Andrew's git / gitweb.git / builtin/reflog.c
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builtin / reflog.con commit Merge branch 'ab/get-short-oid' (ab48bc0)
   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/* Remember to update object flag allocation in object.h */
  56#define INCOMPLETE      (1u<<10)
  57#define STUDYING        (1u<<11)
  58#define REACHABLE       (1u<<12)
  59
  60static int tree_is_complete(const struct object_id *oid)
  61{
  62        struct tree_desc desc;
  63        struct name_entry entry;
  64        int complete;
  65        struct tree *tree;
  66
  67        tree = lookup_tree(oid);
  68        if (!tree)
  69                return 0;
  70        if (tree->object.flags & SEEN)
  71                return 1;
  72        if (tree->object.flags & INCOMPLETE)
  73                return 0;
  74
  75        if (!tree->buffer) {
  76                enum object_type type;
  77                unsigned long size;
  78                void *data = read_object_file(oid, &type, &size);
  79                if (!data) {
  80                        tree->object.flags |= INCOMPLETE;
  81                        return 0;
  82                }
  83                tree->buffer = data;
  84                tree->size = size;
  85        }
  86        init_tree_desc(&desc, tree->buffer, tree->size);
  87        complete = 1;
  88        while (tree_entry(&desc, &entry)) {
  89                if (!has_sha1_file(entry.oid->hash) ||
  90                    (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid))) {
  91                        tree->object.flags |= INCOMPLETE;
  92                        complete = 0;
  93                }
  94        }
  95        free_tree_buffer(tree);
  96
  97        if (complete)
  98                tree->object.flags |= SEEN;
  99        return complete;
 100}
 101
 102static int commit_is_complete(struct commit *commit)
 103{
 104        struct object_array study;
 105        struct object_array found;
 106        int is_incomplete = 0;
 107        int i;
 108
 109        /* early return */
 110        if (commit->object.flags & SEEN)
 111                return 1;
 112        if (commit->object.flags & INCOMPLETE)
 113                return 0;
 114        /*
 115         * Find all commits that are reachable and are not marked as
 116         * SEEN.  Then make sure the trees and blobs contained are
 117         * complete.  After that, mark these commits also as SEEN.
 118         * If some of the objects that are needed to complete this
 119         * commit are missing, mark this commit as INCOMPLETE.
 120         */
 121        memset(&study, 0, sizeof(study));
 122        memset(&found, 0, sizeof(found));
 123        add_object_array(&commit->object, NULL, &study);
 124        add_object_array(&commit->object, NULL, &found);
 125        commit->object.flags |= STUDYING;
 126        while (study.nr) {
 127                struct commit *c;
 128                struct commit_list *parent;
 129
 130                c = (struct commit *)object_array_pop(&study);
 131                if (!c->object.parsed && !parse_object(&c->object.oid))
 132                        c->object.flags |= INCOMPLETE;
 133
 134                if (c->object.flags & INCOMPLETE) {
 135                        is_incomplete = 1;
 136                        break;
 137                }
 138                else if (c->object.flags & SEEN)
 139                        continue;
 140                for (parent = c->parents; parent; parent = parent->next) {
 141                        struct commit *p = parent->item;
 142                        if (p->object.flags & STUDYING)
 143                                continue;
 144                        p->object.flags |= STUDYING;
 145                        add_object_array(&p->object, NULL, &study);
 146                        add_object_array(&p->object, NULL, &found);
 147                }
 148        }
 149        if (!is_incomplete) {
 150                /*
 151                 * make sure all commits in "found" array have all the
 152                 * necessary objects.
