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.h"
  13 #include "tag.h"
  14 #include "submodule.h"
  15 #include "worktree.h"
  16 #include "repository.h"
  17
  18 /*
  19  * List of all available backends
  20  */
  21 static struct ref_storage_be *refs_backends = &refs_be_files;
  22
  23 static struct ref_storage_be *find_ref_storage_backend(const char *name)
  24 {
  25         struct ref_storage_be *be;
  26         for (be = refs_backends; be; be = be->next)
  27                 if (!strcmp(be->name, name))
  28                         return be;
  29         return NULL;
  30 }
  31
  32 int ref_storage_backend_exists(const char *name)
  33 {
  34         return find_ref_storage_backend(name) != NULL;
  35 }
  36
  37 /*
  38  * How to handle various characters in refnames:
  39  * 0: An acceptable character for refs
  40  * 1: End-of-component
  41  * 2: ., look for a preceding . to reject .. in refs
  42  * 3: {, look for a preceding @ to reject @{ in refs
  43  * 4: A bad character: ASCII control characters, and
  44  *    ":", "?", "[", "\", "^", "~", SP, or TAB
  45  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  46  */
  47 static unsigned char refname_disposition[256] = {
  48         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  49         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  50         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
  51         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
  52         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
  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, 3, 0, 0, 4, 4
  56 };
  57
  58 /*
  59  * Try to read one refname component from the front of refname.
  60  * Return the length of the component found, or -1 if the component is
  61  * not legal.  It is legal if it is something reasonable to have under
  62  * ".git/refs/"; We do not like it if:
  63  *
  64  * - any path component of it begins with ".", or
  65  * - it has double dots "..", or
  66  * - it has ASCII control characters, or
  67  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
  68  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
  69  * - it ends with a "/", or
  70  * - it ends with ".lock", or
  71  * - it contains a "@{" portion
  72  */
  73 static int check_refname_component(const char *refname, int *flags)
  74 {
  75         const char *cp;
  76         char last = '\0';
  77
  78         for (cp = refname; ; cp++) {
  79                 int ch = *cp & 255;
  80                 unsigned char disp = refname_disposition[ch];
  81                 switch (disp) {
  82                 case 1:
  83                         goto out;
  84                 case 2:
  85                         if (last == '.')
  86                                 return -1; /* Refname contains "..". */
  87                         break;
  88                 case 3:
  89                         if (last == '@')
  90                                 return -1; /* Refname contains "@{". */
  91                         break;
  92                 case 4:
  93                         return -1;
  94                 case 5:
  95                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
  96                                 return -1; /* refspec can't be a pattern */
  97
  98                         /*
  99                          * Unset the pattern flag so that we only accept
 100                          * a single asterisk for one side of refspec.
 101                          */
 102                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
 103                         break;
 104                 }
 105                 last = ch;
 106         }
 107 out:
 108         if (cp == refname)
 109                 return 0; /* Component has zero length. */
 110         if (refname[0] == '.')
 111                 return -1; /* Component starts with '.'. */
 112         if (cp - refname >= LOCK_SUFFIX_LEN &&
 113             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
 114                 return -1; /* Refname ends with ".lock". */
 115         return cp - refname;
 116 }
 117
 118 int check_refname_format(const char *refname, int flags)
 119 {
 120         int component_len, component_count = 0;
 121
 122         if (!strcmp(refname, "@"))
 123                 /* Refname is a single character '@'. */
 124                 return -1;
 125
 126         while (1) {
 127                 /* We are at the start of a path component. */
 128                 component_len = check_refname_component(refname, &flags);
 129                 if (component_len <= 0)
 130                         return -1;
 131
 132                 component_count++;
 133                 if (refname[component_len] == '\0')
 134                         break;
 135                 /* Skip to next component. */
 136                 refname += component_len + 1;
 137         }
 138
 139         if (refname[component_len - 1] == '.')
 140                 return -1; /* Refname ends with '.'. */
 141         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
 142                 return -1; /* Refname has only one component. */
 143         return 0;
 144 }
 145
 146 int refname_is_safe(const char *refname)
 147 {
 148         const char *rest;
 149
 150         if (skip_prefix(refname, "refs/", &rest)) {
 151                 char *buf;
 152                 int result;
 153                 size_t restlen = strlen(rest);
 154
 155                 /* rest must not be empty, or start or end with "/" */
 156                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
 157                         return 0;
 158
 159                 /*
 160                  * Does the refname try to escape refs/?
 161                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
 162                  * is not.
 163                  */
 164                 buf = xmallocz(restlen);
 165                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
 166                 free(buf);
 167                 return result;
 168         }
 169
 170         do {
 171                 if (!isupper(*refname) && *refname != '_')
 172                         return 0;
 173                 refname++;
 174         } while (*refname);
 175         return 1;
 176 }
 177
 178 /*
 179  * Return true if refname, which has the specified oid and flags, can
 180  * be resolved to an object in the database. If the referred-to object
 181  * does not exist, emit a warning and return false.
 182  */
 183 int ref_resolves_to_object(const char *refname,
 184                            const struct object_id *oid,
 185                            unsigned int flags)
 186 {
 187         if (flags & REF_ISBROKEN)
 188                 return 0;
 189         if (!has_sha1_file(oid->hash)) {
 190                 error("%s does not point to a valid object!", refname);
 191                 return 0;
 192         }
 193         return 1;
 194 }
 195
 196 char *refs_resolve_refdup(struct ref_store *refs,
 197                           const char *refname, int resolve_flags,
 198                           struct object_id *oid, int *flags)
 199 {
 200         const char *result;
 201
 202         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
 203                                          oid, flags);
 204         return xstrdup_or_null(result);
 205 }
 206
 207 char *resolve_refdup(const char *refname, int resolve_flags,
 208                      struct object_id *oid, int *flags)
 209 {
 210         return refs_resolve_refdup(get_main_ref_store(the_repository),
 211                                    refname, resolve_flags,
 212                                    oid, flags);
 213 }
 214
 215 /* The argument to filter_refs */
 216 struct ref_filter {
 217         const char *pattern;
 218         each_ref_fn *fn;
 219         void *cb_data;
 220 };
 221
 222 int refs_read_ref_full(struct ref_store *refs, const char *refname,
 223                        int resolve_flags, struct object_id *oid, int *flags)
 224 {
 225         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
 226                 return 0;
 227         return -1;
 228 }
 229
 230 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 231 {
 232         return refs_read_ref_full(get_main_ref_store(the_repository), refname,
 233                                   resolve_flags, oid, flags);
 234 }
 235
 236 int read_ref(const char *refname, struct object_id *oid)
 237 {
 238         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
 239 }
 240
 241 int ref_exists(const char *refname)
 242 {
 243         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
 244 }
 245
 246 static int match_ref_pattern(const char *refname,
