builtin/reflog.c

   1 #include "builtin.h"
   2 #include "lockfile.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 /* NEEDSWORK: switch to using parse_options */
  12 static const char reflog_expire_usage[] =
  13 "git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
  14 static const char reflog_delete_usage[] =
  15 "git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
  16 static const char reflog_exists_usage[] =
  17 "git reflog exists <ref>";
  18
  19 static unsigned long default_reflog_expire;
  20 static unsigned long default_reflog_expire_unreachable;
  21
  22 struct cmd_reflog_expire_cb {
  23         struct rev_info revs;
  24         int stalefix;
  25         unsigned long expire_total;
  26         unsigned long expire_unreachable;
  27         int recno;
  28 };
  29
  30 struct expire_reflog_policy_cb {
  31         enum {
  32                 UE_NORMAL,
  33                 UE_ALWAYS,
  34                 UE_HEAD
  35         } unreachable_expire_kind;
  36         struct commit_list *mark_list;
  37         unsigned long mark_limit;
  38         struct cmd_reflog_expire_cb cmd;
  39         struct commit *tip_commit;
  40         struct commit_list *tips;
  41 };
  42
  43 struct collected_reflog {
  44         unsigned char sha1[20];
  45         char reflog[FLEX_ARRAY];
  46 };
  47
  48 struct collect_reflog_cb {
  49         struct collected_reflog **e;
  50         int alloc;
  51         int nr;
  52 };
  53
  54 #define INCOMPLETE      (1u<<10)
  55 #define STUDYING        (1u<<11)
  56 #define REACHABLE       (1u<<12)
  57
  58 static int tree_is_complete(const unsigned char *sha1)
  59 {
  60         struct tree_desc desc;
  61         struct name_entry entry;
  62         int complete;
  63         struct tree *tree;
  64
  65         tree = lookup_tree(sha1);
  66         if (!tree)
  67                 return 0;
  68         if (tree->object.flags & SEEN)
  69                 return 1;
  70         if (tree->object.flags & INCOMPLETE)
  71                 return 0;
  72
  73         if (!tree->buffer) {
  74                 enum object_type type;
  75                 unsigned long size;
  76                 void *data = read_sha1_file(sha1, &type, &size);
  77                 if (!data) {
  78                         tree->object.flags |= INCOMPLETE;
  79                         return 0;
  80                 }
  81                 tree->buffer = data;
  82                 tree->size = size;
  83         }
  84         init_tree_desc(&desc, tree->buffer, tree->size);
  85         complete = 1;
  86         while (tree_entry(&desc, &entry)) {
  87                 if (!has_sha1_file(entry.oid->hash) ||
  88                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid->hash))) {
  89                         tree->object.flags |= INCOMPLETE;
  90                         complete = 0;
  91                 }
  92         }
  93         free_tree_buffer(tree);
  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.oid.hash))
 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.oid.hash)) {
 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 /*
 214  * Starting from commits in the cb->mark_list, mark commits that are
 215  * reachable from them.  Stop the traversal at commits older than
 216  * the expire_limit and queue them back, so that the caller can call
 217  * us again to restart the traversal with longer expire_limit.
 218  */
 219 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 220 {
 221         struct commit_list *pending;
 222         unsigned long expire_limit = cb->mark_limit;
 223         struct commit_list *leftover = NULL;
 224
 225         for (pending = cb->mark_list; pending; pending = pending->next)
 226                 pending->item->object.flags &= ~REACHABLE;
 227
 228         pending = cb->mark_list;
 229         while (pending) {
 230                 struct commit_list *parent;
 231                 struct commit *commit = pop_commit(&pending);
 232                 if (commit->object.flags & REACHABLE)
 233                         continue;
 234                 if (parse_commit(commit))
 235                         continue;
 236                 commit->object.flags |= REACHABLE;
 237                 if (commit->date < expire_limit) {
 238                         commit_list_insert(commit, &leftover);
 239                         continue;
 240                 }
 241                 commit->object.flags |= REACHABLE;
 242                 parent = commit->parents;
 243                 while (parent) {
 244                         commit = parent->item;
 245                         parent = parent->next;
 246                         if (commit->object.flags & REACHABLE)
 247                                 continue;
 248                         commit_list_insert(commit, &pending);
 249                 }
 250         }
 251         cb->mark_list = leftover;
 252 }
 253
 254 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, unsigned char *sha1)
 255 {
 256         /*
 257          * We may or may not have the commit yet - if not, look it
 258          * up using the supplied sha1.
