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

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "lockfile.h"
   4 #include "commit.h"
   5 #include "refs.h"
   6 #include "dir.h"
   7 #include "tree-walk.h"
   8 #include "diff.h"
   9 #include "revision.h"
  10 #include "reachable.h"
  11
  12 /* NEEDSWORK: switch to using parse_options */
  13 static const char reflog_expire_usage[] =
  14 "git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
  15 static const char reflog_delete_usage[] =
  16 "git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
  17 static const char reflog_exists_usage[] =
  18 "git reflog exists <ref>";
  19
  20 static timestamp_t default_reflog_expire;
  21 static timestamp_t default_reflog_expire_unreachable;
  22
  23 struct cmd_reflog_expire_cb {
  24         struct rev_info revs;
  25         int stalefix;
  26         timestamp_t expire_total;
  27         timestamp_t expire_unreachable;
  28         int recno;
  29 };
  30
  31 struct expire_reflog_policy_cb {
  32         enum {
  33                 UE_NORMAL,
  34                 UE_ALWAYS,
  35                 UE_HEAD
  36         } unreachable_expire_kind;
  37         struct commit_list *mark_list;
  38         unsigned long mark_limit;
  39         struct cmd_reflog_expire_cb cmd;
  40         struct commit *tip_commit;
  41         struct commit_list *tips;
  42 };
  43
  44 struct collected_reflog {
  45         struct object_id oid;
  46         char reflog[FLEX_ARRAY];
  47 };
  48
  49 struct collect_reflog_cb {
  50         struct collected_reflog **e;
  51         int alloc;
  52         int nr;
  53 };
  54
  55 /* Remember to update object flag allocation in object.h */
  56 #define INCOMPLETE      (1u<<10)
  57 #define STUDYING        (1u<<11)
  58 #define REACHABLE       (1u<<12)
  59
  60 static int tree_is_complete(const struct object_id *oid)
  61 {
  62         struct tree_desc desc;
  63         struct name_entry entry;
  64         int complete;
  65         struct tree *tree;
  66
  67         tree = lookup_tree(oid);
  68         if (!tree)
  69                 return 0;
  70         if (tree->object.flags & SEEN)
  71                 return 1;
  72         if (tree->object.flags & INCOMPLETE)
  73                 return 0;
  74
  75         if (!tree->buffer) {
  76                 enum object_type type;
  77                 unsigned long size;
  78                 void *data = read_sha1_file(oid->hash, &type, &size);
  79                 if (!data) {
  80                         tree->object.flags |= INCOMPLETE;
  81                         return 0;
  82                 }
  83                 tree->buffer = data;
  84                 tree->size = size;
  85         }
  86         init_tree_desc(&desc, tree->buffer, tree->size);
  87         complete = 1;
  88         while (tree_entry(&desc, &entry)) {
  89                 if (!has_sha1_file(entry.oid->hash) ||
  90                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid))) {
  91                         tree->object.flags |= INCOMPLETE;
  92                         complete = 0;
  93                 }
  94         }
  95         free_tree_buffer(tree);
  96
  97         if (complete)
  98                 tree->object.flags |= SEEN;
  99         return complete;
 100 }
 101
 102 static int commit_is_complete(struct commit *commit)
 103 {
 104         struct object_array study;
 105         struct object_array found;
 106         int is_incomplete = 0;
 107         int i;
 108
 109         /* early return */
 110         if (commit->object.flags & SEEN)
 111                 return 1;
 112         if (commit->object.flags & INCOMPLETE)
 113                 return 0;
 114         /*
 115          * Find all commits that are reachable and are not marked as
 116          * SEEN.  Then make sure the trees and blobs contained are
 117          * complete.  After that, mark these commits also as SEEN.
 118          * If some of the objects that are needed to complete this
 119          * commit are missing, mark this commit as INCOMPLETE.
