| 1 | #ifndef REFS_REFS_INTERNAL_H |
| 2 | #define REFS_REFS_INTERNAL_H |
| 3 | |
| 4 | #include "refs.h" |
| 5 | #include "iterator.h" |
| 6 | #include "string-list.h" |
| 7 | |
| 8 | struct fsck_options; |
| 9 | struct ref_transaction; |
| 10 | |
| 11 | /* |
| 12 | * Data structures and functions for the internal use of the refs |
| 13 | * module. Code outside of the refs module should use only the public |
| 14 | * functions defined in "refs.h", and should *not* include this file. |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * The following flags can appear in `ref_update::flags`. Their |
| 19 | * numerical values must not conflict with those of REF_NO_DEREF and |
| 20 | * REF_FORCE_CREATE_REFLOG, which are also stored in |
| 21 | * `ref_update::flags`. |
| 22 | */ |
| 23 | |
| 24 | /* |
| 25 | * The reference should be updated to new_oid. |
| 26 | */ |
| 27 | #define REF_HAVE_NEW (1 << 2) |
| 28 | |
| 29 | /* |
| 30 | * The current reference's value should be checked to make sure that |
| 31 | * it agrees with old_oid. |
| 32 | */ |
| 33 | #define REF_HAVE_OLD (1 << 3) |
| 34 | |
| 35 | /* |
| 36 | * Used as a flag in ref_update::flags when we want to log a ref |
| 37 | * update but not actually perform it. This is used when a symbolic |
| 38 | * ref update is split up. |
| 39 | */ |
| 40 | #define REF_LOG_ONLY (1 << 7) |
| 41 | |
| 42 | /* |
| 43 | * The reference contains a peeled object ID. This is used when the |
| 44 | * new_oid is pointing to a tag object and the reference backend |
| 45 | * wants to also store the peeled value for optimized retrieval. |
| 46 | */ |
| 47 | #define REF_HAVE_PEELED (1 << 15) |
| 48 | |
| 49 | /* |
| 50 | * Return the length of time to retry acquiring a loose reference lock |
| 51 | * before giving up, in milliseconds: |
| 52 | */ |
| 53 | long get_files_ref_lock_timeout_ms(struct repository *repo); |
| 54 | |
| 55 | /* |
| 56 | * Return true iff refname is minimally safe. "Safe" here means that |
| 57 | * deleting a loose reference by this name will not do any damage, for |
| 58 | * example by causing a file that is not a reference to be deleted. |
| 59 | * This function does not check that the reference name is legal; for |
| 60 | * that, use check_refname_format(). |
| 61 | * |
| 62 | * A refname that starts with "refs/" is considered safe iff it |
| 63 | * doesn't contain any "." or ".." components or consecutive '/' |
| 64 | * characters, end with '/', or (on Windows) contain any '\' |
| 65 | * characters. Names that do not start with "refs/" are considered |
| 66 | * safe iff they consist entirely of upper case characters and '_' |
| 67 | * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR"). |
| 68 | */ |
| 69 | int refname_is_safe(const char *refname); |
| 70 | |
| 71 | /* |
| 72 | * Helper function: return true if refname, which has the specified |
| 73 | * oid and flags, can be resolved to an object in the database. If the |
| 74 | * referred-to object does not exist, emit a warning and return false. |
| 75 | */ |
| 76 | int ref_resolves_to_object(const char *refname, |
| 77 | struct repository *repo, |
| 78 | const struct object_id *oid, |
| 79 | unsigned int flags); |
| 80 | |
| 81 | /** |
| 82 | * Information needed for a single ref update. Set new_oid to the new |
| 83 | * value or to null_oid to delete the ref. To check the old value |
| 84 | * while the ref is locked, set (flags & REF_HAVE_OLD) and set old_oid |
| 85 | * to the old value, or to null_oid to ensure the ref does not exist |
| 86 | * before update. |
| 87 | */ |
| 88 | struct ref_update { |
| 89 | /* |
| 90 | * If (flags & REF_HAVE_NEW), set the reference to this value |
| 91 | * (or delete it, if `new_oid` is `null_oid`). |
| 92 | */ |
| 93 | struct object_id new_oid; |
