Andrew's git / gitweb.git / builtin/reflog.c
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builtin / reflog.con commit Merge branch 'dt/refs-backend-preamble' (b6d323f)
   1#include "builtin.h"
   2#include "lockfile.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/* NEEDSWORK: switch to using parse_options */
  12static const char reflog_expire_usage[] =
  13"git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
  14static const char reflog_delete_usage[] =
  15"git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
  16static const char reflog_exists_usage[] =
  17"git reflog exists <ref>";
  18
  19static unsigned long default_reflog_expire;
  20static unsigned long default_reflog_expire_unreachable;
  21
  22struct cmd_reflog_expire_cb {
  23        struct rev_info revs;
  24        int stalefix;
  25        unsigned long expire_total;
  26        unsigned long expire_unreachable;
  27        int recno;
  28};
  29
  30struct expire_reflog_policy_cb {
  31        enum {
  32                UE_NORMAL,
  33                UE_ALWAYS,
  34                UE_HEAD
  35        } unreachable_expire_kind;
  36        struct commit_list *mark_list;
  37        unsigned long mark_limit;
  38        struct cmd_reflog_expire_cb cmd;
  39        struct commit *tip_commit;
  40        struct commit_list *tips;
  41};
  42
  43struct collected_reflog {
  44        unsigned char sha1[20];
  45        char reflog[FLEX_ARRAY];
  46};
  47
  48struct collect_reflog_cb {
  49        struct collected_reflog **e;
  50        int alloc;
  51        int nr;
  52};
  53
  54#define INCOMPLETE      (1u<<10)
  55#define STUDYING        (1u<<11)
  56#define REACHABLE       (1u<<12)
  57
  58static int tree_is_complete(const unsigned char *sha1)
  59{
  60        struct tree_desc desc;
  61        struct name_entry entry;
  62        int complete;
  63        struct tree *tree;
  64
  65        tree = lookup_tree(sha1);
  66        if (!tree)
  67                return 0;
  68        if (tree->object.flags & SEEN)
  69                return 1;
  70        if (tree->object.flags & INCOMPLETE)
  71                return 0;
  72
  73        if (!tree->buffer) {
  74                enum object_type type;
  75                unsigned long size;
  76                void *data = read_sha1_file(sha1, &type, &size);
  77                if (!data) {
  78                        tree->object.flags |= INCOMPLETE;
  79                        return 0;
  80                }
  81                tree->buffer = data;
  82                tree->size = size;
  83        }
  84        init_tree_desc(&desc, tree->buffer, tree->size);
  85        complete = 1;
  86        while (tree_entry(&desc, &entry)) {
  87                if (!has_sha1_file(entry.sha1) ||
  88                    (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  89                        tree->object.flags |= INCOMPLETE;
  90                        complete = 0;
  91                }
  92        }
  93        free_tree_buffer(tree);
  94
  95        if (complete)
  96                tree->object.flags |= SEEN;
  97        return complete;
  98}
  99
 100static int commit_is_complete(struct commit *commit)
 101{
 102        struct object_array study;
 103        struct object_array found;
 104        int is_incomplete = 0;
 105        int i;
 106
 107        /* early return */
 108        if (commit->object.flags & SEEN)
 109                return 1;
 110        if (commit->object.flags & INCOMPLETE)
 111                return 0;
 112        /*
 113         * Find all commits that are reachable and are not marked as
 114         * SEEN.  Then make sure the trees and blobs contained are
 115         * complete.  After that, mark these commits also as SEEN.
 116         * If some of the objects that are needed to complete this
 117         * commit are missing, mark this commit as INCOMPLETE.
 118         */
 119        memset(&study, 0, sizeof(study));
 120        memset(&found, 0, sizeof(found));
 121        add_object_array(&commit->object, NULL, &study);
 122        add_object_array(&commit->object, NULL, &found);
 123        commit->object.flags |= STUDYING;
 124        while (study.nr) {
 125                struct commit *c;
 126                struct commit_list *parent;
 127
 128                c = (struct commit *)study.objects[--study.nr].item;
 129                if (!c->object.parsed && !parse_object(c->object.sha1))
 130                        c->object.flags |= INCOMPLETE;
 131
 132                if (c->object.flags & INCOMPLETE) {
 133                        is_incomplete = 1;
 134                        break;
 135                }
 136                else if (c->object.flags & SEEN)
 137                        continue;
 138                for (parent = c->parents; parent; parent = parent->next) {
 139                        struct commit *p = parent->item;
 140                        if (p->object.flags & STUDYING)
 141                                continue;
 142                        p->object.flags |= STUDYING;
 143                        add_object_array(&p->object, NULL, &study);
 144                        add_object_array(&p->object, NULL, &found);
 145                }
 146        }
 147        if (!is_incomplete) {
 148                /*
 149                 * make sure all commits in "found" array have all the
 150                 * necessary objects.
