freshlybakedca.ke
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1#define USE_THE_REPOSITORY_VARIABLE
2
3#include "git-compat-util.h"
4#include "commit.h"
5#include "commit-graph.h"
6#include "decorate.h"
7#include "hex.h"
8#include "prio-queue.h"
9#include "ref-filter.h"
10#include "revision.h"
11#include "tag.h"
12#include "commit-reach.h"
13#include "ewah/ewok.h"
14
15/* Remember to update object flag allocation in object.h */
16#define PARENT1 (1u<<16)
17#define PARENT2 (1u<<17)
18#define STALE (1u<<18)
19#define RESULT (1u<<19)
20
21static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
22
23static int compare_commits_by_gen(const void *_a, const void *_b)
24{
25 const struct commit *a = *(const struct commit * const *)_a;
26 const struct commit *b = *(const struct commit * const *)_b;
27
28 timestamp_t generation_a = commit_graph_generation(a);
29 timestamp_t generation_b = commit_graph_generation(b);
30
31 if (generation_a < generation_b)
32 return -1;
33 if (generation_a > generation_b)
34 return 1;
35 if (a->date < b->date)
36 return -1;
37 if (a->date > b->date)
38 return 1;
39 return 0;
40}
41
42static int queue_has_nonstale(struct prio_queue *queue)
43{
44 for (size_t i = 0; i < queue->nr; i++) {
45 struct commit *commit = queue->array[i].data;
46 if (!(commit->object.flags & STALE))
47 return 1;
48 }
49 return 0;
50}
51
52/* all input commits in one and twos[] must have been parsed! */
53static int paint_down_to_common(struct repository *r,
54 struct commit *one, int n,
55 struct commit **twos,
56 timestamp_t min_generation,
57 int ignore_missing_commits,
58 struct commit_list **result)
59{
60 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
61 int i;
62 timestamp_t last_gen = GENERATION_NUMBER_INFINITY;
63
64 if (!min_generation && !corrected_commit_dates_enabled(r))
65 queue.compare = compare_commits_by_commit_date;
66
67 one->object.flags |= PARENT1;
68 if (!n) {
69 commit_list_append(one, result);
70 return 0;
71 }
72 prio_queue_put(&queue, one);
73
74 for (i = 0; i < n; i++) {
75 twos[i]->object.flags |= PARENT2;
76 prio_queue_put(&queue, twos[i]);
77 }
78
79 while (queue_has_nonstale(&queue)) {
80 struct commit *commit = prio_queue_get(&queue);
81 struct commit_list *parents;
82 int flags;
83 timestamp_t generation = commit_graph_generation(commit);
84
85 if (min_generation && generation > last_gen)
86 BUG("bad generation skip %"PRItime" > %"PRItime" at %s",
87 generation, last_gen,
88 oid_to_hex(&commit->object.oid));
89 last_gen = generation;
90
91 if (generation < min_generation)
92 break;
93
94 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
95 if (flags == (PARENT1 | PARENT2)) {
96 if (!(commit->object.flags & RESULT)) {
97 commit->object.flags |= RESULT;
98 commit_list_insert_by_date(commit, result);
99 }
100 /* Mark parents of a found merge stale */
101 flags |= STALE;
102 }
103 parents = commit->parents;
104 while (parents) {
105 struct commit *p = parents->item;
106 parents = parents->next;
107 if ((p->object.flags & flags) == flags)
108 continue;
109 if (repo_parse_commit(r, p)) {
110 clear_prio_queue(&queue);
111 free_commit_list(*result);
112 *result = NULL;
113 /*
114 * At this stage, we know that the commit is
115 * missing: `repo_parse_commit()` uses
116 * `OBJECT_INFO_DIE_IF_CORRUPT` and therefore
117 * corrupt commits would already have been
118 * dispatched with a `die()`.
119 */
120 if (ignore_missing_commits)
121 return 0;
122 return error(_("could not parse commit %s"),
123 oid_to_hex(&p->object.oid));
124 }
125 p->object.flags |= flags;
126 prio_queue_put(&queue, p);
127 }
128 }
129
130 clear_prio_queue(&queue);
131 return 0;
132}
133
134static int merge_bases_many(struct repository *r,
135 struct commit *one, int n,
136 struct commit **twos,
137 struct commit_list **result)
138{
139 struct commit_list *list = NULL;
140 int i;
141
142 for (i = 0; i < n; i++) {
143 if (one == twos[i]) {
144 /*
145 * We do not mark this even with RESULT so we do not
146 * have to clean it up.
