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 "commit-slab.h"
  18 #include "repository.h"
  19
  20 void set_alternate_shallow_file(struct repository *r, const char *path, int override)
  21 {
  22         if (r->parsed_objects->is_shallow != -1)
  23                 BUG("is_repository_shallow must not be called before set_alternate_shallow_file");
  24         if (r->parsed_objects->alternate_shallow_file && !override)
  25                 return;
  26         free(r->parsed_objects->alternate_shallow_file);
  27         r->parsed_objects->alternate_shallow_file = xstrdup_or_null(path);
  28 }
  29
  30 int register_shallow(struct repository *r, const struct object_id *oid)
  31 {
  32         struct commit_graft *graft =
  33                 xmalloc(sizeof(struct commit_graft));
  34         struct commit *commit = lookup_commit(the_repository, oid);
  35
  36         oidcpy(&graft->oid, oid);
  37         graft->nr_parent = -1;
  38         if (commit && commit->object.parsed)
  39                 commit->parents = NULL;
  40         return register_commit_graft(r, graft, 0);
  41 }
  42
  43 int is_repository_shallow(struct repository *r)
  44 {
  45         FILE *fp;
  46         char buf[1024];
  47         const char *path = r->parsed_objects->alternate_shallow_file;
  48
  49         if (r->parsed_objects->is_shallow >= 0)
  50                 return r->parsed_objects->is_shallow;
  51
  52         if (!path)
  53                 path = git_path_shallow(r);
  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(r->parsed_objects->shallow_stat);
  61                 r->parsed_objects->is_shallow = 0;
  62                 return r->parsed_objects->is_shallow;
  63         }
  64         stat_validity_update(r->parsed_objects->shallow_stat, fileno(fp));
  65         r->parsed_objects->is_shallow = 1;
  66
  67         while (fgets(buf, sizeof(buf), fp)) {
  68                 struct object_id oid;
  69                 if (get_oid_hex(buf, &oid))
  70                         die("bad shallow line: %s", buf);
  71                 register_shallow(r, &oid);
  72         }
  73         fclose(fp);
  74         return r->parsed_objects->is_shallow;
  75 }
  76
  77 /*
  78  * TODO: use "int" elemtype instead of "int *" when/if commit-slab
  79  * supports a "valid" flag.
  80  */
  81 define_commit_slab(commit_depth, int *);
  82 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  83                 int shallow_flag, int not_shallow_flag)
  84 {
  85         int i = 0, cur_depth = 0;
  86         struct commit_list *result = NULL;
  87         struct object_array stack = OBJECT_ARRAY_INIT;
  88         struct commit *commit = NULL;
  89         struct commit_graft *graft;
  90         struct commit_depth depths;
  91
  92         init_commit_depth(&depths);
  93         while (commit || i < heads->nr || stack.nr) {
  94                 struct commit_list *p;
  95                 if (!commit) {
  96                         if (i < heads->nr) {
  97                                 int **depth_slot;
  98                                 commit = (struct commit *)
  99                                         deref_tag(the_repository,
 100                                                   heads->objects[i++].item,
 101                                                   NULL, 0);
 102                                 if (!commit || commit->object.type != OBJ_COMMIT) {
 103                                         commit = NULL;
 104                                         continue;
 105                                 }
 106                                 depth_slot = commit_depth_at(&depths, commit);
 107                                 if (!*depth_slot)
 108                                         *depth_slot = xmalloc(sizeof(int));
 109                                 **depth_slot = 0;
 110                                 cur_depth = 0;
 111                         } else {
 112                                 commit = (struct commit *)
 113                                         object_array_pop(&stack);
 114                                 cur_depth = **commit_depth_at(&depths, commit);
 115                         }
 116                 }
 117                 parse_commit_or_die(commit);
 118                 cur_depth++;
 119                 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
 120                     (is_repository_shallow(the_repository) && !commit->parents &&
 121                      (graft = lookup_commit_graft(the_repository, &commit->object.oid)) != NULL &&
 122                      graft->nr_parent < 0)) {
