refs.h

   1 #ifndef REFS_H
   2 #define REFS_H
   3
   4 /*
   5  * A ref_transaction represents a collection of ref updates
   6  * that should succeed or fail together.
   7  *
   8  * Calling sequence
   9  * ----------------
  10  * - Allocate and initialize a `struct ref_transaction` by calling
  11  *   `ref_transaction_begin()`.
  12  *
  13  * - List intended ref updates by calling functions like
  14  *   `ref_transaction_update()` and `ref_transaction_create()`.
  15  *
  16  * - Call `ref_transaction_commit()` to execute the transaction.
  17  *   If this succeeds, the ref updates will have taken place and
  18  *   the transaction cannot be rolled back.
  19  *
  20  * - At any time call `ref_transaction_free()` to discard the
  21  *   transaction and free associated resources.  In particular,
  22  *   this rolls back the transaction if it has not been
  23  *   successfully committed.
  24  *
  25  * Error handling
  26  * --------------
  27  *
  28  * On error, transaction functions append a message about what
  29  * went wrong to the 'err' argument.  The message mentions what
  30  * ref was being updated (if any) when the error occurred so it
  31  * can be passed to 'die' or 'error' as-is.
  32  *
  33  * The message is appended to err without first clearing err.
  34  * err will not be '\n' terminated.
  35  */
  36 struct ref_transaction;
  37
  38 /*
  39  * Bit values set in the flags argument passed to each_ref_fn():
  40  */
  41
  42 /* Reference is a symbolic reference. */
  43 #define REF_ISSYMREF 0x01
  44
  45 /* Reference is a packed reference. */
  46 #define REF_ISPACKED 0x02
  47
  48 /*
  49  * Reference cannot be resolved to an object name: dangling symbolic
  50  * reference (directly or indirectly), corrupt reference file,
  51  * reference exists but name is bad, or symbolic reference refers to
  52  * ill-formatted reference name.
  53  */
  54 #define REF_ISBROKEN 0x04
  55
  56 /*
  57  * Reference name is not well formed.
  58  *
  59  * See git-check-ref-format(1) for the definition of well formed ref names.
  60  */
  61 #define REF_BAD_NAME 0x08
  62
  63 /*
  64  * The signature for the callback function for the for_each_*()
  65  * functions below.  The memory pointed to by the refname and sha1
  66  * arguments is only guaranteed to be valid for the duration of a
  67  * single callback invocation.
  68  */
  69 typedef int each_ref_fn(const char *refname,
  70                         const unsigned char *sha1, int flags, void *cb_data);
  71
  72 /*
  73  * The following functions invoke the specified callback function for
  74  * each reference indicated.  If the function ever returns a nonzero
  75  * value, stop the iteration and return that value.  Please note that
  76  * it is not safe to modify references while an iteration is in
  77  * progress, unless the same callback function invocation that
  78  * modifies the reference also returns a nonzero value to immediately
  79  * stop the iteration.
  80  */
  81 extern int head_ref(each_ref_fn, void *);
  82 extern int for_each_ref(each_ref_fn, void *);
  83 extern int for_each_ref_in(const char *, each_ref_fn, void *);
  84 extern int for_each_tag_ref(each_ref_fn, void *);
  85 extern int for_each_branch_ref(each_ref_fn, void *);
  86 extern int for_each_remote_ref(each_ref_fn, void *);
  87 extern int for_each_replace_ref(each_ref_fn, void *);
  88 extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
  89 extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
  90
  91 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  92 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  93 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
  94                 each_ref_fn fn, void *cb_data);
  95 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  96 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  97 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  98
  99 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
 100 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
 101
 102 static inline const char *has_glob_specials(const char *pattern)
 103 {
 104         return strpbrk(pattern, "?*[");
 105 }
 106
 107 /* can be used to learn about broken ref and symref */
 108 extern int for_each_rawref(each_ref_fn, void *);
 109
 110 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
 111 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
 112
 113 /*
 114  * Lock the packed-refs file for writing.  Flags is passed to
 115  * hold_lock_file_for_update().  Return 0 on success.
