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         static struct lock_file lock;
 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,
 674                                                LOCK_DIE_ON_ERROR,
 675                                                get_files_ref_lock_timeout_ms());
 676         if (fd < 0) {
 677                 strbuf_addf(err, "could not open '%s' for writing: %s",
 678                             filename, strerror(errno));
 679                 goto done;
 680         }
 681
 682         if (old_oid) {
 683                 struct object_id actual_old_oid;
 684
 685                 if (read_ref(pseudoref, &actual_old_oid))
 686                         die("could not read ref '%s'", pseudoref);
 687                 if (oidcmp(&actual_old_oid, old_oid)) {
 688                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 689                         rollback_lock_file(&lock);
 690                         goto done;
 691                 }
 692         }
 693
 694         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 695                 strbuf_addf(err, "could not write to '%s'", filename);
 696                 rollback_lock_file(&lock);
 697                 goto done;
 698         }
 699
 700         commit_lock_file(&lock);
 701         ret = 0;
 702 done:
 703         strbuf_release(&buf);
 704         return ret;
 705 }
 706
 707 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 708 {
 709         static struct lock_file lock;
 710         const char *filename;
 711
 712         filename = git_path("%s", pseudoref);
 713
 714         if (old_oid && !is_null_oid(old_oid)) {
 715                 int fd;
 716                 struct object_id actual_old_oid;
 717
 718                 fd = hold_lock_file_for_update_timeout(
 719                                 &lock, filename, LOCK_DIE_ON_ERROR,
 720                                 get_files_ref_lock_timeout_ms());
 721                 if (fd < 0)
 722                         die_errno(_("Could not open '%s' for writing"), filename);
 723                 if (read_ref(pseudoref, &actual_old_oid))
 724                         die("could not read ref '%s'", pseudoref);
 725                 if (oidcmp(&actual_old_oid, old_oid)) {
 726                         warning("Unexpected sha1 when deleting %s", pseudoref);
 727                         rollback_lock_file(&lock);
 728                         return -1;
 729                 }
 730
 731                 unlink(filename);
 732                 rollback_lock_file(&lock);
 733         } else {
 734                 unlink(filename);
 735         }
 736
 737         return 0;
 738 }
 739
 740 int refs_delete_ref(struct ref_store *refs, const char *msg,
 741                     const char *refname,
 742                     const struct object_id *old_oid,
 743                     unsigned int flags)
 744 {
 745         struct ref_transaction *transaction;
 746         struct strbuf err = STRBUF_INIT;
 747
 748         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 749                 assert(refs == get_main_ref_store(the_repository));
 750                 return delete_pseudoref(refname, old_oid);
 751         }
 752
 753         transaction = ref_store_transaction_begin(refs, &err);
 754         if (!transaction ||
 755             ref_transaction_delete(transaction, refname, old_oid,
 756                                    flags, msg, &err) ||
 757             ref_transaction_commit(transaction, &err)) {
 758                 error("%s", err.buf);
 759                 ref_transaction_free(transaction);
 760                 strbuf_release(&err);
 761                 return 1;
 762         }
 763         ref_transaction_free(transaction);
 764         strbuf_release(&err);
 765         return 0;
 766 }
 767
 768 int delete_ref(const char *msg, const char *refname,
 769                const struct object_id *old_oid, unsigned int flags)
 770 {
 771         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
 772                                old_oid, flags);
 773 }
 774
 775 int copy_reflog_msg(char *buf, const char *msg)
 776 {
 777         char *cp = buf;
 778         char c;
 779         int wasspace = 1;
 780
 781         *cp++ = '\t';
 782         while ((c = *msg++)) {
 783                 if (wasspace && isspace(c))
 784                         continue;
 785                 wasspace = isspace(c);
 786                 if (wasspace)
 787                         c = ' ';
 788                 *cp++ = c;
 789         }
 790         while (buf < cp && isspace(cp[-1]))
 791                 cp--;
 792         *cp++ = '\n';
 793         return cp - buf;
 794 }
 795
 796 int should_autocreate_reflog(const char *refname)
 797 {
 798         switch (log_all_ref_updates) {
 799         case LOG_REFS_ALWAYS:
 800                 return 1;
 801         case LOG_REFS_NORMAL:
 802                 return starts_with(refname, "refs/heads/") ||
 803                         starts_with(refname, "refs/remotes/") ||
 804                         starts_with(refname, "refs/notes/") ||
 805                         !strcmp(refname, "HEAD");
 806         default:
 807                 return 0;
 808         }
 809 }
 810
 811 int is_branch(const char *refname)
 812 {
 813         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 814 }
 815
 816 struct read_ref_at_cb {
 817         const char *refname;
 818         timestamp_t at_time;
 819         int cnt;
 820         int reccnt;
 821         struct object_id *oid;
 822         int found_it;
 823
 824         struct object_id ooid;
 825         struct object_id noid;
 826         int tz;
 827         timestamp_t date;
 828         char **msg;
 829         timestamp_t *cutoff_time;
 830         int *cutoff_tz;
 831         int *cutoff_cnt;
 832 };
 833
 834 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 835                 const char *email, timestamp_t timestamp, int tz,
 836                 const char *message, void *cb_data)
 837 {
 838         struct read_ref_at_cb *cb = cb_data;
 839
 840         cb->reccnt++;
 841         cb->tz = tz;
 842         cb->date = timestamp;
 843
 844         if (timestamp <= cb->at_time || cb->cnt == 0) {
 845                 if (cb->msg)
 846                         *cb->msg = xstrdup(message);
 847                 if (cb->cutoff_time)
 848                         *cb->cutoff_time = timestamp;
 849                 if (cb->cutoff_tz)
 850                         *cb->cutoff_tz = tz;
 851                 if (cb->cutoff_cnt)
 852                         *cb->cutoff_cnt = cb->reccnt - 1;
 853                 /*
 854                  * we have not yet updated cb->[n|o]oid so they still
 855                  * hold the values for the previous record.
