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] <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 verbose;
  29         unsigned long expire_total;
  30         unsigned long expire_unreachable;
  31         int recno;
  32 };
  33
  34 struct expire_reflog_cb {
  35         FILE *newlog;
  36         const char *ref;
  37         struct commit *ref_commit;
  38         struct cmd_reflog_expire_cb *cmd;
  39         unsigned char last_kept_sha1[20];
  40 };
  41
  42 struct collected_reflog {
  43         unsigned char sha1[20];
  44         char reflog[FLEX_ARRAY];
  45 };
  46 struct collect_reflog_cb {
  47         struct collected_reflog **e;
  48         int alloc;
  49         int nr;
  50 };
  51
  52 #define INCOMPLETE      (1u<<10)
  53 #define STUDYING        (1u<<11)
  54
  55 static int tree_is_complete(const unsigned char *sha1)
  56 {
  57         struct tree_desc desc;
  58         struct name_entry entry;
  59         int complete;
  60         struct tree *tree;
  61
  62         tree = lookup_tree(sha1);
  63         if (!tree)
  64                 return 0;
  65         if (tree->object.flags & SEEN)
  66                 return 1;
  67         if (tree->object.flags & INCOMPLETE)
  68                 return 0;
  69
  70         if (!tree->buffer) {
  71                 enum object_type type;
  72                 unsigned long size;
  73                 void *data = read_sha1_file(sha1, &type, &size);
  74                 if (!data) {
  75                         tree->object.flags |= INCOMPLETE;
  76                         return 0;
  77                 }
  78                 tree->buffer = data;
  79                 tree->size = size;
  80         }
  81         init_tree_desc(&desc, tree->buffer, tree->size);
  82         complete = 1;
  83         while (tree_entry(&desc, &entry)) {
  84                 if (!has_sha1_file(entry.sha1) ||
  85                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  86                         tree->object.flags |= INCOMPLETE;
  87                         complete = 0;
  88                 }
  89         }
  90         free(tree->buffer);
  91         tree->buffer = NULL;
  92
  93         if (complete)
  94                 tree->object.flags |= SEEN;
  95         return complete;
  96 }
  97
  98 static int commit_is_complete(struct commit *commit)
  99 {
 100         struct object_array study;
 101         struct object_array found;
 102         int is_incomplete = 0;
 103         int i;
 104
 105         /* early return */
 106         if (commit->object.flags & SEEN)
 107                 return 1;
 108         if (commit->object.flags & INCOMPLETE)
 109                 return 0;
 110         /*
 111          * Find all commits that are reachable and are not marked as
 112          * SEEN.  Then make sure the trees and blobs contained are
 113          * complete.  After that, mark these commits also as SEEN.
 114          * If some of the objects that are needed to complete this
 115          * commit are missing, mark this commit as INCOMPLETE.
 116          */
 117         memset(&study, 0, sizeof(study));
 118         memset(&found, 0, sizeof(found));
 119         add_object_array(&commit->object, NULL, &study);
 120         add_object_array(&commit->object, NULL, &found);
 121         commit->object.flags |= STUDYING;
 122         while (study.nr) {
 123                 struct commit *c;
 124                 struct commit_list *parent;
 125
 126                 c = (struct commit *)study.objects[--study.nr].item;
 127                 if (!c->object.parsed && !parse_object(c->object.sha1))
 128                         c->object.flags |= INCOMPLETE;
 129
 130                 if (c->object.flags & INCOMPLETE) {
 131                         is_incomplete = 1;
 132                         break;
 133                 }
 134                 else if (c->object.flags & SEEN)
 135                         continue;
 136                 for (parent = c->parents; parent; parent = parent->next) {
 137                         struct commit *p = parent->item;
 138                         if (p->object.flags & STUDYING)
 139                                 continue;
 140                         p->object.flags |= STUDYING;
 141                         add_object_array(&p->object, NULL, &study);
 142                         add_object_array(&p->object, NULL, &found);
 143                 }
 144         }
 145         if (!is_incomplete) {
 146                 /*
 147                  * make sure all commits in "found" array have all the
 148                  * necessary objects.
