Andrew's git / gitweb.git / commit-graph.c
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commit-graph.con commit Merge branch 'jc/denoise-rm-to-resolve' (5e9d978)
   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                free(graph);
 302                return NULL;
 303        }
 304
 305        return graph;
 306}
 307
 308static struct commit_graph *load_commit_graph_one(const char *graph_file)
 309{
 310
 311        struct stat st;
 312        int fd;
 313        struct commit_graph *g;
 314        int open_ok = open_commit_graph(graph_file, &fd, &st);
 315
 316        if (!open_ok)
 317                return NULL;
 318
 319        g = load_commit_graph_one_fd_st(fd, &st);
 320
 321        if (g)
 322                g->filename = xstrdup(graph_file);
 323
 324        return g;
 325}
 326
 327static struct commit_graph *load_commit_graph_v1(struct repository *r, const char *obj_dir)
 328{
 329        char *graph_name = get_commit_graph_filename(obj_dir);
 330        struct commit_graph *g = load_commit_graph_one(graph_name);
 331        free(graph_name);
 332
 333        if (g)
 334                g->obj_dir = obj_dir;
 335
 336        return g;
 337}
 338
 339static int add_graph_to_chain(struct commit_graph *g,
 340                              struct commit_graph *chain,
 341                              struct object_id *oids,
 342                              int n)
 343{
 344        struct commit_graph *cur_g = chain;
 345
 346        if (n && !g->chunk_base_graphs) {
 347                warning(_("commit-graph has no base graphs chunk"));
 348                return 0;
 349        }
 350
 351        while (n) {
 352                n--;
 353
 354                if (!cur_g ||
 355                    !oideq(&oids[n], &cur_g->oid) ||
 356                    !hasheq(oids[n].hash, g->chunk_base_graphs + g->hash_len * n)) {
 357                        warning(_("commit-graph chain does not match"));
 358                        return 0;
 359                }
 360
 361                cur_g = cur_g->base_graph;
 362        }
 363
 364        g->base_graph = chain;
 365
 366        if (chain)
 367                g->num_commits_in_base = chain->num_commits + chain->num_commits_in_base;
 368
 369        return 1;
 370}
 371
 372static struct commit_graph *load_commit_graph_chain(struct repository *r, const char *obj_dir)
 373{
 374        struct commit_graph *graph_chain = NULL;
 375        struct strbuf line = STRBUF_INIT;
 376        struct stat st;
 377        struct object_id *oids;
 378        int i = 0, valid = 1, count;
 379        char *chain_name = get_chain_filename(obj_dir);
 380        FILE *fp;
 381        int stat_res;
 382
 383        fp = fopen(chain_name, "r");
 384        stat_res = stat(chain_name, &st);
 385        free(chain_name);
 386
 387        if (!fp ||
 388            stat_res ||
 389            st.st_size <= the_hash_algo->hexsz)
 390                return NULL;
 391
 392        count = st.st_size / (the_hash_algo->hexsz + 1);
 393        oids = xcalloc(count, sizeof(struct object_id));
 394
 395        prepare_alt_odb(r);
 396
 397        for (i = 0; i < count; i++) {
 398                struct object_directory *odb;
 399
 400                if (strbuf_getline_lf(&line, fp) == EOF)
 401                        break;
 402
 403                if (get_oid_hex(line.buf, &oids[i])) {
 404                        warning(_("invalid commit-graph chain: line '%s' not a hash"),
 405                                line.buf);
 406                        valid = 0;
 407                        break;
 408                }
 409
 410                valid = 0;
 411                for (odb = r->objects->odb; odb; odb = odb->next) {
 412                        char *graph_name = get_split_graph_filename(odb->path, line.buf);
 413                        struct commit_graph *g = load_commit_graph_one(graph_name);
 414
 415                        free(graph_name);
 416
 417                        if (g) {
 418                                g->obj_dir = odb->path;
 419
 420                                if (add_graph_to_chain(g, graph_chain, oids, i)) {
 421                                        graph_chain = g;
 422                                        valid = 1;
 423                                }
 424
 425                                break;
 426                        }
 427                }
 428
 429                if (!valid) {
 430                        warning(_("unable to find all commit-graph files"));
 431                        break;
 432                }
 433        }
 434
 435        free(oids);
 436        fclose(fp);
 437
 438        return graph_chain;
 439}
 440
 441struct commit_graph *read_commit_graph_one(struct repository *r, const char *obj_dir)
 442{
 443        struct commit_graph *g = load_commit_graph_v1(r, obj_dir);
 444
 445        if (!g)
 446                g = load_commit_graph_chain(r, obj_dir);
 447
 448        return g;
 449}
 450
 451static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 452{
 453
 454        if (r->objects->commit_graph)
 455                return;
 456
 457        r->objects->commit_graph = read_commit_graph_one(r, obj_dir);
 458}
 459
 460/*
 461 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
 462 *
 463 * On the first invocation, this function attemps to load the commit
 464 * graph if the_repository is configured to have one.
 465 */
 466static int prepare_commit_graph(struct repository *r)
 467{
 468        struct object_directory *odb;
 469        int config_value;
 470
 471        if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 472                die("dying as requested by the '%s' variable on commit-graph load!",
 473                    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
 474
 475        if (r->objects->commit_graph_attempted)
 476                return !!r->objects->commit_graph;
 477        r->objects->commit_graph_attempted = 1;
 478
 479        if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 480            (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
 481            !config_value))
 482                /*
 483                 * This repository is not configured to use commit graphs, so
 484                 * do not load one. (But report commit_graph_attempted anyway
 485                 * so that commit graph loading is not attempted again for this
 486                 * repository.)