 247                              const struct string_list_item *item)
 248 {
 249         int matched = 0;
 250         if (item->util == NULL) {
 251                 if (!wildmatch(item->string, refname, 0))
 252                         matched = 1;
 253         } else {
 254                 const char *rest;
 255                 if (skip_prefix(refname, item->string, &rest) &&
 256                     (!*rest || *rest == '/'))
 257                         matched = 1;
 258         }
 259         return matched;
 260 }
 261
 262 int ref_filter_match(const char *refname,
 263                      const struct string_list *include_patterns,
 264                      const struct string_list *exclude_patterns)
 265 {
 266         struct string_list_item *item;
 267
 268         if (exclude_patterns && exclude_patterns->nr) {
 269                 for_each_string_list_item(item, exclude_patterns) {
 270                         if (match_ref_pattern(refname, item))
 271                                 return 0;
 272                 }
 273         }
 274
 275         if (include_patterns && include_patterns->nr) {
 276                 int found = 0;
 277                 for_each_string_list_item(item, include_patterns) {
 278                         if (match_ref_pattern(refname, item)) {
 279                                 found = 1;
 280                                 break;
 281                         }
 282                 }
 283
 284                 if (!found)
 285                         return 0;
 286         }
 287         return 1;
 288 }
 289
 290 static int filter_refs(const char *refname, const struct object_id *oid,
 291                            int flags, void *data)
 292 {
 293         struct ref_filter *filter = (struct ref_filter *)data;
 294
 295         if (wildmatch(filter->pattern, refname, 0))
 296                 return 0;
 297         return filter->fn(refname, oid, flags, filter->cb_data);
 298 }
 299
 300 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
 301 {
 302         struct object *o = lookup_unknown_object(name->hash);
 303
 304         if (o->type == OBJ_NONE) {
 305                 int type = oid_object_info(name, NULL);
 306                 if (type < 0 || !object_as_type(o, type, 0))
 307                         return PEEL_INVALID;
 308         }
 309
 310         if (o->type != OBJ_TAG)
 311                 return PEEL_NON_TAG;
 312
 313         o = deref_tag_noverify(o);
 314         if (!o)
 315                 return PEEL_INVALID;
 316
 317         oidcpy(oid, &o->oid);
 318         return PEEL_PEELED;
 319 }
 320
 321 struct warn_if_dangling_data {
 322         FILE *fp;
 323         const char *refname;
 324         const struct string_list *refnames;
 325         const char *msg_fmt;
 326 };
 327
 328 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
 329                                    int flags, void *cb_data)
 330 {
 331         struct warn_if_dangling_data *d = cb_data;
 332         const char *resolves_to;
 333
 334         if (!(flags & REF_ISSYMREF))
 335                 return 0;
 336
 337         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
 338         if (!resolves_to
 339             || (d->refname
 340                 ? strcmp(resolves_to, d->refname)
 341                 : !string_list_has_string(d->refnames, resolves_to))) {
 342                 return 0;
 343         }
 344
 345         fprintf(d->fp, d->msg_fmt, refname);
 346         fputc('\n', d->fp);
 347         return 0;
 348 }
 349
 350 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 351 {
 352         struct warn_if_dangling_data data;
 353
 354         data.fp = fp;
 355         data.refname = refname;
 356         data.refnames = NULL;
 357         data.msg_fmt = msg_fmt;
 358         for_each_rawref(warn_if_dangling_symref, &data);
 359 }
 360
 361 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
 362 {
 363         struct warn_if_dangling_data data;
 364
 365         data.fp = fp;
 366         data.refname = NULL;
 367         data.refnames = refnames;
 368         data.msg_fmt = msg_fmt;
 369         for_each_rawref(warn_if_dangling_symref, &data);
 370 }
 371
 372 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 373 {
 374         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
 375 }
 376
 377 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 378 {
 379         return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
 380 }
 381
 382 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 383 {
 384         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
 385 }
 386
 387 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 388 {
 389         return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
 390 }
 391
 392 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 393 {
 394         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
 395 }
 396
 397 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 398 {
 399         return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
 400 }
 401
 402 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 403 {
 404         struct strbuf buf = STRBUF_INIT;
 405         int ret = 0;
 406         struct object_id oid;
 407         int flag;
 408
 409         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
 410         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
 411                 ret = fn(buf.buf, &oid, flag, cb_data);
 412         strbuf_release(&buf);
 413
 414         return ret;
 415 }
 416
 417 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
 418                         const char *pattern)
 419 {
 420         struct strbuf normalized_pattern = STRBUF_INIT;
 421
 422         if (*pattern == '/')
 423                 BUG("pattern must not start with '/'");
 424
 425         if (prefix) {
 426                 strbuf_addstr(&normalized_pattern, prefix);
 427         }
 428         else if (!starts_with(pattern, "refs/"))
 429                 strbuf_addstr(&normalized_pattern, "refs/");
 430         strbuf_addstr(&normalized_pattern, pattern);
 431         strbuf_strip_suffix(&normalized_pattern, "/");
 432
 433         item->string = strbuf_detach(&normalized_pattern, NULL);
 434         item->util = has_glob_specials(pattern) ? NULL : item->string;
 435         strbuf_release(&normalized_pattern);
 436 }
 437
 438 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 439         const char *prefix, void *cb_data)
 440 {
 441         struct strbuf real_pattern = STRBUF_INIT;
 442         struct ref_filter filter;
 443         int ret;
 444
 445         if (!prefix && !starts_with(pattern, "refs/"))
 446                 strbuf_addstr(&real_pattern, "refs/");
 447         else if (prefix)
 448                 strbuf_addstr(&real_pattern, prefix);
 449         strbuf_addstr(&real_pattern, pattern);
 450
 451         if (!has_glob_specials(pattern)) {
 452                 /* Append implied '/' '*' if not present. */
 453                 strbuf_complete(&real_pattern, '/');
 454                 /* No need to check for '*', there is none. */
 455                 strbuf_addch(&real_pattern, '*');
 456         }
 457
 458         filter.pattern = real_pattern.buf;
 459         filter.fn = fn;
 460         filter.cb_data = cb_data;
 461         ret = for_each_ref(filter_refs, &filter);
 462
 463         strbuf_release(&real_pattern);
 464         return ret;
 465 }
 466
 467 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
 468 {
 469         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
 470 }
 471
 472 const char *prettify_refname(const char *name)
 473 {
 474         if (skip_prefix(name, "refs/heads/", &name) ||
 475             skip_prefix(name, "refs/tags/", &name) ||
 476             skip_prefix(name, "refs/remotes/", &name))
 477                 ; /* nothing */
 478         return name;
 479 }
 480
 481 static const char *ref_rev_parse_rules[] = {
 482         "%.*s",
 483         "refs/%.*s",
 484         "refs/tags/%.*s",
 485         "refs/heads/%.*s",
 486         "refs/remotes/%.*s",
 487         "refs/remotes/%.*s/HEAD",
 488         NULL
 489 };
 490
 491 int refname_match(const char *abbrev_name, const char *full_name)
 492 {
 493         const char **p;
 494         const int abbrev_name_len = strlen(abbrev_name);
 495
 496         for (p = ref_rev_parse_rules; *p; p++) {
 497                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 498                         return 1;
 499                 }
 500         }
 501
 502         return 0;
 503 }
 504
 505 /*
 506  * *string and *len will only be substituted, and *string returned (for
 507  * later free()ing) if the string passed in is a magic short-hand form
 508  * to name a branch.
