builtin / reflog.con commit Merge branch 'rj/sparse-updates' (14599b4)
   1#include "builtin.h"
   2#include "config.h"
   3#include "lockfile.h"
   4#include "commit.h"
   5#include "refs.h"
   6#include "dir.h"
   7#include "tree-walk.h"
   8#include "diff.h"
   9#include "revision.h"
  10#include "reachable.h"
  11
  12/* NEEDSWORK: switch to using parse_options */
  13static const char reflog_expire_usage[] =
  14"git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
  15static const char reflog_delete_usage[] =
  16"git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
  17static const char reflog_exists_usage[] =
  18"git reflog exists <ref>";
  19
  20static timestamp_t default_reflog_expire;
  21static timestamp_t default_reflog_expire_unreachable;
  22
  23struct cmd_reflog_expire_cb {
  24        struct rev_info revs;
  25        int stalefix;
  26        timestamp_t expire_total;
  27        timestamp_t expire_unreachable;
  28        int recno;
  29};
  30
  31struct expire_reflog_policy_cb {
  32        enum {
  33                UE_NORMAL,
  34                UE_ALWAYS,
  35                UE_HEAD
  36        } unreachable_expire_kind;
  37        struct commit_list *mark_list;
  38        unsigned long mark_limit;
  39        struct cmd_reflog_expire_cb cmd;
  40        struct commit *tip_commit;
  41        struct commit_list *tips;
  42};
  43
  44struct collected_reflog {
  45        struct object_id oid;
  46        char reflog[FLEX_ARRAY];
  47};
  48
  49struct collect_reflog_cb {
  50        struct collected_reflog **e;
  51        int alloc;
  52        int nr;
  53};
  54
  55#define INCOMPLETE      (1u<<10)
  56#define STUDYING        (1u<<11)
  57#define REACHABLE       (1u<<12)
  58
  59static int tree_is_complete(const struct object_id *oid)
  60{
  61        struct tree_desc desc;
  62        struct name_entry entry;
  63        int complete;
  64        struct tree *tree;
  65
  66        tree = lookup_tree(oid);
  67        if (!tree)
  68                return 0;
  69        if (tree->object.flags & SEEN)
  70                return 1;
  71        if (tree->object.flags & INCOMPLETE)
  72                return 0;
  73
  74        if (!tree->buffer) {
  75                enum object_type type;
  76                unsigned long size;
  77                void *data = read_sha1_file(oid->hash, &type, &size);
  78                if (!data) {
  79                        tree->object.flags |= INCOMPLETE;
  80                        return 0;
  81                }
  82                tree->buffer = data;
  83                tree->size = size;
  84        }
  85        init_tree_desc(&desc, tree->buffer, tree->size);
  86        complete = 1;
  87        while (tree_entry(&desc, &entry)) {
  88                if (!has_sha1_file(entry.oid->hash) ||
  89                    (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid))) {
  90                        tree->object.flags |= INCOMPLETE;
  91                        complete = 0;
  92                }
  93        }
  94        free_tree_buffer(tree);
  95
  96        if (complete)
  97                tree->object.flags |= SEEN;
  98        return complete;
  99}
 100
 101static int commit_is_complete(struct commit *commit)
 102{
 103        struct object_array study;
 104        struct object_array found;
 105        int is_incomplete = 0;
 106        int i;
 107
 108        /* early return */
 109        if (commit->object.flags & SEEN)
 110                return 1;
 111        if (commit->object.flags & INCOMPLETE)
 112                return 0;
 113        /*
 114         * Find all commits that are reachable and are not marked as
 115         * SEEN.  Then make sure the trees and blobs contained are
 116         * complete.  After that, mark these commits also as SEEN.
 117         * If some of the objects that are needed to complete this
 118         * commit are missing, mark this commit as INCOMPLETE.
