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