code: /*
   * Copyright © 2014-2017 EntIT Software LLC, a Micro Focus company (L.P.)
   *
   * Licensed 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 io.cloudslang.runtime.impl.python.external;
  
  import io.cloudslang.runtime.api.python.ExternalPythonProcessRunService;
  import io.cloudslang.runtime.api.python.PythonEvaluationResult;
  import io.cloudslang.runtime.api.python.PythonExecutionResult;
  import io.cloudslang.runtime.impl.python.PythonExecutionEngine;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.io.Serializable;
  import java.util.Map;
  import java.util.Set;
  import java.util.function.Supplier;
  
  public class ExternalPythonExecutionEngine implements PythonExecutionEngine {
  
      private static final Logger logger = LogManager.getLogger(ExternalPythonExecutionEngine.class);
      private static final Supplier<ExternalPythonProcessRunService> pythonRunServiceSupplier;
      public static final String SCHEDULED_EXECUTOR_STRATEGY = "scheduled-executor";
      public static final String COMPLETABLE_EXECUTOR_STRATEGY = "completable-future";
  
      static {
          String timeoutStrategy = System.getProperty("python.timeoutStrategy", SCHEDULED_EXECUTOR_STRATEGY);
          if (StringUtils.equalsIgnoreCase(timeoutStrategy, SCHEDULED_EXECUTOR_STRATEGY)) {
              pythonRunServiceSupplier = () -> new ExternalPythonExecutorScheduledExecutorTimeout();
  
          } else if (StringUtils.equalsIgnoreCase(timeoutStrategy, COMPLETABLE_EXECUTOR_STRATEGY)) {
              pythonRunServiceSupplier = () -> new ExternalPythonExecutorCompletableFutureTimeout();
  
          } else { // Use default
              pythonRunServiceSupplier = () -> new ExternalPythonExecutorScheduledExecutorTimeout();
          }
          logger.info("python timeout strategy: " + pythonRunServiceSupplier.get().getStrategyName());
      }
  
      @Override
      public PythonExecutionResult exec(Set<String> dependencies, String script, Map<String, Serializable> vars) {
          ExternalPythonProcessRunService pythonExecutor = pythonRunServiceSupplier.get();
          return pythonExecutor.exec(script, vars);
      }
  
      @Override
      public PythonEvaluationResult eval(String prepareEnvironmentScript, String script, Map<String, Serializable> vars) {
          ExternalPythonProcessRunService pythonExecutor = pythonRunServiceSupplier.get();
          return pythonExecutor.eval(script, prepareEnvironmentScript, vars);
      }
  
      @Override
      public PythonEvaluationResult test(String prepareEnvironmentScript, String script, Map<String, Serializable> vars, long timeout) {
          ExternalPythonProcessRunService pythonExecutor = pythonRunServiceSupplier.get();
          return pythonExecutor.test(script, prepareEnvironmentScript, vars, timeout);
      }
  }
  