builtin-reflog.c

   1 #include "cache.h"
   2 #include "builtin.h"
   3 #include "commit.h"
   4 #include "refs.h"
   5 #include "dir.h"
   6 #include "tree-walk.h"
   7 #include "diff.h"
   8 #include "revision.h"
   9 #include "reachable.h"
  10
  11 /*
  12  * reflog expire
  13  */
  14
  15 static const char reflog_expire_usage[] =
  16 "git reflog (show|expire) [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
  17 static const char reflog_delete_usage[] =
  18 "git reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
  19
  20 static unsigned long default_reflog_expire;
  21 static unsigned long default_reflog_expire_unreachable;
  22
  23 struct cmd_reflog_expire_cb {
  24         struct rev_info revs;
  25         int dry_run;
  26         int stalefix;
  27         int rewrite;
  28         int updateref;
  29         int verbose;
  30         unsigned long expire_total;
  31         unsigned long expire_unreachable;
  32         int recno;
  33 };
  34
  35 struct expire_reflog_cb {
  36         FILE *newlog;
  37         const char *ref;
  38         struct commit *ref_commit;
  39         struct cmd_reflog_expire_cb *cmd;
  40         unsigned char last_kept_sha1[20];
  41 };
  42
  43 struct collected_reflog {
  44         unsigned char sha1[20];
  45         char reflog[FLEX_ARRAY];
  46 };
  47 struct collect_reflog_cb {
  48         struct collected_reflog **e;
  49         int alloc;
  50         int nr;
  51 };
  52
  53 #define INCOMPLETE      (1u<<10)
  54 #define STUDYING        (1u<<11)
  55 #define REACHABLE       (1u<<12)
  56
  57 static int tree_is_complete(const unsigned char *sha1)
  58 {
  59         struct tree_desc desc;
  60         struct name_entry entry;
  61         int complete;
  62         struct tree *tree;
  63
  64         tree = lookup_tree(sha1);
  65         if (!tree)
  66                 return 0;
  67         if (tree->object.flags & SEEN)
  68                 return 1;
  69         if (tree->object.flags & INCOMPLETE)
  70                 return 0;
  71
  72         if (!tree->buffer) {
  73                 enum object_type type;
  74                 unsigned long size;
  75                 void *data = read_sha1_file(sha1, &type, &size);
  76                 if (!data) {
  77                         tree->object.flags |= INCOMPLETE;
  78                         return 0;
  79                 }
  80                 tree->buffer = data;
  81                 tree->size = size;
  82         }
  83         init_tree_desc(&desc, tree->buffer, tree->size);
  84         complete = 1;
  85         while (tree_entry(&desc, &entry)) {
  86                 if (!has_sha1_file(entry.sha1) ||
  87                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  88                         tree->object.flags |= INCOMPLETE;
  89                         complete = 0;
  90                 }
  91         }
  92         free(tree->buffer);
  93         tree->buffer = NULL;
  94
  95         if (complete)
  96                 tree->object.flags |= SEEN;
  97         return complete;
  98 }
  99
 100 static int commit_is_complete(struct commit *commit)
 101 {
 102         struct object_array study;
 103         struct object_array found;
 104         int is_incomplete = 0;
 105         int i;
 106
 107         /* early return */
 108         if (commit->object.flags & SEEN)
 109                 return 1;
 110         if (commit->object.flags & INCOMPLETE)
 111                 return 0;
 112         /*
 113          * Find all commits that are reachable and are not marked as
 114          * SEEN.  Then make sure the trees and blobs contained are
 115          * complete.  After that, mark these commits also as SEEN.
 116          * If some of the objects that are needed to complete this
 117          * commit are missing, mark this commit as INCOMPLETE.
