static

in datasketches-memory-java8/src/main/java/org/apache/datasketches/memory/internal/UnsafeUtil.java [85:123]

• 27 lines of code
• 4 McCabe index (conditional complexity)

  static {
    try {
      final Constructor<Unsafe> unsafeConstructor = Unsafe.class.getDeclaredConstructor();
      unsafeConstructor.setAccessible(true);
      unsafe = unsafeConstructor.newInstance();

      // Alternative, but may not work across different JVMs.
      //      Field field = Unsafe.class.getDeclaredField("theUnsafe");
      //      field.setAccessible(true);
      //      unsafe = (Unsafe) field.get(null);

    } catch (final InstantiationException | IllegalAccessException | IllegalArgumentException
        | InvocationTargetException | NoSuchMethodException e) {
      e.printStackTrace();
      throw new RuntimeException("Unable to acquire Unsafe. " + e);
    }

    //4 on 32-bit systems. 4 on 64-bit systems < 32GB, otherwise 8.
    //This alone is not an indicator of compressed ref (coop)
    ADDRESS_SIZE = unsafe.addressSize();

    ARRAY_BOOLEAN_BASE_OFFSET = unsafe.arrayBaseOffset(boolean[].class);
    ARRAY_BYTE_BASE_OFFSET = unsafe.arrayBaseOffset(byte[].class);
    ARRAY_SHORT_BASE_OFFSET = unsafe.arrayBaseOffset(short[].class);
    ARRAY_CHAR_BASE_OFFSET = unsafe.arrayBaseOffset(char[].class);
    ARRAY_INT_BASE_OFFSET = unsafe.arrayBaseOffset(int[].class);
    ARRAY_LONG_BASE_OFFSET = unsafe.arrayBaseOffset(long[].class);
    ARRAY_FLOAT_BASE_OFFSET = unsafe.arrayBaseOffset(float[].class);
    ARRAY_DOUBLE_BASE_OFFSET = unsafe.arrayBaseOffset(double[].class);
    ARRAY_OBJECT_BASE_OFFSET = unsafe.arrayBaseOffset(Object[].class);

    ARRAY_OBJECT_INDEX_SCALE = unsafe.arrayIndexScale(Object[].class);
    OBJECT_SHIFT = ARRAY_OBJECT_INDEX_SCALE == 4 ? 2 : 3;

    final String jdkVer = System.getProperty("java.version");
    final int[] p = parseJavaVersion(jdkVer);
    JDK = p[0] + "." + p[1];
    JDK_MAJOR = (p[0] == 1) ? p[1] : p[0];
  }