 487                 */
 488                return 0;
 489
 490        if (!commit_graph_compatible(r))
 491                return 0;
 492
 493        prepare_alt_odb(r);
 494        for (odb = r->objects->odb;
 495             !r->objects->commit_graph && odb;
 496             odb = odb->next)
 497                prepare_commit_graph_one(r, odb->path);
 498        return !!r->objects->commit_graph;
 499}
 500
 501int generation_numbers_enabled(struct repository *r)
 502{
 503        uint32_t first_generation;
 504        struct commit_graph *g;
 505        if (!prepare_commit_graph(r))
 506               return 0;
 507
 508        g = r->objects->commit_graph;
 509
 510        if (!g->num_commits)
 511                return 0;
 512
 513        first_generation = get_be32(g->chunk_commit_data +
 514                                    g->hash_len + 8) >> 2;
 515
 516        return !!first_generation;
 517}
 518
 519static void close_commit_graph_one(struct commit_graph *g)
 520{
 521        if (!g)
 522                return;
 523
 524        close_commit_graph_one(g->base_graph);
 525        free_commit_graph(g);
 526}
 527
 528void close_commit_graph(struct raw_object_store *o)
 529{
 530        close_commit_graph_one(o->commit_graph);
 531        o->commit_graph = NULL;
 532}
 533
 534static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
 535{
 536        return bsearch_hash(oid->hash, g->chunk_oid_fanout,
 537                            g->chunk_oid_lookup, g->hash_len, pos);
 538}
 539
 540static void load_oid_from_graph(struct commit_graph *g,
 541                                uint32_t pos,
 542                                struct object_id *oid)
 543{
 544        uint32_t lex_index;
 545
 546        while (g && pos < g->num_commits_in_base)
 547                g = g->base_graph;
 548
 549        if (!g)
 550                BUG("NULL commit-graph");
 551
 552        if (pos >= g->num_commits + g->num_commits_in_base)
 553                die(_("invalid commit position. commit-graph is likely corrupt"));
 554
 555        lex_index = pos - g->num_commits_in_base;
 556
 557        hashcpy(oid->hash, g->chunk_oid_lookup + g->hash_len * lex_index);
 558}
 559
 560static struct commit_list **insert_parent_or_die(struct repository *r,
 561                                                 struct commit_graph *g,
 562                                                 uint32_t pos,
 563                                                 struct commit_list **pptr)
 564{
 565        struct commit *c;
 566        struct object_id oid;
 567
 568        if (pos >= g->num_commits + g->num_commits_in_base)
 569                die("invalid parent position %"PRIu32, pos);
 570
 571        load_oid_from_graph(g, pos, &oid);
 572        c = lookup_commit(r, &oid);
 573        if (!c)
 574                die(_("could not find commit %s"), oid_to_hex(&oid));
 575        c->graph_pos = pos;
 576        return &commit_list_insert(c, pptr)->next;
 577}
 578
 579static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
 580{
 581        const unsigned char *commit_data;
 582        uint32_t lex_index;
 583
 584        while (pos < g->num_commits_in_base)
 585                g = g->base_graph;
 586
 587        lex_index = pos - g->num_commits_in_base;
 588        commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index;
 589        item->graph_pos = pos;
 590        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 591}
 592
 593static inline void set_commit_tree(struct commit *c, struct tree *t)
 594{
 595        c->maybe_tree = t;
 596}
 597
 598static int fill_commit_in_graph(struct repository *r,
 599                                struct commit *item,
 600                                struct commit_graph *g, uint32_t pos)
 601{
 602        uint32_t edge_value;
 603        uint32_t *parent_data_ptr;
 604        uint64_t date_low, date_high;
 605        struct commit_list **pptr;
 606        const unsigned char *commit_data;
 607        uint32_t lex_index;
 608
 609        while (pos < g->num_commits_in_base)
 610                g = g->base_graph;
 611
 612        if (pos >= g->num_commits + g->num_commits_in_base)
 613                die(_("invalid commit position. commit-graph is likely corrupt"));
 614
 615        /*
 616         * Store the "full" position, but then use the
 617         * "local" position for the rest of the calculation.
 618         */
 619        item->graph_pos = pos;
 620        lex_index = pos - g->num_commits_in_base;
 621
 622        commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index;
 623
 624        item->object.parsed = 1;
 625
 626        set_commit_tree(item, NULL);
 627
 628        date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 629        date_low = get_be32(commit_data + g->hash_len + 12);
 630        item->date = (timestamp_t)((date_high << 32) | date_low);
 631
 632        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 633
 634        pptr = &item->parents;
 635
 636        edge_value = get_be32(commit_data + g->hash_len);
 637        if (edge_value == GRAPH_PARENT_NONE)
 638                return 1;
 639        pptr = insert_parent_or_die(r, g, edge_value, pptr);
 640
 641        edge_value = get_be32(commit_data + g->hash_len + 4);
 642        if (edge_value == GRAPH_PARENT_NONE)
 643                return 1;
 644        if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 645                pptr = insert_parent_or_die(r, g, edge_value, pptr);
 646                return 1;
 647        }
 648
 649        parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 650                          4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 651        do {
 652                edge_value = get_be32(parent_data_ptr);
 653                pptr = insert_parent_or_die(r, g,
 654                                            edge_value & GRAPH_EDGE_LAST_MASK,
 655                                            pptr);
 656                parent_data_ptr++;
 657        } while (!(edge_value & GRAPH_LAST_EDGE));
 658
 659        return 1;
 660}
 661
 662static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 663{
 664        if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 665                *pos = item->graph_pos;
 666                return 1;
 667        } else {
 668                struct commit_graph *cur_g = g;
 669                uint32_t lex_index;
 670
 671                while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index))
 672                        cur_g = cur_g->base_graph;
 673
 674                if (cur_g) {
 675                        *pos = lex_index + cur_g->num_commits_in_base;
 676                        return 1;
 677                }
 678
 679                return 0;
 680        }
 681}
 682
 683static int parse_commit_in_graph_one(struct repository *r,
 684                                     struct commit_graph *g,
 685                                     struct commit *item)
 686{
 687        uint32_t pos;
 688
 689        if (item->object.parsed)
 690                return 1;
 691
 692        if (find_commit_in_graph(item, g, &pos))
 693                return fill_commit_in_graph(r, item, g, pos);
 694
 695        return 0;
 696}
 697
 698int parse_commit_in_graph(struct repository *r, struct commit *item)
 699{
 700        if (!prepare_commit_graph(r))
 701                return 0;
 702        return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 703}
 704
 705void load_commit_graph_info(struct repository *r, struct commit *item)
 706{
 707        uint32_t pos;
 708        if (!prepare_commit_graph(r))
 709                return;
 710        if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 711                fill_commit_graph_info(item, r->objects->commit_graph, pos);
 712}
 713
 714static struct tree *load_tree_for_commit(struct repository *r,
 715                                         struct commit_graph *g,
 716                                         struct commit *c)
 717{
 718        struct object_id oid;
 719        const unsigned char *commit_data;
 720
 721        while (c->graph_pos < g->num_commits_in_base)
 722                g = g->base_graph;
 723
 724        commit_data = g->chunk_commit_data +
 725                        GRAPH_DATA_WIDTH * (c->graph_pos - g->num_commits_in_base);
 726
 727        hashcpy(oid.hash, commit_data);
 728        set_commit_tree(c, lookup_tree(r, &oid));
 729
 730        return c->maybe_tree;
 731}
 732
 733static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 734                                                 struct commit_graph *g,
 735                                                 const struct commit *c)
 736{
 737        if (c->maybe_tree)
 738                return c->maybe_tree;
 739        if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 740                BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 741
 742        return load_tree_for_commit(r, g, (struct commit *)c);
 743}
 744
 745struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 746{
 747        return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 748}
 749
 750struct packed_commit_list {
 751        struct commit **list;
 752        int nr;
 753        int alloc;
 754};
 755
 756struct packed_oid_list {
 757        struct object_id *list;
 758        int nr;
 759        int alloc;
 760};
 761
 762struct write_commit_graph_context {
 763        struct repository *r;
 764        char *obj_dir;
 765        char *graph_name;
 766        struct packed_oid_list oids;
 767        struct packed_commit_list commits;
 768        int num_extra_edges;
 769        unsigned long approx_nr_objects;
 770        struct progress *progress;
 771        int progress_done;
 772        uint64_t progress_cnt;
 773
 774        char *base_graph_name;
 775        int num_commit_graphs_before;
 776        int num_commit_graphs_after;
 777        char **commit_graph_filenames_before;
 778        char **commit_graph_filenames_after;
 779        char **commit_graph_hash_after;
 780        uint32_t new_num_commits_in_base;
 781        struct commit_graph *new_base_graph;
 782
 783        unsigned append:1,
 784                 report_progress:1,
 785                 split:1;
 786
 787        const struct split_commit_graph_opts *split_opts;
 788};
 789
 790static void write_graph_chunk_fanout(struct hashfile *f,
 791                                     struct write_commit_graph_context *ctx)
 792{
 793        int i, count = 0;
 794        struct commit **list = ctx->commits.list;
 795
 796        /*
 797         * Write the first-level table (the list is sorted,
 798         * but we use a 256-entry lookup to be able to avoid
 799         * having to do eight extra binary search iterations).
