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(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 }
 620
 621 static int is_pseudoref_syntax(const char *refname)
 622 {
 623         const char *c;
 624
 625         for (c = refname; *c; c++) {
 626                 if (!isupper(*c) && *c != '-' && *c != '_')
 627                         return 0;
 628         }
 629
 630         return 1;
 631 }
 632
 633 enum ref_type ref_type(const char *refname)
 634 {
 635         if (is_per_worktree_ref(refname))
 636                 return REF_TYPE_PER_WORKTREE;
 637         if (is_pseudoref_syntax(refname))
 638                 return REF_TYPE_PSEUDOREF;
 639        return REF_TYPE_NORMAL;
 640 }
 641
 642 long get_files_ref_lock_timeout_ms(void)
 643 {
 644         static int configured = 0;
 645
 646         /* The default timeout is 100 ms: */
 647         static int timeout_ms = 100;
 648
 649         if (!configured) {
 650                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 651                 configured = 1;
 652         }
 653
 654         return timeout_ms;
 655 }
 656
 657 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
 658                            const struct object_id *old_oid, struct strbuf *err)
 659 {
 660         const char *filename;
 661         int fd;
 662         static struct lock_file lock;
 663         struct strbuf buf = STRBUF_INIT;
 664         int ret = -1;
 665
 666         if (!oid)
 667                 return 0;
 668
 669         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 670
 671         filename = git_path("%s", pseudoref);
 672         fd = hold_lock_file_for_update_timeout(&lock, filename,
 673                                                LOCK_DIE_ON_ERROR,
 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                         die("could not read ref '%s'", pseudoref);
 686                 if (oidcmp(&actual_old_oid, old_oid)) {
 687                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 688                         rollback_lock_file(&lock);
 689                         goto done;
 690                 }
 691         }
 692
 693         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 694                 strbuf_addf(err, "could not write to '%s'", filename);
 695                 rollback_lock_file(&lock);
 696                 goto done;
 697         }
 698
 699         commit_lock_file(&lock);
 700         ret = 0;
 701 done:
 702         strbuf_release(&buf);
 703         return ret;
 704 }
 705
 706 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 707 {
 708         static struct lock_file lock;
 709         const char *filename;
 710
 711         filename = git_path("%s", pseudoref);
 712
 713         if (old_oid && !is_null_oid(old_oid)) {
 714                 int fd;
 715                 struct object_id actual_old_oid;
 716
 717                 fd = hold_lock_file_for_update_timeout(
 718                                 &lock, filename, LOCK_DIE_ON_ERROR,
 719                                 get_files_ref_lock_timeout_ms());
 720                 if (fd < 0)
 721                         die_errno(_("Could not open '%s' for writing"), filename);
 722                 if (read_ref(pseudoref, &actual_old_oid))
 723                         die("could not read ref '%s'", pseudoref);
 724                 if (oidcmp(&actual_old_oid, old_oid)) {
 725                         warning("Unexpected sha1 when deleting %s", pseudoref);
 726                         rollback_lock_file(&lock);
 727                         return -1;
 728                 }
 729
 730                 unlink(filename);
 731                 rollback_lock_file(&lock);
 732         } else {
 733                 unlink(filename);
 734         }
 735
 736         return 0;
 737 }
 738
 739 int refs_delete_ref(struct ref_store *refs, const char *msg,
 740                     const char *refname,
 741                     const struct object_id *old_oid,
 742                     unsigned int flags)
 743 {
 744         struct ref_transaction *transaction;
 745         struct strbuf err = STRBUF_INIT;
 746
 747         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 748                 assert(refs == get_main_ref_store(the_repository));
 749                 return delete_pseudoref(refname, old_oid);
 750         }
 751
 752         transaction = ref_store_transaction_begin(refs, &err);
 753         if (!transaction ||
 754             ref_transaction_delete(transaction, refname, old_oid,
 755                                    flags, msg, &err) ||
 756             ref_transaction_commit(transaction, &err)) {
 757                 error("%s", err.buf);
 758                 ref_transaction_free(transaction);
 759                 strbuf_release(&err);
 760                 return 1;
 761         }
 762         ref_transaction_free(transaction);
 763         strbuf_release(&err);
 764         return 0;
 765 }
 766
 767 int delete_ref(const char *msg, const char *refname,
 768                const struct object_id *old_oid, unsigned int flags)
 769 {
 770         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
 771                                old_oid, flags);
 772 }
 773
 774 int copy_reflog_msg(char *buf, const char *msg)
 775 {
 776         char *cp = buf;
 777         char c;
 778         int wasspace = 1;
 779
 780         *cp++ = '\t';
 781         while ((c = *msg++)) {
 782                 if (wasspace && isspace(c))
 783                         continue;
 784                 wasspace = isspace(c);
 785                 if (wasspace)
 786                         c = ' ';
 787                 *cp++ = c;
 788         }
 789         while (buf < cp && isspace(cp[-1]))
 790                 cp--;
 791         *cp++ = '\n';
 792         return cp - buf;
 793 }
 794
 795 int should_autocreate_reflog(const char *refname)
 796 {
 797         switch (log_all_ref_updates) {
 798         case LOG_REFS_ALWAYS:
 799                 return 1;
 800         case LOG_REFS_NORMAL:
 801                 return starts_with(refname, "refs/heads/") ||
 802                         starts_with(refname, "refs/remotes/") ||
 803                         starts_with(refname, "refs/notes/") ||
 804                         !strcmp(refname, "HEAD");
 805         default:
 806                 return 0;
 807         }
 808 }
 809
 810 int is_branch(const char *refname)
 811 {
 812         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 813 }
 814
 815 struct read_ref_at_cb {
 816         const char *refname;
 817         timestamp_t at_time;
 818         int cnt;
 819         int reccnt;
 820         struct object_id *oid;
 821         int found_it;
 822
 823         struct object_id ooid;
 824         struct object_id noid;
 825         int tz;
 826         timestamp_t date;
 827         char **msg;
 828         timestamp_t *cutoff_time;
 829         int *cutoff_tz;
 830         int *cutoff_cnt;
 831 };
 832
 833 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 834                 const char *email, timestamp_t timestamp, int tz,
 835                 const char *message, void *cb_data)
 836 {
 837         struct read_ref_at_cb *cb = cb_data;
 838
 839         cb->reccnt++;
 840         cb->tz = tz;
 841         cb->date = timestamp;
 842
 843         if (timestamp <= cb->at_time || cb->cnt == 0) {
 844                 if (cb->msg)
 845                         *cb->msg = xstrdup(message);
 846                 if (cb->cutoff_time)
 847                         *cb->cutoff_time = timestamp;
 848                 if (cb->cutoff_tz)
 849                         *cb->cutoff_tz = tz;
 850                 if (cb->cutoff_cnt)
 851                         *cb->cutoff_cnt = cb->reccnt - 1;
 852                 /*
 853                  * we have not yet updated cb->[n|o]oid so they still
 854                  * hold the values for the previous record.