 509  */
 510 static char *substitute_branch_name(const char **string, int *len)
 511 {
 512         struct strbuf buf = STRBUF_INIT;
 513         int ret = interpret_branch_name(*string, *len, &buf, 0);
 514
 515         if (ret == *len) {
 516                 size_t size;
 517                 *string = strbuf_detach(&buf, &size);
 518                 *len = size;
 519                 return (char *)*string;
 520         }
 521
 522         return NULL;
 523 }
 524
 525 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
 526 {
 527         char *last_branch = substitute_branch_name(&str, &len);
 528         int   refs_found  = expand_ref(str, len, oid, ref);
 529         free(last_branch);
 530         return refs_found;
 531 }
 532
 533 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
 534 {
 535         const char **p, *r;
 536         int refs_found = 0;
 537         struct strbuf fullref = STRBUF_INIT;
 538
 539         *ref = NULL;
 540         for (p = ref_rev_parse_rules; *p; p++) {
 541                 struct object_id oid_from_ref;
 542                 struct object_id *this_result;
 543                 int flag;
 544
 545                 this_result = refs_found ? &oid_from_ref : oid;
 546                 strbuf_reset(&fullref);
 547                 strbuf_addf(&fullref, *p, len, str);
 548                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
 549                                        this_result, &flag);
 550                 if (r) {
 551                         if (!refs_found++)
 552                                 *ref = xstrdup(r);
 553                         if (!warn_ambiguous_refs)
 554                                 break;
 555                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
 556                         warning("ignoring dangling symref %s.", fullref.buf);
 557                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
 558                         warning("ignoring broken ref %s.", fullref.buf);
 559                 }
 560         }
 561         strbuf_release(&fullref);
 562         return refs_found;
 563 }
 564
 565 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 566 {
 567         char *last_branch = substitute_branch_name(&str, &len);
 568         const char **p;
 569         int logs_found = 0;
 570         struct strbuf path = STRBUF_INIT;
 571
 572         *log = NULL;
 573         for (p = ref_rev_parse_rules; *p; p++) {
 574                 struct object_id hash;
 575                 const char *ref, *it;
 576
 577                 strbuf_reset(&path);
 578                 strbuf_addf(&path, *p, len, str);
 579                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
 580                                          &hash, NULL);
 581                 if (!ref)
 582                         continue;
 583                 if (reflog_exists(path.buf))
 584                         it = path.buf;
 585                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
 586                         it = ref;
 587                 else
 588                         continue;
 589                 if (!logs_found++) {
 590                         *log = xstrdup(it);
 591                         oidcpy(oid, &hash);
 592                 }
 593                 if (!warn_ambiguous_refs)
 594                         break;
 595         }
 596         strbuf_release(&path);
 597         free(last_branch);
 598         return logs_found;
 599 }
 600
 601 static int is_per_worktree_ref(const char *refname)
 602 {
 603         return !strcmp(refname, "HEAD") ||
 604                 starts_with(refname, "refs/bisect/");
 605 }
 606
 607 static int is_pseudoref_syntax(const char *refname)
 608 {
 609         const char *c;
 610
 611         for (c = refname; *c; c++) {
 612                 if (!isupper(*c) && *c != '-' && *c != '_')
 613                         return 0;
 614         }
 615
 616         return 1;
 617 }
 618
 619 enum ref_type ref_type(const char *refname)
 620 {
 621         if (is_per_worktree_ref(refname))
 622                 return REF_TYPE_PER_WORKTREE;
 623         if (is_pseudoref_syntax(refname))
 624                 return REF_TYPE_PSEUDOREF;
 625        return REF_TYPE_NORMAL;
 626 }
 627
 628 long get_files_ref_lock_timeout_ms(void)
 629 {
 630         static int configured = 0;
 631
 632         /* The default timeout is 100 ms: */
 633         static int timeout_ms = 100;
 634
 635         if (!configured) {
 636                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 637                 configured = 1;
 638         }
 639
 640         return timeout_ms;
 641 }
 642
 643 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
 644                            const struct object_id *old_oid, struct strbuf *err)
 645 {
 646         const char *filename;
 647         int fd;
 648         static struct lock_file lock;
 649         struct strbuf buf = STRBUF_INIT;
 650         int ret = -1;
 651
 652         if (!oid)
 653                 return 0;
 654
 655         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 656
 657         filename = git_path("%s", pseudoref);
 658         fd = hold_lock_file_for_update_timeout(&lock, filename,
 659                                                LOCK_DIE_ON_ERROR,
 660                                                get_files_ref_lock_timeout_ms());
 661         if (fd < 0) {
 662                 strbuf_addf(err, "could not open '%s' for writing: %s",
 663                             filename, strerror(errno));
 664                 goto done;
 665         }
 666
 667         if (old_oid) {
 668                 struct object_id actual_old_oid;
 669
 670                 if (read_ref(pseudoref, &actual_old_oid))
 671                         die("could not read ref '%s'", pseudoref);
 672                 if (oidcmp(&actual_old_oid, old_oid)) {
 673                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 674                         rollback_lock_file(&lock);
 675                         goto done;
 676                 }
 677         }
 678
 679         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 680                 strbuf_addf(err, "could not write to '%s'", filename);
 681                 rollback_lock_file(&lock);
 682                 goto done;
 683         }
 684
 685         commit_lock_file(&lock);
 686         ret = 0;
 687 done:
 688         strbuf_release(&buf);
 689         return ret;
 690 }
 691
 692 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 693 {
 694         static struct lock_file lock;
 695         const char *filename;
 696
 697         filename = git_path("%s", pseudoref);
 698
 699         if (old_oid && !is_null_oid(old_oid)) {
 700                 int fd;
 701                 struct object_id actual_old_oid;
 702
 703                 fd = hold_lock_file_for_update_timeout(
 704                                 &lock, filename, LOCK_DIE_ON_ERROR,
 705                                 get_files_ref_lock_timeout_ms());
 706                 if (fd < 0)
 707                         die_errno(_("Could not open '%s' for writing"), filename);
 708                 if (read_ref(pseudoref, &actual_old_oid))
 709                         die("could not read ref '%s'", pseudoref);
 710                 if (oidcmp(&actual_old_oid, old_oid)) {
 711                         warning("Unexpected sha1 when deleting %s", pseudoref);
 712                         rollback_lock_file(&lock);
 713                         return -1;
 714                 }
 715
 716                 unlink(filename);
 717                 rollback_lock_file(&lock);
 718         } else {
 719                 unlink(filename);
 720         }
 721
 722         return 0;
 723 }
 724
 725 int refs_delete_ref(struct ref_store *refs, const char *msg,
 726                     const char *refname,
 727                     const struct object_id *old_oid,
 728                     unsigned int flags)
 729 {
 730         struct ref_transaction *transaction;
 731         struct strbuf err = STRBUF_INIT;
 732
 733         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 734                 assert(refs == get_main_ref_store(the_repository));
 735                 return delete_pseudoref(refname, old_oid);
 736         }
 737
 738         transaction = ref_store_transaction_begin(refs, &err);
 739         if (!transaction ||
 740             ref_transaction_delete(transaction, refname, old_oid,
 741                                    flags, msg, &err) ||
 742             ref_transaction_commit(transaction, &err)) {
 743                 error("%s", err.buf);
 744                 ref_transaction_free(transaction);
 745                 strbuf_release(&err);
 746                 return 1;
 747         }
 748         ref_transaction_free(transaction);
 749         strbuf_release(&err);
 750         return 0;
 751 }
 752
 753 int delete_ref(const char *msg, const char *refname,
 754                const struct object_id *old_oid, unsigned int flags)
 755 {
 756         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
 757                                old_oid, flags);
 758 }
 759
 760 int copy_reflog_msg(char *buf, const char *msg)
 761 {
 762         char *cp = buf;
 763         char c;
 764         int wasspace = 1;
 765
 766         *cp++ = '\t';
 767         while ((c = *msg++)) {
 768                 if (wasspace && isspace(c))
 769                         continue;
 770                 wasspace = isspace(c);
 771                 if (wasspace)
 772                         c = ' ';
 773                 *cp++ = c;
 774         }
 775         while (buf < cp && isspace(cp[-1]))
 776                 cp--;
 777         *cp++ = '\n';
 778         return cp - buf;
 779 }
 780
 781 int should_autocreate_reflog(const char *refname)
 782 {
 783         switch (log_all_ref_updates) {
 784         case LOG_REFS_ALWAYS:
 785                 return 1;
 786         case LOG_REFS_NORMAL:
 787                 return starts_with(refname, "refs/heads/") ||
 788                         starts_with(refname, "refs/remotes/") ||
 789                         starts_with(refname, "refs/notes/") ||
 790                         !strcmp(refname, "HEAD");
 791         default:
 792                 return 0;
 793         }
 794 }
 795
 796 int is_branch(const char *refname)
 797 {
 798         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 799 }
 800
 801 struct read_ref_at_cb {
 802         const char *refname;
 803         timestamp_t at_time;
 804         int cnt;
 805         int reccnt;
 806         struct object_id *oid;
 807         int found_it;
 808
 809         struct object_id ooid;
 810         struct object_id noid;
 811         int tz;
 812         timestamp_t date;
 813         char **msg;
 814         timestamp_t *cutoff_time;
 815         int *cutoff_tz;
 816         int *cutoff_cnt;
 817 };
 818
 819 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 820                 const char *email, timestamp_t timestamp, int tz,
 821                 const char *message, void *cb_data)
 822 {
 823         struct read_ref_at_cb *cb = cb_data;
 824
 825         cb->reccnt++;
 826         cb->tz = tz;
 827         cb->date = timestamp;
 828
 829         if (timestamp <= cb->at_time || cb->cnt == 0) {
 830                 if (cb->msg)
 831                         *cb->msg = xstrdup(message);
 832                 if (cb->cutoff_time)
 833                         *cb->cutoff_time = timestamp;
 834                 if (cb->cutoff_tz)
 835                         *cb->cutoff_tz = tz;
 836                 if (cb->cutoff_cnt)
 837                         *cb->cutoff_cnt = cb->reccnt - 1;
 838                 /*
 839                  * we have not yet updated cb->[n|o]oid so they still
 840                  * hold the values for the previous record.
