builtin-reflog.c

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