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
  16 static int is_shallow = -1;
  17 static struct stat_validity shallow_stat;
  18 static char *alternate_shallow_file;
  19
  20 void set_alternate_shallow_file(const char *path, int override)
  21 {
  22         if (is_shallow != -1)
  23                 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
  24         if (alternate_shallow_file && !override)
  25                 return;
  26         free(alternate_shallow_file);
  27         alternate_shallow_file = xstrdup_or_null(path);
  28 }
  29
  30 int register_shallow(const unsigned char *sha1)
  31 {
  32         struct commit_graft *graft =
  33                 xmalloc(sizeof(struct commit_graft));
  34         struct commit *commit = lookup_commit(sha1);
  35
  36         hashcpy(graft->oid.hash, sha1);
  37         graft->nr_parent = -1;
  38         if (commit && commit->object.parsed)
  39                 commit->parents = NULL;
  40         return register_commit_graft(graft, 0);
  41 }
  42
  43 int is_repository_shallow(void)
  44 {
  45         FILE *fp;
  46         char buf[1024];
  47         const char *path = alternate_shallow_file;
  48
  49         if (is_shallow >= 0)
  50                 return is_shallow;
  51
  52         if (!path)
  53                 path = git_path_shallow();
  54         /*
  55          * fetch-pack sets '--shallow-file ""' as an indicator that no
  56          * shallow file should be used. We could just open it and it
  57          * will likely fail. But let's do an explicit check instead.
  58          */
  59         if (!*path || (fp = fopen(path, "r")) == NULL) {
  60                 stat_validity_clear(&shallow_stat);
  61                 is_shallow = 0;
  62                 return is_shallow;
  63         }
  64         stat_validity_update(&shallow_stat, fileno(fp));
  65         is_shallow = 1;
  66
  67         while (fgets(buf, sizeof(buf), fp)) {
  68                 unsigned char sha1[20];
  69                 if (get_sha1_hex(buf, sha1))
  70                         die("bad shallow line: %s", buf);
  71                 register_shallow(sha1);
  72         }
  73         fclose(fp);
  74         return is_shallow;
  75 }
  76
  77 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  78                 int shallow_flag, int not_shallow_flag)
  79 {
  80         int i = 0, cur_depth = 0;
  81         struct commit_list *result = NULL;
  82         struct object_array stack = OBJECT_ARRAY_INIT;
  83         struct commit *commit = NULL;
  84         struct commit_graft *graft;
  85
  86         while (commit || i < heads->nr || stack.nr) {
  87                 struct commit_list *p;
  88                 if (!commit) {
  89                         if (i < heads->nr) {
  90                                 commit = (struct commit *)
  91                                         deref_tag(heads->objects[i++].item, NULL, 0);
  92                                 if (!commit || commit->object.type != OBJ_COMMIT) {
  93                                         commit = NULL;
  94                                         continue;
  95                                 }
  96                                 if (!commit->util)
  97                                         commit->util = xmalloc(sizeof(int));
  98                                 *(int *)commit->util = 0;
  99                                 cur_depth = 0;
 100                         } else {
 101                                 commit = (struct commit *)
 102                                         stack.objects[--stack.nr].item;
 103                                 cur_depth = *(int *)commit->util;
 104                         }
 105                 }
 106                 parse_commit_or_die(commit);
 107                 cur_depth++;
 108                 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
 109                     (is_repository_shallow() && !commit->parents &&
 110                      (graft = lookup_commit_graft(commit->object.oid.hash)) != NULL &&
 111                      graft->nr_parent < 0)) {
 112                         commit_list_insert(commit, &result);
 113                         commit->object.flags |= shallow_flag;
 114                         commit = NULL;
 115                         continue;
 116                 }
 117                 commit->object.flags |= not_shallow_flag;
 118                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 119                         if (!p->item->util) {
 120                                 int *pointer = xmalloc(sizeof(int));
 121                                 p->item->util = pointer;
 122                                 *pointer =  cur_depth;
 123                         } else {
 124                                 int *pointer = p->item->util;
 125                                 if (cur_depth >= *pointer)
 126                                         continue;
 127                                 *pointer = cur_depth;
 128                         }
 129                         if (p->next)
 130                                 add_object_array(&p->item->object,
 131                                                 NULL, &stack);
 132                         else {
 133                                 commit = p->item;
 134                                 cur_depth = *(int *)commit->util;
 135                         }
 136                 }
 137         }
 138
 139         return result;
 140 }
 141
 142 static void show_commit(struct commit *commit, void *data)
 143 {
 144         commit_list_insert(commit, data);
 145 }
 146
 147 /*
 148  * Given rev-list arguments, run rev-list. All reachable commits
 149  * except border ones are marked with not_shallow_flag. Border commits
 150  * are marked with shallow_flag. The list of border/shallow commits
 151  * are also returned.
