Merge branch 'maint-2.4' into maint-2.5
[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 struct object_id *oid,
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(oid->hash, 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
356                         for_each_ref(push_tip_to_list, &cb->tips);
357                         for (elem = cb->tips; elem; elem = elem->next)
358                                 commit_list_insert(elem->item, &cb->mark_list);
359                 } else {
360                         commit_list_insert(cb->tip_commit, &cb->mark_list);
361                 }
362                 cb->mark_limit = cb->cmd.expire_total;
363                 mark_reachable(cb);
364         }
365 }
366
367 static void reflog_expiry_cleanup(void *cb_data)
368 {
369         struct expire_reflog_policy_cb *cb = cb_data;
370
371         if (cb->unreachable_expire_kind != UE_ALWAYS) {
372                 if (cb->unreachable_expire_kind == UE_HEAD) {
373                         struct commit_list *elem;
374                         for (elem = cb->tips; elem; elem = elem->next)
375                                 clear_commit_marks(elem->item, REACHABLE);
376                         free_commit_list(cb->tips);
377                 } else {
378                         clear_commit_marks(cb->tip_commit, REACHABLE);
379                 }
380         }
381 }
382
383 static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
384 {
385         struct collected_reflog *e;
386         struct collect_reflog_cb *cb = cb_data;
387         size_t namelen = strlen(ref);
388
389         e = xmalloc(sizeof(*e) + namelen + 1);
390         hashcpy(e->sha1, oid->hash);
391         memcpy(e->reflog, ref, namelen + 1);
392         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
393         cb->e[cb->nr++] = e;
394         return 0;
395 }
396
397 static struct reflog_expire_cfg {
398         struct reflog_expire_cfg *next;
399         unsigned long expire_total;
400         unsigned long expire_unreachable;
401         size_t len;
402         char pattern[FLEX_ARRAY];
403 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
404
405 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
406 {
407         struct reflog_expire_cfg *ent;
408
409         if (!reflog_expire_cfg_tail)
410                 reflog_expire_cfg_tail = &reflog_expire_cfg;
411
412         for (ent = reflog_expire_cfg; ent; ent = ent->next)
413                 if (ent->len == len &&
414                     !memcmp(ent->pattern, pattern, len))
415                         return ent;
416
417         ent = xcalloc(1, (sizeof(*ent) + len));
418         memcpy(ent->pattern, pattern, len);
419         ent->len = len;
420         *reflog_expire_cfg_tail = ent;
421         reflog_expire_cfg_tail = &(ent->next);
422         return ent;
423 }
424
425 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
426 {
427         if (!value)
428                 return config_error_nonbool(var);
429         if (parse_expiry_date(value, expire))
430                 return error(_("%s' for '%s' is not a valid timestamp"),
431                              value, var);
432         return 0;
433 }
434
435 /* expiry timer slot */
436 #define EXPIRE_TOTAL   01
437 #define EXPIRE_UNREACH 02
438
439 static int reflog_expire_config(const char *var, const char *value, void *cb)
440 {
441         const char *pattern, *key;
442         int pattern_len;
443         unsigned long expire;
444         int slot;
445         struct reflog_expire_cfg *ent;
446
447         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
448                 return git_default_config(var, value, cb);
449
450         if (!strcmp(key, "reflogexpire")) {
451                 slot = EXPIRE_TOTAL;
452                 if (parse_expire_cfg_value(var, value, &expire))
453                         return -1;
454         } else if (!strcmp(key, "reflogexpireunreachable")) {
455                 slot = EXPIRE_UNREACH;
456                 if (parse_expire_cfg_value(var, value, &expire))
457                         return -1;
458         } else
459                 return git_default_config(var, value, cb);
460
461         if (!pattern) {
462                 switch (slot) {
463                 case EXPIRE_TOTAL:
464                         default_reflog_expire = expire;
465                         break;
466                 case EXPIRE_UNREACH:
467                         default_reflog_expire_unreachable = expire;
468                         break;