 841                  */
 842                 if (!is_null_oid(&cb->ooid)) {
 843                         oidcpy(cb->oid, noid);
 844                         if (oidcmp(&cb->ooid, noid))
 845                                 warning("Log for ref %s has gap after %s.",
 846                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 847                 }
 848                 else if (cb->date == cb->at_time)
 849                         oidcpy(cb->oid, noid);
 850                 else if (oidcmp(noid, cb->oid))
 851                         warning("Log for ref %s unexpectedly ended on %s.",
 852                                 cb->refname, show_date(cb->date, cb->tz,
 853                                                        DATE_MODE(RFC2822)));
 854                 oidcpy(&cb->ooid, ooid);
 855                 oidcpy(&cb->noid, noid);
 856                 cb->found_it = 1;
 857                 return 1;
 858         }
 859         oidcpy(&cb->ooid, ooid);
 860         oidcpy(&cb->noid, noid);
 861         if (cb->cnt > 0)
 862                 cb->cnt--;
 863         return 0;
 864 }
 865
 866 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 867                                   const char *email, timestamp_t timestamp,
 868                                   int tz, const char *message, void *cb_data)
 869 {
 870         struct read_ref_at_cb *cb = cb_data;
 871
 872         if (cb->msg)
 873                 *cb->msg = xstrdup(message);
 874         if (cb->cutoff_time)
 875                 *cb->cutoff_time = timestamp;
 876         if (cb->cutoff_tz)
 877                 *cb->cutoff_tz = tz;
 878         if (cb->cutoff_cnt)
 879                 *cb->cutoff_cnt = cb->reccnt;
 880         oidcpy(cb->oid, ooid);
 881         if (is_null_oid(cb->oid))
 882                 oidcpy(cb->oid, noid);
 883         /* We just want the first entry */
 884         return 1;
 885 }
 886
 887 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 888                 struct object_id *oid, char **msg,
 889                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 890 {
 891         struct read_ref_at_cb cb;
 892
 893         memset(&cb, 0, sizeof(cb));
 894         cb.refname = refname;
 895         cb.at_time = at_time;
 896         cb.cnt = cnt;
 897         cb.msg = msg;
 898         cb.cutoff_time = cutoff_time;
 899         cb.cutoff_tz = cutoff_tz;
 900         cb.cutoff_cnt = cutoff_cnt;
 901         cb.oid = oid;
 902
 903         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 904
 905         if (!cb.reccnt) {
 906                 if (flags & GET_OID_QUIETLY)
 907                         exit(128);
 908                 else
 909                         die("Log for %s is empty.", refname);
 910         }
 911         if (cb.found_it)
 912                 return 0;
 913
 914         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 915
 916         return 1;
 917 }
 918
 919 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 920                                                     struct strbuf *err)
 921 {
 922         struct ref_transaction *tr;
 923         assert(err);
 924
 925         tr = xcalloc(1, sizeof(struct ref_transaction));
 926         tr->ref_store = refs;
 927         return tr;
 928 }
 929
 930 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 931 {
 932         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
 933 }
 934
 935 void ref_transaction_free(struct ref_transaction *transaction)
 936 {
 937         size_t i;
 938
 939         if (!transaction)
 940                 return;
 941
 942         switch (transaction->state) {
 943         case REF_TRANSACTION_OPEN:
 944         case REF_TRANSACTION_CLOSED:
 945                 /* OK */
 946                 break;
 947         case REF_TRANSACTION_PREPARED:
 948                 die("BUG: free called on a prepared reference transaction");
 949                 break;
 950         default:
 951                 die("BUG: unexpected reference transaction state");
 952                 break;
 953         }
 954
 955         for (i = 0; i < transaction->nr; i++) {
 956                 free(transaction->updates[i]->msg);
 957                 free(transaction->updates[i]);
 958         }
 959         free(transaction->updates);
 960         free(transaction);
 961 }
 962
 963 struct ref_update *ref_transaction_add_update(
 964                 struct ref_transaction *transaction,
 965                 const char *refname, unsigned int flags,
 966                 const struct object_id *new_oid,
 967                 const struct object_id *old_oid,
 968                 const char *msg)
 969 {
 970         struct ref_update *update;
 971
 972         if (transaction->state != REF_TRANSACTION_OPEN)
 973                 die("BUG: update called for transaction that is not open");
 974
 975         FLEX_ALLOC_STR(update, refname, refname);
 976         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 977         transaction->updates[transaction->nr++] = update;
 978
 979         update->flags = flags;
 980
 981         if (flags & REF_HAVE_NEW)
 982                 oidcpy(&update->new_oid, new_oid);
 983         if (flags & REF_HAVE_OLD)
 984                 oidcpy(&update->old_oid, old_oid);
 985         update->msg = xstrdup_or_null(msg);
 986         return update;
 987 }
 988
 989 int ref_transaction_update(struct ref_transaction *transaction,
 990                            const char *refname,
 991                            const struct object_id *new_oid,
 992                            const struct object_id *old_oid,
 993                            unsigned int flags, const char *msg,
 994                            struct strbuf *err)
 995 {
 996         assert(err);
 997
 998         if ((new_oid && !is_null_oid(new_oid)) ?