 855                  */
 856                 if (!is_null_oid(&cb->ooid)) {
 857                         oidcpy(cb->oid, noid);
 858                         if (oidcmp(&cb->ooid, noid))
 859                                 warning("Log for ref %s has gap after %s.",
 860                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 861                 }
 862                 else if (cb->date == cb->at_time)
 863                         oidcpy(cb->oid, noid);
 864                 else if (oidcmp(noid, cb->oid))
 865                         warning("Log for ref %s unexpectedly ended on %s.",
 866                                 cb->refname, show_date(cb->date, cb->tz,
 867                                                        DATE_MODE(RFC2822)));
 868                 oidcpy(&cb->ooid, ooid);
 869                 oidcpy(&cb->noid, noid);
 870                 cb->found_it = 1;
 871                 return 1;
 872         }
 873         oidcpy(&cb->ooid, ooid);
 874         oidcpy(&cb->noid, noid);
 875         if (cb->cnt > 0)
 876                 cb->cnt--;
 877         return 0;
 878 }
 879
 880 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 881                                   const char *email, timestamp_t timestamp,
 882                                   int tz, const char *message, void *cb_data)
 883 {
 884         struct read_ref_at_cb *cb = cb_data;
 885
 886         if (cb->msg)
 887                 *cb->msg = xstrdup(message);
 888         if (cb->cutoff_time)
 889                 *cb->cutoff_time = timestamp;
 890         if (cb->cutoff_tz)
 891                 *cb->cutoff_tz = tz;
 892         if (cb->cutoff_cnt)
 893                 *cb->cutoff_cnt = cb->reccnt;
 894         oidcpy(cb->oid, ooid);
 895         if (is_null_oid(cb->oid))
 896                 oidcpy(cb->oid, noid);
 897         /* We just want the first entry */
 898         return 1;
 899 }
 900
 901 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 902                 struct object_id *oid, char **msg,
 903                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 904 {
 905         struct read_ref_at_cb cb;
 906
 907         memset(&cb, 0, sizeof(cb));
 908         cb.refname = refname;
 909         cb.at_time = at_time;
 910         cb.cnt = cnt;
 911         cb.msg = msg;
 912         cb.cutoff_time = cutoff_time;
 913         cb.cutoff_tz = cutoff_tz;
 914         cb.cutoff_cnt = cutoff_cnt;
 915         cb.oid = oid;
 916
 917         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 918
 919         if (!cb.reccnt) {
 920                 if (flags & GET_OID_QUIETLY)
 921                         exit(128);
 922                 else
 923                         die("Log for %s is empty.", refname);
 924         }
 925         if (cb.found_it)
 926                 return 0;
 927
 928         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 929
 930         return 1;
 931 }
 932
 933 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 934                                                     struct strbuf *err)
 935 {
 936         struct ref_transaction *tr;
 937         assert(err);
 938
 939         tr = xcalloc(1, sizeof(struct ref_transaction));
 940         tr->ref_store = refs;
 941         return tr;
 942 }
 943
 944 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 945 {
 946         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
 947 }
 948
 949 void ref_transaction_free(struct ref_transaction *transaction)
 950 {
 951         size_t i;
 952
 953         if (!transaction)
 954                 return;
 955
 956         switch (transaction->state) {
 957         case REF_TRANSACTION_OPEN:
 958         case REF_TRANSACTION_CLOSED:
 959                 /* OK */
 960                 break;
 961         case REF_TRANSACTION_PREPARED:
 962                 die("BUG: free called on a prepared reference transaction");
 963                 break;
 964         default:
 965                 die("BUG: unexpected reference transaction state");
 966                 break;
 967         }
 968
 969         for (i = 0; i < transaction->nr; i++) {
 970                 free(transaction->updates[i]->msg);
 971                 free(transaction->updates[i]);
 972         }
 973         free(transaction->updates);
 974         free(transaction);
 975 }
 976
 977 struct ref_update *ref_transaction_add_update(
 978                 struct ref_transaction *transaction,
 979                 const char *refname, unsigned int flags,
 980                 const struct object_id *new_oid,
 981                 const struct object_id *old_oid,
 982                 const char *msg)
 983 {
 984         struct ref_update *update;
 985
 986         if (transaction->state != REF_TRANSACTION_OPEN)
 987                 die("BUG: update called for transaction that is not open");
 988
 989         FLEX_ALLOC_STR(update, refname, refname);
 990         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 991         transaction->updates[transaction->nr++] = update;
 992
 993         update->flags = flags;
 994
 995         if (flags & REF_HAVE_NEW)
 996                 oidcpy(&update->new_oid, new_oid);
 997         if (flags & REF_HAVE_OLD)
 998                 oidcpy(&update->old_oid, old_oid);
 999         update->msg = xstrdup_or_null(msg);
1000         return update;
1001 }
1002
1003 int ref_transaction_update(struct ref_transaction *transaction,
1004                            const char *refname,
1005                            const struct object_id *new_oid,
1006                            const struct object_id *old_oid,
1007                            unsigned int flags, const char *msg,
1008                            struct strbuf *err)
1009 {
1010         assert(err);
1011
1012         if ((new_oid && !is_null_oid(new_oid)) ?
