Andrew's git / gitweb.git / builtin-reflog.c
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builtin-reflog.con commit Clean up reflog unreachability pruning decision (9ffb15d)
   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
  15static const char reflog_expire_usage[] =
  16"git reflog (show|expire) [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
  17static const char reflog_delete_usage[] =
  18"git reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
  19
  20static unsigned long default_reflog_expire;
  21static unsigned long default_reflog_expire_unreachable;
  22
  23struct cmd_reflog_expire_cb {
  24        struct rev_info revs;
  25        int dry_run;
  26        int stalefix;
  27        int rewrite;
  28        int updateref;
  29        int verbose;
  30        unsigned long expire_total;
  31        unsigned long expire_unreachable;
  32        int recno;
  33};
  34
  35struct expire_reflog_cb {
  36        FILE *newlog;
  37        const char *ref;
  38        struct commit *ref_commit;
  39        struct cmd_reflog_expire_cb *cmd;
  40        unsigned char last_kept_sha1[20];
  41};
  42
  43struct collected_reflog {
  44        unsigned char sha1[20];
  45        char reflog[FLEX_ARRAY];
  46};
  47struct collect_reflog_cb {
  48        struct collected_reflog **e;
  49        int alloc;
  50        int nr;
  51};
  52
  53#define INCOMPLETE      (1u<<10)
  54#define STUDYING        (1u<<11)
  55
  56static int tree_is_complete(const unsigned char *sha1)
  57{
  58        struct tree_desc desc;
  59        struct name_entry entry;
  60        int complete;
  61        struct tree *tree;
  62
  63        tree = lookup_tree(sha1);
  64        if (!tree)
  65                return 0;
  66        if (tree->object.flags & SEEN)
  67                return 1;
  68        if (tree->object.flags & INCOMPLETE)
  69                return 0;
  70
  71        if (!tree->buffer) {
  72                enum object_type type;
  73                unsigned long size;
  74                void *data = read_sha1_file(sha1, &type, &size);
  75                if (!data) {
  76                        tree->object.flags |= INCOMPLETE;
  77                        return 0;
  78                }
  79                tree->buffer = data;
  80                tree->size = size;
  81        }
  82        init_tree_desc(&desc, tree->buffer, tree->size);
  83        complete = 1;
  84        while (tree_entry(&desc, &entry)) {
  85                if (!has_sha1_file(entry.sha1) ||
  86                    (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
  87                        tree->object.flags |= INCOMPLETE;
  88                        complete = 0;
  89                }
  90        }
  91        free(tree->buffer);
  92        tree->buffer = NULL;
  93
  94        if (complete)
  95                tree->object.flags |= SEEN;
  96        return complete;
  97}
  98
  99static int commit_is_complete(struct commit *commit)
 100{
 101        struct object_array study;
 102        struct object_array found;
 103        int is_incomplete = 0;
 104        int i;
 105
 106        /* early return */
 107        if (commit->object.flags & SEEN)
 108                return 1;
 109        if (commit->object.flags & INCOMPLETE)
 110                return 0;
 111        /*
 112         * Find all commits that are reachable and are not marked as
 113         * SEEN.  Then make sure the trees and blobs contained are
 114         * complete.  After that, mark these commits also as SEEN.
 115         * If some of the objects that are needed to complete this
 116         * commit are missing, mark this commit as INCOMPLETE.
 117         */
 118        memset(&study, 0, sizeof(study));
 119        memset(&found, 0, sizeof(found));
 120        add_object_array(&commit->object, NULL, &study);
 121        add_object_array(&commit->object, NULL, &found);
 122        commit->object.flags |= STUDYING;
 123        while (study.nr) {
 124                struct commit *c;
 125                struct commit_list *parent;
 126
 127                c = (struct commit *)study.objects[--study.nr].item;
 128                if (!c->object.parsed && !parse_object(c->object.sha1))
 129                        c->object.flags |= INCOMPLETE;
 130
 131                if (c->object.flags & INCOMPLETE) {
 132                        is_incomplete = 1;
 133                        break;
 134                }
 135                else if (c->object.flags & SEEN)
 136                        continue;
 137                for (parent = c->parents; parent; parent = parent->next) {
 138                        struct commit *p = parent->item;
 139                        if (p->object.flags & STUDYING)
 140                                continue;
 141                        p->object.flags |= STUDYING;
 142                        add_object_array(&p->object, NULL, &study);
 143                        add_object_array(&p->object, NULL, &found);
 144                }
 145        }
 146        if (!is_incomplete) {
 147                /*
 148                 * make sure all commits in "found" array have all the
 149                 * necessary objects.
