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 #define INCOMPLETE      (1u<<10)
  56 #define STUDYING        (1u<<11)
  57 #define REACHABLE       (1u<<12)
  58
  59 static int tree_is_complete(const struct object_id *oid)
  60 {
  61         struct tree_desc desc;
  62         struct name_entry entry;
  63         int complete;
  64         struct tree *tree;
  65
  66         tree = lookup_tree(oid);
  67         if (!tree)
  68                 return 0;
  69         if (tree->object.flags & SEEN)
  70                 return 1;
  71         if (tree->object.flags & INCOMPLETE)
  72                 return 0;
  73
  74         if (!tree->buffer) {
  75                 enum object_type type;
  76                 unsigned long size;
  77                 void *data = read_sha1_file(oid->hash, &type, &size);
  78                 if (!data) {
  79                         tree->object.flags |= INCOMPLETE;
  80                         return 0;
  81                 }
  82                 tree->buffer = data;
  83                 tree->size = size;
  84         }
  85         init_tree_desc(&desc, tree->buffer, tree->size);
  86         complete = 1;
  87         while (tree_entry(&desc, &entry)) {
  88                 if (!has_sha1_file(entry.oid->hash) ||
  89                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid))) {
  90                         tree->object.flags |= INCOMPLETE;
  91                         complete = 0;
  92                 }
  93         }
  94         free_tree_buffer(tree);
  95
  96         if (complete)
  97                 tree->object.flags |= SEEN;
  98         return complete;
  99 }
 100
 101 static int commit_is_complete(struct commit *commit)
 102 {
 103         struct object_array study;
 104         struct object_array found;
 105         int is_incomplete = 0;
 106         int i;
 107
 108         /* early return */
 109         if (commit->object.flags & SEEN)
 110                 return 1;
 111         if (commit->object.flags & INCOMPLETE)
 112                 return 0;
 113         /*
 114          * Find all commits that are reachable and are not marked as
 115          * SEEN.  Then make sure the trees and blobs contained are
 116          * complete.  After that, mark these commits also as SEEN.
 117          * If some of the objects that are needed to complete this
 118          * commit are missing, mark this commit as INCOMPLETE.
 119          */
 120         memset(&study, 0, sizeof(study));
 121         memset(&found, 0, sizeof(found));
 122         add_object_array(&commit->object, NULL, &study);
 123         add_object_array(&commit->object, NULL, &found);
 124         commit->object.flags |= STUDYING;
 125         while (study.nr) {
 126                 struct commit *c;
 127                 struct commit_list *parent;
 128
 129                 c = (struct commit *)object_array_pop(&study);
 130                 if (!c->object.parsed && !parse_object(&c->object.oid))
 131                         c->object.flags |= INCOMPLETE;
 132
 133                 if (c->object.flags & INCOMPLETE) {
 134                         is_incomplete = 1;
 135                         break;
 136                 }
 137                 else if (c->object.flags & SEEN)
 138                         continue;
 139                 for (parent = c->parents; parent; parent = parent->next) {
 140                         struct commit *p = parent->item;
 141                         if (p->object.flags & STUDYING)
 142                                 continue;
 143                         p->object.flags |= STUDYING;
 144                         add_object_array(&p->object, NULL, &study);
 145                         add_object_array(&p->object, NULL, &found);
 146                 }
 147         }
 148         if (!is_incomplete) {
 149                 /*
 150                  * make sure all commits in "found" array have all the
 151                  * necessary objects.
 152                  */
 153                 for (i = 0; i < found.nr; i++) {
 154                         struct commit *c =
 155                                 (struct commit *)found.objects[i].item;
 156                         if (!tree_is_complete(&c->tree->object.oid)) {
 157                                 is_incomplete = 1;
 158                                 c->object.flags |= INCOMPLETE;
 159                         }
 160                 }
 161                 if (!is_incomplete) {
 162                         /* mark all found commits as complete, iow SEEN */
 163                         for (i = 0; i < found.nr; i++)
 164                                 found.objects[i].item->flags |= SEEN;
 165                 }
 166         }
 167         /* clear flags from the objects we traversed */
 168         for (i = 0; i < found.nr; i++)
 169                 found.objects[i].item->flags &= ~STUDYING;
 170         if (is_incomplete)
 171                 commit->object.flags |= INCOMPLETE;
 172         else {
 173                 /*
 174                  * If we come here, we have (1) traversed the ancestry chain
 175                  * from the "commit" until we reach SEEN commits (which are
 176                  * known to be complete), and (2) made sure that the commits
 177                  * encountered during the above traversal refer to trees that
 178                  * are complete.  Which means that we know *all* the commits
 179                  * we have seen during this process are complete.
