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 org.apache.spark.ShuffleDependency;
  import org.apache.spark.sql.types.StructType;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.celeborn.reflect.DynFields;
  
  public class CustomShuffleDependencyUtils {
  
    private static final Logger logger = LoggerFactory.getLogger(CustomShuffleDependencyUtils.class);
  
    /**
     * Columnar Shuffle requires a field, `ShuffleDependency#schema`, which does not exist in vanilla
     * Spark.
     */
    private static final DynFields.UnboundField<StructType> SCHEMA_FIELD =
        DynFields.builder().hiddenImpl(ShuffleDependency.class, "schema").defaultAlwaysNull().build();
  
    public static StructType getSchema(ShuffleDependency<?, ?, ?> dep) {
      StructType schema = null;
      try {
        schema = SCHEMA_FIELD.bind(dep).get();
      } catch (Exception e) {
        logger.error("Failed to bind shuffle dependency of shuffle {}.", dep.shuffleId(), e);
      }
      if (schema == null) {
        logger.warn(
            "Failed to get Schema of shuffle {}, columnar shuffle won't work properly.",
            dep.shuffleId());
      }
      return schema;
    }
  }
  