 856                  */
 857                 if (!is_null_oid(&cb->ooid)) {
 858                         oidcpy(cb->oid, noid);
 859                         if (oidcmp(&cb->ooid, noid))
 860                                 warning("Log for ref %s has gap after %s.",
 861                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 862                 }
 863                 else if (cb->date == cb->at_time)
 864                         oidcpy(cb->oid, noid);
 865                 else if (oidcmp(noid, cb->oid))
 866                         warning("Log for ref %s unexpectedly ended on %s.",
 867                                 cb->refname, show_date(cb->date, cb->tz,
 868                                                        DATE_MODE(RFC2822)));
 869                 oidcpy(&cb->ooid, ooid);
 870                 oidcpy(&cb->noid, noid);
 871                 cb->found_it = 1;
 872                 return 1;
 873         }
 874         oidcpy(&cb->ooid, ooid);
 875         oidcpy(&cb->noid, noid);
 876         if (cb->cnt > 0)
 877                 cb->cnt--;
 878         return 0;
 879 }
 880
 881 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 882                                   const char *email, timestamp_t timestamp,
 883                                   int tz, const char *message, void *cb_data)
 884 {
 885         struct read_ref_at_cb *cb = cb_data;
 886
 887         if (cb->msg)
 888                 *cb->msg = xstrdup(message);
 889         if (cb->cutoff_time)
 890                 *cb->cutoff_time = timestamp;
 891         if (cb->cutoff_tz)
 892                 *cb->cutoff_tz = tz;
 893         if (cb->cutoff_cnt)
 894                 *cb->cutoff_cnt = cb->reccnt;
 895         oidcpy(cb->oid, ooid);
 896         if (is_null_oid(cb->oid))
 897                 oidcpy(cb->oid, noid);
 898         /* We just want the first entry */
 899         return 1;
 900 }
 901
 902 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 903                 struct object_id *oid, char **msg,
 904                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 905 {
 906         struct read_ref_at_cb cb;
 907
 908         memset(&cb, 0, sizeof(cb));
 909         cb.refname = refname;
 910         cb.at_time = at_time;
 911         cb.cnt = cnt;
 912         cb.msg = msg;
 913         cb.cutoff_time = cutoff_time;
 914         cb.cutoff_tz = cutoff_tz;
 915         cb.cutoff_cnt = cutoff_cnt;
 916         cb.oid = oid;
 917
 918         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 919
 920         if (!cb.reccnt) {
 921                 if (flags & GET_OID_QUIETLY)
 922                         exit(128);
 923                 else
 924                         die("Log for %s is empty.", refname);
 925         }
 926         if (cb.found_it)
 927                 return 0;
 928
 929         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 930
 931         return 1;
 932 }
 933
 934 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 935                                                     struct strbuf *err)
 936 {
 937         struct ref_transaction *tr;
 938         assert(err);
 939
 940         tr = xcalloc(1, sizeof(struct ref_transaction));
 941         tr->ref_store = refs;
 942         return tr;
 943 }
 944
 945 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 946 {
 947         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
 948 }
 949
 950 void ref_transaction_free(struct ref_transaction *transaction)
 951 {
 952         size_t i;
 953
 954         if (!transaction)
 955                 return;
 956
 957         switch (transaction->state) {
 958         case REF_TRANSACTION_OPEN:
 959         case REF_TRANSACTION_CLOSED:
 960                 /* OK */
 961                 break;
 962         case REF_TRANSACTION_PREPARED:
 963                 die("BUG: free called on a prepared reference transaction");
 964                 break;
 965         default:
 966                 die("BUG: unexpected reference transaction state");
 967                 break;
 968         }
 969
 970         for (i = 0; i < transaction->nr; i++) {
 971                 free(transaction->updates[i]->msg);
 972                 free(transaction->updates[i]);
 973         }
 974         free(transaction->updates);
 975         free(transaction);
 976 }
 977
 978 struct ref_update *ref_transaction_add_update(
 979                 struct ref_transaction *transaction,
 980                 const char *refname, unsigned int flags,
 981                 const struct object_id *new_oid,
 982                 const struct object_id *old_oid,
 983                 const char *msg)
 984 {
 985         struct ref_update *update;
 986
 987         if (transaction->state != REF_TRANSACTION_OPEN)
 988                 die("BUG: update called for transaction that is not open");
 989
 990         FLEX_ALLOC_STR(update, refname, refname);
 991         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 992         transaction->updates[transaction->nr++] = update;
 993
 994         update->flags = flags;
 995
 996         if (flags & REF_HAVE_NEW)
 997                 oidcpy(&update->new_oid, new_oid);
 998         if (flags & REF_HAVE_OLD)
 999                 oidcpy(&update->old_oid, old_oid);
1000         update->msg = xstrdup_or_null(msg);
1001         return update;
1002 }
1003
1004 int ref_transaction_update(struct ref_transaction *transaction,
1005                            const char *refname,
1006                            const struct object_id *new_oid,
1007                            const struct object_id *old_oid,
1008                            unsigned int flags, const char *msg,
1009                            struct strbuf *err)
1010 {
1011         assert(err);
1012
1013         if ((new_oid && !is_null_oid(new_oid)) ?
