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