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 enum expire_reflog_flags {
  24         EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
  25         EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
  26         EXPIRE_REFLOGS_VERBOSE = 1 << 2,
  27         EXPIRE_REFLOGS_REWRITE = 1 << 3
  28 };
  29
  30 struct cmd_reflog_expire_cb {
  31         struct rev_info revs;
  32         int stalefix;
  33         unsigned long expire_total;
  34         unsigned long expire_unreachable;
  35         int recno;
  36 };
  37
  38 struct expire_reflog_policy_cb {
  39         enum {
  40                 UE_NORMAL,
  41                 UE_ALWAYS,
  42                 UE_HEAD
  43         } unreachable_expire_kind;
  44         struct commit_list *mark_list;
  45         unsigned long mark_limit;
  46         struct cmd_reflog_expire_cb *cmd;
  47         struct commit *tip_commit;
  48         struct commit_list *tips;
  49 };
  50
  51 struct expire_reflog_cb {
  52         unsigned int flags;
  53         void *policy_cb;
  54         FILE *newlog;
  55         unsigned char last_kept_sha1[20];
  56 };
  57
  58 struct collected_reflog {
  59         unsigned char sha1[20];
  60         char reflog[FLEX_ARRAY];
  61 };
  62
  63 struct collect_reflog_cb {
  64         struct collected_reflog **e;
  65         int alloc;
  66         int nr;
  67 };
  68
  69 #define INCOMPLETE      (1u<<10)
  70 #define STUDYING        (1u<<11)
  71 #define REACHABLE       (1u<<12)
  72
  73 static int tree_is_complete(const unsigned char *sha1)
  74 {
  75         struct tree_desc desc;
  76         struct name_entry entry;
  77         int complete;
  78         struct tree *tree;
  79
  80         tree = lookup_tree(sha1);
  81         if (!tree)
  82                 return 0;
  83         if (tree->object.flags & SEEN)
  84                 return 1;
  85         if (tree->object.flags & INCOMPLETE)
  86                 return 0;
  87
  88         if (!tree->buffer) {
  89                 enum object_type type;
  90                 unsigned long size;
  91                 void *data = read_sha1_file(sha1, &type, &size);
  92                 if (!data) {
  93                         tree->object.flags |= INCOMPLETE;
  94                         return 0;
  95                 }
  96                 tree->buffer = data;
  97                 tree->size = size;
  98         }
  99         init_tree_desc(&desc, tree->buffer, tree->size);
 100         complete = 1;
 101         while (tree_entry(&desc, &entry)) {
 102                 if (!has_sha1_file(entry.sha1) ||
 103                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
 104                         tree->object.flags |= INCOMPLETE;
 105                         complete = 0;
 106                 }
 107         }
 108         free_tree_buffer(tree);
 109
 110         if (complete)
 111                 tree->object.flags |= SEEN;
 112         return complete;
 113 }
 114
 115 static int commit_is_complete(struct commit *commit)
 116 {
 117         struct object_array study;
 118         struct object_array found;
 119         int is_incomplete = 0;
 120         int i;
 121
 122         /* early return */
 123         if (commit->object.flags & SEEN)
 124                 return 1;
 125         if (commit->object.flags & INCOMPLETE)
 126                 return 0;
 127         /*
 128          * Find all commits that are reachable and are not marked as
 129          * SEEN.  Then make sure the trees and blobs contained are
 130          * complete.  After that, mark these commits also as SEEN.
 131          * If some of the objects that are needed to complete this
 132          * commit are missing, mark this commit as INCOMPLETE.
