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 inline void set_commit_tree(struct commit *c, struct tree *t)
 401 {
 402         c->maybe_tree = t;
 403 }
 404
 405 static int fill_commit_in_graph(struct repository *r,
 406                                 struct commit *item,
 407                                 struct commit_graph *g, uint32_t pos)
 408 {
 409         uint32_t edge_value;
 410         uint32_t *parent_data_ptr;
 411         uint64_t date_low, date_high;
 412         struct commit_list **pptr;
 413         const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
 414
 415         item->object.parsed = 1;
 416         item->graph_pos = pos;
 417
 418         set_commit_tree(item, NULL);
 419
 420         date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 421         date_low = get_be32(commit_data + g->hash_len + 12);
 422         item->date = (timestamp_t)((date_high << 32) | date_low);
 423
 424         item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 425
 426         pptr = &item->parents;
 427
 428         edge_value = get_be32(commit_data + g->hash_len);
 429         if (edge_value == GRAPH_PARENT_NONE)
 430                 return 1;
 431         pptr = insert_parent_or_die(r, g, edge_value, pptr);
 432
 433         edge_value = get_be32(commit_data + g->hash_len + 4);
 434         if (edge_value == GRAPH_PARENT_NONE)
 435                 return 1;
 436         if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 437                 pptr = insert_parent_or_die(r, g, edge_value, pptr);
 438                 return 1;
 439         }
 440
 441         parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 442                           4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 443         do {
 444                 edge_value = get_be32(parent_data_ptr);
 445                 pptr = insert_parent_or_die(r, g,
 446                                             edge_value & GRAPH_EDGE_LAST_MASK,
 447                                             pptr);
 448                 parent_data_ptr++;
 449         } while (!(edge_value & GRAPH_LAST_EDGE));
 450
 451         return 1;
 452 }
 453
 454 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 455 {
 456         if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 457                 *pos = item->graph_pos;
 458                 return 1;
 459         } else {
 460                 return bsearch_graph(g, &(item->object.oid), pos);
 461         }
 462 }
 463
 464 static int parse_commit_in_graph_one(struct repository *r,
 465                                      struct commit_graph *g,
 466                                      struct commit *item)
 467 {
 468         uint32_t pos;
 469
 470         if (item->object.parsed)
 471                 return 1;
 472
 473         if (find_commit_in_graph(item, g, &pos))
 474                 return fill_commit_in_graph(r, item, g, pos);
 475
 476         return 0;
 477 }
 478
 479 int parse_commit_in_graph(struct repository *r, struct commit *item)
 480 {
 481         if (!prepare_commit_graph(r))
 482                 return 0;
 483         return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 484 }
 485
 486 void load_commit_graph_info(struct repository *r, struct commit *item)
 487 {
 488         uint32_t pos;
 489         if (!prepare_commit_graph(r))
 490                 return;
 491         if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 492                 fill_commit_graph_info(item, r->objects->commit_graph, pos);
 493 }
 494
 495 static struct tree *load_tree_for_commit(struct repository *r,
 496                                          struct commit_graph *g,
 497                                          struct commit *c)
 498 {
 499         struct object_id oid;
 500         const unsigned char *commit_data = g->chunk_commit_data +
 501                                            GRAPH_DATA_WIDTH * (c->graph_pos);
 502
 503         hashcpy(oid.hash, commit_data);
 504         set_commit_tree(c, lookup_tree(r, &oid));
 505
 506         return c->maybe_tree;
 507 }
 508
 509 static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 510                                                  struct commit_graph *g,
 511                                                  const struct commit *c)
 512 {
 513         if (c->maybe_tree)
 514                 return c->maybe_tree;
 515         if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 516                 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 517
 518         return load_tree_for_commit(r, g, (struct commit *)c);
 519 }
 520
 521 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 522 {
 523         return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 524 }
 525
 526 static void write_graph_chunk_fanout(struct hashfile *f,
 527                                      struct commit **commits,
 528                                      int nr_commits,
 529                                      struct progress *progress,
 530                                      uint64_t *progress_cnt)
 531 {
 532         int i, count = 0;
 533         struct commit **list = commits;
 534
 535         /*
 536          * Write the first-level table (the list is sorted,
 537          * but we use a 256-entry lookup to be able to avoid
 538          * having to do eight extra binary search iterations).
