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 "sha1-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
  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)
 129 {
 130         struct object_entry *entry = packlist_find(writer.to_pack, oid);
 131
 132         if (!entry) {
 133                 die("Failed to write bitmap index. Packfile doesn't have full closure "
 134                         "(object %s is missing)", oid_to_hex(oid));
 135         }
 136
 137         return oe_in_pack_pos(writer.to_pack, entry);
 138 }
 139
 140 static void compute_xor_offsets(void)
 141 {
 142         static const int MAX_XOR_OFFSET_SEARCH = 10;
 143
 144         int i, next = 0;
 145
 146         while (next < writer.selected_nr) {
 147                 struct bitmapped_commit *stored = &writer.selected[next];
 148
 149                 int best_offset = 0;
 150                 struct ewah_bitmap *best_bitmap = stored->bitmap;
 151                 struct ewah_bitmap *test_xor;
 152
 153                 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
 154                         int curr = next - i;
 155
 156                         if (curr < 0)
 157                                 break;
 158
 159                         test_xor = ewah_pool_new();
 160                         ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
 161
 162                         if (test_xor->buffer_size < best_bitmap->buffer_size) {
 163                                 if (best_bitmap != stored->bitmap)
 164                                         ewah_pool_free(best_bitmap);
 165
 166                                 best_bitmap = test_xor;
 167                                 best_offset = i;
 168                         } else {
 169                                 ewah_pool_free(test_xor);
 170                         }
 171                 }
 172
 173                 stored->xor_offset = best_offset;
 174                 stored->write_as = best_bitmap;
 175
 176                 next++;
 177         }
 178 }
 179
 180 struct bb_commit {
 181         struct commit_list *reverse_edges;
 182         struct bitmap *commit_mask;
 183         struct bitmap *bitmap;
 184         unsigned selected:1,
 185                  maximal:1;
 186         unsigned idx; /* within selected array */
 187 };
 188
 189 define_commit_slab(bb_data, struct bb_commit);
 190
 191 struct bitmap_builder {
 192         struct bb_data data;
 193         struct commit **commits;
 194         size_t commits_nr, commits_alloc;
 195 };
 196
 197 static void bitmap_builder_init(struct bitmap_builder *bb,
 198                                 struct bitmap_writer *writer,
 199                                 struct bitmap_index *old_bitmap)
 200 {
 201         struct rev_info revs;
 202         struct commit *commit;
 203         struct commit_list *reusable = NULL;
 204         struct commit_list *r;
 205         unsigned int i, num_maximal = 0;
 206
 207         memset(bb, 0, sizeof(*bb));
 208         init_bb_data(&bb->data);
 209
 210         reset_revision_walk();
 211         repo_init_revisions(writer->to_pack->repo, &revs, NULL);
 212         revs.topo_order = 1;
 213         revs.first_parent_only = 1;
 214
 215         for (i = 0; i < writer->selected_nr; i++) {
 216                 struct commit *c = writer->selected[i].commit;
 217                 struct bb_commit *ent = bb_data_at(&bb->data, c);
 218
 219                 ent->selected = 1;
 220                 ent->maximal = 1;
 221                 ent->idx = i;
 222
 223                 ent->commit_mask = bitmap_new();
 224                 bitmap_set(ent->commit_mask, i);
 225
 226                 add_pending_object(&revs, &c->object, "");
 227         }
 228
 229         if (prepare_revision_walk(&revs))
 230                 die("revision walk setup failed");
 231
 232         while ((commit = get_revision(&revs))) {
 233                 struct commit_list *p = commit->parents;
 234                 struct bb_commit *c_ent;
 235
 236                 parse_commit_or_die(commit);
 237
 238                 c_ent = bb_data_at(&bb->data, commit);
 239
 240                 /*
 241                  * If there is no commit_mask, there is no reason to iterate
 242                  * over this commit; it is not selected (if it were, it would
 243                  * not have a blank commit mask) and all its children have
 244                  * existing bitmaps (see the comment starting with "This commit
 245                  * has an existing bitmap" below), so it does not contribute
 246                  * anything to the final bitmap file or its descendants.
