pack-bitmap-write.c

   1 #include "cache.h"
   2 #include "object-store.h"
   3 #include "commit.h"
   4 #include "tag.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "list-objects.h"
   8 #include "progress.h"
   9 #include "pack-revindex.h"
  10 #include "pack.h"
  11 #include "pack-bitmap.h"
  12 #include "hash-lookup.h"
  13 #include "pack-objects.h"
  14 #include "commit-reach.h"
  15 #include "prio-queue.h"
  16
  17 struct bitmapped_commit {
  18         struct commit *commit;
  19         struct ewah_bitmap *bitmap;
  20         struct ewah_bitmap *write_as;
  21         int flags;
  22         int xor_offset;
  23         uint32_t commit_pos;
  24 };
  25
  26 struct bitmap_writer {
  27         struct ewah_bitmap *commits;
  28         struct ewah_bitmap *trees;
  29         struct ewah_bitmap *blobs;
  30         struct ewah_bitmap *tags;
  31
  32         kh_oid_map_t *bitmaps;
  33         struct packing_data *to_pack;
  34
  35         struct bitmapped_commit *selected;
  36         unsigned int selected_nr, selected_alloc;
  37
  38         struct progress *progress;
  39         int show_progress;
  40         unsigned char pack_checksum[GIT_MAX_RAWSZ];
  41 };
  42
  43 static struct bitmap_writer writer;
  44
  45 void bitmap_writer_show_progress(int show)
  46 {
  47         writer.show_progress = show;
  48 }
  49
  50 /**
  51  * Build the initial type index for the packfile or multi-pack-index
  52  */
  53 void bitmap_writer_build_type_index(struct packing_data *to_pack,
  54                                     struct pack_idx_entry **index,
  55                                     uint32_t index_nr)
  56 {
  57         uint32_t i;
  58
  59         writer.commits = ewah_new();
  60         writer.trees = ewah_new();
  61         writer.blobs = ewah_new();
  62         writer.tags = ewah_new();
  63         ALLOC_ARRAY(to_pack->in_pack_pos, to_pack->nr_objects);
  64
  65         for (i = 0; i < index_nr; ++i) {
  66                 struct object_entry *entry = (struct object_entry *)index[i];
  67                 enum object_type real_type;
  68
  69                 oe_set_in_pack_pos(to_pack, entry, i);
  70
  71                 switch (oe_type(entry)) {
  72                 case OBJ_COMMIT:
  73                 case OBJ_TREE:
  74                 case OBJ_BLOB:
  75                 case OBJ_TAG:
  76                         real_type = oe_type(entry);
  77                         break;
  78
  79                 default:
  80                         real_type = oid_object_info(to_pack->repo,
  81                                                     &entry->idx.oid, NULL);
  82                         break;
  83                 }
  84
  85                 switch (real_type) {
  86                 case OBJ_COMMIT:
  87                         ewah_set(writer.commits, i);
  88                         break;
  89
  90                 case OBJ_TREE:
  91                         ewah_set(writer.trees, i);
  92                         break;
  93
  94                 case OBJ_BLOB:
  95                         ewah_set(writer.blobs, i);
  96                         break;
  97
  98                 case OBJ_TAG:
  99                         ewah_set(writer.tags, i);
 100                         break;
 101
 102                 default:
 103                         die("Missing type information for %s (%d/%d)",
 104                             oid_to_hex(&entry->idx.oid), real_type,
 105                             oe_type(entry));
 106                 }
 107         }
 108 }
 109
 110 /**
 111  * Compute the actual bitmaps
 112  */
 113
 114 static inline void push_bitmapped_commit(struct commit *commit)
 115 {
 116         if (writer.selected_nr >= writer.selected_alloc) {
 117                 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
 118                 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
 119         }
 120
 121         writer.selected[writer.selected_nr].commit = commit;
 122         writer.selected[writer.selected_nr].bitmap = NULL;
 123         writer.selected[writer.selected_nr].flags = 0;
 124
 125         writer.selected_nr++;
 126 }
 127
 128 static uint32_t find_object_pos(const struct object_id *oid, int *found)
 129 {
 130         struct object_entry *entry = packlist_find(writer.to_pack, oid);
 131
 132         if (!entry) {
 133                 if (found)
 134                         *found = 0;
