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
  18 /*
  19  * List of all available backends
  20  */
  21 static struct ref_storage_be *refs_backends = &refs_be_files;
  22
  23 static struct ref_storage_be *find_ref_storage_backend(const char *name)
  24 {
  25         struct ref_storage_be *be;
  26         for (be = refs_backends; be; be = be->next)
  27                 if (!strcmp(be->name, name))
  28                         return be;
  29         return NULL;
  30 }
  31
  32 int ref_storage_backend_exists(const char *name)
  33 {
  34         return find_ref_storage_backend(name) != NULL;
  35 }
  36
  37 /*
  38  * How to handle various characters in refnames:
  39  * 0: An acceptable character for refs
  40  * 1: End-of-component
  41  * 2: ., look for a preceding . to reject .. in refs
  42  * 3: {, look for a preceding @ to reject @{ in refs
  43  * 4: A bad character: ASCII control characters, and
  44  *    ":", "?", "[", "\", "^", "~", SP, or TAB
  45  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  46  */
  47 static unsigned char refname_disposition[256] = {
  48         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  49         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  50         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
  51         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
  52         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
  54         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  55         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
  56 };
  57
  58 /*
  59  * Try to read one refname component from the front of refname.
  60  * Return the length of the component found, or -1 if the component is
  61  * not legal.  It is legal if it is something reasonable to have under
  62  * ".git/refs/"; We do not like it if:
  63  *
  64  * - any path component of it begins with ".", or
  65  * - it has double dots "..", or
  66  * - it has ASCII control characters, or
  67  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
  68  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
  69  * - it ends with a "/", or
  70  * - it ends with ".lock", or
  71  * - it contains a "@{" portion
  72  */
  73 static int check_refname_component(const char *refname, int *flags)
  74 {
  75         const char *cp;
  76         char last = '\0';
  77
  78         for (cp = refname; ; cp++) {
  79                 int ch = *cp & 255;
  80                 unsigned char disp = refname_disposition[ch];
  81                 switch (disp) {
  82                 case 1:
  83                         goto out;
  84                 case 2:
  85                         if (last == '.')
  86                                 return -1; /* Refname contains "..". */
  87                         break;
  88                 case 3:
  89                         if (last == '@')
  90                                 return -1; /* Refname contains "@{". */
  91                         break;
  92                 case 4:
  93                         return -1;
  94                 case 5:
  95                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
  96                                 return -1; /* refspec can't be a pattern */
  97
  98                         /*
  99                          * Unset the pattern flag so that we only accept
 100                          * a single asterisk for one side of refspec.
 101                          */
 102                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
 103                         break;
 104                 }
 105                 last = ch;
 106         }
 107 out:
 108         if (cp == refname)
 109                 return 0; /* Component has zero length. */
 110         if (refname[0] == '.')
 111                 return -1; /* Component starts with '.'. */
 112         if (cp - refname >= LOCK_SUFFIX_LEN &&
 113             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
 114                 return -1; /* Refname ends with ".lock". */
 115         return cp - refname;
 116 }
 117
 118 int check_refname_format(const char *refname, int flags)
 119 {
 120         int component_len, component_count = 0;
 121
 122         if (!strcmp(refname, "@"))
 123                 /* Refname is a single character '@'. */
 124                 return -1;
 125
 126         while (1) {
 127                 /* We are at the start of a path component. */
 128                 component_len = check_refname_component(refname, &flags);
 129                 if (component_len <= 0)
 130                         return -1;
 131
 132                 component_count++;
 133                 if (refname[component_len] == '\0')
 134                         break;
 135                 /* Skip to next component. */
 136                 refname += component_len + 1;
 137         }
 138
 139         if (refname[component_len - 1] == '.')
 140                 return -1; /* Refname ends with '.'. */
 141         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
 142                 return -1; /* Refname has only one component. */
 143         return 0;
 144 }
 145
 146 int refname_is_safe(const char *refname)
 147 {
 148         const char *rest;
 149
 150         if (skip_prefix(refname, "refs/", &rest)) {
 151                 char *buf;
 152                 int result;
 153                 size_t restlen = strlen(rest);
 154
 155                 /* rest must not be empty, or start or end with "/" */
 156                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
 157                         return 0;
 158
 159                 /*
 160                  * Does the refname try to escape refs/?
 161                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
 162                  * is not.
 163                  */
 164                 buf = xmallocz(restlen);
 165                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
 166                 free(buf);
 167                 return result;
 168         }
 169
 170         do {
 171                 if (!isupper(*refname) && *refname != '_')
 172                         return 0;
 173                 refname++;
 174         } while (*refname);
 175         return 1;
 176 }
 177
 178 /*
 179  * Return true if refname, which has the specified oid and flags, can
 180  * be resolved to an object in the database. If the referred-to object
 181  * does not exist, emit a warning and return false.
 182  */
 183 int ref_resolves_to_object(const char *refname,
 184                            const struct object_id *oid,
 185                            unsigned int flags)
 186 {
 187         if (flags & REF_ISBROKEN)
 188                 return 0;
 189         if (!has_sha1_file(oid->hash)) {
 190                 error("%s does not point to a valid object!", refname);
 191                 return 0;
 192         }
 193         return 1;
 194 }
 195
 196 char *refs_resolve_refdup(struct ref_store *refs,
 197                           const char *refname, int resolve_flags,
 198                           struct object_id *oid, int *flags)
 199 {
 200         const char *result;
 201
 202         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
 203                                          oid, flags);
 204         return xstrdup_or_null(result);
 205 }
 206
 207 char *resolve_refdup(const char *refname, int resolve_flags,
 208                      struct object_id *oid, int *flags)
 209 {
 210         return refs_resolve_refdup(get_main_ref_store(),
 211                                    refname, resolve_flags,
 212                                    oid, flags);
 213 }
 214
 215 /* The argument to filter_refs */
 216 struct ref_filter {
 217         const char *pattern;
 218         each_ref_fn *fn;
 219         void *cb_data;
 220 };
 221
 222 int refs_read_ref_full(struct ref_store *refs, const char *refname,
 223                        int resolve_flags, struct object_id *oid, int *flags)
 224 {
 225         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
 226                 return 0;
 227         return -1;
 228 }
 229
 230 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 231 {
 232         return refs_read_ref_full(get_main_ref_store(), refname,
 233                                   resolve_flags, oid, flags);
 234 }
 235
 236 int read_ref(const char *refname, struct object_id *oid)
 237 {
 238         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
 239 }
 240
 241 int ref_exists(const char *refname)
 242 {
 243         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
 244 }
 245
 246 static int match_ref_pattern(const char *refname,
 247                              const struct string_list_item *item)
 248 {
 249         int matched = 0;
 250         if (item->util == NULL) {
 251                 if (!wildmatch(item->string, refname, 0))
