1#include "cache.h"
2#include "tag.h"
3#include "commit.h"
4#include "pkt-line.h"
5#include "utf8.h"
6#include "diff.h"
7#include "revision.h"
8int save_commit_buffer = 1;
10const char *commit_type = "commit";
12static struct commit *check_commit(struct object *obj,
14 const unsigned char *sha1,
15 int quiet)
16{
17 if (obj->type != OBJ_COMMIT) {
18 if (!quiet)
19 error("Object %s is a %s, not a commit",
20 sha1_to_hex(sha1), typename(obj->type));
21 return NULL;
22 }
23 return (struct commit *) obj;
24}
25struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
27 int quiet)
28{
29 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
30 if (!obj)
32 return NULL;
33 return check_commit(obj, sha1, quiet);
34}
35struct commit *lookup_commit_reference(const unsigned char *sha1)
37{
38 return lookup_commit_reference_gently(sha1, 0);
39}
40struct commit *lookup_commit(const unsigned char *sha1)
42{
43 struct object *obj = lookup_object(sha1);
44 if (!obj)
45 return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
46 if (!obj->type)
47 obj->type = OBJ_COMMIT;
48 return check_commit(obj, sha1, 0);
49}
50static unsigned long parse_commit_date(const char *buf, const char *tail)
52{
53 const char *dateptr;
54 if (buf + 6 >= tail)
56 return 0;
57 if (memcmp(buf, "author", 6))
58 return 0;
59 while (buf < tail && *buf++ != '\n')
60 /* nada */;
61 if (buf + 9 >= tail)
62 return 0;
63 if (memcmp(buf, "committer", 9))
64 return 0;
65 while (buf < tail && *buf++ != '>')
66 /* nada */;
67 if (buf >= tail)
68 return 0;
69 dateptr = buf;
70 while (buf < tail && *buf++ != '\n')
71 /* nada */;
72 if (buf >= tail)
73 return 0;
74 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
75 return strtoul(dateptr, NULL, 10);
76}
77static struct commit_graft **commit_graft;
79static int commit_graft_alloc, commit_graft_nr;
80static int commit_graft_pos(const unsigned char *sha1)
82{
83 int lo, hi;
84 lo = 0;
85 hi = commit_graft_nr;
86 while (lo < hi) {
87 int mi = (lo + hi) / 2;
88 struct commit_graft *graft = commit_graft[mi];
89 int cmp = hashcmp(sha1, graft->sha1);
90 if (!cmp)
91 return mi;
92 if (cmp < 0)
93 hi = mi;
94 else
95 lo = mi + 1;
96 }
97 return -lo - 1;
98}
99int register_commit_graft(struct commit_graft *graft, int ignore_dups)
101{
102 int pos = commit_graft_pos(graft->sha1);
103 if (0 <= pos) {
105 if (ignore_dups)
106 free(graft);
107 else {
108 free(commit_graft[pos]);
109 commit_graft[pos] = graft;
110 }
111 return 1;
112 }
113 pos = -pos - 1;
114 if (commit_graft_alloc <= ++commit_graft_nr) {
115 commit_graft_alloc = alloc_nr(commit_graft_alloc);
116 commit_graft = xrealloc(commit_graft,
117 sizeof(*commit_graft) *
118 commit_graft_alloc);
119 }
120 if (pos < commit_graft_nr)
121 memmove(commit_graft + pos + 1,
122 commit_graft + pos,
123 (commit_graft_nr - pos - 1) *
124 sizeof(*commit_graft));
125 commit_graft[pos] = graft;
126 return 0;
127}
128struct commit_graft *read_graft_line(char *buf, int len)
130{
131 /* The format is just "Commit Parent1 Parent2 ...\n" */
132 int i;
133 struct commit_graft *graft = NULL;
134 if (buf[len-1] == '\n')
136 buf[--len] = 0;
137 if (buf[0] == '#' || buf[0] == '\0')
138 return NULL;
139 if ((len + 1) % 41) {
140 bad_graft_data:
141 error("bad graft data: %s", buf);
142 free(graft);
