reflog.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2
   3 #include "git-compat-util.h"
   4 #include "gettext.h"
   5 #include "object-store-ll.h"
   6 #include "reflog.h"
   7 #include "refs.h"
   8 #include "revision.h"
   9 #include "tree.h"
  10 #include "tree-walk.h"
  11
  12 /* Remember to update object flag allocation in object.h */
  13 #define INCOMPLETE      (1u<<10)
  14 #define STUDYING        (1u<<11)
  15 #define REACHABLE       (1u<<12)
  16
  17 static int tree_is_complete(const struct object_id *oid)
  18 {
  19         struct tree_desc desc;
  20         struct name_entry entry;
  21         int complete;
  22         struct tree *tree;
  23
  24         tree = lookup_tree(the_repository, oid);
  25         if (!tree)
  26                 return 0;
  27         if (tree->object.flags & SEEN)
  28                 return 1;
  29         if (tree->object.flags & INCOMPLETE)
  30                 return 0;
  31
  32         if (!tree->buffer) {
  33                 enum object_type type;
  34                 unsigned long size;
  35                 void *data = repo_read_object_file(the_repository, oid, &type,
  36                                                    &size);
  37                 if (!data) {
  38                         tree->object.flags |= INCOMPLETE;
  39                         return 0;
  40                 }
  41                 tree->buffer = data;
  42                 tree->size = size;
  43         }
  44         init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
  45         complete = 1;
  46         while (tree_entry(&desc, &entry)) {
  47                 if (!repo_has_object_file(the_repository, &entry.oid) ||
  48                     (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
  49                         tree->object.flags |= INCOMPLETE;
  50                         complete = 0;
  51                 }
  52         }
  53         free_tree_buffer(tree);
  54
  55         if (complete)
  56                 tree->object.flags |= SEEN;
  57         return complete;
  58 }
  59
  60 static int commit_is_complete(struct commit *commit)
  61 {
  62         struct object_array study;
  63         struct object_array found;
  64         int is_incomplete = 0;
  65         int i;
  66
  67         /* early return */
  68         if (commit->object.flags & SEEN)
  69                 return 1;
  70         if (commit->object.flags & INCOMPLETE)
  71                 return 0;
  72         /*
  73          * Find all commits that are reachable and are not marked as
  74          * SEEN.  Then make sure the trees and blobs contained are
  75          * complete.  After that, mark these commits also as SEEN.
  76          * If some of the objects that are needed to complete this
  77          * commit are missing, mark this commit as INCOMPLETE.
  78          */
  79         memset(&study, 0, sizeof(study));
  80         memset(&found, 0, sizeof(found));
  81         add_object_array(&commit->object, NULL, &study);
  82         add_object_array(&commit->object, NULL, &found);
  83         commit->object.flags |= STUDYING;
  84         while (study.nr) {
  85                 struct commit *c;
  86                 struct commit_list *parent;
  87
  88                 c = (struct commit *)object_array_pop(&study);
  89                 if (!c->object.parsed && !parse_object(the_repository, &c->object.oid))
  90                         c->object.flags |= INCOMPLETE;
  91
  92                 if (c->object.flags & INCOMPLETE) {
  93                         is_incomplete = 1;
  94                         break;
  95                 }
  96                 else if (c->object.flags & SEEN)
  97                         continue;
  98                 for (parent = c->parents; parent; parent = parent->next) {
  99                         struct commit *p = parent->item;
 100                         if (p->object.flags & STUDYING)
 101                                 continue;
 102                         p->object.flags |= STUDYING;
 103                         add_object_array(&p->object, NULL, &study);
 104                         add_object_array(&p->object, NULL, &found);
 105                 }
 106         }
 107         if (!is_incomplete) {
 108                 /*
 109                  * make sure all commits in "found" array have all the
 110                  * necessary objects.
