git.oblomov.eu Git - git/blob - shallow.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "tempfile.h"
   4 #include "lockfile.h"
   5 #include "object-store.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "pkt-line.h"
   9 #include "remote.h"
  10 #include "refs.h"
  11 #include "sha1-array.h"
  12 #include "diff.h"
  13 #include "revision.h"
  14 #include "commit-slab.h"
  15 #include "list-objects.h"
  16 #include "commit-reach.h"
  17
  18 void set_alternate_shallow_file(struct repository *r, const char *path, int override)
  19 {
  20         if (r->parsed_objects->is_shallow != -1)
  21                 BUG("is_repository_shallow must not be called before set_alternate_shallow_file");
  22         if (r->parsed_objects->alternate_shallow_file && !override)
  23                 return;
  24         free(r->parsed_objects->alternate_shallow_file);
  25         r->parsed_objects->alternate_shallow_file = xstrdup_or_null(path);
  26 }
  27
  28 int register_shallow(struct repository *r, const struct object_id *oid)
  29 {
  30         struct commit_graft *graft =
  31                 xmalloc(sizeof(struct commit_graft));
  32         struct commit *commit = lookup_commit(the_repository, oid);
  33
  34         oidcpy(&graft->oid, oid);
  35         graft->nr_parent = -1;
  36         if (commit && commit->object.parsed)
  37                 commit->parents = NULL;
  38         return register_commit_graft(r, graft, 0);
  39 }
  40
  41 int is_repository_shallow(struct repository *r)
  42 {
  43         /*
  44          * NEEDSWORK: This function updates
  45          * r->parsed_objects->{is_shallow,shallow_stat} as a side effect but
  46          * there is no corresponding function to clear them when the shallow
  47          * file is updated.
  48          */
  49
  50         FILE *fp;
  51         char buf[1024];
  52         const char *path = r->parsed_objects->alternate_shallow_file;
  53
  54         if (r->parsed_objects->is_shallow >= 0)
  55                 return r->parsed_objects->is_shallow;
  56
  57         if (!path)
  58                 path = git_path_shallow(r);
  59         /*
  60          * fetch-pack sets '--shallow-file ""' as an indicator that no
  61          * shallow file should be used. We could just open it and it
  62          * will likely fail. But let's do an explicit check instead.
  63          */
  64         if (!*path || (fp = fopen(path, "r")) == NULL) {
  65                 stat_validity_clear(r->parsed_objects->shallow_stat);
  66                 r->parsed_objects->is_shallow = 0;
  67                 return r->parsed_objects->is_shallow;
  68         }
  69         stat_validity_update(r->parsed_objects->shallow_stat, fileno(fp));
  70         r->parsed_objects->is_shallow = 1;
  71
  72         while (fgets(buf, sizeof(buf), fp)) {
  73                 struct object_id oid;
  74                 if (get_oid_hex(buf, &oid))
  75                         die("bad shallow line: %s", buf);
  76                 register_shallow(r, &oid);
  77         }
  78         fclose(fp);
  79         return r->parsed_objects->is_shallow;
  80 }
  81
  82 /*
  83  * TODO: use "int" elemtype instead of "int *" when/if commit-slab
  84  * supports a "valid" flag.
