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fastutil简单测试下性能

news 2025/8/11 12:01:42

前言

简单测试一下fastutil的实现和Java类库实现的速率。
使用jmh进行测试。
简单解释一下，每轮测试预热2次，每次1s；实测2次，每次1秒。
进行5轮测试。数组大小3种。

package fastutil;import it.unimi.dsi.fastutil.ints.IntArrayList;
import org.openjdk.jmh.annotations.*;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;@State(Scope.Benchmark)
@Warmup(iterations = 2, time = 1000, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 2, time = 1000, timeUnit = TimeUnit.MILLISECONDS)
@Fork(value = 5)
public class ArrayListTest {@Param({"500000", "5000000", "50000000"})public int size;@Benchmark@BenchmarkMode(Mode.AverageTime)public List<Integer> insertArrayList() {List<Integer> list = new ArrayList<>(size);for (int i = 0; i < size; i++) {list.add(i);}return list;}@Benchmark@BenchmarkMode(Mode.AverageTime)public List<Integer> insertIntArrayList() {List<Integer> list = new IntArrayList(size);for (int i = 0; i < size; i++) {list.add(i);}return list;}@Benchmark@BenchmarkMode(Mode.AverageTime)public List<Integer> insertIntArrayList2() {IntArrayList list = new IntArrayList(size);for (int i = 0; i < size; i++) {list.add(i);}return list;}
}

测试结果

Benchmark                            (size)  Mode  Cnt   Score    Error  Units
ArrayListTest.insertArrayList        500000  avgt   10   0.010 ±  0.001   s/op
ArrayListTest.insertArrayList       5000000  avgt   10   0.097 ±  0.014   s/op
ArrayListTest.insertArrayList      50000000  avgt   10   1.045 ±  0.051   s/op
ArrayListTest.insertIntArrayList     500000  avgt   10   0.002 ±  0.001   s/op
ArrayListTest.insertIntArrayList    5000000  avgt   10   0.019 ±  0.001   s/op
ArrayListTest.insertIntArrayList   50000000  avgt   10   0.187 ±  0.006   s/op
ArrayListTest.insertIntArrayList2    500000  avgt   10  ≈ 10⁻³            s/op
ArrayListTest.insertIntArrayList2   5000000  avgt   10   0.006 ±  0.001   s/op
ArrayListTest.insertIntArrayList2  50000000  avgt   10   0.057 ±  0.003   s/op