 150                 */
 151                for (i = 0; i < found.nr; i++) {
 152                        struct commit *c =
 153                                (struct commit *)found.objects[i].item;
 154                        if (!tree_is_complete(c->tree->object.sha1)) {
 155                                is_incomplete = 1;
 156                                c->object.flags |= INCOMPLETE;
 157                        }
 158                }
 159                if (!is_incomplete) {
 160                        /* mark all found commits as complete, iow SEEN */
 161                        for (i = 0; i < found.nr; i++)
 162                                found.objects[i].item->flags |= SEEN;
 163                }
 164        }
 165        /* clear flags from the objects we traversed */
 166        for (i = 0; i < found.nr; i++)
 167                found.objects[i].item->flags &= ~STUDYING;
 168        if (is_incomplete)
 169                commit->object.flags |= INCOMPLETE;
 170        else {
 171                /*
 172                 * If we come here, we have (1) traversed the ancestry chain
 173                 * from the "commit" until we reach SEEN commits (which are
 174                 * known to be complete), and (2) made sure that the commits
 175                 * encountered during the above traversal refer to trees that
 176                 * are complete.  Which means that we know *all* the commits
 177                 * we have seen during this process are complete.
 178                 */
 179                for (i = 0; i < found.nr; i++)
 180                        found.objects[i].item->flags |= SEEN;
 181        }
 182        /* free object arrays */
 183        free(study.objects);
 184        free(found.objects);
 185        return !is_incomplete;
 186}
 187
 188static int keep_entry(struct commit **it, unsigned char *sha1)
 189{
 190        struct commit *commit;
 191
 192        if (is_null_sha1(sha1))
 193                return 1;
 194        commit = lookup_commit_reference_gently(sha1, 1);
 195        if (!commit)
 196                return 0;
 197
 198        /*
 199         * Make sure everything in this commit exists.
 200         *
 201         * We have walked all the objects reachable from the refs
 202         * and cache earlier.  The commits reachable by this commit
 203         * must meet SEEN commits -- and then we should mark them as
 204         * SEEN as well.
 205         */
 206        if (!commit_is_complete(commit))
 207                return 0;
 208        *it = commit;
 209        return 1;
 210}
 211
 212static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
 213{
 214        /*
 215         * We may or may not have the commit yet - if not, look it
 216         * up using the supplied sha1.
 217         */
 218        if (!commit) {
 219                if (is_null_sha1(sha1))
 220                        return 0;
 221
 222                commit = lookup_commit_reference_gently(sha1, 1);
 223
 224                /* Not a commit -- keep it */
 225                if (!commit)
 226                        return 0;
 227        }
 228
 229        /* Reachable from the current ref?  Don't prune. */
 230        if (in_merge_bases(commit, &cb->ref_commit, 1))
 231                return 0;
 232
 233        /* We can't reach it - prune it. */
 234        return 1;
 235}
 236
 237static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 238                const char *email, unsigned long timestamp, int tz,
 239                const char *message, void *cb_data)
 240{
 241        struct expire_reflog_cb *cb = cb_data;
 242        struct commit *old, *new;
 243
 244        if (timestamp < cb->cmd->expire_total)
 245                goto prune;
 246
 247        if (cb->cmd->rewrite)
 248                osha1 = cb->last_kept_sha1;
 249
 250        old = new = NULL;
 251        if (cb->cmd->stalefix &&
 252            (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 253                goto prune;
 254
 255        if (timestamp < cb->cmd->expire_unreachable) {
 256                if (!cb->ref_commit)
 257                        goto prune;
 258                if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 259                        goto prune;
 260        }
 261
 262        if (cb->cmd->recno && --(cb->cmd->recno) == 0)
 263                goto prune;
 264
 265        if (cb->newlog) {
 266                char sign = (tz < 0) ? '-' : '+';
 267                int zone = (tz < 0) ? (-tz) : tz;
 268                fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
 269                        sha1_to_hex(osha1), sha1_to_hex(nsha1),
 270                        email, timestamp, sign, zone,
 271                        message);
 272                hashcpy(cb->last_kept_sha1, nsha1);
 273        }
 274        if (cb->cmd->verbose)
 275                printf("keep %s", message);
 276        return 0;
 277 prune:
 278        if (!cb->newlog || cb->cmd->verbose)
 279                printf("%sprune %s", cb->newlog ? "" : "would ", message);
 280        return 0;
 281}
 282
 283static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 284{
 285        struct cmd_reflog_expire_cb *cmd = cb_data;
 286        struct expire_reflog_cb cb;
 287        struct ref_lock *lock;
 288        char *log_file, *newlog_path = NULL;
 289        int status = 0;
 290
 291        memset(&cb, 0, sizeof(cb));
 292
 293        /*
 294         * we take the lock for the ref itself to prevent it from
 295         * getting updated.
