List vs HashSet performance for small lists (single contains op)

scratch_121.txt

  public static List<Integer> generate(int series) {
    return Stream.iterate(new int[]{0, 1}, s -> new int[]{s[1], s[0] + s[1]})
        .limit(series)
        .map(n -> n[0])
        .collect(Collectors.toList());
  }

  public static void main(String[] args) {
    generate(30).forEach(n -> {
      List<String> collected = Stream.generate(() -> UUID.randomUUID().toString()).limit(n).collect(Collectors.toList());
      String sample = UUID.randomUUID().toString();

      Stopwatch sw1 = Stopwatch.createStarted();
      collected.contains(sample);
      long microList = sw1.elapsed(TimeUnit.MICROSECONDS);

      HashSet<String> set = Sets.newHashSet(collected);
      Stopwatch sw = Stopwatch.createStarted();
      set.contains(sample);
      long microSet = sw.elapsed(TimeUnit.MICROSECONDS);

      System.out.printf("%d %d %d %n", n, microList, microSet);
    });


0 26 12 
1 2 0 
1 1 0 
2 1 0 
3 1 0 
5 2 1 
8 2 1 
13 3 0 
21 5 1 
34 7 1 
55 8 1 
89 13 1 
144 17 1 
233 33 1 
377 701 1 
610 68 1 
987 111 2 
1597 186 1 
2584 1797 1 
4181 566 2 
6765 753 4 
10946 1275 3 
17711 1901 3 
28657 2718 3 
46368 2395 4 
75025 1132 2 
121393 1722 2 
196418 2042 3 
317811 4838 2 
514229 6117 2