shallow.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "commit.h"
   4 #include "tag.h"
   5 #include "pkt-line.h"
   6 #include "remote.h"
   7 #include "refs.h"
   8 #include "sha1-array.h"
   9 #include "diff.h"
  10 #include "revision.h"
  11 #include "commit-slab.h"
  12 #include "sigchain.h"
  13
  14 static int is_shallow = -1;
  15 static struct stat_validity shallow_stat;
  16 static char *alternate_shallow_file;
  17
  18 void set_alternate_shallow_file(const char *path, int override)
  19 {
  20         if (is_shallow != -1)
  21                 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
  22         if (alternate_shallow_file && !override)
  23                 return;
  24         free(alternate_shallow_file);
  25         alternate_shallow_file = path ? xstrdup(path) : NULL;
  26 }
  27
  28 int register_shallow(const unsigned char *sha1)
  29 {
  30         struct commit_graft *graft =
  31                 xmalloc(sizeof(struct commit_graft));
  32         struct commit *commit = lookup_commit(sha1);
  33
  34         hashcpy(graft->sha1, sha1);
  35         graft->nr_parent = -1;
  36         if (commit && commit->object.parsed)
  37                 commit->parents = NULL;
  38         return register_commit_graft(graft, 0);
  39 }
  40
  41 int is_repository_shallow(void)
  42 {
  43         FILE *fp;
  44         char buf[1024];
  45         const char *path = alternate_shallow_file;
  46
  47         if (is_shallow >= 0)
  48                 return is_shallow;
  49
  50         if (!path)
  51                 path = git_path("shallow");
  52         /*
  53          * fetch-pack sets '--shallow-file ""' as an indicator that no
  54          * shallow file should be used. We could just open it and it
  55          * will likely fail. But let's do an explicit check instead.
  56          */
  57         if (!*path || (fp = fopen(path, "r")) == NULL) {
  58                 stat_validity_clear(&shallow_stat);
  59                 is_shallow = 0;
  60                 return is_shallow;
  61         }
  62         stat_validity_update(&shallow_stat, fileno(fp));
  63         is_shallow = 1;
  64
  65         while (fgets(buf, sizeof(buf), fp)) {
  66                 unsigned char sha1[20];
  67                 if (get_sha1_hex(buf, sha1))
  68                         die("bad shallow line: %s", buf);
  69                 register_shallow(sha1);
  70         }
  71         fclose(fp);
  72         return is_shallow;
  73 }
  74
  75 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  76                 int shallow_flag, int not_shallow_flag)
  77 {
  78         int i = 0, cur_depth = 0;
  79         struct commit_list *result = NULL;
  80         struct object_array stack = OBJECT_ARRAY_INIT;
  81         struct commit *commit = NULL;
  82         struct commit_graft *graft;
  83
  84         while (commit || i < heads->nr || stack.nr) {
  85                 struct commit_list *p;
  86                 if (!commit) {
  87                         if (i < heads->nr) {
  88                                 commit = (struct commit *)
  89                                         deref_tag(heads->objects[i++].item, NULL, 0);
  90                                 if (!commit || commit->object.type != OBJ_COMMIT) {
  91                                         commit = NULL;
  92                                         continue;
  93                                 }
  94                                 if (!commit->util)
  95                                         commit->util = xmalloc(sizeof(int));
  96                                 *(int *)commit->util = 0;
  97                                 cur_depth = 0;
  98                         } else {
  99                                 commit = (struct commit *)
 100                                         stack.objects[--stack.nr].item;
 101                                 cur_depth = *(int *)commit->util;
 102                         }
 103                 }
 104                 parse_commit_or_die(commit);
 105                 cur_depth++;
 106                 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
 107                     (is_repository_shallow() && !commit->parents &&
 108                      (graft = lookup_commit_graft(commit->object.sha1)) != NULL &&
 109                      graft->nr_parent < 0)) {
 110                         commit_list_insert(commit, &result);
 111                         commit->object.flags |= shallow_flag;
 112                         commit = NULL;
 113                         continue;
 114                 }
 115                 commit->object.flags |= not_shallow_flag;
 116                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 117                         if (!p->item->util) {
 118                                 int *pointer = xmalloc(sizeof(int));
 119                                 p->item->util = pointer;
 120                                 *pointer =  cur_depth;
