content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.apache.cassandra.db;
  
  import java.nio.ByteBuffer;
  
  import org.apache.cassandra.utils.ObjectSizes;
  
  /**
   * The clustering column values for a row.
   * <p>
   * A {@code Clustering} is a {@code ClusteringPrefix} that must always be "complete", i.e. have
   * as many values as there is clustering columns in the table it is part of. It is the clustering
   * prefix used by rows.
   * <p>
   * Note however that while it's size must be equal to the table clustering size, a clustering can have
   * {@code null} values (this is currently only allowed in COMPACT table for historical reasons, but we
   * could imagine lifting that limitation if we decide it make sense from a CQL point of view).
   */
  public class BufferClustering extends AbstractBufferClusteringPrefix implements Clustering<ByteBuffer>
  {
      private static final long EMPTY_SIZE = ObjectSizes.measure(new BufferClustering(EMPTY_VALUES_ARRAY));
  
      public BufferClustering(ByteBuffer... values)
      {
          super(Kind.CLUSTERING, values);
      }
  
      public long unsharedHeapSize()
      {
          if (this == Clustering.EMPTY || this == Clustering.STATIC_CLUSTERING)
              return 0;
          return EMPTY_SIZE + ObjectSizes.sizeOnHeapOf(values);
      }
  
      public long unsharedHeapSizeExcludingData()
      {
          if (this == Clustering.EMPTY || this == Clustering.STATIC_CLUSTERING)
              return 0;
          return EMPTY_SIZE + ObjectSizes.sizeOnHeapExcludingDataOf(values);
      }
  
      public static BufferClustering make(ByteBuffer... values)
      {
          return new BufferClustering(values);
      }
  
      @Override
      public Clustering<?> ensureAccessorFactorySupport()
      {
          return this;
      }
  }
  