 123                         commit_list_insert(commit, &result);
 124                         commit->object.flags |= shallow_flag;
 125                         commit = NULL;
 126                         continue;
 127                 }
 128                 commit->object.flags |= not_shallow_flag;
 129                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 130                         int **depth_slot = commit_depth_at(&depths, p->item);
 131                         if (!*depth_slot) {
 132                                 *depth_slot = xmalloc(sizeof(int));
 133                                 **depth_slot = cur_depth;
 134                         } else {
 135                                 if (cur_depth >= **depth_slot)
 136                                         continue;
 137                                 **depth_slot = cur_depth;
 138                         }
 139                         if (p->next)
 140                                 add_object_array(&p->item->object,
 141                                                 NULL, &stack);
 142                         else {
 143                                 commit = p->item;
 144                                 cur_depth = **commit_depth_at(&depths, commit);
 145                         }
 146                 }
 147         }
 148         for (i = 0; i < depths.slab_count; i++) {
 149                 int j;
 150
 151                 for (j = 0; j < depths.slab_size; j++)
 152                         free(depths.slab[i][j]);
 153         }
 154         clear_commit_depth(&depths);
 155
 156         return result;
 157 }
 158
 159 static void show_commit(struct commit *commit, void *data)
 160 {
 161         commit_list_insert(commit, data);
 162 }
 163
 164 /*
 165  * Given rev-list arguments, run rev-list. All reachable commits
 166  * except border ones are marked with not_shallow_flag. Border commits
 167  * are marked with shallow_flag. The list of border/shallow commits
 168  * are also returned.
 169  */
 170 struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
 171                                                     int shallow_flag,
 172                                                     int not_shallow_flag)
 173 {
 174         struct commit_list *result = NULL, *p;
 175         struct commit_list *not_shallow_list = NULL;
 176         struct rev_info revs;
 177         int both_flags = shallow_flag | not_shallow_flag;
 178
 179         /*
 180          * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
 181          * set at this point. But better be safe than sorry.
 182          */
 183         clear_object_flags(both_flags);
 184
 185         is_repository_shallow(the_repository); /* make sure shallows are read */
 186
 187         init_revisions(&revs, NULL);
 188         save_commit_buffer = 0;
 189         setup_revisions(ac, av, &revs, NULL);
 190
 191         if (prepare_revision_walk(&revs))
 192                 die("revision walk setup failed");
 193         traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
 194
 195         if (!not_shallow_list)
 196                 die("no commits selected for shallow requests");
 197
 198         /* Mark all reachable commits as NOT_SHALLOW */
 199         for (p = not_shallow_list; p; p = p->next)
 200                 p->item->object.flags |= not_shallow_flag;
 201
 202         /*
 203          * mark border commits SHALLOW + NOT_SHALLOW.
 204          * We cannot clear NOT_SHALLOW right now. Imagine border
 205          * commit A is processed first, then commit B, whose parent is
 206          * A, later. If NOT_SHALLOW on A is cleared at step 1, B
 207          * itself is considered border at step 2, which is incorrect.
 208          */
 209         for (p = not_shallow_list; p; p = p->next) {
 210                 struct commit *c = p->item;
 211                 struct commit_list *parent;
 212
 213                 if (parse_commit(c))
 214                         die("unable to parse commit %s",
 215                             oid_to_hex(&c->object.oid));
 216
 217                 for (parent = c->parents; parent; parent = parent->next)
 218                         if (!(parent->item->object.flags & not_shallow_flag)) {
 219                                 c->object.flags |= shallow_flag;
 220                                 commit_list_insert(c, &result);
 221                                 break;
 222                         }
 223         }
 224         free_commit_list(not_shallow_list);
 225
 226         /*
 227          * Now we can clean up NOT_SHALLOW on border commits. Having
 228          * both flags set can confuse the caller.
