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 expire [--verbose] [--dry-run] [--fix-stale] [--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 #define INCOMPLETE      (1u<<10)
  38 #define STUDYING        (1u<<11)
  39
  40 static int tree_is_complete(const unsigned char *sha1)
  41 {
  42         struct tree_desc desc;
  43         struct name_entry entry;
  44         int complete;
  45         struct tree *tree;
  46
  47         tree = lookup_tree(sha1);
  48         if (!tree)
  49                 return 0;
  50         if (tree->object.flags & SEEN)
  51                 return 1;
  52         if (tree->object.flags & INCOMPLETE)
  53                 return 0;
  54
  55         desc.buf = tree->buffer;
  56         desc.size = tree->size;
  57         if (!desc.buf) {
  58                 char type[20];
  59                 void *data = read_sha1_file(sha1, type, &desc.size);
  60                 if (!data) {
  61                         tree->object.flags |= INCOMPLETE;
  62                         return 0;
  63                 }
  64                 desc.buf = data;
  65                 tree->buffer = data;
  66         }
  67         complete = 1;
  68         while (tree_entry(&desc, &entry)) {
  69                 if (!has_sha1_file(entry.sha1) ||
  70                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  71                         tree->object.flags |= INCOMPLETE;
  72                         complete = 0;
  73                 }
  74         }
  75         free(tree->buffer);
  76         tree->buffer = NULL;
  77
  78         if (complete)
  79                 tree->object.flags |= SEEN;
  80         return complete;
  81 }
  82
  83 static int commit_is_complete(struct commit *commit)
  84 {
  85         struct object_array study;
  86         struct object_array found;
  87         int is_incomplete = 0;
  88         int i;
  89
  90         /* early return */
  91         if (commit->object.flags & SEEN)
  92                 return 1;
  93         if (commit->object.flags & INCOMPLETE)
  94                 return 0;
  95         /*
  96          * Find all commits that are reachable and are not marked as
  97          * SEEN.  Then make sure the trees and blobs contained are
  98          * complete.  After that, mark these commits also as SEEN.
  99          * If some of the objects that are needed to complete this
 100          * commit are missing, mark this commit as INCOMPLETE.
 101          */
 102         memset(&study, 0, sizeof(study));
 103         memset(&found, 0, sizeof(found));
 104         add_object_array(&commit->object, NULL, &study);
 105         add_object_array(&commit->object, NULL, &found);
 106         commit->object.flags |= STUDYING;
 107         while (study.nr) {
 108                 struct commit *c;
 109                 struct commit_list *parent;
 110
 111                 c = (struct commit *)study.objects[--study.nr].item;
 112                 if (!c->object.parsed && !parse_object(c->object.sha1))
 113                         c->object.flags |= INCOMPLETE;
 114
 115                 if (c->object.flags & INCOMPLETE) {
 116                         is_incomplete = 1;
 117                         break;
 118                 }
 119                 else if (c->object.flags & SEEN)
 120                         continue;
 121                 for (parent = c->parents; parent; parent = parent->next) {
 122                         struct commit *p = parent->item;
 123                         if (p->object.flags & STUDYING)
 124                                 continue;
 125                         p->object.flags |= STUDYING;
 126                         add_object_array(&p->object, NULL, &study);
 127                         add_object_array(&p->object, NULL, &found);
 128                 }
 129         }
 130         if (!is_incomplete) {
 131                 /*
 132                  * make sure all commits in "found" array have all the
 133                  * necessary objects.
 134                  */
 135                 for (i = 0; i < found.nr; i++) {
 136                         struct commit *c =
 137                                 (struct commit *)found.objects[i].item;
 138                         if (!tree_is_complete(c->tree->object.sha1)) {
 139                                 is_incomplete = 1;
 140                                 c->object.flags |= INCOMPLETE;
 141                         }
 142                 }
 143                 if (!is_incomplete) {
 144                         /* mark all found commits as complete, iow SEEN */
 145                         for (i = 0; i < found.nr; i++)
 146                                 found.objects[i].item->flags |= SEEN;
 147                 }
 148         }
 149         /* clear flags from the objects we traversed */
 150         for (i = 0; i < found.nr; i++)
 151                 found.objects[i].item->flags &= ~STUDYING;
 152         if (is_incomplete)
 153                 commit->object.flags |= INCOMPLETE;
 154         else {
 155                 /*
 156                  * If we come here, we have (1) traversed the ancestry chain
 157                  * from the "commit" until we reach SEEN commits (which are
 158                  * known to be complete), and (2) made sure that the commits
 159                  * encountered during the above traversal refer to trees that
 160                  * are complete.  Which means that we know *all* the commits
 161                  * we have seen during this process are complete.