 133          */
 134         memset(&study, 0, sizeof(study));
 135         memset(&found, 0, sizeof(found));
 136         add_object_array(&commit->object, NULL, &study);
 137         add_object_array(&commit->object, NULL, &found);
 138         commit->object.flags |= STUDYING;
 139         while (study.nr) {
 140                 struct commit *c;
 141                 struct commit_list *parent;
 142
 143                 c = (struct commit *)study.objects[--study.nr].item;
 144                 if (!c->object.parsed && !parse_object(c->object.sha1))
 145                         c->object.flags |= INCOMPLETE;
 146
 147                 if (c->object.flags & INCOMPLETE) {
 148                         is_incomplete = 1;
 149                         break;
 150                 }
 151                 else if (c->object.flags & SEEN)
 152                         continue;
 153                 for (parent = c->parents; parent; parent = parent->next) {
 154                         struct commit *p = parent->item;
 155                         if (p->object.flags & STUDYING)
 156                                 continue;
 157                         p->object.flags |= STUDYING;
 158                         add_object_array(&p->object, NULL, &study);
 159                         add_object_array(&p->object, NULL, &found);
 160                 }
 161         }
 162         if (!is_incomplete) {
 163                 /*
 164                  * make sure all commits in "found" array have all the
 165                  * necessary objects.
 166                  */
 167                 for (i = 0; i < found.nr; i++) {
 168                         struct commit *c =
 169                                 (struct commit *)found.objects[i].item;
 170                         if (!tree_is_complete(c->tree->object.sha1)) {
 171                                 is_incomplete = 1;
 172                                 c->object.flags |= INCOMPLETE;
 173                         }
 174                 }
 175                 if (!is_incomplete) {
 176                         /* mark all found commits as complete, iow SEEN */
 177                         for (i = 0; i < found.nr; i++)
 178                                 found.objects[i].item->flags |= SEEN;
 179                 }
 180         }
 181         /* clear flags from the objects we traversed */
 182         for (i = 0; i < found.nr; i++)
 183                 found.objects[i].item->flags &= ~STUDYING;
 184         if (is_incomplete)
 185                 commit->object.flags |= INCOMPLETE;
 186         else {
 187                 /*
 188                  * If we come here, we have (1) traversed the ancestry chain
 189                  * from the "commit" until we reach SEEN commits (which are
 190                  * known to be complete), and (2) made sure that the commits
 191                  * encountered during the above traversal refer to trees that
 192                  * are complete.  Which means that we know *all* the commits
 193                  * we have seen during this process are complete.
 194                  */
 195                 for (i = 0; i < found.nr; i++)
 196                         found.objects[i].item->flags |= SEEN;
 197         }
 198         /* free object arrays */
 199         free(study.objects);
 200         free(found.objects);
 201         return !is_incomplete;
 202 }
 203
 204 static int keep_entry(struct commit **it, unsigned char *sha1)
 205 {
 206         struct commit *commit;
 207
 208         if (is_null_sha1(sha1))
 209                 return 1;
 210         commit = lookup_commit_reference_gently(sha1, 1);
 211         if (!commit)
 212                 return 0;
 213
 214         /*
 215          * Make sure everything in this commit exists.
 216          *
 217          * We have walked all the objects reachable from the refs
 218          * and cache earlier.  The commits reachable by this commit
 219          * must meet SEEN commits -- and then we should mark them as
 220          * SEEN as well.
 221          */
 222         if (!commit_is_complete(commit))
 223                 return 0;
 224         *it = commit;
 225         return 1;
 226 }
 227
 228 /*
 229  * Starting from commits in the cb->mark_list, mark commits that are
 230  * reachable from them.  Stop the traversal at commits older than
 231  * the expire_limit and queue them back, so that the caller can call
 232  * us again to restart the traversal with longer expire_limit.
 233  */
 234 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 235 {
 236         struct commit *commit;
 237         struct commit_list *pending;
 238         unsigned long expire_limit = cb->mark_limit;
 239         struct commit_list *leftover = NULL;
 240
 241         for (pending = cb->mark_list; pending; pending = pending->next)
 242                 pending->item->object.flags &= ~REACHABLE;
 243
 244         pending = cb->mark_list;
 245         while (pending) {
 246                 struct commit_list *entry = pending;
 247                 struct commit_list *parent;
 248                 pending = entry->next;
 249                 commit = entry->item;
 250                 free(entry);
 251                 if (commit->object.flags & REACHABLE)
 252                         continue;
 253                 if (parse_commit(commit))
 254                         continue;
 255                 commit->object.flags |= REACHABLE;
 256                 if (commit->date < expire_limit) {
 257                         commit_list_insert(commit, &leftover);
 258                         continue;
 259                 }
 260                 commit->object.flags |= REACHABLE;
 261                 parent = commit->parents;
 262                 while (parent) {
 263                         commit = parent->item;
 264                         parent = parent->next;
 265                         if (commit->object.flags & REACHABLE)
 266                                 continue;
 267                         commit_list_insert(commit, &pending);
 268                 }
 269         }
 270         cb->mark_list = leftover;
 271 }
 272
 273 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, unsigned char *sha1)
 274 {
 275         /*
 276          * We may or may not have the commit yet - if not, look it
 277          * up using the supplied sha1.
