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 /*
  12  * reflog expire
  13  */
  14
  15 static const char reflog_expire_usage[] =
  16 "git reflog 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         enum {
  38                 UE_NORMAL,
  39                 UE_ALWAYS,
  40                 UE_HEAD
  41         } unreachable_expire_kind;
  42         struct commit_list *mark_list;
  43         unsigned long mark_limit;
  44         struct cmd_reflog_expire_cb *cmd;
  45         unsigned char last_kept_sha1[20];
  46 };
  47
  48 struct collected_reflog {
  49         unsigned char sha1[20];
  50         char reflog[FLEX_ARRAY];
  51 };
  52 struct collect_reflog_cb {
  53         struct collected_reflog **e;
  54         int alloc;
  55         int nr;
  56 };
  57
  58 #define INCOMPLETE      (1u<<10)
  59 #define STUDYING        (1u<<11)
  60 #define REACHABLE       (1u<<12)
  61
  62 static int tree_is_complete(const unsigned char *sha1)
  63 {
  64         struct tree_desc desc;
  65         struct name_entry entry;
  66         int complete;
  67         struct tree *tree;
  68
  69         tree = lookup_tree(sha1);
  70         if (!tree)
  71                 return 0;
  72         if (tree->object.flags & SEEN)
  73                 return 1;
  74         if (tree->object.flags & INCOMPLETE)
  75                 return 0;
  76
  77         if (!tree->buffer) {
  78                 enum object_type type;
  79                 unsigned long size;
  80                 void *data = read_sha1_file(sha1, &type, &size);
  81                 if (!data) {
  82                         tree->object.flags |= INCOMPLETE;
  83                         return 0;
  84                 }
  85                 tree->buffer = data;
  86                 tree->size = size;
  87         }
  88         init_tree_desc(&desc, tree->buffer, tree->size);
  89         complete = 1;
  90         while (tree_entry(&desc, &entry)) {
  91                 if (!has_sha1_file(entry.sha1) ||
  92                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  93                         tree->object.flags |= INCOMPLETE;
  94                         complete = 0;
  95                 }
  96         }
  97         free_tree_buffer(tree);
  98
  99         if (complete)
 100                 tree->object.flags |= SEEN;
 101         return complete;
 102 }
 103
 104 static int commit_is_complete(struct commit *commit)
 105 {
 106         struct object_array study;
 107         struct object_array found;
 108         int is_incomplete = 0;
 109         int i;
 110
 111         /* early return */
 112         if (commit->object.flags & SEEN)
 113                 return 1;
 114         if (commit->object.flags & INCOMPLETE)
 115                 return 0;
 116         /*
 117          * Find all commits that are reachable and are not marked as
 118          * SEEN.  Then make sure the trees and blobs contained are
 119          * complete.  After that, mark these commits also as SEEN.
 120          * If some of the objects that are needed to complete this
 121          * commit are missing, mark this commit as INCOMPLETE.
 122          */
 123         memset(&study, 0, sizeof(study));
 124         memset(&found, 0, sizeof(found));
 125         add_object_array(&commit->object, NULL, &study);
 126         add_object_array(&commit->object, NULL, &found);
 127         commit->object.flags |= STUDYING;
 128         while (study.nr) {
 129                 struct commit *c;
 130                 struct commit_list *parent;
 131
 132                 c = (struct commit *)study.objects[--study.nr].item;
 133                 if (!c->object.parsed && !parse_object(c->object.sha1))
 134                         c->object.flags |= INCOMPLETE;
 135
 136                 if (c->object.flags & INCOMPLETE) {
 137                         is_incomplete = 1;
 138                         break;
 139                 }
 140                 else if (c->object.flags & SEEN)
 141                         continue;
 142                 for (parent = c->parents; parent; parent = parent->next) {
 143                         struct commit *p = parent->item;
 144                         if (p->object.flags & STUDYING)
 145                                 continue;
 146                         p->object.flags |= STUDYING;
 147                         add_object_array(&p->object, NULL, &study);
 148                         add_object_array(&p->object, NULL, &found);
 149                 }
 150         }
 151         if (!is_incomplete) {
 152                 /*
 153                  * make sure all commits in "found" array have all the
 154                  * necessary objects.
