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.launcher;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.InputStreamReader;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.regex.Pattern;
  
  import static org.apache.spark.launcher.CommandBuilderUtils.*;
  
  /**
   * Abstract Spark command builder that defines common functionality.
   */
  abstract class AbstractCommandBuilder {
  
    boolean verbose;
    String appName;
    String appResource;
    String deployMode;
    String javaHome;
    String mainClass;
    String master;
    protected String propertiesFile;
    final List<String> appArgs;
    final List<String> jars;
    final List<String> files;
    final List<String> pyFiles;
    final Map<String, String> childEnv;
    final Map<String, String> conf;
  
    // The merged configuration for the application. Cached to avoid having to read / parse
    // properties files multiple times.
    private Map<String, String> effectiveConfig;
  
    AbstractCommandBuilder() {
      this.appArgs = new ArrayList<>();
      this.childEnv = new HashMap<>();
      this.conf = new HashMap<>();
      this.files = new ArrayList<>();
      this.jars = new ArrayList<>();
      this.pyFiles = new ArrayList<>();
    }
  
    /**
     * Builds the command to execute.
     *
     * @param env A map containing environment variables for the child process. It may already contain
     *            entries defined by the user (such as SPARK_HOME, or those defined by the
     *            SparkLauncher constructor that takes an environment), and may be modified to
     *            include other variables needed by the process to be executed.
     */
    abstract List<String> buildCommand(Map<String, String> env)
        throws IOException, IllegalArgumentException;
  
    /**
     * Builds a list of arguments to run java.
     *
     * This method finds the java executable to use and appends JVM-specific options for running a
     * class with Spark in the classpath. It also loads options from the "java-opts" file in the
     * configuration directory being used.
     *
     * Callers should still add at least the class to run, as well as any arguments to pass to the
     * class.
     */
    List<String> buildJavaCommand(String extraClassPath) throws IOException {
      List<String> cmd = new ArrayList<>();
      String envJavaHome;
  
      if (javaHome != null) {
        cmd.add(join(File.separator, javaHome, "bin", "java"));
      } else if ((envJavaHome = System.getenv("JAVA_HOME")) != null) {
          cmd.add(join(File.separator, envJavaHome, "bin", "java"));
      } else {
          cmd.add(join(File.separator, System.getProperty("java.home"), "bin", "java"));
      }
  
      // Load extra JAVA_OPTS from conf/java-opts, if it exists.
      File javaOpts = new File(join(File.separator, getConfDir(), "java-opts"));
      if (javaOpts.isFile()) {
        BufferedReader br = new BufferedReader(new InputStreamReader(
            new FileInputStream(javaOpts), StandardCharsets.UTF_8));
        try {
          String line;
          while ((line = br.readLine()) != null) {
            addOptionString(cmd, line);
          }
        } finally {
          br.close();
        }
      }
  
      cmd.add("-cp");
      cmd.add(join(File.pathSeparator, buildClassPath(extraClassPath)));
      return cmd;
    }
  
    void addOptionString(List<String> cmd, String options) {
      if (!isEmpty(options)) {
        for (String opt : parseOptionString(options)) {
          cmd.add(opt);
        }
      }
    }
  
    /**
     * Builds the classpath for the application. Returns a list with one classpath entry per element;
     * each entry is formatted in the way expected by <i>java.net.URLClassLoader</i> (more
     * specifically, with trailing slashes for directories).
     */
    List<String> buildClassPath(String appClassPath) throws IOException {
      String sparkHome = getSparkHome();
  
      List<String> cp = new ArrayList<>();
      addToClassPath(cp, getenv("SPARK_CLASSPATH"));
      addToClassPath(cp, appClassPath);
  
      addToClassPath(cp, getConfDir());
  
      boolean prependClasses = !isEmpty(getenv("SPARK_PREPEND_CLASSES"));
      boolean isTesting = "1".equals(getenv("SPARK_TESTING"));
      if (prependClasses || isTesting) {
        String scala = getScalaVersion();
        List<String> projects = Arrays.asList(
          "common/network-common",
          "common/network-shuffle",
          "common/network-yarn",
          "common/sketch",
          "common/tags",
          "common/unsafe",
          "core",
          "examples",
          "graphx",
          "launcher",
          "mllib",
          "repl",
          "sql/catalyst",
          "sql/core",
          "sql/hive",
          "sql/hive-thriftserver",
          "streaming",
          "yarn"
        );
        if (prependClasses) {
          if (!isTesting) {
            System.err.println(
              "NOTE: SPARK_PREPEND_CLASSES is set, placing locally compiled Spark classes ahead of " +
              "assembly.");
          }
          for (String project : projects) {
            addToClassPath(cp, String.format("%s/%s/target/scala-%s/classes", sparkHome, project,
              scala));
          }
        }
        if (isTesting) {
          for (String project : projects) {
            addToClassPath(cp, String.format("%s/%s/target/scala-%s/test-classes", sparkHome,
              project, scala));
          }
        }
  