 229          */
 230         for (p = result; p; p = p->next) {
 231                 struct object *o = &p->item->object;
 232                 if ((o->flags & both_flags) == both_flags)
 233                         o->flags &= ~not_shallow_flag;
 234         }
 235         return result;
 236 }
 237
 238 static void check_shallow_file_for_update(struct repository *r)
 239 {
 240         if (r->parsed_objects->is_shallow == -1)
 241                 BUG("shallow must be initialized by now");
 242
 243         if (!stat_validity_check(r->parsed_objects->shallow_stat, git_path_shallow(the_repository)))
 244                 die("shallow file has changed since we read it");
 245 }
 246
 247 #define SEEN_ONLY 1
 248 #define VERBOSE   2
 249 #define QUICK 4
 250
 251 struct write_shallow_data {
 252         struct strbuf *out;
 253         int use_pack_protocol;
 254         int count;
 255         unsigned flags;
 256 };
 257
 258 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 259 {
 260         struct write_shallow_data *data = cb_data;
 261         const char *hex = oid_to_hex(&graft->oid);
 262         if (graft->nr_parent != -1)
 263                 return 0;
 264         if (data->flags & QUICK) {
 265                 if (!has_object_file(&graft->oid))
 266                         return 0;
 267         } else if (data->flags & SEEN_ONLY) {
 268                 struct commit *c = lookup_commit(the_repository, &graft->oid);
 269                 if (!c || !(c->object.flags & SEEN)) {
 270                         if (data->flags & VERBOSE)
 271                                 printf("Removing %s from .git/shallow\n",
 272                                        oid_to_hex(&c->object.oid));
 273                         return 0;
 274                 }
 275         }
 276         data->count++;
 277         if (data->use_pack_protocol)
 278                 packet_buf_write(data->out, "shallow %s", hex);
 279         else {
 280                 strbuf_addstr(data->out, hex);
 281                 strbuf_addch(data->out, '\n');
 282         }
 283         return 0;
 284 }
 285
 286 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
 287                                    const struct oid_array *extra,
 288                                    unsigned flags)
 289 {
 290         struct write_shallow_data data;
 291         int i;
 292         data.out = out;
 293         data.use_pack_protocol = use_pack_protocol;
 294         data.count = 0;
 295         data.flags = flags;
 296         for_each_commit_graft(write_one_shallow, &data);
 297         if (!extra)
 298                 return data.count;
 299         for (i = 0; i < extra->nr; i++) {
 300                 strbuf_addstr(out, oid_to_hex(extra->oid + i));
 301                 strbuf_addch(out, '\n');
 302                 data.count++;
 303         }
 304         return data.count;
 305 }
 306
 307 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 308                           const struct oid_array *extra)
 309 {
 310         return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 311 }
 312
 313 const char *setup_temporary_shallow(const struct oid_array *extra)
 314 {
 315         struct tempfile *temp;
 316         struct strbuf sb = STRBUF_INIT;
 317
 318         if (write_shallow_commits(&sb, 0, extra)) {
 319                 temp = xmks_tempfile(git_path("shallow_XXXXXX"));
 320
 321                 if (write_in_full(temp->fd, sb.buf, sb.len) < 0 ||
 322                     close_tempfile_gently(temp) < 0)
 323                         die_errno("failed to write to %s",
 324                                   get_tempfile_path(temp));
 325                 strbuf_release(&sb);
 326                 return get_tempfile_path(temp);
 327         }
 328         /*
 329          * is_repository_shallow() sees empty string as "no shallow
 330          * file".
