reflog.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2 #define DISABLE_SIGN_COMPARE_WARNINGS
   3
   4 #include "git-compat-util.h"
   5 #include "config.h"
   6 #include "gettext.h"
   7 #include "parse-options.h"
   8 #include "odb.h"
   9 #include "reflog.h"
  10 #include "refs.h"
  11 #include "revision.h"
  12 #include "tree.h"
  13 #include "tree-walk.h"
  14 #include "wildmatch.h"
  15
  16 static struct reflog_expire_entry_option *find_cfg_ent(struct reflog_expire_options *opts,
  17                                                        const char *pattern, size_t len)
  18 {
  19         struct reflog_expire_entry_option *ent;
  20
  21         if (!opts->entries_tail)
  22                 opts->entries_tail = &opts->entries;
  23
  24         for (ent = opts->entries; ent; ent = ent->next)
  25                 if (!xstrncmpz(ent->pattern, pattern, len))
  26                         return ent;
  27
  28         FLEX_ALLOC_MEM(ent, pattern, pattern, len);
  29         *opts->entries_tail = ent;
  30         opts->entries_tail = &(ent->next);
  31         return ent;
  32 }
  33
  34 int reflog_expire_config(const char *var, const char *value,
  35                          const struct config_context *ctx, void *cb)
  36 {
  37         struct reflog_expire_options *opts = cb;
  38         const char *pattern, *key;
  39         size_t pattern_len;
  40         timestamp_t expire;
  41         int slot;
  42         struct reflog_expire_entry_option *ent;
  43
  44         if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
  45                 return git_default_config(var, value, ctx, cb);
  46
  47         if (!strcmp(key, "reflogexpire")) {
  48                 slot = REFLOG_EXPIRE_TOTAL;
  49                 if (git_config_expiry_date(&expire, var, value))
  50                         return -1;
  51         } else if (!strcmp(key, "reflogexpireunreachable")) {
  52                 slot = REFLOG_EXPIRE_UNREACH;
  53                 if (git_config_expiry_date(&expire, var, value))
  54                         return -1;
  55         } else
  56                 return git_default_config(var, value, ctx, cb);
  57
  58         if (!pattern) {
  59                 switch (slot) {
  60                 case REFLOG_EXPIRE_TOTAL:
  61                         opts->default_expire_total = expire;
  62                         break;
  63                 case REFLOG_EXPIRE_UNREACH:
  64                         opts->default_expire_unreachable = expire;
  65                         break;
  66                 }
  67                 return 0;
  68         }
  69
  70         ent = find_cfg_ent(opts, pattern, pattern_len);
  71         if (!ent)
  72                 return -1;
  73         switch (slot) {
  74         case REFLOG_EXPIRE_TOTAL:
  75                 ent->expire_total = expire;
  76                 break;
  77         case REFLOG_EXPIRE_UNREACH:
  78                 ent->expire_unreachable = expire;
  79                 break;
  80         }
  81         return 0;
  82 }
  83
  84 void reflog_clear_expire_config(struct reflog_expire_options *opts)
  85 {
  86         struct reflog_expire_entry_option *ent = opts->entries, *tmp;
  87
  88         while (ent) {
  89                 tmp = ent;
  90                 ent = ent->next;
  91                 free(tmp);
  92         }
  93
  94         opts->entries = NULL;
  95         opts->entries_tail = NULL;
  96 }
  97
  98 void reflog_expire_options_set_refname(struct reflog_expire_options *cb,
  99                                        const char *ref)
 100 {
 101         struct reflog_expire_entry_option *ent;
 102
 103         if (cb->explicit_expiry == (REFLOG_EXPIRE_TOTAL|REFLOG_EXPIRE_UNREACH))
 104                 return; /* both given explicitly -- nothing to tweak */
 105
 106         for (ent = cb->entries; ent; ent = ent->next) {
 107                 if (!wildmatch(ent->pattern, ref, 0)) {
 108                         if (!(cb->explicit_expiry & REFLOG_EXPIRE_TOTAL))
 109                                 cb->expire_total = ent->expire_total;
 110                         if (!(cb->explicit_expiry & REFLOG_EXPIRE_UNREACH))
 111                                 cb->expire_unreachable = ent->expire_unreachable;
 112                         return;
 113                 }
 114         }
 115
 116         /*
 117          * If unconfigured, make stash never expire
 118          */
 119         if (!strcmp(ref, "refs/stash")) {
 120                 if (!(cb->explicit_expiry & REFLOG_EXPIRE_TOTAL))
 121                         cb->expire_total = 0;
 122                 if (!(cb->explicit_expiry & REFLOG_EXPIRE_UNREACH))
