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}
162int 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}
318struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
320{
321 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
322 new_list->item = item;
323 new_list->next = *list_p;
324 *list_p = new_list;
325 return new_list;
326}
327void free_commit_list(struct commit_list *list)
329{
330 while (list) {
331 struct commit_list *temp = list;
332 list = temp->next;
333 free(temp);
334 }
335}
336struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
338{
339 struct commit_list **pp = list;
340 struct commit_list *p;
341 while ((p = *pp) != NULL) {
342 if (p->item->date < item->date) {
343 break;
344 }
345 pp = &p->next;
346 }
347 return commit_list_insert(item, pp);
348}
349void sort_by_date(struct commit_list **list)
352{
353 struct commit_list *ret = NULL;
354 while (*list) {
355 insert_by_date((*list)->item, &ret);
356 *list = (*list)->next;
357 }
358 *list = ret;
359}
360struct commit *pop_most_recent_commit(struct commit_list **list,
362 unsigned int mark)
363{
364 struct commit *ret = (*list)->item;
365 struct commit_list *parents = ret->parents;
366 struct commit_list *old = *list;
367 *list = (*list)->next;
369 free(old);
370 while (parents) {
372 struct commit *commit = parents->item;
373 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
374 commit->object.flags |= mark;
375 insert_by_date(commit, list);
376 }
377 parents = parents->next;
378 }
379 return ret;
380}
381void clear_commit_marks(struct commit *commit, unsigned int mark)
383{
384 while (commit) {
385 struct commit_list *parents;
386 if (!(mark & commit->object.flags))
388 return;
389 commit->object.flags &= ~mark;
391 parents = commit->parents;
393 if (!parents)
394 return;
395 while ((parents = parents->next))
397 clear_commit_marks(parents->item, mark);
398 commit = commit->parents->item;
400 }
401}
402struct commit *pop_commit(struct commit_list **stack)
404{
405 struct commit_list *top = *stack;
406 struct commit *item = top ? top->item : NULL;
407 if (top) {
409 *stack = top->next;
410 free(top);
411 }
412 return item;
413}
414/*
416 * Performs an in-place topological sort on the list supplied.
417 */
418void sort_in_topological_order(struct commit_list ** list, int lifo)
419{
420 struct commit_list *next, *orig = *list;
421 struct commit_list *work, **insert;
422 struct commit_list **pptr;
423 if (!orig)
425 return;
426 *list = NULL;
427 /* Mark them and clear the indegree */
429 for (next = orig; next; next = next->next) {
430 struct commit *commit = next->item;
431 commit->indegree = 1;
432 }
433 /* update the indegree */
435 for (next = orig; next; next = next->next) {
436 struct commit_list * parents = next->item->parents;
437 while (parents) {
438 struct commit *parent = parents->item;
439 if (parent->indegree)
441 parent->indegree++;
442 parents = parents->next;
443 }
444 }
445 /*
447 * find the tips
448 *
449 * tips are nodes not reachable from any other node in the list
450 *
451 * the tips serve as a starting set for the work queue.
452 */
453 work = NULL;
454 insert = &work;
455 for (next = orig; next; next = next->next) {
456 struct commit *commit = next->item;
457 if (commit->indegree == 1)
459 insert = &commit_list_insert(commit, insert)->next;
460 }
461 /* process the list in topological order */
463 if (!lifo)
464 sort_by_date(&work);
465 pptr = list;
467 *list = NULL;
468 while (work) {
469 struct commit *commit;
470 struct commit_list *parents, *work_item;
471 work_item = work;
473 work = work_item->next;
474 work_item->next = NULL;
475 commit = work_item->item;
477 for (parents = commit->parents; parents ; parents = parents->next) {
478 struct commit *parent=parents->item;
479 if (!parent->indegree)
481 continue;
482 /*
484 * parents are only enqueued for emission
485 * when all their children have been emitted thereby
486 * guaranteeing topological order.
487 */
488 if (--parent->indegree == 1) {
489 if (!lifo)
490 insert_by_date(parent, &work);
491 else
492 commit_list_insert(parent, &work);
493 }
494 }
495 /*
496 * work_item is a commit all of whose children
497 * have already been emitted. we can emit it now.