 252                         matched = 1;
 253         } else {
 254                 const char *rest;
 255                 if (skip_prefix(refname, item->string, &rest) &&
 256                     (!*rest || *rest == '/'))
 257                         matched = 1;
 258         }
 259         return matched;
 260 }
 261
 262 int ref_filter_match(const char *refname,
 263                      const struct string_list *include_patterns,
 264                      const struct string_list *exclude_patterns)
 265 {
 266         struct string_list_item *item;
 267
 268         if (exclude_patterns && exclude_patterns->nr) {
 269                 for_each_string_list_item(item, exclude_patterns) {
 270                         if (match_ref_pattern(refname, item))
 271                                 return 0;
 272                 }
 273         }
 274
 275         if (include_patterns && include_patterns->nr) {
 276                 int found = 0;
 277                 for_each_string_list_item(item, include_patterns) {
 278                         if (match_ref_pattern(refname, item)) {
 279                                 found = 1;
 280                                 break;
 281                         }
 282                 }
 283
 284                 if (!found)
 285                         return 0;
 286         }
 287         return 1;
 288 }
 289
 290 static int filter_refs(const char *refname, const struct object_id *oid,
 291                            int flags, void *data)
 292 {
 293         struct ref_filter *filter = (struct ref_filter *)data;
 294
 295         if (wildmatch(filter->pattern, refname, 0))
 296                 return 0;
 297         return filter->fn(refname, oid, flags, filter->cb_data);
 298 }
 299
 300 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
 301 {
 302         struct object *o = lookup_unknown_object(name->hash);
 303
 304         if (o->type == OBJ_NONE) {
 305                 int type = oid_object_info(name, NULL);
 306                 if (type < 0 || !object_as_type(o, type, 0))
 307                         return PEEL_INVALID;
 308         }
 309
 310         if (o->type != OBJ_TAG)
 311                 return PEEL_NON_TAG;
 312
 313         o = deref_tag_noverify(o);
 314         if (!o)
 315                 return PEEL_INVALID;
 316
 317         oidcpy(oid, &o->oid);
 318         return PEEL_PEELED;
 319 }
 320
 321 struct warn_if_dangling_data {
 322         FILE *fp;
 323         const char *refname;
 324         const struct string_list *refnames;
 325         const char *msg_fmt;
 326 };
 327
 328 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
 329                                    int flags, void *cb_data)
 330 {
 331         struct warn_if_dangling_data *d = cb_data;
 332         const char *resolves_to;
 333
 334         if (!(flags & REF_ISSYMREF))
 335                 return 0;
 336
 337         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
 338         if (!resolves_to
 339             || (d->refname
 340                 ? strcmp(resolves_to, d->refname)
 341                 : !string_list_has_string(d->refnames, resolves_to))) {
 342                 return 0;
 343         }
 344
 345         fprintf(d->fp, d->msg_fmt, refname);
 346         fputc('\n', d->fp);
 347         return 0;
 348 }
 349
 350 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 351 {
 352         struct warn_if_dangling_data data;
 353
 354         data.fp = fp;
 355         data.refname = refname;
 356         data.refnames = NULL;
 357         data.msg_fmt = msg_fmt;
 358         for_each_rawref(warn_if_dangling_symref, &data);
 359 }
 360
 361 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
 362 {
 363         struct warn_if_dangling_data data;
 364
 365         data.fp = fp;
 366         data.refname = NULL;
 367         data.refnames = refnames;
 368         data.msg_fmt = msg_fmt;
 369         for_each_rawref(warn_if_dangling_symref, &data);
 370 }
 371
 372 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 373 {
 374         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
 375 }
 376
 377 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 378 {
 379         return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
 380 }
 381
 382 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 383 {
 384         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
 385 }
 386
 387 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 388 {
 389         return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
 390 }
 391
 392 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 393 {
 394         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
 395 }
 396
 397 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 398 {
 399         return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
 400 }
 401
 402 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 403 {
 404         struct strbuf buf = STRBUF_INIT;
 405         int ret = 0;
 406         struct object_id oid;
 407         int flag;
 408
 409         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
 410         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
 411                 ret = fn(buf.buf, &oid, flag, cb_data);
 412         strbuf_release(&buf);
 413
 414         return ret;
 415 }
 416
 417 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
 418                         const char *pattern)
 419 {
 420         struct strbuf normalized_pattern = STRBUF_INIT;
 421
 422         if (*pattern == '/')
 423                 BUG("pattern must not start with '/'");
 424
 425         if (prefix) {
 426                 strbuf_addstr(&normalized_pattern, prefix);
 427         }
 428         else if (!starts_with(pattern, "refs/"))
 429                 strbuf_addstr(&normalized_pattern, "refs/");
 430         strbuf_addstr(&normalized_pattern, pattern);
 431         strbuf_strip_suffix(&normalized_pattern, "/");
 432
 433         item->string = strbuf_detach(&normalized_pattern, NULL);
 434         item->util = has_glob_specials(pattern) ? NULL : item->string;
 435         strbuf_release(&normalized_pattern);
 436 }
 437
 438 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 439         const char *prefix, void *cb_data)
 440 {
 441         struct strbuf real_pattern = STRBUF_INIT;
 442         struct ref_filter filter;
 443         int ret;
 444
 445         if (!prefix && !starts_with(pattern, "refs/"))
 446                 strbuf_addstr(&real_pattern, "refs/");
 447         else if (prefix)
 448                 strbuf_addstr(&real_pattern, prefix);
 449         strbuf_addstr(&real_pattern, pattern);
 450
 451         if (!has_glob_specials(pattern)) {
 452                 /* Append implied '/' '*' if not present. */
 453                 strbuf_complete(&real_pattern, '/');
 454                 /* No need to check for '*', there is none. */
 455                 strbuf_addch(&real_pattern, '*');
 456         }
 457
 458         filter.pattern = real_pattern.buf;
 459         filter.fn = fn;
 460         filter.cb_data = cb_data;
 461         ret = for_each_ref(filter_refs, &filter);
 462
 463         strbuf_release(&real_pattern);
 464         return ret;
 465 }
 466
 467 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
 468 {
 469         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
 470 }
 471
 472 const char *prettify_refname(const char *name)
 473 {
 474         if (skip_prefix(name, "refs/heads/", &name) ||
 475             skip_prefix(name, "refs/tags/", &name) ||
 476             skip_prefix(name, "refs/remotes/", &name))
 477                 ; /* nothing */
 478         return name;
 479 }
 480
 481 static const char *ref_rev_parse_rules[] = {
 482         "%.*s",
 483         "refs/%.*s",
 484         "refs/tags/%.*s",
 485         "refs/heads/%.*s",
 486         "refs/remotes/%.*s",
 487         "refs/remotes/%.*s/HEAD",
 488         NULL
 489 };
 490
 491 int refname_match(const char *abbrev_name, const char *full_name)
 492 {
 493         const char **p;
 494         const int abbrev_name_len = strlen(abbrev_name);
 495
 496         for (p = ref_rev_parse_rules; *p; p++) {
 497                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 498                         return 1;
 499                 }
 500         }
 501
 502         return 0;
 503 }
 504
 505 /*
 506  * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
 507  * the results to 'prefixes'
 508  */
 509 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
 510 {
 511         const char **p;
 512         int len = strlen(prefix);
 513
 514         for (p = ref_rev_parse_rules; *p; p++)
 515                 argv_array_pushf(prefixes, *p, len, prefix);
 516 }
 517
 518 /*
 519  * *string and *len will only be substituted, and *string returned (for
 520  * later free()ing) if the string passed in is a magic short-hand form
 521  * to name a branch.
