commit-graph.con commit Merge branch 'jk/delta-islands-progress-fix' (a4c8352)
   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
  43char *get_commit_graph_filename(const char *obj_dir)
  44{
  45        return xstrfmt("%s/info/commit-graph", obj_dir);
  46}
  47
  48static uint8_t oid_version(void)
  49{
  50        return 1;
  51}
  52
  53static 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
  61extern int read_replace_refs;
  62
  63static 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
  83int 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
  95struct 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
 119static 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
 149struct 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                free(graph);
 272                return NULL;
 273        }
 274
 275        return graph;
 276}
 277
 278static struct commit_graph *load_commit_graph_one(const char *graph_file)
 279{
 280
 281        struct stat st;
 282        int fd;
 283        int open_ok = open_commit_graph(graph_file, &fd, &st);
 284
 285        if (!open_ok)
 286                return NULL;
 287
 288        return load_commit_graph_one_fd_st(fd, &st);
 289}
 290
 291static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 292{
 293        char *graph_name;
 294
 295        if (r->objects->commit_graph)
 296                return;
 297
 298        graph_name = get_commit_graph_filename(obj_dir);
 299        r->objects->commit_graph =
 300                load_commit_graph_one(graph_name);
 301
 302        FREE_AND_NULL(graph_name);
 303}
 304
 305/*
 306 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
 307 *
 308 * On the first invocation, this function attemps to load the commit
 309 * graph if the_repository is configured to have one.
 310 */
 311static int prepare_commit_graph(struct repository *r)
 312{
 313        struct object_directory *odb;
 314        int config_value;
 315
 316        if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 317                die("dying as requested by the '%s' variable on commit-graph load!",
 318                    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
 319
 320        if (r->objects->commit_graph_attempted)
 321                return !!r->objects->commit_graph;
 322        r->objects->commit_graph_attempted = 1;
 323
 324        if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 325            (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
 326            !config_value))
 327                /*
 328                 * This repository is not configured to use commit graphs, so
 329                 * do not load one. (But report commit_graph_attempted anyway
 330                 * so that commit graph loading is not attempted again for this
 331                 * repository.)
 332                 */
 333                return 0;
 334
 335        if (!commit_graph_compatible(r))
 336                return 0;
 337
 338        prepare_alt_odb(r);
 339        for (odb = r->objects->odb;
 340             !r->objects->commit_graph && odb;
 341             odb = odb->next)
 342                prepare_commit_graph_one(r, odb->path);
 343        return !!r->objects->commit_graph;
 344}
 345
 346int generation_numbers_enabled(struct repository *r)
 347{
 348        uint32_t first_generation;
 349        struct commit_graph *g;
 350        if (!prepare_commit_graph(r))
 351               return 0;
 352
 353        g = r->objects->commit_graph;
 354
 355        if (!g->num_commits)
 356                return 0;
 357
 358        first_generation = get_be32(g->chunk_commit_data +
 359                                    g->hash_len + 8) >> 2;
 360
 361        return !!first_generation;
 362}
 363
 364void close_commit_graph(struct raw_object_store *o)
 365{
 366        free_commit_graph(o->commit_graph);
 367        o->commit_graph = NULL;
 368}
 369
 370static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
 371{
 372        return bsearch_hash(oid->hash, g->chunk_oid_fanout,
 373                            g->chunk_oid_lookup, g->hash_len, pos);
 374}
 375
 376static struct commit_list **insert_parent_or_die(struct repository *r,
 377                                                 struct commit_graph *g,
 378                                                 uint64_t pos,
 379                                                 struct commit_list **pptr)
 380{
 381        struct commit *c;
 382        struct object_id oid;
 383
 384        if (pos >= g->num_commits)
 385                die("invalid parent position %"PRIu64, pos);
 386
 387        hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
 388        c = lookup_commit(r, &oid);
 389        if (!c)
 390                die(_("could not find commit %s"), oid_to_hex(&oid));
 391        c->graph_pos = pos;
 392        return &commit_list_insert(c, pptr)->next;
 393}
 394
 395static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
 396{
 397        const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
 398        item->graph_pos = pos;
 399        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 400}
 401
 402static inline void set_commit_tree(struct commit *c, struct tree *t)
 403{
 404        c->maybe_tree = t;
 405}
 406
 407static int fill_commit_in_graph(struct repository *r,
 408                                struct commit *item,
 409                                struct commit_graph *g, uint32_t pos)
 410{
