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

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "lockfile.h"
   4 #include "object-store.h"
   5 #include "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 #include "worktree.h"
  14
  15 /* NEEDSWORK: switch to using parse_options */
  16 static const char reflog_expire_usage[] =
  17 N_("git reflog expire [--expire=<time>] "
  18    "[--expire-unreachable=<time>] "
  19    "[--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] "
  20    "[--verbose] [--all] <refs>...");
  21 static const char reflog_delete_usage[] =
  22 N_("git reflog delete [--rewrite] [--updateref] "
  23    "[--dry-run | -n] [--verbose] <refs>...");
  24 static const char reflog_exists_usage[] =
  25 N_("git reflog exists <ref>");
  26
  27 static timestamp_t default_reflog_expire;
  28 static timestamp_t default_reflog_expire_unreachable;
  29
  30 struct cmd_reflog_expire_cb {
  31         struct rev_info revs;
  32         int stalefix;
  33         timestamp_t expire_total;
  34         timestamp_t expire_unreachable;
  35         int recno;
  36 };
  37
  38 struct expire_reflog_policy_cb {
  39         enum {
  40                 UE_NORMAL,
  41                 UE_ALWAYS,
  42                 UE_HEAD
  43         } unreachable_expire_kind;
  44         struct commit_list *mark_list;
  45         unsigned long mark_limit;
  46         struct cmd_reflog_expire_cb cmd;
  47         struct commit *tip_commit;
  48         struct commit_list *tips;
  49 };
  50
  51 struct collected_reflog {
  52         struct object_id oid;
  53         char reflog[FLEX_ARRAY];
  54 };
  55
  56 struct collect_reflog_cb {
  57         struct collected_reflog **e;
  58         int alloc;
  59         int nr;
  60         struct worktree *wt;
  61 };
  62
  63 /* Remember to update object flag allocation in object.h */
  64 #define INCOMPLETE      (1u<<10)
  65 #define STUDYING        (1u<<11)
  66 #define REACHABLE       (1u<<12)
  67
  68 static int tree_is_complete(const struct object_id *oid)
  69 {
  70         struct tree_desc desc;
  71         struct name_entry entry;
  72         int complete;
  73         struct tree *tree;
  74
  75         tree = lookup_tree(the_repository, oid);
  76         if (!tree)
  77                 return 0;
  78         if (tree->object.flags & SEEN)
  79                 return 1;
  80         if (tree->object.flags & INCOMPLETE)
  81                 return 0;
  82
  83         if (!tree->buffer) {
  84                 enum object_type type;
  85                 unsigned long size;
  86                 void *data = read_object_file(oid, &type, &size);
  87                 if (!data) {
  88                         tree->object.flags |= INCOMPLETE;
  89                         return 0;
  90                 }
  91                 tree->buffer = data;
  92                 tree->size = size;
  93         }
  94         init_tree_desc(&desc, tree->buffer, tree->size);
  95         complete = 1;
  96         while (tree_entry(&desc, &entry)) {
  97                 if (!has_object_file(&entry.oid) ||
  98                     (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
  99                         tree->object.flags |= INCOMPLETE;
 100                         complete = 0;
 101                 }
 102         }
 103         free_tree_buffer(tree);
 104
 105         if (complete)
 106                 tree->object.flags |= SEEN;
 107         return complete;
 108 }
 109
 110 static int commit_is_complete(struct commit *commit)
 111 {
 112         struct object_array study;
 113         struct object_array found;
 114         int is_incomplete = 0;
 115         int i;
 116
 117         /* early return */
 118         if (commit->object.flags & SEEN)
 119                 return 1;
 120         if (commit->object.flags & INCOMPLETE)
 121                 return 0;
 122         /*
 123          * Find all commits that are reachable and are not marked as
 124          * SEEN.  Then make sure the trees and blobs contained are
 125          * complete.  After that, mark these commits also as SEEN.
 126          * If some of the objects that are needed to complete this
 127          * commit are missing, mark this commit as INCOMPLETE.
