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,
  60  * reference exists but name is bad, or symbolic reference refers to
  61  * ill-formatted reference name.
  62  */
  63 #define REF_ISBROKEN 0x04
  64
  65 /*
  66  * Reference name is not well formed.
  67  *
  68  * See git-check-ref-format(1) for the definition of well formed ref names.
  69  */
  70 #define REF_BAD_NAME 0x08
  71
  72 /*
  73  * The signature for the callback function for the for_each_*()
  74  * functions below.  The memory pointed to by the refname and sha1
  75  * arguments is only guaranteed to be valid for the duration of a
  76  * single callback invocation.
  77  */
  78 typedef int each_ref_fn(const char *refname,
  79                         const unsigned char *sha1, int flags, void *cb_data);
  80
  81 /*
  82  * The following functions invoke the specified callback function for
  83  * each reference indicated.  If the function ever returns a nonzero
  84  * value, stop the iteration and return that value.  Please note that
  85  * it is not safe to modify references while an iteration is in
  86  * progress, unless the same callback function invocation that
  87  * modifies the reference also returns a nonzero value to immediately
  88  * stop the iteration.
  89  */
  90 extern int head_ref(each_ref_fn, void *);
  91 extern int for_each_ref(each_ref_fn, void *);
  92 extern int for_each_ref_in(const char *, each_ref_fn, void *);
  93 extern int for_each_tag_ref(each_ref_fn, void *);
  94 extern int for_each_branch_ref(each_ref_fn, void *);
  95 extern int for_each_remote_ref(each_ref_fn, void *);
  96 extern int for_each_replace_ref(each_ref_fn, void *);
  97 extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
  98 extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
  99
 100 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 101 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 102 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
 103                 each_ref_fn fn, void *cb_data);
 104 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 105 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 106 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
 107
 108 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
 109 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
 110
 111 static inline const char *has_glob_specials(const char *pattern)
 112 {
 113         return strpbrk(pattern, "?*[");
 114 }
 115
 116 /* can be used to learn about broken ref and symref */
 117 extern int for_each_rawref(each_ref_fn, void *);
 118
 119 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
 120 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
 121
 122 /*
 123  * Lock the packed-refs file for writing.  Flags is passed to
 124  * hold_lock_file_for_update().  Return 0 on success.
 125  * Errno is set to something meaningful on error.
 126  */
 127 extern int lock_packed_refs(int flags);
 128
 129 /*
 130  * Add a reference to the in-memory packed reference cache.  This may
 131  * only be called while the packed-refs file is locked (see
 132  * lock_packed_refs()).  To actually write the packed-refs file, call
 133  * commit_packed_refs().
 134  */
 135 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
 136
 137 /*
 138  * Write the current version of the packed refs cache from memory to
 139  * disk.  The packed-refs file must already be locked for writing (see
 140  * lock_packed_refs()).  Return zero on success.
 141  * Sets errno to something meaningful on error.
 142  */
 143 extern int commit_packed_refs(void);
 144
 145 /*
 146  * Rollback the lockfile for the packed-refs file, and discard the
 147  * in-memory packed reference cache.  (The packed-refs file will be
 148  * read anew if it is needed again after this function is called.)
 149  */
 150 extern void rollback_packed_refs(void);
 151
 152 /*
 153  * Flags for controlling behaviour of pack_refs()
 154  * PACK_REFS_PRUNE: Prune loose refs after packing
 155  * PACK_REFS_ALL:   Pack _all_ refs, not just tags and already packed refs
 156  */
 157 #define PACK_REFS_PRUNE 0x0001
 158 #define PACK_REFS_ALL   0x0002
 159
 160 /*
 161  * Write a packed-refs file for the current repository.
 162  * flags: Combination of the above PACK_REFS_* flags.
 163  */
 164 int pack_refs(unsigned int flags);
 165
 166 extern int repack_without_refs(const char **refnames, int n,
 167                                struct strbuf *err);
 168
 169 extern int ref_exists(const char *);
 170
 171 extern int is_branch(const char *refname);
 172
 173 /*
 174  * If refname is a non-symbolic reference that refers to a tag object,
 175  * and the tag can be (recursively) dereferenced to a non-tag object,
 176  * store the SHA1 of the referred-to object to sha1 and return 0.  If
 177  * any of these conditions are not met, return a non-zero value.
 178  * Symbolic references are considered unpeelable, even if they
 179  * ultimately resolve to a peelable tag.
 180  */
 181 extern int peel_ref(const char *refname, unsigned char *sha1);
 182
 183 /*
 184  * Flags controlling lock_any_ref_for_update(), ref_transaction_update(),
 185  * ref_transaction_create(), etc.
 186  * REF_NODEREF: act on the ref directly, instead of dereferencing
 187  *              symbolic references.
 188  * REF_DELETING: tolerate broken refs
 189  *
 190  * Flags >= 0x100 are reserved for internal use.
 191  */
 192 #define REF_NODEREF     0x01
 193 #define REF_DELETING    0x02
 194 /*
 195  * This function sets errno to something meaningful on failure.
 196  */
 197 extern struct ref_lock *lock_any_ref_for_update(const char *refname,
 198                                                 const unsigned char *old_sha1,
 199                                                 int flags, int *type_p);
 200
 201 /** Close the file descriptor owned by a lock and return the status */
 202 extern int close_ref(struct ref_lock *lock);
 203
 204 /** Close and commit the ref locked by the lock */
 205 extern int commit_ref(struct ref_lock *lock);
 206
 207 /** Release any lock taken but not written. **/
 208 extern void unlock_ref(struct ref_lock *lock);
 209
 210 /*
 211  * Setup reflog before using. Set errno to something meaningful on failure.