 123                         cb->expire_unreachable = 0;
 124                 return;
 125         }
 126
 127         /* Nothing matched -- use the default value */
 128         if (!(cb->explicit_expiry & REFLOG_EXPIRE_TOTAL))
 129                 cb->expire_total = cb->default_expire_total;
 130         if (!(cb->explicit_expiry & REFLOG_EXPIRE_UNREACH))
 131                 cb->expire_unreachable = cb->default_expire_unreachable;
 132 }
 133
 134 /* Remember to update object flag allocation in object.h */
 135 #define INCOMPLETE      (1u<<10)
 136 #define STUDYING        (1u<<11)
 137 #define REACHABLE       (1u<<12)
 138
 139 static int tree_is_complete(const struct object_id *oid)
 140 {
 141         struct tree_desc desc;
 142         struct name_entry entry;
 143         int complete;
 144         struct tree *tree;
 145
 146         tree = lookup_tree(the_repository, oid);
 147         if (!tree)
 148                 return 0;
 149         if (tree->object.flags & SEEN)
 150                 return 1;
 151         if (tree->object.flags & INCOMPLETE)
 152                 return 0;
 153
 154         if (!tree->buffer) {
 155                 enum object_type type;
 156                 unsigned long size;
 157                 void *data = odb_read_object(the_repository->objects, oid,
 158                                              &type, &size);
 159                 if (!data) {
 160                         tree->object.flags |= INCOMPLETE;
 161                         return 0;
 162                 }
 163                 tree->buffer = data;
 164                 tree->size = size;
 165         }
 166         init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
 167         complete = 1;
 168         while (tree_entry(&desc, &entry)) {
 169                 if (!odb_has_object(the_repository->objects, &entry.oid,
 170                                 HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR) ||
 171                     (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
 172                         tree->object.flags |= INCOMPLETE;
 173                         complete = 0;
 174                 }
 175         }
 176         free_tree_buffer(tree);
 177
 178         if (complete)
 179                 tree->object.flags |= SEEN;
 180         return complete;
 181 }
 182
 183 static int commit_is_complete(struct commit *commit)
 184 {
 185         struct object_array study;
 186         struct object_array found;
 187         int is_incomplete = 0;
 188         int i;
 189
 190         /* early return */
 191         if (commit->object.flags & SEEN)
 192                 return 1;
 193         if (commit->object.flags & INCOMPLETE)
 194                 return 0;
 195         /*
 196          * Find all commits that are reachable and are not marked as
 197          * SEEN.  Then make sure the trees and blobs contained are
 198          * complete.  After that, mark these commits also as SEEN.
 199          * If some of the objects that are needed to complete this
 200          * commit are missing, mark this commit as INCOMPLETE.
 201          */
 202         memset(&study, 0, sizeof(study));
 203         memset(&found, 0, sizeof(found));
 204         add_object_array(&commit->object, NULL, &study);
 205         add_object_array(&commit->object, NULL, &found);
 206         commit->object.flags |= STUDYING;
 207         while (study.nr) {
 208                 struct commit *c;
 209                 struct commit_list *parent;
 210
 211                 c = (struct commit *)object_array_pop(&study);
 212                 if (!c->object.parsed && !parse_object(the_repository, &c->object.oid))
 213                         c->object.flags |= INCOMPLETE;
 214
 215                 if (c->object.flags & INCOMPLETE) {
 216                         is_incomplete = 1;
 217                         break;
 218                 }
 219                 else if (c->object.flags & SEEN)
 220                         continue;
 221                 for (parent = c->parents; parent; parent = parent->next) {
 222                         struct commit *p = parent->item;
 223                         if (p->object.flags & STUDYING)
 224                                 continue;
 225                         p->object.flags |= STUDYING;
 226                         add_object_array(&p->object, NULL, &study);
 227                         add_object_array(&p->object, NULL, &found);
 228                 }
 229         }
 230         if (!is_incomplete) {
 231                 /*
 232                  * make sure all commits in "found" array have all the
 233                  * necessary objects.
