package com.shrimpking.t4;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2024/9/12 12:09
 */
public interface Test
{
    void test();
}
package com.shrimpking.t4;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2024/9/12 12:10
 */
public class Tester
{
    public static long runTest(Test t){
        long start = System.currentTimeMillis();
        t.test();
        long end = System.currentTimeMillis();
        return end - start;
    }
}
package com.shrimpking.t4;

import java.util.stream.LongStream;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2024/9/12 12:09
 */
public class ParallelStreamPerformance
{
    public static void main(String[] args)
    {
        LongStream stream1 = LongStream.rangeClosed(1L,1000L);
//        long time1 = Tester.runTest(new Test()
//        {
//            @Override
//            public void test()
//            {
//                stream1.reduce(0L,Long::sum);
//            }
//        });
        long time1 = Tester.runTest(() -> stream1.reduce(0L,Long::sum));
        System.out.println("串行流花费时间：" + time1);

        LongStream stream2 = LongStream.rangeClosed(1L,1000L).parallel();
        long time2 = Tester.runTest(()-> stream2.reduce(0L,Long::sum));
        System.out.println("并行流花费时间：" + time2);

        LongStream stream3 = LongStream.rangeClosed(1L,100000000L);
        long time3 = Tester.runTest(() -> stream3.reduce(0L,Long::sum));
        System.out.println("数据量大串行流花费时间：" + time3);

        LongStream stream4 = LongStream.rangeClosed(1L,100000000L).parallel();
        long time4 = Tester.runTest(() -> stream4.reduce(0L,Long::sum));
        System.out.println("数据量大并行流花费时间：" + time4);

        //并行流的性能
        //处理少量数据时，并行流与串行流差距不大
        //处理大量数据时，并行流优势明显


    }
}