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.asterix.column.filter.iterable.evaluator;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.asterix.column.values.IColumnValuesReader;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  
  public class ColumnarRepeatedIterableFilterEvaluator extends AbstractIterableFilterEvaluator {
      private final List<IColumnValuesReader> repeatedReaders;
  
      ColumnarRepeatedIterableFilterEvaluator(IScalarEvaluator evaluator, List<IColumnValuesReader> readers) {
          super(evaluator, readers);
          repeatedReaders = new ArrayList<>();
          for (IColumnValuesReader reader : readers) {
              if (reader.isRepeated()) {
                  repeatedReaders.add(reader);
              }
          }
      }
  
      @Override
      public boolean evaluate() throws HyracksDataException {
          boolean result = false;
          while (!result && next()) {
              // TODO handle nested repetition (x = unnest --> y = unnest --> select (x = 1 AND y = 3))
              // TODO we need a way to 'rewind' y for each x
              result = evaluateRepeated();
          }
          return result;
      }
  
      private boolean evaluateRepeated() throws HyracksDataException {
          boolean result = false;
          boolean doNext;
          do {
              doNext = false;
              result |= inspect();
              for (int i = 0; i < repeatedReaders.size(); i++) {
                  IColumnValuesReader reader = repeatedReaders.get(i);
                  boolean repeatedValue = reader.isRepeatedValue() && !reader.isLastDelimiter();
                  doNext |= repeatedValue;
                  if (repeatedValue) {
                      reader.next();
                  }
              }
          } while (doNext);
          return result;
      }
  }
  