git.oblomov.eu Git - git/blob - commit-graph.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "dir.h"
   4 #include "git-compat-util.h"
   5 #include "lockfile.h"
   6 #include "pack.h"
   7 #include "packfile.h"
   8 #include "commit.h"
   9 #include "object.h"
  10 #include "refs.h"
  11 #include "revision.h"
  12 #include "sha1-lookup.h"
  13 #include "commit-graph.h"
  14 #include "object-store.h"
  15 #include "alloc.h"
  16 #include "hashmap.h"
  17 #include "replace-object.h"
  18 #include "progress.h"
  19
  20 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
  21 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
  22 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
  23 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
  24 #define GRAPH_CHUNKID_EXTRAEDGES 0x45444745 /* "EDGE" */
  25
  26 #define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
  27
  28 #define GRAPH_VERSION_1 0x1
  29 #define GRAPH_VERSION GRAPH_VERSION_1
  30
  31 #define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
  32 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
  33 #define GRAPH_PARENT_NONE 0x70000000
  34
  35 #define GRAPH_LAST_EDGE 0x80000000
  36
  37 #define GRAPH_HEADER_SIZE 8
  38 #define GRAPH_FANOUT_SIZE (4 * 256)
  39 #define GRAPH_CHUNKLOOKUP_WIDTH 12
  40 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
  41                         + GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
  42
  43 char *get_commit_graph_filename(const char *obj_dir)
  44 {
  45         return xstrfmt("%s/info/commit-graph", obj_dir);
  46 }
  47
  48 static uint8_t oid_version(void)
  49 {
  50         return 1;
  51 }
  52
  53 static struct commit_graph *alloc_commit_graph(void)
  54 {
  55         struct commit_graph *g = xcalloc(1, sizeof(*g));
  56         g->graph_fd = -1;
  57
  58         return g;
  59 }
  60
  61 extern int read_replace_refs;
  62
  63 static int commit_graph_compatible(struct repository *r)
  64 {
  65         if (!r->gitdir)
  66                 return 0;
  67
  68         if (read_replace_refs) {
  69                 prepare_replace_object(r);
  70                 if (hashmap_get_size(&r->objects->replace_map->map))
  71                         return 0;
  72         }
  73
  74         prepare_commit_graft(r);
  75         if (r->parsed_objects && r->parsed_objects->grafts_nr)
  76                 return 0;
  77         if (is_repository_shallow(r))
  78                 return 0;
  79
  80         return 1;
  81 }
  82
  83 int open_commit_graph(const char *graph_file, int *fd, struct stat *st)
  84 {
  85         *fd = git_open(graph_file);
  86         if (*fd < 0)
  87                 return 0;
  88         if (fstat(*fd, st)) {
  89                 close(*fd);
  90                 return 0;
  91         }
  92         return 1;
  93 }
  94
  95 struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st)
  96 {
  97         void *graph_map;
  98         size_t graph_size;
  99         struct commit_graph *ret;
 100
 101         graph_size = xsize_t(st->st_size);
 102
 103         if (graph_size < GRAPH_MIN_SIZE) {
 104                 close(fd);
 105                 error(_("commit-graph file is too small"));
 106                 return NULL;
 107         }
 108         graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
 109         ret = parse_commit_graph(graph_map, fd, graph_size);
 110
 111         if (!ret) {
 112                 munmap(graph_map, graph_size);
 113                 close(fd);
 114         }
 115
 116         return ret;
 117 }
 118
 119 static int verify_commit_graph_lite(struct commit_graph *g)
 120 {
 121         /*
 122          * Basic validation shared between parse_commit_graph()
 123          * which'll be called every time the graph is used, and the
 124          * much more expensive verify_commit_graph() used by
 125          * "commit-graph verify".
 126          *
 127          * There should only be very basic checks here to ensure that
 128          * we don't e.g. segfault in fill_commit_in_graph(), but
 129          * because this is a very hot codepath nothing that e.g. loops
 130          * over g->num_commits, or runs a checksum on the commit-graph
 131          * itself.
