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 expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 213                 const char *email, unsigned long timestamp, int tz,
 214                 const char *message, void *cb_data)
 215 {
 216         struct expire_reflog_cb *cb = cb_data;
 217         struct commit *old, *new;
 218
 219         if (timestamp < cb->cmd->expire_total)
 220                 goto prune;
 221
 222         if (cb->cmd->rewrite)
 223                 osha1 = cb->last_kept_sha1;
 224
 225         old = new = NULL;
 226         if (cb->cmd->stalefix &&
 227             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 228                 goto prune;
 229
 230         if (timestamp < cb->cmd->expire_unreachable) {
 231                 if (!cb->ref_commit)
 232                         goto prune;
 233                 if (!old && !is_null_sha1(osha1))
 234                         old = lookup_commit_reference_gently(osha1, 1);
 235                 if (!new && !is_null_sha1(nsha1))
 236                         new = lookup_commit_reference_gently(nsha1, 1);
 237                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
 238                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
 239                         goto prune;
 240         }
 241
 242         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 243                 goto prune;
 244
 245         if (cb->newlog) {
 246                 char sign = (tz < 0) ? '-' : '+';
 247                 int zone = (tz < 0) ? (-tz) : tz;
 248                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 249                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 250                         email, timestamp, sign, zone,
 251                         message);
 252                 hashcpy(cb->last_kept_sha1, nsha1);
 253         }
 254         if (cb->cmd->verbose)
 255                 printf("keep %s", message);
 256         return 0;
 257  prune:
 258         if (!cb->newlog || cb->cmd->verbose)
 259                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 260         return 0;
 261 }
 262
 263 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 264 {
 265         struct cmd_reflog_expire_cb *cmd = cb_data;
 266         struct expire_reflog_cb cb;
 267         struct ref_lock *lock;
 268         char *log_file, *newlog_path = NULL;
 269         int status = 0;
 270
 271         memset(&cb, 0, sizeof(cb));
 272         /* we take the lock for the ref itself to prevent it from
 273          * getting updated.
 274          */
 275         lock = lock_any_ref_for_update(ref, sha1, 0);
 276         if (!lock)
 277                 return error("cannot lock ref '%s'", ref);
 278         log_file = xstrdup(git_path("logs/%s", ref));
 279         if (!file_exists(log_file))
 280                 goto finish;
 281         if (!cmd->dry_run) {
 282                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 283                 cb.newlog = fopen(newlog_path, "w");
 284         }
 285
 286         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 287         cb.ref = ref;
 288         cb.cmd = cmd;
 289         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 290  finish:
 291         if (cb.newlog) {
 292                 if (fclose(cb.newlog)) {
 293                         status |= error("%s: %s", strerror(errno),
 294                                         newlog_path);
 295                         unlink(newlog_path);
 296                 } else if (cmd->updateref &&
 297                         (write_in_full(lock->lock_fd,
 298                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 299                          write_in_full(lock->lock_fd, "\n", 1) != 1 ||
 300                          close_ref(lock) < 0)) {
 301                         status |= error("Couldn't write %s",
 302                                 lock->lk->filename);
 303                         unlink(newlog_path);
 304                 } else if (rename(newlog_path, log_file)) {
 305                         status |= error("cannot rename %s to %s",
 306                                         newlog_path, log_file);
 307                         unlink(newlog_path);
 308                 } else if (cmd->updateref && commit_ref(lock)) {
 309                         status |= error("Couldn't set %s", lock->ref_name);
 310                 } else {
 311                         adjust_shared_perm(log_file);
 312                 }
 313         }
 314         free(newlog_path);
 315         free(log_file);
 316         unlock_ref(lock);
 317         return status;
 318 }
 319
 320 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 321 {
 322         struct collected_reflog *e;
 323         struct collect_reflog_cb *cb = cb_data;
 324         size_t namelen = strlen(ref);
 325
 326         e = xmalloc(sizeof(*e) + namelen + 1);
 327         hashcpy(e->sha1, sha1);
 328         memcpy(e->reflog, ref, namelen + 1);
 329         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 330         cb->e[cb->nr++] = e;
 331         return 0;
 332 }
 333
 334 static int reflog_expire_config(const char *var, const char *value, void *cb)
 335 {
 336         if (!strcmp(var, "gc.reflogexpire")) {
 337                 if (!value)
 338                         config_error_nonbool(var);
 339                 default_reflog_expire = approxidate(value);
 340                 return 0;
 341         }
 342         if (!strcmp(var, "gc.reflogexpireunreachable")) {
 343                 if (!value)
 344                         config_error_nonbool(var);
 345                 default_reflog_expire_unreachable = approxidate(value);
 346                 return 0;
 347         }
 348         return git_default_config(var, value, cb);
 349 }
 350
 351 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 352 {
 353         struct cmd_reflog_expire_cb cb;
 354         unsigned long now = time(NULL);
 355         int i, status, do_all;
 356
 357         git_config(reflog_expire_config, NULL);
 358
 359         save_commit_buffer = 0;
 360         do_all = status = 0;
 361         memset(&cb, 0, sizeof(cb));
 362
 363         if (!default_reflog_expire_unreachable)
 364                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 365         if (!default_reflog_expire)
 366                 default_reflog_expire = now - 90 * 24 * 3600;
 367         cb.expire_total = default_reflog_expire;
 368         cb.expire_unreachable = default_reflog_expire_unreachable;
 369
 370         /*
 371          * We can trust the commits and objects reachable from refs
 372          * even in older repository.  We cannot trust what's reachable
 373          * from reflog if the repository was pruned with older git.
