refs.h

   1 #ifndef REFS_H
   2 #define REFS_H
   3
   4 /*
   5  * Resolve a reference, recursively following symbolic refererences.
   6  *
   7  * Store the referred-to object's name in sha1 and return the name of
   8  * the non-symbolic reference that ultimately pointed at it.  The
   9  * return value, if not NULL, is a pointer into either a static buffer
  10  * or the input ref.
  11  *
  12  * If the reference cannot be resolved to an object, the behavior
  13  * depends on the RESOLVE_REF_READING flag:
  14  *
  15  * - If RESOLVE_REF_READING is set, return NULL.
  16  *
  17  * - If RESOLVE_REF_READING is not set, clear sha1 and return the name of
  18  *   the last reference name in the chain, which will either be a non-symbolic
  19  *   reference or an undefined reference.  If this is a prelude to
  20  *   "writing" to the ref, the return value is the name of the ref
  21  *   that will actually be created or changed.
  22  *
  23  * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
  24  * level of symbolic reference.  The value stored in sha1 for a symbolic
  25  * reference will always be null_sha1 in this case, and the return
  26  * value is the reference that the symref refers to directly.
  27  *
  28  * If flags is non-NULL, set the value that it points to the
  29  * combination of REF_ISPACKED (if the reference was found among the
  30  * packed references), REF_ISSYMREF (if the initial reference was a
  31  * symbolic reference), REF_BAD_NAME (if the reference name is ill
  32  * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
  33  * (if the ref is malformed or has a bad name). See refs.h for more detail
  34  * on each flag.
  35  *
  36  * If ref is not a properly-formatted, normalized reference, return
  37  * NULL.  If more than MAXDEPTH recursive symbolic lookups are needed,
  38  * give up and return NULL.
  39  *
  40  * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
  41  * name is invalid according to git-check-ref-format(1).  If the name
  42  * is bad then the value stored in sha1 will be null_sha1 and the two
  43  * flags REF_ISBROKEN and REF_BAD_NAME will be set.
  44  *
  45  * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
  46  * directory and do not consist of all caps and underscores cannot be
  47  * resolved. The function returns NULL for such ref names.
  48  * Caps and underscores refers to the special refs, such as HEAD,
  49  * FETCH_HEAD and friends, that all live outside of the refs/ directory.
  50  */
  51 #define RESOLVE_REF_READING 0x01
  52 #define RESOLVE_REF_NO_RECURSE 0x02
  53 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
  54
  55 extern const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
  56                                       unsigned char *sha1, int *flags);
  57
  58 extern char *resolve_refdup(const char *refname, int resolve_flags,
  59                             unsigned char *sha1, int *flags);
  60
  61 extern int read_ref_full(const char *refname, int resolve_flags,
  62                          unsigned char *sha1, int *flags);
  63 extern int read_ref(const char *refname, unsigned char *sha1);
  64
  65 extern int ref_exists(const char *refname);
  66
  67 extern int is_branch(const char *refname);
  68
  69 /*
  70  * If refname is a non-symbolic reference that refers to a tag object,
  71  * and the tag can be (recursively) dereferenced to a non-tag object,
  72  * store the SHA1 of the referred-to object to sha1 and return 0.  If
  73  * any of these conditions are not met, return a non-zero value.
  74  * Symbolic references are considered unpeelable, even if they
  75  * ultimately resolve to a peelable tag.
  76  */
  77 extern int peel_ref(const char *refname, unsigned char *sha1);
  78
  79 /**
  80  * Resolve refname in the nested "gitlink" repository that is located
  81  * at path.  If the resolution is successful, return 0 and set sha1 to
  82  * the name of the object; otherwise, return a non-zero value.
  83  */
  84 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
  85
  86 /*
  87  * Return true iff abbrev_name is a possible abbreviation for
  88  * full_name according to the rules defined by ref_rev_parse_rules in
  89  * refs.c.