 180                  */
 181                 for (i = 0; i < found.nr; i++)
 182                         found.objects[i].item->flags |= SEEN;
 183         }
 184         /* free object arrays */
 185         object_array_clear(&study);
 186         object_array_clear(&found);
 187         return !is_incomplete;
 188 }
 189
 190 static int keep_entry(struct commit **it, struct object_id *oid)
 191 {
 192         struct commit *commit;
 193
 194         if (is_null_oid(oid))
 195                 return 1;
 196         commit = lookup_commit_reference_gently(oid, 1);
 197         if (!commit)
 198                 return 0;
 199
 200         /*
 201          * Make sure everything in this commit exists.
 202          *
 203          * We have walked all the objects reachable from the refs
 204          * and cache earlier.  The commits reachable by this commit
 205          * must meet SEEN commits -- and then we should mark them as
 206          * SEEN as well.
 207          */
 208         if (!commit_is_complete(commit))
 209                 return 0;
 210         *it = commit;
 211         return 1;
 212 }
 213
 214 /*
 215  * Starting from commits in the cb->mark_list, mark commits that are
 216  * reachable from them.  Stop the traversal at commits older than
 217  * the expire_limit and queue them back, so that the caller can call
 218  * us again to restart the traversal with longer expire_limit.
 219  */
 220 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 221 {
 222         struct commit_list *pending;
 223         timestamp_t 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 *parent;
 232                 struct commit *commit = pop_commit(&pending);
 233                 if (commit->object.flags & REACHABLE)
 234                         continue;
 235                 if (parse_commit(commit))
 236                         continue;
 237                 commit->object.flags |= REACHABLE;
 238                 if (commit->date < expire_limit) {
 239                         commit_list_insert(commit, &leftover);
 240                         continue;
 241                 }
 242                 commit->object.flags |= REACHABLE;
 243                 parent = commit->parents;
 244                 while (parent) {
 245                         commit = parent->item;
 246                         parent = parent->next;
 247                         if (commit->object.flags & REACHABLE)
 248                                 continue;
 249                         commit_list_insert(commit, &pending);
 250                 }
 251         }
 252         cb->mark_list = leftover;
 253 }
 254
 255 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 256 {
 257         /*
 258          * We may or may not have the commit yet - if not, look it
 259          * up using the supplied sha1.
 260          */
 261         if (!commit) {
 262                 if (is_null_oid(oid))
 263                         return 0;
 264
 265                 commit = lookup_commit_reference_gently(oid, 1);
 266
 267                 /* Not a commit -- keep it */
 268                 if (!commit)
 269                         return 0;
 270         }
 271
 272         /* Reachable from the current ref?  Don't prune. */
 273         if (commit->object.flags & REACHABLE)
 274                 return 0;
 275
 276         if (cb->mark_list && cb->mark_limit) {
 277                 cb->mark_limit = 0; /* dig down to the root */
 278                 mark_reachable(cb);
 279         }
 280
 281         return !(commit->object.flags & REACHABLE);
 282 }
 283
 284 /*
 285  * Return true iff the specified reflog entry should be expired.
 286  */
 287 static int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 288                                     const char *email, timestamp_t timestamp, int tz,
 289                                     const char *message, void *cb_data)
 290 {
 291         struct expire_reflog_policy_cb *cb = cb_data;
 292         struct commit *old, *new;
 293
 294         if (timestamp < cb->cmd.expire_total)
 295                 return 1;
 296
 297         old = new = NULL;
 298         if (cb->cmd.stalefix &&
 299             (!keep_entry(&old, ooid) || !keep_entry(&new, noid)))
 300                 return 1;
 301
 302         if (timestamp < cb->cmd.expire_unreachable) {
 303                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 304                         return 1;
 305                 if (unreachable(cb, old, ooid) || unreachable(cb, new, noid))
 306                         return 1;
 307         }
 308
 309         if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 310                 return 1;
 311
 312         return 0;
 313 }
 314
 315 static int push_tip_to_list(const char *refname, const struct object_id *oid,
 316                             int flags, void *cb_data)
 317 {
 318         struct commit_list **list = cb_data;
 319         struct commit *tip_commit;
