[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go b/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go
new file mode 100644
index 0000000..3bcfa4d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go
@@ -0,0 +1,51 @@
+// Copyright 2017 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 mvcc
+
+import "go.etcd.io/etcd/mvcc/mvccpb"
+
+func (tw *watchableStoreTxnWrite) End() {
+	changes := tw.Changes()
+	if len(changes) == 0 {
+		tw.TxnWrite.End()
+		return
+	}
+
+	rev := tw.Rev() + 1
+	evs := make([]mvccpb.Event, len(changes))
+	for i, change := range changes {
+		evs[i].Kv = &changes[i]
+		if change.CreateRevision == 0 {
+			evs[i].Type = mvccpb.DELETE
+			evs[i].Kv.ModRevision = rev
+		} else {
+			evs[i].Type = mvccpb.PUT
+		}
+	}
+
+	// end write txn under watchable store lock so the updates are visible
+	// when asynchronous event posting checks the current store revision
+	tw.s.mu.Lock()
+	tw.s.notify(rev, evs)
+	tw.TxnWrite.End()
+	tw.s.mu.Unlock()
+}
+
+type watchableStoreTxnWrite struct {
+	TxnWrite
+	s *watchableStore
+}
+
+func (s *watchableStore) Write() TxnWrite { return &watchableStoreTxnWrite{s.store.Write(), s} }