 132          */
 133         if (!g->chunk_oid_fanout) {
 134                 error("commit-graph is missing the OID Fanout chunk");
 135                 return 1;
 136         }
 137         if (!g->chunk_oid_lookup) {
 138                 error("commit-graph is missing the OID Lookup chunk");
 139                 return 1;
 140         }
 141         if (!g->chunk_commit_data) {
 142                 error("commit-graph is missing the Commit Data chunk");
 143                 return 1;
 144         }
 145
 146         return 0;
 147 }
 148
 149 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
 150                                         size_t graph_size)
 151 {
 152         const unsigned char *data, *chunk_lookup;
 153         uint32_t i;
 154         struct commit_graph *graph;
 155         uint64_t last_chunk_offset;
 156         uint32_t last_chunk_id;
 157         uint32_t graph_signature;
 158         unsigned char graph_version, hash_version;
 159
 160         if (!graph_map)
 161                 return NULL;
 162
 163         if (graph_size < GRAPH_MIN_SIZE)
 164                 return NULL;
 165
 166         data = (const unsigned char *)graph_map;
 167
 168         graph_signature = get_be32(data);
 169         if (graph_signature != GRAPH_SIGNATURE) {
 170                 error(_("commit-graph signature %X does not match signature %X"),
 171                       graph_signature, GRAPH_SIGNATURE);
 172                 return NULL;
 173         }
 174
 175         graph_version = *(unsigned char*)(data + 4);
 176         if (graph_version != GRAPH_VERSION) {
 177                 error(_("commit-graph version %X does not match version %X"),
 178                       graph_version, GRAPH_VERSION);
 179                 return NULL;
 180         }
 181
 182         hash_version = *(unsigned char*)(data + 5);
 183         if (hash_version != oid_version()) {
 184                 error(_("commit-graph hash version %X does not match version %X"),
 185                       hash_version, oid_version());
 186                 return NULL;
 187         }
 188
 189         graph = alloc_commit_graph();
 190
 191         graph->hash_len = the_hash_algo->rawsz;
 192         graph->num_chunks = *(unsigned char*)(data + 6);
 193         graph->graph_fd = fd;
 194         graph->data = graph_map;
 195         graph->data_len = graph_size;
 196
 197         last_chunk_id = 0;
 198         last_chunk_offset = 8;
 199         chunk_lookup = data + 8;
 200         for (i = 0; i < graph->num_chunks; i++) {
 201                 uint32_t chunk_id;
 202                 uint64_t chunk_offset;
 203                 int chunk_repeated = 0;
 204
 205                 if (data + graph_size - chunk_lookup <
 206                     GRAPH_CHUNKLOOKUP_WIDTH) {
 207                         error(_("commit-graph chunk lookup table entry missing; file may be incomplete"));
 208                         free(graph);
 209                         return NULL;
 210                 }
 211
 212                 chunk_id = get_be32(chunk_lookup + 0);
 213                 chunk_offset = get_be64(chunk_lookup + 4);
 214
 215                 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
 216
 217                 if (chunk_offset > graph_size - the_hash_algo->rawsz) {
 218                         error(_("commit-graph improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
 219                               (uint32_t)chunk_offset);
 220                         free(graph);
 221                         return NULL;
 222                 }
 223
 224                 switch (chunk_id) {
 225                 case GRAPH_CHUNKID_OIDFANOUT:
 226                         if (graph->chunk_oid_fanout)
 227                                 chunk_repeated = 1;
 228                         else
 229                                 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
 230                         break;
 231
 232                 case GRAPH_CHUNKID_OIDLOOKUP:
 233                         if (graph->chunk_oid_lookup)
 234                                 chunk_repeated = 1;
 235                         else
 236                                 graph->chunk_oid_lookup = data + chunk_offset;
 237                         break;
 238
 239                 case GRAPH_CHUNKID_DATA:
 240                         if (graph->chunk_commit_data)
 241                                 chunk_repeated = 1;
 242                         else
 243                                 graph->chunk_commit_data = data + chunk_offset;
 244                         break;
 245
 246                 case GRAPH_CHUNKID_EXTRAEDGES:
 247                         if (graph->chunk_extra_edges)
 248                                 chunk_repeated = 1;
 249                         else
 250                                 graph->chunk_extra_edges = data + chunk_offset;
 251                         break;
 252                 }
 253
 254                 if (chunk_repeated) {
 255                         error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
 256                         free(graph);
 257                         return NULL;
 258                 }
 259
 260                 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
 261                 {
 262                         graph->num_commits = (chunk_offset - last_chunk_offset)
 263                                              / graph->hash_len;
 264                 }
 265
 266                 last_chunk_id = chunk_id;
 267                 last_chunk_offset = chunk_offset;
 268         }
 269
 270         if (verify_commit_graph_lite(graph))
 271                 return NULL;
 272
 273         return graph;
 274 }
 275
 276 static struct commit_graph *load_commit_graph_one(const char *graph_file)
 277 {
 278
 279         struct stat st;
 280         int fd;
 281         int open_ok = open_commit_graph(graph_file, &fd, &st);
 282
 283         if (!open_ok)
 284                 return NULL;
 285
 286         return load_commit_graph_one_fd_st(fd, &st);
 287 }
 288
 289 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 290 {
 291         char *graph_name;
 292
 293         if (r->objects->commit_graph)
 294                 return;
 295
 296         graph_name = get_commit_graph_filename(obj_dir);
 297         r->objects->commit_graph =
 298                 load_commit_graph_one(graph_name);
 299
 300         FREE_AND_NULL(graph_name);
 301 }
 302
 303 /*
 304  * Return 1 if commit_graph is non-NULL, and 0 otherwise.
 305  *
 306  * On the first invocation, this function attemps to load the commit
 307  * graph if the_repository is configured to have one.
 308  */
 309 static int prepare_commit_graph(struct repository *r)
 310 {
 311         struct object_directory *odb;
 312         int config_value;
 313
 314         if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 315                 die("dying as requested by the '%s' variable on commit-graph load!",
 316                     GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
 317
 318         if (r->objects->commit_graph_attempted)
 319                 return !!r->objects->commit_graph;
 320         r->objects->commit_graph_attempted = 1;
 321
 322         if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 323             (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
 324             !config_value))
 325                 /*
 326                  * This repository is not configured to use commit graphs, so
 327                  * do not load one. (But report commit_graph_attempted anyway
 328                  * so that commit graph loading is not attempted again for this
 329                  * repository.)
