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.beam.runners.spark;
  
  import static java.util.stream.Collectors.toMap;
  
  import java.io.Serializable;
  import java.util.Arrays;
  import java.util.Map;
  import javax.annotation.Nullable;
  import org.apache.beam.runners.spark.translation.SparkContextFactory;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.values.KV;
  import org.apache.spark.SparkConf;
  import org.apache.spark.api.java.JavaSparkContext;
  import org.junit.rules.ExternalResource;
  import org.junit.runner.Description;
  import org.junit.runners.model.Statement;
  
  public class SparkContextRule extends ExternalResource implements Serializable {
    private transient SparkConf sparkConf;
    private transient @Nullable JavaSparkContext sparkContext = null;
  
    public SparkContextRule(String sparkMaster, Map<String, String> sparkConfig) {
      sparkConf = new SparkConf();
      sparkConfig.forEach(sparkConf::set);
      sparkConf.setMaster(sparkMaster);
    }
  
    public SparkContextRule(KV<String, String>... sparkConfig) {
      this("local", sparkConfig);
    }
  
    public SparkContextRule(String sparkMaster, KV<String, String>... sparkConfig) {
      this(sparkMaster, Arrays.stream(sparkConfig).collect(toMap(KV::getKey, KV::getValue)));
    }
  
    public JavaSparkContext getSparkContext() {
      if (sparkContext == null) {
        throw new IllegalStateException("SparkContext not available");
      }
      return sparkContext;
    }
  
    public SparkContextOptions createPipelineOptions() {
      return configure(TestPipeline.testingPipelineOptions());
    }
  
    public SparkContextOptions configure(PipelineOptions opts) {
      SparkContextOptions ctxOpts = opts.as(SparkContextOptions.class);
      ctxOpts.setUsesProvidedSparkContext(true);
      ctxOpts.setProvidedSparkContext(getSparkContext());
      return ctxOpts;
    }
  
    @Override
    public Statement apply(Statement base, Description description) {
      sparkConf.setAppName(description.getDisplayName());
      return super.apply(base, description);
    }
  
    @Override
    protected void before() throws Throwable {
      sparkContext = new JavaSparkContext(sparkConf);
      SparkContextFactory.setProvidedSparkContext(sparkContext);
    }
  
    @Override
    protected void after() {
      SparkContextFactory.clearProvidedSparkContext();
      getSparkContext().stop();
      sparkContext = null;
    }
  }
  