 128          */
 129         memset(&study, 0, sizeof(study));
 130         memset(&found, 0, sizeof(found));
 131         add_object_array(&commit->object, NULL, &study);
 132         add_object_array(&commit->object, NULL, &found);
 133         commit->object.flags |= STUDYING;
 134         while (study.nr) {
 135                 struct commit *c;
 136                 struct commit_list *parent;
 137
 138                 c = (struct commit *)object_array_pop(&study);
 139                 if (!c->object.parsed && !parse_object(the_repository, &c->object.oid))
 140                         c->object.flags |= INCOMPLETE;
 141
 142                 if (c->object.flags & INCOMPLETE) {
 143                         is_incomplete = 1;
 144                         break;
 145                 }
 146                 else if (c->object.flags & SEEN)
 147                         continue;
 148                 for (parent = c->parents; parent; parent = parent->next) {
 149                         struct commit *p = parent->item;
 150                         if (p->object.flags & STUDYING)
 151                                 continue;
 152                         p->object.flags |= STUDYING;
 153                         add_object_array(&p->object, NULL, &study);
 154                         add_object_array(&p->object, NULL, &found);
 155                 }
 156         }
 157         if (!is_incomplete) {
 158                 /*
 159                  * make sure all commits in "found" array have all the
 160                  * necessary objects.
 161                  */
 162                 for (i = 0; i < found.nr; i++) {
 163                         struct commit *c =
 164                                 (struct commit *)found.objects[i].item;
 165                         if (!tree_is_complete(get_commit_tree_oid(c))) {
 166                                 is_incomplete = 1;
 167                                 c->object.flags |= INCOMPLETE;
 168                         }
 169                 }
 170                 if (!is_incomplete) {
 171                         /* mark all found commits as complete, iow SEEN */
 172                         for (i = 0; i < found.nr; i++)
 173                                 found.objects[i].item->flags |= SEEN;
 174                 }
 175         }
 176         /* clear flags from the objects we traversed */
 177         for (i = 0; i < found.nr; i++)
 178                 found.objects[i].item->flags &= ~STUDYING;
 179         if (is_incomplete)
 180                 commit->object.flags |= INCOMPLETE;
 181         else {
 182                 /*
 183                  * If we come here, we have (1) traversed the ancestry chain
 184                  * from the "commit" until we reach SEEN commits (which are
 185                  * known to be complete), and (2) made sure that the commits
 186                  * encountered during the above traversal refer to trees that
 187                  * are complete.  Which means that we know *all* the commits
 188                  * we have seen during this process are complete.
 189                  */
 190                 for (i = 0; i < found.nr; i++)
 191                         found.objects[i].item->flags |= SEEN;
 192         }
 193         /* free object arrays */
 194         object_array_clear(&study);
 195         object_array_clear(&found);
 196         return !is_incomplete;
 197 }
 198
 199 static int keep_entry(struct commit **it, struct object_id *oid)
 200 {
 201         struct commit *commit;
 202
 203         if (is_null_oid(oid))
 204                 return 1;
 205         commit = lookup_commit_reference_gently(the_repository, oid, 1);
 206         if (!commit)
 207                 return 0;
 208
 209         /*
 210          * Make sure everything in this commit exists.
 211          *
 212          * We have walked all the objects reachable from the refs
 213          * and cache earlier.  The commits reachable by this commit
 214          * must meet SEEN commits -- and then we should mark them as
 215          * SEEN as well.
 216          */
 217         if (!commit_is_complete(commit))
 218                 return 0;
 219         *it = commit;
 220         return 1;
 221 }
 222
 223 /*
 224  * Starting from commits in the cb->mark_list, mark commits that are
 225  * reachable from them.  Stop the traversal at commits older than
 226  * the expire_limit and queue them back, so that the caller can call
 227  * us again to restart the traversal with longer expire_limit.
 228  */
 229 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 230 {
 231         struct commit_list *pending;
 232         timestamp_t expire_limit = cb->mark_limit;
 233         struct commit_list *leftover = NULL;
 234
 235         for (pending = cb->mark_list; pending; pending = pending->next)
 236                 pending->item->object.flags &= ~REACHABLE;
 237
 238         pending = cb->mark_list;
 239         while (pending) {
 240                 struct commit_list *parent;
 241                 struct commit *commit = pop_commit(&pending);
 242                 if (commit->object.flags & REACHABLE)
 243                         continue;
 244                 if (parse_commit(commit))
 245                         continue;
 246                 commit->object.flags |= REACHABLE;
 247                 if (commit->date < expire_limit) {
 248                         commit_list_insert(commit, &leftover);
 249                         continue;
 250                 }
 251                 commit->object.flags |= REACHABLE;
 252                 parent = commit->parents;
 253                 while (parent) {
 254                         commit = parent->item;
 255                         parent = parent->next;
 256                         if (commit->object.flags & REACHABLE)
 257                                 continue;
 258                         commit_list_insert(commit, &pending);
 259                 }
 260         }
 261         cb->mark_list = leftover;
 262 }
 263
 264 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 265 {
 266         /*
 267          * We may or may not have the commit yet - if not, look it
 268          * up using the supplied sha1.
