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}
195static struct 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 unsigned n_refs = 0;
247 if (item->object.parsed)
249 return 0;
250 item->object.parsed = 1;
251 tail += size;
252 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
253 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
254 if (get_sha1_hex(bufptr + 5, parent) < 0)
255 return error("bad tree pointer in commit %s",
256 sha1_to_hex(item->object.sha1));
257 item->tree = lookup_tree(parent);
258 if (item->tree)
259 n_refs++;
260 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
261 pptr = &item->parents;
262 graft = lookup_commit_graft(item->object.sha1);
264 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
265 struct commit *new_parent;
266 if (tail <= bufptr + 48 ||
268 get_sha1_hex(bufptr + 7, parent) ||
269 bufptr[47] != '\n')
270 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
271 bufptr += 48;
272 if (graft)
273 continue;
274 new_parent = lookup_commit(parent);
275 if (new_parent) {
276 pptr = &commit_list_insert(new_parent, pptr)->next;
277 n_refs++;
278 }
279 }
280 if (graft) {
281 int i;
282 struct commit *new_parent;
283 for (i = 0; i < graft->nr_parent; i++) {
284 new_parent = lookup_commit(graft->parent[i]);
285 if (!new_parent)
286 continue;
287 pptr = &commit_list_insert(new_parent, pptr)->next;
288 n_refs++;
289 }
290 }
291 item->date = parse_commit_date(bufptr, tail);
292 if (track_object_refs) {
294 unsigned i = 0;
295 struct commit_list *p;
296 struct object_refs *refs = alloc_object_refs(n_refs);
297 if (item->tree)
298 refs->ref[i++] = &item->tree->object;
299 for (p = item->parents; p; p = p->next)
300 refs->ref[i++] = &p->item->object;
301 set_object_refs(&item->object, refs);
302 }
303 return 0;
305}
306int parse_commit(struct commit *item)
308{
309 enum object_type type;
310 void *buffer;
311 unsigned long size;
312 int ret;
313 if (item->object.parsed)
315 return 0;
316 buffer = read_sha1_file(item->object.sha1, &type, &size);
317 if (!buffer)
318 return error("Could not read %s",
319 sha1_to_hex(item->object.sha1));
320 if (type != OBJ_COMMIT) {
321 free(buffer);
322 return error("Object %s not a commit",
323 sha1_to_hex(item->object.sha1));
324 }
325 ret = parse_commit_buffer(item, buffer, size);
326 if (save_commit_buffer && !ret) {
327 item->buffer = buffer;
328 return 0;
329 }
330 free(buffer);
331 return ret;
332}
333struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
335{
336 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
337 new_list->item = item;
338 new_list->next = *list_p;
339 *list_p = new_list;
340 return new_list;
341}
342void free_commit_list(struct commit_list *list)
344{
345 while (list) {
346 struct commit_list *temp = list;
347 list = temp->next;
348 free(temp);
349 }
350}
351struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
353{
354 struct commit_list **pp = list;
355 struct commit_list *p;
356 while ((p = *pp) != NULL) {
357 if (p->item->date < item->date) {
358 break;
359 }
360 pp = &p->next;
361 }
362 return commit_list_insert(item, pp);
363}
364void sort_by_date(struct commit_list **list)
367{
368 struct commit_list *ret = NULL;
369 while (*list) {
370 insert_by_date((*list)->item, &ret);
371 *list = (*list)->next;
372 }
373 *list = ret;
374}
375struct commit *pop_most_recent_commit(struct commit_list **list,
377 unsigned int mark)
378{
379 struct commit *ret = (*list)->item;
380 struct commit_list *parents = ret->parents;
381 struct commit_list *old = *list;
382 *list = (*list)->next;
384 free(old);
385 while (parents) {
387 struct commit *commit = parents->item;
388 parse_commit(commit);
389 if (!(commit->object.flags & mark)) {
390 commit->object.flags |= mark;
391 insert_by_date(commit, list);
392 }
393 parents = parents->next;
394 }
395 return ret;
396}
397void clear_commit_marks(struct commit *commit, unsigned int mark)
399{
400 while (commit) {
401 struct commit_list *parents;
402 if (!(mark & commit->object.flags))
404 return;
405 commit->object.flags &= ~mark;
407 parents = commit->parents;
409 if (!parents)
410 return;
411 while ((parents = parents->next))
413 clear_commit_marks(parents->item, mark);
414 commit = commit->parents->item;
416 }
417}
418struct commit *pop_commit(struct commit_list **stack)
420{
421 struct commit_list *top = *stack;
422 struct commit *item = top ? top->item : NULL;
423 if (top) {
425 *stack = top->next;
426 free(top);
427 }
428 return item;
429}
430/*
432 * Performs an in-place topological sort on the list supplied.
433 */
434void sort_in_topological_order(struct commit_list ** list, int lifo)
435{
436 struct commit_list *next, *orig = *list;
437 struct commit_list *work, **insert;
438 struct commit_list **pptr;
439 if (!orig)
441 return;
442 *list = NULL;
443 /* Mark them and clear the indegree */
445 for (next = orig; next; next = next->next) {
446 struct commit *commit = next->item;
447 commit->object.flags |= TOPOSORT;
448 commit->indegree = 0;
449 }
450 /* update the indegree */
452 for (next = orig; next; next = next->next) {
453 struct commit_list * parents = next->item->parents;
454 while (parents) {
455 struct commit *parent = parents->item;
456 if (parent->object.flags & TOPOSORT)
458 parent->indegree++;
459 parents = parents->next;
460 }
461 }
462 /*
464 * find the tips
465 *
466 * tips are nodes not reachable from any other node in the list
467 *
468 * the tips serve as a starting set for the work queue.
