git.oblomov.eu Git - git/blob - commit-reach.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "commit-graph.h"
   4 #include "decorate.h"
   5 #include "prio-queue.h"
   6 #include "tree.h"
   7 #include "ref-filter.h"
   8 #include "revision.h"
   9 #include "tag.h"
  10 #include "commit-reach.h"
  11
  12 /* Remember to update object flag allocation in object.h */
  13 #define REACHABLE       (1u<<15)
  14 #define PARENT1         (1u<<16)
  15 #define PARENT2         (1u<<17)
  16 #define STALE           (1u<<18)
  17 #define RESULT          (1u<<19)
  18
  19 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
  20
  21 static int queue_has_nonstale(struct prio_queue *queue)
  22 {
  23         int i;
  24         for (i = 0; i < queue->nr; i++) {
  25                 struct commit *commit = queue->array[i].data;
  26                 if (!(commit->object.flags & STALE))
  27                         return 1;
  28         }
  29         return 0;
  30 }
  31
  32 /* all input commits in one and twos[] must have been parsed! */
  33 static struct commit_list *paint_down_to_common(struct repository *r,
  34                                                 struct commit *one, int n,
  35                                                 struct commit **twos,
  36                                                 int min_generation)
  37 {
  38         struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
  39         struct commit_list *result = NULL;
  40         int i;
  41         uint32_t last_gen = GENERATION_NUMBER_INFINITY;
  42
  43         if (!min_generation)
  44                 queue.compare = compare_commits_by_commit_date;
  45
  46         one->object.flags |= PARENT1;
  47         if (!n) {
  48                 commit_list_append(one, &result);
  49                 return result;
  50         }
  51         prio_queue_put(&queue, one);
  52
  53         for (i = 0; i < n; i++) {
  54                 twos[i]->object.flags |= PARENT2;
  55                 prio_queue_put(&queue, twos[i]);
  56         }
  57
  58         while (queue_has_nonstale(&queue)) {
  59                 struct commit *commit = prio_queue_get(&queue);
  60                 struct commit_list *parents;
  61                 int flags;
  62
  63                 if (min_generation && commit->generation > last_gen)
  64                         BUG("bad generation skip %8x > %8x at %s",
  65                             commit->generation, last_gen,
  66                             oid_to_hex(&commit->object.oid));
  67                 last_gen = commit->generation;
  68
  69                 if (commit->generation < min_generation)
  70                         break;
  71
  72                 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
  73                 if (flags == (PARENT1 | PARENT2)) {
  74                         if (!(commit->object.flags & RESULT)) {
  75                                 commit->object.flags |= RESULT;
  76                                 commit_list_insert_by_date(commit, &result);
  77                         }
  78                         /* Mark parents of a found merge stale */
  79                         flags |= STALE;
  80                 }
  81                 parents = commit->parents;
  82                 while (parents) {
  83                         struct commit *p = parents->item;
  84                         parents = parents->next;
  85                         if ((p->object.flags & flags) == flags)
  86                                 continue;
  87                         if (repo_parse_commit(r, p))
  88                                 return NULL;
  89                         p->object.flags |= flags;
  90                         prio_queue_put(&queue, p);
  91                 }
  92         }
  93
  94         clear_prio_queue(&queue);
  95         return result;
  96 }
  97
  98 static struct commit_list *merge_bases_many(struct repository *r,
  99                                             struct commit *one, int n,
 100                                             struct commit **twos)
 101 {
 102         struct commit_list *list = NULL;
 103         struct commit_list *result = NULL;
 104         int i;
 105
 106         for (i = 0; i < n; i++) {
 107                 if (one == twos[i])
 108                         /*
 109                          * We do not mark this even with RESULT so we do not
 110                          * have to clean it up.
