PerfTest.java

package proj.zoie.test;

import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
import it.unimi.dsi.fastutil.ints.IntRBTreeSet;
import it.unimi.dsi.fastutil.ints.IntSet;

import java.util.Arrays;
import java.util.BitSet;
import java.util.Random;

import org.junit.Test;

public class PerfTest {

  @Test
  public void perfTest() {
    Random rand = new Random();
    int max = 5000000;
    int[] docs = new int[max];
    for (int i = 0; i < docs.length; ++i) {
      docs[i] = i;
    }
    int limit = 10000;
    IntSet set1 = new IntRBTreeSet();
    while (set1.size() < limit) {
      set1.add(rand.nextInt(max));
    }

    IntSet set2 = new IntOpenHashSet();
    for (int i : set1) {
      set2.add(i);
    }

    int[] set3 = set1.toIntArray();
    Arrays.sort(set3);

    BitSet set4 = new BitSet();
    for (int i : set1) {
      set4.set(i);
    }

    long start, end;

    start = System.nanoTime();
    for (int i = 0; i < docs.length; ++i) {
      set1.contains(i);
    }
    end = System.nanoTime();
    System.out.println("set1: " + (end - start) / 1000000);

    start = System.nanoTime();
    for (int i = 0; i < docs.length; ++i) {
      set2.contains(i);
    }
    end = System.nanoTime();
    System.out.println("set2: " + (end - start) / 1000000);

    start = System.nanoTime();
    for (int i = 0; i < docs.length; ++i) {
      Arrays.binarySearch(set3, i);
    }
    end = System.nanoTime();
    System.out.println("set3: " + (end - start) / 1000000);

    start = System.nanoTime();
    for (int i = 0; i < docs.length; ++i) {
      set4.get(i);
    }
    end = System.nanoTime();
    System.out.println("set4: " + (end - start) / 1000000);
  }

}