 153                 */
 154                for (i = 0; i < found.nr; i++) {
 155                        struct commit *c =
 156                                (struct commit *)found.objects[i].item;
 157                        if (!tree_is_complete(get_commit_tree_oid(c))) {
 158                                is_incomplete = 1;
 159                                c->object.flags |= INCOMPLETE;
 160                        }
 161                }
 162                if (!is_incomplete) {
 163                        /* mark all found commits as complete, iow SEEN */
 164                        for (i = 0; i < found.nr; i++)
 165                                found.objects[i].item->flags |= SEEN;
 166                }
 167        }
 168        /* clear flags from the objects we traversed */
 169        for (i = 0; i < found.nr; i++)
 170                found.objects[i].item->flags &= ~STUDYING;
 171        if (is_incomplete)
 172                commit->object.flags |= INCOMPLETE;
 173        else {
 174                /*
 175                 * If we come here, we have (1) traversed the ancestry chain
 176                 * from the "commit" until we reach SEEN commits (which are
 177                 * known to be complete), and (2) made sure that the commits
 178                 * encountered during the above traversal refer to trees that
 179                 * are complete.  Which means that we know *all* the commits
 180                 * we have seen during this process are complete.
 181                 */
 182                for (i = 0; i < found.nr; i++)
 183                        found.objects[i].item->flags |= SEEN;
 184        }
 185        /* free object arrays */
 186        object_array_clear(&study);
 187        object_array_clear(&found);
 188        return !is_incomplete;
 189}
 190
 191static int keep_entry(struct commit **it, struct object_id *oid)
 192{
 193        struct commit *commit;
 194
 195        if (is_null_oid(oid))
 196                return 1;
 197        commit = lookup_commit_reference_gently(oid, 1);
 198        if (!commit)
 199                return 0;
 200
 201        /*
 202         * Make sure everything in this commit exists.
 203         *
 204         * We have walked all the objects reachable from the refs
 205         * and cache earlier.  The commits reachable by this commit
 206         * must meet SEEN commits -- and then we should mark them as
 207         * SEEN as well.
 208         */
 209        if (!commit_is_complete(commit))
 210                return 0;
 211        *it = commit;
 212        return 1;
 213}
 214
 215/*
 216 * Starting from commits in the cb->mark_list, mark commits that are
 217 * reachable from them.  Stop the traversal at commits older than
 218 * the expire_limit and queue them back, so that the caller can call
 219 * us again to restart the traversal with longer expire_limit.
 220 */
 221static void mark_reachable(struct expire_reflog_policy_cb *cb)
 222{
 223        struct commit_list *pending;
 224        timestamp_t expire_limit = cb->mark_limit;
 225        struct commit_list *leftover = NULL;
 226
 227        for (pending = cb->mark_list; pending; pending = pending->next)
 228                pending->item->object.flags &= ~REACHABLE;
 229
 230        pending = cb->mark_list;
 231        while (pending) {
 232                struct commit_list *parent;
 233                struct commit *commit = pop_commit(&pending);
 234                if (commit->object.flags & REACHABLE)
 235                        continue;
 236                if (parse_commit(commit))
 237                        continue;
 238                commit->object.flags |= REACHABLE;
 239                if (commit->date < expire_limit) {
 240                        commit_list_insert(commit, &leftover);
 241                        continue;
 242                }
 243                commit->object.flags |= REACHABLE;
 244                parent = commit->parents;
 245                while (parent) {
 246                        commit = parent->item;
 247                        parent = parent->next;
 248                        if (commit->object.flags & REACHABLE)
 249                                continue;
 250                        commit_list_insert(commit, &pending);
 251                }
 252        }
 253        cb->mark_list = leftover;
 254}
 255
 256static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
 257{
 258        /*
 259         * We may or may not have the commit yet - if not, look it
 260         * up using the supplied sha1.
 261         */
 262        if (!commit) {
 263                if (is_null_oid(oid))
 264                        return 0;
 265
 266                commit = lookup_commit_reference_gently(oid, 1);
 267
 268                /* Not a commit -- keep it */
 269                if (!commit)
 270                        return 0;
 271        }
 272
 273        /* Reachable from the current ref?  Don't prune. */
 274        if (commit->object.flags & REACHABLE)
 275                return 0;
 276
 277        if (cb->mark_list && cb->mark_limit) {
 278                cb->mark_limit = 0; /* dig down to the root */
 279                mark_reachable(cb);
 280        }
 281
 282        return !(commit->object.flags & REACHABLE);
 283}
 284
 285/*
 286 * Return true iff the specified reflog entry should be expired.
