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(int fd, 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_write(fd, "shallow %s", hex);
212 else {
213 if (write_in_full(fd, hex, 40) != 40)
214 break;
215 if (write_in_full(fd, "\n", 1) != 1)
216 break;
217 }
218 }
219 return count;
220}
221int unregister_shallow(const unsigned char *sha1)
223{
224 int pos = commit_graft_pos(sha1);
225 if (pos < 0)
226 return -1;
227 if (pos + 1 < commit_graft_nr)
228 memcpy(commit_graft + pos, commit_graft + pos + 1,
229 sizeof(struct commit_graft *)
230 * (commit_graft_nr - pos - 1));
231 commit_graft_nr--;
232 return 0;
233}
234int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
236{
237 char *tail = buffer;
238 char *bufptr = buffer;
239 unsigned char parent[20];
240 struct commit_list **pptr;
241 struct commit_graft *graft;
242 if (item->object.parsed)
244 return 0;
245 item->object.parsed = 1;
246 tail += size;
247 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
248 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
249 if (get_sha1_hex(bufptr + 5, parent) < 0)
250 return error("bad tree pointer in commit %s",
251 sha1_to_hex(item->object.sha1));
252 item->tree = lookup_tree(parent);
253 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
254 pptr = &item->parents;
255 graft = lookup_commit_graft(item->object.sha1);
257 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
258 struct commit *new_parent;
259 if (tail <= bufptr + 48 ||
261 get_sha1_hex(bufptr + 7, parent) ||
262 bufptr[47] != '\n')
263 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
264 bufptr += 48;
265 if (graft)
266 continue;
267 new_parent = lookup_commit(parent);
268 if (new_parent)
269 pptr = &commit_list_insert(new_parent, pptr)->next;
270 }
271 if (graft) {
272 int i;
273 struct commit *new_parent;
274 for (i = 0; i < graft->nr_parent; i++) {
275 new_parent = lookup_commit(graft->parent[i]);
276 if (!new_parent)
277 continue;
278 pptr = &commit_list_insert(new_parent, pptr)->next;
279 }
280 }
281 item->date = parse_commit_date(bufptr, tail);
282 return 0;
284}
285int parse_commit(struct commit *item)
287{
288 enum object_type type;
289 void *buffer;
290 unsigned long size;
291 int ret;
292 if (!item)
294 return -1;
295 if (item->object.parsed)
296 return 0;
297 buffer = read_sha1_file(item->object.sha1, &type, &size);
298 if (!buffer)
299 return error("Could not read %s",
300 sha1_to_hex(item->object.sha1));
301 if (type != OBJ_COMMIT) {
302 free(buffer);
303 return error("Object %s not a commit",
304 sha1_to_hex(item->object.sha1));
305 }
306 ret = parse_commit_buffer(item, buffer, size);
307 if (save_commit_buffer && !ret) {
308 item->buffer = buffer;
309 return 0;
310 }
311 free(buffer);
312 return ret;
313}
314struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
316{
317 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
318 new_list->item = item;
319 new_list->next = *list_p;
320 *list_p = new_list;
321 return new_list;
322}
323unsigned commit_list_count(const struct commit_list *l)
325{
326 unsigned c = 0;
327 for (; l; l = l->next )
328 c++;
329 return c;
330}
331void free_commit_list(struct commit_list *list)
333{
334 while (list) {
335 struct commit_list *temp = list;
336 list = temp->next;
337 free(temp);
338 }
339}
340struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
342{
343 struct commit_list **pp = list;
344 struct commit_list *p;
345 while ((p = *pp) != NULL) {
346 if (p->item->date < item->date) {
347 break;
348 }
349 pp = &p->next;
350 }
351 return commit_list_insert(item, pp);
352}
353void sort_by_date(struct commit_list **list)
356{
357 struct commit_list *ret = NULL;
358 while (*list) {
359 insert_by_date((*list)->item, &ret);
360 *list = (*list)->next;
361 }
362 *list = ret;
363}
364struct commit *pop_most_recent_commit(struct commit_list **list,
366 unsigned int mark)
367{
368 struct commit *ret = (*list)->item;
369 struct commit_list *parents = ret->parents;
370 struct commit_list *old = *list;
371 *list = (*list)->next;
373 free(old);
374 while (parents) {
376 struct commit *commit = parents->item;
377 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
378 commit->object.flags |= mark;
379 insert_by_date(commit, list);
380 }
381 parents = parents->next;
382 }
383 return ret;
384}
385void clear_commit_marks(struct commit *commit, unsigned int mark)
387{
388 while (commit) {
389 struct commit_list *parents;
390 if (!(mark & commit->object.flags))
392 return;
393 commit->object.flags &= ~mark;
395 parents = commit->parents;
397 if (!parents)
398 return;
399 while ((parents = parents->next))
401 clear_commit_marks(parents->item, mark);
402 commit = commit->parents->item;
404 }
405}
406struct commit *pop_commit(struct commit_list **stack)
408{
409 struct commit_list *top = *stack;
410 struct commit *item = top ? top->item : NULL;
411 if (top) {
413 *stack = top->next;
414 free(top);
415 }
416 return item;
417}
418/*
420 * Performs an in-place topological sort on the list supplied.