 162                  */
 163                 for (i = 0; i < found.nr; i++)
 164                         found.objects[i].item->flags |= SEEN;
 165         }
 166         /* free object arrays */
 167         free(study.objects);
 168         free(found.objects);
 169         return !is_incomplete;
 170 }
 171
 172 static int keep_entry(struct commit **it, unsigned char *sha1)
 173 {
 174         struct commit *commit;
 175
 176         *it = NULL;
 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         if (cb->cmd->stalefix &&
 208             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 209                 goto prune;
 210
 211         if ((timestamp < cb->cmd->expire_unreachable) &&
 212             (!cb->ref_commit ||
 213              (old && !in_merge_bases(old, cb->ref_commit)) ||
 214              (new && !in_merge_bases(new, cb->ref_commit))))
 215                 goto prune;
 216
 217         if (cb->newlog) {
 218                 char sign = (tz < 0) ? '-' : '+';
 219                 int zone = (tz < 0) ? (-tz) : tz;
 220                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 221                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 222                         email, timestamp, sign, zone,
 223                         message);
 224         }
 225         if (cb->cmd->verbose)
 226                 printf("keep %s", message);
 227         return 0;
 228  prune:
 229         if (!cb->newlog || cb->cmd->verbose)
 230                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 231         return 0;
 232 }
 233
 234 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 235 {
 236         struct cmd_reflog_expire_cb *cmd = cb_data;
 237         struct expire_reflog_cb cb;
 238         struct ref_lock *lock;
 239         char *newlog_path = NULL;
 240         int status = 0;
 241
 242         if (strncmp(ref, "refs/", 5))
 243                 return error("not a ref '%s'", ref);
 244
 245         memset(&cb, 0, sizeof(cb));
 246         /* we take the lock for the ref itself to prevent it from
 247          * getting updated.
 248          */
 249         lock = lock_ref_sha1(ref + 5, sha1);
 250         if (!lock)
 251                 return error("cannot lock ref '%s'", ref);
 252         if (!file_exists(lock->log_file))
 253                 goto finish;
 254         if (!cmd->dry_run) {
 255                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 256                 cb.newlog = fopen(newlog_path, "w");
 257         }
 258
 259         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 260         if (!cb.ref_commit)
 261                 fprintf(stderr,
 262                         "warning: ref '%s' does not point at a commit\n", ref);
 263         cb.ref = ref;
 264         cb.cmd = cmd;
 265         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 266  finish:
 267         if (cb.newlog) {
 268                 if (fclose(cb.newlog))
 269                         status |= error("%s: %s", strerror(errno),
 270                                         newlog_path);
 271                 if (rename(newlog_path, lock->log_file)) {
 272                         status |= error("cannot rename %s to %s",
 273                                         newlog_path, lock->log_file);
 274                         unlink(newlog_path);
 275                 }
 276         }
 277         free(newlog_path);
 278         unlock_ref(lock);
 279         return status;
 280 }
 281
 282 static int reflog_expire_config(const char *var, const char *value)
 283 {
 284         if (!strcmp(var, "gc.reflogexpire"))
 285                 default_reflog_expire = approxidate(value);
 286         else if (!strcmp(var, "gc.reflogexpireunreachable"))
 287                 default_reflog_expire_unreachable = approxidate(value);
 288         else
 289                 return git_default_config(var, value);
 290         return 0;
 291 }
 292
 293 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 294 {
 295         struct cmd_reflog_expire_cb cb;
 296         unsigned long now = time(NULL);
 297         int i, status, do_all;
 298
 299         git_config(reflog_expire_config);
 300
 301         save_commit_buffer = 0;
 302         do_all = status = 0;
 303         memset(&cb, 0, sizeof(cb));
 304
 305         if (!default_reflog_expire_unreachable)
 306                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 307         if (!default_reflog_expire)
 308                 default_reflog_expire = now - 90 * 24 * 3600;
 309         cb.expire_total = default_reflog_expire;
 310         cb.expire_unreachable = default_reflog_expire_unreachable;
 311
 312         /*
 313          * We can trust the commits and objects reachable from refs
 314          * even in older repository.  We cannot trust what's reachable
 315          * from reflog if the repository was pruned with older git.
 316          */
 317
 318         for (i = 1; i < argc; i++) {
 319                 const char *arg = argv[i];
 320                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 321                         cb.dry_run = 1;
 322                 else if (!strncmp(arg, "--expire=", 9))
 323                         cb.expire_total = approxidate(arg + 9);
 324                 else if (!strncmp(arg, "--expire-unreachable=", 21))
 325                         cb.expire_unreachable = approxidate(arg + 21);
 326                 else if (!strcmp(arg, "--stale-fix"))
 327                         cb.stalefix = 1;
 328                 else if (!strcmp(arg, "--all"))
 329                         do_all = 1;
 330                 else if (!strcmp(arg, "--verbose"))
 331                         cb.verbose = 1;
 332                 else if (!strcmp(arg, "--")) {
 333                         i++;
 334                         break;
 335                 }
 336                 else if (arg[0] == '-')
 337                         usage(reflog_expire_usage);
 338                 else
 339                         break;
 340         }
 341         if (cb.stalefix) {
 342                 init_revisions(&cb.revs, prefix);
 343                 if (cb.verbose)
 344                         printf("Marking reachable objects...");
 345                 mark_reachable_objects(&cb.revs, 0);
 346                 if (cb.verbose)
 347                         putchar('\n');
 348         }
 349
 350         if (do_all)
 351                 status |= for_each_ref(expire_reflog, &cb);
 352         while (i < argc) {
 353                 const char *ref = argv[i++];
 354                 unsigned char sha1[20];
 355                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 356                         status |= error("%s points nowhere!", ref);
 357                         continue;
 358                 }
 359                 status |= expire_reflog(ref, sha1, 0, &cb);
 360         }
 361         return status;
 362 }
 363
 364 /*
 365  * main "reflog"
 366  */
 367
 368 static const char reflog_usage[] =
 369 "git-reflog (expire | ...)";
 370
 371 int cmd_reflog(int argc, const char **argv, const char *prefix)
 372 {
 373         if (argc < 2)
 374                 usage(reflog_usage);
 375         else if (!strcmp(argv[1], "expire"))
 376                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 377         else
 378                 usage(reflog_usage);
 379 }