 135                 warning("Failed to write bitmap index. Packfile doesn't have full closure "
 136                         "(object %s is missing)", oid_to_hex(oid));
 137                 return 0;
 138         }
 139
 140         if (found)
 141                 *found = 1;
 142         return oe_in_pack_pos(writer.to_pack, entry);
 143 }
 144
 145 static void compute_xor_offsets(void)
 146 {
 147         static const int MAX_XOR_OFFSET_SEARCH = 10;
 148
 149         int i, next = 0;
 150
 151         while (next < writer.selected_nr) {
 152                 struct bitmapped_commit *stored = &writer.selected[next];
 153
 154                 int best_offset = 0;
 155                 struct ewah_bitmap *best_bitmap = stored->bitmap;
 156                 struct ewah_bitmap *test_xor;
 157
 158                 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
 159                         int curr = next - i;
 160
 161                         if (curr < 0)
 162                                 break;
 163
 164                         test_xor = ewah_pool_new();
 165                         ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
 166
 167                         if (test_xor->buffer_size < best_bitmap->buffer_size) {
 168                                 if (best_bitmap != stored->bitmap)
 169                                         ewah_pool_free(best_bitmap);
 170
 171                                 best_bitmap = test_xor;
 172                                 best_offset = i;
 173                         } else {
 174                                 ewah_pool_free(test_xor);
 175                         }
 176                 }
 177
 178                 stored->xor_offset = best_offset;
 179                 stored->write_as = best_bitmap;
 180
 181                 next++;
 182         }
 183 }
 184
 185 struct bb_commit {
 186         struct commit_list *reverse_edges;
 187         struct bitmap *commit_mask;
 188         struct bitmap *bitmap;
 189         unsigned selected:1,
 190                  maximal:1;
 191         unsigned idx; /* within selected array */
 192 };
 193
 194 define_commit_slab(bb_data, struct bb_commit);
 195
 196 struct bitmap_builder {
 197         struct bb_data data;
 198         struct commit **commits;
 199         size_t commits_nr, commits_alloc;
 200 };
 201
 202 static void bitmap_builder_init(struct bitmap_builder *bb,
 203                                 struct bitmap_writer *writer,
 204                                 struct bitmap_index *old_bitmap)
 205 {
 206         struct rev_info revs;
 207         struct commit *commit;
 208         struct commit_list *reusable = NULL;
 209         struct commit_list *r;
 210         unsigned int i, num_maximal = 0;
 211
 212         memset(bb, 0, sizeof(*bb));
 213         init_bb_data(&bb->data);
 214
 215         reset_revision_walk();
 216         repo_init_revisions(writer->to_pack->repo, &revs, NULL);
 217         revs.topo_order = 1;
 218         revs.first_parent_only = 1;
 219
 220         for (i = 0; i < writer->selected_nr; i++) {
 221                 struct commit *c = writer->selected[i].commit;
 222                 struct bb_commit *ent = bb_data_at(&bb->data, c);
 223
 224                 ent->selected = 1;
 225                 ent->maximal = 1;
 226                 ent->idx = i;
 227
 228                 ent->commit_mask = bitmap_new();
 229                 bitmap_set(ent->commit_mask, i);
 230
 231                 add_pending_object(&revs, &c->object, "");
 232         }
 233
 234         if (prepare_revision_walk(&revs))
 235                 die("revision walk setup failed");
 236
 237         while ((commit = get_revision(&revs))) {
 238                 struct commit_list *p = commit->parents;
 239                 struct bb_commit *c_ent;
 240
 241                 parse_commit_or_die(commit);
 242
 243                 c_ent = bb_data_at(&bb->data, commit);
 244
 245                 /*
 246                  * If there is no commit_mask, there is no reason to iterate
 247                  * over this commit; it is not selected (if it were, it would
 248                  * not have a blank commit mask) and all its children have
 249                  * existing bitmaps (see the comment starting with "This commit
 250                  * has an existing bitmap" below), so it does not contribute
 251                  * anything to the final bitmap file or its descendants.
