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