 800         */
 801        for (i = 0; i < 256; i++) {
 802                while (count < ctx->commits.nr) {
 803                        if ((*list)->object.oid.hash[0] != i)
 804                                break;
 805                        display_progress(ctx->progress, ++ctx->progress_cnt);
 806                        count++;
 807                        list++;
 808                }
 809
 810                hashwrite_be32(f, count);
 811        }
 812}
 813
 814static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 815                                   struct write_commit_graph_context *ctx)
 816{
 817        struct commit **list = ctx->commits.list;
 818        int count;
 819        for (count = 0; count < ctx->commits.nr; count++, list++) {
 820                display_progress(ctx->progress, ++ctx->progress_cnt);
 821                hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 822        }
 823}
 824
 825static const unsigned char *commit_to_sha1(size_t index, void *table)
 826{
 827        struct commit **commits = table;
 828        return commits[index]->object.oid.hash;
 829}
 830
 831static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 832                                   struct write_commit_graph_context *ctx)
 833{
 834        struct commit **list = ctx->commits.list;
 835        struct commit **last = ctx->commits.list + ctx->commits.nr;
 836        uint32_t num_extra_edges = 0;
 837
 838        while (list < last) {
 839                struct commit_list *parent;
 840                int edge_value;
 841                uint32_t packedDate[2];
 842                display_progress(ctx->progress, ++ctx->progress_cnt);
 843
 844                parse_commit_no_graph(*list);
 845                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 846
 847                parent = (*list)->parents;
 848
 849                if (!parent)
 850                        edge_value = GRAPH_PARENT_NONE;
 851                else {
 852                        edge_value = sha1_pos(parent->item->object.oid.hash,
 853                                              ctx->commits.list,
 854                                              ctx->commits.nr,
 855                                              commit_to_sha1);
 856
 857                        if (edge_value >= 0)
 858                                edge_value += ctx->new_num_commits_in_base;
 859                        else {
 860                                uint32_t pos;
 861                                if (find_commit_in_graph(parent->item,
 862                                                         ctx->new_base_graph,
 863                                                         &pos))
 864                                        edge_value = pos;
 865                        }
 866
 867                        if (edge_value < 0)
 868                                BUG("missing parent %s for commit %s",
 869                                    oid_to_hex(&parent->item->object.oid),
 870                                    oid_to_hex(&(*list)->object.oid));
 871                }
 872
 873                hashwrite_be32(f, edge_value);
 874
 875                if (parent)
 876                        parent = parent->next;
 877
 878                if (!parent)
 879                        edge_value = GRAPH_PARENT_NONE;
 880                else if (parent->next)
 881                        edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 882                else {
 883                        edge_value = sha1_pos(parent->item->object.oid.hash,
 884                                              ctx->commits.list,
 885                                              ctx->commits.nr,
 886                                              commit_to_sha1);
 887
 888                        if (edge_value >= 0)
 889                                edge_value += ctx->new_num_commits_in_base;
 890                        else {
 891                                uint32_t pos;
 892                                if (find_commit_in_graph(parent->item,
 893                                                         ctx->new_base_graph,
 894                                                         &pos))
 895                                        edge_value = pos;
 896                        }
 897
 898                        if (edge_value < 0)
 899                                BUG("missing parent %s for commit %s",
 900                                    oid_to_hex(&parent->item->object.oid),
 901                                    oid_to_hex(&(*list)->object.oid));
 902                }
 903
 904                hashwrite_be32(f, edge_value);
 905
 906                if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 907                        do {
 908                                num_extra_edges++;
 909                                parent = parent->next;
 910                        } while (parent);
 911                }
 912
 913                if (sizeof((*list)->date) > 4)
 914                        packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 915                else
 916                        packedDate[0] = 0;
 917
 918                packedDate[0] |= htonl((*list)->generation << 2);
 919
 920                packedDate[1] = htonl((*list)->date);
 921                hashwrite(f, packedDate, 8);
 922
 923                list++;
 924        }
 925}
 926
 927static void write_graph_chunk_extra_edges(struct hashfile *f,
 928                                          struct write_commit_graph_context *ctx)
 929{
 930        struct commit **list = ctx->commits.list;
 931        struct commit **last = ctx->commits.list + ctx->commits.nr;
 932        struct commit_list *parent;
 933
 934        while (list < last) {
 935                int num_parents = 0;
 936
 937                display_progress(ctx->progress, ++ctx->progress_cnt);
 938
 939                for (parent = (*list)->parents; num_parents < 3 && parent;
 940                     parent = parent->next)
 941                        num_parents++;
 942
 943                if (num_parents <= 2) {
 944                        list++;
 945                        continue;
 946                }
 947
 948                /* Since num_parents > 2, this initializer is safe. */
 949                for (parent = (*list)->parents->next; parent; parent = parent->next) {
 950                        int edge_value = sha1_pos(parent->item->object.oid.hash,
 951                                                  ctx->commits.list,
 952                                                  ctx->commits.nr,
 953                                                  commit_to_sha1);
 954
 955                        if (edge_value >= 0)
 956                                edge_value += ctx->new_num_commits_in_base;
 957                        else {
 958                                uint32_t pos;
 959                                if (find_commit_in_graph(parent->item,
 960                                                         ctx->new_base_graph,
 961                                                         &pos))
 962                                        edge_value = pos;
 963                        }
 964
 965                        if (edge_value < 0)
 966                                BUG("missing parent %s for commit %s",
 967                                    oid_to_hex(&parent->item->object.oid),
 968                                    oid_to_hex(&(*list)->object.oid));
 969                        else if (!parent->next)
 970                                edge_value |= GRAPH_LAST_EDGE;
 971
 972                        hashwrite_be32(f, edge_value);
 973                }
 974
 975                list++;
 976        }
 977}
 978
 979static int oid_compare(const void *_a, const void *_b)
 980{
 981        const struct object_id *a = (const struct object_id *)_a;
 982        const struct object_id *b = (const struct object_id *)_b;
 983        return oidcmp(a, b);
 984}
 985
 986static int add_packed_commits(const struct object_id *oid,
 987                              struct packed_git *pack,
 988                              uint32_t pos,
 989                              void *data)
 990{
 991        struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
 992        enum object_type type;
 993        off_t offset = nth_packed_object_offset(pack, pos);
 994        struct object_info oi = OBJECT_INFO_INIT;
 995
 996        if (ctx->progress)
 997                display_progress(ctx->progress, ++ctx->progress_done);
 998
 999        oi.typep = &type;
1000        if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
1001                die(_("unable to get type of object %s"), oid_to_hex(oid));
1002
1003        if (type != OBJ_COMMIT)
1004                return 0;
1005
1006        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1007        oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
1008        ctx->oids.nr++;
1009
1010        return 0;
1011}
1012
1013static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
1014{
1015        struct commit_list *parent;
1016        for (parent = commit->parents; parent; parent = parent->next) {
1017                if (!(parent->item->object.flags & UNINTERESTING)) {
1018                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1019                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
1020                        ctx->oids.nr++;
1021                        parent->item->object.flags |= UNINTERESTING;
1022                }
1023        }
1024}
1025
1026static void close_reachable(struct write_commit_graph_context *ctx)
1027{
1028        int i;
1029        struct commit *commit;
1030
1031        if (ctx->report_progress)
1032                ctx->progress = start_delayed_progress(
1033                                        _("Loading known commits in commit graph"),
1034                                        ctx->oids.nr);
1035        for (i = 0; i < ctx->oids.nr; i++) {
1036                display_progress(ctx->progress, i + 1);
1037                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1038                if (commit)
1039                        commit->object.flags |= UNINTERESTING;
1040        }
1041        stop_progress(&ctx->progress);
1042
1043        /*
1044         * As this loop runs, ctx->oids.nr may grow, but not more
1045         * than the number of missing commits in the reachable
1046         * closure.
