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.h"
  13 #include "tag.h"
  14 #include "submodule.h"
  15 #include "worktree.h"
  16
  17 /*
  18  * List of all available backends
  19  */
  20 static struct ref_storage_be *refs_backends = &refs_be_files;
  21
  22 static struct ref_storage_be *find_ref_storage_backend(const char *name)
  23 {
  24         struct ref_storage_be *be;
  25         for (be = refs_backends; be; be = be->next)
  26                 if (!strcmp(be->name, name))
  27                         return be;
  28         return NULL;
  29 }
  30
  31 int ref_storage_backend_exists(const char *name)
  32 {
  33         return find_ref_storage_backend(name) != NULL;
  34 }
  35
  36 /*
  37  * How to handle various characters in refnames:
  38  * 0: An acceptable character for refs
  39  * 1: End-of-component
  40  * 2: ., look for a preceding . to reject .. in refs
  41  * 3: {, look for a preceding @ to reject @{ in refs
  42  * 4: A bad character: ASCII control characters, and
  43  *    ":", "?", "[", "\", "^", "~", SP, or TAB
  44  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  45  */
  46 static unsigned char refname_disposition[256] = {
  47         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  48         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  49         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
  50         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
  51         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  52         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
  53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  54         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
  55 };
  56
  57 /*
  58  * Try to read one refname component from the front of refname.
  59  * Return the length of the component found, or -1 if the component is
  60  * not legal.  It is legal if it is something reasonable to have under
  61  * ".git/refs/"; We do not like it if:
  62  *
  63  * - any path component of it begins with ".", or
  64  * - it has double dots "..", or
  65  * - it has ASCII control characters, or
  66  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
  67  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
  68  * - it ends with a "/", or
  69  * - it ends with ".lock", or
  70  * - it contains a "@{" portion
  71  */
  72 static int check_refname_component(const char *refname, int *flags)
  73 {
  74         const char *cp;
  75         char last = '\0';
  76
  77         for (cp = refname; ; cp++) {
  78                 int ch = *cp & 255;
  79                 unsigned char disp = refname_disposition[ch];
  80                 switch (disp) {
  81                 case 1:
  82                         goto out;
  83                 case 2:
  84                         if (last == '.')
  85                                 return -1; /* Refname contains "..". */
  86                         break;
  87                 case 3:
  88                         if (last == '@')
  89                                 return -1; /* Refname contains "@{". */
  90                         break;
  91                 case 4:
  92                         return -1;
  93                 case 5:
  94                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
  95                                 return -1; /* refspec can't be a pattern */
  96
  97                         /*
  98                          * Unset the pattern flag so that we only accept
  99                          * a single asterisk for one side of refspec.
 100                          */
 101                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
 102                         break;
 103                 }
 104                 last = ch;
 105         }
 106 out:
 107         if (cp == refname)
 108                 return 0; /* Component has zero length. */
 109         if (refname[0] == '.')
 110                 return -1; /* Component starts with '.'. */
 111         if (cp - refname >= LOCK_SUFFIX_LEN &&
 112             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
 113                 return -1; /* Refname ends with ".lock". */
 114         return cp - refname;
 115 }
 116
 117 int check_refname_format(const char *refname, int flags)
 118 {
 119         int component_len, component_count = 0;
 120
 121         if (!strcmp(refname, "@"))
 122                 /* Refname is a single character '@'. */
 123                 return -1;
 124
 125         while (1) {
 126                 /* We are at the start of a path component. */
 127                 component_len = check_refname_component(refname, &flags);
 128                 if (component_len <= 0)
 129                         return -1;
 130
 131                 component_count++;
 132                 if (refname[component_len] == '\0')
 133                         break;
 134                 /* Skip to next component. */
 135                 refname += component_len + 1;
 136         }
 137
 138         if (refname[component_len - 1] == '.')
 139                 return -1; /* Refname ends with '.'. */
 140         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
 141                 return -1; /* Refname has only one component. */
 142         return 0;
 143 }
 144
 145 int refname_is_safe(const char *refname)
 146 {
 147         const char *rest;
 148
 149         if (skip_prefix(refname, "refs/", &rest)) {
 150                 char *buf;
 151                 int result;
 152                 size_t restlen = strlen(rest);
 153
 154                 /* rest must not be empty, or start or end with "/" */
 155                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
 156                         return 0;
 157
 158                 /*
 159                  * Does the refname try to escape refs/?
 160                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
 161                  * is not.
 162                  */
 163                 buf = xmallocz(restlen);
 164                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
 165                 free(buf);
 166                 return result;
 167         }
 168
 169         do {
 170                 if (!isupper(*refname) && *refname != '_')
 171                         return 0;
 172                 refname++;
 173         } while (*refname);
 174         return 1;
 175 }
 176
 177 /*
 178  * Return true if refname, which has the specified oid and flags, can
 179  * be resolved to an object in the database. If the referred-to object
 180  * does not exist, emit a warning and return false.
 181  */
 182 int ref_resolves_to_object(const char *refname,
 183                            const struct object_id *oid,
 184                            unsigned int flags)
 185 {
 186         if (flags & REF_ISBROKEN)
 187                 return 0;
 188         if (!has_sha1_file(oid->hash)) {
 189                 error("%s does not point to a valid object!", refname);
 190                 return 0;
 191         }
 192         return 1;
 193 }
 194
 195 char *refs_resolve_refdup(struct ref_store *refs,
 196                           const char *refname, int resolve_flags,
 197                           struct object_id *oid, int *flags)
 198 {
 199         const char *result;
 200
 201         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
 202                                          oid, flags);
 203         return xstrdup_or_null(result);
 204 }
 205
 206 char *resolve_refdup(const char *refname, int resolve_flags,
 207                      struct object_id *oid, int *flags)
 208 {
 209         return refs_resolve_refdup(get_main_ref_store(),
 210                                    refname, resolve_flags,
 211                                    oid, flags);
 212 }
 213
 214 /* The argument to filter_refs */
 215 struct ref_filter {
 216         const char *pattern;
 217         each_ref_fn *fn;
 218         void *cb_data;
 219 };
 220
 221 int refs_read_ref_full(struct ref_store *refs, const char *refname,
 222                        int resolve_flags, struct object_id *oid, int *flags)
 223 {
 224         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
 225                 return 0;
 226         return -1;
 227 }
 228
 229 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 230 {
 231         return refs_read_ref_full(get_main_ref_store(), refname,
 232                                   resolve_flags, oid, flags);
 233 }
 234
 235 int read_ref(const char *refname, struct object_id *oid)
 236 {
 237         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
 238 }
 239
 240 int ref_exists(const char *refname)
 241 {
 242         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
 243 }
 244