 116  * Errno is set to something meaningful on error.
 117  */
 118 extern int lock_packed_refs(int flags);
 119
 120 /*
 121  * Add a reference to the in-memory packed reference cache.  This may
 122  * only be called while the packed-refs file is locked (see
 123  * lock_packed_refs()).  To actually write the packed-refs file, call
 124  * commit_packed_refs().
 125  */
 126 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
 127
 128 /*
 129  * Write the current version of the packed refs cache from memory to
 130  * disk.  The packed-refs file must already be locked for writing (see
 131  * lock_packed_refs()).  Return zero on success.
 132  * Sets errno to something meaningful on error.
 133  */
 134 extern int commit_packed_refs(void);
 135
 136 /*
 137  * Rollback the lockfile for the packed-refs file, and discard the
 138  * in-memory packed reference cache.  (The packed-refs file will be
 139  * read anew if it is needed again after this function is called.)
 140  */
 141 extern void rollback_packed_refs(void);
 142
 143 /*
 144  * Flags for controlling behaviour of pack_refs()
 145  * PACK_REFS_PRUNE: Prune loose refs after packing
 146  * PACK_REFS_ALL:   Pack _all_ refs, not just tags and already packed refs
 147  */
 148 #define PACK_REFS_PRUNE 0x0001
 149 #define PACK_REFS_ALL   0x0002
 150
 151 /*
 152  * Write a packed-refs file for the current repository.
 153  * flags: Combination of the above PACK_REFS_* flags.
 154  */
 155 int pack_refs(unsigned int flags);
 156
 157 /*
 158  * Rewrite the packed-refs file, omitting any refs listed in
 159  * 'refnames'. On error, packed-refs will be unchanged, the return
 160  * value is nonzero, and a message about the error is written to the
 161  * 'err' strbuf.
 162  *
 163  * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
 164  */
 165 extern int repack_without_refs(struct string_list *refnames,
 166                                struct strbuf *err);
 167
 168 extern int ref_exists(const char *);
 169
 170 extern int is_branch(const char *refname);
 171
 172 /*
 173  * If refname is a non-symbolic reference that refers to a tag object,
 174  * and the tag can be (recursively) dereferenced to a non-tag object,
 175  * store the SHA1 of the referred-to object to sha1 and return 0.  If
 176  * any of these conditions are not met, return a non-zero value.
 177  * Symbolic references are considered unpeelable, even if they
 178  * ultimately resolve to a peelable tag.
 179  */
 180 extern int peel_ref(const char *refname, unsigned char *sha1);
 181
 182 /*
 183  * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
 184  * REF_NODEREF: act on the ref directly, instead of dereferencing
 185  *              symbolic references.
 186  *
 187  * Other flags are reserved for internal use.
 188  */
 189 #define REF_NODEREF     0x01
 190
 191 /*
 192  * Setup reflog before using. Set errno to something meaningful on failure.
 193  */
 194 int log_ref_setup(const char *refname, struct strbuf *logfile);
 195
 196 /** Reads log for the value of ref during at_time. **/
 197 extern int read_ref_at(const char *refname, unsigned int flags,
 198                        unsigned long at_time, int cnt,
 199                        unsigned char *sha1, char **msg,
 200                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 201
 202 /** Check if a particular reflog exists */
 203 extern int reflog_exists(const char *refname);
 204
 205 /** Delete a reflog */
 206 extern int delete_reflog(const char *refname);
 207
 208 /* iterate over reflog entries */
 209 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 210 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 211 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 212
 213 /*
 214  * Calls the specified function for each reflog file until it returns nonzero,
 215  * and returns the value
 216  */
 217 extern int for_each_reflog(each_ref_fn, void *);
 218
 219 #define REFNAME_ALLOW_ONELEVEL 1
 220 #define REFNAME_REFSPEC_PATTERN 2
 221
 222 /*
 223  * Return 0 iff refname has the correct format for a refname according
 224  * to the rules described in Documentation/git-check-ref-format.txt.