 152  */
 153 struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
 154                                                     int shallow_flag,
 155                                                     int not_shallow_flag)
 156 {
 157         struct commit_list *result = NULL, *p;
 158         struct commit_list *not_shallow_list = NULL;
 159         struct rev_info revs;
 160         int both_flags = shallow_flag | not_shallow_flag;
 161
 162         /*
 163          * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
 164          * set at this point. But better be safe than sorry.
 165          */
 166         clear_object_flags(both_flags);
 167
 168         is_repository_shallow(); /* make sure shallows are read */
 169
 170         init_revisions(&revs, NULL);
 171         save_commit_buffer = 0;
 172         setup_revisions(ac, av, &revs, NULL);
 173
 174         if (prepare_revision_walk(&revs))
 175                 die("revision walk setup failed");
 176         traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
 177
 178         /* Mark all reachable commits as NOT_SHALLOW */
 179         for (p = not_shallow_list; p; p = p->next)
 180                 p->item->object.flags |= not_shallow_flag;
 181
 182         /*
 183          * mark border commits SHALLOW + NOT_SHALLOW.
 184          * We cannot clear NOT_SHALLOW right now. Imagine border
 185          * commit A is processed first, then commit B, whose parent is
 186          * A, later. If NOT_SHALLOW on A is cleared at step 1, B
 187          * itself is considered border at step 2, which is incorrect.
 188          */
 189         for (p = not_shallow_list; p; p = p->next) {
 190                 struct commit *c = p->item;
 191                 struct commit_list *parent;
 192
 193                 if (parse_commit(c))
 194                         die("unable to parse commit %s",
 195                             oid_to_hex(&c->object.oid));
 196
 197                 for (parent = c->parents; parent; parent = parent->next)
 198                         if (!(parent->item->object.flags & not_shallow_flag)) {
 199                                 c->object.flags |= shallow_flag;
 200                                 commit_list_insert(c, &result);
 201                                 break;
 202                         }
 203         }
 204         free_commit_list(not_shallow_list);
 205
 206         /*
 207          * Now we can clean up NOT_SHALLOW on border commits. Having
 208          * both flags set can confuse the caller.
