Andrew's git - gitweb.git/blob

   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#define GRAPH_CHUNKID_BASE 0x42415345 /* "BASE" */
  26
  27#define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
  28
  29#define GRAPH_VERSION_1 0x1
  30#define GRAPH_VERSION GRAPH_VERSION_1
  31
  32#define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
  33#define GRAPH_EDGE_LAST_MASK 0x7fffffff
  34#define GRAPH_PARENT_NONE 0x70000000
  35
  36#define GRAPH_LAST_EDGE 0x80000000
  37
  38#define GRAPH_HEADER_SIZE 8
  39#define GRAPH_FANOUT_SIZE (4 * 256)
  40#define GRAPH_CHUNKLOOKUP_WIDTH 12
  41#define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
  42                        + GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
  43
  44char *get_commit_graph_filename(const char *obj_dir)
  45{
  46        char *filename = xstrfmt("%s/info/commit-graph", obj_dir);
  47        char *normalized = xmalloc(strlen(filename) + 1);
  48        normalize_path_copy(normalized, filename);
  49        free(filename);
  50        return normalized;
  51}
  52
  53static char *get_split_graph_filename(const char *obj_dir,
  54                                      const char *oid_hex)
  55{
  56        char *filename = xstrfmt("%s/info/commit-graphs/graph-%s.graph",
  57                                 obj_dir,
  58                                 oid_hex);
  59        char *normalized = xmalloc(strlen(filename) + 1);
  60        normalize_path_copy(normalized, filename);
  61        free(filename);
  62        return normalized;
  63}
  64
  65static char *get_chain_filename(const char *obj_dir)
  66{
  67        return xstrfmt("%s/info/commit-graphs/commit-graph-chain", obj_dir);
  68}
  69
  70static uint8_t oid_version(void)
  71{
  72        return 1;
  73}
  74
  75static struct commit_graph *alloc_commit_graph(void)
  76{
  77        struct commit_graph *g = xcalloc(1, sizeof(*g));
  78        g->graph_fd = -1;
  79
  80        return g;
  81}
  82
  83extern int read_replace_refs;
  84
  85static int commit_graph_compatible(struct repository *r)
  86{
  87        if (!r->gitdir)
  88                return 0;
  89
  90        if (read_replace_refs) {
  91                prepare_replace_object(r);
  92                if (hashmap_get_size(&r->objects->replace_map->map))
  93                        return 0;
  94        }
  95
  96        prepare_commit_graft(r);
  97        if (r->parsed_objects && r->parsed_objects->grafts_nr)
  98                return 0;
  99        if (is_repository_shallow(r))
 100                return 0;
 101
 102        return 1;
 103}
 104
 105int open_commit_graph(const char *graph_file, int *fd, struct stat *st)
 106{
 107        *fd = git_open(graph_file);
 108        if (*fd < 0)
 109                return 0;
 110        if (fstat(*fd, st)) {
 111                close(*fd);
 112                return 0;
 113        }
 114        return 1;
 115}
 116
 117struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st)
 118{
 119        void *graph_map;
 120        size_t graph_size;
 121        struct commit_graph *ret;
 122
 123        graph_size = xsize_t(st->st_size);
 124
 125        if (graph_size < GRAPH_MIN_SIZE) {
 126                close(fd);
 127                error(_("commit-graph file is too small"));
 128                return NULL;
 129        }
 130        graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
 131        ret = parse_commit_graph(graph_map, fd, graph_size);
 132
 133        if (!ret) {
 134                munmap(graph_map, graph_size);
 135                close(fd);
 136        }
 137
 138        return ret;
 139}
 140
 141static int verify_commit_graph_lite(struct commit_graph *g)
 142{
 143        /*
 144         * Basic validation shared between parse_commit_graph()
 145         * which'll be called every time the graph is used, and the
 146         * much more expensive verify_commit_graph() used by
 147         * "commit-graph verify".
 148         *
 149         * There should only be very basic checks here to ensure that
 150         * we don't e.g. segfault in fill_commit_in_graph(), but
 151         * because this is a very hot codepath nothing that e.g. loops
 152         * over g->num_commits, or runs a checksum on the commit-graph
 153         * itself.
 154         */
 155        if (!g->chunk_oid_fanout) {
 156                error("commit-graph is missing the OID Fanout chunk");
 157                return 1;
 158        }
 159        if (!g->chunk_oid_lookup) {
 160                error("commit-graph is missing the OID Lookup chunk");
 161                return 1;
 162        }
 163        if (!g->chunk_commit_data) {
 164                error("commit-graph is missing the Commit Data chunk");
 165                return 1;
 166        }
 167
 168        return 0;
 169}
 170
 171struct commit_graph *parse_commit_graph(void *graph_map, int fd,
 172                                        size_t graph_size)
 173{
 174        const unsigned char *data, *chunk_lookup;
 175        uint32_t i;
 176        struct commit_graph *graph;
 177        uint64_t last_chunk_offset;
 178        uint32_t last_chunk_id;
 179        uint32_t graph_signature;
 180        unsigned char graph_version, hash_version;
 181
 182        if (!graph_map)
 183                return NULL;
 184
 185        if (graph_size < GRAPH_MIN_SIZE)
 186                return NULL;
 187
 188        data = (const unsigned char *)graph_map;
 189
 190        graph_signature = get_be32(data);
 191        if (graph_signature != GRAPH_SIGNATURE) {
 192                error(_("commit-graph signature %X does not match signature %X"),
 193                      graph_signature, GRAPH_SIGNATURE);
 194                return NULL;
 195        }
 196
 197        graph_version = *(unsigned char*)(data + 4);
 198        if (graph_version != GRAPH_VERSION) {
 199                error(_("commit-graph version %X does not match version %X"),
 200                      graph_version, GRAPH_VERSION);
 201                return NULL;
 202        }
 203
 204        hash_version = *(unsigned char*)(data + 5);
 205        if (hash_version != oid_version()) {
 206                error(_("commit-graph hash version %X does not match version %X"),
 207                      hash_version, oid_version());
 208                return NULL;
 209        }
 210
 211        graph = alloc_commit_graph();
 212
 213        graph->hash_len = the_hash_algo->rawsz;
 214        graph->num_chunks = *(unsigned char*)(data + 6);
 215        graph->graph_fd = fd;
 216        graph->data = graph_map;
 217        graph->data_len = graph_size;
 218
 219        last_chunk_id = 0;
 220        last_chunk_offset = 8;
 221        chunk_lookup = data + 8;
 222        for (i = 0; i < graph->num_chunks; i++) {
 223                uint32_t chunk_id;
 224                uint64_t chunk_offset;
 225                int chunk_repeated = 0;
 226
 227                if (data + graph_size - chunk_lookup <
 228                    GRAPH_CHUNKLOOKUP_WIDTH) {
 229                        error(_("commit-graph chunk lookup table entry missing; file may be incomplete"));
 230                        free(graph);
 231                        return NULL;
 232                }
 233
 234                chunk_id = get_be32(chunk_lookup + 0);
 235                chunk_offset = get_be64(chunk_lookup + 4);
 236
 237                chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
 238
 239                if (chunk_offset > graph_size - the_hash_algo->rawsz) {
 240                        error(_("commit-graph improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
 241                              (uint32_t)chunk_offset);
 242                        free(graph);
 243                        return NULL;
 244                }
 245
 246                switch (chunk_id) {
 247                case GRAPH_CHUNKID_OIDFANOUT:
 248                        if (graph->chunk_oid_fanout)
 249                                chunk_repeated = 1;
 250                        else
 251                                graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
 252                        break;
 253
 254                case GRAPH_CHUNKID_OIDLOOKUP:
 255                        if (graph->chunk_oid_lookup)
 256                                chunk_repeated = 1;
 257                        else
 258                                graph->chunk_oid_lookup = data + chunk_offset;
 259                        break;
 260
 261                case GRAPH_CHUNKID_DATA:
 262                        if (graph->chunk_commit_data)
 263                                chunk_repeated = 1;
 264                        else
 265                                graph->chunk_commit_data = data + chunk_offset;
 266                        break;
 267
 268                case GRAPH_CHUNKID_EXTRAEDGES:
 269                        if (graph->chunk_extra_edges)
 270                                chunk_repeated = 1;
 271                        else
 272                                graph->chunk_extra_edges = data + chunk_offset;
 273                        break;
 274
 275                case GRAPH_CHUNKID_BASE:
 276                        if (graph->chunk_base_graphs)
 277                                chunk_repeated = 1;
 278                        else
 279                                graph->chunk_base_graphs = data + chunk_offset;
 280                }
 281
 282                if (chunk_repeated) {
 283                        error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
 284                        free(graph);
 285                        return NULL;
 286                }
 287
 288                if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
 289                {
 290                        graph->num_commits = (chunk_offset - last_chunk_offset)
 291                                             / graph->hash_len;
 292                }
 293
 294                last_chunk_id = chunk_id;
 295                last_chunk_offset = chunk_offset;
 296        }
 297
 298        hashcpy(graph->oid.hash, graph->data + graph->data_len - graph->hash_len);
 299
 300        if (verify_commit_graph_lite(graph))
 301                return NULL;
 302
 303        return graph;
 304}
 305
 306static struct commit_graph *load_commit_graph_one(const char *graph_file)
