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;
023
024import cascading.management.CascadingServices;
025
026/**
027 * FlowSession implementations provide a call-back interface into the current flow management system, if any.
028 * <p>
029 * A FlowSession is effectively unique to the current {@link Flow}, where a {@link FlowProcess} is unique
030 * to each underlying 'job'.
031 *
032 * @see FlowProcess
033 */
034public class FlowSession
035  {
036  /** Field NULL is a noop implementation of FlowSession. */
037  public static final FlowSession NULL = new FlowSession();
038
039  protected CascadingServices cascadingServices;
040
041  /** Field currentProcess */
042  private FlowProcess currentProcess = FlowProcess.NULL; // is set via accessor
043
044  public FlowSession()
045    {
046    }
047
048  public FlowSession( CascadingServices cascadingServices )
049    {
050    this.cascadingServices = cascadingServices;
051    }
052
053  /**
054   * Method setCurrentProcess sets the currentProcess of this FlowSession object.
055   *
056   * @param currentProcess the currentProcess of this FlowSession object.
057   */
058  public void setCurrentProcess( FlowProcess currentProcess )
059    {
060    this.currentProcess = currentProcess;
061    }
062
063  /**
064   * Method getCurrentProcess returns the currentProcess of this FlowSession object.
065   *
066   * @return the currentProcess (type FlowProcess) of this FlowSession object.
067   */
068  public FlowProcess getCurrentProcess()
069    {
070    return currentProcess;
071    }
072
073  public CascadingServices getCascadingServices()
074    {
075    return cascadingServices;
076    }
077
078  /**
079   * Method getID returns the parent {@link Flow} ID value.
080   *
081   * @return of type String
082   */
083  public String getID()
084    {
085    return currentProcess.getStringProperty( Flow.CASCADING_FLOW_ID );
086    }
087  }