1014             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1015             !refname_is_safe(refname)) {
1016                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1017                             refname);
1018                 return -1;
1019         }
1020
1021         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1022                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1023
1024         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1025
1026         ref_transaction_add_update(transaction, refname, flags,
1027                                    new_oid, old_oid, msg);
1028         return 0;
1029 }
1030
1031 int ref_transaction_create(struct ref_transaction *transaction,
1032                            const char *refname,
1033                            const struct object_id *new_oid,
1034                            unsigned int flags, const char *msg,
1035                            struct strbuf *err)
1036 {
1037         if (!new_oid || is_null_oid(new_oid))
1038                 die("BUG: create called without valid new_oid");
1039         return ref_transaction_update(transaction, refname, new_oid,
1040                                       &null_oid, flags, msg, err);
1041 }
1042
1043 int ref_transaction_delete(struct ref_transaction *transaction,
1044                            const char *refname,
1045                            const struct object_id *old_oid,
1046                            unsigned int flags, const char *msg,
1047                            struct strbuf *err)
1048 {
1049         if (old_oid && is_null_oid(old_oid))
1050                 die("BUG: delete called with old_oid set to zeros");
1051         return ref_transaction_update(transaction, refname,
1052                                       &null_oid, old_oid,
1053                                       flags, msg, err);
1054 }
1055
1056 int ref_transaction_verify(struct ref_transaction *transaction,
1057                            const char *refname,
1058                            const struct object_id *old_oid,
1059                            unsigned int flags,
1060                            struct strbuf *err)
1061 {
1062         if (!old_oid)
1063                 die("BUG: verify called with old_oid set to NULL");
1064         return ref_transaction_update(transaction, refname,
1065                                       NULL, old_oid,
1066                                       flags, NULL, err);
1067 }
1068
1069 int refs_update_ref(struct ref_store *refs, const char *msg,
1070                     const char *refname, const struct object_id *new_oid,
1071                     const struct object_id *old_oid, unsigned int flags,
1072                     enum action_on_err onerr)
1073 {
1074         struct ref_transaction *t = NULL;
1075         struct strbuf err = STRBUF_INIT;
1076         int ret = 0;
1077
1078         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1079                 assert(refs == get_main_ref_store(the_repository));
1080                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1081         } else {
1082                 t = ref_store_transaction_begin(refs, &err);
1083                 if (!t ||
1084                     ref_transaction_update(t, refname, new_oid, old_oid,
1085                                            flags, msg, &err) ||
1086                     ref_transaction_commit(t, &err)) {
1087                         ret = 1;
1088                         ref_transaction_free(t);
1089                 }
1090         }
1091         if (ret) {
1092                 const char *str = "update_ref failed for ref '%s': %s";
1093
1094                 switch (onerr) {
1095                 case UPDATE_REFS_MSG_ON_ERR:
1096                         error(str, refname, err.buf);
1097                         break;
1098                 case UPDATE_REFS_DIE_ON_ERR:
1099                         die(str, refname, err.buf);
1100                         break;
1101                 case UPDATE_REFS_QUIET_ON_ERR:
1102                         break;
1103                 }
1104                 strbuf_release(&err);
1105                 return 1;
1106         }
1107         strbuf_release(&err);
1108         if (t)
1109                 ref_transaction_free(t);
1110         return 0;
1111 }
1112
1113 int update_ref(const char *msg, const char *refname,
1114                const struct object_id *new_oid,
1115                const struct object_id *old_oid,
1116                unsigned int flags, enum action_on_err onerr)
1117 {
1118         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1119                                old_oid, flags, onerr);
1120 }
1121
1122 char *shorten_unambiguous_ref(const char *refname, int strict)
1123 {
1124         int i;
1125         static char **scanf_fmts;
1126         static int nr_rules;
1127         char *short_name;
1128         struct strbuf resolved_buf = STRBUF_INIT;
1129
1130         if (!nr_rules) {
1131                 /*
1132                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1133                  * Generate a format suitable for scanf from a
1134                  * ref_rev_parse_rules rule by interpolating "%s" at the
1135                  * location of the "%.*s".