 247                  */
 248                 if (!c_ent->commit_mask)
 249                         continue;
 250
 251                 if (old_bitmap && bitmap_for_commit(old_bitmap, commit)) {
 252                         /*
 253                          * This commit has an existing bitmap, so we can
 254                          * get its bits immediately without an object
 255                          * walk. That is, it is reusable as-is and there is no
 256                          * need to continue walking beyond it.
 257                          *
 258                          * Mark it as such and add it to bb->commits separately
 259                          * to avoid allocating a position in the commit mask.
 260                          */
 261                         commit_list_insert(commit, &reusable);
 262                         goto next;
 263                 }
 264
 265                 if (c_ent->maximal) {
 266                         num_maximal++;
 267                         ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
 268                         bb->commits[bb->commits_nr++] = commit;
 269                 }
 270
 271                 if (p) {
 272                         struct bb_commit *p_ent = bb_data_at(&bb->data, p->item);
 273                         int c_not_p, p_not_c;
 274
 275                         if (!p_ent->commit_mask) {
 276                                 p_ent->commit_mask = bitmap_new();
 277                                 c_not_p = 1;
 278                                 p_not_c = 0;
 279                         } else {
 280                                 c_not_p = bitmap_is_subset(c_ent->commit_mask, p_ent->commit_mask);
 281                                 p_not_c = bitmap_is_subset(p_ent->commit_mask, c_ent->commit_mask);
 282                         }
 283
 284                         if (!c_not_p)
 285                                 continue;
 286
 287                         bitmap_or(p_ent->commit_mask, c_ent->commit_mask);
 288
 289                         if (p_not_c)
 290                                 p_ent->maximal = 1;
 291                         else {
 292                                 p_ent->maximal = 0;
 293                                 free_commit_list(p_ent->reverse_edges);
 294                                 p_ent->reverse_edges = NULL;
 295                         }
 296
 297                         if (c_ent->maximal) {
 298                                 commit_list_insert(commit, &p_ent->reverse_edges);
 299                         } else {
 300                                 struct commit_list *cc = c_ent->reverse_edges;
 301
 302                                 for (; cc; cc = cc->next) {
 303                                         if (!commit_list_contains(cc->item, p_ent->reverse_edges))
 304                                                 commit_list_insert(cc->item, &p_ent->reverse_edges);
 305                                 }
 306                         }
 307                 }
 308
 309 next:
 310                 bitmap_free(c_ent->commit_mask);
 311                 c_ent->commit_mask = NULL;
 312         }
 313
 314         for (r = reusable; r; r = r->next) {
 315                 ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
 316                 bb->commits[bb->commits_nr++] = r->item;
 317         }
 318
 319         trace2_data_intmax("pack-bitmap-write", the_repository,
 320                            "num_selected_commits", writer->selected_nr);
 321         trace2_data_intmax("pack-bitmap-write", the_repository,
 322                            "num_maximal_commits", num_maximal);
 323
 324         free_commit_list(reusable);
 325 }
 326
 327 static void bitmap_builder_clear(struct bitmap_builder *bb)
 328 {
 329         clear_bb_data(&bb->data);
 330         free(bb->commits);
 331         bb->commits_nr = bb->commits_alloc = 0;
 332 }
 333
 334 static void fill_bitmap_tree(struct bitmap *bitmap,
 335                              struct tree *tree)
 336 {
 337         uint32_t pos;
 338         struct tree_desc desc;
 339         struct name_entry entry;
 340
 341         /*
 342          * If our bit is already set, then there is nothing to do. Both this
 343          * tree and all of its children will be set.
