Add ConcurrentLruCache2

spring-core/src/jmh/java/org/springframework/util/ConcurrentLruCache2Benchmark.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2002-present the original author or 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
+ *
+ *      https://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 org.springframework.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
+
+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.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Threads;
+import org.openjdk.jmh.annotations.Warmup;
+import org.openjdk.jmh.infra.Blackhole;
+
+/**
+ * Benchmarks comparing {@link ConcurrentLruCache} and {@link ConcurrentLruCache2}.
+ * @author Brian Clozel
+ */
+@BenchmarkMode(Mode.Throughput)
+@Fork(3)
+@Threads(8)
+@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
+public class ConcurrentLruCache2Benchmark {
+
+	@Benchmark
+	public void legacyCache(LegacyBenchmarkData data, Blackhole bh) {
+		for (String element : data.elements) {
+			String value = data.lruCache.get(element);
+			bh.consume(value);
+		}
+	}
+
+	@Benchmark
+	public void lruCache2(LruCache2BenchmarkData data, Blackhole bh) {
+		for (String element : data.elements) {
+			String value = data.lruCache.get(element);
+			if (value == null) {
+				value = data.generator.apply(element);
+				data.lruCache.put(element, value);
+			}
+			bh.consume(value);
+		}
+	}
+
+	@State(Scope.Benchmark)
+	public static class LegacyBenchmarkData {
+
+		ConcurrentLruCache<String, String> lruCache;
+
+		@Param({"100"})
+		public int capacity;
+
+		@Param({"0.1"})
+		public float cacheMissRate;
+
+		public List<String> elements;
+
+		public Function<String, String> generator;
+
+		@Setup(Level.Iteration)
+		public void setup() {
+			this.generator = key -> key + "value";
+			this.lruCache = new ConcurrentLruCache<>(this.capacity, this.generator);
+			Assert.isTrue(this.cacheMissRate < 1, "cache miss rate should be < 1");
+			Random random = new Random();
+			int elementsCount = Math.round(this.capacity * (1 + this.cacheMissRate));
+			this.elements = new ArrayList<>(elementsCount);
+			random.ints(elementsCount).forEach(value -> this.elements.add(String.valueOf(value)));
+			this.elements.sort(String::compareTo);
+		}
+	}
+
+	@State(Scope.Benchmark)
+	public static class LruCache2BenchmarkData {
+
+		ConcurrentLruCache2<String, String> lruCache;
+
+		@Param({"100"})
+		public int capacity;
+
+		@Param({"0.1"})
+		public float cacheMissRate;
+
+		public List<String> elements;
+
+		public Function<String, String> generator;
+
+		@Setup(Level.Iteration)
+		public void setup() {
+			this.generator = key -> key + "value";
+			this.lruCache = new ConcurrentLruCache2<>(this.capacity);
+			Assert.isTrue(this.cacheMissRate < 1, "cache miss rate should be < 1");
+			Random random = new Random();
+			int elementsCount = Math.round(this.capacity * (1 + this.cacheMissRate));
+			this.elements = new ArrayList<>(elementsCount);
+			random.ints(elementsCount).forEach(value -> this.elements.add(String.valueOf(value)));
+			this.elements.sort(String::compareTo);
+		}
+	}
+}
+