 111                          */
 112                         return commit_list_insert(one, &result);
 113         }
 114
 115         if (repo_parse_commit(r, one))
 116                 return NULL;
 117         for (i = 0; i < n; i++) {
 118                 if (repo_parse_commit(r, twos[i]))
 119                         return NULL;
 120         }
 121
 122         list = paint_down_to_common(r, one, n, twos, 0);
 123
 124         while (list) {
 125                 struct commit *commit = pop_commit(&list);
 126                 if (!(commit->object.flags & STALE))
 127                         commit_list_insert_by_date(commit, &result);
 128         }
 129         return result;
 130 }
 131
 132 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 133 {
 134         struct commit_list *i, *j, *k, *ret = NULL;
 135
 136         if (!in)
 137                 return ret;
 138
 139         commit_list_insert(in->item, &ret);
 140
 141         for (i = in->next; i; i = i->next) {
 142                 struct commit_list *new_commits = NULL, *end = NULL;
 143
 144                 for (j = ret; j; j = j->next) {
 145                         struct commit_list *bases;
 146                         bases = get_merge_bases(i->item, j->item);
 147                         if (!new_commits)
 148                                 new_commits = bases;
 149                         else
 150                                 end->next = bases;
 151                         for (k = bases; k; k = k->next)
 152                                 end = k;
 153                 }
 154                 ret = new_commits;
 155         }
 156         return ret;
 157 }
 158
 159 static int remove_redundant(struct repository *r, struct commit **array, int cnt)
 160 {
 161         /*
 162          * Some commit in the array may be an ancestor of
 163          * another commit.  Move such commit to the end of
 164          * the array, and return the number of commits that
 165          * are independent from each other.
 166          */
 167         struct commit **work;
 168         unsigned char *redundant;
 169         int *filled_index;
 170         int i, j, filled;
 171
 172         work = xcalloc(cnt, sizeof(*work));
 173         redundant = xcalloc(cnt, 1);
 174         ALLOC_ARRAY(filled_index, cnt - 1);
 175
 176         for (i = 0; i < cnt; i++)
 177                 repo_parse_commit(r, array[i]);
 178         for (i = 0; i < cnt; i++) {
 179                 struct commit_list *common;
 180                 uint32_t min_generation = array[i]->generation;
 181
 182                 if (redundant[i])
 183                         continue;
 184                 for (j = filled = 0; j < cnt; j++) {
 185                         if (i == j || redundant[j])
 186                                 continue;
 187                         filled_index[filled] = j;
 188                         work[filled++] = array[j];
 189
 190                         if (array[j]->generation < min_generation)
 191                                 min_generation = array[j]->generation;
 192                 }
 193                 common = paint_down_to_common(r, array[i], filled,
 194                                               work, min_generation);
 195                 if (array[i]->object.flags & PARENT2)
 196                         redundant[i] = 1;
 197                 for (j = 0; j < filled; j++)
 198                         if (work[j]->object.flags & PARENT1)
 199                                 redundant[filled_index[j]] = 1;
 200                 clear_commit_marks(array[i], all_flags);
 201                 clear_commit_marks_many(filled, work, all_flags);
 202                 free_commit_list(common);
 203         }
 204
 205         /* Now collect the result */
 206         COPY_ARRAY(work, array, cnt);
 207         for (i = filled = 0; i < cnt; i++)
 208                 if (!redundant[i])
 209                         array[filled++] = work[i];
 210         for (j = filled, i = 0; i < cnt; i++)
 211                 if (redundant[i])
 212                         array[j++] = work[i];
 213         free(work);
 214         free(redundant);
 215         free(filled_index);
 216         return filled;
 217 }
 218
 219 static struct commit_list *get_merge_bases_many_0(struct repository *r,
