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 extern int repack_without_refs(const char **refnames, int n,
 158                                struct strbuf *err);
 159
 160 extern int ref_exists(const char *);
 161
 162 extern int is_branch(const char *refname);
 163
 164 /*
 165  * If refname is a non-symbolic reference that refers to a tag object,
 166  * and the tag can be (recursively) dereferenced to a non-tag object,
 167  * store the SHA1 of the referred-to object to sha1 and return 0.  If
 168  * any of these conditions are not met, return a non-zero value.
 169  * Symbolic references are considered unpeelable, even if they
 170  * ultimately resolve to a peelable tag.
 171  */
 172 extern int peel_ref(const char *refname, unsigned char *sha1);
 173
 174 /*
 175  * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
 176  * REF_NODEREF: act on the ref directly, instead of dereferencing
 177  *              symbolic references.
 178  * REF_DELETING: tolerate broken refs
 179  *
 180  * Flags >= 0x100 are reserved for internal use.
 181  */
 182 #define REF_NODEREF     0x01
 183 #define REF_DELETING    0x02
 184
 185 /*
 186  * Setup reflog before using. Set errno to something meaningful on failure.
 187  */
 188 int log_ref_setup(const char *refname, char *logfile, int bufsize);
 189
 190 /** Reads log for the value of ref during at_time. **/
 191 extern int read_ref_at(const char *refname, unsigned int flags,
 192                        unsigned long at_time, int cnt,
 193                        unsigned char *sha1, char **msg,
 194                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 195
 196 /** Check if a particular reflog exists */
 197 extern int reflog_exists(const char *refname);
 198
 199 /** Delete a reflog */
 200 extern int delete_reflog(const char *refname);
 201
 202 /* iterate over reflog entries */
 203 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 204 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 205 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 206
 207 /*
 208  * Calls the specified function for each reflog file until it returns nonzero,
 209  * and returns the value
 210  */
 211 extern int for_each_reflog(each_ref_fn, void *);
 212
 213 #define REFNAME_ALLOW_ONELEVEL 1
 214 #define REFNAME_REFSPEC_PATTERN 2
 215
 216 /*
 217  * Return 0 iff refname has the correct format for a refname according
 218  * to the rules described in Documentation/git-check-ref-format.txt.
 219  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 220  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 221  * allow a "*" wildcard character in place of one of the name
 222  * components.  No leading or repeated slashes are accepted.
 223  */
 224 extern int check_refname_format(const char *refname, int flags);
 225
 226 extern const char *prettify_refname(const char *refname);
 227 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 228
 229 /** rename ref, return 0 on success **/
 230 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 231
 232 /**
 233  * Resolve refname in the nested "gitlink" repository that is located
 234  * at path.  If the resolution is successful, return 0 and set sha1 to
 235  * the name of the object; otherwise, return a non-zero value.
 236  */
 237 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
 238
 239 enum action_on_err {
 240         UPDATE_REFS_MSG_ON_ERR,
 241         UPDATE_REFS_DIE_ON_ERR,
 242         UPDATE_REFS_QUIET_ON_ERR
 243 };
 244
 245 /*
 246  * Begin a reference transaction.  The reference transaction must
 247  * be freed by calling ref_transaction_free().
 248  */
 249 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 250
 251 /*
 252  * The following functions add a reference check or update to a
 253  * ref_transaction.  In all of them, refname is the name of the
 254  * reference to be affected.  The functions make internal copies of
 255  * refname and msg, so the caller retains ownership of these parameters.
 256  * flags can be REF_NODEREF; it is passed to update_ref_lock().
 257  */
 258
 259 /*
 260  * Add a reference update to transaction.  new_sha1 is the value that
 261  * the reference should have after the update, or null_sha1 if it should
 262  * be deleted.  If have_old is true, then old_sha1 holds the value
 263  * that the reference should have had before the update, or zeros if
 264  * it must not have existed beforehand.
 265  * Function returns 0 on success and non-zero on failure. A failure to update
 266  * means that the transaction as a whole has failed and will need to be
 267  * rolled back.