147 */
148 *result = commit_list_insert(one, result);
149 return 0;
150 }
151 }
152
153 if (!one)
154 return 0;
155 if (repo_parse_commit(r, one))
156 return error(_("could not parse commit %s"),
157 oid_to_hex(&one->object.oid));
158 for (i = 0; i < n; i++) {
159 if (!twos[i])
160 return 0;
161 if (repo_parse_commit(r, twos[i]))
162 return error(_("could not parse commit %s"),
163 oid_to_hex(&twos[i]->object.oid));
164 }
165
166 if (paint_down_to_common(r, one, n, twos, 0, 0, &list)) {
167 free_commit_list(list);
168 return -1;
169 }
170
171 while (list) {
172 struct commit *commit = pop_commit(&list);
173 if (!(commit->object.flags & STALE))
174 commit_list_insert_by_date(commit, result);
175 }
176 return 0;
177}
178
179int get_octopus_merge_bases(struct commit_list *in, struct commit_list **result)
180{
181 struct commit_list *i, *j, *k;
182
183 if (!in)
184 return 0;
185
186 commit_list_insert(in->item, result);
187
188 for (i = in->next; i; i = i->next) {
189 struct commit_list *new_commits = NULL, *end = NULL;
190
191 for (j = *result; j; j = j->next) {
192 struct commit_list *bases = NULL;
193 if (repo_get_merge_bases(the_repository, i->item,
194 j->item, &bases) < 0) {
195 free_commit_list(bases);
196 free_commit_list(*result);
197 *result = NULL;
198 return -1;
199 }
200 if (!new_commits)
201 new_commits = bases;
202 else
203 end->next = bases;
204 for (k = bases; k; k = k->next)
205 end = k;
206 }
207 free_commit_list(*result);
208 *result = new_commits;
209 }
210 return 0;
211}
212
213static int remove_redundant_no_gen(struct repository *r,
214 struct commit **array,
215 size_t cnt, size_t *dedup_cnt)
216{
217 struct commit **work;
218 unsigned char *redundant;
219 size_t *filled_index;
220 size_t i, j, filled;
221
222 CALLOC_ARRAY(work, cnt);
223 redundant = xcalloc(cnt, 1);
224 ALLOC_ARRAY(filled_index, cnt - 1);
225
226 for (i = 0; i < cnt; i++)
227 repo_parse_commit(r, array[i]);
228 for (i = 0; i < cnt; i++) {
229 struct commit_list *common = NULL;
230 timestamp_t min_generation = commit_graph_generation(array[i]);
231
232 if (redundant[i])
233 continue;
234 for (j = filled = 0; j < cnt; j++) {
235 timestamp_t curr_generation;
236 if (i == j || redundant[j])
237 continue;
238 filled_index[filled] = j;
239 work[filled++] = array[j];
240
241 curr_generation = commit_graph_generation(array[j]);
242 if (curr_generation < min_generation)
243 min_generation = curr_generation;
244 }
245 if (paint_down_to_common(r, array[i], filled,
246 work, min_generation, 0, &common)) {
247 clear_commit_marks(array[i], all_flags);
248 clear_commit_marks_many(filled, work, all_flags);
249 free_commit_list(common);
250 free(work);
251 free(redundant);
252 free(filled_index);
253 return -1;
254 }
255 if (array[i]->object.flags & PARENT2)
256 redundant[i] = 1;
257 for (j = 0; j < filled; j++)
258 if (work[j]->object.flags & PARENT1)
259 redundant[filled_index[j]] = 1;
260 clear_commit_marks(array[i], all_flags);
261 clear_commit_marks_many(filled, work, all_flags);
262 free_commit_list(common);
263 }
264
265 /* Now collect the result */
266 COPY_ARRAY(work, array, cnt);
267 for (i = filled = 0; i < cnt; i++)
268 if (!redundant[i])
269 array[filled++] = work[i];
270 *dedup_cnt = filled;
271 free(work);
272 free(redundant);
273 free(filled_index);
274 return 0;
275}
276
277static int remove_redundant_with_gen(struct repository *r,
278 struct commit **array, size_t cnt,
279 size_t *dedup_cnt)
280{
281 size_t i, count_non_stale = 0, count_still_independent = cnt;
282 timestamp_t min_generation = GENERATION_NUMBER_INFINITY;
283 struct commit **walk_start, **sorted;
284 size_t walk_start_nr = 0, walk_start_alloc = cnt;
285 size_t min_gen_pos = 0;
286
287 /*
288 * Sort the input by generation number, ascending. This allows
289 * us to increase the "min_generation" limit when we discover
290 * the commit with lowest generation is STALE. The index
291 * min_gen_pos points to the current position within 'array'
292 * that is not yet known to be STALE.
293 */
294 DUP_ARRAY(sorted, array, cnt);
295 QSORT(sorted, cnt, compare_commits_by_gen);
296 min_generation = commit_graph_generation(sorted[0]);
297
298 ALLOC_ARRAY(walk_start, walk_start_alloc);
299
300 /* Mark all parents of the input as STALE */
301 for (i = 0; i < cnt; i++) {
302 struct commit_list *parents;
303
304 repo_parse_commit(r, array[i]);
305 array[i]->object.flags |= RESULT;
306 parents = array[i]->parents;
307
308 while (parents) {
309 repo_parse_commit(r, parents->item);
310 if (!(parents->item->object.flags & STALE)) {
311 parents->item->object.flags |= STALE;
312 ALLOC_GROW(walk_start, walk_start_nr + 1, walk_start_alloc);
313 walk_start[walk_start_nr++] = parents->item;
314 }
315 parents = parents->next;
316 }
317 }
318
319 QSORT(walk_start, walk_start_nr, compare_commits_by_gen);
320
321 /* remove STALE bit for now to allow walking through parents */
322 for (i = 0; i < walk_start_nr; i++)
323 walk_start[i]->object.flags &= ~STALE;
324
325 /*
326 * Start walking from the highest generation. Hopefully, it will
327 * find all other items during the first-parent walk, and we can
328 * terminate early. Otherwise, we will do the same amount of work
329 * as before.