 330                  */
 331                 return 0;
 332
 333         if (!commit_graph_compatible(r))
 334                 return 0;
 335
 336         prepare_alt_odb(r);
 337         for (odb = r->objects->odb;
 338              !r->objects->commit_graph && odb;
 339              odb = odb->next)
 340                 prepare_commit_graph_one(r, odb->path);
 341         return !!r->objects->commit_graph;
 342 }
 343
 344 int generation_numbers_enabled(struct repository *r)
 345 {
 346         uint32_t first_generation;
 347         struct commit_graph *g;
 348         if (!prepare_commit_graph(r))
 349                return 0;
 350
 351         g = r->objects->commit_graph;
 352
 353         if (!g->num_commits)
 354                 return 0;
 355
 356         first_generation = get_be32(g->chunk_commit_data +
 357                                     g->hash_len + 8) >> 2;
 358
 359         return !!first_generation;
 360 }
 361
 362 void close_commit_graph(struct repository *r)
 363 {
 364         free_commit_graph(r->objects->commit_graph);
 365         r->objects->commit_graph = NULL;
 366 }
 367
 368 static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
 369 {
 370         return bsearch_hash(oid->hash, g->chunk_oid_fanout,
 371                             g->chunk_oid_lookup, g->hash_len, pos);
 372 }
 373
 374 static struct commit_list **insert_parent_or_die(struct repository *r,
 375                                                  struct commit_graph *g,
 376                                                  uint64_t pos,
 377                                                  struct commit_list **pptr)
 378 {
 379         struct commit *c;
 380         struct object_id oid;
 381
 382         if (pos >= g->num_commits)
 383                 die("invalid parent position %"PRIu64, pos);
 384
 385         hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
 386         c = lookup_commit(r, &oid);
 387         if (!c)
 388                 die(_("could not find commit %s"), oid_to_hex(&oid));
 389         c->graph_pos = pos;
 390         return &commit_list_insert(c, pptr)->next;
 391 }
 392
 393 static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
 394 {
 395         const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
 396         item->graph_pos = pos;
 397         item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 398 }
 399
 400 static int fill_commit_in_graph(struct repository *r,
 401                                 struct commit *item,
 402                                 struct commit_graph *g, uint32_t pos)
 403 {
 404         uint32_t edge_value;
 405         uint32_t *parent_data_ptr;
 406         uint64_t date_low, date_high;
 407         struct commit_list **pptr;
 408         const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
 409
 410         item->object.parsed = 1;
 411         item->graph_pos = pos;
 412
 413         item->maybe_tree = NULL;
 414
 415         date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 416         date_low = get_be32(commit_data + g->hash_len + 12);
 417         item->date = (timestamp_t)((date_high << 32) | date_low);
 418
 419         item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 420
 421         pptr = &item->parents;
 422
 423         edge_value = get_be32(commit_data + g->hash_len);
 424         if (edge_value == GRAPH_PARENT_NONE)
 425                 return 1;
 426         pptr = insert_parent_or_die(r, g, edge_value, pptr);
 427
 428         edge_value = get_be32(commit_data + g->hash_len + 4);
 429         if (edge_value == GRAPH_PARENT_NONE)
 430                 return 1;
 431         if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 432                 pptr = insert_parent_or_die(r, g, edge_value, pptr);
 433                 return 1;
 434         }
 435
 436         parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 437                           4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 438         do {
 439                 edge_value = get_be32(parent_data_ptr);
 440                 pptr = insert_parent_or_die(r, g,
 441                                             edge_value & GRAPH_EDGE_LAST_MASK,
 442                                             pptr);
 443                 parent_data_ptr++;
 444         } while (!(edge_value & GRAPH_LAST_EDGE));
 445
 446         return 1;
 447 }
 448
 449 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 450 {
 451         if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 452                 *pos = item->graph_pos;
 453                 return 1;
 454         } else {
 455                 return bsearch_graph(g, &(item->object.oid), pos);
 456         }
 457 }
 458
 459 static int parse_commit_in_graph_one(struct repository *r,
 460                                      struct commit_graph *g,
 461                                      struct commit *item)
 462 {
 463         uint32_t pos;
 464
 465         if (item->object.parsed)
 466                 return 1;
 467
 468         if (find_commit_in_graph(item, g, &pos))
 469                 return fill_commit_in_graph(r, item, g, pos);
 470
 471         return 0;
 472 }
 473
 474 int parse_commit_in_graph(struct repository *r, struct commit *item)
 475 {
 476         if (!prepare_commit_graph(r))
 477                 return 0;
 478         return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 479 }
 480
 481 void load_commit_graph_info(struct repository *r, struct commit *item)
 482 {
 483         uint32_t pos;
 484         if (!prepare_commit_graph(r))
 485                 return;
 486         if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 487                 fill_commit_graph_info(item, r->objects->commit_graph, pos);
 488 }
 489
 490 static struct tree *load_tree_for_commit(struct repository *r,
 491                                          struct commit_graph *g,
 492                                          struct commit *c)
 493 {
 494         struct object_id oid;
 495         const unsigned char *commit_data = g->chunk_commit_data +
 496                                            GRAPH_DATA_WIDTH * (c->graph_pos);
 497
 498         hashcpy(oid.hash, commit_data);
 499         c->maybe_tree = lookup_tree(r, &oid);
 500
 501         return c->maybe_tree;
 502 }
 503
 504 static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 505                                                  struct commit_graph *g,
 506                                                  const struct commit *c)
 507 {
 508         if (c->maybe_tree)
 509                 return c->maybe_tree;
 510         if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 511                 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 512
 513         return load_tree_for_commit(r, g, (struct commit *)c);
 514 }
 515
 516 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 517 {
 518         return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 519 }
 520
 521 static void write_graph_chunk_fanout(struct hashfile *f,
 522                                      struct commit **commits,
 523                                      int nr_commits,
 524                                      struct progress *progress,
 525                                      uint64_t *progress_cnt)
 526 {
 527         int i, count = 0;
 528         struct commit **list = commits;
 529
 530         /*
 531          * Write the first-level table (the list is sorted,
 532          * but we use a 256-entry lookup to be able to avoid
 533          * having to do eight extra binary search iterations).
