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.index.sasi.utils;
  
  import java.nio.ByteBuffer;
  
  import org.apache.cassandra.index.sasi.disk.Descriptor;
  import org.apache.cassandra.index.sasi.disk.OnDiskIndex;
  import org.apache.cassandra.index.sasi.disk.TokenTreeBuilder;
  import org.apache.cassandra.index.sasi.sa.IndexedTerm;
  import org.apache.cassandra.index.sasi.sa.TermIterator;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.utils.Pair;
  
  public class CombinedTermIterator extends TermIterator
  {
      final Descriptor descriptor;
      final RangeIterator<OnDiskIndex.DataTerm, CombinedTerm> union;
      final ByteBuffer min;
      final ByteBuffer max;
  
      public CombinedTermIterator(OnDiskIndex... sas)
      {
          this(Descriptor.CURRENT, sas);
      }
  
      public CombinedTermIterator(Descriptor d, OnDiskIndex... parts)
      {
          descriptor = d;
          union = OnDiskIndexIterator.union(parts);
  
          AbstractType<?> comparator = parts[0].getComparator(); // assumes all SAs have same comparator
          ByteBuffer minimum = parts[0].minTerm();
          ByteBuffer maximum = parts[0].maxTerm();
  
          for (int i = 1; i < parts.length; i++)
          {
              OnDiskIndex part = parts[i];
              if (part == null)
                  continue;
  
              minimum = comparator.compare(minimum, part.minTerm()) > 0 ? part.minTerm() : minimum;
              maximum = comparator.compare(maximum, part.maxTerm()) < 0 ? part.maxTerm() : maximum;
          }
  
          min = minimum;
          max = maximum;
      }
  
      public ByteBuffer minTerm()
      {
          return min;
      }
  
      public ByteBuffer maxTerm()
      {
          return max;
      }
  
      protected Pair<IndexedTerm, TokenTreeBuilder> computeNext()
      {
          if (!union.hasNext())
          {
              return endOfData();
          }
          else
          {
              CombinedTerm term = union.next();
              return Pair.create(new IndexedTerm(term.getTerm(), term.isPartial()), term.getTokenTreeBuilder());
          }
  
      }
  }
  