| 94 | |
| 95 | /* |
| 96 | * If (flags & REF_HAVE_OLD), check that the reference |
| 97 | * previously had this value (or didn't previously exist, if |
| 98 | * `old_oid` is `null_oid`). |
| 99 | */ |
| 100 | struct object_id old_oid; |
| 101 | |
| 102 | /* |
| 103 | * If the new_oid points to a tag object, set this to the peeled |
| 104 | * object ID for optimized retrieval without needed to hit the odb. |
| 105 | */ |
| 106 | struct object_id peeled; |
| 107 | |
| 108 | /* |
| 109 | * If set, point the reference to this value. This can also be |
| 110 | * used to convert regular references to become symbolic refs. |
| 111 | * Cannot be set together with `new_oid`. |
| 112 | */ |
| 113 | const char *new_target; |
| 114 | |
| 115 | /* |
| 116 | * If set, check that the reference previously pointed to this |
| 117 | * value. Cannot be set together with `old_oid`. |
| 118 | */ |
| 119 | const char *old_target; |
| 120 | |
| 121 | /* |
| 122 | * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, |
| 123 | * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags. |
| 124 | */ |
| 125 | unsigned int flags; |
| 126 | |
| 127 | void *backend_data; |
| 128 | unsigned int type; |
| 129 | char *msg; |
| 130 | char *committer_info; |
| 131 | |
| 132 | /* |
| 133 | * The index overrides the default sort algorithm. This is needed |
| 134 | * when migrating reflogs and we want to ensure we carry over the |
| 135 | * same order. |
| 136 | */ |
| 137 | uint64_t index; |
| 138 | |
| 139 | /* |
| 140 | * Used in batched reference updates to mark if a given update |
| 141 | * was rejected. |
| 142 | */ |
| 143 | enum ref_transaction_error rejection_err; |
| 144 | const char *rejection_details; |
| 145 | |
| 146 | /* |
| 147 | * If this ref_update was split off of a symref update via |
| 148 | * split_symref_update(), then this member points at that |
| 149 | * update. This is used for two purposes: |
| 150 | * 1. When reporting errors, we report the refname under which |
| 151 | * the update was originally requested. |
| 152 | * 2. When we read the old value of this reference, we |
| 153 | * propagate it back to its parent update for recording in |
| 154 | * the latter's reflog. |
| 155 | */ |
| 156 | struct ref_update *parent_update; |
| 157 | |
| 158 | const char refname[FLEX_ARRAY]; |
| 159 | }; |
| 160 | |
| 161 | int refs_read_raw_ref(struct ref_store *ref_store, const char *refname, |
| 162 | struct object_id *oid, struct strbuf *referent, |
| 163 | unsigned int *type, int *failure_errno); |
| 164 | |
| 165 | /* |
| 166 | * Mark a given update as rejected with a given reason. |
| 167 | */ |
| 168 | int ref_transaction_maybe_set_rejected(struct ref_transaction *transaction, |
| 169 | size_t update_idx, |
| 170 | enum ref_transaction_error err, |
| 171 | struct strbuf *details); |
| 172 | |
| 173 | /* |
| 174 | * Add a ref_update with the specified properties to transaction, and |
| 175 | * return a pointer to the new object. This function does not verify |
| 176 | * that refname is well-formed. new_oid and old_oid are only |
| 177 | * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits, |
| 178 | * respectively, are set in flags. |
| 179 | */ |
| 180 | struct ref_update *ref_transaction_add_update( |
| 181 | struct ref_transaction *transaction, |
| 182 | const char *refname, unsigned int flags, |
| 183 | const struct object_id *new_oid, |
| 184 | const struct object_id *old_oid, |
| 185 | const struct object_id *peeled, |
| 186 | const char *new_target, const char *old_target, |
| 187 | const char *committer_info, |
| 188 | const char *msg); |
| 189 | |
| 190 | /* |
| 191 | * Transaction states. |
| 192 | * |
| 193 | * OPEN: The transaction is initialized and new updates can still be |