 534          */
 535         for (i = 0; i < 256; i++) {
 536                 while (count < nr_commits) {
 537                         if ((*list)->object.oid.hash[0] != i)
 538                                 break;
 539                         display_progress(progress, ++*progress_cnt);
 540                         count++;
 541                         list++;
 542                 }
 543
 544                 hashwrite_be32(f, count);
 545         }
 546 }
 547
 548 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 549                                    struct commit **commits, int nr_commits,
 550                                    struct progress *progress,
 551                                    uint64_t *progress_cnt)
 552 {
 553         struct commit **list = commits;
 554         int count;
 555         for (count = 0; count < nr_commits; count++, list++) {
 556                 display_progress(progress, ++*progress_cnt);
 557                 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 558         }
 559 }
 560
 561 static const unsigned char *commit_to_sha1(size_t index, void *table)
 562 {
 563         struct commit **commits = table;
 564         return commits[index]->object.oid.hash;
 565 }
 566
 567 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 568                                    struct commit **commits, int nr_commits,
 569                                    struct progress *progress,
 570                                    uint64_t *progress_cnt)
 571 {
 572         struct commit **list = commits;
 573         struct commit **last = commits + nr_commits;
 574         uint32_t num_extra_edges = 0;
 575
 576         while (list < last) {
 577                 struct commit_list *parent;
 578                 int edge_value;
 579                 uint32_t packedDate[2];
 580                 display_progress(progress, ++*progress_cnt);
 581
 582                 parse_commit_no_graph(*list);
 583                 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 584
 585                 parent = (*list)->parents;
 586
 587                 if (!parent)
 588                         edge_value = GRAPH_PARENT_NONE;
 589                 else {
 590                         edge_value = sha1_pos(parent->item->object.oid.hash,
 591                                               commits,
 592                                               nr_commits,
 593                                               commit_to_sha1);
 594
 595                         if (edge_value < 0)
 596                                 BUG("missing parent %s for commit %s",
 597                                     oid_to_hex(&parent->item->object.oid),
 598                                     oid_to_hex(&(*list)->object.oid));
 599                 }
 600
 601                 hashwrite_be32(f, edge_value);
 602
 603                 if (parent)
 604                         parent = parent->next;
 605
 606                 if (!parent)
 607                         edge_value = GRAPH_PARENT_NONE;
 608                 else if (parent->next)
 609                         edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 610                 else {
 611                         edge_value = sha1_pos(parent->item->object.oid.hash,
 612                                               commits,
 613                                               nr_commits,
 614                                               commit_to_sha1);
 615                         if (edge_value < 0)
 616                                 BUG("missing parent %s for commit %s",
 617                                     oid_to_hex(&parent->item->object.oid),
 618                                     oid_to_hex(&(*list)->object.oid));
 619                 }
 620
 621                 hashwrite_be32(f, edge_value);
 622
 623                 if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 624                         do {
 625                                 num_extra_edges++;
 626                                 parent = parent->next;
 627                         } while (parent);
 628                 }
 629
 630                 if (sizeof((*list)->date) > 4)
 631                         packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 632                 else
 633                         packedDate[0] = 0;
 634
 635                 packedDate[0] |= htonl((*list)->generation << 2);
 636
 637                 packedDate[1] = htonl((*list)->date);
 638                 hashwrite(f, packedDate, 8);
 639
 640                 list++;
 641         }
 642 }
 643
 644 static void write_graph_chunk_extra_edges(struct hashfile *f,
 645                                           struct commit **commits,
 646                                           int nr_commits,
 647                                           struct progress *progress,
 648                                           uint64_t *progress_cnt)
 649 {
 650         struct commit **list = commits;
 651         struct commit **last = commits + nr_commits;
 652         struct commit_list *parent;
 653
 654         while (list < last) {
 655                 int num_parents = 0;
 656
 657                 display_progress(progress, ++*progress_cnt);
 658
 659                 for (parent = (*list)->parents; num_parents < 3 && parent;
 660                      parent = parent->next)
 661                         num_parents++;
 662
 663                 if (num_parents <= 2) {
 664                         list++;
 665                         continue;
 666                 }
 667
 668                 /* Since num_parents > 2, this initializer is safe. */
 669                 for (parent = (*list)->parents->next; parent; parent = parent->next) {
 670                         int edge_value = sha1_pos(parent->item->object.oid.hash,
 671                                                   commits,
 672                                                   nr_commits,
 673                                                   commit_to_sha1);
 674
 675                         if (edge_value < 0)
 676                                 BUG("missing parent %s for commit %s",
 677                                     oid_to_hex(&parent->item->object.oid),
 678                                     oid_to_hex(&(*list)->object.oid));
 679                         else if (!parent->next)
 680                                 edge_value |= GRAPH_LAST_EDGE;
 681
 682                         hashwrite_be32(f, edge_value);
 683                 }
 684
 685                 list++;
 686         }
 687 }
 688
