git.oblomov.eu Git - git/blob - refs.c

   1 /*
   2  * The backend-independent part of the reference module.
   3  */
   4
   5 #include "cache.h"
   6 #include "config.h"
   7 #include "hashmap.h"
   8 #include "lockfile.h"
   9 #include "iterator.h"
  10 #include "refs.h"
  11 #include "refs/refs-internal.h"
  12 #include "object-store.h"
  13 #include "object.h"
  14 #include "tag.h"
  15 #include "submodule.h"
  16 #include "worktree.h"
  17 #include "argv-array.h"
  18 #include "repository.h"
  19
  20 /*
  21  * List of all available backends
  22  */
  23 static struct ref_storage_be *refs_backends = &refs_be_files;
  24
  25 static struct ref_storage_be *find_ref_storage_backend(const char *name)
  26 {
  27         struct ref_storage_be *be;
  28         for (be = refs_backends; be; be = be->next)
  29                 if (!strcmp(be->name, name))
  30                         return be;
  31         return NULL;
  32 }
  33
  34 int ref_storage_backend_exists(const char *name)
  35 {
  36         return find_ref_storage_backend(name) != NULL;
  37 }
  38
  39 /*
  40  * How to handle various characters in refnames:
  41  * 0: An acceptable character for refs
  42  * 1: End-of-component
  43  * 2: ., look for a preceding . to reject .. in refs
  44  * 3: {, look for a preceding @ to reject @{ in refs
  45  * 4: A bad character: ASCII control characters, and
  46  *    ":", "?", "[", "\", "^", "~", SP, or TAB
  47  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  48  */
  49 static unsigned char refname_disposition[256] = {
  50         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  51         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  52         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
  53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
  54         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  55         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
  56         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  57         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
  58 };
  59
  60 /*
  61  * Try to read one refname component from the front of refname.
  62  * Return the length of the component found, or -1 if the component is
  63  * not legal.  It is legal if it is something reasonable to have under
  64  * ".git/refs/"; We do not like it if:
  65  *
  66  * - any path component of it begins with ".", or
  67  * - it has double dots "..", or
  68  * - it has ASCII control characters, or
  69  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
  70  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
  71  * - it ends with a "/", or
  72  * - it ends with ".lock", or
  73  * - it contains a "@{" portion
  74  */
  75 static int check_refname_component(const char *refname, int *flags)
  76 {
  77         const char *cp;
  78         char last = '\0';
  79
  80         for (cp = refname; ; cp++) {
  81                 int ch = *cp & 255;
  82                 unsigned char disp = refname_disposition[ch];
  83                 switch (disp) {
  84                 case 1:
  85                         goto out;
  86                 case 2:
  87                         if (last == '.')
  88                                 return -1; /* Refname contains "..". */
  89                         break;
  90                 case 3:
  91                         if (last == '@')
  92                                 return -1; /* Refname contains "@{". */
  93                         break;
  94                 case 4:
  95                         return -1;
  96                 case 5:
  97                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
  98                                 return -1; /* refspec can't be a pattern */
  99
 100                         /*
 101                          * Unset the pattern flag so that we only accept
 102                          * a single asterisk for one side of refspec.
 103                          */
 104                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
 105                         break;
 106                 }
 107                 last = ch;
 108         }
 109 out:
 110         if (cp == refname)
 111                 return 0; /* Component has zero length. */
 112         if (refname[0] == '.')
 113                 return -1; /* Component starts with '.'. */
 114         if (cp - refname >= LOCK_SUFFIX_LEN &&
 115             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
 116                 return -1; /* Refname ends with ".lock". */
 117         return cp - refname;
 118 }
 119
 120 int check_refname_format(const char *refname, int flags)
 121 {
 122         int component_len, component_count = 0;
 123
 124         if (!strcmp(refname, "@"))
 125                 /* Refname is a single character '@'. */
 126                 return -1;
 127
 128         while (1) {
 129                 /* We are at the start of a path component. */
 130                 component_len = check_refname_component(refname, &flags);
 131                 if (component_len <= 0)
 132                         return -1;
 133
 134                 component_count++;
 135                 if (refname[component_len] == '\0')
 136                         break;
 137                 /* Skip to next component. */
 138                 refname += component_len + 1;
 139         }
 140
 141         if (refname[component_len - 1] == '.')
 142                 return -1; /* Refname ends with '.'. */
 143         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
 144                 return -1; /* Refname has only one component. */
 145         return 0;
 146 }
 147
 148 int refname_is_safe(const char *refname)
 149 {
 150         const char *rest;
 151
 152         if (skip_prefix(refname, "refs/", &rest)) {
 153                 char *buf;
 154                 int result;
 155                 size_t restlen = strlen(rest);
 156
 157                 /* rest must not be empty, or start or end with "/" */
 158                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
 159                         return 0;
 160
 161                 /*
 162                  * Does the refname try to escape refs/?
 163                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
 164                  * is not.
 165                  */
 166                 buf = xmallocz(restlen);
 167                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
 168                 free(buf);
 169                 return result;
 170         }
 171
 172         do {
 173                 if (!isupper(*refname) && *refname != '_')
 174                         return 0;
 175                 refname++;
 176         } while (*refname);
 177         return 1;
 178 }
 179
 180 /*
 181  * Return true if refname, which has the specified oid and flags, can
 182  * be resolved to an object in the database. If the referred-to object
 183  * does not exist, emit a warning and return false.
 184  */
 185 int ref_resolves_to_object(const char *refname,
 186                            const struct object_id *oid,
 187                            unsigned int flags)
 188 {
 189         if (flags & REF_ISBROKEN)
 190                 return 0;
 191         if (!has_sha1_file(oid->hash)) {
 192                 error("%s does not point to a valid object!", refname);
 193                 return 0;
 194         }
 195         return 1;
 196 }
 197
 198 char *refs_resolve_refdup(struct ref_store *refs,
 199                           const char *refname, int resolve_flags,
 200                           struct object_id *oid, int *flags)
 201 {
 202         const char *result;
 203
 204         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
 205                                          oid, flags);
 206         return xstrdup_or_null(result);
 207 }
 208
 209 char *resolve_refdup(const char *refname, int resolve_flags,
 210                      struct object_id *oid, int *flags)
 211 {
 212         return refs_resolve_refdup(get_main_ref_store(the_repository),
 213                                    refname, resolve_flags,
 214                                    oid, flags);
 215 }
 216
 217 /* The argument to filter_refs */
 218 struct ref_filter {
 219         const char *pattern;
 220         each_ref_fn *fn;
 221         void *cb_data;
 222 };
 223
 224 int refs_read_ref_full(struct ref_store *refs, const char *refname,
 225                        int resolve_flags, struct object_id *oid, int *flags)
 226 {
 227         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
 228                 return 0;
 229         return -1;
 230 }
 231
 232 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 233 {
 234         return refs_read_ref_full(get_main_ref_store(the_repository), refname,
 235                                   resolve_flags, oid, flags);
 236 }
 237
 238 int read_ref(const char *refname, struct object_id *oid)
 239 {
 240         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
 241 }
 242
 243 int ref_exists(const char *refname)
 244 {
 245         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
 246 }
 247