 149                  */
 150                 for (i = 0; i < found.nr; i++) {
 151                         struct commit *c =
 152                                 (struct commit *)found.objects[i].item;
 153                         if (!tree_is_complete(c->tree->object.sha1)) {
 154                                 is_incomplete = 1;
 155                                 c->object.flags |= INCOMPLETE;
 156                         }
 157                 }
 158                 if (!is_incomplete) {
 159                         /* mark all found commits as complete, iow SEEN */
 160                         for (i = 0; i < found.nr; i++)
 161                                 found.objects[i].item->flags |= SEEN;
 162                 }
 163         }
 164         /* clear flags from the objects we traversed */
 165         for (i = 0; i < found.nr; i++)
 166                 found.objects[i].item->flags &= ~STUDYING;
 167         if (is_incomplete)
 168                 commit->object.flags |= INCOMPLETE;
 169         else {
 170                 /*
 171                  * If we come here, we have (1) traversed the ancestry chain
 172                  * from the "commit" until we reach SEEN commits (which are
 173                  * known to be complete), and (2) made sure that the commits
 174                  * encountered during the above traversal refer to trees that
 175                  * are complete.  Which means that we know *all* the commits
 176                  * we have seen during this process are complete.
 177                  */
 178                 for (i = 0; i < found.nr; i++)
 179                         found.objects[i].item->flags |= SEEN;
 180         }
 181         /* free object arrays */
 182         free(study.objects);
 183         free(found.objects);
 184         return !is_incomplete;
 185 }
 186
 187 static int keep_entry(struct commit **it, unsigned char *sha1)
 188 {
 189         struct commit *commit;
 190
 191         if (is_null_sha1(sha1))
 192                 return 1;
 193         commit = lookup_commit_reference_gently(sha1, 1);
 194         if (!commit)
 195                 return 0;
 196
 197         /*
 198          * Make sure everything in this commit exists.
 199          *
 200          * We have walked all the objects reachable from the refs
 201          * and cache earlier.  The commits reachable by this commit
 202          * must meet SEEN commits -- and then we should mark them as
 203          * SEEN as well.
 204          */
 205         if (!commit_is_complete(commit))
 206                 return 0;
 207         *it = commit;
 208         return 1;
 209 }
 210
 211 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 212                 const char *email, unsigned long timestamp, int tz,
 213                 const char *message, void *cb_data)
 214 {
 215         struct expire_reflog_cb *cb = cb_data;
 216         struct commit *old, *new;
 217
 218         if (timestamp < cb->cmd->expire_total)
 219                 goto prune;
 220
 221         if (cb->cmd->rewrite)
 222                 osha1 = cb->last_kept_sha1;
 223
 224         old = new = NULL;
 225         if (cb->cmd->stalefix &&
 226             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 227                 goto prune;
 228
 229         if (timestamp < cb->cmd->expire_unreachable) {
 230                 if (!cb->ref_commit)
 231                         goto prune;
 232                 if (!old && !is_null_sha1(osha1))
 233                         old = lookup_commit_reference_gently(osha1, 1);
 234                 if (!new && !is_null_sha1(nsha1))
 235                         new = lookup_commit_reference_gently(nsha1, 1);
 236                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
 237                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
 238                         goto prune;
 239         }
 240
 241         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 242                 goto prune;
 243
 244         if (cb->newlog) {
 245                 char sign = (tz < 0) ? '-' : '+';
 246                 int zone = (tz < 0) ? (-tz) : tz;
 247                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 248                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 249                         email, timestamp, sign, zone,
 250                         message);
 251                 hashcpy(cb->last_kept_sha1, nsha1);
 252         }
 253         if (cb->cmd->verbose)
 254                 printf("keep %s", message);
 255         return 0;
 256  prune:
 257         if (!cb->newlog || cb->cmd->verbose)
 258                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 259         return 0;
 260 }
 261
 262 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 263 {
 264         struct cmd_reflog_expire_cb *cmd = cb_data;
 265         struct expire_reflog_cb cb;
 266         struct ref_lock *lock;
 267         char *log_file, *newlog_path = NULL;
 268         int status = 0;
 269
 270         memset(&cb, 0, sizeof(cb));
 271         /* we take the lock for the ref itself to prevent it from
 272          * getting updated.
