Andrew's git / gitweb.git / commit-graph.c
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commit-graph.con commit ci: restore running httpd tests (3960290)
   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        strbuf_release(&line);
 438
 439        return graph_chain;
 440}
 441
 442struct commit_graph *read_commit_graph_one(struct repository *r, const char *obj_dir)
 443{
 444        struct commit_graph *g = load_commit_graph_v1(r, obj_dir);
 445
 446        if (!g)
 447                g = load_commit_graph_chain(r, obj_dir);
 448
 449        return g;
 450}
 451
 452static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 453{
 454
 455        if (r->objects->commit_graph)
 456                return;
 457
 458        r->objects->commit_graph = read_commit_graph_one(r, obj_dir);
 459}
 460
 461/*
 462 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
 463 *
 464 * On the first invocation, this function attemps to load the commit
 465 * graph if the_repository is configured to have one.
 466 */
 467static int prepare_commit_graph(struct repository *r)
 468{
 469        struct object_directory *odb;
 470        int config_value;
 471
 472        if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 473                die("dying as requested by the '%s' variable on commit-graph load!",
 474                    GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
 475
 476        if (r->objects->commit_graph_attempted)
 477                return !!r->objects->commit_graph;
 478        r->objects->commit_graph_attempted = 1;
 479
 480        if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 481            (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
 482            !config_value))
 483                /*
 484                 * This repository is not configured to use commit graphs, so
 485                 * do not load one. (But report commit_graph_attempted anyway
 486                 * so that commit graph loading is not attempted again for this
 487                 * repository.)
 488                 */
 489                return 0;
 490
 491        if (!commit_graph_compatible(r))
 492                return 0;
 493
 494        prepare_alt_odb(r);
 495        for (odb = r->objects->odb;
 496             !r->objects->commit_graph && odb;
 497             odb = odb->next)
 498                prepare_commit_graph_one(r, odb->path);
 499        return !!r->objects->commit_graph;
 500}
 501
 502int generation_numbers_enabled(struct repository *r)
 503{
 504        uint32_t first_generation;
 505        struct commit_graph *g;
 506        if (!prepare_commit_graph(r))
 507               return 0;
 508
 509        g = r->objects->commit_graph;
 510
 511        if (!g->num_commits)
 512                return 0;
 513
 514        first_generation = get_be32(g->chunk_commit_data +
 515                                    g->hash_len + 8) >> 2;
 516
 517        return !!first_generation;
 518}
 519
 520static void close_commit_graph_one(struct commit_graph *g)
 521{
 522        if (!g)
 523                return;
 524
 525        close_commit_graph_one(g->base_graph);
 526        free_commit_graph(g);
 527}
 528
 529void close_commit_graph(struct raw_object_store *o)
 530{
 531        close_commit_graph_one(o->commit_graph);
 532        o->commit_graph = NULL;
 533}
 534
 535static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
 536{
 537        return bsearch_hash(oid->hash, g->chunk_oid_fanout,
 538                            g->chunk_oid_lookup, g->hash_len, pos);
 539}
 540
 541static void load_oid_from_graph(struct commit_graph *g,
 542                                uint32_t pos,
 543                                struct object_id *oid)
 544{
 545        uint32_t lex_index;
 546
 547        while (g && pos < g->num_commits_in_base)
 548                g = g->base_graph;
 549
 550        if (!g)
 551                BUG("NULL commit-graph");
 552
 553        if (pos >= g->num_commits + g->num_commits_in_base)
 554                die(_("invalid commit position. commit-graph is likely corrupt"));
 555
 556        lex_index = pos - g->num_commits_in_base;
 557
 558        hashcpy(oid->hash, g->chunk_oid_lookup + g->hash_len * lex_index);
 559}
 560
 561static struct commit_list **insert_parent_or_die(struct repository *r,
 562                                                 struct commit_graph *g,
 563                                                 uint32_t pos,
 564                                                 struct commit_list **pptr)
 565{
 566        struct commit *c;
 567        struct object_id oid;
 568
 569        if (pos >= g->num_commits + g->num_commits_in_base)
 570                die("invalid parent position %"PRIu32, pos);
 571
 572        load_oid_from_graph(g, pos, &oid);
 573        c = lookup_commit(r, &oid);
 574        if (!c)
 575                die(_("could not find commit %s"), oid_to_hex(&oid));
 576        c->graph_pos = pos;
 577        return &commit_list_insert(c, pptr)->next;
 578}
 579
 580static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
 581{
 582        const unsigned char *commit_data;
 583        uint32_t lex_index;
 584
 585        while (pos < g->num_commits_in_base)
 586                g = g->base_graph;
 587
 588        lex_index = pos - g->num_commits_in_base;
 589        commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index;
 590        item->graph_pos = pos;
 591        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 592}
 593
 594static inline void set_commit_tree(struct commit *c, struct tree *t)
 595{
 596        c->maybe_tree = t;
 597}
 598
 599static int fill_commit_in_graph(struct repository *r,
 600                                struct commit *item,
 601                                struct commit_graph *g, uint32_t pos)
 602{
 603        uint32_t edge_value;
 604        uint32_t *parent_data_ptr;
 605        uint64_t date_low, date_high;
 606        struct commit_list **pptr;
 607        const unsigned char *commit_data;
 608        uint32_t lex_index;
 609
 610        while (pos < g->num_commits_in_base)
 611                g = g->base_graph;
 612
 613        if (pos >= g->num_commits + g->num_commits_in_base)
 614                die(_("invalid commit position. commit-graph is likely corrupt"));
 615
 616        /*
 617         * Store the "full" position, but then use the
 618         * "local" position for the rest of the calculation.