 118          */
 119         memset(&study, 0, sizeof(study));
 120         memset(&found, 0, sizeof(found));
 121         add_object_array(&commit->object, NULL, &study);
 122         add_object_array(&commit->object, NULL, &found);
 123         commit->object.flags |= STUDYING;
 124         while (study.nr) {
 125                 struct commit *c;
 126                 struct commit_list *parent;
 127
 128                 c = (struct commit *)study.objects[--study.nr].item;
 129                 if (!c->object.parsed && !parse_object(c->object.sha1))
 130                         c->object.flags |= INCOMPLETE;
 131
 132                 if (c->object.flags & INCOMPLETE) {
 133                         is_incomplete = 1;
 134                         break;
 135                 }
 136                 else if (c->object.flags & SEEN)
 137                         continue;
 138                 for (parent = c->parents; parent; parent = parent->next) {
 139                         struct commit *p = parent->item;
 140                         if (p->object.flags & STUDYING)
 141                                 continue;
 142                         p->object.flags |= STUDYING;
 143                         add_object_array(&p->object, NULL, &study);
 144                         add_object_array(&p->object, NULL, &found);
 145                 }
 146         }
 147         if (!is_incomplete) {
 148                 /*
 149                  * make sure all commits in "found" array have all the
 150                  * necessary objects.
 151                  */
 152                 for (i = 0; i < found.nr; i++) {
 153                         struct commit *c =
 154                                 (struct commit *)found.objects[i].item;
 155                         if (!tree_is_complete(c->tree->object.sha1)) {
 156                                 is_incomplete = 1;
 157                                 c->object.flags |= INCOMPLETE;
 158                         }
 159                 }
 160                 if (!is_incomplete) {
 161                         /* mark all found commits as complete, iow SEEN */
 162                         for (i = 0; i < found.nr; i++)
 163                                 found.objects[i].item->flags |= SEEN;
 164                 }
 165         }
 166         /* clear flags from the objects we traversed */
 167         for (i = 0; i < found.nr; i++)
 168                 found.objects[i].item->flags &= ~STUDYING;
 169         if (is_incomplete)
 170                 commit->object.flags |= INCOMPLETE;
 171         else {
 172                 /*
 173                  * If we come here, we have (1) traversed the ancestry chain
 174                  * from the "commit" until we reach SEEN commits (which are
 175                  * known to be complete), and (2) made sure that the commits
 176                  * encountered during the above traversal refer to trees that
 177                  * are complete.  Which means that we know *all* the commits
 178                  * we have seen during this process are complete.
 179                  */
 180                 for (i = 0; i < found.nr; i++)
 181                         found.objects[i].item->flags |= SEEN;
 182         }
 183         /* free object arrays */
 184         free(study.objects);
 185         free(found.objects);
 186         return !is_incomplete;
 187 }
 188
 189 static int keep_entry(struct commit **it, unsigned char *sha1)
 190 {
 191         struct commit *commit;
 192
 193         if (is_null_sha1(sha1))
 194                 return 1;
 195         commit = lookup_commit_reference_gently(sha1, 1);
 196         if (!commit)
 197                 return 0;
 198
 199         /*
 200          * Make sure everything in this commit exists.
 201          *
 202          * We have walked all the objects reachable from the refs
 203          * and cache earlier.  The commits reachable by this commit
 204          * must meet SEEN commits -- and then we should mark them as
 205          * SEEN as well.
 206          */
 207         if (!commit_is_complete(commit))
 208                 return 0;
 209         *it = commit;
 210         return 1;
 211 }
 212
 213 static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
 214 {
 215         /*
 216          * We may or may not have the commit yet - if not, look it
 217          * up using the supplied sha1.
 218          */
 219         if (!commit) {
 220                 if (is_null_sha1(sha1))
 221                         return 0;
 222
 223                 commit = lookup_commit_reference_gently(sha1, 1);
 224
 225                 /* Not a commit -- keep it */
 226                 if (!commit)
 227                         return 0;
 228         }
 229
 230         /* Reachable from the current ref?  Don't prune. */
 231         if (commit->object.flags & REACHABLE)
 232                 return 0;
 233         if (in_merge_bases(commit, &cb->ref_commit, 1))
 234                 return 0;
 235
 236         /* We can't reach it - prune it. */
 237         return 1;
 238 }
 239
 240 static void mark_reachable(struct commit *commit, unsigned long expire_limit)
 241 {
 242         /*
 243          * We need to compute whether the commit on either side of a reflog
 244          * entry is reachable from the tip of the ref for all entries.