 307{
 308
 309        struct stat st;
 310        int fd;
 311        struct commit_graph *g;
 312        int open_ok = open_commit_graph(graph_file, &fd, &st);
 313
 314        if (!open_ok)
 315                return NULL;
 316
 317        g = load_commit_graph_one_fd_st(fd, &st);
 318
 319        if (g)
 320                g->filename = xstrdup(graph_file);
 321
 322        return g;
 323}
 324
 325static struct commit_graph *load_commit_graph_v1(struct repository *r, const char *obj_dir)
 326{
 327        char *graph_name = get_commit_graph_filename(obj_dir);
 328        struct commit_graph *g = load_commit_graph_one(graph_name);
 329        free(graph_name);
 330
 331        if (g)
 332                g->obj_dir = obj_dir;
 333
 334        return g;
 335}
 336
 337static int add_graph_to_chain(struct commit_graph *g,
 338                              struct commit_graph *chain,
 339                              struct object_id *oids,
 340                              int n)
 341{
 342        struct commit_graph *cur_g = chain;
 343
 344        if (n && !g->chunk_base_graphs) {
 345                warning(_("commit-graph has no base graphs chunk"));
 346                return 0;
 347        }
 348
 349        while (n) {
 350                n--;
 351
 352                if (!cur_g ||
 353                    !oideq(&oids[n], &cur_g->oid) ||
 354                    !hasheq(oids[n].hash, g->chunk_base_graphs + g->hash_len * n)) {
 355                        warning(_("commit-graph chain does not match"));
 356                        return 0;
 357                }
 358
 359                cur_g = cur_g->base_graph;
 360        }
 361
 362        g->base_graph = chain;
 363
 364        if (chain)
 365                g->num_commits_in_base = chain->num_commits + chain->num_commits_in_base;
 366
 367        return 1;
 368}
 369
 370static struct commit_graph *load_commit_graph_chain(struct repository *r, const char *obj_dir)
 371{
 372        struct commit_graph *graph_chain = NULL;
 373        struct strbuf line = STRBUF_INIT;
 374        struct stat st;
 375        struct object_id *oids;
 376        int i = 0, valid = 1, count;
 377        char *chain_name = get_chain_filename(obj_dir);
 378        FILE *fp;
 379        int stat_res;
 380
 381        fp = fopen(chain_name, "r");
 382        stat_res = stat(chain_name, &st);
 383        free(chain_name);
 384
 385        if (!fp ||
 386            stat_res ||
 387            st.st_size <= the_hash_algo->hexsz)
 388                return NULL;
 389
 390        count = st.st_size / (the_hash_algo->hexsz + 1);
 391        oids = xcalloc(count, sizeof(struct object_id));
 392
 393        prepare_alt_odb(r);
 394
 395        for (i = 0; i < count; i++) {
 396                struct object_directory *odb;
 397
 398                if (strbuf_getline_lf(&line, fp) == EOF)
 399                        break;
 400
 401                if (get_oid_hex(line.buf, &oids[i])) {
 402                        warning(_("invalid commit-graph chain: line '%s' not a hash"),
 403                                line.buf);
 404                        valid = 0;
 405                        break;
 406                }
 407
 408                valid = 0;
 409                for (odb = r->objects->odb; odb; odb = odb->next) {
 410                        char *graph_name = get_split_graph_filename(odb->path, line.buf);
 411                        struct commit_graph *g = load_commit_graph_one(graph_name);
 412
 413                        free(graph_name);
 414
 415                        if (g) {
 416                                g->obj_dir = odb->path;
 417
 418                                if (add_graph_to_chain(g, graph_chain, oids, i)) {
 419                                        graph_chain = g;
 420                                        valid = 1;
 421                                }
 422
 423                                break;
 424                        }
 425                }
 426
 427                if (!valid) {
 428                        warning(_("unable to find all commit-graph files"));
 429                        break;
 430                }
 431        }
 432
 433        free(oids);
 434        fclose(fp);
 435        strbuf_release(&line);
 436
 437        return graph_chain;
 438}
 439
 440struct commit_graph *read_commit_graph_one(struct repository *r, const char *obj_dir)
 441{
 442        struct commit_graph *g = load_commit_graph_v1(r, obj_dir);
 443
 444        if (!g)
 445                g = load_commit_graph_chain(r, obj_dir);
 446
 447        return g;
 448}
 449
 450static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 451{
 452
 453        if (r->objects->commit_graph)
 454                return;
 455
 456        r->objects->commit_graph = read_commit_graph_one(r, obj_dir);
 457}
 458
 459/*
 460 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
 461 *
 462 * On the first invocation, this function attemps to load the commit
 463 * graph if the_repository is configured to have one.
 464 */
 465static int prepare_commit_graph(struct repository *r)
 466{
 467        struct object_directory *odb;
 468        int config_value;
 469
 470        if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 471                die("dying as requested by the '%s' variable on commit-graph load!",
 472                    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
 473
 474        if (r->objects->commit_graph_attempted)
 475                return !!r->objects->commit_graph;
 476        r->objects->commit_graph_attempted = 1;
 477
 478        if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 479            (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
 480            !config_value))
 481                /*
 482                 * This repository is not configured to use commit graphs, so
 483                 * do not load one. (But report commit_graph_attempted anyway
 484                 * so that commit graph loading is not attempted again for this
 485                 * repository.)
 486                 */
 487                return 0;
 488
 489        if (!commit_graph_compatible(r))
 490                return 0;
 491
 492        prepare_alt_odb(r);
 493        for (odb = r->objects->odb;
 494             !r->objects->commit_graph && odb;
 495             odb = odb->next)
 496                prepare_commit_graph_one(r, odb->path);
 497        return !!r->objects->commit_graph;
 498}
 499
 500int generation_numbers_enabled(struct repository *r)
 501{
 502        uint32_t first_generation;
 503        struct commit_graph *g;
 504        if (!prepare_commit_graph(r))
 505               return 0;
 506
 507        g = r->objects->commit_graph;
 508
 509        if (!g->num_commits)
 510                return 0;
 511
 512        first_generation = get_be32(g->chunk_commit_data +
 513                                    g->hash_len + 8) >> 2;
 514
 515        return !!first_generation;
 516}
 517
 518static void close_commit_graph_one(struct commit_graph *g)
 519{
 520        if (!g)
 521                return;
 522
 523        close_commit_graph_one(g->base_graph);
 524        free_commit_graph(g);
 525}
 526
 527void close_commit_graph(struct raw_object_store *o)
 528{
 529        close_commit_graph_one(o->commit_graph);
 530        o->commit_graph = NULL;
 531}
 532
 533static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
 534{
 535        return bsearch_hash(oid->hash, g->chunk_oid_fanout,
 536                            g->chunk_oid_lookup, g->hash_len, pos);
 537}
 538
 539static void load_oid_from_graph(struct commit_graph *g,
 540                                uint32_t pos,
 541                                struct object_id *oid)
 542{
 543        uint32_t lex_index;
 544
 545        while (g && pos < g->num_commits_in_base)
 546                g = g->base_graph;
 547
 548        if (!g)
 549                BUG("NULL commit-graph");
 550
 551        if (pos >= g->num_commits + g->num_commits_in_base)
 552                die(_("invalid commit position. commit-graph is likely corrupt"));
 553
 554        lex_index = pos - g->num_commits_in_base;
 555
 556        hashcpy(oid->hash, g->chunk_oid_lookup + g->hash_len * lex_index);
 557}
 558
 559static struct commit_list **insert_parent_or_die(struct repository *r,
 560                                                 struct commit_graph *g,
 561                                                 uint32_t pos,
 562                                                 struct commit_list **pptr)
 563{
 564        struct commit *c;
 565        struct object_id oid;
 566
 567        if (pos >= g->num_commits + g->num_commits_in_base)
 568                die("invalid parent position %"PRIu32, pos);
 569
 570        load_oid_from_graph(g, pos, &oid);
 571        c = lookup_commit(r, &oid);
 572        if (!c)
 573                die(_("could not find commit %s"), oid_to_hex(&oid));
 574        c->graph_pos = pos;
 575        return &commit_list_insert(c, pptr)->next;
 576}
 577
 578static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
 579{
 580        const unsigned char *commit_data;
 581        uint32_t lex_index;
 582
 583        while (pos < g->num_commits_in_base)
 584                g = g->base_graph;
 585
 586        lex_index = pos - g->num_commits_in_base;
 587        commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index;
 588        item->graph_pos = pos;
 589        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 590}
 591
 592static int fill_commit_in_graph(struct repository *r,
 593                                struct commit *item,
 594                                struct commit_graph *g, uint32_t pos)
 595{
 596        uint32_t edge_value;
 597        uint32_t *parent_data_ptr;
 598        uint64_t date_low, date_high;
 599        struct commit_list **pptr;
 600        const unsigned char *commit_data;
 601        uint32_t lex_index;
 602
 603        while (pos < g->num_commits_in_base)
 604                g = g->base_graph;
 605
 606        if (pos >= g->num_commits + g->num_commits_in_base)
 607                die(_("invalid commit position. commit-graph is likely corrupt"));
 608
 609        /*
 610         * Store the "full" position, but then use the
 611         * "local" position for the rest of the calculation.