 522  */
 523 static char *substitute_branch_name(const char **string, int *len)
 524 {
 525         struct strbuf buf = STRBUF_INIT;
 526         int ret = interpret_branch_name(*string, *len, &buf, 0);
 527
 528         if (ret == *len) {
 529                 size_t size;
 530                 *string = strbuf_detach(&buf, &size);
 531                 *len = size;
 532                 return (char *)*string;
 533         }
 534
 535         return NULL;
 536 }
 537
 538 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
 539 {
 540         char *last_branch = substitute_branch_name(&str, &len);
 541         int   refs_found  = expand_ref(str, len, oid, ref);
 542         free(last_branch);
 543         return refs_found;
 544 }
 545
 546 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
 547 {
 548         const char **p, *r;
 549         int refs_found = 0;
 550         struct strbuf fullref = STRBUF_INIT;
 551
 552         *ref = NULL;
 553         for (p = ref_rev_parse_rules; *p; p++) {
 554                 struct object_id oid_from_ref;
 555                 struct object_id *this_result;
 556                 int flag;
 557
 558                 this_result = refs_found ? &oid_from_ref : oid;
 559                 strbuf_reset(&fullref);
 560                 strbuf_addf(&fullref, *p, len, str);
 561                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
 562                                        this_result, &flag);
 563                 if (r) {
 564                         if (!refs_found++)
 565                                 *ref = xstrdup(r);
 566                         if (!warn_ambiguous_refs)
 567                                 break;
 568                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
 569                         warning("ignoring dangling symref %s.", fullref.buf);
 570                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
 571                         warning("ignoring broken ref %s.", fullref.buf);
 572                 }
 573         }
 574         strbuf_release(&fullref);
 575         return refs_found;
 576 }
 577
 578 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 579 {
 580         char *last_branch = substitute_branch_name(&str, &len);
 581         const char **p;
 582         int logs_found = 0;
 583         struct strbuf path = STRBUF_INIT;
 584
 585         *log = NULL;
 586         for (p = ref_rev_parse_rules; *p; p++) {
 587                 struct object_id hash;
 588                 const char *ref, *it;
 589
 590                 strbuf_reset(&path);
 591                 strbuf_addf(&path, *p, len, str);
 592                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
 593                                          &hash, NULL);
 594                 if (!ref)
 595                         continue;
 596                 if (reflog_exists(path.buf))
 597                         it = path.buf;
 598                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
 599                         it = ref;
 600                 else
 601                         continue;
 602                 if (!logs_found++) {
 603                         *log = xstrdup(it);
 604                         oidcpy(oid, &hash);
 605                 }
 606                 if (!warn_ambiguous_refs)
 607                         break;
 608         }
 609         strbuf_release(&path);
 610         free(last_branch);
 611         return logs_found;
 612 }
 613
 614 static int is_per_worktree_ref(const char *refname)
 615 {
 616         return !strcmp(refname, "HEAD") ||
 617                 starts_with(refname, "refs/bisect/");
 618 }
 619
 620 static int is_pseudoref_syntax(const char *refname)
 621 {
 622         const char *c;
 623
 624         for (c = refname; *c; c++) {
 625                 if (!isupper(*c) && *c != '-' && *c != '_')
 626                         return 0;
 627         }
 628
 629         return 1;
 630 }
 631
 632 enum ref_type ref_type(const char *refname)
 633 {
 634         if (is_per_worktree_ref(refname))
 635                 return REF_TYPE_PER_WORKTREE;
 636         if (is_pseudoref_syntax(refname))
 637                 return REF_TYPE_PSEUDOREF;
 638        return REF_TYPE_NORMAL;
 639 }
 640
 641 long get_files_ref_lock_timeout_ms(void)
 642 {
 643         static int configured = 0;
 644
 645         /* The default timeout is 100 ms: */
 646         static int timeout_ms = 100;
 647
 648         if (!configured) {
 649                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 650                 configured = 1;
 651         }
 652
 653         return timeout_ms;
 654 }
 655
 656 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
 657                            const struct object_id *old_oid, struct strbuf *err)
 658 {
 659         const char *filename;
 660         int fd;
 661         static struct lock_file lock;
 662         struct strbuf buf = STRBUF_INIT;
 663         int ret = -1;
 664
 665         if (!oid)
 666                 return 0;
 667
 668         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 669
 670         filename = git_path("%s", pseudoref);
 671         fd = hold_lock_file_for_update_timeout(&lock, filename,
 672                                                LOCK_DIE_ON_ERROR,
 673                                                get_files_ref_lock_timeout_ms());
 674         if (fd < 0) {
 675                 strbuf_addf(err, "could not open '%s' for writing: %s",
 676                             filename, strerror(errno));
 677                 goto done;
 678         }
 679
 680         if (old_oid) {
 681                 struct object_id actual_old_oid;
 682
 683                 if (read_ref(pseudoref, &actual_old_oid))
 684                         die("could not read ref '%s'", pseudoref);
 685                 if (oidcmp(&actual_old_oid, old_oid)) {
 686                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 687                         rollback_lock_file(&lock);
 688                         goto done;
 689                 }
 690         }
 691
 692         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 693                 strbuf_addf(err, "could not write to '%s'", filename);
 694                 rollback_lock_file(&lock);
 695                 goto done;
 696         }
 697
 698         commit_lock_file(&lock);
 699         ret = 0;
 700 done:
 701         strbuf_release(&buf);
 702         return ret;
 703 }
 704
 705 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
 706 {
 707         static struct lock_file lock;
 708         const char *filename;
 709
 710         filename = git_path("%s", pseudoref);
 711
 712         if (old_oid && !is_null_oid(old_oid)) {
 713                 int fd;
 714                 struct object_id actual_old_oid;
 715
 716                 fd = hold_lock_file_for_update_timeout(
 717                                 &lock, filename, LOCK_DIE_ON_ERROR,
 718                                 get_files_ref_lock_timeout_ms());
 719                 if (fd < 0)
 720                         die_errno(_("Could not open '%s' for writing"), filename);
 721                 if (read_ref(pseudoref, &actual_old_oid))
 722                         die("could not read ref '%s'", pseudoref);
 723                 if (oidcmp(&actual_old_oid, old_oid)) {
 724                         warning("Unexpected sha1 when deleting %s", pseudoref);
 725                         rollback_lock_file(&lock);
 726                         return -1;
 727                 }
 728
 729                 unlink(filename);
 730                 rollback_lock_file(&lock);
 731         } else {
 732                 unlink(filename);
 733         }
 734
 735         return 0;
 736 }
 737
 738 int refs_delete_ref(struct ref_store *refs, const char *msg,
 739                     const char *refname,
 740                     const struct object_id *old_oid,
 741                     unsigned int flags)
 742 {
 743         struct ref_transaction *transaction;
 744         struct strbuf err = STRBUF_INIT;
 745
 746         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 747                 assert(refs == get_main_ref_store());
 748                 return delete_pseudoref(refname, old_oid);
 749         }
 750
 751         transaction = ref_store_transaction_begin(refs, &err);
 752         if (!transaction ||
 753             ref_transaction_delete(transaction, refname, old_oid,
 754                                    flags, msg, &err) ||
 755             ref_transaction_commit(transaction, &err)) {
 756                 error("%s", err.buf);
 757                 ref_transaction_free(transaction);
 758                 strbuf_release(&err);
 759                 return 1;
 760         }
 761         ref_transaction_free(transaction);
 762         strbuf_release(&err);
 763         return 0;
 764 }
 765
 766 int delete_ref(const char *msg, const char *refname,
 767                const struct object_id *old_oid, unsigned int flags)
 768 {
 769         return refs_delete_ref(get_main_ref_store(), msg, refname,
 770                                old_oid, flags);
 771 }
 772
 773 int copy_reflog_msg(char *buf, const char *msg)
 774 {
 775         char *cp = buf;
 776         char c;
 777         int wasspace = 1;
 778
 779         *cp++ = '\t';
 780         while ((c = *msg++)) {
 781                 if (wasspace && isspace(c))
 782                         continue;
 783                 wasspace = isspace(c);
 784                 if (wasspace)
 785                         c = ' ';
 786                 *cp++ = c;
 787         }
 788         while (buf < cp && isspace(cp[-1]))
 789                 cp--;
 790         *cp++ = '\n';
 791         return cp - buf;
 792 }
 793
 794 int should_autocreate_reflog(const char *refname)
 795 {
 796         switch (log_all_ref_updates) {
 797         case LOG_REFS_ALWAYS:
 798                 return 1;
 799         case LOG_REFS_NORMAL:
 800                 return starts_with(refname, "refs/heads/") ||
 801                         starts_with(refname, "refs/remotes/") ||
 802                         starts_with(refname, "refs/notes/") ||
 803                         !strcmp(refname, "HEAD");
 804         default:
 805                 return 0;
 806         }
 807 }
 808
 809 int is_branch(const char *refname)
 810 {
 811         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 812 }
 813
 814 struct read_ref_at_cb {
 815         const char *refname;
 816         timestamp_t at_time;
 817         int cnt;
 818         int reccnt;
 819         struct object_id *oid;
 820         int found_it;
 821
 822         struct object_id ooid;
 823         struct object_id noid;
 824         int tz;
 825         timestamp_t date;
 826         char **msg;
 827         timestamp_t *cutoff_time;
 828         int *cutoff_tz;
 829         int *cutoff_cnt;
 830 };
 831
 832 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 833                 const char *email, timestamp_t timestamp, int tz,
 834                 const char *message, void *cb_data)
 835 {
 836         struct read_ref_at_cb *cb = cb_data;
 837
 838         cb->reccnt++;
 839         cb->tz = tz;
 840         cb->date = timestamp;
 841
 842         if (timestamp <= cb->at_time || cb->cnt == 0) {
 843                 if (cb->msg)
 844                         *cb->msg = xstrdup(message);
 845                 if (cb->cutoff_time)
 846                         *cb->cutoff_time = timestamp;
 847                 if (cb->cutoff_tz)
 848                         *cb->cutoff_tz = tz;
 849                 if (cb->cutoff_cnt)
 850                         *cb->cutoff_cnt = cb->reccnt - 1;
 851                 /*
 852                  * we have not yet updated cb->[n|o]oid so they still
 853                  * hold the values for the previous record.
