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         unsigned char sha1[20];
  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         hashcpy(e->sha1, oid->hash);
 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 static int parse_expire_cfg_value(const char *var, const char *value, timestamp_t *expire)
 420 {
 421         if (!value)
 422                 return config_error_nonbool(var);
 423         if (parse_expiry_date(value, expire))
 424                 return error(_("'%s' for '%s' is not a valid timestamp"),
 425                              value, var);
 426         return 0;
 427 }
 428
 429 /* expiry timer slot */
 430 #define EXPIRE_TOTAL   01
 431 #define EXPIRE_UNREACH 02
 432
 433 static int reflog_expire_config(const char *var, const char *value, void *cb)
 434 {
 435         const char *pattern, *key;
 436         int pattern_len;
 437         timestamp_t expire;
 438         int slot;
 439         struct reflog_expire_cfg *ent;
 440
 441         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 442                 return git_default_config(var, value, cb);
 443
 444         if (!strcmp(key, "reflogexpire")) {
 445                 slot = EXPIRE_TOTAL;
 446                 if (parse_expire_cfg_value(var, value, &expire))
 447                         return -1;
 448         } else if (!strcmp(key, "reflogexpireunreachable")) {
 449                 slot = EXPIRE_UNREACH;
 450                 if (parse_expire_cfg_value(var, value, &expire))
 451                         return -1;
 452         } else
 453                 return git_default_config(var, value, cb);
 454
 455         if (!pattern) {
 456                 switch (slot) {
 457                 case EXPIRE_TOTAL:
 458                         default_reflog_expire = expire;
 459                         break;
 460                 case EXPIRE_UNREACH:
 461                         default_reflog_expire_unreachable = expire;
 462                         break;
 463                 }
 464                 return 0;
 465         }
 466
 467         ent = find_cfg_ent(pattern, pattern_len);
 468         if (!ent)
 469                 return -1;
 470         switch (slot) {
 471         case EXPIRE_TOTAL:
 472                 ent->expire_total = expire;
 473                 break;
 474         case EXPIRE_UNREACH:
 475                 ent->expire_unreachable = expire;
 476                 break;
 477         }
 478         return 0;
 479 }
 480
 481 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 482 {
 483         struct reflog_expire_cfg *ent;
 484
 485         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 486                 return; /* both given explicitly -- nothing to tweak */
 487
 488         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 489                 if (!wildmatch(ent->pattern, ref, 0)) {
 490                         if (!(slot & EXPIRE_TOTAL))
 491                                 cb->expire_total = ent->expire_total;
 492                         if (!(slot & EXPIRE_UNREACH))
 493                                 cb->expire_unreachable = ent->expire_unreachable;
 494                         return;
 495                 }
 496         }
 497
 498         /*
 499          * If unconfigured, make stash never expire
 500          */
 501         if (!strcmp(ref, "refs/stash")) {
 502                 if (!(slot & EXPIRE_TOTAL))
 503                         cb->expire_total = 0;
 504                 if (!(slot & EXPIRE_UNREACH))
 505                         cb->expire_unreachable = 0;
 506                 return;
 507         }
 508
 509         /* Nothing matched -- use the default value */
 510         if (!(slot & EXPIRE_TOTAL))
 511                 cb->expire_total = default_reflog_expire;
 512         if (!(slot & EXPIRE_UNREACH))
 513                 cb->expire_unreachable = default_reflog_expire_unreachable;
 514 }
 515
 516 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 517 {
 518         struct expire_reflog_policy_cb cb;
 519         timestamp_t now = time(NULL);
 520         int i, status, do_all;
 521         int explicit_expiry = 0;
 522         unsigned int flags = 0;
 523
 524         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 525         default_reflog_expire = now - 90 * 24 * 3600;
 526         git_config(reflog_expire_config, NULL);
 527
 528         save_commit_buffer = 0;
 529         do_all = status = 0;
 530         memset(&cb, 0, sizeof(cb));
 531
 532         cb.cmd.expire_total = default_reflog_expire;
 533         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 534
 535         for (i = 1; i < argc; i++) {
 536                 const char *arg = argv[i];
 537                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 538                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 539                 else if (starts_with(arg, "--expire=")) {
 540                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 541                                 die(_("'%s' is not a valid timestamp"), arg);
 542                         explicit_expiry |= EXPIRE_TOTAL;
 543                 }
 544                 else if (starts_with(arg, "--expire-unreachable=")) {
 545                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 546                                 die(_("'%s' is not a valid timestamp"), arg);
 547                         explicit_expiry |= EXPIRE_UNREACH;
 548                 }
 549                 else if (!strcmp(arg, "--stale-fix"))
 550                         cb.cmd.stalefix = 1;
 551                 else if (!strcmp(arg, "--rewrite"))
 552                         flags |= EXPIRE_REFLOGS_REWRITE;
 553                 else if (!strcmp(arg, "--updateref"))
 554                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 555                 else if (!strcmp(arg, "--all"))
 556                         do_all = 1;
 557                 else if (!strcmp(arg, "--verbose"))
 558                         flags |= EXPIRE_REFLOGS_VERBOSE;
 559                 else if (!strcmp(arg, "--")) {
 560                         i++;
 561                         break;
 562                 }
 563                 else if (arg[0] == '-')
 564                         usage(reflog_expire_usage);
 565                 else
 566                         break;
 567         }
 568
 569         /*
 570          * We can trust the commits and objects reachable from refs
 571          * even in older repository.  We cannot trust what's reachable
 572          * from reflog if the repository was pruned with older git.