 411        uint32_t edge_value;
 412        uint32_t *parent_data_ptr;
 413        uint64_t date_low, date_high;
 414        struct commit_list **pptr;
 415        const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
 416
 417        item->object.parsed = 1;
 418        item->graph_pos = pos;
 419
 420        set_commit_tree(item, NULL);
 421
 422        date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 423        date_low = get_be32(commit_data + g->hash_len + 12);
 424        item->date = (timestamp_t)((date_high << 32) | date_low);
 425
 426        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 427
 428        pptr = &item->parents;
 429
 430        edge_value = get_be32(commit_data + g->hash_len);
 431        if (edge_value == GRAPH_PARENT_NONE)
 432                return 1;
 433        pptr = insert_parent_or_die(r, g, edge_value, pptr);
 434
 435        edge_value = get_be32(commit_data + g->hash_len + 4);
 436        if (edge_value == GRAPH_PARENT_NONE)
 437                return 1;
 438        if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 439                pptr = insert_parent_or_die(r, g, edge_value, pptr);
 440                return 1;
 441        }
 442
 443        parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 444                          4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 445        do {
 446                edge_value = get_be32(parent_data_ptr);
 447                pptr = insert_parent_or_die(r, g,
 448                                            edge_value & GRAPH_EDGE_LAST_MASK,
 449                                            pptr);
 450                parent_data_ptr++;
 451        } while (!(edge_value & GRAPH_LAST_EDGE));
 452
 453        return 1;
 454}
 455
 456static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 457{
 458        if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 459                *pos = item->graph_pos;
 460                return 1;
 461        } else {
 462                return bsearch_graph(g, &(item->object.oid), pos);
 463        }
 464}
 465
 466static int parse_commit_in_graph_one(struct repository *r,
 467                                     struct commit_graph *g,
 468                                     struct commit *item)
 469{
 470        uint32_t pos;
 471
 472        if (item->object.parsed)
 473                return 1;
 474
 475        if (find_commit_in_graph(item, g, &pos))
 476                return fill_commit_in_graph(r, item, g, pos);
 477
 478        return 0;
 479}
 480
 481int parse_commit_in_graph(struct repository *r, struct commit *item)
 482{
 483        if (!prepare_commit_graph(r))
 484                return 0;
 485        return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 486}
 487
 488void load_commit_graph_info(struct repository *r, struct commit *item)
 489{
 490        uint32_t pos;
 491        if (!prepare_commit_graph(r))
 492                return;
 493        if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 494                fill_commit_graph_info(item, r->objects->commit_graph, pos);
 495}
 496
 497static struct tree *load_tree_for_commit(struct repository *r,
 498                                         struct commit_graph *g,
 499                                         struct commit *c)
 500{
 501        struct object_id oid;
 502        const unsigned char *commit_data = g->chunk_commit_data +
 503                                           GRAPH_DATA_WIDTH * (c->graph_pos);
 504
 505        hashcpy(oid.hash, commit_data);
 506        set_commit_tree(c, lookup_tree(r, &oid));
 507
 508        return c->maybe_tree;
 509}
 510
 511static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 512                                                 struct commit_graph *g,
 513                                                 const struct commit *c)
 514{
 515        if (c->maybe_tree)
 516                return c->maybe_tree;
 517        if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 518                BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 519
 520        return load_tree_for_commit(r, g, (struct commit *)c);
 521}
 522
 523struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 524{
 525        return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 526}
 527
 528struct packed_commit_list {
 529        struct commit **list;
 530        int nr;
 531        int alloc;
 532};
 533
 534struct packed_oid_list {
 535        struct object_id *list;
 536        int nr;
 537        int alloc;
 538};
 539
 540struct write_commit_graph_context {
 541        struct repository *r;
 542        const char *obj_dir;
 543        char *graph_name;
 544        struct packed_oid_list oids;
 545        struct packed_commit_list commits;
 546        int num_extra_edges;
 547        unsigned long approx_nr_objects;
 548        struct progress *progress;
 549        int progress_done;
 550        uint64_t progress_cnt;
 551        unsigned append:1,
 552                 report_progress:1;
 553};
 554
 555static void write_graph_chunk_fanout(struct hashfile *f,
 556                                     struct write_commit_graph_context *ctx)
 557{
 558        int i, count = 0;
 559        struct commit **list = ctx->commits.list;
 560
 561        /*
 562         * Write the first-level table (the list is sorted,
 563         * but we use a 256-entry lookup to be able to avoid
 564         * having to do eight extra binary search iterations).