  90  */
  91 extern int refname_match(const char *abbrev_name, const char *full_name);
  92
  93 extern int expand_ref(const char *str, int len, unsigned char *sha1, char **ref);
  94 extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
  95 extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
  96
  97 /*
  98  * A ref_transaction represents a collection of ref updates
  99  * that should succeed or fail together.
 100  *
 101  * Calling sequence
 102  * ----------------
 103  * - Allocate and initialize a `struct ref_transaction` by calling
 104  *   `ref_transaction_begin()`.
 105  *
 106  * - List intended ref updates by calling functions like
 107  *   `ref_transaction_update()` and `ref_transaction_create()`.
 108  *
 109  * - Call `ref_transaction_commit()` to execute the transaction.
 110  *   If this succeeds, the ref updates will have taken place and
 111  *   the transaction cannot be rolled back.
 112  *
 113  * - At any time call `ref_transaction_free()` to discard the
 114  *   transaction and free associated resources.  In particular,
 115  *   this rolls back the transaction if it has not been
 116  *   successfully committed.
 117  *
 118  * Error handling
 119  * --------------
 120  *
 121  * On error, transaction functions append a message about what
 122  * went wrong to the 'err' argument.  The message mentions what
 123  * ref was being updated (if any) when the error occurred so it
 124  * can be passed to 'die' or 'error' as-is.
 125  *
 126  * The message is appended to err without first clearing err.
 127  * err will not be '\n' terminated.
 128  */
 129 struct ref_transaction;
 130
 131 /*
 132  * Bit values set in the flags argument passed to each_ref_fn():
 133  */
 134
 135 /* Reference is a symbolic reference. */
 136 #define REF_ISSYMREF 0x01
 137
 138 /* Reference is a packed reference. */
 139 #define REF_ISPACKED 0x02
 140
 141 /*
 142  * Reference cannot be resolved to an object name: dangling symbolic
 143  * reference (directly or indirectly), corrupt reference file,
 144  * reference exists but name is bad, or symbolic reference refers to
 145  * ill-formatted reference name.
 146  */
 147 #define REF_ISBROKEN 0x04
 148
 149 /*
 150  * Reference name is not well formed.
 151  *
 152  * See git-check-ref-format(1) for the definition of well formed ref names.
 153  */
 154 #define REF_BAD_NAME 0x08
 155
 156 /*
 157  * The signature for the callback function for the for_each_*()
 158  * functions below.  The memory pointed to by the refname and sha1
 159  * arguments is only guaranteed to be valid for the duration of a
 160  * single callback invocation.
 161  */
 162 typedef int each_ref_fn(const char *refname,
 163                         const struct object_id *oid, int flags, void *cb_data);
 164
 165 /*
 166  * The following functions invoke the specified callback function for
 167  * each reference indicated.  If the function ever returns a nonzero
 168  * value, stop the iteration and return that value.  Please note that
 169  * it is not safe to modify references while an iteration is in
 170  * progress, unless the same callback function invocation that
 171  * modifies the reference also returns a nonzero value to immediately
 172  * stop the iteration.
 173  */
 174 extern int head_ref(each_ref_fn fn, void *cb_data);
 175 extern int for_each_ref(each_ref_fn fn, void *cb_data);
 176 extern int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
 177 extern int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken);
 178 extern int for_each_tag_ref(each_ref_fn fn, void *cb_data);
 179 extern int for_each_branch_ref(each_ref_fn fn, void *cb_data);
 180 extern int for_each_remote_ref(each_ref_fn fn, void *cb_data);
 181 extern int for_each_replace_ref(each_ref_fn fn, void *cb_data);
 182 extern int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
 183 extern int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, const char *prefix, void *cb_data);
 184
 185 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 186 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 187 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
 188                 each_ref_fn fn, void *cb_data);
 189 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 190 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 191 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 192
 193 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
 194 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
 195
 196 /* can be used to learn about broken ref and symref */
 197 extern int for_each_rawref(each_ref_fn fn, void *cb_data);
 198
 199 static inline const char *has_glob_specials(const char *pattern)
 200 {
 201         return strpbrk(pattern, "?*[");
 202 }
 203
 204 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
 205 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
 206
 207 /*
 208  * Flags for controlling behaviour of pack_refs()
 209  * PACK_REFS_PRUNE: Prune loose refs after packing
 210  * PACK_REFS_ALL:   Pack _all_ refs, not just tags and already packed refs
 211  */
 212 #define PACK_REFS_PRUNE 0x0001
 213 #define PACK_REFS_ALL   0x0002
 214
 215 /*
 216  * Write a packed-refs file for the current repository.