 245          * Mark commits that are reachable from the tip down to the
 246          * time threshold first; we know a commit marked thusly is
 247          * reachable from the tip without running in_merge_bases()
 248          * at all.
 249          */
 250         struct commit_list *pending = NULL;
 251
 252         commit_list_insert(commit, &pending);
 253         while (pending) {
 254                 struct commit_list *entry = pending;
 255                 struct commit_list *parent;
 256                 pending = entry->next;
 257                 commit = entry->item;
 258                 free(entry);
 259                 if (commit->object.flags & REACHABLE)
 260                         continue;
 261                 if (parse_commit(commit))
 262                         continue;
 263                 commit->object.flags |= REACHABLE;
 264                 if (commit->date < expire_limit)
 265                         continue;
 266                 parent = commit->parents;
 267                 while (parent) {
 268                         commit = parent->item;
 269                         parent = parent->next;
 270                         if (commit->object.flags & REACHABLE)
 271                                 continue;
 272                         commit_list_insert(commit, &pending);
 273                 }
 274         }
 275 }
 276
 277 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 278                 const char *email, unsigned long timestamp, int tz,
 279                 const char *message, void *cb_data)
 280 {
 281         struct expire_reflog_cb *cb = cb_data;
 282         struct commit *old, *new;
 283
 284         if (timestamp < cb->cmd->expire_total)
 285                 goto prune;
 286
 287         if (cb->cmd->rewrite)
 288                 osha1 = cb->last_kept_sha1;
 289
 290         old = new = NULL;
 291         if (cb->cmd->stalefix &&
 292             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 293                 goto prune;
 294
 295         if (timestamp < cb->cmd->expire_unreachable) {
 296                 if (!cb->ref_commit)
 297                         goto prune;
 298                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 299                         goto prune;
 300         }
 301
 302         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 303                 goto prune;
 304
 305         if (cb->newlog) {
 306                 char sign = (tz < 0) ? '-' : '+';
 307                 int zone = (tz < 0) ? (-tz) : tz;
 308                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 309                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 310                         email, timestamp, sign, zone,
 311                         message);
 312                 hashcpy(cb->last_kept_sha1, nsha1);
 313         }
 314         if (cb->cmd->verbose)
 315                 printf("keep %s", message);
 316         return 0;
 317  prune:
 318         if (!cb->newlog || cb->cmd->verbose)
 319                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 320         return 0;
 321 }
 322
 323 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 324 {
 325         struct cmd_reflog_expire_cb *cmd = cb_data;
 326         struct expire_reflog_cb cb;
 327         struct ref_lock *lock;
 328         char *log_file, *newlog_path = NULL;
 329         int status = 0;
 330
 331         memset(&cb, 0, sizeof(cb));
 332
 333         /*
 334          * we take the lock for the ref itself to prevent it from
 335          * getting updated.
