[2470] defined getNullCallbacks and its trivial callback function.

src/lib/dns/master_loader_callbacks.cc

@@ -0,0 +1,34 @@
+// Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <dns/master_loader_callbacks.h>
+
+#include <string>
+
+namespace isc {
+namespace dns {
+
+namespace {
+void
+nullCallback(const std::string&, size_t, const std::string&) {
+}
+}
+
+MasterLoaderCallbacks
+MasterLoaderCallbacks::getNullCallbacks() {
+    return (MasterLoaderCallbacks(nullCallback, nullCallback));
+}
+
+} // end namespace dns
+} // end namespace isc