 296         */
 297        lock = lock_any_ref_for_update(ref, sha1, 0);
 298        if (!lock)
 299                return error("cannot lock ref '%s'", ref);
 300        log_file = git_pathdup("logs/%s", ref);
 301        if (!file_exists(log_file))
 302                goto finish;
 303        if (!cmd->dry_run) {
 304                newlog_path = git_pathdup("logs/%s.lock", ref);
 305                cb.newlog = fopen(newlog_path, "w");
 306        }
 307
 308        cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
 309        cb.ref = ref;
 310        cb.cmd = cmd;
 311        for_each_reflog_ent(ref, expire_reflog_ent, &cb);
 312 finish:
 313        if (cb.newlog) {
 314                if (fclose(cb.newlog)) {
 315                        status |= error("%s: %s", strerror(errno),
 316                                        newlog_path);
 317                        unlink(newlog_path);
 318                } else if (cmd->updateref &&
 319                        (write_in_full(lock->lock_fd,
 320                                sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
 321                         write_in_full(lock->lock_fd, "\n", 1) != 1 ||
 322                         close_ref(lock) < 0)) {
 323                        status |= error("Couldn't write %s",
 324                                lock->lk->filename);
 325                        unlink(newlog_path);
 326                } else if (rename(newlog_path, log_file)) {
 327                        status |= error("cannot rename %s to %s",
 328                                        newlog_path, log_file);
 329                        unlink(newlog_path);
 330                } else if (cmd->updateref && commit_ref(lock)) {
 331                        status |= error("Couldn't set %s", lock->ref_name);
 332                } else {
 333                        adjust_shared_perm(log_file);
 334                }
 335        }
 336        free(newlog_path);
 337        free(log_file);
 338        unlock_ref(lock);
 339        return status;
 340}
 341
 342static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
 343{
 344        struct collected_reflog *e;
 345        struct collect_reflog_cb *cb = cb_data;
 346        size_t namelen = strlen(ref);
 347
 348        e = xmalloc(sizeof(*e) + namelen + 1);
 349        hashcpy(e->sha1, sha1);
 350        memcpy(e->reflog, ref, namelen + 1);
 351        ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 352        cb->e[cb->nr++] = e;
 353        return 0;
 354}
 355
 356static struct reflog_expire_cfg {
 357        struct reflog_expire_cfg *next;
 358        unsigned long expire_total;
 359        unsigned long expire_unreachable;
 360        size_t len;
 361        char pattern[FLEX_ARRAY];
 362} *reflog_expire_cfg, **reflog_expire_cfg_tail;
 363
 364static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 365{
 366        struct reflog_expire_cfg *ent;
 367
 368        if (!reflog_expire_cfg_tail)
 369                reflog_expire_cfg_tail = &reflog_expire_cfg;
 370
 371        for (ent = reflog_expire_cfg; ent; ent = ent->next)
 372                if (ent->len == len &&
 373                    !memcmp(ent->pattern, pattern, len))
 374                        return ent;
 375
 376        ent = xcalloc(1, (sizeof(*ent) + len));
 377        memcpy(ent->pattern, pattern, len);
 378        ent->len = len;
 379        *reflog_expire_cfg_tail = ent;
 380        reflog_expire_cfg_tail = &(ent->next);
 381        return ent;
 382}
 383
 384static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
 385{
 386        if (!value)
 387                return config_error_nonbool(var);
 388        if (!strcmp(value, "never") || !strcmp(value, "false")) {
 389                *expire = 0;
 390                return 0;
 391        }
 392        *expire = approxidate(value);
 393        return 0;
 394}
 395
 396/* expiry timer slot */
 397#define EXPIRE_TOTAL   01
 398#define EXPIRE_UNREACH 02
 399
 400static int reflog_expire_config(const char *var, const char *value, void *cb)
 401{
 402        const char *lastdot = strrchr(var, '.');
 403        unsigned long expire;
 404        int slot;
 405        struct reflog_expire_cfg *ent;
 406
 407        if (!lastdot || prefixcmp(var, "gc."))