 336          */
 337         lock = lock_any_ref_for_update(ref, sha1, 0);
 338         if (!lock)
 339                 return error("cannot lock ref '%s'", ref);
 340         log_file = git_pathdup("logs/%s", ref);
 341         if (!file_exists(log_file))
 342                 goto finish;
 343         if (!cmd->dry_run) {
 344                 newlog_path = git_pathdup("logs/%s.lock", ref);
 345                 cb.newlog = fopen(newlog_path, "w");
 346         }
 347
 348         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 349         cb.ref = ref;
 350         cb.cmd = cmd;
 351         if (cb.ref_commit)
 352                 mark_reachable(cb.ref_commit, cmd->expire_total);
 353         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 354         if (cb.ref_commit)
 355                 clear_commit_marks(cb.ref_commit, REACHABLE);
 356  finish:
 357         if (cb.newlog) {
 358                 if (fclose(cb.newlog)) {
 359                         status |= error("%s: %s", strerror(errno),
 360                                         newlog_path);
 361                         unlink(newlog_path);
 362                 } else if (cmd->updateref &&
 363                         (write_in_full(lock->lock_fd,
 364                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 365                          write_str_in_full(lock->lock_fd, "\n") != 1 ||
 366                          close_ref(lock) < 0)) {
 367                         status |= error("Couldn't write %s",
 368                                 lock->lk->filename);
 369                         unlink(newlog_path);
 370                 } else if (rename(newlog_path, log_file)) {
 371                         status |= error("cannot rename %s to %s",
 372                                         newlog_path, log_file);
 373                         unlink(newlog_path);
 374                 } else if (cmd->updateref && commit_ref(lock)) {
 375                         status |= error("Couldn't set %s", lock->ref_name);
 376                 } else {
 377                         adjust_shared_perm(log_file);
 378                 }
 379         }
 380         free(newlog_path);
 381         free(log_file);
 382         unlock_ref(lock);
 383         return status;
 384 }
 385
 386 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 387 {
 388         struct collected_reflog *e;
 389         struct collect_reflog_cb *cb = cb_data;
 390         size_t namelen = strlen(ref);
 391
 392         e = xmalloc(sizeof(*e) + namelen + 1);
 393         hashcpy(e->sha1, sha1);
 394         memcpy(e->reflog, ref, namelen + 1);
 395         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 396         cb->e[cb->nr++] = e;
 397         return 0;
 398 }
 399
 400 static struct reflog_expire_cfg {
 401         struct reflog_expire_cfg *next;
 402         unsigned long expire_total;
 403         unsigned long expire_unreachable;
 404         size_t len;
 405         char pattern[FLEX_ARRAY];
 406 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 407
 408 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 409 {
 410         struct reflog_expire_cfg *ent;
 411
 412         if (!reflog_expire_cfg_tail)
 413                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 414
 415         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 416                 if (ent->len == len &&
 417                     !memcmp(ent->pattern, pattern, len))
 418                         return ent;
 419
 420         ent = xcalloc(1, (sizeof(*ent) + len));
 421         memcpy(ent->pattern, pattern, len);
 422         ent->len = len;
 423         *reflog_expire_cfg_tail = ent;
 424         reflog_expire_cfg_tail = &(ent->next);
 425         return ent;
 426 }
 427
 428 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 429 {
 430         if (!value)
 431                 return config_error_nonbool(var);
 432         if (!strcmp(value, "never") || !strcmp(value, "false")) {
 433                 *expire = 0;
 434                 return 0;
 435         }
 436         *expire = approxidate(value);
 437         return 0;
 438 }
 439
 440 /* expiry timer slot */
 441 #define EXPIRE_TOTAL   01
 442 #define EXPIRE_UNREACH 02
 443
 444 static int reflog_expire_config(const char *var, const char *value, void *cb)
 445 {
 446         const char *lastdot = strrchr(var, '.');
 447         unsigned long expire;
 448         int slot;
 449         struct reflog_expire_cfg *ent;
 450
 451         if (!lastdot || prefixcmp(var, "gc."))