 252                  */
 253                 if (!c_ent->commit_mask)
 254                         continue;
 255
 256                 if (old_bitmap && bitmap_for_commit(old_bitmap, commit)) {
 257                         /*
 258                          * This commit has an existing bitmap, so we can
 259                          * get its bits immediately without an object
 260                          * walk. That is, it is reusable as-is and there is no
 261                          * need to continue walking beyond it.
 262                          *
 263                          * Mark it as such and add it to bb->commits separately
 264                          * to avoid allocating a position in the commit mask.
 265                          */
 266                         commit_list_insert(commit, &reusable);
 267                         goto next;
 268                 }
 269
 270                 if (c_ent->maximal) {
 271                         num_maximal++;
 272                         ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
 273                         bb->commits[bb->commits_nr++] = commit;
 274                 }
 275
 276                 if (p) {
 277                         struct bb_commit *p_ent = bb_data_at(&bb->data, p->item);
 278                         int c_not_p, p_not_c;
 279
 280                         if (!p_ent->commit_mask) {
 281                                 p_ent->commit_mask = bitmap_new();
 282                                 c_not_p = 1;
 283                                 p_not_c = 0;
 284                         } else {
 285                                 c_not_p = bitmap_is_subset(c_ent->commit_mask, p_ent->commit_mask);
 286                                 p_not_c = bitmap_is_subset(p_ent->commit_mask, c_ent->commit_mask);
 287                         }
 288
 289                         if (!c_not_p)
 290                                 continue;
 291
 292                         bitmap_or(p_ent->commit_mask, c_ent->commit_mask);
 293
 294                         if (p_not_c)
 295                                 p_ent->maximal = 1;
 296                         else {
 297                                 p_ent->maximal = 0;
 298                                 free_commit_list(p_ent->reverse_edges);
 299                                 p_ent->reverse_edges = NULL;
 300                         }
 301
 302                         if (c_ent->maximal) {
 303                                 commit_list_insert(commit, &p_ent->reverse_edges);
 304                         } else {
 305                                 struct commit_list *cc = c_ent->reverse_edges;
 306
 307                                 for (; cc; cc = cc->next) {
 308                                         if (!commit_list_contains(cc->item, p_ent->reverse_edges))
 309                                                 commit_list_insert(cc->item, &p_ent->reverse_edges);
 310                                 }
 311                         }
 312                 }
 313
 314 next:
 315                 bitmap_free(c_ent->commit_mask);
 316                 c_ent->commit_mask = NULL;
 317         }
 318
 319         for (r = reusable; r; r = r->next) {
 320                 ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
 321                 bb->commits[bb->commits_nr++] = r->item;
 322         }
 323
 324         trace2_data_intmax("pack-bitmap-write", the_repository,
 325                            "num_selected_commits", writer->selected_nr);
 326         trace2_data_intmax("pack-bitmap-write", the_repository,
 327                            "num_maximal_commits", num_maximal);
 328
 329         free_commit_list(reusable);
 330 }
 331
 332 static void bitmap_builder_clear(struct bitmap_builder *bb)
 333 {
 334         clear_bb_data(&bb->data);
 335         free(bb->commits);
 336         bb->commits_nr = bb->commits_alloc = 0;
 337 }
 338
 339 static int fill_bitmap_tree(struct bitmap *bitmap,
 340                             struct tree *tree)
 341 {
 342         int found;
 343         uint32_t pos;
 344         struct tree_desc desc;
 345         struct name_entry entry;
 346
 347         /*
 348          * If our bit is already set, then there is nothing to do. Both this
 349          * tree and all of its children will be set.
