https://github.com/Terracotta-OSS/offheap-store/: A library that offers data structures allocated off the java heap. 
/*
 * Copyright 2015 Terracotta, Inc., a Software AG company.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.terracotta.offheapstore.storage;

public enum PointerSize {

  INT(Integer.SIZE), LONG(Long.SIZE);

  private final int size;

  PointerSize(int size) {
    this.size = size;
  }

  public int bitSize() {
    return size;
  }

  public int byteSize() {
    return size / Byte.SIZE;
  }
}