 999             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1000             !refname_is_safe(refname)) {
1001                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1002                             refname);
1003                 return -1;
1004         }
1005
1006         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1007                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1008
1009         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1010
1011         ref_transaction_add_update(transaction, refname, flags,
1012                                    new_oid, old_oid, msg);
1013         return 0;
1014 }
1015
1016 int ref_transaction_create(struct ref_transaction *transaction,
1017                            const char *refname,
1018                            const struct object_id *new_oid,
1019                            unsigned int flags, const char *msg,
1020                            struct strbuf *err)
1021 {
1022         if (!new_oid || is_null_oid(new_oid))
1023                 die("BUG: create called without valid new_oid");
1024         return ref_transaction_update(transaction, refname, new_oid,
1025                                       &null_oid, flags, msg, err);
1026 }
1027
1028 int ref_transaction_delete(struct ref_transaction *transaction,
1029                            const char *refname,
1030                            const struct object_id *old_oid,
1031                            unsigned int flags, const char *msg,
1032                            struct strbuf *err)
1033 {
1034         if (old_oid && is_null_oid(old_oid))
1035                 die("BUG: delete called with old_oid set to zeros");
1036         return ref_transaction_update(transaction, refname,
1037                                       &null_oid, old_oid,
1038                                       flags, msg, err);
1039 }
1040
1041 int ref_transaction_verify(struct ref_transaction *transaction,
1042                            const char *refname,
1043                            const struct object_id *old_oid,
1044                            unsigned int flags,
1045                            struct strbuf *err)
1046 {
1047         if (!old_oid)
1048                 die("BUG: verify called with old_oid set to NULL");
1049         return ref_transaction_update(transaction, refname,
1050                                       NULL, old_oid,
1051                                       flags, NULL, err);
1052 }
1053
1054 int refs_update_ref(struct ref_store *refs, const char *msg,
1055                     const char *refname, const struct object_id *new_oid,
1056                     const struct object_id *old_oid, unsigned int flags,
1057                     enum action_on_err onerr)
1058 {
1059         struct ref_transaction *t = NULL;
1060         struct strbuf err = STRBUF_INIT;
1061         int ret = 0;
1062
1063         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1064                 assert(refs == get_main_ref_store(the_repository));
1065                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1066         } else {
1067                 t = ref_store_transaction_begin(refs, &err);
1068                 if (!t ||
1069                     ref_transaction_update(t, refname, new_oid, old_oid,
1070                                            flags, msg, &err) ||
1071                     ref_transaction_commit(t, &err)) {
1072                         ret = 1;
1073                         ref_transaction_free(t);
1074                 }
1075         }
1076         if (ret) {
1077                 const char *str = "update_ref failed for ref '%s': %s";
1078
1079                 switch (onerr) {
1080                 case UPDATE_REFS_MSG_ON_ERR:
1081                         error(str, refname, err.buf);
1082                         break;
1083                 case UPDATE_REFS_DIE_ON_ERR:
1084                         die(str, refname, err.buf);
1085                         break;
1086                 case UPDATE_REFS_QUIET_ON_ERR:
1087                         break;
1088                 }
1089                 strbuf_release(&err);
1090                 return 1;
1091         }
1092         strbuf_release(&err);
1093         if (t)
1094                 ref_transaction_free(t);
1095         return 0;
1096 }
1097
1098 int update_ref(const char *msg, const char *refname,
1099                const struct object_id *new_oid,
1100                const struct object_id *old_oid,
1101                unsigned int flags, enum action_on_err onerr)
1102 {
1103         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1104                                old_oid, flags, onerr);
1105 }
1106
1107 char *shorten_unambiguous_ref(const char *refname, int strict)
1108 {
1109         int i;
1110         static char **scanf_fmts;
1111         static int nr_rules;
1112         char *short_name;
1113         struct strbuf resolved_buf = STRBUF_INIT;
1114
1115         if (!nr_rules) {
1116                 /*
1117                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1118                  * Generate a format suitable for scanf from a
1119                  * ref_rev_parse_rules rule by interpolating "%s" at the
1120                  * location of the "%.*s".
1121                  */
1122                 size_t total_len = 0;
1123                 size_t offset = 0;
1124
1125                 /* the rule list is NULL terminated, count them first */
1126                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1127                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1128                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1129
1130                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1131
1132                 offset = 0;
1133                 for (i = 0; i < nr_rules; i++) {
1134                         assert(offset < total_len);
1135                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1136                         offset += snprintf(scanf_fmts[i], total_len - offset,
1137                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1138                 }
1139         }
1140
1141         /* bail out if there are no rules */
1142         if (!nr_rules)
1143                 return xstrdup(refname);
1144
1145         /* buffer for scanf result, at most refname must fit */
1146         short_name = xstrdup(refname);
1147
1148         /* skip first rule, it will always match */
1149         for (i = nr_rules - 1; i > 0 ; --i) {
1150                 int j;
1151                 int rules_to_fail = i;
1152                 int short_name_len;
1153
1154                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1155                         continue;
1156
1157                 short_name_len = strlen(short_name);
1158
1159                 /*
1160                  * in strict mode, all (except the matched one) rules
1161                  * must fail to resolve to a valid non-ambiguous ref
1162                  */
1163                 if (strict)
1164                         rules_to_fail = nr_rules;
1165
1166                 /*
1167                  * check if the short name resolves to a valid ref,
1168                  * but use only rules prior to the matched one
1169                  */
1170                 for (j = 0; j < rules_to_fail; j++) {
1171                         const char *rule = ref_rev_parse_rules[j];
1172
1173                         /* skip matched rule */
1174                         if (i == j)
1175                                 continue;
1176
1177                         /*
1178                          * the short name is ambiguous, if it resolves
1179                          * (with this previous rule) to a valid ref
1180                          * read_ref() returns 0 on success
1181                          */
1182                         strbuf_reset(&resolved_buf);
1183                         strbuf_addf(&resolved_buf, rule,
1184                                     short_name_len, short_name);
1185                         if (ref_exists(resolved_buf.buf))
1186                                 break;
1187                 }
1188
1189                 /*
1190                  * short name is non-ambiguous if all previous rules
1191                  * haven't resolved to a valid ref
1192                  */
1193                 if (j == rules_to_fail) {
1194                         strbuf_release(&resolved_buf);
1195                         return short_name;
1196                 }
1197         }
1198
1199         strbuf_release(&resolved_buf);
1200         free(short_name);
1201         return xstrdup(refname);
1202 }
1203
1204 static struct string_list *hide_refs;
1205
1206 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1207 {
1208         const char *key;
1209         if (!strcmp("transfer.hiderefs", var) ||
1210             (!parse_config_key(var, section, NULL, NULL, &key) &&
1211              !strcmp(key, "hiderefs"))) {
1212                 char *ref;
1213                 int len;
1214
1215                 if (!value)
1216                         return config_error_nonbool(var);
1217                 ref = xstrdup(value);
1218                 len = strlen(ref);
1219                 while (len && ref[len - 1] == '/')
1220                         ref[--len] = '\0';
1221                 if (!hide_refs) {
1222                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1223                         hide_refs->strdup_strings = 1;
1224                 }
1225                 string_list_append(hide_refs, ref);
1226         }
1227         return 0;
1228 }
1229
1230 int ref_is_hidden(const char *refname, const char *refname_full)
1231 {
1232         int i;
1233
1234         if (!hide_refs)
1235                 return 0;
1236         for (i = hide_refs->nr - 1; i >= 0; i--) {
1237                 const char *match = hide_refs->items[i].string;
1238                 const char *subject;
1239                 int neg = 0;
1240                 const char *p;
1241
1242                 if (*match == '!') {
1243                         neg = 1;
1244                         match++;
1245                 }
1246
1247                 if (*match == '^') {
1248                         subject = refname_full;
1249                         match++;
1250                 } else {
1251                         subject = refname;
1252                 }
1253
1254                 /* refname can be NULL when namespaces are used. */
1255                 if (subject &&
1256                     skip_prefix(subject, match, &p) &&
1257                     (!*p || *p == '/'))
1258                         return !neg;
1259         }
1260         return 0;
1261 }
1262
1263 const char *find_descendant_ref(const char *dirname,
1264                                 const struct string_list *extras,
1265                                 const struct string_list *skip)
1266 {
1267         int pos;
1268
1269         if (!extras)
1270                 return NULL;
1271
1272         /*
1273          * Look at the place where dirname would be inserted into
1274          * extras. If there is an entry at that position that starts
1275          * with dirname (remember, dirname includes the trailing
1276          * slash) and is not in skip, then we have a conflict.
