git.oblomov.eu Git - git/blob - builtin/reflog.c

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