 278          */
 279         if (!commit) {
 280                 if (is_null_sha1(sha1))
 281                         return 0;
 282
 283                 commit = lookup_commit_reference_gently(sha1, 1);
 284
 285                 /* Not a commit -- keep it */
 286                 if (!commit)
 287                         return 0;
 288         }
 289
 290         /* Reachable from the current ref?  Don't prune. */
 291         if (commit->object.flags & REACHABLE)
 292                 return 0;
 293
 294         if (cb->mark_list && cb->mark_limit) {
 295                 cb->mark_limit = 0; /* dig down to the root */
 296                 mark_reachable(cb);
 297         }
 298
 299         return !(commit->object.flags & REACHABLE);
 300 }
 301
 302 /*
 303  * Return true iff the specified reflog entry should be expired.
 304  */
 305 static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 306                                     const char *email, unsigned long timestamp, int tz,
 307                                     const char *message, void *cb_data)
 308 {
 309         struct expire_reflog_policy_cb *cb = cb_data;
 310         struct commit *old, *new;
 311
 312         if (timestamp < cb->cmd->expire_total)
 313                 return 1;
 314
 315         old = new = NULL;
 316         if (cb->cmd->stalefix &&
 317             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 318                 return 1;
 319
 320         if (timestamp < cb->cmd->expire_unreachable) {
 321                 if (cb->unreachable_expire_kind == UE_ALWAYS)
 322                         return 1;
 323                 if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 324                         return 1;
 325         }
 326
 327         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 328                 return 1;
 329
 330         return 0;
 331 }
 332
 333 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 334                 const char *email, unsigned long timestamp, int tz,
 335                 const char *message, void *cb_data)
 336 {
 337         struct expire_reflog_cb *cb = cb_data;
 338         struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
 339
 340         if (cb->flags & EXPIRE_REFLOGS_REWRITE)
 341                 osha1 = cb->last_kept_sha1;
 342
 343         if (should_expire_reflog_ent(osha1, nsha1, email, timestamp, tz,
 344                                      message, policy_cb)) {
 345                 if (!cb->newlog)
 346                         printf("would prune %s", message);
 347                 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
 348                         printf("prune %s", message);
 349         } else {
 350                 if (cb->newlog) {
 351                         char sign = (tz < 0) ? '-' : '+';
 352                         int zone = (tz < 0) ? (-tz) : tz;
 353                         fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 354                                 sha1_to_hex(osha1), sha1_to_hex(nsha1),
 355                                 email, timestamp, sign, zone,
 356                                 message);
 357                         hashcpy(cb->last_kept_sha1, nsha1);
 358                 }
 359                 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
 360                         printf("keep %s", message);
 361         }
 362         return 0;
 363 }
 364
 365 static int push_tip_to_list(const char *refname, const unsigned char *sha1,
 366                             int flags, void *cb_data)
 367 {
 368         struct commit_list **list = cb_data;
 369         struct commit *tip_commit;
 370         if (flags & REF_ISSYMREF)
 371                 return 0;
 372         tip_commit = lookup_commit_reference_gently(sha1, 1);
 373         if (!tip_commit)
 374                 return 0;
 375         commit_list_insert(tip_commit, list);