| 194 | * added to it. An OPEN transaction can be prepared, |
| 195 | * committed, freed, or aborted (freeing and aborting an open |
| 196 | * transaction are equivalent). |
| 197 | * |
| 198 | * PREPARED: ref_transaction_prepare(), which locks all of the |
| 199 | * references involved in the update and checks that the |
| 200 | * update has no errors, has been called successfully for the |
| 201 | * transaction. A PREPARED transaction can be committed or |
| 202 | * aborted. |
| 203 | * |
| 204 | * CLOSED: The transaction is no longer active. A transaction becomes |
| 205 | * CLOSED if there is a failure while building the transaction |
| 206 | * or if a transaction is committed or aborted. A CLOSED |
| 207 | * transaction can only be freed. |
| 208 | */ |
| 209 | enum ref_transaction_state { |
| 210 | REF_TRANSACTION_OPEN = 0, |
| 211 | REF_TRANSACTION_PREPARED = 1, |
| 212 | REF_TRANSACTION_CLOSED = 2 |
| 213 | }; |
| 214 | |
| 215 | /* |
| 216 | * Data structure to hold indices of updates which were rejected, for batched |
| 217 | * reference updates. While the updates themselves hold the rejection error, |
| 218 | * this structure allows a transaction to iterate only over the rejected |
| 219 | * updates. |
| 220 | */ |
| 221 | struct ref_transaction_rejections { |
| 222 | size_t *update_indices; |
| 223 | size_t alloc; |
| 224 | size_t nr; |
| 225 | }; |
| 226 | |
| 227 | /* |
| 228 | * Data structure for holding a reference transaction, which can |
| 229 | * consist of checks and updates to multiple references, carried out |
| 230 | * as atomically as possible. This structure is opaque to callers. |
| 231 | */ |
| 232 | struct ref_transaction { |
| 233 | struct ref_store *ref_store; |
| 234 | struct ref_update **updates; |
| 235 | struct string_list refnames; |
| 236 | size_t alloc; |
| 237 | size_t nr; |
| 238 | enum ref_transaction_state state; |
| 239 | struct ref_transaction_rejections *rejections; |
| 240 | void *backend_data; |
| 241 | unsigned int flags; |
| 242 | uint64_t max_index; |
| 243 | }; |
| 244 | |
| 245 | /* |
| 246 | * Check for entries in extras that are within the specified |
| 247 | * directory, where dirname is a reference directory name including |
| 248 | * the trailing slash (e.g., "refs/heads/foo/"). Ignore any |
| 249 | * conflicting references that are found in skip. If there is a |
| 250 | * conflicting reference, return its name. |
| 251 | * |
| 252 | * extras and skip must be sorted lists of reference names. Either one |
| 253 | * can be NULL, signifying the empty list. |
| 254 | */ |
| 255 | const char *find_descendant_ref(const char *dirname, |
| 256 | const struct string_list *extras, |
| 257 | const struct string_list *skip); |
| 258 | |
| 259 | /* We allow "recursive" symbolic refs. Only within reason, though */ |
| 260 | #define SYMREF_MAXDEPTH 5 |
| 261 | |
| 262 | /* |
| 263 | * Data structure for holding a reference iterator. See refs.h for |
| 264 | * more details and usage instructions. |
| 265 | */ |
| 266 | struct ref_iterator { |
| 267 | struct ref_iterator_vtable *vtable; |
| 268 | struct reference ref; |
| 269 | }; |
| 270 | |
| 271 | /* |
| 272 | * An iterator over nothing (its first ref_iterator_advance() call |
| 273 | * returns ITER_DONE). |
| 274 | */ |
| 275 | struct ref_iterator *empty_ref_iterator_begin(void); |
| 276 | |
| 277 | /* |
| 278 | * Return true iff ref_iterator is an empty_ref_iterator. |
| 279 | */ |
| 280 | int is_empty_ref_iterator(struct ref_iterator *ref_iterator); |
| 281 | |
| 282 | /* |
| 283 | * A callback function used to instruct merge_ref_iterator how to |
| 284 | * interleave the entries from iter0 and iter1. The function should |
| 285 | * return one of the constants defined in enum iterator_selection. It |
