diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go
new file mode 100644
index 0000000..7ea03de
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go
@@ -0,0 +1,34 @@
+// 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 v2store
+
+type eventQueue struct {
+	Events   []*Event
+	Size     int
+	Front    int
+	Back     int
+	Capacity int
+}
+
+func (eq *eventQueue) insert(e *Event) {
+	eq.Events[eq.Back] = e
+	eq.Back = (eq.Back + 1) % eq.Capacity
+
+	if eq.Size == eq.Capacity { //dequeue
+		eq.Front = (eq.Front + 1) % eq.Capacity
+	} else {
+		eq.Size++
+	}
+}