  85  */
  86 define_commit_slab(commit_depth, int *);
  87 static void free_depth_in_slab(int **ptr)
  88 {
  89         FREE_AND_NULL(*ptr);
  90 }
  91 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  92                 int shallow_flag, int not_shallow_flag)
  93 {
  94         int i = 0, cur_depth = 0;
  95         struct commit_list *result = NULL;
  96         struct object_array stack = OBJECT_ARRAY_INIT;
  97         struct commit *commit = NULL;
  98         struct commit_graft *graft;
  99         struct commit_depth depths;
 100
 101         init_commit_depth(&depths);
 102         while (commit || i < heads->nr || stack.nr) {
 103                 struct commit_list *p;
 104                 if (!commit) {
 105                         if (i < heads->nr) {
 106                                 int **depth_slot;
 107                                 commit = (struct commit *)
 108                                         deref_tag(the_repository,
 109                                                   heads->objects[i++].item,
 110                                                   NULL, 0);
 111                                 if (!commit || commit->object.type != OBJ_COMMIT) {
 112                                         commit = NULL;
 113                                         continue;
 114                                 }
 115                                 depth_slot = commit_depth_at(&depths, commit);
 116                                 if (!*depth_slot)
 117                                         *depth_slot = xmalloc(sizeof(int));
 118                                 **depth_slot = 0;
 119                                 cur_depth = 0;
 120                         } else {
 121                                 commit = (struct commit *)
 122                                         object_array_pop(&stack);
 123                                 cur_depth = **commit_depth_at(&depths, commit);
 124                         }
 125                 }
 126                 parse_commit_or_die(commit);
 127                 cur_depth++;
 128                 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
 129                     (is_repository_shallow(the_repository) && !commit->parents &&
 130                      (graft = lookup_commit_graft(the_repository, &commit->object.oid)) != NULL &&
 131                      graft->nr_parent < 0)) {
 132                         commit_list_insert(commit, &result);
 133                         commit->object.flags |= shallow_flag;
 134                         commit = NULL;
 135                         continue;
 136                 }
 137                 commit->object.flags |= not_shallow_flag;
 138                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 139                         int **depth_slot = commit_depth_at(&depths, p->item);
 140                         if (!*depth_slot) {
 141                                 *depth_slot = xmalloc(sizeof(int));
 142                                 **depth_slot = cur_depth;
 143                         } else {
 144                                 if (cur_depth >= **depth_slot)
 145                                         continue;
 146                                 **depth_slot = cur_depth;
 147                         }
 148                         if (p->next)
 149                                 add_object_array(&p->item->object,
 150                                                 NULL, &stack);
 151                         else {
 152                                 commit = p->item;
 153                                 cur_depth = **commit_depth_at(&depths, commit);
 154                         }
 155                 }
 156         }
 157         deep_clear_commit_depth(&depths, free_depth_in_slab);
 158
 159         return result;
 160 }
 161
 162 static void show_commit(struct commit *commit, void *data)
 163 {
 164         commit_list_insert(commit, data);
 165 }
 166
 167 /*
 168  * Given rev-list arguments, run rev-list. All reachable commits
 169  * except border ones are marked with not_shallow_flag. Border commits
 170  * are marked with shallow_flag. The list of border/shallow commits
 171  * are also returned.
 172  */
 173 struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
 174                                                     int shallow_flag,
 175                                                     int not_shallow_flag)
 176 {
 177         struct commit_list *result = NULL, *p;
 178         struct commit_list *not_shallow_list = NULL;
 179         struct rev_info revs;
 180         int both_flags = shallow_flag | not_shallow_flag;
 181
 182         /*
 183          * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
 184          * set at this point. But better be safe than sorry.
 185          */
 186         clear_object_flags(both_flags);
 187
 188         is_repository_shallow(the_repository); /* make sure shallows are read */
 189
 190         repo_init_revisions(the_repository, &revs, NULL);
 191         save_commit_buffer = 0;
 192         setup_revisions(ac, av, &revs, NULL);
 193
 194         if (prepare_revision_walk(&revs))
 195                 die("revision walk setup failed");
 196         traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
 197
 198         if (!not_shallow_list)
 199                 die("no commits selected for shallow requests");
 200
 201         /* Mark all reachable commits as NOT_SHALLOW */
 202         for (p = not_shallow_list; p; p = p->next)
 203                 p->item->object.flags |= not_shallow_flag;
 204
 205         /*
 206          * mark border commits SHALLOW + NOT_SHALLOW.
 207          * We cannot clear NOT_SHALLOW right now. Imagine border
 208          * commit A is processed first, then commit B, whose parent is
 209          * A, later. If NOT_SHALLOW on A is cleared at step 1, B
 210          * itself is considered border at step 2, which is incorrect.