 268  */
 269 int ref_transaction_update(struct ref_transaction *transaction,
 270                            const char *refname,
 271                            const unsigned char *new_sha1,
 272                            const unsigned char *old_sha1,
 273                            int flags, int have_old, const char *msg,
 274                            struct strbuf *err);
 275
 276 /*
 277  * Add a reference creation to transaction.  new_sha1 is the value
 278  * that the reference should have after the update; it must not be the
 279  * null SHA-1.  It is verified that the reference does not exist
 280  * already.
 281  * Function returns 0 on success and non-zero on failure. A failure to create
 282  * means that the transaction as a whole has failed and will need to be
 283  * rolled back.
 284  */
 285 int ref_transaction_create(struct ref_transaction *transaction,
 286                            const char *refname,
 287                            const unsigned char *new_sha1,
 288                            int flags, const char *msg,
 289                            struct strbuf *err);
 290
 291 /*
 292  * Add a reference deletion to transaction.  If have_old is true, then
 293  * old_sha1 holds the value that the reference should have had before
 294  * the update (which must not be the null SHA-1).
 295  * Function returns 0 on success and non-zero on failure. A failure to delete
 296  * means that the transaction as a whole has failed and will need to be
 297  * rolled back.
 298  */
 299 int ref_transaction_delete(struct ref_transaction *transaction,
 300                            const char *refname,
 301                            const unsigned char *old_sha1,
 302                            int flags, int have_old, const char *msg,
 303                            struct strbuf *err);
 304
 305 /*
 306  * Commit all of the changes that have been queued in transaction, as
 307  * atomically as possible.
 308  *
 309  * Returns 0 for success, or one of the below error codes for errors.
 310  */
 311 /* Naming conflict (for example, the ref names A and A/B conflict). */
 312 #define TRANSACTION_NAME_CONFLICT -1
 313 /* All other errors. */
 314 #define TRANSACTION_GENERIC_ERROR -2
 315 int ref_transaction_commit(struct ref_transaction *transaction,
 316                            struct strbuf *err);
 317
 318 /*
 319  * Free an existing transaction and all associated data.
 320  */
 321 void ref_transaction_free(struct ref_transaction *transaction);
 322
 323 /** Lock a ref and then write its file */
 324 int update_ref(const char *action, const char *refname,
 325                 const unsigned char *sha1, const unsigned char *oldval,
 326                 int flags, enum action_on_err onerr);
 327
 328 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 329 extern int ref_is_hidden(const char *);
 330
 331 enum expire_reflog_flags {
 332         EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
 333         EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
 334         EXPIRE_REFLOGS_VERBOSE = 1 << 2,
 335         EXPIRE_REFLOGS_REWRITE = 1 << 3
 336 };
 337
 338 /*
 339  * The following interface is used for reflog expiration. The caller
 340  * calls reflog_expire(), supplying it with three callback functions,
 341  * of the following types. The callback functions define the
 342  * expiration policy that is desired.
 343  *
 344  * reflog_expiry_prepare_fn -- Called once after the reference is
 345  *     locked.
 346  *
 347  * reflog_expiry_should_prune_fn -- Called once for each entry in the
 348  *     existing reflog. It should return true iff that entry should be
 349  *     pruned.
 350  *
 351  * reflog_expiry_cleanup_fn -- Called once before the reference is
 352  *     unlocked again.
 353  */
 354 typedef void reflog_expiry_prepare_fn(const char *refname,
 355                                       const unsigned char *sha1,
 356                                       void *cb_data);
 357 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
 358                                           unsigned char *nsha1,
 359                                           const char *email,
 360                                           unsigned long timestamp, int tz,
 361                                           const char *message, void *cb_data);
 362 typedef void reflog_expiry_cleanup_fn(void *cb_data);
 363
 364 /*
 365  * Expire reflog entries for the specified reference. sha1 is the old
 366  * value of the reference. flags is a combination of the constants in
 367  * enum expire_reflog_flags. The three function pointers are described
 368  * above. On success, return zero.
 369  */
 370 extern int reflog_expire(const char *refname, const unsigned char *sha1,
 371                          unsigned int flags,
 372                          reflog_expiry_prepare_fn prepare_fn,
 373                          reflog_expiry_should_prune_fn should_prune_fn,
 374                          reflog_expiry_cleanup_fn cleanup_fn,
 375                          void *policy_cb_data);
 376
 377 #endif /* REFS_H */