Andrew's git / gitweb.git / commit-graph.c
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commit-graph.con commit general UI improvements (05293f9)
   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
 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        prepare_repo_settings(r);
 480
 481        if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
 482            r->settings.core_commit_graph != 1)
 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                 check_oids:1;
 788
 789        const struct split_commit_graph_opts *split_opts;
 790};
 791
 792static void write_graph_chunk_fanout(struct hashfile *f,
 793                                     struct write_commit_graph_context *ctx)
 794{
 795        int i, count = 0;
 796        struct commit **list = ctx->commits.list;
 797
 798        /*
 799         * Write the first-level table (the list is sorted,
 800         * but we use a 256-entry lookup to be able to avoid
 801         * having to do eight extra binary search iterations).
 802         */
 803        for (i = 0; i < 256; i++) {
 804                while (count < ctx->commits.nr) {
 805                        if ((*list)->object.oid.hash[0] != i)
 806                                break;
 807                        display_progress(ctx->progress, ++ctx->progress_cnt);
 808                        count++;
 809                        list++;
 810                }
 811
 812                hashwrite_be32(f, count);
 813        }
 814}
 815
 816static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
 817                                   struct write_commit_graph_context *ctx)
 818{
 819        struct commit **list = ctx->commits.list;
 820        int count;
 821        for (count = 0; count < ctx->commits.nr; count++, list++) {
 822                display_progress(ctx->progress, ++ctx->progress_cnt);
 823                hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
 824        }
 825}
 826
 827static const unsigned char *commit_to_sha1(size_t index, void *table)
 828{
 829        struct commit **commits = table;
 830        return commits[index]->object.oid.hash;
 831}
 832
 833static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 834                                   struct write_commit_graph_context *ctx)
 835{
 836        struct commit **list = ctx->commits.list;
 837        struct commit **last = ctx->commits.list + ctx->commits.nr;
 838        uint32_t num_extra_edges = 0;
 839
 840        while (list < last) {
 841                struct commit_list *parent;
 842                int edge_value;
 843                uint32_t packedDate[2];
 844                display_progress(ctx->progress, ++ctx->progress_cnt);
 845
 846                parse_commit_no_graph(*list);
 847                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 848
 849                parent = (*list)->parents;
 850
 851                if (!parent)
 852                        edge_value = GRAPH_PARENT_NONE;
 853                else {
 854                        edge_value = sha1_pos(parent->item->object.oid.hash,
 855                                              ctx->commits.list,
 856                                              ctx->commits.nr,
 857                                              commit_to_sha1);
 858
 859                        if (edge_value >= 0)
 860                                edge_value += ctx->new_num_commits_in_base;
 861                        else {
 862                                uint32_t pos;
 863                                if (find_commit_in_graph(parent->item,
 864                                                         ctx->new_base_graph,
 865                                                         &pos))
 866                                        edge_value = pos;
 867                        }
 868
 869                        if (edge_value < 0)
 870                                BUG("missing parent %s for commit %s",
 871                                    oid_to_hex(&parent->item->object.oid),
 872                                    oid_to_hex(&(*list)->object.oid));
 873                }
 874
 875                hashwrite_be32(f, edge_value);
 876
 877                if (parent)
 878                        parent = parent->next;
 879
 880                if (!parent)
 881                        edge_value = GRAPH_PARENT_NONE;
 882                else if (parent->next)
 883                        edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 884                else {
 885                        edge_value = sha1_pos(parent->item->object.oid.hash,
 886                                              ctx->commits.list,
 887                                              ctx->commits.nr,
 888                                              commit_to_sha1);
 889
 890                        if (edge_value >= 0)
 891                                edge_value += ctx->new_num_commits_in_base;
 892                        else {
 893                                uint32_t pos;
 894                                if (find_commit_in_graph(parent->item,
 895                                                         ctx->new_base_graph,
 896                                                         &pos))
 897                                        edge_value = pos;
 898                        }
 899
 900                        if (edge_value < 0)
 901                                BUG("missing parent %s for commit %s",
 902                                    oid_to_hex(&parent->item->object.oid),
 903                                    oid_to_hex(&(*list)->object.oid));
 904                }
 905
 906                hashwrite_be32(f, edge_value);
 907
 908                if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 909                        do {
 910                                num_extra_edges++;
 911                                parent = parent->next;
 912                        } while (parent);
 913                }
 914
 915                if (sizeof((*list)->date) > 4)
 916                        packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
 917                else
 918                        packedDate[0] = 0;
 919
 920                packedDate[0] |= htonl((*list)->generation << 2);
 921
 922                packedDate[1] = htonl((*list)->date);
 923                hashwrite(f, packedDate, 8);
 924
 925                list++;
 926        }
 927}
 928
 929static void write_graph_chunk_extra_edges(struct hashfile *f,
 930                                          struct write_commit_graph_context *ctx)
 931{
 932        struct commit **list = ctx->commits.list;
