diff options
| -rw-r--r-- | builtin/pack-objects.c | 214 | ||||
| -rw-r--r-- | pack-bitmap.c | 150 | ||||
| -rw-r--r-- | pack-bitmap.h | 3 |
3 files changed, 281 insertions, 86 deletions
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 08b562da72..28e56a94f7 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -92,7 +92,7 @@ static struct progress *progress_state; static struct packed_git *reuse_packfile; static uint32_t reuse_packfile_objects; -static off_t reuse_packfile_offset; +static struct bitmap *reuse_packfile_bitmap; static int use_bitmap_index_default = 1; static int use_bitmap_index = -1; @@ -785,57 +785,185 @@ static struct object_entry **compute_write_order(void) return wo; } -static off_t write_reused_pack(struct hashfile *f) + +/* + * A reused set of objects. All objects in a chunk have the same + * relative position in the original packfile and the generated + * packfile. + */ + +static struct reused_chunk { + /* The offset of the first object of this chunk in the original + * packfile. */ + off_t original; + /* The offset of the first object of this chunk in the generated + * packfile minus "original". */ + off_t difference; +} *reused_chunks; +static int reused_chunks_nr; +static int reused_chunks_alloc; + +static void record_reused_object(off_t where, off_t offset) +{ + if (reused_chunks_nr && reused_chunks[reused_chunks_nr-1].difference == offset) + return; + + ALLOC_GROW(reused_chunks, reused_chunks_nr + 1, + reused_chunks_alloc); + reused_chunks[reused_chunks_nr].original = where; + reused_chunks[reused_chunks_nr].difference = offset; + reused_chunks_nr++; +} + +/* + * Binary search to find the chunk that "where" is in. Note + * that we're not looking for an exact match, just the first + * chunk that contains it (which implicitly ends at the start + * of the next chunk. + */ +static off_t find_reused_offset(off_t where) { - unsigned char buffer[8192]; - off_t to_write, total; - int fd; + int lo = 0, hi = reused_chunks_nr; + while (lo < hi) { + int mi = lo + ((hi - lo) / 2); + if (where == reused_chunks[mi].original) + return reused_chunks[mi].difference; + if (where < reused_chunks[mi].original) + hi = mi; + else + lo = mi + 1; + } - if (!is_pack_valid(reuse_packfile)) - die(_("packfile is invalid: %s"), reuse_packfile->pack_name); + /* + * The first chunk starts at zero, so we can't have gone below + * there. + */ + assert(lo); + return reused_chunks[lo-1].difference; +} - fd = git_open(reuse_packfile->pack_name); - if (fd < 0) - die_errno(_("unable to open packfile for reuse: %s"), - reuse_packfile->pack_name); +static void write_reused_pack_one(size_t pos, struct hashfile *out, + struct pack_window **w_curs) +{ + off_t offset, next, cur; + enum object_type type; + unsigned long size; - if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1) - die_errno(_("unable to seek in reused packfile")); + offset = reuse_packfile->revindex[pos].offset; + next = reuse_packfile->revindex[pos + 1].offset; - if (reuse_packfile_offset < 0) - reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz; + record_reused_object(offset, offset - hashfile_total(out)); - total = to_write = reuse_packfile_offset - sizeof(struct pack_header); + cur = offset; + type = unpack_object_header(reuse_packfile, w_curs, &cur, &size); + assert(type >= 0); - while (to_write) { - int read_pack = xread(fd, buffer, sizeof(buffer)); + if (type == OBJ_OFS_DELTA) { + off_t base_offset; + off_t fixup; + + unsigned char header[MAX_PACK_OBJECT_HEADER]; + unsigned len; + + base_offset = get_delta_base(reuse_packfile, w_curs, &cur, type, offset); + assert(base_offset != 0); + + /* Convert to REF_DELTA if we must... */ + if (!allow_ofs_delta) { + int base_pos = find_revindex_position(reuse_packfile, base_offset); + const unsigned char *base_sha1 = + nth_packed_object_sha1(reuse_packfile, + reuse_packfile->revindex[base_pos].nr); + + len = encode_in_pack_object_header(header, sizeof(header), + OBJ_REF_DELTA, size); + hashwrite(out, header, len); + hashwrite(out, base_sha1, 20); + copy_pack_data(out, reuse_packfile, w_curs, cur, next - cur); + return; + } - if (read_pack <= 0) - die_errno(_("unable to read from reused packfile")); + /* Otherwise see if we need to rewrite the offset... */ + fixup = find_reused_offset(offset) - + find_reused_offset(base_offset); + if (fixup) { + unsigned char ofs_header[10]; + unsigned i, ofs_len; + off_t ofs = offset - base_offset - fixup; - if (read_pack > to_write) - read_pack = to_write; + len = encode_in_pack_object_header(header, sizeof(header), + OBJ_OFS_DELTA, size); - hashwrite(f, buffer, read_pack); - to_write -= read_pack; + i = sizeof(ofs_header) - 1; + ofs_header[i] = ofs & 127; + while (ofs >>= 7) + ofs_header[--i] = 128 | (--ofs & 127); + + ofs_len = sizeof(ofs_header) - i; + + hashwrite(out, header, len); + hashwrite(out, ofs_header + sizeof(ofs_header) - ofs_len, ofs_len); + copy_pack_data(out, reuse_packfile, w_curs, cur, next - cur); + return; + } + + /* ...otherwise we have no fixup, and can write it verbatim */ + } + + copy_pack_data(out, reuse_packfile, w_curs, offset, next - offset); +} + +static size_t write_reused_pack_verbatim(struct hashfile *out, + struct pack_window **w_curs) +{ + size_t pos = 0; + + while (pos < reuse_packfile_bitmap->word_alloc && + reuse_packfile_bitmap->words[pos] == (eword_t)~0) + pos++; + + if (pos) { + off_t to_write; + + written = (pos * BITS_IN_EWORD); + to_write = reuse_packfile->revindex[written].offset + - sizeof(struct pack_header); + + /* We're recording one chunk, not one object. */ + record_reused_object(sizeof(struct pack_header), 0); + hashflush(out); + copy_pack_data(out, reuse_packfile, w_curs, + sizeof(struct pack_header), to_write); - /* - * We don't know the actual number of objects written, - * only how many bytes written, how many bytes total, and - * how many objects total. So we can fake it by pretending all - * objects we are writing are the same size. This gives us a - * smooth progress meter, and at the end it matches the true - * answer. - */ - written = reuse_packfile_objects * - (((double)(total - to_write)) / total); display_progress(progress_state, written); } + return pos; +} + +static void write_reused_pack(struct hashfile *f) +{ + size_t i = 0; + uint32_t offset; + struct pack_window *w_curs = NULL; + + if (allow_ofs_delta) + i = write_reused_pack_verbatim(f, &w_curs); + + for (; i < reuse_packfile_bitmap->word_alloc; ++i) { + eword_t word = reuse_packfile_bitmap->words[i]; + size_t pos = (i * BITS_IN_EWORD); + + for (offset = 0; offset < BITS_IN_EWORD; ++offset) { + if ((word >> offset) == 0) + break; + + offset += ewah_bit_ctz64(word >> offset); + write_reused_pack_one(pos + offset, f, &w_curs); + display_progress(progress_state, ++written); + } + } - close(fd); - written = reuse_packfile_objects; - display_progress(progress_state, written); - return reuse_packfile_offset - sizeof(struct pack_header); + unuse_pack(&w_curs); } static const char no_split_warning[] = N_( @@ -868,11 +996,9 @@ static void write_pack_file(void) offset = write_pack_header(f, nr_remaining); if (reuse_packfile) { - off_t packfile_size; assert(pack_to_stdout); - - packfile_size = write_reused_pack(f); - offset += packfile_size; + write_reused_pack(f); + offset = hashfile_total(f); } nr_written = 0; @@ -2677,6 +2803,7 @@ static void prepare_pack(int window, int depth) if (nr_deltas && n > 1) { unsigned nr_done = 0; + if (progress) progress_state = start_progress(_("Compressing objects"), nr_deltas); @@ -3062,7 +3189,6 @@ static int pack_options_allow_reuse(void) { return allow_pack_reuse && pack_to_stdout && - allow_ofs_delta && !ignore_packed_keep_on_disk && !ignore_packed_keep_in_core && (!local || !have_non_local_packs) && @@ -3079,7 +3205,7 @@ static int get_object_list_from_bitmap(struct rev_info *revs) bitmap_git, &reuse_packfile, &reuse_packfile_objects, - &reuse_packfile_offset)) { + &reuse_packfile_bitmap)) { assert(reuse_packfile_objects); nr_result += reuse_packfile_objects; display_progress(progress_state, nr_result); diff --git a/pack-bitmap.c b/pack-bitmap.c index 41330a461e..9254a7c98a 100644 --- a/pack-bitmap.c +++ b/pack-bitmap.c @@ -326,6 +326,13 @@ 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; } @@ -770,65 +777,126 @@ cleanup: return NULL; } -int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git, - struct packed_git **packfile, - uint32_t *entries, - off_t *up_to) +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; + } + /* - * Reuse the packfile content if we need more than - * 90% of its objects + * If we got here, then the object is OK to reuse. Mark it. */ - static const double REUSE_PERCENT = 0.9; + 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; - uint32_t reuse_threshold; - uint32_t i, reuse_objects = 0; + struct bitmap *reuse; + struct pack_window *w_curs = NULL; + size_t i = 0; + uint32_t offset; 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; - } + while (i < result->word_alloc && result->words[i] == (eword_t)~0) + i++; - reuse_objects += BITS_IN_EWORD; - } + /* 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; -#ifdef GIT_BITMAP_DEBUG - { - const unsigned char *sha1; - struct revindex_entry *entry; + reuse = bitmap_word_alloc(i); + memset(reuse->words, 0xFF, i * sizeof(eword_t)); - 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 + for (; i < result->word_alloc; ++i) { + eword_t word = result->words[i]; + size_t pos = (i * BITS_IN_EWORD); - if (!reuse_objects) - return -1; + for (offset = 0; offset < BITS_IN_EWORD; ++offset) { + if ((word >> offset) == 0) + break; - 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; + offset += ewah_bit_ctz64(word >> offset); + try_partial_reuse(bitmap_git, pos + offset, reuse, &w_curs); + } } - reuse_threshold = bitmap_popcount(bitmap_git->result) * REUSE_PERCENT; + unuse_pack(&w_curs); - if (reuse_objects < reuse_threshold) + *entries = bitmap_popcount(reuse); + if (!*entries) { + bitmap_free(reuse); return -1; + } - bitmap_git->reuse_objects = *entries = reuse_objects; - *up_to = bitmap_git->pack->revindex[reuse_objects].offset; - *packfile = bitmap_git->pack; - + /* + * 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; } diff --git a/pack-bitmap.h b/pack-bitmap.h index 5425767f0f..91bdbfc837 100644 --- a/pack-bitmap.h +++ b/pack-bitmap.h @@ -50,7 +50,8 @@ void test_bitmap_walk(struct rev_info *revs); struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs); int reuse_partial_packfile_from_bitmap(struct bitmap_index *, struct packed_git **packfile, - uint32_t *entries, off_t *up_to); + uint32_t *entries, + struct bitmap **reuse_out); int rebuild_existing_bitmaps(struct bitmap_index *, struct packing_data *mapping, kh_oid_map_t *reused_bitmaps, int show_progress); void free_bitmap_index(struct bitmap_index *); |