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 #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         if (!tree->buffer) {
  56                 enum object_type type;
  57                 unsigned long size;
  58                 void *data = read_sha1_file(sha1, &type, &size);
  59                 if (!data) {
  60                         tree->object.flags |= INCOMPLETE;
  61                         return 0;
  62                 }
  63                 tree->buffer = data;
  64                 tree->size = size;
  65         }
  66         init_tree_desc(&desc, tree->buffer, tree->size);
  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         if (is_null_sha1(sha1))
 177                 return 1;
 178         commit = lookup_commit_reference_gently(sha1, 1);
 179         if (!commit)
 180                 return 0;
 181
 182         /*
 183          * Make sure everything in this commit exists.
 184          *
 185          * We have walked all the objects reachable from the refs
 186          * and cache earlier.  The commits reachable by this commit
 187          * must meet SEEN commits -- and then we should mark them as
 188          * SEEN as well.
 189          */
 190         if (!commit_is_complete(commit))
 191                 return 0;
 192         *it = commit;
 193         return 1;
 194 }
 195
 196 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 197                 const char *email, unsigned long timestamp, int tz,
 198                 const char *message, void *cb_data)
 199 {
 200         struct expire_reflog_cb *cb = cb_data;
 201         struct commit *old, *new;
 202
 203         if (timestamp < cb->cmd->expire_total)
 204                 goto prune;
 205
 206         old = new = NULL;
 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                 if (!cb->ref_commit)
 213                         goto prune;
 214                 if (!old && !is_null_sha1(osha1))
 215                         old = lookup_commit_reference_gently(osha1, 1);
 216                 if (!new && !is_null_sha1(nsha1))
 217                         new = lookup_commit_reference_gently(nsha1, 1);
 218                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
 219                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
 220                         goto prune;
 221         }
 222
 223         if (cb->newlog) {
 224                 char sign = (tz < 0) ? '-' : '+';
 225                 int zone = (tz < 0) ? (-tz) : tz;
 226                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 227                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
 228                         email, timestamp, sign, zone,
 229                         message);
 230         }
 231         if (cb->cmd->verbose)
 232                 printf("keep %s", message);
 233         return 0;
 234  prune:
 235         if (!cb->newlog || cb->cmd->verbose)
 236                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
 237         return 0;
 238 }
 239
 240 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 241 {
 242         struct cmd_reflog_expire_cb *cmd = cb_data;
 243         struct expire_reflog_cb cb;
 244         struct ref_lock *lock;
 245         char *log_file, *newlog_path = NULL;
 246         int status = 0;
 247
 248         memset(&cb, 0, sizeof(cb));
 249         /* we take the lock for the ref itself to prevent it from
 250          * getting updated.
 251          */
 252         lock = lock_any_ref_for_update(ref, sha1, 0);
 253         if (!lock)
 254                 return error("cannot lock ref '%s'", ref);
 255         log_file = xstrdup(git_path("logs/%s", ref));
 256         if (!file_exists(log_file))
 257                 goto finish;
 258         if (!cmd->dry_run) {
 259                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
 260                 cb.newlog = fopen(newlog_path, "w");
 261         }
 262
 263         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 264         cb.ref = ref;
 265         cb.cmd = cmd;
 266         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 267  finish:
 268         if (cb.newlog) {
 269                 if (fclose(cb.newlog))
 270                         status |= error("%s: %s", strerror(errno),
 271                                         newlog_path);
 272                 if (rename(newlog_path, log_file)) {
 273                         status |= error("cannot rename %s to %s",
 274                                         newlog_path, log_file);
 275                         unlink(newlog_path);
 276                 }
 277         }
 278         free(newlog_path);
 279         free(log_file);
 280         unlock_ref(lock);
 281         return status;
 282 }
 283
 284 static int reflog_expire_config(const char *var, const char *value)
 285 {
 286         if (!strcmp(var, "gc.reflogexpire"))
 287                 default_reflog_expire = approxidate(value);
 288         else if (!strcmp(var, "gc.reflogexpireunreachable"))
 289                 default_reflog_expire_unreachable = approxidate(value);
 290         else
 291                 return git_default_config(var, value);
 292         return 0;
 293 }
 294
 295 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 296 {
 297         struct cmd_reflog_expire_cb cb;
 298         unsigned long now = time(NULL);
 299         int i, status, do_all;
 300
 301         git_config(reflog_expire_config);
 302
 303         save_commit_buffer = 0;
 304         do_all = status = 0;
 305         memset(&cb, 0, sizeof(cb));
 306
 307         if (!default_reflog_expire_unreachable)
 308                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 309         if (!default_reflog_expire)
 310                 default_reflog_expire = now - 90 * 24 * 3600;
 311         cb.expire_total = default_reflog_expire;
 312         cb.expire_unreachable = default_reflog_expire_unreachable;
 313
 314         /*
 315          * We can trust the commits and objects reachable from refs
 316          * even in older repository.  We cannot trust what's reachable
 317          * from reflog if the repository was pruned with older git.
 318          */
 319
 320         for (i = 1; i < argc; i++) {
 321                 const char *arg = argv[i];
 322                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 323                         cb.dry_run = 1;
 324                 else if (!prefixcmp(arg, "--expire="))
 325                         cb.expire_total = approxidate(arg + 9);
 326                 else if (!prefixcmp(arg, "--expire-unreachable="))
 327                         cb.expire_unreachable = approxidate(arg + 21);
 328                 else if (!strcmp(arg, "--stale-fix"))
 329                         cb.stalefix = 1;
 330                 else if (!strcmp(arg, "--all"))
 331                         do_all = 1;
 332                 else if (!strcmp(arg, "--verbose"))
 333                         cb.verbose = 1;
 334                 else if (!strcmp(arg, "--")) {
 335                         i++;
 336                         break;
 337                 }
 338                 else if (arg[0] == '-')
 339                         usage(reflog_expire_usage);
 340                 else
 341                         break;
 342         }
 343         if (cb.stalefix) {
 344                 init_revisions(&cb.revs, prefix);
 345                 if (cb.verbose)
 346                         printf("Marking reachable objects...");
 347                 mark_reachable_objects(&cb.revs, 0);
 348                 if (cb.verbose)
 349                         putchar('\n');
 350         }
 351
 352         if (do_all)
 353                 status |= for_each_reflog(expire_reflog, &cb);
 354         while (i < argc) {
 355                 const char *ref = argv[i++];
 356                 unsigned char sha1[20];
 357                 if (!resolve_ref(ref, sha1, 1, NULL)) {
 358                         status |= error("%s points nowhere!", ref);
 359                         continue;
 360                 }
 361                 status |= expire_reflog(ref, sha1, 0, &cb);
 362         }
 363         return status;
 364 }
 365
 366 /*
 367  * main "reflog"
 368  */
 369
 370 static const char reflog_usage[] =
 371 "git-reflog (expire | ...)";
 372
 373 int cmd_reflog(int argc, const char **argv, const char *prefix)
 374 {
 375         /* With no command, we default to showing it. */
 376         if (argc < 2 || *argv[1] == '-')
 377                 return cmd_log_reflog(argc, argv, prefix);
 378
 379         if (!strcmp(argv[1], "show"))
 380                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
 381
 382         if (!strcmp(argv[1], "expire"))
 383                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 384
 385         /* Not a recognized reflog command..*/
 386         usage(reflog_usage);
 387 }