commit-reach: prepare get_merge_bases to handle any repo
[git/git.git] / commit-reach.c
CommitLineData
5227c385 1#include "cache.h"
5227c385 2#include "commit.h"
920f93ca 3#include "commit-graph.h"
1d614d41
DS
4#include "decorate.h"
5#include "prio-queue.h"
6#include "tree.h"
6621c838 7#include "ref-filter.h"
1d614d41
DS
8#include "revision.h"
9#include "tag.h"
5227c385
DS
10#include "commit-reach.h"
11
12/* Remember to update object flag allocation in object.h */
ba3ca1ed 13#define REACHABLE (1u<<15)
5227c385
DS
14#define PARENT1 (1u<<16)
15#define PARENT2 (1u<<17)
16#define STALE (1u<<18)
17#define RESULT (1u<<19)
18
19static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
20
21static 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! */
c383830a
SB
33static struct commit_list *paint_down_to_common(struct repository *r,
34 struct commit *one, int n,
5227c385
DS
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
1b7a91da
JH
43 if (!min_generation)
44 queue.compare = compare_commits_by_commit_date;
45
5227c385
DS
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
1b7a91da 63 if (min_generation && commit->generation > last_gen)
5227c385
DS
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;
c383830a 87 if (repo_parse_commit(r, p))
5227c385
DS
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
18256a91
SB
98static struct commit_list *merge_bases_many(struct repository *r,
99 struct commit *one, int n,
100 struct commit **twos)
5227c385
DS
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
18256a91 115 if (repo_parse_commit(r, one))
5227c385
DS
116 return NULL;
117 for (i = 0; i < n; i++) {
18256a91 118 if (repo_parse_commit(r, twos[i]))
5227c385
DS
119 return NULL;
120 }
121
18256a91 122 list = paint_down_to_common(r, one, n, twos, 0);
5227c385
DS
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
132struct 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
ed8a0e3a 159static int remove_redundant(struct repository *r, struct commit **array, int cnt)
5227c385
DS
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++)
ed8a0e3a 177 repo_parse_commit(r, array[i]);
5227c385
DS
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 }
ed8a0e3a 193 common = paint_down_to_common(r, array[i], filled,
c383830a 194 work, min_generation);
5227c385
DS
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
f28e87f5
SB
219static struct commit_list *get_merge_bases_many_0(struct repository *r,
220 struct commit *one,
5227c385
DS
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
f28e87f5 230 result = merge_bases_many(r, one, n, twos);
5227c385
DS
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
f28e87f5 253 cnt = remove_redundant(r, rslt, cnt);
5227c385
DS
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
21a9651b
SB
261struct commit_list *repo_get_merge_bases_many(struct repository *r,
262 struct commit *one,
263 int n,
264 struct commit **twos)
5227c385 265{
21a9651b 266 return get_merge_bases_many_0(r, one, n, twos, 1);
5227c385
DS
267}
268
21a9651b
SB
269struct commit_list *repo_get_merge_bases_many_dirty(struct repository *r,
270 struct commit *one,
271 int n,
272 struct commit **twos)
5227c385 273{
21a9651b 274 return get_merge_bases_many_0(r, one, n, twos, 0);
5227c385
DS
275}
276
21a9651b
SB
277struct commit_list *repo_get_merge_bases(struct repository *r,
278 struct commit *one,
279 struct commit *two)
5227c385 280{
21a9651b 281 return get_merge_bases_many_0(r, one, 1, &two, 1);
5227c385
DS
282}
283
284/*
285 * Is "commit" a descendant of one of the elements on the "with_commit" list?
286 */
287int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
288{
289 if (!with_commit)
290 return 1;
5227c385 291
6cc01743
DS
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;
5227c385 309 }
5227c385
DS
310}
311
312/*
313 * Is "commit" an ancestor of one of the "references"?
314 */
315int 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
c383830a
SB
333 bases = paint_down_to_common(the_repository, commit,
334 nr_reference, reference,
335 commit->generation);
5227c385
DS
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 */
347int in_merge_bases(struct commit *commit, struct commit *reference)
348{
349 return in_merge_bases_many(commit, 1, &reference);
350}
351
352struct 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 }
ed8a0e3a 378 num_head = remove_redundant(the_repository, array, num_head);
5227c385
DS
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
385void 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}
1d614d41 391
1d614d41
DS
392int 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;
1e3497a2 396 struct commit_list *old_commit_list = NULL;
1d614d41
DS
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
1e3497a2
DS
417 commit_list_insert(old_commit, &old_commit_list);
418 return is_descendant_of(new_commit, old_commit_list);
1d614d41 419}
920f93ca
DS
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 */
428struct 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
436static int in_commit_list(const struct commit_list *want, struct commit *c)
437{
438 for (; want; want = want->next)
e43d2dcc 439 if (oideq(&want->item->object.oid, &c->object.oid))
920f93ca
DS
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 */
448static 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
474static 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
481static 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
532int 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}
ba3ca1ed 539
4fbcca4e 540static int compare_commits_by_gen(const void *_a, const void *_b)
ba3ca1ed 541{
4fbcca4e
DS
542 const struct commit *a = (const struct commit *)_a;
543 const struct commit *b = (const struct commit *)_b;
ba3ca1ed 544
4fbcca4e
DS
545 if (a->generation < b->generation)
546 return -1;
547 if (a->generation > b->generation)
548 return 1;
549 return 0;
ba3ca1ed
DS
550}
551
552int can_all_from_reach_with_flag(struct object_array *from,
553 unsigned int with_flag,
554 unsigned int assign_flag,
4fbcca4e
DS
555 time_t min_commit_date,
556 uint32_t min_generation)
ba3ca1ed 557{
4fbcca4e 558 struct commit **list = NULL;
ba3ca1ed 559 int i;
b67f6b26 560 int nr_commits;
4fbcca4e 561 int result = 1;
ba3ca1ed 562
4fbcca4e 563 ALLOC_ARRAY(list, from->nr);
b67f6b26 564 nr_commits = 0;
ba3ca1ed 565 for (i = 0; i < from->nr; i++) {
b67f6b26 566 struct object *from_one = from->objects[i].item;
ba3ca1ed 567
b67f6b26
DS
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) {
85806440
DS
574 /*
575 * no way to tell if this is reachable by
b67f6b26
DS
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++;
ba3ca1ed 592 }
4fbcca4e 593
b67f6b26 594 QSORT(list, nr_commits, compare_commits_by_gen);
4fbcca4e 595
b67f6b26 596 for (i = 0; i < nr_commits; i++) {
4fbcca4e
DS
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
638cleanup:
85806440 639 clear_commit_marks_many(nr_commits, list, RESULT | assign_flag);
4067a646
DS
640 free(list);
641
642 for (i = 0; i < from->nr; i++)
643 from->objects[i].item->flags &= ~assign_flag;
644
4fbcca4e 645 return result;
ba3ca1ed 646}
1792bc12
DS
647
648int 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;
4fbcca4e 655 uint32_t min_generation = GENERATION_NUMBER_INFINITY;
1792bc12
DS
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;
4fbcca4e
DS
663
664 if (from_iter->item->generation < min_generation)
665 min_generation = from_iter->item->generation;
1792bc12
DS
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;
4fbcca4e
DS
675
676 if (to_iter->item->generation < min_generation)
677 min_generation = to_iter->item->generation;
1792bc12
DS
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,
4fbcca4e 686 min_commit_date, min_generation);
1792bc12
DS
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}