 211          */
 212         for (p = not_shallow_list; p; p = p->next) {
 213                 struct commit *c = p->item;
 214                 struct commit_list *parent;
 215
 216                 if (parse_commit(c))
 217                         die("unable to parse commit %s",
 218                             oid_to_hex(&c->object.oid));
 219
 220                 for (parent = c->parents; parent; parent = parent->next)
 221                         if (!(parent->item->object.flags & not_shallow_flag)) {
 222                                 c->object.flags |= shallow_flag;
 223                                 commit_list_insert(c, &result);
 224                                 break;
 225                         }
 226         }
 227         free_commit_list(not_shallow_list);
 228
 229         /*
 230          * Now we can clean up NOT_SHALLOW on border commits. Having
 231          * both flags set can confuse the caller.
 232          */
 233         for (p = result; p; p = p->next) {
 234                 struct object *o = &p->item->object;
 235                 if ((o->flags & both_flags) == both_flags)
 236                         o->flags &= ~not_shallow_flag;
 237         }
 238         return result;
 239 }
 240
 241 static void check_shallow_file_for_update(struct repository *r)
 242 {
 243         if (r->parsed_objects->is_shallow == -1)
 244                 BUG("shallow must be initialized by now");
 245
 246         if (!stat_validity_check(r->parsed_objects->shallow_stat,
 247                                  git_path_shallow(r)))
 248                 die("shallow file has changed since we read it");
 249 }
 250
 251 #define SEEN_ONLY 1
 252 #define VERBOSE   2
 253 #define QUICK 4
 254
 255 struct write_shallow_data {
 256         struct strbuf *out;
 257         int use_pack_protocol;
 258         int count;
 259         unsigned flags;
 260 };
 261
 262 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 263 {
 264         struct write_shallow_data *data = cb_data;
 265         const char *hex = oid_to_hex(&graft->oid);
 266         if (graft->nr_parent != -1)
 267                 return 0;
 268         if (data->flags & QUICK) {
 269                 if (!has_object_file(&graft->oid))
 270                         return 0;
 271         } else if (data->flags & SEEN_ONLY) {
 272                 struct commit *c = lookup_commit(the_repository, &graft->oid);
 273                 if (!c || !(c->object.flags & SEEN)) {
 274                         if (data->flags & VERBOSE)
 275                                 printf("Removing %s from .git/shallow\n",
 276                                        oid_to_hex(&c->object.oid));
 277                         return 0;
 278                 }
 279         }
 280         data->count++;
 281         if (data->use_pack_protocol)
 282                 packet_buf_write(data->out, "shallow %s", hex);
 283         else {
 284                 strbuf_addstr(data->out, hex);
 285                 strbuf_addch(data->out, '\n');
 286         }
 287         return 0;
 288 }
 289
 290 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
 291                                    const struct oid_array *extra,
 292                                    unsigned flags)
 293 {
 294         struct write_shallow_data data;
 295         int i;
 296         data.out = out;
 297         data.use_pack_protocol = use_pack_protocol;
 298         data.count = 0;
 299         data.flags = flags;
 300         for_each_commit_graft(write_one_shallow, &data);
 301         if (!extra)
 302                 return data.count;
 303         for (i = 0; i < extra->nr; i++) {
 304                 strbuf_addstr(out, oid_to_hex(extra->oid + i));
 305                 strbuf_addch(out, '\n');
 306                 data.count++;
 307         }
 308         return data.count;
 309 }
 310
 311 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 312                           const struct oid_array *extra)
 313 {
 314         return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 315 }
 316
 317 const char *setup_temporary_shallow(const struct oid_array *extra)
 318 {
 319         struct tempfile *temp;
 320         struct strbuf sb = STRBUF_INIT;
 321
 322         if (write_shallow_commits(&sb, 0, extra)) {
 323                 temp = xmks_tempfile(git_path("shallow_XXXXXX"));
 324
 325                 if (write_in_full(temp->fd, sb.buf, sb.len) < 0 ||
 326                     close_tempfile_gently(temp) < 0)
 327                         die_errno("failed to write to %s",
 328                                   get_tempfile_path(temp));
 329                 strbuf_release(&sb);
 330                 return get_tempfile_path(temp);
 331         }
 332         /*
 333          * is_repository_shallow() sees empty string as "no shallow
 334          * file".