 151                 */
 152                for (i = 0; i < found.nr; i++) {
 153                        struct commit *c =
 154                                (struct commit *)found.objects[i].item;
 155                        if (!tree_is_complete(c->tree->object.sha1)) {
 156                                is_incomplete = 1;
 157                                c->object.flags |= INCOMPLETE;
 158                        }
 159                }
 160                if (!is_incomplete) {
 161                        /* mark all found commits as complete, iow SEEN */
 162                        for (i = 0; i < found.nr; i++)
 163                                found.objects[i].item->flags |= SEEN;
 164                }
 165        }
 166        /* clear flags from the objects we traversed */
 167        for (i = 0; i < found.nr; i++)
 168                found.objects[i].item->flags &= ~STUDYING;
 169        if (is_incomplete)
 170                commit->object.flags |= INCOMPLETE;
 171        else {
 172                /*
 173                 * If we come here, we have (1) traversed the ancestry chain
 174                 * from the "commit" until we reach SEEN commits (which are
 175                 * known to be complete), and (2) made sure that the commits
 176                 * encountered during the above traversal refer to trees that
 177                 * are complete.  Which means that we know *all* the commits
 178                 * we have seen during this process are complete.
 179                 */
 180                for (i = 0; i < found.nr; i++)
 181                        found.objects[i].item->flags |= SEEN;
 182        }
 183        /* free object arrays */
 184        free(study.objects);
 185        free(found.objects);
 186        return !is_incomplete;
 187}
 188
 189static int keep_entry(struct commit **it, unsigned char *sha1)
 190{
 191        struct commit *commit;
 192
 193        if (is_null_sha1(sha1))
 194                return 1;
 195        commit = lookup_commit_reference_gently(sha1, 1);
 196        if (!commit)
 197                return 0;
 198
 199        /*
 200         * Make sure everything in this commit exists.
 201         *
 202         * We have walked all the objects reachable from the refs
 203         * and cache earlier.  The commits reachable by this commit
 204         * must meet SEEN commits -- and then we should mark them as
 205         * SEEN as well.
 206         */
 207        if (!commit_is_complete(commit))
 208                return 0;
 209        *it = commit;
 210        return 1;
 211}
 212
 213/*
 214 * Starting from commits in the cb->mark_list, mark commits that are
 215 * reachable from them.  Stop the traversal at commits older than
 216 * the expire_limit and queue them back, so that the caller can call
 217 * us again to restart the traversal with longer expire_limit.
 218 */
 219static void mark_reachable(struct expire_reflog_policy_cb *cb)
 220{
 221        struct commit *commit;
 222        struct commit_list *pending;
 223        unsigned long 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 *entry = pending;
 232                struct commit_list *parent;
 233                pending = entry->next;
 234                commit = entry->item;
 235                free(entry);
 236                if (commit->object.flags & REACHABLE)
 237                        continue;
 238                if (parse_commit(commit))
 239                        continue;
 240                commit->object.flags |= REACHABLE;
 241                if (commit->date < expire_limit) {
 242                        commit_list_insert(commit, &leftover);
 243                        continue;
 244                }
 245                commit->object.flags |= REACHABLE;
 246                parent = commit->parents;
 247                while (parent) {
 248                        commit = parent->item;
 249                        parent = parent->next;
 250                        if (commit->object.flags & REACHABLE)
 251                                continue;
 252                        commit_list_insert(commit, &pending);
 253                }
 254        }
 255        cb->mark_list = leftover;
 256}
 257
 258static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, unsigned char *sha1)
 259{
 260        /*
 261         * We may or may not have the commit yet - if not, look it
 262         * up using the supplied sha1.