 539          */
 540         for (i = 0; i < 256; i++) {
 541                 while (count < nr_commits) {
 542                         if ((*list)->object.oid.hash[0] != i)
 543                                 break;
 544                         display_progress(progress, ++*progress_cnt);
 545                         count++;
 546                         list++;
 547                 }
 548
 549                 hashwrite_be32(f, count);
 550         }
 551 }
 552
 553 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 554                                    struct commit **commits, int nr_commits,
 555                                    struct progress *progress,
 556                                    uint64_t *progress_cnt)
 557 {
 558         struct commit **list = commits;
 559         int count;
 560         for (count = 0; count < nr_commits; count++, list++) {
 561                 display_progress(progress, ++*progress_cnt);
 562                 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 563         }
 564 }
 565
 566 static const unsigned char *commit_to_sha1(size_t index, void *table)
 567 {
 568         struct commit **commits = table;
 569         return commits[index]->object.oid.hash;
 570 }
 571
 572 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 573                                    struct commit **commits, int nr_commits,
 574                                    struct progress *progress,
 575                                    uint64_t *progress_cnt)
 576 {
 577         struct commit **list = commits;
 578         struct commit **last = commits + nr_commits;
 579         uint32_t num_extra_edges = 0;
 580
 581         while (list < last) {
 582                 struct commit_list *parent;
 583                 int edge_value;
 584                 uint32_t packedDate[2];
 585                 display_progress(progress, ++*progress_cnt);
 586
 587                 parse_commit_no_graph(*list);
 588                 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 589
 590                 parent = (*list)->parents;
 591
 592                 if (!parent)
 593                         edge_value = GRAPH_PARENT_NONE;
 594                 else {
 595                         edge_value = sha1_pos(parent->item->object.oid.hash,
 596                                               commits,
 597                                               nr_commits,
 598                                               commit_to_sha1);
 599
 600                         if (edge_value < 0)
 601                                 BUG("missing parent %s for commit %s",
 602                                     oid_to_hex(&parent->item->object.oid),
 603                                     oid_to_hex(&(*list)->object.oid));
 604                 }
 605
 606                 hashwrite_be32(f, edge_value);
 607
 608                 if (parent)
 609                         parent = parent->next;
 610
 611                 if (!parent)
 612                         edge_value = GRAPH_PARENT_NONE;
 613                 else if (parent->next)
 614                         edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 615                 else {
 616                         edge_value = sha1_pos(parent->item->object.oid.hash,
 617                                               commits,
 618                                               nr_commits,
 619                                               commit_to_sha1);
 620                         if (edge_value < 0)
 621                                 BUG("missing parent %s for commit %s",
 622                                     oid_to_hex(&parent->item->object.oid),
 623                                     oid_to_hex(&(*list)->object.oid));
 624                 }
 625
 626                 hashwrite_be32(f, edge_value);
 627
 628                 if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 629                         do {
 630                                 num_extra_edges++;
 631                                 parent = parent->next;
 632                         } while (parent);
 633                 }
 634
 635                 if (sizeof((*list)->date) > 4)
 636                         packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 637                 else
 638                         packedDate[0] = 0;
 639
 640                 packedDate[0] |= htonl((*list)->generation << 2);
 641
 642                 packedDate[1] = htonl((*list)->date);
 643                 hashwrite(f, packedDate, 8);
 644
 645                 list++;
 646         }
 647 }
 648
 649 static void write_graph_chunk_extra_edges(struct hashfile *f,
 650                                           struct commit **commits,
 651                                           int nr_commits,
 652                                           struct progress *progress,
