001/*
002 * Copyright (c) 2016-2017 Chris K Wensel <chris@wensel.net>. All Rights Reserved.
003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
004 *
005 * Project and contact information: http://www.cascading.org/
006 *
007 * This file is part of the Cascading project.
008 *
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *     http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 */
021
022package cascading.flow.planner.rule;
023
024/**
025 */
026public enum ProcessLevel
027  {
028    /**
029     * Applies assertions or transformations to the whole FlowElement assembly.
030     */
031    Assembly,
032
033    /**
034     * Applies to sub-graphs of a flow where a step is a submitted unit of cluster work.
035     */
036    Step,
037
038    /**
039     * Applies to generation sub-graphs of steps where is a node is a unit of processing with a step.
040     * <p>
041     * In MapReduce its a Map or Reduce node (where Map and Reduce are Kinds).
042     * <p>
043     * In Tez its a Processor.
044     */
045    Node,
046
047    /**
048     * Applies to sub-graphs within nodes having a single streamed input, and multiple accumulated inputs.
049     * <p>
050     * In MapReduce, a Mapper task can arbitrarily process a given input file via the MultiInputSplit.
051     * <p>
052     * Tez currently does not allow multiply physical inputs per processor.
053     */
054    Pipeline;
055
056  public static ProcessLevel parent( ProcessLevel level )
057    {
058    if( level == Assembly )
059      return null;
060
061    return ProcessLevel.values()[ level.ordinal() - 1 ];
062    }
063  }