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.calcite.interpreter;
  
  import org.apache.calcite.DataContext;
  import org.apache.calcite.jdbc.CalcitePrepare;
  import org.apache.calcite.rel.RelNode;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * Relational expression that can implement itself using an interpreter.
   */
  public interface InterpretableRel extends RelNode {
    /** Creates an interpreter node to implement this relational expression. */
    Node implement(InterpreterImplementor implementor);
  
    /** Context when a {@link RelNode} is being converted to an interpreter
     * {@link Node}. */
    class InterpreterImplementor {
      public final Compiler compiler;
      public final Map<String, Object> internalParameters =
          new LinkedHashMap<>();
      public final CalcitePrepare.@Nullable SparkHandler spark;
      public final DataContext dataContext;
      public final Map<RelNode, List<Sink>> relSinks = new HashMap<>();
  
      public InterpreterImplementor(Compiler compiler,
          CalcitePrepare.@Nullable SparkHandler spark,
          DataContext dataContext) {
        this.compiler = compiler;
        this.spark = spark;
        this.dataContext = dataContext;
      }
    }
  }
  