 263         */
 264        if (!commit) {
 265                if (is_null_sha1(sha1))
 266                        return 0;
 267
 268                commit = lookup_commit_reference_gently(sha1, 1);
 269
 270                /* Not a commit -- keep it */
 271                if (!commit)
 272                        return 0;
 273        }
 274
 275        /* Reachable from the current ref?  Don't prune. */
 276        if (commit->object.flags & REACHABLE)
 277                return 0;
 278
 279        if (cb->mark_list && cb->mark_limit) {
 280                cb->mark_limit = 0; /* dig down to the root */
 281                mark_reachable(cb);
 282        }
 283
 284        return !(commit->object.flags & REACHABLE);
 285}
 286
 287/*
 288 * Return true iff the specified reflog entry should be expired.
 289 */
 290static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 291                                    const char *email, unsigned long timestamp, int tz,
 292                                    const char *message, void *cb_data)
 293{
 294        struct expire_reflog_policy_cb *cb = cb_data;
 295        struct commit *old, *new;
 296
 297        if (timestamp < cb->cmd.expire_total)
 298                return 1;
 299
 300        old = new = NULL;
 301        if (cb->cmd.stalefix &&
 302            (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 303                return 1;
 304
 305        if (timestamp < cb->cmd.expire_unreachable) {
 306                if (cb->unreachable_expire_kind == UE_ALWAYS)
 307                        return 1;
 308                if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 309                        return 1;
 310        }
 311
 312        if (cb->cmd.recno && --(cb->cmd.recno) == 0)
 313                return 1;
 314
 315        return 0;
 316}
 317
 318static int push_tip_to_list(const char *refname, const struct object_id *oid,
 319                            int flags, void *cb_data)
 320{
 321        struct commit_list **list = cb_data;
 322        struct commit *tip_commit;
 323        if (flags & REF_ISSYMREF)
 324                return 0;
 325        tip_commit = lookup_commit_reference_gently(oid->hash, 1);
 326        if (!tip_commit)
 327                return 0;
 328        commit_list_insert(tip_commit, list);
 329        return 0;
 330}
 331
 332static void reflog_expiry_prepare(const char *refname,
 333                                  const unsigned char *sha1,
 334                                  void *cb_data)
 335{
 336        struct expire_reflog_policy_cb *cb = cb_data;
 337
 338        if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
 339                cb->tip_commit = NULL;
 340                cb->unreachable_expire_kind = UE_HEAD;
 341        } else {
 342                cb->tip_commit = lookup_commit_reference_gently(sha1, 1);
 343                if (!cb->tip_commit)
 344                        cb->unreachable_expire_kind = UE_ALWAYS;
 345                else
 346                        cb->unreachable_expire_kind = UE_NORMAL;
 347        }
 348
 349        if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
 350                cb->unreachable_expire_kind = UE_ALWAYS;
 351
 352        cb->mark_list = NULL;
 353        cb->tips = NULL;
 354        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 355                if (cb->unreachable_expire_kind == UE_HEAD) {
 356                        struct commit_list *elem;
 357
 358                        for_each_ref(push_tip_to_list, &cb->tips);
 359                        for (elem = cb->tips; elem; elem = elem->next)
 360                                commit_list_insert(elem->item, &cb->mark_list);
 361                } else {
 362                        commit_list_insert(cb->tip_commit, &cb->mark_list);
 363                }
 364                cb->mark_limit = cb->cmd.expire_total;
 365                mark_reachable(cb);
 366        }
 367}
 368
 369static void reflog_expiry_cleanup(void *cb_data)
 370{
 371        struct expire_reflog_policy_cb *cb = cb_data;
 372
 373        if (cb->unreachable_expire_kind != UE_ALWAYS) {
 374                if (cb->unreachable_expire_kind == UE_HEAD) {
 375                        struct commit_list *elem;
 376                        for (elem = cb->tips; elem; elem = elem->next)
 377                                clear_commit_marks(elem->item, REACHABLE);
 378                        free_commit_list(cb->tips);
 379                } else {
 380                        clear_commit_marks(cb->tip_commit, REACHABLE);
 381                }
 382        }
 383}
 384
 385static int collect_reflog(const char *ref, const struct object_id *oid, int unused, void *cb_data)
 386{
 387        struct collected_reflog *e;
 388        struct collect_reflog_cb *cb = cb_data;
 389        size_t namelen = strlen(ref);
 390