 619         */
 620        item->graph_pos = pos;
 621        lex_index = pos - g->num_commits_in_base;
 622
 623        commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index;
 624
 625        item->object.parsed = 1;
 626
 627        set_commit_tree(item, NULL);
 628
 629        date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
 630        date_low = get_be32(commit_data + g->hash_len + 12);
 631        item->date = (timestamp_t)((date_high << 32) | date_low);
 632
 633        item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 634
 635        pptr = &item->parents;
 636
 637        edge_value = get_be32(commit_data + g->hash_len);
 638        if (edge_value == GRAPH_PARENT_NONE)
 639                return 1;
 640        pptr = insert_parent_or_die(r, g, edge_value, pptr);
 641
 642        edge_value = get_be32(commit_data + g->hash_len + 4);
 643        if (edge_value == GRAPH_PARENT_NONE)
 644                return 1;
 645        if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 646                pptr = insert_parent_or_die(r, g, edge_value, pptr);
 647                return 1;
 648        }
 649
 650        parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 651                          4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 652        do {
 653                edge_value = get_be32(parent_data_ptr);
 654                pptr = insert_parent_or_die(r, g,
 655                                            edge_value & GRAPH_EDGE_LAST_MASK,
 656                                            pptr);
 657                parent_data_ptr++;
 658        } while (!(edge_value & GRAPH_LAST_EDGE));
 659
 660        return 1;
 661}
 662
 663static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
 664{
 665        if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
 666                *pos = item->graph_pos;
 667                return 1;
 668        } else {
 669                struct commit_graph *cur_g = g;
 670                uint32_t lex_index;
 671
 672                while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index))
 673                        cur_g = cur_g->base_graph;
 674
 675                if (cur_g) {
 676                        *pos = lex_index + cur_g->num_commits_in_base;
 677                        return 1;
 678                }
 679
 680                return 0;
 681        }
 682}
 683
 684static int parse_commit_in_graph_one(struct repository *r,
 685                                     struct commit_graph *g,
 686                                     struct commit *item)
 687{
 688        uint32_t pos;
 689
 690        if (item->object.parsed)
 691                return 1;
 692
 693        if (find_commit_in_graph(item, g, &pos))
 694                return fill_commit_in_graph(r, item, g, pos);
 695
 696        return 0;
 697}
 698
 699int parse_commit_in_graph(struct repository *r, struct commit *item)
 700{
 701        if (!prepare_commit_graph(r))
 702                return 0;
 703        return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 704}
 705
 706void load_commit_graph_info(struct repository *r, struct commit *item)
 707{
 708        uint32_t pos;
 709        if (!prepare_commit_graph(r))
 710                return;
 711        if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
 712                fill_commit_graph_info(item, r->objects->commit_graph, pos);
 713}
 714
 715static struct tree *load_tree_for_commit(struct repository *r,
 716                                         struct commit_graph *g,
 717                                         struct commit *c)
 718{
 719        struct object_id oid;
 720        const unsigned char *commit_data;
 721
 722        while (c->graph_pos < g->num_commits_in_base)
 723                g = g->base_graph;
 724
 725        commit_data = g->chunk_commit_data +
 726                        GRAPH_DATA_WIDTH * (c->graph_pos - g->num_commits_in_base);
 727
 728        hashcpy(oid.hash, commit_data);
 729        set_commit_tree(c, lookup_tree(r, &oid));
 730
 731        return c->maybe_tree;
 732}
 733
 734static struct tree *get_commit_tree_in_graph_one(struct repository *r,
 735                                                 struct commit_graph *g,
 736                                                 const struct commit *c)
 737{
 738        if (c->maybe_tree)
 739                return c->maybe_tree;
 740        if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 741                BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 742
 743        return load_tree_for_commit(r, g, (struct commit *)c);
 744}
 745
 746struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 747{
 748        return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 749}
 750
 751struct packed_commit_list {
 752        struct commit **list;
 753        int nr;
 754        int alloc;
 755};
 756
 757struct packed_oid_list {
 758        struct object_id *list;
 759        int nr;
 760        int alloc;
 761};
 762
 763struct write_commit_graph_context {
 764        struct repository *r;
 765        char *obj_dir;
 766        char *graph_name;
 767        struct packed_oid_list oids;
 768        struct packed_commit_list commits;
 769        int num_extra_edges;
 770        unsigned long approx_nr_objects;
 771        struct progress *progress;
 772        int progress_done;
 773        uint64_t progress_cnt;
 774
 775        char *base_graph_name;
 776        int num_commit_graphs_before;
 777        int num_commit_graphs_after;
 778        char **commit_graph_filenames_before;
 779        char **commit_graph_filenames_after;
 780        char **commit_graph_hash_after;
 781        uint32_t new_num_commits_in_base;
 782        struct commit_graph *new_base_graph;
 783
 784        unsigned append:1,
 785                 report_progress:1,
 786                 split:1;
 787
 788        const struct split_commit_graph_opts *split_opts;
 789};
 790
 791static void write_graph_chunk_fanout(struct hashfile *f,
 792                                     struct write_commit_graph_context *ctx)
 793{
 794        int i, count = 0;
 795        struct commit **list = ctx->commits.list;
 796
 797        /*
 798         * Write the first-level table (the list is sorted,
 799         * but we use a 256-entry lookup to be able to avoid
 800         * having to do eight extra binary search iterations).
 801         */
 802        for (i = 0; i < 256; i++) {
 803                while (count < ctx->commits.nr) {
 804                        if ((*list)->object.oid.hash[0] != i)
 805                                break;
 806                        display_progress(ctx->progress, ++ctx->progress_cnt);
 807                        count++;
 808                        list++;
 809                }
 810
 811                hashwrite_be32(f, count);
 812        }
 813}
 814
 815static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 816                                   struct write_commit_graph_context *ctx)
 817{
 818        struct commit **list = ctx->commits.list;
 819        int count;
 820        for (count = 0; count < ctx->commits.nr; count++, list++) {
 821                display_progress(ctx->progress, ++ctx->progress_cnt);
 822                hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 823        }
 824}
 825
 826static const unsigned char *commit_to_sha1(size_t index, void *table)
 827{
 828        struct commit **commits = table;
 829        return commits[index]->object.oid.hash;
 830}
 831
 832static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 833                                   struct write_commit_graph_context *ctx)
 834{
 835        struct commit **list = ctx->commits.list;
 836        struct commit **last = ctx->commits.list + ctx->commits.nr;
 837        uint32_t num_extra_edges = 0;
 838
 839        while (list < last) {
 840                struct commit_list *parent;
 841                int edge_value;
 842                uint32_t packedDate[2];
 843                display_progress(ctx->progress, ++ctx->progress_cnt);
 844
 845                parse_commit_no_graph(*list);
 846                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 847
 848                parent = (*list)->parents;
 849
 850                if (!parent)
 851                        edge_value = GRAPH_PARENT_NONE;
 852                else {
 853                        edge_value = sha1_pos(parent->item->object.oid.hash,