 111                  */
 112                 for (i = 0; i < found.nr; i++) {
 113                         struct commit *c =
 114                                 (struct commit *)found.objects[i].item;
 115                         if (!tree_is_complete(get_commit_tree_oid(c))) {
 116                                 is_incomplete = 1;
 117                                 c->object.flags |= INCOMPLETE;
 118                         }
 119                 }
 120                 if (!is_incomplete) {
 121                         /* mark all found commits as complete, iow SEEN */
 122                         for (i = 0; i < found.nr; i++)
 123                                 found.objects[i].item->flags |= SEEN;
 124                 }
 125         }
 126         /* clear flags from the objects we traversed */
 127         for (i = 0; i < found.nr; i++)
 128                 found.objects[i].item->flags &= ~STUDYING;
 129         if (is_incomplete)
 130                 commit->object.flags |= INCOMPLETE;
 131         else {
 132                 /*
 133                  * If we come here, we have (1) traversed the ancestry chain
 134                  * from the "commit" until we reach SEEN commits (which are
 135                  * known to be complete), and (2) made sure that the commits
 136                  * encountered during the above traversal refer to trees that
 137                  * are complete.  Which means that we know *all* the commits
 138                  * we have seen during this process are complete.
 139                  */
 140                 for (i = 0; i < found.nr; i++)
 141                         found.objects[i].item->flags |= SEEN;
 142         }
 143         /* free object arrays */
 144         object_array_clear(&study);
 145         object_array_clear(&found);
 146         return !is_incomplete;
 147 }
 148
 149 static int keep_entry(struct commit **it, struct object_id *oid)
 150 {
 151         struct commit *commit;
 152
 153         if (is_null_oid(oid))
 154                 return 1;
 155         commit = lookup_commit_reference_gently(the_repository, oid, 1);
 156         if (!commit)
 157                 return 0;
 158
 159         /*
 160          * Make sure everything in this commit exists.
 161          *
 162          * We have walked all the objects reachable from the refs
 163          * and cache earlier.  The commits reachable by this commit
 164          * must meet SEEN commits -- and then we should mark them as
 165          * SEEN as well.
 166          */
 167         if (!commit_is_complete(commit))
 168                 return 0;
 169         *it = commit;
 170         return 1;
 171 }
 172
 173 /*
 174  * Starting from commits in the cb->mark_list, mark commits that are
 175  * reachable from them.  Stop the traversal at commits older than
 176  * the expire_limit and queue them back, so that the caller can call
 177  * us again to restart the traversal with longer expire_limit.
 178  */
 179 static void mark_reachable(struct expire_reflog_policy_cb *cb)
 180 {
 181         struct commit_list *pending;
 182         timestamp_t expire_limit = cb->mark_limit;
 183         struct commit_list *leftover = NULL;
 184
 185         for (pending = cb->mark_list; pending; pending = pending->next)
 186                 pending->item->object.flags &= ~REACHABLE;
 187
 188         pending = cb->mark_list;
 189         while (pending) {
 190                 struct commit_list *parent;
 191                 struct commit *commit = pop_commit(&pending);
 192                 if (commit->object.flags & REACHABLE)
 193                         continue;
 194                 if (repo_parse_commit(the_repository, commit))
 195                         continue;
 196                 commit->object.flags |= REACHABLE;
 197                 if (commit->date < expire_limit) {
 198                         commit_list_insert(commit, &leftover);
 199                         continue;
 200                 }
 201                 parent = commit->parents;
 202                 while (parent) {
 203                         commit = parent->item;
 204                         parent = parent->next;
 205                         if (commit->object.flags & REACHABLE)
 206                                 continue;
 207                         commit_list_insert(commit, &pending);
 208                 }
 209         }
 210         cb->mark_list = leftover;
 211 }
 212
 213 static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 214 {
 215         /*
 216          * We may or may not have the commit yet - if not, look it
 217          * up using the supplied sha1.