 120          */
 121         memset(&study, 0, sizeof(study));
 122         memset(&found, 0, sizeof(found));
 123         add_object_array(&commit->object, NULL, &study);
 124         add_object_array(&commit->object, NULL, &found);
 125         commit->object.flags |= STUDYING;
 126         while (study.nr) {
 127                 struct commit *c;
 128                 struct commit_list *parent;
 129
 130                 c = (struct commit *)object_array_pop(&study);
 131                 if (!c->object.parsed && !parse_object(&c->object.oid))
 132                         c->object.flags |= INCOMPLETE;
 133
 134                 if (c->object.flags & INCOMPLETE) {
 135                         is_incomplete = 1;
 136                         break;
 137                 }
 138                 else if (c->object.flags & SEEN)
 139                         continue;
 140                 for (parent = c->parents; parent; parent = parent->next) {
 141                         struct commit *p = parent->item;
 142                         if (p->object.flags & STUDYING)
 143                                 continue;
 144                         p->object.flags |= STUDYING;
 145                         add_object_array(&p->object, NULL, &study);
 146                         add_object_array(&p->object, NULL, &found);
 147                 }
 148         }
 149         if (!is_incomplete) {
 150                 /*
 151                  * make sure all commits in "found" array have all the
 152                  * necessary objects.
 153                  */
 154                 for (i = 0; i < found.nr; i++) {
 155                         struct commit *c =
 156                                 (struct commit *)found.objects[i].item;
 157                         if (!tree_is_complete(&c->tree->object.oid)) {
 158                                 is_incomplete = 1;
 159                                 c->object.flags |= INCOMPLETE;
 160                         }
 161                 }
 162                 if (!is_incomplete) {
 163                         /* mark all found commits as complete, iow SEEN */
 164                         for (i = 0; i < found.nr; i++)
 165                                 found.objects[i].item->flags |= SEEN;
 166                 }
 167         }
 168         /* clear flags from the objects we traversed */
 169         for (i = 0; i < found.nr; i++)
 170                 found.objects[i].item->flags &= ~STUDYING;
 171         if (is_incomplete)
 172                 commit->object.flags |= INCOMPLETE;
 173         else {
 174                 /*
 175                  * If we come here, we have (1) traversed the ancestry chain
 176                  * from the "commit" until we reach SEEN commits (which are
 177                  * known to be complete), and (2) made sure that the commits
 178                  * encountered during the above traversal refer to trees that
 179                  * are complete.  Which means that we know *all* the commits
 180                  * we have seen during this process are complete.
 181                  */
 182                 for (i = 0; i < found.nr; i++)
 183                         found.objects[i].item->flags |= SEEN;
 184         }
 185         /* free object arrays */
 186         object_array_clear(&study);
 187         object_array_clear(&found);
 188         return !is_incomplete;
 189 }
 190
 191 static int keep_entry(struct commit **it, struct object_id *oid)
 192 {
 193         struct commit *commit;
 194
 195         if (is_null_oid(oid))
 196                 return 1;
 197         commit = lookup_commit_reference_gently(oid, 1);
 198         if (!commit)
 199                 return 0;
 200
 201         /*
 202          * Make sure everything in this commit exists.
 203          *
 204          * We have walked all the objects reachable from the refs
 205          * and cache earlier.  The commits reachable by this commit
 206          * must meet SEEN commits -- and then we should mark them as
 207          * SEEN as well.
 208          */
 209         if (!commit_is_complete(commit))
 210                 return 0;
 211         *it = commit;
 212         return 1;
 213 }
 214
 215 /*
 216  * Starting from commits in the cb->mark_list, mark commits that are
 217  * reachable from them.  Stop the traversal at commits older than
 218  * the expire_limit and queue them back, so that the caller can call
 219  * us again to restart the traversal with longer expire_limit.