 155                  */
 156                 for (i = 0; i < found.nr; i++) {
 157                         struct commit *c =
 158                                 (struct commit *)found.objects[i].item;
 159                         if (!tree_is_complete(c->tree->object.sha1)) {
 160                                 is_incomplete = 1;
 161                                 c->object.flags |= INCOMPLETE;
 162                         }
 163                 }
 164                 if (!is_incomplete) {
 165                         /* mark all found commits as complete, iow SEEN */
 166                         for (i = 0; i < found.nr; i++)
 167                                 found.objects[i].item->flags |= SEEN;
 168                 }
 169         }
 170         /* clear flags from the objects we traversed */
 171         for (i = 0; i < found.nr; i++)
 172                 found.objects[i].item->flags &= ~STUDYING;
 173         if (is_incomplete)
 174                 commit->object.flags |= INCOMPLETE;
 175         else {
 176                 /*
 177                  * If we come here, we have (1) traversed the ancestry chain
 178                  * from the "commit" until we reach SEEN commits (which are
 179                  * known to be complete), and (2) made sure that the commits
 180                  * encountered during the above traversal refer to trees that
 181                  * are complete.  Which means that we know *all* the commits
 182                  * we have seen during this process are complete.
 183                  */
 184                 for (i = 0; i < found.nr; i++)
 185                         found.objects[i].item->flags |= SEEN;
 186         }
 187         /* free object arrays */
 188         free(study.objects);
 189         free(found.objects);
 190         return !is_incomplete;
 191 }
 192
 193 static int keep_entry(struct commit **it, unsigned char *sha1)
 194 {
 195         struct commit *commit;
 196
 197         if (is_null_sha1(sha1))
 198                 return 1;
 199         commit = lookup_commit_reference_gently(sha1, 1);
 200         if (!commit)
 201                 return 0;
 202
 203         /*
 204          * Make sure everything in this commit exists.
 205          *
 206          * We have walked all the objects reachable from the refs
 207          * and cache earlier.  The commits reachable by this commit
 208          * must meet SEEN commits -- and then we should mark them as
 209          * SEEN as well.
 210          */
 211         if (!commit_is_complete(commit))
 212                 return 0;
 213         *it = commit;
 214         return 1;
 215 }
 216
 217 /*
 218  * Starting from commits in the cb->mark_list, mark commits that are
 219  * reachable from them.  Stop the traversal at commits older than
 220  * the expire_limit and queue them back, so that the caller can call
 221  * us again to restart the traversal with longer expire_limit.
 222  */
 223 static void mark_reachable(struct expire_reflog_cb *cb)
 224 {
 225         struct commit *commit;
 226         struct commit_list *pending;
 227         unsigned long expire_limit = cb->mark_limit;
 228         struct commit_list *leftover = NULL;
 229
 230         for (pending = cb->mark_list; pending; pending = pending->next)
 231                 pending->item->object.flags &= ~REACHABLE;
 232
 233         pending = cb->mark_list;
 234         while (pending) {
 235                 struct commit_list *entry = pending;
 236                 struct commit_list *parent;
 237                 pending = entry->next;
 238                 commit = entry->item;
 239                 free(entry);
 240                 if (commit->object.flags & REACHABLE)
 241                         continue;
 242                 if (parse_commit(commit))
 243                         continue;
 244                 commit->object.flags |= REACHABLE;
 245                 if (commit->date < expire_limit) {
 246                         commit_list_insert(commit, &leftover);
 247                         continue;
 248                 }
 249                 commit->object.flags |= REACHABLE;
 250                 parent = commit->parents;
 251                 while (parent) {
 252                         commit = parent->item;
 253                         parent = parent->next;
 254                         if (commit->object.flags & REACHABLE)
 255                                 continue;
 256                         commit_list_insert(commit, &pending);
 257                 }
 258         }
 259         cb->mark_list = leftover;
 260 }
 261
 262 static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
 263 {
 264         /*
 265          * We may or may not have the commit yet - if not, look it
 266          * up using the supplied sha1.