 612         */
 613        item->graph_pos = pos;
 614        lex_index = pos - g->num_commits_in_base;
 615
 616        commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index;
 617
 618        item->object.parsed = 1;
 619
 620        item->maybe_tree = NULL;
 621
 622        date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 623        date_low = get_be32(commit_data + g->hash_len + 12);
 624        item->date = (timestamp_t)((date_high << 32) | date_low);
 625
 626        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 627
 628        pptr = &item->parents;
 629
 630        edge_value = get_be32(commit_data + g->hash_len);
 631        if (edge_value == GRAPH_PARENT_NONE)
 632                return 1;
 633        pptr = insert_parent_or_die(r, g, edge_value, pptr);
 634
 635        edge_value = get_be32(commit_data + g->hash_len + 4);
 636        if (edge_value == GRAPH_PARENT_NONE)
 637                return 1;
 638        if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 639                pptr = insert_parent_or_die(r, g, edge_value, pptr);
 640                return 1;
 641        }
 642
 643        parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 644                          4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 645        do {
 646                edge_value = get_be32(parent_data_ptr);
 647                pptr = insert_parent_or_die(r, g,
 648                                            edge_value & GRAPH_EDGE_LAST_MASK,
 649                                            pptr);
 650                parent_data_ptr++;
 651        } while (!(edge_value & GRAPH_LAST_EDGE));
 652
 653        return 1;
 654}
 655
 656static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 657{
 658        if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 659                *pos = item->graph_pos;
 660                return 1;
 661        } else {
 662                struct commit_graph *cur_g = g;
 663                uint32_t lex_index;
 664
 665                while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index))
 666                        cur_g = cur_g->base_graph;
 667
 668                if (cur_g) {
 669                        *pos = lex_index + cur_g->num_commits_in_base;
 670                        return 1;
 671                }
 672
 673                return 0;
 674        }
 675}
 676
 677static int parse_commit_in_graph_one(struct repository *r,
 678                                     struct commit_graph *g,
 679                                     struct commit *item)
 680{
 681        uint32_t pos;
 682
 683        if (item->object.parsed)
 684                return 1;
 685
 686        if (find_commit_in_graph(item, g, &pos))
 687                return fill_commit_in_graph(r, item, g, pos);
 688
 689        return 0;
 690}
 691
 692int parse_commit_in_graph(struct repository *r, struct commit *item)
 693{
 694        if (!prepare_commit_graph(r))
 695                return 0;
 696        return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 697}
 698
 699void load_commit_graph_info(struct repository *r, struct commit *item)
 700{
 701        uint32_t pos;
 702        if (!prepare_commit_graph(r))
 703                return;
 704        if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 705                fill_commit_graph_info(item, r->objects->commit_graph, pos);
 706}
 707
 708static struct tree *load_tree_for_commit(struct repository *r,
 709                                         struct commit_graph *g,
 710                                         struct commit *c)
 711{
 712        struct object_id oid;
 713        const unsigned char *commit_data;
 714
 715        while (c->graph_pos < g->num_commits_in_base)
 716                g = g->base_graph;
 717
 718        commit_data = g->chunk_commit_data +
 719                        GRAPH_DATA_WIDTH * (c->graph_pos - g->num_commits_in_base);
 720
 721        hashcpy(oid.hash, commit_data);
 722        c->maybe_tree = lookup_tree(r, &oid);
 723
 724        return c->maybe_tree;
 725}
 726
 727static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 728                                                 struct commit_graph *g,
 729                                                 const struct commit *c)
 730{
 731        if (c->maybe_tree)
 732                return c->maybe_tree;
 733        if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 734                BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 735
 736        return load_tree_for_commit(r, g, (struct commit *)c);
 737}
 738
 739struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 740{
 741        return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 742}
 743
 744struct packed_commit_list {
 745        struct commit **list;
 746        int nr;
 747        int alloc;
 748};
 749
 750struct packed_oid_list {
 751        struct object_id *list;
 752        int nr;
 753        int alloc;
 754};
 755
 756struct write_commit_graph_context {
 757        struct repository *r;
 758        char *obj_dir;
 759        char *graph_name;
 760        struct packed_oid_list oids;
 761        struct packed_commit_list commits;
 762        int num_extra_edges;
 763        unsigned long approx_nr_objects;
 764        struct progress *progress;
 765        int progress_done;
 766        uint64_t progress_cnt;
 767
 768        char *base_graph_name;
 769        int num_commit_graphs_before;
 770        int num_commit_graphs_after;
 771        char **commit_graph_filenames_before;
 772        char **commit_graph_filenames_after;
 773        char **commit_graph_hash_after;
 774        uint32_t new_num_commits_in_base;
 775        struct commit_graph *new_base_graph;
 776
 777        unsigned append:1,
 778                 report_progress:1,
 779                 split:1;
 780
 781        const struct split_commit_graph_opts *split_opts;
 782};
 783
 784static void write_graph_chunk_fanout(struct hashfile *f,
 785                                     struct write_commit_graph_context *ctx)
 786{
 787        int i, count = 0;
 788        struct commit **list = ctx->commits.list;
 789
 790        /*
 791         * Write the first-level table (the list is sorted,
 792         * but we use a 256-entry lookup to be able to avoid
 793         * having to do eight extra binary search iterations).