1277          */
1278         for (pos = string_list_find_insert_index(extras, dirname, 0);
1279              pos < extras->nr; pos++) {
1280                 const char *extra_refname = extras->items[pos].string;
1281
1282                 if (!starts_with(extra_refname, dirname))
1283                         break;
1284
1285                 if (!skip || !string_list_has_string(skip, extra_refname))
1286                         return extra_refname;
1287         }
1288         return NULL;
1289 }
1290
1291 int refs_rename_ref_available(struct ref_store *refs,
1292                               const char *old_refname,
1293                               const char *new_refname)
1294 {
1295         struct string_list skip = STRING_LIST_INIT_NODUP;
1296         struct strbuf err = STRBUF_INIT;
1297         int ok;
1298
1299         string_list_insert(&skip, old_refname);
1300         ok = !refs_verify_refname_available(refs, new_refname,
1301                                             NULL, &skip, &err);
1302         if (!ok)
1303                 error("%s", err.buf);
1304
1305         string_list_clear(&skip, 0);
1306         strbuf_release(&err);
1307         return ok;
1308 }
1309
1310 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1311 {
1312         struct object_id oid;
1313         int flag;
1314
1315         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1316                                 &oid, &flag))
1317                 return fn("HEAD", &oid, flag, cb_data);
1318
1319         return 0;
1320 }
1321
1322 int head_ref(each_ref_fn fn, void *cb_data)
1323 {
1324         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1325 }
1326
1327 struct ref_iterator *refs_ref_iterator_begin(
1328                 struct ref_store *refs,
1329                 const char *prefix, int trim, int flags)
1330 {
1331         struct ref_iterator *iter;
1332
1333         if (ref_paranoia < 0)
1334                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1335         if (ref_paranoia)
1336                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1337
1338         iter = refs->be->iterator_begin(refs, prefix, flags);
1339
1340         /*
1341          * `iterator_begin()` already takes care of prefix, but we
1342          * might need to do some trimming:
1343          */
1344         if (trim)
1345                 iter = prefix_ref_iterator_begin(iter, "", trim);
1346
1347         /* Sanity check for subclasses: */
1348         if (!iter->ordered)
1349                 BUG("reference iterator is not ordered");
1350
1351         return iter;
1352 }
1353
1354 /*
1355  * Call fn for each reference in the specified submodule for which the
1356  * refname begins with prefix. If trim is non-zero, then trim that
1357  * many characters off the beginning of each refname before passing
1358  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1359  * include broken references in the iteration. If fn ever returns a
1360  * non-zero value, stop the iteration and return that value;
1361  * otherwise, return 0.
1362  */
1363 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1364                            each_ref_fn fn, int trim, int flags, void *cb_data)
1365 {
1366         struct ref_iterator *iter;
1367
1368         if (!refs)
1369                 return 0;
1370
1371         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1372
1373         return do_for_each_ref_iterator(iter, fn, cb_data);
1374 }
1375
1376 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1377 {
1378         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1379 }
1380
1381 int for_each_ref(each_ref_fn fn, void *cb_data)
1382 {
1383         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1384 }
1385
1386 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1387                          each_ref_fn fn, void *cb_data)
1388 {
1389         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1390 }
1391
1392 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1393 {
1394         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1395 }
1396
1397 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1398 {
1399         unsigned int flag = 0;
1400
1401         if (broken)
1402                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1403         return do_for_each_ref(get_main_ref_store(the_repository),
1404                                prefix, fn, 0, flag, cb_data);
1405 }
1406
1407 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1408                              each_ref_fn fn, void *cb_data,
1409                              unsigned int broken)
1410 {
1411         unsigned int flag = 0;
1412
1413         if (broken)
1414                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1415         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1416 }
1417
1418 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1419 {
1420         return do_for_each_ref(get_main_ref_store(r),
1421                                git_replace_ref_base, fn,
1422                                strlen(git_replace_ref_base),
1423                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1424 }
1425
1426 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1427 {
1428         struct strbuf buf = STRBUF_INIT;
1429         int ret;
1430         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1431         ret = do_for_each_ref(get_main_ref_store(the_repository),
1432                               buf.buf, fn, 0, 0, cb_data);
1433         strbuf_release(&buf);
1434         return ret;
1435 }
1436
1437 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1438 {
1439         return do_for_each_ref(refs, "", fn, 0,
1440                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1441 }
1442
1443 int for_each_rawref(each_ref_fn fn, void *cb_data)
1444 {
1445         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1446 }
1447
1448 int refs_read_raw_ref(struct ref_store *ref_store,
1449                       const char *refname, struct object_id *oid,
1450                       struct strbuf *referent, unsigned int *type)
1451 {
1452         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1453 }
1454
1455 /* This function needs to return a meaningful errno on failure */
1456 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1457                                     const char *refname,
1458                                     int resolve_flags,
1459                                     struct object_id *oid, int *flags)
1460 {
1461         static struct strbuf sb_refname = STRBUF_INIT;
1462         struct object_id unused_oid;
1463         int unused_flags;
1464         int symref_count;
1465
1466         if (!oid)
1467                 oid = &unused_oid;
1468         if (!flags)
1469                 flags = &unused_flags;
1470
1471         *flags = 0;
1472
1473         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1474                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1475                     !refname_is_safe(refname)) {
1476                         errno = EINVAL;
1477                         return NULL;
1478                 }
1479
1480                 /*
1481                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1482                  * missing refs and refs that were present but invalid,
1483                  * to complain about the latter to stderr.
1484                  *
1485                  * We don't know whether the ref exists, so don't set
1486                  * REF_ISBROKEN yet.
1487                  */
1488                 *flags |= REF_BAD_NAME;
1489         }
1490
1491         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1492                 unsigned int read_flags = 0;
1493
1494                 if (refs_read_raw_ref(refs, refname,
1495                                       oid, &sb_refname, &read_flags)) {
1496                         *flags |= read_flags;
1497
1498                         /* In reading mode, refs must eventually resolve */
1499                         if (resolve_flags & RESOLVE_REF_READING)
1500                                 return NULL;
1501
1502                         /*
1503                          * Otherwise a missing ref is OK. But the files backend
1504                          * may show errors besides ENOENT if there are
1505                          * similarly-named refs.
1506                          */
1507                         if (errno != ENOENT &&
1508                             errno != EISDIR &&
1509                             errno != ENOTDIR)
1510                                 return NULL;
1511
1512                         oidclr(oid);
1513                         if (*flags & REF_BAD_NAME)
1514                                 *flags |= REF_ISBROKEN;
1515                         return refname;
1516                 }
1517
1518                 *flags |= read_flags;
1519
1520                 if (!(read_flags & REF_ISSYMREF)) {
1521                         if (*flags & REF_BAD_NAME) {
1522                                 oidclr(oid);
1523                                 *flags |= REF_ISBROKEN;
1524                         }
1525                         return refname;
1526                 }
1527
1528                 refname = sb_refname.buf;
1529                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1530                         oidclr(oid);
1531                         return refname;
1532                 }
1533                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1534                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1535                             !refname_is_safe(refname)) {
1536                                 errno = EINVAL;
1537                                 return NULL;
1538                         }
1539
1540                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1541                 }
1542         }
1543
1544         errno = ELOOP;
1545         return NULL;
1546 }
1547
1548 /* backend functions */
1549 int refs_init_db(struct strbuf *err)
1550 {
1551         struct ref_store *refs = get_main_ref_store(the_repository);
1552
1553         return refs->be->init_db(refs, err);
1554 }
1555
1556 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1557                                struct object_id *oid, int *flags)
1558 {
1559         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1560                                        resolve_flags, oid, flags);
1561 }
1562
1563 int resolve_gitlink_ref(const char *submodule, const char *refname,
1564                         struct object_id *oid)
1565 {
1566         struct ref_store *refs;
1567         int flags;
1568
1569         refs = get_submodule_ref_store(submodule);
1570
1571         if (!refs)
1572                 return -1;
1573
1574         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1575             is_null_oid(oid))
1576                 return -1;
1577         return 0;
1578 }
1579
1580 struct ref_store_hash_entry
1581 {
1582         struct hashmap_entry ent; /* must be the first member! */
1583
1584         struct ref_store *refs;
1585
1586         /* NUL-terminated identifier of the ref store: */
1587         char name[FLEX_ARRAY];
1588 };
1589
1590 static int ref_store_hash_cmp(const void *unused_cmp_data,
1591                               const void *entry, const void *entry_or_key,
1592                               const void *keydata)
1593 {
1594         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1595         const char *name = keydata ? keydata : e2->name;
1596
1597         return strcmp(e1->name, name);
1598 }
1599
1600 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1601                 const char *name, struct ref_store *refs)
1602 {
1603         struct ref_store_hash_entry *entry;
1604
1605         FLEX_ALLOC_STR(entry, name, name);
1606         hashmap_entry_init(entry, strhash(name));
1607         entry->refs = refs;
1608         return entry;
1609 }
1610
1611 /* A hashmap of ref_stores, stored by submodule name: */
1612 static struct hashmap submodule_ref_stores;
1613
1614 /* A hashmap of ref_stores, stored by worktree id: */
1615 static struct hashmap worktree_ref_stores;
1616
1617 /*
1618  * Look up a ref store by name. If that ref_store hasn't been
1619  * registered yet, return NULL.