 287 */
 288static int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 289                                    const char *email, timestamp_t timestamp, int tz,
 290                                    const char *message, void *cb_data)
 291{
 292        struct expire_reflog_policy_cb *cb = cb_data;
 293        struct commit *old_commit, *new_commit;
 294
 295        if (timestamp < cb->cmd.expire_total)
 296                return 1;
 297
 298        old_commit = new_commit = NULL;
 299        if (cb->cmd.stalefix &&
 300            (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
 301                return 1;
 302
 303        if (timestamp < cb->cmd.expire_unreachable) {
 304                if (cb->unreachable_expire_kind == UE_ALWAYS)
 305                        return 1;
 306                if (unreachable(cb, old_commit, ooid) || unreachable(cb, new_commit, noid))
 307                        return 1;
 308        }
 309
 310        if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 311                return 1;
 312
 313        return 0;
 314}
 315
 316static int push_tip_to_list(const char *refname, const struct object_id *oid,
 317                            int flags, void *cb_data)
 318{
 319        struct commit_list **list = cb_data;
 320        struct commit *tip_commit;
 321        if (flags & REF_ISSYMREF)
 322                return 0;
 323        tip_commit = lookup_commit_reference_gently(oid, 1);
 324        if (!tip_commit)
 325                return 0;
 326        commit_list_insert(tip_commit, list);
 327        return 0;
 328}
 329
 330static void reflog_expiry_prepare(const char *refname,
 331                                  const struct object_id *oid,
 332                                  void *cb_data)
 333{
 334        struct expire_reflog_policy_cb *cb = cb_data;
 335
 336        if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
 337                cb->tip_commit = NULL;
 338                cb->unreachable_expire_kind = UE_HEAD;
 339        } else {
 340                cb->tip_commit = lookup_commit_reference_gently(oid, 1);
 341                if (!cb->tip_commit)
 342                        cb->unreachable_expire_kind = UE_ALWAYS;
 343                else
 344                        cb->unreachable_expire_kind = UE_NORMAL;
 345        }
 346
 347        if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 348                cb->unreachable_expire_kind = UE_ALWAYS;
 349
 350        cb->mark_list = NULL;
 351        cb->tips = NULL;
 352        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 353                if (cb->unreachable_expire_kind == UE_HEAD) {
 354                        struct commit_list *elem;
 355
 356                        for_each_ref(push_tip_to_list, &cb->tips);
 357                        for (elem = cb->tips; elem; elem = elem->next)
 358                                commit_list_insert(elem->item, &cb->mark_list);
 359                } else {
 360                        commit_list_insert(cb->tip_commit, &cb->mark_list);
 361                }
 362                cb->mark_limit = cb->cmd.expire_total;
 363                mark_reachable(cb);
 364        }
 365}
 366
 367static void reflog_expiry_cleanup(void *cb_data)
 368{
 369        struct expire_reflog_policy_cb *cb = cb_data;
 370
 371        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 372                if (cb->unreachable_expire_kind == UE_HEAD) {
 373                        struct commit_list *elem;
 374                        for (elem = cb->tips; elem; elem = elem->next)
 375                                clear_commit_marks(elem->item, REACHABLE);
 376                        free_commit_list(cb->tips);
 377                } else {
 378                        clear_commit_marks(cb->tip_commit, REACHABLE);
 379                }
 380        }
 381}
 382
 383static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 384{
 385        struct collected_reflog *e;
 386        struct collect_reflog_cb *cb = cb_data;
 387
 388        FLEX_ALLOC_STR(e, reflog, ref);
 389        oidcpy(&e->oid, oid);
 390        ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 391        cb->e[cb->nr++] = e;
 392        return 0;
 393}
 394
 395static struct reflog_expire_cfg {
 396        struct reflog_expire_cfg *next;
 397        timestamp_t expire_total;
 398        timestamp_t expire_unreachable;
 399        char pattern[FLEX_ARRAY];
 400} *reflog_expire_cfg, **reflog_expire_cfg_tail;
 401