1136                  */
1137                 size_t total_len = 0;
1138                 size_t offset = 0;
1139
1140                 /* the rule list is NULL terminated, count them first */
1141                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1142                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1143                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1144
1145                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1146
1147                 offset = 0;
1148                 for (i = 0; i < nr_rules; i++) {
1149                         assert(offset < total_len);
1150                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1151                         offset += snprintf(scanf_fmts[i], total_len - offset,
1152                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1153                 }
1154         }
1155
1156         /* bail out if there are no rules */
1157         if (!nr_rules)
1158                 return xstrdup(refname);
1159
1160         /* buffer for scanf result, at most refname must fit */
1161         short_name = xstrdup(refname);
1162
1163         /* skip first rule, it will always match */
1164         for (i = nr_rules - 1; i > 0 ; --i) {
1165                 int j;
1166                 int rules_to_fail = i;
1167                 int short_name_len;
1168
1169                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1170                         continue;
1171
1172                 short_name_len = strlen(short_name);
1173
1174                 /*
1175                  * in strict mode, all (except the matched one) rules
1176                  * must fail to resolve to a valid non-ambiguous ref
1177                  */
1178                 if (strict)
1179                         rules_to_fail = nr_rules;
1180
1181                 /*
1182                  * check if the short name resolves to a valid ref,
1183                  * but use only rules prior to the matched one
1184                  */
1185                 for (j = 0; j < rules_to_fail; j++) {
1186                         const char *rule = ref_rev_parse_rules[j];
1187
1188                         /* skip matched rule */
1189                         if (i == j)
1190                                 continue;
1191
1192                         /*
1193                          * the short name is ambiguous, if it resolves
1194                          * (with this previous rule) to a valid ref
1195                          * read_ref() returns 0 on success
1196                          */
1197                         strbuf_reset(&resolved_buf);
1198                         strbuf_addf(&resolved_buf, rule,
1199                                     short_name_len, short_name);
1200                         if (ref_exists(resolved_buf.buf))
1201                                 break;
1202                 }
1203
1204                 /*
1205                  * short name is non-ambiguous if all previous rules
1206                  * haven't resolved to a valid ref
1207                  */
1208                 if (j == rules_to_fail) {
1209                         strbuf_release(&resolved_buf);
1210                         return short_name;
1211                 }
1212         }
1213
1214         strbuf_release(&resolved_buf);
1215         free(short_name);
1216         return xstrdup(refname);
1217 }
1218
1219 static struct string_list *hide_refs;
1220
1221 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1222 {
1223         const char *key;
1224         if (!strcmp("transfer.hiderefs", var) ||
1225             (!parse_config_key(var, section, NULL, NULL, &key) &&
1226              !strcmp(key, "hiderefs"))) {
1227                 char *ref;
1228                 int len;
1229
1230                 if (!value)
1231                         return config_error_nonbool(var);
1232                 ref = xstrdup(value);
1233                 len = strlen(ref);
1234                 while (len && ref[len - 1] == '/')
1235                         ref[--len] = '\0';
1236                 if (!hide_refs) {
1237                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1238                         hide_refs->strdup_strings = 1;
1239                 }
1240                 string_list_append(hide_refs, ref);
1241         }
1242         return 0;
1243 }
1244
1245 int ref_is_hidden(const char *refname, const char *refname_full)
1246 {
1247         int i;
1248
1249         if (!hide_refs)
1250                 return 0;
1251         for (i = hide_refs->nr - 1; i >= 0; i--) {
1252                 const char *match = hide_refs->items[i].string;
1253                 const char *subject;
1254                 int neg = 0;
1255                 const char *p;
1256
1257                 if (*match == '!') {
1258                         neg = 1;
1259                         match++;
1260                 }
1261
1262                 if (*match == '^') {
1263                         subject = refname_full;
1264                         match++;
1265                 } else {
1266                         subject = refname;
1267                 }
1268
1269                 /* refname can be NULL when namespaces are used. */
1270                 if (subject &&
1271                     skip_prefix(subject, match, &p) &&
1272                     (!*p || *p == '/'))
1273                         return !neg;
1274         }
1275         return 0;
1276 }
1277
1278 const char *find_descendant_ref(const char *dirname,
1279                                 const struct string_list *extras,
1280                                 const struct string_list *skip)
1281 {
1282         int pos;
1283
1284         if (!extras)
1285                 return NULL;
1286
1287         /*
1288          * Look at the place where dirname would be inserted into
1289          * extras. If there is an entry at that position that starts
1290          * with dirname (remember, dirname includes the trailing
1291          * slash) and is not in skip, then we have a conflict.
1292          */
1293         for (pos = string_list_find_insert_index(extras, dirname, 0);
1294              pos < extras->nr; pos++) {
1295                 const char *extra_refname = extras->items[pos].string;
1296
1297                 if (!starts_with(extra_refname, dirname))
1298                         break;
1299
1300                 if (!skip || !string_list_has_string(skip, extra_refname))
1301                         return extra_refname;
1302         }
1303         return NULL;
1304 }
1305
1306 int refs_rename_ref_available(struct ref_store *refs,
1307                               const char *old_refname,
1308                               const char *new_refname)
1309 {
1310         struct string_list skip = STRING_LIST_INIT_NODUP;
1311         struct strbuf err = STRBUF_INIT;
1312         int ok;
1313
1314         string_list_insert(&skip, old_refname);
1315         ok = !refs_verify_refname_available(refs, new_refname,
1316                                             NULL, &skip, &err);
1317         if (!ok)
1318                 error("%s", err.buf);
1319
1320         string_list_clear(&skip, 0);
1321         strbuf_release(&err);
1322         return ok;
1323 }
1324
1325 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1326 {
1327         struct object_id oid;
1328         int flag;
1329
1330         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1331                                 &oid, &flag))
1332                 return fn("HEAD", &oid, flag, cb_data);
1333
1334         return 0;
1335 }
1336
1337 int head_ref(each_ref_fn fn, void *cb_data)
1338 {
1339         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1340 }
1341
1342 struct ref_iterator *refs_ref_iterator_begin(
1343                 struct ref_store *refs,
1344                 const char *prefix, int trim, int flags)
1345 {
1346         struct ref_iterator *iter;
1347
1348         if (ref_paranoia < 0)
1349                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1350         if (ref_paranoia)
1351                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1352
1353         iter = refs->be->iterator_begin(refs, prefix, flags);
1354
1355         /*
1356          * `iterator_begin()` already takes care of prefix, but we
1357          * might need to do some trimming:
1358          */
1359         if (trim)
1360                 iter = prefix_ref_iterator_begin(iter, "", trim);
1361
1362         /* Sanity check for subclasses: */
1363         if (!iter->ordered)
1364                 BUG("reference iterator is not ordered");
1365
1366         return iter;
1367 }
1368
1369 /*
1370  * Call fn for each reference in the specified submodule for which the
1371  * refname begins with prefix. If trim is non-zero, then trim that
1372  * many characters off the beginning of each refname before passing
1373  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1374  * include broken references in the iteration. If fn ever returns a
1375  * non-zero value, stop the iteration and return that value;
1376  * otherwise, return 0.