 376         return 0;
 377 }
 378
 379 static void reflog_expiry_prepare(const char *refname,
 380                                   const unsigned char *sha1,
 381                                   struct expire_reflog_policy_cb *cb)
 382 {
 383         if (!cb->cmd->expire_unreachable || !strcmp(refname, "HEAD")) {
 384                 cb->tip_commit = NULL;
 385                 cb->unreachable_expire_kind = UE_HEAD;
 386         } else {
 387                 cb->tip_commit = lookup_commit_reference_gently(sha1, 1);
 388                 if (!cb->tip_commit)
 389                         cb->unreachable_expire_kind = UE_ALWAYS;
 390                 else
 391                         cb->unreachable_expire_kind = UE_NORMAL;
 392         }
 393
 394         if (cb->cmd->expire_unreachable <= cb->cmd->expire_total)
 395                 cb->unreachable_expire_kind = UE_ALWAYS;
 396
 397         cb->mark_list = NULL;
 398         cb->tips = NULL;
 399         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 400                 if (cb->unreachable_expire_kind == UE_HEAD) {
 401                         struct commit_list *elem;
 402                         for_each_ref(push_tip_to_list, &cb->tips);
 403                         for (elem = cb->tips; elem; elem = elem->next)
 404                                 commit_list_insert(elem->item, &cb->mark_list);
 405                 } else {
 406                         commit_list_insert(cb->tip_commit, &cb->mark_list);
 407                 }
 408                 cb->mark_limit = cb->cmd->expire_total;
 409                 mark_reachable(cb);
 410         }
 411 }
 412
 413 static void reflog_expiry_cleanup(struct expire_reflog_policy_cb *cb)
 414 {
 415         if (cb->unreachable_expire_kind != UE_ALWAYS) {
 416                 if (cb->unreachable_expire_kind == UE_HEAD) {
 417                         struct commit_list *elem;
 418                         for (elem = cb->tips; elem; elem = elem->next)
 419                                 clear_commit_marks(elem->item, REACHABLE);
 420                         free_commit_list(cb->tips);
 421                 } else {
 422                         clear_commit_marks(cb->tip_commit, REACHABLE);
 423                 }
 424         }
 425 }
 426
 427 static int expire_reflog(const char *refname, const unsigned char *sha1,
 428                          unsigned int flags, struct cmd_reflog_expire_cb *cmd)
 429 {
 430         static struct lock_file reflog_lock;
 431         struct expire_reflog_cb cb;
 432         struct expire_reflog_policy_cb policy_cb;
 433         struct ref_lock *lock;
 434         char *log_file;
 435         int status = 0;
 436
 437         memset(&cb, 0, sizeof(cb));
 438         memset(&policy_cb, 0, sizeof(policy_cb));
 439         cb.flags = flags;
 440         cb.policy_cb = &policy_cb;
 441
 442         /*
 443          * The reflog file is locked by holding the lock on the
 444          * reference itself, plus we might need to update the
 445          * reference if --updateref was specified:
 446          */
 447         lock = lock_any_ref_for_update(refname, sha1, 0, NULL);
 448         if (!lock)
 449                 return error("cannot lock ref '%s'", refname);
 450         if (!reflog_exists(refname)) {
 451                 unlock_ref(lock);
 452                 return 0;
 453         }
 454
 455         log_file = git_pathdup("logs/%s", refname);
 456         if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
 457                 /*
 458                  * Even though holding $GIT_DIR/logs/$reflog.lock has
 459                  * no locking implications, we use the lock_file
 460                  * machinery here anyway because it does a lot of the
 461                  * work we need, including cleaning up if the program
 462                  * exits unexpectedly.
