->result; + struct bitmap *reuse; + struct pack_window *w_curs = NULL; + size_t i = 0; + uint32_t offset; + uint32_t objects_nr; + + assert(result); + + load_reverse_index(bitmap_git); + + if (bitmap_is_midx(bitmap_git)) + pack = bitmap_git->midx->packs[midx_preferred_pack(bitmap_git)]; + else + pack = bitmap_git->pack; + objects_nr = pack->num_objects; + + while (i < result->word_alloc && result->words[i] == (eword_t)~0) + i++; + + /* + * Don't mark objects not in the packfile or preferred pack. This bitmap + * marks objects eligible for reuse, but the pack-reuse code only + * understands how to reuse a single pack. Since the preferred pack is + * guaranteed to have all bases for its deltas (in a multi-pack bitmap), + * we use it instead of another pack. In single-pack bitmaps, the choice + * is made for us. + */ + if (i > objects_nr / BITS_IN_EWORD) + i = objects_nr / 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); + if (try_partial_reuse(pack, pos + offset, + reuse, &w_curs) < 0) { + /* + * try_partial_reuse indicated we couldn't reuse + * any bits, so there is no point in trying more + * bits in the current word, or any other words + * in result. + * + * Jump out of both loops to avoid future + * unnecessary calls to try_partial_reuse. + */ + goto done; + } + } + } + +done: + 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 = 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_num_objects(bitmap_git) + 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 bitmap *commits; + struct bitmap *trees; + struct bitmap *blobs; + struct bitmap *tags; + struct progress *prg; + size_t seen; +}; + +static void test_bitmap_type(struct bitmap_test_data *tdata, + struct object *obj, int pos) +{ + enum object_type bitmap_type = OBJ_NONE; + int bitmaps_nr = 0; + + if (bitmap_get(tdata->commits, pos)) { + bitmap_type = OBJ_COMMIT; + bitmaps_nr++; + } + if (bitmap_get(tdata->trees, pos)) { + bitmap_type = OBJ_TREE; + bitmaps_nr++; + } + if (bitmap_get(tdata->blobs, pos)) { + bitmap_type = OBJ_BLOB; + bitmaps_nr++; + } + if (bitmap_get(tdata->tags, pos)) { + bitmap_type = OBJ_TAG; + bitmaps_nr++; + } + + if (bitmap_type == OBJ_NONE) + die(_("object '%s' not found in type bitmaps"), + oid_to_hex(&obj->oid)); + + if (bitmaps_nr > 1) + die(_("object '%s' does not have a unique type"), + oid_to_hex(&obj->oid)); + + if (bitmap_type != obj->type) + die(_("object '%s': real type '%s', expected: '%s'"), + oid_to_hex(&obj->oid), + type_name(obj->type), + type_name(bitmap_type)); +} + +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'"), oid_to_hex(&object->oid)); + test_bitmap_type(tdata, object, bitmap_pos); + + 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'"), oid_to_hex(&commit->object.oid)); + test_bitmap_type(tdata, &commit->object, bitmap_pos); + + 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; + size_t result_popcnt; + struct bitmap_test_data tdata; + struct bitmap_index *bitmap_git; + struct ewah_bitmap *bm; + + 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_ln(stderr, "Bitmap v%d test (%d entries%s)", + bitmap_git->version, + bitmap_git->entry_count, + bitmap_git->table_lookup ? "" : " loaded"); + + root = revs->pending.objects[0].item; + bm = bitmap_for_commit(bitmap_git, (struct commit *)root); + + if (bm) { + fprintf_ln(stderr, "Found bitmap for '%s'. %d bits / %08x checksum", + oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm)); + + result = ewah_to_bitmap(bm); + } + + if (!result) + 