 220  */
 221 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 222 {
 223         struct commit_list *pending;
 224         timestamp_t expire_limit = cb->mark_limit;
 225         struct commit_list *leftover = NULL;
 226
 227         for (pending = cb->mark_list; pending; pending = pending->next)
 228                 pending->item->object.flags &= ~REACHABLE;
 229
 230         pending = cb->mark_list;
 231         while (pending) {
 232                 struct commit_list *parent;
 233                 struct commit *commit = pop_commit(&pending);
 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, struct object_id *oid)
 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_oid(oid))
 264                         return 0;
 265
 266                 commit = lookup_commit_reference_gently(oid, 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(struct object_id *ooid, struct object_id *noid,
 289                                     const char *email, timestamp_t timestamp, int tz,
 290                                     const char *message, void *cb_data)
 291 {
 292         struct expire_reflog_policy_cb *cb = cb_data;
 293         struct commit *old_commit, *new_commit;
 294
 295         if (timestamp < cb->cmd.expire_total)
 296                 return 1;
 297
 298         old_commit = new_commit = NULL;
 299         if (cb->cmd.stalefix &&
 300             (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
 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_commit, ooid) || unreachable(cb, new_commit, noid))
 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, 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 struct object_id *oid,
 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(oid, 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
 388         FLEX_ALLOC_STR(e, reflog, ref);
 389         oidcpy(&e->oid, oid);
 390         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 391         cb->e[cb->nr++] = e;
 392         return 0;
 393 }
 394
 395 static struct reflog_expire_cfg {
 396         struct reflog_expire_cfg *next;
 397         timestamp_t expire_total;
 398         timestamp_t expire_unreachable;
 399         char pattern[FLEX_ARRAY];
 400 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 401
 402 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 403 {
 404         struct reflog_expire_cfg *ent;
 405
 406         if (!reflog_expire_cfg_tail)
 407                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 408
 409         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 410                 if (!strncmp(ent->pattern, pattern, len) &&
 411                     ent->pattern[len] == '\0')
 412                         return ent;
 413
 414         FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 415         *reflog_expire_cfg_tail = ent;
 416         reflog_expire_cfg_tail = &(ent->next);
 417         return ent;
 418 }
 419
 420 /* expiry timer slot */
 421 #define EXPIRE_TOTAL   01
 422 #define EXPIRE_UNREACH 02
 423
 424 static int reflog_expire_config(const char *var, const char *value, void *cb)
 425 {
 426         const char *pattern, *key;
 427         int pattern_len;
 428         timestamp_t expire;
 429         int slot;
 430         struct reflog_expire_cfg *ent;
 431
 432         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 433                 return git_default_config(var, value, cb);
 434
 435         if (!strcmp(key, "reflogexpire")) {
 436                 slot = EXPIRE_TOTAL;
 437                 if (git_config_expiry_date(&expire, var, value))
 438                         return -1;
 439         } else if (!strcmp(key, "reflogexpireunreachable")) {
 440                 slot = EXPIRE_UNREACH;
 441                 if (git_config_expiry_date(&expire, var, value))
 442                         return -1;
 443         } else
 444                 return git_default_config(var, value, cb);
 445
 446         if (!pattern) {
 447                 switch (slot) {
 448                 case EXPIRE_TOTAL:
 449                         default_reflog_expire = expire;
 450                         break;
 451                 case EXPIRE_UNREACH:
 452                         default_reflog_expire_unreachable = expire;
 453                         break;
 454                 }
 455                 return 0;
 456         }
 457
 458         ent = find_cfg_ent(pattern, pattern_len);
 459         if (!ent)
 460                 return -1;
 461         switch (slot) {
 462         case EXPIRE_TOTAL:
 463                 ent->expire_total = expire;
 464                 break;
 465         case EXPIRE_UNREACH:
 466                 ent->expire_unreachable = expire;
 467                 break;
 468         }
 469         return 0;
 470 }
 471
 472 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 473 {
 474         struct reflog_expire_cfg *ent;
 475
 476         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 477                 return; /* both given explicitly -- nothing to tweak */
 478
 479         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 480                 if (!wildmatch(ent->pattern, ref, 0)) {
 481                         if (!(slot & EXPIRE_TOTAL))
 482                                 cb->expire_total = ent->expire_total;
 483                         if (!(slot & EXPIRE_UNREACH))
