Merge branch 'rb/hpe'
[git.git] / commit-reach.c
blobd5a39defd3d5144f83d4f48e43e54e1f7f49ab29
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"
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)
19 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
21 static int queue_has_nonstale(struct prio_queue *queue)
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;
29 return 0;
32 /* all input commits in one and twos[] must have been parsed! */
33 static struct commit_list *paint_down_to_common(struct commit *one, int n,
34 struct commit **twos,
35 int min_generation)
37 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
38 struct commit_list *result = NULL;
39 int i;
40 uint32_t last_gen = GENERATION_NUMBER_INFINITY;
42 if (!min_generation)
43 queue.compare = compare_commits_by_commit_date;
45 one->object.flags |= PARENT1;
46 if (!n) {
47 commit_list_append(one, &result);
48 return result;
50 prio_queue_put(&queue, one);
52 for (i = 0; i < n; i++) {
53 twos[i]->object.flags |= PARENT2;
54 prio_queue_put(&queue, twos[i]);
57 while (queue_has_nonstale(&queue)) {
58 struct commit *commit = prio_queue_get(&queue);
59 struct commit_list *parents;
60 int flags;
62 if (min_generation && commit->generation > last_gen)
63 BUG("bad generation skip %8x > %8x at %s",
64 commit->generation, last_gen,
65 oid_to_hex(&commit->object.oid));
66 last_gen = commit->generation;
68 if (commit->generation < min_generation)
69 break;
71 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
72 if (flags == (PARENT1 | PARENT2)) {
73 if (!(commit->object.flags & RESULT)) {
74 commit->object.flags |= RESULT;
75 commit_list_insert_by_date(commit, &result);
77 /* Mark parents of a found merge stale */
78 flags |= STALE;
80 parents = commit->parents;
81 while (parents) {
82 struct commit *p = parents->item;
83 parents = parents->next;
84 if ((p->object.flags & flags) == flags)
85 continue;
86 if (parse_commit(p))
87 return NULL;
88 p->object.flags |= flags;
89 prio_queue_put(&queue, p);
93 clear_prio_queue(&queue);
94 return result;
97 static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
99 struct commit_list *list = NULL;
100 struct commit_list *result = NULL;
101 int i;
103 for (i = 0; i < n; i++) {
104 if (one == twos[i])
106 * We do not mark this even with RESULT so we do not
107 * have to clean it up.
109 return commit_list_insert(one, &result);
112 if (parse_commit(one))
113 return NULL;
114 for (i = 0; i < n; i++) {
115 if (parse_commit(twos[i]))
116 return NULL;
119 list = paint_down_to_common(one, n, twos, 0);
121 while (list) {
122 struct commit *commit = pop_commit(&list);
123 if (!(commit->object.flags & STALE))
124 commit_list_insert_by_date(commit, &result);
126 return result;
129 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
131 struct commit_list *i, *j, *k, *ret = NULL;
133 if (!in)
134 return ret;
136 commit_list_insert(in->item, &ret);
138 for (i = in->next; i; i = i->next) {
139 struct commit_list *new_commits = NULL, *end = NULL;
141 for (j = ret; j; j = j->next) {
142 struct commit_list *bases;
143 bases = get_merge_bases(i->item, j->item);
144 if (!new_commits)
145 new_commits = bases;
146 else
147 end->next = bases;
148 for (k = bases; k; k = k->next)
149 end = k;
151 ret = new_commits;
153 return ret;
156 static int remove_redundant(struct commit **array, int cnt)
159 * Some commit in the array may be an ancestor of
160 * another commit. Move such commit to the end of
161 * the array, and return the number of commits that
162 * are independent from each other.
