JMH - ArrayListに初期値によるパフォーマンス調査

ArrayListBenchmark.java

package com.qiita.nimzo6689.bench;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
import lombok.SneakyThrows;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
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.State;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.results.format.ResultFormatType;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

/**
 *
 * @author ueokaj
 */
@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Warmup(iterations = 5)
@Measurement(iterations = 5)
@BenchmarkMode(Mode.AverageTime)
@Fork(2)
public class ArrayListBenchmark {

    private static final int size = 100;

    @Benchmark
    public void withInitialSize() {
        List<Integer> sizeList = new ArrayList<>(size);
        IntStream.range(0, size).forEach(i -> sizeList.add(i));
    }

    @Benchmark
    public void withoutInitialSize() {
        List<Integer> defaultList = new ArrayList<>();
        IntStream.range(0, size).forEach(i -> defaultList.add(i));
    }

    @SneakyThrows
    public static void main(String[] args) {
        Options opt = new OptionsBuilder()
                .include(ArrayListBenchmark.class.getSimpleName())
                .resultFormat(ResultFormatType.CSV)
                .build();
        new Runner(opt).run();
    }

}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.qiita.nimzo6689</groupId>
    <artifactId>MyApp</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    
    <dependencies>
        <!-- Utilities -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.12</version>
            <scope>provided</scope>
        </dependency>
        <!--Tuning-->
        <dependency>
            <groupId>org.openjdk.jmh</groupId>
            <artifactId>jmh-core</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>org.openjdk.jmh</groupId>
            <artifactId>jmh-generator-annprocess</artifactId>
            <version>1.19</version>
        </dependency>
    </dependencies>
    
</project>