 573          */
 574         if (cb.cmd.stalefix) {
 575                 init_revisions(&cb.cmd.revs, prefix);
 576                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 577                         printf("Marking reachable objects...");
 578                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 579                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 580                         putchar('\n');
 581         }
 582
 583         if (do_all) {
 584                 struct collect_reflog_cb collected;
 585                 int i;
 586
 587                 memset(&collected, 0, sizeof(collected));
 588                 for_each_reflog(collect_reflog, &collected);
 589                 for (i = 0; i < collected.nr; i++) {
 590                         struct collected_reflog *e = collected.e[i];
 591                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 592                         status |= reflog_expire(e->reflog, e->sha1, flags,
 593                                                 reflog_expiry_prepare,
 594                                                 should_expire_reflog_ent,
 595                                                 reflog_expiry_cleanup,
 596                                                 &cb);
 597                         free(e);
 598                 }
 599                 free(collected.e);
 600         }
 601
 602         for (; i < argc; i++) {
 603                 char *ref;
 604                 unsigned char sha1[20];
 605                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 606                         status |= error("%s points nowhere!", argv[i]);
 607                         continue;
 608                 }
 609                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 610                 status |= reflog_expire(ref, sha1, flags,
 611                                         reflog_expiry_prepare,
 612                                         should_expire_reflog_ent,
 613                                         reflog_expiry_cleanup,
 614                                         &cb);
 615         }
 616         return status;
 617 }
 618
 619 static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 620                 const char *email, timestamp_t timestamp, int tz,
 621                 const char *message, void *cb_data)
 622 {
 623         struct expire_reflog_policy_cb *cb = cb_data;
 624         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 625                 cb->cmd.recno++;
 626         return 0;
 627 }
 628
 629 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 630 {
 631         struct expire_reflog_policy_cb cb;
 632         int i, status = 0;
 633         unsigned int flags = 0;
 634
 635         memset(&cb, 0, sizeof(cb));
 636
 637         for (i = 1; i < argc; i++) {
 638                 const char *arg = argv[i];
 639                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 640                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 641                 else if (!strcmp(arg, "--rewrite"))
 642                         flags |= EXPIRE_REFLOGS_REWRITE;
 643                 else if (!strcmp(arg, "--updateref"))
 644                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 645                 else if (!strcmp(arg, "--verbose"))
 646                         flags |= EXPIRE_REFLOGS_VERBOSE;
 647                 else if (!strcmp(arg, "--")) {
 648                         i++;
 649                         break;
 650                 }
 651                 else if (arg[0] == '-')
 652                         usage(reflog_delete_usage);
 653                 else
 654                         break;
 655         }
 656
 657         if (argc - i < 1)
 658                 return error("Nothing to delete?");
 659
 660         for ( ; i < argc; i++) {
 661                 const char *spec = strstr(argv[i], "@{");
 662                 unsigned char sha1[20];
 663                 char *ep, *ref;
 664                 int recno;
 665
 666                 if (!spec) {
 667                         status |= error("Not a reflog: %s", argv[i]);
 668                         continue;
 669                 }
 670
 671                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 672                         status |= error("no reflog for '%s'", argv[i]);
 673                         continue;
 674                 }
 675
 676                 recno = strtoul(spec + 2, &ep, 10);
 677                 if (*ep == '}') {
 678                         cb.cmd.recno = -recno;
 679                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 680                 } else {
 681                         cb.cmd.expire_total = approxidate(spec + 2);
 682                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 683                         cb.cmd.expire_total = 0;
 684                 }
 685
 686                 status |= reflog_expire(ref, sha1, flags,
 687                                         reflog_expiry_prepare,
 688                                         should_expire_reflog_ent,
 689                                         reflog_expiry_cleanup,
 690                                         &cb);
 691                 free(ref);
 692         }
 693         return status;
 694 }
 695
 696 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 697 {
 698         int i, start = 0;
 699
 700         for (i = 1; i < argc; i++) {
 701                 const char *arg = argv[i];
 702                 if (!strcmp(arg, "--")) {
 703                         i++;
 704                         break;
 705                 }
 706                 else if (arg[0] == '-')
 707                         usage(reflog_exists_usage);
 708                 else
 709                         break;
 710         }
 711
 712         start = i;
 713
 714         if (argc - start != 1)
 715                 usage(reflog_exists_usage);
 716
 717         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 718                 die("invalid ref format: %s", argv[start]);
 719         return !reflog_exists(argv[start]);
 720 }
 721
 722 /*
 723  * main "reflog"
 724  */
 725
 726 static const char reflog_usage[] =
 727 "git reflog [ show | expire | delete | exists ]";
 728
 729 int cmd_reflog(int argc, const char **argv, const char *prefix)
 730 {
 731         if (argc > 1 && !strcmp(argv[1], "-h"))
 732                 usage(reflog_usage);
 733
 734         /* With no command, we default to showing it. */
 735         if (argc < 2 || *argv[1] == '-')
 736                 return cmd_log_reflog(argc, argv, prefix);
 737
 738         if (!strcmp(argv[1], "show"))
 739                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 740
 741         if (!strcmp(argv[1], "expire"))
 742                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 743
 744         if (!strcmp(argv[1], "delete"))
 745                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 746
 747         if (!strcmp(argv[1], "exists"))
 748                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 749
 750         return cmd_log_reflog(argc, argv, prefix);
 751 }