 854                  */
 855                 if (!is_null_oid(&cb->ooid)) {
 856                         oidcpy(cb->oid, noid);
 857                         if (oidcmp(&cb->ooid, noid))
 858                                 warning("Log for ref %s has gap after %s.",
 859                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 860                 }
 861                 else if (cb->date == cb->at_time)
 862                         oidcpy(cb->oid, noid);
 863                 else if (oidcmp(noid, cb->oid))
 864                         warning("Log for ref %s unexpectedly ended on %s.",
 865                                 cb->refname, show_date(cb->date, cb->tz,
 866                                                        DATE_MODE(RFC2822)));
 867                 oidcpy(&cb->ooid, ooid);
 868                 oidcpy(&cb->noid, noid);
 869                 cb->found_it = 1;
 870                 return 1;
 871         }
 872         oidcpy(&cb->ooid, ooid);
 873         oidcpy(&cb->noid, noid);
 874         if (cb->cnt > 0)
 875                 cb->cnt--;
 876         return 0;
 877 }
 878
 879 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 880                                   const char *email, timestamp_t timestamp,
 881                                   int tz, const char *message, void *cb_data)
 882 {
 883         struct read_ref_at_cb *cb = cb_data;
 884
 885         if (cb->msg)
 886                 *cb->msg = xstrdup(message);
 887         if (cb->cutoff_time)
 888                 *cb->cutoff_time = timestamp;
 889         if (cb->cutoff_tz)
 890                 *cb->cutoff_tz = tz;
 891         if (cb->cutoff_cnt)
 892                 *cb->cutoff_cnt = cb->reccnt;
 893         oidcpy(cb->oid, ooid);
 894         if (is_null_oid(cb->oid))
 895                 oidcpy(cb->oid, noid);
 896         /* We just want the first entry */
 897         return 1;
 898 }
 899
 900 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 901                 struct object_id *oid, char **msg,
 902                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 903 {
 904         struct read_ref_at_cb cb;
 905
 906         memset(&cb, 0, sizeof(cb));
 907         cb.refname = refname;
 908         cb.at_time = at_time;
 909         cb.cnt = cnt;
 910         cb.msg = msg;
 911         cb.cutoff_time = cutoff_time;
 912         cb.cutoff_tz = cutoff_tz;
 913         cb.cutoff_cnt = cutoff_cnt;
 914         cb.oid = oid;
 915
 916         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 917
 918         if (!cb.reccnt) {
 919                 if (flags & GET_OID_QUIETLY)
 920                         exit(128);
 921                 else
 922                         die("Log for %s is empty.", refname);
 923         }
 924         if (cb.found_it)
 925                 return 0;
 926
 927         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 928
 929         return 1;
 930 }
 931
 932 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 933                                                     struct strbuf *err)
 934 {
 935         struct ref_transaction *tr;
 936         assert(err);
 937
 938         tr = xcalloc(1, sizeof(struct ref_transaction));
 939         tr->ref_store = refs;
 940         return tr;
 941 }
 942
 943 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 944 {
 945         return ref_store_transaction_begin(get_main_ref_store(), err);
 946 }
 947
 948 void ref_transaction_free(struct ref_transaction *transaction)
 949 {
 950         size_t i;
 951
 952         if (!transaction)
 953                 return;
 954
 955         switch (transaction->state) {
 956         case REF_TRANSACTION_OPEN:
 957         case REF_TRANSACTION_CLOSED:
 958                 /* OK */
 959                 break;
 960         case REF_TRANSACTION_PREPARED:
 961                 die("BUG: free called on a prepared reference transaction");
 962                 break;
 963         default:
 964                 die("BUG: unexpected reference transaction state");
 965                 break;
 966         }
 967
 968         for (i = 0; i < transaction->nr; i++) {
 969                 free(transaction->updates[i]->msg);
 970                 free(transaction->updates[i]);
 971         }
 972         free(transaction->updates);
 973         free(transaction);
 974 }
 975
 976 struct ref_update *ref_transaction_add_update(
 977                 struct ref_transaction *transaction,
 978                 const char *refname, unsigned int flags,
 979                 const struct object_id *new_oid,
 980                 const struct object_id *old_oid,
 981                 const char *msg)
 982 {
 983         struct ref_update *update;
 984
 985         if (transaction->state != REF_TRANSACTION_OPEN)
 986                 die("BUG: update called for transaction that is not open");
 987
 988         FLEX_ALLOC_STR(update, refname, refname);
 989         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 990         transaction->updates[transaction->nr++] = update;
 991
 992         update->flags = flags;
 993
 994         if (flags & REF_HAVE_NEW)
 995                 oidcpy(&update->new_oid, new_oid);
 996         if (flags & REF_HAVE_OLD)
 997                 oidcpy(&update->old_oid, old_oid);
 998         update->msg = xstrdup_or_null(msg);
 999         return update;
1000 }
1001
1002 int ref_transaction_update(struct ref_transaction *transaction,
1003                            const char *refname,
1004                            const struct object_id *new_oid,
1005                            const struct object_id *old_oid,
1006                            unsigned int flags, const char *msg,
1007                            struct strbuf *err)
1008 {
1009         assert(err);
1010
1011         if ((new_oid && !is_null_oid(new_oid)) ?