1013             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1014             !refname_is_safe(refname)) {
1015                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1016                             refname);
1017                 return -1;
1018         }
1019
1020         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1021                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1022
1023         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1024
1025         ref_transaction_add_update(transaction, refname, flags,
1026                                    new_oid, old_oid, msg);
1027         return 0;
1028 }
1029
1030 int ref_transaction_create(struct ref_transaction *transaction,
1031                            const char *refname,
1032                            const struct object_id *new_oid,
1033                            unsigned int flags, const char *msg,
1034                            struct strbuf *err)
1035 {
1036         if (!new_oid || is_null_oid(new_oid))
1037                 die("BUG: create called without valid new_oid");
1038         return ref_transaction_update(transaction, refname, new_oid,
1039                                       &null_oid, flags, msg, err);
1040 }
1041
1042 int ref_transaction_delete(struct ref_transaction *transaction,
1043                            const char *refname,
1044                            const struct object_id *old_oid,
1045                            unsigned int flags, const char *msg,
1046                            struct strbuf *err)
1047 {
1048         if (old_oid && is_null_oid(old_oid))
1049                 die("BUG: delete called with old_oid set to zeros");
1050         return ref_transaction_update(transaction, refname,
1051                                       &null_oid, old_oid,
1052                                       flags, msg, err);
1053 }
1054
1055 int ref_transaction_verify(struct ref_transaction *transaction,
1056                            const char *refname,
1057                            const struct object_id *old_oid,
1058                            unsigned int flags,
1059                            struct strbuf *err)
1060 {
1061         if (!old_oid)
1062                 die("BUG: verify called with old_oid set to NULL");
1063         return ref_transaction_update(transaction, refname,
1064                                       NULL, old_oid,
1065                                       flags, NULL, err);
1066 }
1067
1068 int refs_update_ref(struct ref_store *refs, const char *msg,
1069                     const char *refname, const struct object_id *new_oid,
1070                     const struct object_id *old_oid, unsigned int flags,
1071                     enum action_on_err onerr)
1072 {
1073         struct ref_transaction *t = NULL;
1074         struct strbuf err = STRBUF_INIT;
1075         int ret = 0;
1076
1077         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1078                 assert(refs == get_main_ref_store(the_repository));
1079                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1080         } else {
1081                 t = ref_store_transaction_begin(refs, &err);
1082                 if (!t ||
1083                     ref_transaction_update(t, refname, new_oid, old_oid,
1084                                            flags, msg, &err) ||
1085                     ref_transaction_commit(t, &err)) {
1086                         ret = 1;
1087                         ref_transaction_free(t);
1088                 }
1089         }
1090         if (ret) {
1091                 const char *str = "update_ref failed for ref '%s': %s";
1092
1093                 switch (onerr) {
1094                 case UPDATE_REFS_MSG_ON_ERR:
1095                         error(str, refname, err.buf);
1096                         break;
1097                 case UPDATE_REFS_DIE_ON_ERR:
1098                         die(str, refname, err.buf);
1099                         break;
1100                 case UPDATE_REFS_QUIET_ON_ERR:
1101                         break;
1102                 }
1103                 strbuf_release(&err);
1104                 return 1;
1105         }
1106         strbuf_release(&err);
1107         if (t)
1108                 ref_transaction_free(t);
1109         return 0;
1110 }
1111
1112 int update_ref(const char *msg, const char *refname,
1113                const struct object_id *new_oid,
1114                const struct object_id *old_oid,
1115                unsigned int flags, enum action_on_err onerr)
1116 {
1117         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1118                                old_oid, flags, onerr);
1119 }
1120
1121 char *shorten_unambiguous_ref(const char *refname, int strict)
1122 {
1123         int i;
1124         static char **scanf_fmts;
1125         static int nr_rules;
1126         char *short_name;
1127         struct strbuf resolved_buf = STRBUF_INIT;
1128
1129         if (!nr_rules) {
1130                 /*
1131                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1132                  * Generate a format suitable for scanf from a
1133                  * ref_rev_parse_rules rule by interpolating "%s" at the
1134                  * location of the "%.*s".