 402static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 403{
 404        struct reflog_expire_cfg *ent;
 405
 406        if (!reflog_expire_cfg_tail)
 407                reflog_expire_cfg_tail = &reflog_expire_cfg;
 408
 409        for (ent = reflog_expire_cfg; ent; ent = ent->next)
 410                if (!strncmp(ent->pattern, pattern, len) &&
 411                    ent->pattern[len] == '\0')
 412                        return ent;
 413
 414        FLEX_ALLOC_MEM(ent, pattern, pattern, len);
 415        *reflog_expire_cfg_tail = ent;
 416        reflog_expire_cfg_tail = &(ent->next);
 417        return ent;
 418}
 419
 420/* expiry timer slot */
 421#define EXPIRE_TOTAL   01
 422#define EXPIRE_UNREACH 02
 423
 424static int reflog_expire_config(const char *var, const char *value, void *cb)
 425{
 426        const char *pattern, *key;
 427        int pattern_len;
 428        timestamp_t expire;
 429        int slot;
 430        struct reflog_expire_cfg *ent;
 431
 432        if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 433                return git_default_config(var, value, cb);
 434
 435        if (!strcmp(key, "reflogexpire")) {
 436                slot = EXPIRE_TOTAL;
 437                if (git_config_expiry_date(&expire, var, value))
 438                        return -1;
 439        } else if (!strcmp(key, "reflogexpireunreachable")) {
 440                slot = EXPIRE_UNREACH;
 441                if (git_config_expiry_date(&expire, var, value))
 442                        return -1;
 443        } else
 444                return git_default_config(var, value, cb);
 445
 446        if (!pattern) {
 447                switch (slot) {
 448                case EXPIRE_TOTAL:
 449                        default_reflog_expire = expire;
 450                        break;
 451                case EXPIRE_UNREACH:
 452                        default_reflog_expire_unreachable = expire;
 453                        break;
 454                }
 455                return 0;
 456        }
 457
 458        ent = find_cfg_ent(pattern, pattern_len);
 459        if (!ent)
 460                return -1;
 461        switch (slot) {
 462        case EXPIRE_TOTAL:
 463                ent->expire_total = expire;
 464                break;
 465        case EXPIRE_UNREACH:
 466                ent->expire_unreachable = expire;
 467                break;
 468        }
 469        return 0;
 470}
 471
 472static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 473{
 474        struct reflog_expire_cfg *ent;
 475
 476        if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 477                return; /* both given explicitly -- nothing to tweak */
 478
 479        for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 480                if (!wildmatch(ent->pattern, ref, 0)) {
 481                        if (!(slot & EXPIRE_TOTAL))
 482                                cb->expire_total = ent->expire_total;
 483                        if (!(slot & EXPIRE_UNREACH))
 484                                cb->expire_unreachable = ent->expire_unreachable;
 485                        return;
 486                }
 487        }
 488
 489        /*
 490         * If unconfigured, make stash never expire
 491         */
 492        if (!strcmp(ref, "refs/stash")) {
 493                if (!(slot & EXPIRE_TOTAL))
 494                        cb->expire_total = 0;
 495                if (!(slot & EXPIRE_UNREACH))
 496                        cb->expire_unreachable = 0;
 497                return;
 498        }
 499
 500        /* Nothing matched -- use the default value */
 501        if (!(slot & EXPIRE_TOTAL))
 502                cb->expire_total = default_reflog_expire;
 503        if (!(slot & EXPIRE_UNREACH))
 504                cb->expire_unreachable = default_reflog_expire_unreachable;
 505}
 506
 507static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 508{
 509        struct expire_reflog_policy_cb cb;
 510        timestamp_t now = time(NULL);
 511        int i, status, do_all;
 512        int explicit_expiry = 0;
 513        unsigned int flags = 0;
 514
 515        default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 516        default_reflog_expire = now - 90 * 24 * 3600;
 517        git_config(reflog_expire_config, NULL);
 518
 519        save_commit_buffer = 0;
 520        do_all = status = 0;
 521        memset(&cb, 0, sizeof(cb));
 522
 523        cb.cmd.expire_total = default_reflog_expire;
 524        cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 525