 267          */
 268         if (!commit) {
 269                 if (is_null_sha1(sha1))
 270                         return 0;
 271
 272                 commit = lookup_commit_reference_gently(sha1, 1);
 273
 274                 /* Not a commit -- keep it */
 275                 if (!commit)
 276                         return 0;
 277         }
 278
 279         /* Reachable from the current ref?  Don't prune. */
 280         if (commit->object.flags & REACHABLE)
 281                 return 0;
 282
 283         if (cb->mark_list && cb->mark_limit) {
 284                 cb->mark_limit = 0; /* dig down to the root */
 285                 mark_reachable(cb);
 286         }
 287
 288         return !(commit->object.flags & REACHABLE);
 289 }
 290
 291 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 292                 const char *email, unsigned long timestamp, int tz,
 293                 const char *message, void *cb_data)
 294 {
 295         struct expire_reflog_cb *cb = cb_data;
 296         struct commit *old, *new;
 297
 298         if (timestamp < cb->cmd->expire_total)
 299                 goto prune;
 300
 301         if (cb->cmd->rewrite)
 302                 osha1 = cb->last_kept_sha1;
 303
 304         old = new = NULL;
 305         if (cb->cmd->stalefix &&
 306             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 307                 goto prune;
 308
 309         if (timestamp < cb->cmd->expire_unreachable) {
 310                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 311                         goto prune;
 312                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 313                         goto prune;
 314         }
 315
 316         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 317                 goto prune;
 318
 319         if (cb->newlog) {
 320                 char sign = (tz < 0) ? '-' : '+';
 321                 int zone = (tz < 0) ? (-tz) : tz;
 322                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 323                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 324                         email, timestamp, sign, zone,
 325                         message);
 326                 hashcpy(cb->last_kept_sha1, nsha1);
 327         }
 328         if (cb->cmd->verbose)
 329                 printf("keep %s", message);
 330         return 0;
 331  prune:
 332         if (!cb->newlog)
 333                 printf("would prune %s", message);
 334         else if (cb->cmd->verbose)
 335                 printf("prune %s", message);
 336         return 0;
 337 }
 338
 339 static int push_tip_to_list(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 340 {
 341         struct commit_list **list = cb_data;
 342         struct commit *tip_commit;
 343         if (flags & REF_ISSYMREF)
 344                 return 0;
 345         tip_commit = lookup_commit_reference_gently(sha1, 1);
 346         if (!tip_commit)
 347                 return 0;
 348         commit_list_insert(tip_commit, list);
 349         return 0;
 350 }
 351
 352 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 353 {
 354         struct cmd_reflog_expire_cb *cmd = cb_data;
 355         struct expire_reflog_cb cb;
 356         struct ref_lock *lock;
 357         char *log_file, *newlog_path = NULL;
 358         struct commit *tip_commit;
 359         struct commit_list *tips;
 360         int status = 0;
 361
 362         memset(&cb, 0, sizeof(cb));
 363
 364         /*
 365          * we take the lock for the ref itself to prevent it from
 366          * getting updated.
 367          */
 368         lock = lock_any_ref_for_update(ref, sha1, 0, NULL);
 369         if (!lock)
 370                 return error("cannot lock ref '%s'", ref);
 371         log_file = git_pathdup("logs/%s", ref);
 372         if (!reflog_exists(ref))
 373                 goto finish;
 374         if (!cmd->dry_run) {
 375                 newlog_path = git_pathdup("logs/%s.lock", ref);
 376                 cb.newlog = fopen(newlog_path, "w");
 377         }
 378
 379         cb.cmd = cmd;
 380
 381         if (!cmd->expire_unreachable || !strcmp(ref, "HEAD")) {
 382                 tip_commit = NULL;
 383                 cb.unreachable_expire_kind = UE_HEAD;
 384         } else {
 385                 tip_commit = lookup_commit_reference_gently(sha1, 1);
 386                 if (!tip_commit)
 387                         cb.unreachable_expire_kind = UE_ALWAYS;
 388                 else
 389                         cb.unreachable_expire_kind = UE_NORMAL;
 390         }
 391
 392         if (cmd->expire_unreachable <= cmd->expire_total)
 393                 cb.unreachable_expire_kind = UE_ALWAYS;
 394
 395         cb.mark_list = NULL;
 396         tips = NULL;
 397         if (cb.unreachable_expire_kind != UE_ALWAYS) {
 398                 if (cb.unreachable_expire_kind == UE_HEAD) {
 399                         struct commit_list *elem;
 400                         for_each_ref(push_tip_to_list, &tips);
 401                         for (elem = tips; elem; elem = elem->next)