 119         */
 120        memset(&study, 0, sizeof(study));
 121        memset(&found, 0, sizeof(found));
 122        add_object_array(&commit->object, NULL, &study);
 123        add_object_array(&commit->object, NULL, &found);
 124        commit->object.flags |= STUDYING;
 125        while (study.nr) {
 126                struct commit *c;
 127                struct commit_list *parent;
 128
 129                c = (struct commit *)object_array_pop(&study);
 130                if (!c->object.parsed && !parse_object(&c->object.oid))
 131                        c->object.flags |= INCOMPLETE;
 132
 133                if (c->object.flags & INCOMPLETE) {
 134                        is_incomplete = 1;
 135                        break;
 136                }
 137                else if (c->object.flags & SEEN)
 138                        continue;
 139                for (parent = c->parents; parent; parent = parent->next) {
 140                        struct commit *p = parent->item;
 141                        if (p->object.flags & STUDYING)
 142                                continue;
 143                        p->object.flags |= STUDYING;
 144                        add_object_array(&p->object, NULL, &study);
 145                        add_object_array(&p->object, NULL, &found);
 146                }
 147        }
 148        if (!is_incomplete) {
 149                /*
 150                 * make sure all commits in "found" array have all the
 151                 * necessary objects.
 152                 */
 153                for (i = 0; i < found.nr; i++) {
 154                        struct commit *c =
 155                                (struct commit *)found.objects[i].item;
 156                        if (!tree_is_complete(&c->tree->object.oid)) {
 157                                is_incomplete = 1;
 158                                c->object.flags |= INCOMPLETE;
 159                        }
 160                }
 161                if (!is_incomplete) {
 162                        /* mark all found commits as complete, iow SEEN */
 163                        for (i = 0; i < found.nr; i++)
 164                                found.objects[i].item->flags |= SEEN;
 165                }
 166        }
 167        /* clear flags from the objects we traversed */
 168        for (i = 0; i < found.nr; i++)
 169                found.objects[i].item->flags &= ~STUDYING;
 170        if (is_incomplete)
 171                commit->object.flags |= INCOMPLETE;
 172        else {
 173                /*
 174                 * If we come here, we have (1) traversed the ancestry chain
 175                 * from the "commit" until we reach SEEN commits (which are
 176                 * known to be complete), and (2) made sure that the commits
 177                 * encountered during the above traversal refer to trees that
 178                 * are complete.  Which means that we know *all* the commits
 179                 * we have seen during this process are complete.
 180                 */
 181                for (i = 0; i < found.nr; i++)
 182                        found.objects[i].item->flags |= SEEN;
 183        }
 184        /* free object arrays */
 185        object_array_clear(&study);
 186        object_array_clear(&found);
 187        return !is_incomplete;
 188}
 189
 190static int keep_entry(struct commit **it, struct object_id *oid)
 191{
 192        struct commit *commit;
 193
 194        if (is_null_oid(oid))
 195                return 1;
 196        commit = lookup_commit_reference_gently(oid, 1);
 197        if (!commit)
 198                return 0;
 199
 200        /*
 201         * Make sure everything in this commit exists.
 202         *
 203         * We have walked all the objects reachable from the refs
 204         * and cache earlier.  The commits reachable by this commit
 205         * must meet SEEN commits -- and then we should mark them as
 206         * SEEN as well.
 207         */
 208        if (!commit_is_complete(commit))
 209                return 0;
 210        *it = commit;
 211        return 1;
 212}
 213
 214/*
 215 * Starting from commits in the cb->mark_list, mark commits that are
 216 * reachable from them.  Stop the traversal at commits older than
 217 * the expire_limit and queue them back, so that the caller can call
 218 * us again to restart the traversal with longer expire_limit.
 219 */
 220static void mark_reachable(struct expire_reflog_policy_cb *cb)
 221{
 222        struct commit_list *pending;
 223        timestamp_t expire_limit = cb->mark_limit;
 224        struct commit_list *leftover = NULL;
 225
 226        for (pending = cb->mark_list; pending; pending = pending->next)
 227                pending->item->object.flags &= ~REACHABLE;
 228
 229        pending = cb->mark_list;
 230        while (pending) {
 231                struct commit_list *parent;
 232                struct commit *commit = pop_commit(&pending);
 233                if (commit->object.flags & REACHABLE)
 234                        continue;
 235                if (parse_commit(commit))
 236                        continue;
 237                commit->object.flags |= REACHABLE;
 238                if (commit->date < expire_limit) {
 239                        commit_list_insert(commit, &leftover);
 240                        continue;
 241                }
 242                commit->object.flags |= REACHABLE;
 243                parent = commit->parents;
 244                while (parent) {
 245                        commit = parent->item;
 246                        parent = parent->next;
 247                        if (commit->object.flags & REACHABLE)
 248                                continue;
 249                        commit_list_insert(commit, &pending);
 250                }
 251        }
 252        cb->mark_list = leftover;
 253}
 254
 255static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 256{
 257        /*
 258         * We may or may not have the commit yet - if not, look it
 259         * up using the supplied sha1.