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.commits = ewah_to_bitmap(bitmap_git->commits); + tdata.trees = ewah_to_bitmap(bitmap_git->trees); + tdata.blobs = ewah_to_bitmap(bitmap_git->blobs); + tdata.tags = ewah_to_bitmap(bitmap_git->tags); + 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_ln(stderr, "OK!"); + else + die(_("mismatch in bitmap results")); + + bitmap_free(result); + bitmap_free(tdata.base); + bitmap_free(tdata.commits); + bitmap_free(tdata.trees); + bitmap_free(tdata.blobs); + bitmap_free(tdata.tags); + free_bitmap_index(bitmap_git); +} + +int test_bitmap_commits(struct repository *r) +{ + struct object_id oid; + MAYBE_UNUSED void *value; + struct bitmap_index *bitmap_git = prepare_bitmap_git(r); + + if (!bitmap_git) + die(_("failed to load bitmap indexes")); + + /* + * As this function is only used to print bitmap selected + * commits, we don't have to read the commit table. + */ + if (bitmap_git->table_lookup) { + if (load_bitmap_entries_v1(bitmap_git) < 0) + die(_("failed to load bitmap indexes")); + } + + kh_foreach(bitmap_git->bitmaps, oid, value, { + printf_ln("%s", oid_to_hex(&oid)); + }); + + free_bitmap_index(bitmap_git); + + return 0; +} + +int test_bitmap_hashes(struct repository *r) +{ + struct bitmap_index *bitmap_git = prepare_bitmap_git(r); + struct object_id oid; + uint32_t i, index_pos; + + if (!bitmap_git || !bitmap_git->hashes) + goto cleanup; + + for (i = 0; i < bitmap_num_objects(bitmap_git); i++) { + if (bitmap_is_midx(bitmap_git)) + index_pos = pack_pos_to_midx(bitmap_git->midx, i); + else + index_pos = pack_pos_to_index(bitmap_git->pack, i); + + nth_bitmap_object_oid(bitmap_git, &oid, index_pos); + + printf_ln("%s %"PRIu32"", + oid_to_hex(&oid), get_be32(bitmap_git->hashes + index_pos)); + } + +cleanup: + free_bitmap_index(bitmap_git); + + return 0; +} + +int rebuild_bitmap(const 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; +} + +uint32_t *create_bitmap_mapping(struct bitmap_index *bitmap_git, + struct packing_data *mapping) +{ + uint32_t i, num_objects; + uint32_t *reposition; + + if (!bitmap_is_midx(bitmap_git)) + load_reverse_index(bitmap_git); + else if (load_midx_revindex(bitmap_git->midx) < 0) + BUG("rebuild_existing_bitmaps: missing required rev-cache " + "extension"); + + num_objects = bitmap_num_objects(bitmap_git); + CALLOC_ARRAY(reposition, num_objects); + + for (i = 0; i < num_objects; ++i) { + struct object_id oid; + struct object_entry *oe; + uint32_t index_pos; + + if (bitmap_is_midx(bitmap_git)) + index_pos = pack_pos_to_midx(bitmap_git->midx, i); + else + index_pos = pack_pos_to_index(bitmap_git->pack, i); + nth_bitmap_object_oid(bitmap_git, &oid, index_pos); + oe = packlist_find(mapping, &oid); + + if (oe) { + reposition[i] = oe_in_pack_pos(mapping, oe) + 1; + if (bitmap_git->hashes && !oe->hash) + oe->hash = get_be32(bitmap_git->hashes + index_pos); + } + } + + return reposition; +} + +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); + if (b->bitmaps) { + struct stored_bitmap *sb; + kh_foreach_value(b->bitmaps, sb, { + ewah_pool_free(sb->root); + free(sb); + }); + } + kh_destroy_oid_map(b->bitmaps); + free(b->ext_index.objects); + free(b->ext_index.hashes); + kh_destroy_oid_pos(b->ext_index.positions); + bitmap_free(b->result); + bitmap_free(b->haves); + if (bitmap_is_midx(b)) { + /* + * Multi-pack bitmaps need to have resources associated with + * their on-disk reverse indexes unmapped so that stale .rev and + * .bitmap files can be removed. + * + * Unlike pack-based