 689 static int commit_compare(const void *_a, const void *_b)
 690 {
 691         const struct object_id *a = (const struct object_id *)_a;
 692         const struct object_id *b = (const struct object_id *)_b;
 693         return oidcmp(a, b);
 694 }
 695
 696 struct packed_commit_list {
 697         struct commit **list;
 698         int nr;
 699         int alloc;
 700 };
 701
 702 struct packed_oid_list {
 703         struct object_id *list;
 704         int nr;
 705         int alloc;
 706         struct progress *progress;
 707         int progress_done;
 708 };
 709
 710 static int add_packed_commits(const struct object_id *oid,
 711                               struct packed_git *pack,
 712                               uint32_t pos,
 713                               void *data)
 714 {
 715         struct packed_oid_list *list = (struct packed_oid_list*)data;
 716         enum object_type type;
 717         off_t offset = nth_packed_object_offset(pack, pos);
 718         struct object_info oi = OBJECT_INFO_INIT;
 719
 720         if (list->progress)
 721                 display_progress(list->progress, ++list->progress_done);
 722
 723         oi.typep = &type;
 724         if (packed_object_info(the_repository, pack, offset, &oi) < 0)
 725                 die(_("unable to get type of object %s"), oid_to_hex(oid));
 726
 727         if (type != OBJ_COMMIT)
 728                 return 0;
 729
 730         ALLOC_GROW(list->list, list->nr + 1, list->alloc);
 731         oidcpy(&(list->list[list->nr]), oid);
 732         list->nr++;
 733
 734         return 0;
 735 }
 736
 737 static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
 738 {
 739         struct commit_list *parent;
 740         for (parent = commit->parents; parent; parent = parent->next) {
 741                 if (!(parent->item->object.flags & UNINTERESTING)) {
 742                         ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
 743                         oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
 744                         oids->nr++;
 745                         parent->item->object.flags |= UNINTERESTING;
 746                 }
 747         }
 748 }
 749
 750 static void close_reachable(struct packed_oid_list *oids, int report_progress)
 751 {
 752         int i;
 753         struct commit *commit;
 754         struct progress *progress = NULL;
 755
 756         if (report_progress)
 757                 progress = start_delayed_progress(
 758                         _("Loading known commits in commit graph"), oids->nr);
 759         for (i = 0; i < oids->nr; i++) {
 760                 display_progress(progress, i + 1);
 761                 commit = lookup_commit(the_repository, &oids->list[i]);
 762                 if (commit)
 763                         commit->object.flags |= UNINTERESTING;
 764         }
 765         stop_progress(&progress);
 766
 767         /*
 768          * As this loop runs, oids->nr may grow, but not more
 769          * than the number of missing commits in the reachable
 770          * closure.
 771          */
 772         if (report_progress)
 773                 progress = start_delayed_progress(
 774                         _("Expanding reachable commits in commit graph"), oids->nr);
 775         for (i = 0; i < oids->nr; i++) {
 776                 display_progress(progress, i + 1);
 777                 commit = lookup_commit(the_repository, &oids->list[i]);
 778
 779                 if (commit && !parse_commit_no_graph(commit))
 780                         add_missing_parents(oids, commit);
 781         }
 782         stop_progress(&progress);
 783
 784         if (report_progress)
 785                 progress = start_delayed_progress(
 786                         _("Clearing commit marks in commit graph"), oids->nr);
 787         for (i = 0; i < oids->nr; i++) {
 788                 display_progress(progress, i + 1);
 789                 commit = lookup_commit(the_repository, &oids->list[i]);
 790
 791                 if (commit)
 792                         commit->object.flags &= ~UNINTERESTING;
 793         }
 794         stop_progress(&progress);
 795 }
 796
 797 static void compute_generation_numbers(struct packed_commit_list* commits,
 798                                        int report_progress)
 799 {
 800         int i;
 801         struct commit_list *list = NULL;
 802         struct progress *progress = NULL;
 803
 804         if (report_progress)
 805                 progress = start_progress(
 806                         _("Computing commit graph generation numbers"),
 807                         commits->nr);
 808         for (i = 0; i < commits->nr; i++) {
 809                 display_progress(progress, i + 1);
 810                 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
 811                     commits->list[i]->generation != GENERATION_NUMBER_ZERO)
 812                         continue;
 813
 814                 commit_list_insert(commits->list[i], &list);
 815                 while (list) {
 816                         struct commit *current = list->item;
 817                         struct commit_list *parent;
 818                         int all_parents_computed = 1;
 819                         uint32_t max_generation = 0;
 820
 821                         for (parent = current->parents; parent; parent = parent->next) {
 822                                 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
 823                                     parent->item->generation == GENERATION_NUMBER_ZERO) {
 824                                         all_parents_computed = 0;
 825                                         commit_list_insert(parent->item, &list);
 826                                         break;
 827                                 } else if (parent->item->generation > max_generation) {
 828                                         max_generation = parent->item->generation;
 829                                 }
 830                         }
 831
 832                         if (all_parents_computed) {
 833                                 current->generation = max_generation + 1;
 834                                 pop_commit(&list);
 835
 836                                 if (current->generation > GENERATION_NUMBER_MAX)
 837                                         current->generation = GENERATION_NUMBER_MAX;
 838                         }
 839                 }
 840         }
 841         stop_progress(&progress);
 842 }
 843
 844 static int add_ref_to_list(const char *refname,