 320         if (flags & REF_ISSYMREF)
 321                 return 0;
 322         tip_commit = lookup_commit_reference_gently(oid, 1);
 323         if (!tip_commit)
 324                 return 0;
 325         commit_list_insert(tip_commit, list);
 326         return 0;
 327 }
 328
 329 static void reflog_expiry_prepare(const char *refname,
 330                                   const struct object_id *oid,
 331                                   void *cb_data)
 332 {
 333         struct expire_reflog_policy_cb *cb = cb_data;
 334
 335         if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
 336                 cb->tip_commit = NULL;
 337                 cb->unreachable_expire_kind = UE_HEAD;
 338         } else {
 339                 cb->tip_commit = lookup_commit_reference_gently(oid, 1);
 340                 if (!cb->tip_commit)
 341                         cb->unreachable_expire_kind = UE_ALWAYS;
 342                 else
 343                         cb->unreachable_expire_kind = UE_NORMAL;
 344         }
 345
 346         if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 347                 cb->unreachable_expire_kind = UE_ALWAYS;
 348
 349         cb->mark_list = NULL;
 350         cb->tips = NULL;
 351         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 352                 if (cb->unreachable_expire_kind == UE_HEAD) {
 353                         struct commit_list *elem;
 354
 355                         for_each_ref(push_tip_to_list, &cb->tips);
 356                         for (elem = cb->tips; elem; elem = elem->next)
 357                                 commit_list_insert(elem->item, &cb->mark_list);
 358                 } else {
 359                         commit_list_insert(cb->tip_commit, &cb->mark_list);
 360                 }
 361                 cb->mark_limit = cb->cmd.expire_total;
 362                 mark_reachable(cb);
 363         }
 364 }
 365
 366 static void reflog_expiry_cleanup(void *cb_data)
 367 {
 368         struct expire_reflog_policy_cb *cb = cb_data;
 369
 370         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 371                 if (cb->unreachable_expire_kind == UE_HEAD) {
 372                         struct commit_list *elem;
 373                         for (elem = cb->tips; elem; elem = elem->next)
 374                                 clear_commit_marks(elem->item, REACHABLE);
 375                         free_commit_list(cb->tips);
 376                 } else {
 377                         clear_commit_marks(cb->tip_commit, REACHABLE);
 378                 }
 379         }
 380 }
 381
 382 static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 383 {
 384         struct collected_reflog *e;
 385         struct collect_reflog_cb *cb = cb_data;
 386
 387         FLEX_ALLOC_STR(e, reflog, ref);
 388         oidcpy(&e->oid, oid);
 389         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 390         cb->e[cb->nr++] = e;
 391         return 0;
 392 }
 393
 394 static struct reflog_expire_cfg {
 395         struct reflog_expire_cfg *next;
 396         timestamp_t expire_total;
 397         timestamp_t expire_unreachable;
 398         char pattern[FLEX_ARRAY];
 399 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 400
 401 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 402 {
 403         struct reflog_expire_cfg *ent;
 404
 405         if (!reflog_expire_cfg_tail)
 406                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 407
 408         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 409                 if (!strncmp(ent->pattern, pattern, len) &&
 410                     ent->pattern[len] == '\0')
 411                         return ent;
 412
 413         FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 414         *reflog_expire_cfg_tail = ent;
 415         reflog_expire_cfg_tail = &(ent->next);
 416         return ent;
 417 }
 418
 419 /* expiry timer slot */
 420 #define EXPIRE_TOTAL   01
 421 #define EXPIRE_UNREACH 02
 422
 423 static int reflog_expire_config(const char *var, const char *value, void *cb)
 424 {
 425         const char *pattern, *key;
 426         int pattern_len;
 427         timestamp_t expire;
 428         int slot;
 429         struct reflog_expire_cfg *ent;
 430
 431         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 432                 return git_default_config(var, value, cb);
 433
 434         if (!strcmp(key, "reflogexpire")) {
 435                 slot = EXPIRE_TOTAL;
 436                 if (git_config_expiry_date(&expire, var, value))
 437                         return -1;
 438         } else if (!strcmp(key, "reflogexpireunreachable")) {
 439                 slot = EXPIRE_UNREACH;
 440                 if (git_config_expiry_date(&expire, var, value))
 441                         return -1;
 442         } else
 443                 return git_default_config(var, value, cb);
 444
 445         if (!pattern) {