469                 }
470                 return 0;
471         }
472
473         ent = find_cfg_ent(pattern, pattern_len);
474         if (!ent)
475                 return -1;
476         switch (slot) {
477         case EXPIRE_TOTAL:
478                 ent->expire_total = expire;
479                 break;
480         case EXPIRE_UNREACH:
481                 ent->expire_unreachable = expire;
482                 break;
483         }
484         return 0;
485 }
486
487 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
488 {
489         struct reflog_expire_cfg *ent;
490
491         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
492                 return; /* both given explicitly -- nothing to tweak */
493
494         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
495                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
496                         if (!(slot & EXPIRE_TOTAL))
497                                 cb->expire_total = ent->expire_total;
498                         if (!(slot & EXPIRE_UNREACH))
499                                 cb->expire_unreachable = ent->expire_unreachable;
500                         return;
501                 }
502         }
503
504         /*
505          * If unconfigured, make stash never expire
506          */
507         if (!strcmp(ref, "refs/stash")) {
508                 if (!(slot & EXPIRE_TOTAL))
509                         cb->expire_total = 0;
510                 if (!(slot & EXPIRE_UNREACH))
511                         cb->expire_unreachable = 0;
512                 return;
513         }
514
515         /* Nothing matched -- use the default value */
516         if (!(slot & EXPIRE_TOTAL))
517                 cb->expire_total = default_reflog_expire;
518         if (!(slot & EXPIRE_UNREACH))
519                 cb->expire_unreachable = default_reflog_expire_unreachable;
520 }
521
522 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
523 {
524         struct expire_reflog_policy_cb cb;
525         unsigned long now = time(NULL);
526         int i, status, do_all;
527         int explicit_expiry = 0;
528         unsigned int flags = 0;
529
530         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
531         default_reflog_expire = now - 90 * 24 * 3600;
532         git_config(reflog_expire_config, NULL);
533
534         save_commit_buffer = 0;
535         do_all = status = 0;
536         memset(&cb, 0, sizeof(cb));
537
538         cb.cmd.expire_total = default_reflog_expire;
539         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
540
541         for (i = 1; i < argc; i++) {
542                 const char *arg = argv[i];
543                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
544                         flags |= EXPIRE_REFLOGS_DRY_RUN;
545                 else if (starts_with(arg, "--expire=")) {
546                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
547                                 die(_("'%s' is not a valid timestamp"), arg);
548                         explicit_expiry |= EXPIRE_TOTAL;
549                 }
550                 else if (starts_with(arg, "--expire-unreachable=")) {
551                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
552                                 die(_("'%s' is not a valid timestamp"), arg);
553                         explicit_expiry |= EXPIRE_UNREACH;
554                 }
555                 else if (!strcmp(arg, "--stale-fix"))
556                         cb.cmd.stalefix = 1;
557                 else if (!strcmp(arg, "--rewrite"))
558                         flags |= EXPIRE_REFLOGS_REWRITE;
559                 else if (!strcmp(arg, "--updateref"))
560                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
561                 else if (!strcmp(arg, "--all"))
562                         do_all = 1;
563                 else if (!strcmp(arg, "--verbose"))
564                         flags |= EXPIRE_REFLOGS_VERBOSE;
565                 else if (!strcmp(arg, "--")) {
566                         i++;
567                         break;
568                 }
569                 else if (arg[0] == '-')
570                         usage(reflog_expire_usage);
571                 else
572                         break;
573         }
574
575         /*
576          * We can trust the commits and objects reachable from refs
577          * even in older repository.  We cannot trust what's reachable
578          * from reflog if the repository was pruned with older git.
