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 unsigned long date;
54 const char *dateptr;
55 if (buf + 6 >= tail)
57 return 0;
58 if (memcmp(buf, "author", 6))
59 return 0;
60 while (buf < tail && *buf++ != '\n')
61 /* nada */;
62 if (buf + 9 >= tail)
63 return 0;
64 if (memcmp(buf, "committer", 9))
65 return 0;
66 while (buf < tail && *buf++ != '>')
67 /* nada */;
68 if (buf >= tail)
69 return 0;
70 dateptr = buf;
71 while (buf < tail && *buf++ != '\n')
72 /* nada */;
73 if (buf >= tail)
74 return 0;
75 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
76 date = strtoul(dateptr, NULL, 10);
77 if (date == ULONG_MAX)
78 date = 0;
79 return date;
80}
81static struct commit_graft **commit_graft;
83static int commit_graft_alloc, commit_graft_nr;
84static int commit_graft_pos(const unsigned char *sha1)
86{
87 int lo, hi;
88 lo = 0;
89 hi = commit_graft_nr;
90 while (lo < hi) {
91 int mi = (lo + hi) / 2;
92 struct commit_graft *graft = commit_graft[mi];
93 int cmp = hashcmp(sha1, graft->sha1);
94 if (!cmp)
95 return mi;
96 if (cmp < 0)
97 hi = mi;
98 else
99 lo = mi + 1;
100 }
101 return -lo - 1;
102}
103int register_commit_graft(struct commit_graft *graft, int ignore_dups)
105{
106 int pos = commit_graft_pos(graft->sha1);
107 if (0 <= pos) {
109 if (ignore_dups)
110 free(graft);
111 else {
112 free(commit_graft[pos]);
113 commit_graft[pos] = graft;
114 }
115 return 1;
116 }
117 pos = -pos - 1;
118 if (commit_graft_alloc <= ++commit_graft_nr) {
119 commit_graft_alloc = alloc_nr(commit_graft_alloc);
120 commit_graft = xrealloc(commit_graft,
121 sizeof(*commit_graft) *
122 commit_graft_alloc);
123 }
124 if (pos < commit_graft_nr)
125 memmove(commit_graft + pos + 1,
126 commit_graft + pos,
127 (commit_graft_nr - pos - 1) *
128 sizeof(*commit_graft));
129 commit_graft[pos] = graft;
130 return 0;
131}
132struct commit_graft *read_graft_line(char *buf, int len)
134{
135 /* The format is just "Commit Parent1 Parent2 ...\n" */
136 int i;
137 struct commit_graft *graft = NULL;
138 if (buf[len-1] == '\n')
140 buf[--len] = 0;
141 if (buf[0] == '#' || buf[0] == '\0')
142 return NULL;
143 if ((len + 1) % 41) {
144 bad_graft_data:
145 error("bad graft data: %s", buf);
146 free(graft);
147 return NULL;
148 }
149 i = (len + 1) / 41 - 1;
150 graft = xmalloc(sizeof(*graft) + 20 * i);
151 graft->nr_parent = i;
152 if (get_sha1_hex(buf, graft->sha1))
153 goto bad_graft_data;
154 for (i = 40; i < len; i += 41) {
155 if (buf[i] != ' ')
156 goto bad_graft_data;
157 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
158 goto bad_graft_data;
159 }
160 return graft;
161}
162static int read_graft_file(const char *graft_file)
164{
165 FILE *fp = fopen(graft_file, "r");
166 char buf[1024];
167 if (!fp)
168 return -1;
169 while (fgets(buf, sizeof(buf), fp)) {
170 /* The format is just "Commit Parent1 Parent2 ...\n" */
171 int len = strlen(buf);
172 struct commit_graft *graft = read_graft_line(buf, len);
173 if (!graft)
174 continue;
175 if (register_commit_graft(graft, 1))
176 error("duplicate graft data: %s", buf);
177 }
178 fclose(fp);
179 return 0;
180}
181static void prepare_commit_graft(void)
183{
184 static int commit_graft_prepared;
185 char *graft_file;
186 if (commit_graft_prepared)
188 return;
189 graft_file = get_graft_file();
190 read_graft_file(graft_file);
191 /* make sure shallows are read */
192 is_repository_shallow();
193 commit_graft_prepared = 1;
194}
195struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
197{
198 int pos;
199 prepare_commit_graft();
200 pos = commit_graft_pos(sha1);
201 if (pos < 0)
202 return NULL;
203 return commit_graft[pos];
204}