330 */
331 for (i = walk_start_nr; i && count_still_independent > 1; i--) {
332 /* push the STALE bits up to min generation */
333 struct commit_list *stack = NULL;
334
335 commit_list_insert(walk_start[i - 1], &stack);
336 walk_start[i - 1]->object.flags |= STALE;
337
338 while (stack) {
339 struct commit_list *parents;
340 struct commit *c = stack->item;
341
342 repo_parse_commit(r, c);
343
344 if (c->object.flags & RESULT) {
345 c->object.flags &= ~RESULT;
346 if (--count_still_independent <= 1)
347 break;
348 if (oideq(&c->object.oid, &sorted[min_gen_pos]->object.oid)) {
349 while (min_gen_pos < cnt - 1 &&
350 (sorted[min_gen_pos]->object.flags & STALE))
351 min_gen_pos++;
352 min_generation = commit_graph_generation(sorted[min_gen_pos]);
353 }
354 }
355
356 if (commit_graph_generation(c) < min_generation) {
357 pop_commit(&stack);
358 continue;
359 }
360
361 parents = c->parents;
362 while (parents) {
363 if (!(parents->item->object.flags & STALE)) {
364 parents->item->object.flags |= STALE;
365 commit_list_insert(parents->item, &stack);
366 break;
367 }
368 parents = parents->next;
369 }
370
371 /* pop if all parents have been visited already */
372 if (!parents)
373 pop_commit(&stack);
374 }
375 free_commit_list(stack);
376 }
377 free(sorted);
378
379 /* clear result */
380 for (i = 0; i < cnt; i++)
381 array[i]->object.flags &= ~RESULT;
382
383 /* rearrange array */
384 for (i = count_non_stale = 0; i < cnt; i++) {
385 if (!(array[i]->object.flags & STALE))
386 array[count_non_stale++] = array[i];
387 }
388
389 /* clear marks */
390 clear_commit_marks_many(walk_start_nr, walk_start, STALE);
391 free(walk_start);
392
393 *dedup_cnt = count_non_stale;
394 return 0;
395}
396
397static int remove_redundant(struct repository *r, struct commit **array,
398 size_t cnt, size_t *dedup_cnt)
399{
400 /*
401 * Some commit in the array may be an ancestor of
402 * another commit. Move the independent commits to the
403 * beginning of 'array' and return their number. Callers
404 * should not rely upon the contents of 'array' after
405 * that number.
406 */
407 if (generation_numbers_enabled(r)) {
408 /*
409 * If we have a single commit with finite generation
410 * number, then the _with_gen algorithm is preferred.
411 */
412 for (size_t i = 0; i < cnt; i++) {
413 if (commit_graph_generation(array[i]) < GENERATION_NUMBER_INFINITY)
414 return remove_redundant_with_gen(r, array, cnt, dedup_cnt);
415 }
416 }
417
418 return remove_redundant_no_gen(r, array, cnt, dedup_cnt);
419}
420
421static int get_merge_bases_many_0(struct repository *r,
422 struct commit *one,
423 size_t n,
424 struct commit **twos,
425 int cleanup,
426 struct commit_list **result)
427{
428 struct commit_list *list;
429 struct commit **rslt;
430 size_t cnt, i;
431 int ret;
432
433 if (merge_bases_many(r, one, n, twos, result) < 0)
434 return -1;
435 for (i = 0; i < n; i++) {
436 if (one == twos[i])
437 return 0;
438 }
439 if (!*result || !(*result)->next) {
440 if (cleanup) {
441 clear_commit_marks(one, all_flags);
442 clear_commit_marks_many(n, twos, all_flags);
443 }
444 return 0;
445 }
446
447 /* There are more than one */
448 cnt = commit_list_count(*result);
449 CALLOC_ARRAY(rslt, cnt);
450 for (list = *result, i = 0; list; list = list->next)
451 rslt[i++] = list->item;
452 free_commit_list(*result);
453 *result = NULL;
454
455 clear_commit_marks(one, all_flags);
456 clear_commit_marks_many(n, twos, all_flags);
457
458 ret = remove_redundant(r, rslt, cnt, &cnt);
459 if (ret < 0) {
460 free(rslt);
461 return -1;
462 }
463 for (i = 0; i < cnt; i++)
464 commit_list_insert_by_date(rslt[i], result);
465 free(rslt);
466 return 0;
467}
468
469int repo_get_merge_bases_many(struct repository *r,
470 struct commit *one,
471 size_t n,
472 struct commit **twos,
473 struct commit_list **result)
474{
475 return get_merge_bases_many_0(r, one, n, twos, 1, result);
476}
477
478int repo_get_merge_bases_many_dirty(struct repository *r,
479 struct commit *one,
480 size_t n,
481 struct commit **twos,
482 struct commit_list **result)
483{
484 return get_merge_bases_many_0(r, one, n, twos, 0, result);
485}
486
487int repo_get_merge_bases(struct repository *r,
488 struct commit *one,
489 struct commit *two,
490 struct commit_list **result)
491{
492 return get_merge_bases_many_0(r, one, 1, &two, 1, result);
493}
494
495/*
496 * Is "commit" a descendant of one of the elements on the "with_commit" list?
497 */
498int repo_is_descendant_of(struct repository *r,
499 struct commit *commit,
500 struct commit_list *with_commit)
501{
502 if (!with_commit)
503 return 1;
504
505 if (generation_numbers_enabled(r)) {
506 struct commit_list *from_list = NULL;
507 int result;
508 commit_list_insert(commit, &from_list);
509 result = can_all_from_reach(from_list, with_commit, 0);
510 free_commit_list(from_list);
511 return result;
512 } else {
513 while (with_commit) {
514 struct commit *other;
515 int ret;
516
517 other = with_commit->item;
518 with_commit = with_commit->next;
519 ret = repo_in_merge_bases_many(r, other, 1, &commit, 0);
520 if (ret)
521 return ret;
522 }
523 return 0;
524 }
525}
526
527/*
528 * Is "commit" an ancestor of one of the "references"?