 335          */
 336         return "";
 337 }
 338
 339 void setup_alternate_shallow(struct lock_file *shallow_lock,
 340                              const char **alternate_shallow_file,
 341                              const struct oid_array *extra)
 342 {
 343         struct strbuf sb = STRBUF_INIT;
 344         int fd;
 345
 346         fd = hold_lock_file_for_update(shallow_lock,
 347                                        git_path_shallow(the_repository),
 348                                        LOCK_DIE_ON_ERROR);
 349         check_shallow_file_for_update(the_repository);
 350         if (write_shallow_commits(&sb, 0, extra)) {
 351                 if (write_in_full(fd, sb.buf, sb.len) < 0)
 352                         die_errno("failed to write to %s",
 353                                   get_lock_file_path(shallow_lock));
 354                 *alternate_shallow_file = get_lock_file_path(shallow_lock);
 355         } else
 356                 /*
 357                  * is_repository_shallow() sees empty string as "no
 358                  * shallow file".
 359                  */
 360                 *alternate_shallow_file = "";
 361         strbuf_release(&sb);
 362 }
 363
 364 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 365 {
 366         int fd = *(int *)cb;
 367         if (graft->nr_parent == -1)
 368                 packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 369         return 0;
 370 }
 371
 372 void advertise_shallow_grafts(int fd)
 373 {
 374         if (!is_repository_shallow(the_repository))
 375                 return;
 376         for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 377 }
 378
 379 /*
 380  * mark_reachable_objects() should have been run prior to this and all
 381  * reachable commits marked as "SEEN", except when quick_prune is non-zero,
 382  * in which case lines are excised from the shallow file if they refer to
 383  * commits that do not exist (any longer).
 384  */
 385 void prune_shallow(unsigned options)
 386 {
 387         struct lock_file shallow_lock = LOCK_INIT;
 388         struct strbuf sb = STRBUF_INIT;
 389         unsigned flags = SEEN_ONLY;
 390         int fd;
 391
 392         if (options & PRUNE_QUICK)
 393                 flags |= QUICK;
 394
 395         if (options & PRUNE_SHOW_ONLY) {
 396                 flags |= VERBOSE;
 397                 write_shallow_commits_1(&sb, 0, NULL, flags);
 398                 strbuf_release(&sb);
 399                 return;
 400         }
 401         fd = hold_lock_file_for_update(&shallow_lock,
 402                                        git_path_shallow(the_repository),
 403                                        LOCK_DIE_ON_ERROR);
 404         check_shallow_file_for_update(the_repository);
 405         if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
 406                 if (write_in_full(fd, sb.buf, sb.len) < 0)
 407                         die_errno("failed to write to %s",
 408                                   get_lock_file_path(&shallow_lock));
 409                 commit_lock_file(&shallow_lock);
 410         } else {
 411                 unlink(git_path_shallow(the_repository));
 412                 rollback_lock_file(&shallow_lock);
 413         }
 414         strbuf_release(&sb);
 415 }
 416
 417 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
 418
 419 /*
 420  * Step 1, split sender shallow commits into "ours" and "theirs"
 421  * Step 2, clean "ours" based on .git/shallow
 422  */
 423 void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
 424 {
 425         int i;
 426         trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
 427         memset(info, 0, sizeof(*info));
 428         info->shallow = sa;
 429         if (!sa)
 430                 return;
 431         ALLOC_ARRAY(info->ours, sa->nr);
 432         ALLOC_ARRAY(info->theirs, sa->nr);
 433         for (i = 0; i < sa->nr; i++) {
 434                 if (has_object_file(sa->oid + i)) {
 435                         struct commit_graft *graft;
 436                         graft = lookup_commit_graft(the_repository,
 437                                                     &sa->oid[i]);
 438                         if (graft && graft->nr_parent < 0)
 439                                 continue;
 440                         info->ours[info->nr_ours++] = i;
 441                 } else
 442                         info->theirs[info->nr_theirs++] = i;
 443         }
 444 }
 445
 446 void clear_shallow_info(struct shallow_info *info)
 447 {
 448         free(info->ours);
 449         free(info->theirs);
 450 }
 451
 452 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
 453
 454 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
 455 {
 456         struct object_id *oid = info->shallow->oid;
 457         int i, dst;
 458         trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
 459         for (i = dst = 0; i < info->nr_theirs; i++) {
 460                 if (i != dst)
 461                         info->theirs[dst] = info->theirs[i];