| 286 | * must not advance either of the iterators itself. |
| 287 | * |
| 288 | * The function must be prepared to handle the case that iter0 and/or |
| 289 | * iter1 is NULL, which indicates that the corresponding sub-iterator |
| 290 | * has been exhausted. Its return value must be consistent with the |
| 291 | * current states of the iterators; e.g., it must not return |
| 292 | * ITER_SKIP_1 if iter1 has already been exhausted. |
| 293 | */ |
| 294 | typedef enum iterator_selection ref_iterator_select_fn( |
| 295 | struct ref_iterator *iter0, struct ref_iterator *iter1, |
| 296 | void *cb_data); |
| 297 | |
| 298 | /* |
| 299 | * An implementation of ref_iterator_select_fn that merges worktree and common |
| 300 | * refs. Per-worktree refs from the common iterator are ignored, worktree refs |
| 301 | * override common refs. Refs are selected lexicographically. |
| 302 | */ |
| 303 | enum iterator_selection ref_iterator_select(struct ref_iterator *iter_worktree, |
| 304 | struct ref_iterator *iter_common, |
| 305 | void *cb_data); |
| 306 | |
| 307 | /* |
| 308 | * Iterate over the entries from iter0 and iter1, with the values |
| 309 | * interleaved as directed by the select function. The iterator takes |
| 310 | * ownership of iter0 and iter1 and frees them when the iteration is |
| 311 | * over. |
| 312 | */ |
| 313 | struct ref_iterator *merge_ref_iterator_begin( |
| 314 | struct ref_iterator *iter0, struct ref_iterator *iter1, |
| 315 | ref_iterator_select_fn *select, void *cb_data); |
| 316 | |
| 317 | /* |
| 318 | * An iterator consisting of the union of the entries from front and |
| 319 | * back. If there are entries common to the two sub-iterators, use the |
| 320 | * one from front. Each iterator must iterate over its entries in |
| 321 | * strcmp() order by refname for this to work. |
| 322 | * |
| 323 | * The new iterator takes ownership of its arguments and frees them |
| 324 | * when the iteration is over. As a convenience to callers, if front |
| 325 | * or back is an empty_ref_iterator, then abort that one immediately |
| 326 | * and return the other iterator directly, without wrapping it. |
| 327 | */ |
| 328 | struct ref_iterator *overlay_ref_iterator_begin( |
| 329 | struct ref_iterator *front, struct ref_iterator *back); |
| 330 | |
| 331 | /* |
| 332 | * Wrap iter0, only letting through the references whose names start |
| 333 | * with prefix. If trim is set, set iter->refname to the name of the |
| 334 | * reference with that many characters trimmed off the front; |
| 335 | * otherwise set it to the full refname. The new iterator takes over |
| 336 | * ownership of iter0 and frees it when iteration is over. It makes |
| 337 | * its own copy of prefix. |
| 338 | * |
| 339 | * As an convenience to callers, if prefix is the empty string and |
| 340 | * trim is zero, this function returns iter0 directly, without |
| 341 | * wrapping it. |
| 342 | */ |
| 343 | struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0, |
| 344 | const char *prefix, |
| 345 | int trim); |
| 346 | |
| 347 | /* Internal implementation of reference iteration: */ |
| 348 | |
| 349 | /* |
| 350 | * Base class constructor for ref_iterators. Initialize the |
| 351 | * ref_iterator part of iter, setting its vtable pointer as specified. |
| 352 | * This is meant to be called only by the initializers of derived |
| 353 | * classes. |
| 354 | */ |
| 355 | void base_ref_iterator_init(struct ref_iterator *iter, |
| 356 | struct ref_iterator_vtable *vtable); |
| 357 | |
| 358 | /* Virtual function declarations for ref_iterators: */ |
| 359 | |
| 360 | /* |
| 361 | * backend-specific implementation of ref_iterator_advance. For symrefs, the |