 234                  */
 235                 for (i = 0; i < found.nr; i++) {
 236                         struct commit *c =
 237                                 (struct commit *)found.objects[i].item;
 238                         if (!tree_is_complete(get_commit_tree_oid(c))) {
 239                                 is_incomplete = 1;
 240                                 c->object.flags |= INCOMPLETE;
 241                         }
 242                 }
 243                 if (!is_incomplete) {
 244                         /* mark all found commits as complete, iow SEEN */
 245                         for (i = 0; i < found.nr; i++)
 246                                 found.objects[i].item->flags |= SEEN;
 247                 }
 248         }
 249         /* clear flags from the objects we traversed */
 250         for (i = 0; i < found.nr; i++)
 251                 found.objects[i].item->flags &= ~STUDYING;
 252         if (is_incomplete)
 253                 commit->object.flags |= INCOMPLETE;
 254         else {
 255                 /*
 256                  * If we come here, we have (1) traversed the ancestry chain
 257                  * from the "commit" until we reach SEEN commits (which are
 258                  * known to be complete), and (2) made sure that the commits
 259                  * encountered during the above traversal refer to trees that
 260                  * are complete.  Which means that we know *all* the commits
 261                  * we have seen during this process are complete.
 262                  */
 263                 for (i = 0; i < found.nr; i++)
 264                         found.objects[i].item->flags |= SEEN;
 265         }
 266         /* free object arrays */
 267         object_array_clear(&study);
 268         object_array_clear(&found);
 269         return !is_incomplete;
 270 }
 271
 272 static int keep_entry(struct commit **it, struct object_id *oid)
 273 {
 274         struct commit *commit;
 275
 276         if (is_null_oid(oid))
 277                 return 1;
 278         commit = lookup_commit_reference_gently(the_repository, oid, 1);
 279         if (!commit)
 280                 return 0;
 281
 282         /*
 283          * Make sure everything in this commit exists.
 284          *
 285          * We have walked all the objects reachable from the refs
 286          * and cache earlier.  The commits reachable by this commit
 287          * must meet SEEN commits -- and then we should mark them as
 288          * SEEN as well.
 289          */
 290         if (!commit_is_complete(commit))
 291                 return 0;
 292         *it = commit;
 293         return 1;
 294 }
 295
 296 /*
 297  * Starting from commits in the cb->mark_list, mark commits that are
 298  * reachable from them.  Stop the traversal at commits older than
 299  * the expire_limit and queue them back, so that the caller can call
 300  * us again to restart the traversal with longer expire_limit.
 301  */
 302 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 303 {
 304         struct commit_list *pending;
 305         timestamp_t expire_limit = cb->mark_limit;
 306         struct commit_list *leftover = NULL;
 307
 308         for (pending = cb->mark_list; pending; pending = pending->next)
 309                 pending->item->object.flags &= ~REACHABLE;
 310
 311         pending = cb->mark_list;
 312         while (pending) {
 313                 struct commit_list *parent;
 314                 struct commit *commit = pop_commit(&pending);
 315                 if (commit->object.flags & REACHABLE)
 316                         continue;
 317                 if (repo_parse_commit(the_repository, commit))
 318                         continue;
 319                 commit->object.flags |= REACHABLE;
 320                 if (commit->date < expire_limit) {
 321                         commit_list_insert(commit, &leftover);
 322                         continue;
 323                 }
 324                 parent = commit->parents;
 325                 while (parent) {
 326                         commit = parent->item;
 327                         parent = parent->next;
 328                         if (commit->object.flags & REACHABLE)
 329                                 continue;
 330                         commit_list_insert(commit, &pending);
 331                 }
 332         }
 333         cb->mark_list = leftover;
 334 }
 335
 336 static int is_unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 337 {
 338         /*
 339          * We may or may not have the commit yet - if not, look it
 340          * up using the supplied sha1.
