refs.h

   1 #ifndef REFS_H
   2 #define REFS_H
   3
   4 struct ref_lock {
   5         char *ref_name;
   6         char *orig_ref_name;
   7         struct lock_file *lk;
   8         unsigned char old_sha1[20];
   9         int lock_fd;
  10         int force_write;
  11 };
  12
  13 /*
  14  * A ref_transaction represents a collection of ref updates
  15  * that should succeed or fail together.
  16  *
  17  * Calling sequence
  18  * ----------------
  19  * - Allocate and initialize a `struct ref_transaction` by calling
  20  *   `ref_transaction_begin()`.
  21  *
  22  * - List intended ref updates by calling functions like
  23  *   `ref_transaction_update()` and `ref_transaction_create()`.
  24  *
  25  * - Call `ref_transaction_commit()` to execute the transaction.
  26  *   If this succeeds, the ref updates will have taken place and
  27  *   the transaction cannot be rolled back.
  28  *
  29  * - At any time call `ref_transaction_free()` to discard the
  30  *   transaction and free associated resources.  In particular,
  31  *   this rolls back the transaction if it has not been
  32  *   successfully committed.
  33  *
  34  * Error handling
  35  * --------------
  36  *
  37  * On error, transaction functions append a message about what
  38  * went wrong to the 'err' argument.  The message mentions what
  39  * ref was being updated (if any) when the error occurred so it
  40  * can be passed to 'die' or 'error' as-is.
  41  *
  42  * The message is appended to err without first clearing err.
  43  * err will not be '\n' terminated.
  44  */
  45 struct ref_transaction;
  46
  47 /*
  48  * Bit values set in the flags argument passed to each_ref_fn():
  49  */
  50
  51 /* Reference is a symbolic reference. */
  52 #define REF_ISSYMREF 0x01
  53
  54 /* Reference is a packed reference. */
  55 #define REF_ISPACKED 0x02
  56
  57 /*
  58  * Reference cannot be resolved to an object name: dangling symbolic
  59  * reference (directly or indirectly), corrupt reference file, or
  60  * symbolic reference refers to ill-formatted reference name.
  61  */
  62 #define REF_ISBROKEN 0x04
  63
  64 /*
  65  * The signature for the callback function for the for_each_*()
  66  * functions below.  The memory pointed to by the refname and sha1
  67  * arguments is only guaranteed to be valid for the duration of a
  68  * single callback invocation.
  69  */
  70 typedef int each_ref_fn(const char *refname,
  71                         const unsigned char *sha1, int flags, void *cb_data);
  72
  73 /*
  74  * The following functions invoke the specified callback function for
  75  * each reference indicated.  If the function ever returns a nonzero
  76  * value, stop the iteration and return that value.  Please note that
  77  * it is not safe to modify references while an iteration is in
  78  * progress, unless the same callback function invocation that
  79  * modifies the reference also returns a nonzero value to immediately
  80  * stop the iteration.
  81  */
  82 extern int head_ref(each_ref_fn, void *);
  83 extern int for_each_ref(each_ref_fn, void *);
  84 extern int for_each_ref_in(const char *, each_ref_fn, void *);
  85 extern int for_each_tag_ref(each_ref_fn, void *);
  86 extern int for_each_branch_ref(each_ref_fn, void *);
  87 extern int for_each_remote_ref(each_ref_fn, void *);
  88 extern int for_each_replace_ref(each_ref_fn, void *);
  89 extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
  90 extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
  91
  92 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  93 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  94 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
  95                 each_ref_fn fn, void *cb_data);
  96 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  97 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  98 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
  99
 100 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
 101 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
 102
 103 static inline const char *has_glob_specials(const char *pattern)
 104 {
 105         return strpbrk(pattern, "?*[");
 106 }
 107
 108 /* can be used to learn about broken ref and symref */
 109 extern int for_each_rawref(each_ref_fn, void *);
 110
 111 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
 112 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list* refnames);
 113
 114 /*
 115  * Lock the packed-refs file for writing.  Flags is passed to
 116  * hold_lock_file_for_update().  Return 0 on success.
 117  * Errno is set to something meaningful on error.
 118  */
 119 extern int lock_packed_refs(int flags);
 120
 121 /*
 122  * Add a reference to the in-memory packed reference cache.  This may
 123  * only be called while the packed-refs file is locked (see
 124  * lock_packed_refs()).  To actually write the packed-refs file, call
 125  * commit_packed_refs().
