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
  18 static unsigned long default_reflog_expire;
  19 static unsigned long default_reflog_expire_unreachable;
  20
  21 struct cmd_reflog_expire_cb {
  22         struct rev_info revs;
  23         int dry_run;
  24         int stalefix;
  25         int verbose;
  26         unsigned long expire_total;
  27         unsigned long expire_unreachable;
  28         int recno;
  29 };
  30
  31 struct expire_reflog_cb {
  32         FILE *newlog;
  33         const char *ref;
  34         struct commit *ref_commit;
  35         struct cmd_reflog_expire_cb *cmd;
  36 };
  37
  38 struct collected_reflog {
  39         unsigned char sha1[20];
  40         char reflog[FLEX_ARRAY];
  41 };
  42 struct collect_reflog_cb {
  43         struct collected_reflog **e;
  44         int alloc;
  45         int nr;
  46 };
  47
  48 #define INCOMPLETE      (1u<<10)
  49 #define STUDYING        (1u<<11)
  50
  51 static int tree_is_complete(const unsigned char *sha1)
  52 {
  53         struct tree_desc desc;
  54         struct name_entry entry;
  55         int complete;
  56         struct tree *tree;
  57
  58         tree = lookup_tree(sha1);
  59         if (!tree)
  60                 return 0;
  61         if (tree->object.flags & SEEN)
  62                 return 1;
  63         if (tree->object.flags & INCOMPLETE)
  64                 return 0;
  65
  66         if (!tree->buffer) {
  67                 enum object_type type;
  68                 unsigned long size;
  69                 void *data = read_sha1_file(sha1, &type, &size);
  70                 if (!data) {
  71                         tree->object.flags |= INCOMPLETE;
  72                         return 0;
  73                 }
  74                 tree->buffer = data;
  75                 tree->size = size;
  76         }
  77         init_tree_desc(&desc, tree->buffer, tree->size);
  78         complete = 1;
  79         while (tree_entry(&desc, &entry)) {
  80                 if (!has_sha1_file(entry.sha1) ||
  81                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  82                         tree->object.flags |= INCOMPLETE;
  83                         complete = 0;
  84                 }
  85         }
  86         free(tree->buffer);
  87         tree->buffer = NULL;
  88
  89         if (complete)
  90                 tree->object.flags |= SEEN;
  91         return complete;
  92 }
  93
  94 static int commit_is_complete(struct commit *commit)
  95 {
  96         struct object_array study;
  97         struct object_array found;
  98         int is_incomplete = 0;
  99         int i;
 100
 101         /* early return */
 102         if (commit->object.flags & SEEN)
 103                 return 1;
 104         if (commit->object.flags & INCOMPLETE)
 105                 return 0;
 106         /*
 107          * Find all commits that are reachable and are not marked as
 108          * SEEN.  Then make sure the trees and blobs contained are
 109          * complete.  After that, mark these commits also as SEEN.
 110          * If some of the objects that are needed to complete this
 111          * commit are missing, mark this commit as INCOMPLETE.
 112          */
 113         memset(&study, 0, sizeof(study));
 114         memset(&found, 0, sizeof(found));
 115         add_object_array(&commit->object, NULL, &study);
 116         add_object_array(&commit->object, NULL, &found);
 117         commit->object.flags |= STUDYING;
 118         while (study.nr) {
 119                 struct commit *c;
 120                 struct commit_list *parent;
 121
 122                 c = (struct commit *)study.objects[--study.nr].item;
 123                 if (!c->object.parsed && !parse_object(c->object.sha1))
 124                         c->object.flags |= INCOMPLETE;
 125
 126                 if (c->object.flags & INCOMPLETE) {
 127                         is_incomplete = 1;
 128                         break;
 129                 }
 130                 else if (c->object.flags & SEEN)
 131                         continue;
 132                 for (parent = c->parents; parent; parent = parent->next) {
 133                         struct commit *p = parent->item;
 134                         if (p->object.flags & STUDYING)
 135                                 continue;
 136                         p->object.flags |= STUDYING;
 137                         add_object_array(&p->object, NULL, &study);
 138                         add_object_array(&p->object, NULL, &found);
 139                 }
 140         }
 141         if (!is_incomplete) {
 142                 /*
 143                  * make sure all commits in "found" array have all the
 144                  * necessary objects.