 408                return git_default_config(var, value, cb);
 409
 410        if (!strcmp(lastdot, ".reflogexpire")) {
 411                slot = EXPIRE_TOTAL;
 412                if (parse_expire_cfg_value(var, value, &expire))
 413                        return -1;
 414        } else if (!strcmp(lastdot, ".reflogexpireunreachable")) {
 415                slot = EXPIRE_UNREACH;
 416                if (parse_expire_cfg_value(var, value, &expire))
 417                        return -1;
 418        } else
 419                return git_default_config(var, value, cb);
 420
 421        if (lastdot == var + 2) {
 422                switch (slot) {
 423                case EXPIRE_TOTAL:
 424                        default_reflog_expire = expire;
 425                        break;
 426                case EXPIRE_UNREACH:
 427                        default_reflog_expire_unreachable = expire;
 428                        break;
 429                }
 430                return 0;
 431        }
 432
 433        ent = find_cfg_ent(var + 3, lastdot - (var+3));
 434        if (!ent)
 435                return -1;
 436        switch (slot) {
 437        case EXPIRE_TOTAL:
 438                ent->expire_total = expire;
 439                break;
 440        case EXPIRE_UNREACH:
 441                ent->expire_unreachable = expire;
 442                break;
 443        }
 444        return 0;
 445}
 446
 447static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
 448{
 449        struct reflog_expire_cfg *ent;
 450
 451        if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
 452                return; /* both given explicitly -- nothing to tweak */
 453
 454        for (ent = reflog_expire_cfg; ent; ent = ent->next) {
 455                if (!fnmatch(ent->pattern, ref, 0)) {
 456                        if (!(slot & EXPIRE_TOTAL))
 457                                cb->expire_total = ent->expire_total;
 458                        if (!(slot & EXPIRE_UNREACH))
 459                                cb->expire_unreachable = ent->expire_unreachable;
 460                        return;
 461                }
 462        }
 463
 464        /*
 465         * If unconfigured, make stash never expire
 466         */
 467        if (!strcmp(ref, "refs/stash")) {
 468                if (!(slot & EXPIRE_TOTAL))
 469                        cb->expire_total = 0;
 470                if (!(slot & EXPIRE_UNREACH))
 471                        cb->expire_unreachable = 0;
 472                return;
 473        }
 474
 475        /* Nothing matched -- use the default value */
 476        if (!(slot & EXPIRE_TOTAL))
 477                cb->expire_total = default_reflog_expire;
 478        if (!(slot & EXPIRE_UNREACH))
 479                cb->expire_unreachable = default_reflog_expire_unreachable;
 480}
 481
 482static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 483{
 484        struct cmd_reflog_expire_cb cb;
 485        unsigned long now = time(NULL);
 486        int i, status, do_all;
 487        int explicit_expiry = 0;
 488
 489        git_config(reflog_expire_config, NULL);
 490
 491        save_commit_buffer = 0;
 492        do_all = status = 0;
 493        memset(&cb, 0, sizeof(cb));
 494
 495        if (!default_reflog_expire_unreachable)
 496                default_reflog_expire_unreachable = now - 30 * 24 * 3600;
 497        if (!default_reflog_expire)
 498                default_reflog_expire = now - 90 * 24 * 3600;
 499        cb.expire_total = default_reflog_expire;
 500        cb.expire_unreachable = default_reflog_expire_unreachable;
 501
 502        for (i = 1; i < argc; i++) {
 503                const char *arg = argv[i];
 504                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 505                        cb.dry_run = 1;
 506                else if (!prefixcmp(arg, "--expire=")) {
 507                        cb.expire_total = approxidate(arg + 9);
 508                        explicit_expiry |= EXPIRE_TOTAL;
 509                }
 510                else if (!prefixcmp(arg, "--expire-unreachable=")) {
 511                        cb.expire_unreachable = approxidate(arg + 21);
 512                        explicit_expiry |= EXPIRE_UNREACH;
 513                }
 514                else if (!strcmp(arg, "--stale-fix"))
 515                        cb.stalefix = 1;
 516                else if (!strcmp(arg, "--rewrite"))
 517                        cb.rewrite = 1;
 518                else if (!strcmp(arg, "--updateref"))
 519                        cb.updateref = 1;
 520                else if (!strcmp(arg, "--all"))
 521                        do_all = 1;
 522                else if (!strcmp(arg, "--verbose"))
 523                        cb.verbose = 1;
 524                else if (!strcmp(arg, "--")) {
 525                        i++;
 526                        break;
 527                }
 528                else if (arg[0] == '-')
 529                        usage(reflog_expire_usage);
 530                else
 531                        break;
 532        }
 533
 534        /*
 535         * We can trust the commits and objects reachable from refs
 536         * even in older repository.  We cannot trust what's reachable
 537         * from reflog if the repository was pruned with older git.