 350          */
 351         pos = find_object_pos(&tree->object.oid, &found);
 352         if (!found)
 353                 return -1;
 354         if (bitmap_get(bitmap, pos))
 355                 return 0;
 356         bitmap_set(bitmap, pos);
 357
 358         if (parse_tree(tree) < 0)
 359                 die("unable to load tree object %s",
 360                     oid_to_hex(&tree->object.oid));
 361         init_tree_desc(&desc, tree->buffer, tree->size);
 362
 363         while (tree_entry(&desc, &entry)) {
 364                 switch (object_type(entry.mode)) {
 365                 case OBJ_TREE:
 366                         if (fill_bitmap_tree(bitmap,
 367                                              lookup_tree(the_repository, &entry.oid)) < 0)
 368                                 return -1;
 369                         break;
 370                 case OBJ_BLOB:
 371                         pos = find_object_pos(&entry.oid, &found);
 372                         if (!found)
 373                                 return -1;
 374                         bitmap_set(bitmap, pos);
 375                         break;
 376                 default:
 377                         /* Gitlink, etc; not reachable */
 378                         break;
 379                 }
 380         }
 381
 382         free_tree_buffer(tree);
 383         return 0;
 384 }
 385
 386 static int fill_bitmap_commit(struct bb_commit *ent,
 387                               struct commit *commit,
 388                               struct prio_queue *queue,
 389                               struct prio_queue *tree_queue,
 390                               struct bitmap_index *old_bitmap,
 391                               const uint32_t *mapping)
 392 {
 393         int found;
 394         uint32_t pos;
 395         if (!ent->bitmap)
 396                 ent->bitmap = bitmap_new();
 397
 398         prio_queue_put(queue, commit);
 399
 400         while (queue->nr) {
 401                 struct commit_list *p;
 402                 struct commit *c = prio_queue_get(queue);
 403
 404                 if (old_bitmap && mapping) {
 405                         struct ewah_bitmap *old = bitmap_for_commit(old_bitmap, c);
 406                         /*
 407                          * If this commit has an old bitmap, then translate that
 408                          * bitmap and add its bits to this one. No need to walk
 409                          * parents or the tree for this commit.
 410                          */
 411                         if (old && !rebuild_bitmap(mapping, old, ent->bitmap))
 412                                 continue;
 413                 }
 414
 415                 /*
 416                  * Mark ourselves and queue our tree. The commit
 417                  * walk ensures we cover all parents.
 418                  */
 419                 pos = find_object_pos(&c->object.oid, &found);
 420                 if (!found)
 421                         return -1;
 422                 bitmap_set(ent->bitmap, pos);
 423                 prio_queue_put(tree_queue, get_commit_tree(c));
 424
 425                 for (p = c->parents; p; p = p->next) {
 426                         pos = find_object_pos(&p->item->object.oid, &found);
 427                         if (!found)
 428                                 return -1;
 429                         if (!bitmap_get(ent->bitmap, pos)) {
 430                                 bitmap_set(ent->bitmap, pos);
 431                                 prio_queue_put(queue, p->item);
 432                         }
 433                 }
 434         }
 435
 436         while (tree_queue->nr) {
 437                 if (fill_bitmap_tree(ent->bitmap,
 438                                      prio_queue_get(tree_queue)) < 0)
 439                         return -1;
 440         }
 441         return 0;
 442 }
 443
 444 static void store_selected(struct bb_commit *ent, struct commit *commit)
 445 {
 446         struct bitmapped_commit *stored = &writer.selected[ent->idx];
 447         khiter_t hash_pos;
 448         int hash_ret;
 449
 450         stored->bitmap = bitmap_to_ewah(ent->bitmap);
 451
 452         hash_pos = kh_put_oid_map(writer.bitmaps, commit->object.oid, &hash_ret);
 453         if (hash_ret == 0)
 454                 die("Duplicate entry when writing index: %s",
 455                     oid_to_hex(&commit->object.oid));
 456         kh_value(writer.bitmaps, hash_pos) = stored;
 457 }
 458
 459 int bitmap_writer_build(struct packing_data *to_pack)
 460 {
 461         struct bitmap_builder bb;
 462         size_t i;
 463         int nr_stored = 0; /* for progress */
 464         struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 465         struct prio_queue tree_queue = { NULL };
 466         struct bitmap_index *old_bitmap;
 467         uint32_t *mapping;
 468         int closed = 1; /* until proven otherwise */