 653                                           uint64_t *progress_cnt)
 654 {
 655         struct commit **list = commits;
 656         struct commit **last = commits + nr_commits;
 657         struct commit_list *parent;
 658
 659         while (list < last) {
 660                 int num_parents = 0;
 661
 662                 display_progress(progress, ++*progress_cnt);
 663
 664                 for (parent = (*list)->parents; num_parents < 3 && parent;
 665                      parent = parent->next)
 666                         num_parents++;
 667
 668                 if (num_parents <= 2) {
 669                         list++;
 670                         continue;
 671                 }
 672
 673                 /* Since num_parents > 2, this initializer is safe. */
 674                 for (parent = (*list)->parents->next; parent; parent = parent->next) {
 675                         int edge_value = sha1_pos(parent->item->object.oid.hash,
 676                                                   commits,
 677                                                   nr_commits,
 678                                                   commit_to_sha1);
 679
 680                         if (edge_value < 0)
 681                                 BUG("missing parent %s for commit %s",
 682                                     oid_to_hex(&parent->item->object.oid),
 683                                     oid_to_hex(&(*list)->object.oid));
 684                         else if (!parent->next)
 685                                 edge_value |= GRAPH_LAST_EDGE;
 686
 687                         hashwrite_be32(f, edge_value);
 688                 }
 689
 690                 list++;
 691         }
 692 }
 693
 694 static int commit_compare(const void *_a, const void *_b)
 695 {
 696         const struct object_id *a = (const struct object_id *)_a;
 697         const struct object_id *b = (const struct object_id *)_b;
 698         return oidcmp(a, b);
 699 }
 700
 701 struct packed_commit_list {
 702         struct commit **list;
 703         int nr;
 704         int alloc;
 705 };
 706
 707 struct packed_oid_list {
 708         struct object_id *list;
 709         int nr;
 710         int alloc;
 711         struct progress *progress;
 712         int progress_done;
 713 };
 714
 715 static int add_packed_commits(const struct object_id *oid,
 716                               struct packed_git *pack,
 717                               uint32_t pos,
 718                               void *data)
 719 {
 720         struct packed_oid_list *list = (struct packed_oid_list*)data;
 721         enum object_type type;
 722         off_t offset = nth_packed_object_offset(pack, pos);
 723         struct object_info oi = OBJECT_INFO_INIT;
 724
 725         if (list->progress)
 726                 display_progress(list->progress, ++list->progress_done);
 727
 728         oi.typep = &type;
 729         if (packed_object_info(the_repository, pack, offset, &oi) < 0)
 730                 die(_("unable to get type of object %s"), oid_to_hex(oid));
 731
 732         if (type != OBJ_COMMIT)
 733                 return 0;
 734
 735         ALLOC_GROW(list->list, list->nr + 1, list->alloc);
 736         oidcpy(&(list->list[list->nr]), oid);
 737         list->nr++;
 738
 739         return 0;
 740 }
 741
 742 static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
 743 {
 744         struct commit_list *parent;
 745         for (parent = commit->parents; parent; parent = parent->next) {
 746                 if (!(parent->item->object.flags & UNINTERESTING)) {
 747                         ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
 748                         oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
 749                         oids->nr++;
 750                         parent->item->object.flags |= UNINTERESTING;
 751                 }
 752         }
 753 }
 754
 755 static void close_reachable(struct packed_oid_list *oids, int report_progress)
 756 {
 757         int i;
 758         struct commit *commit;
 759         struct progress *progress = NULL;
 760
 761         if (report_progress)
 762                 progress = start_delayed_progress(
 763                         _("Loading known commits in commit graph"), oids->nr);
 764         for (i = 0; i < oids->nr; i++) {
 765                 display_progress(progress, i + 1);
 766                 commit = lookup_commit(the_repository, &oids->list[i]);
 767                 if (commit)
 768                         commit->object.flags |= UNINTERESTING;
 769         }
 770         stop_progress(&progress);
 771
 772         /*
 773          * As this loop runs, oids->nr may grow, but not more
 774          * than the number of missing commits in the reachable
 775          * closure.