 854                                              ctx->commits.list,
 855                                              ctx->commits.nr,
 856                                              commit_to_sha1);
 857
 858                        if (edge_value >= 0)
 859                                edge_value += ctx->new_num_commits_in_base;
 860                        else {
 861                                uint32_t pos;
 862                                if (find_commit_in_graph(parent->item,
 863                                                         ctx->new_base_graph,
 864                                                         &pos))
 865                                        edge_value = pos;
 866                        }
 867
 868                        if (edge_value < 0)
 869                                BUG("missing parent %s for commit %s",
 870                                    oid_to_hex(&parent->item->object.oid),
 871                                    oid_to_hex(&(*list)->object.oid));
 872                }
 873
 874                hashwrite_be32(f, edge_value);
 875
 876                if (parent)
 877                        parent = parent->next;
 878
 879                if (!parent)
 880                        edge_value = GRAPH_PARENT_NONE;
 881                else if (parent->next)
 882                        edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 883                else {
 884                        edge_value = sha1_pos(parent->item->object.oid.hash,
 885                                              ctx->commits.list,
 886                                              ctx->commits.nr,
 887                                              commit_to_sha1);
 888
 889                        if (edge_value >= 0)
 890                                edge_value += ctx->new_num_commits_in_base;
 891                        else {
 892                                uint32_t pos;
 893                                if (find_commit_in_graph(parent->item,
 894                                                         ctx->new_base_graph,
 895                                                         &pos))
 896                                        edge_value = pos;
 897                        }
 898
 899                        if (edge_value < 0)
 900                                BUG("missing parent %s for commit %s",
 901                                    oid_to_hex(&parent->item->object.oid),
 902                                    oid_to_hex(&(*list)->object.oid));
 903                }
 904
 905                hashwrite_be32(f, edge_value);
 906
 907                if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 908                        do {
 909                                num_extra_edges++;
 910                                parent = parent->next;
 911                        } while (parent);
 912                }
 913
 914                if (sizeof((*list)->date) > 4)
 915                        packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 916                else
 917                        packedDate[0] = 0;
 918
 919                packedDate[0] |= htonl((*list)->generation << 2);
 920
 921                packedDate[1] = htonl((*list)->date);
 922                hashwrite(f, packedDate, 8);
 923
 924                list++;
 925        }
 926}
 927
 928static void write_graph_chunk_extra_edges(struct hashfile *f,
 929                                          struct write_commit_graph_context *ctx)
 930{
 931        struct commit **list = ctx->commits.list;
 932        struct commit **last = ctx->commits.list + ctx->commits.nr;
 933        struct commit_list *parent;
 934
 935        while (list < last) {
 936                int num_parents = 0;
 937
 938                display_progress(ctx->progress, ++ctx->progress_cnt);
 939
 940                for (parent = (*list)->parents; num_parents < 3 && parent;
 941                     parent = parent->next)
 942                        num_parents++;
 943
 944                if (num_parents <= 2) {
 945                        list++;
 946                        continue;
 947                }
 948
 949                /* Since num_parents > 2, this initializer is safe. */
 950                for (parent = (*list)->parents->next; parent; parent = parent->next) {
 951                        int edge_value = sha1_pos(parent->item->object.oid.hash,
 952                                                  ctx->commits.list,
 953                                                  ctx->commits.nr,
 954                                                  commit_to_sha1);
 955
 956                        if (edge_value >= 0)
 957                                edge_value += ctx->new_num_commits_in_base;
 958                        else {
 959                                uint32_t pos;
 960                                if (find_commit_in_graph(parent->item,
 961                                                         ctx->new_base_graph,
 962                                                         &pos))
 963                                        edge_value = pos;
 964                        }
 965
 966                        if (edge_value < 0)
 967                                BUG("missing parent %s for commit %s",
 968                                    oid_to_hex(&parent->item->object.oid),
 969                                    oid_to_hex(&(*list)->object.oid));
 970                        else if (!parent->next)
 971                                edge_value |= GRAPH_LAST_EDGE;
 972
 973                        hashwrite_be32(f, edge_value);
 974                }
 975
 976                list++;
 977        }
 978}
 979
 980static int oid_compare(const void *_a, const void *_b)
 981{
 982        const struct object_id *a = (const struct object_id *)_a;
 983        const struct object_id *b = (const struct object_id *)_b;
 984        return oidcmp(a, b);
 985}
 986
 987static int add_packed_commits(const struct object_id *oid,
 988                              struct packed_git *pack,
 989                              uint32_t pos,
 990                              void *data)
 991{
 992        struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
 993        enum object_type type;
 994        off_t offset = nth_packed_object_offset(pack, pos);
 995        struct object_info oi = OBJECT_INFO_INIT;
 996
 997        if (ctx->progress)
 998                display_progress(ctx->progress, ++ctx->progress_done);
 999
1000        oi.typep = &type;
1001        if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
1002                die(_("unable to get type of object %s"), oid_to_hex(oid));
1003
1004        if (type != OBJ_COMMIT)
1005                return 0;
1006
1007        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1008        oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
1009        ctx->oids.nr++;
1010
1011        return 0;
1012}
1013
1014static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
1015{
1016        struct commit_list *parent;
1017        for (parent = commit->parents; parent; parent = parent->next) {
1018                if (!(parent->item->object.flags & UNINTERESTING)) {
1019                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1020                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
1021                        ctx->oids.nr++;
1022                        parent->item->object.flags |= UNINTERESTING;
1023                }
1024        }
1025}
1026
1027static void close_reachable(struct write_commit_graph_context *ctx)
1028{
1029        int i;
1030        struct commit *commit;
1031
1032        if (ctx->report_progress)
1033                ctx->progress = start_delayed_progress(
1034                                        _("Loading known commits in commit graph"),
1035                                        ctx->oids.nr);
1036        for (i = 0; i < ctx->oids.nr; i++) {
1037                display_progress(ctx->progress, i + 1);
1038                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1039                if (commit)
1040                        commit->object.flags |= UNINTERESTING;
1041        }
1042        stop_progress(&ctx->progress);
1043
1044        /*
1045         * As this loop runs, ctx->oids.nr may grow, but not more
1046         * than the number of missing commits in the reachable
1047         * closure.
