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.structuredstreaming;
  
  import static java.util.stream.Collectors.toMap;
  import static org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop.fun1;
  
  import java.io.Serializable;
  import java.util.Arrays;
  import java.util.Map;
  import javax.annotation.Nullable;
  import org.apache.beam.runners.spark.structuredstreaming.translation.SparkSessionFactory;
  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.sql.SparkSession;
  import org.junit.rules.ExternalResource;
  import org.junit.rules.TestRule;
  import org.junit.runner.Description;
  import org.junit.runners.model.Statement;
  
  public class SparkSessionRule extends ExternalResource implements Serializable {
    private transient SparkSession.Builder builder;
    private transient @Nullable SparkSession session = null;
  
    public SparkSessionRule(String sparkMaster, Map<String, String> sparkConfig) {
      builder = SparkSessionFactory.sessionBuilder(sparkMaster);
      sparkConfig.forEach(builder::config);
    }
  
    public SparkSessionRule(KV<String, String>... sparkConfig) {
      this("local[2]", sparkConfig);
    }
  
    public SparkSessionRule(String sparkMaster, KV<String, String>... sparkConfig) {
      this(sparkMaster, Arrays.stream(sparkConfig).collect(toMap(KV::getKey, KV::getValue)));
    }
  
    public SparkSession getSession() {
      if (session == null) {
        throw new IllegalStateException("SparkSession not available");
      }
      return session;
    }
  
    public PipelineOptions createPipelineOptions() {
      return configure(TestPipeline.testingPipelineOptions());
    }
  
    public PipelineOptions configure(PipelineOptions options) {
      SparkStructuredStreamingPipelineOptions opts =
          options.as(SparkStructuredStreamingPipelineOptions.class);
      opts.setUseActiveSparkSession(true);
      opts.setRunner(SparkStructuredStreamingRunner.class);
      opts.setTestMode(true);
      return opts;
    }
  
    /** {@code true} if sessions contains cached Datasets or RDDs. */
    public boolean hasCachedData() {
      return !session.sharedState().cacheManager().isEmpty()
          || !session.sparkContext().getPersistentRDDs().isEmpty();
    }
  
    public TestRule clearCache() {
      return new ExternalResource() {
        @Override
        protected void after() {
          // clear cached datasets
          session.sharedState().cacheManager().clearCache();
          // clear cached RDDs
          session.sparkContext().getPersistentRDDs().foreach(fun1(t -> t._2.unpersist(true)));
        }
      };
    }
  
    @Override
    public Statement apply(Statement base, Description description) {
      builder.appName(description.getDisplayName());
      return super.apply(base, description);
    }
  
    @Override
    protected void before() throws Throwable {
      session = builder.getOrCreate();
    }
  
    @Override
    protected void after() {
      getSession().stop();
      session = null;
    }
  }
  