 209          */
 210         for (p = result; p; p = p->next) {
 211                 struct object *o = &p->item->object;
 212                 if ((o->flags & both_flags) == both_flags)
 213                         o->flags &= ~not_shallow_flag;
 214         }
 215         return result;
 216 }
 217
 218 static void check_shallow_file_for_update(void)
 219 {
 220         if (is_shallow == -1)
 221                 die("BUG: shallow must be initialized by now");
 222
 223         if (!stat_validity_check(&shallow_stat, git_path_shallow()))
 224                 die("shallow file has changed since we read it");
 225 }
 226
 227 #define SEEN_ONLY 1
 228 #define VERBOSE   2
 229
 230 struct write_shallow_data {
 231         struct strbuf *out;
 232         int use_pack_protocol;
 233         int count;
 234         unsigned flags;
 235 };
 236
 237 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 238 {
 239         struct write_shallow_data *data = cb_data;
 240         const char *hex = oid_to_hex(&graft->oid);
 241         if (graft->nr_parent != -1)
 242                 return 0;
 243         if (data->flags & SEEN_ONLY) {
 244                 struct commit *c = lookup_commit(graft->oid.hash);
 245                 if (!c || !(c->object.flags & SEEN)) {
 246                         if (data->flags & VERBOSE)
 247                                 printf("Removing %s from .git/shallow\n",
 248                                        oid_to_hex(&c->object.oid));
 249                         return 0;
 250                 }
 251         }
 252         data->count++;
 253         if (data->use_pack_protocol)
 254                 packet_buf_write(data->out, "shallow %s", hex);
 255         else {
 256                 strbuf_addstr(data->out, hex);
 257                 strbuf_addch(data->out, '\n');
 258         }
 259         return 0;
 260 }
 261
 262 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
 263                                    const struct sha1_array *extra,
 264                                    unsigned flags)
 265 {
 266         struct write_shallow_data data;
 267         int i;
 268         data.out = out;
 269         data.use_pack_protocol = use_pack_protocol;
 270         data.count = 0;
 271         data.flags = flags;
 272         for_each_commit_graft(write_one_shallow, &data);
 273         if (!extra)
 274                 return data.count;
 275         for (i = 0; i < extra->nr; i++) {
 276                 strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
 277                 strbuf_addch(out, '\n');
 278                 data.count++;
 279         }
 280         return data.count;
 281 }
 282
 283 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 284                           const struct sha1_array *extra)
 285 {
 286         return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 287 }
 288
 289 static struct tempfile temporary_shallow;
 290
 291 const char *setup_temporary_shallow(const struct sha1_array *extra)
 292 {
 293         struct strbuf sb = STRBUF_INIT;
 294         int fd;
 295
 296         if (write_shallow_commits(&sb, 0, extra)) {
 297                 fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
 298
 299                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 300                         die_errno("failed to write to %s",
 301                                   get_tempfile_path(&temporary_shallow));
 302                 close_tempfile(&temporary_shallow);
 303                 strbuf_release(&sb);
 304                 return get_tempfile_path(&temporary_shallow);
 305         }
 306         /*
 307          * is_repository_shallow() sees empty string as "no shallow
 308          * file".
 309          */
 310         return get_tempfile_path(&temporary_shallow);
 311 }
 312
 313 void setup_alternate_shallow(struct lock_file *shallow_lock,
 314                              const char **alternate_shallow_file,
 315                              const struct sha1_array *extra)
 316 {
 317         struct strbuf sb = STRBUF_INIT;
 318         int fd;
 319
 320         fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
 321                                        LOCK_DIE_ON_ERROR);
 322         check_shallow_file_for_update();
 323         if (write_shallow_commits(&sb, 0, extra)) {
 324                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 325                         die_errno("failed to write to %s",
 326                                   get_lock_file_path(shallow_lock));
 327                 *alternate_shallow_file = get_lock_file_path(shallow_lock);
 328         } else
 329                 /*
 330                  * is_repository_shallow() sees empty string as "no
 331                  * shallow file".
 332                  */
 333                 *alternate_shallow_file = "";
 334         strbuf_release(&sb);
 335 }
 336
 337 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 338 {
 339         int fd = *(int *)cb;
 340         if (graft->nr_parent == -1)
 341                 packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 342         return 0;
 343 }
 344
 345 void advertise_shallow_grafts(int fd)
 346 {
 347         if (!is_repository_shallow())
 348                 return;
 349         for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 350 }
 351
 352 /*
 353  * mark_reachable_objects() should have been run prior to this and all
 354  * reachable commits marked as "SEEN".