 341          */
 342         if (!commit) {
 343                 if (is_null_oid(oid))
 344                         return 0;
 345
 346                 commit = lookup_commit_reference_gently(the_repository, oid,
 347                                                         1);
 348
 349                 /* Not a commit -- keep it */
 350                 if (!commit)
 351                         return 0;
 352         }
 353
 354         /* Reachable from the current ref?  Don't prune. */
 355         if (commit->object.flags & REACHABLE)
 356                 return 0;
 357
 358         if (cb->mark_list && cb->mark_limit) {
 359                 cb->mark_limit = 0; /* dig down to the root */
 360                 mark_reachable(cb);
 361         }
 362
 363         return !(commit->object.flags & REACHABLE);
 364 }
 365
 366 /*
 367  * Return true iff the specified reflog entry should be expired.
 368  */
 369 int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 370                              const char *email UNUSED,
 371                              timestamp_t timestamp, int tz UNUSED,
 372                              const char *message UNUSED, void *cb_data)
 373 {
 374         struct expire_reflog_policy_cb *cb = cb_data;
 375         struct commit *old_commit, *new_commit;
 376
 377         if (timestamp < cb->opts.expire_total)
 378                 return 1;
 379
 380         old_commit = new_commit = NULL;
 381         if (cb->opts.stalefix &&
 382             (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
 383                 return 1;
 384
 385         if (timestamp < cb->opts.expire_unreachable) {
 386                 switch (cb->unreachable_expire_kind) {
 387                 case UE_ALWAYS:
 388                         return 1;
 389                 case UE_NORMAL:
 390                 case UE_HEAD:
 391                         if (is_unreachable(cb, old_commit, ooid) || is_unreachable(cb, new_commit, noid))
 392                                 return 1;
 393                         break;
 394                 }
 395         }
 396
 397         if (cb->opts.recno && --(cb->opts.recno) == 0)
 398                 return 1;
 399
 400         return 0;
 401 }
 402
 403 int should_expire_reflog_ent_verbose(struct object_id *ooid,
 404                                      struct object_id *noid,
 405                                      const char *email,
 406                                      timestamp_t timestamp, int tz,
 407                                      const char *message, void *cb_data)
 408 {
 409         struct expire_reflog_policy_cb *cb = cb_data;
 410         int expire;
 411
 412         expire = should_expire_reflog_ent(ooid, noid, email, timestamp, tz,
 413                                           message, cb);
 414
 415         if (!expire)
 416                 printf("keep %s", message);
 417         else if (cb->dry_run)
 418                 printf("would prune %s", message);
 419         else
 420                 printf("prune %s", message);
 421
 422         return expire;
 423 }
 424
 425 static int push_tip_to_list(const char *refname UNUSED,
 426                             const char *referent UNUSED,
 427                             const struct object_id *oid,
 428                             int flags, void *cb_data)
 429 {
 430         struct commit_list **list = cb_data;
 431         struct commit *tip_commit;
 432         if (flags & REF_ISSYMREF)
 433                 return 0;
 434         tip_commit = lookup_commit_reference_gently(the_repository, oid, 1);
 435         if (!tip_commit)
 436                 return 0;
 437         commit_list_insert(tip_commit, list);
 438         return 0;
 439 }
 440
 441 static int is_head(const char *refname)
 442 {
 443         const char *stripped_refname;
 444         parse_worktree_ref(refname, NULL, NULL, &stripped_refname);
 445         return !strcmp(stripped_refname, "HEAD");
 446 }
 447
 448 void reflog_expiry_prepare(const char *refname,
 449                            const struct object_id *oid,
 450                            void *cb_data)
 451 {
 452         struct expire_reflog_policy_cb *cb = cb_data;
 453         struct commit_list *elem;
 454         struct commit *commit = NULL;
 455
 456         if (!cb->opts.expire_unreachable || is_head(refname)) {
 457                 cb->unreachable_expire_kind = UE_HEAD;
 458         } else {
 459                 commit = lookup_commit_reference_gently(the_repository,