 259          */
 260         if (!commit) {
 261                 if (is_null_sha1(sha1))
 262                         return 0;
 263
 264                 commit = lookup_commit_reference_gently(sha1, 1);
 265
 266                 /* Not a commit -- keep it */
 267                 if (!commit)
 268                         return 0;
 269         }
 270
 271         /* Reachable from the current ref?  Don't prune. */
 272         if (commit->object.flags & REACHABLE)
 273                 return 0;
 274
 275         if (cb->mark_list && cb->mark_limit) {
 276                 cb->mark_limit = 0; /* dig down to the root */
 277                 mark_reachable(cb);
 278         }
 279
 280         return !(commit->object.flags & REACHABLE);
 281 }
 282
 283 /*
 284  * Return true iff the specified reflog entry should be expired.
 285  */
 286 static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 287                                     const char *email, unsigned long timestamp, int tz,
 288                                     const char *message, void *cb_data)
 289 {
 290         struct expire_reflog_policy_cb *cb = cb_data;
 291         struct commit *old, *new;
 292
 293         if (timestamp < cb->cmd.expire_total)
 294                 return 1;
 295
 296         old = new = NULL;
 297         if (cb->cmd.stalefix &&
 298             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 299                 return 1;
 300
 301         if (timestamp < cb->cmd.expire_unreachable) {
 302                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 303                         return 1;
 304                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 305                         return 1;
 306         }
 307
 308         if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 309                 return 1;
 310
 311         return 0;
 312 }
 313
 314 static int push_tip_to_list(const char *refname, const struct object_id *oid,
 315                             int flags, void *cb_data)
 316 {
 317         struct commit_list **list = cb_data;
 318         struct commit *tip_commit;
 319         if (flags & REF_ISSYMREF)
 320                 return 0;
 321         tip_commit = lookup_commit_reference_gently(oid->hash, 1);
 322         if (!tip_commit)
 323                 return 0;
 324         commit_list_insert(tip_commit, list);
 325         return 0;
 326 }
 327
 328 static void reflog_expiry_prepare(const char *refname,
 329                                   const unsigned char *sha1,
 330                                   void *cb_data)
 331 {
 332         struct expire_reflog_policy_cb *cb = cb_data;
 333
 334         if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
 335                 cb->tip_commit = NULL;
 336                 cb->unreachable_expire_kind = UE_HEAD;
 337         } else {
 338                 cb->tip_commit = lookup_commit_reference_gently(sha1, 1);
 339                 if (!cb->tip_commit)
 340                         cb->unreachable_expire_kind = UE_ALWAYS;
 341                 else
 342                         cb->unreachable_expire_kind = UE_NORMAL;
 343         }
 344
 345         if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 346                 cb->unreachable_expire_kind = UE_ALWAYS;
 347
 348         cb->mark_list = NULL;
 349         cb->tips = NULL;
 350         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 351                 if (cb->unreachable_expire_kind == UE_HEAD) {
 352                         struct commit_list *elem;
 353
 354                         for_each_ref(push_tip_to_list, &cb->tips);
 355                         for (elem = cb->tips; elem; elem = elem->next)
 356                                 commit_list_insert(elem->item, &cb->mark_list);
 357                 } else {
 358                         commit_list_insert(cb->tip_commit, &cb->mark_list);
 359                 }
 360                 cb->mark_limit = cb->cmd.expire_total;
 361                 mark_reachable(cb);
 362         }
 363 }
 364
 365 static void reflog_expiry_cleanup(void *cb_data)
 366 {
 367         struct expire_reflog_policy_cb *cb = cb_data;