| 362 | * function should set REF_ISSYMREF, and it should also dereference the symref |
| 363 | * to provide the OID referent. It should respect do_for_each_ref_flags |
| 364 | * that were passed to refs_ref_iterator_begin(). |
| 365 | */ |
| 366 | typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator); |
| 367 | |
| 368 | /* |
| 369 | * Seek the iterator to the first matching reference. If the |
| 370 | * REF_ITERATOR_SEEK_SET_PREFIX flag is set, it would behave the same as if a |
| 371 | * new iterator was created with the provided refname as prefix. |
| 372 | */ |
| 373 | typedef int ref_iterator_seek_fn(struct ref_iterator *ref_iterator, |
| 374 | const char *refname, unsigned int flags); |
| 375 | |
| 376 | /* |
| 377 | * Implementations of this function should free any resources specific |
| 378 | * to the derived class. |
| 379 | */ |
| 380 | typedef void ref_iterator_release_fn(struct ref_iterator *ref_iterator); |
| 381 | |
| 382 | struct ref_iterator_vtable { |
| 383 | ref_iterator_advance_fn *advance; |
| 384 | ref_iterator_seek_fn *seek; |
| 385 | ref_iterator_release_fn *release; |
| 386 | }; |
| 387 | |
| 388 | struct ref_store; |
| 389 | |
| 390 | /* refs backends */ |
| 391 | |
| 392 | /* ref_store_init flags */ |
| 393 | #define REF_STORE_READ (1 << 0) |
| 394 | #define REF_STORE_WRITE (1 << 1) /* can perform update operations */ |
| 395 | #define REF_STORE_ODB (1 << 2) /* has access to object database */ |
| 396 | #define REF_STORE_MAIN (1 << 3) |
| 397 | #define REF_STORE_ALL_CAPS (REF_STORE_READ | \ |
| 398 | REF_STORE_WRITE | \ |
| 399 | REF_STORE_ODB | \ |
| 400 | REF_STORE_MAIN) |
| 401 | |
| 402 | /* |
| 403 | * Options for initializing the ref backend. All backend-agnostic information |
| 404 | * which backends required will be held here. |
| 405 | */ |
| 406 | struct ref_store_init_options { |
| 407 | /* The kind of operations that the ref_store is allowed to perform. */ |
| 408 | unsigned int access_flags; |
| 409 | }; |
| 410 | |
| 411 | /* |
| 412 | * Initialize the ref_store for the specified gitdir. These functions |
| 413 | * should call base_ref_store_init() to initialize the shared part of |
| 414 | * the ref_store and to record the ref_store for later lookup. |
| 415 | */ |
| 416 | typedef struct ref_store *ref_store_init_fn(struct repository *repo, |
| 417 | const char *payload, |
| 418 | const char *gitdir, |
| 419 | const struct ref_store_init_options *opts); |
| 420 | /* |
| 421 | * Release all memory and resources associated with the ref store. |
| 422 | */ |
| 423 | typedef void ref_store_release_fn(struct ref_store *refs); |
| 424 | |
| 425 | typedef int ref_store_create_on_disk_fn(struct ref_store *refs, |
| 426 | int flags, |
| 427 | struct strbuf *err); |
| 428 | |
| 429 | /* |
| 430 | * Remove the reference store from disk. |
| 431 | */ |
| 432 | typedef int ref_store_remove_on_disk_fn(struct ref_store *refs, |
| 433 | struct strbuf *err); |
| 434 | |
| 435 | typedef int ref_transaction_prepare_fn(struct ref_store *refs, |
| 436 | struct ref_transaction *transaction, |
| 437 | struct strbuf *err); |
| 438 | |
| 439 | typedef int ref_transaction_finish_fn(struct ref_store *refs, |
| 440 | struct ref_transaction *transaction, |
| 441 | struct strbuf *err); |
| 442 | |
| 443 | typedef int ref_transaction_abort_fn(struct ref_store *refs, |
| 444 | struct ref_transaction *transaction, |
| 445 | struct strbuf *err); |
| 446 | |
| 447 | typedef int optimize_fn(struct ref_store *ref_store, |
| 448 | struct refs_optimize_opts *opts); |
| 449 | |
| 450 | typedef int optimize_required_fn(struct ref_store *ref_store, |
| 451 | struct refs_optimize_opts *opts, |
| 452 | bool *required); |
| 453 | |
| 454 | typedef int rename_ref_fn(struct ref_store *ref_store, |