 565         */
 566        for (i = 0; i < 256; i++) {
 567                while (count < ctx->commits.nr) {
 568                        if ((*list)->object.oid.hash[0] != i)
 569                                break;
 570                        display_progress(ctx->progress, ++ctx->progress_cnt);
 571                        count++;
 572                        list++;
 573                }
 574
 575                hashwrite_be32(f, count);
 576        }
 577}
 578
 579static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 580                                   struct write_commit_graph_context *ctx)
 581{
 582        struct commit **list = ctx->commits.list;
 583        int count;
 584        for (count = 0; count < ctx->commits.nr; count++, list++) {
 585                display_progress(ctx->progress, ++ctx->progress_cnt);
 586                hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 587        }
 588}
 589
 590static const unsigned char *commit_to_sha1(size_t index, void *table)
 591{
 592        struct commit **commits = table;
 593        return commits[index]->object.oid.hash;
 594}
 595
 596static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 597                                   struct write_commit_graph_context *ctx)
 598{
 599        struct commit **list = ctx->commits.list;
 600        struct commit **last = ctx->commits.list + ctx->commits.nr;
 601        uint32_t num_extra_edges = 0;
 602
 603        while (list < last) {
 604                struct commit_list *parent;
 605                int edge_value;
 606                uint32_t packedDate[2];
 607                display_progress(ctx->progress, ++ctx->progress_cnt);
 608
 609                parse_commit_no_graph(*list);
 610                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 611
 612                parent = (*list)->parents;
 613
 614                if (!parent)
 615                        edge_value = GRAPH_PARENT_NONE;
 616                else {
 617                        edge_value = sha1_pos(parent->item->object.oid.hash,
 618                                              ctx->commits.list,
 619                                              ctx->commits.nr,
 620                                              commit_to_sha1);
 621
 622                        if (edge_value < 0)
 623                                BUG("missing parent %s for commit %s",
 624                                    oid_to_hex(&parent->item->object.oid),
 625                                    oid_to_hex(&(*list)->object.oid));
 626                }
 627
 628                hashwrite_be32(f, edge_value);
 629
 630                if (parent)
 631                        parent = parent->next;
 632
 633                if (!parent)
 634                        edge_value = GRAPH_PARENT_NONE;
 635                else if (parent->next)
 636                        edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 637                else {
 638                        edge_value = sha1_pos(parent->item->object.oid.hash,
 639                                              ctx->commits.list,
 640                                              ctx->commits.nr,
 641                                              commit_to_sha1);
 642                        if (edge_value < 0)
 643                                BUG("missing parent %s for commit %s",
 644                                    oid_to_hex(&parent->item->object.oid),
 645                                    oid_to_hex(&(*list)->object.oid));
 646                }
 647
 648                hashwrite_be32(f, edge_value);
 649
 650                if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 651                        do {
 652                                num_extra_edges++;
 653                                parent = parent->next;
 654                        } while (parent);
 655                }
 656
 657                if (sizeof((*list)->date) > 4)
 658                        packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 659                else
 660                        packedDate[0] = 0;
 661
 662                packedDate[0] |= htonl((*list)->generation << 2);
 663
 664                packedDate[1] = htonl((*list)->date);
 665                hashwrite(f, packedDate, 8);
 666
 667                list++;
 668        }
 669}
 670
 671static void write_graph_chunk_extra_edges(struct hashfile *f,
 672                                          struct write_commit_graph_context *ctx)
 673{
 674        struct commit **list = ctx->commits.list;
 675        struct commit **last = ctx->commits.list + ctx->commits.nr;
 676        struct commit_list *parent;
 677
 678        while (list < last) {
 679                int num_parents = 0;
 680
 681                display_progress(ctx->progress, ++ctx->progress_cnt);
 682
 683                for (parent = (*list)->parents; num_parents < 3 && parent;
 684                     parent = parent->next)
 685                        num_parents++;
 686
 687                if (num_parents <= 2) {
 688                        list++;
 689                        continue;
 690                }
 691
 692                /* Since num_parents > 2, this initializer is safe. */
 693                for (parent = (*list)->parents->next; parent; parent = parent->next) {
 694                        int edge_value = sha1_pos(parent->item->object.oid.hash,
 695                                                  ctx->commits.list,
 696                                                  ctx->commits.nr,
 697                                                  commit_to_sha1);
 698
 699                        if (edge_value < 0)