 462                 if (has_object_file(oid + info->theirs[i]))
 463                         dst++;
 464         }
 465         info->nr_theirs = dst;
 466 }
 467
 468 define_commit_slab(ref_bitmap, uint32_t *);
 469
 470 #define POOL_SIZE (512 * 1024)
 471
 472 struct paint_info {
 473         struct ref_bitmap ref_bitmap;
 474         unsigned nr_bits;
 475         char **pools;
 476         char *free, *end;
 477         unsigned pool_count;
 478 };
 479
 480 static uint32_t *paint_alloc(struct paint_info *info)
 481 {
 482         unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
 483         unsigned size = nr * sizeof(uint32_t);
 484         void *p;
 485         if (!info->pool_count || size > info->end - info->free) {
 486                 if (size > POOL_SIZE)
 487                         BUG("pool size too small for %d in paint_alloc()",
 488                             size);
 489                 info->pool_count++;
 490                 REALLOC_ARRAY(info->pools, info->pool_count);
 491                 info->free = xmalloc(POOL_SIZE);
 492                 info->pools[info->pool_count - 1] = info->free;
 493                 info->end = info->free + POOL_SIZE;
 494         }
 495         p = info->free;
 496         info->free += size;
 497         return p;
 498 }
 499
 500 /*
 501  * Given a commit SHA-1, walk down to parents until either SEEN,
 502  * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 503  * all walked commits.
 504  */
 505 static void paint_down(struct paint_info *info, const struct object_id *oid,
 506                        unsigned int id)
 507 {
 508         unsigned int i, nr;
 509         struct commit_list *head = NULL;
 510         int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
 511         size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 512         struct commit *c = lookup_commit_reference_gently(the_repository, oid,
 513                                                           1);
 514         uint32_t *tmp; /* to be freed before return */
 515         uint32_t *bitmap;
 516
 517         if (!c)
 518                 return;
 519
 520         tmp = xmalloc(bitmap_size);
 521         bitmap = paint_alloc(info);
 522         memset(bitmap, 0, bitmap_size);
 523         bitmap[id / 32] |= (1U << (id % 32));
 524         commit_list_insert(c, &head);
 525         while (head) {
 526                 struct commit_list *p;
 527                 struct commit *c = pop_commit(&head);
 528                 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
 529
 530                 /* XXX check "UNINTERESTING" from pack bitmaps if available */
 531                 if (c->object.flags & (SEEN | UNINTERESTING))
 532                         continue;
 533                 else
 534                         c->object.flags |= SEEN;
 535
 536                 if (*refs == NULL)
 537                         *refs = bitmap;
 538                 else {
 539                         memcpy(tmp, *refs, bitmap_size);
 540                         for (i = 0; i < bitmap_nr; i++)
 541                                 tmp[i] |= bitmap[i];
 542                         if (memcmp(tmp, *refs, bitmap_size)) {
 543                                 *refs = paint_alloc(info);
 544                                 memcpy(*refs, tmp, bitmap_size);
 545                         }
 546                 }
 547
 548                 if (c->object.flags & BOTTOM)
 549                         continue;
 550
 551                 if (parse_commit(c))
 552                         die("unable to parse commit %s",
 553                             oid_to_hex(&c->object.oid));
 554
 555                 for (p = c->parents; p; p = p->next) {
 556                         if (p->item->object.flags & SEEN)
 557                                 continue;
 558                         commit_list_insert(p->item, &head);
 559                 }
 560         }
 561
 562         nr = get_max_object_index();
 563         for (i = 0; i < nr; i++) {
 564                 struct object *o = get_indexed_object(i);
 565                 if (o && o->type == OBJ_COMMIT)
 566                         o->flags &= ~SEEN;
 567         }
 568
 569         free(tmp);
 570 }
 571
 572 static int mark_uninteresting(const char *refname, const struct object_id *oid,
 573                               int flags, void *cb_data)
 574 {
 575         struct commit *commit = lookup_commit_reference_gently(the_repository,
 576                                                                oid, 1);
 577         if (!commit)
 578                 return 0;
 579         commit->object.flags |= UNINTERESTING;
 580         mark_parents_uninteresting(commit);
 581         return 0;
 582 }
 583
 584 static void post_assign_shallow(struct shallow_info *info,
 585                                 struct ref_bitmap *ref_bitmap,
 586                                 int *ref_status);
 587 /*
 588  * Step 6(+7), associate shallow commits with new refs
 589  *
 590  * info->ref must be initialized before calling this function.