 845                            const struct object_id *oid,
 846                            int flags, void *cb_data)
 847 {
 848         struct string_list *list = (struct string_list *)cb_data;
 849
 850         string_list_append(list, oid_to_hex(oid));
 851         return 0;
 852 }
 853
 854 int write_commit_graph_reachable(const char *obj_dir, unsigned int flags)
 855 {
 856         struct string_list list = STRING_LIST_INIT_DUP;
 857         int result;
 858
 859         for_each_ref(add_ref_to_list, &list);
 860         result = write_commit_graph(obj_dir, NULL, &list,
 861                                     flags);
 862
 863         string_list_clear(&list, 0);
 864         return result;
 865 }
 866
 867 int write_commit_graph(const char *obj_dir,
 868                        struct string_list *pack_indexes,
 869                        struct string_list *commit_hex,
 870                        unsigned int flags)
 871 {
 872         struct packed_oid_list oids;
 873         struct packed_commit_list commits;
 874         struct hashfile *f;
 875         uint32_t i, count_distinct = 0;
 876         char *graph_name = NULL;
 877         struct lock_file lk = LOCK_INIT;
 878         uint32_t chunk_ids[5];
 879         uint64_t chunk_offsets[5];
 880         int num_chunks;
 881         int num_extra_edges;
 882         struct commit_list *parent;
 883         struct progress *progress = NULL;
 884         const unsigned hashsz = the_hash_algo->rawsz;
 885         uint64_t progress_cnt = 0;
 886         struct strbuf progress_title = STRBUF_INIT;
 887         unsigned long approx_nr_objects;
 888         int res = 0;
 889         int append = flags & COMMIT_GRAPH_APPEND;
 890         int report_progress = flags & COMMIT_GRAPH_PROGRESS;
 891
 892         if (!commit_graph_compatible(the_repository))
 893                 return 0;
 894
 895         oids.nr = 0;
 896         approx_nr_objects = approximate_object_count();
 897         oids.alloc = approx_nr_objects / 32;
 898         oids.progress = NULL;
 899         oids.progress_done = 0;
 900         commits.list = NULL;
 901
 902         if (append) {
 903                 prepare_commit_graph_one(the_repository, obj_dir);
 904                 if (the_repository->objects->commit_graph)
 905                         oids.alloc += the_repository->objects->commit_graph->num_commits;
 906         }
 907
 908         if (oids.alloc < 1024)
 909                 oids.alloc = 1024;
 910         ALLOC_ARRAY(oids.list, oids.alloc);
 911
 912         if (append && the_repository->objects->commit_graph) {
 913                 struct commit_graph *commit_graph =
 914                         the_repository->objects->commit_graph;
 915                 for (i = 0; i < commit_graph->num_commits; i++) {
 916                         const unsigned char *hash = commit_graph->chunk_oid_lookup +
 917                                 commit_graph->hash_len * i;
 918                         hashcpy(oids.list[oids.nr++].hash, hash);
 919                 }
 920         }
 921
 922         if (pack_indexes) {
 923                 struct strbuf packname = STRBUF_INIT;
 924                 int dirlen;
 925                 strbuf_addf(&packname, "%s/pack/", obj_dir);
 926                 dirlen = packname.len;
 927                 if (report_progress) {
 928                         strbuf_addf(&progress_title,
 929                                     Q_("Finding commits for commit graph in %d pack",
 930                                        "Finding commits for commit graph in %d packs",
 931                                        pack_indexes->nr),
 932                                     pack_indexes->nr);
 933                         oids.progress = start_delayed_progress(progress_title.buf, 0);
 934                         oids.progress_done = 0;
 935                 }
 936                 for (i = 0; i < pack_indexes->nr; i++) {
 937                         struct packed_git *p;
 938                         strbuf_setlen(&packname, dirlen);
 939                         strbuf_addstr(&packname, pack_indexes->items[i].string);
 940                         p = add_packed_git(packname.buf, packname.len, 1);
 941                         if (!p) {
 942                                 error(_("error adding pack %s"), packname.buf);
 943                                 res = -1;
 944                                 goto cleanup;
 945                         }
 946                         if (open_pack_index(p)) {
 947                                 error(_("error opening index for %s"), packname.buf);
 948                                 res = -1;
 949                                 goto cleanup;
 950                         }
 951                         for_each_object_in_pack(p, add_packed_commits, &oids,
 952                                                 FOR_EACH_OBJECT_PACK_ORDER);
 953                         close_pack(p);
 954                         free(p);
 955                 }
 956                 stop_progress(&oids.progress);
 957                 strbuf_reset(&progress_title);
 958                 strbuf_release(&packname);
 959         }
 960
 961         if (commit_hex) {
 962                 if (report_progress) {
 963                         strbuf_addf(&progress_title,
 964                                     Q_("Finding commits for commit graph from %d ref",
 965                                        "Finding commits for commit graph from %d refs",
 966                                        commit_hex->nr),
 967                                     commit_hex->nr);
 968                         progress = start_delayed_progress(progress_title.buf,
 969                                                           commit_hex->nr);
 970                 }
 971                 for (i = 0; i < commit_hex->nr; i++) {
 972                         const char *end;
 973                         struct object_id oid;
 974                         struct commit *result;
 975
 976                         display_progress(progress, i + 1);
 977                         if (commit_hex->items[i].string &&
 978                             parse_oid_hex(commit_hex->items[i].string, &oid, &end))
 979                                 continue;
 980
 981                         result = lookup_commit_reference_gently(the_repository, &oid, 1);
 982
 983                         if (result) {
 984                                 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
 985                                 oidcpy(&oids.list[oids.nr], &(result->object.oid));