 248 static int match_ref_pattern(const char *refname,
 249                              const struct string_list_item *item)
 250 {
 251         int matched = 0;
 252         if (item->util == NULL) {
 253                 if (!wildmatch(item->string, refname, 0))
 254                         matched = 1;
 255         } else {
 256                 const char *rest;
 257                 if (skip_prefix(refname, item->string, &rest) &&
 258                     (!*rest || *rest == '/'))
 259                         matched = 1;
 260         }
 261         return matched;
 262 }
 263
 264 int ref_filter_match(const char *refname,
 265                      const struct string_list *include_patterns,
 266                      const struct string_list *exclude_patterns)
 267 {
 268         struct string_list_item *item;
 269
 270         if (exclude_patterns && exclude_patterns->nr) {
 271                 for_each_string_list_item(item, exclude_patterns) {
 272                         if (match_ref_pattern(refname, item))
 273                                 return 0;
 274                 }
 275         }
 276
 277         if (include_patterns && include_patterns->nr) {
 278                 int found = 0;
 279                 for_each_string_list_item(item, include_patterns) {
 280                         if (match_ref_pattern(refname, item)) {
 281                                 found = 1;
 282                                 break;
 283                         }
 284                 }
 285
 286                 if (!found)
 287                         return 0;
 288         }
 289         return 1;
 290 }
 291
 292 static int filter_refs(const char *refname, const struct object_id *oid,
 293                            int flags, void *data)
 294 {
 295         struct ref_filter *filter = (struct ref_filter *)data;
 296
 297         if (wildmatch(filter->pattern, refname, 0))
 298                 return 0;
 299         return filter->fn(refname, oid, flags, filter->cb_data);
 300 }
 301
 302 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
 303 {
 304         struct object *o = lookup_unknown_object(name->hash);
 305
 306         if (o->type == OBJ_NONE) {
 307                 int type = oid_object_info(the_repository, name, NULL);
 308                 if (type < 0 || !object_as_type(o, type, 0))
 309                         return PEEL_INVALID;
 310         }
 311
 312         if (o->type != OBJ_TAG)
 313                 return PEEL_NON_TAG;
 314
 315         o = deref_tag_noverify(o);
 316         if (!o)
 317                 return PEEL_INVALID;
 318
 319         oidcpy(oid, &o->oid);
 320         return PEEL_PEELED;
 321 }
 322
 323 struct warn_if_dangling_data {
 324         FILE *fp;
 325         const char *refname;
 326         const struct string_list *refnames;
 327         const char *msg_fmt;
 328 };
 329
 330 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
 331                                    int flags, void *cb_data)
 332 {
 333         struct warn_if_dangling_data *d = cb_data;
 334         const char *resolves_to;
 335
 336         if (!(flags & REF_ISSYMREF))
 337                 return 0;
 338
 339         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
 340         if (!resolves_to
 341             || (d->refname
 342                 ? strcmp(resolves_to, d->refname)
 343                 : !string_list_has_string(d->refnames, resolves_to))) {
 344                 return 0;
 345         }
 346
 347         fprintf(d->fp, d->msg_fmt, refname);
 348         fputc('\n', d->fp);
 349         return 0;
 350 }
 351
 352 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 353 {
 354         struct warn_if_dangling_data data;
 355
 356         data.fp = fp;
 357         data.refname = refname;
 358         data.refnames = NULL;
 359         data.msg_fmt = msg_fmt;
 360         for_each_rawref(warn_if_dangling_symref, &data);
 361 }
 362
 363 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
 364 {
 365         struct warn_if_dangling_data data;
 366
 367         data.fp = fp;
 368         data.refname = NULL;
 369         data.refnames = refnames;
 370         data.msg_fmt = msg_fmt;
 371         for_each_rawref(warn_if_dangling_symref, &data);
 372 }
 373
 374 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 375 {
 376         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
 377 }
 378
 379 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 380 {
 381         return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
 382 }
 383
 384 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 385 {
 386         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
 387 }
 388
 389 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 390 {
 391         return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
 392 }
 393
 394 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 395 {
 396         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
 397 }
 398
 399 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 400 {
 401         return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
 402 }
 403
 404 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 405 {
 406         struct strbuf buf = STRBUF_INIT;
 407         int ret = 0;
 408         struct object_id oid;
 409         int flag;
 410
 411         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
 412         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
 413                 ret = fn(buf.buf, &oid, flag, cb_data);
 414         strbuf_release(&buf);
 415
 416         return ret;
 417 }
 418
 419 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
 420                         const char *pattern)
 421 {
 422         struct strbuf normalized_pattern = STRBUF_INIT;
 423
 424         if (*pattern == '/')
 425                 BUG("pattern must not start with '/'");
 426
 427         if (prefix) {
 428                 strbuf_addstr(&normalized_pattern, prefix);
 429         }
 430         else if (!starts_with(pattern, "refs/"))
 431                 strbuf_addstr(&normalized_pattern, "refs/");
 432         strbuf_addstr(&normalized_pattern, pattern);
 433         strbuf_strip_suffix(&normalized_pattern, "/");
 434
 435         item->string = strbuf_detach(&normalized_pattern, NULL);
 436         item->util = has_glob_specials(pattern) ? NULL : item->string;
 437         strbuf_release(&normalized_pattern);
 438 }
 439
 440 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 441         const char *prefix, void *cb_data)
 442 {
 443         struct strbuf real_pattern = STRBUF_INIT;
 444         struct ref_filter filter;
 445         int ret;
 446
 447         if (!prefix && !starts_with(pattern, "refs/"))
 448                 strbuf_addstr(&real_pattern, "refs/");
 449         else if (prefix)
 450                 strbuf_addstr(&real_pattern, prefix);
 451         strbuf_addstr(&real_pattern, pattern);
 452
 453         if (!has_glob_specials(pattern)) {
 454                 /* Append implied '/' '*' if not present. */
 455                 strbuf_complete(&real_pattern, '/');
 456                 /* No need to check for '*', there is none. */
 457                 strbuf_addch(&real_pattern, '*');
 458         }
 459
 460         filter.pattern = real_pattern.buf;
 461         filter.fn = fn;
 462         filter.cb_data = cb_data;
 463         ret = for_each_ref(filter_refs, &filter);
 464
 465         strbuf_release(&real_pattern);
 466         return ret;
 467 }
 468
 469 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
 470 {
 471         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
 472 }
 473
 474 const char *prettify_refname(const char *name)
 475 {
 476         if (skip_prefix(name, "refs/heads/", &name) ||
 477             skip_prefix(name, "refs/tags/", &name) ||
 478             skip_prefix(name, "refs/remotes/", &name))
 479                 ; /* nothing */
 480         return name;
 481 }
 482
 483 static const char *ref_rev_parse_rules[] = {
 484         "%.*s",
 485         "refs/%.*s",
 486         "refs/tags/%.*s",
 487         "refs/heads/%.*s",
 488         "refs/remotes/%.*s",
 489         "refs/remotes/%.*s/HEAD",
 490         NULL
 491 };
 492
 493 int refname_match(const char *abbrev_name, const char *full_name)
 494 {
 495         const char **p;
 496         const int abbrev_name_len = strlen(abbrev_name);
 497
 498         for (p = ref_rev_parse_rules; *p; p++) {
 499                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 500                         return 1;
 501                 }
 502         }
 503
 504         return 0;
 505 }
 506
 507 /*
 508  * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
 509  * the results to 'prefixes'
 510  */
 511 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
 512 {
 513         const char **p;
 514         int len = strlen(prefix);
 515
 516         for (p = ref_rev_parse_rules; *p; p++)
 517                 argv_array_pushf(prefixes, *p, len, prefix);
 518 }
 519
 520 /*
 521  * *string and *len will only be substituted, and *string returned (for
 522  * later free()ing) if the string passed in is a magic short-hand form
 523  * to name a branch.
