4d3dd17f9ff9029a1d8f5767afbf94998e7cd389
   1#ifndef REFS_REFS_INTERNAL_H
   2#define REFS_REFS_INTERNAL_H
   3
   4/*
   5 * Data structures and functions for the internal use of the refs
   6 * module. Code outside of the refs module should use only the public
   7 * functions defined in "refs.h", and should *not* include this file.
   8 */
   9
  10/*
  11 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
  12 * refs (i.e., because the reference is about to be deleted anyway).
  13 */
  14#define REF_DELETING    0x02
  15
  16/*
  17 * Used as a flag in ref_update::flags when a loose ref is being
  18 * pruned. This flag must only be used when REF_NODEREF is set.
  19 */
  20#define REF_ISPRUNING   0x04
  21
  22/*
  23 * Used as a flag in ref_update::flags when the reference should be
  24 * updated to new_sha1.
  25 */
  26#define REF_HAVE_NEW    0x08
  27
  28/*
  29 * Used as a flag in ref_update::flags when old_sha1 should be
  30 * checked.
  31 */
  32#define REF_HAVE_OLD    0x10
  33
  34/*
  35 * Used as a flag in ref_update::flags when the lockfile needs to be
  36 * committed.
  37 */
  38#define REF_NEEDS_COMMIT 0x20
  39
  40/*
  41 * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a
  42 * value to ref_update::flags
  43 */
  44
  45/*
  46 * Used as a flag in ref_update::flags when we want to log a ref
  47 * update but not actually perform it.  This is used when a symbolic
  48 * ref update is split up.
  49 */
  50#define REF_LOG_ONLY 0x80
  51
  52/*
  53 * Internal flag, meaning that the containing ref_update was via an
  54 * update to HEAD.
  55 */
  56#define REF_UPDATE_VIA_HEAD 0x100
  57
  58/*
  59 * Used as a flag in ref_update::flags when the loose reference has
  60 * been deleted.
  61 */
  62#define REF_DELETED_LOOSE 0x200
  63
  64/*
  65 * Return true iff refname is minimally safe. "Safe" here means that
  66 * deleting a loose reference by this name will not do any damage, for
  67 * example by causing a file that is not a reference to be deleted.
  68 * This function does not check that the reference name is legal; for
  69 * that, use check_refname_format().
  70 *
  71 * A refname that starts with "refs/" is considered safe iff it
  72 * doesn't contain any "." or ".." components or consecutive '/'
  73 * characters, end with '/', or (on Windows) contain any '\'
  74 * characters. Names that do not start with "refs/" are considered
  75 * safe iff they consist entirely of upper case characters and '_'
  76 * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
  77 */
  78int refname_is_safe(const char *refname);
  79
  80enum peel_status {
  81        /* object was peeled successfully: */
  82        PEEL_PEELED = 0,
  83
  84        /*
  85         * object cannot be peeled because the named object (or an
  86         * object referred to by a tag in the peel chain), does not
  87         * exist.
  88         */
  89        PEEL_INVALID = -1,
  90
  91        /* object cannot be peeled because it is not a tag: */
  92        PEEL_NON_TAG = -2,
  93
  94        /* ref_entry contains no peeled value because it is a symref: */
  95        PEEL_IS_SYMREF = -3,
  96
  97        /*
  98         * ref_entry cannot be peeled because it is broken (i.e., the
  99         * symbolic reference cannot even be resolved to an object
 100         * name):
 101         */
 102        PEEL_BROKEN = -4
 103};
 104
 105/*
 106 * Peel the named object; i.e., if the object is a tag, resolve the
 107 * tag recursively until a non-tag is found.  If successful, store the
 108 * result to sha1 and return PEEL_PEELED.  If the object is not a tag
 109 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
 110 * and leave sha1 unchanged.
 111 */
 112enum peel_status peel_object(const unsigned char *name, unsigned char *sha1);
 113
 114/*
 115 * Copy the reflog message msg to buf, which has been allocated sufficiently
 116 * large, while cleaning up the whitespaces.  Especially, convert LF to space,
 117 * because reflog file is one line per entry.
 118 */
 119int copy_reflog_msg(char *buf, const char *msg);
 120
 121/**
 122 * Information needed for a single ref update. Set new_sha1 to the new
 123 * value or to null_sha1 to delete the ref. To check the old value
 124 * while the ref is locked, set (flags & REF_HAVE_OLD) and set
 125 * old_sha1 to the old value, or to null_sha1 to ensure the ref does
 126 * not exist before update.