1135                  */
1136                 size_t total_len = 0;
1137                 size_t offset = 0;
1138
1139                 /* the rule list is NULL terminated, count them first */
1140                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1141                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1142                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1143
1144                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1145
1146                 offset = 0;
1147                 for (i = 0; i < nr_rules; i++) {
1148                         assert(offset < total_len);
1149                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1150                         offset += snprintf(scanf_fmts[i], total_len - offset,
1151                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1152                 }
1153         }
1154
1155         /* bail out if there are no rules */
1156         if (!nr_rules)
1157                 return xstrdup(refname);
1158
1159         /* buffer for scanf result, at most refname must fit */
1160         short_name = xstrdup(refname);
1161
1162         /* skip first rule, it will always match */
1163         for (i = nr_rules - 1; i > 0 ; --i) {
1164                 int j;
1165                 int rules_to_fail = i;
1166                 int short_name_len;
1167
1168                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1169                         continue;
1170
1171                 short_name_len = strlen(short_name);
1172
1173                 /*
1174                  * in strict mode, all (except the matched one) rules
1175                  * must fail to resolve to a valid non-ambiguous ref
1176                  */
1177                 if (strict)
1178                         rules_to_fail = nr_rules;
1179
1180                 /*
1181                  * check if the short name resolves to a valid ref,
1182                  * but use only rules prior to the matched one
1183                  */
1184                 for (j = 0; j < rules_to_fail; j++) {
1185                         const char *rule = ref_rev_parse_rules[j];
1186
1187                         /* skip matched rule */
1188                         if (i == j)
1189                                 continue;
1190
1191                         /*
1192                          * the short name is ambiguous, if it resolves
1193                          * (with this previous rule) to a valid ref
1194                          * read_ref() returns 0 on success
1195                          */
1196                         strbuf_reset(&resolved_buf);
1197                         strbuf_addf(&resolved_buf, rule,
1198                                     short_name_len, short_name);
1199                         if (ref_exists(resolved_buf.buf))
1200                                 break;
1201                 }
1202
1203                 /*
1204                  * short name is non-ambiguous if all previous rules
1205                  * haven't resolved to a valid ref
1206                  */
1207                 if (j == rules_to_fail) {
1208                         strbuf_release(&resolved_buf);
1209                         return short_name;
1210                 }
1211         }
1212
1213         strbuf_release(&resolved_buf);
1214         free(short_name);
1215         return xstrdup(refname);
1216 }
1217
1218 static struct string_list *hide_refs;
1219
1220 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1221 {
1222         const char *key;
1223         if (!strcmp("transfer.hiderefs", var) ||
1224             (!parse_config_key(var, section, NULL, NULL, &key) &&
1225              !strcmp(key, "hiderefs"))) {
1226                 char *ref;
1227                 int len;
1228
1229                 if (!value)
1230                         return config_error_nonbool(var);
1231                 ref = xstrdup(value);
1232                 len = strlen(ref);
1233                 while (len && ref[len - 1] == '/')
1234                         ref[--len] = '\0';
1235                 if (!hide_refs) {
1236                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1237                         hide_refs->strdup_strings = 1;
1238                 }
1239                 string_list_append(hide_refs, ref);
1240         }
1241         return 0;
1242 }
1243
1244 int ref_is_hidden(const char *refname, const char *refname_full)
1245 {
1246         int i;
1247
1248         if (!hide_refs)
1249                 return 0;
1250         for (i = hide_refs->nr - 1; i >= 0; i--) {
1251                 const char *match = hide_refs->items[i].string;
1252                 const char *subject;
1253                 int neg = 0;
1254                 const char *p;
1255
1256                 if (*match == '!') {
1257                         neg = 1;
1258                         match++;
1259                 }
1260
1261                 if (*match == '^') {
1262                         subject = refname_full;
1263                         match++;
1264                 } else {
1265                         subject = refname;
1266                 }
1267
1268                 /* refname can be NULL when namespaces are used. */
1269                 if (subject &&
1270                     skip_prefix(subject, match, &p) &&
1271                     (!*p || *p == '/'))
1272                         return !neg;
1273         }
1274         return 0;
1275 }
1276
1277 const char *find_descendant_ref(const char *dirname,
1278                                 const struct string_list *extras,
1279                                 const struct string_list *skip)
1280 {
1281         int pos;
1282
1283         if (!extras)
1284                 return NULL;
1285
1286         /*
1287          * Look at the place where dirname would be inserted into
1288          * extras. If there is an entry at that position that starts
1289          * with dirname (remember, dirname includes the trailing
1290          * slash) and is not in skip, then we have a conflict.
1291          */
1292         for (pos = string_list_find_insert_index(extras, dirname, 0);
1293              pos < extras->nr; pos++) {
1294                 const char *extra_refname = extras->items[pos].string;
1295
1296                 if (!starts_with(extra_refname, dirname))
1297                         break;
1298
1299                 if (!skip || !string_list_has_string(skip, extra_refname))
1300                         return extra_refname;
1301         }
1302         return NULL;
1303 }
1304
1305 int refs_rename_ref_available(struct ref_store *refs,
1306                               const char *old_refname,
1307                               const char *new_refname)
1308 {
1309         struct string_list skip = STRING_LIST_INIT_NODUP;
1310         struct strbuf err = STRBUF_INIT;
1311         int ok;
1312
1313         string_list_insert(&skip, old_refname);
1314         ok = !refs_verify_refname_available(refs, new_refname,
1315                                             NULL, &skip, &err);
1316         if (!ok)
1317                 error("%s", err.buf);
1318
1319         string_list_clear(&skip, 0);
1320         strbuf_release(&err);
1321         return ok;
1322 }
1323
1324 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1325 {
1326         struct object_id oid;
1327         int flag;
1328
1329         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1330                                 &oid, &flag))
1331                 return fn("HEAD", &oid, flag, cb_data);
1332
1333         return 0;
1334 }
1335
1336 int head_ref(each_ref_fn fn, void *cb_data)
1337 {
1338         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1339 }
1340
1341 struct ref_iterator *refs_ref_iterator_begin(
1342                 struct ref_store *refs,
1343                 const char *prefix, int trim, int flags)
1344 {
1345         struct ref_iterator *iter;
1346
1347         if (ref_paranoia < 0)
1348                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1349         if (ref_paranoia)
1350                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1351
1352         iter = refs->be->iterator_begin(refs, prefix, flags);
1353
1354         /*
1355          * `iterator_begin()` already takes care of prefix, but we
1356          * might need to do some trimming:
1357          */
1358         if (trim)
1359                 iter = prefix_ref_iterator_begin(iter, "", trim);
1360
1361         /* Sanity check for subclasses: */
1362         if (!iter->ordered)
1363                 BUG("reference iterator is not ordered");
1364
1365         return iter;
1366 }
1367
1368 /*
1369  * Call fn for each reference in the specified submodule for which the
1370  * refname begins with prefix. If trim is non-zero, then trim that
1371  * many characters off the beginning of each refname before passing
1372  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1373  * include broken references in the iteration. If fn ever returns a
1374  * non-zero value, stop the iteration and return that value;
1375  * otherwise, return 0.