 260         */
 261        if (!commit) {
 262                if (is_null_oid(oid))
 263                        return 0;
 264
 265                commit = lookup_commit_reference_gently(oid, 1);
 266
 267                /* Not a commit -- keep it */
 268                if (!commit)
 269                        return 0;
 270        }
 271
 272        /* Reachable from the current ref?  Don't prune. */
 273        if (commit->object.flags & REACHABLE)
 274                return 0;
 275
 276        if (cb->mark_list && cb->mark_limit) {
 277                cb->mark_limit = 0; /* dig down to the root */
 278                mark_reachable(cb);
 279        }
 280
 281        return !(commit->object.flags & REACHABLE);
 282}
 283
 284/*
 285 * Return true iff the specified reflog entry should be expired.
 286 */
 287static int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 288                                    const char *email, timestamp_t timestamp, int tz,
 289                                    const char *message, void *cb_data)
 290{
 291        struct expire_reflog_policy_cb *cb = cb_data;
 292        struct commit *old, *new;
 293
 294        if (timestamp < cb->cmd.expire_total)
 295                return 1;
 296
 297        old = new = NULL;
 298        if (cb->cmd.stalefix &&
 299            (!keep_entry(&old, ooid) || !keep_entry(&new, noid)))
 300                return 1;
 301
 302        if (timestamp < cb->cmd.expire_unreachable) {
 303                if (cb->unreachable_expire_kind == UE_ALWAYS)
 304                        return 1;
 305                if (unreachable(cb, old, ooid) || unreachable(cb, new, noid))
 306                        return 1;
 307        }
 308
 309        if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 310                return 1;
 311
 312        return 0;
 313}
 314
 315static int push_tip_to_list(const char *refname, const struct object_id *oid,
 316                            int flags, void *cb_data)
 317{
 318        struct commit_list **list = cb_data;
 319        struct commit *tip_commit;
 320        if (flags & REF_ISSYMREF)
 321                return 0;
 322        tip_commit = lookup_commit_reference_gently(oid, 1);
 323        if (!tip_commit)
 324                return 0;
 325        commit_list_insert(tip_commit, list);
 326        return 0;
 327}
 328
 329static void reflog_expiry_prepare(const char *refname,
 330                                  const struct object_id *oid,
 331                                  void *cb_data)
 332{
 333        struct expire_reflog_policy_cb *cb = cb_data;
 334
 335        if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
 336                cb->tip_commit = NULL;
 337                cb->unreachable_expire_kind = UE_HEAD;
 338        } else {
 339                cb->tip_commit = lookup_commit_reference_gently(oid, 1);
 340                if (!cb->tip_commit)
 341                        cb->unreachable_expire_kind = UE_ALWAYS;
 342                else
 343                        cb->unreachable_expire_kind = UE_NORMAL;
 344        }
 345
 346        if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 347                cb->unreachable_expire_kind = UE_ALWAYS;
 348
 349        cb->mark_list = NULL;
 350        cb->tips = NULL;
 351        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 352                if (cb->unreachable_expire_kind == UE_HEAD) {
 353                        struct commit_list *elem;
 354
 355                        for_each_ref(push_tip_to_list, &cb->tips);
 356                        for (elem = cb->tips; elem; elem = elem->next)
 357                                commit_list_insert(elem->item, &cb->mark_list);
 358                } else {
 359                        commit_list_insert(cb->tip_commit, &cb->mark_list);
 360                }
 361                cb->mark_limit = cb->cmd.expire_total;
 362                mark_reachable(cb);
 363        }
 364}
 365
 366static void reflog_expiry_cleanup(void *cb_data)
 367{
 368        struct expire_reflog_policy_cb *cb = cb_data;
 369
 370        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 371                if (cb->unreachable_expire_kind == UE_HEAD) {
 372                        struct commit_list *elem;
 373                        for (elem = cb->tips; elem; elem = elem->next)
 374                                clear_commit_marks(elem->item, REACHABLE);
 375                        free_commit_list(cb->tips);
 376                } else {
 377                        clear_commit_marks(cb->tip_commit, REACHABLE);
 378                }
 379        }
 380}
 381
 382static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 383{
 384        struct collected_reflog *e;
