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