mvcc: add keyIndex benchmark test

Useful later when trying to optimize our restore operations.

mvcc/index_bench_test.go

@@ -0,0 +1,41 @@
+// Copyright 2016 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 (
+	"fmt"
+	"testing"
+)
+
+func BenchmarkIndexRestore(b *testing.B) {
+	var (
+		keys            = make([][]byte, b.N)
+		createds        = make([]revision, b.N)
+		modifieds       = make([]revision, b.N)
+		ver       int64 = 1
+	)
+	for i := 0; i < b.N; i++ {
+		keys[i] = []byte(fmt.Sprintf("foo%d", i))
+		createds[i] = revision{int64(i), 0}
+		modifieds[i] = revision{int64(i), 1}
+	}
+
+	kvindex := newTreeIndex()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		kvindex.Restore(keys[i], createds[i], modifieds[i], ver)
+	}
+}