| 455 | const char *oldref, const char *newref, |
| 456 | const char *logmsg); |
| 457 | typedef int copy_ref_fn(struct ref_store *ref_store, |
| 458 | const char *oldref, const char *newref, |
| 459 | const char *logmsg); |
| 460 | |
| 461 | /* |
| 462 | * Iterate over the references in `ref_store` whose names start with |
| 463 | * `prefix`. `prefix` is matched as a literal string, without regard |
| 464 | * for path separators. If prefix is NULL or the empty string, iterate |
| 465 | * over all references in `ref_store`. The output is ordered by |
| 466 | * refname. |
| 467 | */ |
| 468 | typedef struct ref_iterator *ref_iterator_begin_fn( |
| 469 | struct ref_store *ref_store, |
| 470 | const char *prefix, const char **exclude_patterns, |
| 471 | unsigned int flags); |
| 472 | |
| 473 | /* reflog functions */ |
| 474 | |
| 475 | /* |
| 476 | * Iterate over the references in the specified ref_store that have a |
| 477 | * reflog. The refs are iterated over in arbitrary order. |
| 478 | */ |
| 479 | typedef struct ref_iterator *reflog_iterator_begin_fn( |
| 480 | struct ref_store *ref_store); |
| 481 | |
| 482 | typedef int for_each_reflog_ent_fn(struct ref_store *ref_store, |
| 483 | const char *refname, |
| 484 | each_reflog_ent_fn fn, |
| 485 | void *cb_data); |
| 486 | typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store, |
| 487 | const char *refname, |
| 488 | each_reflog_ent_fn fn, |
| 489 | void *cb_data); |
| 490 | typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname); |
| 491 | typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname, |
| 492 | struct strbuf *err); |
| 493 | typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname); |
| 494 | typedef int reflog_expire_fn(struct ref_store *ref_store, |
| 495 | const char *refname, |
| 496 | unsigned int flags, |
| 497 | reflog_expiry_prepare_fn prepare_fn, |
| 498 | reflog_expiry_should_prune_fn should_prune_fn, |
| 499 | reflog_expiry_cleanup_fn cleanup_fn, |
| 500 | void *policy_cb_data); |
| 501 | |
| 502 | /* |
| 503 | * Read a reference from the specified reference store, non-recursively. |
| 504 | * Set type to describe the reference, and: |
| 505 | * |
| 506 | * - If refname is the name of a normal reference, fill in oid |
| 507 | * (leaving referent unchanged). |
| 508 | * |
| 509 | * - If refname is the name of a symbolic reference, write the full |
| 510 | * name of the reference to which it refers (e.g. |
| 511 | * "refs/heads/master") to referent and set the REF_ISSYMREF bit in |
| 512 | * type (leaving oid unchanged). The caller is responsible for |
| 513 | * validating that referent is a valid reference name. |
| 514 | * |
| 515 | * WARNING: refname might be used as part of a filename, so it is |
| 516 | * important from a security standpoint that it be safe in the sense |
| 517 | * of refname_is_safe(). Moreover, for symrefs this function sets |
| 518 | * referent to whatever the repository says, which might not be a |
| 519 | * properly-formatted or even safe reference name. NEITHER INPUT NOR |
| 520 | * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION. |
| 521 | * |
| 522 | * Return 0 on success, or -1 on failure. If the ref exists but is neither a |
| 523 | * symbolic ref nor an object ID, it is broken. In this case set REF_ISBROKEN in |
| 524 | * type, and return -1 (failure_errno should not be ENOENT) |
| 525 | * |
| 526 | * failure_errno provides errno codes that are interpreted beyond error |
| 527 | * reporting. The following error codes have special meaning: |
| 528 | * * ENOENT: the ref doesn't exist |
| 529 | * * EISDIR: ref name is a directory |
| 530 | * * ENOTDIR: ref prefix is not a directory |
| 531 | * |
| 532 | * Backend-specific flags might be set in type as well, regardless of |