1376  */
1377 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1378                            each_ref_fn fn, int trim, int flags, void *cb_data)
1379 {
1380         struct ref_iterator *iter;
1381
1382         if (!refs)
1383                 return 0;
1384
1385         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1386
1387         return do_for_each_ref_iterator(iter, fn, cb_data);
1388 }
1389
1390 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1391 {
1392         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1393 }
1394
1395 int for_each_ref(each_ref_fn fn, void *cb_data)
1396 {
1397         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1398 }
1399
1400 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1401                          each_ref_fn fn, void *cb_data)
1402 {
1403         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1404 }
1405
1406 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1407 {
1408         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1409 }
1410
1411 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1412 {
1413         unsigned int flag = 0;
1414
1415         if (broken)
1416                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1417         return do_for_each_ref(get_main_ref_store(the_repository),
1418                                prefix, fn, 0, flag, cb_data);
1419 }
1420
1421 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1422                              each_ref_fn fn, void *cb_data,
1423                              unsigned int broken)
1424 {
1425         unsigned int flag = 0;
1426
1427         if (broken)
1428                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1429         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1430 }
1431
1432 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1433 {
1434         return do_for_each_ref(get_main_ref_store(r),
1435                                git_replace_ref_base, fn,
1436                                strlen(git_replace_ref_base),
1437                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1438 }
1439
1440 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1441 {
1442         struct strbuf buf = STRBUF_INIT;
1443         int ret;
1444         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1445         ret = do_for_each_ref(get_main_ref_store(the_repository),
1446                               buf.buf, fn, 0, 0, cb_data);
1447         strbuf_release(&buf);
1448         return ret;
1449 }
1450
1451 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1452 {
1453         return do_for_each_ref(refs, "", fn, 0,
1454                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1455 }
1456
1457 int for_each_rawref(each_ref_fn fn, void *cb_data)
1458 {
1459         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1460 }
1461
1462 int refs_read_raw_ref(struct ref_store *ref_store,
1463                       const char *refname, struct object_id *oid,
1464                       struct strbuf *referent, unsigned int *type)
1465 {
1466         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1467 }
1468
1469 /* This function needs to return a meaningful errno on failure */
1470 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1471                                     const char *refname,
1472                                     int resolve_flags,
1473                                     struct object_id *oid, int *flags)
1474 {
1475         static struct strbuf sb_refname = STRBUF_INIT;
1476         struct object_id unused_oid;
1477         int unused_flags;
1478         int symref_count;
1479
1480         if (!oid)
1481                 oid = &unused_oid;
1482         if (!flags)
1483                 flags = &unused_flags;
1484
1485         *flags = 0;
1486
1487         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1488                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1489                     !refname_is_safe(refname)) {
1490                         errno = EINVAL;
1491                         return NULL;
1492                 }
1493
1494                 /*
1495                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1496                  * missing refs and refs that were present but invalid,
1497                  * to complain about the latter to stderr.
1498                  *
1499                  * We don't know whether the ref exists, so don't set
1500                  * REF_ISBROKEN yet.
1501                  */
1502                 *flags |= REF_BAD_NAME;
1503         }
1504
1505         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1506                 unsigned int read_flags = 0;
1507
1508                 if (refs_read_raw_ref(refs, refname,
1509                                       oid, &sb_refname, &read_flags)) {
1510                         *flags |= read_flags;
1511
1512                         /* In reading mode, refs must eventually resolve */
1513                         if (resolve_flags & RESOLVE_REF_READING)
1514                                 return NULL;
1515
1516                         /*
1517                          * Otherwise a missing ref is OK. But the files backend
1518                          * may show errors besides ENOENT if there are
1519                          * similarly-named refs.