 331          */
 332         return "";
 333 }
 334
 335 void setup_alternate_shallow(struct lock_file *shallow_lock,
 336                              const char **alternate_shallow_file,
 337                              const struct oid_array *extra)
 338 {
 339         struct strbuf sb = STRBUF_INIT;
 340         int fd;
 341
 342         fd = hold_lock_file_for_update(shallow_lock,
 343                                        git_path_shallow(the_repository),
 344                                        LOCK_DIE_ON_ERROR);
 345         check_shallow_file_for_update(the_repository);
 346         if (write_shallow_commits(&sb, 0, extra)) {
 347                 if (write_in_full(fd, sb.buf, sb.len) < 0)
 348                         die_errno("failed to write to %s",
 349                                   get_lock_file_path(shallow_lock));
 350                 *alternate_shallow_file = get_lock_file_path(shallow_lock);
 351         } else
 352                 /*
 353                  * is_repository_shallow() sees empty string as "no
 354                  * shallow file".
 355                  */
 356                 *alternate_shallow_file = "";
 357         strbuf_release(&sb);
 358 }
 359
 360 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 361 {
 362         int fd = *(int *)cb;
 363         if (graft->nr_parent == -1)
 364                 packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 365         return 0;
 366 }
 367
 368 void advertise_shallow_grafts(int fd)
 369 {
 370         if (!is_repository_shallow(the_repository))
 371                 return;
 372         for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 373 }
 374
 375 /*
 376  * mark_reachable_objects() should have been run prior to this and all
 377  * reachable commits marked as "SEEN", except when quick_prune is non-zero,
 378  * in which case lines are excised from the shallow file if they refer to
 379  * commits that do not exist (any longer).
 380  */
 381 void prune_shallow(unsigned options)
 382 {
 383         struct lock_file shallow_lock = LOCK_INIT;
 384         struct strbuf sb = STRBUF_INIT;
 385         unsigned flags = SEEN_ONLY;
 386         int fd;
 387
 388         if (options & PRUNE_QUICK)
 389                 flags |= QUICK;
 390
 391         if (options & PRUNE_SHOW_ONLY) {
 392                 flags |= VERBOSE;
 393                 write_shallow_commits_1(&sb, 0, NULL, flags);
 394                 strbuf_release(&sb);
 395                 return;
 396         }
 397         fd = hold_lock_file_for_update(&shallow_lock,
 398                                        git_path_shallow(the_repository),
 399                                        LOCK_DIE_ON_ERROR);
 400         check_shallow_file_for_update(the_repository);
 401         if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
 402                 if (write_in_full(fd, sb.buf, sb.len) < 0)
 403                         die_errno("failed to write to %s",
 404                                   get_lock_file_path(&shallow_lock));
 405                 commit_lock_file(&shallow_lock);
 406         } else {
 407                 unlink(git_path_shallow(the_repository));
 408                 rollback_lock_file(&shallow_lock);
 409         }
 410         strbuf_release(&sb);
 411 }
 412
 413 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
 414
 415 /*
 416  * Step 1, split sender shallow commits into "ours" and "theirs"
 417  * Step 2, clean "ours" based on .git/shallow
 418  */
 419 void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
 420 {
 421         int i;
 422         trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
 423         memset(info, 0, sizeof(*info));
 424         info->shallow = sa;
 425         if (!sa)
 426                 return;
 427         ALLOC_ARRAY(info->ours, sa->nr);
 428         ALLOC_ARRAY(info->theirs, sa->nr);
 429         for (i = 0; i < sa->nr; i++) {
 430                 if (has_object_file(sa->oid + i)) {
 431                         struct commit_graft *graft;
 432                         graft = lookup_commit_graft(the_repository,
 433                                                     &sa->oid[i]);
 434                         if (graft && graft->nr_parent < 0)
 435                                 continue;
 436                         info->ours[info->nr_ours++] = i;
 437                 } else
 438                         info->theirs[info->nr_theirs++] = i;
 439         }
 440 }
 441
 442 void clear_shallow_info(struct shallow_info *info)
 443 {
 444         free(info->ours);
 445         free(info->theirs);
 446 }
 447
 448 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
 449
 450 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
 451 {
 452         struct object_id *oid = info->shallow->oid;
 453         int i, dst;
 454         trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
 455         for (i = dst = 0; i < info->nr_theirs; i++) {
 456                 if (i != dst)
 457                         info->theirs[dst] = info->theirs[i];