529 */
530int repo_in_merge_bases_many(struct repository *r, struct commit *commit,
531 int nr_reference, struct commit **reference,
532 int ignore_missing_commits)
533{
534 struct commit_list *bases = NULL;
535 int ret = 0, i;
536 timestamp_t generation, max_generation = GENERATION_NUMBER_ZERO;
537
538 if (repo_parse_commit(r, commit))
539 return ignore_missing_commits ? 0 : -1;
540 for (i = 0; i < nr_reference; i++) {
541 if (repo_parse_commit(r, reference[i]))
542 return ignore_missing_commits ? 0 : -1;
543
544 generation = commit_graph_generation(reference[i]);
545 if (generation > max_generation)
546 max_generation = generation;
547 }
548
549 generation = commit_graph_generation(commit);
550 if (generation > max_generation)
551 return ret;
552
553 if (paint_down_to_common(r, commit,
554 nr_reference, reference,
555 generation, ignore_missing_commits, &bases))
556 ret = -1;
557 else if (commit->object.flags & PARENT2)
558 ret = 1;
559 clear_commit_marks(commit, all_flags);
560 clear_commit_marks_many(nr_reference, reference, all_flags);
561 free_commit_list(bases);
562 return ret;
563}
564
565/*
566 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
567 */
568int repo_in_merge_bases(struct repository *r,
569 struct commit *commit,
570 struct commit *reference)
571{
572 int res;
573 struct commit_list *list = NULL;
574 struct commit_list **next = &list;
575
576 next = commit_list_append(commit, next);
577 res = repo_is_descendant_of(r, reference, list);
578 free_commit_list(list);
579
580 return res;
581}
582
583struct commit_list *reduce_heads(struct commit_list *heads)
584{
585 struct commit_list *p;
586 struct commit_list *result = NULL, **tail = &result;
587 struct commit **array;
588 size_t num_head, i;
589 int ret;
590
591 if (!heads)
592 return NULL;
593
594 /* Uniquify */
595 for (p = heads; p; p = p->next)
596 p->item->object.flags &= ~STALE;
597 for (p = heads, num_head = 0; p; p = p->next) {
598 if (p->item->object.flags & STALE)
599 continue;
600 p->item->object.flags |= STALE;
601 num_head++;
602 }
603 CALLOC_ARRAY(array, num_head);
604 for (p = heads, i = 0; p; p = p->next) {
605 if (p->item->object.flags & STALE) {
606 array[i++] = p->item;
607 p->item->object.flags &= ~STALE;
608 }
609 }
610
611 ret = remove_redundant(the_repository, array, num_head, &num_head);
612 if (ret < 0) {
613 free(array);
614 return NULL;
615 }
616
617 for (i = 0; i < num_head; i++)
618 tail = &commit_list_insert(array[i], tail)->next;
619 free(array);
620 return result;
621}
622
623void reduce_heads_replace(struct commit_list **heads)
624{
625 struct commit_list *result = reduce_heads(*heads);
626 free_commit_list(*heads);
627 *heads = result;
628}
629
630int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
631{
632 struct object *o;
633 struct commit *old_commit, *new_commit;
634 struct commit_list *old_commit_list = NULL;
635 int ret;
636
637 /*
638 * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
639 * old_commit. Otherwise we require --force.
640 */
641 o = deref_tag(the_repository, parse_object(the_repository, old_oid),
642 NULL, 0);
643 if (!o || o->type != OBJ_COMMIT)
644 return 0;
645 old_commit = (struct commit *) o;
646
647 o = deref_tag(the_repository, parse_object(the_repository, new_oid),
648 NULL, 0);
649 if (!o || o->type != OBJ_COMMIT)
650 return 0;
651 new_commit = (struct commit *) o;
652
653 if (repo_parse_commit(the_repository, new_commit) < 0)
654 return 0;
655
656 commit_list_insert(old_commit, &old_commit_list);
657 ret = repo_is_descendant_of(the_repository,
658 new_commit, old_commit_list);
659 if (ret < 0)
660 exit(128);
661 free_commit_list(old_commit_list);
662 return ret;
663}
664
665/*
666 * Mimicking the real stack, this stack lives on the heap, avoiding stack
667 * overflows.
668 *
669 * At each recursion step, the stack items points to the commits whose
670 * ancestors are to be inspected.
671 */
672struct contains_stack {
673 int nr, alloc;
674 struct contains_stack_entry {
675 struct commit *commit;
676 struct commit_list *parents;
677 } *contains_stack;
678};
679
680static int in_commit_list(const struct commit_list *want, struct commit *c)
681{
682 for (; want; want = want->next)
683 if (oideq(&want->item->object.oid, &c->object.oid))
684 return 1;
685 return 0;
686}
687
688/*
689 * Test whether the candidate is contained in the list.
690 * Do not recurse to find out, though, but return -1 if inconclusive.