 355  */
 356 void prune_shallow(int show_only)
 357 {
 358         static struct lock_file shallow_lock;
 359         struct strbuf sb = STRBUF_INIT;
 360         int fd;
 361
 362         if (show_only) {
 363                 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
 364                 strbuf_release(&sb);
 365                 return;
 366         }
 367         fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
 368                                        LOCK_DIE_ON_ERROR);
 369         check_shallow_file_for_update();
 370         if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
 371                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 372                         die_errno("failed to write to %s",
 373                                   get_lock_file_path(&shallow_lock));
 374                 commit_lock_file(&shallow_lock);
 375         } else {
 376                 unlink(git_path_shallow());
 377                 rollback_lock_file(&shallow_lock);
 378         }
 379         strbuf_release(&sb);
 380 }
 381
 382 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
 383
 384 /*
 385  * Step 1, split sender shallow commits into "ours" and "theirs"
 386  * Step 2, clean "ours" based on .git/shallow
 387  */
 388 void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
 389 {
 390         int i;
 391         trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
 392         memset(info, 0, sizeof(*info));
 393         info->shallow = sa;
 394         if (!sa)
 395                 return;
 396         ALLOC_ARRAY(info->ours, sa->nr);
 397         ALLOC_ARRAY(info->theirs, sa->nr);
 398         for (i = 0; i < sa->nr; i++) {
 399                 if (has_sha1_file(sa->sha1[i])) {
 400                         struct commit_graft *graft;
 401                         graft = lookup_commit_graft(sa->sha1[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         unsigned char (*sha1)[20] = info->shallow->sha1;
 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_sha1_file(sha1[info->theirs[i]]))
 427                         dst++;
 428         }
 429         info->nr_theirs = dst;
 430 }
 431
 432 define_commit_slab(ref_bitmap, uint32_t *);
 433
 434 struct paint_info {
 435         struct ref_bitmap ref_bitmap;
 436         unsigned nr_bits;
 437         char **slab;
 438         char *free, *end;
 439         unsigned slab_count;
 440 };
 441
 442 static uint32_t *paint_alloc(struct paint_info *info)
 443 {
 444         unsigned nr = (info->nr_bits + 31) / 32;
 445         unsigned size = nr * sizeof(uint32_t);
 446         void *p;
 447         if (!info->slab_count || info->free + size > info->end) {
 448                 info->slab_count++;
 449                 REALLOC_ARRAY(info->slab, info->slab_count);
 450                 info->free = xmalloc(COMMIT_SLAB_SIZE);
 451                 info->slab[info->slab_count - 1] = info->free;
 452                 info->end = info->free + COMMIT_SLAB_SIZE;
 453         }
 454         p = info->free;
 455         info->free += size;
 456         return p;
 457 }
 458
 459 /*
 460  * Given a commit SHA-1, walk down to parents until either SEEN,
 461  * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 462  * all walked commits.
 463  */
 464 static void paint_down(struct paint_info *info, const unsigned char *sha1,
 465                        int id)
 466 {
 467         unsigned int i, nr;
 468         struct commit_list *head = NULL;
 469         int bitmap_nr = (info->nr_bits + 31) / 32;
 470         size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 471         uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
 472         uint32_t *bitmap = paint_alloc(info);
 473         struct commit *c = lookup_commit_reference_gently(sha1, 1);
 474         if (!c)
 475                 return;
 476         memset(bitmap, 0, bitmap_size);
 477         bitmap[id / 32] |= (1 << (id % 32));
 478         commit_list_insert(c, &head);
 479         while (head) {
 480                 struct commit_list *p;
 481                 struct commit *c = pop_commit(&head);
 482                 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
 483
 484                 /* XXX check "UNINTERESTING" from pack bitmaps if available */
 485                 if (c->object.flags & (SEEN | UNINTERESTING))
 486                         continue;
 487                 else
 488                         c->object.flags |= SEEN;
 489
 490                 if (*refs == NULL)
 491                         *refs = bitmap;
 492                 else {
 493                         memcpy(tmp, *refs, bitmap_size);
 494                         for (i = 0; i < bitmap_nr; i++)
 495                                 tmp[i] |= bitmap[i];
 496                         if (memcmp(tmp, *refs, bitmap_size)) {
 497                                 *refs = paint_alloc(info);
 498                                 memcpy(*refs, tmp, bitmap_size);
 499                         }
 500                 }
 501
 502                 if (c->object.flags & BOTTOM)
 503                         continue;
 504
 505                 if (parse_commit(c))
 506                         die("unable to parse commit %s",
 507                             oid_to_hex(&c->object.oid));
 508
 509                 for (p = c->parents; p; p = p->next) {
 510                         uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
 511                                                           p->item);
 512                         if (p->item->object.flags & SEEN)
 513                                 continue;
 514                         if (*p_refs == NULL || *p_refs == *refs)
 515                                 *p_refs = *refs;
 516                         commit_list_insert(p->item, &head);
 517                 }
 518         }
 519
 520         nr = get_max_object_index();
 521         for (i = 0; i < nr; i++) {
 522                 struct object *o = get_indexed_object(i);
 523                 if (o && o->type == OBJ_COMMIT)
 524                         o->flags &= ~SEEN;
 525         }
 526
 527         free(tmp);
 528 }
 529
 530 static int mark_uninteresting(const char *refname, const struct object_id *oid,
 531                               int flags, void *cb_data)
 532 {
 533         struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
 534         if (!commit)
 535                 return 0;
 536         commit->object.flags |= UNINTERESTING;
 537         mark_parents_uninteresting(commit);
 538         return 0;
 539 }
 540
 541 static void post_assign_shallow(struct shallow_info *info,
 542                                 struct ref_bitmap *ref_bitmap,
 543                                 int *ref_status);
 544 /*
 545  * Step 6(+7), associate shallow commits with new refs
 546  *
 547  * info->ref must be initialized before calling this function.