 127 */
 128struct ref_update {
 129
 130        /*
 131         * If (flags & REF_HAVE_NEW), set the reference to this value:
 132         */
 133        struct object_id new_oid;
 134
 135        /*
 136         * If (flags & REF_HAVE_OLD), check that the reference
 137         * previously had this value:
 138         */
 139        struct object_id old_oid;
 140
 141        /*
 142         * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
 143         * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY,
 144         * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and
 145         * REF_DELETED_LOOSE:
 146         */
 147        unsigned int flags;
 148
 149        void *backend_data;
 150        unsigned int type;
 151        char *msg;
 152
 153        /*
 154         * If this ref_update was split off of a symref update via
 155         * split_symref_update(), then this member points at that
 156         * update. This is used for two purposes:
 157         * 1. When reporting errors, we report the refname under which
 158         *    the update was originally requested.
 159         * 2. When we read the old value of this reference, we
 160         *    propagate it back to its parent update for recording in
 161         *    the latter's reflog.
 162         */
 163        struct ref_update *parent_update;
 164
 165        const char refname[FLEX_ARRAY];
 166};
 167
 168int refs_read_raw_ref(struct ref_store *ref_store,
 169                      const char *refname, unsigned char *sha1,
 170                      struct strbuf *referent, unsigned int *type);
 171
 172/*
 173 * Add a ref_update with the specified properties to transaction, and
 174 * return a pointer to the new object. This function does not verify
 175 * that refname is well-formed. new_sha1 and old_sha1 are only
 176 * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
 177 * respectively, are set in flags.
 178 */
 179struct ref_update *ref_transaction_add_update(
 180                struct ref_transaction *transaction,
 181                const char *refname, unsigned int flags,
 182                const unsigned char *new_sha1,
 183                const unsigned char *old_sha1,
 184                const char *msg);
 185
 186/*
 187 * Transaction states.
 188 *
 189 * OPEN:   The transaction is initialized and new updates can still be
 190 *         added to it. An OPEN transaction can be prepared,
 191 *         committed, freed, or aborted (freeing and aborting an open
 192 *         transaction are equivalent).
 193 *
 194 * PREPARED: ref_transaction_prepare(), which locks all of the
 195 *         references involved in the update and checks that the
 196 *         update has no errors, has been called successfully for the
 197 *         transaction. A PREPARED transaction can be committed or
 198 *         aborted.
 199 *
 200 * CLOSED: The transaction is no longer active. A transaction becomes
 201 *         CLOSED if there is a failure while building the transaction
 202 *         or if a transaction is committed or aborted. A CLOSED
 203 *         transaction can only be freed.
 204 */
 205enum ref_transaction_state {
 206        REF_TRANSACTION_OPEN     = 0,
 207        REF_TRANSACTION_PREPARED = 1,
 208        REF_TRANSACTION_CLOSED   = 2
 209};
 210
 211/*
 212 * Data structure for holding a reference transaction, which can
 213 * consist of checks and updates to multiple references, carried out
 214 * as atomically as possible.  This structure is opaque to callers.
 215 */
 216struct ref_transaction {
 217        struct ref_store *ref_store;
 218        struct ref_update **updates;
 219        size_t alloc;
 220        size_t nr;
 221        enum ref_transaction_state state;
 222};
 223
 224/*
 225 * Check for entries in extras that are within the specified
 226 * directory, where dirname is a reference directory name including
 227 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
 228 * conflicting references that are found in skip. If there is a
 229 * conflicting reference, return its name.
 230 *
 231 * extras and skip must be sorted lists of reference names. Either one
 232 * can be NULL, signifying the empty list.
 233 */
 234const char *find_descendant_ref(const char *dirname,
 235                                const struct string_list *extras,
 236                                const struct string_list *skip);
 237
 238/*
 239 * Check whether an attempt to rename old_refname to new_refname would
 240 * cause a D/F conflict with any existing reference (other than
 241 * possibly old_refname). If there would be a conflict, emit an error
 242 * message and return false; otherwise, return true.
 243 *
 244 * Note that this function is not safe against all races with other
 245 * processes (though rename_ref() catches some races that might get by
 246 * this check).