1377  */
1378 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1379                            each_ref_fn fn, int trim, int flags, void *cb_data)
1380 {
1381         struct ref_iterator *iter;
1382
1383         if (!refs)
1384                 return 0;
1385
1386         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1387
1388         return do_for_each_ref_iterator(iter, fn, cb_data);
1389 }
1390
1391 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1392 {
1393         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1394 }
1395
1396 int for_each_ref(each_ref_fn fn, void *cb_data)
1397 {
1398         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1399 }
1400
1401 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1402                          each_ref_fn fn, void *cb_data)
1403 {
1404         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1405 }
1406
1407 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1408 {
1409         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1410 }
1411
1412 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1413 {
1414         unsigned int flag = 0;
1415
1416         if (broken)
1417                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1418         return do_for_each_ref(get_main_ref_store(the_repository),
1419                                prefix, fn, 0, flag, cb_data);
1420 }
1421
1422 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1423                              each_ref_fn fn, void *cb_data,
1424                              unsigned int broken)
1425 {
1426         unsigned int flag = 0;
1427
1428         if (broken)
1429                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1430         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1431 }
1432
1433 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1434 {
1435         return do_for_each_ref(get_main_ref_store(r),
1436                                git_replace_ref_base, fn,
1437                                strlen(git_replace_ref_base),
1438                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1439 }
1440
1441 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1442 {
1443         struct strbuf buf = STRBUF_INIT;
1444         int ret;
1445         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1446         ret = do_for_each_ref(get_main_ref_store(the_repository),
1447                               buf.buf, fn, 0, 0, cb_data);
1448         strbuf_release(&buf);
1449         return ret;
1450 }
1451
1452 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1453 {
1454         return do_for_each_ref(refs, "", fn, 0,
1455                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1456 }
1457
1458 int for_each_rawref(each_ref_fn fn, void *cb_data)
1459 {
1460         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1461 }
1462
1463 int refs_read_raw_ref(struct ref_store *ref_store,
1464                       const char *refname, struct object_id *oid,
1465                       struct strbuf *referent, unsigned int *type)
1466 {
1467         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1468 }
1469
1470 /* This function needs to return a meaningful errno on failure */
1471 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1472                                     const char *refname,
1473                                     int resolve_flags,
1474                                     struct object_id *oid, int *flags)
1475 {
1476         static struct strbuf sb_refname = STRBUF_INIT;
1477         struct object_id unused_oid;
1478         int unused_flags;
1479         int symref_count;
1480
1481         if (!oid)
1482                 oid = &unused_oid;
1483         if (!flags)
1484                 flags = &unused_flags;
1485
1486         *flags = 0;
1487
1488         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1489                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1490                     !refname_is_safe(refname)) {
1491                         errno = EINVAL;
1492                         return NULL;
1493                 }
1494
1495                 /*
1496                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1497                  * missing refs and refs that were present but invalid,
1498                  * to complain about the latter to stderr.
1499                  *
1500                  * We don't know whether the ref exists, so don't set
1501                  * REF_ISBROKEN yet.
1502                  */
1503                 *flags |= REF_BAD_NAME;
1504         }
1505
1506         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1507                 unsigned int read_flags = 0;
1508
1509                 if (refs_read_raw_ref(refs, refname,
1510                                       oid, &sb_refname, &read_flags)) {
1511                         *flags |= read_flags;
1512
1513                         /* In reading mode, refs must eventually resolve */
1514                         if (resolve_flags & RESOLVE_REF_READING)
1515                                 return NULL;
1516
1517                         /*
1518                          * Otherwise a missing ref is OK. But the files backend
1519                          * may show errors besides ENOENT if there are
1520                          * similarly-named refs.