143 return NULL;
144 }
145 i = (len + 1) / 41 - 1;
146 graft = xmalloc(sizeof(*graft) + 20 * i);
147 graft->nr_parent = i;
148 if (get_sha1_hex(buf, graft->sha1))
149 goto bad_graft_data;
150 for (i = 40; i < len; i += 41) {
151 if (buf[i] != ' ')
152 goto bad_graft_data;
153 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
154 goto bad_graft_data;
155 }
156 return graft;
157}
158static int read_graft_file(const char *graft_file)
160{
161 FILE *fp = fopen(graft_file, "r");
162 char buf[1024];
163 if (!fp)
164 return -1;
165 while (fgets(buf, sizeof(buf), fp)) {
166 /* The format is just "Commit Parent1 Parent2 ...\n" */
167 int len = strlen(buf);
168 struct commit_graft *graft = read_graft_line(buf, len);
169 if (!graft)
170 continue;
171 if (register_commit_graft(graft, 1))
172 error("duplicate graft data: %s", buf);
173 }
174 fclose(fp);
175 return 0;
176}
177static void prepare_commit_graft(void)
179{
180 static int commit_graft_prepared;
181 char *graft_file;
182 if (commit_graft_prepared)
184 return;
185 graft_file = get_graft_file();
186 read_graft_file(graft_file);
187 /* make sure shallows are read */
188 is_repository_shallow();
189 commit_graft_prepared = 1;
190}
191struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
193{
194 int pos;
195 prepare_commit_graft();
196 pos = commit_graft_pos(sha1);
197 if (pos < 0)
198 return NULL;
199 return commit_graft[pos];
200}
201int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
203{
204 int i, count = 0;
205 for (i = 0; i < commit_graft_nr; i++)
206 if (commit_graft[i]->nr_parent < 0) {
207 const char *hex =
208 sha1_to_hex(commit_graft[i]->sha1);
209 count++;
210 if (use_pack_protocol)
211 packet_buf_write(out, "shallow %s", hex);
212 else {
213 strbuf_addstr(out, hex);
214 strbuf_addch(out, '\n');
215 }
216 }
217 return count;
218}
219int unregister_shallow(const unsigned char *sha1)
221{
222 int pos = commit_graft_pos(sha1);
223 if (pos < 0)
224 return -1;
225 if (pos + 1 < commit_graft_nr)
226 memcpy(commit_graft + pos, commit_graft + pos + 1,
227 sizeof(struct commit_graft *)
228 * (commit_graft_nr - pos - 1));
229 commit_graft_nr--;
230 return 0;
231}
232int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
234{
235 char *tail = buffer;
236 char *bufptr = buffer;
237 unsigned char parent[20];
238 struct commit_list **pptr;
239 struct commit_graft *graft;
240 if (item->object.parsed)
242 return 0;
243 item->object.parsed = 1;
244 tail += size;
245 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
246 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
247 if (get_sha1_hex(bufptr + 5, parent) < 0)
248 return error("bad tree pointer in commit %s",
249 sha1_to_hex(item->object.sha1));
250 item->tree = lookup_tree(parent);
251 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
252 pptr = &item->parents;
253 graft = lookup_commit_graft(item->object.sha1);
255 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
256 struct commit *new_parent;
257 if (tail <= bufptr + 48 ||
259 get_sha1_hex(bufptr + 7, parent) ||
260 bufptr[47] != '\n')
261 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
262 bufptr += 48;
263 /*
264 * The clone is shallow if nr_parent < 0, and we must
265 * not traverse its real parents even when we unhide them.