 484                                 cb->expire_unreachable = ent->expire_unreachable;
 485                         return;
 486                 }
 487         }
 488
 489         /*
 490          * If unconfigured, make stash never expire
 491          */
 492         if (!strcmp(ref, "refs/stash")) {
 493                 if (!(slot & EXPIRE_TOTAL))
 494                         cb->expire_total = 0;
 495                 if (!(slot & EXPIRE_UNREACH))
 496                         cb->expire_unreachable = 0;
 497                 return;
 498         }
 499
 500         /* Nothing matched -- use the default value */
 501         if (!(slot & EXPIRE_TOTAL))
 502                 cb->expire_total = default_reflog_expire;
 503         if (!(slot & EXPIRE_UNREACH))
 504                 cb->expire_unreachable = default_reflog_expire_unreachable;
 505 }
 506
 507 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 508 {
 509         struct expire_reflog_policy_cb cb;
 510         timestamp_t now = time(NULL);
 511         int i, status, do_all;
 512         int explicit_expiry = 0;
 513         unsigned int flags = 0;
 514
 515         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 516         default_reflog_expire = now - 90 * 24 * 3600;
 517         git_config(reflog_expire_config, NULL);
 518
 519         save_commit_buffer = 0;
 520         do_all = status = 0;
 521         memset(&cb, 0, sizeof(cb));
 522
 523         cb.cmd.expire_total = default_reflog_expire;
 524         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 525
 526         for (i = 1; i < argc; i++) {
 527                 const char *arg = argv[i];
 528                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 529                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 530                 else if (starts_with(arg, "--expire=")) {
 531                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 532                                 die(_("'%s' is not a valid timestamp"), arg);
 533                         explicit_expiry |= EXPIRE_TOTAL;
 534                 }
 535                 else if (starts_with(arg, "--expire-unreachable=")) {
 536                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 537                                 die(_("'%s' is not a valid timestamp"), arg);
 538                         explicit_expiry |= EXPIRE_UNREACH;
 539                 }
 540                 else if (!strcmp(arg, "--stale-fix"))
 541                         cb.cmd.stalefix = 1;
 542                 else if (!strcmp(arg, "--rewrite"))
 543                         flags |= EXPIRE_REFLOGS_REWRITE;
 544                 else if (!strcmp(arg, "--updateref"))
 545                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 546                 else if (!strcmp(arg, "--all"))
 547                         do_all = 1;
 548                 else if (!strcmp(arg, "--verbose"))
 549                         flags |= EXPIRE_REFLOGS_VERBOSE;
 550                 else if (!strcmp(arg, "--")) {
 551                         i++;
 552                         break;
 553                 }
 554                 else if (arg[0] == '-')
 555                         usage(reflog_expire_usage);
 556                 else
 557                         break;
 558         }
 559
 560         /*
 561          * We can trust the commits and objects reachable from refs
 562          * even in older repository.  We cannot trust what's reachable
 563          * from reflog if the repository was pruned with older git.
 564          */
 565         if (cb.cmd.stalefix) {
 566                 init_revisions(&cb.cmd.revs, prefix);
 567                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 568                         printf("Marking reachable objects...");
 569                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 570                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 571                         putchar('\n');
 572         }
 573
 574         if (do_all) {
 575                 struct collect_reflog_cb collected;
 576                 int i;
 577
 578                 memset(&collected, 0, sizeof(collected));
 579                 for_each_reflog(collect_reflog, &collected);
 580                 for (i = 0; i < collected.nr; i++) {
 581                         struct collected_reflog *e = collected.e[i];
 582                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 583                         status |= reflog_expire(e->reflog, &e->oid, flags,
 584                                                 reflog_expiry_prepare,
 585                                                 should_expire_reflog_ent,
 586                                                 reflog_expiry_cleanup,
 587                                                 &cb);
 588                         free(e);
 589                 }
 590                 free(collected.e);
 591         }
 592
 593         for (; i < argc; i++) {
 594                 char *ref;
 595                 struct object_id oid;
 596                 if (!dwim_log(argv[i], strlen(argv[i]), &oid, &ref)) {
 597                         status |= error("%s points nowhere!", argv[i]);
 598                         continue;
 599                 }
 600                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 601                 status |= reflog_expire(ref, &oid, flags,
