--- /dev/null
+# Copyright (C) 2011, 2012 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import struct
+
+
+def msg_pack_into(fmt, buf, offset, *args):
+ needed_len = offset + struct.calcsize(fmt)
+ if len(buf) < needed_len:
+ buf += bytearray(needed_len - len(buf))
+
+ struct.pack_into(fmt, buf, offset, *args)