1047         */
1048        if (ctx->report_progress)
1049                ctx->progress = start_delayed_progress(
1050                                        _("Expanding reachable commits in commit graph"),
1051                                        ctx->oids.nr);
1052        for (i = 0; i < ctx->oids.nr; i++) {
1053                display_progress(ctx->progress, i + 1);
1054                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1055
1056                if (!commit)
1057                        continue;
1058                if (ctx->split) {
1059                        if (!parse_commit(commit) &&
1060                            commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
1061                                add_missing_parents(ctx, commit);
1062                } else if (!parse_commit_no_graph(commit))
1063                        add_missing_parents(ctx, commit);
1064        }
1065        stop_progress(&ctx->progress);
1066
1067        if (ctx->report_progress)
1068                ctx->progress = start_delayed_progress(
1069                                        _("Clearing commit marks in commit graph"),
1070                                        ctx->oids.nr);
1071        for (i = 0; i < ctx->oids.nr; i++) {
1072                display_progress(ctx->progress, i + 1);
1073                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1074
1075                if (commit)
1076                        commit->object.flags &= ~UNINTERESTING;
1077        }
1078        stop_progress(&ctx->progress);
1079}
1080
1081static void compute_generation_numbers(struct write_commit_graph_context *ctx)
1082{
1083        int i;
1084        struct commit_list *list = NULL;
1085
1086        if (ctx->report_progress)
1087                ctx->progress = start_progress(
1088                                        _("Computing commit graph generation numbers"),
1089                                        ctx->commits.nr);
1090        for (i = 0; i < ctx->commits.nr; i++) {
1091                display_progress(ctx->progress, i + 1);
1092                if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
1093                    ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
1094                        continue;
1095
1096                commit_list_insert(ctx->commits.list[i], &list);
1097                while (list) {
1098                        struct commit *current = list->item;
1099                        struct commit_list *parent;
1100                        int all_parents_computed = 1;
1101                        uint32_t max_generation = 0;
1102
1103                        for (parent = current->parents; parent; parent = parent->next) {
1104                                if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
1105                                    parent->item->generation == GENERATION_NUMBER_ZERO) {
1106                                        all_parents_computed = 0;
1107                                        commit_list_insert(parent->item, &list);
1108                                        break;
1109                                } else if (parent->item->generation > max_generation) {
1110                                        max_generation = parent->item->generation;
1111                                }
1112                        }
1113
1114                        if (all_parents_computed) {
1115                                current->generation = max_generation + 1;
1116                                pop_commit(&list);
1117
1118                                if (current->generation > GENERATION_NUMBER_MAX)
1119                                        current->generation = GENERATION_NUMBER_MAX;
1120                        }
1121                }
1122        }
1123        stop_progress(&ctx->progress);
1124}
1125
1126static int add_ref_to_list(const char *refname,
1127                           const struct object_id *oid,
1128                           int flags, void *cb_data)
1129{
1130        struct string_list *list = (struct string_list *)cb_data;
1131
1132        string_list_append(list, oid_to_hex(oid));
1133        return 0;
1134}
1135
1136int write_commit_graph_reachable(const char *obj_dir, unsigned int flags,
1137                                 const struct split_commit_graph_opts *split_opts)
1138{
1139        struct string_list list = STRING_LIST_INIT_DUP;
1140        int result;
1141
1142        for_each_ref(add_ref_to_list, &list);
1143        result = write_commit_graph(obj_dir, NULL, &list,
1144                                    flags, split_opts);
1145
1146        string_list_clear(&list, 0);
1147        return result;
1148}
1149
1150static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
1151                                struct string_list *pack_indexes)
1152{
1153        uint32_t i;
1154        struct strbuf progress_title = STRBUF_INIT;
1155        struct strbuf packname = STRBUF_INIT;
1156        int dirlen;
1157
1158        strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
1159        dirlen = packname.len;
1160        if (ctx->report_progress) {
1161                strbuf_addf(&progress_title,
1162                            Q_("Finding commits for commit graph in %d pack",
1163                               "Finding commits for commit graph in %d packs",
1164                               pack_indexes->nr),
1165                            pack_indexes->nr);
1166                ctx->progress = start_delayed_progress(progress_title.buf, 0);
1167                ctx->progress_done = 0;
1168        }
1169        for (i = 0; i < pack_indexes->nr; i++) {
1170                struct packed_git *p;
1171                strbuf_setlen(&packname, dirlen);
1172                strbuf_addstr(&packname, pack_indexes->items[i].string);
1173                p = add_packed_git(packname.buf, packname.len, 1);
1174                if (!p) {
1175                        error(_("error adding pack %s"), packname.buf);
1176                        return -1;
1177                }
1178                if (open_pack_index(p)) {
1179                        error(_("error opening index for %s"), packname.buf);
1180                        return -1;
1181                }
1182                for_each_object_in_pack(p, add_packed_commits, ctx,
1183                                        FOR_EACH_OBJECT_PACK_ORDER);
1184                close_pack(p);
1185                free(p);
1186        }
1187
1188        stop_progress(&ctx->progress);
1189        strbuf_reset(&progress_title);
1190        strbuf_release(&packname);
1191
1192        return 0;
1193}
1194
1195static void fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
1196                                      struct string_list *commit_hex)
1197{
1198        uint32_t i;
1199        struct strbuf progress_title = STRBUF_INIT;
1200
1201        if (ctx->report_progress) {
1202                strbuf_addf(&progress_title,
1203                            Q_("Finding commits for commit graph from %d ref",
1204                               "Finding commits for commit graph from %d refs",
1205                               commit_hex->nr),
1206                            commit_hex->nr);
1207                ctx->progress = start_delayed_progress(
1208                                        progress_title.buf,
1209                                        commit_hex->nr);
1210        }
1211        for (i = 0; i < commit_hex->nr; i++) {
1212                const char *end;
1213                struct object_id oid;
1214                struct commit *result;
1215
1216                display_progress(ctx->progress, i + 1);
1217                if (commit_hex->items[i].string &&
1218                    parse_oid_hex(commit_hex->items[i].string, &oid, &end))
1219                        continue;
1220
1221                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1222
1223                if (result) {
1224                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1225                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
1226                        ctx->oids.nr++;
1227                }
1228        }
1229        stop_progress(&ctx->progress);
1230        strbuf_release(&progress_title);
1231}
1232
1233static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
1234{
1235        if (ctx->report_progress)
1236                ctx->progress = start_delayed_progress(
1237                        _("Finding commits for commit graph among packed objects"),
1238                        ctx->approx_nr_objects);
1239        for_each_packed_object(add_packed_commits, ctx,