 217  * flags: Combination of the above PACK_REFS_* flags.
 218  */
 219 int pack_refs(unsigned int flags);
 220
 221 /*
 222  * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
 223  * REF_NODEREF: act on the ref directly, instead of dereferencing
 224  *              symbolic references.
 225  *
 226  * Other flags are reserved for internal use.
 227  */
 228 #define REF_NODEREF     0x01
 229 #define REF_FORCE_CREATE_REFLOG 0x40
 230
 231 /*
 232  * Setup reflog before using. Fill in err and return -1 on failure.
 233  */
 234 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
 235
 236 /** Reads log for the value of ref during at_time. **/
 237 extern int read_ref_at(const char *refname, unsigned int flags,
 238                        unsigned long at_time, int cnt,
 239                        unsigned char *sha1, char **msg,
 240                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 241
 242 /** Check if a particular reflog exists */
 243 extern int reflog_exists(const char *refname);
 244
 245 /*
 246  * Delete the specified reference. If old_sha1 is non-NULL, then
 247  * verify that the current value of the reference is old_sha1 before
 248  * deleting it. If old_sha1 is NULL, delete the reference if it
 249  * exists, regardless of its old value. It is an error for old_sha1 to
 250  * be NULL_SHA1. flags is passed through to ref_transaction_delete().
 251  */
 252 extern int delete_ref(const char *refname, const unsigned char *old_sha1,
 253                       unsigned int flags);
 254
 255 /*
 256  * Delete the specified references. If there are any problems, emit
 257  * errors but attempt to keep going (i.e., the deletes are not done in
 258  * an all-or-nothing transaction).
 259  */
 260 extern int delete_refs(struct string_list *refnames);
 261
 262 /** Delete a reflog */
 263 extern int delete_reflog(const char *refname);
 264
 265 /* iterate over reflog entries */
 266 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 267 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 268 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 269
 270 /*
 271  * Calls the specified function for each reflog file until it returns nonzero,
 272  * and returns the value
 273  */
 274 extern int for_each_reflog(each_ref_fn, void *);
 275
 276 #define REFNAME_ALLOW_ONELEVEL 1
 277 #define REFNAME_REFSPEC_PATTERN 2
 278
 279 /*
 280  * Return 0 iff refname has the correct format for a refname according
 281  * to the rules described in Documentation/git-check-ref-format.txt.
 282  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 283  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 284  * allow a single "*" wildcard character in the refspec. No leading or
 285  * repeated slashes are accepted.
 286  */
 287 extern int check_refname_format(const char *refname, int flags);
 288
 289 extern const char *prettify_refname(const char *refname);
 290
 291 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 292
 293 /** rename ref, return 0 on success **/
 294 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 295
 296 extern int create_symref(const char *refname, const char *target, const char *logmsg);
 297
 298 enum action_on_err {
 299         UPDATE_REFS_MSG_ON_ERR,
 300         UPDATE_REFS_DIE_ON_ERR,
 301         UPDATE_REFS_QUIET_ON_ERR
 302 };
 303
 304 /*
 305  * Begin a reference transaction.  The reference transaction must
 306  * be freed by calling ref_transaction_free().
 307  */
 308 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 309
 310 /*
 311  * Reference transaction updates
 312  *
 313  * The following four functions add a reference check or update to a
 314  * ref_transaction.  They have some common similar parameters:
 315  *
 316  *     transaction -- a pointer to an open ref_transaction, obtained
 317  *         from ref_transaction_begin().