205int write_shallow_commits(int fd, int use_pack_protocol)
207{
208 int i, count = 0;
209 for (i = 0; i < commit_graft_nr; i++)
210 if (commit_graft[i]->nr_parent < 0) {
211 const char *hex =
212 sha1_to_hex(commit_graft[i]->sha1);
213 count++;
214 if (use_pack_protocol)
215 packet_write(fd, "shallow %s", hex);
216 else {
217 if (write_in_full(fd, hex, 40) != 40)
218 break;
219 if (write_in_full(fd, "\n", 1) != 1)
220 break;
221 }
222 }
223 return count;
224}
225int unregister_shallow(const unsigned char *sha1)
227{
228 int pos = commit_graft_pos(sha1);
229 if (pos < 0)
230 return -1;
231 if (pos + 1 < commit_graft_nr)
232 memcpy(commit_graft + pos, commit_graft + pos + 1,
233 sizeof(struct commit_graft *)
234 * (commit_graft_nr - pos - 1));
235 commit_graft_nr--;
236 return 0;
237}
238int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
240{
241 char *tail = buffer;
242 char *bufptr = buffer;
243 unsigned char parent[20];
244 struct commit_list **pptr;
245 struct commit_graft *graft;
246 if (item->object.parsed)
248 return 0;
249 item->object.parsed = 1;
250 tail += size;
251 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
252 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
253 if (get_sha1_hex(bufptr + 5, parent) < 0)
254 return error("bad tree pointer in commit %s",
255 sha1_to_hex(item->object.sha1));
256 item->tree = lookup_tree(parent);
257 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
258 pptr = &item->parents;
259 graft = lookup_commit_graft(item->object.sha1);
261 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
262 struct commit *new_parent;
263 if (tail <= bufptr + 48 ||
265 get_sha1_hex(bufptr + 7, parent) ||
266 bufptr[47] != '\n')
267 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
268 bufptr += 48;
269 if (graft)
270 continue;
271 new_parent = lookup_commit(parent);
272 if (new_parent)
273 pptr = &commit_list_insert(new_parent, pptr)->next;
274 }
275 if (graft) {
276 int i;
277 struct commit *new_parent;
278 for (i = 0; i < graft->nr_parent; i++) {
279 new_parent = lookup_commit(graft->parent[i]);
280 if (!new_parent)
281 continue;
282 pptr = &commit_list_insert(new_parent, pptr)->next;
283 }
284 }
285 item->date = parse_commit_date(bufptr, tail);
286 return 0;
288}
289int parse_commit(struct commit *item)
291{
292 enum object_type type;
293 void *buffer;
294 unsigned long size;
295 int ret;
296 if (!item)
298 return -1;
299 if (item->object.parsed)
300 return 0;
301 buffer = read_sha1_file(item->object.sha1, &type, &size);
302 if (!buffer)
303 return error("Could not read %s",
304 sha1_to_hex(item->object.sha1));
305 if (type != OBJ_COMMIT) {
306 free(buffer);
307 return error("Object %s not a commit",
308 sha1_to_hex(item->object.sha1));
309 }
310 ret = parse_commit_buffer(item, buffer, size);
311 if (save_commit_buffer && !ret) {
312 item->buffer = buffer;
313 return 0;
314 }
315 free(buffer);
316 return ret;
317}
318static void unparse_commit_list(struct commit_list *list)
320{
321 for (; list; list = list->next)
322 unparse_commit(list->item);
323}
324void unparse_commit(struct commit *item)
326{
327 item->object.flags = 0;
328 item->object.used = 0;
329 if (item->object.parsed) {
330 item->object.parsed = 0;
331 if (item->parents) {
332 unparse_commit_list(item->parents);
333 free_commit_list(item->parents);
334 item->parents = NULL;
335 }
336 }
337}
338struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
340{
341 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
342 new_list->item = item;
343 new_list->next = *list_p;
344 *list_p = new_list;
345 return new_list;
346}
347unsigned commit_list_count(const struct commit_list *l)
349{
350 unsigned c = 0;
