Function for updating refs.

A function intended to be called from builtins updating refs
by locking them before write, specially those that came from
scripts using "git update-ref".

[jc: with minor fixups]

Signed-off-by: Carlos Rica <jasampler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/refs.h b/refs.h
index f234eb76ba..6eb98a4caf 100644
--- a/refs.h
+++ b/refs.h
@@ -64,4 +64,10 @@ extern int rename_ref(const char *oldref, const char *newref, const char *logmsg
 /** resolve ref in nested "gitlink" repository */
 extern int resolve_gitlink_ref(const char *name, const char *refname, unsigned char *result);
 
+/** lock a ref and then write its file */
+enum action_on_err { MSG_ON_ERR, DIE_ON_ERR, QUIET_ON_ERR };
+int update_ref(const char *action, const char *refname,
+		const unsigned char *sha1, const unsigned char *oldval,
+		int flags, enum action_on_err onerr);
+
 #endif /* REFS_H */