 368
 369         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 370                 if (cb->unreachable_expire_kind == UE_HEAD) {
 371                         struct commit_list *elem;
 372                         for (elem = cb->tips; elem; elem = elem->next)
 373                                 clear_commit_marks(elem->item, REACHABLE);
 374                         free_commit_list(cb->tips);
 375                 } else {
 376                         clear_commit_marks(cb->tip_commit, REACHABLE);
 377                 }
 378         }
 379 }
 380
 381 static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 382 {
 383         struct collected_reflog *e;
 384         struct collect_reflog_cb *cb = cb_data;
 385
 386         FLEX_ALLOC_STR(e, reflog, ref);
 387         hashcpy(e->sha1, oid->hash);
 388         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 389         cb->e[cb->nr++] = e;
 390         return 0;
 391 }
 392
 393 static struct reflog_expire_cfg {
 394         struct reflog_expire_cfg *next;
 395         unsigned long expire_total;
 396         unsigned long expire_unreachable;
 397         char pattern[FLEX_ARRAY];
 398 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 399
 400 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 401 {
 402         struct reflog_expire_cfg *ent;
 403
 404         if (!reflog_expire_cfg_tail)
 405                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 406
 407         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 408                 if (!strncmp(ent->pattern, pattern, len) &&
 409                     ent->pattern[len] == '\0')
 410                         return ent;
 411
 412         FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 413         *reflog_expire_cfg_tail = ent;
 414         reflog_expire_cfg_tail = &(ent->next);
 415         return ent;
 416 }
 417
 418 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 419 {
 420         if (!value)
 421                 return config_error_nonbool(var);
 422         if (parse_expiry_date(value, expire))
 423                 return error(_("'%s' for '%s' is not a valid timestamp"),
 424                              value, var);
 425         return 0;
 426 }
 427
 428 /* expiry timer slot */
 429 #define EXPIRE_TOTAL   01
 430 #define EXPIRE_UNREACH 02
 431
 432 static int reflog_expire_config(const char *var, const char *value, void *cb)
 433 {
 434         const char *pattern, *key;
 435         int pattern_len;
 436         unsigned long expire;
 437         int slot;
 438         struct reflog_expire_cfg *ent;
 439
 440         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 441                 return git_default_config(var, value, cb);
 442
 443         if (!strcmp(key, "reflogexpire")) {
 444                 slot = EXPIRE_TOTAL;
 445                 if (parse_expire_cfg_value(var, value, &expire))
 446                         return -1;
 447         } else if (!strcmp(key, "reflogexpireunreachable")) {
 448                 slot = EXPIRE_UNREACH;
 449                 if (parse_expire_cfg_value(var, value, &expire))
 450                         return -1;
 451         } else
 452                 return git_default_config(var, value, cb);
 453
 454         if (!pattern) {
 455                 switch (slot) {
 456                 case EXPIRE_TOTAL:
 457                         default_reflog_expire = expire;
 458                         break;
 459                 case EXPIRE_UNREACH:
 460                         default_reflog_expire_unreachable = expire;
 461                         break;
 462                 }
 463                 return 0;
 464         }
 465
 466         ent = find_cfg_ent(pattern, pattern_len);
 467         if (!ent)
 468                 return -1;
 469         switch (slot) {
 470         case EXPIRE_TOTAL:
 471                 ent->expire_total = expire;
 472                 break;
 473         case EXPIRE_UNREACH:
 474                 ent->expire_unreachable = expire;
 475                 break;
 476         }
 477         return 0;
 478 }
 479