 776          */
 777         if (report_progress)
 778                 progress = start_delayed_progress(
 779                         _("Expanding reachable commits in commit graph"), oids->nr);
 780         for (i = 0; i < oids->nr; i++) {
 781                 display_progress(progress, i + 1);
 782                 commit = lookup_commit(the_repository, &oids->list[i]);
 783
 784                 if (commit && !parse_commit_no_graph(commit))
 785                         add_missing_parents(oids, commit);
 786         }
 787         stop_progress(&progress);
 788
 789         if (report_progress)
 790                 progress = start_delayed_progress(
 791                         _("Clearing commit marks in commit graph"), oids->nr);
 792         for (i = 0; i < oids->nr; i++) {
 793                 display_progress(progress, i + 1);
 794                 commit = lookup_commit(the_repository, &oids->list[i]);
 795
 796                 if (commit)
 797                         commit->object.flags &= ~UNINTERESTING;
 798         }
 799         stop_progress(&progress);
 800 }
 801
 802 static void compute_generation_numbers(struct packed_commit_list* commits,
 803                                        int report_progress)
 804 {
 805         int i;
 806         struct commit_list *list = NULL;
 807         struct progress *progress = NULL;
 808
 809         if (report_progress)
 810                 progress = start_progress(
 811                         _("Computing commit graph generation numbers"),
 812                         commits->nr);
 813         for (i = 0; i < commits->nr; i++) {
 814                 display_progress(progress, i + 1);
 815                 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
 816                     commits->list[i]->generation != GENERATION_NUMBER_ZERO)
 817                         continue;
 818
 819                 commit_list_insert(commits->list[i], &list);
 820                 while (list) {
 821                         struct commit *current = list->item;
 822                         struct commit_list *parent;
 823                         int all_parents_computed = 1;
 824                         uint32_t max_generation = 0;
 825
 826                         for (parent = current->parents; parent; parent = parent->next) {
 827                                 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
 828                                     parent->item->generation == GENERATION_NUMBER_ZERO) {
 829                                         all_parents_computed = 0;
 830                                         commit_list_insert(parent->item, &list);
 831                                         break;
 832                                 } else if (parent->item->generation > max_generation) {
 833                                         max_generation = parent->item->generation;
 834                                 }
 835                         }
 836
 837                         if (all_parents_computed) {
 838                                 current->generation = max_generation + 1;
 839                                 pop_commit(&list);
 840
 841                                 if (current->generation > GENERATION_NUMBER_MAX)
 842                                         current->generation = GENERATION_NUMBER_MAX;
 843                         }
 844                 }
 845         }
 846         stop_progress(&progress);
 847 }
 848
 849 static int add_ref_to_list(const char *refname,
 850                            const struct object_id *oid,
 851                            int flags, void *cb_data)
 852 {
 853         struct string_list *list = (struct string_list *)cb_data;
 854
 855         string_list_append(list, oid_to_hex(oid));
 856         return 0;
 857 }
 858
 859 void write_commit_graph_reachable(const char *obj_dir, int append,
 860                                   int report_progress)
 861 {
 862         struct string_list list = STRING_LIST_INIT_DUP;
 863
 864         for_each_ref(add_ref_to_list, &list);
 865         write_commit_graph(obj_dir, NULL, &list, append, report_progress);
 866
 867         string_list_clear(&list, 0);
 868 }
 869
 870 void write_commit_graph(const char *obj_dir,
 871                         struct string_list *pack_indexes,
 872                         struct string_list *commit_hex,
 873                         int append, int report_progress)
 874 {
 875         struct packed_oid_list oids;
 876         struct packed_commit_list commits;
 877         struct hashfile *f;
 878         uint32_t i, count_distinct = 0;
 879         char *graph_name;
 880         struct lock_file lk = LOCK_INIT;
 881         uint32_t chunk_ids[5];
 882         uint64_t chunk_offsets[5];
 883         int num_chunks;
 884         int num_extra_edges;
 885         struct commit_list *parent;
 886         struct progress *progress = NULL;
 887         const unsigned hashsz = the_hash_algo->rawsz;
 888         uint64_t progress_cnt = 0;
 889         struct strbuf progress_title = STRBUF_INIT;
 890         unsigned long approx_nr_objects;
 891
 892         if (!commit_graph_compatible(the_repository))
 893                 return;
 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
 901         if (append) {
 902                 prepare_commit_graph_one(the_repository, obj_dir);
 903                 if (the_repository->objects->commit_graph)
 904                         oids.alloc += the_repository->objects->commit_graph->num_commits;
 905         }
 906
 907         if (oids.alloc < 1024)
 908                 oids.alloc = 1024;
 909         ALLOC_ARRAY(oids.list, oids.alloc);
 910
 911         if (append && the_repository->objects->commit_graph) {
 912                 struct commit_graph *commit_graph =
 913                         the_repository->objects->commit_graph;
 914                 for (i = 0; i < commit_graph->num_commits; i++) {
 915                         const unsigned char *hash = commit_graph->chunk_oid_lookup +
 916                                 commit_graph->hash_len * i;