 463                  */
 464                 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
 465                         struct strbuf err = STRBUF_INIT;
 466                         unable_to_lock_message(log_file, errno, &err);
 467                         error("%s", err.buf);
 468                         strbuf_release(&err);
 469                         goto failure;
 470                 }
 471                 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
 472                 if (!cb.newlog) {
 473                         error("cannot fdopen %s (%s)",
 474                               reflog_lock.filename.buf, strerror(errno));
 475                         goto failure;
 476                 }
 477         }
 478
 479         policy_cb.cmd = cmd;
 480
 481         reflog_expiry_prepare(refname, sha1, &policy_cb);
 482         for_each_reflog_ent(refname, expire_reflog_ent, &cb);
 483         reflog_expiry_cleanup(&policy_cb);
 484
 485         if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
 486                 if (close_lock_file(&reflog_lock)) {
 487                         status |= error("couldn't write %s: %s", log_file,
 488                                         strerror(errno));
 489                 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) &&
 490                         (write_in_full(lock->lock_fd,
 491                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 492                          write_str_in_full(lock->lock_fd, "\n") != 1 ||
 493                          close_ref(lock) < 0)) {
 494                         status |= error("couldn't write %s",
 495                                         lock->lk->filename.buf);
 496                         rollback_lock_file(&reflog_lock);
 497                 } else if (commit_lock_file(&reflog_lock)) {
 498                         status |= error("unable to commit reflog '%s' (%s)",
 499                                         log_file, strerror(errno));
 500                 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
 501                         status |= error("couldn't set %s", lock->ref_name);
 502                 }
 503         }
 504         free(log_file);
 505         unlock_ref(lock);
 506         return status;
 507
 508  failure:
 509         rollback_lock_file(&reflog_lock);
 510         free(log_file);
 511         unlock_ref(lock);
 512         return -1;
 513 }
 514
 515 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 516 {
 517         struct collected_reflog *e;
 518         struct collect_reflog_cb *cb = cb_data;
 519         size_t namelen = strlen(ref);
 520
 521         e = xmalloc(sizeof(*e) + namelen + 1);
 522         hashcpy(e->sha1, sha1);
 523         memcpy(e->reflog, ref, namelen + 1);
 524         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 525         cb->e[cb->nr++] = e;
 526         return 0;
 527 }
 528
 529 static struct reflog_expire_cfg {
 530         struct reflog_expire_cfg *next;
 531         unsigned long expire_total;
 532         unsigned long expire_unreachable;
 533         size_t len;
 534         char pattern[FLEX_ARRAY];
 535 } *reflog_expire_cfg, **reflog_expire_cfg_tail;
 536
 537 static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 538 {
 539         struct reflog_expire_cfg *ent;
 540
 541         if (!reflog_expire_cfg_tail)
 542                 reflog_expire_cfg_tail = &reflog_expire_cfg;
 543
 544         for (ent = reflog_expire_cfg; ent; ent = ent->next)
 545                 if (ent->len == len &&
 546                     !memcmp(ent->pattern, pattern, len))
 547                         return ent;
 548
 549         ent = xcalloc(1, (sizeof(*ent) + len));
 550         memcpy(ent->pattern, pattern, len);
 551         ent->len = len;
 552         *reflog_expire_cfg_tail = ent;
 553         reflog_expire_cfg_tail = &(ent->next);
 554         return ent;
 555 }
 556
 557 static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 558 {
 559         if (!value)
 560                 return config_error_nonbool(var);
 561         if (parse_expiry_date(value, expire))
 562                 return error(_("%s' for '%s' is not a valid timestamp"),
 563                              value, var);
 564         return 0;
 565 }
 566
 567 /* expiry timer slot */
 568 #define EXPIRE_TOTAL   01
 569 #define EXPIRE_UNREACH 02
 570
 571 static int reflog_expire_config(const char *var, const char *value, void *cb)
 572 {
 573         const char *pattern, *key;
 574         int pattern_len;
 575         unsigned long expire;
 576         int slot;
 577         struct reflog_expire_cfg *ent;
 578
 579         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 580                 return git_default_config(var, value, cb);
 581
 582         if (!strcmp(key, "reflogexpire")) {
 583                 slot = EXPIRE_TOTAL;
 584                 if (parse_expire_cfg_value(var, value, &expire))
 585                         return -1;
 586         } else if (!strcmp(key, "reflogexpireunreachable")) {
 587                 slot = EXPIRE_UNREACH;
 588                 if (parse_expire_cfg_value(var, value, &expire))