1048         */
1049        if (ctx->report_progress)
1050                ctx->progress = start_delayed_progress(
1051                                        _("Expanding reachable commits in commit graph"),
1052                                        ctx->oids.nr);
1053        for (i = 0; i < ctx->oids.nr; i++) {
1054                display_progress(ctx->progress, i + 1);
1055                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1056
1057                if (!commit)
1058                        continue;
1059                if (ctx->split) {
1060                        if (!parse_commit(commit) &&
1061                            commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
1062                                add_missing_parents(ctx, commit);
1063                } else if (!parse_commit_no_graph(commit))
1064                        add_missing_parents(ctx, commit);
1065        }
1066        stop_progress(&ctx->progress);
1067
1068        if (ctx->report_progress)
1069                ctx->progress = start_delayed_progress(
1070                                        _("Clearing commit marks in commit graph"),
1071                                        ctx->oids.nr);
1072        for (i = 0; i < ctx->oids.nr; i++) {
1073                display_progress(ctx->progress, i + 1);
1074                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1075
1076                if (commit)
1077                        commit->object.flags &= ~UNINTERESTING;
1078        }
1079        stop_progress(&ctx->progress);
1080}
1081
1082static void compute_generation_numbers(struct write_commit_graph_context *ctx)
1083{
1084        int i;
1085        struct commit_list *list = NULL;
1086
1087        if (ctx->report_progress)
1088                ctx->progress = start_progress(
1089                                        _("Computing commit graph generation numbers"),
1090                                        ctx->commits.nr);
1091        for (i = 0; i < ctx->commits.nr; i++) {
1092                display_progress(ctx->progress, i + 1);
1093                if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
1094                    ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
1095                        continue;
1096
1097                commit_list_insert(ctx->commits.list[i], &list);
1098                while (list) {
1099                        struct commit *current = list->item;
1100                        struct commit_list *parent;
1101                        int all_parents_computed = 1;
1102                        uint32_t max_generation = 0;
1103
1104                        for (parent = current->parents; parent; parent = parent->next) {
1105                                if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
1106                                    parent->item->generation == GENERATION_NUMBER_ZERO) {
1107                                        all_parents_computed = 0;
1108                                        commit_list_insert(parent->item, &list);
1109                                        break;
1110                                } else if (parent->item->generation > max_generation) {
1111                                        max_generation = parent->item->generation;
1112                                }
1113                        }
1114
1115                        if (all_parents_computed) {
1116                                current->generation = max_generation + 1;
1117                                pop_commit(&list);
1118
1119                                if (current->generation > GENERATION_NUMBER_MAX)
1120                                        current->generation = GENERATION_NUMBER_MAX;
1121                        }
1122                }
1123        }
1124        stop_progress(&ctx->progress);
1125}
1126
1127static int add_ref_to_list(const char *refname,
1128                           const struct object_id *oid,
1129                           int flags, void *cb_data)
1130{
1131        struct string_list *list = (struct string_list *)cb_data;
1132
1133        string_list_append(list, oid_to_hex(oid));
1134        return 0;
1135}
1136
1137int write_commit_graph_reachable(const char *obj_dir, unsigned int flags,
1138                                 const struct split_commit_graph_opts *split_opts)
1139{
1140        struct string_list list = STRING_LIST_INIT_DUP;
1141        int result;
1142
1143        for_each_ref(add_ref_to_list, &list);
1144        result = write_commit_graph(obj_dir, NULL, &list,
1145                                    flags, split_opts);
1146
1147        string_list_clear(&list, 0);
1148        return result;
1149}
1150
1151static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
1152                                struct string_list *pack_indexes)
1153{
1154        uint32_t i;
1155        struct strbuf progress_title = STRBUF_INIT;
1156        struct strbuf packname = STRBUF_INIT;
1157        int dirlen;
1158
1159        strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
1160        dirlen = packname.len;
1161        if (ctx->report_progress) {
1162                strbuf_addf(&progress_title,
1163                            Q_("Finding commits for commit graph in %d pack",
1164                               "Finding commits for commit graph in %d packs",
1165                               pack_indexes->nr),
1166                            pack_indexes->nr);
1167                ctx->progress = start_delayed_progress(progress_title.buf, 0);
1168                ctx->progress_done = 0;
1169        }
1170        for (i = 0; i < pack_indexes->nr; i++) {
1171                struct packed_git *p;
1172                strbuf_setlen(&packname, dirlen);
1173                strbuf_addstr(&packname, pack_indexes->items[i].string);
1174                p = add_packed_git(packname.buf, packname.len, 1);
1175                if (!p) {
1176                        error(_("error adding pack %s"), packname.buf);
1177                        return -1;
1178                }
1179                if (open_pack_index(p)) {
1180                        error(_("error opening index for %s"), packname.buf);
1181                        return -1;
1182                }
1183                for_each_object_in_pack(p, add_packed_commits, ctx,
1184                                        FOR_EACH_OBJECT_PACK_ORDER);
1185                close_pack(p);
1186                free(p);
1187        }
1188
1189        stop_progress(&ctx->progress);
1190        strbuf_release(&progress_title);
1191        strbuf_release(&packname);
1192
1193        return 0;
1194}
1195
1196static void fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
1197                                      struct string_list *commit_hex)
1198{
1199        uint32_t i;
1200        struct strbuf progress_title = STRBUF_INIT;
1201
1202        if (ctx->report_progress) {
1203                strbuf_addf(&progress_title,
1204                            Q_("Finding commits for commit graph from %d ref",
1205                               "Finding commits for commit graph from %d refs",
1206                               commit_hex->nr),
1207                            commit_hex->nr);
1208                ctx->progress = start_delayed_progress(
1209                                        progress_title.buf,
1210                                        commit_hex->nr);
1211        }
1212        for (i = 0; i < commit_hex->nr; i++) {
1213                const char *end;
1214                struct object_id oid;
1215                struct commit *result;
1216
1217                display_progress(ctx->progress, i + 1);
1218                if (commit_hex->items[i].string &&
1219                    parse_oid_hex(commit_hex->items[i].string, &oid, &end))
1220                        continue;
1221
1222                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1223
1224                if (result) {
1225                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1226                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
1227                        ctx->oids.nr++;
1228                }
1229        }
1230        stop_progress(&ctx->progress);
1231        strbuf_release(&progress_title);
1232}
1233
1234static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
1235{
1236        if (ctx->report_progress)
1237                ctx->progress = start_delayed_progress(
1238                        _("Finding commits for commit graph among packed objects"),
1239                        ctx->approx_nr_objects);
1240        for_each_packed_object(add_packed_commits, ctx,