 700                                BUG("missing parent %s for commit %s",
 701                                    oid_to_hex(&parent->item->object.oid),
 702                                    oid_to_hex(&(*list)->object.oid));
 703                        else if (!parent->next)
 704                                edge_value |= GRAPH_LAST_EDGE;
 705
 706                        hashwrite_be32(f, edge_value);
 707                }
 708
 709                list++;
 710        }
 711}
 712
 713static int commit_compare(const void *_a, const void *_b)
 714{
 715        const struct object_id *a = (const struct object_id *)_a;
 716        const struct object_id *b = (const struct object_id *)_b;
 717        return oidcmp(a, b);
 718}
 719
 720static int add_packed_commits(const struct object_id *oid,
 721                              struct packed_git *pack,
 722                              uint32_t pos,
 723                              void *data)
 724{
 725        struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
 726        enum object_type type;
 727        off_t offset = nth_packed_object_offset(pack, pos);
 728        struct object_info oi = OBJECT_INFO_INIT;
 729
 730        if (ctx->progress)
 731                display_progress(ctx->progress, ++ctx->progress_done);
 732
 733        oi.typep = &type;
 734        if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
 735                die(_("unable to get type of object %s"), oid_to_hex(oid));
 736
 737        if (type != OBJ_COMMIT)
 738                return 0;
 739
 740        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
 741        oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
 742        ctx->oids.nr++;
 743
 744        return 0;
 745}
 746
 747static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
 748{
 749        struct commit_list *parent;
 750        for (parent = commit->parents; parent; parent = parent->next) {
 751                if (!(parent->item->object.flags & UNINTERESTING)) {
 752                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
 753                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
 754                        ctx->oids.nr++;
 755                        parent->item->object.flags |= UNINTERESTING;
 756                }
 757        }
 758}
 759
 760static void close_reachable(struct write_commit_graph_context *ctx)
 761{
 762        int i;
 763        struct commit *commit;
 764
 765        if (ctx->report_progress)
 766                ctx->progress = start_delayed_progress(
 767                                        _("Loading known commits in commit graph"),
 768                                        ctx->oids.nr);
 769        for (i = 0; i < ctx->oids.nr; i++) {
 770                display_progress(ctx->progress, i + 1);
 771                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
 772                if (commit)
 773                        commit->object.flags |= UNINTERESTING;
 774        }
 775        stop_progress(&ctx->progress);
 776
 777        /*
 778         * As this loop runs, ctx->oids.nr may grow, but not more
 779         * than the number of missing commits in the reachable
 780         * closure.
 781         */
 782        if (ctx->report_progress)
 783                ctx->progress = start_delayed_progress(
 784                                        _("Expanding reachable commits in commit graph"),
 785                                        ctx->oids.nr);
 786        for (i = 0; i < ctx->oids.nr; i++) {
 787                display_progress(ctx->progress, i + 1);
 788                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
 789
 790                if (commit && !parse_commit_no_graph(commit))
 791                        add_missing_parents(ctx, commit);
 792        }
 793        stop_progress(&ctx->progress);
 794
 795        if (ctx->report_progress)
 796                ctx->progress = start_delayed_progress(
 797                                        _("Clearing commit marks in commit graph"),
 798                                        ctx->oids.nr);
 799        for (i = 0; i < ctx->oids.nr; i++) {
 800                display_progress(ctx->progress, i + 1);
 801                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
 802
 803                if (commit)
 804                        commit->object.flags &= ~UNINTERESTING;
 805        }
 806        stop_progress(&ctx->progress);
 807}
 808
 809static void compute_generation_numbers(struct write_commit_graph_context *ctx)
 810{
 811        int i;
 812        struct commit_list *list = NULL;
 813
 814        if (ctx->report_progress)
 815                ctx->progress = start_progress(
 816                                        _("Computing commit graph generation numbers"),
 817                                        ctx->commits.nr);
 818        for (i = 0; i < ctx->commits.nr; i++) {
 819                display_progress(ctx->progress, i + 1);
 820                if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
 821                    ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
 822                        continue;
 823
 824                commit_list_insert(ctx->commits.list[i], &list);
 825                while (list) {
 826                        struct commit *current = list->item;
 827                        struct commit_list *parent;
 828                        int all_parents_computed = 1;
 829                        uint32_t max_generation = 0;
 830
 831                        for (parent = current->parents; parent; parent = parent->next) {
 832                                if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