 121                         } else {
 122                                 int *pointer = p->item->util;
 123                                 if (cur_depth >= *pointer)
 124                                         continue;
 125                                 *pointer = cur_depth;
 126                         }
 127                         if (p->next)
 128                                 add_object_array(&p->item->object,
 129                                                 NULL, &stack);
 130                         else {
 131                                 commit = p->item;
 132                                 cur_depth = *(int *)commit->util;
 133                         }
 134                 }
 135         }
 136
 137         return result;
 138 }
 139
 140 void check_shallow_file_for_update(void)
 141 {
 142         if (is_shallow == -1)
 143                 die("BUG: shallow must be initialized by now");
 144
 145         if (!stat_validity_check(&shallow_stat, git_path("shallow")))
 146                 die("shallow file has changed since we read it");
 147 }
 148
 149 #define SEEN_ONLY 1
 150 #define VERBOSE   2
 151
 152 struct write_shallow_data {
 153         struct strbuf *out;
 154         int use_pack_protocol;
 155         int count;
 156         unsigned flags;
 157 };
 158
 159 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 160 {
 161         struct write_shallow_data *data = cb_data;
 162         const char *hex = sha1_to_hex(graft->sha1);
 163         if (graft->nr_parent != -1)
 164                 return 0;
 165         if (data->flags & SEEN_ONLY) {
 166                 struct commit *c = lookup_commit(graft->sha1);
 167                 if (!c || !(c->object.flags & SEEN)) {
 168                         if (data->flags & VERBOSE)
 169                                 printf("Removing %s from .git/shallow\n",
 170                                        sha1_to_hex(c->object.sha1));
 171                         return 0;
 172                 }
 173         }
 174         data->count++;
 175         if (data->use_pack_protocol)
 176                 packet_buf_write(data->out, "shallow %s", hex);
 177         else {
 178                 strbuf_addstr(data->out, hex);
 179                 strbuf_addch(data->out, '\n');
 180         }
 181         return 0;
 182 }
 183
 184 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
 185                                    const struct sha1_array *extra,
 186                                    unsigned flags)
 187 {
 188         struct write_shallow_data data;
 189         int i;
 190         data.out = out;
 191         data.use_pack_protocol = use_pack_protocol;
 192         data.count = 0;
 193         data.flags = flags;
 194         for_each_commit_graft(write_one_shallow, &data);
 195         if (!extra)
 196                 return data.count;
 197         for (i = 0; i < extra->nr; i++) {
 198                 strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
 199                 strbuf_addch(out, '\n');
 200                 data.count++;
 201         }
 202         return data.count;
 203 }
 204
 205 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 206                           const struct sha1_array *extra)
 207 {
 208         return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 209 }
 210
 211 static struct strbuf temporary_shallow = STRBUF_INIT;
 212
 213 static void remove_temporary_shallow(void)
 214 {
 215         if (temporary_shallow.len) {
 216                 unlink_or_warn(temporary_shallow.buf);
 217                 strbuf_reset(&temporary_shallow);
 218         }
 219 }
 220
 221 static void remove_temporary_shallow_on_signal(int signo)
 222 {
 223         remove_temporary_shallow();
 224         sigchain_pop(signo);
 225         raise(signo);
 226 }
 227
 228 const char *setup_temporary_shallow(const struct sha1_array *extra)
 229 {
 230         static int installed_handler;
 231         struct strbuf sb = STRBUF_INIT;
 232         int fd;
 233
 234         if (temporary_shallow.len)
 235                 die("BUG: attempt to create two temporary shallow files");
 236
 237         if (write_shallow_commits(&sb, 0, extra)) {
 238                 strbuf_addstr(&temporary_shallow, git_path("shallow_XXXXXX"));
 239                 fd = xmkstemp(temporary_shallow.buf);
 240
 241                 if (!installed_handler) {
 242                         atexit(remove_temporary_shallow);
 243                         sigchain_push_common(remove_temporary_shallow_on_signal);
 244                 }
 245
 246                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 247                         die_errno("failed to write to %s",
 248                                   temporary_shallow.buf);
 249                 close(fd);
 250                 strbuf_release(&sb);
 251                 return temporary_shallow.buf;
 252         }
 253         /*
 254          * is_repository_shallow() sees empty string as "no shallow
 255          * file".