1012             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1013             !refname_is_safe(refname)) {
1014                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1015                             refname);
1016                 return -1;
1017         }
1018
1019         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1020                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1021
1022         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1023
1024         ref_transaction_add_update(transaction, refname, flags,
1025                                    new_oid, old_oid, msg);
1026         return 0;
1027 }
1028
1029 int ref_transaction_create(struct ref_transaction *transaction,
1030                            const char *refname,
1031                            const struct object_id *new_oid,
1032                            unsigned int flags, const char *msg,
1033                            struct strbuf *err)
1034 {
1035         if (!new_oid || is_null_oid(new_oid))
1036                 die("BUG: create called without valid new_oid");
1037         return ref_transaction_update(transaction, refname, new_oid,
1038                                       &null_oid, flags, msg, err);
1039 }
1040
1041 int ref_transaction_delete(struct ref_transaction *transaction,
1042                            const char *refname,
1043                            const struct object_id *old_oid,
1044                            unsigned int flags, const char *msg,
1045                            struct strbuf *err)
1046 {
1047         if (old_oid && is_null_oid(old_oid))
1048                 die("BUG: delete called with old_oid set to zeros");
1049         return ref_transaction_update(transaction, refname,
1050                                       &null_oid, old_oid,
1051                                       flags, msg, err);
1052 }
1053
1054 int ref_transaction_verify(struct ref_transaction *transaction,
1055                            const char *refname,
1056                            const struct object_id *old_oid,
1057                            unsigned int flags,
1058                            struct strbuf *err)
1059 {
1060         if (!old_oid)
1061                 die("BUG: verify called with old_oid set to NULL");
1062         return ref_transaction_update(transaction, refname,
1063                                       NULL, old_oid,
1064                                       flags, NULL, err);
1065 }
1066
1067 int refs_update_ref(struct ref_store *refs, const char *msg,
1068                     const char *refname, const struct object_id *new_oid,
1069                     const struct object_id *old_oid, unsigned int flags,
1070                     enum action_on_err onerr)
1071 {
1072         struct ref_transaction *t = NULL;
1073         struct strbuf err = STRBUF_INIT;
1074         int ret = 0;
1075
1076         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1077                 assert(refs == get_main_ref_store());
1078                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1079         } else {
1080                 t = ref_store_transaction_begin(refs, &err);
1081                 if (!t ||
1082                     ref_transaction_update(t, refname, new_oid, old_oid,
1083                                            flags, msg, &err) ||
1084                     ref_transaction_commit(t, &err)) {
1085                         ret = 1;
1086                         ref_transaction_free(t);
1087                 }
1088         }
1089         if (ret) {
1090                 const char *str = "update_ref failed for ref '%s': %s";
1091
1092                 switch (onerr) {
1093                 case UPDATE_REFS_MSG_ON_ERR:
1094                         error(str, refname, err.buf);
1095                         break;
1096                 case UPDATE_REFS_DIE_ON_ERR:
1097                         die(str, refname, err.buf);
1098                         break;
1099                 case UPDATE_REFS_QUIET_ON_ERR:
1100                         break;
1101                 }
1102                 strbuf_release(&err);
1103                 return 1;
1104         }
1105         strbuf_release(&err);
1106         if (t)
1107                 ref_transaction_free(t);
1108         return 0;
1109 }
1110
1111 int update_ref(const char *msg, const char *refname,
1112                const struct object_id *new_oid,
1113                const struct object_id *old_oid,
1114                unsigned int flags, enum action_on_err onerr)
1115 {
1116         return refs_update_ref(get_main_ref_store(), msg, refname, new_oid,
1117                                old_oid, flags, onerr);
1118 }
1119
1120 char *shorten_unambiguous_ref(const char *refname, int strict)
1121 {
1122         int i;
1123         static char **scanf_fmts;
1124         static int nr_rules;
1125         char *short_name;
1126         struct strbuf resolved_buf = STRBUF_INIT;
1127
1128         if (!nr_rules) {
1129                 /*
1130                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1131                  * Generate a format suitable for scanf from a
1132                  * ref_rev_parse_rules rule by interpolating "%s" at the
1133                  * location of the "%.*s".
1134                  */
1135                 size_t total_len = 0;
1136                 size_t offset = 0;
1137
1138                 /* the rule list is NULL terminated, count them first */
1139                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1140                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1141                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1142
1143                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1144
1145                 offset = 0;
1146                 for (i = 0; i < nr_rules; i++) {
1147                         assert(offset < total_len);
1148                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1149                         offset += snprintf(scanf_fmts[i], total_len - offset,
1150                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1151                 }
1152         }
1153
1154         /* bail out if there are no rules */
1155         if (!nr_rules)
1156                 return xstrdup(refname);
1157
1158         /* buffer for scanf result, at most refname must fit */
1159         short_name = xstrdup(refname);
1160
1161         /* skip first rule, it will always match */
1162         for (i = nr_rules - 1; i > 0 ; --i) {
1163                 int j;
1164                 int rules_to_fail = i;
1165                 int short_name_len;
1166
1167                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1168                         continue;
1169
1170                 short_name_len = strlen(short_name);
1171
1172                 /*
1173                  * in strict mode, all (except the matched one) rules
1174                  * must fail to resolve to a valid non-ambiguous ref
1175                  */
1176                 if (strict)
1177                         rules_to_fail = nr_rules;
1178
1179                 /*
1180                  * check if the short name resolves to a valid ref,
1181                  * but use only rules prior to the matched one
1182                  */
1183                 for (j = 0; j < rules_to_fail; j++) {
1184                         const char *rule = ref_rev_parse_rules[j];
1185
1186                         /* skip matched rule */
1187                         if (i == j)
1188                                 continue;
1189
1190                         /*
1191                          * the short name is ambiguous, if it resolves
1192                          * (with this previous rule) to a valid ref
1193                          * read_ref() returns 0 on success
1194                          */
1195                         strbuf_reset(&resolved_buf);
1196                         strbuf_addf(&resolved_buf, rule,
1197                                     short_name_len, short_name);
1198                         if (ref_exists(resolved_buf.buf))
1199                                 break;
1200                 }
1201
1202                 /*
1203                  * short name is non-ambiguous if all previous rules
1204                  * haven't resolved to a valid ref
1205                  */
1206                 if (j == rules_to_fail) {
1207                         strbuf_release(&resolved_buf);
1208                         return short_name;
1209                 }
1210         }
1211
1212         strbuf_release(&resolved_buf);
1213         free(short_name);
1214         return xstrdup(refname);
1215 }
1216
1217 static struct string_list *hide_refs;
1218
1219 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1220 {
1221         const char *key;
1222         if (!strcmp("transfer.hiderefs", var) ||
1223             (!parse_config_key(var, section, NULL, NULL, &key) &&
1224              !strcmp(key, "hiderefs"))) {
1225                 char *ref;
1226                 int len;
1227
1228                 if (!value)
1229                         return config_error_nonbool(var);
1230                 ref = xstrdup(value);
1231                 len = strlen(ref);
1232                 while (len && ref[len - 1] == '/')
1233                         ref[--len] = '\0';
1234                 if (!hide_refs) {
1235                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1236                         hide_refs->strdup_strings = 1;
1237                 }
1238                 string_list_append(hide_refs, ref);
1239         }
1240         return 0;
1241 }
1242
1243 int ref_is_hidden(const char *refname, const char *refname_full)
1244 {
1245         int i;
1246
1247         if (!hide_refs)
1248                 return 0;
1249         for (i = hide_refs->nr - 1; i >= 0; i--) {
1250                 const char *match = hide_refs->items[i].string;
1251                 const char *subject;
1252                 int neg = 0;
1253                 const char *p;
1254
1255                 if (*match == '!') {
1256                         neg = 1;
1257                         match++;
1258                 }
1259
1260                 if (*match == '^') {
1261                         subject = refname_full;
1262                         match++;
1263                 } else {
1264                         subject = refname;
1265                 }
1266
1267                 /* refname can be NULL when namespaces are used. */
1268                 if (subject &&
1269                     skip_prefix(subject, match, &p) &&
1270                     (!*p || *p == '/'))
1271                         return !neg;
1272         }
1273         return 0;
1274 }
1275
1276 const char *find_descendant_ref(const char *dirname,
1277                                 const struct string_list *extras,
1278                                 const struct string_list *skip)
1279 {
1280         int pos;
1281
1282         if (!extras)
1283                 return NULL;
1284
1285         /*
1286          * Look at the place where dirname would be inserted into
1287          * extras. If there is an entry at that position that starts
1288          * with dirname (remember, dirname includes the trailing
1289          * slash) and is not in skip, then we have a conflict.