 446                 switch (slot) {
 447                 case EXPIRE_TOTAL:
 448                         default_reflog_expire = expire;
 449                         break;
 450                 case EXPIRE_UNREACH:
 451                         default_reflog_expire_unreachable = expire;
 452                         break;
 453                 }
 454                 return 0;
 455         }
 456
 457         ent = find_cfg_ent(pattern, pattern_len);
 458         if (!ent)
 459                 return -1;
 460         switch (slot) {
 461         case EXPIRE_TOTAL:
 462                 ent->expire_total = expire;
 463                 break;
 464         case EXPIRE_UNREACH:
 465                 ent->expire_unreachable = expire;
 466                 break;
 467         }
 468         return 0;
 469 }
 470
 471 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 472 {
 473         struct reflog_expire_cfg *ent;
 474
 475         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 476                 return; /* both given explicitly -- nothing to tweak */
 477
 478         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 479                 if (!wildmatch(ent->pattern, ref, 0)) {
 480                         if (!(slot & EXPIRE_TOTAL))
 481                                 cb->expire_total = ent->expire_total;
 482                         if (!(slot & EXPIRE_UNREACH))
 483                                 cb->expire_unreachable = ent->expire_unreachable;
 484                         return;
 485                 }
 486         }
 487
 488         /*
 489          * If unconfigured, make stash never expire
 490          */
 491         if (!strcmp(ref, "refs/stash")) {
 492                 if (!(slot & EXPIRE_TOTAL))
 493                         cb->expire_total = 0;
 494                 if (!(slot & EXPIRE_UNREACH))
 495                         cb->expire_unreachable = 0;
 496                 return;
 497         }
 498
 499         /* Nothing matched -- use the default value */
 500         if (!(slot & EXPIRE_TOTAL))
 501                 cb->expire_total = default_reflog_expire;
 502         if (!(slot & EXPIRE_UNREACH))
 503                 cb->expire_unreachable = default_reflog_expire_unreachable;
 504 }
 505
 506 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 507 {
 508         struct expire_reflog_policy_cb cb;
 509         timestamp_t now = time(NULL);
 510         int i, status, do_all;
 511         int explicit_expiry = 0;
 512         unsigned int flags = 0;
 513
 514         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 515         default_reflog_expire = now - 90 * 24 * 3600;
 516         git_config(reflog_expire_config, NULL);
 517
 518         save_commit_buffer = 0;
 519         do_all = status = 0;
 520         memset(&cb, 0, sizeof(cb));
 521
 522         cb.cmd.expire_total = default_reflog_expire;
 523         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 524
 525         for (i = 1; i < argc; i++) {
 526                 const char *arg = argv[i];
 527                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 528                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 529                 else if (starts_with(arg, "--expire=")) {
 530                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 531                                 die(_("'%s' is not a valid timestamp"), arg);
 532                         explicit_expiry |= EXPIRE_TOTAL;
 533                 }
 534                 else if (starts_with(arg, "--expire-unreachable=")) {
 535                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 536                                 die(_("'%s' is not a valid timestamp"), arg);
 537                         explicit_expiry |= EXPIRE_UNREACH;
 538                 }
 539                 else if (!strcmp(arg, "--stale-fix"))
 540                         cb.cmd.stalefix = 1;
 541                 else if (!strcmp(arg, "--rewrite"))
 542                         flags |= EXPIRE_REFLOGS_REWRITE;
 543                 else if (!strcmp(arg, "--updateref"))
 544                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 545                 else if (!strcmp(arg, "--all"))
 546                         do_all = 1;
 547                 else if (!strcmp(arg, "--verbose"))
 548                         flags |= EXPIRE_REFLOGS_VERBOSE;
 549                 else if (!strcmp(arg, "--")) {
 550                         i++;
 551                         break;
 552                 }
 553                 else if (arg[0] == '-')
 554                         usage(reflog_expire_usage);
 555                 else
 556                         break;
 557         }
 558
 559         /*
 560          * We can trust the commits and objects reachable from refs
 561          * even in older repository.  We cannot trust what's reachable
 562          * from reflog if the repository was pruned with older git.