 145                  */
 146                 for (i = 0; i < found.nr; i++) {
 147                         struct commit *c =
 148                                 (struct commit *)found.objects[i].item;
 149                         if (!tree_is_complete(c->tree->object.sha1)) {
 150                                 is_incomplete = 1;
 151                                 c->object.flags |= INCOMPLETE;
 152                         }
 153                 }
 154                 if (!is_incomplete) {
 155                         /* mark all found commits as complete, iow SEEN */
 156                         for (i = 0; i < found.nr; i++)
 157                                 found.objects[i].item->flags |= SEEN;
 158                 }
 159         }
 160         /* clear flags from the objects we traversed */
 161         for (i = 0; i < found.nr; i++)
 162                 found.objects[i].item->flags &= ~STUDYING;
 163         if (is_incomplete)
 164                 commit->object.flags |= INCOMPLETE;
 165         else {
 166                 /*
 167                  * If we come here, we have (1) traversed the ancestry chain
 168                  * from the "commit" until we reach SEEN commits (which are
 169                  * known to be complete), and (2) made sure that the commits
 170                  * encountered during the above traversal refer to trees that
 171                  * are complete.  Which means that we know *all* the commits
 172                  * we have seen during this process are complete.
 173                  */
 174                 for (i = 0; i < found.nr; i++)
 175                         found.objects[i].item->flags |= SEEN;
 176         }
 177         /* free object arrays */
 178         free(study.objects);
 179         free(found.objects);
 180         return !is_incomplete;
 181 }
 182
 183 static int keep_entry(struct commit **it, unsigned char *sha1)
 184 {
 185         struct commit *commit;
 186
 187         if (is_null_sha1(sha1))
 188                 return 1;
 189         commit = lookup_commit_reference_gently(sha1, 1);
 190         if (!commit)
 191                 return 0;
 192
 193         /*
 194          * Make sure everything in this commit exists.
 195          *
 196          * We have walked all the objects reachable from the refs
 197          * and cache earlier.  The commits reachable by this commit
 198          * must meet SEEN commits -- and then we should mark them as
 199          * SEEN as well.
 200          */
 201         if (!commit_is_complete(commit))
 202                 return 0;
 203         *it = commit;
 204         return 1;
 205 }
 206
 207 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 208                 const char *email, unsigned long timestamp, int tz,
 209                 const char *message, void *cb_data)
 210 {
 211         struct expire_reflog_cb *cb = cb_data;
 212         struct commit *old, *new;
 213
 214         if (timestamp < cb->cmd->expire_total)
 215                 goto prune;
 216
 217         old = new = NULL;
 218         if (cb->cmd->stalefix &&
 219             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 220                 goto prune;
 221
 222         if (timestamp < cb->cmd->expire_unreachable) {
 223                 if (!cb->ref_commit)
 224                         goto prune;
 225                 if (!old && !is_null_sha1(osha1))
 226                         old = lookup_commit_reference_gently(osha1, 1);
 227                 if (!new && !is_null_sha1(nsha1))
 228                         new = lookup_commit_reference_gently(nsha1, 1);
 229                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
 230                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
 231                         goto prune;
 232         }
 233
 234         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 235                 goto prune;
 236
 237         if (cb->newlog) {
 238                 char sign = (tz < 0) ? '-' : '+';
 239                 int zone = (tz < 0) ? (-tz) : tz;
 240                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 241                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 242                         email, timestamp, sign, zone,
 243                         message);
 244         }
 245         if (cb->cmd->verbose)
 246                 printf("keep %s", message);
 247         return 0;
 248  prune:
 249         if (!cb->newlog || cb->cmd->verbose)
 250                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 251         return 0;
 252 }
 253
 254 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 255 {
 256         struct cmd_reflog_expire_cb *cmd = cb_data;
 257         struct expire_reflog_cb cb;
 258         struct ref_lock *lock;
 259         char *log_file, *newlog_path = NULL;
 260         int status = 0;
 261
 262         memset(&cb, 0, sizeof(cb));
 263         /* we take the lock for the ref itself to prevent it from
 264          * getting updated.