 833                                    parent->item->generation == GENERATION_NUMBER_ZERO) {
 834                                        all_parents_computed = 0;
 835                                        commit_list_insert(parent->item, &list);
 836                                        break;
 837                                } else if (parent->item->generation > max_generation) {
 838                                        max_generation = parent->item->generation;
 839                                }
 840                        }
 841
 842                        if (all_parents_computed) {
 843                                current->generation = max_generation + 1;
 844                                pop_commit(&list);
 845
 846                                if (current->generation > GENERATION_NUMBER_MAX)
 847                                        current->generation = GENERATION_NUMBER_MAX;
 848                        }
 849                }
 850        }
 851        stop_progress(&ctx->progress);
 852}
 853
 854static int add_ref_to_list(const char *refname,
 855                           const struct object_id *oid,
 856                           int flags, void *cb_data)
 857{
 858        struct string_list *list = (struct string_list *)cb_data;
 859
 860        string_list_append(list, oid_to_hex(oid));
 861        return 0;
 862}
 863
 864int write_commit_graph_reachable(const char *obj_dir, unsigned int flags)
 865{
 866        struct string_list list = STRING_LIST_INIT_DUP;
 867        int result;
 868
 869        for_each_ref(add_ref_to_list, &list);
 870        result = write_commit_graph(obj_dir, NULL, &list,
 871                                    flags);
 872
 873        string_list_clear(&list, 0);
 874        return result;
 875}
 876
 877static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
 878                                struct string_list *pack_indexes)
 879{
 880        uint32_t i;
 881        struct strbuf progress_title = STRBUF_INIT;
 882        struct strbuf packname = STRBUF_INIT;
 883        int dirlen;
 884
 885        strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
 886        dirlen = packname.len;
 887        if (ctx->report_progress) {
 888                strbuf_addf(&progress_title,
 889                            Q_("Finding commits for commit graph in %d pack",
 890                               "Finding commits for commit graph in %d packs",
 891                               pack_indexes->nr),
 892                            pack_indexes->nr);
 893                ctx->progress = start_delayed_progress(progress_title.buf, 0);
 894                ctx->progress_done = 0;
 895        }
 896        for (i = 0; i < pack_indexes->nr; i++) {
 897                struct packed_git *p;
 898                strbuf_setlen(&packname, dirlen);
 899                strbuf_addstr(&packname, pack_indexes->items[i].string);
 900                p = add_packed_git(packname.buf, packname.len, 1);
 901                if (!p) {
 902                        error(_("error adding pack %s"), packname.buf);
 903                        return -1;
 904                }
 905                if (open_pack_index(p)) {
 906                        error(_("error opening index for %s"), packname.buf);
 907                        return -1;
 908                }
 909                for_each_object_in_pack(p, add_packed_commits, ctx,
 910                                        FOR_EACH_OBJECT_PACK_ORDER);
 911                close_pack(p);
 912                free(p);
 913        }
 914
 915        stop_progress(&ctx->progress);
 916        strbuf_reset(&progress_title);
 917        strbuf_release(&packname);
 918
 919        return 0;
 920}
 921
 922static void fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
 923                                      struct string_list *commit_hex)
 924{
 925        uint32_t i;
 926        struct strbuf progress_title = STRBUF_INIT;
 927
 928        if (ctx->report_progress) {
 929                strbuf_addf(&progress_title,
 930                            Q_("Finding commits for commit graph from %d ref",
 931                               "Finding commits for commit graph from %d refs",
 932                               commit_hex->nr),
 933                            commit_hex->nr);
 934                ctx->progress = start_delayed_progress(
 935                                        progress_title.buf,
 936                                        commit_hex->nr);
 937        }
 938        for (i = 0; i < commit_hex->nr; i++) {
 939                const char *end;
 940                struct object_id oid;
 941                struct commit *result;
 942
 943                display_progress(ctx->progress, i + 1);
 944                if (commit_hex->items[i].string &&
 945                    parse_oid_hex(commit_hex->items[i].string, &oid, &end))
 946                        continue;
 947
 948                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
 949
 950                if (result) {
 951                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
 952                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
 953                        ctx->oids.nr++;
 954                }
 955        }
 956        stop_progress(&ctx->progress);
 957        strbuf_release(&progress_title);
 958}
 959
 960static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
 961{
 962        if (ctx->report_progress)
 963                ctx->progress = start_delayed_progress(
 964                        _("Finding commits for commit graph among packed objects"),
 965                        ctx->approx_nr_objects);