 602                                         reflog_expiry_prepare,
 603                                         should_expire_reflog_ent,
 604                                         reflog_expiry_cleanup,
 605                                         &cb);
 606         }
 607         return status;
 608 }
 609
 610 static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 611                 const char *email, timestamp_t timestamp, int tz,
 612                 const char *message, void *cb_data)
 613 {
 614         struct expire_reflog_policy_cb *cb = cb_data;
 615         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 616                 cb->cmd.recno++;
 617         return 0;
 618 }
 619
 620 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 621 {
 622         struct expire_reflog_policy_cb cb;
 623         int i, status = 0;
 624         unsigned int flags = 0;
 625
 626         memset(&cb, 0, sizeof(cb));
 627
 628         for (i = 1; i < argc; i++) {
 629                 const char *arg = argv[i];
 630                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 631                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 632                 else if (!strcmp(arg, "--rewrite"))
 633                         flags |= EXPIRE_REFLOGS_REWRITE;
 634                 else if (!strcmp(arg, "--updateref"))
 635                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 636                 else if (!strcmp(arg, "--verbose"))
 637                         flags |= EXPIRE_REFLOGS_VERBOSE;
 638                 else if (!strcmp(arg, "--")) {
 639                         i++;
 640                         break;
 641                 }
 642                 else if (arg[0] == '-')
 643                         usage(reflog_delete_usage);
 644                 else
 645                         break;
 646         }
 647
 648         if (argc - i < 1)
 649                 return error("Nothing to delete?");
 650
 651         for ( ; i < argc; i++) {
 652                 const char *spec = strstr(argv[i], "@{");
 653                 struct object_id oid;
 654                 char *ep, *ref;
 655                 int recno;
 656
 657                 if (!spec) {
 658                         status |= error("Not a reflog: %s", argv[i]);
 659                         continue;
 660                 }
 661
 662                 if (!dwim_log(argv[i], spec - argv[i], &oid, &ref)) {
 663                         status |= error("no reflog for '%s'", argv[i]);
 664                         continue;
 665                 }
 666
 667                 recno = strtoul(spec + 2, &ep, 10);
 668                 if (*ep == '}') {
 669                         cb.cmd.recno = -recno;
 670                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 671                 } else {
 672                         cb.cmd.expire_total = approxidate(spec + 2);
 673                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 674                         cb.cmd.expire_total = 0;
 675                 }
 676
 677                 status |= reflog_expire(ref, &oid, flags,
 678                                         reflog_expiry_prepare,
 679                                         should_expire_reflog_ent,
 680                                         reflog_expiry_cleanup,
 681                                         &cb);
 682                 free(ref);
 683         }
 684         return status;
 685 }
 686
 687 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 688 {
 689         int i, start = 0;
 690
 691         for (i = 1; i < argc; i++) {
 692                 const char *arg = argv[i];
 693                 if (!strcmp(arg, "--")) {
 694                         i++;
 695                         break;
 696                 }
 697                 else if (arg[0] == '-')
 698                         usage(reflog_exists_usage);
 699                 else
 700                         break;
 701         }
 702
 703         start = i;
 704
 705         if (argc - start != 1)
 706                 usage(reflog_exists_usage);
 707
 708         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 709                 die("invalid ref format: %s", argv[start]);
 710         return !reflog_exists(argv[start]);
 711 }
 712
 713 /*
 714  * main "reflog"
 715  */
 716
 717 static const char reflog_usage[] =
 718 "git reflog [ show | expire | delete | exists ]";
 719
 720 int cmd_reflog(int argc, const char **argv, const char *prefix)
 721 {
 722         if (argc > 1 && !strcmp(argv[1], "-h"))
 723                 usage(reflog_usage);
 724
 725         /* With no command, we default to showing it. */
 726         if (argc < 2 || *argv[1] == '-')
 727                 return cmd_log_reflog(argc, argv, prefix);
 728
 729         if (!strcmp(argv[1], "show"))
 730                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 731
 732         if (!strcmp(argv[1], "expire"))
 733                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 734
 735         if (!strcmp(argv[1], "delete"))
 736                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 737
 738         if (!strcmp(argv[1], "exists"))
 739                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 740
 741         return cmd_log_reflog(argc, argv, prefix);
 742 }