 563          */
 564         if (cb.cmd.stalefix) {
 565                 init_revisions(&cb.cmd.revs, prefix);
 566                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 567                         printf("Marking reachable objects...");
 568                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 569                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 570                         putchar('\n');
 571         }
 572
 573         if (do_all) {
 574                 struct collect_reflog_cb collected;
 575                 int i;
 576
 577                 memset(&collected, 0, sizeof(collected));
 578                 for_each_reflog(collect_reflog, &collected);
 579                 for (i = 0; i < collected.nr; i++) {
 580                         struct collected_reflog *e = collected.e[i];
 581                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 582                         status |= reflog_expire(e->reflog, &e->oid, flags,
 583                                                 reflog_expiry_prepare,
 584                                                 should_expire_reflog_ent,
 585                                                 reflog_expiry_cleanup,
 586                                                 &cb);
 587                         free(e);
 588                 }
 589                 free(collected.e);
 590         }
 591
 592         for (; i < argc; i++) {
 593                 char *ref;
 594                 struct object_id oid;
 595                 if (!dwim_log(argv[i], strlen(argv[i]), &oid, &ref)) {
 596                         status |= error("%s points nowhere!", argv[i]);
 597                         continue;
 598                 }
 599                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 600                 status |= reflog_expire(ref, &oid, flags,
 601                                         reflog_expiry_prepare,
 602                                         should_expire_reflog_ent,
 603                                         reflog_expiry_cleanup,
 604                                         &cb);
 605         }
 606         return status;
 607 }
 608
 609 static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 610                 const char *email, timestamp_t timestamp, int tz,
 611                 const char *message, void *cb_data)
 612 {
 613         struct expire_reflog_policy_cb *cb = cb_data;
 614         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 615                 cb->cmd.recno++;
 616         return 0;
 617 }
 618
 619 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 620 {
 621         struct expire_reflog_policy_cb cb;
 622         int i, status = 0;
 623         unsigned int flags = 0;
 624
 625         memset(&cb, 0, sizeof(cb));
 626
 627         for (i = 1; i < argc; i++) {
 628                 const char *arg = argv[i];
 629                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 630                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 631                 else if (!strcmp(arg, "--rewrite"))
 632                         flags |= EXPIRE_REFLOGS_REWRITE;
 633                 else if (!strcmp(arg, "--updateref"))
 634                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 635                 else if (!strcmp(arg, "--verbose"))
 636                         flags |= EXPIRE_REFLOGS_VERBOSE;
 637                 else if (!strcmp(arg, "--")) {
 638                         i++;
 639                         break;
 640                 }
 641                 else if (arg[0] == '-')
 642                         usage(reflog_delete_usage);
 643                 else
 644                         break;
 645         }
 646
 647         if (argc - i < 1)
 648                 return error("Nothing to delete?");
 649
 650         for ( ; i < argc; i++) {
 651                 const char *spec = strstr(argv[i], "@{");
 652                 struct object_id oid;
 653                 char *ep, *ref;
 654                 int recno;
 655
 656                 if (!spec) {
 657                         status |= error("Not a reflog: %s", argv[i]);
 658                         continue;
 659                 }
 660
 661                 if (!dwim_log(argv[i], spec - argv[i], &oid, &ref)) {
 662                         status |= error("no reflog for '%s'", argv[i]);
 663                         continue;
 664                 }
 665
 666                 recno = strtoul(spec + 2, &ep, 10);
 667                 if (*ep == '}') {
 668                         cb.cmd.recno = -recno;
 669                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 670                 } else {
 671                         cb.cmd.expire_total = approxidate(spec + 2);
 672                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 673                         cb.cmd.expire_total = 0;
 674                 }
 675
 676                 status |= reflog_expire(ref, &oid, flags,
 677                                         reflog_expiry_prepare,
 678                                         should_expire_reflog_ent,
 679                                         reflog_expiry_cleanup,
 680                                         &cb);
 681                 free(ref);
 682         }
 683         return status;
 684 }
 685
 686 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 687 {
 688         int i, start = 0;
 689
 690         for (i = 1; i < argc; i++) {
 691                 const char *arg = argv[i];
 692                 if (!strcmp(arg, "--")) {
 693                         i++;
 694                         break;
 695                 }
 696                 else if (arg[0] == '-')
 697                         usage(reflog_exists_usage);
 698                 else
 699                         break;
 700         }
 701
 702         start = i;
 703
 704         if (argc - start != 1)
 705                 usage(reflog_exists_usage);
 706
 707         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 708                 die("invalid ref format: %s", argv[start]);
 709         return !reflog_exists(argv[start]);
 710 }
 711
 712 /*
 713  * main "reflog"
 714  */
 715
 716 static const char reflog_usage[] =
 717 "git reflog [ show | expire | delete | exists ]";
 718
 719 int cmd_reflog(int argc, const char **argv, const char *prefix)
 720 {
 721         if (argc > 1 && !strcmp(argv[1], "-h"))
 722                 usage(reflog_usage);
 723
 724         /* With no command, we default to showing it. */
 725         if (argc < 2 || *argv[1] == '-')
 726                 return cmd_log_reflog(argc, argv, prefix);
 727
 728         if (!strcmp(argv[1], "show"))
 729                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 730
 731         if (!strcmp(argv[1], "expire"))
 732                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 733
 734         if (!strcmp(argv[1], "delete"))
 735                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 736
 737         if (!strcmp(argv[1], "exists"))
 738                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 739
 740         return cmd_log_reflog(argc, argv, prefix);
 741 }