 402                                 commit_list_insert(elem->item, &cb.mark_list);
 403                 } else {
 404                         commit_list_insert(tip_commit, &cb.mark_list);
 405                 }
 406                 cb.mark_limit = cmd->expire_total;
 407                 mark_reachable(&cb);
 408         }
 409
 410         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 411
 412         if (cb.unreachable_expire_kind != UE_ALWAYS) {
 413                 if (cb.unreachable_expire_kind == UE_HEAD) {
 414                         struct commit_list *elem;
 415                         for (elem = tips; elem; elem = elem->next)
 416                                 clear_commit_marks(elem->item, REACHABLE);
 417                         free_commit_list(tips);
 418                 } else {
 419                         clear_commit_marks(tip_commit, REACHABLE);
 420                 }
 421         }
 422  finish:
 423         if (cb.newlog) {
 424                 if (fclose(cb.newlog)) {
 425                         status |= error("%s: %s", strerror(errno),
 426                                         newlog_path);
 427                         unlink(newlog_path);
 428                 } else if (cmd->updateref &&
 429                         (write_in_full(lock->lock_fd,
 430                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 431                          write_str_in_full(lock->lock_fd, "\n") != 1 ||
 432                          close_ref(lock) < 0)) {
 433                         status |= error("Couldn't write %s",
 434                                         lock->lk->filename.buf);
 435                         unlink(newlog_path);
 436                 } else if (rename(newlog_path, log_file)) {
 437                         status |= error("cannot rename %s to %s",
 438                                         newlog_path, log_file);
 439                         unlink(newlog_path);
 440                 } else if (cmd->updateref && commit_ref(lock)) {
 441                         status |= error("Couldn't set %s", lock->ref_name);
 442                 } else {
 443                         adjust_shared_perm(log_file);
 444                 }
 445         }
 446         free(newlog_path);
 447         free(log_file);
 448         unlock_ref(lock);
 449         return status;
 450 }
 451
 452 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 453 {
 454         struct collected_reflog *e;
 455         struct collect_reflog_cb *cb = cb_data;
 456         size_t namelen = strlen(ref);
 457
 458         e = xmalloc(sizeof(*e) + namelen + 1);
 459         hashcpy(e->sha1, sha1);
 460         memcpy(e->reflog, ref, namelen + 1);
 461         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 462         cb->e[cb->nr++] = e;
 463         return 0;
 464 }
 465
 466 static struct reflog_expire_cfg {
 467         struct reflog_expire_cfg *next;
 468         unsigned long expire_total;
 469         unsigned long expire_unreachable;
 470         size_t len;
 471         char pattern[FLEX_ARRAY];
 472 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 473
 474 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 475 {
 476         struct reflog_expire_cfg *ent;
 477
 478         if (!reflog_expire_cfg_tail)
 479                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 480
 481         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 482                 if (ent->len == len &&
 483                     !memcmp(ent->pattern, pattern, len))
 484                         return ent;
 485
 486         ent = xcalloc(1, (sizeof(*ent) + len));
 487         memcpy(ent->pattern, pattern, len);
 488         ent->len = len;
 489         *reflog_expire_cfg_tail = ent;
 490         reflog_expire_cfg_tail = &(ent->next);
 491         return ent;
 492 }
 493
 494 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 495 {
 496         if (!value)
 497                 return config_error_nonbool(var);
 498         if (parse_expiry_date(value, expire))
 499                 return error(_("%s' for '%s' is not a valid timestamp"),
 500                              value, var);
 501         return 0;
 502 }
 503
 504 /* expiry timer slot */
 505 #define EXPIRE_TOTAL   01
 506 #define EXPIRE_UNREACH 02
 507
 508 static int reflog_expire_config(const char *var, const char *value, void *cb)
 509 {
 510         const char *pattern, *key;
 511         int pattern_len;
 512         unsigned long expire;
 513         int slot;
 514         struct reflog_expire_cfg *ent;
 515
 516         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 517                 return git_default_config(var, value, cb);
 518
 519         if (!strcmp(key, "reflogexpire")) {
 520                 slot = EXPIRE_TOTAL;
 521                 if (parse_expire_cfg_value(var, value, &expire))
 522                         return -1;
 523         } else if (!strcmp(key, "reflogexpireunreachable")) {
 524                 slot = EXPIRE_UNREACH;
