Merge branch 'cb/open-noatime-clear-errno'
[git] / builtin / reflog.c
1 #include "builtin.h"
2 #include "lockfile.h"
3 #include "commit.h"
4 #include "refs.h"
5 #include "dir.h"
6 #include "tree-walk.h"
7 #include "diff.h"
8 #include "revision.h"
9 #include "reachable.h"
10
11 /* NEEDSWORK: switch to using parse_options */
12 static const char reflog_expire_usage[] =
13 "git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
14 static const char reflog_delete_usage[] =
15 "git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
16 static const char reflog_exists_usage[] =
17 "git reflog exists <ref>";
18
19 static unsigned long default_reflog_expire;
20 static unsigned long default_reflog_expire_unreachable;
21
22 struct cmd_reflog_expire_cb {
23         struct rev_info revs;
24         int stalefix;
25         unsigned long expire_total;
26         unsigned long expire_unreachable;
27         int recno;
28 };
29
30 struct expire_reflog_policy_cb {
31         enum {
32                 UE_NORMAL,
33                 UE_ALWAYS,
34                 UE_HEAD
35         } unreachable_expire_kind;
36         struct commit_list *mark_list;
37         unsigned long mark_limit;
38         struct cmd_reflog_expire_cb cmd;
39         struct commit *tip_commit;
40         struct commit_list *tips;
41 };
42
43 struct collected_reflog {
44         unsigned char sha1[20];
45         char reflog[FLEX_ARRAY];
46 };
47
48 struct collect_reflog_cb {
49         struct collected_reflog **e;
50         int alloc;
51         int nr;
52 };
53
54 #define INCOMPLETE      (1u<<10)
55 #define STUDYING        (1u<<11)
56 #define REACHABLE       (1u<<12)
57
58 static int tree_is_complete(const unsigned char *sha1)
59 {
60         struct tree_desc desc;
61         struct name_entry entry;
62         int complete;
63         struct tree *tree;
64
65         tree = lookup_tree(sha1);
66         if (!tree)
67                 return 0;
68         if (tree->object.flags & SEEN)
69                 return 1;
70         if (tree->object.flags & INCOMPLETE)
71                 return 0;
72
73         if (!tree->buffer) {
74                 enum object_type type;
75                 unsigned long size;
76                 void *data = read_sha1_file(sha1, &type, &size);
77                 if (!data) {
78                         tree->object.flags |= INCOMPLETE;
79                         return 0;
80                 }
81                 tree->buffer = data;
82                 tree->size = size;
83         }
84         init_tree_desc(&desc, tree->buffer, tree->size);
85         complete = 1;
86         while (tree_entry(&desc, &entry)) {
87                 if (!has_sha1_file(entry.sha1) ||
88                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
89                         tree->object.flags |= INCOMPLETE;
90                         complete = 0;
91                 }
92         }
93         free_tree_buffer(tree);
94
95         if (complete)
96                 tree->object.flags |= SEEN;
97         return complete;
98 }
99
100 static int commit_is_complete(struct commit *commit)
101 {
102         struct object_array study;
103         struct object_array found;
104         int is_incomplete = 0;
105         int i;
106
107         /* early return */
108         if (commit->object.flags & SEEN)
109                 return 1;
110         if (commit->object.flags & INCOMPLETE)
111                 return 0;
112         /*
113          * Find all commits that are reachable and are not marked as
114          * SEEN.  Then make sure the trees and blobs contained are
115          * complete.  After that, mark these commits also as SEEN.
116          * If some of the objects that are needed to complete this
117          * commit are missing, mark this commit as INCOMPLETE.