 247 */
 248int refs_rename_ref_available(struct ref_store *refs,
 249                              const char *old_refname,
 250                              const char *new_refname);
 251
 252/* We allow "recursive" symbolic refs. Only within reason, though */
 253#define SYMREF_MAXDEPTH 5
 254
 255/* Include broken references in a do_for_each_ref*() iteration: */
 256#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
 257
 258/*
 259 * Reference iterators
 260 *
 261 * A reference iterator encapsulates the state of an in-progress
 262 * iteration over references. Create an instance of `struct
 263 * ref_iterator` via one of the functions in this module.
 264 *
 265 * A freshly-created ref_iterator doesn't yet point at a reference. To
 266 * advance the iterator, call ref_iterator_advance(). If successful,
 267 * this sets the iterator's refname, oid, and flags fields to describe
 268 * the next reference and returns ITER_OK. The data pointed at by
 269 * refname and oid belong to the iterator; if you want to retain them
 270 * after calling ref_iterator_advance() again or calling
 271 * ref_iterator_abort(), you must make a copy. When the iteration has
 272 * been exhausted, ref_iterator_advance() releases any resources
 273 * assocated with the iteration, frees the ref_iterator object, and
 274 * returns ITER_DONE. If you want to abort the iteration early, call
 275 * ref_iterator_abort(), which also frees the ref_iterator object and
 276 * any associated resources. If there was an internal error advancing
 277 * to the next entry, ref_iterator_advance() aborts the iteration,
 278 * frees the ref_iterator, and returns ITER_ERROR.
 279 *
 280 * The reference currently being looked at can be peeled by calling
 281 * ref_iterator_peel(). This function is often faster than peel_ref(),
 282 * so it should be preferred when iterating over references.
 283 *
 284 * Putting it all together, a typical iteration looks like this:
 285 *
 286 *     int ok;
 287 *     struct ref_iterator *iter = ...;
 288 *
 289 *     while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
 290 *             if (want_to_stop_iteration()) {
 291 *                     ok = ref_iterator_abort(iter);
 292 *                     break;
 293 *             }
 294 *
 295 *             // Access information about the current reference:
 296 *             if (!(iter->flags & REF_ISSYMREF))
 297 *                     printf("%s is %s\n", iter->refname, oid_to_hex(&iter->oid));
 298 *
 299 *             // If you need to peel the reference:
 300 *             ref_iterator_peel(iter, &oid);
 301 *     }
 302 *
 303 *     if (ok != ITER_DONE)
 304 *             handle_error();
 305 */
 306struct ref_iterator {
 307        struct ref_iterator_vtable *vtable;
 308        const char *refname;
 309        const struct object_id *oid;
 310        unsigned int flags;
 311};
 312
 313/*
 314 * Advance the iterator to the first or next item and return ITER_OK.
 315 * If the iteration is exhausted, free the resources associated with
 316 * the ref_iterator and return ITER_DONE. On errors, free the iterator
 317 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
 318 * call this function again after it has returned ITER_DONE or
 319 * ITER_ERROR.
 320 */
 321int ref_iterator_advance(struct ref_iterator *ref_iterator);
 322
 323/*
 324 * If possible, peel the reference currently being viewed by the
 325 * iterator. Return 0 on success.
 326 */
 327int ref_iterator_peel(struct ref_iterator *ref_iterator,
 328                      struct object_id *peeled);
 329
 330/*
 331 * End the iteration before it has been exhausted, freeing the
 332 * reference iterator and any associated resources and returning
 333 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
 334 */
 335int ref_iterator_abort(struct ref_iterator *ref_iterator);
 336
 337/*
 338 * An iterator over nothing (its first ref_iterator_advance() call
 339 * returns ITER_DONE).
 340 */
 341struct ref_iterator *empty_ref_iterator_begin(void);
 342
 343/*
 344 * Return true iff ref_iterator is an empty_ref_iterator.
 345 */
 346int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
 347
 348/*
 349 * Return an iterator that goes over each reference in `refs` for
 350 * which the refname begins with prefix. If trim is non-zero, then
 351 * trim that many characters off the beginning of each refname. flags
 352 * can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in
 353 * the iteration.