 525                 if (parse_expire_cfg_value(var, value, &expire))
 526                         return -1;
 527         } else
 528                 return git_default_config(var, value, cb);
 529
 530         if (!pattern) {
 531                 switch (slot) {
 532                 case EXPIRE_TOTAL:
 533                         default_reflog_expire = expire;
 534                         break;
 535                 case EXPIRE_UNREACH:
 536                         default_reflog_expire_unreachable = expire;
 537                         break;
 538                 }
 539                 return 0;
 540         }
 541
 542         ent = find_cfg_ent(pattern, pattern_len);
 543         if (!ent)
 544                 return -1;
 545         switch (slot) {
 546         case EXPIRE_TOTAL:
 547                 ent->expire_total = expire;
 548                 break;
 549         case EXPIRE_UNREACH:
 550                 ent->expire_unreachable = expire;
 551                 break;
 552         }
 553         return 0;
 554 }
 555
 556 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 557 {
 558         struct reflog_expire_cfg *ent;
 559
 560         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 561                 return; /* both given explicitly -- nothing to tweak */
 562
 563         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 564                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
 565                         if (!(slot & EXPIRE_TOTAL))
 566                                 cb->expire_total = ent->expire_total;
 567                         if (!(slot & EXPIRE_UNREACH))
 568                                 cb->expire_unreachable = ent->expire_unreachable;
 569                         return;
 570                 }
 571         }
 572
 573         /*
 574          * If unconfigured, make stash never expire
 575          */
 576         if (!strcmp(ref, "refs/stash")) {
 577                 if (!(slot & EXPIRE_TOTAL))
 578                         cb->expire_total = 0;
 579                 if (!(slot & EXPIRE_UNREACH))
 580                         cb->expire_unreachable = 0;
 581                 return;
 582         }
 583
 584         /* Nothing matched -- use the default value */
 585         if (!(slot & EXPIRE_TOTAL))
 586                 cb->expire_total = default_reflog_expire;
 587         if (!(slot & EXPIRE_UNREACH))
 588                 cb->expire_unreachable = default_reflog_expire_unreachable;
 589 }
 590
 591 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 592 {
 593         struct cmd_reflog_expire_cb cb;
 594         unsigned long now = time(NULL);
 595         int i, status, do_all;
 596         int explicit_expiry = 0;
 597
 598         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 599         default_reflog_expire = now - 90 * 24 * 3600;
 600         git_config(reflog_expire_config, NULL);
 601
 602         save_commit_buffer = 0;
 603         do_all = status = 0;
 604         memset(&cb, 0, sizeof(cb));
 605
 606         cb.expire_total = default_reflog_expire;
 607         cb.expire_unreachable = default_reflog_expire_unreachable;
 608
 609         for (i = 1; i < argc; i++) {
 610                 const char *arg = argv[i];
 611                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 612                         cb.dry_run = 1;
 613                 else if (starts_with(arg, "--expire=")) {
 614                         if (parse_expiry_date(arg + 9, &cb.expire_total))
 615                                 die(_("'%s' is not a valid timestamp"), arg);
 616                         explicit_expiry |= EXPIRE_TOTAL;
 617                 }
 618                 else if (starts_with(arg, "--expire-unreachable=")) {
 619                         if (parse_expiry_date(arg + 21, &cb.expire_unreachable))
 620                                 die(_("'%s' is not a valid timestamp"), arg);
 621                         explicit_expiry |= EXPIRE_UNREACH;
 622                 }
 623                 else if (!strcmp(arg, "--stale-fix"))
 624                         cb.stalefix = 1;
 625                 else if (!strcmp(arg, "--rewrite"))
 626                         cb.rewrite = 1;
 627                 else if (!strcmp(arg, "--updateref"))
 628                         cb.updateref = 1;
 629                 else if (!strcmp(arg, "--all"))
 630                         do_all = 1;
 631                 else if (!strcmp(arg, "--verbose"))
 632                         cb.verbose = 1;
 633                 else if (!strcmp(arg, "--")) {
 634                         i++;
 635                         break;
 636                 }
 637                 else if (arg[0] == '-')
 638                         usage(reflog_expire_usage);
 639                 else
 640                         break;
 641         }
 642
 643         /*
 644          * We can trust the commits and objects reachable from refs
 645          * even in older repository.  We cannot trust what's reachable
 646          * from reflog if the repository was pruned with older git.