 245 static int match_ref_pattern(const char *refname,
 246                              const struct string_list_item *item)
 247 {
 248         int matched = 0;
 249         if (item->util == NULL) {
 250                 if (!wildmatch(item->string, refname, 0))
 251                         matched = 1;
 252         } else {
 253                 const char *rest;
 254                 if (skip_prefix(refname, item->string, &rest) &&
 255                     (!*rest || *rest == '/'))
 256                         matched = 1;
 257         }
 258         return matched;
 259 }
 260
 261 int ref_filter_match(const char *refname,
 262                      const struct string_list *include_patterns,
 263                      const struct string_list *exclude_patterns)
 264 {
 265         struct string_list_item *item;
 266
 267         if (exclude_patterns && exclude_patterns->nr) {
 268                 for_each_string_list_item(item, exclude_patterns) {
 269                         if (match_ref_pattern(refname, item))
 270                                 return 0;
 271                 }
 272         }
 273
 274         if (include_patterns && include_patterns->nr) {
 275                 int found = 0;
 276                 for_each_string_list_item(item, include_patterns) {
 277                         if (match_ref_pattern(refname, item)) {
 278                                 found = 1;
 279                                 break;
 280                         }
 281                 }
 282
 283                 if (!found)
 284                         return 0;
 285         }
 286         return 1;
 287 }
 288
 289 static int filter_refs(const char *refname, const struct object_id *oid,
 290                            int flags, void *data)
 291 {
 292         struct ref_filter *filter = (struct ref_filter *)data;
 293
 294         if (wildmatch(filter->pattern, refname, 0))
 295                 return 0;
 296         return filter->fn(refname, oid, flags, filter->cb_data);
 297 }
 298
 299 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
 300 {
 301         struct object *o = lookup_unknown_object(name->hash);
 302
 303         if (o->type == OBJ_NONE) {
 304                 int type = oid_object_info(name, NULL);
 305                 if (type < 0 || !object_as_type(o, type, 0))
 306                         return PEEL_INVALID;
 307         }
 308
 309         if (o->type != OBJ_TAG)
 310                 return PEEL_NON_TAG;
 311
 312         o = deref_tag_noverify(o);
 313         if (!o)
 314                 return PEEL_INVALID;
 315
 316         oidcpy(oid, &o->oid);
 317         return PEEL_PEELED;
 318 }
 319
 320 struct warn_if_dangling_data {
 321         FILE *fp;
 322         const char *refname;
 323         const struct string_list *refnames;
 324         const char *msg_fmt;
 325 };
 326
 327 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
 328                                    int flags, void *cb_data)
 329 {
 330         struct warn_if_dangling_data *d = cb_data;
 331         const char *resolves_to;
 332
 333         if (!(flags & REF_ISSYMREF))
 334                 return 0;
 335
 336         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
 337         if (!resolves_to
 338             || (d->refname
 339                 ? strcmp(resolves_to, d->refname)
 340                 : !string_list_has_string(d->refnames, resolves_to))) {
 341                 return 0;
 342         }
 343
 344         fprintf(d->fp, d->msg_fmt, refname);
 345         fputc('\n', d->fp);
 346         return 0;
 347 }
 348
 349 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 350 {
 351         struct warn_if_dangling_data data;
 352
 353         data.fp = fp;
 354         data.refname = refname;
 355         data.refnames = NULL;
 356         data.msg_fmt = msg_fmt;
 357         for_each_rawref(warn_if_dangling_symref, &data);
 358 }
 359
 360 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
 361 {
 362         struct warn_if_dangling_data data;
 363
 364         data.fp = fp;
 365         data.refname = NULL;
 366         data.refnames = refnames;
 367         data.msg_fmt = msg_fmt;
 368         for_each_rawref(warn_if_dangling_symref, &data);
 369 }
 370
 371 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 372 {
 373         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
 374 }
 375
 376 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 377 {
 378         return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
 379 }
 380
 381 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 382 {
 383         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
 384 }
 385
 386 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 387 {
 388         return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
 389 }
 390
 391 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 392 {
 393         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
 394 }
 395
 396 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 397 {
 398         return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
 399 }
 400
 401 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 402 {
 403         struct strbuf buf = STRBUF_INIT;
 404         int ret = 0;
 405         struct object_id oid;
 406         int flag;
 407
 408         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
 409         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
 410                 ret = fn(buf.buf, &oid, flag, cb_data);
 411         strbuf_release(&buf);
 412
 413         return ret;
 414 }
 415
 416 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
 417                         const char *pattern)
 418 {
 419         struct strbuf normalized_pattern = STRBUF_INIT;
 420
 421         if (*pattern == '/')
 422                 BUG("pattern must not start with '/'");
 423
 424         if (prefix) {
 425                 strbuf_addstr(&normalized_pattern, prefix);
 426         }
 427         else if (!starts_with(pattern, "refs/"))
 428                 strbuf_addstr(&normalized_pattern, "refs/");
 429         strbuf_addstr(&normalized_pattern, pattern);
 430         strbuf_strip_suffix(&normalized_pattern, "/");
 431
 432         item->string = strbuf_detach(&normalized_pattern, NULL);
 433         item->util = has_glob_specials(pattern) ? NULL : item->string;
 434         strbuf_release(&normalized_pattern);
 435 }
 436
 437 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 438         const char *prefix, void *cb_data)
 439 {
 440         struct strbuf real_pattern = STRBUF_INIT;
 441         struct ref_filter filter;
 442         int ret;
 443
 444         if (!prefix && !starts_with(pattern, "refs/"))
 445                 strbuf_addstr(&real_pattern, "refs/");
 446         else if (prefix)
 447                 strbuf_addstr(&real_pattern, prefix);
 448         strbuf_addstr(&real_pattern, pattern);
 449
 450         if (!has_glob_specials(pattern)) {
 451                 /* Append implied '/' '*' if not present. */
 452                 strbuf_complete(&real_pattern, '/');
 453                 /* No need to check for '*', there is none. */
 454                 strbuf_addch(&real_pattern, '*');
 455         }
 456
 457         filter.pattern = real_pattern.buf;
 458         filter.fn = fn;
 459         filter.cb_data = cb_data;
 460         ret = for_each_ref(filter_refs, &filter);
 461
 462         strbuf_release(&real_pattern);
 463         return ret;
 464 }
 465
 466 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
 467 {
 468         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
 469 }
 470
 471 const char *prettify_refname(const char *name)
 472 {
 473         if (skip_prefix(name, "refs/heads/", &name) ||
 474             skip_prefix(name, "refs/tags/", &name) ||
 475             skip_prefix(name, "refs/remotes/", &name))
 476                 ; /* nothing */
 477         return name;
 478 }
 479
 480 static const char *ref_rev_parse_rules[] = {
 481         "%.*s",
 482         "refs/%.*s",
 483         "refs/tags/%.*s",
 484         "refs/heads/%.*s",
 485         "refs/remotes/%.*s",
 486         "refs/remotes/%.*s/HEAD",
 487         NULL
 488 };
 489
 490 int refname_match(const char *abbrev_name, const char *full_name)
 491 {
 492         const char **p;
 493         const int abbrev_name_len = strlen(abbrev_name);
 494
 495         for (p = ref_rev_parse_rules; *p; p++) {
 496                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 497                         return 1;
 498                 }
 499         }
 500
 501         return 0;
 502 }
 503
 504 /*
 505  * *string and *len will only be substituted, and *string returned (for
 506  * later free()ing) if the string passed in is a magic short-hand form
 507  * to name a branch.
