code: /*
   * Copyright 2012-2018 Chronicle Map Contributors
   *
   * 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 eg;
  
  import net.openhft.chronicle.map.ChronicleMap;
  import net.openhft.chronicle.map.MapSegmentContext;
  import org.junit.Test;
  
  import java.util.Arrays;
  import java.util.LongSummaryStatistics;
  
  public class AverageValueSizeTest {
  
      public static <V> double averageValueSize(Class<V> valueClass, Iterable<V> values) {
          try (ChronicleMap<Integer, V> testMap = ChronicleMap.of(Integer.class, valueClass)
                  // doesn't matter, anyway not a single value will be written to a map
                  .averageValueSize(1)
                  .entries(1)
                  .create()) {
              LongSummaryStatistics statistics = new LongSummaryStatistics();
              for (V value : values) {
                  try (MapSegmentContext<Integer, V, ?> c = testMap.segmentContext(0)) {
                      statistics.accept(c.wrapValueAsData(value).size());
                  }
              }
              return statistics.getAverage();
          }
      }
  
      @Test
      public void averageValueSizeTest() {
          System.out.println(averageValueSize(String.class,
                  Arrays.asList("banana", "apple", "watermelon")));
      }
  }
  