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

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