118          */
119         memset(&study, 0, sizeof(study));
120         memset(&found, 0, sizeof(found));
121         add_object_array(&commit->object, NULL, &study);
122         add_object_array(&commit->object, NULL, &found);
123         commit->object.flags |= STUDYING;
124         while (study.nr) {
125                 struct commit *c;
126                 struct commit_list *parent;
127
128                 c = (struct commit *)study.objects[--study.nr].item;
129                 if (!c->object.parsed && !parse_object(c->object.sha1))
130                         c->object.flags |= INCOMPLETE;
131
132                 if (c->object.flags & INCOMPLETE) {
133                         is_incomplete = 1;
134                         break;
135                 }
136                 else if (c->object.flags & SEEN)
137                         continue;
138                 for (parent = c->parents; parent; parent = parent->next) {
139                         struct commit *p = parent->item;
140                         if (p->object.flags & STUDYING)
141                                 continue;
142                         p->object.flags |= STUDYING;
143                         add_object_array(&p->object, NULL, &study);
144                         add_object_array(&p->object, NULL, &found);
145                 }
146         }
147         if (!is_incomplete) {
148                 /*
149                  * make sure all commits in "found" array have all the
150                  * necessary objects.
151                  */
152                 for (i = 0; i < found.nr; i++) {
153                         struct commit *c =
154                                 (struct commit *)found.objects[i].item;
155                         if (!tree_is_complete(c->tree->object.sha1)) {
156                                 is_incomplete = 1;
157                                 c->object.flags |= INCOMPLETE;
158                         }
159                 }
160                 if (!is_incomplete) {
161                         /* mark all found commits as complete, iow SEEN */
162                         for (i = 0; i < found.nr; i++)
163                                 found.objects[i].item->flags |= SEEN;
164                 }
165         }
166         /* clear flags from the objects we traversed */
167         for (i = 0; i < found.nr; i++)
168                 found.objects[i].item->flags &= ~STUDYING;
169         if (is_incomplete)
170                 commit->object.flags |= INCOMPLETE;
171         else {
172                 /*
173                  * If we come here, we have (1) traversed the ancestry chain
174                  * from the "commit" until we reach SEEN commits (which are
175                  * known to be complete), and (2) made sure that the commits
176                  * encountered during the above traversal refer to trees that
177                  * are complete.  Which means that we know *all* the commits
178                  * we have seen during this process are complete.
179                  */
180                 for (i = 0; i < found.nr; i++)
181                         found.objects[i].item->flags |= SEEN;
182         }
183         /* free object arrays */
184         free(study.objects);
185         free(found.objects);
186         return !is_incomplete;
187 }
188
189 static int keep_entry(struct commit **it, unsigned char *sha1)
190 {
191         struct commit *commit;
192
193         if (is_null_sha1(sha1))
194                 return 1;
195         commit = lookup_commit_reference_gently(sha1, 1);
196         if (!commit)
197                 return 0;
198
199         /*
200          * Make sure everything in this commit exists.
201          *
202          * We have walked all the objects reachable from the refs
203          * and cache earlier.  The commits reachable by this commit
204          * must meet SEEN commits -- and then we should mark them as
205          * SEEN as well.
206          */
207         if (!commit_is_complete(commit))
208                 return 0;
209         *it = commit;
210         return 1;
211 }
212
213 /*
214  * Starting from commits in the cb->mark_list, mark commits that are
215  * reachable from them.  Stop the traversal at commits older than
216  * the expire_limit and queue them back, so that the caller can call
217  * us again to restart the traversal with longer expire_limit.
218  */
219 static void mark_reachable(struct expire_reflog_policy_cb *cb)
220 {
221         struct commit *commit;
222         struct commit_list *pending;
223         unsigned long expire_limit = cb->mark_limit;
224         struct commit_list *leftover = NULL;
225
226         for (pending = cb->mark_list; pending; pending = pending->next)
227                 pending->item->object.flags &= ~REACHABLE;
228
229         pending = cb->mark_list;
230         while (pending) {
231                 struct commit_list *entry = pending;
232                 struct commit_list *parent;
233                 pending = entry->next;
234                 commit = entry->item;
235                 free(entry);
236                 if (commit->object.flags & REACHABLE)
237                         continue;
238                 if (parse_commit(commit))
239                         continue;
240                 commit->object.flags |= REACHABLE;
241                 if (commit->date < expire_limit) {
242                         commit_list_insert(commit, &leftover);
243                         continue;
244                 }
245                 commit->object.flags |= REACHABLE;
246                 parent = commit->parents;
247                 while (parent) {
248                         commit = parent->item;
249                         parent = parent->next;
250                         if (commit->object.flags & REACHABLE)
251                                 continue;
252                         commit_list_insert(commit, &pending);
253                 }
254         }
255         cb->mark_list = leftover;
256 }
257
258 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, unsigned char *sha1)
259 {
260         /*
261          * We may or may not have the commit yet - if not, look it
262          * up using the supplied sha1.
