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.service.reads.repair;
  
  import java.util.List;
  
  import org.apache.cassandra.db.Columns;
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.ReadCommand;
  import org.apache.cassandra.db.RegularAndStaticColumns;
  import org.apache.cassandra.db.partitions.UnfilteredPartitionIterators;
  import org.apache.cassandra.db.rows.UnfilteredRowIterator;
  import org.apache.cassandra.db.rows.UnfilteredRowIterators;
  import org.apache.cassandra.locator.Endpoints;
  import org.apache.cassandra.locator.ReplicaPlan;
  
  public class PartitionIteratorMergeListener<E extends Endpoints<E>>
          implements UnfilteredPartitionIterators.MergeListener
  {
      private final ReplicaPlan.ForRead<E, ?> replicaPlan;
      private final ReadCommand command;
      private final ReadRepair readRepair;
  
      public PartitionIteratorMergeListener(ReplicaPlan.ForRead<E, ?> replicaPlan, ReadCommand command, ReadRepair readRepair)
      {
          this.replicaPlan = replicaPlan;
          this.command = command;
          this.readRepair = readRepair;
      }
  
      public UnfilteredRowIterators.MergeListener getRowMergeListener(DecoratedKey partitionKey, List<UnfilteredRowIterator> versions)
      {
          return new RowIteratorMergeListener<>(partitionKey, columns(versions), isReversed(versions), replicaPlan, command, readRepair);
      }
  
      public static RegularAndStaticColumns columns(List<UnfilteredRowIterator> versions)
      {
          Columns statics = Columns.NONE;
          Columns regulars = Columns.NONE;
          for (UnfilteredRowIterator iter : versions)
          {
              if (iter == null)
                  continue;
  
              RegularAndStaticColumns cols = iter.columns();
              statics = statics.mergeTo(cols.statics);
              regulars = regulars.mergeTo(cols.regulars);
          }
          return new RegularAndStaticColumns(statics, regulars);
      }
  
      protected boolean isReversed(List<UnfilteredRowIterator> versions)
      {
          for (UnfilteredRowIterator iter : versions)
          {
              if (iter == null)
                  continue;
  
              // Everything will be in the same order
              return iter.isReverseOrder();
          }
  
          assert false : "Expected at least one iterator";
          return false;
      }
  
      public void close()
      {
      }
  }
  
  