1241                               FOR_EACH_OBJECT_PACK_ORDER);
1242        if (ctx->progress_done < ctx->approx_nr_objects)
1243                display_progress(ctx->progress, ctx->approx_nr_objects);
1244        stop_progress(&ctx->progress);
1245}
1246
1247static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
1248{
1249        uint32_t i, count_distinct = 1;
1250
1251        if (ctx->report_progress)
1252                ctx->progress = start_delayed_progress(
1253                        _("Counting distinct commits in commit graph"),
1254                        ctx->oids.nr);
1255        display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
1256        QSORT(ctx->oids.list, ctx->oids.nr, oid_compare);
1257
1258        for (i = 1; i < ctx->oids.nr; i++) {
1259                display_progress(ctx->progress, i + 1);
1260                if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i])) {
1261                        if (ctx->split) {
1262                                struct commit *c = lookup_commit(ctx->r, &ctx->oids.list[i]);
1263
1264                                if (!c || c->graph_pos != COMMIT_NOT_FROM_GRAPH)
1265                                        continue;
1266                        }
1267
1268                        count_distinct++;
1269                }
1270        }
1271        stop_progress(&ctx->progress);
1272
1273        return count_distinct;
1274}
1275
1276static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
1277{
1278        uint32_t i;
1279        struct commit_list *parent;
1280
1281        ctx->num_extra_edges = 0;
1282        if (ctx->report_progress)
1283                ctx->progress = start_delayed_progress(
1284                        _("Finding extra edges in commit graph"),
1285                        ctx->oids.nr);
1286        for (i = 0; i < ctx->oids.nr; i++) {
1287                int num_parents = 0;
1288                display_progress(ctx->progress, i + 1);
1289                if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1290                        continue;
1291
1292                ALLOC_GROW(ctx->commits.list, ctx->commits.nr + 1, ctx->commits.alloc);
1293                ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1294
1295                if (ctx->split &&
1296                    ctx->commits.list[ctx->commits.nr]->graph_pos != COMMIT_NOT_FROM_GRAPH)
1297                        continue;
1298
1299                parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1300
1301                for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1302                     parent; parent = parent->next)
1303                        num_parents++;
1304
1305                if (num_parents > 2)
1306                        ctx->num_extra_edges += num_parents - 1;
1307
1308                ctx->commits.nr++;
1309        }
1310        stop_progress(&ctx->progress);
1311}
1312
1313static int write_graph_chunk_base_1(struct hashfile *f,
1314                                    struct commit_graph *g)
1315{
1316        int num = 0;
1317
1318        if (!g)
1319                return 0;
1320
1321        num = write_graph_chunk_base_1(f, g->base_graph);
1322        hashwrite(f, g->oid.hash, the_hash_algo->rawsz);
1323        return num + 1;
1324}
1325
1326static int write_graph_chunk_base(struct hashfile *f,
1327                                  struct write_commit_graph_context *ctx)
1328{
1329        int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
1330
1331        if (num != ctx->num_commit_graphs_after - 1) {
1332                error(_("failed to write correct number of base graph ids"));
1333                return -1;
1334        }
1335
1336        return 0;
1337}
1338
1339static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1340{
1341        uint32_t i;
1342        int fd;
1343        struct hashfile *f;
1344        struct lock_file lk = LOCK_INIT;
1345        uint32_t chunk_ids[6];
1346        uint64_t chunk_offsets[6];
1347        const unsigned hashsz = the_hash_algo->rawsz;
1348        struct strbuf progress_title = STRBUF_INIT;
1349        int num_chunks = 3;
1350        struct object_id file_hash;
1351
1352        if (ctx->split) {
1353                struct strbuf tmp_file = STRBUF_INIT;
1354
1355                strbuf_addf(&tmp_file,
1356                            "%s/info/commit-graphs/tmp_graph_XXXXXX",
1357                            ctx->obj_dir);
1358                ctx->graph_name = strbuf_detach(&tmp_file, NULL);
1359        } else {
1360                ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1361        }
1362
1363        if (safe_create_leading_directories(ctx->graph_name)) {
1364                UNLEAK(ctx->graph_name);
1365                error(_("unable to create leading directories of %s"),
1366                        ctx->graph_name);
1367                return -1;
1368        }
1369
1370        if (ctx->split) {
1371                char *lock_name = get_chain_filename(ctx->obj_dir);
1372
1373                hold_lock_file_for_update(&lk, lock_name, LOCK_DIE_ON_ERROR);
1374
1375                fd = git_mkstemp_mode(ctx->graph_name, 0444);
1376                if (fd < 0) {
1377                        error(_("unable to create '%s'"), ctx->graph_name);
1378                        return -1;
1379                }
1380
1381                f = hashfd(fd, ctx->graph_name);
1382        } else {
1383                hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1384                fd = lk.tempfile->fd;
1385                f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1386        }
1387
1388        chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1389        chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1390        chunk_ids[2] = GRAPH_CHUNKID_DATA;
1391        if (ctx->num_extra_edges) {
1392                chunk_ids[num_chunks] = GRAPH_CHUNKID_EXTRAEDGES;
1393                num_chunks++;
1394        }
1395        if (ctx->num_commit_graphs_after > 1) {
1396                chunk_ids[num_chunks] = GRAPH_CHUNKID_BASE;
1397                num_chunks++;
1398        }
1399
1400        chunk_ids[num_chunks] = 0;
1401
1402        chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1403        chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1404        chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1405        chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1406
1407        num_chunks = 3;
1408        if (ctx->num_extra_edges) {
1409                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1410                                                4 * ctx->num_extra_edges;
1411                num_chunks++;
1412        }
1413        if (ctx->num_commit_graphs_after > 1) {
1414                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1415                                                hashsz * (ctx->num_commit_graphs_after - 1);
1416                num_chunks++;
1417        }
1418
1419        hashwrite_be32(f, GRAPH_SIGNATURE);
1420
1421        hashwrite_u8(f, GRAPH_VERSION);
1422        hashwrite_u8(f, oid_version());
1423        hashwrite_u8(f, num_chunks);
1424        hashwrite_u8(f, ctx->num_commit_graphs_after - 1);
1425
1426        for (i = 0; i <= num_chunks; i++) {
1427                uint32_t chunk_write[3];
1428
1429                chunk_write[0] = htonl(chunk_ids[i]);
1430                chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1431                chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1432                hashwrite(f, chunk_write, 12);
1433        }
1434
1435        if (ctx->report_progress) {
1436                strbuf_addf(&progress_title,
1437                            Q_("Writing out commit graph in %d pass",
1438                               "Writing out commit graph in %d passes",
1439                               num_chunks),
1440                            num_chunks);
1441                ctx->progress = start_delayed_progress(
1442                        progress_title.buf,
1443                        num_chunks * ctx->commits.nr);
1444        }
1445        write_graph_chunk_fanout(f, ctx);
1446        write_graph_chunk_oids(f, hashsz, ctx);
1447        write_graph_chunk_data(f, hashsz, ctx);
1448        if (ctx->num_extra_edges)
1449                write_graph_chunk_extra_edges(f, ctx);
1450        if (ctx->num_commit_graphs_after > 1 &&
1451            write_graph_chunk_base(f, ctx)) {
1452                return -1;
1453        }
1454        stop_progress(&ctx->progress);
1455        strbuf_release(&progress_title);
1456
1457        if (ctx->split && ctx->base_graph_name && ctx->num_commit_graphs_after > 1) {