263          */
264         if (!commit) {
265                 if (is_null_sha1(sha1))
266                         return 0;
267
268                 commit = lookup_commit_reference_gently(sha1, 1);
269
270                 /* Not a commit -- keep it */
271                 if (!commit)
272                         return 0;
273         }
274
275         /* Reachable from the current ref?  Don't prune. */
276         if (commit->object.flags & REACHABLE)
277                 return 0;
278
279         if (cb->mark_list && cb->mark_limit) {
280                 cb->mark_limit = 0; /* dig down to the root */
281                 mark_reachable(cb);
282         }
283
284         return !(commit->object.flags & REACHABLE);
285 }
286
287 /*
288  * Return true iff the specified reflog entry should be expired.
289  */
290 static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
291                                     const char *email, unsigned long timestamp, int tz,
292                                     const char *message, void *cb_data)
293 {
294         struct expire_reflog_policy_cb *cb = cb_data;
295         struct commit *old, *new;
296
297         if (timestamp < cb->cmd.expire_total)
298                 return 1;
299
300         old = new = NULL;
301         if (cb->cmd.stalefix &&
302             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
303                 return 1;
304
305         if (timestamp < cb->cmd.expire_unreachable) {
306                 if (cb->unreachable_expire_kind == UE_ALWAYS)
307                         return 1;
308                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
309                         return 1;
310         }
311
312         if (cb->cmd.recno && --(cb->cmd.recno) == 0)
313                 return 1;
314
315         return 0;
316 }
317
318 static int push_tip_to_list(const char *refname, const struct object_id *oid,
319                             int flags, void *cb_data)
320 {
321         struct commit_list **list = cb_data;
322         struct commit *tip_commit;
323         if (flags & REF_ISSYMREF)
324                 return 0;
325         tip_commit = lookup_commit_reference_gently(oid->hash, 1);
326         if (!tip_commit)
327                 return 0;
328         commit_list_insert(tip_commit, list);
329         return 0;
330 }
331
332 static void reflog_expiry_prepare(const char *refname,
333                                   const unsigned char *sha1,
334                                   void *cb_data)
335 {
336         struct expire_reflog_policy_cb *cb = cb_data;
337
338         if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
339                 cb->tip_commit = NULL;
340                 cb->unreachable_expire_kind = UE_HEAD;
341         } else {
342                 cb->tip_commit = lookup_commit_reference_gently(sha1, 1);
343                 if (!cb->tip_commit)
344                         cb->unreachable_expire_kind = UE_ALWAYS;
345                 else
346                         cb->unreachable_expire_kind = UE_NORMAL;
347         }
348
349         if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
350                 cb->unreachable_expire_kind = UE_ALWAYS;
351
352         cb->mark_list = NULL;
353         cb->tips = NULL;
354         if (cb->unreachable_expire_kind != UE_ALWAYS) {
355                 if (cb->unreachable_expire_kind == UE_HEAD) {
356                         struct commit_list *elem;
357
358                         for_each_ref(push_tip_to_list, &cb->tips);
359                         for (elem = cb->tips; elem; elem = elem->next)
360                                 commit_list_insert(elem->item, &cb->mark_list);
361                 } else {
362                         commit_list_insert(cb->tip_commit, &cb->mark_list);
363                 }
364                 cb->mark_limit = cb->cmd.expire_total;
365                 mark_reachable(cb);
366         }
367 }
368
369 static void reflog_expiry_cleanup(void *cb_data)
370 {
371         struct expire_reflog_policy_cb *cb = cb_data;
372
373         if (cb->unreachable_expire_kind != UE_ALWAYS) {