 647          */
 648         if (cb.stalefix) {
 649                 init_revisions(&cb.revs, prefix);
 650                 if (cb.verbose)
 651                         printf("Marking reachable objects...");
 652                 mark_reachable_objects(&cb.revs, 0, 0, NULL);
 653                 if (cb.verbose)
 654                         putchar('\n');
 655         }
 656
 657         if (do_all) {
 658                 struct collect_reflog_cb collected;
 659                 int i;
 660
 661                 memset(&collected, 0, sizeof(collected));
 662                 for_each_reflog(collect_reflog, &collected);
 663                 for (i = 0; i < collected.nr; i++) {
 664                         struct collected_reflog *e = collected.e[i];
 665                         set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
 666                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 667                         free(e);
 668                 }
 669                 free(collected.e);
 670         }
 671
 672         for (; i < argc; i++) {
 673                 char *ref;
 674                 unsigned char sha1[20];
 675                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 676                         status |= error("%s points nowhere!", argv[i]);
 677                         continue;
 678                 }
 679                 set_reflog_expiry_param(&cb, explicit_expiry, ref);
 680                 status |= expire_reflog(ref, sha1, 0, &cb);
 681         }
 682         return status;
 683 }
 684
 685 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 686                 const char *email, unsigned long timestamp, int tz,
 687                 const char *message, void *cb_data)
 688 {
 689         struct cmd_reflog_expire_cb *cb = cb_data;
 690         if (!cb->expire_total || timestamp < cb->expire_total)
 691                 cb->recno++;
 692         return 0;
 693 }
 694
 695 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 696 {
 697         struct cmd_reflog_expire_cb cb;
 698         int i, status = 0;
 699
 700         memset(&cb, 0, sizeof(cb));
 701
 702         for (i = 1; i < argc; i++) {
 703                 const char *arg = argv[i];
 704                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 705                         cb.dry_run = 1;
 706                 else if (!strcmp(arg, "--rewrite"))
 707                         cb.rewrite = 1;
 708                 else if (!strcmp(arg, "--updateref"))
 709                         cb.updateref = 1;
 710                 else if (!strcmp(arg, "--verbose"))
 711                         cb.verbose = 1;
 712                 else if (!strcmp(arg, "--")) {
 713                         i++;
 714                         break;
 715                 }
 716                 else if (arg[0] == '-')
 717                         usage(reflog_delete_usage);
 718                 else
 719                         break;
 720         }
 721
 722         if (argc - i < 1)
 723                 return error("Nothing to delete?");
 724
 725         for ( ; i < argc; i++) {
 726                 const char *spec = strstr(argv[i], "@{");
 727                 unsigned char sha1[20];
 728                 char *ep, *ref;
 729                 int recno;
 730
 731                 if (!spec) {
 732                         status |= error("Not a reflog: %s", argv[i]);
 733                         continue;
 734                 }
 735
 736                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 737                         status |= error("no reflog for '%s'", argv[i]);
 738                         continue;
 739                 }
 740
 741                 recno = strtoul(spec + 2, &ep, 10);
 742                 if (*ep == '}') {
 743                         cb.recno = -recno;
 744                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 745                 } else {
 746                         cb.expire_total = approxidate(spec + 2);
 747                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 748                         cb.expire_total = 0;
 749                 }
 750
 751                 status |= expire_reflog(ref, sha1, 0, &cb);
 752                 free(ref);
 753         }
 754         return status;
 755 }
 756
 757 /*
 758  * main "reflog"
 759  */
 760
 761 static const char reflog_usage[] =
 762 "git reflog [ show | expire | delete ]";
 763
 764 int cmd_reflog(int argc, const char **argv, const char *prefix)
 765 {
 766         if (argc > 1 && !strcmp(argv[1], "-h"))
 767                 usage(reflog_usage);
 768
 769         /* With no command, we default to showing it. */
 770         if (argc < 2 || *argv[1] == '-')
 771                 return cmd_log_reflog(argc, argv, prefix);
 772
 773         if (!strcmp(argv[1], "show"))
 774                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 775
 776         if (!strcmp(argv[1], "expire"))
 777                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 778
 779         if (!strcmp(argv[1], "delete"))
 780                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 781
 782         return cmd_log_reflog(argc, argv, prefix);
 783 }