266 */
267 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
268 continue;
269 new_parent = lookup_commit(parent);
270 if (new_parent)
271 pptr = &commit_list_insert(new_parent, pptr)->next;
272 }
273 if (graft) {
274 int i;
275 struct commit *new_parent;
276 for (i = 0; i < graft->nr_parent; i++) {
277 new_parent = lookup_commit(graft->parent[i]);
278 if (!new_parent)
279 continue;
280 pptr = &commit_list_insert(new_parent, pptr)->next;
281 }
282 }
283 item->date = parse_commit_date(bufptr, tail);
284 return 0;
286}
287int parse_commit(struct commit *item)
289{
290 enum object_type type;
291 void *buffer;
292 unsigned long size;
293 int ret;
294 if (!item)
296 return -1;
297 if (item->object.parsed)
298 return 0;
299 buffer = read_sha1_file(item->object.sha1, &type, &size);
300 if (!buffer)
301 return error("Could not read %s",
302 sha1_to_hex(item->object.sha1));
303 if (type != OBJ_COMMIT) {
304 free(buffer);
305 return error("Object %s not a commit",
306 sha1_to_hex(item->object.sha1));
307 }
308 ret = parse_commit_buffer(item, buffer, size);
309 if (save_commit_buffer && !ret) {
310 item->buffer = buffer;
311 return 0;
312 }
313 free(buffer);
314 return ret;
315}
316struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
318{
319 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
320 new_list->item = item;
321 new_list->next = *list_p;
322 *list_p = new_list;
323 return new_list;
324}
325unsigned commit_list_count(const struct commit_list *l)
327{
328 unsigned c = 0;
329 for (; l; l = l->next )
330 c++;
331 return c;
332}
333void free_commit_list(struct commit_list *list)
335{
336 while (list) {
337 struct commit_list *temp = list;
338 list = temp->next;
339 free(temp);
340 }
341}
342struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
344{
345 struct commit_list **pp = list;
346 struct commit_list *p;
347 while ((p = *pp) != NULL) {
348 if (p->item->date < item->date) {
349 break;
350 }
351 pp = &p->next;
352 }
353 return commit_list_insert(item, pp);
354}
355void sort_by_date(struct commit_list **list)
358{
359 struct commit_list *ret = NULL;
360 while (*list) {
361 insert_by_date((*list)->item, &ret);
362 *list = (*list)->next;
363 }
364 *list = ret;
365}
366struct commit *pop_most_recent_commit(struct commit_list **list,
368 unsigned int mark)
369{
370 struct commit *ret = (*list)->item;
371 struct commit_list *parents = ret->parents;
372 struct commit_list *old = *list;
373 *list = (*list)->next;
375 free(old);
376 while (parents) {
378 struct commit *commit = parents->item;
379 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
380 commit->object.flags |= mark;
381 insert_by_date(commit, list);
382 }
383 parents = parents->next;
384 }
385 return ret;
386}
387void clear_commit_marks(struct commit *commit, unsigned int mark)
389{
390 while (commit) {
391 struct commit_list *parents;
392 if (!(mark & commit->object.flags))
394 return;
395 commit->object.flags &= ~mark;
397 parents = commit->parents;
399 if (!parents)
400 return;
401 while ((parents = parents->next))
403 clear_commit_marks(parents->item, mark);
404 commit = commit->parents->item;
406 }
407}
408struct commit *pop_commit(struct commit_list **stack)
410{
411 struct commit_list *top = *stack;
412 struct commit *item = top ? top->item : NULL;
413 if (top) {
415 *stack = top->next;
416 free(top);
417 }
418 return item;
419}
420/*
422 * Performs an in-place topological sort on the list supplied.
423 */
424void sort_in_topological_order(struct commit_list ** list, int lifo)
425{
426 struct commit_list *next, *orig = *list;
427 struct commit_list *work, **insert;
428 struct commit_list **pptr;
429 if (!orig)
431 return;
432 *list = NULL;
433 /* Mark them and clear the indegree */
435 for (next = orig; next; next = next->next) {
436 struct commit *commit = next->item;
437 commit->indegree = 1;
438 }
439 /* update the indegree */
441 for (next = orig; next; next = next->next) {
442 struct commit_list * parents = next->item->parents;
443 while (parents) {
444 struct commit *parent = parents->item;
445 if (parent->indegree)
447 parent->indegree++;
448 parents = parents->next;
449 }
450 }
451 /*
453 * find the tips
454 *
455 * tips are nodes not reachable from any other node in the list
456 *
457 * the tips serve as a starting set for the work queue.