1240                               FOR_EACH_OBJECT_PACK_ORDER);
1241        if (ctx->progress_done < ctx->approx_nr_objects)
1242                display_progress(ctx->progress, ctx->approx_nr_objects);
1243        stop_progress(&ctx->progress);
1244}
1245
1246static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
1247{
1248        uint32_t i, count_distinct = 1;
1249
1250        if (ctx->report_progress)
1251                ctx->progress = start_delayed_progress(
1252                        _("Counting distinct commits in commit graph"),
1253                        ctx->oids.nr);
1254        display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
1255        QSORT(ctx->oids.list, ctx->oids.nr, oid_compare);
1256
1257        for (i = 1; i < ctx->oids.nr; i++) {
1258                display_progress(ctx->progress, i + 1);
1259                if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i])) {
1260                        if (ctx->split) {
1261                                struct commit *c = lookup_commit(ctx->r, &ctx->oids.list[i]);
1262
1263                                if (!c || c->graph_pos != COMMIT_NOT_FROM_GRAPH)
1264                                        continue;
1265                        }
1266
1267                        count_distinct++;
1268                }
1269        }
1270        stop_progress(&ctx->progress);
1271
1272        return count_distinct;
1273}
1274
1275static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
1276{
1277        uint32_t i;
1278        struct commit_list *parent;
1279
1280        ctx->num_extra_edges = 0;
1281        if (ctx->report_progress)
1282                ctx->progress = start_delayed_progress(
1283                        _("Finding extra edges in commit graph"),
1284                        ctx->oids.nr);
1285        for (i = 0; i < ctx->oids.nr; i++) {
1286                int num_parents = 0;
1287                display_progress(ctx->progress, i + 1);
1288                if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1289                        continue;
1290
1291                ALLOC_GROW(ctx->commits.list, ctx->commits.nr + 1, ctx->commits.alloc);
1292                ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1293
1294                if (ctx->split &&
1295                    ctx->commits.list[ctx->commits.nr]->graph_pos != COMMIT_NOT_FROM_GRAPH)
1296                        continue;
1297
1298                parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1299
1300                for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1301                     parent; parent = parent->next)
1302                        num_parents++;
1303
1304                if (num_parents > 2)
1305                        ctx->num_extra_edges += num_parents - 1;
1306
1307                ctx->commits.nr++;
1308        }
1309        stop_progress(&ctx->progress);
1310}
1311
1312static int write_graph_chunk_base_1(struct hashfile *f,
1313                                    struct commit_graph *g)
1314{
1315        int num = 0;
1316
1317        if (!g)
1318                return 0;
1319
1320        num = write_graph_chunk_base_1(f, g->base_graph);
1321        hashwrite(f, g->oid.hash, the_hash_algo->rawsz);
1322        return num + 1;
1323}
1324
1325static int write_graph_chunk_base(struct hashfile *f,
1326                                  struct write_commit_graph_context *ctx)
1327{
1328        int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
1329
1330        if (num != ctx->num_commit_graphs_after - 1) {
1331                error(_("failed to write correct number of base graph ids"));
1332                return -1;
1333        }
1334
1335        return 0;
1336}
1337
1338static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1339{
1340        uint32_t i;
1341        int fd;
1342        struct hashfile *f;
1343        struct lock_file lk = LOCK_INIT;
1344        uint32_t chunk_ids[6];
1345        uint64_t chunk_offsets[6];
1346        const unsigned hashsz = the_hash_algo->rawsz;
1347        struct strbuf progress_title = STRBUF_INIT;
1348        int num_chunks = 3;
1349        struct object_id file_hash;
1350
1351        if (ctx->split) {
1352                struct strbuf tmp_file = STRBUF_INIT;
1353
1354                strbuf_addf(&tmp_file,
1355                            "%s/info/commit-graphs/tmp_graph_XXXXXX",
1356                            ctx->obj_dir);
1357                ctx->graph_name = strbuf_detach(&tmp_file, NULL);
1358        } else {
1359                ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1360        }
1361
1362        if (safe_create_leading_directories(ctx->graph_name)) {
1363                UNLEAK(ctx->graph_name);
1364                error(_("unable to create leading directories of %s"),
1365                        ctx->graph_name);
1366                return -1;
1367        }
1368
1369        if (ctx->split) {
1370                char *lock_name = get_chain_filename(ctx->obj_dir);
1371
1372                hold_lock_file_for_update(&lk, lock_name, LOCK_DIE_ON_ERROR);
1373
1374                fd = git_mkstemp_mode(ctx->graph_name, 0444);
1375                if (fd < 0) {
1376                        error(_("unable to create '%s'"), ctx->graph_name);
1377                        return -1;
1378                }
1379
1380                f = hashfd(fd, ctx->graph_name);
1381        } else {
1382                hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1383                fd = lk.tempfile->fd;
1384                f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1385        }
1386
1387        chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1388        chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1389        chunk_ids[2] = GRAPH_CHUNKID_DATA;
1390        if (ctx->num_extra_edges) {
1391                chunk_ids[num_chunks] = GRAPH_CHUNKID_EXTRAEDGES;
1392                num_chunks++;
1393        }
1394        if (ctx->num_commit_graphs_after > 1) {
1395                chunk_ids[num_chunks] = GRAPH_CHUNKID_BASE;
1396                num_chunks++;
1397        }
1398
1399        chunk_ids[num_chunks] = 0;
1400
1401        chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1402        chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1403        chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1404        chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1405
1406        num_chunks = 3;
1407        if (ctx->num_extra_edges) {
1408                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1409                                                4 * ctx->num_extra_edges;
1410                num_chunks++;
1411        }
1412        if (ctx->num_commit_graphs_after > 1) {
1413                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1414                                                hashsz * (ctx->num_commit_graphs_after - 1);
1415                num_chunks++;
1416        }
1417
1418        hashwrite_be32(f, GRAPH_SIGNATURE);
1419
1420        hashwrite_u8(f, GRAPH_VERSION);
1421        hashwrite_u8(f, oid_version());
1422        hashwrite_u8(f, num_chunks);
1423        hashwrite_u8(f, ctx->num_commit_graphs_after - 1);
1424
1425        for (i = 0; i <= num_chunks; i++) {
1426                uint32_t chunk_write[3];
1427
1428                chunk_write[0] = htonl(chunk_ids[i]);
1429                chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1430                chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1431                hashwrite(f, chunk_write, 12);
1432        }
1433
1434        if (ctx->report_progress) {
1435                strbuf_addf(&progress_title,
1436                            Q_("Writing out commit graph in %d pass",
1437                               "Writing out commit graph in %d passes",
1438                               num_chunks),
1439                            num_chunks);
1440                ctx->progress = start_delayed_progress(
1441                        progress_title.buf,
1442                        num_chunks * ctx->commits.nr);
1443        }
1444        write_graph_chunk_fanout(f, ctx);
1445        write_graph_chunk_oids(f, hashsz, ctx);
1446        write_graph_chunk_data(f, hashsz, ctx);
1447        if (ctx->num_extra_edges)
1448                write_graph_chunk_extra_edges(f, ctx);
1449        if (ctx->num_commit_graphs_after > 1 &&
1450            write_graph_chunk_base(f, ctx)) {
1451                return -1;
1452        }
1453        stop_progress(&ctx->progress);
1454        strbuf_release(&progress_title);
1455
1456        if (ctx->split && ctx->base_graph_name && ctx->num_commit_graphs_after > 1) {