| 533 | * outcome. |
| 534 | * |
| 535 | * It is OK for refname to point into referent. If so: |
| 536 | * |
| 537 | * - if the function succeeds with REF_ISSYMREF, referent will be |
| 538 | * overwritten and the memory formerly pointed to by it might be |
| 539 | * changed or even freed. |
| 540 | * |
| 541 | * - in all other cases, referent will be untouched, and therefore |
| 542 | * refname will still be valid and unchanged. |
| 543 | */ |
| 544 | typedef int read_raw_ref_fn(struct ref_store *ref_store, const char *refname, |
| 545 | struct object_id *oid, struct strbuf *referent, |
| 546 | unsigned int *type, int *failure_errno); |
| 547 | |
| 548 | /* |
| 549 | * Read a symbolic reference from the specified reference store. This function |
| 550 | * is optional: if not implemented by a backend, then `read_raw_ref_fn` is used |
| 551 | * to read the symbolcic reference instead. It is intended to be implemented |
| 552 | * only in case the backend can optimize the reading of symbolic references. |
| 553 | * |
| 554 | * Return 0 on success, or -1 on failure. `referent` will be set to the target |
| 555 | * of the symbolic reference on success. This function explicitly does not |
| 556 | * distinguish between error cases and the reference not being a symbolic |
| 557 | * reference to allow backends to optimize this operation in case symbolic and |
| 558 | * non-symbolic references are treated differently. |
| 559 | */ |
| 560 | typedef int read_symbolic_ref_fn(struct ref_store *ref_store, const char *refname, |
| 561 | struct strbuf *referent); |
| 562 | |
| 563 | typedef int fsck_fn(struct ref_store *ref_store, |
| 564 | struct fsck_options *o, |
| 565 | struct worktree *wt); |
| 566 | |
| 567 | struct ref_storage_be { |
| 568 | const char *name; |
| 569 | ref_store_init_fn *init; |
| 570 | ref_store_release_fn *release; |
| 571 | ref_store_create_on_disk_fn *create_on_disk; |
| 572 | ref_store_remove_on_disk_fn *remove_on_disk; |
| 573 | |
| 574 | ref_transaction_prepare_fn *transaction_prepare; |
| 575 | ref_transaction_finish_fn *transaction_finish; |
| 576 | ref_transaction_abort_fn *transaction_abort; |
| 577 | |
| 578 | optimize_fn *optimize; |
| 579 | optimize_required_fn *optimize_required; |
| 580 | rename_ref_fn *rename_ref; |
| 581 | copy_ref_fn *copy_ref; |
| 582 | |
| 583 | ref_iterator_begin_fn *iterator_begin; |
| 584 | read_raw_ref_fn *read_raw_ref; |
| 585 | |
| 586 | /* |
| 587 | * Please refer to `refs_read_symbolic_ref()` for the expected |
| 588 | * behaviour. |
| 589 | */ |
| 590 | read_symbolic_ref_fn *read_symbolic_ref; |
| 591 | |
| 592 | reflog_iterator_begin_fn *reflog_iterator_begin; |
| 593 | for_each_reflog_ent_fn *for_each_reflog_ent; |
| 594 | for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse; |
| 595 | reflog_exists_fn *reflog_exists; |
| 596 | create_reflog_fn *create_reflog; |
| 597 | delete_reflog_fn *delete_reflog; |
| 598 | reflog_expire_fn *reflog_expire; |
| 599 | |
| 600 | fsck_fn *fsck; |
| 601 | }; |
| 602 | |
| 603 | extern struct ref_storage_be refs_be_files; |
| 604 | extern struct ref_storage_be refs_be_reftable; |
| 605 | extern struct ref_storage_be refs_be_packed; |
| 606 | |
| 607 | /* |
| 608 | * A representation of the reference store for the main repository or |
| 609 | * a submodule. The ref_store instances for submodules are kept in a |
| 610 | * hash map; see repo_get_submodule_ref_store() for more info. |
| 611 | */ |
| 612 | struct ref_store { |
| 613 | /* The backend describing this ref_store's storage scheme: */ |
| 614 | const struct ref_storage_be *be; |
| 615 | |
| 616 | struct repository *repo; |
| 617 | |
| 618 | /* |
| 619 | * The gitdir that this ref_store applies to. Note that this is not |