 591  *
 592  * If used is not NULL, it's an array of info->shallow->nr
 593  * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 594  * m-th shallow commit from info->shallow.
 595  *
 596  * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 597  * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 598  * the ref needs some shallow commits from either info->ours or
 599  * info->theirs.
 600  */
 601 void assign_shallow_commits_to_refs(struct shallow_info *info,
 602                                     uint32_t **used, int *ref_status)
 603 {
 604         struct object_id *oid = info->shallow->oid;
 605         struct oid_array *ref = info->ref;
 606         unsigned int i, nr;
 607         int *shallow, nr_shallow = 0;
 608         struct paint_info pi;
 609
 610         trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
 611         ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
 612         for (i = 0; i < info->nr_ours; i++)
 613                 shallow[nr_shallow++] = info->ours[i];
 614         for (i = 0; i < info->nr_theirs; i++)
 615                 shallow[nr_shallow++] = info->theirs[i];
 616
 617         /*
 618          * Prepare the commit graph to track what refs can reach what
 619          * (new) shallow commits.
 620          */
 621         nr = get_max_object_index();
 622         for (i = 0; i < nr; i++) {
 623                 struct object *o = get_indexed_object(i);
 624                 if (!o || o->type != OBJ_COMMIT)
 625                         continue;
 626
 627                 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
 628         }
 629
 630         memset(&pi, 0, sizeof(pi));
 631         init_ref_bitmap(&pi.ref_bitmap);
 632         pi.nr_bits = ref->nr;
 633
 634         /*
 635          * "--not --all" to cut short the traversal if new refs
 636          * connect to old refs. If not (e.g. force ref updates) it'll
 637          * have to go down to the current shallow commits.
 638          */
 639         head_ref(mark_uninteresting, NULL);
 640         for_each_ref(mark_uninteresting, NULL);
 641
 642         /* Mark potential bottoms so we won't go out of bound */
 643         for (i = 0; i < nr_shallow; i++) {
 644                 struct commit *c = lookup_commit(the_repository,
 645                                                  &oid[shallow[i]]);
 646                 c->object.flags |= BOTTOM;
 647         }
 648
 649         for (i = 0; i < ref->nr; i++)
 650                 paint_down(&pi, ref->oid + i, i);
 651
 652         if (used) {
 653                 int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
 654                 memset(used, 0, sizeof(*used) * info->shallow->nr);
 655                 for (i = 0; i < nr_shallow; i++) {
 656                         const struct commit *c = lookup_commit(the_repository,
 657                                                                &oid[shallow[i]]);
 658                         uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
 659                         if (*map)
 660                                 used[shallow[i]] = xmemdupz(*map, bitmap_size);
 661                 }
 662                 /*
 663                  * unreachable shallow commits are not removed from
 664                  * "ours" and "theirs". The user is supposed to run
 665                  * step 7 on every ref separately and not trust "ours"
 666                  * and "theirs" any more.
