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.hadoop.planner.rule.expression; 023 024import cascading.flow.planner.iso.expression.ElementCapture; 025import cascading.flow.planner.iso.expression.ExpressionGraph; 026import cascading.flow.planner.iso.expression.FlowElementExpression; 027import cascading.flow.planner.iso.expression.NonSafeOperationExpression; 028import cascading.flow.planner.iso.expression.TypeExpression; 029import cascading.flow.planner.rule.RuleExpression; 030import cascading.flow.planner.rule.expressiongraph.NonSafeAndSplitAndSyncPipeExpressionGraph; 031import cascading.pipe.Pipe; 032import cascading.tap.Tap; 033 034/** 035 * Captures a split against a non-safe Operation to prevent the operation from running 036 * in parallel mappers. 037 * <p> 038 * THis variant allows a non-safe operation to be followed by any Pipe. this assumes other rules 039 * enforce splitting to only be on Each or Pipe types. 040 */ 041public class BalanceNonSafePipeSplitExpression extends RuleExpression 042 { 043 public BalanceNonSafePipeSplitExpression() 044 { 045 super( 046 new NonSafeAndSplitAndSyncPipeExpressionGraph(), 047 048 new ExpressionGraph() 049 .arcs( 050 new FlowElementExpression( Tap.class ), 051 new NonSafeOperationExpression(), 052 new FlowElementExpression( Pipe.class, TypeExpression.Topo.SplitOnly ) 053 ), 054 055 new ExpressionGraph() 056 .arcs( 057 new FlowElementExpression( ElementCapture.Primary, Pipe.class, TypeExpression.Topo.Tail ) 058 ) 059 ); 060 } 061 }