421 */
422void sort_in_topological_order(struct commit_list ** list, int lifo)
423{
424 struct commit_list *next, *orig = *list;
425 struct commit_list *work, **insert;
426 struct commit_list **pptr;
427 if (!orig)
429 return;
430 *list = NULL;
431 /* Mark them and clear the indegree */
433 for (next = orig; next; next = next->next) {
434 struct commit *commit = next->item;
435 commit->indegree = 1;
436 }
437 /* update the indegree */
439 for (next = orig; next; next = next->next) {
440 struct commit_list * parents = next->item->parents;
441 while (parents) {
442 struct commit *parent = parents->item;
443 if (parent->indegree)
445 parent->indegree++;
446 parents = parents->next;
447 }
448 }
449 /*
451 * find the tips
452 *
453 * tips are nodes not reachable from any other node in the list
454 *
455 * the tips serve as a starting set for the work queue.
456 */
457 work = NULL;
458 insert = &work;
459 for (next = orig; next; next = next->next) {
460 struct commit *commit = next->item;
461 if (commit->indegree == 1)
463 insert = &commit_list_insert(commit, insert)->next;
464 }
465 /* process the list in topological order */
467 if (!lifo)
468 sort_by_date(&work);
469 pptr = list;
471 *list = NULL;
472 while (work) {
473 struct commit *commit;
474 struct commit_list *parents, *work_item;
475 work_item = work;
477 work = work_item->next;
478 work_item->next = NULL;
479 commit = work_item->item;
481 for (parents = commit->parents; parents ; parents = parents->next) {
482 struct commit *parent=parents->item;
483 if (!parent->indegree)
485 continue;
486 /*
488 * parents are only enqueued for emission
489 * when all their children have been emitted thereby
490 * guaranteeing topological order.
491 */
492 if (--parent->indegree == 1) {
493 if (!lifo)
494 insert_by_date(parent, &work);
495 else
496 commit_list_insert(parent, &work);
497 }
498 }
499 /*
500 * work_item is a commit all of whose children
501 * have already been emitted. we can emit it now.
502 */
503 commit->indegree = 0;
504 *pptr = work_item;
505 pptr = &work_item->next;
506 }
507}
508/* merge-base stuff */
510/* bits #0..15 in revision.h */
512#define PARENT1 (1u<<16)
513#define PARENT2 (1u<<17)
514#define STALE (1u<<18)
515#define RESULT (1u<<19)
516static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
518static struct commit *interesting(struct commit_list *list)
520{
521 while (list) {
522 struct commit *commit = list->item;
523 list = list->next;
524 if (commit->object.flags & STALE)
525 continue;
526 return commit;
527 }
528 return NULL;
529}
530static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
532{
533 struct commit_list *list = NULL;
534 struct commit_list *result = NULL;
535 int i;
536 for (i = 0; i < n; i++) {
538 if (one == twos[i])
539 /*
540 * We do not mark this even with RESULT so we do not
541 * have to clean it up.
542 */
543 return commit_list_insert(one, &result);
544 }
545 if (parse_commit(one))
547 return NULL;
548 for (i = 0; i < n; i++) {
549 if (parse_commit(twos[i]))
550 return NULL;
551 }
552 one->object.flags |= PARENT1;
554 insert_by_date(one, &list);
555 for (i = 0; i < n; i++) {
556 twos[i]->object.flags |= PARENT2;
557 insert_by_date(twos[i], &list);
558 }
559 while (interesting(list)) {
561 struct commit *commit;
562 struct commit_list *parents;
563 struct commit_list *n;
564 int flags;
565 commit = list->item;
567 n = list->next;
568 free(list);
569 list = n;
570 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
572 if (flags == (PARENT1 | PARENT2)) {
573 if (!(commit->object.flags & RESULT)) {
574 commit->object.flags |= RESULT;
575 insert_by_date(commit, &result);
576 }
577 /* Mark parents of a found merge stale */
578 flags |= STALE;
579 }
580 parents = commit->parents;
581 while (parents) {
582 struct commit *p = parents->item;
583 parents = parents->next;
584 if ((p->object.flags & flags) == flags)
585 continue;
586 if (parse_commit(p))
587 return NULL;
588 p->object.flags |= flags;
589 insert_by_date(p, &list);
590 }
591 }
592 /* Clean up the result to remove stale ones */
594 free_commit_list(list);
595 list = result; result = NULL;
596 while (list) {
597 struct commit_list *n = list->next;
598 if (!(list->item->object.flags & STALE))
599 insert_by_date(list->item, &result);
600 free(list);
601 list = n;
602 }
603 return result;
604}
605struct commit_list *get_octopus_merge_bases(struct commit_list *in)
607{