164 struct commit **work;
165 unsigned char *redundant;
166 int *filled_index;
167 int i, j, filled;
169 work = xcalloc(cnt, sizeof(*work));
170 redundant = xcalloc(cnt, 1);
171 ALLOC_ARRAY(filled_index, cnt - 1);
173 for (i = 0; i < cnt; i++)
174 parse_commit(array[i]);
175 for (i = 0; i < cnt; i++) {
176 struct commit_list *common;
177 uint32_t min_generation = array[i]->generation;
179 if (redundant[i])
180 continue;
181 for (j = filled = 0; j < cnt; j++) {
182 if (i == j || redundant[j])
183 continue;
184 filled_index[filled] = j;
185 work[filled++] = array[j];
187 if (array[j]->generation < min_generation)
188 min_generation = array[j]->generation;
190 common = paint_down_to_common(array[i], filled, work,
191 min_generation);
192 if (array[i]->object.flags & PARENT2)
193 redundant[i] = 1;
194 for (j = 0; j < filled; j++)
195 if (work[j]->object.flags & PARENT1)
196 redundant[filled_index[j]] = 1;
197 clear_commit_marks(array[i], all_flags);
198 clear_commit_marks_many(filled, work, all_flags);
199 free_commit_list(common);
202 /* Now collect the result */
203 COPY_ARRAY(work, array, cnt);
204 for (i = filled = 0; i < cnt; i++)
205 if (!redundant[i])
206 array[filled++] = work[i];
207 for (j = filled, i = 0; i < cnt; i++)
208 if (redundant[i])
209 array[j++] = work[i];
210 free(work);
211 free(redundant);
212 free(filled_index);
213 return filled;
216 static struct commit_list *get_merge_bases_many_0(struct commit *one,
217 int n,
218 struct commit **twos,
219 int cleanup)
221 struct commit_list *list;
222 struct commit **rslt;
223 struct commit_list *result;
224 int cnt, i;
226 result = merge_bases_many(one, n, twos);
227 for (i = 0; i < n; i++) {
228 if (one == twos[i])
229 return result;
231 if (!result || !result->next) {
232 if (cleanup) {
233 clear_commit_marks(one, all_flags);
234 clear_commit_marks_many(n, twos, all_flags);
236 return result;
239 /* There are more than one */
240 cnt = commit_list_count(result);
241 rslt = xcalloc(cnt, sizeof(*rslt));
242 for (list = result, i = 0; list; list = list->next)
243 rslt[i++] = list->item;
244 free_commit_list(result);
246 clear_commit_marks(one, all_flags);
247 clear_commit_marks_many(n, twos, all_flags);
249 cnt = remove_redundant(rslt, cnt);
250 result = NULL;
251 for (i = 0; i < cnt; i++)
252 commit_list_insert_by_date(rslt[i], &result);
253 free(rslt);
254 return result;
257 struct commit_list *get_merge_bases_many(struct commit *one,
258 int n,
259 struct commit **twos)
261 return get_merge_bases_many_0(one, n, twos, 1);
264 struct commit_list *get_merge_bases_many_dirty(struct commit *one,
265 int n,
266 struct commit **twos)
268 return get_merge_bases_many_0(one, n, twos, 0);
271 struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
273 return get_merge_bases_many_0(one, 1, &two, 1);
277 * Is "commit" a descendant of one of the elements on the "with_commit" list?
279 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
281 if (!with_commit)
282 return 1;
284 if (generation_numbers_enabled(the_repository)) {
285 struct commit_list *from_list = NULL;
286 int result;
287 commit_list_insert(commit, &from_list);
288 result = can_all_from_reach(from_list, with_commit, 0);
289 free_commit_list(from_list);
290 return result;
291 } else {
292 while (with_commit) {
293 struct commit *other;
295 other = with_commit->item;
296 with_commit = with_commit->next;
297 if (in_merge_bases(other, commit))
298 return 1;
300 return 0;
305 * Is "commit" an ancestor of one of the "references"?