1620  */
1621 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1622                                               const char *name)
1623 {
1624         struct ref_store_hash_entry *entry;
1625
1626         if (!map->tablesize)
1627                 /* It's initialized on demand in register_ref_store(). */
1628                 return NULL;
1629
1630         entry = hashmap_get_from_hash(map, strhash(name), name);
1631         return entry ? entry->refs : NULL;
1632 }
1633
1634 /*
1635  * Create, record, and return a ref_store instance for the specified
1636  * gitdir.
1637  */
1638 static struct ref_store *ref_store_init(const char *gitdir,
1639                                         unsigned int flags)
1640 {
1641         const char *be_name = "files";
1642         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1643         struct ref_store *refs;
1644
1645         if (!be)
1646                 die("BUG: reference backend %s is unknown", be_name);
1647
1648         refs = be->init(gitdir, flags);
1649         return refs;
1650 }
1651
1652 struct ref_store *get_main_ref_store(struct repository *r)
1653 {
1654         if (r->refs)
1655                 return r->refs;
1656
1657         if (!r->gitdir)
1658                 BUG("attempting to get main_ref_store outside of repository");
1659
1660         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1661         return r->refs;
1662 }
1663
1664 /*
1665  * Associate a ref store with a name. It is a fatal error to call this
1666  * function twice for the same name.
1667  */
1668 static void register_ref_store_map(struct hashmap *map,
1669                                    const char *type,
1670                                    struct ref_store *refs,
1671                                    const char *name)
1672 {
1673         if (!map->tablesize)
1674                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1675
1676         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1677                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1678 }
1679
1680 struct ref_store *get_submodule_ref_store(const char *submodule)
1681 {
1682         struct strbuf submodule_sb = STRBUF_INIT;
1683         struct ref_store *refs;
1684         char *to_free = NULL;
1685         size_t len;
1686
1687         if (!submodule)
1688                 return NULL;
1689
1690         len = strlen(submodule);
1691         while (len && is_dir_sep(submodule[len - 1]))
1692                 len--;
1693         if (!len)
1694                 return NULL;
1695
1696         if (submodule[len])
1697                 /* We need to strip off one or more trailing slashes */
1698                 submodule = to_free = xmemdupz(submodule, len);
1699
1700         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1701         if (refs)
1702                 goto done;
1703
1704         strbuf_addstr(&submodule_sb, submodule);
1705         if (!is_nonbare_repository_dir(&submodule_sb))
1706                 goto done;
1707
1708         if (submodule_to_gitdir(&submodule_sb, submodule))
1709                 goto done;
1710
1711         /* assume that add_submodule_odb() has been called */
1712         refs = ref_store_init(submodule_sb.buf,
1713                               REF_STORE_READ | REF_STORE_ODB);
1714         register_ref_store_map(&submodule_ref_stores, "submodule",
1715                                refs, submodule);
1716
1717 done:
1718         strbuf_release(&submodule_sb);
1719         free(to_free);
1720
1721         return refs;
1722 }
1723
1724 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1725 {
1726         struct ref_store *refs;
1727         const char *id;
1728
1729         if (wt->is_current)
1730                 return get_main_ref_store(the_repository);
1731
1732         id = wt->id ? wt->id : "/";
1733         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1734         if (refs)
1735                 return refs;
1736
1737         if (wt->id)
1738                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1739                                       REF_STORE_ALL_CAPS);
1740         else
1741                 refs = ref_store_init(get_git_common_dir(),
1742                                       REF_STORE_ALL_CAPS);
1743
1744         if (refs)
1745                 register_ref_store_map(&worktree_ref_stores, "worktree",
1746                                        refs, id);
1747         return refs;
1748 }
1749
1750 void base_ref_store_init(struct ref_store *refs,
1751                          const struct ref_storage_be *be)
1752 {
1753         refs->be = be;
1754 }
1755
1756 /* backend functions */
1757 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1758 {
1759         return refs->be->pack_refs(refs, flags);
1760 }
1761
1762 int refs_peel_ref(struct ref_store *refs, const char *refname,
1763                   struct object_id *oid)
1764 {
1765         int flag;
1766         struct object_id base;
1767
1768         if (current_ref_iter && current_ref_iter->refname == refname) {
1769                 struct object_id peeled;
1770
1771                 if (ref_iterator_peel(current_ref_iter, &peeled))
1772                         return -1;
1773                 oidcpy(oid, &peeled);
1774                 return 0;
1775         }
1776
1777         if (refs_read_ref_full(refs, refname,
1778                                RESOLVE_REF_READING, &base, &flag))
1779                 return -1;
1780
1781         return peel_object(&base, oid);
1782 }
1783
1784 int peel_ref(const char *refname, struct object_id *oid)
1785 {
1786         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1787 }
1788
1789 int refs_create_symref(struct ref_store *refs,
1790                        const char *ref_target,
1791                        const char *refs_heads_master,
1792                        const char *logmsg)
1793 {
1794         return refs->be->create_symref(refs, ref_target,
1795                                        refs_heads_master,
1796                                        logmsg);
1797 }
1798
1799 int create_symref(const char *ref_target, const char *refs_heads_master,
1800                   const char *logmsg)
1801 {
1802         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1803                                   refs_heads_master, logmsg);
1804 }
1805
1806 int ref_update_reject_duplicates(struct string_list *refnames,
1807                                  struct strbuf *err)
1808 {
1809         size_t i, n = refnames->nr;
1810
1811         assert(err);
1812
1813         for (i = 1; i < n; i++) {
1814                 int cmp = strcmp(refnames->items[i - 1].string,
1815                                  refnames->items[i].string);
1816
1817                 if (!cmp) {
1818                         strbuf_addf(err,
1819                                     "multiple updates for ref '%s' not allowed.",
1820                                     refnames->items[i].string);
1821                         return 1;
1822                 } else if (cmp > 0) {
1823                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1824                 }
1825         }
1826         return 0;
1827 }
1828
1829 int ref_transaction_prepare(struct ref_transaction *transaction,
1830                             struct strbuf *err)
1831 {
1832         struct ref_store *refs = transaction->ref_store;
1833
1834         switch (transaction->state) {
1835         case REF_TRANSACTION_OPEN:
1836                 /* Good. */
1837                 break;
1838         case REF_TRANSACTION_PREPARED:
1839                 die("BUG: prepare called twice on reference transaction");
1840                 break;
1841         case REF_TRANSACTION_CLOSED:
1842                 die("BUG: prepare called on a closed reference transaction");
1843                 break;
1844         default:
1845                 die("BUG: unexpected reference transaction state");
1846                 break;
1847         }
1848
1849         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1850                 strbuf_addstr(err,
1851                               _("ref updates forbidden inside quarantine environment"));
1852                 return -1;
1853         }
1854
1855         return refs->be->transaction_prepare(refs, transaction, err);
1856 }
1857
1858 int ref_transaction_abort(struct ref_transaction *transaction,
1859                           struct strbuf *err)
1860 {
1861         struct ref_store *refs = transaction->ref_store;
1862         int ret = 0;
1863
1864         switch (transaction->state) {
1865         case REF_TRANSACTION_OPEN:
1866                 /* No need to abort explicitly. */
1867                 break;
1868         case REF_TRANSACTION_PREPARED:
1869                 ret = refs->be->transaction_abort(refs, transaction, err);
1870                 break;
1871         case REF_TRANSACTION_CLOSED:
1872                 die("BUG: abort called on a closed reference transaction");
1873                 break;
1874         default:
1875                 die("BUG: unexpected reference transaction state");
1876                 break;
1877         }
1878
1879         ref_transaction_free(transaction);
1880         return ret;
1881 }
1882
1883 int ref_transaction_commit(struct ref_transaction *transaction,
1884                            struct strbuf *err)
1885 {
1886         struct ref_store *refs = transaction->ref_store;
1887         int ret;
1888
1889         switch (transaction->state) {
1890         case REF_TRANSACTION_OPEN:
1891                 /* Need to prepare first. */
1892                 ret = ref_transaction_prepare(transaction, err);
1893                 if (ret)
1894                         return ret;
1895                 break;
1896         case REF_TRANSACTION_PREPARED:
1897                 /* Fall through to finish. */
1898                 break;
1899         case REF_TRANSACTION_CLOSED:
1900                 die("BUG: commit called on a closed reference transaction");
1901                 break;
1902         default:
1903                 die("BUG: unexpected reference transaction state");
1904                 break;
1905         }
1906
1907         return refs->be->transaction_finish(refs, transaction, err);
1908 }
1909
1910 int refs_verify_refname_available(struct ref_store *refs,
1911                                   const char *refname,
1912                                   const struct string_list *extras,
1913                                   const struct string_list *skip,
1914                                   struct strbuf *err)
1915 {
1916         const char *slash;
1917         const char *extra_refname;
1918         struct strbuf dirname = STRBUF_INIT;
1919         struct strbuf referent = STRBUF_INIT;
1920         struct object_id oid;
1921         unsigned int type;
1922         struct ref_iterator *iter;
1923         int ok;
1924         int ret = -1;
1925
1926         /*
1927          * For the sake of comments in this function, suppose that
1928          * refname is "refs/foo/bar".
