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