 220                                                   struct commit *one,
 221                                                   int n,
 222                                                   struct commit **twos,
 223                                                   int cleanup)
 224 {
 225         struct commit_list *list;
 226         struct commit **rslt;
 227         struct commit_list *result;
 228         int cnt, i;
 229
 230         result = merge_bases_many(r, one, n, twos);
 231         for (i = 0; i < n; i++) {
 232                 if (one == twos[i])
 233                         return result;
 234         }
 235         if (!result || !result->next) {
 236                 if (cleanup) {
 237                         clear_commit_marks(one, all_flags);
 238                         clear_commit_marks_many(n, twos, all_flags);
 239                 }
 240                 return result;
 241         }
 242
 243         /* There are more than one */
 244         cnt = commit_list_count(result);
 245         rslt = xcalloc(cnt, sizeof(*rslt));
 246         for (list = result, i = 0; list; list = list->next)
 247                 rslt[i++] = list->item;
 248         free_commit_list(result);
 249
 250         clear_commit_marks(one, all_flags);
 251         clear_commit_marks_many(n, twos, all_flags);
 252
 253         cnt = remove_redundant(r, rslt, cnt);
 254         result = NULL;
 255         for (i = 0; i < cnt; i++)
 256                 commit_list_insert_by_date(rslt[i], &result);
 257         free(rslt);
 258         return result;
 259 }
 260
 261 struct commit_list *repo_get_merge_bases_many(struct repository *r,
 262                                               struct commit *one,
 263                                               int n,
 264                                               struct commit **twos)
 265 {
 266         return get_merge_bases_many_0(r, one, n, twos, 1);
 267 }
 268
 269 struct commit_list *repo_get_merge_bases_many_dirty(struct repository *r,
 270                                                     struct commit *one,
 271                                                     int n,
 272                                                     struct commit **twos)
 273 {
 274         return get_merge_bases_many_0(r, one, n, twos, 0);
 275 }
 276
 277 struct commit_list *repo_get_merge_bases(struct repository *r,
 278                                          struct commit *one,
 279                                          struct commit *two)
 280 {
 281         return get_merge_bases_many_0(r, one, 1, &two, 1);
 282 }
 283
 284 /*
 285  * Is "commit" a descendant of one of the elements on the "with_commit" list?
 286  */
 287 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 288 {
 289         if (!with_commit)
 290                 return 1;
 291
 292         if (generation_numbers_enabled(the_repository)) {
 293                 struct commit_list *from_list = NULL;
 294                 int result;
 295                 commit_list_insert(commit, &from_list);
 296                 result = can_all_from_reach(from_list, with_commit, 0);
 297                 free_commit_list(from_list);
 298                 return result;
 299         } else {
 300                 while (with_commit) {
 301                         struct commit *other;
 302
 303                         other = with_commit->item;
 304                         with_commit = with_commit->next;
 305                         if (in_merge_bases(other, commit))
 306                                 return 1;
 307                 }
 308                 return 0;
 309         }
 310 }
 311
 312 /*
 313  * Is "commit" an ancestor of one of the "references"?
 314  */
 315 int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
 316 {
 317         struct commit_list *bases;
 318         int ret = 0, i;
 319         uint32_t min_generation = GENERATION_NUMBER_INFINITY;
 320
 321         if (parse_commit(commit))
 322                 return ret;
 323         for (i = 0; i < nr_reference; i++) {
 324                 if (parse_commit(reference[i]))
 325                         return ret;
 326                 if (reference[i]->generation < min_generation)
 327                         min_generation = reference[i]->generation;
