EnumSet

enumset

sergej@sergej-P50:~/Development/IdeaProjects/playground$ /home/sergej/.sdkman/candidates/java/13.0.1.hs-adpt/bin/java -version
openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.1+9)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 13.0.1+9, mixed mode, sharing)

sergej@sergej-P50:~/Development/IdeaProjects/playground$ uname -a
Linux sergej-P50 4.18.0-25-generic #26-Ubuntu SMP Mon Jun 24 09:32:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

jol >> java.util.RegularEnumSet, size=1584
jol >> org.eclipse.collections.impl.set.mutable.UnifiedSet, size=976
jol >> org.eclipse.collections.impl.set.immutable.ImmutableUnifiedSet, size=992


  @Test
  void set() {
    EnumSet<V> jdkEnumSet = EnumSet.allOf(V.class);
    measureJol(jdkEnumSet);

    MutableSet<V> ecMutableSet = Sets.mutable.of(V.values());
    measureJol(ecMutableSet);

    ImmutableSet<V> immutableSet = Sets.immutable.of(V.values());
    measureJol(immutableSet);
  }

  enum V {
    MY_VALUE_1,
    MY_VALUE_2,
    MY_VALUE_3,
    MY_VALUE_4,
    MY_VALUE_5,
    MY_VALUE_6,
    MY_VALUE_7,
    MY_VALUE_8,
    MY_VALUE_9,
    MY_VALUE_10,
  }
  
  private static void measureJol(Object o) {
    long memory = GraphLayout.parseInstance(o).totalSize();
    System.out.printf("jol >> %s, size=%d%n", o.getClass().getCanonicalName(), memory);
  }