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  *   `transaction_begin()`.
  21  *
  22  * - List intended ref updates by calling functions like
  23  *   `transaction_update_sha1()` and `transaction_create_sha1()`.
  24  *
  25  * - Call `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 `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  * Flags for controlling behaviour of pack_refs()
 116  * PACK_REFS_PRUNE: Prune loose refs after packing
 117  * PACK_REFS_ALL:   Pack _all_ refs, not just tags and already packed refs
 118  */
 119 #define PACK_REFS_PRUNE 0x0001
 120 #define PACK_REFS_ALL   0x0002
 121
 122 /*
 123  * Write a packed-refs file for the current repository.
 124  * flags: Combination of the above PACK_REFS_* flags.
 125  */
 126 int pack_refs(unsigned int flags);
 127
 128 extern int ref_exists(const char *);
 129
 130 extern int is_branch(const char *refname);
 131
 132 /*
 133  * If refname is a non-symbolic reference that refers to a tag object,
 134  * and the tag can be (recursively) dereferenced to a non-tag object,
 135  * store the SHA1 of the referred-to object to sha1 and return 0.  If
 136  * any of these conditions are not met, return a non-zero value.
 137  * Symbolic references are considered unpeelable, even if they
 138  * ultimately resolve to a peelable tag.
 139  */
 140 extern int peel_ref(const char *refname, unsigned char *sha1);
 141
 142 /*
 143  * Flags controlling transaction_update_sha1(), transaction_create_sha1(), etc.
 144  * REF_NODEREF: act on the ref directly, instead of dereferencing
 145  *              symbolic references.
 146  * REF_ALLOWBROKEN: allow locking refs that are broken.
 147  * Flags >= 0x100 are reserved for internal use.
 148  */
 149 #define REF_NODEREF     0x01
 150 #define REF_ALLOWBROKEN 0x02
 151
 152 /** Reads log for the value of ref during at_time. **/
 153 extern int read_ref_at(const char *refname, unsigned long at_time, int cnt,
 154                        unsigned char *sha1, char **msg,
 155                        unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 156
 157 /** Check if a particular reflog exists */
 158 extern int reflog_exists(const char *refname);
 159
 160 /** Create reflog. Set errno to something meaningful on failure. */
 161 extern int create_reflog(const char *refname);
 162
 163 /** Delete a reflog */
 164 extern int delete_reflog(const char *refname);
 165
 166 /* iterate over reflog entries */
 167 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
 168 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 169 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 170
 171 /*
 172  * Calls the specified function for each reflog file until it returns nonzero,
 173  * and returns the value
 174  */
 175 extern int for_each_reflog(each_ref_fn, void *);
 176
 177 #define REFNAME_ALLOW_ONELEVEL 1
 178 #define REFNAME_REFSPEC_PATTERN 2
 179 #define REFNAME_DOT_COMPONENT 4
 180
 181 /*
 182  * Return 0 iff refname has the correct format for a refname according
 183  * to the rules described in Documentation/git-check-ref-format.txt.
 184  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
 185  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
 186  * allow a "*" wildcard character in place of one of the name
 187  * components.  No leading or repeated slashes are accepted.  If
 188  * REFNAME_DOT_COMPONENT is set in flags, then allow refname
 189  * components to start with "." (but not a whole component equal to
 190  * "." or "..").
 191  */
 192 extern int check_refname_format(const char *refname, int flags);
 193
 194 extern const char *prettify_refname(const char *refname);
 195 extern char *shorten_unambiguous_ref(const char *refname, int strict);
 196
 197 /** rename ref, return 0 on success **/
 198 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 199
 200 /**
 201  * Resolve refname in the nested "gitlink" repository that is located
 202  * at path.  If the resolution is successful, return 0 and set sha1 to
 203  * the name of the object; otherwise, return a non-zero value.
 204  */
 205 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
 206
 207 enum action_on_err {
 208         UPDATE_REFS_MSG_ON_ERR,
 209         UPDATE_REFS_DIE_ON_ERR,
 210         UPDATE_REFS_QUIET_ON_ERR
 211 };
 212
 213 /*
 214  * Begin a reference transaction.  The reference transaction must
 215  * be freed by calling transaction_free().
 216  */
 217 struct ref_transaction *transaction_begin(struct strbuf *err);
 218
 219 /*
 220  * The following functions add a reference check or update to a
 221  * ref_transaction.  In all of them, refname is the name of the
 222  * reference to be affected.  The functions make internal copies of
 223  * refname, so the caller retains ownership of the parameter.  flags
 224  * can be REF_NODEREF; it is passed to update_ref_lock().
