text: /*
   * 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.tinkerpop.gremlin.spark.process.computer;
  
  import org.apache.spark.launcher.SparkLauncher;
  import org.apache.spark.serializer.KryoSerializer;
  import org.apache.tinkerpop.gremlin.AbstractFileGraphProvider;
  import org.apache.tinkerpop.gremlin.GraphProvider;
  import org.apache.tinkerpop.gremlin.LoadGraphWith;
  import org.apache.tinkerpop.gremlin.hadoop.Constants;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopEdge;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopElement;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopGraph;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopProperty;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopVertex;
  import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopVertexProperty;
  import org.apache.tinkerpop.gremlin.hadoop.structure.io.FileSystemStorageCheck;
  import org.apache.tinkerpop.gremlin.hadoop.structure.io.HadoopPools;
  import org.apache.tinkerpop.gremlin.hadoop.structure.io.graphson.GraphSONInputFormat;
  import org.apache.tinkerpop.gremlin.hadoop.structure.io.gryo.GryoInputFormat;
  import org.apache.tinkerpop.gremlin.hadoop.structure.io.gryo.GryoOutputFormat;
  import org.apache.tinkerpop.gremlin.process.computer.Computer;
  import org.apache.tinkerpop.gremlin.process.computer.GraphComputer;
  import org.apache.tinkerpop.gremlin.process.computer.util.ComputerGraph;
  import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
  import org.apache.tinkerpop.gremlin.process.traversal.step.map.ConnectedComponentTest;
  import org.apache.tinkerpop.gremlin.process.traversal.step.map.PageRankTest;
  import org.apache.tinkerpop.gremlin.process.traversal.step.map.PeerPressureTest;
  import org.apache.tinkerpop.gremlin.process.traversal.step.map.ProgramTest;
  import org.apache.tinkerpop.gremlin.process.traversal.step.map.ShortestPathTest;
  import org.apache.tinkerpop.gremlin.spark.structure.Spark;
  import org.apache.tinkerpop.gremlin.spark.structure.io.PersistedOutputRDD;
  import org.apache.tinkerpop.gremlin.spark.structure.io.SparkContextStorageCheck;
  import org.apache.tinkerpop.gremlin.spark.structure.io.ToyGraphInputRDD;
  import org.apache.tinkerpop.gremlin.spark.structure.io.gryo.GryoRegistrator;
  import org.apache.tinkerpop.gremlin.structure.Graph;
  import org.apache.tinkerpop.gremlin.structure.io.gryo.kryoshim.KryoShimServiceLoader;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * @author Marko A. Rodriguez (http://markorodriguez.com)
   * @author Stephen Mallette (http://stephen.genoprime.com)
   */
  @GraphProvider.Descriptor(computer = SparkGraphComputer.class)
  public class SparkHadoopGraphProvider extends AbstractFileGraphProvider {
  
      static final String PREVIOUS_SPARK_PROVIDER = "previous.spark.provider";
      private final int AVAILABLE_PROCESSORS = Runtime.getRuntime().availableProcessors();
  
      public static final Set<Class> IMPLEMENTATION = Collections.unmodifiableSet(new HashSet<Class>() {{
          add(HadoopEdge.class);
          add(HadoopElement.class);
          add(HadoopGraph.class);
          add(HadoopProperty.class);
          add(HadoopVertex.class);
          add(HadoopVertexProperty.class);
          add(ComputerGraph.class);
          add(ComputerGraph.ComputerElement.class);
          add(ComputerGraph.ComputerVertex.class);
          add(ComputerGraph.ComputerEdge.class);
          add(ComputerGraph.ComputerVertexProperty.class);
          add(ComputerGraph.ComputerAdjacentVertex.class);
          add(ComputerGraph.ComputerProperty.class);
      }});
  
      @Override
      public void loadGraphData(final Graph graph, final LoadGraphWith loadGraphWith, final Class testClass, final String testName) {
          if (loadGraphWith != null) ((HadoopGraph) graph).configuration().setInputLocation(getInputLocation(graph, loadGraphWith.value()));
      }
  
