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.marshal;
  
  import java.nio.ByteBuffer;
  import java.util.List;
  
  import javax.annotation.Nullable;
  
  import org.apache.cassandra.db.rows.ColumnData;
  import org.apache.cassandra.db.rows.ComplexColumnData;
  
  /**
   * Base type for the types being composed of multi-elements like Collections, Tuples, UDTs or Vectors.
   * This class unifies the methods used by the CQL layer to work with those types,
   * and it includes both frozen and non-frozen multi-element types.
   */
  public abstract class MultiElementType<T> extends AbstractType<T>
  {
      protected MultiElementType(ComparisonType comparisonType)
      {
          super(comparisonType);
      }
  
      /**
       * Returns the serialized representation of the value composed of the specified elements.
       *
       * @param elements the serialized values of the elements
       * @return the serialized representation of the value composed of the specified elements.
       */
      public abstract <V> V pack(List<V> elements, ValueAccessor<V> accessor);
  
      /**
       * Returns the serialized representation of the value composed of the specified elements.
       *
       * @param elements the serialized values of the elements
       * @return the serialized representation of the value composed of the specified elements.
       */
      public ByteBuffer pack(List<ByteBuffer> elements)
      {
          return pack(elements, ByteBufferAccessor.instance);
      }
  
      /**
       * Returns the serialized representation of the elements composing the specified value.
       *
       * @param value a serialized value of this type
       * @return the serialized representation of the elements composing the specified value.
       */
      /**
       * Returns the serialized representation of the elements composing the specified value.
       *
       * @param value a serialized value of this type
       * @return the serialized representation of the elements composing the specified value.
       */
      public abstract <V> List<V> unpack(V value, ValueAccessor<V> accessor);
  
      public final List<byte[]> unpack(byte[] value)
      {
          return unpack(value, ByteArrayAccessor.instance);
      }
  
      public final List<ByteBuffer> unpack(ByteBuffer value)
      {
          return unpack(value, ByteBufferAccessor.instance);
      }
  
      /**
       * Checks if this type supports bind markers for its elements when the type value is provided through a literal.
       * @return {@code true} if this type supports bind markers for its elements, {@code false} otherwise.
       */
      public boolean supportsElementBindMarkers()
      {
          return true;
      }
  
      /**
       * Filter and sort the elements, if needed, before validating them.
       * <p>
       * This method takes as input a list of elements, eliminates duplicates and reorders them if needed (e.g. {@code SetType} and {@code MapType}) and validate them.
       * @param buffers the elements of this type
       * @return the elements filtered and sorted as they are used for serialization.
       */
      public abstract List<ByteBuffer> filterSortAndValidateElements(List<ByteBuffer> buffers);
  
      /**
       * Compares the multicell value represensted by the column data with the specified elements.
       * @param columnData the column data representing the multicell value
       * @param elements the elements to compare
       * @return a negative integer, zero, or a positive integer as the column data is less than, equal to, or greater than the elements.
       * @throws UnsupportedOperationException if the comparison is not supported by this type.
       */
      public abstract int compareCQL(ComplexColumnData columnData, List<ByteBuffer> elements);
  
      /**
       * Returns the type of the element at the specified key or index (optional operation).
       * @param keyOrIndex the key or index of the element
       * @return the type of the element at the specified key or index.
       * @throws UnsupportedOperationException if this method is not supported by this type.
       */
      public AbstractType<?> elementType(ByteBuffer keyOrIndex)
      {
          throw new UnsupportedOperationException(this + " does not support retrieving element types by key or index");
      }
  
      /**
       * Returns the element of the column data at the specified key or index (optional operation).
       * @param columnData the column data representing the multicell value
       * @param keyOrIndex the key or index of the element to return
       * @return the element of the column data at the specified key or index.
       * @throws UnsupportedOperationException if this method is not supported by this type.
       */
      public ByteBuffer getElement(@Nullable ColumnData columnData, ByteBuffer keyOrIndex)
      {
          throw new UnsupportedOperationException(this + " does not support retrieving elements by key or index");
      }
  }
  
  