351 for (; l; l = l->next )
352 c++;
353 return c;
354}
355void free_commit_list(struct commit_list *list)
357{
358 while (list) {
359 struct commit_list *temp = list;
360 list = temp->next;
361 free(temp);
362 }
363}
364struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
366{
367 struct commit_list **pp = list;
368 struct commit_list *p;
369 while ((p = *pp) != NULL) {
370 if (p->item->date < item->date) {
371 break;
372 }
373 pp = &p->next;
374 }
375 return commit_list_insert(item, pp);
376}
377void sort_by_date(struct commit_list **list)
380{
381 struct commit_list *ret = NULL;
382 while (*list) {
383 insert_by_date((*list)->item, &ret);
384 *list = (*list)->next;
385 }
386 *list = ret;
387}
388struct commit *pop_most_recent_commit(struct commit_list **list,
390 unsigned int mark)
391{
392 struct commit *ret = (*list)->item;
393 struct commit_list *parents = ret->parents;
394 struct commit_list *old = *list;
395 *list = (*list)->next;
397 free(old);
398 while (parents) {
400 struct commit *commit = parents->item;
401 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
402 commit->object.flags |= mark;
403 insert_by_date(commit, list);
404 }
405 parents = parents->next;
406 }
407 return ret;
408}
409void clear_commit_marks(struct commit *commit, unsigned int mark)
411{
412 while (commit) {
413 struct commit_list *parents;
414 if (!(mark & commit->object.flags))
416 return;
417 commit->object.flags &= ~mark;
419 parents = commit->parents;
421 if (!parents)
422 return;
423 while ((parents = parents->next))
425 clear_commit_marks(parents->item, mark);
426 commit = commit->parents->item;
428 }
429}
430struct commit *pop_commit(struct commit_list **stack)
432{
433 struct commit_list *top = *stack;
434 struct commit *item = top ? top->item : NULL;
435 if (top) {
437 *stack = top->next;
438 free(top);
439 }
440 return item;
441}
442/*
444 * Performs an in-place topological sort on the list supplied.
445 */
446void sort_in_topological_order(struct commit_list ** list, int lifo)
447{
448 struct commit_list *next, *orig = *list;
449 struct commit_list *work, **insert;
450 struct commit_list **pptr;
451 if (!orig)
453 return;
454 *list = NULL;
455 /* Mark them and clear the indegree */
457 for (next = orig; next; next = next->next) {
458 struct commit *commit = next->item;
459 commit->indegree = 1;
460 }
461 /* update the indegree */
463 for (next = orig; next; next = next->next) {
464 struct commit_list * parents = next->item->parents;
465 while (parents) {
466 struct commit *parent = parents->item;
467 if (parent->indegree)
469 parent->indegree++;
470 parents = parents->next;
471 }
472 }
473 /*
475 * find the tips
476 *
477 * tips are nodes not reachable from any other node in the list
478 *
479 * the tips serve as a starting set for the work queue.
480 */
481 work = NULL;
482 insert = &work;
483 for (next = orig; next; next = next->next) {
484 struct commit *commit = next->item;
485 if (commit->indegree == 1)
487 insert = &commit_list_insert(commit, insert)->next;
488 }
489 /* process the list in topological order */
491 if (!lifo)
492 sort_by_date(&work);
493 pptr = list;
495 *list = NULL;
496 while (work) {
497 struct commit *commit;
498 struct commit_list *parents, *work_item;
499 work_item = work;
501 work = work_item->next;
502 work_item->next = NULL;
503 commit = work_item->item;
505 for (parents = commit->parents; parents ; parents = parents->next) {
506 struct commit *parent=parents->item;
507 if (!parent->indegree)
509 continue;
510 /*
512 * parents are only enqueued for emission
513 * when all their children have been emitted thereby
514 * guaranteeing topological order.