 269          */
 270         if (!commit) {
 271                 if (is_null_oid(oid))
 272                         return 0;
 273
 274                 commit = lookup_commit_reference_gently(the_repository, oid,
 275                                                         1);
 276
 277                 /* Not a commit -- keep it */
 278                 if (!commit)
 279                         return 0;
 280         }
 281
 282         /* Reachable from the current ref?  Don't prune. */
 283         if (commit->object.flags & REACHABLE)
 284                 return 0;
 285
 286         if (cb->mark_list && cb->mark_limit) {
 287                 cb->mark_limit = 0; /* dig down to the root */
 288                 mark_reachable(cb);
 289         }
 290
 291         return !(commit->object.flags & REACHABLE);
 292 }
 293
 294 /*
 295  * Return true iff the specified reflog entry should be expired.
 296  */
 297 static int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 298                                     const char *email, timestamp_t timestamp, int tz,
 299                                     const char *message, void *cb_data)
 300 {
 301         struct expire_reflog_policy_cb *cb = cb_data;
 302         struct commit *old_commit, *new_commit;
 303
 304         if (timestamp < cb->cmd.expire_total)
 305                 return 1;
 306
 307         old_commit = new_commit = NULL;
 308         if (cb->cmd.stalefix &&
 309             (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
 310                 return 1;
 311
 312         if (timestamp < cb->cmd.expire_unreachable) {
 313                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 314                         return 1;
 315                 if (unreachable(cb, old_commit, ooid) || unreachable(cb, new_commit, noid))
 316                         return 1;
 317         }
 318
 319         if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 320                 return 1;
 321
 322         return 0;
 323 }
 324
 325 static int push_tip_to_list(const char *refname, const struct object_id *oid,
 326                             int flags, void *cb_data)
 327 {
 328         struct commit_list **list = cb_data;
 329         struct commit *tip_commit;
 330         if (flags & REF_ISSYMREF)
 331                 return 0;
 332         tip_commit = lookup_commit_reference_gently(the_repository, oid, 1);
 333         if (!tip_commit)
 334                 return 0;
 335         commit_list_insert(tip_commit, list);
 336         return 0;
 337 }
 338
 339 static int is_head(const char *refname)
 340 {
 341         switch (ref_type(refname)) {
 342         case REF_TYPE_OTHER_PSEUDOREF:
 343         case REF_TYPE_MAIN_PSEUDOREF:
 344                 if (parse_worktree_ref(refname, NULL, NULL, &refname))
 345                         BUG("not a worktree ref: %s", refname);
 346                 break;
 347         default:
 348                 break;
 349         }
 350         return !strcmp(refname, "HEAD");
 351 }
 352
 353 static void reflog_expiry_prepare(const char *refname,
 354                                   const struct object_id *oid,
 355                                   void *cb_data)
 356 {
 357         struct expire_reflog_policy_cb *cb = cb_data;
 358
 359         if (!cb->cmd.expire_unreachable || is_head(refname)) {
 360                 cb->tip_commit = NULL;
 361                 cb->unreachable_expire_kind = UE_HEAD;
 362         } else {
 363                 cb->tip_commit = lookup_commit_reference_gently(the_repository,
 364                                                                 oid, 1);
 365                 if (!cb->tip_commit)
 366                         cb->unreachable_expire_kind = UE_ALWAYS;
 367                 else
 368                         cb->unreachable_expire_kind = UE_NORMAL;
 369         }
 370
 371         if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 372                 cb->unreachable_expire_kind = UE_ALWAYS;
 373
 374         cb->mark_list = NULL;
 375         cb->tips = NULL;
 376         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 377                 if (cb->unreachable_expire_kind == UE_HEAD) {
 378                         struct commit_list *elem;
 379
 380                         for_each_ref(push_tip_to_list, &cb->tips);
 381                         for (elem = cb->tips; elem; elem = elem->next)
 382                                 commit_list_insert(elem->item, &cb->mark_list);
 383                 } else {
 384                         commit_list_insert(cb->tip_commit, &cb->mark_list);
 385                 }
 386                 cb->mark_limit = cb->cmd.expire_total;
 387                 mark_reachable(cb);
 388         }
 389 }
 390
 391 static void reflog_expiry_cleanup(void *cb_data)
 392 {
 393         struct expire_reflog_policy_cb *cb = cb_data;
 394
 395         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 396                 if (cb->unreachable_expire_kind == UE_HEAD) {
 397                         struct commit_list *elem;
 398                         for (elem = cb->tips; elem; elem = elem->next)
 399                                 clear_commit_marks(elem->item, REACHABLE);
 400                         free_commit_list(cb->tips);
 401                 } else {
 402                         clear_commit_marks(cb->tip_commit, REACHABLE);
 403                 }
 404         }
 405 }
 406
 407 static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 408 {
 409         struct collected_reflog *e;
 410         struct collect_reflog_cb *cb = cb_data;
 411         struct strbuf newref = STRBUF_INIT;
 412
 413         /*
 414          * Avoid collecting the same shared ref multiple times because
 415          * they are available via all worktrees.