 225  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 226  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 227  * allow a "*" wildcard character in place of one of the name
 228  * components.  No leading or repeated slashes are accepted.
 229  */
 230 extern int check_refname_format(const char *refname, int flags);
 231
 232 extern const char *prettify_refname(const char *refname);
 233 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 234
 235 /** rename ref, return 0 on success **/
 236 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 237
 238 /**
 239  * Resolve refname in the nested "gitlink" repository that is located
 240  * at path.  If the resolution is successful, return 0 and set sha1 to
 241  * the name of the object; otherwise, return a non-zero value.
 242  */
 243 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
 244
 245 enum action_on_err {
 246         UPDATE_REFS_MSG_ON_ERR,
 247         UPDATE_REFS_DIE_ON_ERR,
 248         UPDATE_REFS_QUIET_ON_ERR
 249 };
 250
 251 /*
 252  * Begin a reference transaction.  The reference transaction must
 253  * be freed by calling ref_transaction_free().
 254  */
 255 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 256
 257 /*
 258  * Reference transaction updates
 259  *
 260  * The following four functions add a reference check or update to a
 261  * ref_transaction.  They have some common similar parameters:
 262  *
 263  *     transaction -- a pointer to an open ref_transaction, obtained
 264  *         from ref_transaction_begin().
 265  *
 266  *     refname -- the name of the reference to be affected.
 267  *
 268  *     flags -- flags affecting the update, passed to
 269  *         update_ref_lock(). Can be REF_NODEREF, which means that
 270  *         symbolic references should not be followed.
 271  *
 272  *     msg -- a message describing the change (for the reflog).
 273  *
 274  *     err -- a strbuf for receiving a description of any error that
 275  *         might have occured.
 276  *
 277  * The functions make internal copies of refname and msg, so the
 278  * caller retains ownership of these parameters.
 279  *
 280  * The functions return 0 on success and non-zero on failure. A
 281  * failure means that the transaction as a whole has failed and needs
 282  * to be rolled back.
 283  */
 284
 285 /*
 286  * Add a reference update to transaction. new_sha1 is the value that
 287  * the reference should have after the update, or null_sha1 if it
 288  * should be deleted. If new_sha1 is NULL, then the reference is not
 289  * changed at all. old_sha1 is the value that the reference must have
 290  * before the update, or null_sha1 if it must not have existed
 291  * beforehand. The old value is checked after the lock is taken to
 292  * prevent races. If the old value doesn't agree with old_sha1, the
 293  * whole transaction fails. If old_sha1 is NULL, then the previous
 294  * value is not checked.
 295  *
 296  * See the above comment "Reference transaction updates" for more
 297  * information.
 298  */
 299 int ref_transaction_update(struct ref_transaction *transaction,
 300                            const char *refname,
 301                            const unsigned char *new_sha1,
 302                            const unsigned char *old_sha1,
 303                            unsigned int flags, const char *msg,
 304                            struct strbuf *err);
 305
 306 /*
 307  * Add a reference creation to transaction. new_sha1 is the value that
 308  * the reference should have after the update; it must not be
 309  * null_sha1. It is verified that the reference does not exist
 310  * already.
 311  *
 312  * See the above comment "Reference transaction updates" for more
 313  * information.
 314  */
 315 int ref_transaction_create(struct ref_transaction *transaction,
 316                            const char *refname,
 317                            const unsigned char *new_sha1,
 318                            unsigned int flags, const char *msg,
 319                            struct strbuf *err);
 320
 321 /*
 322  * Add a reference deletion to transaction. If old_sha1 is non-NULL,
 323  * then it holds the value that the reference should have had before
 324  * the update (which must not be null_sha1).
 325  *
 326  * See the above comment "Reference transaction updates" for more
 327  * information.