1290          */
1291         for (pos = string_list_find_insert_index(extras, dirname, 0);
1292              pos < extras->nr; pos++) {
1293                 const char *extra_refname = extras->items[pos].string;
1294
1295                 if (!starts_with(extra_refname, dirname))
1296                         break;
1297
1298                 if (!skip || !string_list_has_string(skip, extra_refname))
1299                         return extra_refname;
1300         }
1301         return NULL;
1302 }
1303
1304 int refs_rename_ref_available(struct ref_store *refs,
1305                               const char *old_refname,
1306                               const char *new_refname)
1307 {
1308         struct string_list skip = STRING_LIST_INIT_NODUP;
1309         struct strbuf err = STRBUF_INIT;
1310         int ok;
1311
1312         string_list_insert(&skip, old_refname);
1313         ok = !refs_verify_refname_available(refs, new_refname,
1314                                             NULL, &skip, &err);
1315         if (!ok)
1316                 error("%s", err.buf);
1317
1318         string_list_clear(&skip, 0);
1319         strbuf_release(&err);
1320         return ok;
1321 }
1322
1323 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1324 {
1325         struct object_id oid;
1326         int flag;
1327
1328         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1329                                 &oid, &flag))
1330                 return fn("HEAD", &oid, flag, cb_data);
1331
1332         return 0;
1333 }
1334
1335 int head_ref(each_ref_fn fn, void *cb_data)
1336 {
1337         return refs_head_ref(get_main_ref_store(), fn, cb_data);
1338 }
1339
1340 struct ref_iterator *refs_ref_iterator_begin(
1341                 struct ref_store *refs,
1342                 const char *prefix, int trim, int flags)
1343 {
1344         struct ref_iterator *iter;
1345
1346         if (ref_paranoia < 0)
1347                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1348         if (ref_paranoia)
1349                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1350
1351         iter = refs->be->iterator_begin(refs, prefix, flags);
1352
1353         /*
1354          * `iterator_begin()` already takes care of prefix, but we
1355          * might need to do some trimming:
1356          */
1357         if (trim)
1358                 iter = prefix_ref_iterator_begin(iter, "", trim);
1359
1360         /* Sanity check for subclasses: */
1361         if (!iter->ordered)
1362                 BUG("reference iterator is not ordered");
1363
1364         return iter;
1365 }
1366
1367 /*
1368  * Call fn for each reference in the specified submodule for which the
1369  * refname begins with prefix. If trim is non-zero, then trim that
1370  * many characters off the beginning of each refname before passing
1371  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1372  * include broken references in the iteration. If fn ever returns a
1373  * non-zero value, stop the iteration and return that value;
1374  * otherwise, return 0.
1375  */
1376 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1377                            each_ref_fn fn, int trim, int flags, void *cb_data)
1378 {
1379         struct ref_iterator *iter;
1380
1381         if (!refs)
1382                 return 0;
1383
1384         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1385
1386         return do_for_each_ref_iterator(iter, fn, cb_data);
1387 }
1388
1389 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1390 {
1391         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1392 }
1393
1394 int for_each_ref(each_ref_fn fn, void *cb_data)
1395 {
1396         return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1397 }
1398
1399 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1400                          each_ref_fn fn, void *cb_data)
1401 {
1402         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1403 }
1404
1405 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1406 {
1407         return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1408 }
1409
1410 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1411 {
1412         unsigned int flag = 0;
1413
1414         if (broken)
1415                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1416         return do_for_each_ref(get_main_ref_store(),
1417                                prefix, fn, 0, flag, cb_data);
1418 }
1419
1420 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1421                              each_ref_fn fn, void *cb_data,
1422                              unsigned int broken)
1423 {
1424         unsigned int flag = 0;
1425
1426         if (broken)
1427                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1428         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1429 }
1430
1431 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1432 {
1433         return do_for_each_ref(get_main_ref_store(),
1434                                git_replace_ref_base, fn,
1435                                strlen(git_replace_ref_base),
1436                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1437 }
1438
1439 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1440 {
1441         struct strbuf buf = STRBUF_INIT;
1442         int ret;
1443         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1444         ret = do_for_each_ref(get_main_ref_store(),
1445                               buf.buf, fn, 0, 0, cb_data);
1446         strbuf_release(&buf);
1447         return ret;
1448 }
1449
1450 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1451 {
1452         return do_for_each_ref(refs, "", fn, 0,
1453                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1454 }
1455
1456 int for_each_rawref(each_ref_fn fn, void *cb_data)
1457 {
1458         return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1459 }
1460
1461 int refs_read_raw_ref(struct ref_store *ref_store,
1462                       const char *refname, struct object_id *oid,
1463                       struct strbuf *referent, unsigned int *type)
1464 {
1465         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1466 }
1467
1468 /* This function needs to return a meaningful errno on failure */
1469 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1470                                     const char *refname,
1471                                     int resolve_flags,
1472                                     struct object_id *oid, int *flags)
1473 {
1474         static struct strbuf sb_refname = STRBUF_INIT;
1475         struct object_id unused_oid;
1476         int unused_flags;
1477         int symref_count;
1478
1479         if (!oid)
1480                 oid = &unused_oid;
1481         if (!flags)
1482                 flags = &unused_flags;
1483
1484         *flags = 0;
1485
1486         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1487                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1488                     !refname_is_safe(refname)) {
1489                         errno = EINVAL;
1490                         return NULL;
1491                 }
1492
1493                 /*
1494                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1495                  * missing refs and refs that were present but invalid,
1496                  * to complain about the latter to stderr.
1497                  *
1498                  * We don't know whether the ref exists, so don't set
1499                  * REF_ISBROKEN yet.
1500                  */
1501                 *flags |= REF_BAD_NAME;
1502         }
1503
1504         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1505                 unsigned int read_flags = 0;
1506
1507                 if (refs_read_raw_ref(refs, refname,
1508                                       oid, &sb_refname, &read_flags)) {
1509                         *flags |= read_flags;
1510
1511                         /* In reading mode, refs must eventually resolve */
1512                         if (resolve_flags & RESOLVE_REF_READING)
1513                                 return NULL;
1514
1515                         /*
1516                          * Otherwise a missing ref is OK. But the files backend
1517                          * may show errors besides ENOENT if there are
1518                          * similarly-named refs.
1519                          */
1520                         if (errno != ENOENT &&
1521                             errno != EISDIR &&
1522                             errno != ENOTDIR)
1523                                 return NULL;
1524
1525                         oidclr(oid);
1526                         if (*flags & REF_BAD_NAME)
1527                                 *flags |= REF_ISBROKEN;
1528                         return refname;
1529                 }
1530
1531                 *flags |= read_flags;
1532
1533                 if (!(read_flags & REF_ISSYMREF)) {
1534                         if (*flags & REF_BAD_NAME) {
1535                                 oidclr(oid);
1536                                 *flags |= REF_ISBROKEN;
1537                         }
1538                         return refname;
1539                 }
1540
1541                 refname = sb_refname.buf;
1542                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1543                         oidclr(oid);
1544                         return refname;
1545                 }
1546                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1547                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1548                             !refname_is_safe(refname)) {
1549                                 errno = EINVAL;
1550                                 return NULL;
1551                         }
1552
1553                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1554                 }
1555         }
1556
1557         errno = ELOOP;
1558         return NULL;
1559 }
1560
1561 /* backend functions */
1562 int refs_init_db(struct strbuf *err)
1563 {
1564         struct ref_store *refs = get_main_ref_store();
1565
1566         return refs->be->init_db(refs, err);
1567 }
1568
1569 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1570                                struct object_id *oid, int *flags)
1571 {
1572         return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1573                                        resolve_flags, oid, flags);
1574 }
1575
1576 int resolve_gitlink_ref(const char *submodule, const char *refname,
1577                         struct object_id *oid)
1578 {
1579         struct ref_store *refs;
1580         int flags;
1581
1582         refs = get_submodule_ref_store(submodule);
1583
1584         if (!refs)
1585                 return -1;
1586
1587         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1588             is_null_oid(oid))
1589                 return -1;
1590         return 0;
1591 }
1592
1593 struct ref_store_hash_entry
1594 {
1595         struct hashmap_entry ent; /* must be the first member! */
1596
1597         struct ref_store *refs;
1598
1599         /* NUL-terminated identifier of the ref store: */
1600         char name[FLEX_ARRAY];
1601 };
1602
1603 static int ref_store_hash_cmp(const void *unused_cmp_data,
1604                               const void *entry, const void *entry_or_key,
1605                               const void *keydata)
1606 {
1607         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1608         const char *name = keydata ? keydata : e2->name;
1609
1610         return strcmp(e1->name, name);
1611 }
1612
1613 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1614                 const char *name, struct ref_store *refs)
1615 {
1616         struct ref_store_hash_entry *entry;
1617
1618         FLEX_ALLOC_STR(entry, name, name);
1619         hashmap_entry_init(entry, strhash(name));
1620         entry->refs = refs;
1621         return entry;
1622 }
1623
1624 /* A pointer to the ref_store for the main repository: */
1625 static struct ref_store *main_ref_store;
1626
1627 /* A hashmap of ref_stores, stored by submodule name: */
1628 static struct hashmap submodule_ref_stores;
1629
1630 /* A hashmap of ref_stores, stored by worktree id: */
1631 static struct hashmap worktree_ref_stores;
1632
1633 /*
1634  * Look up a ref store by name. If that ref_store hasn't been
1635  * registered yet, return NULL.
