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 /*
 292  * Return true iff the specified reflog entry should be expired.
 293  */
 294 static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 295                                     const char *email, unsigned long timestamp, int tz,
 296                                     const char *message, void *cb_data)
 297 {
 298         struct expire_reflog_cb *cb = cb_data;
 299         struct commit *old, *new;
 300
 301         if (timestamp < cb->cmd->expire_total)
 302                 return 1;
 303
 304         old = new = NULL;
 305         if (cb->cmd->stalefix &&
 306             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 307                 return 1;
 308
 309         if (timestamp < cb->cmd->expire_unreachable) {
 310                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 311                         return 1;
 312                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 313                         return 1;
 314         }
 315
 316         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 317                 return 1;
 318
 319         return 0;
 320 }
 321
 322 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 323                 const char *email, unsigned long timestamp, int tz,
 324                 const char *message, void *cb_data)
 325 {
 326         struct expire_reflog_cb *cb = cb_data;
 327
 328         if (cb->cmd->rewrite)
 329                 osha1 = cb->last_kept_sha1;
 330
 331         if (should_expire_reflog_ent(osha1, nsha1, email, timestamp, tz,
 332                                      message, cb_data)) {
 333                 if (!cb->newlog)
 334                         printf("would prune %s", message);
 335                 else if (cb->cmd->verbose)
 336                         printf("prune %s", message);
 337         } else {
 338                 if (cb->newlog) {
 339                         char sign = (tz < 0) ? '-' : '+';
 340                         int zone = (tz < 0) ? (-tz) : tz;
 341                         fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 342                                 sha1_to_hex(osha1), sha1_to_hex(nsha1),
 343                                 email, timestamp, sign, zone,
 344                                 message);
 345                         hashcpy(cb->last_kept_sha1, nsha1);
 346                 }
 347                 if (cb->cmd->verbose)
 348                         printf("keep %s", message);
 349         }
 350         return 0;
 351 }
 352
 353 static int push_tip_to_list(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 354 {
 355         struct commit_list **list = cb_data;
 356         struct commit *tip_commit;
 357         if (flags & REF_ISSYMREF)
 358                 return 0;
 359         tip_commit = lookup_commit_reference_gently(sha1, 1);
 360         if (!tip_commit)
 361                 return 0;
 362         commit_list_insert(tip_commit, list);
 363         return 0;
 364 }
 365
 366 static int expire_reflog(const char *refname, const unsigned char *sha1,
 367                          struct cmd_reflog_expire_cb *cmd)
 368 {
 369         static struct lock_file reflog_lock;
 370         struct expire_reflog_cb cb;
 371         struct ref_lock *lock;
 372         char *log_file;
 373         struct commit *tip_commit;
 374         struct commit_list *tips;
 375         int status = 0;
 376
 377         memset(&cb, 0, sizeof(cb));
 378
 379         /*
 380          * The reflog file is locked by holding the lock on the
 381          * reference itself, plus we might need to update the
 382          * reference if --updateref was specified:
 383          */
 384         lock = lock_any_ref_for_update(refname, sha1, 0, NULL);
 385         if (!lock)
 386                 return error("cannot lock ref '%s'", refname);
 387         if (!reflog_exists(refname)) {
 388                 unlock_ref(lock);
 389                 return 0;
 390         }
 391
 392         log_file = git_pathdup("logs/%s", refname);
 393         if (!cmd->dry_run) {
 394                 /*
 395                  * Even though holding $GIT_DIR/logs/$reflog.lock has
 396                  * no locking implications, we use the lock_file
 397                  * machinery here anyway because it does a lot of the
 398                  * work we need, including cleaning up if the program
 399                  * exits unexpectedly.