 265          */
 266         lock = lock_any_ref_for_update(ref, sha1, 0);
 267         if (!lock)
 268                 return error("cannot lock ref '%s'", ref);
 269         log_file = xstrdup(git_path("logs/%s", ref));
 270         if (!file_exists(log_file))
 271                 goto finish;
 272         if (!cmd->dry_run) {
 273                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 274                 cb.newlog = fopen(newlog_path, "w");
 275         }
 276
 277         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 278         cb.ref = ref;
 279         cb.cmd = cmd;
 280         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 281  finish:
 282         if (cb.newlog) {
 283                 if (fclose(cb.newlog)) {
 284                         status |= error("%s: %s", strerror(errno),
 285                                         newlog_path);
 286                         unlink(newlog_path);
 287                 } else if (rename(newlog_path, log_file)) {
 288                         status |= error("cannot rename %s to %s",
 289                                         newlog_path, log_file);
 290                         unlink(newlog_path);
 291                 }
 292         }
 293         free(newlog_path);
 294         free(log_file);
 295         unlock_ref(lock);
 296         return status;
 297 }
 298
 299 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 300 {
 301         struct collected_reflog *e;
 302         struct collect_reflog_cb *cb = cb_data;
 303         size_t namelen = strlen(ref);
 304
 305         e = xmalloc(sizeof(*e) + namelen + 1);
 306         hashcpy(e->sha1, sha1);
 307         memcpy(e->reflog, ref, namelen + 1);
 308         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 309         cb->e[cb->nr++] = e;
 310         return 0;
 311 }
 312
 313 static int reflog_expire_config(const char *var, const char *value)
 314 {
 315         if (!strcmp(var, "gc.reflogexpire")) {
 316                 if (!value)
 317                         config_error_nonbool(var);
 318                 default_reflog_expire = approxidate(value);
 319                 return 0;
 320         }
 321         if (!strcmp(var, "gc.reflogexpireunreachable")) {
 322                 if (!value)
 323                         config_error_nonbool(var);
 324                 default_reflog_expire_unreachable = approxidate(value);
 325                 return 0;
 326         }
 327         return git_default_config(var, value);
 328 }
 329
 330 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 331 {
 332         struct cmd_reflog_expire_cb cb;
 333         unsigned long now = time(NULL);
 334         int i, status, do_all;
 335
 336         git_config(reflog_expire_config);
 337
 338         save_commit_buffer = 0;
 339         do_all = status = 0;
 340         memset(&cb, 0, sizeof(cb));
 341
 342         if (!default_reflog_expire_unreachable)
 343                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 344         if (!default_reflog_expire)
 345                 default_reflog_expire = now - 90 * 24 * 3600;
 346         cb.expire_total = default_reflog_expire;
 347         cb.expire_unreachable = default_reflog_expire_unreachable;
 348
 349         /*
 350          * We can trust the commits and objects reachable from refs
 351          * even in older repository.  We cannot trust what's reachable
 352          * from reflog if the repository was pruned with older git.