469 */
470 work = NULL;
471 insert = &work;
472 for (next = orig; next; next = next->next) {
473 struct commit *commit = next->item;
474 if (!commit->indegree)
476 insert = &commit_list_insert(commit, insert)->next;
477 }
478 /* process the list in topological order */
480 if (!lifo)
481 sort_by_date(&work);
482 pptr = list;
484 *list = NULL;
485 while (work) {
486 struct commit *commit;
487 struct commit_list *parents, *work_item;
488 work_item = work;
490 work = work_item->next;
491 work_item->next = NULL;
492 commit = work_item->item;
494 for (parents = commit->parents; parents ; parents = parents->next) {
495 struct commit *parent=parents->item;
496 if (!(parent->object.flags & TOPOSORT))
498 continue;
499 /*
501 * parents are only enqueued for emission
502 * when all their children have been emitted thereby
503 * guaranteeing topological order.
504 */
505 if (!--parent->indegree) {
506 if (!lifo)
507 insert_by_date(parent, &work);
508 else
509 commit_list_insert(parent, &work);
510 }
511 }
512 /*
513 * work_item is a commit all of whose children
514 * have already been emitted. we can emit it now.
515 */
516 commit->object.flags &= ~TOPOSORT;
517 *pptr = work_item;
518 pptr = &work_item->next;
519 }
520}
521/* merge-base stuff */
523/* bits #0..15 in revision.h */
525#define PARENT1 (1u<<16)
526#define PARENT2 (1u<<17)
527#define STALE (1u<<18)
528#define RESULT (1u<<19)
529static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
531static struct commit *interesting(struct commit_list *list)
533{
534 while (list) {
535 struct commit *commit = list->item;
536 list = list->next;
537 if (commit->object.flags & STALE)
538 continue;
539 return commit;
540 }
541 return NULL;
542}
543static struct commit_list *merge_bases(struct commit *one, struct commit *two)
545{
546 struct commit_list *list = NULL;
547 struct commit_list *result = NULL;
548 if (one == two)
550 /* We do not mark this even with RESULT so we do not
551 * have to clean it up.
552 */
553 return commit_list_insert(one, &result);
554 parse_commit(one);
556 parse_commit(two);
557 one->object.flags |= PARENT1;
559 two->object.flags |= PARENT2;
560 insert_by_date(one, &list);
561 insert_by_date(two, &list);
562 while (interesting(list)) {
564 struct commit *commit;
565 struct commit_list *parents;
566 struct commit_list *n;
567 int flags;
568 commit = list->item;
570 n = list->next;
571 free(list);
572 list = n;
573 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
575 if (flags == (PARENT1 | PARENT2)) {
576 if (!(commit->object.flags & RESULT)) {
577 commit->object.flags |= RESULT;
578 insert_by_date(commit, &result);
579 }
580 /* Mark parents of a found merge stale */
581 flags |= STALE;
582 }
583 parents = commit->parents;
584 while (parents) {
585 struct commit *p = parents->item;
586 parents = parents->next;
587 if ((p->object.flags & flags) == flags)
588 continue;
589 parse_commit(p);
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 *n = list->next;
600 if (!(list->item->object.flags & STALE))
601 insert_by_date(list->item, &result);
602 free(list);
603 list = n;
604 }
605 return result;
606}
607struct commit_list *get_merge_bases(struct commit *one,
609 struct commit *two, int cleanup)
610{
611 struct commit_list *list;
612 struct commit **rslt;
613 struct commit_list *result;
614 int cnt, i, j;
615 result = merge_bases(one, two);
617 if (one == two)
618 return result;
619 if (!result || !result->next) {
620 if (cleanup) {
621 clear_commit_marks(one, all_flags);
622 clear_commit_marks(two, all_flags);
623 }
624 return result;
625 }
626 /* There are more than one */
628 cnt = 0;
629 list = result;
630 while (list) {
631 list = list->next;
632 cnt++;
633 }
634 rslt = xcalloc(cnt, sizeof(*rslt));
635 for (list = result, i = 0; list; list = list->next)
636 rslt[i++] = list->item;
637 free_commit_list(result);
638 clear_commit_marks(one, all_flags);
640 clear_commit_marks(two, all_flags);
641 for (i = 0; i < cnt - 1; i++) {
642 for (j = i+1; j < cnt; j++) {
643 if (!rslt[i] || !rslt[j])
644 continue;
645 result = merge_bases(rslt[i], rslt[j]);
646 clear_commit_marks(rslt[i], all_flags);
647 clear_commit_marks(rslt[j], all_flags);
648 for (list = result; list; list = list->next) {
649 if (rslt[i] == list->item)
650 rslt[i] = NULL;
651 if (rslt[j] == list->item)
652 rslt[j] = NULL;
653 }
654 }
655 }
656 /* Surviving ones in rslt[] are the independent results */
658 result = NULL;
659 for (i = 0; i < cnt; i++) {
660 if (rslt[i])
661 insert_by_date(rslt[i], &result);
662 }
663 free(rslt);
664 return result;
665}
666int in_merge_bases(struct commit *commit, struct commit **reference, int num)
668{
669 struct commit_list *bases, *b;
670 int ret = 0;
671 if (num == 1)
673 bases = get_merge_bases(commit, *reference, 1);
674 else
675 die("not yet");
676 for (b = bases; b; b = b->next) {
677 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
678 ret = 1;
679 break;
680 }
681 }
682 free_commit_list(bases);
684 return ret;
685}