 391        e = xmalloc(sizeof(*e) + namelen + 1);
 392        hashcpy(e->sha1, oid->hash);
 393        memcpy(e->reflog, ref, namelen + 1);
 394        ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 395        cb->e[cb->nr++] = e;
 396        return 0;
 397}
 398
 399static struct reflog_expire_cfg {
 400        struct reflog_expire_cfg *next;
 401        unsigned long expire_total;
 402        unsigned long expire_unreachable;
 403        size_t len;
 404        char pattern[FLEX_ARRAY];
 405} *reflog_expire_cfg, **reflog_expire_cfg_tail;
 406
 407static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 408{
 409        struct reflog_expire_cfg *ent;
 410
 411        if (!reflog_expire_cfg_tail)
 412                reflog_expire_cfg_tail = &reflog_expire_cfg;
 413
 414        for (ent = reflog_expire_cfg; ent; ent = ent->next)
 415                if (ent->len == len &&
 416                    !memcmp(ent->pattern, pattern, len))
 417                        return ent;
 418
 419        ent = xcalloc(1, (sizeof(*ent) + len));
 420        memcpy(ent->pattern, pattern, len);
 421        ent->len = len;
 422        *reflog_expire_cfg_tail = ent;
 423        reflog_expire_cfg_tail = &(ent->next);
 424        return ent;
 425}
 426
 427static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 428{
 429        if (!value)
 430                return config_error_nonbool(var);
 431        if (parse_expiry_date(value, expire))
 432                return error(_("%s' for '%s' is not a valid timestamp"),
 433                             value, var);
 434        return 0;
 435}
 436
 437/* expiry timer slot */
 438#define EXPIRE_TOTAL   01
 439#define EXPIRE_UNREACH 02
 440
 441static int reflog_expire_config(const char *var, const char *value, void *cb)
 442{
 443        const char *pattern, *key;
 444        int pattern_len;
 445        unsigned long expire;
 446        int slot;
 447        struct reflog_expire_cfg *ent;
 448
 449        if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
 450                return git_default_config(var, value, cb);
 451
 452        if (!strcmp(key, "reflogexpire")) {
 453                slot = EXPIRE_TOTAL;
 454                if (parse_expire_cfg_value(var, value, &expire))
 455                        return -1;
 456        } else if (!strcmp(key, "reflogexpireunreachable")) {
 457                slot = EXPIRE_UNREACH;
 458                if (parse_expire_cfg_value(var, value, &expire))
 459                        return -1;
 460        } else
 461                return git_default_config(var, value, cb);
 462
 463        if (!pattern) {
 464                switch (slot) {
 465                case EXPIRE_TOTAL:
 466                        default_reflog_expire = expire;
 467                        break;
 468                case EXPIRE_UNREACH:
 469                        default_reflog_expire_unreachable = expire;
 470                        break;
 471                }
 472                return 0;
 473        }
 474
 475        ent = find_cfg_ent(pattern, pattern_len);
 476        if (!ent)
 477                return -1;
 478        switch (slot) {
 479        case EXPIRE_TOTAL:
 480                ent->expire_total = expire;
 481                break;
 482        case EXPIRE_UNREACH:
 483                ent->expire_unreachable = expire;
 484                break;
 485        }
 486        return 0;
 487}
 488
 489static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 490{
 491        struct reflog_expire_cfg *ent;
 492
 493        if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 494                return; /* both given explicitly -- nothing to tweak */
 495
 496        for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 497                if (!wildmatch(ent->pattern, ref, 0, NULL)) {
 498                        if (!(slot & EXPIRE_TOTAL))
 499                                cb->expire_total = ent->expire_total;
 500                        if (!(slot & EXPIRE_UNREACH))
 501                                cb->expire_unreachable = ent->expire_unreachable;
 502                        return;
 503                }
 504        }
 505
 506        /*
 507         * If unconfigured, make stash never expire
 508         */
 509        if (!strcmp(ref, "refs/stash")) {
 510                if (!(slot & EXPIRE_TOTAL))
 511                        cb->expire_total = 0;
 512                if (!(slot & EXPIRE_UNREACH))
 513                        cb->expire_unreachable = 0;
 514                return;
 515        }
 516
 517        /* Nothing matched -- use the default value */
 518        if (!(slot & EXPIRE_TOTAL))
 519                cb->expire_total = default_reflog_expire;
 520        if (!(slot & EXPIRE_UNREACH))
 521                cb->expire_unreachable = default_reflog_expire_unreachable;
 522}
 523