374                 if (cb->unreachable_expire_kind == UE_HEAD) {
375                         struct commit_list *elem;
376                         for (elem = cb->tips; elem; elem = elem->next)
377                                 clear_commit_marks(elem->item, REACHABLE);
378                         free_commit_list(cb->tips);
379                 } else {
380                         clear_commit_marks(cb->tip_commit, REACHABLE);
381                 }
382         }
383 }
384
385 static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
386 {
387         struct collected_reflog *e;
388         struct collect_reflog_cb *cb = cb_data;
389         size_t namelen = strlen(ref);
390
391         e = xmalloc(sizeof(*e) + namelen + 1);
392         hashcpy(e->sha1, oid->hash);
393         memcpy(e->reflog, ref, namelen + 1);
394         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
395         cb->e[cb->nr++] = e;
396         return 0;
397 }
398
399 static struct reflog_expire_cfg {
400         struct reflog_expire_cfg *next;
401         unsigned long expire_total;
402         unsigned long expire_unreachable;
403         size_t len;
404         char pattern[FLEX_ARRAY];
405 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
406
407 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
408 {
409         struct reflog_expire_cfg *ent;
410
411         if (!reflog_expire_cfg_tail)
412                 reflog_expire_cfg_tail = &reflog_expire_cfg;
413
414         for (ent = reflog_expire_cfg; ent; ent = ent->next)
415                 if (ent->len == len &&
416                     !memcmp(ent->pattern, pattern, len))
417                         return ent;
418
419         ent = xcalloc(1, (sizeof(*ent) + len));
420         memcpy(ent->pattern, pattern, len);
421         ent->len = len;
422         *reflog_expire_cfg_tail = ent;
423         reflog_expire_cfg_tail = &(ent->next);
424         return ent;
425 }
426
427 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
428 {
429         if (!value)
430                 return config_error_nonbool(var);
431         if (parse_expiry_date(value, expire))
432                 return error(_("%s' for '%s' is not a valid timestamp"),
433                              value, var);
434         return 0;
435 }
436
437 /* expiry timer slot */
438 #define EXPIRE_TOTAL   01
439 #define EXPIRE_UNREACH 02
440
441 static int reflog_expire_config(const char *var, const char *value, void *cb)
442 {
443         const char *pattern, *key;
444         int pattern_len;
445         unsigned long expire;
446         int slot;
447         struct reflog_expire_cfg *ent;
448
449         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
450                 return git_default_config(var, value, cb);
451
452         if (!strcmp(key, "reflogexpire")) {
453                 slot = EXPIRE_TOTAL;
454                 if (parse_expire_cfg_value(var, value, &expire))
455                         return -1;
456         } else if (!strcmp(key, "reflogexpireunreachable")) {
457                 slot = EXPIRE_UNREACH;
458                 if (parse_expire_cfg_value(var, value, &expire))
459                         return -1;
460         } else
461                 return git_default_config(var, value, cb);
462
463         if (!pattern) {
464                 switch (slot) {
465                 case EXPIRE_TOTAL:
466                         default_reflog_expire = expire;
467                         break;
468                 case EXPIRE_UNREACH:
469                         default_reflog_expire_unreachable = expire;
470                         break;
471                 }
472                 return 0;
473         }
474
475         ent = find_cfg_ent(pattern, pattern_len);
476         if (!ent)
477                 return -1;
478         switch (slot) {
479         case EXPIRE_TOTAL:
480                 ent->expire_total = expire;
481                 break;
482         case EXPIRE_UNREACH:
483                 ent->expire_unreachable = expire;
484                 break;
485         }