 917                         hashcpy(oids.list[oids.nr++].hash, hash);
 918                 }
 919         }
 920
 921         if (pack_indexes) {
 922                 struct strbuf packname = STRBUF_INIT;
 923                 int dirlen;
 924                 strbuf_addf(&packname, "%s/pack/", obj_dir);
 925                 dirlen = packname.len;
 926                 if (report_progress) {
 927                         strbuf_addf(&progress_title,
 928                                     Q_("Finding commits for commit graph in %d pack",
 929                                        "Finding commits for commit graph in %d packs",
 930                                        pack_indexes->nr),
 931                                     pack_indexes->nr);
 932                         oids.progress = start_delayed_progress(progress_title.buf, 0);
 933                         oids.progress_done = 0;
 934                 }
 935                 for (i = 0; i < pack_indexes->nr; i++) {
 936                         struct packed_git *p;
 937                         strbuf_setlen(&packname, dirlen);
 938                         strbuf_addstr(&packname, pack_indexes->items[i].string);
 939                         p = add_packed_git(packname.buf, packname.len, 1);
 940                         if (!p)
 941                                 die(_("error adding pack %s"), packname.buf);
 942                         if (open_pack_index(p))
 943                                 die(_("error opening index for %s"), packname.buf);
 944                         for_each_object_in_pack(p, add_packed_commits, &oids,
 945                                                 FOR_EACH_OBJECT_PACK_ORDER);
 946                         close_pack(p);
 947                         free(p);
 948                 }
 949                 stop_progress(&oids.progress);
 950                 strbuf_reset(&progress_title);
 951                 strbuf_release(&packname);
 952         }
 953
 954         if (commit_hex) {
 955                 if (report_progress) {
 956                         strbuf_addf(&progress_title,
 957                                     Q_("Finding commits for commit graph from %d ref",
 958                                        "Finding commits for commit graph from %d refs",
 959                                        commit_hex->nr),
 960                                     commit_hex->nr);
 961                         progress = start_delayed_progress(progress_title.buf,
 962                                                           commit_hex->nr);
 963                 }
 964                 for (i = 0; i < commit_hex->nr; i++) {
 965                         const char *end;
 966                         struct object_id oid;
 967                         struct commit *result;
 968
 969                         display_progress(progress, i + 1);
 970                         if (commit_hex->items[i].string &&
 971                             parse_oid_hex(commit_hex->items[i].string, &oid, &end))
 972                                 continue;
 973
 974                         result = lookup_commit_reference_gently(the_repository, &oid, 1);
 975
 976                         if (result) {
 977                                 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
 978                                 oidcpy(&oids.list[oids.nr], &(result->object.oid));
 979                                 oids.nr++;
 980                         }
 981                 }
 982                 stop_progress(&progress);
 983                 strbuf_reset(&progress_title);
 984         }
 985
 986         if (!pack_indexes && !commit_hex) {
 987                 if (report_progress)
 988                         oids.progress = start_delayed_progress(
 989                                 _("Finding commits for commit graph among packed objects"),
 990                                 approx_nr_objects);
 991                 for_each_packed_object(add_packed_commits, &oids,
 992                                        FOR_EACH_OBJECT_PACK_ORDER);
 993                 if (oids.progress_done < approx_nr_objects)
 994                         display_progress(oids.progress, approx_nr_objects);
 995                 stop_progress(&oids.progress);
 996         }
 997
 998         close_reachable(&oids, report_progress);
 999
1000         if (report_progress)
1001                 progress = start_delayed_progress(
1002                         _("Counting distinct commits in commit graph"),
1003                         oids.nr);
1004         display_progress(progress, 0); /* TODO: Measure QSORT() progress */
1005         QSORT(oids.list, oids.nr, commit_compare);
1006         count_distinct = 1;
1007         for (i = 1; i < oids.nr; i++) {
1008                 display_progress(progress, i + 1);
1009                 if (!oideq(&oids.list[i - 1], &oids.list[i]))
1010                         count_distinct++;
1011         }
1012         stop_progress(&progress);
1013
1014         if (count_distinct >= GRAPH_EDGE_LAST_MASK)
1015                 die(_("the commit graph format cannot write %d commits"), count_distinct);
1016
1017         commits.nr = 0;
1018         commits.alloc = count_distinct;
1019         ALLOC_ARRAY(commits.list, commits.alloc);
1020
1021         num_extra_edges = 0;
1022         if (report_progress)
1023                 progress = start_delayed_progress(
1024                         _("Finding extra edges in commit graph"),
1025                         oids.nr);
1026         for (i = 0; i < oids.nr; i++) {
1027                 int num_parents = 0;
1028                 display_progress(progress, i + 1);
1029                 if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
1030                         continue;
1031
1032                 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
1033                 parse_commit_no_graph(commits.list[commits.nr]);
1034
1035                 for (parent = commits.list[commits.nr]->parents;