 933        struct commit **last = ctx->commits.list + ctx->commits.nr;
 934        struct commit_list *parent;
 935
 936        while (list < last) {
 937                int num_parents = 0;
 938
 939                display_progress(ctx->progress, ++ctx->progress_cnt);
 940
 941                for (parent = (*list)->parents; num_parents < 3 && parent;
 942                     parent = parent->next)
 943                        num_parents++;
 944
 945                if (num_parents <= 2) {
 946                        list++;
 947                        continue;
 948                }
 949
 950                /* Since num_parents > 2, this initializer is safe. */
 951                for (parent = (*list)->parents->next; parent; parent = parent->next) {
 952                        int edge_value = sha1_pos(parent->item->object.oid.hash,
 953                                                  ctx->commits.list,
 954                                                  ctx->commits.nr,
 955                                                  commit_to_sha1);
 956
 957                        if (edge_value >= 0)
 958                                edge_value += ctx->new_num_commits_in_base;
 959                        else {
 960                                uint32_t pos;
 961                                if (find_commit_in_graph(parent->item,
 962                                                         ctx->new_base_graph,
 963                                                         &pos))
 964                                        edge_value = pos;
 965                        }
 966
 967                        if (edge_value < 0)
 968                                BUG("missing parent %s for commit %s",
 969                                    oid_to_hex(&parent->item->object.oid),
 970                                    oid_to_hex(&(*list)->object.oid));
 971                        else if (!parent->next)
 972                                edge_value |= GRAPH_LAST_EDGE;
 973
 974                        hashwrite_be32(f, edge_value);
 975                }
 976
 977                list++;
 978        }
 979}
 980
 981static int oid_compare(const void *_a, const void *_b)
 982{
 983        const struct object_id *a = (const struct object_id *)_a;
 984        const struct object_id *b = (const struct object_id *)_b;
 985        return oidcmp(a, b);
 986}
 987
 988static int add_packed_commits(const struct object_id *oid,
 989                              struct packed_git *pack,
 990                              uint32_t pos,
 991                              void *data)
 992{
 993        struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
 994        enum object_type type;
 995        off_t offset = nth_packed_object_offset(pack, pos);
 996        struct object_info oi = OBJECT_INFO_INIT;
 997
 998        if (ctx->progress)
 999                display_progress(ctx->progress, ++ctx->progress_done);
1000
1001        oi.typep = &type;
1002        if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
1003                die(_("unable to get type of object %s"), oid_to_hex(oid));
1004
1005        if (type != OBJ_COMMIT)
1006                return 0;
1007
1008        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1009        oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
1010        ctx->oids.nr++;
1011
1012        return 0;
1013}
1014
1015static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
1016{
1017        struct commit_list *parent;
1018        for (parent = commit->parents; parent; parent = parent->next) {
1019                if (!(parent->item->object.flags & UNINTERESTING)) {
1020                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1021                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
1022                        ctx->oids.nr++;
1023                        parent->item->object.flags |= UNINTERESTING;
1024                }
1025        }
1026}
1027
1028static void close_reachable(struct write_commit_graph_context *ctx)
1029{
1030        int i;
1031        struct commit *commit;
1032
1033        if (ctx->report_progress)
1034                ctx->progress = start_delayed_progress(
1035                                        _("Loading known commits in commit graph"),
1036                                        ctx->oids.nr);
1037        for (i = 0; i < ctx->oids.nr; i++) {
1038                display_progress(ctx->progress, i + 1);
1039                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1040                if (commit)
1041                        commit->object.flags |= UNINTERESTING;
1042        }
1043        stop_progress(&ctx->progress);
1044
1045        /*
1046         * As this loop runs, ctx->oids.nr may grow, but not more
1047         * than the number of missing commits in the reachable
1048         * closure.
1049         */
1050        if (ctx->report_progress)
1051                ctx->progress = start_delayed_progress(
1052                                        _("Expanding reachable commits in commit graph"),
1053                                        ctx->oids.nr);
1054        for (i = 0; i < ctx->oids.nr; i++) {
1055                display_progress(ctx->progress, i + 1);
1056                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1057
1058                if (!commit)
1059                        continue;
1060                if (ctx->split) {
1061                        if (!parse_commit(commit) &&
1062                            commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
1063                                add_missing_parents(ctx, commit);
1064                } else if (!parse_commit_no_graph(commit))
1065                        add_missing_parents(ctx, commit);
1066        }
1067        stop_progress(&ctx->progress);
1068
1069        if (ctx->report_progress)
1070                ctx->progress = start_delayed_progress(
1071                                        _("Clearing commit marks in commit graph"),
1072                                        ctx->oids.nr);
1073        for (i = 0; i < ctx->oids.nr; i++) {
1074                display_progress(ctx->progress, i + 1);
1075                commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1076
1077                if (commit)
1078                        commit->object.flags &= ~UNINTERESTING;
1079        }
1080        stop_progress(&ctx->progress);
1081}
1082
1083static void compute_generation_numbers(struct write_commit_graph_context *ctx)
1084{
1085        int i;
1086        struct commit_list *list = NULL;
1087
1088        if (ctx->report_progress)