 589                         return -1;
 590         } else
 591                 return git_default_config(var, value, cb);
 592
 593         if (!pattern) {
 594                 switch (slot) {
 595                 case EXPIRE_TOTAL:
 596                         default_reflog_expire = expire;
 597                         break;
 598                 case EXPIRE_UNREACH:
 599                         default_reflog_expire_unreachable = expire;
 600                         break;
 601                 }
 602                 return 0;
 603         }
 604
 605         ent = find_cfg_ent(pattern, pattern_len);
 606         if (!ent)
 607                 return -1;
 608         switch (slot) {
 609         case EXPIRE_TOTAL:
 610                 ent->expire_total = expire;
 611                 break;
 612         case EXPIRE_UNREACH:
 613                 ent->expire_unreachable = expire;
 614                 break;
 615         }
 616         return 0;
 617 }
 618
 619 static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 620 {
 621         struct reflog_expire_cfg *ent;
 622
 623         if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 624                 return; /* both given explicitly -- nothing to tweak */
 625
 626         for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 627                 if (!wildmatch(ent->pattern, ref, 0, NULL)) {
 628                         if (!(slot & EXPIRE_TOTAL))
 629                                 cb->expire_total = ent->expire_total;
 630                         if (!(slot & EXPIRE_UNREACH))
 631                                 cb->expire_unreachable = ent->expire_unreachable;
 632                         return;
 633                 }
 634         }
 635
 636         /*
 637          * If unconfigured, make stash never expire
 638          */
 639         if (!strcmp(ref, "refs/stash")) {
 640                 if (!(slot & EXPIRE_TOTAL))
 641                         cb->expire_total = 0;
 642                 if (!(slot & EXPIRE_UNREACH))
 643                         cb->expire_unreachable = 0;
 644                 return;
 645         }
 646
 647         /* Nothing matched -- use the default value */
 648         if (!(slot & EXPIRE_TOTAL))
 649                 cb->expire_total = default_reflog_expire;
 650         if (!(slot & EXPIRE_UNREACH))
 651                 cb->expire_unreachable = default_reflog_expire_unreachable;
 652 }
 653
 654 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 655 {
 656         struct cmd_reflog_expire_cb cb;
 657         unsigned long now = time(NULL);
 658         int i, status, do_all;
 659         int explicit_expiry = 0;
 660         unsigned int flags = 0;
 661
 662         default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 663         default_reflog_expire = now - 90 * 24 * 3600;
 664         git_config(reflog_expire_config, NULL);
 665
 666         save_commit_buffer = 0;
 667         do_all = status = 0;
 668         memset(&cb, 0, sizeof(cb));
 669
 670         cb.expire_total = default_reflog_expire;
 671         cb.expire_unreachable = default_reflog_expire_unreachable;
 672
 673         for (i = 1; i < argc; i++) {
 674                 const char *arg = argv[i];
 675                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 676                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 677                 else if (starts_with(arg, "--expire=")) {
 678                         if (parse_expiry_date(arg + 9, &cb.expire_total))
 679                                 die(_("'%s' is not a valid timestamp"), arg);
 680                         explicit_expiry |= EXPIRE_TOTAL;
 681                 }
 682                 else if (starts_with(arg, "--expire-unreachable=")) {
 683                         if (parse_expiry_date(arg + 21, &cb.expire_unreachable))
 684                                 die(_("'%s' is not a valid timestamp"), arg);
 685                         explicit_expiry |= EXPIRE_UNREACH;
 686                 }
 687                 else if (!strcmp(arg, "--stale-fix"))
 688                         cb.stalefix = 1;
 689                 else if (!strcmp(arg, "--rewrite"))
 690                         flags |= EXPIRE_REFLOGS_REWRITE;
 691                 else if (!strcmp(arg, "--updateref"))
 692                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 693                 else if (!strcmp(arg, "--all"))
 694                         do_all = 1;
 695                 else if (!strcmp(arg, "--verbose"))
 696                         flags |= EXPIRE_REFLOGS_VERBOSE;
 697                 else if (!strcmp(arg, "--")) {
 698                         i++;
 699                         break;
 700                 }
 701                 else if (arg[0] == '-')
 702                         usage(reflog_expire_usage);
 703                 else
 704                         break;
 705         }
 706
 707         /*
 708          * We can trust the commits and objects reachable from refs
 709          * even in older repository.  We cannot trust what's reachable
 710          * from reflog if the repository was pruned with older git.