 218          */
 219         if (!commit) {
 220                 if (is_null_oid(oid))
 221                         return 0;
 222
 223                 commit = lookup_commit_reference_gently(the_repository, oid,
 224                                                         1);
 225
 226                 /* Not a commit -- keep it */
 227                 if (!commit)
 228                         return 0;
 229         }
 230
 231         /* Reachable from the current ref?  Don't prune. */
 232         if (commit->object.flags & REACHABLE)
 233                 return 0;
 234
 235         if (cb->mark_list && cb->mark_limit) {
 236                 cb->mark_limit = 0; /* dig down to the root */
 237                 mark_reachable(cb);
 238         }
 239
 240         return !(commit->object.flags & REACHABLE);
 241 }
 242
 243 /*
 244  * Return true iff the specified reflog entry should be expired.
 245  */
 246 int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 247                              const char *email UNUSED,
 248                              timestamp_t timestamp, int tz UNUSED,
 249                              const char *message UNUSED, void *cb_data)
 250 {
 251         struct expire_reflog_policy_cb *cb = cb_data;
 252         struct commit *old_commit, *new_commit;
 253
 254         if (timestamp < cb->cmd.expire_total)
 255                 return 1;
 256
 257         old_commit = new_commit = NULL;
 258         if (cb->cmd.stalefix &&
 259             (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
 260                 return 1;
 261
 262         if (timestamp < cb->cmd.expire_unreachable) {
 263                 switch (cb->unreachable_expire_kind) {
 264                 case UE_ALWAYS:
 265                         return 1;
 266                 case UE_NORMAL:
 267                 case UE_HEAD:
 268                         if (unreachable(cb, old_commit, ooid) || unreachable(cb, new_commit, noid))
 269                                 return 1;
 270                         break;
 271                 }
 272         }
 273
 274         if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 275                 return 1;
 276
 277         return 0;
 278 }
 279
 280 int should_expire_reflog_ent_verbose(struct object_id *ooid,
 281                                      struct object_id *noid,
 282                                      const char *email,
 283                                      timestamp_t timestamp, int tz,
 284                                      const char *message, void *cb_data)
 285 {
 286         struct expire_reflog_policy_cb *cb = cb_data;
 287         int expire;
 288
 289         expire = should_expire_reflog_ent(ooid, noid, email, timestamp, tz,
 290                                           message, cb);
 291
 292         if (!expire)
 293                 printf("keep %s", message);
 294         else if (cb->dry_run)
 295                 printf("would prune %s", message);
 296         else
 297                 printf("prune %s", message);
 298
 299         return expire;
 300 }
 301
 302 static int push_tip_to_list(const char *refname UNUSED,
 303                             const struct object_id *oid,
 304                             int flags, void *cb_data)
 305 {
 306         struct commit_list **list = cb_data;
 307         struct commit *tip_commit;
 308         if (flags & REF_ISSYMREF)
 309                 return 0;
 310         tip_commit = lookup_commit_reference_gently(the_repository, oid, 1);
 311         if (!tip_commit)
 312                 return 0;
 313         commit_list_insert(tip_commit, list);
 314         return 0;
 315 }
 316
 317 static int is_head(const char *refname)
 318 {
 319         const char *stripped_refname;
 320         parse_worktree_ref(refname, NULL, NULL, &stripped_refname);
 321         return !strcmp(stripped_refname, "HEAD");
 322 }
 323
 324 void reflog_expiry_prepare(const char *refname,
 325                            const struct object_id *oid,
 326                            void *cb_data)
 327 {
 328         struct expire_reflog_policy_cb *cb = cb_data;
 329         struct commit_list *elem;
 330         struct commit *commit = NULL;
 331
 332         if (!cb->cmd.expire_unreachable || is_head(refname)) {
 333                 cb->unreachable_expire_kind = UE_HEAD;
 334         } else {
 335                 commit = lookup_commit(the_repository, oid);