 794         */
 795        for (i = 0; i < 256; i++) {
 796                while (count < ctx->commits.nr) {
 797                        if ((*list)->object.oid.hash[0] != i)
 798                                break;
 799                        display_progress(ctx->progress, ++ctx->progress_cnt);
 800                        count++;
 801                        list++;
 802                }
 803
 804                hashwrite_be32(f, count);
 805        }
 806}
 807
 808static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 809                                   struct write_commit_graph_context *ctx)
 810{
 811        struct commit **list = ctx->commits.list;
 812        int count;
 813        for (count = 0; count < ctx->commits.nr; count++, list++) {
 814                display_progress(ctx->progress, ++ctx->progress_cnt);
 815                hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 816        }
 817}
 818
 819static const unsigned char *commit_to_sha1(size_t index, void *table)
 820{
 821        struct commit **commits = table;
 822        return commits[index]->object.oid.hash;
 823}
 824
 825static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 826                                   struct write_commit_graph_context *ctx)
 827{
 828        struct commit **list = ctx->commits.list;
 829        struct commit **last = ctx->commits.list + ctx->commits.nr;
 830        uint32_t num_extra_edges = 0;
 831
 832        while (list < last) {
 833                struct commit_list *parent;
 834                int edge_value;
 835                uint32_t packedDate[2];
 836                display_progress(ctx->progress, ++ctx->progress_cnt);
 837
 838                parse_commit_no_graph(*list);
 839                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 840
 841                parent = (*list)->parents;
 842
 843                if (!parent)
 844                        edge_value = GRAPH_PARENT_NONE;
 845                else {
 846                        edge_value = sha1_pos(parent->item->object.oid.hash,
 847                                              ctx->commits.list,
 848                                              ctx->commits.nr,
 849                                              commit_to_sha1);
 850
 851                        if (edge_value >= 0)
 852                                edge_value += ctx->new_num_commits_in_base;
 853                        else {
 854                                uint32_t pos;
 855                                if (find_commit_in_graph(parent->item,
 856                                                         ctx->new_base_graph,
 857                                                         &pos))
 858                                        edge_value = pos;
 859                        }
 860
 861                        if (edge_value < 0)
 862                                BUG("missing parent %s for commit %s",
 863                                    oid_to_hex(&parent->item->object.oid),
 864                                    oid_to_hex(&(*list)->object.oid));
 865                }
 866
 867                hashwrite_be32(f, edge_value);
 868
 869                if (parent)
 870                        parent = parent->next;
 871
 872                if (!parent)
 873                        edge_value = GRAPH_PARENT_NONE;
 874                else if (parent->next)
 875                        edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 876                else {
 877                        edge_value = sha1_pos(parent->item->object.oid.hash,
 878                                              ctx->commits.list,
 879                                              ctx->commits.nr,
 880                                              commit_to_sha1);
 881
 882                        if (edge_value >= 0)
 883                                edge_value += ctx->new_num_commits_in_base;
 884                        else {
 885                                uint32_t pos;
 886                                if (find_commit_in_graph(parent->item,
 887                                                         ctx->new_base_graph,
 888                                                         &pos))
 889                                        edge_value = pos;
 890                        }
 891
 892                        if (edge_value < 0)
 893                                BUG("missing parent %s for commit %s",
 894                                    oid_to_hex(&parent->item->object.oid),
 895                                    oid_to_hex(&(*list)->object.oid));
 896                }
 897
 898                hashwrite_be32(f, edge_value);
 899
 900                if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 901                        do {
 902                                num_extra_edges++;
 903                                parent = parent->next;
 904                        } while (parent);
 905                }
 906
 907                if (sizeof((*list)->date) > 4)
 908                        packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 909                else
 910                        packedDate[0] = 0;
 911
 912                packedDate[0] |= htonl((*list)->generation << 2);
 913
 914                packedDate[1] = htonl((*list)->date);
 915                hashwrite(f, packedDate, 8);
 916
 917                list++;
 918        }
 919}
 920
 921static void write_graph_chunk_extra_edges(struct hashfile *f,
 922                                          struct write_commit_graph_context *ctx)
 923{
 924        struct commit **list = ctx->commits.list;
 925        struct commit **last = ctx->commits.list + ctx->commits.nr;
 926        struct commit_list *parent;
 927
 928        while (list < last) {
 929                int num_parents = 0;
 930
 931                display_progress(ctx->progress, ++ctx->progress_cnt);
 932
 933                for (parent = (*list)->parents; num_parents < 3 && parent;
 934                     parent = parent->next)
 935                        num_parents++;
 936
 937                if (num_parents <= 2) {
 938                        list++;
 939                        continue;
 940                }
 941
 942                /* Since num_parents > 2, this initializer is safe. */
 943                for (parent = (*list)->parents->next; parent; parent = parent->next) {
 944                        int edge_value = sha1_pos(parent->item->object.oid.hash,
 945                                                  ctx->commits.list,
 946                                                  ctx->commits.nr,
 947                                                  commit_to_sha1);
 948
 949                        if (edge_value >= 0)
 950                                edge_value += ctx->new_num_commits_in_base;
 951                        else {
 952                                uint32_t pos;
 953                                if (find_commit_in_graph(parent->item,
 954                                                         ctx->new_base_graph,
 955                                                         &pos))
 956                                        edge_value = pos;
 957                        }
 958
 959                        if (edge_value < 0)
 960                                BUG("missing parent %s for commit %s",
 961                                    oid_to_hex(&parent->item->object.oid),
 962                                    oid_to_hex(&(*list)->object.oid));
 963                        else if (!parent->next)
 964                                edge_value |= GRAPH_LAST_EDGE;
 965
 966                        hashwrite_be32(f, edge_value);
 967                }
 968
 969                list++;
 970        }
 971}
 972
 973static int oid_compare(const void *_a, const void *_b)
 974{
 975        const struct object_id *a = (const struct object_id *)_a;
 976        const struct object_id *b = (const struct object_id *)_b;
 977        return oidcmp(a, b);
 978}
 979
 980static int add_packed_commits(const struct object_id *oid,
 981                              struct packed_git *pack,
 982                              uint32_t pos,
 983                              void *data)
 984{
 985        struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
 986        enum object_type type;
 987        off_t offset = nth_packed_object_offset(pack, pos);
 988        struct object_info oi = OBJECT_INFO_INIT;
 989
 990        if (ctx->progress)
 991                display_progress(ctx->progress, ++ctx->progress_done);
 992
 993        oi.typep = &type;
 994        if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
 995                die(_("unable to get type of object %s"), oid_to_hex(oid));
 996
 997        if (type != OBJ_COMMIT)
 998                return 0;
 999
1000        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1001        oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
1002        ctx->oids.nr++;
1003
1004        return 0;
1005}
1006
1007static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
1008{
1009        struct commit_list *parent;
1010        for (parent = commit->parents; parent; parent = parent->next) {
1011                if (!(parent->item->object.flags & UNINTERESTING)) {
1012                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1013                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
1014                        ctx->oids.nr++;
1015                        parent->item->object.flags |= UNINTERESTING;
1016                }
1017        }
1018}
1019
1020static void close_reachable(struct write_commit_graph_context *ctx)
1021{
1022        int i;
1023        struct commit *commit;
1024
1025        if (ctx->report_progress)
1026                ctx->progress = start_delayed_progress(
1027                                        _("Loading known commits in commit graph"),
1028                                        ctx->oids.nr);
1029        for (i = 0; i < ctx->oids.nr; i++) {
1030                display_progress(ctx->progress, i + 1);
1031                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1032                if (commit)
1033                        commit->object.flags |= UNINTERESTING;
1034        }
1035        stop_progress(&ctx->progress);
1036
1037        /*
1038         * As this loop runs, ctx->oids.nr may grow, but not more
1039         * than the number of missing commits in the reachable
1040         * closure.