 508  */
 509 static char *substitute_branch_name(const char **string, int *len)
 510 {
 511         struct strbuf buf = STRBUF_INIT;
 512         int ret = interpret_branch_name(*string, *len, &buf, 0);
 513
 514         if (ret == *len) {
 515                 size_t size;
 516                 *string = strbuf_detach(&buf, &size);
 517                 *len = size;
 518                 return (char *)*string;
 519         }
 520
 521         return NULL;
 522 }
 523
 524 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
 525 {
 526         char *last_branch = substitute_branch_name(&str, &len);
 527         int   refs_found  = expand_ref(str, len, oid, ref);
 528         free(last_branch);
 529         return refs_found;
 530 }
 531
 532 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
 533 {
 534         const char **p, *r;
 535         int refs_found = 0;
 536         struct strbuf fullref = STRBUF_INIT;
 537
 538         *ref = NULL;
 539         for (p = ref_rev_parse_rules; *p; p++) {
 540                 struct object_id oid_from_ref;
 541                 struct object_id *this_result;
 542                 int flag;
 543
 544                 this_result = refs_found ? &oid_from_ref : oid;
 545                 strbuf_reset(&fullref);
 546                 strbuf_addf(&fullref, *p, len, str);
 547                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
 548                                        this_result, &flag);
 549                 if (r) {
 550                         if (!refs_found++)
 551                                 *ref = xstrdup(r);
 552                         if (!warn_ambiguous_refs)
 553                                 break;
 554                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
 555                         warning("ignoring dangling symref %s.", fullref.buf);
 556                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
 557                         warning("ignoring broken ref %s.", fullref.buf);
 558                 }
 559         }
 560         strbuf_release(&fullref);
 561         return refs_found;
 562 }
 563
 564 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 565 {
 566         char *last_branch = substitute_branch_name(&str, &len);
 567         const char **p;
 568         int logs_found = 0;
 569         struct strbuf path = STRBUF_INIT;
 570
 571         *log = NULL;
 572         for (p = ref_rev_parse_rules; *p; p++) {
 573                 struct object_id hash;
 574                 const char *ref, *it;
 575
 576                 strbuf_reset(&path);
 577                 strbuf_addf(&path, *p, len, str);
 578                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
 579                                          &hash, NULL);
 580                 if (!ref)
 581                         continue;
 582                 if (reflog_exists(path.buf))
 583                         it = path.buf;
 584                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
 585                         it = ref;
 586                 else
 587                         continue;
 588                 if (!logs_found++) {
 589                         *log = xstrdup(it);
 590                         oidcpy(oid, &hash);
 591                 }
 592                 if (!warn_ambiguous_refs)
 593                         break;
 594         }
 595         strbuf_release(&path);
 596         free(last_branch);
 597         return logs_found;
 598 }
 599
 600 static int is_per_worktree_ref(const char *refname)
 601 {
 602         return !strcmp(refname, "HEAD") ||
 603                 starts_with(refname, "refs/bisect/");
 604 }
 605
 606 static int is_pseudoref_syntax(const char *refname)
 607 {
 608         const char *c;
 609
 610         for (c = refname; *c; c++) {
 611                 if (!isupper(*c) && *c != '-' && *c != '_')
 612                         return 0;
 613         }
 614
 615         return 1;
 616 }
 617
 618 enum ref_type ref_type(const char *refname)
 619 {
 620         if (is_per_worktree_ref(refname))
 621                 return REF_TYPE_PER_WORKTREE;
 622         if (is_pseudoref_syntax(refname))
 623                 return REF_TYPE_PSEUDOREF;
 624        return REF_TYPE_NORMAL;
 625 }
 626
 627 long get_files_ref_lock_timeout_ms(void)
 628 {
 629         static int configured = 0;
 630
 631         /* The default timeout is 100 ms: */
 632         static int timeout_ms = 100;
 633
 634         if (!configured) {
 635                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 636                 configured = 1;
 637         }
 638
 639         return timeout_ms;
 640 }
 641
 642 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
 643                            const struct object_id *old_oid, struct strbuf *err)
 644 {
 645         const char *filename;
 646         int fd;
 647         static struct lock_file lock;
 648         struct strbuf buf = STRBUF_INIT;
 649         int ret = -1;
 650
 651         if (!oid)
 652                 return 0;
 653
 654         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 655
 656         filename = git_path("%s", pseudoref);
 657         fd = hold_lock_file_for_update_timeout(&lock, filename,
 658                                                LOCK_DIE_ON_ERROR,
 659                                                get_files_ref_lock_timeout_ms());
 660         if (fd < 0) {
 661                 strbuf_addf(err, "could not open '%s' for writing: %s",
 662                             filename, strerror(errno));
 663                 goto done;
 664         }
 665
 666         if (old_oid) {
 667                 struct object_id actual_old_oid;
 668
 669                 if (read_ref(pseudoref, &actual_old_oid))
 670                         die("could not read ref '%s'", pseudoref);
 671                 if (oidcmp(&actual_old_oid, old_oid)) {
 672                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 673                         rollback_lock_file(&lock);
 674                         goto done;
 675                 }
 676         }
 677
 678         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 679                 strbuf_addf(err, "could not write to '%s'", filename);
 680                 rollback_lock_file(&lock);
 681                 goto done;
 682         }
 683
 684         commit_lock_file(&lock);
 685         ret = 0;
 686 done:
 687         strbuf_release(&buf);
 688         return ret;
 689 }
 690
 691 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 692 {
 693         static struct lock_file lock;
 694         const char *filename;
 695
 696         filename = git_path("%s", pseudoref);
 697
 698         if (old_oid && !is_null_oid(old_oid)) {
 699                 int fd;
 700                 struct object_id actual_old_oid;
 701
 702                 fd = hold_lock_file_for_update_timeout(
 703                                 &lock, filename, LOCK_DIE_ON_ERROR,
 704                                 get_files_ref_lock_timeout_ms());
 705                 if (fd < 0)
 706                         die_errno(_("Could not open '%s' for writing"), filename);
 707                 if (read_ref(pseudoref, &actual_old_oid))
 708                         die("could not read ref '%s'", pseudoref);
 709                 if (oidcmp(&actual_old_oid, old_oid)) {
 710                         warning("Unexpected sha1 when deleting %s", pseudoref);
 711                         rollback_lock_file(&lock);
 712                         return -1;
 713                 }
 714
 715                 unlink(filename);
 716                 rollback_lock_file(&lock);
 717         } else {
 718                 unlink(filename);
 719         }
 720
 721         return 0;
 722 }
 723
 724 int refs_delete_ref(struct ref_store *refs, const char *msg,
 725                     const char *refname,
 726                     const struct object_id *old_oid,
 727                     unsigned int flags)
 728 {
 729         struct ref_transaction *transaction;
 730         struct strbuf err = STRBUF_INIT;
 731
 732         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 733                 assert(refs == get_main_ref_store());
 734                 return delete_pseudoref(refname, old_oid);
 735         }
 736
 737         transaction = ref_store_transaction_begin(refs, &err);
 738         if (!transaction ||
 739             ref_transaction_delete(transaction, refname, old_oid,
 740                                    flags, msg, &err) ||
 741             ref_transaction_commit(transaction, &err)) {
 742                 error("%s", err.buf);
 743                 ref_transaction_free(transaction);
 744                 strbuf_release(&err);
 745                 return 1;
 746         }
 747         ref_transaction_free(transaction);
 748         strbuf_release(&err);
 749         return 0;
 750 }
 751
 752 int delete_ref(const char *msg, const char *refname,
 753                const struct object_id *old_oid, unsigned int flags)
 754 {
 755         return refs_delete_ref(get_main_ref_store(), msg, refname,
 756                                old_oid, flags);
 757 }
 758
 759 int copy_reflog_msg(char *buf, const char *msg)
 760 {
 761         char *cp = buf;
 762         char c;
 763         int wasspace = 1;
 764
 765         *cp++ = '\t';
 766         while ((c = *msg++)) {
 767                 if (wasspace && isspace(c))
 768                         continue;
 769                 wasspace = isspace(c);
 770                 if (wasspace)
 771                         c = ' ';
 772                 *cp++ = c;
 773         }
 774         while (buf < cp && isspace(cp[-1]))
 775                 cp--;
 776         *cp++ = '\n';
 777         return cp - buf;
 778 }
 779
 780 int should_autocreate_reflog(const char *refname)
 781 {
 782         switch (log_all_ref_updates) {
 783         case LOG_REFS_ALWAYS:
 784                 return 1;
 785         case LOG_REFS_NORMAL:
 786                 return starts_with(refname, "refs/heads/") ||
 787                         starts_with(refname, "refs/remotes/") ||
 788                         starts_with(refname, "refs/notes/") ||
 789                         !strcmp(refname, "HEAD");
 790         default:
 791                 return 0;
 792         }
 793 }
 794
 795 int is_branch(const char *refname)
 796 {
 797         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 798 }
 799
 800 struct read_ref_at_cb {
 801         const char *refname;
 802         timestamp_t at_time;
 803         int cnt;
 804         int reccnt;
 805         struct object_id *oid;
 806         int found_it;
 807
 808         struct object_id ooid;
 809         struct object_id noid;
 810         int tz;
 811         timestamp_t date;
 812         char **msg;
 813         timestamp_t *cutoff_time;
 814         int *cutoff_tz;
 815         int *cutoff_cnt;
 816 };
 817
 818 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 819                 const char *email, timestamp_t timestamp, int tz,
 820                 const char *message, void *cb_data)
 821 {
 822         struct read_ref_at_cb *cb = cb_data;
 823
 824         cb->reccnt++;
 825         cb->tz = tz;
 826         cb->date = timestamp;
 827
 828         if (timestamp <= cb->at_time || cb->cnt == 0) {
 829                 if (cb->msg)
 830                         *cb->msg = xstrdup(message);
 831                 if (cb->cutoff_time)
 832                         *cb->cutoff_time = timestamp;
 833                 if (cb->cutoff_tz)
 834                         *cb->cutoff_tz = tz;
 835                 if (cb->cutoff_cnt)
 836                         *cb->cutoff_cnt = cb->reccnt - 1;
 837                 /*
 838                  * we have not yet updated cb->[n|o]oid so they still
 839                  * hold the values for the previous record.