 524static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 525{
 526        struct expire_reflog_policy_cb cb;
 527        unsigned long now = time(NULL);
 528        int i, status, do_all;
 529        int explicit_expiry = 0;
 530        unsigned int flags = 0;
 531
 532        default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 533        default_reflog_expire = now - 90 * 24 * 3600;
 534        git_config(reflog_expire_config, NULL);
 535
 536        save_commit_buffer = 0;
 537        do_all = status = 0;
 538        memset(&cb, 0, sizeof(cb));
 539
 540        cb.cmd.expire_total = default_reflog_expire;
 541        cb.cmd.expire_unreachable = default_reflog_expire_unreachable;
 542
 543        for (i = 1; i < argc; i++) {
 544                const char *arg = argv[i];
 545                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 546                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 547                else if (starts_with(arg, "--expire=")) {
 548                        if (parse_expiry_date(arg + 9, &cb.cmd.expire_total))
 549                                die(_("'%s' is not a valid timestamp"), arg);
 550                        explicit_expiry |= EXPIRE_TOTAL;
 551                }
 552                else if (starts_with(arg, "--expire-unreachable=")) {
 553                        if (parse_expiry_date(arg + 21, &cb.cmd.expire_unreachable))
 554                                die(_("'%s' is not a valid timestamp"), arg);
 555                        explicit_expiry |= EXPIRE_UNREACH;
 556                }
 557                else if (!strcmp(arg, "--stale-fix"))
 558                        cb.cmd.stalefix = 1;
 559                else if (!strcmp(arg, "--rewrite"))
 560                        flags |= EXPIRE_REFLOGS_REWRITE;
 561                else if (!strcmp(arg, "--updateref"))
 562                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 563                else if (!strcmp(arg, "--all"))
 564                        do_all = 1;
 565                else if (!strcmp(arg, "--verbose"))
 566                        flags |= EXPIRE_REFLOGS_VERBOSE;
 567                else if (!strcmp(arg, "--")) {
 568                        i++;
 569                        break;
 570                }
 571                else if (arg[0] == '-')
 572                        usage(reflog_expire_usage);
 573                else
 574                        break;
 575        }
 576
 577        /*
 578         * We can trust the commits and objects reachable from refs
 579         * even in older repository.  We cannot trust what's reachable
 580         * from reflog if the repository was pruned with older git.
 581         */
 582        if (cb.cmd.stalefix) {
 583                init_revisions(&cb.cmd.revs, prefix);
 584                if (flags & EXPIRE_REFLOGS_VERBOSE)
 585                        printf("Marking reachable objects...");
 586                mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);
 587                if (flags & EXPIRE_REFLOGS_VERBOSE)
 588                        putchar('\n');
 589        }
 590
 591        if (do_all) {
 592                struct collect_reflog_cb collected;
 593                int i;
 594
 595                memset(&collected, 0, sizeof(collected));
 596                for_each_reflog(collect_reflog, &collected);
 597                for (i = 0; i < collected.nr; i++) {
 598                        struct collected_reflog *e = collected.e[i];
 599                        set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
 600                        status |= reflog_expire(e->reflog, e->sha1, flags,
 601                                                reflog_expiry_prepare,
 602                                                should_expire_reflog_ent,
 603                                                reflog_expiry_cleanup,
 604                                                &cb);
 605                        free(e);
 606                }
 607                free(collected.e);
 608        }
 609
 610        for (; i < argc; i++) {
 611                char *ref;
 612                unsigned char sha1[20];
 613                if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 614                        status |= error("%s points nowhere!", argv[i]);
 615                        continue;
 616                }
 617                set_reflog_expiry_param(&cb.cmd, explicit_expiry, ref);
 618                status |= reflog_expire(ref, sha1, flags,
 619                                        reflog_expiry_prepare,
 620                                        should_expire_reflog_ent,
 621                                        reflog_expiry_cleanup,
 622                                        &cb);
 623        }
 624        return status;
 625}
 626
 627static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 628                const char *email, unsigned long timestamp, int tz,