 318  *
 319  *     refname -- the name of the reference to be affected.
 320  *
 321  *     flags -- flags affecting the update, passed to
 322  *         update_ref_lock(). Can be REF_NODEREF, which means that
 323  *         symbolic references should not be followed.
 324  *
 325  *     msg -- a message describing the change (for the reflog).
 326  *
 327  *     err -- a strbuf for receiving a description of any error that
 328  *         might have occured.
 329  *
 330  * The functions make internal copies of refname and msg, so the
 331  * caller retains ownership of these parameters.
 332  *
 333  * The functions return 0 on success and non-zero on failure. A
 334  * failure means that the transaction as a whole has failed and needs
 335  * to be rolled back.
 336  */
 337
 338 /*
 339  * Add a reference update to transaction. new_sha1 is the value that
 340  * the reference should have after the update, or null_sha1 if it
 341  * should be deleted. If new_sha1 is NULL, then the reference is not
 342  * changed at all. old_sha1 is the value that the reference must have
 343  * before the update, or null_sha1 if it must not have existed
 344  * beforehand. The old value is checked after the lock is taken to
 345  * prevent races. If the old value doesn't agree with old_sha1, the
 346  * whole transaction fails. If old_sha1 is NULL, then the previous
 347  * value is not checked.
 348  *
 349  * See the above comment "Reference transaction updates" for more
 350  * information.
 351  */
 352 int ref_transaction_update(struct ref_transaction *transaction,
 353                            const char *refname,
 354                            const unsigned char *new_sha1,
 355                            const unsigned char *old_sha1,
 356                            unsigned int flags, const char *msg,
 357                            struct strbuf *err);
 358
 359 /*
 360  * Add a reference creation to transaction. new_sha1 is the value that
 361  * the reference should have after the update; it must not be
 362  * null_sha1. It is verified that the reference does not exist
 363  * already.
 364  *
 365  * See the above comment "Reference transaction updates" for more
 366  * information.
 367  */
 368 int ref_transaction_create(struct ref_transaction *transaction,
 369                            const char *refname,
 370                            const unsigned char *new_sha1,
 371                            unsigned int flags, const char *msg,
 372                            struct strbuf *err);
 373
 374 /*
 375  * Add a reference deletion to transaction. If old_sha1 is non-NULL,
 376  * then it holds the value that the reference should have had before
 377  * the update (which must not be null_sha1).
 378  *
 379  * See the above comment "Reference transaction updates" for more
 380  * information.
 381  */
 382 int ref_transaction_delete(struct ref_transaction *transaction,
 383                            const char *refname,
 384                            const unsigned char *old_sha1,
 385                            unsigned int flags, const char *msg,
 386                            struct strbuf *err);
 387
 388 /*
 389  * Verify, within a transaction, that refname has the value old_sha1,
 390  * or, if old_sha1 is null_sha1, then verify that the reference
 391  * doesn't exist. old_sha1 must be non-NULL.
 392  *
 393  * See the above comment "Reference transaction updates" for more
 394  * information.
 395  */
 396 int ref_transaction_verify(struct ref_transaction *transaction,
 397                            const char *refname,
 398                            const unsigned char *old_sha1,
 399                            unsigned int flags,
 400                            struct strbuf *err);
 401
 402 /*
 403  * Commit all of the changes that have been queued in transaction, as
 404  * atomically as possible.
 405  *
 406  * Returns 0 for success, or one of the below error codes for errors.
 407  */
 408 /* Naming conflict (for example, the ref names A and A/B conflict). */
 409 #define TRANSACTION_NAME_CONFLICT -1
 410 /* All other errors. */
 411 #define TRANSACTION_GENERIC_ERROR -2
 412 int ref_transaction_commit(struct ref_transaction *transaction,
 413                            struct strbuf *err);
 414
 415 /*
 416  * Like ref_transaction_commit(), but optimized for creating
 417  * references when originally initializing a repository (e.g., by "git
 418  * clone"). It writes the new references directly to packed-refs
 419  * without locking the individual references.