 840                  */
 841                 if (!is_null_oid(&cb->ooid)) {
 842                         oidcpy(cb->oid, noid);
 843                         if (oidcmp(&cb->ooid, noid))
 844                                 warning("Log for ref %s has gap after %s.",
 845                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 846                 }
 847                 else if (cb->date == cb->at_time)
 848                         oidcpy(cb->oid, noid);
 849                 else if (oidcmp(noid, cb->oid))
 850                         warning("Log for ref %s unexpectedly ended on %s.",
 851                                 cb->refname, show_date(cb->date, cb->tz,
 852                                                        DATE_MODE(RFC2822)));
 853                 oidcpy(&cb->ooid, ooid);
 854                 oidcpy(&cb->noid, noid);
 855                 cb->found_it = 1;
 856                 return 1;
 857         }
 858         oidcpy(&cb->ooid, ooid);
 859         oidcpy(&cb->noid, noid);
 860         if (cb->cnt > 0)
 861                 cb->cnt--;
 862         return 0;
 863 }
 864
 865 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 866                                   const char *email, timestamp_t timestamp,
 867                                   int tz, const char *message, void *cb_data)
 868 {
 869         struct read_ref_at_cb *cb = cb_data;
 870
 871         if (cb->msg)
 872                 *cb->msg = xstrdup(message);
 873         if (cb->cutoff_time)
 874                 *cb->cutoff_time = timestamp;
 875         if (cb->cutoff_tz)
 876                 *cb->cutoff_tz = tz;
 877         if (cb->cutoff_cnt)
 878                 *cb->cutoff_cnt = cb->reccnt;
 879         oidcpy(cb->oid, ooid);
 880         if (is_null_oid(cb->oid))
 881                 oidcpy(cb->oid, noid);
 882         /* We just want the first entry */
 883         return 1;
 884 }
 885
 886 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 887                 struct object_id *oid, char **msg,
 888                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 889 {
 890         struct read_ref_at_cb cb;
 891
 892         memset(&cb, 0, sizeof(cb));
 893         cb.refname = refname;
 894         cb.at_time = at_time;
 895         cb.cnt = cnt;
 896         cb.msg = msg;
 897         cb.cutoff_time = cutoff_time;
 898         cb.cutoff_tz = cutoff_tz;
 899         cb.cutoff_cnt = cutoff_cnt;
 900         cb.oid = oid;
 901
 902         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 903
 904         if (!cb.reccnt) {
 905                 if (flags & GET_OID_QUIETLY)
 906                         exit(128);
 907                 else
 908                         die("Log for %s is empty.", refname);
 909         }
 910         if (cb.found_it)
 911                 return 0;
 912
 913         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 914
 915         return 1;
 916 }
 917
 918 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 919                                                     struct strbuf *err)
 920 {
 921         struct ref_transaction *tr;
 922         assert(err);
 923
 924         tr = xcalloc(1, sizeof(struct ref_transaction));
 925         tr->ref_store = refs;
 926         return tr;
 927 }
 928
 929 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 930 {
 931         return ref_store_transaction_begin(get_main_ref_store(), err);
 932 }
 933
 934 void ref_transaction_free(struct ref_transaction *transaction)
 935 {
 936         size_t i;
 937
 938         if (!transaction)
 939                 return;
 940
 941         switch (transaction->state) {
 942         case REF_TRANSACTION_OPEN:
 943         case REF_TRANSACTION_CLOSED:
 944                 /* OK */
 945                 break;
 946         case REF_TRANSACTION_PREPARED:
 947                 die("BUG: free called on a prepared reference transaction");
 948                 break;
 949         default:
 950                 die("BUG: unexpected reference transaction state");
 951                 break;
 952         }
 953
 954         for (i = 0; i < transaction->nr; i++) {
 955                 free(transaction->updates[i]->msg);
 956                 free(transaction->updates[i]);
 957         }
 958         free(transaction->updates);
 959         free(transaction);
 960 }
 961
 962 struct ref_update *ref_transaction_add_update(
 963                 struct ref_transaction *transaction,
 964                 const char *refname, unsigned int flags,
 965                 const struct object_id *new_oid,
 966                 const struct object_id *old_oid,
 967                 const char *msg)
 968 {
 969         struct ref_update *update;
 970
 971         if (transaction->state != REF_TRANSACTION_OPEN)
 972                 die("BUG: update called for transaction that is not open");
 973
 974         FLEX_ALLOC_STR(update, refname, refname);
 975         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 976         transaction->updates[transaction->nr++] = update;
 977
 978         update->flags = flags;
 979
 980         if (flags & REF_HAVE_NEW)
 981                 oidcpy(&update->new_oid, new_oid);
 982         if (flags & REF_HAVE_OLD)
 983                 oidcpy(&update->old_oid, old_oid);
 984         update->msg = xstrdup_or_null(msg);
 985         return update;
 986 }
 987
 988 int ref_transaction_update(struct ref_transaction *transaction,
 989                            const char *refname,
 990                            const struct object_id *new_oid,
 991                            const struct object_id *old_oid,
 992                            unsigned int flags, const char *msg,
 993                            struct strbuf *err)
 994 {
 995         assert(err);
 996
 997         if ((new_oid && !is_null_oid(new_oid)) ?