691 */
692static enum contains_result contains_test(struct commit *candidate,
693 const struct commit_list *want,
694 struct contains_cache *cache,
695 timestamp_t cutoff)
696{
697 enum contains_result *cached = contains_cache_at(cache, candidate);
698
699 /* If we already have the answer cached, return that. */
700 if (*cached)
701 return *cached;
702
703 /* or are we it? */
704 if (in_commit_list(want, candidate)) {
705 *cached = CONTAINS_YES;
706 return CONTAINS_YES;
707 }
708
709 /* Otherwise, we don't know; prepare to recurse */
710 parse_commit_or_die(candidate);
711
712 if (commit_graph_generation(candidate) < cutoff)
713 return CONTAINS_NO;
714
715 return CONTAINS_UNKNOWN;
716}
717
718static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
719{
720 ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
721 contains_stack->contains_stack[contains_stack->nr].commit = candidate;
722 contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
723}
724
725static enum contains_result contains_tag_algo(struct commit *candidate,
726 const struct commit_list *want,
727 struct contains_cache *cache)
728{
729 struct contains_stack contains_stack = { 0, 0, NULL };
730 enum contains_result result;
731 timestamp_t cutoff = GENERATION_NUMBER_INFINITY;
732 const struct commit_list *p;
733
734 for (p = want; p; p = p->next) {
735 timestamp_t generation;
736 struct commit *c = p->item;
737 load_commit_graph_info(the_repository, c);
738 generation = commit_graph_generation(c);
739 if (generation < cutoff)
740 cutoff = generation;
741 }
742
743 result = contains_test(candidate, want, cache, cutoff);
744 if (result != CONTAINS_UNKNOWN)
745 return result;
746
747 push_to_contains_stack(candidate, &contains_stack);
748 while (contains_stack.nr) {
749 struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
750 struct commit *commit = entry->commit;
751 struct commit_list *parents = entry->parents;
752
753 if (!parents) {
754 *contains_cache_at(cache, commit) = CONTAINS_NO;
755 contains_stack.nr--;
756 }
757 /*
758 * If we just popped the stack, parents->item has been marked,
759 * therefore contains_test will return a meaningful yes/no.
760 */
761 else switch (contains_test(parents->item, want, cache, cutoff)) {
762 case CONTAINS_YES:
763 *contains_cache_at(cache, commit) = CONTAINS_YES;
764 contains_stack.nr--;
765 break;
766 case CONTAINS_NO:
767 entry->parents = parents->next;
768 break;
769 case CONTAINS_UNKNOWN:
770 push_to_contains_stack(parents->item, &contains_stack);
771 break;
772 }
773 }
774 free(contains_stack.contains_stack);
775 return contains_test(candidate, want, cache, cutoff);
776}
777
778int commit_contains(struct ref_filter *filter, struct commit *commit,
779 struct commit_list *list, struct contains_cache *cache)
780{
781 if (filter->with_commit_tag_algo)
782 return contains_tag_algo(commit, list, cache) == CONTAINS_YES;
783 return repo_is_descendant_of(the_repository, commit, list);
784}
785
786int can_all_from_reach_with_flag(struct object_array *from,
787 unsigned int with_flag,
788 unsigned int assign_flag,
789 timestamp_t min_commit_date,
790 timestamp_t min_generation)
791{
792 struct commit **list = NULL;
793 size_t i;
794 size_t nr_commits;
795 int result = 1;
796
797 ALLOC_ARRAY(list, from->nr);
798 nr_commits = 0;
799 for (i = 0; i < from->nr; i++) {
800 struct object *from_one = from->objects[i].item;
801
802 if (!from_one || from_one->flags & assign_flag)
803 continue;
804
805 from_one = deref_tag(the_repository, from_one,
806 "a from object", 0);
807 if (!from_one || from_one->type != OBJ_COMMIT) {
808 /*
809 * no way to tell if this is reachable by
810 * looking at the ancestry chain alone, so
811 * leave a note to ourselves not to worry about
812 * this object anymore.
813 */
814 from->objects[i].item->flags |= assign_flag;
815 continue;
816 }
817
818 list[nr_commits] = (struct commit *)from_one;
819 if (repo_parse_commit(the_repository, list[nr_commits]) ||
820 commit_graph_generation(list[nr_commits]) < min_generation) {
821 result = 0;
822 goto cleanup;
823 }
824
825 nr_commits++;
826 }
827
828 QSORT(list, nr_commits, compare_commits_by_gen);
829
830 for (i = 0; i < nr_commits; i++) {
831 /* DFS from list[i] */
832 struct commit_list *stack = NULL;
833
834 list[i]->object.flags |= assign_flag;
835 commit_list_insert(list[i], &stack);
836
837 while (stack) {
838 struct commit_list *parent;
839
840 if (stack->item->object.flags & (with_flag | RESULT)) {
841 pop_commit(&stack);
842 if (stack)
843 stack->item->object.flags |= RESULT;
844 continue;
845 }
846
847 for (parent = stack->item->parents; parent; parent = parent->next) {
848 if (parent->item->object.flags & (with_flag | RESULT))
849 stack->item->object.flags |= RESULT;
850
851 if (!(parent->item->object.flags & assign_flag)) {
852 parent->item->object.flags |= assign_flag;
853
854 if (repo_parse_commit(the_repository, parent->item) ||
855 parent->item->date < min_commit_date ||
856 commit_graph_generation(parent->item) < min_generation)
857 continue;
858
859 commit_list_insert(parent->item, &stack);
860 break;
861 }
862 }
863
864 if (!parent)
865 pop_commit(&stack);
866 }
867