1520                          */
1521                         if (errno != ENOENT &&
1522                             errno != EISDIR &&
1523                             errno != ENOTDIR)
1524                                 return NULL;
1525
1526                         oidclr(oid);
1527                         if (*flags & REF_BAD_NAME)
1528                                 *flags |= REF_ISBROKEN;
1529                         return refname;
1530                 }
1531
1532                 *flags |= read_flags;
1533
1534                 if (!(read_flags & REF_ISSYMREF)) {
1535                         if (*flags & REF_BAD_NAME) {
1536                                 oidclr(oid);
1537                                 *flags |= REF_ISBROKEN;
1538                         }
1539                         return refname;
1540                 }
1541
1542                 refname = sb_refname.buf;
1543                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1544                         oidclr(oid);
1545                         return refname;
1546                 }
1547                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1548                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1549                             !refname_is_safe(refname)) {
1550                                 errno = EINVAL;
1551                                 return NULL;
1552                         }
1553
1554                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1555                 }
1556         }
1557
1558         errno = ELOOP;
1559         return NULL;
1560 }
1561
1562 /* backend functions */
1563 int refs_init_db(struct strbuf *err)
1564 {
1565         struct ref_store *refs = get_main_ref_store(the_repository);
1566
1567         return refs->be->init_db(refs, err);
1568 }
1569
1570 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1571                                struct object_id *oid, int *flags)
1572 {
1573         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1574                                        resolve_flags, oid, flags);
1575 }
1576
1577 int resolve_gitlink_ref(const char *submodule, const char *refname,
1578                         struct object_id *oid)
1579 {
1580         struct ref_store *refs;
1581         int flags;
1582
1583         refs = get_submodule_ref_store(submodule);
1584
1585         if (!refs)
1586                 return -1;
1587
1588         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1589             is_null_oid(oid))
1590                 return -1;
1591         return 0;
1592 }
1593
1594 struct ref_store_hash_entry
1595 {
1596         struct hashmap_entry ent; /* must be the first member! */
1597
1598         struct ref_store *refs;
1599
1600         /* NUL-terminated identifier of the ref store: */
1601         char name[FLEX_ARRAY];
1602 };
1603
1604 static int ref_store_hash_cmp(const void *unused_cmp_data,
1605                               const void *entry, const void *entry_or_key,
1606                               const void *keydata)
1607 {
1608         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1609         const char *name = keydata ? keydata : e2->name;
1610
1611         return strcmp(e1->name, name);
1612 }
1613
1614 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1615                 const char *name, struct ref_store *refs)
1616 {
1617         struct ref_store_hash_entry *entry;
1618
1619         FLEX_ALLOC_STR(entry, name, name);
1620         hashmap_entry_init(entry, strhash(name));
1621         entry->refs = refs;
1622         return entry;
1623 }
1624
1625 /* A hashmap of ref_stores, stored by submodule name: */
1626 static struct hashmap submodule_ref_stores;
1627
1628 /* A hashmap of ref_stores, stored by worktree id: */
1629 static struct hashmap worktree_ref_stores;
1630
1631 /*
1632  * Look up a ref store by name. If that ref_store hasn't been
1633  * registered yet, return NULL.
1634  */
1635 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1636                                               const char *name)
1637 {
1638         struct ref_store_hash_entry *entry;
1639
1640         if (!map->tablesize)
1641                 /* It's initialized on demand in register_ref_store(). */
1642                 return NULL;
1643
1644         entry = hashmap_get_from_hash(map, strhash(name), name);
1645         return entry ? entry->refs : NULL;
1646 }
1647
1648 /*
1649  * Create, record, and return a ref_store instance for the specified
1650  * gitdir.
1651  */
1652 static struct ref_store *ref_store_init(const char *gitdir,
1653                                         unsigned int flags)
1654 {
1655         const char *be_name = "files";
1656         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1657         struct ref_store *refs;
1658
1659         if (!be)
1660                 die("BUG: reference backend %s is unknown", be_name);
1661
1662         refs = be->init(gitdir, flags);
1663         return refs;
1664 }
1665
1666 struct ref_store *get_main_ref_store(struct repository *r)
1667 {
1668         if (r->refs)
1669                 return r->refs;
1670
1671         if (!r->gitdir)
1672                 BUG("attempting to get main_ref_store outside of repository");
1673
1674         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1675         return r->refs;
1676 }
1677
1678 /*
1679  * Associate a ref store with a name. It is a fatal error to call this
1680  * function twice for the same name.
1681  */
1682 static void register_ref_store_map(struct hashmap *map,
1683                                    const char *type,
1684                                    struct ref_store *refs,
1685                                    const char *name)
1686 {
1687         if (!map->tablesize)
1688                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1689
1690         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1691                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1692 }
1693
1694 struct ref_store *get_submodule_ref_store(const char *submodule)
1695 {
1696         struct strbuf submodule_sb = STRBUF_INIT;
1697         struct ref_store *refs;
1698         char *to_free = NULL;
1699         size_t len;
1700
1701         if (!submodule)
1702                 return NULL;
1703
1704         len = strlen(submodule);
1705         while (len && is_dir_sep(submodule[len - 1]))
1706                 len--;
1707         if (!len)
1708                 return NULL;
1709
1710         if (submodule[len])
1711                 /* We need to strip off one or more trailing slashes */
1712                 submodule = to_free = xmemdupz(submodule, len);
1713
1714         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1715         if (refs)
1716                 goto done;
1717
1718         strbuf_addstr(&submodule_sb, submodule);
1719         if (!is_nonbare_repository_dir(&submodule_sb))
1720                 goto done;
1721
1722         if (submodule_to_gitdir(&submodule_sb, submodule))
1723                 goto done;
1724
1725         /* assume that add_submodule_odb() has been called */
1726         refs = ref_store_init(submodule_sb.buf,
1727                               REF_STORE_READ | REF_STORE_ODB);
1728         register_ref_store_map(&submodule_ref_stores, "submodule",
1729                                refs, submodule);
1730
1731 done:
1732         strbuf_release(&submodule_sb);
1733         free(to_free);
1734
1735         return refs;
1736 }