 986                                 oids.nr++;
 987                         }
 988                 }
 989                 stop_progress(&progress);
 990                 strbuf_reset(&progress_title);
 991         }
 992
 993         if (!pack_indexes && !commit_hex) {
 994                 if (report_progress)
 995                         oids.progress = start_delayed_progress(
 996                                 _("Finding commits for commit graph among packed objects"),
 997                                 approx_nr_objects);
 998                 for_each_packed_object(add_packed_commits, &oids,
 999                                        FOR_EACH_OBJECT_PACK_ORDER);
1000                 if (oids.progress_done < approx_nr_objects)
1001                         display_progress(oids.progress, approx_nr_objects);
1002                 stop_progress(&oids.progress);
1003         }
1004
1005         close_reachable(&oids, report_progress);
1006
1007         if (report_progress)
1008                 progress = start_delayed_progress(
1009                         _("Counting distinct commits in commit graph"),
1010                         oids.nr);
1011         display_progress(progress, 0); /* TODO: Measure QSORT() progress */
1012         QSORT(oids.list, oids.nr, commit_compare);
1013         count_distinct = 1;
1014         for (i = 1; i < oids.nr; i++) {
1015                 display_progress(progress, i + 1);
1016                 if (!oideq(&oids.list[i - 1], &oids.list[i]))
1017                         count_distinct++;
1018         }
1019         stop_progress(&progress);
1020
1021         if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1022                 error(_("the commit graph format cannot write %d commits"), count_distinct);
1023                 res = -1;
1024                 goto cleanup;
1025         }
1026
1027         commits.nr = 0;
1028         commits.alloc = count_distinct;
1029         ALLOC_ARRAY(commits.list, commits.alloc);
1030
1031         num_extra_edges = 0;
1032         if (report_progress)
1033                 progress = start_delayed_progress(
1034                         _("Finding extra edges in commit graph"),
1035                         oids.nr);
1036         for (i = 0; i < oids.nr; i++) {
1037                 int num_parents = 0;
1038                 display_progress(progress, i + 1);
1039                 if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
1040                         continue;
1041
1042                 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
1043                 parse_commit_no_graph(commits.list[commits.nr]);
1044
1045                 for (parent = commits.list[commits.nr]->parents;
1046                      parent; parent = parent->next)
1047                         num_parents++;
1048
1049                 if (num_parents > 2)
1050                         num_extra_edges += num_parents - 1;
1051
1052                 commits.nr++;
1053         }
1054         num_chunks = num_extra_edges ? 4 : 3;
1055         stop_progress(&progress);
1056
1057         if (commits.nr >= GRAPH_EDGE_LAST_MASK) {
1058                 error(_("too many commits to write graph"));
1059                 res = -1;
1060                 goto cleanup;
1061         }
1062
1063         compute_generation_numbers(&commits, report_progress);
1064
1065         graph_name = get_commit_graph_filename(obj_dir);
1066         if (safe_create_leading_directories(graph_name)) {
1067                 UNLEAK(graph_name);
1068                 error(_("unable to create leading directories of %s"),
1069                         graph_name);
1070                 res = -1;
1071                 goto cleanup;
1072         }
1073
1074         hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
1075         f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1076
1077         hashwrite_be32(f, GRAPH_SIGNATURE);
1078
1079         hashwrite_u8(f, GRAPH_VERSION);
1080         hashwrite_u8(f, oid_version());
1081         hashwrite_u8(f, num_chunks);
1082         hashwrite_u8(f, 0); /* unused padding byte */
1083
1084         chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1085         chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1086         chunk_ids[2] = GRAPH_CHUNKID_DATA;
1087         if (num_extra_edges)
1088                 chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
1089         else
1090                 chunk_ids[3] = 0;
1091         chunk_ids[4] = 0;
1092
1093         chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1094         chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1095         chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
1096         chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
1097         chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
1098
1099         for (i = 0; i <= num_chunks; i++) {
1100                 uint32_t chunk_write[3];
1101
1102                 chunk_write[0] = htonl(chunk_ids[i]);
1103                 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1104                 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1105                 hashwrite(f, chunk_write, 12);
1106         }
1107
1108         if (report_progress) {
1109                 strbuf_addf(&progress_title,
1110                             Q_("Writing out commit graph in %d pass",
1111                                "Writing out commit graph in %d passes",
1112                                num_chunks),
1113                             num_chunks);
1114                 progress = start_delayed_progress(
1115                         progress_title.buf,
1116                         num_chunks * commits.nr);
1117         }
1118         write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
1119         write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1120         write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1121         if (num_extra_edges)
1122                 write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
1123         stop_progress(&progress);
1124         strbuf_release(&progress_title);
1125
1126         close_commit_graph(the_repository);
1127         finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1128         commit_lock_file(&lk);
1129
1130 cleanup:
1131         free(graph_name);
1132         free(commits.list);
1133         free(oids.list);
1134
1135         return res;
1136 }
1137
1138 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1139 static int verify_commit_graph_error;
1140
1141 static void graph_report(const char *fmt, ...)