 548  *
 549  * If used is not NULL, it's an array of info->shallow->nr
 550  * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 551  * m-th shallow commit from info->shallow.
 552  *
 553  * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 554  * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 555  * the ref needs some shallow commits from either info->ours or
 556  * info->theirs.
 557  */
 558 void assign_shallow_commits_to_refs(struct shallow_info *info,
 559                                     uint32_t **used, int *ref_status)
 560 {
 561         unsigned char (*sha1)[20] = info->shallow->sha1;
 562         struct sha1_array *ref = info->ref;
 563         unsigned int i, nr;
 564         int *shallow, nr_shallow = 0;
 565         struct paint_info pi;
 566
 567         trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
 568         ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
 569         for (i = 0; i < info->nr_ours; i++)
 570                 shallow[nr_shallow++] = info->ours[i];
 571         for (i = 0; i < info->nr_theirs; i++)
 572                 shallow[nr_shallow++] = info->theirs[i];
 573
 574         /*
 575          * Prepare the commit graph to track what refs can reach what
 576          * (new) shallow commits.
 577          */
 578         nr = get_max_object_index();
 579         for (i = 0; i < nr; i++) {
 580                 struct object *o = get_indexed_object(i);
 581                 if (!o || o->type != OBJ_COMMIT)
 582                         continue;
 583
 584                 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
 585         }
 586
 587         memset(&pi, 0, sizeof(pi));
 588         init_ref_bitmap(&pi.ref_bitmap);
 589         pi.nr_bits = ref->nr;
 590
 591         /*
 592          * "--not --all" to cut short the traversal if new refs
 593          * connect to old refs. If not (e.g. force ref updates) it'll
 594          * have to go down to the current shallow commits.
 595          */
 596         head_ref(mark_uninteresting, NULL);
 597         for_each_ref(mark_uninteresting, NULL);
 598
 599         /* Mark potential bottoms so we won't go out of bound */
 600         for (i = 0; i < nr_shallow; i++) {
 601                 struct commit *c = lookup_commit(sha1[shallow[i]]);
 602                 c->object.flags |= BOTTOM;
 603         }
 604
 605         for (i = 0; i < ref->nr; i++)
 606                 paint_down(&pi, ref->sha1[i], i);
 607
 608         if (used) {
 609                 int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
 610                 memset(used, 0, sizeof(*used) * info->shallow->nr);
 611                 for (i = 0; i < nr_shallow; i++) {
 612                         const struct commit *c = lookup_commit(sha1[shallow[i]]);
 613                         uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
 614                         if (*map)
 615                                 used[shallow[i]] = xmemdupz(*map, bitmap_size);
 616                 }
 617                 /*
 618                  * unreachable shallow commits are not removed from
 619                  * "ours" and "theirs". The user is supposed to run
 620                  * step 7 on every ref separately and not trust "ours"
 621                  * and "theirs" any more.