307 int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
309 struct commit_list *bases;
310 int ret = 0, i;
311 uint32_t min_generation = GENERATION_NUMBER_INFINITY;
313 if (parse_commit(commit))
314 return ret;
315 for (i = 0; i < nr_reference; i++) {
316 if (parse_commit(reference[i]))
317 return ret;
318 if (reference[i]->generation < min_generation)
319 min_generation = reference[i]->generation;
322 if (commit->generation > min_generation)
323 return ret;
325 bases = paint_down_to_common(commit, nr_reference, reference, commit->generation);
326 if (commit->object.flags & PARENT2)
327 ret = 1;
328 clear_commit_marks(commit, all_flags);
329 clear_commit_marks_many(nr_reference, reference, all_flags);
330 free_commit_list(bases);
331 return ret;
335 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
337 int in_merge_bases(struct commit *commit, struct commit *reference)
339 return in_merge_bases_many(commit, 1, &reference);
342 struct commit_list *reduce_heads(struct commit_list *heads)
344 struct commit_list *p;
345 struct commit_list *result = NULL, **tail = &result;
346 struct commit **array;
347 int num_head, i;
349 if (!heads)
350 return NULL;
352 /* Uniquify */
353 for (p = heads; p; p = p->next)
354 p->item->object.flags &= ~STALE;
355 for (p = heads, num_head = 0; p; p = p->next) {
356 if (p->item->object.flags & STALE)
357 continue;
358 p->item->object.flags |= STALE;
359 num_head++;
361 array = xcalloc(num_head, sizeof(*array));
362 for (p = heads, i = 0; p; p = p->next) {
363 if (p->item->object.flags & STALE) {
364 array[i++] = p->item;
365 p->item->object.flags &= ~STALE;
368 num_head = remove_redundant(array, num_head);
369 for (i = 0; i < num_head; i++)
370 tail = &commit_list_insert(array[i], tail)->next;
371 free(array);
372 return result;
375 void reduce_heads_replace(struct commit_list **heads)
377 struct commit_list *result = reduce_heads(*heads);
378 free_commit_list(*heads);
379 *heads = result;
382 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
384 struct object *o;
385 struct commit *old_commit, *new_commit;
386 struct commit_list *old_commit_list = NULL;
389 * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
390 * old_commit. Otherwise we require --force.
392 o = deref_tag(the_repository, parse_object(the_repository, old_oid),
393 NULL, 0);
394 if (!o || o->type != OBJ_COMMIT)
395 return 0;
396 old_commit = (struct commit *) o;
398 o = deref_tag(the_repository, parse_object(the_repository, new_oid),
399 NULL, 0);
400 if (!o || o->type != OBJ_COMMIT)
401 return 0;
402 new_commit = (struct commit *) o;
404 if (parse_commit(new_commit) < 0)
405 return 0;
407 commit_list_insert(old_commit, &old_commit_list);
408 return is_descendant_of(new_commit, old_commit_list);
412 * Mimicking the real stack, this stack lives on the heap, avoiding stack
413 * overflows.
415 * At each recursion step, the stack items points to the commits whose
416 * ancestors are to be inspected.
418 struct contains_stack {
419 int nr, alloc;
420 struct contains_stack_entry {
421 struct commit *commit;
422 struct commit_list *parents;
423 } *contains_stack;
426 static int in_commit_list(const struct commit_list *want, struct commit *c)
428 for (; want; want = want->next)
429 if (oideq(&want->item->object.oid, &c->object.oid))
430 return 1;
431 return 0;
435 * Test whether the candidate is contained in the list.
436 * Do not recurse to find out, though, but return -1 if inconclusive.
438 static enum contains_result contains_test(struct commit *candidate,
439 const struct commit_list *want,
440 struct contains_cache *cache,
441 uint32_t cutoff)
443 enum contains_result *cached = contains_cache_at(cache, candidate);
445 /* If we already have the answer cached, return that. */
446 if (*cached)
447 return *cached;
449 /* or are we it? */
450 if (in_commit_list(want, candidate)) {
451 *cached = CONTAINS_YES;
452 return CONTAINS_YES;
455 /* Otherwise, we don't know; prepare to recurse */
456 parse_commit_or_die(candidate);
458 if (candidate->generation < cutoff)
459 return CONTAINS_NO;
461 return CONTAINS_UNKNOWN;
464 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
466 ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
467 contains_stack->contains_stack[contains_stack->nr].commit = candidate;
468 contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
471 static enum contains_result contains_tag_algo(struct commit *candidate,
472 const struct commit_list *want,
473 struct contains_cache *cache)
475 struct contains_stack contains_stack = { 0, 0, NULL };
476 enum contains_result result;
477 uint32_t cutoff = GENERATION_NUMBER_INFINITY;
478 const struct commit_list *p;
480 for (p = want; p; p = p->next) {
481 struct commit *c = p->item;
482 load_commit_graph_info(the_repository, c);
483 if (c->generation < cutoff)
484 cutoff = c->generation;
487 result = contains_test(candidate, want, cache, cutoff);
488 if (result != CONTAINS_UNKNOWN)
489 return result;
491 push_to_contains_stack(candidate, &contains_stack);
492 while (contains_stack.nr) {
493 struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
494 struct commit *commit = entry->commit;
495 struct commit_list *parents = entry->parents;
497 if (!parents) {
498 *contains_cache_at(cache, commit) = CONTAINS_NO;
499 contains_stack.nr--;
502 * If we just popped the stack, parents->item has been marked,
503 * therefore contains_test will return a meaningful yes/no.
