67 lines
1.5 KiB
Java
67 lines
1.5 KiB
Java
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// understandingcollections/jmhtests/MapPerformanceJMH.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 Maps
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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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@State(Scope.Thread)
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public class MapPerformanceJMH {
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private Map<Integer, Integer> map;
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@Param({"hashmap", "treemap"})
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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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if (type.equals("hashmap")) {
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map = new HashMap<Integer, Integer>();
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} else if (type.equals("treemap")) {
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map = new TreeMap<Integer, Integer>();
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} else {
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throw new IllegalStateException("Unknown type: " + type);
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}
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begin = 1;
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end = 256;
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for (int i = begin; i < end; i++) {
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map.put(i, i);
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}
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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(map.get(i));
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}
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}
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// These are incomplete placeholders from the
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// original MapPerformance.jaava:
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/* @Benchmark
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int put() {
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for(int i = 0; i < loops; i++) {
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map.clear();
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for(int j = 0; j < size; j++)
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map.put(j, j);
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}
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return loops * size;
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}*/
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/* @Benchmark
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int iterate() {
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for(int i = 0; i < loops; i ++) {
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Iterator it = map.entrySet().iterator();
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while(it.hasNext())
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it.next();
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}
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}*/
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}
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