1521                          */
1522                         if (errno != ENOENT &&
1523                             errno != EISDIR &&
1524                             errno != ENOTDIR)
1525                                 return NULL;
1526
1527                         oidclr(oid);
1528                         if (*flags & REF_BAD_NAME)
1529                                 *flags |= REF_ISBROKEN;
1530                         return refname;
1531                 }
1532
1533                 *flags |= read_flags;
1534
1535                 if (!(read_flags & REF_ISSYMREF)) {
1536                         if (*flags & REF_BAD_NAME) {
1537                                 oidclr(oid);
1538                                 *flags |= REF_ISBROKEN;
1539                         }
1540                         return refname;
1541                 }
1542
1543                 refname = sb_refname.buf;
1544                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1545                         oidclr(oid);
1546                         return refname;
1547                 }
1548                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1549                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1550                             !refname_is_safe(refname)) {
1551                                 errno = EINVAL;
1552                                 return NULL;
1553                         }
1554
1555                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1556                 }
1557         }
1558
1559         errno = ELOOP;
1560         return NULL;
1561 }
1562
1563 /* backend functions */
1564 int refs_init_db(struct strbuf *err)
1565 {
1566         struct ref_store *refs = get_main_ref_store(the_repository);
1567
1568         return refs->be->init_db(refs, err);
1569 }
1570
1571 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1572                                struct object_id *oid, int *flags)
1573 {
1574         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1575                                        resolve_flags, oid, flags);
1576 }
1577
1578 int resolve_gitlink_ref(const char *submodule, const char *refname,
1579                         struct object_id *oid)
1580 {
1581         struct ref_store *refs;
1582         int flags;
1583
1584         refs = get_submodule_ref_store(submodule);
1585
1586         if (!refs)
1587                 return -1;
1588
1589         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1590             is_null_oid(oid))
1591                 return -1;
1592         return 0;
1593 }
1594
1595 struct ref_store_hash_entry
1596 {
1597         struct hashmap_entry ent; /* must be the first member! */
1598
1599         struct ref_store *refs;
1600
1601         /* NUL-terminated identifier of the ref store: */
1602         char name[FLEX_ARRAY];
1603 };
1604
1605 static int ref_store_hash_cmp(const void *unused_cmp_data,
1606                               const void *entry, const void *entry_or_key,
1607                               const void *keydata)
1608 {
1609         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1610         const char *name = keydata ? keydata : e2->name;
1611
1612         return strcmp(e1->name, name);
1613 }
1614
1615 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1616                 const char *name, struct ref_store *refs)
1617 {
1618         struct ref_store_hash_entry *entry;
1619
1620         FLEX_ALLOC_STR(entry, name, name);
1621         hashmap_entry_init(entry, strhash(name));
1622         entry->refs = refs;
1623         return entry;
1624 }
1625
1626 /* A hashmap of ref_stores, stored by submodule name: */
1627 static struct hashmap submodule_ref_stores;
1628
1629 /* A hashmap of ref_stores, stored by worktree id: */
1630 static struct hashmap worktree_ref_stores;
1631
1632 /*
1633  * Look up a ref store by name. If that ref_store hasn't been
1634  * registered yet, return NULL.
1635  */
1636 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1637                                               const char *name)
1638 {
1639         struct ref_store_hash_entry *entry;
1640
1641         if (!map->tablesize)
1642                 /* It's initialized on demand in register_ref_store(). */
1643                 return NULL;
1644
1645         entry = hashmap_get_from_hash(map, strhash(name), name);
1646         return entry ? entry->refs : NULL;
1647 }
1648
1649 /*
1650  * Create, record, and return a ref_store instance for the specified
1651  * gitdir.
1652  */
1653 static struct ref_store *ref_store_init(const char *gitdir,
1654                                         unsigned int flags)
1655 {
1656         const char *be_name = "files";
1657         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1658         struct ref_store *refs;
1659
1660         if (!be)
1661                 die("BUG: reference backend %s is unknown", be_name);
1662
1663         refs = be->init(gitdir, flags);
1664         return refs;
1665 }
1666
1667 struct ref_store *get_main_ref_store(struct repository *r)
1668 {
1669         if (r->refs)
1670                 return r->refs;
1671
1672         if (!r->gitdir)
1673                 BUG("attempting to get main_ref_store outside of repository");
1674
1675         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1676         return r->refs;
1677 }
1678
1679 /*
1680  * Associate a ref store with a name. It is a fatal error to call this
1681  * function twice for the same name.
1682  */
1683 static void register_ref_store_map(struct hashmap *map,
1684                                    const char *type,
1685                                    struct ref_store *refs,
1686                                    const char *name)
1687 {
1688         if (!map->tablesize)
1689                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1690
1691         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1692                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1693 }
1694
1695 struct ref_store *get_submodule_ref_store(const char *submodule)
1696 {
1697         struct strbuf submodule_sb = STRBUF_INIT;
1698         struct ref_store *refs;
1699         char *to_free = NULL;
1700         size_t len;
1701
1702         if (!submodule)
1703                 return NULL;
1704
1705         len = strlen(submodule);
1706         while (len && is_dir_sep(submodule[len - 1]))
1707                 len--;
1708         if (!len)
1709                 return NULL;
1710
1711         if (submodule[len])
1712                 /* We need to strip off one or more trailing slashes */
1713                 submodule = to_free = xmemdupz(submodule, len);
1714
1715         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1716         if (refs)
1717                 goto done;
1718
1719         strbuf_addstr(&submodule_sb, submodule);
1720         if (!is_nonbare_repository_dir(&submodule_sb))
1721                 goto done;
1722
1723         if (submodule_to_gitdir(&submodule_sb, submodule))
1724                 goto done;
1725
1726         /* assume that add_submodule_odb() has been called */
1727         refs = ref_store_init(submodule_sb.buf,
1728                               REF_STORE_READ | REF_STORE_ODB);
1729         register_ref_store_map(&submodule_ref_stores, "submodule",
1730                                refs, submodule);
1731
1732 done:
1733         strbuf_release(&submodule_sb);
1734         free(to_free);
1735
1736         return refs;
1737 }