 354 */
 355struct ref_iterator *refs_ref_iterator_begin(
 356                struct ref_store *refs,
 357                const char *prefix, int trim, int flags);
 358
 359/*
 360 * A callback function used to instruct merge_ref_iterator how to
 361 * interleave the entries from iter0 and iter1. The function should
 362 * return one of the constants defined in enum iterator_selection. It
 363 * must not advance either of the iterators itself.
 364 *
 365 * The function must be prepared to handle the case that iter0 and/or
 366 * iter1 is NULL, which indicates that the corresponding sub-iterator
 367 * has been exhausted. Its return value must be consistent with the
 368 * current states of the iterators; e.g., it must not return
 369 * ITER_SKIP_1 if iter1 has already been exhausted.
 370 */
 371typedef enum iterator_selection ref_iterator_select_fn(
 372                struct ref_iterator *iter0, struct ref_iterator *iter1,
 373                void *cb_data);
 374
 375/*
 376 * Iterate over the entries from iter0 and iter1, with the values
 377 * interleaved as directed by the select function. The iterator takes
 378 * ownership of iter0 and iter1 and frees them when the iteration is
 379 * over.
 380 */
 381struct ref_iterator *merge_ref_iterator_begin(
 382                struct ref_iterator *iter0, struct ref_iterator *iter1,
 383                ref_iterator_select_fn *select, void *cb_data);
 384
 385/*
 386 * An iterator consisting of the union of the entries from front and
 387 * back. If there are entries common to the two sub-iterators, use the
 388 * one from front. Each iterator must iterate over its entries in
 389 * strcmp() order by refname for this to work.
 390 *
 391 * The new iterator takes ownership of its arguments and frees them
 392 * when the iteration is over. As a convenience to callers, if front
 393 * or back is an empty_ref_iterator, then abort that one immediately
 394 * and return the other iterator directly, without wrapping it.
 395 */
 396struct ref_iterator *overlay_ref_iterator_begin(
 397                struct ref_iterator *front, struct ref_iterator *back);
 398
 399/*
 400 * Wrap iter0, only letting through the references whose names start
 401 * with prefix. If trim is set, set iter->refname to the name of the
 402 * reference with that many characters trimmed off the front;
 403 * otherwise set it to the full refname. The new iterator takes over
 404 * ownership of iter0 and frees it when iteration is over. It makes
 405 * its own copy of prefix.
 406 *
 407 * As an convenience to callers, if prefix is the empty string and
 408 * trim is zero, this function returns iter0 directly, without
 409 * wrapping it.
 410 */
 411struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 412                                               const char *prefix,
 413                                               int trim);
 414
 415/* Internal implementation of reference iteration: */
 416
 417/*
 418 * Base class constructor for ref_iterators. Initialize the
 419 * ref_iterator part of iter, setting its vtable pointer as specified.
 420 * This is meant to be called only by the initializers of derived
 421 * classes.
 422 */
 423void base_ref_iterator_init(struct ref_iterator *iter,
 424                            struct ref_iterator_vtable *vtable);
 425
 426/*
 427 * Base class destructor for ref_iterators. Destroy the ref_iterator
 428 * part of iter and shallow-free the object. This is meant to be
 429 * called only by the destructors of derived classes.
 430 */
 431void base_ref_iterator_free(struct ref_iterator *iter);
 432
 433/* Virtual function declarations for ref_iterators: */
 434
 435typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
 436
 437typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
 438                                 struct object_id *peeled);
 439
 440/*
 441 * Implementations of this function should free any resources specific
 442 * to the derived class, then call base_ref_iterator_free() to clean
 443 * up and free the ref_iterator object.
 444 */
 445typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
 446
 447struct ref_iterator_vtable {
 448        ref_iterator_advance_fn *advance;
 449        ref_iterator_peel_fn *peel;
 450        ref_iterator_abort_fn *abort;
 451};
 452
 453/*
 454 * current_ref_iter is a performance hack: when iterating over
 455 * references using the for_each_ref*() functions, current_ref_iter is
 456 * set to the reference iterator before calling the callback function.
 457 * If the callback function calls peel_ref(), then peel_ref() first
 458 * checks whether the reference to be peeled is the one referred to by
 459 * the iterator (it usually is) and if so, asks the iterator for the
 460 * peeled version of the reference if it is available. This avoids a
 461 * refname lookup in a common case. current_ref_iter is set to NULL
 462 * when the iteration is over.
