int force_write;
};
+/*
+ * A ref_transaction represents a collection of ref updates
+ * that should succeed or fail together.
+ *
+ * Calling sequence
+ * ----------------
+ * - Allocate and initialize a `struct ref_transaction` by calling
+ * `ref_transaction_begin()`.
+ *
+ * - List intended ref updates by calling functions like
+ * `ref_transaction_update()` and `ref_transaction_create()`.
+ *
+ * - Call `ref_transaction_commit()` to execute the transaction.
+ * If this succeeds, the ref updates will have taken place and
+ * the transaction cannot be rolled back.
+ *
+ * - At any time call `ref_transaction_free()` to discard the
+ * transaction and free associated resources. In particular,
+ * this rolls back the transaction if it has not been
+ * successfully committed.
+ *
+ * Error handling
+ * --------------
+ *
+ * On error, transaction functions append a message about what
+ * went wrong to the 'err' argument. The message mentions what
+ * ref was being updated (if any) when the error occurred so it
+ * can be passed to 'die' or 'error' as-is.
+ *
+ * The message is appended to err without first clearing err.
+ * err will not be '\n' terminated.
+ */
+struct ref_transaction;
+
+/*
+ * Bit values set in the flags argument passed to each_ref_fn():
+ */
+
+/* Reference is a symbolic reference. */
#define REF_ISSYMREF 0x01
+
+/* Reference is a packed reference. */
#define REF_ISPACKED 0x02
+
+/*
+ * Reference cannot be resolved to an object name: dangling symbolic
+ * reference (directly or indirectly), corrupt reference file, or
+ * symbolic reference refers to ill-formatted reference name.
+ */
#define REF_ISBROKEN 0x04
/*
- * Calls the specified function for each ref file until it returns
- * nonzero, and returns the value. Please note that it is not safe to
- * modify references while an iteration is in progress, unless the
- * same callback function invocation that modifies the reference also
- * returns a nonzero value to immediately stop the iteration.
+ * The signature for the callback function for the for_each_*()
+ * functions below. The memory pointed to by the refname and sha1
+ * arguments is only guaranteed to be valid for the duration of a
+ * single callback invocation.
+ */
+typedef int each_ref_fn(const char *refname,
+ const unsigned char *sha1, int flags, void *cb_data);
+
+/*
+ * The following functions invoke the specified callback function for
+ * each reference indicated. If the function ever returns a nonzero
+ * value, stop the iteration and return that value. Please note that
+ * it is not safe to modify references while an iteration is in
+ * progress, unless the same callback function invocation that
+ * modifies the reference also returns a nonzero value to immediately
+ * stop the iteration.
*/
-typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data);
extern int head_ref(each_ref_fn, void *);
extern int for_each_ref(each_ref_fn, void *);
extern int for_each_ref_in(const char *, each_ref_fn, void *);
extern int for_each_rawref(each_ref_fn, void *);
extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
+extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
+
+/*
+ * Lock the packed-refs file for writing. Flags is passed to
+ * hold_lock_file_for_update(). Return 0 on success.
+ * Errno is set to something meaningful on error.
+ */
+extern int lock_packed_refs(int flags);
/*
- * Add a reference to the in-memory packed reference cache. To actually
- * write the reference to the packed-refs file, call pack_refs().
+ * Add a reference to the in-memory packed reference cache. This may
+ * only be called while the packed-refs file is locked (see
+ * lock_packed_refs()). To actually write the packed-refs file, call
+ * commit_packed_refs().
*/
extern void add_packed_ref(const char *refname, const unsigned char *sha1);
+/*
+ * Write the current version of the packed refs cache from memory to
+ * disk. The packed-refs file must already be locked for writing (see
+ * lock_packed_refs()). Return zero on success.
+ * Sets errno to something meaningful on error.
+ */
+extern int commit_packed_refs(void);
+
+/*
+ * Rollback the lockfile for the packed-refs file, and discard the
+ * in-memory packed reference cache. (The packed-refs file will be
+ * read anew if it is needed again after this function is called.)
+ */
+extern void rollback_packed_refs(void);
+
+/*
+ * Flags for controlling behaviour of pack_refs()
+ * PACK_REFS_PRUNE: Prune loose refs after packing
+ * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
+ */
+#define PACK_REFS_PRUNE 0x0001
+#define PACK_REFS_ALL 0x0002
+
+/*
+ * Write a packed-refs file for the current repository.
+ * flags: Combination of the above PACK_REFS_* flags.
+ */
+int pack_refs(unsigned int flags);
+
+extern int repack_without_refs(const char **refnames, int n,
+ struct strbuf *err);
+
extern int ref_exists(const char *);
-extern int peel_ref(const char *refname, unsigned char *sha1);
+extern int is_branch(const char *refname);
-/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/
-extern struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1);
+/*
+ * If refname is a non-symbolic reference that refers to a tag object,
+ * and the tag can be (recursively) dereferenced to a non-tag object,
+ * store the SHA1 of the referred-to object to sha1 and return 0. If
+ * any of these conditions are not met, return a non-zero value.
