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.spark.shuffle.celeborn;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.ServiceLoader;
  
  public class ShuffleFallbackPolicyFactory {
  
    public static List<ShuffleFallbackPolicy> getShuffleFallbackPolicies() {
      List<ShuffleFallbackPolicy> shuffleFallbackPolicies = new ArrayList<>();
      // Loading order of ShuffleFallbackPolicy should be ForceFallbackPolicy,
      // ShufflePartitionsFallbackPolicy, QuotaFallbackPolicy, WorkersAvailableFallbackPolicy, Custom
      // to reduce unnecessary RPC for check whether to fallback.
      shuffleFallbackPolicies.add(ForceFallbackPolicy.INSTANCE);
      shuffleFallbackPolicies.add(ShufflePartitionsFallbackPolicy.INSTANCE);
      shuffleFallbackPolicies.add(QuotaFallbackPolicy.INSTANCE);
      shuffleFallbackPolicies.add(WorkersAvailableFallbackPolicy.INSTANCE);
      for (ShuffleFallbackPolicy shuffleFallbackPolicy :
          ServiceLoader.load(ShuffleFallbackPolicy.class)) {
        if (!(shuffleFallbackPolicy instanceof ForceFallbackPolicy
            || shuffleFallbackPolicy instanceof ShufflePartitionsFallbackPolicy
            || shuffleFallbackPolicy instanceof QuotaFallbackPolicy
            || shuffleFallbackPolicy instanceof WorkersAvailableFallbackPolicy)) {
          shuffleFallbackPolicies.add(shuffleFallbackPolicy);
        }
      }
      return shuffleFallbackPolicies;
    }
  }
  