498 */
499 commit->indegree = 0;
500 *pptr = work_item;
501 pptr = &work_item->next;
502 }
503}
504/* merge-base stuff */
506/* bits #0..15 in revision.h */
508#define PARENT1 (1u<<16)
509#define PARENT2 (1u<<17)
510#define STALE (1u<<18)
511#define RESULT (1u<<19)
512static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
514static struct commit *interesting(struct commit_list *list)
516{
517 while (list) {
518 struct commit *commit = list->item;
519 list = list->next;
520 if (commit->object.flags & STALE)
521 continue;
522 return commit;
523 }
524 return NULL;
525}
526static struct commit_list *merge_bases(struct commit *one, struct commit *two)
528{
529 struct commit_list *list = NULL;
530 struct commit_list *result = NULL;
531 if (one == two)
533 /* We do not mark this even with RESULT so we do not
534 * have to clean it up.
535 */
536 return commit_list_insert(one, &result);
537 if (parse_commit(one))
539 return NULL;
540 if (parse_commit(two))
541 return NULL;
542 one->object.flags |= PARENT1;
544 two->object.flags |= PARENT2;
545 insert_by_date(one, &list);
546 insert_by_date(two, &list);
547 while (interesting(list)) {
549 struct commit *commit;
550 struct commit_list *parents;
551 struct commit_list *n;
552 int flags;
553 commit = list->item;
555 n = list->next;
556 free(list);
557 list = n;
558 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
560 if (flags == (PARENT1 | PARENT2)) {
561 if (!(commit->object.flags & RESULT)) {
562 commit->object.flags |= RESULT;
563 insert_by_date(commit, &result);
564 }
565 /* Mark parents of a found merge stale */
566 flags |= STALE;
567 }
568 parents = commit->parents;
569 while (parents) {
570 struct commit *p = parents->item;
571 parents = parents->next;
572 if ((p->object.flags & flags) == flags)
573 continue;
574 if (parse_commit(p))
575 return NULL;
576 p->object.flags |= flags;
577 insert_by_date(p, &list);
578 }
579 }
580 /* Clean up the result to remove stale ones */
582 free_commit_list(list);
583 list = result; result = NULL;
584 while (list) {
585 struct commit_list *n = list->next;
586 if (!(list->item->object.flags & STALE))
587 insert_by_date(list->item, &result);
588 free(list);
589 list = n;
590 }
591 return result;
592}
593struct commit_list *get_merge_bases(struct commit *one,
595 struct commit *two, int cleanup)
596{
597 struct commit_list *list;
598 struct commit **rslt;
599 struct commit_list *result;
600 int cnt, i, j;
601 result = merge_bases(one, two);
603 if (one == two)
604 return result;
605 if (!result || !result->next) {
606 if (cleanup) {
607 clear_commit_marks(one, all_flags);
608 clear_commit_marks(two, all_flags);
609 }
610 return result;
611 }
612 /* There are more than one */
614 cnt = 0;
615 list = result;
616 while (list) {
617 list = list->next;
618 cnt++;
619 }
620 rslt = xcalloc(cnt, sizeof(*rslt));
621 for (list = result, i = 0; list; list = list->next)
622 rslt[i++] = list->item;
623 free_commit_list(result);
624 clear_commit_marks(one, all_flags);
626 clear_commit_marks(two, all_flags);
627 for (i = 0; i < cnt - 1; i++) {
628 for (j = i+1; j < cnt; j++) {
629 if (!rslt[i] || !rslt[j])
630 continue;
631 result = merge_bases(rslt[i], rslt[j]);
632 clear_commit_marks(rslt[i], all_flags);
633 clear_commit_marks(rslt[j], all_flags);
634 for (list = result; list; list = list->next) {
635 if (rslt[i] == list->item)
636 rslt[i] = NULL;
637 if (rslt[j] == list->item)
638 rslt[j] = NULL;
639 }
640 }
641 }
642 /* Surviving ones in rslt[] are the independent results */
644 result = NULL;
645 for (i = 0; i < cnt; i++) {
646 if (rslt[i])
647 insert_by_date(rslt[i], &result);
648 }
649 free(rslt);
650 return result;
651}
652int in_merge_bases(struct commit *commit, struct commit **reference, int num)
654{
655 struct commit_list *bases, *b;
656 int ret = 0;
657 if (num == 1)
659 bases = get_merge_bases(commit, *reference, 1);
660 else
661 die("not yet");
662 for (b = bases; b; b = b->next) {
663 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
664 ret = 1;
665 break;
666 }
667 }
668 free_commit_list(bases);
670 return ret;
671}