 966        for_each_packed_object(add_packed_commits, ctx,
 967                               FOR_EACH_OBJECT_PACK_ORDER);
 968        if (ctx->progress_done < ctx->approx_nr_objects)
 969                display_progress(ctx->progress, ctx->approx_nr_objects);
 970        stop_progress(&ctx->progress);
 971}
 972
 973static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
 974{
 975        uint32_t i, count_distinct = 1;
 976
 977        if (ctx->report_progress)
 978                ctx->progress = start_delayed_progress(
 979                        _("Counting distinct commits in commit graph"),
 980                        ctx->oids.nr);
 981        display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
 982        QSORT(ctx->oids.list, ctx->oids.nr, commit_compare);
 983
 984        for (i = 1; i < ctx->oids.nr; i++) {
 985                display_progress(ctx->progress, i + 1);
 986                if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
 987                        count_distinct++;
 988        }
 989        stop_progress(&ctx->progress);
 990
 991        return count_distinct;
 992}
 993
 994static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
 995{
 996        uint32_t i;
 997        struct commit_list *parent;
 998
 999        ctx->num_extra_edges = 0;
1000        if (ctx->report_progress)
1001                ctx->progress = start_delayed_progress(
1002                        _("Finding extra edges in commit graph"),
1003                        ctx->oids.nr);
1004        for (i = 0; i < ctx->oids.nr; i++) {
1005                int num_parents = 0;
1006                display_progress(ctx->progress, i + 1);
1007                if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1008                        continue;
1009
1010                ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1011                parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1012
1013                for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1014                     parent; parent = parent->next)
1015                        num_parents++;
1016
1017                if (num_parents > 2)
1018                        ctx->num_extra_edges += num_parents - 1;
1019
1020                ctx->commits.nr++;
1021        }
1022        stop_progress(&ctx->progress);
1023}
1024
1025static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1026{
1027        uint32_t i;
1028        struct hashfile *f;
1029        struct lock_file lk = LOCK_INIT;
1030        uint32_t chunk_ids[5];
1031        uint64_t chunk_offsets[5];
1032        const unsigned hashsz = the_hash_algo->rawsz;
1033        struct strbuf progress_title = STRBUF_INIT;
1034        int num_chunks = ctx->num_extra_edges ? 4 : 3;
1035
1036        ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1037        if (safe_create_leading_directories(ctx->graph_name)) {
1038                UNLEAK(ctx->graph_name);
1039                error(_("unable to create leading directories of %s"),
1040                        ctx->graph_name);
1041                return -1;
1042        }
1043
1044        hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1045        f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1046
1047        hashwrite_be32(f, GRAPH_SIGNATURE);
1048
1049        hashwrite_u8(f, GRAPH_VERSION);
1050        hashwrite_u8(f, oid_version());
1051        hashwrite_u8(f, num_chunks);
1052        hashwrite_u8(f, 0); /* unused padding byte */
1053
1054        chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1055        chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1056        chunk_ids[2] = GRAPH_CHUNKID_DATA;
1057        if (ctx->num_extra_edges)
1058                chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
1059        else
1060                chunk_ids[3] = 0;
1061        chunk_ids[4] = 0;
1062
1063        chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1064        chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1065        chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1066        chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1067        chunk_offsets[4] = chunk_offsets[3] + 4 * ctx->num_extra_edges;
1068
1069        for (i = 0; i <= num_chunks; i++) {
1070                uint32_t chunk_write[3];
1071
1072                chunk_write[0] = htonl(chunk_ids[i]);
1073                chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1074                chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1075                hashwrite(f, chunk_write, 12);
1076        }
1077
1078        if (ctx->report_progress) {
1079                strbuf_addf(&progress_title,
1080                            Q_("Writing out commit graph in %d pass",
1081                               "Writing out commit graph in %d passes",
1082                               num_chunks),
1083                            num_chunks);
1084                ctx->progress = start_delayed_progress(
1085                        progress_title.buf,
1086                        num_chunks * ctx->commits.nr);
1087        }
1088        write_graph_chunk_fanout(f, ctx);
1089        write_graph_chunk_oids(f, hashsz, ctx);
1090        write_graph_chunk_data(f, hashsz, ctx);
1091        if (ctx->num_extra_edges)
1092                write_graph_chunk_extra_edges(f, ctx);
1093        stop_progress(&ctx->progress);
1094        strbuf_release(&progress_title);
1095
1096        close_commit_graph(ctx->r->objects);
1097        finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1098        commit_lock_file(&lk);
1099
1100        return 0;
1101}
1102
1103int write_commit_graph(const char *obj_dir,