      @Override
      public Set<Class> getImplementations() {
          return IMPLEMENTATION;
      }
  
      @Override
      public Map<String, Object> getBaseConfiguration(final String graphName, final Class<?> test, final String testMethodName, final LoadGraphWith.GraphData loadGraphWith) {
          this.graphSONInput = RANDOM.nextBoolean();
          if (this.getClass().equals(SparkHadoopGraphProvider.class) && !SparkHadoopGraphProvider.class.getCanonicalName().equals(System.getProperty(PREVIOUS_SPARK_PROVIDER, null))) {
              Spark.close();
              HadoopPools.close();
              KryoShimServiceLoader.close();
              System.setProperty(PREVIOUS_SPARK_PROVIDER, SparkHadoopGraphProvider.class.getCanonicalName());
          }
  
          final Map<String,Object> config = new HashMap<String, Object>() {{
              put(Graph.GRAPH, HadoopGraph.class.getName());
              put(Constants.GREMLIN_HADOOP_GRAPH_READER, graphSONInput ? GraphSONInputFormat.class.getCanonicalName() : GryoInputFormat.class.getCanonicalName());
              put(Constants.GREMLIN_HADOOP_GRAPH_WRITER, GryoOutputFormat.class.getCanonicalName());
              put(Constants.GREMLIN_HADOOP_OUTPUT_LOCATION, getWorkingDirectory());
              put(Constants.GREMLIN_HADOOP_JARS_IN_DISTRIBUTED_CACHE, false);
  
              put(Constants.GREMLIN_SPARK_PERSIST_CONTEXT, true);  // this makes the test suite go really fast
          }};
  
          // toy graph inputRDD does not have corresponding outputRDD so where jobs chain, it fails (failing makes sense)
          if (null != loadGraphWith &&
                  !test.equals(ProgramTest.Traversals.class) &&
                  !test.equals(PageRankTest.Traversals.class) &&
                  !test.equals(ConnectedComponentTest.Traversals.class) &&
                  !test.equals(ShortestPathTest.Traversals.class) &&
                  !test.equals(PeerPressureTest.Traversals.class) &&
                  !test.equals(FileSystemStorageCheck.class) &&
                  !testMethodName.equals("shouldSupportJobChaining") &&  // GraphComputerTest.shouldSupportJobChaining
                  RANDOM.nextBoolean()) {
              config.put(Constants.GREMLIN_HADOOP_GRAPH_READER, ToyGraphInputRDD.class.getCanonicalName());
          }
  
          // tests persisted RDDs
          if (test.equals(SparkContextStorageCheck.class)) {
              config.put(Constants.GREMLIN_HADOOP_GRAPH_READER, ToyGraphInputRDD.class.getCanonicalName());
              config.put(Constants.GREMLIN_HADOOP_GRAPH_WRITER, PersistedOutputRDD.class.getCanonicalName());
          }
  
          config.put(Constants.GREMLIN_HADOOP_DEFAULT_GRAPH_COMPUTER, SparkGraphComputer.class.getCanonicalName());
          config.put(SparkLauncher.SPARK_MASTER, "local[" + AVAILABLE_PROCESSORS + "]");
          config.put(Constants.SPARK_SERIALIZER, KryoSerializer.class.getCanonicalName());
          config.put(Constants.SPARK_KRYO_REGISTRATOR, GryoRegistrator.class.getCanonicalName());
          config.put(Constants.SPARK_KRYO_REGISTRATION_REQUIRED, true);
          return config;
      }
  
      @Override
      public GraphTraversalSource traversal(final Graph graph) {
          return RANDOM.nextBoolean() ?
                  graph.traversal().withComputer(Computer.compute(SparkGraphComputer.class).workers(RANDOM.nextInt(AVAILABLE_PROCESSORS) + 1)) :
                  graph.traversal().withComputer();
      }
  
      @Override
      public GraphComputer getGraphComputer(final Graph graph) {
          return RANDOM.nextBoolean() ?
                  graph.compute().workers(RANDOM.nextInt(AVAILABLE_PROCESSORS) + 1) :
                  graph.compute(SparkGraphComputer.class);
      }
  }