bitmaps, multi-pack bitmaps can be read and + * written in the same 'git multi-pack-index write --bitmap' + * process. Close resources so they can be removed safely on + * platforms like Windows. + */ + close_midx_revindex(b->midx); + } + 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); +} + +static off_t get_disk_usage_for_type(struct bitmap_index *bitmap_git, + enum object_type object_type) +{ + struct bitmap *result = bitmap_git->result; + off_t total = 0; + struct ewah_iterator it; + eword_t filter; + size_t i; + + init_type_iterator(&it, bitmap_git, object_type); + for (i = 0; i < result->word_alloc && + ewah_iterator_next(&filter, &it); i++) { + eword_t word = result->words[i] & filter; + size_t base = (i * BITS_IN_EWORD); + unsigned offset; + + if (!word) + continue; + + for (offset = 0; offset < BITS_IN_EWORD; offset++) { + if ((word >> offset) == 0) + break; + + offset += ewah_bit_ctz64(word >> offset); + + if (bitmap_is_midx(bitmap_git)) { + uint32_t pack_pos; + uint32_t midx_pos = pack_pos_to_midx(bitmap_git->midx, base + offset); + off_t offset = nth_midxed_offset(bitmap_git->midx, midx_pos); + + uint32_t pack_id = nth_midxed_pack_int_id(bitmap_git->midx, midx_pos); + struct packed_git *pack = bitmap_git->midx->packs[pack_id]; + + if (offset_to_pack_pos(pack, offset, &pack_pos) < 0) { + struct object_id oid; + nth_midxed_object_oid(&oid, bitmap_git->midx, midx_pos); + + die(_("could not find '%s' in pack '%s' at offset %"PRIuMAX), + oid_to_hex(&oid), + pack->pack_name, + (uintmax_t)offset); + } + + total += pack_pos_to_offset(pack, pack_pos + 1) - offset; + } else { + size_t pos = base + offset; + total += pack_pos_to_offset(bitmap_git->pack, pos + 1) - + pack_pos_to_offset(bitmap_git->pack, pos); + } + } + } + + return total; +} + +static off_t get_disk_usage_for_extended(struct bitmap_index *bitmap_git) +{ + struct bitmap *result = bitmap_git->result; + struct eindex *eindex = &bitmap_git->ext_index; + off_t total = 0; + struct object_info oi = OBJECT_INFO_INIT; + off_t object_size; + size_t i; + + oi.disk_sizep = &object_size; + + for (i = 0; i < eindex->count; i++) { + struct object *obj = eindex->objects[i]; + + if (!bitmap_get(result, bitmap_num_objects(bitmap_git) + i)) + continue; + + if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0) + die(_("unable to get disk usage of '%s'"), + oid_to_hex(&obj->oid)); + + total += object_size; + } + return total; +} + +off_t get_disk_usage_from_bitmap(struct bitmap_index *bitmap_git, + struct rev_info *revs) +{ + off_t total = 0; + + total += get_disk_usage_for_type(bitmap_git, OBJ_COMMIT); + if (revs->tree_objects) + total += get_disk_usage_for_type(bitmap_git, OBJ_TREE); + if (revs->blob_objects) + total += get_disk_usage_for_type(bitmap_git, OBJ_BLOB); + if (revs->tag_objects) + total += get_disk_usage_for_type(bitmap_git, OBJ_TAG); + + total += get_disk_usage_for_extended(bitmap_git); + + return total; +} + +int bitmap_is_midx(struct bitmap_index *bitmap_git) +{ + return !!bitmap_git->midx; +} + +const struct string_list *bitmap_preferred_tips(struct repository *r) +{ + return repo_config_get_value_multi(r, "pack.preferbitmaptips"); +} + +int bitmap_is_preferred_refname(struct repository *r, const char *refname) +{ + const struct string_list *preferred_tips = bitmap_preferred_tips(r); + struct string_list_item *item; + + if (!preferred_tips) + return 0; + + for_each_string_list_item(item, preferred_tips) { + if (starts_with(refname, item->string)) + return 1; + } + + return 0; +} |