1041         */
1042        if (ctx->report_progress)
1043                ctx->progress = start_delayed_progress(
1044                                        _("Expanding reachable commits in commit graph"),
1045                                        ctx->oids.nr);
1046        for (i = 0; i < ctx->oids.nr; i++) {
1047                display_progress(ctx->progress, i + 1);
1048                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1049
1050                if (!commit)
1051                        continue;
1052                if (ctx->split) {
1053                        if (!parse_commit(commit) &&
1054                            commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
1055                                add_missing_parents(ctx, commit);
1056                } else if (!parse_commit_no_graph(commit))
1057                        add_missing_parents(ctx, commit);
1058        }
1059        stop_progress(&ctx->progress);
1060
1061        if (ctx->report_progress)
1062                ctx->progress = start_delayed_progress(
1063                                        _("Clearing commit marks in commit graph"),
1064                                        ctx->oids.nr);
1065        for (i = 0; i < ctx->oids.nr; i++) {
1066                display_progress(ctx->progress, i + 1);
1067                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1068
1069                if (commit)
1070                        commit->object.flags &= ~UNINTERESTING;
1071        }
1072        stop_progress(&ctx->progress);
1073}
1074
1075static void compute_generation_numbers(struct write_commit_graph_context *ctx)
1076{
1077        int i;
1078        struct commit_list *list = NULL;
1079
1080        if (ctx->report_progress)
1081                ctx->progress = start_progress(
1082                                        _("Computing commit graph generation numbers"),
1083                                        ctx->commits.nr);
1084        for (i = 0; i < ctx->commits.nr; i++) {
1085                display_progress(ctx->progress, i + 1);
1086                if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
1087                    ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
1088                        continue;
1089
1090                commit_list_insert(ctx->commits.list[i], &list);
1091                while (list) {
1092                        struct commit *current = list->item;
1093                        struct commit_list *parent;
1094                        int all_parents_computed = 1;
1095                        uint32_t max_generation = 0;
1096
1097                        for (parent = current->parents; parent; parent = parent->next) {
1098                                if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
1099                                    parent->item->generation == GENERATION_NUMBER_ZERO) {
1100                                        all_parents_computed = 0;
1101                                        commit_list_insert(parent->item, &list);
1102                                        break;
1103                                } else if (parent->item->generation > max_generation) {
1104                                        max_generation = parent->item->generation;
1105                                }
1106                        }
1107
1108                        if (all_parents_computed) {
1109                                current->generation = max_generation + 1;
1110                                pop_commit(&list);
1111
1112                                if (current->generation > GENERATION_NUMBER_MAX)
1113                                        current->generation = GENERATION_NUMBER_MAX;
1114                        }
1115                }
1116        }
1117        stop_progress(&ctx->progress);
1118}
1119
1120static int add_ref_to_list(const char *refname,
1121                           const struct object_id *oid,
1122                           int flags, void *cb_data)
1123{
1124        struct string_list *list = (struct string_list *)cb_data;
1125
1126        string_list_append(list, oid_to_hex(oid));
1127        return 0;
1128}
1129
1130int write_commit_graph_reachable(const char *obj_dir, unsigned int flags,
1131                                 const struct split_commit_graph_opts *split_opts)
1132{
1133        struct string_list list = STRING_LIST_INIT_DUP;
1134        int result;
1135
1136        for_each_ref(add_ref_to_list, &list);
1137        result = write_commit_graph(obj_dir, NULL, &list,
1138                                    flags, split_opts);
1139
1140        string_list_clear(&list, 0);
1141        return result;
1142}
1143
1144static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
1145                                struct string_list *pack_indexes)
1146{
1147        uint32_t i;
1148        struct strbuf progress_title = STRBUF_INIT;
1149        struct strbuf packname = STRBUF_INIT;
1150        int dirlen;
1151
1152        strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
1153        dirlen = packname.len;
1154        if (ctx->report_progress) {
1155                strbuf_addf(&progress_title,
1156                            Q_("Finding commits for commit graph in %d pack",
1157                               "Finding commits for commit graph in %d packs",
1158                               pack_indexes->nr),
1159                            pack_indexes->nr);
1160                ctx->progress = start_delayed_progress(progress_title.buf, 0);
1161                ctx->progress_done = 0;
1162        }
1163        for (i = 0; i < pack_indexes->nr; i++) {
1164                struct packed_git *p;
1165                strbuf_setlen(&packname, dirlen);
1166                strbuf_addstr(&packname, pack_indexes->items[i].string);
1167                p = add_packed_git(packname.buf, packname.len, 1);
1168                if (!p) {
1169                        error(_("error adding pack %s"), packname.buf);
1170                        return -1;
1171                }
1172                if (open_pack_index(p)) {
1173                        error(_("error opening index for %s"), packname.buf);
1174                        return -1;
1175                }
1176                for_each_object_in_pack(p, add_packed_commits, ctx,
1177                                        FOR_EACH_OBJECT_PACK_ORDER);
1178                close_pack(p);
1179                free(p);
1180        }
1181
1182        stop_progress(&ctx->progress);
1183        strbuf_release(&progress_title);
1184        strbuf_release(&packname);
1185
1186        return 0;
1187}
1188
1189static void fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
1190                                      struct string_list *commit_hex)
1191{
1192        uint32_t i;
1193        struct strbuf progress_title = STRBUF_INIT;
1194
1195        if (ctx->report_progress) {
1196                strbuf_addf(&progress_title,
1197                            Q_("Finding commits for commit graph from %d ref",
1198                               "Finding commits for commit graph from %d refs",
1199                               commit_hex->nr),
1200                            commit_hex->nr);
1201                ctx->progress = start_delayed_progress(
1202                                        progress_title.buf,
1203                                        commit_hex->nr);
1204        }
1205        for (i = 0; i < commit_hex->nr; i++) {
1206                const char *end;
1207                struct object_id oid;
1208                struct commit *result;
1209
1210                display_progress(ctx->progress, i + 1);
1211                if (commit_hex->items[i].string &&
1212                    parse_oid_hex(commit_hex->items[i].string, &oid, &end))
1213                        continue;
1214
1215                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1216
1217                if (result) {
1218                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1219                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
1220                        ctx->oids.nr++;
1221                }
1222        }
1223        stop_progress(&ctx->progress);
1224        strbuf_release(&progress_title);
1225}
1226
1227static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
1228{
1229        if (ctx->report_progress)
1230                ctx->progress = start_delayed_progress(
1231                        _("Finding commits for commit graph among packed objects"),
1232                        ctx->approx_nr_objects);
1233        for_each_packed_object(add_packed_commits, ctx,
1234                               FOR_EACH_OBJECT_PACK_ORDER);
1235        if (ctx->progress_done < ctx->approx_nr_objects)
1236                display_progress(ctx->progress, ctx->approx_nr_objects);
1237        stop_progress(&ctx->progress);
1238}
1239
1240static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
1241{
1242        uint32_t i, count_distinct = 1;
1243
1244        if (ctx->report_progress)
1245                ctx->progress = start_delayed_progress(
1246                        _("Counting distinct commits in commit graph"),
1247                        ctx->oids.nr);
1248        display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
1249        QSORT(ctx->oids.list, ctx->oids.nr, oid_compare);
1250
1251        for (i = 1; i < ctx->oids.nr; i++) {
1252                display_progress(ctx->progress, i + 1);
1253                if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i])) {
1254                        if (ctx->split) {
1255                                struct commit *c = lookup_commit(ctx->r, &ctx->oids.list[i]);
1256
1257                                if (!c || c->graph_pos != COMMIT_NOT_FROM_GRAPH)
1258                                        continue;
1259                        }
1260
1261                        count_distinct++;
1262                }
1263        }
1264        stop_progress(&ctx->progress);
1265
1266        return count_distinct;
1267}
1268
1269static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
1270{
1271        uint32_t i;
1272        struct commit_list *parent;
1273
1274        ctx->num_extra_edges = 0;
1275        if (ctx->report_progress)
1276                ctx->progress = start_delayed_progress(
1277                        _("Finding extra edges in commit graph"),
1278                        ctx->oids.nr);
1279        for (i = 0; i < ctx->oids.nr; i++) {
1280                int num_parents = 0;
1281                display_progress(ctx->progress, i + 1);
1282                if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1283                        continue;
1284
1285                ALLOC_GROW(ctx->commits.list, ctx->commits.nr + 1, ctx->commits.alloc);
1286                ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1287
1288                if (ctx->split &&
1289                    ctx->commits.list[ctx->commits.nr]->graph_pos != COMMIT_NOT_FROM_GRAPH)
1290                        continue;
1291
1292                parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1293
1294                for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1295                     parent; parent = parent->next)
1296                        num_parents++;
1297
1298                if (num_parents > 2)
1299                        ctx->num_extra_edges += num_parents - 1;
1300
1301                ctx->commits.nr++;
1302        }
1303        stop_progress(&ctx->progress);
1304}
1305
