shallow.con commit Merge branch 'jk/alt-odb-cleanup' (dec0401)
   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
  16static int is_shallow = -1;
  17static struct stat_validity shallow_stat;
  18static char *alternate_shallow_file;
  19
  20void 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
  30int 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
  43int 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
  77struct 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
 142static 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 */
 153struct 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
 218static 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
 230struct write_shallow_data {
 231        struct strbuf *out;
 232        int use_pack_protocol;
 233        int count;
 234        unsigned flags;
 235};
 236
 237static 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
 262static 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
 283int 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
 289static struct tempfile temporary_shallow;
 290
 291const 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
 313void 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
 337static 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(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 342        return 0;
 343}
 344
 345void 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 */
 356void 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
 382struct 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 */
 388void 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
 410void 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
 418void 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
 432define_commit_slab(ref_bitmap, uint32_t *);
 433
 434struct 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
 442static 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 */
 464static 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
 530static 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
 541static 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 */
 558void 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
 633struct commit_array {
 634        struct commit **commits;
 635        int nr, alloc;
 636};
 637
 638static 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
 649static 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 */
 662static 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 */
 721int 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}