DistributedCacheUtil.java

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 *
 * Pentaho Big Data
 *
 * Copyright (C) 2002-2015 by Pentaho : http://www.pentaho.com
 *
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 * 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
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 *    http://www.apache.org/licenses/LICENSE-2.0
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package org.pentaho.hadoop.shim.api;

import org.apache.commons.vfs2.FileObject;
import org.pentaho.hadoop.shim.api.fs.FileSystem;
import org.pentaho.hadoop.shim.api.fs.Path;

import java.io.IOException;

/**
 * A collection of methods for working with Hadoop's Distributed Cache mechanism.
 *
 * @author Jordan Ganoff (jganoff@pentaho.com)
 */
public interface DistributedCacheUtil {

  /**
   * Does a Kettle environment exist in the given file system at the provided path?
   *
   * @param fs                  File system to look in
   * @param kettleEnvInstallDir Path to check for a Kettle environment
   * @return {@code true} if there is a valid kettle environment in the file system at the path provided.
   * @throws IOException Error communicating with the file system.
   */
  boolean isKettleEnvironmentInstalledAt( FileSystem fs, Path kettleEnvInstallDir ) throws IOException;

  /**
   * Configure the configuration object to use the Kettle environment staged in the file system and path provided.
   *
   * @param conf                Configuration to update
   * @param fs                  File system to look in
   * @param kettleEnvInstallDir Path to the Kettle environment to use when executing a MapReduce job with the
   *                            configuration provided
   * @throws Exception Error locating the Kettle environment or configuring
   */
  void configureWithKettleEnvironment( Configuration conf, FileSystem fs, Path kettleEnvInstallDir ) throws Exception;

  /**
   * Installs the contents of a pre-configured Kettle environment into a Hadoop file system.
   *
   * @param pmrLibArchive       Archive to stage into the file system
   * @param fs                  File system to write to
   * @param destination         Directory to stage environment into
   * @param bigDataPluginFolder Location of the big data plugin to stage into the Kettle environment
   * @param additionalPlugins   Comma-separated list of directory paths relative to a root Kettle plugin folder
   *                            representing directories that should be copied into the installation
   * @throws Exception Error staging the Kettle environment
   */
  void installKettleEnvironment( FileObject pmrLibArchive, FileSystem fs, Path destination,
                                 FileObject bigDataPluginFolder, String additionalPlugins ) throws Exception;

}