1306static int write_graph_chunk_base_1(struct hashfile *f,
1307                                    struct commit_graph *g)
1308{
1309        int num = 0;
1310
1311        if (!g)
1312                return 0;
1313
1314        num = write_graph_chunk_base_1(f, g->base_graph);
1315        hashwrite(f, g->oid.hash, the_hash_algo->rawsz);
1316        return num + 1;
1317}
1318
1319static int write_graph_chunk_base(struct hashfile *f,
1320                                  struct write_commit_graph_context *ctx)
1321{
1322        int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
1323
1324        if (num != ctx->num_commit_graphs_after - 1) {
1325                error(_("failed to write correct number of base graph ids"));
1326                return -1;
1327        }
1328
1329        return 0;
1330}
1331
1332static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1333{
1334        uint32_t i;
1335        int fd;
1336        struct hashfile *f;
1337        struct lock_file lk = LOCK_INIT;
1338        uint32_t chunk_ids[6];
1339        uint64_t chunk_offsets[6];
1340        const unsigned hashsz = the_hash_algo->rawsz;
1341        struct strbuf progress_title = STRBUF_INIT;
1342        int num_chunks = 3;
1343        struct object_id file_hash;
1344
1345        if (ctx->split) {
1346                struct strbuf tmp_file = STRBUF_INIT;
1347
1348                strbuf_addf(&tmp_file,
1349                            "%s/info/commit-graphs/tmp_graph_XXXXXX",
1350                            ctx->obj_dir);
1351                ctx->graph_name = strbuf_detach(&tmp_file, NULL);
1352        } else {
1353                ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1354        }
1355
1356        if (safe_create_leading_directories(ctx->graph_name)) {
1357                UNLEAK(ctx->graph_name);
1358                error(_("unable to create leading directories of %s"),
1359                        ctx->graph_name);
1360                return -1;
1361        }
1362
1363        if (ctx->split) {
1364                char *lock_name = get_chain_filename(ctx->obj_dir);
1365
1366                hold_lock_file_for_update(&lk, lock_name, LOCK_DIE_ON_ERROR);
1367
1368                fd = git_mkstemp_mode(ctx->graph_name, 0444);
1369                if (fd < 0) {
1370                        error(_("unable to create '%s'"), ctx->graph_name);
1371                        return -1;
1372                }
1373
1374                f = hashfd(fd, ctx->graph_name);
1375        } else {
1376                hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1377                fd = lk.tempfile->fd;
1378                f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1379        }
1380
1381        chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1382        chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1383        chunk_ids[2] = GRAPH_CHUNKID_DATA;
1384        if (ctx->num_extra_edges) {
1385                chunk_ids[num_chunks] = GRAPH_CHUNKID_EXTRAEDGES;
1386                num_chunks++;
1387        }
1388        if (ctx->num_commit_graphs_after > 1) {
1389                chunk_ids[num_chunks] = GRAPH_CHUNKID_BASE;
1390                num_chunks++;
1391        }
1392
1393        chunk_ids[num_chunks] = 0;
1394
1395        chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1396        chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1397        chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1398        chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1399
1400        num_chunks = 3;
1401        if (ctx->num_extra_edges) {
1402                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1403                                                4 * ctx->num_extra_edges;
1404                num_chunks++;
1405        }
1406        if (ctx->num_commit_graphs_after > 1) {
1407                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1408                                                hashsz * (ctx->num_commit_graphs_after - 1);
1409                num_chunks++;
1410        }
1411
1412        hashwrite_be32(f, GRAPH_SIGNATURE);
1413
1414        hashwrite_u8(f, GRAPH_VERSION);
1415        hashwrite_u8(f, oid_version());
1416        hashwrite_u8(f, num_chunks);
1417        hashwrite_u8(f, ctx->num_commit_graphs_after - 1);
1418
1419        for (i = 0; i <= num_chunks; i++) {
1420                uint32_t chunk_write[3];
1421
1422                chunk_write[0] = htonl(chunk_ids[i]);
1423                chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1424                chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1425                hashwrite(f, chunk_write, 12);
1426        }
1427
1428        if (ctx->report_progress) {
1429                strbuf_addf(&progress_title,
1430                            Q_("Writing out commit graph in %d pass",
1431                               "Writing out commit graph in %d passes",
1432                               num_chunks),
1433                            num_chunks);
1434                ctx->progress = start_delayed_progress(
1435                        progress_title.buf,
1436                        num_chunks * ctx->commits.nr);
1437        }
1438        write_graph_chunk_fanout(f, ctx);
1439        write_graph_chunk_oids(f, hashsz, ctx);
1440        write_graph_chunk_data(f, hashsz, ctx);
1441        if (ctx->num_extra_edges)
1442                write_graph_chunk_extra_edges(f, ctx);
1443        if (ctx->num_commit_graphs_after > 1 &&
1444            write_graph_chunk_base(f, ctx)) {
1445                return -1;
1446        }
1447        stop_progress(&ctx->progress);
1448        strbuf_release(&progress_title);
1449
1450        if (ctx->split && ctx->base_graph_name && ctx->num_commit_graphs_after > 1) {
1451                char *new_base_hash = xstrdup(oid_to_hex(&ctx->new_base_graph->oid));
1452                char *new_base_name = get_split_graph_filename(ctx->new_base_graph->obj_dir, new_base_hash);
1453
1454                free(ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2]);
1455                free(ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2]);
1456                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2] = new_base_name;
1457                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2] = new_base_hash;
1458        }
1459
1460        close_commit_graph(ctx->r->objects);
1461        finalize_hashfile(f, file_hash.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1462
1463        if (ctx->split) {
1464                FILE *chainf = fdopen_lock_file(&lk, "w");
1465                char *final_graph_name;
1466                int result;
1467
1468                close(fd);
1469
1470                if (!chainf) {
1471                        error(_("unable to open commit-graph chain file"));
1472                        return -1;
1473                }
1474
1475                if (ctx->base_graph_name) {
1476                        const char *dest = ctx->commit_graph_filenames_after[
1477                                                ctx->num_commit_graphs_after - 2];
1478
1479                        if (strcmp(ctx->base_graph_name, dest)) {
1480                                result = rename(ctx->base_graph_name, dest);
1481
1482                                if (result) {
1483                                        error(_("failed to rename base commit-graph file"));
1484                                        return -1;
1485                                }
1486                        }
1487                } else {
1488                        char *graph_name = get_commit_graph_filename(ctx->obj_dir);
1489                        unlink(graph_name);
1490                }
1491
1492                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1] = xstrdup(oid_to_hex(&file_hash));
1493                final_graph_name = get_split_graph_filename(ctx->obj_dir,
1494                                        ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1]);
1495                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 1] = final_graph_name;
1496
1497                result = rename(ctx->graph_name, final_graph_name);
1498
1499                for (i = 0; i < ctx->num_commit_graphs_after; i++)
1500                        fprintf(lk.tempfile->fp, "%s\n", ctx->commit_graph_hash_after[i]);
1501
1502                if (result) {
1503                        error(_("failed to rename temporary commit-graph file"));
1504                        return -1;
1505                }
1506        }
1507
1508        commit_lock_file(&lk);
1509
1510        return 0;
1511}
1512
1513static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
1514{
1515        struct commit_graph *g = ctx->r->objects->commit_graph;
1516        uint32_t num_commits = ctx->commits.nr;
1517        uint32_t i;
1518
1519        int max_commits = 0;
1520        int size_mult = 2;
1521
1522        if (ctx->split_opts) {
1523                max_commits = ctx->split_opts->max_commits;
1524                size_mult = ctx->split_opts->size_multiple;
1525        }
1526
1527        g = ctx->r->objects->commit_graph;
1528        ctx->num_commit_graphs_after = ctx->num_commit_graphs_before + 1;
1529
1530        while (g && (g->num_commits <= size_mult * num_commits ||
1531                    (max_commits && num_commits > max_commits))) {
1532                if (strcmp(g->obj_dir, ctx->obj_dir))
1533                        break;
1534
1535                num_commits += g->num_commits;
1536                g = g->base_graph;
1537
1538                ctx->num_commit_graphs_after--;
1539        }
1540
1541        ctx->new_base_graph = g;
1542
1543        if (ctx->num_commit_graphs_after == 2) {
1544                char *old_graph_name = get_commit_graph_filename(g->obj_dir);
1545
1546                if (!strcmp(g->filename, old_graph_name) &&
1547                    strcmp(g->obj_dir, ctx->obj_dir)) {
1548                        ctx->num_commit_graphs_after = 1;
1549                        ctx->new_base_graph = NULL;
1550                }
1551
1552                free(old_graph_name);
1553        }
1554
1555        ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
1556        ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
1557
1558        for (i = 0; i < ctx->num_commit_graphs_after &&
1559                    i < ctx->num_commit_graphs_before; i++)
1560                ctx->commit_graph_filenames_after[i] = xstrdup(ctx->commit_graph_filenames_before[i]);
1561
1562        i = ctx->num_commit_graphs_before - 1;
1563        g = ctx->r->objects->commit_graph;
1564
1565        while (g) {
1566                if (i < ctx->num_commit_graphs_after)
1567                        ctx->commit_graph_hash_after[i] = xstrdup(oid_to_hex(&g->oid));
1568
1569                i--;
1570                g = g->base_graph;
1571        }
1572}
1573
1574static void merge_commit_graph(struct write_commit_graph_context *ctx,
1575                               struct commit_graph *g)
1576{
1577        uint32_t i;
1578        uint32_t offset = g->num_commits_in_base;
1579
1580        ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
1581
1582        for (i = 0; i < g->num_commits; i++) {
1583                struct object_id oid;
1584                struct commit *result;
1585
1586                display_progress(ctx->progress, i + 1);
1587
1588                load_oid_from_graph(g, i + offset, &oid);
1589
1590                /* only add commits if they still exist in the repo */
