Add parser-only microbenchmark

Author: smalyshev

benchmarks/src/main/java/org/elasticsearch/benchmark/xcontent/JsonParserBenchmark.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.benchmark.xcontent;
+
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.io.Streams;
+import org.elasticsearch.xcontent.XContentParser;
+import org.elasticsearch.xcontent.XContentParserConfiguration;
+import org.elasticsearch.xcontent.XContentType;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+import org.openjdk.jmh.infra.Blackhole;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+
+@Fork(1)
+@Warmup(iterations = 5)
+@Measurement(iterations = 10)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Thread)
+public class JsonParserBenchmark {
+    private Map<String, BytesReference> sourceBytes;
+    private BytesReference source;
+    private Random random;
+    private List<String> sourcesRandomized;
+
+    final String[] sources = new String[] { "monitor_cluster_stats.json", "monitor_index_stats.json", "monitor_node_stats.json" };
+
+    @Setup(Level.Iteration)
+    public void randomizeSource() {
+        sourcesRandomized = Arrays.asList(sources);
+        Collections.shuffle(sourcesRandomized, random);
+    }
+
+    @Setup(Level.Trial)
+    public void setup() throws IOException {
+        random = new Random();
+        sourceBytes = Arrays.stream(sources).collect(Collectors.toMap(s -> s, s -> {
+            try {
+                return readSource(s);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }));
+    }
+
+    @Benchmark
+    public void parseJson(Blackhole bh) throws IOException {
+        sourcesRandomized.forEach(source -> {
+            try {
+                final XContentParser parser = XContentType.JSON.xContent()
+                    .createParser(XContentParserConfiguration.EMPTY, sourceBytes.get(source).streamInput());
+                bh.consume(parser.mapOrdered());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
+
+    private BytesReference readSource(String fileName) throws IOException {
+        return Streams.readFully(JsonParserBenchmark.class.getResourceAsStream(fileName));
+    }
+}