1089                ctx->progress = start_progress(
1090                                        _("Computing commit graph generation numbers"),
1091                                        ctx->commits.nr);
1092        for (i = 0; i < ctx->commits.nr; i++) {
1093                display_progress(ctx->progress, i + 1);
1094                if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
1095                    ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
1096                        continue;
1097
1098                commit_list_insert(ctx->commits.list[i], &list);
1099                while (list) {
1100                        struct commit *current = list->item;
1101                        struct commit_list *parent;
1102                        int all_parents_computed = 1;
1103                        uint32_t max_generation = 0;
1104
1105                        for (parent = current->parents; parent; parent = parent->next) {
1106                                if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
1107                                    parent->item->generation == GENERATION_NUMBER_ZERO) {
1108                                        all_parents_computed = 0;
1109                                        commit_list_insert(parent->item, &list);
1110                                        break;
1111                                } else if (parent->item->generation > max_generation) {
1112                                        max_generation = parent->item->generation;
1113                                }
1114                        }
1115
1116                        if (all_parents_computed) {
1117                                current->generation = max_generation + 1;
1118                                pop_commit(&list);
1119
1120                                if (current->generation > GENERATION_NUMBER_MAX)
1121                                        current->generation = GENERATION_NUMBER_MAX;
1122                        }
1123                }
1124        }
1125        stop_progress(&ctx->progress);
1126}
1127
1128static int add_ref_to_list(const char *refname,
1129                           const struct object_id *oid,
1130                           int flags, void *cb_data)
1131{
1132        struct string_list *list = (struct string_list *)cb_data;
1133
1134        string_list_append(list, oid_to_hex(oid));
1135        return 0;
1136}
1137
1138int write_commit_graph_reachable(const char *obj_dir,
1139                                 enum commit_graph_write_flags flags,
1140                                 const struct split_commit_graph_opts *split_opts)
1141{
1142        struct string_list list = STRING_LIST_INIT_DUP;
1143        int result;
1144
1145        for_each_ref(add_ref_to_list, &list);
1146        result = write_commit_graph(obj_dir, NULL, &list,
1147                                    flags, split_opts);
1148
1149        string_list_clear(&list, 0);
1150        return result;
1151}
1152
1153static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
1154                                struct string_list *pack_indexes)
1155{
1156        uint32_t i;
1157        struct strbuf progress_title = STRBUF_INIT;
1158        struct strbuf packname = STRBUF_INIT;
1159        int dirlen;
1160
1161        strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
1162        dirlen = packname.len;
1163        if (ctx->report_progress) {
1164                strbuf_addf(&progress_title,
1165                            Q_("Finding commits for commit graph in %d pack",
1166                               "Finding commits for commit graph in %d packs",
1167                               pack_indexes->nr),
1168                            pack_indexes->nr);
1169                ctx->progress = start_delayed_progress(progress_title.buf, 0);
1170                ctx->progress_done = 0;
1171        }
1172        for (i = 0; i < pack_indexes->nr; i++) {
1173                struct packed_git *p;
1174                strbuf_setlen(&packname, dirlen);
1175                strbuf_addstr(&packname, pack_indexes->items[i].string);
1176                p = add_packed_git(packname.buf, packname.len, 1);
1177                if (!p) {
1178                        error(_("error adding pack %s"), packname.buf);
1179                        return -1;
1180                }
1181                if (open_pack_index(p)) {
1182                        error(_("error opening index for %s"), packname.buf);
1183                        return -1;
1184                }
1185                for_each_object_in_pack(p, add_packed_commits, ctx,
1186                                        FOR_EACH_OBJECT_PACK_ORDER);
1187                close_pack(p);
1188                free(p);
1189        }
1190
1191        stop_progress(&ctx->progress);
1192        strbuf_release(&progress_title);
1193        strbuf_release(&packname);
1194
1195        return 0;
1196}
1197
1198static int fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
1199                                     struct string_list *commit_hex)
1200{
1201        uint32_t i;
1202        struct strbuf progress_title = STRBUF_INIT;
1203
1204        if (ctx->report_progress) {
1205                strbuf_addf(&progress_title,
1206                            Q_("Finding commits for commit graph from %d ref",
1207                               "Finding commits for commit graph from %d refs",
1208                               commit_hex->nr),
1209                            commit_hex->nr);
1210                ctx->progress = start_delayed_progress(
1211                                        progress_title.buf,
1212                                        commit_hex->nr);
1213        }
1214        for (i = 0; i < commit_hex->nr; i++) {
1215                const char *end;
1216                struct object_id oid;
1217                struct commit *result;
1218
1219                display_progress(ctx->progress, i + 1);
1220                if (!parse_oid_hex(commit_hex->items[i].string, &oid, &end) &&
1221                    (result = lookup_commit_reference_gently(ctx->r, &oid, 1))) {
1222                        ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1223                        oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
1224                        ctx->oids.nr++;
1225                } else if (ctx->check_oids) {
1226                        error(_("invalid commit object id: %s"),
1227                            commit_hex->items[i].string);
1228                        return -1;
1229                }
1230        }
1231        stop_progress(&ctx->progress);
1232        strbuf_release(&progress_title);