1036                      parent; parent = parent->next)
1037                         num_parents++;
1038
1039                 if (num_parents > 2)
1040                         num_extra_edges += num_parents - 1;
1041
1042                 commits.nr++;
1043         }
1044         num_chunks = num_extra_edges ? 4 : 3;
1045         stop_progress(&progress);
1046
1047         if (commits.nr >= GRAPH_EDGE_LAST_MASK)
1048                 die(_("too many commits to write graph"));
1049
1050         compute_generation_numbers(&commits, report_progress);
1051
1052         graph_name = get_commit_graph_filename(obj_dir);
1053         if (safe_create_leading_directories(graph_name)) {
1054                 UNLEAK(graph_name);
1055                 die_errno(_("unable to create leading directories of %s"),
1056                           graph_name);
1057         }
1058
1059         hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
1060         f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1061
1062         hashwrite_be32(f, GRAPH_SIGNATURE);
1063
1064         hashwrite_u8(f, GRAPH_VERSION);
1065         hashwrite_u8(f, oid_version());
1066         hashwrite_u8(f, num_chunks);
1067         hashwrite_u8(f, 0); /* unused padding byte */
1068
1069         chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1070         chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1071         chunk_ids[2] = GRAPH_CHUNKID_DATA;
1072         if (num_extra_edges)
1073                 chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
1074         else
1075                 chunk_ids[3] = 0;
1076         chunk_ids[4] = 0;
1077
1078         chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1079         chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1080         chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
1081         chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
1082         chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
1083
1084         for (i = 0; i <= num_chunks; i++) {
1085                 uint32_t chunk_write[3];
1086
1087                 chunk_write[0] = htonl(chunk_ids[i]);
1088                 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1089                 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1090                 hashwrite(f, chunk_write, 12);
1091         }
1092
1093         if (report_progress) {
1094                 strbuf_addf(&progress_title,
1095                             Q_("Writing out commit graph in %d pass",
1096                                "Writing out commit graph in %d passes",
1097                                num_chunks),
1098                             num_chunks);
1099                 progress = start_delayed_progress(
1100                         progress_title.buf,
1101                         num_chunks * commits.nr);
1102         }
1103         write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
1104         write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1105         write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1106         if (num_extra_edges)
1107                 write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
1108         stop_progress(&progress);
1109         strbuf_release(&progress_title);
1110
1111         close_commit_graph(the_repository);
1112         finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1113         commit_lock_file(&lk);
1114
1115         free(graph_name);
1116         free(commits.list);
1117         free(oids.list);
1118 }
1119
1120 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1121 static int verify_commit_graph_error;
1122
1123 static void graph_report(const char *fmt, ...)
1124 {
1125         va_list ap;
1126
1127         verify_commit_graph_error = 1;
1128         va_start(ap, fmt);
1129         vfprintf(stderr, fmt, ap);
1130         fprintf(stderr, "\n");
1131         va_end(ap);
1132 }
1133
1134 #define GENERATION_ZERO_EXISTS 1
1135 #define GENERATION_NUMBER_EXISTS 2
1136
1137 int verify_commit_graph(struct repository *r, struct commit_graph *g)
1138 {
1139         uint32_t i, cur_fanout_pos = 0;
1140         struct object_id prev_oid, cur_oid, checksum;
1141         int generation_zero = 0;
1142         struct hashfile *f;
1143         int devnull;
1144         struct progress *progress = NULL;
1145
1146         if (!g) {
1147                 graph_report("no commit-graph file loaded");
1148                 return 1;
1149         }
1150
1151         verify_commit_graph_error = verify_commit_graph_lite(g);
1152         if (verify_commit_graph_error)
1153                 return verify_commit_graph_error;
1154
1155         devnull = open("/dev/null", O_WRONLY);
1156         f = hashfd(devnull, NULL);
1157         hashwrite(f, g->data, g->data_len - g->hash_len);
1158         finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1159         if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1160                 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1161                 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1162         }
1163
1164         for (i = 0; i < g->num_commits; i++) {
1165                 struct commit *graph_commit;
1166
1167                 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1168
1169                 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1170                         graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1171                                      oid_to_hex(&prev_oid),
1172                                      oid_to_hex(&cur_oid));
1173
1174                 oidcpy(&prev_oid, &cur_oid);
1175
1176                 while (cur_oid.hash[0] > cur_fanout_pos) {
1177                         uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1178
1179                         if (i != fanout_value)
1180                                 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1181                                              cur_fanout_pos, fanout_value, i);
1182                         cur_fanout_pos++;