 460                                                         oid, 1);
 461                 if (commit && is_null_oid(&commit->object.oid))
 462                         commit = NULL;
 463                 cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;
 464         }
 465
 466         if (cb->opts.expire_unreachable <= cb->opts.expire_total)
 467                 cb->unreachable_expire_kind = UE_ALWAYS;
 468
 469         switch (cb->unreachable_expire_kind) {
 470         case UE_ALWAYS:
 471                 return;
 472         case UE_HEAD:
 473                 refs_for_each_ref(get_main_ref_store(the_repository),
 474                                   push_tip_to_list, &cb->tips);
 475                 for (elem = cb->tips; elem; elem = elem->next)
 476                         commit_list_insert(elem->item, &cb->mark_list);
 477                 break;
 478         case UE_NORMAL:
 479                 commit_list_insert(commit, &cb->mark_list);
 480                 /* For reflog_expiry_cleanup() below */
 481                 cb->tip_commit = commit;
 482         }
 483         cb->mark_limit = cb->opts.expire_total;
 484         mark_reachable(cb);
 485 }
 486
 487 void reflog_expiry_cleanup(void *cb_data)
 488 {
 489         struct expire_reflog_policy_cb *cb = cb_data;
 490         struct commit_list *elem;
 491
 492         switch (cb->unreachable_expire_kind) {
 493         case UE_ALWAYS:
 494                 return;
 495         case UE_HEAD:
 496                 for (elem = cb->tips; elem; elem = elem->next)
 497                         clear_commit_marks(elem->item, REACHABLE);
 498                 free_commit_list(cb->tips);
 499                 break;
 500         case UE_NORMAL:
 501                 clear_commit_marks(cb->tip_commit, REACHABLE);
 502                 break;
 503         }
 504         for (elem = cb->mark_list; elem; elem = elem->next)
 505                 clear_commit_marks(elem->item, REACHABLE);
 506         free_commit_list(cb->mark_list);
 507 }
 508
 509 int count_reflog_ent(struct object_id *ooid UNUSED,
 510                      struct object_id *noid UNUSED,
 511                      const char *email UNUSED,
 512                      timestamp_t timestamp, int tz UNUSED,
 513                      const char *message UNUSED, void *cb_data)
 514 {
 515         struct reflog_expire_options *cb = cb_data;
 516         if (!cb->expire_total || timestamp < cb->expire_total)
 517                 cb->recno++;
 518         return 0;
 519 }
 520
 521 int reflog_delete(const char *rev, enum expire_reflog_flags flags, int verbose)
 522 {
 523         struct reflog_expire_options opts = { 0 };
 524         int status = 0;
 525         reflog_expiry_should_prune_fn *should_prune_fn = should_expire_reflog_ent;
 526         const char *spec = strstr(rev, "@{");
 527         char *ep, *ref;
 528         int recno;
 529         struct expire_reflog_policy_cb cb = {
 530                 .dry_run = !!(flags & EXPIRE_REFLOGS_DRY_RUN),
 531         };
 532
 533         if (verbose)
 534                 should_prune_fn = should_expire_reflog_ent_verbose;
 535
 536         if (!spec)
 537                 return error(_("not a reflog: %s"), rev);
 538
 539         if (!repo_dwim_log(the_repository, rev, spec - rev, NULL, &ref)) {
 540                 status |= error(_("no reflog for '%s'"), rev);
 541                 goto cleanup;
 542         }
 543
 544         recno = strtoul(spec + 2, &ep, 10);
 545         if (*ep == '}') {
 546                 opts.recno = -recno;
 547                 refs_for_each_reflog_ent(get_main_ref_store(the_repository),
 548                                          ref, count_reflog_ent, &opts);
 549         } else {
 550                 opts.expire_total = approxidate(spec + 2);
 551                 refs_for_each_reflog_ent(get_main_ref_store(the_repository),
 552                                          ref, count_reflog_ent, &opts);
 553                 opts.expire_total = 0;
 554         }
 555
 556         cb.opts = opts;
 557         status |= refs_reflog_expire(get_main_ref_store(the_repository), ref,
 558                                      flags,
 559                                      reflog_expiry_prepare,
 560                                      should_prune_fn,
 561                                      reflog_expiry_cleanup,
 562                                      &cb);
 563
 564  cleanup:
 565         free(ref);
 566         return status;
 567 }