1233
1234        return 0;
1235}
1236
1237static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
1238{
1239        if (ctx->report_progress)
1240                ctx->progress = start_delayed_progress(
1241                        _("Finding commits for commit graph among packed objects"),
1242                        ctx->approx_nr_objects);
1243        for_each_packed_object(add_packed_commits, ctx,
1244                               FOR_EACH_OBJECT_PACK_ORDER);
1245        if (ctx->progress_done < ctx->approx_nr_objects)
1246                display_progress(ctx->progress, ctx->approx_nr_objects);
1247        stop_progress(&ctx->progress);
1248}
1249
1250static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
1251{
1252        uint32_t i, count_distinct = 1;
1253
1254        if (ctx->report_progress)
1255                ctx->progress = start_delayed_progress(
1256                        _("Counting distinct commits in commit graph"),
1257                        ctx->oids.nr);
1258        display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
1259        QSORT(ctx->oids.list, ctx->oids.nr, oid_compare);
1260
1261        for (i = 1; i < ctx->oids.nr; i++) {
1262                display_progress(ctx->progress, i + 1);
1263                if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i])) {
1264                        if (ctx->split) {
1265                                struct commit *c = lookup_commit(ctx->r, &ctx->oids.list[i]);
1266
1267                                if (!c || c->graph_pos != COMMIT_NOT_FROM_GRAPH)
1268                                        continue;
1269                        }
1270
1271                        count_distinct++;
1272                }
1273        }
1274        stop_progress(&ctx->progress);
1275
1276        return count_distinct;
1277}
1278
1279static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
1280{
1281        uint32_t i;
1282        struct commit_list *parent;
1283
1284        ctx->num_extra_edges = 0;
1285        if (ctx->report_progress)
1286                ctx->progress = start_delayed_progress(
1287                        _("Finding extra edges in commit graph"),
1288                        ctx->oids.nr);
1289        for (i = 0; i < ctx->oids.nr; i++) {
1290                int num_parents = 0;
1291                display_progress(ctx->progress, i + 1);
1292                if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1293                        continue;
1294
1295                ALLOC_GROW(ctx->commits.list, ctx->commits.nr + 1, ctx->commits.alloc);
1296                ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1297
1298                if (ctx->split &&
1299                    ctx->commits.list[ctx->commits.nr]->graph_pos != COMMIT_NOT_FROM_GRAPH)
1300                        continue;
1301
1302                parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1303
1304                for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1305                     parent; parent = parent->next)
1306                        num_parents++;
1307
1308                if (num_parents > 2)
1309                        ctx->num_extra_edges += num_parents - 1;
1310
1311                ctx->commits.nr++;
1312        }
1313        stop_progress(&ctx->progress);
1314}
1315
1316static int write_graph_chunk_base_1(struct hashfile *f,
1317                                    struct commit_graph *g)
1318{
1319        int num = 0;
1320
1321        if (!g)
1322                return 0;
1323
1324        num = write_graph_chunk_base_1(f, g->base_graph);
1325        hashwrite(f, g->oid.hash, the_hash_algo->rawsz);
1326        return num + 1;
1327}
1328
1329static int write_graph_chunk_base(struct hashfile *f,
1330                                  struct write_commit_graph_context *ctx)
1331{
1332        int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
1333
1334        if (num != ctx->num_commit_graphs_after - 1) {
1335                error(_("failed to write correct number of base graph ids"));
1336                return -1;
1337        }
1338
1339        return 0;
1340}
1341
1342static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1343{
1344        uint32_t i;
1345        int fd;
1346        struct hashfile *f;
1347        struct lock_file lk = LOCK_INIT;
1348        uint32_t chunk_ids[6];
1349        uint64_t chunk_offsets[6];
1350        const unsigned hashsz = the_hash_algo->rawsz;
1351        struct strbuf progress_title = STRBUF_INIT;
1352        int num_chunks = 3;
1353        struct object_id file_hash;
1354
1355        if (ctx->split) {
1356                struct strbuf tmp_file = STRBUF_INIT;
1357
1358                strbuf_addf(&tmp_file,
1359                            "%s/info/commit-graphs/tmp_graph_XXXXXX",
1360                            ctx->obj_dir);
1361                ctx->graph_name = strbuf_detach(&tmp_file, NULL);
1362        } else {
1363                ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1364        }
1365
1366        if (safe_create_leading_directories(ctx->graph_name)) {
1367                UNLEAK(ctx->graph_name);
1368                error(_("unable to create leading directories of %s"),
1369                        ctx->graph_name);
1370                return -1;
1371        }
1372
1373        if (ctx->split) {
1374                char *lock_name = get_chain_filename(ctx->obj_dir);
1375
1376                hold_lock_file_for_update(&lk, lock_name, LOCK_DIE_ON_ERROR);
1377
1378                fd = git_mkstemp_mode(ctx->graph_name, 0444);
1379                if (fd < 0) {
1380                        error(_("unable to create '%s'"), ctx->graph_name);
1381                        return -1;
1382                }
1383
1384                f = hashfd(fd, ctx->graph_name);
1385        } else {
1386                hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1387                fd = lk.tempfile->fd;
1388                f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1389        }
1390
1391        chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1392        chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1393        chunk_ids[2] = GRAPH_CHUNKID_DATA;
1394        if (ctx->num_extra_edges) {
1395                chunk_ids[num_chunks] = GRAPH_CHUNKID_EXTRAEDGES;
1396                num_chunks++;
1397        }
1398        if (ctx->num_commit_graphs_after > 1) {
1399                chunk_ids[num_chunks] = GRAPH_CHUNKID_BASE;
1400                num_chunks++;
1401        }
1402
1403        chunk_ids[num_chunks] = 0;
1404