505 else switch (contains_test(parents->item, want, cache, cutoff)) {
506 case CONTAINS_YES:
507 *contains_cache_at(cache, commit) = CONTAINS_YES;
508 contains_stack.nr--;
509 break;
510 case CONTAINS_NO:
511 entry->parents = parents->next;
512 break;
513 case CONTAINS_UNKNOWN:
514 push_to_contains_stack(parents->item, &contains_stack);
515 break;
518 free(contains_stack.contains_stack);
519 return contains_test(candidate, want, cache, cutoff);
522 int commit_contains(struct ref_filter *filter, struct commit *commit,
523 struct commit_list *list, struct contains_cache *cache)
525 if (filter->with_commit_tag_algo)
526 return contains_tag_algo(commit, list, cache) == CONTAINS_YES;
527 return is_descendant_of(commit, list);
530 static int compare_commits_by_gen(const void *_a, const void *_b)
532 const struct commit *a = *(const struct commit * const *)_a;
533 const struct commit *b = *(const struct commit * const *)_b;
535 if (a->generation < b->generation)
536 return -1;
537 if (a->generation > b->generation)
538 return 1;
539 return 0;
542 int can_all_from_reach_with_flag(struct object_array *from,
543 unsigned int with_flag,
544 unsigned int assign_flag,
545 time_t min_commit_date,
546 uint32_t min_generation)
548 struct commit **list = NULL;
549 int i;
550 int nr_commits;
551 int result = 1;
553 ALLOC_ARRAY(list, from->nr);
554 nr_commits = 0;
555 for (i = 0; i < from->nr; i++) {
556 struct object *from_one = from->objects[i].item;
558 if (!from_one || from_one->flags & assign_flag)
559 continue;
561 from_one = deref_tag(the_repository, from_one,
562 "a from object", 0);
563 if (!from_one || from_one->type != OBJ_COMMIT) {
565 * no way to tell if this is reachable by
566 * looking at the ancestry chain alone, so
567 * leave a note to ourselves not to worry about
568 * this object anymore.