608 struct commit_list *i, *j, *k, *ret = NULL;
609 struct commit_list **pptr = &ret;
610 for (i = in; i; i = i->next) {
612 if (!ret)
613 pptr = &commit_list_insert(i->item, pptr)->next;
614 else {
615 struct commit_list *new = NULL, *end = NULL;
616 for (j = ret; j; j = j->next) {
618 struct commit_list *bases;
619 bases = get_merge_bases(i->item, j->item, 1);
620 if (!new)
621 new = bases;
622 else
623 end->next = bases;
624 for (k = bases; k; k = k->next)
625 end = k;
626 }
627 ret = new;
628 }
629 }
630 return ret;
631}
632struct commit_list *get_merge_bases_many(struct commit *one,
634 int n,
635 struct commit **twos,
636 int cleanup)
637{
638 struct commit_list *list;
639 struct commit **rslt;
640 struct commit_list *result;
641 int cnt, i, j;
642 result = merge_bases_many(one, n, twos);
644 for (i = 0; i < n; i++) {
645 if (one == twos[i])
646 return result;
647 }
648 if (!result || !result->next) {
649 if (cleanup) {
650 clear_commit_marks(one, all_flags);
651 for (i = 0; i < n; i++)
652 clear_commit_marks(twos[i], all_flags);
653 }
654 return result;
655 }
656 /* There are more than one */
658 cnt = 0;
659 list = result;
660 while (list) {
661 list = list->next;
662 cnt++;
663 }
664 rslt = xcalloc(cnt, sizeof(*rslt));
665 for (list = result, i = 0; list; list = list->next)
666 rslt[i++] = list->item;
667 free_commit_list(result);
668 clear_commit_marks(one, all_flags);
670 for (i = 0; i < n; i++)
671 clear_commit_marks(twos[i], all_flags);
672 for (i = 0; i < cnt - 1; i++) {
673 for (j = i+1; j < cnt; j++) {
674 if (!rslt[i] || !rslt[j])
675 continue;
676 result = merge_bases_many(rslt[i], 1, &rslt[j]);
677 clear_commit_marks(rslt[i], all_flags);
678 clear_commit_marks(rslt[j], all_flags);
679 for (list = result; list; list = list->next) {
680 if (rslt[i] == list->item)
681 rslt[i] = NULL;
682 if (rslt[j] == list->item)
683 rslt[j] = NULL;
684 }
685 }
686 }
687 /* Surviving ones in rslt[] are the independent results */
689 result = NULL;
690 for (i = 0; i < cnt; i++) {
691 if (rslt[i])
692 insert_by_date(rslt[i], &result);
693 }
694 free(rslt);
695 return result;
696}
697struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
699 int cleanup)
700{
701 return get_merge_bases_many(one, 1, &two, cleanup);
702}
703int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
705{
706 if (!with_commit)
707 return 1;
708 while (with_commit) {
709 struct commit *other;
710 other = with_commit->item;
712 with_commit = with_commit->next;
713 if (in_merge_bases(other, &commit, 1))
714 return 1;
715 }
716 return 0;
717}
718int in_merge_bases(struct commit *commit, struct commit **reference, int num)
720{
721 struct commit_list *bases, *b;
722 int ret = 0;
723 if (num == 1)
725 bases = get_merge_bases(commit, *reference, 1);
726 else
727 die("not yet");
728 for (b = bases; b; b = b->next) {
729 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
730 ret = 1;
731 break;
732 }
733 }
734 free_commit_list(bases);
736 return ret;
737}
738struct commit_list *reduce_heads(struct commit_list *heads)
740{
741 struct commit_list *p;
742 struct commit_list *result = NULL, **tail = &result;
743 struct commit **other;
744 size_t num_head, num_other;
745 if (!heads)
747 return NULL;
748 /* Avoid unnecessary reallocations */
750 for (p = heads, num_head = 0; p; p = p->next)
751 num_head++;
752 other = xcalloc(sizeof(*other), num_head);
753 /* For each commit, see if it can be reached by others */
755 for (p = heads; p; p = p->next) {
756 struct commit_list *q, *base;
757 /* Do we already have this in the result? */
759 for (q = result; q; q = q->next)
760 if (p->item == q->item)
761 break;
762 if (q)
763 continue;
764 num_other = 0;
766 for (q = heads; q; q = q->next) {
767 if (p->item == q->item)
768 continue;
769 other[num_other++] = q->item;
770 }
771 if (num_other)
772 base = get_merge_bases_many(p->item, num_other, other, 1);
773 else
774 base = NULL;
775 /*
776 * If p->item does not have anything common with other
777 * commits, there won't be any merge base. If it is
778 * reachable from some of the others, p->item will be
779 * the merge base. If its history is connected with
780 * others, but p->item is not reachable by others, we
781 * will get something other than p->item back.
782 */
783 if (!base || (base->item != p->item))
784 tail = &(commit_list_insert(p->item, tail)->next);
785 free_commit_list(base);
786 }
787 free(other);
788 return result;
789}