 385        struct collect_reflog_cb *cb = cb_data;
 386
 387        FLEX_ALLOC_STR(e, reflog, ref);
 388        oidcpy(&e->oid, oid);
 389        ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 390        cb->e[cb->nr++] = e;
 391        return 0;
 392}
 393
 394static struct reflog_expire_cfg {
 395        struct reflog_expire_cfg *next;
 396        timestamp_t expire_total;
 397        timestamp_t expire_unreachable;
 398        char pattern[FLEX_ARRAY];
 399} *reflog_expire_cfg, **reflog_expire_cfg_tail;
 400
 401static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 402{
 403        struct reflog_expire_cfg *ent;
 404
 405        if (!reflog_expire_cfg_tail)
 406                reflog_expire_cfg_tail = &reflog_expire_cfg;
 407
 408        for (ent = reflog_expire_cfg; ent; ent = ent->next)
 409                if (!strncmp(ent->pattern, pattern, len) &&
 410                    ent->pattern[len] == '\0')
 411                        return ent;
 412
 413        FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 414        *reflog_expire_cfg_tail = ent;
 415        reflog_expire_cfg_tail = &(ent->next);
 416        return ent;
 417}
 418
 419/* expiry timer slot */
 420#define EXPIRE_TOTAL   01
 421#define EXPIRE_UNREACH 02
 422
 423static int reflog_expire_config(const char *var, const char *value, void *cb)
 424{
 425        const char *pattern, *key;
 426        int pattern_len;
 427        timestamp_t expire;
 428        int slot;
 429        struct reflog_expire_cfg *ent;
 430
 431        if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 432                return git_default_config(var, value, cb);
 433
 434        if (!strcmp(key, "reflogexpire")) {
 435                slot = EXPIRE_TOTAL;
 436                if (git_config_expiry_date(&expire, var, value))
 437                        return -1;
 438        } else if (!strcmp(key, "reflogexpireunreachable")) {
 439                slot = EXPIRE_UNREACH;
 440                if (git_config_expiry_date(&expire, var, value))
 441                        return -1;
 442        } else
 443                return git_default_config(var, value, cb);
 444
 445        if (!pattern) {
 446                switch (slot) {
 447                case EXPIRE_TOTAL:
 448                        default_reflog_expire = expire;
 449                        break;
 450                case EXPIRE_UNREACH:
 451                        default_reflog_expire_unreachable = expire;
 452                        break;
 453                }
 454                return 0;
 455        }
 456
 457        ent = find_cfg_ent(pattern, pattern_len);
 458        if (!ent)
 459                return -1;
 460        switch (slot) {
 461        case EXPIRE_TOTAL:
 462                ent->expire_total = expire;
 463                break;
 464        case EXPIRE_UNREACH:
 465                ent->expire_unreachable = expire;
 466                break;
 467        }
 468        return 0;
 469}
 470
 471static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 472{
 473        struct reflog_expire_cfg *ent;
 474
 475        if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 476                return; /* both given explicitly -- nothing to tweak */
 477
 478        for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 479                if (!wildmatch(ent->pattern, ref, 0)) {
 480                        if (!(slot & EXPIRE_TOTAL))
 481                                cb->expire_total = ent->expire_total;
 482                        if (!(slot & EXPIRE_UNREACH))
 483                                cb->expire_unreachable = ent->expire_unreachable;
 484                        return;
 485                }
 486        }
 487
 488        /*
 489         * If unconfigured, make stash never expire
 490         */
 491        if (!strcmp(ref, "refs/stash")) {
 492                if (!(slot & EXPIRE_TOTAL))
 493                        cb->expire_total = 0;
 494                if (!(slot & EXPIRE_UNREACH))
 495                        cb->expire_unreachable = 0;
 496                return;
 497        }
 498
 499        /* Nothing matched -- use the default value */
 500        if (!(slot & EXPIRE_TOTAL))
 501                cb->expire_total = default_reflog_expire;
 502        if (!(slot & EXPIRE_UNREACH))
 503                cb->expire_unreachable = default_reflog_expire_unreachable;
 504}
 505
 506static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 507{
 508        struct expire_reflog_policy_cb cb;
 509        timestamp_t now = time(NULL);
 510        int i, status, do_all;
 511        int explicit_expiry = 0;
 512        unsigned int flags = 0;
 513
