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 }