 452                 return git_default_config(var, value, cb);
 453
 454         if (!strcmp(lastdot, ".reflogexpire")) {
 455                 slot = EXPIRE_TOTAL;
 456                 if (parse_expire_cfg_value(var, value, &expire))
 457                         return -1;
 458         } else if (!strcmp(lastdot, ".reflogexpireunreachable")) {
 459                 slot = EXPIRE_UNREACH;
 460                 if (parse_expire_cfg_value(var, value, &expire))
 461                         return -1;
 462         } else
 463                 return git_default_config(var, value, cb);
 464
 465         if (lastdot == var + 2) {
 466                 switch (slot) {
 467                 case EXPIRE_TOTAL:
 468                         default_reflog_expire = expire;
 469                         break;
 470                 case EXPIRE_UNREACH:
 471                         default_reflog_expire_unreachable = expire;
 472                         break;
 473                 }
 474                 return 0;
 475         }
 476
 477         ent = find_cfg_ent(var + 3, lastdot - (var+3));
 478         if (!ent)
 479                 return -1;
 480         switch (slot) {
 481         case EXPIRE_TOTAL:
 482                 ent->expire_total = expire;
 483                 break;
 484         case EXPIRE_UNREACH:
 485                 ent->expire_unreachable = expire;
 486                 break;
 487         }
 488         return 0;
 489 }
 490
 491 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 492 {
 493         struct reflog_expire_cfg *ent;
 494
 495         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 496                 return; /* both given explicitly -- nothing to tweak */
 497
 498         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 499                 if (!fnmatch(ent->pattern, ref, 0)) {
 500                         if (!(slot & EXPIRE_TOTAL))
 501                                 cb->expire_total = ent->expire_total;
 502                         if (!(slot & EXPIRE_UNREACH))
 503                                 cb->expire_unreachable = ent->expire_unreachable;
 504                         return;
 505                 }
 506         }
 507
 508         /*
 509          * If unconfigured, make stash never expire
 510          */
 511         if (!strcmp(ref, "refs/stash")) {
 512                 if (!(slot & EXPIRE_TOTAL))
 513                         cb->expire_total = 0;
 514                 if (!(slot & EXPIRE_UNREACH))
 515                         cb->expire_unreachable = 0;
 516                 return;
 517         }
 518
 519         /* Nothing matched -- use the default value */
 520         if (!(slot & EXPIRE_TOTAL))
 521                 cb->expire_total = default_reflog_expire;
 522         if (!(slot & EXPIRE_UNREACH))
 523                 cb->expire_unreachable = default_reflog_expire_unreachable;
 524 }
 525
 526 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 527 {
 528         struct cmd_reflog_expire_cb cb;
 529         unsigned long now = time(NULL);
 530         int i, status, do_all;
 531         int explicit_expiry = 0;
 532
 533         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 534         default_reflog_expire = now - 90 * 24 * 3600;
 535         git_config(reflog_expire_config, NULL);
 536
 537         save_commit_buffer = 0;
 538         do_all = status = 0;
 539         memset(&cb, 0, sizeof(cb));
 540
 541         cb.expire_total = default_reflog_expire;
 542         cb.expire_unreachable = default_reflog_expire_unreachable;
 543
 544         for (i = 1; i < argc; i++) {
 545                 const char *arg = argv[i];
 546                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 547                         cb.dry_run = 1;
 548                 else if (!prefixcmp(arg, "--expire=")) {
 549                         cb.expire_total = approxidate(arg + 9);
 550                         explicit_expiry |= EXPIRE_TOTAL;
 551                 }
 552                 else if (!prefixcmp(arg, "--expire-unreachable=")) {
 553                         cb.expire_unreachable = approxidate(arg + 21);
 554                         explicit_expiry |= EXPIRE_UNREACH;
 555                 }
 556                 else if (!strcmp(arg, "--stale-fix"))
 557                         cb.stalefix = 1;
 558                 else if (!strcmp(arg, "--rewrite"))
 559                         cb.rewrite = 1;
 560                 else if (!strcmp(arg, "--updateref"))
 561                         cb.updateref = 1;
 562                 else if (!strcmp(arg, "--all"))
 563                         do_all = 1;
 564                 else if (!strcmp(arg, "--verbose"))
 565                         cb.verbose = 1;
 566                 else if (!strcmp(arg, "--")) {
 567                         i++;
 568                         break;
 569                 }
 570                 else if (arg[0] == '-')
 571                         usage(reflog_expire_usage);
 572                 else
 573                         break;
 574         }
 575
 576         /*
 577          * We can trust the commits and objects reachable from refs
 578          * even in older repository.  We cannot trust what's reachable
 579          * from reflog if the repository was pruned with older git.