 524  */
 525 static char *substitute_branch_name(const char **string, int *len)
 526 {
 527         struct strbuf buf = STRBUF_INIT;
 528         int ret = interpret_branch_name(*string, *len, &buf, 0);
 529
 530         if (ret == *len) {
 531                 size_t size;
 532                 *string = strbuf_detach(&buf, &size);
 533                 *len = size;
 534                 return (char *)*string;
 535         }
 536
 537         return NULL;
 538 }
 539
 540 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
 541 {
 542         char *last_branch = substitute_branch_name(&str, &len);
 543         int   refs_found  = expand_ref(str, len, oid, ref);
 544         free(last_branch);
 545         return refs_found;
 546 }
 547
 548 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
 549 {
 550         const char **p, *r;
 551         int refs_found = 0;
 552         struct strbuf fullref = STRBUF_INIT;
 553
 554         *ref = NULL;
 555         for (p = ref_rev_parse_rules; *p; p++) {
 556                 struct object_id oid_from_ref;
 557                 struct object_id *this_result;
 558                 int flag;
 559
 560                 this_result = refs_found ? &oid_from_ref : oid;
 561                 strbuf_reset(&fullref);
 562                 strbuf_addf(&fullref, *p, len, str);
 563                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
 564                                        this_result, &flag);
 565                 if (r) {
 566                         if (!refs_found++)
 567                                 *ref = xstrdup(r);
 568                         if (!warn_ambiguous_refs)
 569                                 break;
 570                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
 571                         warning("ignoring dangling symref %s.", fullref.buf);
 572                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
 573                         warning("ignoring broken ref %s.", fullref.buf);
 574                 }
 575         }
 576         strbuf_release(&fullref);
 577         return refs_found;
 578 }
 579
 580 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 581 {
 582         char *last_branch = substitute_branch_name(&str, &len);
 583         const char **p;
 584         int logs_found = 0;
 585         struct strbuf path = STRBUF_INIT;
 586
 587         *log = NULL;
 588         for (p = ref_rev_parse_rules; *p; p++) {
 589                 struct object_id hash;
 590                 const char *ref, *it;
 591
 592                 strbuf_reset(&path);
 593                 strbuf_addf(&path, *p, len, str);
 594                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
 595                                          &hash, NULL);
 596                 if (!ref)
 597                         continue;
 598                 if (reflog_exists(path.buf))
 599                         it = path.buf;
 600                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
 601                         it = ref;
 602                 else
 603                         continue;
 604                 if (!logs_found++) {
 605                         *log = xstrdup(it);
 606                         oidcpy(oid, &hash);
 607                 }
 608                 if (!warn_ambiguous_refs)
 609                         break;
 610         }
 611         strbuf_release(&path);
 612         free(last_branch);
 613         return logs_found;
 614 }
 615
 616 static int is_per_worktree_ref(const char *refname)
 617 {
 618         return !strcmp(refname, "HEAD") ||
 619                 starts_with(refname, "refs/bisect/") ||
 620                 starts_with(refname, "refs/rewritten/");
 621 }
 622
 623 static int is_pseudoref_syntax(const char *refname)
 624 {
 625         const char *c;
 626
 627         for (c = refname; *c; c++) {
 628                 if (!isupper(*c) && *c != '-' && *c != '_')
 629                         return 0;
 630         }
 631
 632         return 1;
 633 }
 634
 635 enum ref_type ref_type(const char *refname)
 636 {
 637         if (is_per_worktree_ref(refname))
 638                 return REF_TYPE_PER_WORKTREE;
 639         if (is_pseudoref_syntax(refname))
 640                 return REF_TYPE_PSEUDOREF;
 641        return REF_TYPE_NORMAL;
 642 }
 643
 644 long get_files_ref_lock_timeout_ms(void)
 645 {
 646         static int configured = 0;
 647
 648         /* The default timeout is 100 ms: */
 649         static int timeout_ms = 100;
 650
 651         if (!configured) {
 652                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 653                 configured = 1;
 654         }
 655
 656         return timeout_ms;
 657 }
 658
 659 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
 660                            const struct object_id *old_oid, struct strbuf *err)
 661 {
 662         const char *filename;
 663         int fd;
 664         struct lock_file lock = LOCK_INIT;
 665         struct strbuf buf = STRBUF_INIT;
 666         int ret = -1;
 667
 668         if (!oid)
 669                 return 0;
 670
 671         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 672
 673         filename = git_path("%s", pseudoref);
 674         fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
 675                                                get_files_ref_lock_timeout_ms());
 676         if (fd < 0) {
 677                 strbuf_addf(err, "could not open '%s' for writing: %s",
 678                             filename, strerror(errno));
 679                 goto done;
 680         }
 681
 682         if (old_oid) {
 683                 struct object_id actual_old_oid;
 684
 685                 if (read_ref(pseudoref, &actual_old_oid)) {
 686                         if (!is_null_oid(old_oid)) {
 687                                 strbuf_addf(err, "could not read ref '%s'",
 688                                             pseudoref);
 689                                 rollback_lock_file(&lock);
 690                                 goto done;
 691                         }
 692                 } else if (is_null_oid(old_oid)) {
 693                         strbuf_addf(err, "ref '%s' already exists",
 694                                     pseudoref);
 695                         rollback_lock_file(&lock);
 696                         goto done;
 697                 } else if (oidcmp(&actual_old_oid, old_oid)) {
 698                         strbuf_addf(err, "unexpected object ID when writing '%s'",
 699                                     pseudoref);
 700                         rollback_lock_file(&lock);
 701                         goto done;
 702                 }
 703         }
 704
 705         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 706                 strbuf_addf(err, "could not write to '%s'", filename);
 707                 rollback_lock_file(&lock);
 708                 goto done;
 709         }
 710
 711         commit_lock_file(&lock);
 712         ret = 0;
 713 done:
 714         strbuf_release(&buf);
 715         return ret;
 716 }
 717
 718 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 719 {
 720         const char *filename;
 721
 722         filename = git_path("%s", pseudoref);
 723
 724         if (old_oid && !is_null_oid(old_oid)) {
 725                 struct lock_file lock = LOCK_INIT;
 726                 int fd;
 727                 struct object_id actual_old_oid;
 728
 729                 fd = hold_lock_file_for_update_timeout(
 730                                 &lock, filename, 0,
 731                                 get_files_ref_lock_timeout_ms());
 732                 if (fd < 0) {
 733                         error_errno(_("could not open '%s' for writing"),
 734                                     filename);
 735                         return -1;
 736                 }
 737                 if (read_ref(pseudoref, &actual_old_oid))
 738                         die("could not read ref '%s'", pseudoref);
 739                 if (oidcmp(&actual_old_oid, old_oid)) {
 740                         error("unexpected object ID when deleting '%s'",
 741                               pseudoref);
 742                         rollback_lock_file(&lock);
 743                         return -1;
 744                 }
 745
 746                 unlink(filename);
 747                 rollback_lock_file(&lock);
 748         } else {
 749                 unlink(filename);
 750         }
 751
 752         return 0;
 753 }
 754
 755 int refs_delete_ref(struct ref_store *refs, const char *msg,
 756                     const char *refname,
 757                     const struct object_id *old_oid,
 758                     unsigned int flags)
 759 {
 760         struct ref_transaction *transaction;
 761         struct strbuf err = STRBUF_INIT;
 762
 763         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 764                 assert(refs == get_main_ref_store(the_repository));
 765                 return delete_pseudoref(refname, old_oid);
 766         }
 767
 768         transaction = ref_store_transaction_begin(refs, &err);
 769         if (!transaction ||
 770             ref_transaction_delete(transaction, refname, old_oid,
 771                                    flags, msg, &err) ||
 772             ref_transaction_commit(transaction, &err)) {
 773                 error("%s", err.buf);
 774                 ref_transaction_free(transaction);
 775                 strbuf_release(&err);
 776                 return 1;
 777         }
 778         ref_transaction_free(transaction);
 779         strbuf_release(&err);
 780         return 0;
 781 }
 782
 783 int delete_ref(const char *msg, const char *refname,
 784                const struct object_id *old_oid, unsigned int flags)
 785 {
 786         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
 787                                old_oid, flags);
 788 }
 789
 790 int copy_reflog_msg(char *buf, const char *msg)
 791 {
 792         char *cp = buf;
 793         char c;
 794         int wasspace = 1;
 795
 796         *cp++ = '\t';
 797         while ((c = *msg++)) {
 798                 if (wasspace && isspace(c))
 799                         continue;
 800                 wasspace = isspace(c);
 801                 if (wasspace)
 802                         c = ' ';
 803                 *cp++ = c;
 804         }
 805         while (buf < cp && isspace(cp[-1]))
 806                 cp--;
 807         *cp++ = '\n';
 808         return cp - buf;
 809 }
 810
 811 int should_autocreate_reflog(const char *refname)
 812 {
 813         switch (log_all_ref_updates) {
 814         case LOG_REFS_ALWAYS:
 815                 return 1;
 816         case LOG_REFS_NORMAL:
 817                 return starts_with(refname, "refs/heads/") ||
 818                         starts_with(refname, "refs/remotes/") ||
 819                         starts_with(refname, "refs/notes/") ||
 820                         !strcmp(refname, "HEAD");
 821         default:
 822                 return 0;
 823         }
 824 }
 825
 826 int is_branch(const char *refname)
 827 {
 828         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 829 }
 830
 831 struct read_ref_at_cb {
 832         const char *refname;
 833         timestamp_t at_time;
 834         int cnt;
 835         int reccnt;
 836         struct object_id *oid;
 837         int found_it;
 838
 839         struct object_id ooid;
 840         struct object_id noid;
 841         int tz;
 842         timestamp_t date;
 843         char **msg;
 844         timestamp_t *cutoff_time;
 845         int *cutoff_tz;
 846         int *cutoff_cnt;
 847 };
 848
 849 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 850                 const char *email, timestamp_t timestamp, int tz,
 851                 const char *message, void *cb_data)
 852 {
 853         struct read_ref_at_cb *cb = cb_data;
 854
 855         cb->reccnt++;
 856         cb->tz = tz;
 857         cb->date = timestamp;
 858
 859         if (timestamp <= cb->at_time || cb->cnt == 0) {
 860                 if (cb->msg)
 861                         *cb->msg = xstrdup(message);
 862                 if (cb->cutoff_time)
 863                         *cb->cutoff_time = timestamp;
 864                 if (cb->cutoff_tz)
 865                         *cb->cutoff_tz = tz;
 866                 if (cb->cutoff_cnt)
 867                         *cb->cutoff_cnt = cb->reccnt - 1;
 868                 /*
 869                  * we have not yet updated cb->[n|o]oid so they still
 870                  * hold the values for the previous record.