 480 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 481 {
 482         struct reflog_expire_cfg *ent;
 483
 484         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 485                 return; /* both given explicitly -- nothing to tweak */
 486
 487         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 488                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
 489                         if (!(slot & EXPIRE_TOTAL))
 490                                 cb->expire_total = ent->expire_total;
 491                         if (!(slot & EXPIRE_UNREACH))
 492                                 cb->expire_unreachable = ent->expire_unreachable;
 493                         return;
 494                 }
 495         }
 496
 497         /*
 498          * If unconfigured, make stash never expire
 499          */
 500         if (!strcmp(ref, "refs/stash")) {
 501                 if (!(slot & EXPIRE_TOTAL))
 502                         cb->expire_total = 0;
 503                 if (!(slot & EXPIRE_UNREACH))
 504                         cb->expire_unreachable = 0;
 505                 return;
 506         }
 507
 508         /* Nothing matched -- use the default value */
 509         if (!(slot & EXPIRE_TOTAL))
 510                 cb->expire_total = default_reflog_expire;
 511         if (!(slot & EXPIRE_UNREACH))
 512                 cb->expire_unreachable = default_reflog_expire_unreachable;
 513 }
 514
 515 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 516 {
 517         struct expire_reflog_policy_cb cb;
 518         unsigned long now = time(NULL);
 519         int i, status, do_all;
 520         int explicit_expiry = 0;
 521         unsigned int flags = 0;
 522
 523         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 524         default_reflog_expire = now - 90 * 24 * 3600;
 525         git_config(reflog_expire_config, NULL);
 526
 527         save_commit_buffer = 0;
 528         do_all = status = 0;
 529         memset(&cb, 0, sizeof(cb));
 530
 531         cb.cmd.expire_total = default_reflog_expire;
 532         cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 533
 534         for (i = 1; i < argc; i++) {
 535                 const char *arg = argv[i];
 536                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 537                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 538                 else if (starts_with(arg, "--expire=")) {
 539                         if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 540                                 die(_("'%s' is not a valid timestamp"), arg);
 541                         explicit_expiry |= EXPIRE_TOTAL;
 542                 }
 543                 else if (starts_with(arg, "--expire-unreachable=")) {
 544                         if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 545                                 die(_("'%s' is not a valid timestamp"), arg);
 546                         explicit_expiry |= EXPIRE_UNREACH;
 547                 }
 548                 else if (!strcmp(arg, "--stale-fix"))
 549                         cb.cmd.stalefix = 1;
 550                 else if (!strcmp(arg, "--rewrite"))
 551                         flags |= EXPIRE_REFLOGS_REWRITE;
 552                 else if (!strcmp(arg, "--updateref"))
 553                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 554                 else if (!strcmp(arg, "--all"))
 555                         do_all = 1;
 556                 else if (!strcmp(arg, "--verbose"))
 557                         flags |= EXPIRE_REFLOGS_VERBOSE;
 558                 else if (!strcmp(arg, "--")) {
 559                         i++;
 560                         break;
 561                 }
 562                 else if (arg[0] == '-')
 563                         usage(reflog_expire_usage);
 564                 else
 565                         break;
 566         }
 567
 568         /*
 569          * We can trust the commits and objects reachable from refs
 570          * even in older repository.  We cannot trust what's reachable
 571          * from reflog if the repository was pruned with older git.