 328  */
 329 int ref_transaction_delete(struct ref_transaction *transaction,
 330                            const char *refname,
 331                            const unsigned char *old_sha1,
 332                            unsigned int flags, const char *msg,
 333                            struct strbuf *err);
 334
 335 /*
 336  * Verify, within a transaction, that refname has the value old_sha1,
 337  * or, if old_sha1 is null_sha1, then verify that the reference
 338  * doesn't exist. old_sha1 must be non-NULL.
 339  *
 340  * See the above comment "Reference transaction updates" for more
 341  * information.
 342  */
 343 int ref_transaction_verify(struct ref_transaction *transaction,
 344                            const char *refname,
 345                            const unsigned char *old_sha1,
 346                            unsigned int flags,
 347                            struct strbuf *err);
 348
 349 /*
 350  * Commit all of the changes that have been queued in transaction, as
 351  * atomically as possible.
 352  *
 353  * Returns 0 for success, or one of the below error codes for errors.
 354  */
 355 /* Naming conflict (for example, the ref names A and A/B conflict). */
 356 #define TRANSACTION_NAME_CONFLICT -1
 357 /* All other errors. */
 358 #define TRANSACTION_GENERIC_ERROR -2
 359 int ref_transaction_commit(struct ref_transaction *transaction,
 360                            struct strbuf *err);
 361
 362 /*
 363  * Free an existing transaction and all associated data.
 364  */
 365 void ref_transaction_free(struct ref_transaction *transaction);
 366
 367 /**
 368  * Lock, update, and unlock a single reference. This function
 369  * basically does a transaction containing a single call to
 370  * ref_transaction_update(). The parameters to this function have the
 371  * same meaning as the corresponding parameters to
 372  * ref_transaction_update(). Handle errors as requested by the `onerr`
 373  * argument.
 374  */
 375 int update_ref(const char *msg, const char *refname,
 376                const unsigned char *new_sha1, const unsigned char *old_sha1,
 377                unsigned int flags, enum action_on_err onerr);
 378
 379 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 380 extern int ref_is_hidden(const char *);
 381
 382 enum expire_reflog_flags {
 383         EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
 384         EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
 385         EXPIRE_REFLOGS_VERBOSE = 1 << 2,
 386         EXPIRE_REFLOGS_REWRITE = 1 << 3
 387 };
 388
 389 /*
 390  * The following interface is used for reflog expiration. The caller
 391  * calls reflog_expire(), supplying it with three callback functions,
 392  * of the following types. The callback functions define the
 393  * expiration policy that is desired.
 394  *
 395  * reflog_expiry_prepare_fn -- Called once after the reference is
 396  *     locked.
 397  *
 398  * reflog_expiry_should_prune_fn -- Called once for each entry in the
 399  *     existing reflog. It should return true iff that entry should be
 400  *     pruned.
 401  *
 402  * reflog_expiry_cleanup_fn -- Called once before the reference is
 403  *     unlocked again.
 404  */
 405 typedef void reflog_expiry_prepare_fn(const char *refname,
 406                                       const unsigned char *sha1,
 407                                       void *cb_data);
 408 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
 409                                           unsigned char *nsha1,
 410                                           const char *email,
 411                                           unsigned long timestamp, int tz,
 412                                           const char *message, void *cb_data);
 413 typedef void reflog_expiry_cleanup_fn(void *cb_data);
 414
 415 /*
 416  * Expire reflog entries for the specified reference. sha1 is the old
 417  * value of the reference. flags is a combination of the constants in
 418  * enum expire_reflog_flags. The three function pointers are described
 419  * above. On success, return zero.
 420  */
 421 extern int reflog_expire(const char *refname, const unsigned char *sha1,
 422                          unsigned int flags,
 423                          reflog_expiry_prepare_fn prepare_fn,
 424                          reflog_expiry_should_prune_fn should_prune_fn,
 425                          reflog_expiry_cleanup_fn cleanup_fn,
 426                          void *policy_cb_data);
 427
 428 #endif /* REFS_H */