486         return 0;
487 }
488
489 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
490 {
491         struct reflog_expire_cfg *ent;
492
493         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
494                 return; /* both given explicitly -- nothing to tweak */
495
496         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
497                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
498                         if (!(slot & EXPIRE_TOTAL))
499                                 cb->expire_total = ent->expire_total;
500                         if (!(slot & EXPIRE_UNREACH))
501                                 cb->expire_unreachable = ent->expire_unreachable;
502                         return;
503                 }
504         }
505
506         /*
507          * If unconfigured, make stash never expire
508          */
509         if (!strcmp(ref, "refs/stash")) {
510                 if (!(slot & EXPIRE_TOTAL))
511                         cb->expire_total = 0;
512                 if (!(slot & EXPIRE_UNREACH))
513                         cb->expire_unreachable = 0;
514                 return;
515         }
516
517         /* Nothing matched -- use the default value */
518         if (!(slot & EXPIRE_TOTAL))
519                 cb->expire_total = default_reflog_expire;
520         if (!(slot & EXPIRE_UNREACH))
521                 cb->expire_unreachable = default_reflog_expire_unreachable;
522 }
523
524 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
525 {
526         struct expire_reflog_policy_cb cb;
527         unsigned long now = time(NULL);
528         int i, status, do_all;
529         int explicit_expiry = 0;
530         unsigned int flags = 0;
531
532         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
533         default_reflog_expire = now - 90 * 24 * 3600;
534         git_config(reflog_expire_config, NULL);
535
536         save_commit_buffer = 0;
537         do_all = status = 0;
538         memset(&cb, 0, sizeof(cb));
539
540         cb.cmd.expire_total = default_reflog_expire;
541         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
542
543         for (i = 1; i < argc; i++) {
544                 const char *arg = argv[i];
545                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
546                         flags |= EXPIRE_REFLOGS_DRY_RUN;
547                 else if (starts_with(arg, "--expire=")) {
548                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
549                                 die(_("'%s' is not a valid timestamp"), arg);
550                         explicit_expiry |= EXPIRE_TOTAL;
551                 }
552                 else if (starts_with(arg, "--expire-unreachable=")) {
553                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
554                                 die(_("'%s' is not a valid timestamp"), arg);
555                         explicit_expiry |= EXPIRE_UNREACH;
556                 }
557                 else if (!strcmp(arg, "--stale-fix"))
558                         cb.cmd.stalefix = 1;
559                 else if (!strcmp(arg, "--rewrite"))
560                         flags |= EXPIRE_REFLOGS_REWRITE;
561                 else if (!strcmp(arg, "--updateref"))
562                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
563                 else if (!strcmp(arg, "--all"))
564                         do_all = 1;
565                 else if (!strcmp(arg, "--verbose"))
566                         flags |= EXPIRE_REFLOGS_VERBOSE;
567                 else if (!strcmp(arg, "--")) {
568                         i++;
569                         break;
570                 }
571                 else if (arg[0] == '-')
572                         usage(reflog_expire_usage);
573                 else
574                         break;
575         }
576
577         /*
578          * We can trust the commits and objects reachable from refs
579          * even in older repository.  We cannot trust what's reachable
580          * from reflog if the repository was pruned with older git.