 463 */
 464extern struct ref_iterator *current_ref_iter;
 465
 466/*
 467 * The common backend for the for_each_*ref* functions. Call fn for
 468 * each reference in iter. If the iterator itself ever returns
 469 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
 470 * the iteration and return that value. Otherwise, return 0. In any
 471 * case, free the iterator when done. This function is basically an
 472 * adapter between the callback style of reference iteration and the
 473 * iterator style.
 474 */
 475int do_for_each_ref_iterator(struct ref_iterator *iter,
 476                             each_ref_fn fn, void *cb_data);
 477
 478/*
 479 * Only include per-worktree refs in a do_for_each_ref*() iteration.
 480 * Normally this will be used with a files ref_store, since that's
 481 * where all reference backends will presumably store their
 482 * per-worktree refs.
 483 */
 484#define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
 485
 486struct ref_store;
 487
 488/* refs backends */
 489
 490/* ref_store_init flags */
 491#define REF_STORE_READ          (1 << 0)
 492#define REF_STORE_WRITE         (1 << 1) /* can perform update operations */
 493#define REF_STORE_ODB           (1 << 2) /* has access to object database */
 494#define REF_STORE_MAIN          (1 << 3)
 495#define REF_STORE_ALL_CAPS      (REF_STORE_READ | \
 496                                 REF_STORE_WRITE | \
 497                                 REF_STORE_ODB | \
 498                                 REF_STORE_MAIN)
 499
 500/*
 501 * Initialize the ref_store for the specified gitdir. These functions
 502 * should call base_ref_store_init() to initialize the shared part of
 503 * the ref_store and to record the ref_store for later lookup.
 504 */
 505typedef struct ref_store *ref_store_init_fn(const char *gitdir,
 506                                            unsigned int flags);
 507
 508typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err);
 509
 510typedef int ref_transaction_prepare_fn(struct ref_store *refs,
 511                                       struct ref_transaction *transaction,
 512                                       struct strbuf *err);
 513
 514typedef int ref_transaction_finish_fn(struct ref_store *refs,
 515                                      struct ref_transaction *transaction,
 516                                      struct strbuf *err);
 517
 518typedef int ref_transaction_abort_fn(struct ref_store *refs,
 519                                     struct ref_transaction *transaction,
 520                                     struct strbuf *err);
 521
 522typedef int ref_transaction_commit_fn(struct ref_store *refs,
 523                                      struct ref_transaction *transaction,
 524                                      struct strbuf *err);
 525
 526typedef int pack_refs_fn(struct ref_store *ref_store, unsigned int flags);
 527typedef int peel_ref_fn(struct ref_store *ref_store,
 528                        const char *refname, unsigned char *sha1);
 529typedef int create_symref_fn(struct ref_store *ref_store,
 530                             const char *ref_target,
 531                             const char *refs_heads_master,
 532                             const char *logmsg);
 533typedef int delete_refs_fn(struct ref_store *ref_store, const char *msg,
 534                           struct string_list *refnames, unsigned int flags);
 535typedef int rename_ref_fn(struct ref_store *ref_store,
 536                          const char *oldref, const char *newref,
 537                          const char *logmsg);
 538
 539/*
 540 * Iterate over the references in `ref_store` whose names start with
 541 * `prefix`. `prefix` is matched as a literal string, without regard
 542 * for path separators. If prefix is NULL or the empty string, iterate
 543 * over all references in `ref_store`.
 544 */
 545typedef struct ref_iterator *ref_iterator_begin_fn(
 546                struct ref_store *ref_store,
 547                const char *prefix, unsigned int flags);
 548
 549/* reflog functions */
 550
 551/*
 552 * Iterate over the references in the specified ref_store that have a
 553 * reflog. The refs are iterated over in arbitrary order.