 328         }
 329
 330         if (commit->generation > min_generation)
 331                 return ret;
 332
 333         bases = paint_down_to_common(the_repository, commit,
 334                                      nr_reference, reference,
 335                                      commit->generation);
 336         if (commit->object.flags & PARENT2)
 337                 ret = 1;
 338         clear_commit_marks(commit, all_flags);
 339         clear_commit_marks_many(nr_reference, reference, all_flags);
 340         free_commit_list(bases);
 341         return ret;
 342 }
 343
 344 /*
 345  * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
 346  */
 347 int in_merge_bases(struct commit *commit, struct commit *reference)
 348 {
 349         return in_merge_bases_many(commit, 1, &reference);
 350 }
 351
 352 struct commit_list *reduce_heads(struct commit_list *heads)
 353 {
 354         struct commit_list *p;
 355         struct commit_list *result = NULL, **tail = &result;
 356         struct commit **array;
 357         int num_head, i;
 358
 359         if (!heads)
 360                 return NULL;
 361
 362         /* Uniquify */
 363         for (p = heads; p; p = p->next)
 364                 p->item->object.flags &= ~STALE;
 365         for (p = heads, num_head = 0; p; p = p->next) {
 366                 if (p->item->object.flags & STALE)
 367                         continue;
 368                 p->item->object.flags |= STALE;
 369                 num_head++;
 370         }
 371         array = xcalloc(num_head, sizeof(*array));
 372         for (p = heads, i = 0; p; p = p->next) {
 373                 if (p->item->object.flags & STALE) {
 374                         array[i++] = p->item;
 375                         p->item->object.flags &= ~STALE;
 376                 }
 377         }
 378         num_head = remove_redundant(the_repository, array, num_head);
 379         for (i = 0; i < num_head; i++)
 380                 tail = &commit_list_insert(array[i], tail)->next;
 381         free(array);
 382         return result;
 383 }
 384
 385 void reduce_heads_replace(struct commit_list **heads)
 386 {
 387         struct commit_list *result = reduce_heads(*heads);
 388         free_commit_list(*heads);
 389         *heads = result;
 390 }
 391
 392 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
 393 {
 394         struct object *o;
 395         struct commit *old_commit, *new_commit;
 396         struct commit_list *old_commit_list = NULL;
 397
 398         /*
 399          * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
 400          * old_commit.  Otherwise we require --force.
 401          */
 402         o = deref_tag(the_repository, parse_object(the_repository, old_oid),
 403                       NULL, 0);
 404         if (!o || o->type != OBJ_COMMIT)
 405                 return 0;
 406         old_commit = (struct commit *) o;
 407
 408         o = deref_tag(the_repository, parse_object(the_repository, new_oid),
 409                       NULL, 0);
 410         if (!o || o->type != OBJ_COMMIT)
 411                 return 0;
 412         new_commit = (struct commit *) o;
 413
 414         if (parse_commit(new_commit) < 0)
 415                 return 0;
 416
 417         commit_list_insert(old_commit, &old_commit_list);
 418         return is_descendant_of(new_commit, old_commit_list);
 419 }
 420
 421 /*
 422  * Mimicking the real stack, this stack lives on the heap, avoiding stack
 423  * overflows.
 424  *
 425  * At each recursion step, the stack items points to the commits whose
 426  * ancestors are to be inspected.
 427  */
 428 struct contains_stack {
 429         int nr, alloc;
 430         struct contains_stack_entry {
 431                 struct commit *commit;
 432                 struct commit_list *parents;
 433         } *contains_stack;
 434 };
 435
 436 static int in_commit_list(const struct commit_list *want, struct commit *c)
 437 {
 438         for (; want; want = want->next)
 439                 if (oideq(&want->item->object.oid, &c->object.oid))
 440                         return 1;
 441         return 0;
 442 }
 443
 444 /*
 445  * Test whether the candidate is contained in the list.
 446  * Do not recurse to find out, though, but return -1 if inconclusive.