 374          */
 375
 376         for (i = 1; i < argc; i++) {
 377                 const char *arg = argv[i];
 378                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 379                         cb.dry_run = 1;
 380                 else if (!prefixcmp(arg, "--expire="))
 381                         cb.expire_total = approxidate(arg + 9);
 382                 else if (!prefixcmp(arg, "--expire-unreachable="))
 383                         cb.expire_unreachable = approxidate(arg + 21);
 384                 else if (!strcmp(arg, "--stale-fix"))
 385                         cb.stalefix = 1;
 386                 else if (!strcmp(arg, "--rewrite"))
 387                         cb.rewrite = 1;
 388                 else if (!strcmp(arg, "--updateref"))
 389                         cb.updateref = 1;
 390                 else if (!strcmp(arg, "--all"))
 391                         do_all = 1;
 392                 else if (!strcmp(arg, "--verbose"))
 393                         cb.verbose = 1;
 394                 else if (!strcmp(arg, "--")) {
 395                         i++;
 396                         break;
 397                 }
 398                 else if (arg[0] == '-')
 399                         usage(reflog_expire_usage);
 400                 else
 401                         break;
 402         }
 403         if (cb.stalefix) {
 404                 init_revisions(&cb.revs, prefix);
 405                 if (cb.verbose)
 406                         printf("Marking reachable objects...");
 407                 mark_reachable_objects(&cb.revs, 0);
 408                 if (cb.verbose)
 409                         putchar('\n');
 410         }
 411
 412         if (do_all) {
 413                 struct collect_reflog_cb collected;
 414                 int i;
 415
 416                 memset(&collected, 0, sizeof(collected));
 417                 for_each_reflog(collect_reflog, &collected);
 418                 for (i = 0; i < collected.nr; i++) {
 419                         struct collected_reflog *e = collected.e[i];
 420                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 421                         free(e);
 422                 }
 423                 free(collected.e);
 424         }
 425
 426         while (i < argc) {
 427                 const char *ref = argv[i++];
 428                 unsigned char sha1[20];
 429                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 430                         status |= error("%s points nowhere!", ref);
 431                         continue;
 432                 }
 433                 status |= expire_reflog(ref, sha1, 0, &cb);
 434         }
 435         return status;
 436 }
 437
 438 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 439                 const char *email, unsigned long timestamp, int tz,
 440                 const char *message, void *cb_data)
 441 {
 442         struct cmd_reflog_expire_cb *cb = cb_data;
 443         if (!cb->expire_total || timestamp < cb->expire_total)
 444                 cb->recno++;
 445         return 0;
 446 }
 447
 448 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 449 {
 450         struct cmd_reflog_expire_cb cb;
 451         int i, status = 0;
 452
 453         memset(&cb, 0, sizeof(cb));
 454
 455         for (i = 1; i < argc; i++) {
 456                 const char *arg = argv[i];
 457                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 458                         cb.dry_run = 1;
 459                 else if (!strcmp(arg, "--rewrite"))
 460                         cb.rewrite = 1;
 461                 else if (!strcmp(arg, "--updateref"))
 462                         cb.updateref = 1;
 463                 else if (!strcmp(arg, "--verbose"))
 464                         cb.verbose = 1;
 465                 else if (!strcmp(arg, "--")) {
 466                         i++;
 467                         break;
 468                 }
 469                 else if (arg[0] == '-')
 470                         usage(reflog_delete_usage);
 471                 else
 472                         break;
 473         }
 474
 475         if (argc - i < 1)
 476                 return error("Nothing to delete?");
 477
 478         for ( ; i < argc; i++) {
 479                 const char *spec = strstr(argv[i], "@{");
 480                 unsigned char sha1[20];
 481                 char *ep, *ref;
 482                 int recno;
 483
 484                 if (!spec) {
 485                         status |= error("Not a reflog: %s", argv[i]);
 486                         continue;
 487                 }
 488
 489                 if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
 490                         status |= error("%s points nowhere!", argv[i]);
 491                         continue;
 492                 }
 493
 494                 recno = strtoul(spec + 2, &ep, 10);
 495                 if (*ep == '}') {
 496                         cb.recno = -recno;
 497                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 498                 } else {
 499                         cb.expire_total = approxidate(spec + 2);
 500                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 501                         cb.expire_total = 0;
 502                 }
 503
 504                 status |= expire_reflog(ref, sha1, 0, &cb);
 505                 free(ref);
 506         }
 507         return status;
 508 }
 509
 510 /*
 511  * main "reflog"
 512  */
 513
 514 static const char reflog_usage[] =
 515 "git-reflog (expire | ...)";
 516
 517 int cmd_reflog(int argc, const char **argv, const char *prefix)
 518 {
 519         /* With no command, we default to showing it. */
 520         if (argc < 2 || *argv[1] == '-')
 521                 return cmd_log_reflog(argc, argv, prefix);
 522
 523         if (!strcmp(argv[1], "show"))
 524                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 525
 526         if (!strcmp(argv[1], "expire"))
 527                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 528
 529         if (!strcmp(argv[1], "delete"))
 530                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 531
 532         /* Not a recognized reflog command..*/
 533         usage(reflog_usage);
 534 }