 469
 470         writer.bitmaps = kh_init_oid_map();
 471         writer.to_pack = to_pack;
 472
 473         if (writer.show_progress)
 474                 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
 475         trace2_region_enter("pack-bitmap-write", "building_bitmaps_total",
 476                             the_repository);
 477
 478         old_bitmap = prepare_bitmap_git(to_pack->repo);
 479         if (old_bitmap)
 480                 mapping = create_bitmap_mapping(old_bitmap, to_pack);
 481         else
 482                 mapping = NULL;
 483
 484         bitmap_builder_init(&bb, &writer, old_bitmap);
 485         for (i = bb.commits_nr; i > 0; i--) {
 486                 struct commit *commit = bb.commits[i-1];
 487                 struct bb_commit *ent = bb_data_at(&bb.data, commit);
 488                 struct commit *child;
 489                 int reused = 0;
 490
 491                 if (fill_bitmap_commit(ent, commit, &queue, &tree_queue,
 492                                        old_bitmap, mapping) < 0) {
 493                         closed = 0;
 494                         break;
 495                 }
 496
 497                 if (ent->selected) {
 498                         store_selected(ent, commit);
 499                         nr_stored++;
 500                         display_progress(writer.progress, nr_stored);
 501                 }
 502
 503                 while ((child = pop_commit(&ent->reverse_edges))) {
 504                         struct bb_commit *child_ent =
 505                                 bb_data_at(&bb.data, child);
 506
 507                         if (child_ent->bitmap)
 508                                 bitmap_or(child_ent->bitmap, ent->bitmap);
 509                         else if (reused)
 510                                 child_ent->bitmap = bitmap_dup(ent->bitmap);
 511                         else {
 512                                 child_ent->bitmap = ent->bitmap;
 513                                 reused = 1;
 514                         }
 515                 }
 516                 if (!reused)
 517                         bitmap_free(ent->bitmap);
 518                 ent->bitmap = NULL;
 519         }
 520         clear_prio_queue(&queue);
 521         clear_prio_queue(&tree_queue);
 522         bitmap_builder_clear(&bb);
 523         free_bitmap_index(old_bitmap);
 524         free(mapping);
 525
 526         trace2_region_leave("pack-bitmap-write", "building_bitmaps_total",
 527                             the_repository);
 528
 529         stop_progress(&writer.progress);
 530
 531         if (closed)
 532                 compute_xor_offsets();
 533         return closed ? 0 : -1;
 534 }
 535
 536 /**
 537  * Select the commits that will be bitmapped
 538  */
 539 static inline unsigned int next_commit_index(unsigned int idx)
 540 {
 541         static const unsigned int MIN_COMMITS = 100;
 542         static const unsigned int MAX_COMMITS = 5000;
 543
 544         static const unsigned int MUST_REGION = 100;
 545         static const unsigned int MIN_REGION = 20000;
 546
 547         unsigned int offset, next;
 548
 549         if (idx <= MUST_REGION)
 550                 return 0;
 551
 552         if (idx <= MIN_REGION) {
 553                 offset = idx - MUST_REGION;
 554                 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
 555         }
 556
 557         offset = idx - MIN_REGION;
 558         next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
 559
 560         return (next > MIN_COMMITS) ? next : MIN_COMMITS;
 561 }
 562
 563 static int date_compare(const void *_a, const void *_b)
 564 {
 565         struct commit *a = *(struct commit **)_a;
 566         struct commit *b = *(struct commit **)_b;
 567         return (long)b->date - (long)a->date;
 568 }
 569
 570 void bitmap_writer_select_commits(struct commit **indexed_commits,
 571                                   unsigned int indexed_commits_nr,
 572                                   int max_bitmaps)
 573 {
 574         unsigned int i = 0, j, next;
 575
 576         QSORT(indexed_commits, indexed_commits_nr, date_compare);
 577
 578         if (writer.show_progress)
 579                 writer.progress = start_progress("Selecting bitmap commits", 0);
 580
 581         if (indexed_commits_nr < 100) {
 582                 for (i = 0; i < indexed_commits_nr; ++i)
 583                         push_bitmapped_commit(indexed_commits[i]);
 584                 return;
 585         }
 586
 587         for (;;) {
 588                 struct commit *chosen = NULL;
 589
 590                 next = next_commit_index(i);
 591
 592                 if (i + next >= indexed_commits_nr)
 593                         break;
 594
 595                 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
 596                         writer.selected_nr = max_bitmaps;
