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.adapter.spark;
  
  import org.apache.calcite.DataContext;
  import org.apache.calcite.linq4j.Enumerable;
  import org.apache.calcite.linq4j.tree.Types;
  
  import org.apache.spark.api.java.JavaRDD;
  import org.apache.spark.api.java.JavaSparkContext;
  import org.apache.spark.api.java.function.FlatMapFunction;
  
  import java.lang.reflect.Method;
  import java.util.HashMap;
  
  /**
   * Built-in methods in the Spark adapter.
   *
   * @see org.apache.calcite.util.BuiltInMethod
   */
  public enum SparkMethod {
    AS_ENUMERABLE(SparkRuntime.class, "asEnumerable", JavaRDD.class),
    ARRAY_TO_RDD(SparkRuntime.class, "createRdd", JavaSparkContext.class,
        Object[].class),
    CREATE_RDD(SparkRuntime.class, "createRdd", JavaSparkContext.class,
        Enumerable.class),
    GET_SPARK_CONTEXT(SparkRuntime.class, "getSparkContext", DataContext.class),
    RDD_FLAT_MAP(JavaRDD.class, "flatMap", FlatMapFunction.class),
    FLAT_MAP_FUNCTION_CALL(FlatMapFunction.class, "call", Object.class);
  
    @SuppressWarnings("ImmutableEnumChecker")
    public final Method method;
  
    private static final HashMap<Method, SparkMethod> MAP = new HashMap<>();
  
    static {
      for (SparkMethod method : SparkMethod.values()) {
        MAP.put(method.method, method);
      }
    }
  
    SparkMethod(Class clazz, String methodName, Class... argumentTypes) {
      this.method = Types.lookupMethod(clazz, methodName, argumentTypes);
    }
  
    public static SparkMethod lookup(Method method) {
      return MAP.get(method);
    }
  }
  