 871                  */
 872                 if (!is_null_oid(&cb->ooid)) {
 873                         oidcpy(cb->oid, noid);
 874                         if (oidcmp(&cb->ooid, noid))
 875                                 warning("Log for ref %s has gap after %s.",
 876                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 877                 }
 878                 else if (cb->date == cb->at_time)
 879                         oidcpy(cb->oid, noid);
 880                 else if (oidcmp(noid, cb->oid))
 881                         warning("Log for ref %s unexpectedly ended on %s.",
 882                                 cb->refname, show_date(cb->date, cb->tz,
 883                                                        DATE_MODE(RFC2822)));
 884                 oidcpy(&cb->ooid, ooid);
 885                 oidcpy(&cb->noid, noid);
 886                 cb->found_it = 1;
 887                 return 1;
 888         }
 889         oidcpy(&cb->ooid, ooid);
 890         oidcpy(&cb->noid, noid);
 891         if (cb->cnt > 0)
 892                 cb->cnt--;
 893         return 0;
 894 }
 895
 896 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 897                                   const char *email, timestamp_t timestamp,
 898                                   int tz, const char *message, void *cb_data)
 899 {
 900         struct read_ref_at_cb *cb = cb_data;
 901
 902         if (cb->msg)
 903                 *cb->msg = xstrdup(message);
 904         if (cb->cutoff_time)
 905                 *cb->cutoff_time = timestamp;
 906         if (cb->cutoff_tz)
 907                 *cb->cutoff_tz = tz;
 908         if (cb->cutoff_cnt)
 909                 *cb->cutoff_cnt = cb->reccnt;
 910         oidcpy(cb->oid, ooid);
 911         if (is_null_oid(cb->oid))
 912                 oidcpy(cb->oid, noid);
 913         /* We just want the first entry */
 914         return 1;
 915 }
 916
 917 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 918                 struct object_id *oid, char **msg,
 919                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 920 {
 921         struct read_ref_at_cb cb;
 922
 923         memset(&cb, 0, sizeof(cb));
 924         cb.refname = refname;
 925         cb.at_time = at_time;
 926         cb.cnt = cnt;
 927         cb.msg = msg;
 928         cb.cutoff_time = cutoff_time;
 929         cb.cutoff_tz = cutoff_tz;
 930         cb.cutoff_cnt = cutoff_cnt;
 931         cb.oid = oid;
 932
 933         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 934
 935         if (!cb.reccnt) {
 936                 if (flags & GET_OID_QUIETLY)
 937                         exit(128);
 938                 else
 939                         die("Log for %s is empty.", refname);
 940         }
 941         if (cb.found_it)
 942                 return 0;
 943
 944         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 945
 946         return 1;
 947 }
 948
 949 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 950                                                     struct strbuf *err)
 951 {
 952         struct ref_transaction *tr;
 953         assert(err);
 954
 955         tr = xcalloc(1, sizeof(struct ref_transaction));
 956         tr->ref_store = refs;
 957         return tr;
 958 }
 959
 960 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 961 {
 962         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
 963 }
 964
 965 void ref_transaction_free(struct ref_transaction *transaction)
 966 {
 967         size_t i;
 968
 969         if (!transaction)
 970                 return;
 971
 972         switch (transaction->state) {
 973         case REF_TRANSACTION_OPEN:
 974         case REF_TRANSACTION_CLOSED:
 975                 /* OK */
 976                 break;
 977         case REF_TRANSACTION_PREPARED:
 978                 BUG("free called on a prepared reference transaction");
 979                 break;
 980         default:
 981                 BUG("unexpected reference transaction state");
 982                 break;
 983         }
 984
 985         for (i = 0; i < transaction->nr; i++) {
 986                 free(transaction->updates[i]->msg);
 987                 free(transaction->updates[i]);
 988         }
 989         free(transaction->updates);
 990         free(transaction);
 991 }
 992
 993 struct ref_update *ref_transaction_add_update(
 994                 struct ref_transaction *transaction,
 995                 const char *refname, unsigned int flags,
 996                 const struct object_id *new_oid,
 997                 const struct object_id *old_oid,
 998                 const char *msg)
 999 {
1000         struct ref_update *update;
1001
1002         if (transaction->state != REF_TRANSACTION_OPEN)
1003                 BUG("update called for transaction that is not open");
1004
1005         FLEX_ALLOC_STR(update, refname, refname);
1006         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
1007         transaction->updates[transaction->nr++] = update;
1008
1009         update->flags = flags;
1010
1011         if (flags & REF_HAVE_NEW)
1012                 oidcpy(&update->new_oid, new_oid);
1013         if (flags & REF_HAVE_OLD)
1014                 oidcpy(&update->old_oid, old_oid);
1015         update->msg = xstrdup_or_null(msg);
1016         return update;
1017 }
1018
1019 int ref_transaction_update(struct ref_transaction *transaction,
1020                            const char *refname,
1021                            const struct object_id *new_oid,
1022                            const struct object_id *old_oid,
1023                            unsigned int flags, const char *msg,
1024                            struct strbuf *err)
1025 {
1026         assert(err);
1027
1028         if ((new_oid && !is_null_oid(new_oid)) ?