 622                  */
 623         } else
 624                 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
 625
 626         clear_ref_bitmap(&pi.ref_bitmap);
 627         for (i = 0; i < pi.slab_count; i++)
 628                 free(pi.slab[i]);
 629         free(pi.slab);
 630         free(shallow);
 631 }
 632
 633 struct commit_array {
 634         struct commit **commits;
 635         int nr, alloc;
 636 };
 637
 638 static int add_ref(const char *refname, const struct object_id *oid,
 639                    int flags, void *cb_data)
 640 {
 641         struct commit_array *ca = cb_data;
 642         ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
 643         ca->commits[ca->nr] = lookup_commit_reference_gently(oid->hash, 1);
 644         if (ca->commits[ca->nr])
 645                 ca->nr++;
 646         return 0;
 647 }
 648
 649 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
 650 {
 651         int i;
 652         if (!ref_status)
 653                 return;
 654         for (i = 0; i < nr; i++)
 655                 if (bitmap[i / 32] & (1 << (i % 32)))
 656                         ref_status[i]++;
 657 }
 658
 659 /*
 660  * Step 7, reachability test on "ours" at commit level
 661  */
 662 static void post_assign_shallow(struct shallow_info *info,
 663                                 struct ref_bitmap *ref_bitmap,
 664                                 int *ref_status)
 665 {
 666         unsigned char (*sha1)[20] = info->shallow->sha1;
 667         struct commit *c;
 668         uint32_t **bitmap;
 669         int dst, i, j;
 670         int bitmap_nr = (info->ref->nr + 31) / 32;
 671         struct commit_array ca;
 672
 673         trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
 674         if (ref_status)
 675                 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
 676
 677         /* Remove unreachable shallow commits from "theirs" */
 678         for (i = dst = 0; i < info->nr_theirs; i++) {
 679                 if (i != dst)
 680                         info->theirs[dst] = info->theirs[i];
 681                 c = lookup_commit(sha1[info->theirs[i]]);
 682                 bitmap = ref_bitmap_at(ref_bitmap, c);
 683                 if (!*bitmap)
 684                         continue;
 685                 for (j = 0; j < bitmap_nr; j++)
 686                         if (bitmap[0][j]) {
 687                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 688                                 dst++;
 689                                 break;
 690                         }
 691         }
 692         info->nr_theirs = dst;
 693
 694         memset(&ca, 0, sizeof(ca));
 695         head_ref(add_ref, &ca);
 696         for_each_ref(add_ref, &ca);
 697
 698         /* Remove unreachable shallow commits from "ours" */
 699         for (i = dst = 0; i < info->nr_ours; i++) {
 700                 if (i != dst)
 701                         info->ours[dst] = info->ours[i];
 702                 c = lookup_commit(sha1[info->ours[i]]);
 703                 bitmap = ref_bitmap_at(ref_bitmap, c);
 704                 if (!*bitmap)
 705                         continue;
 706                 for (j = 0; j < bitmap_nr; j++)
 707                         if (bitmap[0][j] &&
 708                             /* Step 7, reachability test at commit level */
 709                             !in_merge_bases_many(c, ca.nr, ca.commits)) {
 710                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 711                                 dst++;
 712                                 break;
 713                         }
 714         }
 715         info->nr_ours = dst;
 716
 717         free(ca.commits);
 718 }
 719
 720 /* (Delayed) step 7, reachability test at commit level */
 721 int delayed_reachability_test(struct shallow_info *si, int c)
 722 {
 723         if (si->need_reachability_test[c]) {
 724                 struct commit *commit = lookup_commit(si->shallow->sha1[c]);
 725
 726                 if (!si->commits) {
 727                         struct commit_array ca;
 728
 729                         memset(&ca, 0, sizeof(ca));
 730                         head_ref(add_ref, &ca);
 731                         for_each_ref(add_ref, &ca);
 732                         si->commits = ca.commits;
 733                         si->nr_commits = ca.nr;
 734                 }
 735
 736                 si->reachable[c] = in_merge_bases_many(commit,
 737                                                        si->nr_commits,
 738                                                        si->commits);
 739                 si->need_reachability_test[c] = 0;
 740         }
 741         return si->reachable[c];
 742 }