868 if (!(list[i]->object.flags & (with_flag | RESULT))) {
869 result = 0;
870 goto cleanup;
871 }
872 }
873
874cleanup:
875 clear_commit_marks_many(nr_commits, list, RESULT | assign_flag);
876 free(list);
877
878 for (i = 0; i < from->nr; i++) {
879 struct object *from_one = from->objects[i].item;
880
881 if (from_one)
882 from_one->flags &= ~assign_flag;
883 }
884
885 return result;
886}
887
888int can_all_from_reach(struct commit_list *from, struct commit_list *to,
889 int cutoff_by_min_date)
890{
891 struct object_array from_objs = OBJECT_ARRAY_INIT;
892 struct commit_list *from_iter = from, *to_iter = to;
893 int result;
894 timestamp_t min_commit_date = cutoff_by_min_date ? from->item->date : 0;
895 timestamp_t min_generation = GENERATION_NUMBER_INFINITY;
896
897 while (from_iter) {
898 add_object_array(&from_iter->item->object, NULL, &from_objs);
899
900 if (!repo_parse_commit(the_repository, from_iter->item)) {
901 timestamp_t generation;
902 if (from_iter->item->date < min_commit_date)
903 min_commit_date = from_iter->item->date;
904
905 generation = commit_graph_generation(from_iter->item);
906 if (generation < min_generation)
907 min_generation = generation;
908 }
909
910 from_iter = from_iter->next;
911 }
912
913 while (to_iter) {
914 if (!repo_parse_commit(the_repository, to_iter->item)) {
915 timestamp_t generation;
916 if (to_iter->item->date < min_commit_date)
917 min_commit_date = to_iter->item->date;
918
919 generation = commit_graph_generation(to_iter->item);
920 if (generation < min_generation)
921 min_generation = generation;
922 }
923
924 to_iter->item->object.flags |= PARENT2;
925
926 to_iter = to_iter->next;
927 }
928
929 result = can_all_from_reach_with_flag(&from_objs, PARENT2, PARENT1,
930 min_commit_date, min_generation);
931
932 while (from) {
933 clear_commit_marks(from->item, PARENT1);
934 from = from->next;
935 }
936
937 while (to) {
938 clear_commit_marks(to->item, PARENT2);
939 to = to->next;
940 }
941
942 object_array_clear(&from_objs);
943 return result;
944}
945
946struct commit_list *get_reachable_subset(struct commit **from, size_t nr_from,
947 struct commit **to, size_t nr_to,
948 unsigned int reachable_flag)
949{
950 struct commit **item;
951 struct commit *current;
952 struct commit_list *found_commits = NULL;
953 struct commit **to_last = to + nr_to;
954 struct commit **from_last = from + nr_from;
955 timestamp_t min_generation = GENERATION_NUMBER_INFINITY;
956 int num_to_find = 0;
957
958 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
959
960 for (item = to; item < to_last; item++) {
961 timestamp_t generation;
962 struct commit *c = *item;
963
964 repo_parse_commit(the_repository, c);
965 generation = commit_graph_generation(c);
966 if (generation < min_generation)
967 min_generation = generation;
968
969 if (!(c->object.flags & PARENT1)) {
970 c->object.flags |= PARENT1;
971 num_to_find++;
972 }
973 }
974
975 for (item = from; item < from_last; item++) {
976 struct commit *c = *item;
977 if (!(c->object.flags & PARENT2)) {
978 c->object.flags |= PARENT2;
979 repo_parse_commit(the_repository, c);
980
981 prio_queue_put(&queue, *item);
982 }
983 }
984
985 while (num_to_find && (current = prio_queue_get(&queue)) != NULL) {
986 struct commit_list *parents;
987
988 if (current->object.flags & PARENT1) {
989 current->object.flags &= ~PARENT1;
990 current->object.flags |= reachable_flag;
991 commit_list_insert(current, &found_commits);
992 num_to_find--;
993 }
994
995 for (parents = current->parents; parents; parents = parents->next) {
996 struct commit *p = parents->item;
997
998 repo_parse_commit(the_repository, p);
999
1000 if (commit_graph_generation(p) < min_generation)
1001 continue;
1002
1003 if (p->object.flags & PARENT2)
1004 continue;
1005
1006 p->object.flags |= PARENT2;
1007 prio_queue_put(&queue, p);
1008 }
1009 }
1010
1011 clear_prio_queue(&queue);
1012
1013 clear_commit_marks_many(nr_to, to, PARENT1);
1014 clear_commit_marks_many(nr_from, from, PARENT2);
1015
1016 return found_commits;
1017}
1018
1019define_commit_slab(bit_arrays, struct bitmap *);
1020static struct bit_arrays bit_arrays;
1021
1022static void insert_no_dup(struct prio_queue *queue, struct commit *c)
1023{
1024 if (c->object.flags & PARENT2)
1025 return;
1026 prio_queue_put(queue, c);
1027 c->object.flags |= PARENT2;
1028}
1029
1030static struct bitmap *get_bit_array(struct commit *c, int width)
1031{
1032 struct bitmap **bitmap = bit_arrays_at(&bit_arrays, c);
1033 if (!*bitmap)
1034 *bitmap = bitmap_word_alloc(width);
1035 return *bitmap;
1036}
1037
1038static void free_bit_array(struct commit *c)
1039{
1040 struct bitmap **bitmap = bit_arrays_at(&bit_arrays, c);
1041 if (!*bitmap)
1042 return;
1043 bitmap_free(*bitmap);
1044 *bitmap = NULL;
1045}
1046
1047void ahead_behind(struct repository *r,
1048 struct commit **commits, size_t commits_nr,
1049 struct ahead_behind_count *counts, size_t counts_nr)
1050{
1051 struct prio_queue queue = { .compare = compare_commits_by_gen_then_commit_date };
1052 size_t width = DIV_ROUND_UP(commits_nr, BITS_IN_EWORD);
1053
1054 if (!commits_nr || !counts_nr)
1055 return;
1056
1057 for (size_t i = 0; i < counts_nr; i++) {