 416          */
 417         if (!cb->wt->is_current && ref_type(ref) == REF_TYPE_NORMAL)
 418                 return 0;
 419
 420         strbuf_worktree_ref(cb->wt, &newref, ref);
 421         FLEX_ALLOC_STR(e, reflog, newref.buf);
 422         strbuf_release(&newref);
 423
 424         oidcpy(&e->oid, oid);
 425         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 426         cb->e[cb->nr++] = e;
 427         return 0;
 428 }
 429
 430 static struct reflog_expire_cfg {
 431         struct reflog_expire_cfg *next;
 432         timestamp_t expire_total;
 433         timestamp_t expire_unreachable;
 434         char pattern[FLEX_ARRAY];
 435 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 436
 437 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 438 {
 439         struct reflog_expire_cfg *ent;
 440
 441         if (!reflog_expire_cfg_tail)
 442                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 443
 444         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 445                 if (!strncmp(ent->pattern, pattern, len) &&
 446                     ent->pattern[len] == '\0')
 447                         return ent;
 448
 449         FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 450         *reflog_expire_cfg_tail = ent;
 451         reflog_expire_cfg_tail = &(ent->next);
 452         return ent;
 453 }
 454
 455 /* expiry timer slot */
 456 #define EXPIRE_TOTAL   01
 457 #define EXPIRE_UNREACH 02
 458
 459 static int reflog_expire_config(const char *var, const char *value, void *cb)
 460 {
 461         const char *pattern, *key;
 462         size_t pattern_len;
 463         timestamp_t expire;
 464         int slot;
 465         struct reflog_expire_cfg *ent;
 466
 467         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 468                 return git_default_config(var, value, cb);
 469
 470         if (!strcmp(key, "reflogexpire")) {
 471                 slot = EXPIRE_TOTAL;
 472                 if (git_config_expiry_date(&expire, var, value))
 473                         return -1;
 474         } else if (!strcmp(key, "reflogexpireunreachable")) {
 475                 slot = EXPIRE_UNREACH;
 476                 if (git_config_expiry_date(&expire, var, value))
 477                         return -1;
 478         } else
 479                 return git_default_config(var, value, cb);
 480
 481         if (!pattern) {
 482                 switch (slot) {
 483                 case EXPIRE_TOTAL:
 484                         default_reflog_expire = expire;
 485                         break;
 486                 case EXPIRE_UNREACH:
 487                         default_reflog_expire_unreachable = expire;
 488                         break;
 489                 }
 490                 return 0;
 491         }
 492
 493         ent = find_cfg_ent(pattern, pattern_len);
 494         if (!ent)
 495                 return -1;
 496         switch (slot) {
 497         case EXPIRE_TOTAL:
 498                 ent->expire_total = expire;
 499                 break;
 500         case EXPIRE_UNREACH:
 501                 ent->expire_unreachable = expire;
 502                 break;
 503         }
 504         return 0;
 505 }
 506
 507 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 508 {
 509         struct reflog_expire_cfg *ent;
 510
 511         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 512                 return; /* both given explicitly -- nothing to tweak */
 513
 514         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 515                 if (!wildmatch(ent->pattern, ref, 0)) {
 516                         if (!(slot & EXPIRE_TOTAL))
 517                                 cb->expire_total = ent->expire_total;
 518                         if (!(slot & EXPIRE_UNREACH))
 519                                 cb->expire_unreachable = ent->expire_unreachable;
 520                         return;
 521                 }
 522         }
 523
 524         /*
 525          * If unconfigured, make stash never expire
 526          */
 527         if (!strcmp(ref, "refs/stash")) {
 528                 if (!(slot & EXPIRE_TOTAL))
 529                         cb->expire_total = 0;
 530                 if (!(slot & EXPIRE_UNREACH))
 531                         cb->expire_unreachable = 0;
 532                 return;
 533         }
 534
 535         /* Nothing matched -- use the default value */
 536         if (!(slot & EXPIRE_TOTAL))
 537                 cb->expire_total = default_reflog_expire;
 538         if (!(slot & EXPIRE_UNREACH))
 539                 cb->expire_unreachable = default_reflog_expire_unreachable;
 540 }
 541
 542 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 543 {
 544         struct expire_reflog_policy_cb cb;
 545         timestamp_t now = time(NULL);
 546         int i, status, do_all, all_worktrees = 1;
 547         int explicit_expiry = 0;
 548         unsigned int flags = 0;
 549
 550         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 551         default_reflog_expire = now - 90 * 24 * 3600;
