Benchmark API response parsing code (#17046)

* Benchmark API response parsing code

* Fixing contents

* Removing unnecessary line

metricbeat/module/elasticsearch/index/data_xpack.go

@@ -96,8 +96,7 @@ var (
 
 func eventsMappingXPack(r mb.ReporterV2, m *MetricSet, info elasticsearch.Info, content []byte) error {
 	var indicesStruct IndicesStruct
-	err := json.Unmarshal(content, &indicesStruct)
-	if err != nil {
+	if err := parseAPIResponse(content, &indicesStruct); err != nil {
 		return errors.Wrap(err, "failure parsing Indices Stats Elasticsearch API response")
 	}
 
@@ -138,6 +137,10 @@ func eventsMappingXPack(r mb.ReporterV2, m *MetricSet, info elasticsearch.Info,
 	return errs.Err()
 }
 
+func parseAPIResponse(content []byte, indicesStruct *IndicesStruct) error {
+	return json.Unmarshal(content, indicesStruct)
+}
+
 // Fields added here are based on same fields being added by internal collection in
 // https://github.com/elastic/elasticsearch/blob/master/x-pack/plugin/monitoring/src/main/java/org/elasticsearch/xpack/monitoring/collector/indices/IndexStatsMonitoringDoc.java#L62-L124
 func addClusterStateFields(indexName string, indexStats, clusterState common.MapStr) error {

metricbeat/module/elasticsearch/index/data_xpack_test.go

@@ -0,0 +1,41 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you 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.
+
+// +build !integration
+
+package index
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func BenchmarkParseAPIResponse(b *testing.B) {
+	// Read in large stats API response fixture
+	content, err := ioutil.ReadFile("_meta/test/stats.800.bench.json")
+	require.NoError(b, err)
+
+	var indicesStruct IndicesStruct
+
+	for i := 0; i < b.N; i++ {
+		err = parseAPIResponse(content, &indicesStruct)
+		require.NoError(b, err)
+	}
+
+}