 458                 if (has_object_file(oid + info->theirs[i]))
 459                         dst++;
 460         }
 461         info->nr_theirs = dst;
 462 }
 463
 464 define_commit_slab(ref_bitmap, uint32_t *);
 465
 466 #define POOL_SIZE (512 * 1024)
 467
 468 struct paint_info {
 469         struct ref_bitmap ref_bitmap;
 470         unsigned nr_bits;
 471         char **pools;
 472         char *free, *end;
 473         unsigned pool_count;
 474 };
 475
 476 static uint32_t *paint_alloc(struct paint_info *info)
 477 {
 478         unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
 479         unsigned size = nr * sizeof(uint32_t);
 480         void *p;
 481         if (!info->pool_count || size > info->end - info->free) {
 482                 if (size > POOL_SIZE)
 483                         BUG("pool size too small for %d in paint_alloc()",
 484                             size);
 485                 info->pool_count++;
 486                 REALLOC_ARRAY(info->pools, info->pool_count);
 487                 info->free = xmalloc(POOL_SIZE);
 488                 info->pools[info->pool_count - 1] = info->free;
 489                 info->end = info->free + POOL_SIZE;
 490         }
 491         p = info->free;
 492         info->free += size;
 493         return p;
 494 }
 495
 496 /*
 497  * Given a commit SHA-1, walk down to parents until either SEEN,
 498  * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 499  * all walked commits.
 500  */
 501 static void paint_down(struct paint_info *info, const struct object_id *oid,
 502                        unsigned int id)
 503 {
 504         unsigned int i, nr;
 505         struct commit_list *head = NULL;
 506         int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
 507         size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 508         struct commit *c = lookup_commit_reference_gently(the_repository, oid,
 509                                                           1);
 510         uint32_t *tmp; /* to be freed before return */
 511         uint32_t *bitmap;
 512
 513         if (!c)
 514                 return;
 515
 516         tmp = xmalloc(bitmap_size);
 517         bitmap = paint_alloc(info);
 518         memset(bitmap, 0, bitmap_size);
 519         bitmap[id / 32] |= (1U << (id % 32));
 520         commit_list_insert(c, &head);
 521         while (head) {
 522                 struct commit_list *p;
 523                 struct commit *c = pop_commit(&head);
 524                 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
 525
 526                 /* XXX check "UNINTERESTING" from pack bitmaps if available */
 527                 if (c->object.flags & (SEEN | UNINTERESTING))
 528                         continue;
 529                 else
 530                         c->object.flags |= SEEN;
 531
 532                 if (*refs == NULL)
 533                         *refs = bitmap;
 534                 else {
 535                         memcpy(tmp, *refs, bitmap_size);
 536                         for (i = 0; i < bitmap_nr; i++)
 537                                 tmp[i] |= bitmap[i];
 538                         if (memcmp(tmp, *refs, bitmap_size)) {
 539                                 *refs = paint_alloc(info);
 540                                 memcpy(*refs, tmp, bitmap_size);
 541                         }
 542                 }
 543
 544                 if (c->object.flags & BOTTOM)
 545                         continue;
 546
 547                 if (parse_commit(c))
 548                         die("unable to parse commit %s",
 549                             oid_to_hex(&c->object.oid));
 550
 551                 for (p = c->parents; p; p = p->next) {
 552                         if (p->item->object.flags & SEEN)
 553                                 continue;
 554                         commit_list_insert(p->item, &head);
 555                 }
 556         }
 557
 558         nr = get_max_object_index();
 559         for (i = 0; i < nr; i++) {
 560                 struct object *o = get_indexed_object(i);
 561                 if (o && o->type == OBJ_COMMIT)
 562                         o->flags &= ~SEEN;
 563         }
 564
 565         free(tmp);
 566 }
 567
 568 static int mark_uninteresting(const char *refname, const struct object_id *oid,
 569                               int flags, void *cb_data)
 570 {
 571         struct commit *commit = lookup_commit_reference_gently(the_repository,
 572                                                                oid, 1);
 573         if (!commit)
 574                 return 0;
 575         commit->object.flags |= UNINTERESTING;
 576         mark_parents_uninteresting(commit);
 577         return 0;
 578 }
 579
 580 static void post_assign_shallow(struct shallow_info *info,
 581                                 struct ref_bitmap *ref_bitmap,
 582                                 int *ref_status);
 583 /*
 584  * Step 6(+7), associate shallow commits with new refs
 585  *
 586  * info->ref must be initialized before calling this function.