1058 counts[i].ahead = 0;
1059 counts[i].behind = 0;
1060 }
1061
1062 ensure_generations_valid(r, commits, commits_nr);
1063
1064 init_bit_arrays(&bit_arrays);
1065
1066 for (size_t i = 0; i < commits_nr; i++) {
1067 struct commit *c = commits[i];
1068 struct bitmap *bitmap = get_bit_array(c, width);
1069
1070 bitmap_set(bitmap, i);
1071 insert_no_dup(&queue, c);
1072 }
1073
1074 while (queue_has_nonstale(&queue)) {
1075 struct commit *c = prio_queue_get(&queue);
1076 struct commit_list *p;
1077 struct bitmap *bitmap_c = get_bit_array(c, width);
1078
1079 for (size_t i = 0; i < counts_nr; i++) {
1080 int reach_from_tip = !!bitmap_get(bitmap_c, counts[i].tip_index);
1081 int reach_from_base = !!bitmap_get(bitmap_c, counts[i].base_index);
1082
1083 if (reach_from_tip ^ reach_from_base) {
1084 if (reach_from_base)
1085 counts[i].behind++;
1086 else
1087 counts[i].ahead++;
1088 }
1089 }
1090
1091 for (p = c->parents; p; p = p->next) {
1092 struct bitmap *bitmap_p;
1093
1094 repo_parse_commit(r, p->item);
1095
1096 bitmap_p = get_bit_array(p->item, width);
1097 bitmap_or(bitmap_p, bitmap_c);
1098
1099 /*
1100 * If this parent is reachable from every starting
1101 * commit, then none of its ancestors can contribute
1102 * to the ahead/behind count. Mark it as STALE, so
1103 * we can stop the walk when every commit in the
1104 * queue is STALE.
1105 */
1106 if (bitmap_popcount(bitmap_p) == commits_nr)
1107 p->item->object.flags |= STALE;
1108
1109 insert_no_dup(&queue, p->item);
1110 }
1111
1112 free_bit_array(c);
1113 }
1114
1115 /* STALE is used here, PARENT2 is used by insert_no_dup(). */
1116 repo_clear_commit_marks(r, PARENT2 | STALE);
1117 while (prio_queue_peek(&queue)) {
1118 struct commit *c = prio_queue_get(&queue);
1119 free_bit_array(c);
1120 }
1121 clear_bit_arrays(&bit_arrays);
1122 clear_prio_queue(&queue);
1123}
1124
1125struct commit_and_index {
1126 struct commit *commit;
1127 unsigned int index;
1128 timestamp_t generation;
1129};
1130
1131static int compare_commit_and_index_by_generation(const void *va, const void *vb)
1132{
1133 const struct commit_and_index *a = (const struct commit_and_index *)va;
1134 const struct commit_and_index *b = (const struct commit_and_index *)vb;
1135
1136 if (a->generation > b->generation)
1137 return 1;
1138 if (a->generation < b->generation)
1139 return -1;
1140 return 0;
1141}
1142
1143void tips_reachable_from_bases(struct repository *r,
1144 struct commit_list *bases,
1145 struct commit **tips, size_t tips_nr,
1146 int mark)
1147{
1148 struct commit_and_index *commits;
1149 size_t min_generation_index = 0;
1150 timestamp_t min_generation;
1151 struct commit_list *stack = NULL;
1152
1153 if (!bases || !tips || !tips_nr)
1154 return;
1155
1156 /*
1157 * Do a depth-first search starting at 'bases' to search for the
1158 * tips. Stop at the lowest (un-found) generation number. When
1159 * finding the lowest commit, increase the minimum generation
1160 * number to the next lowest (un-found) generation number.
1161 */
1162
1163 CALLOC_ARRAY(commits, tips_nr);
1164
1165 for (size_t i = 0; i < tips_nr; i++) {
1166 commits[i].commit = tips[i];
1167 commits[i].index = i;
1168 commits[i].generation = commit_graph_generation(tips[i]);
1169 }
1170
1171 /* Sort with generation number ascending. */
1172 QSORT(commits, tips_nr, compare_commit_and_index_by_generation);
1173 min_generation = commits[0].generation;
1174
1175 while (bases) {
1176 repo_parse_commit(r, bases->item);
1177 commit_list_insert(bases->item, &stack);
1178 bases = bases->next;
1179 }
1180
1181 while (stack) {
1182 int explored_all_parents = 1;
1183 struct commit_list *p;
1184 struct commit *c = stack->item;
1185 timestamp_t c_gen = commit_graph_generation(c);
1186
1187 /* Does it match any of our tips? */
1188 for (size_t j = min_generation_index; j < tips_nr; j++) {
1189 if (c_gen < commits[j].generation)
1190 break;
1191
1192 if (commits[j].commit == c) {
1193 tips[commits[j].index]->object.flags |= mark;
1194
1195 if (j == min_generation_index) {
1196 unsigned int k = j + 1;
1197 while (k < tips_nr &&
1198 (tips[commits[k].index]->object.flags & mark))
1199 k++;
1200
1201 /* Terminate early if all found. */
1202 if (k >= tips_nr)
1203 goto done;
1204
1205 min_generation_index = k;
1206 min_generation = commits[k].generation;
1207 }
1208 }
1209 }
1210
1211 for (p = c->parents; p; p = p->next) {
1212 repo_parse_commit(r, p->item);
1213
1214 /* Have we already explored this parent? */
1215 if (p->item->object.flags & SEEN)
1216 continue;
1217
1218 /* Is it below the current minimum generation? */
1219 if (commit_graph_generation(p->item) < min_generation)
1220 continue;
1221
1222 /* Ok, we will explore from here on. */
1223 p->item->object.flags |= SEEN;
1224 explored_all_parents = 0;
1225 commit_list_insert(p->item, &stack);
1226 break;
1227 }
1228
1229 if (explored_all_parents)
1230 pop_commit(&stack);
1231 }
1232
1233done:
1234 free(commits);
1235 repo_clear_commit_marks(r, SEEN);
1236 free_commit_list(stack);
1237}
1238
1239/*
1240 * This slab initializes integers to zero, so use "-1" for "tip is best" and
1241 * "i + 1" for "bases[i] is best".