 256          */
 257         return temporary_shallow.buf;
 258 }
 259
 260 void setup_alternate_shallow(struct lock_file *shallow_lock,
 261                              const char **alternate_shallow_file,
 262                              const struct sha1_array *extra)
 263 {
 264         struct strbuf sb = STRBUF_INIT;
 265         int fd;
 266
 267         fd = hold_lock_file_for_update(shallow_lock, git_path("shallow"),
 268                                        LOCK_DIE_ON_ERROR);
 269         check_shallow_file_for_update();
 270         if (write_shallow_commits(&sb, 0, extra)) {
 271                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 272                         die_errno("failed to write to %s",
 273                                   shallow_lock->filename.buf);
 274                 *alternate_shallow_file = shallow_lock->filename.buf;
 275         } else
 276                 /*
 277                  * is_repository_shallow() sees empty string as "no
 278                  * shallow file".
 279                  */
 280                 *alternate_shallow_file = "";
 281         strbuf_release(&sb);
 282 }
 283
 284 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 285 {
 286         int fd = *(int *)cb;
 287         if (graft->nr_parent == -1)
 288                 packet_write(fd, "shallow %s\n", sha1_to_hex(graft->sha1));
 289         return 0;
 290 }
 291
 292 void advertise_shallow_grafts(int fd)
 293 {
 294         if (!is_repository_shallow())
 295                 return;
 296         for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 297 }
 298
 299 /*
 300  * mark_reachable_objects() should have been run prior to this and all
 301  * reachable commits marked as "SEEN".
 302  */
 303 void prune_shallow(int show_only)
 304 {
 305         static struct lock_file shallow_lock;
 306         struct strbuf sb = STRBUF_INIT;
 307         int fd;
 308
 309         if (show_only) {
 310                 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
 311                 strbuf_release(&sb);
 312                 return;
 313         }
 314         fd = hold_lock_file_for_update(&shallow_lock, git_path("shallow"),
 315                                        LOCK_DIE_ON_ERROR);
 316         check_shallow_file_for_update();
 317         if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
 318                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 319                         die_errno("failed to write to %s",
 320                                   shallow_lock.filename.buf);
 321                 commit_lock_file(&shallow_lock);
 322         } else {
 323                 unlink(git_path("shallow"));
 324                 rollback_lock_file(&shallow_lock);
 325         }
 326         strbuf_release(&sb);
 327 }
 328
 329 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
 330
 331 /*
 332  * Step 1, split sender shallow commits into "ours" and "theirs"
 333  * Step 2, clean "ours" based on .git/shallow
 334  */
 335 void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
 336 {
 337         int i;
 338         trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
 339         memset(info, 0, sizeof(*info));
 340         info->shallow = sa;
 341         if (!sa)
 342                 return;
 343         info->ours = xmalloc(sizeof(*info->ours) * sa->nr);
 344         info->theirs = xmalloc(sizeof(*info->theirs) * sa->nr);
 345         for (i = 0; i < sa->nr; i++) {
 346                 if (has_sha1_file(sa->sha1[i])) {
 347                         struct commit_graft *graft;
 348                         graft = lookup_commit_graft(sa->sha1[i]);
 349                         if (graft && graft->nr_parent < 0)
 350                                 continue;
 351                         info->ours[info->nr_ours++] = i;
 352                 } else
 353                         info->theirs[info->nr_theirs++] = i;
 354         }
 355 }
 356
 357 void clear_shallow_info(struct shallow_info *info)
 358 {
 359         free(info->ours);
 360         free(info->theirs);
 361 }
 362
 363 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
 364
 365 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
 366 {
 367         unsigned char (*sha1)[20] = info->shallow->sha1;
 368         int i, dst;
 369         trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
 370         for (i = dst = 0; i < info->nr_theirs; i++) {
 371                 if (i != dst)
 372                         info->theirs[dst] = info->theirs[i];
 373                 if (has_sha1_file(sha1[info->theirs[i]]))
 374                         dst++;
 375         }
 376         info->nr_theirs = dst;
 377 }
 378
 379 define_commit_slab(ref_bitmap, uint32_t *);
 380
 381 struct paint_info {