 580          */
 581         if (cb.stalefix) {
 582                 init_revisions(&cb.revs, prefix);
 583                 if (cb.verbose)
 584                         printf("Marking reachable objects...");
 585                 mark_reachable_objects(&cb.revs, 0);
 586                 if (cb.verbose)
 587                         putchar('\n');
 588         }
 589
 590         if (do_all) {
 591                 struct collect_reflog_cb collected;
 592                 int i;
 593
 594                 memset(&collected, 0, sizeof(collected));
 595                 for_each_reflog(collect_reflog, &collected);
 596                 for (i = 0; i < collected.nr; i++) {
 597                         struct collected_reflog *e = collected.e[i];
 598                         set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
 599                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 600                         free(e);
 601                 }
 602                 free(collected.e);
 603         }
 604
 605         for (; i < argc; i++) {
 606                 char *ref;
 607                 unsigned char sha1[20];
 608                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 609                         status |= error("%s points nowhere!", argv[i]);
 610                         continue;
 611                 }
 612                 set_reflog_expiry_param(&cb, explicit_expiry, ref);
 613                 status |= expire_reflog(ref, sha1, 0, &cb);
 614         }
 615         return status;
 616 }
 617
 618 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 619                 const char *email, unsigned long timestamp, int tz,
 620                 const char *message, void *cb_data)
 621 {
 622         struct cmd_reflog_expire_cb *cb = cb_data;
 623         if (!cb->expire_total || timestamp < cb->expire_total)
 624                 cb->recno++;
 625         return 0;
 626 }
 627
 628 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 629 {
 630         struct cmd_reflog_expire_cb cb;
 631         int i, status = 0;
 632
 633         memset(&cb, 0, sizeof(cb));
 634
 635         for (i = 1; i < argc; i++) {
 636                 const char *arg = argv[i];
 637                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 638                         cb.dry_run = 1;
 639                 else if (!strcmp(arg, "--rewrite"))
 640                         cb.rewrite = 1;
 641                 else if (!strcmp(arg, "--updateref"))
 642                         cb.updateref = 1;
 643                 else if (!strcmp(arg, "--verbose"))
 644                         cb.verbose = 1;
 645                 else if (!strcmp(arg, "--")) {
 646                         i++;
 647                         break;
 648                 }
 649                 else if (arg[0] == '-')
 650                         usage(reflog_delete_usage);
 651                 else
 652                         break;
 653         }
 654
 655         if (argc - i < 1)
 656                 return error("Nothing to delete?");
 657
 658         for ( ; i < argc; i++) {
 659                 const char *spec = strstr(argv[i], "@{");
 660                 unsigned char sha1[20];
 661                 char *ep, *ref;
 662                 int recno;
 663
 664                 if (!spec) {
 665                         status |= error("Not a reflog: %s", argv[i]);
 666                         continue;
 667                 }
 668
 669                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 670                         status |= error("no reflog for '%s'", argv[i]);
 671                         continue;
 672                 }
 673
 674                 recno = strtoul(spec + 2, &ep, 10);
 675                 if (*ep == '}') {
 676                         cb.recno = -recno;
 677                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 678                 } else {
 679                         cb.expire_total = approxidate(spec + 2);
 680                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 681                         cb.expire_total = 0;
 682                 }
 683
 684                 status |= expire_reflog(ref, sha1, 0, &cb);
 685                 free(ref);
 686         }
 687         return status;
 688 }
 689
 690 /*
 691  * main "reflog"
 692  */
 693
 694 static const char reflog_usage[] =
 695 "git reflog [ show | expire | delete ]";
 696
 697 int cmd_reflog(int argc, const char **argv, const char *prefix)
 698 {
 699         if (argc > 1 && !strcmp(argv[1], "-h"))
 700                 usage(reflog_usage);
 701
 702         /* With no command, we default to showing it. */
 703         if (argc < 2 || *argv[1] == '-')
 704                 return cmd_log_reflog(argc, argv, prefix);
 705
 706         if (!strcmp(argv[1], "show"))
 707                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 708
 709         if (!strcmp(argv[1], "expire"))
 710                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 711
 712         if (!strcmp(argv[1], "delete"))
 713                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 714
 715         /* Not a recognized reflog command..*/
 716         usage(reflog_usage);
 717 }