1929          */
1930
1931         assert(err);
1932
1933         strbuf_grow(&dirname, strlen(refname) + 1);
1934         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1935                 /* Expand dirname to the new prefix, not including the trailing slash: */
1936                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1937
1938                 /*
1939                  * We are still at a leading dir of the refname (e.g.,
1940                  * "refs/foo"; if there is a reference with that name,
1941                  * it is a conflict, *unless* it is in skip.
1942                  */
1943                 if (skip && string_list_has_string(skip, dirname.buf))
1944                         continue;
1945
1946                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1947                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1948                                     dirname.buf, refname);
1949                         goto cleanup;
1950                 }
1951
1952                 if (extras && string_list_has_string(extras, dirname.buf)) {
1953                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1954                                     refname, dirname.buf);
1955                         goto cleanup;
1956                 }
1957         }
1958
1959         /*
1960          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1961          * There is no point in searching for a reference with that
1962          * name, because a refname isn't considered to conflict with
1963          * itself. But we still need to check for references whose
1964          * names are in the "refs/foo/bar/" namespace, because they
1965          * *do* conflict.
1966          */
1967         strbuf_addstr(&dirname, refname + dirname.len);
1968         strbuf_addch(&dirname, '/');
1969
1970         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1971                                        DO_FOR_EACH_INCLUDE_BROKEN);
1972         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1973                 if (skip &&
1974                     string_list_has_string(skip, iter->refname))
1975                         continue;
1976
1977                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1978                             iter->refname, refname);
1979                 ref_iterator_abort(iter);
1980                 goto cleanup;
1981         }
1982
1983         if (ok != ITER_DONE)
1984                 die("BUG: error while iterating over references");
1985
1986         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1987         if (extra_refname)
1988                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1989                             refname, extra_refname);
1990         else
1991                 ret = 0;
1992
1993 cleanup:
1994         strbuf_release(&referent);
1995         strbuf_release(&dirname);
1996         return ret;
1997 }
1998
1999 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2000 {
2001         struct ref_iterator *iter;
2002
2003         iter = refs->be->reflog_iterator_begin(refs);
2004
2005         return do_for_each_ref_iterator(iter, fn, cb_data);
2006 }
2007
2008 int for_each_reflog(each_ref_fn fn, void *cb_data)
2009 {
2010         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2011 }
2012
2013 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2014                                      const char *refname,
2015                                      each_reflog_ent_fn fn,
2016                                      void *cb_data)
2017 {
2018         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2019                                                      fn, cb_data);
2020 }
2021
2022 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2023                                 void *cb_data)
2024 {
2025         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2026                                                 refname, fn, cb_data);
2027 }
2028
2029 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2030                              each_reflog_ent_fn fn, void *cb_data)
2031 {
2032         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2033 }
2034
2035 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2036                         void *cb_data)
2037 {
2038         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2039                                         fn, cb_data);
2040 }
2041
2042 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2043 {
2044         return refs->be->reflog_exists(refs, refname);
2045 }
2046
2047 int reflog_exists(const char *refname)
2048 {
2049         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2050 }
2051
2052 int refs_create_reflog(struct ref_store *refs, const char *refname,
2053                        int force_create, struct strbuf *err)
2054 {
2055         return refs->be->create_reflog(refs, refname, force_create, err);
2056 }
2057
2058 int safe_create_reflog(const char *refname, int force_create,
2059                        struct strbuf *err)
2060 {
2061         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2062                                   force_create, err);
2063 }
2064
2065 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2066 {
2067         return refs->be->delete_reflog(refs, refname);
2068 }
2069
2070 int delete_reflog(const char *refname)
2071 {
2072         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2073 }
2074
2075 int refs_reflog_expire(struct ref_store *refs,
2076                        const char *refname, const struct object_id *oid,
2077                        unsigned int flags,
2078                        reflog_expiry_prepare_fn prepare_fn,
2079                        reflog_expiry_should_prune_fn should_prune_fn,
2080                        reflog_expiry_cleanup_fn cleanup_fn,
2081                        void *policy_cb_data)
2082 {
2083         return refs->be->reflog_expire(refs, refname, oid, flags,
2084                                        prepare_fn, should_prune_fn,
2085                                        cleanup_fn, policy_cb_data);
2086 }
2087
2088 int reflog_expire(const char *refname, const struct object_id *oid,
2089                   unsigned int flags,
2090                   reflog_expiry_prepare_fn prepare_fn,
2091                   reflog_expiry_should_prune_fn should_prune_fn,
2092                   reflog_expiry_cleanup_fn cleanup_fn,
2093                   void *policy_cb_data)
2094 {
2095         return refs_reflog_expire(get_main_ref_store(the_repository),
2096                                   refname, oid, flags,
2097                                   prepare_fn, should_prune_fn,
2098                                   cleanup_fn, policy_cb_data);
2099 }
2100
2101 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2102                                    struct strbuf *err)
2103 {
2104         struct ref_store *refs = transaction->ref_store;
2105
2106         return refs->be->initial_transaction_commit(refs, transaction, err);
2107 }
2108
2109 int refs_delete_refs(struct ref_store *refs, const char *msg,
2110                      struct string_list *refnames, unsigned int flags)
2111 {
2112         return refs->be->delete_refs(refs, msg, refnames, flags);
2113 }
2114
2115 int delete_refs(const char *msg, struct string_list *refnames,
2116                 unsigned int flags)
2117 {
2118         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2119 }
2120
2121 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2122                     const char *newref, const char *logmsg)
2123 {
2124         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2125 }
2126
2127 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2128 {
2129         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2130 }
2131
2132 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2133                     const char *newref, const char *logmsg)
2134 {
2135         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2136 }
2137
2138 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2139 {
2140         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2141 }