 514        default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 515        default_reflog_expire = now - 90 * 24 * 3600;
 516        git_config(reflog_expire_config, NULL);
 517
 518        save_commit_buffer = 0;
 519        do_all = status = 0;
 520        memset(&cb, 0, sizeof(cb));
 521
 522        cb.cmd.expire_total = default_reflog_expire;
 523        cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 524
 525        for (i = 1; i < argc; i++) {
 526                const char *arg = argv[i];
 527                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 528                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 529                else if (starts_with(arg, "--expire=")) {
 530                        if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 531                                die(_("'%s' is not a valid timestamp"), arg);
 532                        explicit_expiry |= EXPIRE_TOTAL;
 533                }
 534                else if (starts_with(arg, "--expire-unreachable=")) {
 535                        if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 536                                die(_("'%s' is not a valid timestamp"), arg);
 537                        explicit_expiry |= EXPIRE_UNREACH;
 538                }
 539                else if (!strcmp(arg, "--stale-fix"))
 540                        cb.cmd.stalefix = 1;
 541                else if (!strcmp(arg, "--rewrite"))
 542                        flags |= EXPIRE_REFLOGS_REWRITE;
 543                else if (!strcmp(arg, "--updateref"))
 544                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 545                else if (!strcmp(arg, "--all"))
 546                        do_all = 1;
 547                else if (!strcmp(arg, "--verbose"))
 548                        flags |= EXPIRE_REFLOGS_VERBOSE;
 549                else if (!strcmp(arg, "--")) {
 550                        i++;
 551                        break;
 552                }
 553                else if (arg[0] == '-')
 554                        usage(reflog_expire_usage);
 555                else
 556                        break;
 557        }
 558
 559        /*
 560         * We can trust the commits and objects reachable from refs
 561         * even in older repository.  We cannot trust what's reachable
 562         * from reflog if the repository was pruned with older git.
 563         */
 564        if (cb.cmd.stalefix) {
 565                init_revisions(&cb.cmd.revs, prefix);
 566                if (flags & EXPIRE_REFLOGS_VERBOSE)
 567                        printf("Marking reachable objects...");
 568                mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 569                if (flags & EXPIRE_REFLOGS_VERBOSE)
 570                        putchar('\n');
 571        }
 572
 573        if (do_all) {
 574                struct collect_reflog_cb collected;
 575                int i;
 576
 577                memset(&collected, 0, sizeof(collected));
 578                for_each_reflog(collect_reflog, &collected);
 579                for (i = 0; i < collected.nr; i++) {
 580                        struct collected_reflog *e = collected.e[i];
 581                        set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 582                        status |= reflog_expire(e->reflog, &e->oid, flags,
 583                                                reflog_expiry_prepare,
 584                                                should_expire_reflog_ent,
 585                                                reflog_expiry_cleanup,
 586                                                &cb);
 587                        free(e);
 588                }
 589                free(collected.e);
 590        }
 591
 592        for (; i < argc; i++) {
 593                char *ref;
 594                struct object_id oid;
 595                if (!dwim_log(argv[i], strlen(argv[i]), &oid, &ref)) {
 596                        status |= error("%s points nowhere!", argv[i]);
 597                        continue;
 598                }
 599                set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 600                status |= reflog_expire(ref, &oid, flags,
 601                                        reflog_expiry_prepare,
 602                                        should_expire_reflog_ent,
 603                                        reflog_expiry_cleanup,
 604                                        &cb);
 605        }
 606        return status;
 607}
 608
 609static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 610                const char *email, timestamp_t timestamp, int tz,
 611                const char *message, void *cb_data)
 612{
 613        struct expire_reflog_policy_cb *cb = cb_data;