1591                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1592
1593                if (result) {
1594                        ctx->commits.list[ctx->commits.nr] = result;
1595                        ctx->commits.nr++;
1596                }
1597        }
1598}
1599
1600static int commit_compare(const void *_a, const void *_b)
1601{
1602        const struct commit *a = *(const struct commit **)_a;
1603        const struct commit *b = *(const struct commit **)_b;
1604        return oidcmp(&a->object.oid, &b->object.oid);
1605}
1606
1607static void sort_and_scan_merged_commits(struct write_commit_graph_context *ctx)
1608{
1609        uint32_t i, num_parents;
1610        struct commit_list *parent;
1611
1612        if (ctx->report_progress)
1613                ctx->progress = start_delayed_progress(
1614                                        _("Scanning merged commits"),
1615                                        ctx->commits.nr);
1616
1617        QSORT(ctx->commits.list, ctx->commits.nr, commit_compare);
1618
1619        ctx->num_extra_edges = 0;
1620        for (i = 0; i < ctx->commits.nr; i++) {
1621                display_progress(ctx->progress, i);
1622
1623                if (i && oideq(&ctx->commits.list[i - 1]->object.oid,
1624                          &ctx->commits.list[i]->object.oid)) {
1625                        die(_("unexpected duplicate commit id %s"),
1626                            oid_to_hex(&ctx->commits.list[i]->object.oid));
1627                } else {
1628                        num_parents = 0;
1629                        for (parent = ctx->commits.list[i]->parents; parent; parent = parent->next)
1630                                num_parents++;
1631
1632                        if (num_parents > 2)
1633                                ctx->num_extra_edges += num_parents - 2;
1634                }
1635        }
1636
1637        stop_progress(&ctx->progress);
1638}
1639
1640static void merge_commit_graphs(struct write_commit_graph_context *ctx)
1641{
1642        struct commit_graph *g = ctx->r->objects->commit_graph;
1643        uint32_t current_graph_number = ctx->num_commit_graphs_before;
1644        struct strbuf progress_title = STRBUF_INIT;
1645
1646        while (g && current_graph_number >= ctx->num_commit_graphs_after) {
1647                current_graph_number--;
1648
1649                if (ctx->report_progress) {
1650                        strbuf_addstr(&progress_title, _("Merging commit-graph"));
1651                        ctx->progress = start_delayed_progress(progress_title.buf, 0);
1652                }
1653
1654                merge_commit_graph(ctx, g);
1655                stop_progress(&ctx->progress);
1656                strbuf_release(&progress_title);
1657
1658                g = g->base_graph;
1659        }
1660
1661        if (g) {
1662                ctx->new_base_graph = g;
1663                ctx->new_num_commits_in_base = g->num_commits + g->num_commits_in_base;
1664        }
1665
1666        if (ctx->new_base_graph)
1667                ctx->base_graph_name = xstrdup(ctx->new_base_graph->filename);
1668
1669        sort_and_scan_merged_commits(ctx);
1670}
1671
1672static void mark_commit_graphs(struct write_commit_graph_context *ctx)
1673{
1674        uint32_t i;
1675        time_t now = time(NULL);
1676
1677        for (i = ctx->num_commit_graphs_after - 1; i < ctx->num_commit_graphs_before; i++) {
1678                struct stat st;
1679                struct utimbuf updated_time;
1680
1681                stat(ctx->commit_graph_filenames_before[i], &st);
1682
1683                updated_time.actime = st.st_atime;
1684                updated_time.modtime = now;
1685                utime(ctx->commit_graph_filenames_before[i], &updated_time);
1686        }
1687}
1688
1689static void expire_commit_graphs(struct write_commit_graph_context *ctx)
1690{
1691        struct strbuf path = STRBUF_INIT;
1692        DIR *dir;
1693        struct dirent *de;
1694        size_t dirnamelen;
1695        timestamp_t expire_time = time(NULL);
1696
1697        if (ctx->split_opts && ctx->split_opts->expire_time)
1698                expire_time -= ctx->split_opts->expire_time;
1699        if (!ctx->split) {
1700                char *chain_file_name = get_chain_filename(ctx->obj_dir);
1701                unlink(chain_file_name);
1702                free(chain_file_name);
1703                ctx->num_commit_graphs_after = 0;
1704        }
1705
1706        strbuf_addstr(&path, ctx->obj_dir);
1707        strbuf_addstr(&path, "/info/commit-graphs");
1708        dir = opendir(path.buf);
1709
1710        if (!dir)
1711                goto out;
1712
1713        strbuf_addch(&path, '/');
1714        dirnamelen = path.len;
1715        while ((de = readdir(dir)) != NULL) {
1716                struct stat st;
1717                uint32_t i, found = 0;
1718
1719                strbuf_setlen(&path, dirnamelen);
1720                strbuf_addstr(&path, de->d_name);
1721
1722                stat(path.buf, &st);
1723
1724                if (st.st_mtime > expire_time)
1725                        continue;
1726                if (path.len < 6 || strcmp(path.buf + path.len - 6, ".graph"))
1727                        continue;
1728
1729                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1730                        if (!strcmp(ctx->commit_graph_filenames_after[i],
1731                                    path.buf)) {
1732                                found = 1;
1733                                break;
1734                        }
1735                }
1736
1737                if (!found)
1738                        unlink(path.buf);
1739        }
1740
1741out:
1742        strbuf_release(&path);
1743}
1744
1745int write_commit_graph(const char *obj_dir,
1746                       struct string_list *pack_indexes,
1747                       struct string_list *commit_hex,
1748                       unsigned int flags,
1749                       const struct split_commit_graph_opts *split_opts)
1750{
1751        struct write_commit_graph_context *ctx;
1752        uint32_t i, count_distinct = 0;
1753        size_t len;
1754        int res = 0;
1755
1756        if (!commit_graph_compatible(the_repository))
1757                return 0;
1758
1759        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1760        ctx->r = the_repository;
1761
1762        /* normalize object dir with no trailing slash */
1763        ctx->obj_dir = xmallocz(strlen(obj_dir) + 1);
1764        normalize_path_copy(ctx->obj_dir, obj_dir);
1765        len = strlen(ctx->obj_dir);
1766        if (len && ctx->obj_dir[len - 1] == '/')
1767                ctx->obj_dir[len - 1] = 0;
1768
1769        ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
1770        ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
1771        ctx->split = flags & COMMIT_GRAPH_SPLIT ? 1 : 0;
1772        ctx->split_opts = split_opts;
1773
1774        if (ctx->split) {
1775                struct commit_graph *g;
1776                prepare_commit_graph(ctx->r);
1777
1778                g = ctx->r->objects->commit_graph;
1779
1780                while (g) {
1781                        ctx->num_commit_graphs_before++;
1782                        g = g->base_graph;
1783                }
1784
1785                if (ctx->num_commit_graphs_before) {
1786                        ALLOC_ARRAY(ctx->commit_graph_filenames_before, ctx->num_commit_graphs_before);
1787                        i = ctx->num_commit_graphs_before;
1788                        g = ctx->r->objects->commit_graph;
1789
1790                        while (g) {
1791                                ctx->commit_graph_filenames_before[--i] = xstrdup(g->filename);
1792                                g = g->base_graph;
1793                        }
1794                }
1795        }
1796
1797        ctx->approx_nr_objects = approximate_object_count();
1798        ctx->oids.alloc = ctx->approx_nr_objects / 32;
1799
1800        if (ctx->split && split_opts && ctx->oids.alloc > split_opts->max_commits)
1801                ctx->oids.alloc = split_opts->max_commits;
1802
1803        if (ctx->append) {
1804                prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1805                if (ctx->r->objects->commit_graph)
1806                        ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1807        }
1808
1809        if (ctx->oids.alloc < 1024)
1810                ctx->oids.alloc = 1024;
1811        ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1812
1813        if (ctx->append && ctx->r->objects->commit_graph) {
1814                struct commit_graph *g = ctx->r->objects->commit_graph;
1815                for (i = 0; i < g->num_commits; i++) {
1816                        const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1817                        hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1818                }
1819        }
1820
1821        if (pack_indexes) {
1822                if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1823                        goto cleanup;
1824        }
1825
1826        if (commit_hex)
1827                fill_oids_from_commit_hex(ctx, commit_hex);
1828
1829        if (!pack_indexes && !commit_hex)
1830                fill_oids_from_all_packs(ctx);
1831
1832        close_reachable(ctx);
1833
1834        count_distinct = count_distinct_commits(ctx);
1835
1836        if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1837                error(_("the commit graph format cannot write %d commits"), count_distinct);
1838                res = -1;
1839                goto cleanup;
1840        }
1841
1842        ctx->commits.alloc = count_distinct;
1843        ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1844
1845        copy_oids_to_commits(ctx);
1846
1847        if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1848                error(_("too many commits to write graph"));
1849                res = -1;
1850                goto cleanup;
1851        }
1852
1853        if (!ctx->commits.nr)
1854                goto cleanup;
1855
1856        if (ctx->split) {
1857                split_graph_merge_strategy(ctx);
1858
1859                merge_commit_graphs(ctx);
1860        } else
1861                ctx->num_commit_graphs_after = 1;
1862
1863        compute_generation_numbers(ctx);
1864
1865        res = write_commit_graph_file(ctx);
1866
1867        if (ctx->split)
1868                mark_commit_graphs(ctx);
1869
1870        expire_commit_graphs(ctx);
1871
1872cleanup:
1873        free(ctx->graph_name);
1874        free(ctx->commits.list);
1875        free(ctx->oids.list);
1876        free(ctx->obj_dir);
1877
1878        if (ctx->commit_graph_filenames_after) {
1879                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1880                        free(ctx->commit_graph_filenames_after[i]);
1881                        free(ctx->commit_graph_hash_after[i]);
1882                }
1883
1884                for (i = 0; i < ctx->num_commit_graphs_before; i++)
1885                        free(ctx->commit_graph_filenames_before[i]);
1886
1887                free(ctx->commit_graph_filenames_after);
1888                free(ctx->commit_graph_filenames_before);
1889                free(ctx->commit_graph_hash_after);
1890        }
1891
1892        free(ctx);
1893
1894        return res;
1895}
1896
1897#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1898static int verify_commit_graph_error;
1899
1900static void graph_report(const char *fmt, ...)