 126  */
 127 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
 128
 129 /*
 130  * Write the current version of the packed refs cache from memory to
 131  * disk.  The packed-refs file must already be locked for writing (see
 132  * lock_packed_refs()).  Return zero on success.
 133  * Sets errno to something meaningful on error.
 134  */
 135 extern int commit_packed_refs(void);
 136
 137 /*
 138  * Rollback the lockfile for the packed-refs file, and discard the
 139  * in-memory packed reference cache.  (The packed-refs file will be
 140  * read anew if it is needed again after this function is called.)
 141  */
 142 extern void rollback_packed_refs(void);
 143
 144 /*
 145  * Flags for controlling behaviour of pack_refs()
 146  * PACK_REFS_PRUNE: Prune loose refs after packing
 147  * PACK_REFS_ALL:   Pack _all_ refs, not just tags and already packed refs
 148  */
 149 #define PACK_REFS_PRUNE 0x0001
 150 #define PACK_REFS_ALL   0x0002
 151
 152 /*
 153  * Write a packed-refs file for the current repository.
 154  * flags: Combination of the above PACK_REFS_* flags.
 155  */
 156 int pack_refs(unsigned int flags);
 157
 158 extern int repack_without_refs(const char **refnames, int n,
 159                                struct strbuf *err);
 160
 161 extern int ref_exists(const char *);
 162
 163 extern int is_branch(const char *refname);
 164
 165 /*
 166  * If refname is a non-symbolic reference that refers to a tag object,
 167  * and the tag can be (recursively) dereferenced to a non-tag object,
 168  * store the SHA1 of the referred-to object to sha1 and return 0.  If
 169  * any of these conditions are not met, return a non-zero value.
 170  * Symbolic references are considered unpeelable, even if they
 171  * ultimately resolve to a peelable tag.
 172  */
 173 extern int peel_ref(const char *refname, unsigned char *sha1);
 174
 175 /*
 176  * Flags controlling lock_any_ref_for_update(), ref_transaction_update(),
 177  * ref_transaction_create(), etc.
 178  * REF_NODEREF: act on the ref directly, instead of dereferencing
 179  *              symbolic references.
 180  *
 181  * Flags >= 0x100 are reserved for internal use.
 182  */
 183 #define REF_NODEREF     0x01
 184 /*
 185  * Locks any ref (for 'HEAD' type refs) and sets errno to something
 186  * meaningful on failure.
 187  */
 188 extern struct ref_lock *lock_any_ref_for_update(const char *refname,
 189                                                 const unsigned char *old_sha1,
 190                                                 int flags, int *type_p);
 191
 192 /** Close the file descriptor owned by a lock and return the status */
 193 extern int close_ref(struct ref_lock *lock);
 194
 195 /** Close and commit the ref locked by the lock */
 196 extern int commit_ref(struct ref_lock *lock);
 197
 198 /** Release any lock taken but not written. **/
 199 extern void unlock_ref(struct ref_lock *lock);
 200
 201 /*
 202  * Setup reflog before using. Set errno to something meaningful on failure.
 203  */
 204 int log_ref_setup(const char *refname, struct strbuf *logfile);
 205
 206 /** Reads log for the value of ref during at_time. **/
 207 extern int read_ref_at(const char *refname, unsigned long at_time, int cnt,
 208                        unsigned char *sha1, char **msg,
 209                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 210
 211 /** Check if a particular reflog exists */
 212 extern int reflog_exists(const char *refname);
 213
 214 /** Delete a reflog */
 215 extern int delete_reflog(const char *refname);
 216
 217 /* iterate over reflog entries */
 218 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 219 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 220 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 221
 222 /*
 223  * Calls the specified function for each reflog file until it returns nonzero,
 224  * and returns the value
 225  */
 226 extern int for_each_reflog(each_ref_fn, void *);
 227
 228 #define REFNAME_ALLOW_ONELEVEL 1
 229 #define REFNAME_REFSPEC_PATTERN 2
 230 #define REFNAME_DOT_COMPONENT 4
 231
 232 /*
 233  * Return 0 iff refname has the correct format for a refname according
 234  * to the rules described in Documentation/git-check-ref-format.txt.
 235  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 236  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 237  * allow a "*" wildcard character in place of one of the name
 238  * components.  No leading or repeated slashes are accepted.  If
 239  * REFNAME_DOT_COMPONENT is set in flags, then allow refname
 240  * components to start with "." (but not a whole component equal to
 241  * "." or "..").