 273          */
 274         lock = lock_any_ref_for_update(ref, sha1, 0);
 275         if (!lock)
 276                 return error("cannot lock ref '%s'", ref);
 277         log_file = xstrdup(git_path("logs/%s", ref));
 278         if (!file_exists(log_file))
 279                 goto finish;
 280         if (!cmd->dry_run) {
 281                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 282                 cb.newlog = fopen(newlog_path, "w");
 283         }
 284
 285         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 286         cb.ref = ref;
 287         cb.cmd = cmd;
 288         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 289  finish:
 290         if (cb.newlog) {
 291                 if (fclose(cb.newlog)) {
 292                         status |= error("%s: %s", strerror(errno),
 293                                         newlog_path);
 294                         unlink(newlog_path);
 295                 } else if (rename(newlog_path, log_file)) {
 296                         status |= error("cannot rename %s to %s",
 297                                         newlog_path, log_file);
 298                         unlink(newlog_path);
 299                 }
 300         }
 301         free(newlog_path);
 302         free(log_file);
 303         unlock_ref(lock);
 304         return status;
 305 }
 306
 307 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 308 {
 309         struct collected_reflog *e;
 310         struct collect_reflog_cb *cb = cb_data;
 311         size_t namelen = strlen(ref);
 312
 313         e = xmalloc(sizeof(*e) + namelen + 1);
 314         hashcpy(e->sha1, sha1);
 315         memcpy(e->reflog, ref, namelen + 1);
 316         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 317         cb->e[cb->nr++] = e;
 318         return 0;
 319 }
 320
 321 static int reflog_expire_config(const char *var, const char *value)
 322 {
 323         if (!strcmp(var, "gc.reflogexpire")) {
 324                 if (!value)
 325                         config_error_nonbool(var);
 326                 default_reflog_expire = approxidate(value);
 327                 return 0;
 328         }
 329         if (!strcmp(var, "gc.reflogexpireunreachable")) {
 330                 if (!value)
 331                         config_error_nonbool(var);
 332                 default_reflog_expire_unreachable = approxidate(value);
 333                 return 0;
 334         }
 335         return git_default_config(var, value);
 336 }
 337
 338 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 339 {
 340         struct cmd_reflog_expire_cb cb;
 341         unsigned long now = time(NULL);
 342         int i, status, do_all;
 343
 344         git_config(reflog_expire_config);
 345
 346         save_commit_buffer = 0;
 347         do_all = status = 0;
 348         memset(&cb, 0, sizeof(cb));
 349
 350         if (!default_reflog_expire_unreachable)
 351                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 352         if (!default_reflog_expire)
 353                 default_reflog_expire = now - 90 * 24 * 3600;
 354         cb.expire_total = default_reflog_expire;
 355         cb.expire_unreachable = default_reflog_expire_unreachable;
 356
 357         /*
 358          * We can trust the commits and objects reachable from refs
 359          * even in older repository.  We cannot trust what's reachable
 360          * from reflog if the repository was pruned with older git.