581          */
582         if (cb.cmd.stalefix) {
583                 init_revisions(&cb.cmd.revs, prefix);
584                 if (flags & EXPIRE_REFLOGS_VERBOSE)
585                         printf("Marking reachable objects...");
586                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
587                 if (flags & EXPIRE_REFLOGS_VERBOSE)
588                         putchar('\n');
589         }
590
591         if (do_all) {
592                 struct collect_reflog_cb collected;
593                 int i;
594
595                 memset(&collected, 0, sizeof(collected));
596                 for_each_reflog(collect_reflog, &collected);
597                 for (i = 0; i < collected.nr; i++) {
598                         struct collected_reflog *e = collected.e[i];
599                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
600                         status |= reflog_expire(e->reflog, e->sha1, flags,
601                                                 reflog_expiry_prepare,
602                                                 should_expire_reflog_ent,
603                                                 reflog_expiry_cleanup,
604                                                 &cb);
605                         free(e);
606                 }
607                 free(collected.e);
608         }
609
610         for (; i < argc; i++) {
611                 char *ref;
612                 unsigned char sha1[20];
613                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
614                         status |= error("%s points nowhere!", argv[i]);
615                         continue;
616                 }
617                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
618                 status |= reflog_expire(ref, sha1, flags,
619                                         reflog_expiry_prepare,
620                                         should_expire_reflog_ent,
621                                         reflog_expiry_cleanup,
622                                         &cb);
623         }
624         return status;
625 }
626
627 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
628                 const char *email, unsigned long timestamp, int tz,
629                 const char *message, void *cb_data)
630 {
631         struct expire_reflog_policy_cb *cb = cb_data;
632         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
633                 cb->cmd.recno++;
634         return 0;
635 }
636
637 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
638 {
639         struct expire_reflog_policy_cb cb;
640         int i, status = 0;
641         unsigned int flags = 0;
642
643         memset(&cb, 0, sizeof(cb));
644
645         for (i = 1; i < argc; i++) {
646                 const char *arg = argv[i];
647                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
648                         flags |= EXPIRE_REFLOGS_DRY_RUN;
649                 else if (!strcmp(arg, "--rewrite"))
650                         flags |= EXPIRE_REFLOGS_REWRITE;
651                 else if (!strcmp(arg, "--updateref"))
652                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
653                 else if (!strcmp(arg, "--verbose"))
654                         flags |= EXPIRE_REFLOGS_VERBOSE;
655                 else if (!strcmp(arg, "--")) {
656                         i++;
657                         break;
658                 }
659                 else if (arg[0] == '-')
660                         usage(reflog_delete_usage);
661                 else
662                         break;
663         }
664
665         if (argc - i < 1)
666                 return error("Nothing to delete?");
667
668         for ( ; i < argc; i++) {
669                 const char *spec = strstr(argv[i], "@{");
670                 unsigned char sha1[20];
671                 char *ep, *ref;
672                 int recno;
673
674                 if (!spec) {
675                         status |= error("Not a reflog: %s", argv[i]);
676                         continue;
677                 }
678
679                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
680                         status |= error("no reflog for '%s'", argv[i]);
681                         continue;
682                 }
683
684                 recno = strtoul(spec + 2, &ep, 10);
685                 if (*ep == '}') {
686                         cb.cmd.recno = -recno;
687                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
688                 } else {
689                         cb.cmd.expire_total = approxidate(spec + 2);
690                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
691                         cb.cmd.expire_total = 0;
692                 }
693
694                 status |= reflog_expire(ref, sha1, flags,
695                                         reflog_expiry_prepare,
696                                         should_expire_reflog_ent,
697                                         reflog_expiry_cleanup,
698                                         &cb);
699                 free(ref);
700         }
701         return status;
702 }
703
704 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
705 {
706         int i, start = 0;
707
708         for (i = 1; i < argc; i++) {
709                 const char *arg = argv[i];
710                 if (!strcmp(arg, "--")) {
711                         i++;
712                         break;
713                 }
714                 else if (arg[0] == '-')
715                         usage(reflog_exists_usage);
716                 else
717                         break;
718         }
719
720         start = i;
721
722         if (argc - start != 1)
723                 usage(reflog_exists_usage);
724
725         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
726                 die("invalid ref format: %s", argv[start]);
727         return !reflog_exists(argv[start]);
728 }
729
730 /*
731  * main "reflog"
732  */
733
734 static const char reflog_usage[] =
735 "git reflog [ show | expire | delete | exists ]";
736
737 int cmd_reflog(int argc, const char **argv, const char *prefix)
738 {
739         if (argc > 1 && !strcmp(argv[1], "-h"))
740                 usage(reflog_usage);
741
742         /* With no command, we default to showing it. */
743         if (argc < 2 || *argv[1] == '-')
744                 return cmd_log_reflog(argc, argv, prefix);
745
746         if (!strcmp(argv[1], "show"))
747                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
748
749         if (!strcmp(argv[1], "expire"))
750                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
751
752         if (!strcmp(argv[1], "delete"))
753                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
754
755         if (!strcmp(argv[1], "exists"))
756                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
757
758         return cmd_log_reflog(argc, argv, prefix);
759 }