1738
1739 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1740 {
1741         struct ref_store *refs;
1742         const char *id;
1743
1744         if (wt->is_current)
1745                 return get_main_ref_store(the_repository);
1746
1747         id = wt->id ? wt->id : "/";
1748         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1749         if (refs)
1750                 return refs;
1751
1752         if (wt->id)
1753                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1754                                       REF_STORE_ALL_CAPS);
1755         else
1756                 refs = ref_store_init(get_git_common_dir(),
1757                                       REF_STORE_ALL_CAPS);
1758
1759         if (refs)
1760                 register_ref_store_map(&worktree_ref_stores, "worktree",
1761                                        refs, id);
1762         return refs;
1763 }
1764
1765 void base_ref_store_init(struct ref_store *refs,
1766                          const struct ref_storage_be *be)
1767 {
1768         refs->be = be;
1769 }
1770
1771 /* backend functions */
1772 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1773 {
1774         return refs->be->pack_refs(refs, flags);
1775 }
1776
1777 int refs_peel_ref(struct ref_store *refs, const char *refname,
1778                   struct object_id *oid)
1779 {
1780         int flag;
1781         struct object_id base;
1782
1783         if (current_ref_iter && current_ref_iter->refname == refname) {
1784                 struct object_id peeled;
1785
1786                 if (ref_iterator_peel(current_ref_iter, &peeled))
1787                         return -1;
1788                 oidcpy(oid, &peeled);
1789                 return 0;
1790         }
1791
1792         if (refs_read_ref_full(refs, refname,
1793                                RESOLVE_REF_READING, &base, &flag))
1794                 return -1;
1795
1796         return peel_object(&base, oid);
1797 }
1798
1799 int peel_ref(const char *refname, struct object_id *oid)
1800 {
1801         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1802 }
1803
1804 int refs_create_symref(struct ref_store *refs,
1805                        const char *ref_target,
1806                        const char *refs_heads_master,
1807                        const char *logmsg)
1808 {
1809         return refs->be->create_symref(refs, ref_target,
1810                                        refs_heads_master,
1811                                        logmsg);
1812 }
1813
1814 int create_symref(const char *ref_target, const char *refs_heads_master,
1815                   const char *logmsg)
1816 {
1817         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1818                                   refs_heads_master, logmsg);
1819 }
1820
1821 int ref_update_reject_duplicates(struct string_list *refnames,
1822                                  struct strbuf *err)
1823 {
1824         size_t i, n = refnames->nr;
1825
1826         assert(err);
1827
1828         for (i = 1; i < n; i++) {
1829                 int cmp = strcmp(refnames->items[i - 1].string,
1830                                  refnames->items[i].string);
1831
1832                 if (!cmp) {
1833                         strbuf_addf(err,
1834                                     "multiple updates for ref '%s' not allowed.",
1835                                     refnames->items[i].string);
1836                         return 1;
1837                 } else if (cmp > 0) {
1838                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1839                 }
1840         }
1841         return 0;
1842 }
1843
1844 int ref_transaction_prepare(struct ref_transaction *transaction,
1845                             struct strbuf *err)
1846 {
1847         struct ref_store *refs = transaction->ref_store;
1848
1849         switch (transaction->state) {
1850         case REF_TRANSACTION_OPEN:
1851                 /* Good. */
1852                 break;
1853         case REF_TRANSACTION_PREPARED:
1854                 die("BUG: prepare called twice on reference transaction");
1855                 break;
1856         case REF_TRANSACTION_CLOSED:
1857                 die("BUG: prepare called on a closed reference transaction");
1858                 break;
1859         default:
1860                 die("BUG: unexpected reference transaction state");
1861                 break;
1862         }
1863
1864         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1865                 strbuf_addstr(err,
1866                               _("ref updates forbidden inside quarantine environment"));
1867                 return -1;
1868         }
1869
1870         return refs->be->transaction_prepare(refs, transaction, err);
1871 }
1872
1873 int ref_transaction_abort(struct ref_transaction *transaction,
1874                           struct strbuf *err)
1875 {
1876         struct ref_store *refs = transaction->ref_store;
1877         int ret = 0;
1878
1879         switch (transaction->state) {
1880         case REF_TRANSACTION_OPEN:
1881                 /* No need to abort explicitly. */
1882                 break;
1883         case REF_TRANSACTION_PREPARED:
1884                 ret = refs->be->transaction_abort(refs, transaction, err);
1885                 break;
1886         case REF_TRANSACTION_CLOSED:
1887                 die("BUG: abort called on a closed reference transaction");
1888                 break;
1889         default:
1890                 die("BUG: unexpected reference transaction state");
1891                 break;
1892         }
1893
1894         ref_transaction_free(transaction);
1895         return ret;
1896 }
1897
1898 int ref_transaction_commit(struct ref_transaction *transaction,
1899                            struct strbuf *err)
1900 {
1901         struct ref_store *refs = transaction->ref_store;
1902         int ret;
1903
1904         switch (transaction->state) {
1905         case REF_TRANSACTION_OPEN:
1906                 /* Need to prepare first. */
1907                 ret = ref_transaction_prepare(transaction, err);
1908                 if (ret)
1909                         return ret;
1910                 break;
1911         case REF_TRANSACTION_PREPARED:
1912                 /* Fall through to finish. */
1913                 break;
1914         case REF_TRANSACTION_CLOSED:
1915                 die("BUG: commit called on a closed reference transaction");
1916                 break;
1917         default:
1918                 die("BUG: unexpected reference transaction state");
1919                 break;
1920         }
1921
1922         return refs->be->transaction_finish(refs, transaction, err);
1923 }
1924
1925 int refs_verify_refname_available(struct ref_store *refs,
1926                                   const char *refname,
1927                                   const struct string_list *extras,
1928                                   const struct string_list *skip,
1929                                   struct strbuf *err)
1930 {
1931         const char *slash;
1932         const char *extra_refname;
1933         struct strbuf dirname = STRBUF_INIT;
1934         struct strbuf referent = STRBUF_INIT;
1935         struct object_id oid;
1936         unsigned int type;
1937         struct ref_iterator *iter;
1938         int ok;
1939         int ret = -1;
1940
1941         /*
1942          * For the sake of comments in this function, suppose that
1943          * refname is "refs/foo/bar".