1458                char *new_base_hash = xstrdup(oid_to_hex(&ctx->new_base_graph->oid));
1459                char *new_base_name = get_split_graph_filename(ctx->new_base_graph->obj_dir, new_base_hash);
1460
1461                free(ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2]);
1462                free(ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2]);
1463                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2] = new_base_name;
1464                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2] = new_base_hash;
1465        }
1466
1467        close_commit_graph(ctx->r->objects);
1468        finalize_hashfile(f, file_hash.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1469
1470        if (ctx->split) {
1471                FILE *chainf = fdopen_lock_file(&lk, "w");
1472                char *final_graph_name;
1473                int result;
1474
1475                close(fd);
1476
1477                if (!chainf) {
1478                        error(_("unable to open commit-graph chain file"));
1479                        return -1;
1480                }
1481
1482                if (ctx->base_graph_name) {
1483                        const char *dest = ctx->commit_graph_filenames_after[
1484                                                ctx->num_commit_graphs_after - 2];
1485
1486                        if (strcmp(ctx->base_graph_name, dest)) {
1487                                result = rename(ctx->base_graph_name, dest);
1488
1489                                if (result) {
1490                                        error(_("failed to rename base commit-graph file"));
1491                                        return -1;
1492                                }
1493                        }
1494                } else {
1495                        char *graph_name = get_commit_graph_filename(ctx->obj_dir);
1496                        unlink(graph_name);
1497                }
1498
1499                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1] = xstrdup(oid_to_hex(&file_hash));
1500                final_graph_name = get_split_graph_filename(ctx->obj_dir,
1501                                        ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1]);
1502                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 1] = final_graph_name;
1503
1504                result = rename(ctx->graph_name, final_graph_name);
1505
1506                for (i = 0; i < ctx->num_commit_graphs_after; i++)
1507                        fprintf(lk.tempfile->fp, "%s\n", ctx->commit_graph_hash_after[i]);
1508
1509                if (result) {
1510                        error(_("failed to rename temporary commit-graph file"));
1511                        return -1;
1512                }
1513        }
1514
1515        commit_lock_file(&lk);
1516
1517        return 0;
1518}
1519
1520static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
1521{
1522        struct commit_graph *g = ctx->r->objects->commit_graph;
1523        uint32_t num_commits = ctx->commits.nr;
1524        uint32_t i;
1525
1526        int max_commits = 0;
1527        int size_mult = 2;
1528
1529        if (ctx->split_opts) {
1530                max_commits = ctx->split_opts->max_commits;
1531                size_mult = ctx->split_opts->size_multiple;
1532        }
1533
1534        g = ctx->r->objects->commit_graph;
1535        ctx->num_commit_graphs_after = ctx->num_commit_graphs_before + 1;
1536
1537        while (g && (g->num_commits <= size_mult * num_commits ||
1538                    (max_commits && num_commits > max_commits))) {
1539                if (strcmp(g->obj_dir, ctx->obj_dir))
1540                        break;
1541
1542                num_commits += g->num_commits;
1543                g = g->base_graph;
1544
1545                ctx->num_commit_graphs_after--;
1546        }
1547
1548        ctx->new_base_graph = g;
1549
1550        if (ctx->num_commit_graphs_after == 2) {
1551                char *old_graph_name = get_commit_graph_filename(g->obj_dir);
1552
1553                if (!strcmp(g->filename, old_graph_name) &&
1554                    strcmp(g->obj_dir, ctx->obj_dir)) {
1555                        ctx->num_commit_graphs_after = 1;
1556                        ctx->new_base_graph = NULL;
1557                }
1558
1559                free(old_graph_name);
1560        }
1561
1562        ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
1563        ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
1564
1565        for (i = 0; i < ctx->num_commit_graphs_after &&
1566                    i < ctx->num_commit_graphs_before; i++)
1567                ctx->commit_graph_filenames_after[i] = xstrdup(ctx->commit_graph_filenames_before[i]);
1568
1569        i = ctx->num_commit_graphs_before - 1;
1570        g = ctx->r->objects->commit_graph;
1571
1572        while (g) {
1573                if (i < ctx->num_commit_graphs_after)
1574                        ctx->commit_graph_hash_after[i] = xstrdup(oid_to_hex(&g->oid));
1575
1576                i--;
1577                g = g->base_graph;
1578        }
1579}
1580
1581static void merge_commit_graph(struct write_commit_graph_context *ctx,
1582                               struct commit_graph *g)
1583{
1584        uint32_t i;
1585        uint32_t offset = g->num_commits_in_base;
1586
1587        ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
1588
1589        for (i = 0; i < g->num_commits; i++) {
1590                struct object_id oid;
1591                struct commit *result;
1592
1593                display_progress(ctx->progress, i + 1);
1594
1595                load_oid_from_graph(g, i + offset, &oid);
1596
1597                /* only add commits if they still exist in the repo */
1598                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1599
1600                if (result) {
1601                        ctx->commits.list[ctx->commits.nr] = result;
1602                        ctx->commits.nr++;
1603                }
1604        }
1605}
1606
1607static int commit_compare(const void *_a, const void *_b)
1608{
1609        const struct commit *a = *(const struct commit **)_a;
1610        const struct commit *b = *(const struct commit **)_b;
1611        return oidcmp(&a->object.oid, &b->object.oid);
1612}
1613
1614static void sort_and_scan_merged_commits(struct write_commit_graph_context *ctx)
1615{
1616        uint32_t i, num_parents;
1617        struct commit_list *parent;
1618
1619        if (ctx->report_progress)
1620                ctx->progress = start_delayed_progress(
1621                                        _("Scanning merged commits"),
1622                                        ctx->commits.nr);
1623
1624        QSORT(ctx->commits.list, ctx->commits.nr, commit_compare);
1625
1626        ctx->num_extra_edges = 0;
1627        for (i = 0; i < ctx->commits.nr; i++) {
1628                display_progress(ctx->progress, i);
1629
1630                if (i && oideq(&ctx->commits.list[i - 1]->object.oid,
1631                          &ctx->commits.list[i]->object.oid)) {
1632                        die(_("unexpected duplicate commit id %s"),
1633                            oid_to_hex(&ctx->commits.list[i]->object.oid));
1634                } else {
1635                        num_parents = 0;
1636                        for (parent = ctx->commits.list[i]->parents; parent; parent = parent->next)
1637                                num_parents++;
1638
1639                        if (num_parents > 2)
1640                                ctx->num_extra_edges += num_parents - 1;
1641                }
1642        }
1643
1644        stop_progress(&ctx->progress);
1645}
1646
1647static void merge_commit_graphs(struct write_commit_graph_context *ctx)
1648{
1649        struct commit_graph *g = ctx->r->objects->commit_graph;
1650        uint32_t current_graph_number = ctx->num_commit_graphs_before;
1651        struct strbuf progress_title = STRBUF_INIT;
1652
1653        while (g && current_graph_number >= ctx->num_commit_graphs_after) {
1654                current_graph_number--;
1655
1656                if (ctx->report_progress) {
1657                        strbuf_addstr(&progress_title, _("Merging commit-graph"));
1658                        ctx->progress = start_delayed_progress(progress_title.buf, 0);
1659                }
1660
1661                merge_commit_graph(ctx, g);
1662                stop_progress(&ctx->progress);
1663                strbuf_release(&progress_title);
1664
1665                g = g->base_graph;
1666        }
1667
1668        if (g) {
1669                ctx->new_base_graph = g;