 400                  */
 401                 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
 402                         struct strbuf err = STRBUF_INIT;
 403                         unable_to_lock_message(log_file, errno, &err);
 404                         error("%s", err.buf);
 405                         strbuf_release(&err);
 406                         goto failure;
 407                 }
 408                 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
 409                 if (!cb.newlog) {
 410                         error("cannot fdopen %s (%s)",
 411                               reflog_lock.filename.buf, strerror(errno));
 412                         goto failure;
 413                 }
 414         }
 415
 416         cb.cmd = cmd;
 417
 418         if (!cmd->expire_unreachable || !strcmp(refname, "HEAD")) {
 419                 tip_commit = NULL;
 420                 cb.unreachable_expire_kind = UE_HEAD;
 421         } else {
 422                 tip_commit = lookup_commit_reference_gently(sha1, 1);
 423                 if (!tip_commit)
 424                         cb.unreachable_expire_kind = UE_ALWAYS;
 425                 else
 426                         cb.unreachable_expire_kind = UE_NORMAL;
 427         }
 428
 429         if (cmd->expire_unreachable <= cmd->expire_total)
 430                 cb.unreachable_expire_kind = UE_ALWAYS;
 431
 432         cb.mark_list = NULL;
 433         tips = NULL;
 434         if (cb.unreachable_expire_kind != UE_ALWAYS) {
 435                 if (cb.unreachable_expire_kind == UE_HEAD) {
 436                         struct commit_list *elem;
 437                         for_each_ref(push_tip_to_list, &tips);
 438                         for (elem = tips; elem; elem = elem->next)
 439                                 commit_list_insert(elem->item, &cb.mark_list);
 440                 } else {
 441                         commit_list_insert(tip_commit, &cb.mark_list);
 442                 }
 443                 cb.mark_limit = cmd->expire_total;
 444                 mark_reachable(&cb);
 445         }
 446
 447         for_each_reflog_ent(refname, expire_reflog_ent, &cb);
 448
 449         if (cb.unreachable_expire_kind != UE_ALWAYS) {
 450                 if (cb.unreachable_expire_kind == UE_HEAD) {
 451                         struct commit_list *elem;
 452                         for (elem = tips; elem; elem = elem->next)
 453                                 clear_commit_marks(elem->item, REACHABLE);
 454                         free_commit_list(tips);
 455                 } else {
 456                         clear_commit_marks(tip_commit, REACHABLE);
 457                 }
 458         }
 459
 460         if (cb.newlog) {
 461                 if (close_lock_file(&reflog_lock)) {
 462                         status |= error("couldn't write %s: %s", log_file,
 463                                         strerror(errno));
 464                 } else if (cmd->updateref &&
 465                         (write_in_full(lock->lock_fd,
 466                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 467                          write_str_in_full(lock->lock_fd, "\n") != 1 ||
 468                          close_ref(lock) < 0)) {
 469                         status |= error("couldn't write %s",
 470                                         lock->lk->filename.buf);
 471                         rollback_lock_file(&reflog_lock);
 472                 } else if (commit_lock_file(&reflog_lock)) {
 473                         status |= error("unable to commit reflog '%s' (%s)",
 474                                         log_file, strerror(errno));
 475                 } else if (cmd->updateref && commit_ref(lock)) {
 476                         status |= error("couldn't set %s", lock->ref_name);
 477                 }
 478         }
 479         free(log_file);
 480         unlock_ref(lock);
 481         return status;
 482
 483  failure:
 484         rollback_lock_file(&reflog_lock);
 485         free(log_file);
 486         unlock_ref(lock);
 487         return -1;
 488 }
 489
 490 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 491 {
 492         struct collected_reflog *e;
 493         struct collect_reflog_cb *cb = cb_data;
 494         size_t namelen = strlen(ref);
 495
 496         e = xmalloc(sizeof(*e) + namelen + 1);
 497         hashcpy(e->sha1, sha1);
 498         memcpy(e->reflog, ref, namelen + 1);
 499         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 500         cb->e[cb->nr++] = e;
 501         return 0;
 502 }
 503
 504 static struct reflog_expire_cfg {
 505         struct reflog_expire_cfg *next;
 506         unsigned long expire_total;
 507         unsigned long expire_unreachable;
 508         size_t len;
 509         char pattern[FLEX_ARRAY];
 510 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 511
 512 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 513 {
 514         struct reflog_expire_cfg *ent;
 515
 516         if (!reflog_expire_cfg_tail)
 517                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 518
 519         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 520                 if (ent->len == len &&
 521                     !memcmp(ent->pattern, pattern, len))
 522                         return ent;
 523
 524         ent = xcalloc(1, (sizeof(*ent) + len));
 525         memcpy(ent->pattern, pattern, len);
 526         ent->len = len;
 527         *reflog_expire_cfg_tail = ent;
 528         reflog_expire_cfg_tail = &(ent->next);
 529         return ent;
 530 }
 531
 532 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 533 {
 534         if (!value)
 535                 return config_error_nonbool(var);
 536         if (parse_expiry_date(value, expire))
 537                 return error(_("%s' for '%s' is not a valid timestamp"),
 538                              value, var);
