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 static int tree_is_complete(const unsigned char *sha1)
  38 {
  39         struct tree_desc desc;
  40         void *buf;
  41         char type[20];
  42
  43         buf = read_sha1_file(sha1, type, &desc.size);
  44         if (!buf)
  45                 return 0;
  46         desc.buf = buf;
  47         while (desc.size) {
  48                 const unsigned char *elem;
  49                 const char *name;
  50                 unsigned mode;
  51
  52                 elem = tree_entry_extract(&desc, &name, &mode);
  53                 if (!has_sha1_file(elem) ||
  54                     (S_ISDIR(mode) && !tree_is_complete(elem))) {
  55                         free(buf);
  56                         return 0;
  57                 }
  58                 update_tree_entry(&desc);
  59         }
  60         free(buf);
  61         return 1;
  62 }
  63
  64 #define INCOMPLETE      (1u<<10)
  65 #define STUDYING        (1u<<11)
  66
  67 static int commit_is_complete(struct commit *commit)
  68 {
  69         struct object_array study;
  70         struct object_array found;
  71         int is_incomplete = 0;
  72         int i;
  73
  74         /* early return */
  75         if (commit->object.flags & SEEN)
  76                 return 1;
  77         if (commit->object.flags & INCOMPLETE)
  78                 return 0;
  79         /*
  80          * Find all commits that are reachable and are not marked as
  81          * SEEN.  Then make sure the trees and blobs contained are
  82          * complete.  After that, mark these commits also as SEEN.
  83          * If some of the objects that are needed to complete this
  84          * commit are missing, mark this commit as INCOMPLETE.
  85          */
  86         memset(&study, 0, sizeof(study));
  87         memset(&found, 0, sizeof(found));
  88         add_object_array(&commit->object, NULL, &study);
  89         add_object_array(&commit->object, NULL, &found);
  90         commit->object.flags |= STUDYING;
  91         while (study.nr) {
  92                 struct commit *c;
  93                 struct commit_list *parent;
  94
  95                 c = (struct commit *)study.objects[--study.nr].item;
  96                 if (!c->object.parsed && !parse_object(c->object.sha1))
  97                         c->object.flags |= INCOMPLETE;
  98
  99                 if (c->object.flags & INCOMPLETE) {
 100                         is_incomplete = 1;
 101                         break;
 102                 }
 103                 else if (c->object.flags & SEEN)
 104                         continue;
 105                 for (parent = c->parents; parent; parent = parent->next) {
 106                         struct commit *p = parent->item;
 107                         if (p->object.flags & STUDYING)
 108                                 continue;
 109                         p->object.flags |= STUDYING;
 110                         add_object_array(&p->object, NULL, &study);
 111                         add_object_array(&p->object, NULL, &found);
 112                 }
 113         }
 114         if (!is_incomplete) {
 115                 /* make sure all commits in found have all the
 116                  * necessary objects.
 117                  */
 118                 for (i = 0; !is_incomplete && i < found.nr; i++) {
 119                         struct commit *c =
 120                                 (struct commit *)found.objects[i].item;
 121                         if (!tree_is_complete(c->tree->object.sha1))
 122                                 is_incomplete = 1;
 123                 }
 124                 if (!is_incomplete) {
 125                         /* mark all found commits as complete, iow SEEN */
 126                         for (i = 0; i < found.nr; i++)
 127                                 found.objects[i].item->flags |= SEEN;
 128                 }
 129         }
 130         /* clear flags from the objects we traversed */
 131         for (i = 0; i < found.nr; i++)
 132                 found.objects[i].item->flags &= ~STUDYING;
 133         if (is_incomplete)
 134                 commit->object.flags |= INCOMPLETE;
 135         /* free object arrays */
 136         free(study.objects);
 137         free(found.objects);
 138         return !is_incomplete;
 139 }
 140
 141 static int keep_entry(struct commit **it, unsigned char *sha1)
 142 {
 143         struct commit *commit;
 144
 145         *it = NULL;
 146         if (is_null_sha1(sha1))
 147                 return 1;
 148         commit = lookup_commit_reference_gently(sha1, 1);
 149         if (!commit)
 150                 return 0;
 151
 152         /*
 153          * Make sure everything in this commit exists.
 154          *
 155          * We have walked all the objects reachable from the refs
 156          * and cache earlier.  The commits reachable by this commit
 157          * must meet SEEN commits -- and then we should mark them as
 158          * SEEN as well.
 159          */
 160         if (!commit_is_complete(commit))
 161                 return 0;
 162         *it = commit;
 163         return 1;
 164 }
 165
 166 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 167                              char *data, void *cb_data)
 168 {
 169         struct expire_reflog_cb *cb = cb_data;
 170         unsigned long timestamp;
 171         char *cp, *ep;
 172         struct commit *old, *new;
 173
 174         cp = strchr(data, '>');
 175         if (!cp || *++cp != ' ')
 176                 goto prune;
 177         timestamp = strtoul(cp, &ep, 10);
 178         if (*ep != ' ')
 179                 goto prune;
 180         if (timestamp < cb->cmd->expire_total)
 181                 goto prune;
 182
 183         if (cb->cmd->stalefix &&
 184             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 185                 goto prune;
 186
 187         if ((timestamp < cb->cmd->expire_unreachable) &&
 188             (!cb->ref_commit ||
 189              (old && !in_merge_bases(old, cb->ref_commit)) ||
 190              (new && !in_merge_bases(new, cb->ref_commit))))
 191                 goto prune;
 192
 193         if (cb->newlog)
 194                 fprintf(cb->newlog, "%s %s %s",
 195                         sha1_to_hex(osha1), sha1_to_hex(nsha1), data);
 196         if (cb->cmd->verbose)
 197                 printf("keep %s", data);
 198         return 0;
 199  prune:
 200         if (!cb->newlog || cb->cmd->verbose)
 201                 printf("%sprune %s", cb->newlog ? "" : "would ", data);
 202         return 0;
 203 }
 204
 205 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 206 {
 207         struct cmd_reflog_expire_cb *cmd = cb_data;
 208         struct expire_reflog_cb cb;
 209         struct ref_lock *lock;
 210         char *newlog_path = NULL;
 211         int status = 0;
 212
 213         if (strncmp(ref, "refs/", 5))
 214                 return error("not a ref '%s'", ref);
 215
 216         memset(&cb, 0, sizeof(cb));
 217         /* we take the lock for the ref itself to prevent it from
 218          * getting updated.