 552         git_config(reflog_expire_config, NULL);
 553
 554         save_commit_buffer = 0;
 555         do_all = status = 0;
 556         memset(&cb, 0, sizeof(cb));
 557
 558         cb.cmd.expire_total = default_reflog_expire;
 559         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 560
 561         for (i = 1; i < argc; i++) {
 562                 const char *arg = argv[i];
 563
 564                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 565                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 566                 else if (skip_prefix(arg, "--expire=", &arg)) {
 567                         if (parse_expiry_date(arg, &cb.cmd.expire_total))
 568                                 die(_("'%s' is not a valid timestamp"), arg);
 569                         explicit_expiry |= EXPIRE_TOTAL;
 570                 }
 571                 else if (skip_prefix(arg, "--expire-unreachable=", &arg)) {
 572                         if (parse_expiry_date(arg, &cb.cmd.expire_unreachable))
 573                                 die(_("'%s' is not a valid timestamp"), arg);
 574                         explicit_expiry |= EXPIRE_UNREACH;
 575                 }
 576                 else if (!strcmp(arg, "--stale-fix"))
 577                         cb.cmd.stalefix = 1;
 578                 else if (!strcmp(arg, "--rewrite"))
 579                         flags |= EXPIRE_REFLOGS_REWRITE;
 580                 else if (!strcmp(arg, "--updateref"))
 581                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 582                 else if (!strcmp(arg, "--all"))
 583                         do_all = 1;
 584                 else if (!strcmp(arg, "--single-worktree"))
 585                         all_worktrees = 0;
 586                 else if (!strcmp(arg, "--verbose"))
 587                         flags |= EXPIRE_REFLOGS_VERBOSE;
 588                 else if (!strcmp(arg, "--")) {
 589                         i++;
 590                         break;
 591                 }
 592                 else if (arg[0] == '-')
 593                         usage(_(reflog_expire_usage));
 594                 else
 595                         break;
 596         }
 597
 598         /*
 599          * We can trust the commits and objects reachable from refs
 600          * even in older repository.  We cannot trust what's reachable
 601          * from reflog if the repository was pruned with older git.
 602          */
 603         if (cb.cmd.stalefix) {
 604                 repo_init_revisions(the_repository, &cb.cmd.revs, prefix);
 605                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 606                         printf(_("Marking reachable objects..."));
 607                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 608                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 609                         putchar('\n');
 610         }
 611
 612         if (do_all) {
 613                 struct collect_reflog_cb collected;
 614                 struct worktree **worktrees, **p;
 615                 int i;
 616
 617                 memset(&collected, 0, sizeof(collected));
 618                 worktrees = get_worktrees(0);
 619                 for (p = worktrees; *p; p++) {
 620                         if (!all_worktrees && !(*p)->is_current)
 621                                 continue;
 622                         collected.wt = *p;
 623                         refs_for_each_reflog(get_worktree_ref_store(*p),
 624                                              collect_reflog, &collected);
 625                 }
 626                 free_worktrees(worktrees);
 627                 for (i = 0; i < collected.nr; i++) {
 628                         struct collected_reflog *e = collected.e[i];
 629                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 630                         status |= reflog_expire(e->reflog, &e->oid, flags,
 631                                                 reflog_expiry_prepare,
 632                                                 should_expire_reflog_ent,
 633                                                 reflog_expiry_cleanup,
 634                                                 &cb);
 635                         free(e);
 636                 }
 637                 free(collected.e);
 638         }
 639
 640         for (; i < argc; i++) {
 641                 char *ref;
 642                 struct object_id oid;
 643                 if (!dwim_log(argv[i], strlen(argv[i]), &oid, &ref)) {
 644                         status |= error(_("%s points nowhere!"), argv[i]);
 645                         continue;
 646                 }
 647                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 648                 status |= reflog_expire(ref, &oid, flags,
 649                                         reflog_expiry_prepare,
 650                                         should_expire_reflog_ent,
 651                                         reflog_expiry_cleanup,
 652                                         &cb);
 653         }