 614        if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 615                cb->cmd.recno++;
 616        return 0;
 617}
 618
 619static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 620{
 621        struct expire_reflog_policy_cb cb;
 622        int i, status = 0;
 623        unsigned int flags = 0;
 624
 625        memset(&cb, 0, sizeof(cb));
 626
 627        for (i = 1; i < argc; i++) {
 628                const char *arg = argv[i];
 629                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 630                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 631                else if (!strcmp(arg, "--rewrite"))
 632                        flags |= EXPIRE_REFLOGS_REWRITE;
 633                else if (!strcmp(arg, "--updateref"))
 634                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 635                else if (!strcmp(arg, "--verbose"))
 636                        flags |= EXPIRE_REFLOGS_VERBOSE;
 637                else if (!strcmp(arg, "--")) {
 638                        i++;
 639                        break;
 640                }
 641                else if (arg[0] == '-')
 642                        usage(reflog_delete_usage);
 643                else
 644                        break;
 645        }
 646
 647        if (argc - i < 1)
 648                return error("Nothing to delete?");
 649
 650        for ( ; i < argc; i++) {
 651                const char *spec = strstr(argv[i], "@{");
 652                struct object_id oid;
 653                char *ep, *ref;
 654                int recno;
 655
 656                if (!spec) {
 657                        status |= error("Not a reflog: %s", argv[i]);
 658                        continue;
 659                }
 660
 661                if (!dwim_log(argv[i], spec - argv[i], &oid, &ref)) {
 662                        status |= error("no reflog for '%s'", argv[i]);
 663                        continue;
 664                }
 665
 666                recno = strtoul(spec + 2, &ep, 10);
 667                if (*ep == '}') {
 668                        cb.cmd.recno = -recno;
 669                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 670                } else {
 671                        cb.cmd.expire_total = approxidate(spec + 2);
 672                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 673                        cb.cmd.expire_total = 0;
 674                }
 675
 676                status |= reflog_expire(ref, &oid, flags,
 677                                        reflog_expiry_prepare,
 678                                        should_expire_reflog_ent,
 679                                        reflog_expiry_cleanup,
 680                                        &cb);
 681                free(ref);
 682        }
 683        return status;
 684}
 685
 686static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 687{
 688        int i, start = 0;
 689
 690        for (i = 1; i < argc; i++) {
 691                const char *arg = argv[i];
 692                if (!strcmp(arg, "--")) {
 693                        i++;
 694                        break;
 695                }
 696                else if (arg[0] == '-')
 697                        usage(reflog_exists_usage);
 698                else
 699                        break;
 700        }
 701
 702        start = i;
 703
 704        if (argc - start != 1)
 705                usage(reflog_exists_usage);
 706
 707        if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 708                die("invalid ref format: %s", argv[start]);
 709        return !reflog_exists(argv[start]);
 710}
 711
 712/*
 713 * main "reflog"
 714 */
 715
 716static const char reflog_usage[] =
 717"git reflog [ show | expire | delete | exists ]";
 718
 719int cmd_reflog(int argc, const char **argv, const char *prefix)
 720{
 721        if (argc > 1 && !strcmp(argv[1], "-h"))
 722                usage(reflog_usage);
 723
 724        /* With no command, we default to showing it. */
 725        if (argc < 2 || *argv[1] == '-')
 726                return cmd_log_reflog(argc, argv, prefix);
 727
 728        if (!strcmp(argv[1], "show"))
 729                return cmd_log_reflog(argc - 1, argv + 1, prefix);
 730
 731        if (!strcmp(argv[1], "expire"))
 732                return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 733
 734        if (!strcmp(argv[1], "delete"))
 735                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 736
 737        if (!strcmp(argv[1], "exists"))
 738                return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 739
 740        return cmd_log_reflog(argc, argv, prefix);
 741}