1457                char *new_base_hash = xstrdup(oid_to_hex(&ctx->new_base_graph->oid));
1458                char *new_base_name = get_split_graph_filename(ctx->new_base_graph->obj_dir, new_base_hash);
1459
1460                free(ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2]);
1461                free(ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2]);
1462                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2] = new_base_name;
1463                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2] = new_base_hash;
1464        }
1465
1466        close_commit_graph(ctx->r->objects);
1467        finalize_hashfile(f, file_hash.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1468
1469        if (ctx->split) {
1470                FILE *chainf = fdopen_lock_file(&lk, "w");
1471                char *final_graph_name;
1472                int result;
1473
1474                close(fd);
1475
1476                if (!chainf) {
1477                        error(_("unable to open commit-graph chain file"));
1478                        return -1;
1479                }
1480
1481                if (ctx->base_graph_name) {
1482                        const char *dest = ctx->commit_graph_filenames_after[
1483                                                ctx->num_commit_graphs_after - 2];
1484
1485                        if (strcmp(ctx->base_graph_name, dest)) {
1486                                result = rename(ctx->base_graph_name, dest);
1487
1488                                if (result) {
1489                                        error(_("failed to rename base commit-graph file"));
1490                                        return -1;
1491                                }
1492                        }
1493                } else {
1494                        char *graph_name = get_commit_graph_filename(ctx->obj_dir);
1495                        unlink(graph_name);
1496                }
1497
1498                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1] = xstrdup(oid_to_hex(&file_hash));
1499                final_graph_name = get_split_graph_filename(ctx->obj_dir,
1500                                        ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1]);
1501                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 1] = final_graph_name;
1502
1503                result = rename(ctx->graph_name, final_graph_name);
1504
1505                for (i = 0; i < ctx->num_commit_graphs_after; i++)
1506                        fprintf(lk.tempfile->fp, "%s\n", ctx->commit_graph_hash_after[i]);
1507
1508                if (result) {
1509                        error(_("failed to rename temporary commit-graph file"));
1510                        return -1;
1511                }
1512        }
1513
1514        commit_lock_file(&lk);
1515
1516        return 0;
1517}
1518
1519static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
1520{
1521        struct commit_graph *g = ctx->r->objects->commit_graph;
1522        uint32_t num_commits = ctx->commits.nr;
1523        uint32_t i;
1524
1525        int max_commits = 0;
1526        int size_mult = 2;
1527
1528        if (ctx->split_opts) {
1529                max_commits = ctx->split_opts->max_commits;
1530                size_mult = ctx->split_opts->size_multiple;
1531        }
1532
1533        g = ctx->r->objects->commit_graph;
1534        ctx->num_commit_graphs_after = ctx->num_commit_graphs_before + 1;
1535
1536        while (g && (g->num_commits <= size_mult * num_commits ||
1537                    (max_commits && num_commits > max_commits))) {
1538                if (strcmp(g->obj_dir, ctx->obj_dir))
1539                        break;
1540
1541                num_commits += g->num_commits;
1542                g = g->base_graph;
1543
1544                ctx->num_commit_graphs_after--;
1545        }
1546
1547        ctx->new_base_graph = g;
1548
1549        if (ctx->num_commit_graphs_after == 2) {
1550                char *old_graph_name = get_commit_graph_filename(g->obj_dir);
1551
1552                if (!strcmp(g->filename, old_graph_name) &&
1553                    strcmp(g->obj_dir, ctx->obj_dir)) {
1554                        ctx->num_commit_graphs_after = 1;
1555                        ctx->new_base_graph = NULL;
1556                }
1557
1558                free(old_graph_name);
1559        }
1560
1561        ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
1562        ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
1563
1564        for (i = 0; i < ctx->num_commit_graphs_after &&
1565                    i < ctx->num_commit_graphs_before; i++)
1566                ctx->commit_graph_filenames_after[i] = xstrdup(ctx->commit_graph_filenames_before[i]);
1567
1568        i = ctx->num_commit_graphs_before - 1;
1569        g = ctx->r->objects->commit_graph;
1570
1571        while (g) {
1572                if (i < ctx->num_commit_graphs_after)
1573                        ctx->commit_graph_hash_after[i] = xstrdup(oid_to_hex(&g->oid));
1574
1575                i--;
1576                g = g->base_graph;
1577        }
1578}
1579
1580static void merge_commit_graph(struct write_commit_graph_context *ctx,
1581                               struct commit_graph *g)
1582{
1583        uint32_t i;
1584        uint32_t offset = g->num_commits_in_base;
1585
1586        ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
1587
1588        for (i = 0; i < g->num_commits; i++) {
1589                struct object_id oid;
1590                struct commit *result;
1591
1592                display_progress(ctx->progress, i + 1);
1593
1594                load_oid_from_graph(g, i + offset, &oid);
1595
1596                /* only add commits if they still exist in the repo */
1597                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1598
1599                if (result) {
1600                        ctx->commits.list[ctx->commits.nr] = result;
1601                        ctx->commits.nr++;
1602                }
1603        }
1604}
1605
1606static int commit_compare(const void *_a, const void *_b)
1607{
1608        const struct commit *a = *(const struct commit **)_a;
1609        const struct commit *b = *(const struct commit **)_b;
1610        return oidcmp(&a->object.oid, &b->object.oid);
1611}
1612
1613static void sort_and_scan_merged_commits(struct write_commit_graph_context *ctx)
1614{
1615        uint32_t i, num_parents;
1616        struct commit_list *parent;
1617
1618        if (ctx->report_progress)
1619                ctx->progress = start_delayed_progress(
1620                                        _("Scanning merged commits"),
1621                                        ctx->commits.nr);
1622
1623        QSORT(ctx->commits.list, ctx->commits.nr, commit_compare);
1624
1625        ctx->num_extra_edges = 0;
1626        for (i = 0; i < ctx->commits.nr; i++) {
1627                display_progress(ctx->progress, i);
1628
1629                if (i && oideq(&ctx->commits.list[i - 1]->object.oid,
1630                          &ctx->commits.list[i]->object.oid)) {
1631                        die(_("unexpected duplicate commit id %s"),
1632                            oid_to_hex(&ctx->commits.list[i]->object.oid));
1633                } else {
1634                        num_parents = 0;
1635                        for (parent = ctx->commits.list[i]->parents; parent; parent = parent->next)
1636                                num_parents++;
1637
1638                        if (num_parents > 2)
1639                                ctx->num_extra_edges += num_parents - 2;
1640                }
1641        }
1642
1643        stop_progress(&ctx->progress);
1644}
1645
1646static void merge_commit_graphs(struct write_commit_graph_context *ctx)
1647{
1648        struct commit_graph *g = ctx->r->objects->commit_graph;
1649        uint32_t current_graph_number = ctx->num_commit_graphs_before;
1650        struct strbuf progress_title = STRBUF_INIT;
1651
1652        while (g && current_graph_number >= ctx->num_commit_graphs_after) {
1653                current_graph_number--;
1654
1655                if (ctx->report_progress) {
1656                        strbuf_addstr(&progress_title, _("Merging commit-graph"));
1657                        ctx->progress = start_delayed_progress(progress_title.buf, 0);
1658                }
1659
1660                merge_commit_graph(ctx, g);
1661                stop_progress(&ctx->progress);
1662                strbuf_release(&progress_title);
1663
1664                g = g->base_graph;
1665        }
1666
1667        if (g) {
1668                ctx->new_base_graph = g;