 538         */
 539        if (cb.stalefix) {
 540                init_revisions(&cb.revs, prefix);
 541                if (cb.verbose)
 542                        printf("Marking reachable objects...");
 543                mark_reachable_objects(&cb.revs, 0);
 544                if (cb.verbose)
 545                        putchar('\n');
 546        }
 547
 548        if (do_all) {
 549                struct collect_reflog_cb collected;
 550                int i;
 551
 552                memset(&collected, 0, sizeof(collected));
 553                for_each_reflog(collect_reflog, &collected);
 554                for (i = 0; i < collected.nr; i++) {
 555                        struct collected_reflog *e = collected.e[i];
 556                        set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
 557                        status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
 558                        free(e);
 559                }
 560                free(collected.e);
 561        }
 562
 563        for (; i < argc; i++) {
 564                char *ref;
 565                unsigned char sha1[20];
 566                if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
 567                        status |= error("%s points nowhere!", argv[i]);
 568                        continue;
 569                }
 570                set_reflog_expiry_param(&cb, explicit_expiry, ref);
 571                status |= expire_reflog(ref, sha1, 0, &cb);
 572        }
 573        return status;
 574}
 575
 576static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 577                const char *email, unsigned long timestamp, int tz,
 578                const char *message, void *cb_data)
 579{
 580        struct cmd_reflog_expire_cb *cb = cb_data;
 581        if (!cb->expire_total || timestamp < cb->expire_total)
 582                cb->recno++;
 583        return 0;
 584}
 585
 586static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
 587{
 588        struct cmd_reflog_expire_cb cb;
 589        int i, status = 0;
 590
 591        memset(&cb, 0, sizeof(cb));
 592
 593        for (i = 1; i < argc; i++) {
 594                const char *arg = argv[i];
 595                if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 596                        cb.dry_run = 1;
 597                else if (!strcmp(arg, "--rewrite"))
 598                        cb.rewrite = 1;
 599                else if (!strcmp(arg, "--updateref"))
 600                        cb.updateref = 1;
 601                else if (!strcmp(arg, "--verbose"))
 602                        cb.verbose = 1;
 603                else if (!strcmp(arg, "--")) {
 604                        i++;
 605                        break;
 606                }
 607                else if (arg[0] == '-')
 608                        usage(reflog_delete_usage);
 609                else
 610                        break;
 611        }
 612
 613        if (argc - i < 1)
 614                return error("Nothing to delete?");
 615
 616        for ( ; i < argc; i++) {
 617                const char *spec = strstr(argv[i], "@{");
 618                unsigned char sha1[20];
 619                char *ep, *ref;
 620                int recno;
 621
 622                if (!spec) {
 623                        status |= error("Not a reflog: %s", argv[i]);
 624                        continue;
 625                }
 626
 627                if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
 628                        status |= error("no reflog for '%s'", argv[i]);
 629                        continue;
 630                }
 631
 632                recno = strtoul(spec + 2, &ep, 10);
 633                if (*ep == '}') {
 634                        cb.recno = -recno;
 635                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 636                } else {
 637                        cb.expire_total = approxidate(spec + 2);
 638                        for_each_reflog_ent(ref, count_reflog_ent, &cb);
 639                        cb.expire_total = 0;
 640                }
 641
 642                status |= expire_reflog(ref, sha1, 0, &cb);
 643                free(ref);
 644        }
 645        return status;
 646}
 647
 648/*
 649 * main "reflog"
 650 */
 651
 652static const char reflog_usage[] =
 653"git reflog (expire | ...)";
 654
 655int cmd_reflog(int argc, const char **argv, const char *prefix)
 656{
 657        /* With no command, we default to showing it. */
 658        if (argc < 2 || *argv[1] == '-')
 659                return cmd_log_reflog(argc, argv, prefix);
 660
 661        if (!strcmp(argv[1], "show"))
 662                return cmd_log_reflog(argc - 1, argv + 1, prefix);
 663
 664        if (!strcmp(argv[1], "expire"))
 665                return cmd_reflog_expire(argc - 1, argv + 1, prefix);
 666
 667        if (!strcmp(argv[1], "delete"))
 668                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 669
 670        /* Not a recognized reflog command..*/
 671        usage(reflog_usage);
 672}