 998             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
 999             !refname_is_safe(refname)) {
1000                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1001                             refname);
1002                 return -1;
1003         }
1004
1005         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1006                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1007
1008         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1009
1010         ref_transaction_add_update(transaction, refname, flags,
1011                                    new_oid, old_oid, msg);
1012         return 0;
1013 }
1014
1015 int ref_transaction_create(struct ref_transaction *transaction,
1016                            const char *refname,
1017                            const struct object_id *new_oid,
1018                            unsigned int flags, const char *msg,
1019                            struct strbuf *err)
1020 {
1021         if (!new_oid || is_null_oid(new_oid))
1022                 die("BUG: create called without valid new_oid");
1023         return ref_transaction_update(transaction, refname, new_oid,
1024                                       &null_oid, flags, msg, err);
1025 }
1026
1027 int ref_transaction_delete(struct ref_transaction *transaction,
1028                            const char *refname,
1029                            const struct object_id *old_oid,
1030                            unsigned int flags, const char *msg,
1031                            struct strbuf *err)
1032 {
1033         if (old_oid && is_null_oid(old_oid))
1034                 die("BUG: delete called with old_oid set to zeros");
1035         return ref_transaction_update(transaction, refname,
1036                                       &null_oid, old_oid,
1037                                       flags, msg, err);
1038 }
1039
1040 int ref_transaction_verify(struct ref_transaction *transaction,
1041                            const char *refname,
1042                            const struct object_id *old_oid,
1043                            unsigned int flags,
1044                            struct strbuf *err)
1045 {
1046         if (!old_oid)
1047                 die("BUG: verify called with old_oid set to NULL");
1048         return ref_transaction_update(transaction, refname,
1049                                       NULL, old_oid,
1050                                       flags, NULL, err);
1051 }
1052
1053 int refs_update_ref(struct ref_store *refs, const char *msg,
1054                     const char *refname, const struct object_id *new_oid,
1055                     const struct object_id *old_oid, unsigned int flags,
1056                     enum action_on_err onerr)
1057 {
1058         struct ref_transaction *t = NULL;
1059         struct strbuf err = STRBUF_INIT;
1060         int ret = 0;
1061
1062         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1063                 assert(refs == get_main_ref_store());
1064                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1065         } else {
1066                 t = ref_store_transaction_begin(refs, &err);
1067                 if (!t ||
1068                     ref_transaction_update(t, refname, new_oid, old_oid,
1069                                            flags, msg, &err) ||
1070                     ref_transaction_commit(t, &err)) {
1071                         ret = 1;
1072                         ref_transaction_free(t);
1073                 }
1074         }
1075         if (ret) {
1076                 const char *str = "update_ref failed for ref '%s': %s";
1077
1078                 switch (onerr) {
1079                 case UPDATE_REFS_MSG_ON_ERR:
1080                         error(str, refname, err.buf);
1081                         break;
1082                 case UPDATE_REFS_DIE_ON_ERR:
1083                         die(str, refname, err.buf);
1084                         break;
1085                 case UPDATE_REFS_QUIET_ON_ERR:
1086                         break;
1087                 }
1088                 strbuf_release(&err);
1089                 return 1;
1090         }
1091         strbuf_release(&err);
1092         if (t)
1093                 ref_transaction_free(t);
1094         return 0;
1095 }
1096
1097 int update_ref(const char *msg, const char *refname,
1098                const struct object_id *new_oid,
1099                const struct object_id *old_oid,
1100                unsigned int flags, enum action_on_err onerr)
1101 {
1102         return refs_update_ref(get_main_ref_store(), msg, refname, new_oid,
1103                                old_oid, flags, onerr);
1104 }
1105
1106 char *shorten_unambiguous_ref(const char *refname, int strict)
1107 {
1108         int i;
1109         static char **scanf_fmts;
1110         static int nr_rules;
1111         char *short_name;
1112         struct strbuf resolved_buf = STRBUF_INIT;
1113
1114         if (!nr_rules) {
1115                 /*
1116                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1117                  * Generate a format suitable for scanf from a
1118                  * ref_rev_parse_rules rule by interpolating "%s" at the
1119                  * location of the "%.*s".
1120                  */
1121                 size_t total_len = 0;
1122                 size_t offset = 0;
1123
1124                 /* the rule list is NULL terminated, count them first */
1125                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1126                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1127                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1128
1129                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1130
1131                 offset = 0;
1132                 for (i = 0; i < nr_rules; i++) {
1133                         assert(offset < total_len);
1134                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1135                         offset += snprintf(scanf_fmts[i], total_len - offset,
1136                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1137                 }
1138         }
1139
1140         /* bail out if there are no rules */
1141         if (!nr_rules)
1142                 return xstrdup(refname);
1143
1144         /* buffer for scanf result, at most refname must fit */
1145         short_name = xstrdup(refname);
1146
1147         /* skip first rule, it will always match */
1148         for (i = nr_rules - 1; i > 0 ; --i) {
1149                 int j;
1150                 int rules_to_fail = i;
1151                 int short_name_len;
1152
1153                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1154                         continue;
1155
1156                 short_name_len = strlen(short_name);
1157
1158                 /*
1159                  * in strict mode, all (except the matched one) rules
1160                  * must fail to resolve to a valid non-ambiguous ref
1161                  */
1162                 if (strict)
1163                         rules_to_fail = nr_rules;
1164
1165                 /*
1166                  * check if the short name resolves to a valid ref,
1167                  * but use only rules prior to the matched one
1168                  */
1169                 for (j = 0; j < rules_to_fail; j++) {
1170                         const char *rule = ref_rev_parse_rules[j];
1171
1172                         /* skip matched rule */
1173                         if (i == j)
1174                                 continue;
1175
1176                         /*
1177                          * the short name is ambiguous, if it resolves
1178                          * (with this previous rule) to a valid ref
1179                          * read_ref() returns 0 on success
1180                          */
1181                         strbuf_reset(&resolved_buf);
1182                         strbuf_addf(&resolved_buf, rule,
1183                                     short_name_len, short_name);
1184                         if (ref_exists(resolved_buf.buf))
1185                                 break;
1186                 }
1187
1188                 /*
1189                  * short name is non-ambiguous if all previous rules
1190                  * haven't resolved to a valid ref
1191                  */
1192                 if (j == rules_to_fail) {
1193                         strbuf_release(&resolved_buf);
1194                         return short_name;
1195                 }
1196         }
1197
1198         strbuf_release(&resolved_buf);
1199         free(short_name);
1200         return xstrdup(refname);
1201 }
1202
1203 static struct string_list *hide_refs;
1204
1205 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1206 {
1207         const char *key;
1208         if (!strcmp("transfer.hiderefs", var) ||
1209             (!parse_config_key(var, section, NULL, NULL, &key) &&
1210              !strcmp(key, "hiderefs"))) {
1211                 char *ref;
1212                 int len;
1213
1214                 if (!value)
1215                         return config_error_nonbool(var);
1216                 ref = xstrdup(value);
1217                 len = strlen(ref);
1218                 while (len && ref[len - 1] == '/')
1219                         ref[--len] = '\0';
1220                 if (!hide_refs) {
1221                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1222                         hide_refs->strdup_strings = 1;
1223                 }
1224                 string_list_append(hide_refs, ref);
1225         }
1226         return 0;
1227 }
1228
1229 int ref_is_hidden(const char *refname, const char *refname_full)
1230 {
1231         int i;
1232
1233         if (!hide_refs)
1234                 return 0;
1235         for (i = hide_refs->nr - 1; i >= 0; i--) {
1236                 const char *match = hide_refs->items[i].string;
1237                 const char *subject;
1238                 int neg = 0;
1239                 const char *p;
1240
1241                 if (*match == '!') {
1242                         neg = 1;
1243                         match++;
1244                 }
1245
1246                 if (*match == '^') {
1247                         subject = refname_full;
1248                         match++;
1249                 } else {
1250                         subject = refname;
1251                 }
1252
1253                 /* refname can be NULL when namespaces are used. */
1254                 if (subject &&
1255                     skip_prefix(subject, match, &p) &&
1256                     (!*p || *p == '/'))
1257                         return !neg;
1258         }
1259         return 0;
1260 }
1261
1262 const char *find_descendant_ref(const char *dirname,
1263                                 const struct string_list *extras,
1264                                 const struct string_list *skip)
1265 {
1266         int pos;
1267
1268         if (!extras)
1269                 return NULL;
1270
1271         /*
1272          * Look at the place where dirname would be inserted into
1273          * extras. If there is an entry at that position that starts
1274          * with dirname (remember, dirname includes the trailing
1275          * slash) and is not in skip, then we have a conflict.