 597                         break;
 598                 }
 599
 600                 if (next == 0) {
 601                         chosen = indexed_commits[i];
 602                 } else {
 603                         chosen = indexed_commits[i + next];
 604
 605                         for (j = 0; j <= next; ++j) {
 606                                 struct commit *cm = indexed_commits[i + j];
 607
 608                                 if ((cm->object.flags & NEEDS_BITMAP) != 0) {
 609                                         chosen = cm;
 610                                         break;
 611                                 }
 612
 613                                 if (cm->parents && cm->parents->next)
 614                                         chosen = cm;
 615                         }
 616                 }
 617
 618                 push_bitmapped_commit(chosen);
 619
 620                 i += next + 1;
 621                 display_progress(writer.progress, i);
 622         }
 623
 624         stop_progress(&writer.progress);
 625 }
 626
 627
 628 static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
 629 {
 630         /* hashwrite will die on error */
 631         hashwrite(f, buf, len);
 632         return len;
 633 }
 634
 635 /**
 636  * Write the bitmap index to disk
 637  */
 638 static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
 639 {
 640         if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
 641                 die("Failed to write bitmap index");
 642 }
 643
 644 static const struct object_id *oid_access(size_t pos, const void *table)
 645 {
 646         const struct pack_idx_entry * const *index = table;
 647         return &index[pos]->oid;
 648 }
 649
 650 static void write_selected_commits_v1(struct hashfile *f,
 651                                       struct pack_idx_entry **index,
 652                                       uint32_t index_nr)
 653 {
 654         int i;
 655
 656         for (i = 0; i < writer.selected_nr; ++i) {
 657                 struct bitmapped_commit *stored = &writer.selected[i];
 658
 659                 int commit_pos =
 660                         oid_pos(&stored->commit->object.oid, index, index_nr, oid_access);
 661
 662                 if (commit_pos < 0)
 663                         BUG("trying to write commit not in index");
 664
 665                 hashwrite_be32(f, commit_pos);
 666                 hashwrite_u8(f, stored->xor_offset);
 667                 hashwrite_u8(f, stored->flags);
 668
 669                 dump_bitmap(f, stored->write_as);
 670         }
 671 }
 672
 673 static void write_hash_cache(struct hashfile *f,
 674                              struct pack_idx_entry **index,
 675                              uint32_t index_nr)
 676 {
 677         uint32_t i;
 678
 679         for (i = 0; i < index_nr; ++i) {
 680                 struct object_entry *entry = (struct object_entry *)index[i];
 681                 hashwrite_be32(f, entry->hash);
 682         }
 683 }
 684
 685 void bitmap_writer_set_checksum(unsigned char *sha1)
 686 {
 687         hashcpy(writer.pack_checksum, sha1);
 688 }
 689
 690 void bitmap_writer_finish(struct pack_idx_entry **index,
 691                           uint32_t index_nr,
 692                           const char *filename,
 693                           uint16_t options)
 694 {
 695         static uint16_t default_version = 1;
 696         static uint16_t flags = BITMAP_OPT_FULL_DAG;
 697         struct strbuf tmp_file = STRBUF_INIT;
 698         struct hashfile *f;
 699
 700         struct bitmap_disk_header header;
 701
 702         int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
 703
 704         f = hashfd(fd, tmp_file.buf);
 705
 706         memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
 707         header.version = htons(default_version);
 708         header.options = htons(flags | options);
 709         header.entry_count = htonl(writer.selected_nr);
 710         hashcpy(header.checksum, writer.pack_checksum);
 711
 712         hashwrite(f, &header, sizeof(header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz);
 713         dump_bitmap(f, writer.commits);
 714         dump_bitmap(f, writer.trees);
 715         dump_bitmap(f, writer.blobs);
 716         dump_bitmap(f, writer.tags);
 717         write_selected_commits_v1(f, index, index_nr);
 718
 719         if (options & BITMAP_OPT_HASH_CACHE)
 720                 write_hash_cache(f, index, index_nr);
 721
 722         finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 723
 724         if (adjust_shared_perm(tmp_file.buf))
 725                 die_errno("unable to make temporary bitmap file readable");
 726
 727         if (rename(tmp_file.buf, filename))
 728                 die_errno("unable to rename temporary bitmap file to '%s'", filename);
 729
 730         strbuf_release(&tmp_file);
 731 }