 219          */
 220         lock = lock_ref_sha1(ref + 5, sha1);
 221         if (!lock)
 222                 return error("cannot lock ref '%s'", ref);
 223         if (!file_exists(lock->log_file))
 224                 goto finish;
 225         if (!cmd->dry_run) {
 226                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 227                 cb.newlog = fopen(newlog_path, "w");
 228         }
 229
 230         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 231         if (!cb.ref_commit)
 232                 fprintf(stderr,
 233                         "warning: ref '%s' does not point at a commit\n", ref);
 234         cb.ref = ref;
 235         cb.cmd = cmd;
 236         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 237  finish:
 238         if (cb.newlog) {
 239                 if (fclose(cb.newlog))
 240                         status |= error("%s: %s", strerror(errno),
 241                                         newlog_path);
 242                 if (rename(newlog_path, lock->log_file)) {
 243                         status |= error("cannot rename %s to %s",
 244                                         newlog_path, lock->log_file);
 245                         unlink(newlog_path);
 246                 }
 247         }
 248         free(newlog_path);
 249         unlock_ref(lock);
 250         return status;
 251 }
 252
 253 static int reflog_expire_config(const char *var, const char *value)
 254 {
 255         if (!strcmp(var, "gc.reflogexpire"))
 256                 default_reflog_expire = approxidate(value);
 257         else if (!strcmp(var, "gc.reflogexpireunreachable"))
 258                 default_reflog_expire_unreachable = approxidate(value);
 259         else
 260                 return git_default_config(var, value);
 261         return 0;
 262 }
 263
 264 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 265 {
 266         struct cmd_reflog_expire_cb cb;
 267         unsigned long now = time(NULL);
 268         int i, status, do_all;
 269
 270         git_config(reflog_expire_config);
 271
 272         save_commit_buffer = 0;
 273         do_all = status = 0;
 274         memset(&cb, 0, sizeof(cb));
 275
 276         if (!default_reflog_expire_unreachable)
 277                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 278         if (!default_reflog_expire)
 279                 default_reflog_expire = now - 90 * 24 * 3600;
 280         cb.expire_total = default_reflog_expire;
 281         cb.expire_unreachable = default_reflog_expire_unreachable;
 282
 283         /*
 284          * We can trust the commits and objects reachable from refs
 285          * even in older repository.  We cannot trust what's reachable
 286          * from reflog if the repository was pruned with older git.
 287          */
 288
 289         for (i = 1; i < argc; i++) {
 290                 const char *arg = argv[i];
 291                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 292                         cb.dry_run = 1;
 293                 else if (!strncmp(arg, "--expire=", 9))
 294                         cb.expire_total = approxidate(arg + 9);
 295                 else if (!strncmp(arg, "--expire-unreachable=", 21))
 296                         cb.expire_unreachable = approxidate(arg + 21);
 297                 else if (!strcmp(arg, "--stale-fix"))
 298                         cb.stalefix = 1;
 299                 else if (!strcmp(arg, "--all"))
 300                         do_all = 1;
 301                 else if (!strcmp(arg, "--verbose"))
 302                         cb.verbose = 1;
 303                 else if (!strcmp(arg, "--")) {
 304                         i++;
 305                         break;
 306                 }
 307                 else if (arg[0] == '-')
 308                         usage(reflog_expire_usage);
 309                 else
 310                         break;
 311         }
 312         if (cb.stalefix) {
 313                 init_revisions(&cb.revs, prefix);
 314                 if (cb.verbose)
 315                         printf("Marking reachable objects...");
 316                 mark_reachable_objects(&cb.revs, 0);
 317                 if (cb.verbose)
 318                         putchar('\n');
 319         }
 320
 321         if (do_all)
 322                 status |= for_each_ref(expire_reflog, &cb);
 323         while (i < argc) {
 324                 const char *ref = argv[i++];
 325                 unsigned char sha1[20];
 326                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 327                         status |= error("%s points nowhere!", ref);
 328                         continue;
 329                 }
 330                 status |= expire_reflog(ref, sha1, 0, &cb);
 331         }
 332         return status;
 333 }
 334
 335 /*
 336  * main "reflog"
 337  */
 338
 339 static const char reflog_usage[] =
 340 "git-reflog (expire | ...)";
 341
 342 int cmd_reflog(int argc, const char **argv, const char *prefix)
 343 {
 344         if (argc < 2)
 345                 usage(reflog_usage);
 346         else if (!strcmp(argv[1], "expire"))
 347                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 348         else
 349                 usage(reflog_usage);
 350 }