1405        chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1406        chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1407        chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1408        chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1409
1410        num_chunks = 3;
1411        if (ctx->num_extra_edges) {
1412                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1413                                                4 * ctx->num_extra_edges;
1414                num_chunks++;
1415        }
1416        if (ctx->num_commit_graphs_after > 1) {
1417                chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1418                                                hashsz * (ctx->num_commit_graphs_after - 1);
1419                num_chunks++;
1420        }
1421
1422        hashwrite_be32(f, GRAPH_SIGNATURE);
1423
1424        hashwrite_u8(f, GRAPH_VERSION);
1425        hashwrite_u8(f, oid_version());
1426        hashwrite_u8(f, num_chunks);
1427        hashwrite_u8(f, ctx->num_commit_graphs_after - 1);
1428
1429        for (i = 0; i <= num_chunks; i++) {
1430                uint32_t chunk_write[3];
1431
1432                chunk_write[0] = htonl(chunk_ids[i]);
1433                chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1434                chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1435                hashwrite(f, chunk_write, 12);
1436        }
1437
1438        if (ctx->report_progress) {
1439                strbuf_addf(&progress_title,
1440                            Q_("Writing out commit graph in %d pass",
1441                               "Writing out commit graph in %d passes",
1442                               num_chunks),
1443                            num_chunks);
1444                ctx->progress = start_delayed_progress(
1445                        progress_title.buf,
1446                        num_chunks * ctx->commits.nr);
1447        }
1448        write_graph_chunk_fanout(f, ctx);
1449        write_graph_chunk_oids(f, hashsz, ctx);
1450        write_graph_chunk_data(f, hashsz, ctx);
1451        if (ctx->num_extra_edges)
1452                write_graph_chunk_extra_edges(f, ctx);
1453        if (ctx->num_commit_graphs_after > 1 &&
1454            write_graph_chunk_base(f, ctx)) {
1455                return -1;
1456        }
1457        stop_progress(&ctx->progress);
1458        strbuf_release(&progress_title);
1459
1460        if (ctx->split && ctx->base_graph_name && ctx->num_commit_graphs_after > 1) {
1461                char *new_base_hash = xstrdup(oid_to_hex(&ctx->new_base_graph->oid));
1462                char *new_base_name = get_split_graph_filename(ctx->new_base_graph->obj_dir, new_base_hash);
1463
1464                free(ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2]);
1465                free(ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2]);
1466                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2] = new_base_name;
1467                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2] = new_base_hash;
1468        }
1469
1470        close_commit_graph(ctx->r->objects);
1471        finalize_hashfile(f, file_hash.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1472
1473        if (ctx->split) {
1474                FILE *chainf = fdopen_lock_file(&lk, "w");
1475                char *final_graph_name;
1476                int result;
1477
1478                close(fd);
1479
1480                if (!chainf) {
1481                        error(_("unable to open commit-graph chain file"));
1482                        return -1;
1483                }
1484
1485                if (ctx->base_graph_name) {
1486                        const char *dest = ctx->commit_graph_filenames_after[
1487                                                ctx->num_commit_graphs_after - 2];
1488
1489                        if (strcmp(ctx->base_graph_name, dest)) {
1490                                result = rename(ctx->base_graph_name, dest);
1491
1492                                if (result) {
1493                                        error(_("failed to rename base commit-graph file"));
1494                                        return -1;
1495                                }
1496                        }
1497                } else {
1498                        char *graph_name = get_commit_graph_filename(ctx->obj_dir);
1499                        unlink(graph_name);
1500                }
1501
1502                ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1] = xstrdup(oid_to_hex(&file_hash));
1503                final_graph_name = get_split_graph_filename(ctx->obj_dir,
1504                                        ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1]);
1505                ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 1] = final_graph_name;
1506
1507                result = rename(ctx->graph_name, final_graph_name);
1508
1509                for (i = 0; i < ctx->num_commit_graphs_after; i++)
1510                        fprintf(lk.tempfile->fp, "%s\n", ctx->commit_graph_hash_after[i]);
1511
1512                if (result) {
1513                        error(_("failed to rename temporary commit-graph file"));
1514                        return -1;
1515                }
1516        }
1517
1518        commit_lock_file(&lk);
1519
1520        return 0;
1521}
1522
1523static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
1524{
1525        struct commit_graph *g = ctx->r->objects->commit_graph;
1526        uint32_t num_commits = ctx->commits.nr;
1527        uint32_t i;
1528
1529        int max_commits = 0;
1530        int size_mult = 2;
1531
1532        if (ctx->split_opts) {
1533                max_commits = ctx->split_opts->max_commits;
1534                size_mult = ctx->split_opts->size_multiple;
1535        }
1536
1537        g = ctx->r->objects->commit_graph;
1538        ctx->num_commit_graphs_after = ctx->num_commit_graphs_before + 1;
1539
1540        while (g && (g->num_commits <= size_mult * num_commits ||
1541                    (max_commits && num_commits > max_commits))) {
1542                if (strcmp(g->obj_dir, ctx->obj_dir))
1543                        break;
1544
1545                num_commits += g->num_commits;
1546                g = g->base_graph;
1547
1548                ctx->num_commit_graphs_after--;
1549        }
1550
1551        ctx->new_base_graph = g;
1552
1553        if (ctx->num_commit_graphs_after == 2) {
1554                char *old_graph_name = get_commit_graph_filename(g->obj_dir);
1555
1556                if (!strcmp(g->filename, old_graph_name) &&
1557                    strcmp(g->obj_dir, ctx->obj_dir)) {
1558                        ctx->num_commit_graphs_after = 1;