 353          */
 354
 355         for (i = 1; i < argc; i++) {
 356                 const char *arg = argv[i];
 357                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 358                         cb.dry_run = 1;
 359                 else if (!prefixcmp(arg, "--expire="))
 360                         cb.expire_total = approxidate(arg + 9);
 361                 else if (!prefixcmp(arg, "--expire-unreachable="))
 362                         cb.expire_unreachable = approxidate(arg + 21);
 363                 else if (!strcmp(arg, "--stale-fix"))
 364                         cb.stalefix = 1;
 365                 else if (!strcmp(arg, "--all"))
 366                         do_all = 1;
 367                 else if (!strcmp(arg, "--verbose"))
 368                         cb.verbose = 1;
 369                 else if (!strcmp(arg, "--")) {
 370                         i++;
 371                         break;
 372                 }
 373                 else if (arg[0] == '-')
 374                         usage(reflog_expire_usage);
 375                 else
 376                         break;
 377         }
 378         if (cb.stalefix) {
 379                 init_revisions(&cb.revs, prefix);
 380                 if (cb.verbose)
 381                         printf("Marking reachable objects...");
 382                 mark_reachable_objects(&cb.revs, 0);
 383                 if (cb.verbose)
 384                         putchar('\n');
 385         }
 386
 387         if (do_all) {
 388                 struct collect_reflog_cb collected;
 389                 int i;
 390
 391                 memset(&collected, 0, sizeof(collected));
 392                 for_each_reflog(collect_reflog, &collected);
 393                 for (i = 0; i < collected.nr; i++) {
 394                         struct collected_reflog *e = collected.e[i];
 395                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 396                         free(e);
 397                 }
 398                 free(collected.e);
 399         }
 400
 401         while (i < argc) {
 402                 const char *ref = argv[i++];
 403                 unsigned char sha1[20];
 404                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 405                         status |= error("%s points nowhere!", ref);
 406                         continue;
 407                 }
 408                 status |= expire_reflog(ref, sha1, 0, &cb);
 409         }
 410         return status;
 411 }
 412
 413 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 414                 const char *email, unsigned long timestamp, int tz,
 415                 const char *message, void *cb_data)
 416 {
 417         struct cmd_reflog_expire_cb *cb = cb_data;
 418         if (!cb->expire_total || timestamp < cb->expire_total)
 419                 cb->recno++;
 420         return 0;
 421 }
 422
 423 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 424 {
 425         struct cmd_reflog_expire_cb cb;
 426         int i, status = 0;
 427
 428         if (argc < 2)
 429                 return error("Nothing to delete?");
 430
 431         memset(&cb, 0, sizeof(cb));
 432
 433         for (i = 1; i < argc; i++) {
 434                 const char *spec = strstr(argv[i], "@{");
 435                 unsigned char sha1[20];
 436                 char *ep, *ref;
 437                 int recno;
 438
 439                 if (!spec) {
 440                         status |= error("Not a reflog: %s", argv[i]);
 441                         continue;
 442                 }
 443
 444                 if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
 445                         status |= error("%s points nowhere!", argv[i]);
 446                         continue;
 447                 }
 448
 449                 recno = strtoul(spec + 2, &ep, 10);
 450                 if (*ep == '}') {
 451                         cb.recno = -recno;
 452                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 453                 } else {
 454                         cb.expire_total = approxidate(spec + 2);
 455                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 456                         cb.expire_total = 0;
 457                 }
 458
 459                 status |= expire_reflog(ref, sha1, 0, &cb);
 460                 free(ref);
 461         }
 462         return status;
 463 }
 464
 465 /*
 466  * main "reflog"
 467  */
 468
 469 static const char reflog_usage[] =
 470 "git-reflog (expire | ...)";
 471
 472 int cmd_reflog(int argc, const char **argv, const char *prefix)
 473 {
 474         /* With no command, we default to showing it. */
 475         if (argc < 2 || *argv[1] == '-')
 476                 return cmd_log_reflog(argc, argv, prefix);
 477
 478         if (!strcmp(argv[1], "show"))
 479                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 480
 481         if (!strcmp(argv[1], "expire"))
 482                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 483
 484         if (!strcmp(argv[1], "delete"))
 485                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 486
 487         /* Not a recognized reflog command..*/
 488         usage(reflog_usage);
 489 }