 336                 if (commit && is_null_oid(&commit->object.oid))
 337                         commit = NULL;
 338                 cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;
 339         }
 340
 341         if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 342                 cb->unreachable_expire_kind = UE_ALWAYS;
 343
 344         switch (cb->unreachable_expire_kind) {
 345         case UE_ALWAYS:
 346                 return;
 347         case UE_HEAD:
 348                 refs_for_each_ref(get_main_ref_store(the_repository),
 349                                   push_tip_to_list, &cb->tips);
 350                 for (elem = cb->tips; elem; elem = elem->next)
 351                         commit_list_insert(elem->item, &cb->mark_list);
 352                 break;
 353         case UE_NORMAL:
 354                 commit_list_insert(commit, &cb->mark_list);
 355                 /* For reflog_expiry_cleanup() below */
 356                 cb->tip_commit = commit;
 357         }
 358         cb->mark_limit = cb->cmd.expire_total;
 359         mark_reachable(cb);
 360 }
 361
 362 void reflog_expiry_cleanup(void *cb_data)
 363 {
 364         struct expire_reflog_policy_cb *cb = cb_data;
 365         struct commit_list *elem;
 366
 367         switch (cb->unreachable_expire_kind) {
 368         case UE_ALWAYS:
 369                 return;
 370         case UE_HEAD:
 371                 for (elem = cb->tips; elem; elem = elem->next)
 372                         clear_commit_marks(elem->item, REACHABLE);
 373                 free_commit_list(cb->tips);
 374                 break;
 375         case UE_NORMAL:
 376                 clear_commit_marks(cb->tip_commit, REACHABLE);
 377                 break;
 378         }
 379         for (elem = cb->mark_list; elem; elem = elem->next)
 380                 clear_commit_marks(elem->item, REACHABLE);
 381         free_commit_list(cb->mark_list);
 382 }
 383
 384 int count_reflog_ent(struct object_id *ooid UNUSED,
 385                      struct object_id *noid UNUSED,
 386                      const char *email UNUSED,
 387                      timestamp_t timestamp, int tz UNUSED,
 388                      const char *message UNUSED, void *cb_data)
 389 {
 390         struct cmd_reflog_expire_cb *cb = cb_data;
 391         if (!cb->expire_total || timestamp < cb->expire_total)
 392                 cb->recno++;
 393         return 0;
 394 }
 395
 396 int reflog_delete(const char *rev, enum expire_reflog_flags flags, int verbose)
 397 {
 398         struct cmd_reflog_expire_cb cmd = { 0 };
 399         int status = 0;
 400         reflog_expiry_should_prune_fn *should_prune_fn = should_expire_reflog_ent;
 401         const char *spec = strstr(rev, "@{");
 402         char *ep, *ref;
 403         int recno;
 404         struct expire_reflog_policy_cb cb = {
 405                 .dry_run = !!(flags & EXPIRE_REFLOGS_DRY_RUN),
 406         };
 407
 408         if (verbose)
 409                 should_prune_fn = should_expire_reflog_ent_verbose;
 410
 411         if (!spec)
 412                 return error(_("not a reflog: %s"), rev);
 413
 414         if (!repo_dwim_log(the_repository, rev, spec - rev, NULL, &ref)) {
 415                 status |= error(_("no reflog for '%s'"), rev);
 416                 goto cleanup;
 417         }
 418
 419         recno = strtoul(spec + 2, &ep, 10);
 420         if (*ep == '}') {
 421                 cmd.recno = -recno;
 422                 refs_for_each_reflog_ent(get_main_ref_store(the_repository),
 423                                          ref, count_reflog_ent, &cmd);
 424         } else {
 425                 cmd.expire_total = approxidate(spec + 2);
 426                 refs_for_each_reflog_ent(get_main_ref_store(the_repository),
 427                                          ref, count_reflog_ent, &cmd);
 428                 cmd.expire_total = 0;
 429         }
 430
 431         cb.cmd = cmd;
 432         status |= refs_reflog_expire(get_main_ref_store(the_repository), ref,
 433                                      flags,
 434                                      reflog_expiry_prepare,
 435                                      should_prune_fn,
 436                                      reflog_expiry_cleanup,
 437                                      &cb);
 438
 439  cleanup:
 440         free(ref);
 441         return status;
 442 }