1636  */
1637 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1638                                               const char *name)
1639 {
1640         struct ref_store_hash_entry *entry;
1641
1642         if (!map->tablesize)
1643                 /* It's initialized on demand in register_ref_store(). */
1644                 return NULL;
1645
1646         entry = hashmap_get_from_hash(map, strhash(name), name);
1647         return entry ? entry->refs : NULL;
1648 }
1649
1650 /*
1651  * Create, record, and return a ref_store instance for the specified
1652  * gitdir.
1653  */
1654 static struct ref_store *ref_store_init(const char *gitdir,
1655                                         unsigned int flags)
1656 {
1657         const char *be_name = "files";
1658         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1659         struct ref_store *refs;
1660
1661         if (!be)
1662                 die("BUG: reference backend %s is unknown", be_name);
1663
1664         refs = be->init(gitdir, flags);
1665         return refs;
1666 }
1667
1668 struct ref_store *get_main_ref_store(void)
1669 {
1670         if (main_ref_store)
1671                 return main_ref_store;
1672
1673         main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1674         return main_ref_store;
1675 }
1676
1677 /*
1678  * Associate a ref store with a name. It is a fatal error to call this
1679  * function twice for the same name.
1680  */
1681 static void register_ref_store_map(struct hashmap *map,
1682                                    const char *type,
1683                                    struct ref_store *refs,
1684                                    const char *name)
1685 {
1686         if (!map->tablesize)
1687                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1688
1689         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1690                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1691 }
1692
1693 struct ref_store *get_submodule_ref_store(const char *submodule)
1694 {
1695         struct strbuf submodule_sb = STRBUF_INIT;
1696         struct ref_store *refs;
1697         char *to_free = NULL;
1698         size_t len;
1699
1700         if (!submodule)
1701                 return NULL;
1702
1703         len = strlen(submodule);
1704         while (len && is_dir_sep(submodule[len - 1]))
1705                 len--;
1706         if (!len)
1707                 return NULL;
1708
1709         if (submodule[len])
1710                 /* We need to strip off one or more trailing slashes */
1711                 submodule = to_free = xmemdupz(submodule, len);
1712
1713         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1714         if (refs)
1715                 goto done;
1716
1717         strbuf_addstr(&submodule_sb, submodule);
1718         if (!is_nonbare_repository_dir(&submodule_sb))
1719                 goto done;
1720
1721         if (submodule_to_gitdir(&submodule_sb, submodule))
1722                 goto done;
1723
1724         /* assume that add_submodule_odb() has been called */
1725         refs = ref_store_init(submodule_sb.buf,
1726                               REF_STORE_READ | REF_STORE_ODB);
1727         register_ref_store_map(&submodule_ref_stores, "submodule",
1728                                refs, submodule);
1729
1730 done:
1731         strbuf_release(&submodule_sb);
1732         free(to_free);
1733
1734         return refs;
1735 }
1736
1737 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1738 {
1739         struct ref_store *refs;
1740         const char *id;
1741
1742         if (wt->is_current)
1743                 return get_main_ref_store();
1744
1745         id = wt->id ? wt->id : "/";
1746         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1747         if (refs)
1748                 return refs;
1749
1750         if (wt->id)
1751                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1752                                       REF_STORE_ALL_CAPS);
1753         else
1754                 refs = ref_store_init(get_git_common_dir(),
1755                                       REF_STORE_ALL_CAPS);
1756
1757         if (refs)
1758                 register_ref_store_map(&worktree_ref_stores, "worktree",
1759                                        refs, id);
1760         return refs;
1761 }
1762
1763 void base_ref_store_init(struct ref_store *refs,
1764                          const struct ref_storage_be *be)
1765 {
1766         refs->be = be;
1767 }
1768
1769 /* backend functions */
1770 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1771 {
1772         return refs->be->pack_refs(refs, flags);
1773 }
1774
1775 int refs_peel_ref(struct ref_store *refs, const char *refname,
1776                   struct object_id *oid)
1777 {
1778         int flag;
1779         struct object_id base;
1780
1781         if (current_ref_iter && current_ref_iter->refname == refname) {
1782                 struct object_id peeled;
1783
1784                 if (ref_iterator_peel(current_ref_iter, &peeled))
1785                         return -1;
1786                 oidcpy(oid, &peeled);
1787                 return 0;
1788         }
1789
1790         if (refs_read_ref_full(refs, refname,
1791                                RESOLVE_REF_READING, &base, &flag))
1792                 return -1;
1793
1794         return peel_object(&base, oid);
1795 }
1796
1797 int peel_ref(const char *refname, struct object_id *oid)
1798 {
1799         return refs_peel_ref(get_main_ref_store(), refname, oid);
1800 }
1801
1802 int refs_create_symref(struct ref_store *refs,
1803                        const char *ref_target,
1804                        const char *refs_heads_master,
1805                        const char *logmsg)
1806 {
1807         return refs->be->create_symref(refs, ref_target,
1808                                        refs_heads_master,
1809                                        logmsg);
1810 }
1811
1812 int create_symref(const char *ref_target, const char *refs_heads_master,
1813                   const char *logmsg)
1814 {
1815         return refs_create_symref(get_main_ref_store(), ref_target,
1816                                   refs_heads_master, logmsg);
1817 }
1818
1819 int ref_update_reject_duplicates(struct string_list *refnames,
1820                                  struct strbuf *err)
1821 {
1822         size_t i, n = refnames->nr;
1823
1824         assert(err);
1825
1826         for (i = 1; i < n; i++) {
1827                 int cmp = strcmp(refnames->items[i - 1].string,
1828                                  refnames->items[i].string);
1829
1830                 if (!cmp) {
1831                         strbuf_addf(err,
1832                                     "multiple updates for ref '%s' not allowed.",
1833                                     refnames->items[i].string);
1834                         return 1;
1835                 } else if (cmp > 0) {
1836                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1837                 }
1838         }
1839         return 0;
1840 }
1841
1842 int ref_transaction_prepare(struct ref_transaction *transaction,
1843                             struct strbuf *err)
1844 {
1845         struct ref_store *refs = transaction->ref_store;
1846
1847         switch (transaction->state) {
1848         case REF_TRANSACTION_OPEN:
1849                 /* Good. */
1850                 break;
1851         case REF_TRANSACTION_PREPARED:
1852                 die("BUG: prepare called twice on reference transaction");
1853                 break;
1854         case REF_TRANSACTION_CLOSED:
1855                 die("BUG: prepare called on a closed reference transaction");
1856                 break;
1857         default:
1858                 die("BUG: unexpected reference transaction state");
1859                 break;
1860         }
1861
1862         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1863                 strbuf_addstr(err,
1864                               _("ref updates forbidden inside quarantine environment"));
1865                 return -1;
1866         }
1867
1868         return refs->be->transaction_prepare(refs, transaction, err);
1869 }
1870
1871 int ref_transaction_abort(struct ref_transaction *transaction,
1872                           struct strbuf *err)
1873 {
1874         struct ref_store *refs = transaction->ref_store;
1875         int ret = 0;
1876
1877         switch (transaction->state) {
1878         case REF_TRANSACTION_OPEN:
1879                 /* No need to abort explicitly. */
1880                 break;
1881         case REF_TRANSACTION_PREPARED:
1882                 ret = refs->be->transaction_abort(refs, transaction, err);
1883                 break;
1884         case REF_TRANSACTION_CLOSED:
1885                 die("BUG: abort called on a closed reference transaction");
1886                 break;
1887         default:
1888                 die("BUG: unexpected reference transaction state");
1889                 break;
1890         }
1891
1892         ref_transaction_free(transaction);
1893         return ret;
1894 }
1895
1896 int ref_transaction_commit(struct ref_transaction *transaction,
1897                            struct strbuf *err)
1898 {
1899         struct ref_store *refs = transaction->ref_store;
1900         int ret;
1901
1902         switch (transaction->state) {
1903         case REF_TRANSACTION_OPEN:
1904                 /* Need to prepare first. */
1905                 ret = ref_transaction_prepare(transaction, err);
1906                 if (ret)
1907                         return ret;
1908                 break;
1909         case REF_TRANSACTION_PREPARED:
1910                 /* Fall through to finish. */
1911                 break;
1912         case REF_TRANSACTION_CLOSED:
1913                 die("BUG: commit called on a closed reference transaction");
1914                 break;
1915         default:
1916                 die("BUG: unexpected reference transaction state");
1917                 break;
1918         }
1919
1920         return refs->be->transaction_finish(refs, transaction, err);
1921 }
1922
1923 int refs_verify_refname_available(struct ref_store *refs,
1924                                   const char *refname,
1925                                   const struct string_list *extras,
1926                                   const struct string_list *skip,
1927                                   struct strbuf *err)
1928 {
1929         const char *slash;
1930         const char *extra_refname;
1931         struct strbuf dirname = STRBUF_INIT;
1932         struct strbuf referent = STRBUF_INIT;
1933         struct object_id oid;
1934         unsigned int type;
1935         struct ref_iterator *iter;
1936         int ok;
1937         int ret = -1;
1938
1939         /*
1940          * For the sake of comments in this function, suppose that
1941          * refname is "refs/foo/bar".
