builtin/reflog.c

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