 382         struct ref_bitmap ref_bitmap;
 383         unsigned nr_bits;
 384         char **slab;
 385         char *free, *end;
 386         unsigned slab_count;
 387 };
 388
 389 static uint32_t *paint_alloc(struct paint_info *info)
 390 {
 391         unsigned nr = (info->nr_bits + 31) / 32;
 392         unsigned size = nr * sizeof(uint32_t);
 393         void *p;
 394         if (!info->slab_count || info->free + size > info->end) {
 395                 info->slab_count++;
 396                 REALLOC_ARRAY(info->slab, info->slab_count);
 397                 info->free = xmalloc(COMMIT_SLAB_SIZE);
 398                 info->slab[info->slab_count - 1] = info->free;
 399                 info->end = info->free + COMMIT_SLAB_SIZE;
 400         }
 401         p = info->free;
 402         info->free += size;
 403         return p;
 404 }
 405
 406 /*
 407  * Given a commit SHA-1, walk down to parents until either SEEN,
 408  * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 409  * all walked commits.
 410  */
 411 static void paint_down(struct paint_info *info, const unsigned char *sha1,
 412                        int id)
 413 {
 414         unsigned int i, nr;
 415         struct commit_list *head = NULL;
 416         int bitmap_nr = (info->nr_bits + 31) / 32;
 417         int bitmap_size = bitmap_nr * sizeof(uint32_t);
 418         uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
 419         uint32_t *bitmap = paint_alloc(info);
 420         struct commit *c = lookup_commit_reference_gently(sha1, 1);
 421         if (!c)
 422                 return;
 423         memset(bitmap, 0, bitmap_size);
 424         bitmap[id / 32] |= (1 << (id % 32));
 425         commit_list_insert(c, &head);
 426         while (head) {
 427                 struct commit_list *p;
 428                 struct commit *c = head->item;
 429                 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
 430
 431                 p = head;
 432                 head = head->next;
 433                 free(p);
 434
 435                 /* XXX check "UNINTERESTING" from pack bitmaps if available */
 436                 if (c->object.flags & (SEEN | UNINTERESTING))
 437                         continue;
 438                 else
 439                         c->object.flags |= SEEN;
 440
 441                 if (*refs == NULL)
 442                         *refs = bitmap;
 443                 else {
 444                         memcpy(tmp, *refs, bitmap_size);
 445                         for (i = 0; i < bitmap_nr; i++)
 446                                 tmp[i] |= bitmap[i];
 447                         if (memcmp(tmp, *refs, bitmap_size)) {
 448                                 *refs = paint_alloc(info);
 449                                 memcpy(*refs, tmp, bitmap_size);
 450                         }
 451                 }
 452
 453                 if (c->object.flags & BOTTOM)
 454                         continue;
 455
 456                 if (parse_commit(c))
 457                         die("unable to parse commit %s",
 458                             sha1_to_hex(c->object.sha1));
 459
 460                 for (p = c->parents; p; p = p->next) {
 461                         uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
 462                                                           p->item);
 463                         if (p->item->object.flags & SEEN)
 464                                 continue;
 465                         if (*p_refs == NULL || *p_refs == *refs)
 466                                 *p_refs = *refs;
 467                         commit_list_insert(p->item, &head);
 468                 }
 469         }
 470
 471         nr = get_max_object_index();
 472         for (i = 0; i < nr; i++) {
 473                 struct object *o = get_indexed_object(i);
 474                 if (o && o->type == OBJ_COMMIT)
 475                         o->flags &= ~SEEN;
 476         }
 477
 478         free(tmp);
 479 }
 480
 481 static int mark_uninteresting(const char *refname,
 482                               const unsigned char *sha1,
 483                               int flags, void *cb_data)
 484 {
 485         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 486         if (!commit)
 487                 return 0;
 488         commit->object.flags |= UNINTERESTING;
 489         mark_parents_uninteresting(commit);
 490         return 0;
 491 }
 492
 493 static void post_assign_shallow(struct shallow_info *info,
 494                                 struct ref_bitmap *ref_bitmap,
 495                                 int *ref_status);
 496 /*
 497  * Step 6(+7), associate shallow commits with new refs
 498  *
 499  * info->ref must be initialized before calling this function.