 212  */
 213 int log_ref_setup(const char *refname, char *logfile, int bufsize);
 214
 215 /** Reads log for the value of ref during at_time. **/
 216 extern int read_ref_at(const char *refname, unsigned int flags,
 217                        unsigned long at_time, int cnt,
 218                        unsigned char *sha1, char **msg,
 219                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 220
 221 /** Check if a particular reflog exists */
 222 extern int reflog_exists(const char *refname);
 223
 224 /** Delete a reflog */
 225 extern int delete_reflog(const char *refname);
 226
 227 /* iterate over reflog entries */
 228 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 229 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 230 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 231
 232 /*
 233  * Calls the specified function for each reflog file until it returns nonzero,
 234  * and returns the value
 235  */
 236 extern int for_each_reflog(each_ref_fn, void *);
 237
 238 #define REFNAME_ALLOW_ONELEVEL 1
 239 #define REFNAME_REFSPEC_PATTERN 2
 240
 241 /*
 242  * Return 0 iff refname has the correct format for a refname according
 243  * to the rules described in Documentation/git-check-ref-format.txt.
 244  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 245  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 246  * allow a "*" wildcard character in place of one of the name
 247  * components.  No leading or repeated slashes are accepted.
 248  */
 249 extern int check_refname_format(const char *refname, int flags);
 250
 251 extern const char *prettify_refname(const char *refname);
 252 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 253
 254 /** rename ref, return 0 on success **/
 255 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 256
 257 /**
 258  * Resolve refname in the nested "gitlink" repository that is located
 259  * at path.  If the resolution is successful, return 0 and set sha1 to
 260  * the name of the object; otherwise, return a non-zero value.
 261  */
 262 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
 263
 264 enum action_on_err {
 265         UPDATE_REFS_MSG_ON_ERR,
 266         UPDATE_REFS_DIE_ON_ERR,
 267         UPDATE_REFS_QUIET_ON_ERR
 268 };
 269
 270 /*
 271  * Begin a reference transaction.  The reference transaction must
 272  * be freed by calling ref_transaction_free().
 273  */
 274 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 275
 276 /*
 277  * The following functions add a reference check or update to a
 278  * ref_transaction.  In all of them, refname is the name of the
 279  * reference to be affected.  The functions make internal copies of
 280  * refname and msg, so the caller retains ownership of these parameters.
 281  * flags can be REF_NODEREF; it is passed to update_ref_lock().
 282  */
 283
 284 /*
 285  * Add a reference update to transaction.  new_sha1 is the value that
 286  * the reference should have after the update, or zeros if it should
 287  * be deleted.  If have_old is true, then old_sha1 holds the value
 288  * that the reference should have had before the update, or zeros if
 289  * it must not have existed beforehand.
 290  * Function returns 0 on success and non-zero on failure. A failure to update
 291  * means that the transaction as a whole has failed and will need to be
 292  * rolled back.
 293  */
 294 int ref_transaction_update(struct ref_transaction *transaction,
 295                            const char *refname,
 296                            const unsigned char *new_sha1,
 297                            const unsigned char *old_sha1,
 298                            int flags, int have_old, const char *msg,
 299                            struct strbuf *err);
 300
 301 /*
 302  * Add a reference creation to transaction.  new_sha1 is the value
 303  * that the reference should have after the update; it must not be the
 304  * null SHA-1.  It is verified that the reference does not exist
 305  * already.
 306  * Function returns 0 on success and non-zero on failure. A failure to create
 307  * means that the transaction as a whole has failed and will need to be
 308  * rolled back.
 309  */
 310 int ref_transaction_create(struct ref_transaction *transaction,
 311                            const char *refname,
 312                            const unsigned char *new_sha1,
 313                            int flags, const char *msg,
 314                            struct strbuf *err);
 315
 316 /*
 317  * Add a reference deletion to transaction.  If have_old is true, then
 318  * old_sha1 holds the value that the reference should have had before
 319  * the update (which must not be the null SHA-1).
 320  * Function returns 0 on success and non-zero on failure. A failure to delete
 321  * means that the transaction as a whole has failed and will need to be
 322  * rolled back.
 323  */
 324 int ref_transaction_delete(struct ref_transaction *transaction,
 325                            const char *refname,
 326                            const unsigned char *old_sha1,
 327                            int flags, int have_old, const char *msg,
 328                            struct strbuf *err);
 329
 330 /*
 331  * Commit all of the changes that have been queued in transaction, as
 332  * atomically as possible.
 333  *
 334  * Returns 0 for success, or one of the below error codes for errors.
 335  */
 336 /* Naming conflict (for example, the ref names A and A/B conflict). */
 337 #define TRANSACTION_NAME_CONFLICT -1
 338 /* All other errors. */
 339 #define TRANSACTION_GENERIC_ERROR -2
 340 int ref_transaction_commit(struct ref_transaction *transaction,
 341                            struct strbuf *err);
 342
 343 /*
 344  * Free an existing transaction and all associated data.
 345  */
 346 void ref_transaction_free(struct ref_transaction *transaction);
 347
 348 /** Lock a ref and then write its file */
 349 int update_ref(const char *action, const char *refname,
 350                 const unsigned char *sha1, const unsigned char *oldval,
 351                 int flags, enum action_on_err onerr);
 352
 353 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 354 extern int ref_is_hidden(const char *);
 355
 356 #endif /* REFS_H */