 654         return status;
 655 }
 656
 657 static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 658                 const char *email, timestamp_t timestamp, int tz,
 659                 const char *message, void *cb_data)
 660 {
 661         struct expire_reflog_policy_cb *cb = cb_data;
 662         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 663                 cb->cmd.recno++;
 664         return 0;
 665 }
 666
 667 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 668 {
 669         struct expire_reflog_policy_cb cb;
 670         int i, status = 0;
 671         unsigned int flags = 0;
 672
 673         memset(&cb, 0, sizeof(cb));
 674
 675         for (i = 1; i < argc; i++) {
 676                 const char *arg = argv[i];
 677                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 678                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 679                 else if (!strcmp(arg, "--rewrite"))
 680                         flags |= EXPIRE_REFLOGS_REWRITE;
 681                 else if (!strcmp(arg, "--updateref"))
 682                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 683                 else if (!strcmp(arg, "--verbose"))
 684                         flags |= EXPIRE_REFLOGS_VERBOSE;
 685                 else if (!strcmp(arg, "--")) {
 686                         i++;
 687                         break;
 688                 }
 689                 else if (arg[0] == '-')
 690                         usage(_(reflog_delete_usage));
 691                 else
 692                         break;
 693         }
 694
 695         if (argc - i < 1)
 696                 return error(_("no reflog specified to delete"));
 697
 698         for ( ; i < argc; i++) {
 699                 const char *spec = strstr(argv[i], "@{");
 700                 struct object_id oid;
 701                 char *ep, *ref;
 702                 int recno;
 703
 704                 if (!spec) {
 705                         status |= error(_("not a reflog: %s"), argv[i]);
 706                         continue;
 707                 }
 708
 709                 if (!dwim_log(argv[i], spec - argv[i], &oid, &ref)) {
 710                         status |= error(_("no reflog for '%s'"), argv[i]);
 711                         continue;
 712                 }
 713
 714                 recno = strtoul(spec + 2, &ep, 10);
 715                 if (*ep == '}') {
 716                         cb.cmd.recno = -recno;
 717                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 718                 } else {
 719                         cb.cmd.expire_total = approxidate(spec + 2);
 720                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 721                         cb.cmd.expire_total = 0;
 722                 }
 723
 724                 status |= reflog_expire(ref, &oid, flags,
 725                                         reflog_expiry_prepare,
 726                                         should_expire_reflog_ent,
 727                                         reflog_expiry_cleanup,
 728                                         &cb);
 729                 free(ref);
 730         }
 731         return status;
 732 }
 733
 734 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 735 {
 736         int i, start = 0;
 737
 738         for (i = 1; i < argc; i++) {
 739                 const char *arg = argv[i];
 740                 if (!strcmp(arg, "--")) {
 741                         i++;
 742                         break;
 743                 }
 744                 else if (arg[0] == '-')
 745                         usage(_(reflog_exists_usage));
 746                 else
 747                         break;
 748         }
 749
 750         start = i;
 751
 752         if (argc - start != 1)
 753                 usage(_(reflog_exists_usage));
 754
 755         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 756                 die(_("invalid ref format: %s"), argv[start]);
 757         return !reflog_exists(argv[start]);
 758 }
 759
 760 /*
 761  * main "reflog"
 762  */
 763
 764 static const char reflog_usage[] =
 765 N_("git reflog [ show | expire | delete | exists ]");
 766
 767 int cmd_reflog(int argc, const char **argv, const char *prefix)
 768 {
 769         if (argc > 1 && !strcmp(argv[1], "-h"))
 770                 usage(_(reflog_usage));
 771
 772         /* With no command, we default to showing it. */
 773         if (argc < 2 || *argv[1] == '-')
 774                 return cmd_log_reflog(argc, argv, prefix);
 775
 776         if (!strcmp(argv[1], "show"))
 777                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 778
 779         if (!strcmp(argv[1], "expire"))
 780                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 781
 782         if (!strcmp(argv[1], "delete"))
 783                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 784
 785         if (!strcmp(argv[1], "exists"))
 786                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 787
 788         return cmd_log_reflog(argc, argv, prefix);
 789 }