 711          */
 712         if (cb.stalefix) {
 713                 init_revisions(&cb.revs, prefix);
 714                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 715                         printf("Marking reachable objects...");
 716                 mark_reachable_objects(&cb.revs, 0, 0, NULL);
 717                 if (flags & EXPIRE_REFLOGS_VERBOSE)
 718                         putchar('\n');
 719         }
 720
 721         if (do_all) {
 722                 struct collect_reflog_cb collected;
 723                 int i;
 724
 725                 memset(&collected, 0, sizeof(collected));
 726                 for_each_reflog(collect_reflog, &collected);
 727                 for (i = 0; i < collected.nr; i++) {
 728                         struct collected_reflog *e = collected.e[i];
 729                         set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
 730                         status |= expire_reflog(e->reflog, e->sha1, flags, &cb);
 731                         free(e);
 732                 }
 733                 free(collected.e);
 734         }
 735
 736         for (; i < argc; i++) {
 737                 char *ref;
 738                 unsigned char sha1[20];
 739                 if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 740                         status |= error("%s points nowhere!", argv[i]);
 741                         continue;
 742                 }
 743                 set_reflog_expiry_param(&cb, explicit_expiry, ref);
 744                 status |= expire_reflog(ref, sha1, flags, &cb);
 745         }
 746         return status;
 747 }
 748
 749 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 750                 const char *email, unsigned long timestamp, int tz,
 751                 const char *message, void *cb_data)
 752 {
 753         struct cmd_reflog_expire_cb *cb = cb_data;
 754         if (!cb->expire_total || timestamp < cb->expire_total)
 755                 cb->recno++;
 756         return 0;
 757 }
 758
 759 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 760 {
 761         struct cmd_reflog_expire_cb cb;
 762         int i, status = 0;
 763         unsigned int flags = 0;
 764
 765         memset(&cb, 0, sizeof(cb));
 766
 767         for (i = 1; i < argc; i++) {
 768                 const char *arg = argv[i];
 769                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 770                         flags |= EXPIRE_REFLOGS_DRY_RUN;
 771                 else if (!strcmp(arg, "--rewrite"))
 772                         flags |= EXPIRE_REFLOGS_REWRITE;
 773                 else if (!strcmp(arg, "--updateref"))
 774                         flags |= EXPIRE_REFLOGS_UPDATE_REF;
 775                 else if (!strcmp(arg, "--verbose"))
 776                         flags |= EXPIRE_REFLOGS_VERBOSE;
 777                 else if (!strcmp(arg, "--")) {
 778                         i++;
 779                         break;
 780                 }
 781                 else if (arg[0] == '-')
 782                         usage(reflog_delete_usage);
 783                 else
 784                         break;
 785         }
 786
 787         if (argc - i < 1)
 788                 return error("Nothing to delete?");
 789
 790         for ( ; i < argc; i++) {
 791                 const char *spec = strstr(argv[i], "@{");
 792                 unsigned char sha1[20];
 793                 char *ep, *ref;
 794                 int recno;
 795
 796                 if (!spec) {
 797                         status |= error("Not a reflog: %s", argv[i]);
 798                         continue;
 799                 }
 800
 801                 if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 802                         status |= error("no reflog for '%s'", argv[i]);
 803                         continue;
 804                 }
 805
 806                 recno = strtoul(spec + 2, &ep, 10);
 807                 if (*ep == '}') {
 808                         cb.recno = -recno;
 809                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 810                 } else {
 811                         cb.expire_total = approxidate(spec + 2);
 812                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 813                         cb.expire_total = 0;
 814                 }
 815
 816                 status |= expire_reflog(ref, sha1, flags, &cb);
 817                 free(ref);
 818         }
 819         return status;
 820 }
 821
 822 /*
 823  * main "reflog"
 824  */
 825
 826 static const char reflog_usage[] =
 827 "git reflog [ show | expire | delete ]";
 828
 829 int cmd_reflog(int argc, const char **argv, const char *prefix)
 830 {
 831         if (argc > 1 && !strcmp(argv[1], "-h"))
 832                 usage(reflog_usage);
 833
 834         /* With no command, we default to showing it. */
 835         if (argc < 2 || *argv[1] == '-')
 836                 return cmd_log_reflog(argc, argv, prefix);
 837
 838         if (!strcmp(argv[1], "show"))
 839                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 840
 841         if (!strcmp(argv[1], "expire"))
 842                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 843
 844         if (!strcmp(argv[1], "delete"))
 845                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 846
 847         return cmd_log_reflog(argc, argv, prefix);
 848 }