1670                ctx->new_num_commits_in_base = g->num_commits + g->num_commits_in_base;
1671        }
1672
1673        if (ctx->new_base_graph)
1674                ctx->base_graph_name = xstrdup(ctx->new_base_graph->filename);
1675
1676        sort_and_scan_merged_commits(ctx);
1677}
1678
1679static void mark_commit_graphs(struct write_commit_graph_context *ctx)
1680{
1681        uint32_t i;
1682        time_t now = time(NULL);
1683
1684        for (i = ctx->num_commit_graphs_after - 1; i < ctx->num_commit_graphs_before; i++) {
1685                struct stat st;
1686                struct utimbuf updated_time;
1687
1688                stat(ctx->commit_graph_filenames_before[i], &st);
1689
1690                updated_time.actime = st.st_atime;
1691                updated_time.modtime = now;
1692                utime(ctx->commit_graph_filenames_before[i], &updated_time);
1693        }
1694}
1695
1696static void expire_commit_graphs(struct write_commit_graph_context *ctx)
1697{
1698        struct strbuf path = STRBUF_INIT;
1699        DIR *dir;
1700        struct dirent *de;
1701        size_t dirnamelen;
1702        timestamp_t expire_time = time(NULL);
1703
1704        if (ctx->split_opts && ctx->split_opts->expire_time)
1705                expire_time -= ctx->split_opts->expire_time;
1706        if (!ctx->split) {
1707                char *chain_file_name = get_chain_filename(ctx->obj_dir);
1708                unlink(chain_file_name);
1709                free(chain_file_name);
1710                ctx->num_commit_graphs_after = 0;
1711        }
1712
1713        strbuf_addstr(&path, ctx->obj_dir);
1714        strbuf_addstr(&path, "/info/commit-graphs");
1715        dir = opendir(path.buf);
1716
1717        if (!dir)
1718                goto out;
1719
1720        strbuf_addch(&path, '/');
1721        dirnamelen = path.len;
1722        while ((de = readdir(dir)) != NULL) {
1723                struct stat st;
1724                uint32_t i, found = 0;
1725
1726                strbuf_setlen(&path, dirnamelen);
1727                strbuf_addstr(&path, de->d_name);
1728
1729                stat(path.buf, &st);
1730
1731                if (st.st_mtime > expire_time)
1732                        continue;
1733                if (path.len < 6 || strcmp(path.buf + path.len - 6, ".graph"))
1734                        continue;
1735
1736                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1737                        if (!strcmp(ctx->commit_graph_filenames_after[i],
1738                                    path.buf)) {
1739                                found = 1;
1740                                break;
1741                        }
1742                }
1743
1744                if (!found)
1745                        unlink(path.buf);
1746        }
1747
1748out:
1749        strbuf_release(&path);
1750}
1751
1752int write_commit_graph(const char *obj_dir,
1753                       struct string_list *pack_indexes,
1754                       struct string_list *commit_hex,
1755                       unsigned int flags,
1756                       const struct split_commit_graph_opts *split_opts)
1757{
1758        struct write_commit_graph_context *ctx;
1759        uint32_t i, count_distinct = 0;
1760        size_t len;
1761        int res = 0;
1762
1763        if (!commit_graph_compatible(the_repository))
1764                return 0;
1765
1766        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1767        ctx->r = the_repository;
1768
1769        /* normalize object dir with no trailing slash */
1770        ctx->obj_dir = xmallocz(strlen(obj_dir) + 1);
1771        normalize_path_copy(ctx->obj_dir, obj_dir);
1772        len = strlen(ctx->obj_dir);
1773        if (len && ctx->obj_dir[len - 1] == '/')
1774                ctx->obj_dir[len - 1] = 0;
1775
1776        ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
1777        ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
1778        ctx->split = flags & COMMIT_GRAPH_SPLIT ? 1 : 0;
1779        ctx->split_opts = split_opts;
1780
1781        if (ctx->split) {
1782                struct commit_graph *g;
1783                prepare_commit_graph(ctx->r);
1784
1785                g = ctx->r->objects->commit_graph;
1786
1787                while (g) {
1788                        ctx->num_commit_graphs_before++;
1789                        g = g->base_graph;
1790                }
1791
1792                if (ctx->num_commit_graphs_before) {
1793                        ALLOC_ARRAY(ctx->commit_graph_filenames_before, ctx->num_commit_graphs_before);
1794                        i = ctx->num_commit_graphs_before;
1795                        g = ctx->r->objects->commit_graph;
1796
1797                        while (g) {
1798                                ctx->commit_graph_filenames_before[--i] = xstrdup(g->filename);
1799                                g = g->base_graph;
1800                        }
1801                }
1802        }
1803
1804        ctx->approx_nr_objects = approximate_object_count();
1805        ctx->oids.alloc = ctx->approx_nr_objects / 32;
1806
1807        if (ctx->split && split_opts && ctx->oids.alloc > split_opts->max_commits)
1808                ctx->oids.alloc = split_opts->max_commits;
1809
1810        if (ctx->append) {
1811                prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1812                if (ctx->r->objects->commit_graph)
1813                        ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1814        }
1815
1816        if (ctx->oids.alloc < 1024)
1817                ctx->oids.alloc = 1024;
1818        ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1819
1820        if (ctx->append && ctx->r->objects->commit_graph) {
1821                struct commit_graph *g = ctx->r->objects->commit_graph;
1822                for (i = 0; i < g->num_commits; i++) {
1823                        const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1824                        hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1825                }
1826        }
1827
1828        if (pack_indexes) {
1829                if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1830                        goto cleanup;
1831        }
1832
1833        if (commit_hex)
1834                fill_oids_from_commit_hex(ctx, commit_hex);
1835
1836        if (!pack_indexes && !commit_hex)
1837                fill_oids_from_all_packs(ctx);
1838
1839        close_reachable(ctx);
1840
1841        count_distinct = count_distinct_commits(ctx);
1842
1843        if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1844                error(_("the commit graph format cannot write %d commits"), count_distinct);
1845                res = -1;
1846                goto cleanup;
1847        }
1848
1849        ctx->commits.alloc = count_distinct;
1850        ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1851
1852        copy_oids_to_commits(ctx);
1853
1854        if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1855                error(_("too many commits to write graph"));
1856                res = -1;
1857                goto cleanup;
1858        }
1859
1860        if (!ctx->commits.nr)
1861                goto cleanup;
1862
1863        if (ctx->split) {
1864                split_graph_merge_strategy(ctx);
1865
1866                merge_commit_graphs(ctx);
1867        } else
1868                ctx->num_commit_graphs_after = 1;
1869
1870        compute_generation_numbers(ctx);
1871
1872        res = write_commit_graph_file(ctx);
1873
1874        if (ctx->split)
1875                mark_commit_graphs(ctx);
1876
1877        expire_commit_graphs(ctx);
1878
1879cleanup:
1880        free(ctx->graph_name);
1881        free(ctx->commits.list);
1882        free(ctx->oids.list);
1883        free(ctx->obj_dir);
1884
1885        if (ctx->commit_graph_filenames_after) {
1886                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1887                        free(ctx->commit_graph_filenames_after[i]);
1888                        free(ctx->commit_graph_hash_after[i]);
1889                }
1890
1891                for (i = 0; i < ctx->num_commit_graphs_before; i++)
1892                        free(ctx->commit_graph_filenames_before[i]);
1893
1894                free(ctx->commit_graph_filenames_after);
1895                free(ctx->commit_graph_filenames_before);
1896                free(ctx->commit_graph_hash_after);
1897        }
1898
1899        free(ctx);
1900
1901        return res;
1902}
1903
1904#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1905static int verify_commit_graph_error;
1906
1907static void graph_report(const char *fmt, ...)