 447  */
 448 static enum contains_result contains_test(struct commit *candidate,
 449                                           const struct commit_list *want,
 450                                           struct contains_cache *cache,
 451                                           uint32_t cutoff)
 452 {
 453         enum contains_result *cached = contains_cache_at(cache, candidate);
 454
 455         /* If we already have the answer cached, return that. */
 456         if (*cached)
 457                 return *cached;
 458
 459         /* or are we it? */
 460         if (in_commit_list(want, candidate)) {
 461                 *cached = CONTAINS_YES;
 462                 return CONTAINS_YES;
 463         }
 464
 465         /* Otherwise, we don't know; prepare to recurse */
 466         parse_commit_or_die(candidate);
 467
 468         if (candidate->generation < cutoff)
 469                 return CONTAINS_NO;
 470
 471         return CONTAINS_UNKNOWN;
 472 }
 473
 474 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
 475 {
 476         ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
 477         contains_stack->contains_stack[contains_stack->nr].commit = candidate;
 478         contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
 479 }
 480
 481 static enum contains_result contains_tag_algo(struct commit *candidate,
 482                                               const struct commit_list *want,
 483                                               struct contains_cache *cache)
 484 {
 485         struct contains_stack contains_stack = { 0, 0, NULL };
 486         enum contains_result result;
 487         uint32_t cutoff = GENERATION_NUMBER_INFINITY;
 488         const struct commit_list *p;
 489
 490         for (p = want; p; p = p->next) {
 491                 struct commit *c = p->item;
 492                 load_commit_graph_info(the_repository, c);
 493                 if (c->generation < cutoff)
 494                         cutoff = c->generation;
 495         }
 496
 497         result = contains_test(candidate, want, cache, cutoff);
 498         if (result != CONTAINS_UNKNOWN)
 499                 return result;
 500
 501         push_to_contains_stack(candidate, &contains_stack);
 502         while (contains_stack.nr) {
 503                 struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
 504                 struct commit *commit = entry->commit;
 505                 struct commit_list *parents = entry->parents;
 506
 507                 if (!parents) {
 508                         *contains_cache_at(cache, commit) = CONTAINS_NO;
 509                         contains_stack.nr--;
 510                 }
 511                 /*
 512                  * If we just popped the stack, parents->item has been marked,
 513                  * therefore contains_test will return a meaningful yes/no.
 514                  */
 515                 else switch (contains_test(parents->item, want, cache, cutoff)) {
 516                 case CONTAINS_YES:
 517                         *contains_cache_at(cache, commit) = CONTAINS_YES;
 518                         contains_stack.nr--;
 519                         break;
 520                 case CONTAINS_NO:
 521                         entry->parents = parents->next;
 522                         break;
 523                 case CONTAINS_UNKNOWN:
 524                         push_to_contains_stack(parents->item, &contains_stack);
 525                         break;
 526                 }
 527         }
 528         free(contains_stack.contains_stack);
 529         return contains_test(candidate, want, cache, cutoff);
 530 }
 531
 532 int commit_contains(struct ref_filter *filter, struct commit *commit,
 533                     struct commit_list *list, struct contains_cache *cache)
 534 {
 535         if (filter->with_commit_tag_algo)
 536                 return contains_tag_algo(commit, list, cache) == CONTAINS_YES;
 537         return is_descendant_of(commit, list);
 538 }
 539
 540 static int compare_commits_by_gen(const void *_a, const void *_b)
 541 {
 542         const struct commit *a = (const struct commit *)_a;
 543         const struct commit *b = (const struct commit *)_b;
 544
 545         if (a->generation < b->generation)
 546                 return -1;
 547         if (a->generation > b->generation)
 548                 return 1;
 549         return 0;
 550 }
 551
 552 int can_all_from_reach_with_flag(struct object_array *from,
 553                                  unsigned int with_flag,
 554                                  unsigned int assign_flag,
 555                                  time_t min_commit_date,
 556                                  uint32_t min_generation)
 557 {
 558         struct commit **list = NULL;
 559         int i;
 560         int nr_commits;
 561         int result = 1;
 562
 563         ALLOC_ARRAY(list, from->nr);
 564         nr_commits = 0;
 565         for (i = 0; i < from->nr; i++) {
 566                 struct object *from_one = from->objects[i].item;
 567
 568                 if (!from_one || from_one->flags & assign_flag)
 569                         continue;
 570
 571                 from_one = deref_tag(the_repository, from_one,
 572                                      "a from object", 0);
 573                 if (!from_one || from_one->type != OBJ_COMMIT) {
 574                         /*
 575                          * no way to tell if this is reachable by
 576                          * looking at the ancestry chain alone, so
 577                          * leave a note to ourselves not to worry about
 578                          * this object anymore.