1142 {
1143         va_list ap;
1144
1145         verify_commit_graph_error = 1;
1146         va_start(ap, fmt);
1147         vfprintf(stderr, fmt, ap);
1148         fprintf(stderr, "\n");
1149         va_end(ap);
1150 }
1151
1152 #define GENERATION_ZERO_EXISTS 1
1153 #define GENERATION_NUMBER_EXISTS 2
1154
1155 int verify_commit_graph(struct repository *r, struct commit_graph *g)
1156 {
1157         uint32_t i, cur_fanout_pos = 0;
1158         struct object_id prev_oid, cur_oid, checksum;
1159         int generation_zero = 0;
1160         struct hashfile *f;
1161         int devnull;
1162         struct progress *progress = NULL;
1163
1164         if (!g) {
1165                 graph_report("no commit-graph file loaded");
1166                 return 1;
1167         }
1168
1169         verify_commit_graph_error = verify_commit_graph_lite(g);
1170         if (verify_commit_graph_error)
1171                 return verify_commit_graph_error;
1172
1173         devnull = open("/dev/null", O_WRONLY);
1174         f = hashfd(devnull, NULL);
1175         hashwrite(f, g->data, g->data_len - g->hash_len);
1176         finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1177         if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1178                 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1179                 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1180         }
1181
1182         for (i = 0; i < g->num_commits; i++) {
1183                 struct commit *graph_commit;
1184
1185                 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1186
1187                 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1188                         graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1189                                      oid_to_hex(&prev_oid),
1190                                      oid_to_hex(&cur_oid));
1191
1192                 oidcpy(&prev_oid, &cur_oid);
1193
1194                 while (cur_oid.hash[0] > cur_fanout_pos) {
1195                         uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1196
1197                         if (i != fanout_value)
1198                                 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1199                                              cur_fanout_pos, fanout_value, i);
1200                         cur_fanout_pos++;
1201                 }
1202
1203                 graph_commit = lookup_commit(r, &cur_oid);
1204                 if (!parse_commit_in_graph_one(r, g, graph_commit))
1205                         graph_report(_("failed to parse commit %s from commit-graph"),
1206                                      oid_to_hex(&cur_oid));
1207         }
1208
1209         while (cur_fanout_pos < 256) {
1210                 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1211
1212                 if (g->num_commits != fanout_value)
1213                         graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1214                                      cur_fanout_pos, fanout_value, i);
1215
1216                 cur_fanout_pos++;
1217         }
1218
1219         if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1220                 return verify_commit_graph_error;
1221
1222         progress = start_progress(_("Verifying commits in commit graph"),
1223                                   g->num_commits);
1224         for (i = 0; i < g->num_commits; i++) {
1225                 struct commit *graph_commit, *odb_commit;
1226                 struct commit_list *graph_parents, *odb_parents;
1227                 uint32_t max_generation = 0;
1228
1229                 display_progress(progress, i + 1);
1230                 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1231
1232                 graph_commit = lookup_commit(r, &cur_oid);
1233                 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1234                 if (parse_commit_internal(odb_commit, 0, 0)) {
1235                         graph_report(_("failed to parse commit %s from object database for commit-graph"),
1236                                      oid_to_hex(&cur_oid));
1237                         continue;
1238                 }
1239
1240                 if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
1241                            get_commit_tree_oid(odb_commit)))
1242                         graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
1243                                      oid_to_hex(&cur_oid),
1244                                      oid_to_hex(get_commit_tree_oid(graph_commit)),
1245                                      oid_to_hex(get_commit_tree_oid(odb_commit)));
1246
1247                 graph_parents = graph_commit->parents;
1248                 odb_parents = odb_commit->parents;
1249
1250                 while (graph_parents) {
1251                         if (odb_parents == NULL) {
1252                                 graph_report(_("commit-graph parent list for commit %s is too long"),
1253                                              oid_to_hex(&cur_oid));
1254                                 break;
1255                         }
1256
1257                         if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1258                                 graph_report(_("commit-graph parent for %s is %s != %s"),
1259                                              oid_to_hex(&cur_oid),
1260                                              oid_to_hex(&graph_parents->item->object.oid),
1261                                              oid_to_hex(&odb_parents->item->object.oid));
1262
1263                         if (graph_parents->item->generation > max_generation)
1264                                 max_generation = graph_parents->item->generation;
1265
1266                         graph_parents = graph_parents->next;
1267                         odb_parents = odb_parents->next;
1268                 }
1269
1270                 if (odb_parents != NULL)
1271                         graph_report(_("commit-graph parent list for commit %s terminates early"),
1272                                      oid_to_hex(&cur_oid));
1273
1274                 if (!graph_commit->generation) {
1275                         if (generation_zero == GENERATION_NUMBER_EXISTS)
1276                                 graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
1277                                              oid_to_hex(&cur_oid));
1278                         generation_zero = GENERATION_ZERO_EXISTS;
1279                 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1280                         graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
1281                                      oid_to_hex(&cur_oid));
1282
1283                 if (generation_zero == GENERATION_ZERO_EXISTS)
1284                         continue;
1285
1286                 /*
1287                  * If one of our parents has generation GENERATION_NUMBER_MAX, then
1288                  * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1289                  * extra logic in the following condition.
1290                  */
1291                 if (max_generation == GENERATION_NUMBER_MAX)
1292                         max_generation--;
1293
1294                 if (graph_commit->generation != max_generation + 1)
1295                         graph_report(_("commit-graph generation for commit %s is %u != %u"),
1296                                      oid_to_hex(&cur_oid),
1297                                      graph_commit->generation,
1298                                      max_generation + 1);
1299
1300                 if (graph_commit->date != odb_commit->date)
1301                         graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
1302                                      oid_to_hex(&cur_oid),
1303                                      graph_commit->date,
1304                                      odb_commit->date);
1305         }
1306         stop_progress(&progress);
1307
1308         return verify_commit_graph_error;
1309 }
1310
1311 void free_commit_graph(struct commit_graph *g)
1312 {
1313         if (!g)
1314                 return;
1315         if (g->graph_fd >= 0) {
1316                 munmap((void *)g->data, g->data_len);
1317                 g->data = NULL;
1318                 close(g->graph_fd);
1319         }
1320         free(g);
1321 }