 500  *
 501  * If used is not NULL, it's an array of info->shallow->nr
 502  * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 503  * m-th shallow commit from info->shallow.
 504  *
 505  * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 506  * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 507  * the ref needs some shallow commits from either info->ours or
 508  * info->theirs.
 509  */
 510 void assign_shallow_commits_to_refs(struct shallow_info *info,
 511                                     uint32_t **used, int *ref_status)
 512 {
 513         unsigned char (*sha1)[20] = info->shallow->sha1;
 514         struct sha1_array *ref = info->ref;
 515         unsigned int i, nr;
 516         int *shallow, nr_shallow = 0;
 517         struct paint_info pi;
 518
 519         trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
 520         shallow = xmalloc(sizeof(*shallow) * (info->nr_ours + info->nr_theirs));
 521         for (i = 0; i < info->nr_ours; i++)
 522                 shallow[nr_shallow++] = info->ours[i];
 523         for (i = 0; i < info->nr_theirs; i++)
 524                 shallow[nr_shallow++] = info->theirs[i];
 525
 526         /*
 527          * Prepare the commit graph to track what refs can reach what
 528          * (new) shallow commits.
 529          */
 530         nr = get_max_object_index();
 531         for (i = 0; i < nr; i++) {
 532                 struct object *o = get_indexed_object(i);
 533                 if (!o || o->type != OBJ_COMMIT)
 534                         continue;
 535
 536                 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
 537         }
 538
 539         memset(&pi, 0, sizeof(pi));
 540         init_ref_bitmap(&pi.ref_bitmap);
 541         pi.nr_bits = ref->nr;
 542
 543         /*
 544          * "--not --all" to cut short the traversal if new refs
 545          * connect to old refs. If not (e.g. force ref updates) it'll
 546          * have to go down to the current shallow commits.
 547          */
 548         head_ref(mark_uninteresting, NULL);
 549         for_each_ref(mark_uninteresting, NULL);
 550
 551         /* Mark potential bottoms so we won't go out of bound */
 552         for (i = 0; i < nr_shallow; i++) {
 553                 struct commit *c = lookup_commit(sha1[shallow[i]]);
 554                 c->object.flags |= BOTTOM;
 555         }
 556
 557         for (i = 0; i < ref->nr; i++)
 558                 paint_down(&pi, ref->sha1[i], i);
 559
 560         if (used) {
 561                 int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
 562                 memset(used, 0, sizeof(*used) * info->shallow->nr);
 563                 for (i = 0; i < nr_shallow; i++) {
 564                         const struct commit *c = lookup_commit(sha1[shallow[i]]);
 565                         uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
 566                         if (*map)
 567                                 used[shallow[i]] = xmemdupz(*map, bitmap_size);
 568                 }
 569                 /*
 570                  * unreachable shallow commits are not removed from
 571                  * "ours" and "theirs". The user is supposed to run
 572                  * step 7 on every ref separately and not trust "ours"
 573                  * and "theirs" any more.