1901{
1902        va_list ap;
1903
1904        verify_commit_graph_error = 1;
1905        va_start(ap, fmt);
1906        vfprintf(stderr, fmt, ap);
1907        fprintf(stderr, "\n");
1908        va_end(ap);
1909}
1910
1911#define GENERATION_ZERO_EXISTS 1
1912#define GENERATION_NUMBER_EXISTS 2
1913
1914int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags)
1915{
1916        uint32_t i, cur_fanout_pos = 0;
1917        struct object_id prev_oid, cur_oid, checksum;
1918        int generation_zero = 0;
1919        struct hashfile *f;
1920        int devnull;
1921        struct progress *progress = NULL;
1922        int local_error = 0;
1923
1924        if (!g) {
1925                graph_report("no commit-graph file loaded");
1926                return 1;
1927        }
1928
1929        verify_commit_graph_error = verify_commit_graph_lite(g);
1930        if (verify_commit_graph_error)
1931                return verify_commit_graph_error;
1932
1933        devnull = open("/dev/null", O_WRONLY);
1934        f = hashfd(devnull, NULL);
1935        hashwrite(f, g->data, g->data_len - g->hash_len);
1936        finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1937        if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1938                graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1939                verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1940        }
1941
1942        for (i = 0; i < g->num_commits; i++) {
1943                struct commit *graph_commit;
1944
1945                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1946
1947                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1948                        graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1949                                     oid_to_hex(&prev_oid),
1950                                     oid_to_hex(&cur_oid));
1951
1952                oidcpy(&prev_oid, &cur_oid);
1953
1954                while (cur_oid.hash[0] > cur_fanout_pos) {
1955                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1956
1957                        if (i != fanout_value)
1958                                graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1959                                             cur_fanout_pos, fanout_value, i);
1960                        cur_fanout_pos++;
1961                }
1962
1963                graph_commit = lookup_commit(r, &cur_oid);
1964                if (!parse_commit_in_graph_one(r, g, graph_commit))
1965                        graph_report(_("failed to parse commit %s from commit-graph"),
1966                                     oid_to_hex(&cur_oid));
1967        }
1968
1969        while (cur_fanout_pos < 256) {
1970                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1971
1972                if (g->num_commits != fanout_value)
1973                        graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1974                                     cur_fanout_pos, fanout_value, i);
1975
1976                cur_fanout_pos++;
1977        }
1978
1979        if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1980                return verify_commit_graph_error;
1981
1982        progress = start_progress(_("Verifying commits in commit graph"),
1983                                  g->num_commits);
1984        for (i = 0; i < g->num_commits; i++) {
1985                struct commit *graph_commit, *odb_commit;
1986                struct commit_list *graph_parents, *odb_parents;
1987                uint32_t max_generation = 0;
1988
1989                display_progress(progress, i + 1);
1990                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1991
1992                graph_commit = lookup_commit(r, &cur_oid);
1993                odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1994                if (parse_commit_internal(odb_commit, 0, 0)) {
1995                        graph_report(_("failed to parse commit %s from object database for commit-graph"),
1996                                     oid_to_hex(&cur_oid));
1997                        continue;
1998                }
1999
2000                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
2001                           get_commit_tree_oid(odb_commit)))
2002                        graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
2003                                     oid_to_hex(&cur_oid),
2004                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
2005                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
2006
2007                graph_parents = graph_commit->parents;
2008                odb_parents = odb_commit->parents;
2009
2010                while (graph_parents) {
2011                        if (odb_parents == NULL) {
2012                                graph_report(_("commit-graph parent list for commit %s is too long"),
2013                                             oid_to_hex(&cur_oid));
2014                                break;
2015                        }
2016
2017                        /* parse parent in case it is in a base graph */
2018                        parse_commit_in_graph_one(r, g, graph_parents->item);
2019
2020                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
2021                                graph_report(_("commit-graph parent for %s is %s != %s"),
2022                                             oid_to_hex(&cur_oid),
2023                                             oid_to_hex(&graph_parents->item->object.oid),
2024                                             oid_to_hex(&odb_parents->item->object.oid));
2025
2026                        if (graph_parents->item->generation > max_generation)
2027                                max_generation = graph_parents->item->generation;
2028
2029                        graph_parents = graph_parents->next;
2030                        odb_parents = odb_parents->next;
2031                }
2032
2033                if (odb_parents != NULL)
2034                        graph_report(_("commit-graph parent list for commit %s terminates early"),
2035                                     oid_to_hex(&cur_oid));
2036
2037                if (!graph_commit->generation) {
2038                        if (generation_zero == GENERATION_NUMBER_EXISTS)
2039                                graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
2040                                             oid_to_hex(&cur_oid));
2041                        generation_zero = GENERATION_ZERO_EXISTS;
2042                } else if (generation_zero == GENERATION_ZERO_EXISTS)
2043                        graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
2044                                     oid_to_hex(&cur_oid));
2045
2046                if (generation_zero == GENERATION_ZERO_EXISTS)
2047                        continue;
2048
2049                /*
2050                 * If one of our parents has generation GENERATION_NUMBER_MAX, then
2051                 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
2052                 * extra logic in the following condition.
2053                 */
2054                if (max_generation == GENERATION_NUMBER_MAX)
2055                        max_generation--;
2056
2057                if (graph_commit->generation != max_generation + 1)
2058                        graph_report(_("commit-graph generation for commit %s is %u != %u"),
2059                                     oid_to_hex(&cur_oid),
2060                                     graph_commit->generation,
2061                                     max_generation + 1);
2062
2063                if (graph_commit->date != odb_commit->date)
2064                        graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
2065                                     oid_to_hex(&cur_oid),
2066                                     graph_commit->date,
2067                                     odb_commit->date);
2068        }
2069        stop_progress(&progress);
2070
2071        local_error = verify_commit_graph_error;
2072
2073        if (!(flags & COMMIT_GRAPH_VERIFY_SHALLOW) && g->base_graph)
2074                local_error |= verify_commit_graph(r, g->base_graph, flags);
2075
2076        return local_error;
2077}
2078
2079void free_commit_graph(struct commit_graph *g)
2080{
2081        if (!g)
2082                return;
2083        if (g->graph_fd >= 0) {
2084                munmap((void *)g->data, g->data_len);
2085                g->data = NULL;
2086                close(g->graph_fd);
2087        }
2088        free(g->filename);
2089        free(g);
2090}