1029             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1030             !refname_is_safe(refname)) {
1031                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1032                             refname);
1033                 return -1;
1034         }
1035
1036         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1037                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1038
1039         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1040
1041         ref_transaction_add_update(transaction, refname, flags,
1042                                    new_oid, old_oid, msg);
1043         return 0;
1044 }
1045
1046 int ref_transaction_create(struct ref_transaction *transaction,
1047                            const char *refname,
1048                            const struct object_id *new_oid,
1049                            unsigned int flags, const char *msg,
1050                            struct strbuf *err)
1051 {
1052         if (!new_oid || is_null_oid(new_oid))
1053                 BUG("create called without valid new_oid");
1054         return ref_transaction_update(transaction, refname, new_oid,
1055                                       &null_oid, flags, msg, err);
1056 }
1057
1058 int ref_transaction_delete(struct ref_transaction *transaction,
1059                            const char *refname,
1060                            const struct object_id *old_oid,
1061                            unsigned int flags, const char *msg,
1062                            struct strbuf *err)
1063 {
1064         if (old_oid && is_null_oid(old_oid))
1065                 BUG("delete called with old_oid set to zeros");
1066         return ref_transaction_update(transaction, refname,
1067                                       &null_oid, old_oid,
1068                                       flags, msg, err);
1069 }
1070
1071 int ref_transaction_verify(struct ref_transaction *transaction,
1072                            const char *refname,
1073                            const struct object_id *old_oid,
1074                            unsigned int flags,
1075                            struct strbuf *err)
1076 {
1077         if (!old_oid)
1078                 BUG("verify called with old_oid set to NULL");
1079         return ref_transaction_update(transaction, refname,
1080                                       NULL, old_oid,
1081                                       flags, NULL, err);
1082 }
1083
1084 int refs_update_ref(struct ref_store *refs, const char *msg,
1085                     const char *refname, const struct object_id *new_oid,
1086                     const struct object_id *old_oid, unsigned int flags,
1087                     enum action_on_err onerr)
1088 {
1089         struct ref_transaction *t = NULL;
1090         struct strbuf err = STRBUF_INIT;
1091         int ret = 0;
1092
1093         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1094                 assert(refs == get_main_ref_store(the_repository));
1095                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1096         } else {
1097                 t = ref_store_transaction_begin(refs, &err);
1098                 if (!t ||
1099                     ref_transaction_update(t, refname, new_oid, old_oid,
1100                                            flags, msg, &err) ||
1101                     ref_transaction_commit(t, &err)) {
1102                         ret = 1;
1103                         ref_transaction_free(t);
1104                 }
1105         }
1106         if (ret) {
1107                 const char *str = "update_ref failed for ref '%s': %s";
1108
1109                 switch (onerr) {
1110                 case UPDATE_REFS_MSG_ON_ERR:
1111                         error(str, refname, err.buf);
1112                         break;
1113                 case UPDATE_REFS_DIE_ON_ERR:
1114                         die(str, refname, err.buf);
1115                         break;
1116                 case UPDATE_REFS_QUIET_ON_ERR:
1117                         break;
1118                 }
1119                 strbuf_release(&err);
1120                 return 1;
1121         }
1122         strbuf_release(&err);
1123         if (t)
1124                 ref_transaction_free(t);
1125         return 0;
1126 }
1127
1128 int update_ref(const char *msg, const char *refname,
1129                const struct object_id *new_oid,
1130                const struct object_id *old_oid,
1131                unsigned int flags, enum action_on_err onerr)
1132 {
1133         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1134                                old_oid, flags, onerr);
1135 }
1136
1137 char *shorten_unambiguous_ref(const char *refname, int strict)
1138 {
1139         int i;
1140         static char **scanf_fmts;
1141         static int nr_rules;
1142         char *short_name;
1143         struct strbuf resolved_buf = STRBUF_INIT;
1144
1145         if (!nr_rules) {
1146                 /*
1147                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1148                  * Generate a format suitable for scanf from a
1149                  * ref_rev_parse_rules rule by interpolating "%s" at the
1150                  * location of the "%.*s".
1151                  */
1152                 size_t total_len = 0;
1153                 size_t offset = 0;
1154
1155                 /* the rule list is NULL terminated, count them first */
1156                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1157                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1158                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1159
1160                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1161
1162                 offset = 0;
1163                 for (i = 0; i < nr_rules; i++) {
1164                         assert(offset < total_len);
1165                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1166                         offset += xsnprintf(scanf_fmts[i], total_len - offset,
1167                                             ref_rev_parse_rules[i], 2, "%s") + 1;
1168                 }
1169         }
1170
1171         /* bail out if there are no rules */
1172         if (!nr_rules)
1173                 return xstrdup(refname);
1174
1175         /* buffer for scanf result, at most refname must fit */
1176         short_name = xstrdup(refname);
1177
1178         /* skip first rule, it will always match */
1179         for (i = nr_rules - 1; i > 0 ; --i) {
1180                 int j;
1181                 int rules_to_fail = i;
1182                 int short_name_len;
1183
1184                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1185                         continue;
1186
1187                 short_name_len = strlen(short_name);
1188
1189                 /*
1190                  * in strict mode, all (except the matched one) rules
1191                  * must fail to resolve to a valid non-ambiguous ref
1192                  */
1193                 if (strict)
1194                         rules_to_fail = nr_rules;
1195
1196                 /*
1197                  * check if the short name resolves to a valid ref,
1198                  * but use only rules prior to the matched one
1199                  */
1200                 for (j = 0; j < rules_to_fail; j++) {
1201                         const char *rule = ref_rev_parse_rules[j];
1202
1203                         /* skip matched rule */
1204                         if (i == j)
1205                                 continue;
1206
1207                         /*
1208                          * the short name is ambiguous, if it resolves
1209                          * (with this previous rule) to a valid ref
1210                          * read_ref() returns 0 on success
1211                          */
1212                         strbuf_reset(&resolved_buf);
1213                         strbuf_addf(&resolved_buf, rule,
1214                                     short_name_len, short_name);
1215                         if (ref_exists(resolved_buf.buf))
1216                                 break;
1217                 }
1218
1219                 /*
1220                  * short name is non-ambiguous if all previous rules
1221                  * haven't resolved to a valid ref
1222                  */
1223                 if (j == rules_to_fail) {
1224                         strbuf_release(&resolved_buf);
1225                         return short_name;
1226                 }
1227         }
1228
1229         strbuf_release(&resolved_buf);
1230         free(short_name);
1231         return xstrdup(refname);
1232 }
1233
1234 static struct string_list *hide_refs;
1235
1236 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1237 {
1238         const char *key;
1239         if (!strcmp("transfer.hiderefs", var) ||
1240             (!parse_config_key(var, section, NULL, NULL, &key) &&
1241              !strcmp(key, "hiderefs"))) {
1242                 char *ref;
1243                 int len;
1244
1245                 if (!value)
1246                         return config_error_nonbool(var);
1247                 ref = xstrdup(value);
1248                 len = strlen(ref);
1249                 while (len && ref[len - 1] == '/')
1250                         ref[--len] = '\0';
1251                 if (!hide_refs) {
1252                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1253                         hide_refs->strdup_strings = 1;
1254                 }
1255                 string_list_append(hide_refs, ref);
1256         }
1257         return 0;
1258 }
1259
1260 int ref_is_hidden(const char *refname, const char *refname_full)
1261 {
1262         int i;
1263
1264         if (!hide_refs)
1265                 return 0;
1266         for (i = hide_refs->nr - 1; i >= 0; i--) {
1267                 const char *match = hide_refs->items[i].string;
1268                 const char *subject;
1269                 int neg = 0;
1270                 const char *p;
1271
1272                 if (*match == '!') {
1273                         neg = 1;
1274                         match++;
1275                 }
1276
1277                 if (*match == '^') {
1278                         subject = refname_full;
1279                         match++;
1280                 } else {
1281                         subject = refname;
1282                 }
1283
1284                 /* refname can be NULL when namespaces are used. */
1285                 if (subject &&
1286                     skip_prefix(subject, match, &p) &&
1287                     (!*p || *p == '/'))
1288                         return !neg;
1289         }
1290         return 0;
1291 }
1292
1293 const char *find_descendant_ref(const char *dirname,
1294                                 const struct string_list *extras,
1295                                 const struct string_list *skip)
1296 {
1297         int pos;
1298
1299         if (!extras)
1300                 return NULL;
1301
1302         /*
1303          * Look at the place where dirname would be inserted into
1304          * extras. If there is an entry at that position that starts
1305          * with dirname (remember, dirname includes the trailing
1306          * slash) and is not in skip, then we have a conflict.