 667                  */
 668         } else
 669                 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
 670
 671         clear_ref_bitmap(&pi.ref_bitmap);
 672         for (i = 0; i < pi.pool_count; i++)
 673                 free(pi.pools[i]);
 674         free(pi.pools);
 675         free(shallow);
 676 }
 677
 678 struct commit_array {
 679         struct commit **commits;
 680         int nr, alloc;
 681 };
 682
 683 static int add_ref(const char *refname, const struct object_id *oid,
 684                    int flags, void *cb_data)
 685 {
 686         struct commit_array *ca = cb_data;
 687         ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
 688         ca->commits[ca->nr] = lookup_commit_reference_gently(the_repository,
 689                                                              oid, 1);
 690         if (ca->commits[ca->nr])
 691                 ca->nr++;
 692         return 0;
 693 }
 694
 695 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
 696 {
 697         unsigned int i;
 698         if (!ref_status)
 699                 return;
 700         for (i = 0; i < nr; i++)
 701                 if (bitmap[i / 32] & (1U << (i % 32)))
 702                         ref_status[i]++;
 703 }
 704
 705 /*
 706  * Step 7, reachability test on "ours" at commit level
 707  */
 708 static void post_assign_shallow(struct shallow_info *info,
 709                                 struct ref_bitmap *ref_bitmap,
 710                                 int *ref_status)
 711 {
 712         struct object_id *oid = info->shallow->oid;
 713         struct commit *c;
 714         uint32_t **bitmap;
 715         int dst, i, j;
 716         int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
 717         struct commit_array ca;
 718
 719         trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
 720         if (ref_status)
 721                 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
 722
 723         /* Remove unreachable shallow commits from "theirs" */
 724         for (i = dst = 0; i < info->nr_theirs; i++) {
 725                 if (i != dst)
 726                         info->theirs[dst] = info->theirs[i];
 727                 c = lookup_commit(the_repository, &oid[info->theirs[i]]);
 728                 bitmap = ref_bitmap_at(ref_bitmap, c);
 729                 if (!*bitmap)
 730                         continue;
 731                 for (j = 0; j < bitmap_nr; j++)
 732                         if (bitmap[0][j]) {
 733                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 734                                 dst++;
 735                                 break;
 736                         }
 737         }
 738         info->nr_theirs = dst;
 739
 740         memset(&ca, 0, sizeof(ca));
 741         head_ref(add_ref, &ca);
 742         for_each_ref(add_ref, &ca);
 743
 744         /* Remove unreachable shallow commits from "ours" */
 745         for (i = dst = 0; i < info->nr_ours; i++) {
 746                 if (i != dst)
 747                         info->ours[dst] = info->ours[i];
 748                 c = lookup_commit(the_repository, &oid[info->ours[i]]);
 749                 bitmap = ref_bitmap_at(ref_bitmap, c);
 750                 if (!*bitmap)
 751                         continue;
 752                 for (j = 0; j < bitmap_nr; j++)
 753                         if (bitmap[0][j] &&
 754                             /* Step 7, reachability test at commit level */
 755                             !in_merge_bases_many(c, ca.nr, ca.commits)) {
 756                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 757                                 dst++;
 758                                 break;
 759                         }
 760         }
 761         info->nr_ours = dst;
 762
 763         free(ca.commits);
 764 }
 765
 766 /* (Delayed) step 7, reachability test at commit level */
 767 int delayed_reachability_test(struct shallow_info *si, int c)
 768 {
 769         if (si->need_reachability_test[c]) {
 770                 struct commit *commit = lookup_commit(the_repository,
 771                                                       &si->shallow->oid[c]);
 772
 773                 if (!si->commits) {
 774                         struct commit_array ca;
 775
 776                         memset(&ca, 0, sizeof(ca));
 777                         head_ref(add_ref, &ca);
 778                         for_each_ref(add_ref, &ca);
 779                         si->commits = ca.commits;
 780                         si->nr_commits = ca.nr;
 781                 }
 782
 783                 si->reachable[c] = in_merge_bases_many(commit,
 784                                                        si->nr_commits,
 785                                                        si->commits);
 786                 si->need_reachability_test[c] = 0;
 787         }
 788         return si->reachable[c];
 789 }