| 620 | * necessarily repo->gitdir if the repo has multiple worktrees. |
| 621 | */ |
| 622 | char *gitdir; |
| 623 | }; |
| 624 | |
| 625 | /* |
| 626 | * Parse contents of a loose ref file. *failure_errno maybe be set to EINVAL for |
| 627 | * invalid contents. |
| 628 | */ |
| 629 | int parse_loose_ref_contents(const struct git_hash_algo *algop, |
| 630 | const char *buf, struct object_id *oid, |
| 631 | struct strbuf *referent, unsigned int *type, |
| 632 | const char **trailing, int *failure_errno); |
| 633 | |
| 634 | /* |
| 635 | * Fill in the generic part of refs and add it to our collection of |
| 636 | * reference stores. |
| 637 | */ |
| 638 | void base_ref_store_init(struct ref_store *refs, struct repository *repo, |
| 639 | const char *path, const struct ref_storage_be *be); |
| 640 | |
| 641 | /* |
| 642 | * Support GIT_TRACE_REFS by optionally wrapping the given ref_store instance. |
| 643 | */ |
| 644 | struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store); |
| 645 | |
| 646 | /* |
| 647 | * Return the refname under which update was originally requested. |
| 648 | */ |
| 649 | const char *ref_update_original_update_refname(struct ref_update *update); |
| 650 | |
| 651 | /* |
| 652 | * Helper function to check if the new value is null, this |
| 653 | * takes into consideration that the update could be a regular |
| 654 | * ref or a symbolic ref. |
| 655 | */ |
| 656 | int ref_update_has_null_new_value(struct ref_update *update); |
| 657 | |
| 658 | /* |
| 659 | * Check whether the old_target values stored in update are consistent |
| 660 | * with the referent, which is the symbolic reference's current value. |
| 661 | * If everything is OK, return 0; otherwise, write an error message to |
| 662 | * err and return -1. |
| 663 | */ |
| 664 | enum ref_transaction_error ref_update_check_old_target(const char *referent, |
| 665 | struct ref_update *update, |
| 666 | struct strbuf *err); |
| 667 | |
| 668 | /* |
| 669 | * Check if the ref must exist, this means that the old_oid or |
| 670 | * old_target is non NULL. Log-only updates never require the old state to |
| 671 | * match. |
| 672 | */ |
| 673 | int ref_update_expects_existing_old_ref(struct ref_update *update); |
| 674 | |
| 675 | /* |
| 676 | * Same as `refs_verify_refname_available()`, but checking for a list of |
| 677 | * refnames instead of only a single item. This is more efficient in the case |
| 678 | * where one needs to check multiple refnames. |
| 679 | * |
| 680 | * If using batched updates, then individual updates are marked rejected, |
| 681 | * reference backends are then in charge of not committing those updates. |
| 682 | */ |
| 683 | enum ref_transaction_error refs_verify_refnames_available(struct ref_store *refs, |
| 684 | const struct string_list *refnames, |
| 685 | const struct string_list *extras, |
| 686 | const struct string_list *skip, |
| 687 | struct ref_transaction *transaction, |
| 688 | unsigned int initial_transaction, |
| 689 | struct strbuf *err); |
| 690 | |
| 691 | /* |
| 692 | * Given a gitdir and the reference storage payload provided, retrieve the |
| 693 | * 'refdir' and 'ref_common_dir'. The former is where references should be |
| 694 | * stored for the current worktree, the latter is the common reference |
| 695 | * directory if working with a linked worktree. If working with the main |
| 696 | * worktree, both values will be the same. |
| 697 | * |
| 698 | * This is used by backends that store references in the repository directly. |
| 699 | */ |
| 700 | void refs_compute_filesystem_location(const char *gitdir, const char *payload, |
| 701 | bool *is_worktree, struct strbuf *refdir, |
| 702 | struct strbuf *ref_common_dir); |
| 703 | |
| 704 | #endif /* REFS_REFS_INTERNAL_H */ |