 344          */
 345         pos = find_object_pos(&tree->object.oid);
 346         if (bitmap_get(bitmap, pos))
 347                 return;
 348         bitmap_set(bitmap, pos);
 349
 350         if (parse_tree(tree) < 0)
 351                 die("unable to load tree object %s",
 352                     oid_to_hex(&tree->object.oid));
 353         init_tree_desc(&desc, tree->buffer, tree->size);
 354
 355         while (tree_entry(&desc, &entry)) {
 356                 switch (object_type(entry.mode)) {
 357                 case OBJ_TREE:
 358                         fill_bitmap_tree(bitmap,
 359                                          lookup_tree(the_repository, &entry.oid));
 360                         break;
 361                 case OBJ_BLOB:
 362                         bitmap_set(bitmap, find_object_pos(&entry.oid));
 363                         break;
 364                 default:
 365                         /* Gitlink, etc; not reachable */
 366                         break;
 367                 }
 368         }
 369
 370         free_tree_buffer(tree);
 371 }
 372
 373 static void fill_bitmap_commit(struct bb_commit *ent,
 374                                struct commit *commit,
 375                                struct prio_queue *queue,
 376                                struct prio_queue *tree_queue,
 377                                struct bitmap_index *old_bitmap,
 378                                const uint32_t *mapping)
 379 {
 380         if (!ent->bitmap)
 381                 ent->bitmap = bitmap_new();
 382
 383         prio_queue_put(queue, commit);
 384
 385         while (queue->nr) {
 386                 struct commit_list *p;
 387                 struct commit *c = prio_queue_get(queue);
 388
 389                 if (old_bitmap && mapping) {
 390                         struct ewah_bitmap *old = bitmap_for_commit(old_bitmap, c);
 391                         /*
 392                          * If this commit has an old bitmap, then translate that
 393                          * bitmap and add its bits to this one. No need to walk
 394                          * parents or the tree for this commit.
 395                          */
 396                         if (old && !rebuild_bitmap(mapping, old, ent->bitmap))
 397                                 continue;
 398                 }
 399
 400                 /*
 401                  * Mark ourselves and queue our tree. The commit
 402                  * walk ensures we cover all parents.
 403                  */
 404                 bitmap_set(ent->bitmap, find_object_pos(&c->object.oid));
 405                 prio_queue_put(tree_queue, get_commit_tree(c));
 406
 407                 for (p = c->parents; p; p = p->next) {
 408                         int pos = find_object_pos(&p->item->object.oid);
 409                         if (!bitmap_get(ent->bitmap, pos)) {
 410                                 bitmap_set(ent->bitmap, pos);
 411                                 prio_queue_put(queue, p->item);
 412                         }
 413                 }
 414         }
 415
 416         while (tree_queue->nr)
 417                 fill_bitmap_tree(ent->bitmap, prio_queue_get(tree_queue));
 418 }
 419
 420 static void store_selected(struct bb_commit *ent, struct commit *commit)
 421 {
 422         struct bitmapped_commit *stored = &writer.selected[ent->idx];
 423         khiter_t hash_pos;
 424         int hash_ret;
 425
 426         stored->bitmap = bitmap_to_ewah(ent->bitmap);
 427
 428         hash_pos = kh_put_oid_map(writer.bitmaps, commit->object.oid, &hash_ret);
 429         if (hash_ret == 0)
 430                 die("Duplicate entry when writing index: %s",
 431                     oid_to_hex(&commit->object.oid));
 432         kh_value(writer.bitmaps, hash_pos) = stored;
 433 }
 434
 435 void bitmap_writer_build(struct packing_data *to_pack)
 436 {
 437         struct bitmap_builder bb;
 438         size_t i;
 439         int nr_stored = 0; /* for progress */
 440         struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 441         struct prio_queue tree_queue = { NULL };
 442         struct bitmap_index *old_bitmap;
 443         uint32_t *mapping;
 444
 445         writer.bitmaps = kh_init_oid_map();
 446         writer.to_pack = to_pack;
 447
 448         if (writer.show_progress)
 449                 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
 450         trace2_region_enter("pack-bitmap-write", "building_bitmaps_total",
 451                             the_repository);
 452