1559                        ctx->new_base_graph = NULL;
1560                }
1561
1562                free(old_graph_name);
1563        }
1564
1565        ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
1566        ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
1567
1568        for (i = 0; i < ctx->num_commit_graphs_after &&
1569                    i < ctx->num_commit_graphs_before; i++)
1570                ctx->commit_graph_filenames_after[i] = xstrdup(ctx->commit_graph_filenames_before[i]);
1571
1572        i = ctx->num_commit_graphs_before - 1;
1573        g = ctx->r->objects->commit_graph;
1574
1575        while (g) {
1576                if (i < ctx->num_commit_graphs_after)
1577                        ctx->commit_graph_hash_after[i] = xstrdup(oid_to_hex(&g->oid));
1578
1579                i--;
1580                g = g->base_graph;
1581        }
1582}
1583
1584static void merge_commit_graph(struct write_commit_graph_context *ctx,
1585                               struct commit_graph *g)
1586{
1587        uint32_t i;
1588        uint32_t offset = g->num_commits_in_base;
1589
1590        ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
1591
1592        for (i = 0; i < g->num_commits; i++) {
1593                struct object_id oid;
1594                struct commit *result;
1595
1596                display_progress(ctx->progress, i + 1);
1597
1598                load_oid_from_graph(g, i + offset, &oid);
1599
1600                /* only add commits if they still exist in the repo */
1601                result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1602
1603                if (result) {
1604                        ctx->commits.list[ctx->commits.nr] = result;
1605                        ctx->commits.nr++;
1606                }
1607        }
1608}
1609
1610static int commit_compare(const void *_a, const void *_b)
1611{
1612        const struct commit *a = *(const struct commit **)_a;
1613        const struct commit *b = *(const struct commit **)_b;
1614        return oidcmp(&a->object.oid, &b->object.oid);
1615}
1616
1617static void sort_and_scan_merged_commits(struct write_commit_graph_context *ctx)
1618{
1619        uint32_t i, num_parents;
1620        struct commit_list *parent;
1621
1622        if (ctx->report_progress)
1623                ctx->progress = start_delayed_progress(
1624                                        _("Scanning merged commits"),
1625                                        ctx->commits.nr);
1626
1627        QSORT(ctx->commits.list, ctx->commits.nr, commit_compare);
1628
1629        ctx->num_extra_edges = 0;
1630        for (i = 0; i < ctx->commits.nr; i++) {
1631                display_progress(ctx->progress, i);
1632
1633                if (i && oideq(&ctx->commits.list[i - 1]->object.oid,
1634                          &ctx->commits.list[i]->object.oid)) {
1635                        die(_("unexpected duplicate commit id %s"),
1636                            oid_to_hex(&ctx->commits.list[i]->object.oid));
1637                } else {
1638                        num_parents = 0;
1639                        for (parent = ctx->commits.list[i]->parents; parent; parent = parent->next)
1640                                num_parents++;
1641
1642                        if (num_parents > 2)
1643                                ctx->num_extra_edges += num_parents - 1;
1644                }
1645        }
1646
1647        stop_progress(&ctx->progress);
1648}
1649
1650static void merge_commit_graphs(struct write_commit_graph_context *ctx)
1651{
1652        struct commit_graph *g = ctx->r->objects->commit_graph;
1653        uint32_t current_graph_number = ctx->num_commit_graphs_before;
1654        struct strbuf progress_title = STRBUF_INIT;
1655
1656        while (g && current_graph_number >= ctx->num_commit_graphs_after) {
1657                current_graph_number--;
1658
1659                if (ctx->report_progress) {
1660                        strbuf_addstr(&progress_title, _("Merging commit-graph"));
1661                        ctx->progress = start_delayed_progress(progress_title.buf, 0);
1662                }
1663
1664                merge_commit_graph(ctx, g);
1665                stop_progress(&ctx->progress);
1666                strbuf_release(&progress_title);
1667
1668                g = g->base_graph;
1669        }
1670
1671        if (g) {
1672                ctx->new_base_graph = g;
1673                ctx->new_num_commits_in_base = g->num_commits + g->num_commits_in_base;
1674        }
1675
1676        if (ctx->new_base_graph)
1677                ctx->base_graph_name = xstrdup(ctx->new_base_graph->filename);
1678
1679        sort_and_scan_merged_commits(ctx);
1680}
1681
1682static void mark_commit_graphs(struct write_commit_graph_context *ctx)
1683{
1684        uint32_t i;
1685        time_t now = time(NULL);
1686
1687        for (i = ctx->num_commit_graphs_after - 1; i < ctx->num_commit_graphs_before; i++) {
1688                struct stat st;
1689                struct utimbuf updated_time;
1690
1691                stat(ctx->commit_graph_filenames_before[i], &st);
1692
1693                updated_time.actime = st.st_atime;
1694                updated_time.modtime = now;
1695                utime(ctx->commit_graph_filenames_before[i], &updated_time);
1696        }
1697}
1698
1699static void expire_commit_graphs(struct write_commit_graph_context *ctx)
1700{
1701        struct strbuf path = STRBUF_INIT;
1702        DIR *dir;
1703        struct dirent *de;
1704        size_t dirnamelen;
1705        timestamp_t expire_time = time(NULL);
1706
1707        if (ctx->split_opts && ctx->split_opts->expire_time)
1708                expire_time -= ctx->split_opts->expire_time;
1709        if (!ctx->split) {
1710                char *chain_file_name = get_chain_filename(ctx->obj_dir);
1711                unlink(chain_file_name);
1712                free(chain_file_name);
1713                ctx->num_commit_graphs_after = 0;
1714        }
1715
1716        strbuf_addstr(&path, ctx->obj_dir);
1717        strbuf_addstr(&path, "/info/commit-graphs");
1718        dir = opendir(path.buf);
1719
1720        if (!dir)
1721                goto out;
1722
1723        strbuf_addch(&path, '/');
1724        dirnamelen = path.len;
1725        while ((de = readdir(dir)) != NULL) {
1726                struct stat st;
1727                uint32_t i, found = 0;
1728
1729                strbuf_setlen(&path, dirnamelen);
1730                strbuf_addstr(&path, de->d_name);
1731
1732                stat(path.buf, &st);
1733
1734                if (st.st_mtime > expire_time)
1735                        continue;