 572          */
 573         if (cb.cmd.stalefix) {
 574                 init_revisions(&cb.cmd.revs, prefix);
 575                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 576                         printf("Marking reachable objects...");
 577                 mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 578                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 579                         putchar('\n');
 580         }
 581
 582         if (do_all) {
 583                 struct collect_reflog_cb collected;
 584                 int i;
 585
 586                 memset(&collected, 0, sizeof(collected));
 587                 for_each_reflog(collect_reflog, &collected);
 588                 for (i = 0; i < collected.nr; i++) {
 589                         struct collected_reflog *e = collected.e[i];
 590                         set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 591                         status |= reflog_expire(e->reflog, e->sha1, flags,
 592                                                 reflog_expiry_prepare,
 593                                                 should_expire_reflog_ent,
 594                                                 reflog_expiry_cleanup,
 595                                                 &cb);
 596                         free(e);
 597                 }
 598                 free(collected.e);
 599         }
 600
 601         for (; i < argc; i++) {
 602                 char *ref;
 603                 unsigned char sha1[20];
 604                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 605                         status |= error("%s points nowhere!", argv[i]);
 606                         continue;
 607                 }
 608                 set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 609                 status |= reflog_expire(ref, sha1, flags,
 610                                         reflog_expiry_prepare,
 611                                         should_expire_reflog_ent,
 612                                         reflog_expiry_cleanup,
 613                                         &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 expire_reflog_policy_cb *cb = cb_data;
 623         if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 624                 cb->cmd.recno++;
 625         return 0;
 626 }
 627
 628 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 629 {
 630         struct expire_reflog_policy_cb cb;
 631         int i, status = 0;
 632         unsigned int flags = 0;
 633
 634         memset(&cb, 0, sizeof(cb));
 635
 636         for (i = 1; i < argc; i++) {
 637                 const char *arg = argv[i];
 638                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 639                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 640                 else if (!strcmp(arg, "--rewrite"))
 641                         flags |= EXPIRE_REFLOGS_REWRITE;
 642                 else if (!strcmp(arg, "--updateref"))
 643                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 644                 else if (!strcmp(arg, "--verbose"))
 645                         flags |= EXPIRE_REFLOGS_VERBOSE;
 646                 else if (!strcmp(arg, "--")) {
 647                         i++;
 648                         break;
 649                 }
 650                 else if (arg[0] == '-')
 651                         usage(reflog_delete_usage);
 652                 else
 653                         break;
 654         }
 655
 656         if (argc - i < 1)
 657                 return error("Nothing to delete?");
 658
 659         for ( ; i < argc; i++) {
 660                 const char *spec = strstr(argv[i], "@{");
 661                 unsigned char sha1[20];
 662                 char *ep, *ref;
 663                 int recno;
 664
 665                 if (!spec) {
 666                         status |= error("Not a reflog: %s", argv[i]);
 667                         continue;
 668                 }
 669
 670                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 671                         status |= error("no reflog for '%s'", argv[i]);
 672                         continue;
 673                 }
 674
 675                 recno = strtoul(spec + 2, &ep, 10);
 676                 if (*ep == '}') {
 677                         cb.cmd.recno = -recno;
 678                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 679                 } else {
 680                         cb.cmd.expire_total = approxidate(spec + 2);
 681                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 682                         cb.cmd.expire_total = 0;
 683                 }
 684
 685                 status |= reflog_expire(ref, sha1, flags,
 686                                         reflog_expiry_prepare,
 687                                         should_expire_reflog_ent,
 688                                         reflog_expiry_cleanup,
 689                                         &cb);
 690                 free(ref);
 691         }
 692         return status;
 693 }
 694
 695 static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 696 {
 697         int i, start = 0;
 698
 699         for (i = 1; i < argc; i++) {
 700                 const char *arg = argv[i];
 701                 if (!strcmp(arg, "--")) {
 702                         i++;
 703                         break;
 704                 }
 705                 else if (arg[0] == '-')
 706                         usage(reflog_exists_usage);
 707                 else
 708                         break;
 709         }
 710
 711         start = i;
 712
 713         if (argc - start != 1)
 714                 usage(reflog_exists_usage);
 715
 716         if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 717                 die("invalid ref format: %s", argv[start]);
 718         return !reflog_exists(argv[start]);
 719 }
 720
 721 /*
 722  * main "reflog"
 723  */
 724
 725 static const char reflog_usage[] =
 726 "git reflog [ show | expire | delete | exists ]";
 727
 728 int cmd_reflog(int argc, const char **argv, const char *prefix)
 729 {
 730         if (argc > 1 && !strcmp(argv[1], "-h"))
 731                 usage(reflog_usage);
 732
 733         /* With no command, we default to showing it. */
 734         if (argc < 2 || *argv[1] == '-')
 735                 return cmd_log_reflog(argc, argv, prefix);
 736
 737         if (!strcmp(argv[1], "show"))
 738                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 739
 740         if (!strcmp(argv[1], "expire"))
 741                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 742
 743         if (!strcmp(argv[1], "delete"))
 744                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 745
 746         if (!strcmp(argv[1], "exists"))
 747                 return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 748
 749         return cmd_log_reflog(argc, argv, prefix);
 750 }