 361          */
 362
 363         for (i = 1; i < argc; i++) {
 364                 const char *arg = argv[i];
 365                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 366                         cb.dry_run = 1;
 367                 else if (!prefixcmp(arg, "--expire="))
 368                         cb.expire_total = approxidate(arg + 9);
 369                 else if (!prefixcmp(arg, "--expire-unreachable="))
 370                         cb.expire_unreachable = approxidate(arg + 21);
 371                 else if (!strcmp(arg, "--stale-fix"))
 372                         cb.stalefix = 1;
 373                 else if (!strcmp(arg, "--rewrite"))
 374                         cb.rewrite = 1;
 375                 else if (!strcmp(arg, "--all"))
 376                         do_all = 1;
 377                 else if (!strcmp(arg, "--verbose"))
 378                         cb.verbose = 1;
 379                 else if (!strcmp(arg, "--")) {
 380                         i++;
 381                         break;
 382                 }
 383                 else if (arg[0] == '-')
 384                         usage(reflog_expire_usage);
 385                 else
 386                         break;
 387         }
 388         if (cb.stalefix) {
 389                 init_revisions(&cb.revs, prefix);
 390                 if (cb.verbose)
 391                         printf("Marking reachable objects...");
 392                 mark_reachable_objects(&cb.revs, 0);
 393                 if (cb.verbose)
 394                         putchar('\n');
 395         }
 396
 397         if (do_all) {
 398                 struct collect_reflog_cb collected;
 399                 int i;
 400
 401                 memset(&collected, 0, sizeof(collected));
 402                 for_each_reflog(collect_reflog, &collected);
 403                 for (i = 0; i < collected.nr; i++) {
 404                         struct collected_reflog *e = collected.e[i];
 405                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 406                         free(e);
 407                 }
 408                 free(collected.e);
 409         }
 410
 411         while (i < argc) {
 412                 const char *ref = argv[i++];
 413                 unsigned char sha1[20];
 414                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 415                         status |= error("%s points nowhere!", ref);
 416                         continue;
 417                 }
 418                 status |= expire_reflog(ref, sha1, 0, &cb);
 419         }
 420         return status;
 421 }
 422
 423 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 424                 const char *email, unsigned long timestamp, int tz,
 425                 const char *message, void *cb_data)
 426 {
 427         struct cmd_reflog_expire_cb *cb = cb_data;
 428         if (!cb->expire_total || timestamp < cb->expire_total)
 429                 cb->recno++;
 430         return 0;
 431 }
 432
 433 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 434 {
 435         struct cmd_reflog_expire_cb cb;
 436         int i, status = 0;
 437
 438         memset(&cb, 0, sizeof(cb));
 439
 440         for (i = 1; i < argc; i++) {
 441                 const char *arg = argv[i];
 442                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 443                         cb.dry_run = 1;
 444                 else if (!strcmp(arg, "--rewrite"))
 445                         cb.rewrite = 1;
 446                 else if (!strcmp(arg, "--verbose"))
 447                         cb.verbose = 1;
 448                 else if (!strcmp(arg, "--")) {
 449                         i++;
 450                         break;
 451                 }
 452                 else if (arg[0] == '-')
 453                         usage(reflog_delete_usage);
 454                 else
 455                         break;
 456         }
 457
 458         if (argc - i < 1)
 459                 return error("Nothing to delete?");
 460
 461         for ( ; i < argc; i++) {
 462                 const char *spec = strstr(argv[i], "@{");
 463                 unsigned char sha1[20];
 464                 char *ep, *ref;
 465                 int recno;
 466
 467                 if (!spec) {
 468                         status |= error("Not a reflog: %s", argv[i]);
 469                         continue;
 470                 }
 471
 472                 if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
 473                         status |= error("%s points nowhere!", argv[i]);
 474                         continue;
 475                 }
 476
 477                 recno = strtoul(spec + 2, &ep, 10);
 478                 if (*ep == '}') {
 479                         cb.recno = -recno;
 480                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 481                 } else {
 482                         cb.expire_total = approxidate(spec + 2);
 483                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
 484                         cb.expire_total = 0;
 485                 }
 486
 487                 status |= expire_reflog(ref, sha1, 0, &cb);
 488                 free(ref);
 489         }
 490         return status;
 491 }
 492
 493 /*
 494  * main "reflog"
 495  */
 496
 497 static const char reflog_usage[] =
 498 "git-reflog (expire | ...)";
 499
 500 int cmd_reflog(int argc, const char **argv, const char *prefix)
 501 {
 502         /* With no command, we default to showing it. */
 503         if (argc < 2 || *argv[1] == '-')
 504                 return cmd_log_reflog(argc, argv, prefix);
 505
 506         if (!strcmp(argv[1], "show"))
 507                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 508
 509         if (!strcmp(argv[1], "expire"))
 510                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 511
 512         if (!strcmp(argv[1], "delete"))
 513                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 514
 515         /* Not a recognized reflog command..*/
 516         usage(reflog_usage);
 517 }