 587  *
 588  * If used is not NULL, it's an array of info->shallow->nr
 589  * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 590  * m-th shallow commit from info->shallow.
 591  *
 592  * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 593  * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 594  * the ref needs some shallow commits from either info->ours or
 595  * info->theirs.
 596  */
 597 void assign_shallow_commits_to_refs(struct shallow_info *info,
 598                                     uint32_t **used, int *ref_status)
 599 {
 600         struct object_id *oid = info->shallow->oid;
 601         struct oid_array *ref = info->ref;
 602         unsigned int i, nr;
 603         int *shallow, nr_shallow = 0;
 604         struct paint_info pi;
 605
 606         trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
 607         ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
 608         for (i = 0; i < info->nr_ours; i++)
 609                 shallow[nr_shallow++] = info->ours[i];
 610         for (i = 0; i < info->nr_theirs; i++)
 611                 shallow[nr_shallow++] = info->theirs[i];
 612
 613         /*
 614          * Prepare the commit graph to track what refs can reach what
 615          * (new) shallow commits.
 616          */
 617         nr = get_max_object_index();
 618         for (i = 0; i < nr; i++) {
 619                 struct object *o = get_indexed_object(i);
 620                 if (!o || o->type != OBJ_COMMIT)
 621                         continue;
 622
 623                 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
 624         }
 625
 626         memset(&pi, 0, sizeof(pi));
 627         init_ref_bitmap(&pi.ref_bitmap);
 628         pi.nr_bits = ref->nr;
 629
 630         /*
 631          * "--not --all" to cut short the traversal if new refs
 632          * connect to old refs. If not (e.g. force ref updates) it'll
 633          * have to go down to the current shallow commits.
 634          */
 635         head_ref(mark_uninteresting, NULL);
 636         for_each_ref(mark_uninteresting, NULL);
 637
 638         /* Mark potential bottoms so we won't go out of bound */
 639         for (i = 0; i < nr_shallow; i++) {
 640                 struct commit *c = lookup_commit(the_repository,
 641                                                  &oid[shallow[i]]);
 642                 c->object.flags |= BOTTOM;
 643         }
 644
 645         for (i = 0; i < ref->nr; i++)
 646                 paint_down(&pi, ref->oid + i, i);
 647
 648         if (used) {
 649                 int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
 650                 memset(used, 0, sizeof(*used) * info->shallow->nr);
 651                 for (i = 0; i < nr_shallow; i++) {
 652                         const struct commit *c = lookup_commit(the_repository,
 653                                                                &oid[shallow[i]]);
 654                         uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
 655                         if (*map)
 656                                 used[shallow[i]] = xmemdupz(*map, bitmap_size);
 657                 }
 658                 /*
 659                  * unreachable shallow commits are not removed from
 660                  * "ours" and "theirs". The user is supposed to run
 661                  * step 7 on every ref separately and not trust "ours"
 662                  * and "theirs" any more.