570 from->objects[i].item->flags |= assign_flag;
571 continue;
574 list[nr_commits] = (struct commit *)from_one;
575 if (parse_commit(list[nr_commits]) ||
576 list[nr_commits]->generation < min_generation) {
577 result = 0;
578 goto cleanup;
581 nr_commits++;
584 QSORT(list, nr_commits, compare_commits_by_gen);
586 for (i = 0; i < nr_commits; i++) {
587 /* DFS from list[i] */
588 struct commit_list *stack = NULL;
590 list[i]->object.flags |= assign_flag;
591 commit_list_insert(list[i], &stack);
593 while (stack) {
594 struct commit_list *parent;
596 if (stack->item->object.flags & (with_flag | RESULT)) {
597 pop_commit(&stack);
598 if (stack)
599 stack->item->object.flags |= RESULT;
600 continue;
603 for (parent = stack->item->parents; parent; parent = parent->next) {
604 if (parent->item->object.flags & (with_flag | RESULT))
605 stack->item->object.flags |= RESULT;
607 if (!(parent->item->object.flags & assign_flag)) {
608 parent->item->object.flags |= assign_flag;
610 if (parse_commit(parent->item) ||
611 parent->item->date < min_commit_date ||
612 parent->item->generation < min_generation)
613 continue;
615 commit_list_insert(parent->item, &stack);
616 break;
620 if (!parent)
621 pop_commit(&stack);
624 if (!(list[i]->object.flags & (with_flag | RESULT))) {
625 result = 0;
626 goto cleanup;
630 cleanup:
631 clear_commit_marks_many(nr_commits, list, RESULT | assign_flag);
632 free(list);
634 for (i = 0; i < from->nr; i++)
635 from->objects[i].item->flags &= ~assign_flag;
637 return result;
640 int can_all_from_reach(struct commit_list *from, struct commit_list *to,
641 int cutoff_by_min_date)
643 struct object_array from_objs = OBJECT_ARRAY_INIT;
644 time_t min_commit_date = cutoff_by_min_date ? from->item->date : 0;
645 struct commit_list *from_iter = from, *to_iter = to;
646 int result;
647 uint32_t min_generation = GENERATION_NUMBER_INFINITY;
649 while (from_iter) {
650 add_object_array(&from_iter->item->object, NULL, &from_objs);
652 if (!parse_commit(from_iter->item)) {
653 if (from_iter->item->date < min_commit_date)
654 min_commit_date = from_iter->item->date;
656 if (from_iter->item->generation < min_generation)
657 min_generation = from_iter->item->generation;
660 from_iter = from_iter->next;
663 while (to_iter) {
664 if (!parse_commit(to_iter->item)) {
665 if (to_iter->item->date < min_commit_date)
666 min_commit_date = to_iter->item->date;
668 if (to_iter->item->generation < min_generation)
669 min_generation = to_iter->item->generation;
672 to_iter->item->object.flags |= PARENT2;
674 to_iter = to_iter->next;
677 result = can_all_from_reach_with_flag(&from_objs, PARENT2, PARENT1,
678 min_commit_date, min_generation);
680 while (from) {
681 clear_commit_marks(from->item, PARENT1);
682 from = from->next;
685 while (to) {
686 clear_commit_marks(to->item, PARENT2);
687 to = to->next;
690 object_array_clear(&from_objs);
691 return result;
694 struct commit_list *get_reachable_subset(struct commit **from, int nr_from,
695 struct commit **to, int nr_to,
696 unsigned int reachable_flag)
698 struct commit **item;
699 struct commit *current;
700 struct commit_list *found_commits = NULL;
701 struct commit **to_last = to + nr_to;
702 struct commit **from_last = from + nr_from;
703 uint32_t min_generation = GENERATION_NUMBER_INFINITY;
704 int num_to_find = 0;
706 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
708 for (item = to; item < to_last; item++) {
709 struct commit *c = *item;
711 parse_commit(c);
712 if (c->generation < min_generation)
713 min_generation = c->generation;
715 if (!(c->object.flags & PARENT1)) {
716 c->object.flags |= PARENT1;
717 num_to_find++;
721 for (item = from; item < from_last; item++) {
722 struct commit *c = *item;
723 if (!(c->object.flags & PARENT2)) {
724 c->object.flags |= PARENT2;
725 parse_commit(c);
727 prio_queue_put(&queue, *item);
731 while (num_to_find && (current = prio_queue_get(&queue)) != NULL) {
732 struct commit_list *parents;
734 if (current->object.flags & PARENT1) {
735 current->object.flags &= ~PARENT1;
736 current->object.flags |= reachable_flag;
737 commit_list_insert(current, &found_commits);
738 num_to_find--;
741 for (parents = current->parents; parents; parents = parents->next) {
742 struct commit *p = parents->item;
744 parse_commit(p);
746 if (p->generation < min_generation)
747 continue;
749 if (p->object.flags & PARENT2)
750 continue;
752 p->object.flags |= PARENT2;
753 prio_queue_put(&queue, p);
757 clear_commit_marks_many(nr_to, to, PARENT1);
758 clear_commit_marks_many(nr_from, from, PARENT2);
760 return found_commits;