 420  *
 421  * It is a bug to call this function when there might be other
 422  * processes accessing the repository or if there are existing
 423  * references that might conflict with the ones being created. All
 424  * old_sha1 values must either be absent or NULL_SHA1.
 425  */
 426 int initial_ref_transaction_commit(struct ref_transaction *transaction,
 427                                    struct strbuf *err);
 428
 429 /*
 430  * Free an existing transaction and all associated data.
 431  */
 432 void ref_transaction_free(struct ref_transaction *transaction);
 433
 434 /**
 435  * Lock, update, and unlock a single reference. This function
 436  * basically does a transaction containing a single call to
 437  * ref_transaction_update(). The parameters to this function have the
 438  * same meaning as the corresponding parameters to
 439  * ref_transaction_update(). Handle errors as requested by the `onerr`
 440  * argument.
 441  */
 442 int update_ref(const char *msg, const char *refname,
 443                const unsigned char *new_sha1, const unsigned char *old_sha1,
 444                unsigned int flags, enum action_on_err onerr);
 445
 446 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 447
 448 /*
 449  * Check whether a ref is hidden. If no namespace is set, both the first and
 450  * the second parameter point to the full ref name. If a namespace is set and
 451  * the ref is inside that namespace, the first parameter is a pointer to the
 452  * name of the ref with the namespace prefix removed. If a namespace is set and
 453  * the ref is outside that namespace, the first parameter is NULL. The second
 454  * parameter always points to the full ref name.
 455  */
 456 extern int ref_is_hidden(const char *, const char *);
 457
 458 enum ref_type {
 459         REF_TYPE_PER_WORKTREE,
 460         REF_TYPE_PSEUDOREF,
 461         REF_TYPE_NORMAL,
 462 };
 463
 464 enum ref_type ref_type(const char *refname);
 465
 466 enum expire_reflog_flags {
 467         EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
 468         EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
 469         EXPIRE_REFLOGS_VERBOSE = 1 << 2,
 470         EXPIRE_REFLOGS_REWRITE = 1 << 3
 471 };
 472
 473 /*
 474  * The following interface is used for reflog expiration. The caller
 475  * calls reflog_expire(), supplying it with three callback functions,
 476  * of the following types. The callback functions define the
 477  * expiration policy that is desired.
 478  *
 479  * reflog_expiry_prepare_fn -- Called once after the reference is
 480  *     locked.
 481  *
 482  * reflog_expiry_should_prune_fn -- Called once for each entry in the
 483  *     existing reflog. It should return true iff that entry should be
 484  *     pruned.
 485  *
 486  * reflog_expiry_cleanup_fn -- Called once before the reference is
 487  *     unlocked again.
 488  */
 489 typedef void reflog_expiry_prepare_fn(const char *refname,
 490                                       const unsigned char *sha1,
 491                                       void *cb_data);
 492 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
 493                                           unsigned char *nsha1,
 494                                           const char *email,
 495                                           unsigned long timestamp, int tz,
 496                                           const char *message, void *cb_data);
 497 typedef void reflog_expiry_cleanup_fn(void *cb_data);
 498
 499 /*
 500  * Expire reflog entries for the specified reference. sha1 is the old
 501  * value of the reference. flags is a combination of the constants in
 502  * enum expire_reflog_flags. The three function pointers are described
 503  * above. On success, return zero.
 504  */
 505 extern int reflog_expire(const char *refname, const unsigned char *sha1,
 506                          unsigned int flags,
 507                          reflog_expiry_prepare_fn prepare_fn,
 508                          reflog_expiry_should_prune_fn should_prune_fn,
 509                          reflog_expiry_cleanup_fn cleanup_fn,
 510                          void *policy_cb_data);
 511
 512 #endif /* REFS_H */