 225  */
 226
 227 /*
 228  * Add a reference update to transaction.  new_sha1 is the value that
 229  * the reference should have after the update, or null_sha1 if it should
 230  * be deleted.  If have_old is true and old_sha is not the null_sha1
 231  * then the previous value of the ref must match or the update will fail.
 232  * If have_old is true and old_sha1 is the null_sha1 then the ref must not
 233  * already exist and a new ref will be created with new_sha1.
 234  * Function returns 0 on success and non-zero on failure. A failure to update
 235  * means that the transaction as a whole has failed and will need to be
 236  * rolled back.
 237  */
 238 int transaction_update_sha1(struct ref_transaction *transaction,
 239                             const char *refname,
 240                             const unsigned char *new_sha1,
 241                             const unsigned char *old_sha1,
 242                             int flags, int have_old, const char *msg,
 243                             struct strbuf *err);
 244
 245 /*
 246  * Add a reference creation to transaction.  new_sha1 is the value
 247  * that the reference should have after the update; it must not be the
 248  * null SHA-1.  It is verified that the reference does not exist
 249  * already.
 250  * Function returns 0 on success and non-zero on failure. A failure to create
 251  * means that the transaction as a whole has failed and will need to be
 252  * rolled back.
 253  */
 254 int transaction_create_sha1(struct ref_transaction *transaction,
 255                             const char *refname,
 256                             const unsigned char *new_sha1,
 257                             int flags, const char *msg,
 258                             struct strbuf *err);
 259
 260 /*
 261  * Add a reference deletion to transaction.  If have_old is true, then
 262  * old_sha1 holds the value that the reference should have had before
 263  * the update (which must not be the null SHA-1).
 264  * Function returns 0 on success and non-zero on failure. A failure to delete
 265  * means that the transaction as a whole has failed and will need to be
 266  * rolled back.
 267  */
 268 int transaction_delete_sha1(struct ref_transaction *transaction,
 269                             const char *refname,
 270                             const unsigned char *old_sha1,
 271                             int flags, int have_old, const char *msg,
 272                             struct strbuf *err);
 273
 274 /*
 275  * Flags controlling transaction_update_reflog().
 276  * REFLOG_TRUNCATE: Truncate the reflog.
 277  *
 278  * Flags >= 0x100 are reserved for internal use.
 279  */
 280 #define REFLOG_TRUNCATE 0x01
 281 #define REFLOG_COMMITTER_INFO_IS_VALID 0x02
 282
 283 /*
 284  * Committer data provided to reflog updates.
 285  * If flags contain REFLOG_COMMITTER_DATA_IS_VALID then
 286  * then the structure contains a prebaked committer string
 287  * just like git_committer_info() would return.
 288  *
 289  * If flags does not contain REFLOG_COMMITTER_DATA_IS_VALID
 290  * then the committer info string will be generated using the passed
 291  * email, timestamp and tz fields.
 292  * This is useful for example from reflog iterators where you are passed
 293  * these fields individually and not as a prebaked git_committer_info()
 294  * string.
 295  */
 296 struct reflog_committer_info {
 297         const char *committer_info;
 298
 299         const char *id;
 300         unsigned long timestamp;
 301         int tz;
 302 };
 303 /*
 304  * Append a reflog entry for refname. If the REFLOG_TRUNCATE flag is set
 305  * this update will first truncate the reflog before writing the entry.
 306  * If msg is NULL no update will be written to the log.
 307  */
 308 int transaction_update_reflog(struct ref_transaction *transaction,
 309                               const char *refname,
 310                               const unsigned char *new_sha1,
 311                               const unsigned char *old_sha1,
 312                               struct reflog_committer_info *ci,
 313                               const char *msg, int flags,
 314                               struct strbuf *err);
 315
 316 /*
 317  * Commit all of the changes that have been queued in transaction, as
 318  * atomically as possible.  Return a nonzero value if there is a
 319  * problem.
 320  * If the transaction is already in failed state this function will return
 321  * an error.
 322  * Function returns 0 on success, -1 for generic failures and
 323  * UPDATE_REFS_NAME_CONFLICT (-2) if the failure was due to a name
 324  * collision (ENOTDIR).
 325  */
 326 #define UPDATE_REFS_NAME_CONFLICT -2
 327 int transaction_commit(struct ref_transaction *transaction,
 328                        struct strbuf *err);
 329
 330 /*
 331  * Free an existing transaction and all associated data.
 332  */
 333 void transaction_free(struct ref_transaction *transaction);
 334
 335 /** Lock a ref and then write its file */
 336 int update_ref(const char *action, const char *refname,
 337                 const unsigned char *sha1, const unsigned char *oldval,
 338                 int flags, enum action_on_err onerr);
 339
 340 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 341 extern int ref_is_hidden(const char *);
 342
 343 #endif /* REFS_H */