1242 */
1243define_commit_slab(best_branch_base, int);
1244static struct best_branch_base best_branch_base;
1245#define get_best(c) (*best_branch_base_at(&best_branch_base, (c)))
1246#define set_best(c,v) (*best_branch_base_at(&best_branch_base, (c)) = (v))
1247
1248int get_branch_base_for_tip(struct repository *r,
1249 struct commit *tip,
1250 struct commit **bases,
1251 size_t bases_nr)
1252{
1253 int best_index = -1;
1254 struct commit *branch_point = NULL;
1255 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
1256 int found_missing_gen = 0;
1257
1258 if (!bases_nr)
1259 return -1;
1260
1261 repo_parse_commit(r, tip);
1262 if (commit_graph_generation(tip) == GENERATION_NUMBER_INFINITY)
1263 found_missing_gen = 1;
1264
1265 /* Check for missing generation numbers. */
1266 for (size_t i = 0; i < bases_nr; i++) {
1267 struct commit *c = bases[i];
1268 repo_parse_commit(r, c);
1269 if (commit_graph_generation(c) == GENERATION_NUMBER_INFINITY)
1270 found_missing_gen = 1;
1271 }
1272
1273 if (found_missing_gen) {
1274 struct commit **commits;
1275 size_t commits_nr = bases_nr + 1;
1276
1277 CALLOC_ARRAY(commits, commits_nr);
1278 COPY_ARRAY(commits, bases, bases_nr);
1279 commits[bases_nr] = tip;
1280 ensure_generations_valid(r, commits, commits_nr);
1281 free(commits);
1282 }
1283
1284 /* Initialize queue and slab now that generations are guaranteed. */
1285 init_best_branch_base(&best_branch_base);
1286 set_best(tip, -1);
1287 prio_queue_put(&queue, tip);
1288
1289 for (size_t i = 0; i < bases_nr; i++) {
1290 struct commit *c = bases[i];
1291 int best = get_best(c);
1292
1293 /* Has this already been marked as best by another commit? */
1294 if (best) {
1295 if (best == -1) {
1296 /* We agree at this position. Stop now. */
1297 best_index = i + 1;
1298 goto cleanup;
1299 }
1300 continue;
1301 }
1302
1303 set_best(c, i + 1);
1304 prio_queue_put(&queue, c);
1305 }
1306
1307 while (queue.nr) {
1308 struct commit *c = prio_queue_get(&queue);
1309 int best_for_c = get_best(c);
1310 int best_for_p, positive;
1311 struct commit *parent;
1312
1313 /* Have we reached a known branch point? It's optimal. */
1314 if (c == branch_point)
1315 break;
1316
1317 repo_parse_commit(r, c);
1318 if (!c->parents)
1319 continue;
1320
1321 parent = c->parents->item;
1322 repo_parse_commit(r, parent);
1323 best_for_p = get_best(parent);
1324
1325 if (!best_for_p) {
1326 /* 'parent' is new, so pass along best_for_c. */
1327 set_best(parent, best_for_c);
1328 prio_queue_put(&queue, parent);
1329 continue;
1330 }
1331
1332 if (best_for_p > 0 && best_for_c > 0) {
1333 /* Collision among bases. Minimize. */
1334 if (best_for_c < best_for_p)
1335 set_best(parent, best_for_c);
1336 continue;
1337 }
1338
1339 /*
1340 * At this point, we have reached a commit that is reachable
1341 * from the tip, either from 'c' or from an earlier commit to
1342 * have 'parent' as its first parent.
1343 *
1344 * Update 'best_index' to match the minimum of all base indices
1345 * to reach 'parent'.
1346 */
1347
1348 /* Exactly one is positive due to initial conditions. */
1349 positive = (best_for_c < 0) ? best_for_p : best_for_c;
1350
1351 if (best_index < 0 || positive < best_index)
1352 best_index = positive;
1353
1354 /* No matter what, track that the parent is reachable from tip. */
1355 set_best(parent, -1);
1356 branch_point = parent;
1357 }
1358
1359cleanup:
1360 clear_best_branch_base(&best_branch_base);
1361 clear_prio_queue(&queue);
1362 return best_index > 0 ? best_index - 1 : -1;
1363}