 242  */
 243 extern int check_refname_format(const char *refname, int flags);
 244
 245 extern const char *prettify_refname(const char *refname);
 246 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 247
 248 /** rename ref, return 0 on success **/
 249 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 250
 251 /**
 252  * Resolve refname in the nested "gitlink" repository that is located
 253  * at path.  If the resolution is successful, return 0 and set sha1 to
 254  * the name of the object; otherwise, return a non-zero value.
 255  */
 256 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
 257
 258 enum action_on_err {
 259         UPDATE_REFS_MSG_ON_ERR,
 260         UPDATE_REFS_DIE_ON_ERR,
 261         UPDATE_REFS_QUIET_ON_ERR
 262 };
 263
 264 /*
 265  * Begin a reference transaction.  The reference transaction must
 266  * be freed by calling ref_transaction_free().
 267  */
 268 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 269
 270 /*
 271  * The following functions add a reference check or update to a
 272  * ref_transaction.  In all of them, refname is the name of the
 273  * reference to be affected.  The functions make internal copies of
 274  * refname, so the caller retains ownership of the parameter.  flags
 275  * can be REF_NODEREF; it is passed to update_ref_lock().
 276  */
 277
 278 /*
 279  * Add a reference update to transaction.  new_sha1 is the value that
 280  * the reference should have after the update, or zeros if it should
 281  * be deleted.  If have_old is true, then old_sha1 holds the value
 282  * that the reference should have had before the update, or zeros if
 283  * it must not have existed beforehand.
 284  * Function returns 0 on success and non-zero on failure. A failure to update
 285  * means that the transaction as a whole has failed and will need to be
 286  * rolled back.
 287  */
 288 int ref_transaction_update(struct ref_transaction *transaction,
 289                            const char *refname,
 290                            const unsigned char *new_sha1,
 291                            const unsigned char *old_sha1,
 292                            int flags, int have_old, const char *msg,
 293                            struct strbuf *err);
 294
 295 /*
 296  * Add a reference creation to transaction.  new_sha1 is the value
 297  * that the reference should have after the update; it must not be the
 298  * null SHA-1.  It is verified that the reference does not exist
 299  * already.
 300  * Function returns 0 on success and non-zero on failure. A failure to create
 301  * means that the transaction as a whole has failed and will need to be
 302  * rolled back.
 303  */
 304 int ref_transaction_create(struct ref_transaction *transaction,
 305                            const char *refname,
 306                            const unsigned char *new_sha1,
 307                            int flags, const char *msg,
 308                            struct strbuf *err);
 309
 310 /*
 311  * Add a reference deletion to transaction.  If have_old is true, then
 312  * old_sha1 holds the value that the reference should have had before
 313  * the update (which must not be the null SHA-1).
 314  * Function returns 0 on success and non-zero on failure. A failure to delete
 315  * means that the transaction as a whole has failed and will need to be
 316  * rolled back.
 317  */
 318 int ref_transaction_delete(struct ref_transaction *transaction,
 319                            const char *refname,
 320                            const unsigned char *old_sha1,
 321                            int flags, int have_old, const char *msg,
 322                            struct strbuf *err);
 323
 324 /*
 325  * Commit all of the changes that have been queued in transaction, as
 326  * atomically as possible.  Return a nonzero value if there is a
 327  * problem.
 328  * If the transaction is already in failed state this function will return
 329  * an error.
 330  * Function returns 0 on success, -1 for generic failures and
 331  * UPDATE_REFS_NAME_CONFLICT (-2) if the failure was due to a name
 332  * collision (ENOTDIR).
 333  */
 334 #define UPDATE_REFS_NAME_CONFLICT -2
 335 int ref_transaction_commit(struct ref_transaction *transaction,
 336                            struct strbuf *err);
 337
 338 /*
 339  * Free an existing transaction and all associated data.
 340  */
 341 void ref_transaction_free(struct ref_transaction *transaction);
 342
 343 /** Lock a ref and then write its file */
 344 int update_ref(const char *action, const char *refname,
 345                 const unsigned char *sha1, const unsigned char *oldval,
 346                 int flags, enum action_on_err onerr);
 347
 348 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 349 extern int ref_is_hidden(const char *);
 350
 351 #endif /* REFS_H */