1669                ctx->new_num_commits_in_base = g->num_commits + g->num_commits_in_base;
1670        }
1671
1672        if (ctx->new_base_graph)
1673                ctx->base_graph_name = xstrdup(ctx->new_base_graph->filename);
1674
1675        sort_and_scan_merged_commits(ctx);
1676}
1677
1678static void mark_commit_graphs(struct write_commit_graph_context *ctx)
1679{
1680        uint32_t i;
1681        time_t now = time(NULL);
1682
1683        for (i = ctx->num_commit_graphs_after - 1; i < ctx->num_commit_graphs_before; i++) {
1684                struct stat st;
1685                struct utimbuf updated_time;
1686
1687                stat(ctx->commit_graph_filenames_before[i], &st);
1688
1689                updated_time.actime = st.st_atime;
1690                updated_time.modtime = now;
1691                utime(ctx->commit_graph_filenames_before[i], &updated_time);
1692        }
1693}
1694
1695static void expire_commit_graphs(struct write_commit_graph_context *ctx)
1696{
1697        struct strbuf path = STRBUF_INIT;
1698        DIR *dir;
1699        struct dirent *de;
1700        size_t dirnamelen;
1701        timestamp_t expire_time = time(NULL);
1702
1703        if (ctx->split_opts && ctx->split_opts->expire_time)
1704                expire_time -= ctx->split_opts->expire_time;
1705        if (!ctx->split) {
1706                char *chain_file_name = get_chain_filename(ctx->obj_dir);
1707                unlink(chain_file_name);
1708                free(chain_file_name);
1709                ctx->num_commit_graphs_after = 0;
1710        }
1711
1712        strbuf_addstr(&path, ctx->obj_dir);
1713        strbuf_addstr(&path, "/info/commit-graphs");
1714        dir = opendir(path.buf);
1715
1716        if (!dir) {
1717                strbuf_release(&path);
1718                return;
1719        }
1720
1721        strbuf_addch(&path, '/');
1722        dirnamelen = path.len;
1723        while ((de = readdir(dir)) != NULL) {
1724                struct stat st;
1725                uint32_t i, found = 0;
1726
1727                strbuf_setlen(&path, dirnamelen);
1728                strbuf_addstr(&path, de->d_name);
1729
1730                stat(path.buf, &st);
1731
1732                if (st.st_mtime > expire_time)
1733                        continue;
1734                if (path.len < 6 || strcmp(path.buf + path.len - 6, ".graph"))
1735                        continue;
1736
1737                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1738                        if (!strcmp(ctx->commit_graph_filenames_after[i],
1739                                    path.buf)) {
1740                                found = 1;
1741                                break;
1742                        }
1743                }
1744
1745                if (!found)
1746                        unlink(path.buf);
1747        }
1748}
1749
1750int write_commit_graph(const char *obj_dir,
1751                       struct string_list *pack_indexes,
1752                       struct string_list *commit_hex,
1753                       unsigned int flags,
1754                       const struct split_commit_graph_opts *split_opts)
1755{
1756        struct write_commit_graph_context *ctx;
1757        uint32_t i, count_distinct = 0;
1758        size_t len;
1759        int res = 0;
1760
1761        if (!commit_graph_compatible(the_repository))
1762                return 0;
1763
1764        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1765        ctx->r = the_repository;
1766
1767        /* normalize object dir with no trailing slash */
1768        ctx->obj_dir = xmallocz(strlen(obj_dir) + 1);
1769        normalize_path_copy(ctx->obj_dir, obj_dir);
1770        len = strlen(ctx->obj_dir);
1771        if (len && ctx->obj_dir[len - 1] == '/')
1772                ctx->obj_dir[len - 1] = 0;
1773
1774        ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
1775        ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
1776        ctx->split = flags & COMMIT_GRAPH_SPLIT ? 1 : 0;
1777        ctx->split_opts = split_opts;
1778
1779        if (ctx->split) {
1780                struct commit_graph *g;
1781                prepare_commit_graph(ctx->r);
1782
1783                g = ctx->r->objects->commit_graph;
1784
1785                while (g) {
1786                        ctx->num_commit_graphs_before++;
1787                        g = g->base_graph;
1788                }
1789
1790                if (ctx->num_commit_graphs_before) {
1791                        ALLOC_ARRAY(ctx->commit_graph_filenames_before, ctx->num_commit_graphs_before);
1792                        i = ctx->num_commit_graphs_before;
1793                        g = ctx->r->objects->commit_graph;
1794
1795                        while (g) {
1796                                ctx->commit_graph_filenames_before[--i] = xstrdup(g->filename);
1797                                g = g->base_graph;
1798                        }
1799                }
1800        }
1801
1802        ctx->approx_nr_objects = approximate_object_count();
1803        ctx->oids.alloc = ctx->approx_nr_objects / 32;
1804
1805        if (ctx->split && split_opts && ctx->oids.alloc > split_opts->max_commits)
1806                ctx->oids.alloc = split_opts->max_commits;
1807
1808        if (ctx->append) {
1809                prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1810                if (ctx->r->objects->commit_graph)
1811                        ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1812        }
1813
1814        if (ctx->oids.alloc < 1024)
1815                ctx->oids.alloc = 1024;
1816        ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1817
1818        if (ctx->append && ctx->r->objects->commit_graph) {
1819                struct commit_graph *g = ctx->r->objects->commit_graph;
1820                for (i = 0; i < g->num_commits; i++) {
1821                        const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1822                        hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1823                }
1824        }
1825
1826        if (pack_indexes) {
1827                if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1828                        goto cleanup;
1829        }
1830
1831        if (commit_hex)
1832                fill_oids_from_commit_hex(ctx, commit_hex);
1833
1834        if (!pack_indexes && !commit_hex)
1835                fill_oids_from_all_packs(ctx);
1836
1837        close_reachable(ctx);
1838
1839        count_distinct = count_distinct_commits(ctx);
1840
1841        if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1842                error(_("the commit graph format cannot write %d commits"), count_distinct);
1843                res = -1;
1844                goto cleanup;
1845        }
1846
1847        ctx->commits.alloc = count_distinct;
1848        ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1849
1850        copy_oids_to_commits(ctx);
1851
1852        if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1853                error(_("too many commits to write graph"));
1854                res = -1;
1855                goto cleanup;
1856        }
1857
1858        if (!ctx->commits.nr)
1859                goto cleanup;
1860
1861        if (ctx->split) {
1862                split_graph_merge_strategy(ctx);
1863
1864                merge_commit_graphs(ctx);
1865        } else
1866                ctx->num_commit_graphs_after = 1;
1867
1868        compute_generation_numbers(ctx);
1869
1870        res = write_commit_graph_file(ctx);
1871
1872        if (ctx->split)
1873                mark_commit_graphs(ctx);
1874
1875        expire_commit_graphs(ctx);
1876
1877cleanup:
1878        free(ctx->graph_name);
1879        free(ctx->commits.list);
1880        free(ctx->oids.list);
1881        free(ctx->obj_dir);
1882
1883        if (ctx->commit_graph_filenames_after) {
1884                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1885                        free(ctx->commit_graph_filenames_after[i]);
1886                        free(ctx->commit_graph_hash_after[i]);
1887                }
1888
1889                for (i = 0; i < ctx->num_commit_graphs_before; i++)
1890                        free(ctx->commit_graph_filenames_before[i]);
1891
1892                free(ctx->commit_graph_filenames_after);
1893                free(ctx->commit_graph_filenames_before);
1894                free(ctx->commit_graph_hash_after);
1895        }
1896
1897        free(ctx);
1898
1899        return res;
1900}
1901
1902#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1903static int verify_commit_graph_error;
1904
1905static void graph_report(const char *fmt, ...)