1276          */
1277         for (pos = string_list_find_insert_index(extras, dirname, 0);
1278              pos < extras->nr; pos++) {
1279                 const char *extra_refname = extras->items[pos].string;
1280
1281                 if (!starts_with(extra_refname, dirname))
1282                         break;
1283
1284                 if (!skip || !string_list_has_string(skip, extra_refname))
1285                         return extra_refname;
1286         }
1287         return NULL;
1288 }
1289
1290 int refs_rename_ref_available(struct ref_store *refs,
1291                               const char *old_refname,
1292                               const char *new_refname)
1293 {
1294         struct string_list skip = STRING_LIST_INIT_NODUP;
1295         struct strbuf err = STRBUF_INIT;
1296         int ok;
1297
1298         string_list_insert(&skip, old_refname);
1299         ok = !refs_verify_refname_available(refs, new_refname,
1300                                             NULL, &skip, &err);
1301         if (!ok)
1302                 error("%s", err.buf);
1303
1304         string_list_clear(&skip, 0);
1305         strbuf_release(&err);
1306         return ok;
1307 }
1308
1309 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1310 {
1311         struct object_id oid;
1312         int flag;
1313
1314         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1315                                 &oid, &flag))
1316                 return fn("HEAD", &oid, flag, cb_data);
1317
1318         return 0;
1319 }
1320
1321 int head_ref(each_ref_fn fn, void *cb_data)
1322 {
1323         return refs_head_ref(get_main_ref_store(), fn, cb_data);
1324 }
1325
1326 struct ref_iterator *refs_ref_iterator_begin(
1327                 struct ref_store *refs,
1328                 const char *prefix, int trim, int flags)
1329 {
1330         struct ref_iterator *iter;
1331
1332         if (ref_paranoia < 0)
1333                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1334         if (ref_paranoia)
1335                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1336
1337         iter = refs->be->iterator_begin(refs, prefix, flags);
1338
1339         /*
1340          * `iterator_begin()` already takes care of prefix, but we
1341          * might need to do some trimming:
1342          */
1343         if (trim)
1344                 iter = prefix_ref_iterator_begin(iter, "", trim);
1345
1346         /* Sanity check for subclasses: */
1347         if (!iter->ordered)
1348                 BUG("reference iterator is not ordered");
1349
1350         return iter;
1351 }
1352
1353 /*
1354  * Call fn for each reference in the specified submodule for which the
1355  * refname begins with prefix. If trim is non-zero, then trim that
1356  * many characters off the beginning of each refname before passing
1357  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1358  * include broken references in the iteration. If fn ever returns a
1359  * non-zero value, stop the iteration and return that value;
1360  * otherwise, return 0.
1361  */
1362 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1363                            each_ref_fn fn, int trim, int flags, void *cb_data)
1364 {
1365         struct ref_iterator *iter;
1366
1367         if (!refs)
1368                 return 0;
1369
1370         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1371
1372         return do_for_each_ref_iterator(iter, fn, cb_data);
1373 }
1374
1375 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1376 {
1377         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1378 }
1379
1380 int for_each_ref(each_ref_fn fn, void *cb_data)
1381 {
1382         return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1383 }
1384
1385 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1386                          each_ref_fn fn, void *cb_data)
1387 {
1388         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1389 }
1390
1391 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1392 {
1393         return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1394 }
1395
1396 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1397 {
1398         unsigned int flag = 0;
1399
1400         if (broken)
1401                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1402         return do_for_each_ref(get_main_ref_store(),
1403                                prefix, fn, 0, flag, cb_data);
1404 }
1405
1406 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1407                              each_ref_fn fn, void *cb_data,
1408                              unsigned int broken)
1409 {
1410         unsigned int flag = 0;
1411
1412         if (broken)
1413                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1414         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1415 }
1416
1417 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1418 {
1419         return do_for_each_ref(get_main_ref_store(),
1420                                git_replace_ref_base, fn,
1421                                strlen(git_replace_ref_base),
1422                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1423 }
1424
1425 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1426 {
1427         struct strbuf buf = STRBUF_INIT;
1428         int ret;
1429         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1430         ret = do_for_each_ref(get_main_ref_store(),
1431                               buf.buf, fn, 0, 0, cb_data);
1432         strbuf_release(&buf);
1433         return ret;
1434 }
1435
1436 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1437 {
1438         return do_for_each_ref(refs, "", fn, 0,
1439                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1440 }
1441
1442 int for_each_rawref(each_ref_fn fn, void *cb_data)
1443 {
1444         return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1445 }
1446
1447 int refs_read_raw_ref(struct ref_store *ref_store,
1448                       const char *refname, struct object_id *oid,
1449                       struct strbuf *referent, unsigned int *type)
1450 {
1451         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1452 }
1453
1454 /* This function needs to return a meaningful errno on failure */
1455 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1456                                     const char *refname,
1457                                     int resolve_flags,
1458                                     struct object_id *oid, int *flags)
1459 {
1460         static struct strbuf sb_refname = STRBUF_INIT;
1461         struct object_id unused_oid;
1462         int unused_flags;
1463         int symref_count;
1464
1465         if (!oid)
1466                 oid = &unused_oid;
1467         if (!flags)
1468                 flags = &unused_flags;
1469
1470         *flags = 0;
1471
1472         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1473                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1474                     !refname_is_safe(refname)) {
1475                         errno = EINVAL;
1476                         return NULL;
1477                 }
1478
1479                 /*
1480                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1481                  * missing refs and refs that were present but invalid,
1482                  * to complain about the latter to stderr.
1483                  *
1484                  * We don't know whether the ref exists, so don't set
1485                  * REF_ISBROKEN yet.
1486                  */
1487                 *flags |= REF_BAD_NAME;
1488         }
1489
1490         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1491                 unsigned int read_flags = 0;
1492
1493                 if (refs_read_raw_ref(refs, refname,
1494                                       oid, &sb_refname, &read_flags)) {
1495                         *flags |= read_flags;
1496
1497                         /* In reading mode, refs must eventually resolve */
1498                         if (resolve_flags & RESOLVE_REF_READING)
1499                                 return NULL;
1500
1501                         /*
1502                          * Otherwise a missing ref is OK. But the files backend
1503                          * may show errors besides ENOENT if there are
1504                          * similarly-named refs.
1505                          */
1506                         if (errno != ENOENT &&
1507                             errno != EISDIR &&
1508                             errno != ENOTDIR)
1509                                 return NULL;
1510
1511                         oidclr(oid);
1512                         if (*flags & REF_BAD_NAME)
1513                                 *flags |= REF_ISBROKEN;
1514                         return refname;
1515                 }
1516
1517                 *flags |= read_flags;
1518
1519                 if (!(read_flags & REF_ISSYMREF)) {
1520                         if (*flags & REF_BAD_NAME) {
1521                                 oidclr(oid);
1522                                 *flags |= REF_ISBROKEN;
1523                         }
1524                         return refname;
1525                 }
1526
1527                 refname = sb_refname.buf;
1528                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1529                         oidclr(oid);
1530                         return refname;
1531                 }
1532                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1533                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1534                             !refname_is_safe(refname)) {
1535                                 errno = EINVAL;
1536                                 return NULL;
1537                         }
1538
1539                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1540                 }
1541         }
1542
1543         errno = ELOOP;
1544         return NULL;
1545 }
1546
1547 /* backend functions */
1548 int refs_init_db(struct strbuf *err)
1549 {
1550         struct ref_store *refs = get_main_ref_store();
1551
1552         return refs->be->init_db(refs, err);
1553 }
1554
1555 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1556                                struct object_id *oid, int *flags)
1557 {
1558         return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1559                                        resolve_flags, oid, flags);
1560 }
1561
1562 int resolve_gitlink_ref(const char *submodule, const char *refname,
1563                         struct object_id *oid)
1564 {
1565         struct ref_store *refs;
1566         int flags;
1567
1568         refs = get_submodule_ref_store(submodule);
1569
1570         if (!refs)
1571                 return -1;
1572
1573         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1574             is_null_oid(oid))
1575                 return -1;
1576         return 0;
1577 }
1578
1579 struct ref_store_hash_entry
1580 {
1581         struct hashmap_entry ent; /* must be the first member! */
1582
1583         struct ref_store *refs;
1584
1585         /* NUL-terminated identifier of the ref store: */
1586         char name[FLEX_ARRAY];
1587 };
1588
1589 static int ref_store_hash_cmp(const void *unused_cmp_data,
1590                               const void *entry, const void *entry_or_key,
1591                               const void *keydata)
1592 {
1593         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1594         const char *name = keydata ? keydata : e2->name;
1595
1596         return strcmp(e1->name, name);
1597 }
1598
1599 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1600                 const char *name, struct ref_store *refs)
1601 {
1602         struct ref_store_hash_entry *entry;
1603
1604         FLEX_ALLOC_STR(entry, name, name);
1605         hashmap_entry_init(entry, strhash(name));
1606         entry->refs = refs;
1607         return entry;
1608 }
1609
1610 /* A pointer to the ref_store for the main repository: */
1611 static struct ref_store *main_ref_store;
1612
1613 /* A hashmap of ref_stores, stored by submodule name: */
1614 static struct hashmap submodule_ref_stores;
1615
1616 /* A hashmap of ref_stores, stored by worktree id: */
1617 static struct hashmap worktree_ref_stores;
1618
1619 /*
1620  * Look up a ref store by name. If that ref_store hasn't been
1621  * registered yet, return NULL.