+ * Symbolic references are considered unpeelable, even if they
+ * ultimately resolve to a peelable tag.
+ */
+extern int peel_ref(const char *refname, unsigned char *sha1);
-/** Locks any ref (for 'HEAD' type refs). */
+/*
+ * Flags controlling lock_any_ref_for_update(), ref_transaction_update(),
+ * ref_transaction_create(), etc.
+ * REF_NODEREF: act on the ref directly, instead of dereferencing
+ * symbolic references.
+ *
+ * Flags >= 0x100 are reserved for internal use.
+ */
#define REF_NODEREF 0x01
+/*
+ * This function sets errno to something meaningful on failure.
+ */
extern struct ref_lock *lock_any_ref_for_update(const char *refname,
const unsigned char *old_sha1,
- int flags);
+ int flags, int *type_p);
/** Close the file descriptor owned by a lock and return the status */
extern int close_ref(struct ref_lock *lock);
extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg);
/*
- * Invalidate the reference cache for the specified submodule. Use
- * submodule=NULL to invalidate the cache for the main module. This
- * function must be called if references are changed via a mechanism
- * other than the refs API.
+ * Setup reflog before using. Set errno to something meaningful on failure.
*/
-extern void invalidate_ref_cache(const char *submodule);
-
-/** Setup reflog before using. **/
-int log_ref_setup(const char *ref_name, char *logfile, int bufsize);
+int log_ref_setup(const char *refname, char *logfile, int bufsize);
/** Reads log for the value of ref during at_time. **/
-extern int read_ref_at(const char *refname, unsigned long at_time, int cnt,
+extern int read_ref_at(const char *refname, unsigned int flags,
+ unsigned long at_time, int cnt,
unsigned char *sha1, char **msg,
unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
+/** Check if a particular reflog exists */
+extern int reflog_exists(const char *refname);
+
+/** Delete a reflog */
+extern int delete_reflog(const char *refname);
+
/* iterate over reflog entries */
typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
-int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long, void *cb_data);
+int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
/*
* Calls the specified function for each reflog file until it returns nonzero,
*/
extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
-/** lock a ref and then write its file */
-enum action_on_err { MSG_ON_ERR, DIE_ON_ERR, QUIET_ON_ERR };
+enum action_on_err {
+ UPDATE_REFS_MSG_ON_ERR,
+ UPDATE_REFS_DIE_ON_ERR,
+ UPDATE_REFS_QUIET_ON_ERR
+};
+
+/*
+ * Begin a reference transaction. The reference transaction must
+ * be freed by calling ref_transaction_free().
+ */
+struct ref_transaction *ref_transaction_begin(struct strbuf *err);
+
+/*
+ * The following functions add a reference check or update to a
+ * ref_transaction. In all of them, refname is the name of the
+ * reference to be affected. The functions make internal copies of
+ * refname, so the caller retains ownership of the parameter. flags
+ * can be REF_NODEREF; it is passed to update_ref_lock().
+ */
+
+/*
+ * Add a reference update to transaction. new_sha1 is the value that
+ * the reference should have after the update, or zeros if it should
+ * be deleted. If have_old is true, then old_sha1 holds the value
+ * that the reference should have had before the update, or zeros if
+ * it must not have existed beforehand.
+ * Function returns 0 on success and non-zero on failure. A failure to update
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back.
+ */
+int ref_transaction_update(struct ref_transaction *transaction,
+ const char *refname,
+ const unsigned char *new_sha1,
+ const unsigned char *old_sha1,
+ int flags, int have_old,
+ struct strbuf *err);
+
+/*
+ * Add a reference creation to transaction. new_sha1 is the value
+ * that the reference should have after the update; it must not be the
+ * null SHA-1. It is verified that the reference does not exist
+ * already.
+ * Function returns 0 on success and non-zero on failure. A failure to create
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back.
+ */
+int ref_transaction_create(struct ref_transaction *transaction,
+ const char *refname,
+ const unsigned char *new_sha1,
+ int flags,
+ struct strbuf *err);
+
+/*
+ * Add a reference deletion to transaction. If have_old is true, then
+ * old_sha1 holds the value that the reference should have had before
+ * the update (which must not be the null SHA-1).
+ * Function returns 0 on success and non-zero on failure. A failure to delete
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back.
+ */
+int ref_transaction_delete(struct ref_transaction *transaction,
+ const char *refname,
+ const unsigned char *old_sha1,
+ int flags, int have_old,
+ struct strbuf *err);
+
+/*
+ * Commit all of the changes that have been queued in transaction, as
+ * atomically as possible. Return a nonzero value if there is a
+ * problem.
+ */
+int ref_transaction_commit(struct ref_transaction *transaction,
+ const char *msg, struct strbuf *err);
+
+/*
+ * Free an existing transaction and all associated data.
+ */
+void ref_transaction_free(struct ref_transaction *transaction);
+
+/** Lock a ref and then write its file */
int update_ref(const char *action, const char *refname,
const unsigned char *sha1, const unsigned char *oldval,
int flags, enum action_on_err onerr);