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.memory;
  
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.SortedSet;
  import java.util.TreeSet;
  import java.util.concurrent.ConcurrentSkipListSet;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.index.sasi.disk.Token;
  import org.apache.cassandra.index.sasi.utils.CombinedValue;
  import org.apache.cassandra.index.sasi.utils.RangeIterator;
  
  import com.carrotsearch.hppc.LongHashSet;
  import com.carrotsearch.hppc.LongSet;
  import org.apache.cassandra.utils.AbstractGuavaIterator;
  
  import com.google.common.collect.PeekingIterator;
  
  public class KeyRangeIterator extends RangeIterator<Long, Token>
  {
      private final DKIterator iterator;
  
      public KeyRangeIterator(ConcurrentSkipListSet<DecoratedKey> keys, int size)
      {
          super((Long) keys.first().getToken().getTokenValue(), (Long) keys.last().getToken().getTokenValue(), size);
          this.iterator = new DKIterator(keys.iterator());
      }
  
      protected Token computeNext()
      {
          return iterator.hasNext() ? new DKToken(iterator.next()) : endOfData();
      }
  
      protected void performSkipTo(Long nextToken)
      {
          while (iterator.hasNext())
          {
              DecoratedKey key = iterator.peek();
              if (Long.compare((long) key.getToken().getTokenValue(), nextToken) >= 0)
                  break;
  
              // consume smaller key
              iterator.next();
          }
      }
  
      public void close() throws IOException
      {}
  
      private static class DKIterator extends AbstractGuavaIterator<DecoratedKey> implements PeekingIterator<DecoratedKey>
      {
          private final Iterator<DecoratedKey> keys;
  
          public DKIterator(Iterator<DecoratedKey> keys)
          {
              this.keys = keys;
          }
  
          protected DecoratedKey computeNext()
          {
              return keys.hasNext() ? keys.next() : endOfData();
          }
      }
  
      private static class DKToken extends Token
      {
          private final SortedSet<DecoratedKey> keys;
  
          public DKToken(final DecoratedKey key)
          {
              super((long) key.getToken().getTokenValue());
  
              keys = new TreeSet<DecoratedKey>(DecoratedKey.comparator)
              {{
                  add(key);
              }};
          }
  
          public LongSet getOffsets()
          {
              LongSet offsets = new LongHashSet(4);
              for (DecoratedKey key : keys)
                  offsets.add((long) key.getToken().getTokenValue());
  
              return offsets;
          }
  
          public void merge(CombinedValue<Long> other)
          {
              if (!(other instanceof Token))
                  return;
  
              Token o = (Token) other;
              assert o.get().equals(token);
  
              if (o instanceof DKToken)
              {
                  keys.addAll(((DKToken) o).keys);
              }
              else
              {
                  for (DecoratedKey key : o)
                      keys.add(key);
              }
          }
  
          public Iterator<DecoratedKey> iterator()
          {
              return keys.iterator();
          }
      }
  }
  