82 lines
1.9 KiB
Java
82 lines
1.9 KiB
Java
// understandingcollections/jmhtests/Lists.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// Demonstrates performance differences in Lists
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package understandingcollections.jmhtests;
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import org.openjdk.jmh.annotations.*;
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import org.openjdk.jmh.infra.Blackhole;
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import java.util.*;
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import static java.util.concurrent.TimeUnit.*;
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@State(Scope.Thread)
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@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
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@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
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@Fork(1)
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@BenchmarkMode(Mode.AverageTime)
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@OutputTimeUnit(MICROSECONDS)
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public class Lists {
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private List<Integer> list;
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@Param({"ArrayList", "LinkedList", "Vector"})
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private String type;
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private int begin;
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private int end;
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@Setup
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public void setup() {
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switch(type) {
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case "ArrayList":
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list = new ArrayList<>();
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break;
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case "LinkedList":
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list = new LinkedList<>();
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break;
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case "Vector":
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list = new Vector<>();
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break;
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default:
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throw new IllegalStateException("Unknown " + type);
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}
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begin = 0;
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end = 256;
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for(int i = begin; i < end; i++) {
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list.add(i);
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}
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}
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@Benchmark
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public void add() {
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for(int i = begin; i < end; i++)
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list.add(i);
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}
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@Benchmark
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public void get(Blackhole bh) {
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for(int i = begin; i < end; i++)
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bh.consume(list.get(i));
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}
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@Benchmark
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public void set() {
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for(int i = begin; i < end; i++)
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list.set(i, 47);
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}
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@Benchmark
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public void iteradd() {
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int half = list.size() / 2;
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ListIterator<Integer> it =
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list.listIterator(half);
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for(int i = begin; i < end; i++)
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it.add(47);
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}
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@Benchmark
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public void insert() {
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for(int i = begin; i < end; i++)
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list.add(5, 47);
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}
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@Benchmark
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public void remove() {
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while(list.size() > 5)
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list.remove(5);
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}
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}
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