 539         return 0;
 540 }
 541
 542 /* expiry timer slot */
 543 #define EXPIRE_TOTAL   01
 544 #define EXPIRE_UNREACH 02
 545
 546 static int reflog_expire_config(const char *var, const char *value, void *cb)
 547 {
 548         const char *pattern, *key;
 549         int pattern_len;
 550         unsigned long expire;
 551         int slot;
 552         struct reflog_expire_cfg *ent;
 553
 554         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 555                 return git_default_config(var, value, cb);
 556
 557         if (!strcmp(key, "reflogexpire")) {
 558                 slot = EXPIRE_TOTAL;
 559                 if (parse_expire_cfg_value(var, value, &expire))
 560                         return -1;
 561         } else if (!strcmp(key, "reflogexpireunreachable")) {
 562                 slot = EXPIRE_UNREACH;
 563                 if (parse_expire_cfg_value(var, value, &expire))
 564                         return -1;
 565         } else
 566                 return git_default_config(var, value, cb);
 567
 568         if (!pattern) {
 569                 switch (slot) {
 570                 case EXPIRE_TOTAL:
 571                         default_reflog_expire = expire;
 572                         break;
 573                 case EXPIRE_UNREACH:
 574                         default_reflog_expire_unreachable = expire;
 575                         break;
 576                 }
 577                 return 0;
 578         }
 579
 580         ent = find_cfg_ent(pattern, pattern_len);
 581         if (!ent)
 582                 return -1;
 583         switch (slot) {
 584         case EXPIRE_TOTAL:
 585                 ent->expire_total = expire;
 586                 break;
 587         case EXPIRE_UNREACH:
 588                 ent->expire_unreachable = expire;
 589                 break;
 590         }
 591         return 0;
 592 }
 593
 594 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 595 {
 596         struct reflog_expire_cfg *ent;
 597
 598         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 599                 return; /* both given explicitly -- nothing to tweak */
 600
 601         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 602                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
 603                         if (!(slot & EXPIRE_TOTAL))
 604                                 cb->expire_total = ent->expire_total;
 605                         if (!(slot & EXPIRE_UNREACH))
 606                                 cb->expire_unreachable = ent->expire_unreachable;
 607                         return;
 608                 }
 609         }
 610
 611         /*
 612          * If unconfigured, make stash never expire
 613          */
 614         if (!strcmp(ref, "refs/stash")) {
 615                 if (!(slot & EXPIRE_TOTAL))
 616                         cb->expire_total = 0;
 617                 if (!(slot & EXPIRE_UNREACH))
 618                         cb->expire_unreachable = 0;
 619                 return;
 620         }
 621
 622         /* Nothing matched -- use the default value */
 623         if (!(slot & EXPIRE_TOTAL))
 624                 cb->expire_total = default_reflog_expire;
 625         if (!(slot & EXPIRE_UNREACH))
 626                 cb->expire_unreachable = default_reflog_expire_unreachable;
 627 }
 628
 629 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 630 {
 631         struct cmd_reflog_expire_cb cb;
 632         unsigned long now = time(NULL);
 633         int i, status, do_all;
 634         int explicit_expiry = 0;
 635
 636         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 637         default_reflog_expire = now - 90 * 24 * 3600;
 638         git_config(reflog_expire_config, NULL);
 639
 640         save_commit_buffer = 0;
 641         do_all = status = 0;
 642         memset(&cb, 0, sizeof(cb));
 643
 644         cb.expire_total = default_reflog_expire;
 645         cb.expire_unreachable = default_reflog_expire_unreachable;
 646
 647         for (i = 1; i < argc; i++) {
 648                 const char *arg = argv[i];
 649                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 650                         cb.dry_run = 1;
 651                 else if (starts_with(arg, "--expire=")) {
 652                         if (parse_expiry_date(arg + 9, &cb.expire_total))
 653                                 die(_("'%s' is not a valid timestamp"), arg);
 654                         explicit_expiry |= EXPIRE_TOTAL;
 655                 }
 656                 else if (starts_with(arg, "--expire-unreachable=")) {
 657                         if (parse_expiry_date(arg + 21, &cb.expire_unreachable))
 658                                 die(_("'%s' is not a valid timestamp"), arg);
 659                         explicit_expiry |= EXPIRE_UNREACH;
 660                 }
 661                 else if (!strcmp(arg, "--stale-fix"))
 662                         cb.stalefix = 1;
 663                 else if (!strcmp(arg, "--rewrite"))
 664                         cb.rewrite = 1;
 665                 else if (!strcmp(arg, "--updateref"))
 666                         cb.updateref = 1;
 667                 else if (!strcmp(arg, "--all"))
 668                         do_all = 1;
 669                 else if (!strcmp(arg, "--verbose"))
 670                         cb.verbose = 1;
 671                 else if (!strcmp(arg, "--")) {
 672                         i++;
 673                         break;
 674                 }
 675                 else if (arg[0] == '-')
 676                         usage(reflog_expire_usage);
 677                 else
 678                         break;
 679         }
 680
 681         /*
 682          * We can trust the commits and objects reachable from refs
 683          * even in older repository.  We cannot trust what's reachable
 684          * from reflog if the repository was pruned with older git.
