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.transform;
  
  import org.apache.cassandra.db.partitions.BasePartitionIterator;
  import org.apache.cassandra.db.rows.BaseRowIterator;
  import org.apache.cassandra.utils.Throwables;
  
  import static org.apache.cassandra.utils.Throwables.merge;
  
  public abstract class BasePartitions<R extends BaseRowIterator<?>, I extends BasePartitionIterator<? extends BaseRowIterator<?>>>
  extends BaseIterator<BaseRowIterator<?>, I, R>
  implements BasePartitionIterator<R>
  {
  
      public BasePartitions(I input)
      {
          super(input);
      }
  
      BasePartitions(BasePartitions<?, ? extends I> copyFrom)
      {
          super(copyFrom);
      }
  
  
      // *********************************
  
  
      protected BaseRowIterator<?> applyOne(BaseRowIterator<?> value, Transformation transformation)
      {
          return value == null ? null : transformation.applyToPartition(value);
      }
  
      void add(Transformation transformation)
      {
          transformation.attachTo(this);
          super.add(transformation);
          next = applyOne(next, transformation);
      }
  
      protected Throwable runOnClose(int length)
      {
          Throwable fail = null;
          Transformation[] fs = stack;
          for (int i = 0 ; i < length ; i++)
          {
              try
              {
                  fs[i].onClose();
              }
              catch (Throwable t)
              {
                  fail = merge(fail, t);
              }
          }
          return fail;
      }
  
      public final boolean hasNext()
      {
          BaseRowIterator<?> next = null;
          try
          {
  
              Stop stop = this.stop;
              while (this.next == null)
              {
                  Transformation[] fs = stack;
                  int len = length;
  
                  while (!stop.isSignalled && !stopChild.isSignalled && input.hasNext())
                  {
                      next = input.next();
                      for (int i = 0 ; next != null & i < len ; i++)
                          next = fs[i].applyToPartition(next);
  
                      if (next != null)
                      {
                          this.next = next;
                          return true;
                      }
                  }
  
                  if (stop.isSignalled || !hasMoreContents())
                      return false;
              }
              return true;
  
          }
          catch (Throwable t)
          {
              if (next != null)
                  Throwables.close(t, next);
              throw t;
          }
      }
  
  }
  
  