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.cql3.selection;
  
  import java.util.List;
  
  import org.apache.cassandra.cql3.ColumnSpecification;
  import org.apache.cassandra.cql3.functions.Function;
  import org.apache.cassandra.cql3.selection.Selector.Factory;
  import org.apache.cassandra.db.filter.ColumnFilter.Builder;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.schema.ColumnMetadata;
  
  /**
   * A base <code>Selector.Factory</code> for list/set, tuples, and vectors.
   */
  abstract class MultiElementFactory extends Factory
  {
      /**
       * The list/set, tuples, and vectors type.
       */
      private final AbstractType<?> type;
  
      /**
       * The list/set, tuples, and vectors element factories.
       */
      private final SelectorFactories factories;
  
      public MultiElementFactory(AbstractType<?> type, SelectorFactories factories)
      {
          this.type = type;
          this.factories = factories;
      }
  
      protected final AbstractType<?> getReturnType()
      {
          return type;
      }
  
      @Override
      public final void addFunctionsTo(List<Function> functions)
      {
          factories.addFunctionsTo(functions);
      }
  
      @Override
      public final boolean isAggregateSelectorFactory()
      {
          return factories.doesAggregation();
      }
  
      @Override
      public final boolean isWritetimeSelectorFactory()
      {
          return factories.containsWritetimeSelectorFactory();
      }
  
      @Override
      public final boolean isTTLSelectorFactory()
      {
          return factories.containsTTLSelectorFactory();
      }
  
      @Override
      boolean areAllFetchedColumnsKnown()
      {
          return factories.areAllFetchedColumnsKnown();
      }
  
      @Override
      void addFetchedColumns(Builder builder)
      {
          factories.addFetchedColumns(builder);
      }
  
      protected final void addColumnMapping(SelectionColumnMapping mapping, ColumnSpecification resultsColumn)
      {
          SelectionColumnMapping tmpMapping = SelectionColumnMapping.newMapping();
          for (Factory factory : factories)
             factory.addColumnMapping(tmpMapping, resultsColumn);
  
          if (tmpMapping.getMappings().get(resultsColumn).isEmpty())
              // add a null mapping for cases where the collection is empty
              mapping.addMapping(resultsColumn, (ColumnMetadata)null);
          else
              // collate the mapped columns from the child factories & add those
              mapping.addMapping(resultsColumn, tmpMapping.getMappings().values());
      }
  }
  