 453         old_bitmap = prepare_bitmap_git(to_pack->repo);
 454         if (old_bitmap)
 455                 mapping = create_bitmap_mapping(old_bitmap, to_pack);
 456         else
 457                 mapping = NULL;
 458
 459         bitmap_builder_init(&bb, &writer, old_bitmap);
 460         for (i = bb.commits_nr; i > 0; i--) {
 461                 struct commit *commit = bb.commits[i-1];
 462                 struct bb_commit *ent = bb_data_at(&bb.data, commit);
 463                 struct commit *child;
 464                 int reused = 0;
 465
 466                 fill_bitmap_commit(ent, commit, &queue, &tree_queue,
 467                                    old_bitmap, mapping);
 468
 469                 if (ent->selected) {
 470                         store_selected(ent, commit);
 471                         nr_stored++;
 472                         display_progress(writer.progress, nr_stored);
 473                 }
 474
 475                 while ((child = pop_commit(&ent->reverse_edges))) {
 476                         struct bb_commit *child_ent =
 477                                 bb_data_at(&bb.data, child);
 478
 479                         if (child_ent->bitmap)
 480                                 bitmap_or(child_ent->bitmap, ent->bitmap);
 481                         else if (reused)
 482                                 child_ent->bitmap = bitmap_dup(ent->bitmap);
 483                         else {
 484                                 child_ent->bitmap = ent->bitmap;
 485                                 reused = 1;
 486                         }
 487                 }
 488                 if (!reused)
 489                         bitmap_free(ent->bitmap);
 490                 ent->bitmap = NULL;
 491         }
 492         clear_prio_queue(&queue);
 493         clear_prio_queue(&tree_queue);
 494         bitmap_builder_clear(&bb);
 495         free(mapping);
 496
 497         trace2_region_leave("pack-bitmap-write", "building_bitmaps_total",
 498                             the_repository);
 499
 500         stop_progress(&writer.progress);
 501
 502         compute_xor_offsets();
 503 }
 504
 505 /**
 506  * Select the commits that will be bitmapped
 507  */
 508 static inline unsigned int next_commit_index(unsigned int idx)
 509 {
 510         static const unsigned int MIN_COMMITS = 100;
 511         static const unsigned int MAX_COMMITS = 5000;
 512
 513         static const unsigned int MUST_REGION = 100;
 514         static const unsigned int MIN_REGION = 20000;
 515
 516         unsigned int offset, next;
 517
 518         if (idx <= MUST_REGION)
 519                 return 0;
 520
 521         if (idx <= MIN_REGION) {
 522                 offset = idx - MUST_REGION;
 523                 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
 524         }
 525
 526         offset = idx - MIN_REGION;
 527         next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
 528
 529         return (next > MIN_COMMITS) ? next : MIN_COMMITS;
 530 }
 531
 532 static int date_compare(const void *_a, const void *_b)
 533 {
 534         struct commit *a = *(struct commit **)_a;
 535         struct commit *b = *(struct commit **)_b;
 536         return (long)b->date - (long)a->date;
 537 }
 538
 539 void bitmap_writer_select_commits(struct commit **indexed_commits,
 540                                   unsigned int indexed_commits_nr,
 541                                   int max_bitmaps)
 542 {
 543         unsigned int i = 0, j, next;
 544
 545         QSORT(indexed_commits, indexed_commits_nr, date_compare);
 546
 547         if (writer.show_progress)
 548                 writer.progress = start_progress("Selecting bitmap commits", 0);
 549
 550         if (indexed_commits_nr < 100) {
 551                 for (i = 0; i < indexed_commits_nr; ++i)
 552                         push_bitmapped_commit(indexed_commits[i]);
 553                 return;
 554         }
 555
 556         for (;;) {
 557                 struct commit *chosen = NULL;
 558
 559                 next = next_commit_index(i);
 560
 561                 if (i + next >= indexed_commits_nr)
 562                         break;
 563
 564                 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
 565                         writer.selected_nr = max_bitmaps;
 566                         break;
 567                 }
 568
 569                 if (next == 0) {
 570                         chosen = indexed_commits[i];
 571                 } else {
 572                         chosen = indexed_commits[i + next];
 573
 574                         for (j = 0; j <= next; ++j) {
