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