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 java.io.IOException;
025
026/**
027 * Class FlowSkipIfSinkNotStale is a {@link cascading.flow.FlowSkipStrategy} implementation that returns
028 * {@code true} if the Flow sink exists and is not stale in relation to the Flow sources.
029 * <p>
030 * This is the default Cascading strategy.
031 *
032 * @see cascading.flow.FlowSkipIfSinkExists
033 */
034public class FlowSkipIfSinkNotStale implements FlowSkipStrategy
035  {
036  public boolean skipFlow( Flow flow ) throws IOException
037    {
038    long sinkModified = flow.getSinkModified();
039
040    return sinkModified > 0 && !flow.areSourcesNewer( sinkModified );
041    }
042  }