diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go
new file mode 100644
index 0000000..2417d22
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go
@@ -0,0 +1,68 @@
+// Copyright 2015 The etcd Authors
+//
+// 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.
+
+package rafthttp
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/raft/raftpb"
+)
+
+// messageEncoder is a encoder that can encode all kinds of messages.
+// It MUST be used with a paired messageDecoder.
+type messageEncoder struct {
+	w io.Writer
+}
+
+func (enc *messageEncoder) encode(m *raftpb.Message) error {
+	if err := binary.Write(enc.w, binary.BigEndian, uint64(m.Size())); err != nil {
+		return err
+	}
+	_, err := enc.w.Write(pbutil.MustMarshal(m))
+	return err
+}
+
+// messageDecoder is a decoder that can decode all kinds of messages.
+type messageDecoder struct {
+	r io.Reader
+}
+
+var (
+	readBytesLimit     uint64 = 512 * 1024 * 1024 // 512 MB
+	ErrExceedSizeLimit        = errors.New("rafthttp: error limit exceeded")
+)
+
+func (dec *messageDecoder) decode() (raftpb.Message, error) {
+	return dec.decodeLimit(readBytesLimit)
+}
+
+func (dec *messageDecoder) decodeLimit(numBytes uint64) (raftpb.Message, error) {
+	var m raftpb.Message
+	var l uint64
+	if err := binary.Read(dec.r, binary.BigEndian, &l); err != nil {
+		return m, err
+	}
+	if l > numBytes {
+		return m, ErrExceedSizeLimit
+	}
+	buf := make([]byte, int(l))
+	if _, err := io.ReadFull(dec.r, buf); err != nil {
+		return m, err
+	}
+	return m, m.Unmarshal(buf)
+}