1104                       struct string_list *pack_indexes,
1105                       struct string_list *commit_hex,
1106                       unsigned int flags)
1107{
1108        struct write_commit_graph_context *ctx;
1109        uint32_t i, count_distinct = 0;
1110        int res = 0;
1111
1112        if (!commit_graph_compatible(the_repository))
1113                return 0;
1114
1115        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1116        ctx->r = the_repository;
1117        ctx->obj_dir = obj_dir;
1118        ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
1119        ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
1120
1121        ctx->approx_nr_objects = approximate_object_count();
1122        ctx->oids.alloc = ctx->approx_nr_objects / 32;
1123
1124        if (ctx->append) {
1125                prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1126                if (ctx->r->objects->commit_graph)
1127                        ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1128        }
1129
1130        if (ctx->oids.alloc < 1024)
1131                ctx->oids.alloc = 1024;
1132        ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1133
1134        if (ctx->append && ctx->r->objects->commit_graph) {
1135                struct commit_graph *g = ctx->r->objects->commit_graph;
1136                for (i = 0; i < g->num_commits; i++) {
1137                        const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1138                        hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1139                }
1140        }
1141
1142        if (pack_indexes) {
1143                if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1144                        goto cleanup;
1145        }
1146
1147        if (commit_hex)
1148                fill_oids_from_commit_hex(ctx, commit_hex);
1149
1150        if (!pack_indexes && !commit_hex)
1151                fill_oids_from_all_packs(ctx);
1152
1153        close_reachable(ctx);
1154
1155        count_distinct = count_distinct_commits(ctx);
1156
1157        if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1158                error(_("the commit graph format cannot write %d commits"), count_distinct);
1159                res = -1;
1160                goto cleanup;
1161        }
1162
1163        ctx->commits.alloc = count_distinct;
1164        ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1165
1166        copy_oids_to_commits(ctx);
1167
1168        if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1169                error(_("too many commits to write graph"));
1170                res = -1;
1171                goto cleanup;
1172        }
1173
1174        compute_generation_numbers(ctx);
1175
1176        res = write_commit_graph_file(ctx);
1177
1178cleanup:
1179        free(ctx->graph_name);
1180        free(ctx->commits.list);
1181        free(ctx->oids.list);
1182        free(ctx);
1183
1184        return res;
1185}
1186
1187#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1188static int verify_commit_graph_error;
1189
1190static void graph_report(const char *fmt, ...)
1191{
1192        va_list ap;
1193
1194        verify_commit_graph_error = 1;
1195        va_start(ap, fmt);
1196        vfprintf(stderr, fmt, ap);
1197        fprintf(stderr, "\n");
1198        va_end(ap);
1199}
1200
1201#define GENERATION_ZERO_EXISTS 1
1202#define GENERATION_NUMBER_EXISTS 2
1203
1204int verify_commit_graph(struct repository *r, struct commit_graph *g)
1205{
1206        uint32_t i, cur_fanout_pos = 0;
1207        struct object_id prev_oid, cur_oid, checksum;
1208        int generation_zero = 0;
1209        struct hashfile *f;
1210        int devnull;
1211        struct progress *progress = NULL;
1212
1213        if (!g) {
1214                graph_report("no commit-graph file loaded");
1215                return 1;
1216        }
1217
1218        verify_commit_graph_error = verify_commit_graph_lite(g);
1219        if (verify_commit_graph_error)
1220                return verify_commit_graph_error;
1221
1222        devnull = open("/dev/null", O_WRONLY);
1223        f = hashfd(devnull, NULL);
1224        hashwrite(f, g->data, g->data_len - g->hash_len);
1225        finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1226        if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1227                graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1228                verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1229        }
1230
1231        for (i = 0; i < g->num_commits; i++) {
1232                struct commit *graph_commit;
1233
1234                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1235
1236                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1237                        graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1238                                     oid_to_hex(&prev_oid),
1239                                     oid_to_hex(&cur_oid));
1240
1241                oidcpy(&prev_oid, &cur_oid);
1242
1243                while (cur_oid.hash[0] > cur_fanout_pos) {
1244                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1245
1246                        if (i != fanout_value)
1247                                graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1248                                             cur_fanout_pos, fanout_value, i);
1249                        cur_fanout_pos++;
1250                }
1251
1252                graph_commit = lookup_commit(r, &cur_oid);
1253                if (!parse_commit_in_graph_one(r, g, graph_commit))