515 */
516 if (--parent->indegree == 1) {
517 if (!lifo)
518 insert_by_date(parent, &work);
519 else
520 commit_list_insert(parent, &work);
521 }
522 }
523 /*
524 * work_item is a commit all of whose children
525 * have already been emitted. we can emit it now.
526 */
527 commit->indegree = 0;
528 *pptr = work_item;
529 pptr = &work_item->next;
530 }
531}
532/* merge-base stuff */
534/* bits #0..15 in revision.h */
536#define PARENT1 (1u<<16)
537#define PARENT2 (1u<<17)
538#define STALE (1u<<18)
539#define RESULT (1u<<19)
540static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
542static struct commit *interesting(struct commit_list *list)
544{
545 while (list) {
546 struct commit *commit = list->item;
547 list = list->next;
548 if (commit->object.flags & STALE)
549 continue;
550 return commit;
551 }
552 return NULL;
553}
554static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
556{
557 struct commit_list *list = NULL;
558 struct commit_list *result = NULL;
559 int i;
560 for (i = 0; i < n; i++) {
562 if (one == twos[i])
563 /*
564 * We do not mark this even with RESULT so we do not
565 * have to clean it up.
566 */
567 return commit_list_insert(one, &result);
568 }
569 if (parse_commit(one))
571 return NULL;
572 for (i = 0; i < n; i++) {
573 if (parse_commit(twos[i]))
574 return NULL;
575 }
576 one->object.flags |= PARENT1;
578 insert_by_date(one, &list);
579 for (i = 0; i < n; i++) {
580 twos[i]->object.flags |= PARENT2;
581 insert_by_date(twos[i], &list);
582 }
583 while (interesting(list)) {
585 struct commit *commit;
586 struct commit_list *parents;
587 struct commit_list *n;
588 int flags;
589 commit = list->item;
591 n = list->next;
592 free(list);
593 list = n;
594 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
596 if (flags == (PARENT1 | PARENT2)) {
597 if (!(commit->object.flags & RESULT)) {
598 commit->object.flags |= RESULT;
599 insert_by_date(commit, &result);
600 }
601 /* Mark parents of a found merge stale */
602 flags |= STALE;
603 }
604 parents = commit->parents;
605 while (parents) {
606 struct commit *p = parents->item;
607 parents = parents->next;
608 if ((p->object.flags & flags) == flags)
609 continue;
610 if (parse_commit(p))
611 return NULL;
612 p->object.flags |= flags;
613 insert_by_date(p, &list);
614 }
615 }
616 /* Clean up the result to remove stale ones */
618 free_commit_list(list);
619 list = result; result = NULL;
620 while (list) {
621 struct commit_list *n = list->next;
622 if (!(list->item->object.flags & STALE))
623 insert_by_date(list->item, &result);
624 free(list);
625 list = n;
626 }
627 return result;
628}
629struct commit_list *get_octopus_merge_bases(struct commit_list *in)
631{
632 struct commit_list *i, *j, *k, *ret = NULL;
633 struct commit_list **pptr = &ret;
634 for (i = in; i; i = i->next) {
636 if (!ret)
637 pptr = &commit_list_insert(i->item, pptr)->next;
638 else {
639 struct commit_list *new = NULL, *end = NULL;
640 for (j = ret; j; j = j->next) {
642 struct commit_list *bases;
643 bases = get_merge_bases(i->item, j->item, 1);
644 if (!new)
645 new = bases;
646 else
647 end->next = bases;
648 for (k = bases; k; k = k->next)
649 end = k;
650 }
651 ret = new;
652 }
653 }
654 return ret;
655}
656struct commit_list *get_merge_bases_many(struct commit *one,
658 int n,
659 struct commit **twos,
660 int cleanup)
661{
662 struct commit_list *list;
663 struct commit **rslt;
664 struct commit_list *result;
665 int cnt, i, j;
666 result = merge_bases_many(one, n, twos);
668 for (i = 0; i < n; i++) {
669 if (one == twos[i])