579          */
580         if (cb.cmd.stalefix) {
581                 init_revisions(&cb.cmd.revs, prefix);
582                 if (flags & EXPIRE_REFLOGS_VERBOSE)
583                         printf("Marking reachable objects...");
584                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
585                 if (flags & EXPIRE_REFLOGS_VERBOSE)
586                         putchar('\n');
587         }
588
589         if (do_all) {
590                 struct collect_reflog_cb collected;
591                 int i;
592
593                 memset(&collected, 0, sizeof(collected));
594                 for_each_reflog(collect_reflog, &collected);
595                 for (i = 0; i < collected.nr; i++) {
596                         struct collected_reflog *e = collected.e[i];
597                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
598                         status |= reflog_expire(e->reflog, e->sha1, flags,
599                                                 reflog_expiry_prepare,
600                                                 should_expire_reflog_ent,
601                                                 reflog_expiry_cleanup,
602                                                 &cb);
603                         free(e);
604                 }
605                 free(collected.e);
606         }
607
608         for (; i < argc; i++) {
609                 char *ref;
610                 unsigned char sha1[20];
611                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
612                         status |= error("%s points nowhere!", argv[i]);
613                         continue;
614                 }
615                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
616                 status |= reflog_expire(ref, sha1, flags,
617                                         reflog_expiry_prepare,
618                                         should_expire_reflog_ent,
619                                         reflog_expiry_cleanup,
620                                         &cb);
621         }
622         return status;
623 }
624
625 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
626                 const char *email, unsigned long timestamp, int tz,
627                 const char *message, void *cb_data)
628 {
629         struct expire_reflog_policy_cb *cb = cb_data;
630         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
631                 cb->cmd.recno++;
632         return 0;
633 }
634
635 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
636 {
637         struct expire_reflog_policy_cb cb;
638         int i, status = 0;
639         unsigned int flags = 0;
640
641         memset(&cb, 0, sizeof(cb));
642
643         for (i = 1; i < argc; i++) {
644                 const char *arg = argv[i];
645                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
646                         flags |= EXPIRE_REFLOGS_DRY_RUN;
647                 else if (!strcmp(arg, "--rewrite"))
648                         flags |= EXPIRE_REFLOGS_REWRITE;
649                 else if (!strcmp(arg, "--updateref"))
650                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
651                 else if (!strcmp(arg, "--verbose"))
652                         flags |= EXPIRE_REFLOGS_VERBOSE;
653                 else if (!strcmp(arg, "--")) {
654                         i++;
655                         break;
656                 }
657                 else if (arg[0] == '-')
658                         usage(reflog_delete_usage);
659                 else
660                         break;
661         }
662
663         if (argc - i < 1)
664                 return error("Nothing to delete?");
665
666         for ( ; i < argc; i++) {
667                 const char *spec = strstr(argv[i], "@{");
668                 unsigned char sha1[20];
669                 char *ep, *ref;
670                 int recno;
671
672                 if (!spec) {
673                         status |= error("Not a reflog: %s", argv[i]);
674                         continue;
675                 }
676
677                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
678                         status |= error("no reflog for '%s'", argv[i]);
679                         continue;
680                 }
681
682                 recno = strtoul(spec + 2, &ep, 10);
683                 if (*ep == '}') {
684                         cb.cmd.recno = -recno;
685                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
686                 } else {
687                         cb.cmd.expire_total = approxidate(spec + 2);
688                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
689                         cb.cmd.expire_total = 0;
690                 }
691
692                 status |= reflog_expire(ref, sha1, flags,
693                                         reflog_expiry_prepare,
694                                         should_expire_reflog_ent,
695                                         reflog_expiry_cleanup,
696                                         &cb);
697                 free(ref);
698         }
699         return status;
700 }
701
702 /*
703  * main "reflog"
704  */
705
706 static const char reflog_usage[] =
707 "git reflog [ show | expire | delete ]";
708
709 int cmd_reflog(int argc, const char **argv, const char *prefix)
710 {
711         if (argc > 1 && !strcmp(argv[1], "-h"))
712                 usage(reflog_usage);
713
714         /* With no command, we default to showing it. */
715         if (argc < 2 || *argv[1] == '-')
716                 return cmd_log_reflog(argc, argv, prefix);
717
718         if (!strcmp(argv[1], "show"))
719                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
720
721         if (!strcmp(argv[1], "expire"))
722                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
723
724         if (!strcmp(argv[1], "delete"))
725                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
726
727         return cmd_log_reflog(argc, argv, prefix);
728 }