1183                 }
1184
1185                 graph_commit = lookup_commit(r, &cur_oid);
1186                 if (!parse_commit_in_graph_one(r, g, graph_commit))
1187                         graph_report(_("failed to parse commit %s from commit-graph"),
1188                                      oid_to_hex(&cur_oid));
1189         }
1190
1191         while (cur_fanout_pos < 256) {
1192                 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1193
1194                 if (g->num_commits != fanout_value)
1195                         graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1196                                      cur_fanout_pos, fanout_value, i);
1197
1198                 cur_fanout_pos++;
1199         }
1200
1201         if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1202                 return verify_commit_graph_error;
1203
1204         progress = start_progress(_("Verifying commits in commit graph"),
1205                                   g->num_commits);
1206         for (i = 0; i < g->num_commits; i++) {
1207                 struct commit *graph_commit, *odb_commit;
1208                 struct commit_list *graph_parents, *odb_parents;
1209                 uint32_t max_generation = 0;
1210
1211                 display_progress(progress, i + 1);
1212                 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1213
1214                 graph_commit = lookup_commit(r, &cur_oid);
1215                 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1216                 if (parse_commit_internal(odb_commit, 0, 0)) {
1217                         graph_report(_("failed to parse commit %s from object database for commit-graph"),
1218                                      oid_to_hex(&cur_oid));
1219                         continue;
1220                 }
1221
1222                 if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
1223                            get_commit_tree_oid(odb_commit)))
1224                         graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
1225                                      oid_to_hex(&cur_oid),
1226                                      oid_to_hex(get_commit_tree_oid(graph_commit)),
1227                                      oid_to_hex(get_commit_tree_oid(odb_commit)));
1228
1229                 graph_parents = graph_commit->parents;
1230                 odb_parents = odb_commit->parents;
1231
1232                 while (graph_parents) {
1233                         if (odb_parents == NULL) {
1234                                 graph_report(_("commit-graph parent list for commit %s is too long"),
1235                                              oid_to_hex(&cur_oid));
1236                                 break;
1237                         }
1238
1239                         if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1240                                 graph_report(_("commit-graph parent for %s is %s != %s"),
1241                                              oid_to_hex(&cur_oid),
1242                                              oid_to_hex(&graph_parents->item->object.oid),
1243                                              oid_to_hex(&odb_parents->item->object.oid));
1244
1245                         if (graph_parents->item->generation > max_generation)
1246                                 max_generation = graph_parents->item->generation;
1247
1248                         graph_parents = graph_parents->next;
1249                         odb_parents = odb_parents->next;
1250                 }
1251
1252                 if (odb_parents != NULL)
1253                         graph_report(_("commit-graph parent list for commit %s terminates early"),
1254                                      oid_to_hex(&cur_oid));
1255
1256                 if (!graph_commit->generation) {
1257                         if (generation_zero == GENERATION_NUMBER_EXISTS)
1258                                 graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
1259                                              oid_to_hex(&cur_oid));
1260                         generation_zero = GENERATION_ZERO_EXISTS;
1261                 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1262                         graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
1263                                      oid_to_hex(&cur_oid));
1264
1265                 if (generation_zero == GENERATION_ZERO_EXISTS)
1266                         continue;
1267
1268                 /*
1269                  * If one of our parents has generation GENERATION_NUMBER_MAX, then
1270                  * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1271                  * extra logic in the following condition.
1272                  */
1273                 if (max_generation == GENERATION_NUMBER_MAX)
1274                         max_generation--;
1275
1276                 if (graph_commit->generation != max_generation + 1)
1277                         graph_report(_("commit-graph generation for commit %s is %u != %u"),
1278                                      oid_to_hex(&cur_oid),
1279                                      graph_commit->generation,
1280                                      max_generation + 1);
1281
1282                 if (graph_commit->date != odb_commit->date)
1283                         graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
1284                                      oid_to_hex(&cur_oid),
1285                                      graph_commit->date,
1286                                      odb_commit->date);
1287         }
1288         stop_progress(&progress);
1289
1290         return verify_commit_graph_error;
1291 }
1292
1293 void free_commit_graph(struct commit_graph *g)
1294 {
1295         if (!g)
1296                 return;
1297         if (g->graph_fd >= 0) {
1298                 munmap((void *)g->data, g->data_len);
1299                 g->data = NULL;
1300                 close(g->graph_fd);
1301         }
1302         free(g);
1303 }