670 return result;
671 }
672 if (!result || !result->next) {
673 if (cleanup) {
674 clear_commit_marks(one, all_flags);
675 for (i = 0; i < n; i++)
676 clear_commit_marks(twos[i], all_flags);
677 }
678 return result;
679 }
680 /* There are more than one */
682 cnt = 0;
683 list = result;
684 while (list) {
685 list = list->next;
686 cnt++;
687 }
688 rslt = xcalloc(cnt, sizeof(*rslt));
689 for (list = result, i = 0; list; list = list->next)
690 rslt[i++] = list->item;
691 free_commit_list(result);
692 clear_commit_marks(one, all_flags);
694 for (i = 0; i < n; i++)
695 clear_commit_marks(twos[i], all_flags);
696 for (i = 0; i < cnt - 1; i++) {
697 for (j = i+1; j < cnt; j++) {
698 if (!rslt[i] || !rslt[j])
699 continue;
700 result = merge_bases_many(rslt[i], 1, &rslt[j]);
701 clear_commit_marks(rslt[i], all_flags);
702 clear_commit_marks(rslt[j], all_flags);
703 for (list = result; list; list = list->next) {
704 if (rslt[i] == list->item)
705 rslt[i] = NULL;
706 if (rslt[j] == list->item)
707 rslt[j] = NULL;
708 }
709 }
710 }
711 /* Surviving ones in rslt[] are the independent results */
713 result = NULL;
714 for (i = 0; i < cnt; i++) {
715 if (rslt[i])
716 insert_by_date(rslt[i], &result);
717 }
718 free(rslt);
719 return result;
720}
721struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
723 int cleanup)
724{
725 return get_merge_bases_many(one, 1, &two, cleanup);
726}
727int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
729{
730 if (!with_commit)
731 return 1;
732 while (with_commit) {
733 struct commit *other;
734 other = with_commit->item;
736 with_commit = with_commit->next;
737 if (in_merge_bases(other, &commit, 1))
738 return 1;
739 }
740 return 0;
741}
742int in_merge_bases(struct commit *commit, struct commit **reference, int num)
744{
745 struct commit_list *bases, *b;
746 int ret = 0;
747 if (num == 1)
749 bases = get_merge_bases(commit, *reference, 1);
750 else
751 die("not yet");
752 for (b = bases; b; b = b->next) {
753 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
754 ret = 1;
755 break;
756 }
757 }
758 free_commit_list(bases);
760 return ret;
761}
762struct commit_list *reduce_heads(struct commit_list *heads)
764{
765 struct commit_list *p;
766 struct commit_list *result = NULL, **tail = &result;
767 struct commit **other;
768 size_t num_head, num_other;
769 if (!heads)
771 return NULL;
772 /* Avoid unnecessary reallocations */
774 for (p = heads, num_head = 0; p; p = p->next)
775 num_head++;
776 other = xcalloc(sizeof(*other), num_head);
777 /* For each commit, see if it can be reached by others */
779 for (p = heads; p; p = p->next) {
780 struct commit_list *q, *base;
781 /* Do we already have this in the result? */
783 for (q = result; q; q = q->next)
784 if (p->item == q->item)
785 break;
786 if (q)
787 continue;
788 num_other = 0;
790 for (q = heads; q; q = q->next) {
791 if (p->item == q->item)
792 continue;
793 other[num_other++] = q->item;
794 }
795 if (num_other)
796 base = get_merge_bases_many(p->item, num_other, other, 1);
797 else
798 base = NULL;
799 /*
800 * If p->item does not have anything common with other
801 * commits, there won't be any merge base. If it is
802 * reachable from some of the others, p->item will be
803 * the merge base. If its history is connected with
804 * others, but p->item is not reachable by others, we
805 * will get something other than p->item back.
806 */
807 if (!base || (base->item != p->item))
808 tail = &(commit_list_insert(p->item, tail)->next);
809 free_commit_list(base);
810 }
811 free(other);
812 return result;
813}