1737
1738 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1739 {
1740         struct ref_store *refs;
1741         const char *id;
1742
1743         if (wt->is_current)
1744                 return get_main_ref_store(the_repository);
1745
1746         id = wt->id ? wt->id : "/";
1747         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1748         if (refs)
1749                 return refs;
1750
1751         if (wt->id)
1752                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1753                                       REF_STORE_ALL_CAPS);
1754         else
1755                 refs = ref_store_init(get_git_common_dir(),
1756                                       REF_STORE_ALL_CAPS);
1757
1758         if (refs)
1759                 register_ref_store_map(&worktree_ref_stores, "worktree",
1760                                        refs, id);
1761         return refs;
1762 }
1763
1764 void base_ref_store_init(struct ref_store *refs,
1765                          const struct ref_storage_be *be)
1766 {
1767         refs->be = be;
1768 }
1769
1770 /* backend functions */
1771 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1772 {
1773         return refs->be->pack_refs(refs, flags);
1774 }
1775
1776 int refs_peel_ref(struct ref_store *refs, const char *refname,
1777                   struct object_id *oid)
1778 {
1779         int flag;
1780         struct object_id base;
1781
1782         if (current_ref_iter && current_ref_iter->refname == refname) {
1783                 struct object_id peeled;
1784
1785                 if (ref_iterator_peel(current_ref_iter, &peeled))
1786                         return -1;
1787                 oidcpy(oid, &peeled);
1788                 return 0;
1789         }
1790
1791         if (refs_read_ref_full(refs, refname,
1792                                RESOLVE_REF_READING, &base, &flag))
1793                 return -1;
1794
1795         return peel_object(&base, oid);
1796 }
1797
1798 int peel_ref(const char *refname, struct object_id *oid)
1799 {
1800         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1801 }
1802
1803 int refs_create_symref(struct ref_store *refs,
1804                        const char *ref_target,
1805                        const char *refs_heads_master,
1806                        const char *logmsg)
1807 {
1808         return refs->be->create_symref(refs, ref_target,
1809                                        refs_heads_master,
1810                                        logmsg);
1811 }
1812
1813 int create_symref(const char *ref_target, const char *refs_heads_master,
1814                   const char *logmsg)
1815 {
1816         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1817                                   refs_heads_master, logmsg);
1818 }
1819
1820 int ref_update_reject_duplicates(struct string_list *refnames,
1821                                  struct strbuf *err)
1822 {
1823         size_t i, n = refnames->nr;
1824
1825         assert(err);
1826
1827         for (i = 1; i < n; i++) {
1828                 int cmp = strcmp(refnames->items[i - 1].string,
1829                                  refnames->items[i].string);
1830
1831                 if (!cmp) {
1832                         strbuf_addf(err,
1833                                     "multiple updates for ref '%s' not allowed.",
1834                                     refnames->items[i].string);
1835                         return 1;
1836                 } else if (cmp > 0) {
1837                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1838                 }
1839         }
1840         return 0;
1841 }
1842
1843 int ref_transaction_prepare(struct ref_transaction *transaction,
1844                             struct strbuf *err)
1845 {
1846         struct ref_store *refs = transaction->ref_store;
1847
1848         switch (transaction->state) {
1849         case REF_TRANSACTION_OPEN:
1850                 /* Good. */
1851                 break;
1852         case REF_TRANSACTION_PREPARED:
1853                 die("BUG: prepare called twice on reference transaction");
1854                 break;
1855         case REF_TRANSACTION_CLOSED:
1856                 die("BUG: prepare called on a closed reference transaction");
1857                 break;
1858         default:
1859                 die("BUG: unexpected reference transaction state");
1860                 break;
1861         }
1862
1863         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1864                 strbuf_addstr(err,
1865                               _("ref updates forbidden inside quarantine environment"));
1866                 return -1;
1867         }
1868
1869         return refs->be->transaction_prepare(refs, transaction, err);
1870 }
1871
1872 int ref_transaction_abort(struct ref_transaction *transaction,
1873                           struct strbuf *err)
1874 {
1875         struct ref_store *refs = transaction->ref_store;
1876         int ret = 0;
1877
1878         switch (transaction->state) {
1879         case REF_TRANSACTION_OPEN:
1880                 /* No need to abort explicitly. */
1881                 break;
1882         case REF_TRANSACTION_PREPARED:
1883                 ret = refs->be->transaction_abort(refs, transaction, err);
1884                 break;
1885         case REF_TRANSACTION_CLOSED:
1886                 die("BUG: abort called on a closed reference transaction");
1887                 break;
1888         default:
1889                 die("BUG: unexpected reference transaction state");
1890                 break;
1891         }
1892
1893         ref_transaction_free(transaction);
1894         return ret;
1895 }
1896
1897 int ref_transaction_commit(struct ref_transaction *transaction,
1898                            struct strbuf *err)
1899 {
1900         struct ref_store *refs = transaction->ref_store;
1901         int ret;
1902
1903         switch (transaction->state) {
1904         case REF_TRANSACTION_OPEN:
1905                 /* Need to prepare first. */
1906                 ret = ref_transaction_prepare(transaction, err);
1907                 if (ret)
1908                         return ret;
1909                 break;
1910         case REF_TRANSACTION_PREPARED:
1911                 /* Fall through to finish. */
1912                 break;
1913         case REF_TRANSACTION_CLOSED:
1914                 die("BUG: commit called on a closed reference transaction");
1915                 break;
1916         default:
1917                 die("BUG: unexpected reference transaction state");
1918                 break;
1919         }
1920
1921         return refs->be->transaction_finish(refs, transaction, err);
1922 }
1923
1924 int refs_verify_refname_available(struct ref_store *refs,
1925                                   const char *refname,
1926                                   const struct string_list *extras,
1927                                   const struct string_list *skip,
1928                                   struct strbuf *err)
1929 {
1930         const char *slash;
1931         const char *extra_refname;
1932         struct strbuf dirname = STRBUF_INIT;
1933         struct strbuf referent = STRBUF_INIT;
1934         struct object_id oid;
1935         unsigned int type;
1936         struct ref_iterator *iter;
1937         int ok;
1938         int ret = -1;
1939
1940         /*
1941          * For the sake of comments in this function, suppose that
1942          * refname is "refs/foo/bar".