 526        for (i = 1; i < argc; i++) {
 527                const char *arg = argv[i];
 528                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 529                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 530                else if (starts_with(arg, "--expire=")) {
 531                        if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 532                                die(_("'%s' is not a valid timestamp"), arg);
 533                        explicit_expiry |= EXPIRE_TOTAL;
 534                }
 535                else if (starts_with(arg, "--expire-unreachable=")) {
 536                        if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 537                                die(_("'%s' is not a valid timestamp"), arg);
 538                        explicit_expiry |= EXPIRE_UNREACH;
 539                }
 540                else if (!strcmp(arg, "--stale-fix"))
 541                        cb.cmd.stalefix = 1;
 542                else if (!strcmp(arg, "--rewrite"))
 543                        flags |= EXPIRE_REFLOGS_REWRITE;
 544                else if (!strcmp(arg, "--updateref"))
 545                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 546                else if (!strcmp(arg, "--all"))
 547                        do_all = 1;
 548                else if (!strcmp(arg, "--verbose"))
 549                        flags |= EXPIRE_REFLOGS_VERBOSE;
 550                else if (!strcmp(arg, "--")) {
 551                        i++;
 552                        break;
 553                }
 554                else if (arg[0] == '-')
 555                        usage(reflog_expire_usage);
 556                else
 557                        break;
 558        }
 559
 560        /*
 561         * We can trust the commits and objects reachable from refs
 562         * even in older repository.  We cannot trust what's reachable
 563         * from reflog if the repository was pruned with older git.
 564         */
 565        if (cb.cmd.stalefix) {
 566                init_revisions(&cb.cmd.revs, prefix);
 567                if (flags & EXPIRE_REFLOGS_VERBOSE)
 568                        printf("Marking reachable objects...");
 569                mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 570                if (flags & EXPIRE_REFLOGS_VERBOSE)
 571                        putchar('\n');
 572        }
 573
 574        if (do_all) {
 575                struct collect_reflog_cb collected;
 576                int i;
 577
 578                memset(&collected, 0, sizeof(collected));
 579                for_each_reflog(collect_reflog, &collected);
 580                for (i = 0; i < collected.nr; i++) {
 581                        struct collected_reflog *e = collected.e[i];
 582                        set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 583                        status |= reflog_expire(e->reflog, &e->oid, flags,
 584                                                reflog_expiry_prepare,
 585                                                should_expire_reflog_ent,
 586                                                reflog_expiry_cleanup,
 587                                                &cb);
 588                        free(e);
 589                }
 590                free(collected.e);
 591        }
 592
 593        for (; i < argc; i++) {
 594                char *ref;
 595                struct object_id oid;
 596                if (!dwim_log(argv[i], strlen(argv[i]), &oid, &ref)) {
 597                        status |= error("%s points nowhere!", argv[i]);
 598                        continue;
 599                }
 600                set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 601                status |= reflog_expire(ref, &oid, flags,
 602                                        reflog_expiry_prepare,
 603                                        should_expire_reflog_ent,
 604                                        reflog_expiry_cleanup,
 605                                        &cb);
 606        }
 607        return status;
 608}
 609
 610static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 611                const char *email, timestamp_t timestamp, int tz,
 612                const char *message, void *cb_data)
 613{
 614        struct expire_reflog_policy_cb *cb = cb_data;
 615        if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 616                cb->cmd.recno++;
 617        return 0;
 618}
 619