1908{
1909        va_list ap;
1910
1911        verify_commit_graph_error = 1;
1912        va_start(ap, fmt);
1913        vfprintf(stderr, fmt, ap);
1914        fprintf(stderr, "\n");
1915        va_end(ap);
1916}
1917
1918#define GENERATION_ZERO_EXISTS 1
1919#define GENERATION_NUMBER_EXISTS 2
1920
1921int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags)
1922{
1923        uint32_t i, cur_fanout_pos = 0;
1924        struct object_id prev_oid, cur_oid, checksum;
1925        int generation_zero = 0;
1926        struct hashfile *f;
1927        int devnull;
1928        struct progress *progress = NULL;
1929        int local_error = 0;
1930
1931        if (!g) {
1932                graph_report("no commit-graph file loaded");
1933                return 1;
1934        }
1935
1936        verify_commit_graph_error = verify_commit_graph_lite(g);
1937        if (verify_commit_graph_error)
1938                return verify_commit_graph_error;
1939
1940        devnull = open("/dev/null", O_WRONLY);
1941        f = hashfd(devnull, NULL);
1942        hashwrite(f, g->data, g->data_len - g->hash_len);
1943        finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1944        if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1945                graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1946                verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1947        }
1948
1949        for (i = 0; i < g->num_commits; i++) {
1950                struct commit *graph_commit;
1951
1952                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1953
1954                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1955                        graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1956                                     oid_to_hex(&prev_oid),
1957                                     oid_to_hex(&cur_oid));
1958
1959                oidcpy(&prev_oid, &cur_oid);
1960
1961                while (cur_oid.hash[0] > cur_fanout_pos) {
1962                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1963
1964                        if (i != fanout_value)
1965                                graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1966                                             cur_fanout_pos, fanout_value, i);
1967                        cur_fanout_pos++;
1968                }
1969
1970                graph_commit = lookup_commit(r, &cur_oid);
1971                if (!parse_commit_in_graph_one(r, g, graph_commit))
1972                        graph_report(_("failed to parse commit %s from commit-graph"),
1973                                     oid_to_hex(&cur_oid));
1974        }
1975
1976        while (cur_fanout_pos < 256) {
1977                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1978
1979                if (g->num_commits != fanout_value)
1980                        graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1981                                     cur_fanout_pos, fanout_value, i);
1982
1983                cur_fanout_pos++;
1984        }
1985
1986        if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1987                return verify_commit_graph_error;
1988
1989        progress = start_progress(_("Verifying commits in commit graph"),
1990                                  g->num_commits);
1991        for (i = 0; i < g->num_commits; i++) {
1992                struct commit *graph_commit, *odb_commit;
1993                struct commit_list *graph_parents, *odb_parents;
1994                uint32_t max_generation = 0;
1995
1996                display_progress(progress, i + 1);
1997                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1998
1999                graph_commit = lookup_commit(r, &cur_oid);
2000                odb_commit = (struct commit *)create_object(r, &cur_oid, alloc_commit_node(r));
2001                if (parse_commit_internal(odb_commit, 0, 0)) {
2002                        graph_report(_("failed to parse commit %s from object database for commit-graph"),
2003                                     oid_to_hex(&cur_oid));
2004                        continue;
2005                }
2006
2007                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
2008                           get_commit_tree_oid(odb_commit)))
2009                        graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
2010                                     oid_to_hex(&cur_oid),
2011                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
2012                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
2013
2014                graph_parents = graph_commit->parents;
2015                odb_parents = odb_commit->parents;
2016
2017                while (graph_parents) {
2018                        if (odb_parents == NULL) {
2019                                graph_report(_("commit-graph parent list for commit %s is too long"),
2020                                             oid_to_hex(&cur_oid));
2021                                break;
2022                        }
2023
2024                        /* parse parent in case it is in a base graph */
2025                        parse_commit_in_graph_one(r, g, graph_parents->item);
2026
2027                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
2028                                graph_report(_("commit-graph parent for %s is %s != %s"),
2029                                             oid_to_hex(&cur_oid),
2030                                             oid_to_hex(&graph_parents->item->object.oid),
2031                                             oid_to_hex(&odb_parents->item->object.oid));
2032
2033                        if (graph_parents->item->generation > max_generation)
2034                                max_generation = graph_parents->item->generation;
2035
2036                        graph_parents = graph_parents->next;
2037                        odb_parents = odb_parents->next;
2038                }
2039
2040                if (odb_parents != NULL)
2041                        graph_report(_("commit-graph parent list for commit %s terminates early"),
2042                                     oid_to_hex(&cur_oid));
2043
2044                if (!graph_commit->generation) {
2045                        if (generation_zero == GENERATION_NUMBER_EXISTS)
2046                                graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
2047                                             oid_to_hex(&cur_oid));
2048                        generation_zero = GENERATION_ZERO_EXISTS;
2049                } else if (generation_zero == GENERATION_ZERO_EXISTS)
2050                        graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
2051                                     oid_to_hex(&cur_oid));
2052
2053                if (generation_zero == GENERATION_ZERO_EXISTS)
2054                        continue;
2055
2056                /*
2057                 * If one of our parents has generation GENERATION_NUMBER_MAX, then
2058                 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
2059                 * extra logic in the following condition.
2060                 */
2061                if (max_generation == GENERATION_NUMBER_MAX)
2062                        max_generation--;
2063
2064                if (graph_commit->generation != max_generation + 1)
2065                        graph_report(_("commit-graph generation for commit %s is %u != %u"),
2066                                     oid_to_hex(&cur_oid),
2067                                     graph_commit->generation,
2068                                     max_generation + 1);
2069
2070                if (graph_commit->date != odb_commit->date)
2071                        graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
2072                                     oid_to_hex(&cur_oid),
2073                                     graph_commit->date,
2074                                     odb_commit->date);
2075        }
2076        stop_progress(&progress);
2077
2078        local_error = verify_commit_graph_error;
2079
2080        if (!(flags & COMMIT_GRAPH_VERIFY_SHALLOW) && g->base_graph)
2081                local_error |= verify_commit_graph(r, g->base_graph, flags);
2082
2083        return local_error;
2084}
2085
2086void free_commit_graph(struct commit_graph *g)
2087{
2088        if (!g)
2089                return;
2090        if (g->graph_fd >= 0) {
2091                munmap((void *)g->data, g->data_len);
2092                g->data = NULL;
2093                close(g->graph_fd);
2094        }
2095        free(g->filename);
2096        free(g);
2097}