1254                        graph_report(_("failed to parse commit %s from commit-graph"),
1255                                     oid_to_hex(&cur_oid));
1256        }
1257
1258        while (cur_fanout_pos < 256) {
1259                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1260
1261                if (g->num_commits != fanout_value)
1262                        graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1263                                     cur_fanout_pos, fanout_value, i);
1264
1265                cur_fanout_pos++;
1266        }
1267
1268        if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1269                return verify_commit_graph_error;
1270
1271        progress = start_progress(_("Verifying commits in commit graph"),
1272                                  g->num_commits);
1273        for (i = 0; i < g->num_commits; i++) {
1274                struct commit *graph_commit, *odb_commit;
1275                struct commit_list *graph_parents, *odb_parents;
1276                uint32_t max_generation = 0;
1277
1278                display_progress(progress, i + 1);
1279                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1280
1281                graph_commit = lookup_commit(r, &cur_oid);
1282                odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1283                if (parse_commit_internal(odb_commit, 0, 0)) {
1284                        graph_report(_("failed to parse commit %s from object database for commit-graph"),
1285                                     oid_to_hex(&cur_oid));
1286                        continue;
1287                }
1288
1289                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
1290                           get_commit_tree_oid(odb_commit)))
1291                        graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
1292                                     oid_to_hex(&cur_oid),
1293                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
1294                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
1295
1296                graph_parents = graph_commit->parents;
1297                odb_parents = odb_commit->parents;
1298
1299                while (graph_parents) {
1300                        if (odb_parents == NULL) {
1301                                graph_report(_("commit-graph parent list for commit %s is too long"),
1302                                             oid_to_hex(&cur_oid));
1303                                break;
1304                        }
1305
1306                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1307                                graph_report(_("commit-graph parent for %s is %s != %s"),
1308                                             oid_to_hex(&cur_oid),
1309                                             oid_to_hex(&graph_parents->item->object.oid),
1310                                             oid_to_hex(&odb_parents->item->object.oid));
1311
1312                        if (graph_parents->item->generation > max_generation)
1313                                max_generation = graph_parents->item->generation;
1314
1315                        graph_parents = graph_parents->next;
1316                        odb_parents = odb_parents->next;
1317                }
1318
1319                if (odb_parents != NULL)
1320                        graph_report(_("commit-graph parent list for commit %s terminates early"),
1321                                     oid_to_hex(&cur_oid));
1322
1323                if (!graph_commit->generation) {
1324                        if (generation_zero == GENERATION_NUMBER_EXISTS)
1325                                graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
1326                                             oid_to_hex(&cur_oid));
1327                        generation_zero = GENERATION_ZERO_EXISTS;
1328                } else if (generation_zero == GENERATION_ZERO_EXISTS)
1329                        graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
1330                                     oid_to_hex(&cur_oid));
1331
1332                if (generation_zero == GENERATION_ZERO_EXISTS)
1333                        continue;
1334
1335                /*
1336                 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1337                 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1338                 * extra logic in the following condition.
1339                 */
1340                if (max_generation == GENERATION_NUMBER_MAX)
1341                        max_generation--;
1342
1343                if (graph_commit->generation != max_generation + 1)
1344                        graph_report(_("commit-graph generation for commit %s is %u != %u"),
1345                                     oid_to_hex(&cur_oid),
1346                                     graph_commit->generation,
1347                                     max_generation + 1);
1348
1349                if (graph_commit->date != odb_commit->date)
1350                        graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
1351                                     oid_to_hex(&cur_oid),
1352                                     graph_commit->date,
1353                                     odb_commit->date);
1354        }
1355        stop_progress(&progress);
1356
1357        return verify_commit_graph_error;
1358}
1359
1360void free_commit_graph(struct commit_graph *g)
1361{
1362        if (!g)
1363                return;
1364        if (g->graph_fd >= 0) {
1365                munmap((void *)g->data, g->data_len);
1366                g->data = NULL;
1367                close(g->graph_fd);
1368        }
1369        free(g);
1370}