 620static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 621{
 622        struct expire_reflog_policy_cb cb;
 623        int i, status = 0;
 624        unsigned int flags = 0;
 625
 626        memset(&cb, 0, sizeof(cb));
 627
 628        for (i = 1; i < argc; i++) {
 629                const char *arg = argv[i];
 630                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 631                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 632                else if (!strcmp(arg, "--rewrite"))
 633                        flags |= EXPIRE_REFLOGS_REWRITE;
 634                else if (!strcmp(arg, "--updateref"))
 635                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 636                else if (!strcmp(arg, "--verbose"))
 637                        flags |= EXPIRE_REFLOGS_VERBOSE;
 638                else if (!strcmp(arg, "--")) {
 639                        i++;
 640                        break;
 641                }
 642                else if (arg[0] == '-')
 643                        usage(reflog_delete_usage);
 644                else
 645                        break;
 646        }
 647
 648        if (argc - i < 1)
 649                return error("Nothing to delete?");
 650
 651        for ( ; i < argc; i++) {
 652                const char *spec = strstr(argv[i], "@{");
 653                struct object_id oid;
 654                char *ep, *ref;
 655                int recno;
 656
 657                if (!spec) {
 658                        status |= error("Not a reflog: %s", argv[i]);
 659                        continue;
 660                }
 661
 662                if (!dwim_log(argv[i], spec - argv[i], &oid, &ref)) {
 663                        status |= error("no reflog for '%s'", argv[i]);
 664                        continue;
 665                }
 666
 667                recno = strtoul(spec + 2, &ep, 10);
 668                if (*ep == '}') {
 669                        cb.cmd.recno = -recno;
 670                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 671                } else {
 672                        cb.cmd.expire_total = approxidate(spec + 2);
 673                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 674                        cb.cmd.expire_total = 0;
 675                }
 676
 677                status |= reflog_expire(ref, &oid, flags,
 678                                        reflog_expiry_prepare,
 679                                        should_expire_reflog_ent,
 680                                        reflog_expiry_cleanup,
 681                                        &cb);
 682                free(ref);
 683        }
 684        return status;
 685}
 686
 687static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 688{
 689        int i, start = 0;
 690
 691        for (i = 1; i < argc; i++) {
 692                const char *arg = argv[i];
 693                if (!strcmp(arg, "--")) {
 694                        i++;
 695                        break;
 696                }
 697                else if (arg[0] == '-')
 698                        usage(reflog_exists_usage);
 699                else
 700                        break;
 701        }
 702
 703        start = i;
 704
 705        if (argc - start != 1)
 706                usage(reflog_exists_usage);
 707
 708        if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 709                die("invalid ref format: %s", argv[start]);
 710        return !reflog_exists(argv[start]);
 711}
 712
 713/*
 714 * main "reflog"
 715 */
 716
 717static const char reflog_usage[] =
 718"git reflog [ show | expire | delete | exists ]";
 719
 720int cmd_reflog(int argc, const char **argv, const char *prefix)
 721{
 722        if (argc > 1 && !strcmp(argv[1], "-h"))
 723                usage(reflog_usage);
 724
 725        /* With no command, we default to showing it. */
 726        if (argc < 2 || *argv[1] == '-')
 727                return cmd_log_reflog(argc, argv, prefix);
 728
 729        if (!strcmp(argv[1], "show"))
 730                return cmd_log_reflog(argc - 1, argv + 1, prefix);
 731
 732        if (!strcmp(argv[1], "expire"))
 733                return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 734
 735        if (!strcmp(argv[1], "delete"))
 736                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 737
 738        if (!strcmp(argv[1], "exists"))
 739                return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 740
 741        return cmd_log_reflog(argc, argv, prefix);
 742}