1943          */
1944
1945         assert(err);
1946
1947         strbuf_grow(&dirname, strlen(refname) + 1);
1948         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1949                 /* Expand dirname to the new prefix, not including the trailing slash: */
1950                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1951
1952                 /*
1953                  * We are still at a leading dir of the refname (e.g.,
1954                  * "refs/foo"; if there is a reference with that name,
1955                  * it is a conflict, *unless* it is in skip.
1956                  */
1957                 if (skip && string_list_has_string(skip, dirname.buf))
1958                         continue;
1959
1960                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1961                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1962                                     dirname.buf, refname);
1963                         goto cleanup;
1964                 }
1965
1966                 if (extras && string_list_has_string(extras, dirname.buf)) {
1967                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1968                                     refname, dirname.buf);
1969                         goto cleanup;
1970                 }
1971         }
1972
1973         /*
1974          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1975          * There is no point in searching for a reference with that
1976          * name, because a refname isn't considered to conflict with
1977          * itself. But we still need to check for references whose
1978          * names are in the "refs/foo/bar/" namespace, because they
1979          * *do* conflict.
1980          */
1981         strbuf_addstr(&dirname, refname + dirname.len);
1982         strbuf_addch(&dirname, '/');
1983
1984         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1985                                        DO_FOR_EACH_INCLUDE_BROKEN);
1986         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1987                 if (skip &&
1988                     string_list_has_string(skip, iter->refname))
1989                         continue;
1990
1991                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1992                             iter->refname, refname);
1993                 ref_iterator_abort(iter);
1994                 goto cleanup;
1995         }
1996
1997         if (ok != ITER_DONE)
1998                 die("BUG: error while iterating over references");
1999
2000         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2001         if (extra_refname)
2002                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2003                             refname, extra_refname);
2004         else
2005                 ret = 0;
2006
2007 cleanup:
2008         strbuf_release(&referent);
2009         strbuf_release(&dirname);
2010         return ret;
2011 }
2012
2013 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2014 {
2015         struct ref_iterator *iter;
2016
2017         iter = refs->be->reflog_iterator_begin(refs);
2018
2019         return do_for_each_ref_iterator(iter, fn, cb_data);
2020 }
2021
2022 int for_each_reflog(each_ref_fn fn, void *cb_data)
2023 {
2024         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2025 }
2026
2027 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2028                                      const char *refname,
2029                                      each_reflog_ent_fn fn,
2030                                      void *cb_data)
2031 {
2032         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2033                                                      fn, cb_data);
2034 }
2035
2036 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2037                                 void *cb_data)
2038 {
2039         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2040                                                 refname, fn, cb_data);
2041 }
2042
2043 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2044                              each_reflog_ent_fn fn, void *cb_data)
2045 {
2046         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2047 }
2048
2049 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2050                         void *cb_data)
2051 {
2052         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2053                                         fn, cb_data);
2054 }
2055
2056 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2057 {
2058         return refs->be->reflog_exists(refs, refname);
2059 }
2060
2061 int reflog_exists(const char *refname)
2062 {
2063         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2064 }
2065
2066 int refs_create_reflog(struct ref_store *refs, const char *refname,
2067                        int force_create, struct strbuf *err)
2068 {
2069         return refs->be->create_reflog(refs, refname, force_create, err);
2070 }
2071
2072 int safe_create_reflog(const char *refname, int force_create,
2073                        struct strbuf *err)
2074 {
2075         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2076                                   force_create, err);
2077 }
2078
2079 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2080 {
2081         return refs->be->delete_reflog(refs, refname);
2082 }
2083
2084 int delete_reflog(const char *refname)
2085 {
2086         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2087 }
2088
2089 int refs_reflog_expire(struct ref_store *refs,
2090                        const char *refname, const struct object_id *oid,
2091                        unsigned int flags,
2092                        reflog_expiry_prepare_fn prepare_fn,
2093                        reflog_expiry_should_prune_fn should_prune_fn,
2094                        reflog_expiry_cleanup_fn cleanup_fn,
2095                        void *policy_cb_data)
2096 {
2097         return refs->be->reflog_expire(refs, refname, oid, flags,
2098                                        prepare_fn, should_prune_fn,
2099                                        cleanup_fn, policy_cb_data);
2100 }
2101
2102 int reflog_expire(const char *refname, const struct object_id *oid,
2103                   unsigned int flags,
2104                   reflog_expiry_prepare_fn prepare_fn,
2105                   reflog_expiry_should_prune_fn should_prune_fn,
2106                   reflog_expiry_cleanup_fn cleanup_fn,
2107                   void *policy_cb_data)
2108 {
2109         return refs_reflog_expire(get_main_ref_store(the_repository),
2110                                   refname, oid, flags,
2111                                   prepare_fn, should_prune_fn,
2112                                   cleanup_fn, policy_cb_data);
2113 }
2114
2115 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2116                                    struct strbuf *err)
2117 {
2118         struct ref_store *refs = transaction->ref_store;
2119
2120         return refs->be->initial_transaction_commit(refs, transaction, err);
2121 }
2122
2123 int refs_delete_refs(struct ref_store *refs, const char *msg,
2124                      struct string_list *refnames, unsigned int flags)
2125 {
2126         return refs->be->delete_refs(refs, msg, refnames, flags);
2127 }
2128
2129 int delete_refs(const char *msg, struct string_list *refnames,
2130                 unsigned int flags)
2131 {
2132         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2133 }
2134
2135 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2136                     const char *newref, const char *logmsg)
2137 {
2138         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2139 }
2140
2141 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2142 {
2143         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2144 }
2145
2146 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2147                     const char *newref, const char *logmsg)
2148 {
2149         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2150 }
2151
2152 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2153 {
2154         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2155 }