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