 579                          */
 580                         from->objects[i].item->flags |= assign_flag;
 581                         continue;
 582                 }
 583
 584                 list[nr_commits] = (struct commit *)from_one;
 585                 if (parse_commit(list[nr_commits]) ||
 586                     list[nr_commits]->generation < min_generation) {
 587                         result = 0;
 588                         goto cleanup;
 589                 }
 590
 591                 nr_commits++;
 592         }
 593
 594         QSORT(list, nr_commits, compare_commits_by_gen);
 595
 596         for (i = 0; i < nr_commits; i++) {
 597                 /* DFS from list[i] */
 598                 struct commit_list *stack = NULL;
 599
 600                 list[i]->object.flags |= assign_flag;
 601                 commit_list_insert(list[i], &stack);
 602
 603                 while (stack) {
 604                         struct commit_list *parent;
 605
 606                         if (stack->item->object.flags & with_flag) {
 607                                 pop_commit(&stack);
 608                                 continue;
 609                         }
 610
 611                         for (parent = stack->item->parents; parent; parent = parent->next) {
 612                                 if (parent->item->object.flags & (with_flag | RESULT))
 613                                         stack->item->object.flags |= RESULT;
 614
 615                                 if (!(parent->item->object.flags & assign_flag)) {
 616                                         parent->item->object.flags |= assign_flag;
 617
 618                                         if (parse_commit(parent->item) ||
 619                                             parent->item->date < min_commit_date ||
 620                                             parent->item->generation < min_generation)
 621                                                 continue;
 622
 623                                         commit_list_insert(parent->item, &stack);
 624                                         break;
 625                                 }
 626                         }
 627
 628                         if (!parent)
 629                                 pop_commit(&stack);
 630                 }
 631
 632                 if (!(list[i]->object.flags & (with_flag | RESULT))) {
 633                         result = 0;
 634                         goto cleanup;
 635                 }
 636         }
 637
 638 cleanup:
 639         clear_commit_marks_many(nr_commits, list, RESULT | assign_flag);
 640         free(list);
 641
 642         for (i = 0; i < from->nr; i++)
 643                 from->objects[i].item->flags &= ~assign_flag;
 644
 645         return result;
 646 }
 647
 648 int can_all_from_reach(struct commit_list *from, struct commit_list *to,
 649                        int cutoff_by_min_date)
 650 {
 651         struct object_array from_objs = OBJECT_ARRAY_INIT;
 652         time_t min_commit_date = cutoff_by_min_date ? from->item->date : 0;
 653         struct commit_list *from_iter = from, *to_iter = to;
 654         int result;
 655         uint32_t min_generation = GENERATION_NUMBER_INFINITY;
 656
 657         while (from_iter) {
 658                 add_object_array(&from_iter->item->object, NULL, &from_objs);
 659
 660                 if (!parse_commit(from_iter->item)) {
 661                         if (from_iter->item->date < min_commit_date)
 662                                 min_commit_date = from_iter->item->date;
 663
 664                         if (from_iter->item->generation < min_generation)
 665                                 min_generation = from_iter->item->generation;
 666                 }
 667
 668                 from_iter = from_iter->next;
 669         }
 670
 671         while (to_iter) {
 672                 if (!parse_commit(to_iter->item)) {
 673                         if (to_iter->item->date < min_commit_date)
 674                                 min_commit_date = to_iter->item->date;
 675
 676                         if (to_iter->item->generation < min_generation)
 677                                 min_generation = to_iter->item->generation;
 678                 }
 679
 680                 to_iter->item->object.flags |= PARENT2;
 681
 682                 to_iter = to_iter->next;
 683         }
 684
 685         result = can_all_from_reach_with_flag(&from_objs, PARENT2, PARENT1,
 686                                               min_commit_date, min_generation);
 687
 688         while (from) {
 689                 clear_commit_marks(from->item, PARENT1);
 690                 from = from->next;
 691         }
 692
 693         while (to) {
 694                 clear_commit_marks(to->item, PARENT2);
 695                 to = to->next;
 696         }
 697
 698         object_array_clear(&from_objs);
 699         return result;
 700 }