 574                  */
 575         } else
 576                 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
 577
 578         clear_ref_bitmap(&pi.ref_bitmap);
 579         for (i = 0; i < pi.slab_count; i++)
 580                 free(pi.slab[i]);
 581         free(pi.slab);
 582         free(shallow);
 583 }
 584
 585 struct commit_array {
 586         struct commit **commits;
 587         int nr, alloc;
 588 };
 589
 590 static int add_ref(const char *refname,
 591                    const unsigned char *sha1, int flags, void *cb_data)
 592 {
 593         struct commit_array *ca = cb_data;
 594         ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
 595         ca->commits[ca->nr] = lookup_commit_reference_gently(sha1, 1);
 596         if (ca->commits[ca->nr])
 597                 ca->nr++;
 598         return 0;
 599 }
 600
 601 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
 602 {
 603         int i;
 604         if (!ref_status)
 605                 return;
 606         for (i = 0; i < nr; i++)
 607                 if (bitmap[i / 32] & (1 << (i % 32)))
 608                         ref_status[i]++;
 609 }
 610
 611 /*
 612  * Step 7, reachability test on "ours" at commit level
 613  */
 614 static void post_assign_shallow(struct shallow_info *info,
 615                                 struct ref_bitmap *ref_bitmap,
 616                                 int *ref_status)
 617 {
 618         unsigned char (*sha1)[20] = info->shallow->sha1;
 619         struct commit *c;
 620         uint32_t **bitmap;
 621         int dst, i, j;
 622         int bitmap_nr = (info->ref->nr + 31) / 32;
 623         struct commit_array ca;
 624
 625         trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
 626         if (ref_status)
 627                 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
 628
 629         /* Remove unreachable shallow commits from "theirs" */
 630         for (i = dst = 0; i < info->nr_theirs; i++) {
 631                 if (i != dst)
 632                         info->theirs[dst] = info->theirs[i];
 633                 c = lookup_commit(sha1[info->theirs[i]]);
 634                 bitmap = ref_bitmap_at(ref_bitmap, c);
 635                 if (!*bitmap)
 636                         continue;
 637                 for (j = 0; j < bitmap_nr; j++)
 638                         if (bitmap[0][j]) {
 639                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 640                                 dst++;
 641                                 break;
 642                         }
 643         }
 644         info->nr_theirs = dst;
 645
 646         memset(&ca, 0, sizeof(ca));
 647         head_ref(add_ref, &ca);
 648         for_each_ref(add_ref, &ca);
 649
 650         /* Remove unreachable shallow commits from "ours" */
 651         for (i = dst = 0; i < info->nr_ours; i++) {
 652                 if (i != dst)
 653                         info->ours[dst] = info->ours[i];
 654                 c = lookup_commit(sha1[info->ours[i]]);
 655                 bitmap = ref_bitmap_at(ref_bitmap, c);
 656                 if (!*bitmap)
 657                         continue;
 658                 for (j = 0; j < bitmap_nr; j++)
 659                         if (bitmap[0][j] &&
 660                             /* Step 7, reachability test at commit level */
 661                             !in_merge_bases_many(c, ca.nr, ca.commits)) {
 662                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 663                                 dst++;
 664                                 break;
 665                         }
 666         }
 667         info->nr_ours = dst;
 668
 669         free(ca.commits);
 670 }
 671
 672 /* (Delayed) step 7, reachability test at commit level */
 673 int delayed_reachability_test(struct shallow_info *si, int c)
 674 {
 675         if (si->need_reachability_test[c]) {
 676                 struct commit *commit = lookup_commit(si->shallow->sha1[c]);
 677
 678                 if (!si->commits) {
 679                         struct commit_array ca;
 680                         memset(&ca, 0, sizeof(ca));
 681                         head_ref(add_ref, &ca);
 682                         for_each_ref(add_ref, &ca);
 683                         si->commits = ca.commits;
 684                         si->nr_commits = ca.nr;
 685                 }
 686
 687                 si->reachable[c] = in_merge_bases_many(commit,
 688                                                        si->nr_commits,
 689                                                        si->commits);
 690                 si->need_reachability_test[c] = 0;
 691         }
 692         return si->reachable[c];
 693 }