1622  */
1623 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1624                                               const char *name)
1625 {
1626         struct ref_store_hash_entry *entry;
1627
1628         if (!map->tablesize)
1629                 /* It's initialized on demand in register_ref_store(). */
1630                 return NULL;
1631
1632         entry = hashmap_get_from_hash(map, strhash(name), name);
1633         return entry ? entry->refs : NULL;
1634 }
1635
1636 /*
1637  * Create, record, and return a ref_store instance for the specified
1638  * gitdir.
1639  */
1640 static struct ref_store *ref_store_init(const char *gitdir,
1641                                         unsigned int flags)
1642 {
1643         const char *be_name = "files";
1644         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1645         struct ref_store *refs;
1646
1647         if (!be)
1648                 die("BUG: reference backend %s is unknown", be_name);
1649
1650         refs = be->init(gitdir, flags);
1651         return refs;
1652 }
1653
1654 struct ref_store *get_main_ref_store(void)
1655 {
1656         if (main_ref_store)
1657                 return main_ref_store;
1658
1659         main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1660         return main_ref_store;
1661 }
1662
1663 /*
1664  * Associate a ref store with a name. It is a fatal error to call this
1665  * function twice for the same name.
1666  */
1667 static void register_ref_store_map(struct hashmap *map,
1668                                    const char *type,
1669                                    struct ref_store *refs,
1670                                    const char *name)
1671 {
1672         if (!map->tablesize)
1673                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1674
1675         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1676                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1677 }
1678
1679 struct ref_store *get_submodule_ref_store(const char *submodule)
1680 {
1681         struct strbuf submodule_sb = STRBUF_INIT;
1682         struct ref_store *refs;
1683         char *to_free = NULL;
1684         size_t len;
1685
1686         if (!submodule)
1687                 return NULL;
1688
1689         len = strlen(submodule);
1690         while (len && is_dir_sep(submodule[len - 1]))
1691                 len--;
1692         if (!len)
1693                 return NULL;
1694
1695         if (submodule[len])
1696                 /* We need to strip off one or more trailing slashes */
1697                 submodule = to_free = xmemdupz(submodule, len);
1698
1699         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1700         if (refs)
1701                 goto done;
1702
1703         strbuf_addstr(&submodule_sb, submodule);
1704         if (!is_nonbare_repository_dir(&submodule_sb))
1705                 goto done;
1706
1707         if (submodule_to_gitdir(&submodule_sb, submodule))
1708                 goto done;
1709
1710         /* assume that add_submodule_odb() has been called */
1711         refs = ref_store_init(submodule_sb.buf,
1712                               REF_STORE_READ | REF_STORE_ODB);
1713         register_ref_store_map(&submodule_ref_stores, "submodule",
1714                                refs, submodule);
1715
1716 done:
1717         strbuf_release(&submodule_sb);
1718         free(to_free);
1719
1720         return refs;
1721 }
1722
1723 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1724 {
1725         struct ref_store *refs;
1726         const char *id;
1727
1728         if (wt->is_current)
1729                 return get_main_ref_store();
1730
1731         id = wt->id ? wt->id : "/";
1732         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1733         if (refs)
1734                 return refs;
1735
1736         if (wt->id)
1737                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1738                                       REF_STORE_ALL_CAPS);
1739         else
1740                 refs = ref_store_init(get_git_common_dir(),
1741                                       REF_STORE_ALL_CAPS);
1742
1743         if (refs)
1744                 register_ref_store_map(&worktree_ref_stores, "worktree",
1745                                        refs, id);
1746         return refs;
1747 }
1748
1749 void base_ref_store_init(struct ref_store *refs,
1750                          const struct ref_storage_be *be)
1751 {
1752         refs->be = be;
1753 }
1754
1755 /* backend functions */
1756 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1757 {
1758         return refs->be->pack_refs(refs, flags);
1759 }
1760
1761 int refs_peel_ref(struct ref_store *refs, const char *refname,
1762                   struct object_id *oid)
1763 {
1764         int flag;
1765         struct object_id base;
1766
1767         if (current_ref_iter && current_ref_iter->refname == refname) {
1768                 struct object_id peeled;
1769
1770                 if (ref_iterator_peel(current_ref_iter, &peeled))
1771                         return -1;
1772                 oidcpy(oid, &peeled);
1773                 return 0;
1774         }
1775
1776         if (refs_read_ref_full(refs, refname,
1777                                RESOLVE_REF_READING, &base, &flag))
1778                 return -1;
1779
1780         return peel_object(&base, oid);
1781 }
1782
1783 int peel_ref(const char *refname, struct object_id *oid)
1784 {
1785         return refs_peel_ref(get_main_ref_store(), refname, oid);
1786 }
1787
1788 int refs_create_symref(struct ref_store *refs,
1789                        const char *ref_target,
1790                        const char *refs_heads_master,
1791                        const char *logmsg)
1792 {
1793         return refs->be->create_symref(refs, ref_target,
1794                                        refs_heads_master,
1795                                        logmsg);
1796 }
1797
1798 int create_symref(const char *ref_target, const char *refs_heads_master,
1799                   const char *logmsg)
1800 {
1801         return refs_create_symref(get_main_ref_store(), ref_target,
1802                                   refs_heads_master, logmsg);
1803 }
1804
1805 int ref_update_reject_duplicates(struct string_list *refnames,
1806                                  struct strbuf *err)
1807 {
1808         size_t i, n = refnames->nr;
1809
1810         assert(err);
1811
1812         for (i = 1; i < n; i++) {
1813                 int cmp = strcmp(refnames->items[i - 1].string,
1814                                  refnames->items[i].string);
1815
1816                 if (!cmp) {
1817                         strbuf_addf(err,
1818                                     "multiple updates for ref '%s' not allowed.",
1819                                     refnames->items[i].string);
1820                         return 1;
1821                 } else if (cmp > 0) {
1822                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1823                 }
1824         }
1825         return 0;
1826 }
1827
1828 int ref_transaction_prepare(struct ref_transaction *transaction,
1829                             struct strbuf *err)
1830 {
1831         struct ref_store *refs = transaction->ref_store;
1832
1833         switch (transaction->state) {
1834         case REF_TRANSACTION_OPEN:
1835                 /* Good. */
1836                 break;
1837         case REF_TRANSACTION_PREPARED:
1838                 die("BUG: prepare called twice on reference transaction");
1839                 break;
1840         case REF_TRANSACTION_CLOSED:
1841                 die("BUG: prepare called on a closed reference transaction");
1842                 break;
1843         default:
1844                 die("BUG: unexpected reference transaction state");
1845                 break;
1846         }
1847
1848         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1849                 strbuf_addstr(err,
1850                               _("ref updates forbidden inside quarantine environment"));
1851                 return -1;
1852         }
1853
1854         return refs->be->transaction_prepare(refs, transaction, err);
1855 }
1856
1857 int ref_transaction_abort(struct ref_transaction *transaction,
1858                           struct strbuf *err)
1859 {
1860         struct ref_store *refs = transaction->ref_store;
1861         int ret = 0;
1862
1863         switch (transaction->state) {
1864         case REF_TRANSACTION_OPEN:
1865                 /* No need to abort explicitly. */
1866                 break;
1867         case REF_TRANSACTION_PREPARED:
1868                 ret = refs->be->transaction_abort(refs, transaction, err);
1869                 break;
1870         case REF_TRANSACTION_CLOSED:
1871                 die("BUG: abort called on a closed reference transaction");
1872                 break;
1873         default:
1874                 die("BUG: unexpected reference transaction state");
1875                 break;
1876         }
1877
1878         ref_transaction_free(transaction);
1879         return ret;
1880 }
1881
1882 int ref_transaction_commit(struct ref_transaction *transaction,
1883                            struct strbuf *err)
1884 {
1885         struct ref_store *refs = transaction->ref_store;
1886         int ret;
1887
1888         switch (transaction->state) {
1889         case REF_TRANSACTION_OPEN:
1890                 /* Need to prepare first. */
1891                 ret = ref_transaction_prepare(transaction, err);
1892                 if (ret)
1893                         return ret;
1894                 break;
1895         case REF_TRANSACTION_PREPARED:
1896                 /* Fall through to finish. */
1897                 break;
1898         case REF_TRANSACTION_CLOSED:
1899                 die("BUG: commit called on a closed reference transaction");
1900                 break;
1901         default:
1902                 die("BUG: unexpected reference transaction state");
1903                 break;
1904         }
1905
1906         return refs->be->transaction_finish(refs, transaction, err);
1907 }
1908
1909 int refs_verify_refname_available(struct ref_store *refs,
1910                                   const char *refname,
1911                                   const struct string_list *extras,
1912                                   const struct string_list *skip,
1913                                   struct strbuf *err)
1914 {
1915         const char *slash;
1916         const char *extra_refname;
1917         struct strbuf dirname = STRBUF_INIT;
1918         struct strbuf referent = STRBUF_INIT;
1919         struct object_id oid;
1920         unsigned int type;
1921         struct ref_iterator *iter;
1922         int ok;
1923         int ret = -1;
1924
1925         /*
1926          * For the sake of comments in this function, suppose that
1927          * refname is "refs/foo/bar".