1906{
1907        va_list ap;
1908
1909        verify_commit_graph_error = 1;
1910        va_start(ap, fmt);
1911        vfprintf(stderr, fmt, ap);
1912        fprintf(stderr, "\n");
1913        va_end(ap);
1914}
1915
1916#define GENERATION_ZERO_EXISTS 1
1917#define GENERATION_NUMBER_EXISTS 2
1918
1919int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags)
1920{
1921        uint32_t i, cur_fanout_pos = 0;
1922        struct object_id prev_oid, cur_oid, checksum;
1923        int generation_zero = 0;
1924        struct hashfile *f;
1925        int devnull;
1926        struct progress *progress = NULL;
1927        int local_error = 0;
1928
1929        if (!g) {
1930                graph_report("no commit-graph file loaded");
1931                return 1;
1932        }
1933
1934        verify_commit_graph_error = verify_commit_graph_lite(g);
1935        if (verify_commit_graph_error)
1936                return verify_commit_graph_error;
1937
1938        devnull = open("/dev/null", O_WRONLY);
1939        f = hashfd(devnull, NULL);
1940        hashwrite(f, g->data, g->data_len - g->hash_len);
1941        finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1942        if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1943                graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1944                verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1945        }
1946
1947        for (i = 0; i < g->num_commits; i++) {
1948                struct commit *graph_commit;
1949
1950                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1951
1952                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1953                        graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1954                                     oid_to_hex(&prev_oid),
1955                                     oid_to_hex(&cur_oid));
1956
1957                oidcpy(&prev_oid, &cur_oid);
1958
1959                while (cur_oid.hash[0] > cur_fanout_pos) {
1960                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1961
1962                        if (i != fanout_value)
1963                                graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1964                                             cur_fanout_pos, fanout_value, i);
1965                        cur_fanout_pos++;
1966                }
1967
1968                graph_commit = lookup_commit(r, &cur_oid);
1969                if (!parse_commit_in_graph_one(r, g, graph_commit))
1970                        graph_report(_("failed to parse commit %s from commit-graph"),
1971                                     oid_to_hex(&cur_oid));
1972        }
1973
1974        while (cur_fanout_pos < 256) {
1975                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1976
1977                if (g->num_commits != fanout_value)
1978                        graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1979                                     cur_fanout_pos, fanout_value, i);
1980
1981                cur_fanout_pos++;
1982        }
1983
1984        if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1985                return verify_commit_graph_error;
1986
1987        progress = start_progress(_("Verifying commits in commit graph"),
1988                                  g->num_commits);
1989        for (i = 0; i < g->num_commits; i++) {
1990                struct commit *graph_commit, *odb_commit;
1991                struct commit_list *graph_parents, *odb_parents;
1992                uint32_t max_generation = 0;
1993
1994                display_progress(progress, i + 1);
1995                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1996
1997                graph_commit = lookup_commit(r, &cur_oid);
1998                odb_commit = (struct commit *)create_object(r, &cur_oid, alloc_commit_node(r));
1999                if (parse_commit_internal(odb_commit, 0, 0)) {
2000                        graph_report(_("failed to parse commit %s from object database for commit-graph"),
2001                                     oid_to_hex(&cur_oid));
2002                        continue;
2003                }
2004
2005                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
2006                           get_commit_tree_oid(odb_commit)))
2007                        graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
2008                                     oid_to_hex(&cur_oid),
2009                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
2010                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
2011
2012                graph_parents = graph_commit->parents;
2013                odb_parents = odb_commit->parents;
2014
2015                while (graph_parents) {
2016                        if (odb_parents == NULL) {
2017                                graph_report(_("commit-graph parent list for commit %s is too long"),
2018                                             oid_to_hex(&cur_oid));
2019                                break;
2020                        }
2021
2022                        /* parse parent in case it is in a base graph */
2023                        parse_commit_in_graph_one(r, g, graph_parents->item);
2024
2025                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
2026                                graph_report(_("commit-graph parent for %s is %s != %s"),
2027                                             oid_to_hex(&cur_oid),
2028                                             oid_to_hex(&graph_parents->item->object.oid),
2029                                             oid_to_hex(&odb_parents->item->object.oid));
2030
2031                        if (graph_parents->item->generation > max_generation)
2032                                max_generation = graph_parents->item->generation;
2033
2034                        graph_parents = graph_parents->next;
2035                        odb_parents = odb_parents->next;
2036                }
2037
2038                if (odb_parents != NULL)
2039                        graph_report(_("commit-graph parent list for commit %s terminates early"),
2040                                     oid_to_hex(&cur_oid));
2041
2042                if (!graph_commit->generation) {
2043                        if (generation_zero == GENERATION_NUMBER_EXISTS)
2044                                graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
2045                                             oid_to_hex(&cur_oid));
2046                        generation_zero = GENERATION_ZERO_EXISTS;
2047                } else if (generation_zero == GENERATION_ZERO_EXISTS)
2048                        graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
2049                                     oid_to_hex(&cur_oid));
2050
2051                if (generation_zero == GENERATION_ZERO_EXISTS)
2052                        continue;
2053
2054                /*
2055                 * If one of our parents has generation GENERATION_NUMBER_MAX, then
2056                 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
2057                 * extra logic in the following condition.
2058                 */
2059                if (max_generation == GENERATION_NUMBER_MAX)
2060                        max_generation--;
2061
2062                if (graph_commit->generation != max_generation + 1)
2063                        graph_report(_("commit-graph generation for commit %s is %u != %u"),
2064                                     oid_to_hex(&cur_oid),
2065                                     graph_commit->generation,
2066                                     max_generation + 1);
2067
2068                if (graph_commit->date != odb_commit->date)
2069                        graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
2070                                     oid_to_hex(&cur_oid),
2071                                     graph_commit->date,
2072                                     odb_commit->date);
2073        }
2074        stop_progress(&progress);
2075
2076        local_error = verify_commit_graph_error;
2077
2078        if (!(flags & COMMIT_GRAPH_VERIFY_SHALLOW) && g->base_graph)
2079                local_error |= verify_commit_graph(r, g->base_graph, flags);
2080
2081        return local_error;
2082}
2083
2084void free_commit_graph(struct commit_graph *g)
2085{
2086        if (!g)
2087                return;
2088        if (g->graph_fd >= 0) {
2089                munmap((void *)g->data, g->data_len);
2090                g->data = NULL;
2091                close(g->graph_fd);
2092        }
2093        free(g->filename);
2094        free(g);
2095}