1307          */
1308         for (pos = string_list_find_insert_index(extras, dirname, 0);
1309              pos < extras->nr; pos++) {
1310                 const char *extra_refname = extras->items[pos].string;
1311
1312                 if (!starts_with(extra_refname, dirname))
1313                         break;
1314
1315                 if (!skip || !string_list_has_string(skip, extra_refname))
1316                         return extra_refname;
1317         }
1318         return NULL;
1319 }
1320
1321 int refs_rename_ref_available(struct ref_store *refs,
1322                               const char *old_refname,
1323                               const char *new_refname)
1324 {
1325         struct string_list skip = STRING_LIST_INIT_NODUP;
1326         struct strbuf err = STRBUF_INIT;
1327         int ok;
1328
1329         string_list_insert(&skip, old_refname);
1330         ok = !refs_verify_refname_available(refs, new_refname,
1331                                             NULL, &skip, &err);
1332         if (!ok)
1333                 error("%s", err.buf);
1334
1335         string_list_clear(&skip, 0);
1336         strbuf_release(&err);
1337         return ok;
1338 }
1339
1340 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1341 {
1342         struct object_id oid;
1343         int flag;
1344
1345         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1346                                 &oid, &flag))
1347                 return fn("HEAD", &oid, flag, cb_data);
1348
1349         return 0;
1350 }
1351
1352 int head_ref(each_ref_fn fn, void *cb_data)
1353 {
1354         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1355 }
1356
1357 struct ref_iterator *refs_ref_iterator_begin(
1358                 struct ref_store *refs,
1359                 const char *prefix, int trim, int flags)
1360 {
1361         struct ref_iterator *iter;
1362
1363         if (ref_paranoia < 0)
1364                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1365         if (ref_paranoia)
1366                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1367
1368         iter = refs->be->iterator_begin(refs, prefix, flags);
1369
1370         /*
1371          * `iterator_begin()` already takes care of prefix, but we
1372          * might need to do some trimming:
1373          */
1374         if (trim)
1375                 iter = prefix_ref_iterator_begin(iter, "", trim);
1376
1377         /* Sanity check for subclasses: */
1378         if (!iter->ordered)
1379                 BUG("reference iterator is not ordered");
1380
1381         return iter;
1382 }
1383
1384 /*
1385  * Call fn for each reference in the specified submodule for which the
1386  * refname begins with prefix. If trim is non-zero, then trim that
1387  * many characters off the beginning of each refname before passing
1388  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1389  * include broken references in the iteration. If fn ever returns a
1390  * non-zero value, stop the iteration and return that value;
1391  * otherwise, return 0.
1392  */
1393 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1394                            each_ref_fn fn, int trim, int flags, void *cb_data)
1395 {
1396         struct ref_iterator *iter;
1397
1398         if (!refs)
1399                 return 0;
1400
1401         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1402
1403         return do_for_each_ref_iterator(iter, fn, cb_data);
1404 }
1405
1406 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1407 {
1408         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1409 }
1410
1411 int for_each_ref(each_ref_fn fn, void *cb_data)
1412 {
1413         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1414 }
1415
1416 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1417                          each_ref_fn fn, void *cb_data)
1418 {
1419         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1420 }
1421
1422 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1423 {
1424         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1425 }
1426
1427 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1428 {
1429         unsigned int flag = 0;
1430
1431         if (broken)
1432                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1433         return do_for_each_ref(get_main_ref_store(the_repository),
1434                                prefix, fn, 0, flag, cb_data);
1435 }
1436
1437 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1438                              each_ref_fn fn, void *cb_data,
1439                              unsigned int broken)
1440 {
1441         unsigned int flag = 0;
1442
1443         if (broken)
1444                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1445         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1446 }
1447
1448 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1449 {
1450         return do_for_each_ref(get_main_ref_store(r),
1451                                git_replace_ref_base, fn,
1452                                strlen(git_replace_ref_base),
1453                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1454 }
1455
1456 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1457 {
1458         struct strbuf buf = STRBUF_INIT;
1459         int ret;
1460         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1461         ret = do_for_each_ref(get_main_ref_store(the_repository),
1462                               buf.buf, fn, 0, 0, cb_data);
1463         strbuf_release(&buf);
1464         return ret;
1465 }
1466
1467 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1468 {
1469         return do_for_each_ref(refs, "", fn, 0,
1470                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1471 }
1472
1473 int for_each_rawref(each_ref_fn fn, void *cb_data)
1474 {
1475         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1476 }
1477
1478 int refs_read_raw_ref(struct ref_store *ref_store,
1479                       const char *refname, struct object_id *oid,
1480                       struct strbuf *referent, unsigned int *type)
1481 {
1482         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1483 }
1484
1485 /* This function needs to return a meaningful errno on failure */
1486 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1487                                     const char *refname,
1488                                     int resolve_flags,
1489                                     struct object_id *oid, int *flags)
1490 {
1491         static struct strbuf sb_refname = STRBUF_INIT;
1492         struct object_id unused_oid;
1493         int unused_flags;
1494         int symref_count;
1495
1496         if (!oid)
1497                 oid = &unused_oid;
1498         if (!flags)
1499                 flags = &unused_flags;
1500
1501         *flags = 0;
1502
1503         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1504                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1505                     !refname_is_safe(refname)) {
1506                         errno = EINVAL;
1507                         return NULL;
1508                 }
1509
1510                 /*
1511                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1512                  * missing refs and refs that were present but invalid,
1513                  * to complain about the latter to stderr.
1514                  *
1515                  * We don't know whether the ref exists, so don't set
1516                  * REF_ISBROKEN yet.
1517                  */
1518                 *flags |= REF_BAD_NAME;
1519         }
1520
1521         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1522                 unsigned int read_flags = 0;
1523
1524                 if (refs_read_raw_ref(refs, refname,
1525                                       oid, &sb_refname, &read_flags)) {
1526                         *flags |= read_flags;
1527
1528                         /* In reading mode, refs must eventually resolve */
1529                         if (resolve_flags & RESOLVE_REF_READING)
1530                                 return NULL;
1531
1532                         /*
1533                          * Otherwise a missing ref is OK. But the files backend
1534                          * may show errors besides ENOENT if there are
1535                          * similarly-named refs.
1536                          */
1537                         if (errno != ENOENT &&
1538                             errno != EISDIR &&
1539                             errno != ENOTDIR)
1540                                 return NULL;
1541
1542                         oidclr(oid);
1543                         if (*flags & REF_BAD_NAME)
1544                                 *flags |= REF_ISBROKEN;
1545                         return refname;
1546                 }
1547
1548                 *flags |= read_flags;
1549
1550                 if (!(read_flags & REF_ISSYMREF)) {
1551                         if (*flags & REF_BAD_NAME) {
1552                                 oidclr(oid);
1553                                 *flags |= REF_ISBROKEN;
1554                         }
1555                         return refname;
1556                 }
1557
1558                 refname = sb_refname.buf;
1559                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1560                         oidclr(oid);
1561                         return refname;
1562                 }
1563                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1564                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1565                             !refname_is_safe(refname)) {
1566                                 errno = EINVAL;
1567                                 return NULL;
1568                         }
1569
1570                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1571                 }
1572         }
1573
1574         errno = ELOOP;
1575         return NULL;
1576 }
1577
1578 /* backend functions */
1579 int refs_init_db(struct strbuf *err)
1580 {
1581         struct ref_store *refs = get_main_ref_store(the_repository);
1582
1583         return refs->be->init_db(refs, err);
1584 }
1585
1586 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1587                                struct object_id *oid, int *flags)
1588 {
1589         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1590                                        resolve_flags, oid, flags);
1591 }
1592
1593 int resolve_gitlink_ref(const char *submodule, const char *refname,
1594                         struct object_id *oid)
1595 {
1596         struct ref_store *refs;
1597         int flags;
1598
1599         refs = get_submodule_ref_store(submodule);
1600
1601         if (!refs)
1602                 return -1;
1603
1604         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1605             is_null_oid(oid))
1606                 return -1;
1607         return 0;
1608 }
1609
1610 struct ref_store_hash_entry
1611 {
1612         struct hashmap_entry ent; /* must be the first member! */
1613
1614         struct ref_store *refs;
1615
1616         /* NUL-terminated identifier of the ref store: */
1617         char name[FLEX_ARRAY];
1618 };
1619
1620 static int ref_store_hash_cmp(const void *unused_cmp_data,
1621                               const void *entry, const void *entry_or_key,
1622                               const void *keydata)
1623 {
1624         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1625         const char *name = keydata ? keydata : e2->name;
1626
1627         return strcmp(e1->name, name);
1628 }
1629
1630 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1631                 const char *name, struct ref_store *refs)
1632 {
1633         struct ref_store_hash_entry *entry;
1634
1635         FLEX_ALLOC_STR(entry, name, name);
1636         hashmap_entry_init(entry, strhash(name));
1637         entry->refs = refs;
1638         return entry;
1639 }
1640
1641 /* A hashmap of ref_stores, stored by submodule name: */
1642 static struct hashmap submodule_ref_stores;
1643
1644 /* A hashmap of ref_stores, stored by worktree id: */
1645 static struct hashmap worktree_ref_stores;
1646
1647 /*
1648  * Look up a ref store by name. If that ref_store hasn't been
1649  * registered yet, return NULL.