1736                if (path.len < 6 || strcmp(path.buf + path.len - 6, ".graph"))
1737                        continue;
1738
1739                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1740                        if (!strcmp(ctx->commit_graph_filenames_after[i],
1741                                    path.buf)) {
1742                                found = 1;
1743                                break;
1744                        }
1745                }
1746
1747                if (!found)
1748                        unlink(path.buf);
1749        }
1750
1751out:
1752        strbuf_release(&path);
1753}
1754
1755int write_commit_graph(const char *obj_dir,
1756                       struct string_list *pack_indexes,
1757                       struct string_list *commit_hex,
1758                       enum commit_graph_write_flags flags,
1759                       const struct split_commit_graph_opts *split_opts)
1760{
1761        struct write_commit_graph_context *ctx;
1762        uint32_t i, count_distinct = 0;
1763        size_t len;
1764        int res = 0;
1765
1766        if (!commit_graph_compatible(the_repository))
1767                return 0;
1768
1769        ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1770        ctx->r = the_repository;
1771
1772        /* normalize object dir with no trailing slash */
1773        ctx->obj_dir = xmallocz(strlen(obj_dir) + 1);
1774        normalize_path_copy(ctx->obj_dir, obj_dir);
1775        len = strlen(ctx->obj_dir);
1776        if (len && ctx->obj_dir[len - 1] == '/')
1777                ctx->obj_dir[len - 1] = 0;
1778
1779        ctx->append = flags & COMMIT_GRAPH_WRITE_APPEND ? 1 : 0;
1780        ctx->report_progress = flags & COMMIT_GRAPH_WRITE_PROGRESS ? 1 : 0;
1781        ctx->split = flags & COMMIT_GRAPH_WRITE_SPLIT ? 1 : 0;
1782        ctx->check_oids = flags & COMMIT_GRAPH_WRITE_CHECK_OIDS ? 1 : 0;
1783        ctx->split_opts = split_opts;
1784
1785        if (ctx->split) {
1786                struct commit_graph *g;
1787                prepare_commit_graph(ctx->r);
1788
1789                g = ctx->r->objects->commit_graph;
1790
1791                while (g) {
1792                        ctx->num_commit_graphs_before++;
1793                        g = g->base_graph;
1794                }
1795
1796                if (ctx->num_commit_graphs_before) {
1797                        ALLOC_ARRAY(ctx->commit_graph_filenames_before, ctx->num_commit_graphs_before);
1798                        i = ctx->num_commit_graphs_before;
1799                        g = ctx->r->objects->commit_graph;
1800
1801                        while (g) {
1802                                ctx->commit_graph_filenames_before[--i] = xstrdup(g->filename);
1803                                g = g->base_graph;
1804                        }
1805                }
1806        }
1807
1808        ctx->approx_nr_objects = approximate_object_count();
1809        ctx->oids.alloc = ctx->approx_nr_objects / 32;
1810
1811        if (ctx->split && split_opts && ctx->oids.alloc > split_opts->max_commits)
1812                ctx->oids.alloc = split_opts->max_commits;
1813
1814        if (ctx->append) {
1815                prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1816                if (ctx->r->objects->commit_graph)
1817                        ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1818        }
1819
1820        if (ctx->oids.alloc < 1024)
1821                ctx->oids.alloc = 1024;
1822        ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1823
1824        if (ctx->append && ctx->r->objects->commit_graph) {
1825                struct commit_graph *g = ctx->r->objects->commit_graph;
1826                for (i = 0; i < g->num_commits; i++) {
1827                        const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1828                        hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1829                }
1830        }
1831
1832        if (pack_indexes) {
1833                if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1834                        goto cleanup;
1835        }
1836
1837        if (commit_hex) {
1838                if ((res = fill_oids_from_commit_hex(ctx, commit_hex)))
1839                        goto cleanup;
1840        }
1841
1842        if (!pack_indexes && !commit_hex)
1843                fill_oids_from_all_packs(ctx);
1844
1845        close_reachable(ctx);
1846
1847        count_distinct = count_distinct_commits(ctx);
1848
1849        if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1850                error(_("the commit graph format cannot write %d commits"), count_distinct);
1851                res = -1;
1852                goto cleanup;
1853        }
1854
1855        ctx->commits.alloc = count_distinct;
1856        ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1857
1858        copy_oids_to_commits(ctx);
1859
1860        if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1861                error(_("too many commits to write graph"));
1862                res = -1;
1863                goto cleanup;
1864        }
1865
1866        if (!ctx->commits.nr)
1867                goto cleanup;
1868
1869        if (ctx->split) {
1870                split_graph_merge_strategy(ctx);
1871
1872                merge_commit_graphs(ctx);
1873        } else
1874                ctx->num_commit_graphs_after = 1;
1875
1876        compute_generation_numbers(ctx);
1877
1878        res = write_commit_graph_file(ctx);
1879
1880        if (ctx->split)
1881                mark_commit_graphs(ctx);
1882
1883        expire_commit_graphs(ctx);
1884
1885cleanup:
1886        free(ctx->graph_name);
1887        free(ctx->commits.list);
1888        free(ctx->oids.list);
1889        free(ctx->obj_dir);
1890
1891        if (ctx->commit_graph_filenames_after) {
1892                for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1893                        free(ctx->commit_graph_filenames_after[i]);
1894                        free(ctx->commit_graph_hash_after[i]);
1895                }
1896
1897                for (i = 0; i < ctx->num_commit_graphs_before; i++)
1898                        free(ctx->commit_graph_filenames_before[i]);
1899
1900                free(ctx->commit_graph_filenames_after);
1901                free(ctx->commit_graph_filenames_before);
1902                free(ctx->commit_graph_hash_after);
1903        }
1904
1905        free(ctx);
1906
1907        return res;
1908}
1909
1910#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1911static int verify_commit_graph_error;
1912
1913static void graph_report(const char *fmt, ...)