 685          */
 686         if (cb.stalefix) {
 687                 init_revisions(&cb.revs, prefix);
 688                 if (cb.verbose)
 689                         printf("Marking reachable objects...");
 690                 mark_reachable_objects(&cb.revs, 0, 0, NULL);
 691                 if (cb.verbose)
 692                         putchar('\n');
 693         }
 694
 695         if (do_all) {
 696                 struct collect_reflog_cb collected;
 697                 int i;
 698
 699                 memset(&collected, 0, sizeof(collected));
 700                 for_each_reflog(collect_reflog, &collected);
 701                 for (i = 0; i < collected.nr; i++) {
 702                         struct collected_reflog *e = collected.e[i];
 703                         set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
 704                         status |= expire_reflog(e->reflog, e->sha1, &cb);
 705                         free(e);
 706                 }
 707                 free(collected.e);
 708         }
 709
 710         for (; i < argc; i++) {
 711                 char *ref;
 712                 unsigned char sha1[20];
 713                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 714                         status |= error("%s points nowhere!", argv[i]);
 715                         continue;
 716                 }
 717                 set_reflog_expiry_param(&cb, explicit_expiry, ref);
 718                 status |= expire_reflog(ref, sha1, &cb);
 719         }
 720         return status;
 721 }
 722
 723 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 724                 const char *email, unsigned long timestamp, int tz,
 725                 const char *message, void *cb_data)
 726 {
 727         struct cmd_reflog_expire_cb *cb = cb_data;
 728         if (!cb->expire_total || timestamp < cb->expire_total)
 729                 cb->recno++;
 730         return 0;
 731 }
 732
 733 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 734 {
 735         struct cmd_reflog_expire_cb cb;
 736         int i, status = 0;
 737
 738         memset(&cb, 0, sizeof(cb));
 739
 740         for (i = 1; i < argc; i++) {
 741                 const char *arg = argv[i];
 742                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 743                         cb.dry_run = 1;
 744                 else if (!strcmp(arg, "--rewrite"))
 745                         cb.rewrite = 1;
 746                 else if (!strcmp(arg, "--updateref"))
 747                         cb.updateref = 1;
 748                 else if (!strcmp(arg, "--verbose"))
 749                         cb.verbose = 1;
 750                 else if (!strcmp(arg, "--")) {
 751                         i++;
 752                         break;
 753                 }
 754                 else if (arg[0] == '-')
 755                         usage(reflog_delete_usage);
 756                 else
 757                         break;
 758         }
 759
 760         if (argc - i < 1)
 761                 return error("Nothing to delete?");
 762
 763         for ( ; i < argc; i++) {
 764                 const char *spec = strstr(argv[i], "@{");
 765                 unsigned char sha1[20];
 766                 char *ep, *ref;
 767                 int recno;
 768
 769                 if (!spec) {
 770                         status |= error("Not a reflog: %s", argv[i]);
 771                         continue;
 772                 }
 773
 774                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 775                         status |= error("no reflog for '%s'", argv[i]);
 776                         continue;
 777                 }
 778
 779                 recno = strtoul(spec + 2, &ep, 10);
 780                 if (*ep == '}') {
 781                         cb.recno = -recno;
 782                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 783                 } else {
 784                         cb.expire_total = approxidate(spec + 2);
 785                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 786                         cb.expire_total = 0;
 787                 }
 788
 789                 status |= expire_reflog(ref, sha1, &cb);
 790                 free(ref);
 791         }
 792         return status;
 793 }
 794
 795 /*
 796  * main "reflog"
 797  */
 798
 799 static const char reflog_usage[] =
 800 "git reflog [ show | expire | delete ]";
 801
 802 int cmd_reflog(int argc, const char **argv, const char *prefix)
 803 {
 804         if (argc > 1 && !strcmp(argv[1], "-h"))
 805                 usage(reflog_usage);
 806
 807         /* With no command, we default to showing it. */
 808         if (argc < 2 || *argv[1] == '-')
 809                 return cmd_log_reflog(argc, argv, prefix);
 810
 811         if (!strcmp(argv[1], "show"))
 812                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 813
 814         if (!strcmp(argv[1], "expire"))
 815                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 816
 817         if (!strcmp(argv[1], "delete"))
 818                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 819
 820         return cmd_log_reflog(argc, argv, prefix);
 821 }