 575                                 struct commit *cm = indexed_commits[i + j];
 576
 577                                 if ((cm->object.flags & NEEDS_BITMAP) != 0) {
 578                                         chosen = cm;
 579                                         break;
 580                                 }
 581
 582                                 if (cm->parents && cm->parents->next)
 583                                         chosen = cm;
 584                         }
 585                 }
 586
 587                 push_bitmapped_commit(chosen);
 588
 589                 i += next + 1;
 590                 display_progress(writer.progress, i);
 591         }
 592
 593         stop_progress(&writer.progress);
 594 }
 595
 596
 597 static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
 598 {
 599         /* hashwrite will die on error */
 600         hashwrite(f, buf, len);
 601         return len;
 602 }
 603
 604 /**
 605  * Write the bitmap index to disk
 606  */
 607 static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
 608 {
 609         if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
 610                 die("Failed to write bitmap index");
 611 }
 612
 613 static const unsigned char *sha1_access(size_t pos, void *table)
 614 {
 615         struct pack_idx_entry **index = table;
 616         return index[pos]->oid.hash;
 617 }
 618
 619 static void write_selected_commits_v1(struct hashfile *f,
 620                                       struct pack_idx_entry **index,
 621                                       uint32_t index_nr)
 622 {
 623         int i;
 624
 625         for (i = 0; i < writer.selected_nr; ++i) {
 626                 struct bitmapped_commit *stored = &writer.selected[i];
 627
 628                 int commit_pos =
 629                         sha1_pos(stored->commit->object.oid.hash, index, index_nr, sha1_access);
 630
 631                 if (commit_pos < 0)
 632                         BUG("trying to write commit not in index");
 633
 634                 hashwrite_be32(f, commit_pos);
 635                 hashwrite_u8(f, stored->xor_offset);
 636                 hashwrite_u8(f, stored->flags);
 637
 638                 dump_bitmap(f, stored->write_as);
 639         }
 640 }
 641
 642 static void write_hash_cache(struct hashfile *f,
 643                              struct pack_idx_entry **index,
 644                              uint32_t index_nr)
 645 {
 646         uint32_t i;
 647
 648         for (i = 0; i < index_nr; ++i) {
 649                 struct object_entry *entry = (struct object_entry *)index[i];
 650                 hashwrite_be32(f, entry->hash);
 651         }
 652 }
 653
 654 void bitmap_writer_set_checksum(unsigned char *sha1)
 655 {
 656         hashcpy(writer.pack_checksum, sha1);
 657 }
 658
 659 void bitmap_writer_finish(struct pack_idx_entry **index,
 660                           uint32_t index_nr,
 661                           const char *filename,
 662                           uint16_t options)
 663 {
 664         static uint16_t default_version = 1;
 665         static uint16_t flags = BITMAP_OPT_FULL_DAG;
 666         struct strbuf tmp_file = STRBUF_INIT;
 667         struct hashfile *f;
 668
 669         struct bitmap_disk_header header;
 670
 671         int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
 672
 673         f = hashfd(fd, tmp_file.buf);
 674
 675         memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
 676         header.version = htons(default_version);
 677         header.options = htons(flags | options);
 678         header.entry_count = htonl(writer.selected_nr);
 679         hashcpy(header.checksum, writer.pack_checksum);
 680
 681         hashwrite(f, &header, sizeof(header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz);
 682         dump_bitmap(f, writer.commits);
 683         dump_bitmap(f, writer.trees);
 684         dump_bitmap(f, writer.blobs);
 685         dump_bitmap(f, writer.tags);
 686         write_selected_commits_v1(f, index, index_nr);
 687
 688         if (options & BITMAP_OPT_HASH_CACHE)
 689                 write_hash_cache(f, index, index_nr);
 690
 691         finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 692
 693         if (adjust_shared_perm(tmp_file.buf))
 694                 die_errno("unable to make temporary bitmap file readable");
 695
 696         if (rename(tmp_file.buf, filename))
 697                 die_errno("unable to rename temporary bitmap file to '%s'", filename);
 698
 699         strbuf_release(&tmp_file);
 700 }