1942          */
1943
1944         assert(err);
1945
1946         strbuf_grow(&dirname, strlen(refname) + 1);
1947         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1948                 /* Expand dirname to the new prefix, not including the trailing slash: */
1949                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1950
1951                 /*
1952                  * We are still at a leading dir of the refname (e.g.,
1953                  * "refs/foo"; if there is a reference with that name,
1954                  * it is a conflict, *unless* it is in skip.
1955                  */
1956                 if (skip && string_list_has_string(skip, dirname.buf))
1957                         continue;
1958
1959                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1960                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1961                                     dirname.buf, refname);
1962                         goto cleanup;
1963                 }
1964
1965                 if (extras && string_list_has_string(extras, dirname.buf)) {
1966                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1967                                     refname, dirname.buf);
1968                         goto cleanup;
1969                 }
1970         }
1971
1972         /*
1973          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1974          * There is no point in searching for a reference with that
1975          * name, because a refname isn't considered to conflict with
1976          * itself. But we still need to check for references whose
1977          * names are in the "refs/foo/bar/" namespace, because they
1978          * *do* conflict.
1979          */
1980         strbuf_addstr(&dirname, refname + dirname.len);
1981         strbuf_addch(&dirname, '/');
1982
1983         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1984                                        DO_FOR_EACH_INCLUDE_BROKEN);
1985         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1986                 if (skip &&
1987                     string_list_has_string(skip, iter->refname))
1988                         continue;
1989
1990                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1991                             iter->refname, refname);
1992                 ref_iterator_abort(iter);
1993                 goto cleanup;
1994         }
1995
1996         if (ok != ITER_DONE)
1997                 die("BUG: error while iterating over references");
1998
1999         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2000         if (extra_refname)
2001                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2002                             refname, extra_refname);
2003         else
2004                 ret = 0;
2005
2006 cleanup:
2007         strbuf_release(&referent);
2008         strbuf_release(&dirname);
2009         return ret;
2010 }
2011
2012 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2013 {
2014         struct ref_iterator *iter;
2015
2016         iter = refs->be->reflog_iterator_begin(refs);
2017
2018         return do_for_each_ref_iterator(iter, fn, cb_data);
2019 }
2020
2021 int for_each_reflog(each_ref_fn fn, void *cb_data)
2022 {
2023         return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
2024 }
2025
2026 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2027                                      const char *refname,
2028                                      each_reflog_ent_fn fn,
2029                                      void *cb_data)
2030 {
2031         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2032                                                      fn, cb_data);
2033 }
2034
2035 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2036                                 void *cb_data)
2037 {
2038         return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
2039                                                 refname, fn, cb_data);
2040 }
2041
2042 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2043                              each_reflog_ent_fn fn, void *cb_data)
2044 {
2045         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2046 }
2047
2048 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2049                         void *cb_data)
2050 {
2051         return refs_for_each_reflog_ent(get_main_ref_store(), refname,
2052                                         fn, cb_data);
2053 }
2054
2055 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2056 {
2057         return refs->be->reflog_exists(refs, refname);
2058 }
2059
2060 int reflog_exists(const char *refname)
2061 {
2062         return refs_reflog_exists(get_main_ref_store(), refname);
2063 }
2064
2065 int refs_create_reflog(struct ref_store *refs, const char *refname,
2066                        int force_create, struct strbuf *err)
2067 {
2068         return refs->be->create_reflog(refs, refname, force_create, err);
2069 }
2070
2071 int safe_create_reflog(const char *refname, int force_create,
2072                        struct strbuf *err)
2073 {
2074         return refs_create_reflog(get_main_ref_store(), refname,
2075                                   force_create, err);
2076 }
2077
2078 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2079 {
2080         return refs->be->delete_reflog(refs, refname);
2081 }
2082
2083 int delete_reflog(const char *refname)
2084 {
2085         return refs_delete_reflog(get_main_ref_store(), refname);
2086 }
2087
2088 int refs_reflog_expire(struct ref_store *refs,
2089                        const char *refname, const struct object_id *oid,
2090                        unsigned int flags,
2091                        reflog_expiry_prepare_fn prepare_fn,
2092                        reflog_expiry_should_prune_fn should_prune_fn,
2093                        reflog_expiry_cleanup_fn cleanup_fn,
2094                        void *policy_cb_data)
2095 {
2096         return refs->be->reflog_expire(refs, refname, oid, flags,
2097                                        prepare_fn, should_prune_fn,
2098                                        cleanup_fn, policy_cb_data);
2099 }
2100
2101 int reflog_expire(const char *refname, const struct object_id *oid,
2102                   unsigned int flags,
2103                   reflog_expiry_prepare_fn prepare_fn,
2104                   reflog_expiry_should_prune_fn should_prune_fn,
2105                   reflog_expiry_cleanup_fn cleanup_fn,
2106                   void *policy_cb_data)
2107 {
2108         return refs_reflog_expire(get_main_ref_store(),
2109                                   refname, oid, flags,
2110                                   prepare_fn, should_prune_fn,
2111                                   cleanup_fn, policy_cb_data);
2112 }
2113
2114 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2115                                    struct strbuf *err)
2116 {
2117         struct ref_store *refs = transaction->ref_store;
2118
2119         return refs->be->initial_transaction_commit(refs, transaction, err);
2120 }
2121
2122 int refs_delete_refs(struct ref_store *refs, const char *msg,
2123                      struct string_list *refnames, unsigned int flags)
2124 {
2125         return refs->be->delete_refs(refs, msg, refnames, flags);
2126 }
2127
2128 int delete_refs(const char *msg, struct string_list *refnames,
2129                 unsigned int flags)
2130 {
2131         return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2132 }
2133
2134 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2135                     const char *newref, const char *logmsg)
2136 {
2137         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2138 }
2139
2140 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2141 {
2142         return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2143 }
2144
2145 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2146                     const char *newref, const char *logmsg)
2147 {
2148         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2149 }
2150
2151 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2152 {
2153         return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
2154 }