458 */
459 work = NULL;
460 insert = &work;
461 for (next = orig; next; next = next->next) {
462 struct commit *commit = next->item;
463 if (commit->indegree == 1)
465 insert = &commit_list_insert(commit, insert)->next;
466 }
467 /* process the list in topological order */
469 if (!lifo)
470 sort_by_date(&work);
471 pptr = list;
473 *list = NULL;
474 while (work) {
475 struct commit *commit;
476 struct commit_list *parents, *work_item;
477 work_item = work;
479 work = work_item->next;
480 work_item->next = NULL;
481 commit = work_item->item;
483 for (parents = commit->parents; parents ; parents = parents->next) {
484 struct commit *parent=parents->item;
485 if (!parent->indegree)
487 continue;
488 /*
490 * parents are only enqueued for emission
491 * when all their children have been emitted thereby
492 * guaranteeing topological order.
493 */
494 if (--parent->indegree == 1) {
495 if (!lifo)
496 insert_by_date(parent, &work);
497 else
498 commit_list_insert(parent, &work);
499 }
500 }
501 /*
502 * work_item is a commit all of whose children
503 * have already been emitted. we can emit it now.
504 */
505 commit->indegree = 0;
506 *pptr = work_item;
507 pptr = &work_item->next;
508 }
509}
510/* merge-base stuff */
512/* bits #0..15 in revision.h */
514#define PARENT1 (1u<<16)
515#define PARENT2 (1u<<17)
516#define STALE (1u<<18)
517#define RESULT (1u<<19)
518static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
520static struct commit *interesting(struct commit_list *list)
522{
523 while (list) {
524 struct commit *commit = list->item;
525 list = list->next;
526 if (commit->object.flags & STALE)
527 continue;
528 return commit;
529 }
530 return NULL;
531}
532static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
534{
535 struct commit_list *list = NULL;
536 struct commit_list *result = NULL;
537 int i;
538 for (i = 0; i < n; i++) {
540 if (one == twos[i])
541 /*
542 * We do not mark this even with RESULT so we do not
543 * have to clean it up.
544 */
545 return commit_list_insert(one, &result);
546 }
547 if (parse_commit(one))
549 return NULL;
550 for (i = 0; i < n; i++) {
551 if (parse_commit(twos[i]))
552 return NULL;
553 }
554 one->object.flags |= PARENT1;
556 insert_by_date(one, &list);
557 for (i = 0; i < n; i++) {
558 twos[i]->object.flags |= PARENT2;
559 insert_by_date(twos[i], &list);
560 }
561 while (interesting(list)) {
563 struct commit *commit;
564 struct commit_list *parents;
565 struct commit_list *next;
566 int flags;
567 commit = list->item;
569 next = list->next;
570 free(list);
571 list = next;
572 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
574 if (flags == (PARENT1 | PARENT2)) {
575 if (!(commit->object.flags & RESULT)) {
576 commit->object.flags |= RESULT;
577 insert_by_date(commit, &result);
578 }
579 /* Mark parents of a found merge stale */
580 flags |= STALE;
581 }
582 parents = commit->parents;
583 while (parents) {
584 struct commit *p = parents->item;
585 parents = parents->next;
586 if ((p->object.flags & flags) == flags)
587 continue;
588 if (parse_commit(p))
589 return NULL;
590 p->object.flags |= flags;
591 insert_by_date(p, &list);
592 }
593 }
594 /* Clean up the result to remove stale ones */
596 free_commit_list(list);
597 list = result; result = NULL;
598 while (list) {
599 struct commit_list *next = list->next;
600 if (!(list->item->object.flags & STALE))
601 insert_by_date(list->item, &result);
602 free(list);
603 list = next;
604 }
605 return result;
606}
607struct commit_list *get_octopus_merge_bases(struct commit_list *in)
609{
610 struct commit_list *i, *j, *k, *ret = NULL;
611 struct commit_list **pptr = &ret;
612 for (i = in; i; i = i->next) {
614 if (!ret)
615 pptr = &commit_list_insert(i->item, pptr)->next;
616 else {
617 struct commit_list *new = NULL, *end = NULL;
618 for (j = ret; j; j = j->next) {
620 struct commit_list *bases;
621 bases = get_merge_bases(i->item, j->item, 1);
622 if (!new)
623 new = bases;
624 else
625 end->next = bases;