1650  */
1651 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1652                                               const char *name)
1653 {
1654         struct ref_store_hash_entry *entry;
1655
1656         if (!map->tablesize)
1657                 /* It's initialized on demand in register_ref_store(). */
1658                 return NULL;
1659
1660         entry = hashmap_get_from_hash(map, strhash(name), name);
1661         return entry ? entry->refs : NULL;
1662 }
1663
1664 /*
1665  * Create, record, and return a ref_store instance for the specified
1666  * gitdir.
1667  */
1668 static struct ref_store *ref_store_init(const char *gitdir,
1669                                         unsigned int flags)
1670 {
1671         const char *be_name = "files";
1672         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1673         struct ref_store *refs;
1674
1675         if (!be)
1676                 BUG("reference backend %s is unknown", be_name);
1677
1678         refs = be->init(gitdir, flags);
1679         return refs;
1680 }
1681
1682 struct ref_store *get_main_ref_store(struct repository *r)
1683 {
1684         if (r->refs)
1685                 return r->refs;
1686
1687         if (!r->gitdir)
1688                 BUG("attempting to get main_ref_store outside of repository");
1689
1690         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1691         return r->refs;
1692 }
1693
1694 /*
1695  * Associate a ref store with a name. It is a fatal error to call this
1696  * function twice for the same name.
1697  */
1698 static void register_ref_store_map(struct hashmap *map,
1699                                    const char *type,
1700                                    struct ref_store *refs,
1701                                    const char *name)
1702 {
1703         if (!map->tablesize)
1704                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1705
1706         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1707                 BUG("%s ref_store '%s' initialized twice", type, name);
1708 }
1709
1710 struct ref_store *get_submodule_ref_store(const char *submodule)
1711 {
1712         struct strbuf submodule_sb = STRBUF_INIT;
1713         struct ref_store *refs;
1714         char *to_free = NULL;
1715         size_t len;
1716
1717         if (!submodule)
1718                 return NULL;
1719
1720         len = strlen(submodule);
1721         while (len && is_dir_sep(submodule[len - 1]))
1722                 len--;
1723         if (!len)
1724                 return NULL;
1725
1726         if (submodule[len])
1727                 /* We need to strip off one or more trailing slashes */
1728                 submodule = to_free = xmemdupz(submodule, len);
1729
1730         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1731         if (refs)
1732                 goto done;
1733
1734         strbuf_addstr(&submodule_sb, submodule);
1735         if (!is_nonbare_repository_dir(&submodule_sb))
1736                 goto done;
1737
1738         if (submodule_to_gitdir(&submodule_sb, submodule))
1739                 goto done;
1740
1741         /* assume that add_submodule_odb() has been called */
1742         refs = ref_store_init(submodule_sb.buf,
1743                               REF_STORE_READ | REF_STORE_ODB);
1744         register_ref_store_map(&submodule_ref_stores, "submodule",
1745                                refs, submodule);
1746
1747 done:
1748         strbuf_release(&submodule_sb);
1749         free(to_free);
1750
1751         return refs;
1752 }
1753
1754 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1755 {
1756         struct ref_store *refs;
1757         const char *id;
1758
1759         if (wt->is_current)
1760                 return get_main_ref_store(the_repository);
1761
1762         id = wt->id ? wt->id : "/";
1763         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1764         if (refs)
1765                 return refs;
1766
1767         if (wt->id)
1768                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1769                                       REF_STORE_ALL_CAPS);
1770         else
1771                 refs = ref_store_init(get_git_common_dir(),
1772                                       REF_STORE_ALL_CAPS);
1773
1774         if (refs)
1775                 register_ref_store_map(&worktree_ref_stores, "worktree",
1776                                        refs, id);
1777         return refs;
1778 }
1779
1780 void base_ref_store_init(struct ref_store *refs,
1781                          const struct ref_storage_be *be)
1782 {
1783         refs->be = be;
1784 }
1785
1786 /* backend functions */
1787 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1788 {
1789         return refs->be->pack_refs(refs, flags);
1790 }
1791
1792 int refs_peel_ref(struct ref_store *refs, const char *refname,
1793                   struct object_id *oid)
1794 {
1795         int flag;
1796         struct object_id base;
1797
1798         if (current_ref_iter && current_ref_iter->refname == refname) {
1799                 struct object_id peeled;
1800
1801                 if (ref_iterator_peel(current_ref_iter, &peeled))
1802                         return -1;
1803                 oidcpy(oid, &peeled);
1804                 return 0;
1805         }
1806
1807         if (refs_read_ref_full(refs, refname,
1808                                RESOLVE_REF_READING, &base, &flag))
1809                 return -1;
1810
1811         return peel_object(&base, oid);
1812 }
1813
1814 int peel_ref(const char *refname, struct object_id *oid)
1815 {
1816         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1817 }
1818
1819 int refs_create_symref(struct ref_store *refs,
1820                        const char *ref_target,
1821                        const char *refs_heads_master,
1822                        const char *logmsg)
1823 {
1824         return refs->be->create_symref(refs, ref_target,
1825                                        refs_heads_master,
1826                                        logmsg);
1827 }
1828
1829 int create_symref(const char *ref_target, const char *refs_heads_master,
1830                   const char *logmsg)
1831 {
1832         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1833                                   refs_heads_master, logmsg);
1834 }
1835
1836 int ref_update_reject_duplicates(struct string_list *refnames,
1837                                  struct strbuf *err)
1838 {
1839         size_t i, n = refnames->nr;
1840
1841         assert(err);
1842
1843         for (i = 1; i < n; i++) {
1844                 int cmp = strcmp(refnames->items[i - 1].string,
1845                                  refnames->items[i].string);
1846
1847                 if (!cmp) {
1848                         strbuf_addf(err,
1849                                     "multiple updates for ref '%s' not allowed.",
1850                                     refnames->items[i].string);
1851                         return 1;
1852                 } else if (cmp > 0) {
1853                         BUG("ref_update_reject_duplicates() received unsorted list");
1854                 }
1855         }
1856         return 0;
1857 }
1858
1859 int ref_transaction_prepare(struct ref_transaction *transaction,
1860                             struct strbuf *err)
1861 {
1862         struct ref_store *refs = transaction->ref_store;
1863
1864         switch (transaction->state) {
1865         case REF_TRANSACTION_OPEN:
1866                 /* Good. */
1867                 break;
1868         case REF_TRANSACTION_PREPARED:
1869                 BUG("prepare called twice on reference transaction");
1870                 break;
1871         case REF_TRANSACTION_CLOSED:
1872                 BUG("prepare called on a closed reference transaction");
1873                 break;
1874         default:
1875                 BUG("unexpected reference transaction state");
1876                 break;
1877         }
1878
1879         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1880                 strbuf_addstr(err,
1881                               _("ref updates forbidden inside quarantine environment"));
1882                 return -1;
1883         }
1884
1885         return refs->be->transaction_prepare(refs, transaction, err);
1886 }
1887
1888 int ref_transaction_abort(struct ref_transaction *transaction,
1889                           struct strbuf *err)
1890 {
1891         struct ref_store *refs = transaction->ref_store;
1892         int ret = 0;
1893
1894         switch (transaction->state) {
1895         case REF_TRANSACTION_OPEN:
1896                 /* No need to abort explicitly. */
1897                 break;
1898         case REF_TRANSACTION_PREPARED:
1899                 ret = refs->be->transaction_abort(refs, transaction, err);
1900                 break;
1901         case REF_TRANSACTION_CLOSED:
1902                 BUG("abort called on a closed reference transaction");
1903                 break;
1904         default:
1905                 BUG("unexpected reference transaction state");
1906                 break;
1907         }
1908
1909         ref_transaction_free(transaction);
1910         return ret;
1911 }
1912
1913 int ref_transaction_commit(struct ref_transaction *transaction,
1914                            struct strbuf *err)
1915 {
1916         struct ref_store *refs = transaction->ref_store;
1917         int ret;
1918
1919         switch (transaction->state) {
1920         case REF_TRANSACTION_OPEN:
1921                 /* Need to prepare first. */
1922                 ret = ref_transaction_prepare(transaction, err);
1923                 if (ret)
1924                         return ret;
1925                 break;
1926         case REF_TRANSACTION_PREPARED:
1927                 /* Fall through to finish. */
1928                 break;
1929         case REF_TRANSACTION_CLOSED:
1930                 BUG("commit called on a closed reference transaction");
1931                 break;
1932         default:
1933                 BUG("unexpected reference transaction state");
1934                 break;
1935         }
1936
1937         return refs->be->transaction_finish(refs, transaction, err);
1938 }
1939
1940 int refs_verify_refname_available(struct ref_store *refs,
1941                                   const char *refname,
1942                                   const struct string_list *extras,
1943                                   const struct string_list *skip,
1944                                   struct strbuf *err)
1945 {
1946         const char *slash;
1947         const char *extra_refname;
1948         struct strbuf dirname = STRBUF_INIT;
1949         struct strbuf referent = STRBUF_INIT;
1950         struct object_id oid;
1951         unsigned int type;
1952         struct ref_iterator *iter;
1953         int ok;
1954         int ret = -1;
1955
1956         /*
1957          * For the sake of comments in this function, suppose that
1958          * refname is "refs/foo/bar".