 629                const char *message, void *cb_data)
 630{
 631        struct expire_reflog_policy_cb *cb = cb_data;
 632        if (!cb->cmd.expire_total || timestamp < cb->cmd.expire_total)
 633                cb->cmd.recno++;
 634        return 0;
 635}
 636
 637static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 638{
 639        struct expire_reflog_policy_cb cb;
 640        int i, status = 0;
 641        unsigned int flags = 0;
 642
 643        memset(&cb, 0, sizeof(cb));
 644
 645        for (i = 1; i < argc; i++) {
 646                const char *arg = argv[i];
 647                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 648                        flags |= EXPIRE_REFLOGS_DRY_RUN;
 649                else if (!strcmp(arg, "--rewrite"))
 650                        flags |= EXPIRE_REFLOGS_REWRITE;
 651                else if (!strcmp(arg, "--updateref"))
 652                        flags |= EXPIRE_REFLOGS_UPDATE_REF;
 653                else if (!strcmp(arg, "--verbose"))
 654                        flags |= EXPIRE_REFLOGS_VERBOSE;
 655                else if (!strcmp(arg, "--")) {
 656                        i++;
 657                        break;
 658                }
 659                else if (arg[0] == '-')
 660                        usage(reflog_delete_usage);
 661                else
 662                        break;
 663        }
 664
 665        if (argc - i < 1)
 666                return error("Nothing to delete?");
 667
 668        for ( ; i < argc; i++) {
 669                const char *spec = strstr(argv[i], "@{");
 670                unsigned char sha1[20];
 671                char *ep, *ref;
 672                int recno;
 673
 674                if (!spec) {
 675                        status |= error("Not a reflog: %s", argv[i]);
 676                        continue;
 677                }
 678
 679                if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 680                        status |= error("no reflog for '%s'", argv[i]);
 681                        continue;
 682                }
 683
 684                recno = strtoul(spec + 2, &ep, 10);
 685                if (*ep == '}') {
 686                        cb.cmd.recno = -recno;
 687                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 688                } else {
 689                        cb.cmd.expire_total = approxidate(spec + 2);
 690                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 691                        cb.cmd.expire_total = 0;
 692                }
 693
 694                status |= reflog_expire(ref, sha1, flags,
 695                                        reflog_expiry_prepare,
 696                                        should_expire_reflog_ent,
 697                                        reflog_expiry_cleanup,
 698                                        &cb);
 699                free(ref);
 700        }
 701        return status;
 702}
 703
 704static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
 705{
 706        int i, start = 0;
 707
 708        for (i = 1; i < argc; i++) {
 709                const char *arg = argv[i];
 710                if (!strcmp(arg, "--")) {
 711                        i++;
 712                        break;
 713                }
 714                else if (arg[0] == '-')
 715                        usage(reflog_exists_usage);
 716                else
 717                        break;
 718        }
 719
 720        start = i;
 721
 722        if (argc - start != 1)
 723                usage(reflog_exists_usage);
 724
 725        if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
 726                die("invalid ref format: %s", argv[start]);
 727        return !reflog_exists(argv[start]);
 728}
 729
 730/*
 731 * main "reflog"
 732 */
 733
 734static const char reflog_usage[] =
 735"git reflog [ show | expire | delete | exists ]";
 736
 737int cmd_reflog(int argc, const char **argv, const char *prefix)
 738{
 739        if (argc > 1 && !strcmp(argv[1], "-h"))
 740                usage(reflog_usage);
 741
 742        /* With no command, we default to showing it. */
 743        if (argc < 2 || *argv[1] == '-')
 744                return cmd_log_reflog(argc, argv, prefix);
 745
 746        if (!strcmp(argv[1], "show"))
 747                return cmd_log_reflog(argc - 1, argv + 1, prefix);
 748
 749        if (!strcmp(argv[1], "expire"))
 750                return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 751
 752        if (!strcmp(argv[1], "delete"))
 753                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 754
 755        if (!strcmp(argv[1], "exists"))
 756                return cmd_reflog_exists(argc - 1, argv + 1, prefix);
 757
 758        return cmd_log_reflog(argc, argv, prefix);
 759}