626 for (k = bases; k; k = k->next)
627 end = k;
628 }
629 ret = new;
630 }
631 }
632 return ret;
633}
634struct commit_list *get_merge_bases_many(struct commit *one,
636 int n,
637 struct commit **twos,
638 int cleanup)
639{
640 struct commit_list *list;
641 struct commit **rslt;
642 struct commit_list *result;
643 int cnt, i, j;
644 result = merge_bases_many(one, n, twos);
646 for (i = 0; i < n; i++) {
647 if (one == twos[i])
648 return result;
649 }
650 if (!result || !result->next) {
651 if (cleanup) {
652 clear_commit_marks(one, all_flags);
653 for (i = 0; i < n; i++)
654 clear_commit_marks(twos[i], all_flags);
655 }
656 return result;
657 }
658 /* There are more than one */
660 cnt = 0;
661 list = result;
662 while (list) {
663 list = list->next;
664 cnt++;
665 }
666 rslt = xcalloc(cnt, sizeof(*rslt));
667 for (list = result, i = 0; list; list = list->next)
668 rslt[i++] = list->item;
669 free_commit_list(result);
670 clear_commit_marks(one, all_flags);
672 for (i = 0; i < n; i++)
673 clear_commit_marks(twos[i], all_flags);
674 for (i = 0; i < cnt - 1; i++) {
675 for (j = i+1; j < cnt; j++) {
676 if (!rslt[i] || !rslt[j])
677 continue;
678 result = merge_bases_many(rslt[i], 1, &rslt[j]);
679 clear_commit_marks(rslt[i], all_flags);
680 clear_commit_marks(rslt[j], all_flags);
681 for (list = result; list; list = list->next) {
682 if (rslt[i] == list->item)
683 rslt[i] = NULL;
684 if (rslt[j] == list->item)
685 rslt[j] = NULL;
686 }
687 }
688 }
689 /* Surviving ones in rslt[] are the independent results */
691 result = NULL;
692 for (i = 0; i < cnt; i++) {
693 if (rslt[i])
694 insert_by_date(rslt[i], &result);
695 }
696 free(rslt);
697 return result;
698}
699struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
701 int cleanup)
702{
703 return get_merge_bases_many(one, 1, &two, cleanup);
704}
705int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
707{
708 if (!with_commit)
709 return 1;
710 while (with_commit) {
711 struct commit *other;
712 other = with_commit->item;
714 with_commit = with_commit->next;
715 if (in_merge_bases(other, &commit, 1))
716 return 1;
717 }
718 return 0;
719}
720int in_merge_bases(struct commit *commit, struct commit **reference, int num)
722{
723 struct commit_list *bases, *b;
724 int ret = 0;
725 if (num == 1)
727 bases = get_merge_bases(commit, *reference, 1);
728 else
729 die("not yet");
730 for (b = bases; b; b = b->next) {
731 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
732 ret = 1;
733 break;
734 }
735 }
736 free_commit_list(bases);
738 return ret;
739}
740struct commit_list *reduce_heads(struct commit_list *heads)
742{
743 struct commit_list *p;
744 struct commit_list *result = NULL, **tail = &result;
745 struct commit **other;
746 size_t num_head, num_other;
747 if (!heads)
749 return NULL;
750 /* Avoid unnecessary reallocations */
752 for (p = heads, num_head = 0; p; p = p->next)
753 num_head++;
754 other = xcalloc(sizeof(*other), num_head);
755 /* For each commit, see if it can be reached by others */
757 for (p = heads; p; p = p->next) {
758 struct commit_list *q, *base;
759 /* Do we already have this in the result? */
761 for (q = result; q; q = q->next)
762 if (p->item == q->item)
763 break;
764 if (q)
765 continue;
766 num_other = 0;
768 for (q = heads; q; q = q->next) {
769 if (p->item == q->item)
770 continue;
771 other[num_other++] = q->item;
772 }
773 if (num_other)
774 base = get_merge_bases_many(p->item, num_other, other, 1);
775 else
776 base = NULL;
777 /*
778 * If p->item does not have anything common with other
779 * commits, there won't be any merge base. If it is
780 * reachable from some of the others, p->item will be
781 * the merge base. If its history is connected with
782 * others, but p->item is not reachable by others, we
783 * will get something other than p->item back.
784 */
785 if (!base || (base->item != p->item))
786 tail = &(commit_list_insert(p->item, tail)->next);
787 free_commit_list(base);
788 }
789 free(other);
790 return result;
791}