1959          */
1960
1961         assert(err);
1962
1963         strbuf_grow(&dirname, strlen(refname) + 1);
1964         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1965                 /* Expand dirname to the new prefix, not including the trailing slash: */
1966                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1967
1968                 /*
1969                  * We are still at a leading dir of the refname (e.g.,
1970                  * "refs/foo"; if there is a reference with that name,
1971                  * it is a conflict, *unless* it is in skip.
1972                  */
1973                 if (skip && string_list_has_string(skip, dirname.buf))
1974                         continue;
1975
1976                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1977                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1978                                     dirname.buf, refname);
1979                         goto cleanup;
1980                 }
1981
1982                 if (extras && string_list_has_string(extras, dirname.buf)) {
1983                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1984                                     refname, dirname.buf);
1985                         goto cleanup;
1986                 }
1987         }
1988
1989         /*
1990          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1991          * There is no point in searching for a reference with that
1992          * name, because a refname isn't considered to conflict with
1993          * itself. But we still need to check for references whose
1994          * names are in the "refs/foo/bar/" namespace, because they
1995          * *do* conflict.
1996          */
1997         strbuf_addstr(&dirname, refname + dirname.len);
1998         strbuf_addch(&dirname, '/');
1999
2000         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
2001                                        DO_FOR_EACH_INCLUDE_BROKEN);
2002         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
2003                 if (skip &&
2004                     string_list_has_string(skip, iter->refname))
2005                         continue;
2006
2007                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
2008                             iter->refname, refname);
2009                 ref_iterator_abort(iter);
2010                 goto cleanup;
2011         }
2012
2013         if (ok != ITER_DONE)
2014                 BUG("error while iterating over references");
2015
2016         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2017         if (extra_refname)
2018                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2019                             refname, extra_refname);
2020         else
2021                 ret = 0;
2022
2023 cleanup:
2024         strbuf_release(&referent);
2025         strbuf_release(&dirname);
2026         return ret;
2027 }
2028
2029 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2030 {
2031         struct ref_iterator *iter;
2032
2033         iter = refs->be->reflog_iterator_begin(refs);
2034
2035         return do_for_each_ref_iterator(iter, fn, cb_data);
2036 }
2037
2038 int for_each_reflog(each_ref_fn fn, void *cb_data)
2039 {
2040         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2041 }
2042
2043 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2044                                      const char *refname,
2045                                      each_reflog_ent_fn fn,
2046                                      void *cb_data)
2047 {
2048         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2049                                                      fn, cb_data);
2050 }
2051
2052 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2053                                 void *cb_data)
2054 {
2055         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2056                                                 refname, fn, cb_data);
2057 }
2058
2059 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2060                              each_reflog_ent_fn fn, void *cb_data)
2061 {
2062         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2063 }
2064
2065 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2066                         void *cb_data)
2067 {
2068         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2069                                         fn, cb_data);
2070 }
2071
2072 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2073 {
2074         return refs->be->reflog_exists(refs, refname);
2075 }
2076
2077 int reflog_exists(const char *refname)
2078 {
2079         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2080 }
2081
2082 int refs_create_reflog(struct ref_store *refs, const char *refname,
2083                        int force_create, struct strbuf *err)
2084 {
2085         return refs->be->create_reflog(refs, refname, force_create, err);
2086 }
2087
2088 int safe_create_reflog(const char *refname, int force_create,
2089                        struct strbuf *err)
2090 {
2091         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2092                                   force_create, err);
2093 }
2094
2095 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2096 {
2097         return refs->be->delete_reflog(refs, refname);
2098 }
2099
2100 int delete_reflog(const char *refname)
2101 {
2102         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2103 }
2104
2105 int refs_reflog_expire(struct ref_store *refs,
2106                        const char *refname, const struct object_id *oid,
2107                        unsigned int flags,
2108                        reflog_expiry_prepare_fn prepare_fn,
2109                        reflog_expiry_should_prune_fn should_prune_fn,
2110                        reflog_expiry_cleanup_fn cleanup_fn,
2111                        void *policy_cb_data)
2112 {
2113         return refs->be->reflog_expire(refs, refname, oid, flags,
2114                                        prepare_fn, should_prune_fn,
2115                                        cleanup_fn, policy_cb_data);
2116 }
2117
2118 int reflog_expire(const char *refname, const struct object_id *oid,
2119                   unsigned int flags,
2120                   reflog_expiry_prepare_fn prepare_fn,
2121                   reflog_expiry_should_prune_fn should_prune_fn,
2122                   reflog_expiry_cleanup_fn cleanup_fn,
2123                   void *policy_cb_data)
2124 {
2125         return refs_reflog_expire(get_main_ref_store(the_repository),
2126                                   refname, oid, flags,
2127                                   prepare_fn, should_prune_fn,
2128                                   cleanup_fn, policy_cb_data);
2129 }
2130
2131 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2132                                    struct strbuf *err)
2133 {
2134         struct ref_store *refs = transaction->ref_store;
2135
2136         return refs->be->initial_transaction_commit(refs, transaction, err);
2137 }
2138
2139 int refs_delete_refs(struct ref_store *refs, const char *msg,
2140                      struct string_list *refnames, unsigned int flags)
2141 {
2142         return refs->be->delete_refs(refs, msg, refnames, flags);
2143 }
2144
2145 int delete_refs(const char *msg, struct string_list *refnames,
2146                 unsigned int flags)
2147 {
2148         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2149 }
2150
2151 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2152                     const char *newref, const char *logmsg)
2153 {
2154         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2155 }
2156
2157 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2158 {
2159         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2160 }
2161
2162 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2163                     const char *newref, const char *logmsg)
2164 {
2165         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2166 }
2167
2168 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2169 {
2170         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2171 }