1914{
1915        va_list ap;
1916
1917        verify_commit_graph_error = 1;
1918        va_start(ap, fmt);
1919        vfprintf(stderr, fmt, ap);
1920        fprintf(stderr, "\n");
1921        va_end(ap);
1922}
1923
1924#define GENERATION_ZERO_EXISTS 1
1925#define GENERATION_NUMBER_EXISTS 2
1926
1927int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags)
1928{
1929        uint32_t i, cur_fanout_pos = 0;
1930        struct object_id prev_oid, cur_oid, checksum;
1931        int generation_zero = 0;
1932        struct hashfile *f;
1933        int devnull;
1934        struct progress *progress = NULL;
1935        int local_error = 0;
1936
1937        if (!g) {
1938                graph_report("no commit-graph file loaded");
1939                return 1;
1940        }
1941
1942        verify_commit_graph_error = verify_commit_graph_lite(g);
1943        if (verify_commit_graph_error)
1944                return verify_commit_graph_error;
1945
1946        devnull = open("/dev/null", O_WRONLY);
1947        f = hashfd(devnull, NULL);
1948        hashwrite(f, g->data, g->data_len - g->hash_len);
1949        finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1950        if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1951                graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1952                verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1953        }
1954
1955        for (i = 0; i < g->num_commits; i++) {
1956                struct commit *graph_commit;
1957
1958                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1959
1960                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1961                        graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1962                                     oid_to_hex(&prev_oid),
1963                                     oid_to_hex(&cur_oid));
1964
1965                oidcpy(&prev_oid, &cur_oid);
1966
1967                while (cur_oid.hash[0] > cur_fanout_pos) {
1968                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1969
1970                        if (i != fanout_value)
1971                                graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1972                                             cur_fanout_pos, fanout_value, i);
1973                        cur_fanout_pos++;
1974                }
1975
1976                graph_commit = lookup_commit(r, &cur_oid);
1977                if (!parse_commit_in_graph_one(r, g, graph_commit))
1978                        graph_report(_("failed to parse commit %s from commit-graph"),
1979                                     oid_to_hex(&cur_oid));
1980        }
1981
1982        while (cur_fanout_pos < 256) {
1983                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1984
1985                if (g->num_commits != fanout_value)
1986                        graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1987                                     cur_fanout_pos, fanout_value, i);
1988
1989                cur_fanout_pos++;
1990        }
1991
1992        if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1993                return verify_commit_graph_error;
1994
1995        progress = start_progress(_("Verifying commits in commit graph"),
1996                                  g->num_commits);
1997        for (i = 0; i < g->num_commits; i++) {
1998                struct commit *graph_commit, *odb_commit;
1999                struct commit_list *graph_parents, *odb_parents;
2000                uint32_t max_generation = 0;
2001
2002                display_progress(progress, i + 1);
2003                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
2004
2005                graph_commit = lookup_commit(r, &cur_oid);
2006                odb_commit = (struct commit *)create_object(r, &cur_oid, alloc_commit_node(r));
2007                if (parse_commit_internal(odb_commit, 0, 0)) {
2008                        graph_report(_("failed to parse commit %s from object database for commit-graph"),
2009                                     oid_to_hex(&cur_oid));
2010                        continue;
2011                }
2012
2013                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
2014                           get_commit_tree_oid(odb_commit)))
2015                        graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
2016                                     oid_to_hex(&cur_oid),
2017                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
2018                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
2019
2020                graph_parents = graph_commit->parents;
2021                odb_parents = odb_commit->parents;
2022
2023                while (graph_parents) {
2024                        if (odb_parents == NULL) {
2025                                graph_report(_("commit-graph parent list for commit %s is too long"),
2026                                             oid_to_hex(&cur_oid));
2027                                break;
2028                        }
2029
2030                        /* parse parent in case it is in a base graph */
2031                        parse_commit_in_graph_one(r, g, graph_parents->item);
2032
2033                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
2034                                graph_report(_("commit-graph parent for %s is %s != %s"),
2035                                             oid_to_hex(&cur_oid),
2036                                             oid_to_hex(&graph_parents->item->object.oid),
2037                                             oid_to_hex(&odb_parents->item->object.oid));
2038
2039                        if (graph_parents->item->generation > max_generation)
2040                                max_generation = graph_parents->item->generation;
2041
2042                        graph_parents = graph_parents->next;
2043                        odb_parents = odb_parents->next;
2044                }
2045
2046                if (odb_parents != NULL)
2047                        graph_report(_("commit-graph parent list for commit %s terminates early"),
2048                                     oid_to_hex(&cur_oid));
2049
2050                if (!graph_commit->generation) {
2051                        if (generation_zero == GENERATION_NUMBER_EXISTS)
2052                                graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
2053                                             oid_to_hex(&cur_oid));
2054                        generation_zero = GENERATION_ZERO_EXISTS;
2055                } else if (generation_zero == GENERATION_ZERO_EXISTS)
2056                        graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
2057                                     oid_to_hex(&cur_oid));
2058
2059                if (generation_zero == GENERATION_ZERO_EXISTS)
2060                        continue;
2061
2062                /*
2063                 * If one of our parents has generation GENERATION_NUMBER_MAX, then
2064                 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
2065                 * extra logic in the following condition.
2066                 */
2067                if (max_generation == GENERATION_NUMBER_MAX)
2068                        max_generation--;
2069
2070                if (graph_commit->generation != max_generation + 1)
2071                        graph_report(_("commit-graph generation for commit %s is %u != %u"),
2072                                     oid_to_hex(&cur_oid),
2073                                     graph_commit->generation,
2074                                     max_generation + 1);
2075
2076                if (graph_commit->date != odb_commit->date)
2077                        graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
2078                                     oid_to_hex(&cur_oid),
2079                                     graph_commit->date,
2080                                     odb_commit->date);
2081        }
2082        stop_progress(&progress);
2083
2084        local_error = verify_commit_graph_error;
2085
2086        if (!(flags & COMMIT_GRAPH_VERIFY_SHALLOW) && g->base_graph)
2087                local_error |= verify_commit_graph(r, g->base_graph, flags);
2088
2089        return local_error;
2090}
2091
2092void free_commit_graph(struct commit_graph *g)
2093{
2094        if (!g)
2095                return;
2096        if (g->graph_fd >= 0) {
2097                munmap((void *)g->data, g->data_len);
2098                g->data = NULL;
2099                close(g->graph_fd);
2100        }
2101        free(g->filename);
2102        free(g);
2103}