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.sai.memory;
  
  import java.util.List;
  
  import org.apache.cassandra.index.sai.iterators.KeyRangeIterator;
  import org.apache.cassandra.index.sai.plan.Expression;
  import org.apache.cassandra.index.sai.utils.PrimaryKey;
  
  /**
   * Analogue of {@link org.apache.cassandra.index.sai.disk.v1.segment.SegmentOrdering}, but for memtables.
   */
  public interface MemtableOrdering
  {
      /**
       * Filter the given list of {@code PrimaryKey} results to the top `limit` results corresponding to the given expression,
       * Returns an iterator over the results that is put back in token order.
       * <p>
       * Assumes that the given list spans the same rows as the implementing index's segment.
       */
      default KeyRangeIterator limitToTopResults(List<PrimaryKey> primaryKeys, Expression expression, int limit)
      {
          throw new UnsupportedOperationException();
      }
  }
  