 554 */
 555typedef struct ref_iterator *reflog_iterator_begin_fn(
 556                struct ref_store *ref_store);
 557
 558typedef int for_each_reflog_ent_fn(struct ref_store *ref_store,
 559                                   const char *refname,
 560                                   each_reflog_ent_fn fn,
 561                                   void *cb_data);
 562typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store,
 563                                           const char *refname,
 564                                           each_reflog_ent_fn fn,
 565                                           void *cb_data);
 566typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname);
 567typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname,
 568                             int force_create, struct strbuf *err);
 569typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname);
 570typedef int reflog_expire_fn(struct ref_store *ref_store,
 571                             const char *refname, const unsigned char *sha1,
 572                             unsigned int flags,
 573                             reflog_expiry_prepare_fn prepare_fn,
 574                             reflog_expiry_should_prune_fn should_prune_fn,
 575                             reflog_expiry_cleanup_fn cleanup_fn,
 576                             void *policy_cb_data);
 577
 578/*
 579 * Read a reference from the specified reference store, non-recursively.
 580 * Set type to describe the reference, and:
 581 *
 582 * - If refname is the name of a normal reference, fill in sha1
 583 *   (leaving referent unchanged).
 584 *
 585 * - If refname is the name of a symbolic reference, write the full
 586 *   name of the reference to which it refers (e.g.
 587 *   "refs/heads/master") to referent and set the REF_ISSYMREF bit in
 588 *   type (leaving sha1 unchanged). The caller is responsible for
 589 *   validating that referent is a valid reference name.
 590 *
 591 * WARNING: refname might be used as part of a filename, so it is
 592 * important from a security standpoint that it be safe in the sense
 593 * of refname_is_safe(). Moreover, for symrefs this function sets
 594 * referent to whatever the repository says, which might not be a
 595 * properly-formatted or even safe reference name. NEITHER INPUT NOR
 596 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
 597 *
 598 * Return 0 on success. If the ref doesn't exist, set errno to ENOENT
 599 * and return -1. If the ref exists but is neither a symbolic ref nor
 600 * a sha1, it is broken; set REF_ISBROKEN in type, set errno to
 601 * EINVAL, and return -1. If there is another error reading the ref,
 602 * set errno appropriately and return -1.
 603 *
 604 * Backend-specific flags might be set in type as well, regardless of
 605 * outcome.
 606 *
 607 * It is OK for refname to point into referent. If so:
 608 *
 609 * - if the function succeeds with REF_ISSYMREF, referent will be
 610 *   overwritten and the memory formerly pointed to by it might be
 611 *   changed or even freed.
 612 *
 613 * - in all other cases, referent will be untouched, and therefore
 614 *   refname will still be valid and unchanged.
 615 */
 616typedef int read_raw_ref_fn(struct ref_store *ref_store,
 617                            const char *refname, unsigned char *sha1,
 618                            struct strbuf *referent, unsigned int *type);
 619
 620struct ref_storage_be {
 621        struct ref_storage_be *next;
 622        const char *name;
 623        ref_store_init_fn *init;
 624        ref_init_db_fn *init_db;
 625
 626        ref_transaction_prepare_fn *transaction_prepare;
 627        ref_transaction_finish_fn *transaction_finish;
 628        ref_transaction_abort_fn *transaction_abort;
 629        ref_transaction_commit_fn *initial_transaction_commit;
 630
 631        pack_refs_fn *pack_refs;
 632        peel_ref_fn *peel_ref;
 633        create_symref_fn *create_symref;
 634        delete_refs_fn *delete_refs;
 635        rename_ref_fn *rename_ref;
 636
 637        ref_iterator_begin_fn *iterator_begin;
 638        read_raw_ref_fn *read_raw_ref;
 639
 640        reflog_iterator_begin_fn *reflog_iterator_begin;
 641        for_each_reflog_ent_fn *for_each_reflog_ent;
 642        for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse;
 643        reflog_exists_fn *reflog_exists;
 644        create_reflog_fn *create_reflog;
 645        delete_reflog_fn *delete_reflog;
 646        reflog_expire_fn *reflog_expire;
 647};
 648
 649extern struct ref_storage_be refs_be_files;
 650
 651/*
 652 * A representation of the reference store for the main repository or
 653 * a submodule. The ref_store instances for submodules are kept in a
 654 * linked list.
 655 */
 656struct ref_store {
 657        /* The backend describing this ref_store's storage scheme: */
 658        const struct ref_storage_be *be;
 659};
 660
 661/*
 662 * Fill in the generic part of refs and add it to our collection of
 663 * reference stores.
 664 */
 665void base_ref_store_init(struct ref_store *refs,
 666                         const struct ref_storage_be *be);
 667
 668#endif /* REFS_REFS_INTERNAL_H */