        // Add this path to include jars that are shaded in the final deliverable created during
        // the maven build. These jars are copied to this directory during the build.
        addToClassPath(cp, String.format("%s/core/target/jars/*", sparkHome));
      }
  
      // Add Spark jars to the classpath. For the testing case, we rely on the test code to set and
      // propagate the test classpath appropriately. For normal invocation, look for the jars
      // directory under SPARK_HOME.
      boolean isTestingSql = "1".equals(getenv("SPARK_SQL_TESTING"));
      String jarsDir = findJarsDir(getSparkHome(), getScalaVersion(), !isTesting && !isTestingSql);
      if (jarsDir != null) {
        addToClassPath(cp, join(File.separator, jarsDir, "*"));
      }
  
      addToClassPath(cp, getenv("HADOOP_CONF_DIR"));
      addToClassPath(cp, getenv("YARN_CONF_DIR"));
      addToClassPath(cp, getenv("SPARK_DIST_CLASSPATH"));
      return cp;
    }
  
    /**
     * Adds entries to the classpath.
     *
     * @param cp List to which the new entries are appended.
     * @param entries New classpath entries (separated by File.pathSeparator).
     */
    private void addToClassPath(List<String> cp, String entries) {
      if (isEmpty(entries)) {
        return;
      }
      String[] split = entries.split(Pattern.quote(File.pathSeparator));
      for (String entry : split) {
        if (!isEmpty(entry)) {
          if (new File(entry).isDirectory() && !entry.endsWith(File.separator)) {
            entry += File.separator;
          }
          cp.add(entry);
        }
      }
    }
  
    String getScalaVersion() {
      String scala = getenv("SPARK_SCALA_VERSION");
      if (scala != null) {
        return scala;
      }
      String sparkHome = getSparkHome();
      File scala210 = new File(sparkHome, "launcher/target/scala-2.10");
      File scala211 = new File(sparkHome, "launcher/target/scala-2.11");
      checkState(!scala210.isDirectory() || !scala211.isDirectory(),
        "Presence of build for both scala versions (2.10 and 2.11) detected.\n" +
        "Either clean one of them or set SPARK_SCALA_VERSION in your environment.");
      if (scala210.isDirectory()) {
        return "2.10";
      } else {
        checkState(scala211.isDirectory(), "Cannot find any build directories.");
        return "2.11";
      }
    }
  
    String getSparkHome() {
      String path = getenv(ENV_SPARK_HOME);
      checkState(path != null,
        "Spark home not found; set it explicitly or use the SPARK_HOME environment variable.");
      return path;
    }
  
    String getenv(String key) {
      return firstNonEmpty(childEnv.get(key), System.getenv(key));
    }
  
    void setPropertiesFile(String path) {
      effectiveConfig = null;
      this.propertiesFile = path;
    }
  
    Map<String, String> getEffectiveConfig() throws IOException {
      if (effectiveConfig == null) {
        effectiveConfig = new HashMap<>(conf);
        Properties p = loadPropertiesFile();
        for (String key : p.stringPropertyNames()) {
          if (!effectiveConfig.containsKey(key)) {
            effectiveConfig.put(key, p.getProperty(key));
          }
        }
      }
      return effectiveConfig;
    }
  
    /**
     * Loads the configuration file for the application, if it exists. This is either the
     * user-specified properties file, or the spark-defaults.conf file under the Spark configuration
     * directory.
     */
    private Properties loadPropertiesFile() throws IOException {
      Properties props = new Properties();
      File propsFile;
      if (propertiesFile != null) {
        propsFile = new File(propertiesFile);
        checkArgument(propsFile.isFile(), "Invalid properties file '%s'.", propertiesFile);
      } else {
        propsFile = new File(getConfDir(), DEFAULT_PROPERTIES_FILE);
      }
  
      if (propsFile.isFile()) {
        FileInputStream fd = null;
        try {
          fd = new FileInputStream(propsFile);
          props.load(new InputStreamReader(fd, StandardCharsets.UTF_8));
          for (Map.Entry<Object, Object> e : props.entrySet()) {
            e.setValue(e.getValue().toString().trim());
          }
        } finally {
          if (fd != null) {
            try {
              fd.close();
            } catch (IOException e) {
              // Ignore.
            }
          }
        }
      }
  
      return props;
    }
  
    private String getConfDir() {
      String confDir = getenv("SPARK_CONF_DIR");
      return confDir != null ? confDir : join(File.separator, getSparkHome(), "conf");
    }
  
  }
  