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.utils.memory;
  
  import java.nio.ByteBuffer;
  
  import org.apache.cassandra.db.BufferDecoratedKey;
  import org.apache.cassandra.db.Clustering;
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.marshal.ByteArrayAccessor;
  import org.apache.cassandra.db.marshal.ByteBufferAccessor;
  import org.apache.cassandra.db.marshal.ValueAccessor;
  import org.apache.cassandra.db.rows.Cell;
  import org.apache.cassandra.utils.ByteBufferUtil;
  
  /**
   * Cloner class that can be use to clone partition elements using on-heap or off-heap buffers.
   *
   */
  public abstract class ByteBufferCloner implements Cloner
  {
      /**
       * Allocate a slice of the given length.
       */
      public abstract ByteBuffer allocate(int size);
  
      @Override
      public DecoratedKey clone(DecoratedKey key)
      {
          return new BufferDecoratedKey(key.getToken(), clone(key.getKey()));
      }
  
      @Override
      public Clustering<?> clone(Clustering<?> clustering)
      {
          return clustering.clone(this);
      }
  
      @Override
      public Cell<?> clone(Cell<?> cell)
      {
          return cell.clone(this);
      }
  
      public final ByteBuffer clone(ByteBuffer buffer)
      {
          return clone(buffer, ByteBufferAccessor.instance);
      }
  
      public final ByteBuffer clone(byte[] bytes)
      {
          return clone(bytes, ByteArrayAccessor.instance);
      }
  
      public final <V> ByteBuffer clone(V value, ValueAccessor<V> accessor)
      {
          assert value != null;
          int size = accessor.size(value);
          if (size == 0)
              return ByteBufferUtil.EMPTY_BYTE_BUFFER;
          ByteBuffer cloned = allocate(size);
  
          cloned.mark();
          accessor.write(value, cloned);
          cloned.reset();
          return cloned;
      }
  }