1928          */
1929
1930         assert(err);
1931
1932         strbuf_grow(&dirname, strlen(refname) + 1);
1933         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1934                 /* Expand dirname to the new prefix, not including the trailing slash: */
1935                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1936
1937                 /*
1938                  * We are still at a leading dir of the refname (e.g.,
1939                  * "refs/foo"; if there is a reference with that name,
1940                  * it is a conflict, *unless* it is in skip.
1941                  */
1942                 if (skip && string_list_has_string(skip, dirname.buf))
1943                         continue;
1944
1945                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1946                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1947                                     dirname.buf, refname);
1948                         goto cleanup;
1949                 }
1950
1951                 if (extras && string_list_has_string(extras, dirname.buf)) {
1952                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1953                                     refname, dirname.buf);
1954                         goto cleanup;
1955                 }
1956         }
1957
1958         /*
1959          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1960          * There is no point in searching for a reference with that
1961          * name, because a refname isn't considered to conflict with
1962          * itself. But we still need to check for references whose
1963          * names are in the "refs/foo/bar/" namespace, because they
1964          * *do* conflict.
1965          */
1966         strbuf_addstr(&dirname, refname + dirname.len);
1967         strbuf_addch(&dirname, '/');
1968
1969         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1970                                        DO_FOR_EACH_INCLUDE_BROKEN);
1971         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1972                 if (skip &&
1973                     string_list_has_string(skip, iter->refname))
1974                         continue;
1975
1976                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1977                             iter->refname, refname);
1978                 ref_iterator_abort(iter);
1979                 goto cleanup;
1980         }
1981
1982         if (ok != ITER_DONE)
1983                 die("BUG: error while iterating over references");
1984
1985         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1986         if (extra_refname)
1987                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1988                             refname, extra_refname);
1989         else
1990                 ret = 0;
1991
1992 cleanup:
1993         strbuf_release(&referent);
1994         strbuf_release(&dirname);
1995         return ret;
1996 }
1997
1998 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1999 {
2000         struct ref_iterator *iter;
2001
2002         iter = refs->be->reflog_iterator_begin(refs);
2003
2004         return do_for_each_ref_iterator(iter, fn, cb_data);
2005 }
2006
2007 int for_each_reflog(each_ref_fn fn, void *cb_data)
2008 {
2009         return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
2010 }
2011
2012 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2013                                      const char *refname,
2014                                      each_reflog_ent_fn fn,
2015                                      void *cb_data)
2016 {
2017         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2018                                                      fn, cb_data);
2019 }
2020
2021 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2022                                 void *cb_data)
2023 {
2024         return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
2025                                                 refname, fn, cb_data);
2026 }
2027
2028 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2029                              each_reflog_ent_fn fn, void *cb_data)
2030 {
2031         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2032 }
2033
2034 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2035                         void *cb_data)
2036 {
2037         return refs_for_each_reflog_ent(get_main_ref_store(), refname,
2038                                         fn, cb_data);
2039 }
2040
2041 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2042 {
2043         return refs->be->reflog_exists(refs, refname);
2044 }
2045
2046 int reflog_exists(const char *refname)
2047 {
2048         return refs_reflog_exists(get_main_ref_store(), refname);
2049 }
2050
2051 int refs_create_reflog(struct ref_store *refs, const char *refname,
2052                        int force_create, struct strbuf *err)
2053 {
2054         return refs->be->create_reflog(refs, refname, force_create, err);
2055 }
2056
2057 int safe_create_reflog(const char *refname, int force_create,
2058                        struct strbuf *err)
2059 {
2060         return refs_create_reflog(get_main_ref_store(), refname,
2061                                   force_create, err);
2062 }
2063
2064 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2065 {
2066         return refs->be->delete_reflog(refs, refname);
2067 }
2068
2069 int delete_reflog(const char *refname)
2070 {
2071         return refs_delete_reflog(get_main_ref_store(), refname);
2072 }
2073
2074 int refs_reflog_expire(struct ref_store *refs,
2075                        const char *refname, const struct object_id *oid,
2076                        unsigned int flags,
2077                        reflog_expiry_prepare_fn prepare_fn,
2078                        reflog_expiry_should_prune_fn should_prune_fn,
2079                        reflog_expiry_cleanup_fn cleanup_fn,
2080                        void *policy_cb_data)
2081 {
2082         return refs->be->reflog_expire(refs, refname, oid, flags,
2083                                        prepare_fn, should_prune_fn,
2084                                        cleanup_fn, policy_cb_data);
2085 }
2086
2087 int reflog_expire(const char *refname, const struct object_id *oid,
2088                   unsigned int flags,
2089                   reflog_expiry_prepare_fn prepare_fn,
2090                   reflog_expiry_should_prune_fn should_prune_fn,
2091                   reflog_expiry_cleanup_fn cleanup_fn,
2092                   void *policy_cb_data)
2093 {
2094         return refs_reflog_expire(get_main_ref_store(),
2095                                   refname, oid, flags,
2096                                   prepare_fn, should_prune_fn,
2097                                   cleanup_fn, policy_cb_data);
2098 }
2099
2100 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2101                                    struct strbuf *err)
2102 {
2103         struct ref_store *refs = transaction->ref_store;
2104
2105         return refs->be->initial_transaction_commit(refs, transaction, err);
2106 }
2107
2108 int refs_delete_refs(struct ref_store *refs, const char *msg,
2109                      struct string_list *refnames, unsigned int flags)
2110 {
2111         return refs->be->delete_refs(refs, msg, refnames, flags);
2112 }
2113
2114 int delete_refs(const char *msg, struct string_list *refnames,
2115                 unsigned int flags)
2116 {
2117         return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2118 }
2119
2120 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2121                     const char *newref, const char *logmsg)
2122 {
2123         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2124 }
2125
2126 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2127 {
2128         return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2129 }
2130
2131 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2132                     const char *newref, const char *logmsg)
2133 {
2134         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2135 }
2136
2137 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2138 {
2139         return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
2140 }