 663                  */
 664         } else
 665                 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
 666
 667         clear_ref_bitmap(&pi.ref_bitmap);
 668         for (i = 0; i < pi.pool_count; i++)
 669                 free(pi.pools[i]);
 670         free(pi.pools);
 671         free(shallow);
 672 }
 673
 674 struct commit_array {
 675         struct commit **commits;
 676         int nr, alloc;
 677 };
 678
 679 static int add_ref(const char *refname, const struct object_id *oid,
 680                    int flags, void *cb_data)
 681 {
 682         struct commit_array *ca = cb_data;
 683         ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
 684         ca->commits[ca->nr] = lookup_commit_reference_gently(the_repository,
 685                                                              oid, 1);
 686         if (ca->commits[ca->nr])
 687                 ca->nr++;
 688         return 0;
 689 }
 690
 691 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
 692 {
 693         unsigned int i;
 694         if (!ref_status)
 695                 return;
 696         for (i = 0; i < nr; i++)
 697                 if (bitmap[i / 32] & (1U << (i % 32)))
 698                         ref_status[i]++;
 699 }
 700
 701 /*
 702  * Step 7, reachability test on "ours" at commit level
 703  */
 704 static void post_assign_shallow(struct shallow_info *info,
 705                                 struct ref_bitmap *ref_bitmap,
 706                                 int *ref_status)
 707 {
 708         struct object_id *oid = info->shallow->oid;
 709         struct commit *c;
 710         uint32_t **bitmap;
 711         int dst, i, j;
 712         int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
 713         struct commit_array ca;
 714
 715         trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
 716         if (ref_status)
 717                 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
 718
 719         /* Remove unreachable shallow commits from "theirs" */
 720         for (i = dst = 0; i < info->nr_theirs; i++) {
 721                 if (i != dst)
 722                         info->theirs[dst] = info->theirs[i];
 723                 c = lookup_commit(the_repository, &oid[info->theirs[i]]);
 724                 bitmap = ref_bitmap_at(ref_bitmap, c);
 725                 if (!*bitmap)
 726                         continue;
 727                 for (j = 0; j < bitmap_nr; j++)
 728                         if (bitmap[0][j]) {
 729                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 730                                 dst++;
 731                                 break;
 732                         }
 733         }
 734         info->nr_theirs = dst;
 735
 736         memset(&ca, 0, sizeof(ca));
 737         head_ref(add_ref, &ca);
 738         for_each_ref(add_ref, &ca);
 739
 740         /* Remove unreachable shallow commits from "ours" */
 741         for (i = dst = 0; i < info->nr_ours; i++) {
 742                 if (i != dst)
 743                         info->ours[dst] = info->ours[i];
 744                 c = lookup_commit(the_repository, &oid[info->ours[i]]);
 745                 bitmap = ref_bitmap_at(ref_bitmap, c);
 746                 if (!*bitmap)
 747                         continue;
 748                 for (j = 0; j < bitmap_nr; j++)
 749                         if (bitmap[0][j] &&
 750                             /* Step 7, reachability test at commit level */
 751                             !in_merge_bases_many(c, ca.nr, ca.commits)) {
 752                                 update_refstatus(ref_status, info->ref->nr, *bitmap);
 753                                 dst++;
 754                                 break;
 755                         }
 756         }
 757         info->nr_ours = dst;
 758
 759         free(ca.commits);
 760 }
 761
 762 /* (Delayed) step 7, reachability test at commit level */
 763 int delayed_reachability_test(struct shallow_info *si, int c)
 764 {
 765         if (si->need_reachability_test[c]) {
 766                 struct commit *commit = lookup_commit(the_repository,
 767                                                       &si->shallow->oid[c]);
 768
 769                 if (!si->commits) {
 770                         struct commit_array ca;
 771
 772                         memset(&ca, 0, sizeof(ca));
 773                         head_ref(add_ref, &ca);
 774                         for_each_ref(add_ref, &ca);
 775                         si->commits = ca.commits;
 776                         si->nr_commits = ca.nr;
 777                 }
 778
 779                 si->reachable[c] = in_merge_bases_many(commit,
 780                                                        si->nr_commits,
 781                                                        si->commits);
 782                 si->need_reachability_test[c] = 0;
 783         }
 784         return si->reachable[c];
 785 }