1944          */
1945
1946         assert(err);
1947
1948         strbuf_grow(&dirname, strlen(refname) + 1);
1949         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1950                 /* Expand dirname to the new prefix, not including the trailing slash: */
1951                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1952
1953                 /*
1954                  * We are still at a leading dir of the refname (e.g.,
1955                  * "refs/foo"; if there is a reference with that name,
1956                  * it is a conflict, *unless* it is in skip.
1957                  */
1958                 if (skip && string_list_has_string(skip, dirname.buf))
1959                         continue;
1960
1961                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1962                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1963                                     dirname.buf, refname);
1964                         goto cleanup;
1965                 }
1966
1967                 if (extras && string_list_has_string(extras, dirname.buf)) {
1968                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1969                                     refname, dirname.buf);
1970                         goto cleanup;
1971                 }
1972         }
1973
1974         /*
1975          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1976          * There is no point in searching for a reference with that
1977          * name, because a refname isn't considered to conflict with
1978          * itself. But we still need to check for references whose
1979          * names are in the "refs/foo/bar/" namespace, because they
1980          * *do* conflict.
1981          */
1982         strbuf_addstr(&dirname, refname + dirname.len);
1983         strbuf_addch(&dirname, '/');
1984
1985         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1986                                        DO_FOR_EACH_INCLUDE_BROKEN);
1987         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1988                 if (skip &&
1989                     string_list_has_string(skip, iter->refname))
1990                         continue;
1991
1992                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1993                             iter->refname, refname);
1994                 ref_iterator_abort(iter);
1995                 goto cleanup;
1996         }
1997
1998         if (ok != ITER_DONE)
1999                 die("BUG: error while iterating over references");
2000
2001         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2002         if (extra_refname)
2003                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2004                             refname, extra_refname);
2005         else
2006                 ret = 0;
2007
2008 cleanup:
2009         strbuf_release(&referent);
2010         strbuf_release(&dirname);
2011         return ret;
2012 }
2013
2014 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2015 {
2016         struct ref_iterator *iter;
2017
2018         iter = refs->be->reflog_iterator_begin(refs);
2019
2020         return do_for_each_ref_iterator(iter, fn, cb_data);
2021 }
2022
2023 int for_each_reflog(each_ref_fn fn, void *cb_data)
2024 {
2025         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2026 }
2027
2028 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2029                                      const char *refname,
2030                                      each_reflog_ent_fn fn,
2031                                      void *cb_data)
2032 {
2033         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2034                                                      fn, cb_data);
2035 }
2036
2037 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2038                                 void *cb_data)
2039 {
2040         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2041                                                 refname, fn, cb_data);
2042 }
2043
2044 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2045                              each_reflog_ent_fn fn, void *cb_data)
2046 {
2047         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2048 }
2049
2050 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2051                         void *cb_data)
2052 {
2053         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2054                                         fn, cb_data);
2055 }
2056
2057 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2058 {
2059         return refs->be->reflog_exists(refs, refname);
2060 }
2061
2062 int reflog_exists(const char *refname)
2063 {
2064         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2065 }
2066
2067 int refs_create_reflog(struct ref_store *refs, const char *refname,
2068                        int force_create, struct strbuf *err)
2069 {
2070         return refs->be->create_reflog(refs, refname, force_create, err);
2071 }
2072
2073 int safe_create_reflog(const char *refname, int force_create,
2074                        struct strbuf *err)
2075 {
2076         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2077                                   force_create, err);
2078 }
2079
2080 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2081 {
2082         return refs->be->delete_reflog(refs, refname);
2083 }
2084
2085 int delete_reflog(const char *refname)
2086 {
2087         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2088 }
2089
2090 int refs_reflog_expire(struct ref_store *refs,
2091                        const char *refname, const struct object_id *oid,
2092                        unsigned int flags,
2093                        reflog_expiry_prepare_fn prepare_fn,
2094                        reflog_expiry_should_prune_fn should_prune_fn,
2095                        reflog_expiry_cleanup_fn cleanup_fn,
2096                        void *policy_cb_data)
2097 {
2098         return refs->be->reflog_expire(refs, refname, oid, flags,
2099                                        prepare_fn, should_prune_fn,
2100                                        cleanup_fn, policy_cb_data);
2101 }
2102
2103 int reflog_expire(const char *refname, const struct object_id *oid,
2104                   unsigned int flags,
2105                   reflog_expiry_prepare_fn prepare_fn,
2106                   reflog_expiry_should_prune_fn should_prune_fn,
2107                   reflog_expiry_cleanup_fn cleanup_fn,
2108                   void *policy_cb_data)
2109 {
2110         return refs_reflog_expire(get_main_ref_store(the_repository),
2111                                   refname, oid, flags,
2112                                   prepare_fn, should_prune_fn,
2113                                   cleanup_fn, policy_cb_data);
2114 }
2115
2116 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2117                                    struct strbuf *err)
2118 {
2119         struct ref_store *refs = transaction->ref_store;
2120
2121         return refs->be->initial_transaction_commit(refs, transaction, err);
2122 }
2123
2124 int refs_delete_refs(struct ref_store *refs, const char *msg,
2125                      struct string_list *refnames, unsigned int flags)
2126 {
2127         return refs->be->delete_refs(refs, msg, refnames, flags);
2128 }
2129
2130 int delete_refs(const char *msg, struct string_list *refnames,
2131                 unsigned int flags)
2132 {
2133         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2134 }
2135
2136 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2137                     const char *newref, const char *logmsg)
2138 {
2139         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2140 }
2141
2142 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2143 {
2144         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2145 }
2146
2147 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2148                     const char *newref, const char *logmsg)
2149 {
2150         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2151 }
2152
2153 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2154 {
2155         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2156 }