001 /* 002 * Copyright (c) 2007-2014 Concurrent, Inc. All Rights Reserved. 003 * 004 * Project and contact information: http://www.cascading.org/ 005 * 006 * This file is part of the Cascading project. 007 * 008 * Licensed under the Apache License, Version 2.0 (the "License"); 009 * you may not use this file except in compliance with the License. 010 * You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, software 015 * distributed under the License is distributed on an "AS IS" BASIS, 016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 017 * See the License for the specific language governing permissions and 018 * limitations under the License. 019 */ 020 021 package cascading.flow.stream; 022 023 import java.io.IOException; 024 025 import cascading.CascadingException; 026 import cascading.flow.FlowProcess; 027 import cascading.operation.Aggregator; 028 import cascading.pipe.Every; 029 import cascading.pipe.OperatorException; 030 import cascading.tuple.Fields; 031 import cascading.tuple.Tuple; 032 import cascading.tuple.TupleEntry; 033 import cascading.tuple.TupleEntryCollector; 034 import cascading.tuple.Tuples; 035 036 /** 037 * 038 */ 039 public class AggregatorEveryStage extends EveryStage<TupleEntry> implements Reducing<TupleEntry, TupleEntry> 040 { 041 private Aggregator aggregator; 042 private Reducing reducing; 043 044 public AggregatorEveryStage( FlowProcess flowProcess, Every every ) 045 { 046 super( flowProcess, every ); 047 } 048 049 @Override 050 public void initialize() 051 { 052 super.initialize(); 053 054 aggregator = every.getAggregator(); 055 056 outputCollector = new TupleEntryCollector( getOperationDeclaredFields() ) 057 { 058 @Override 059 protected void collect( TupleEntry resultEntry ) throws IOException 060 { 061 Tuple outgoing = outgoingBuilder.makeResult( incomingEntry.getTuple(), resultEntry.getTuple() ); 062 063 outgoingEntry.setTuple( outgoing ); 064 065 try 066 { 067 reducing.completeGroup( AggregatorEveryStage.this, outgoingEntry ); 068 } 069 finally 070 { 071 Tuples.asModifiable( outgoing ); 072 } 073 } 074 }; 075 076 reducing = (Reducing) getNext(); 077 } 078 079 @Override 080 protected Fields getIncomingPassThroughFields() 081 { 082 return incomingScopes.get( 0 ).getIncomingAggregatorPassThroughFields(); 083 } 084 085 @Override 086 protected Fields getIncomingArgumentsFields() 087 { 088 return incomingScopes.get( 0 ).getIncomingAggregatorArgumentFields(); 089 } 090 091 @Override 092 protected Fields getOutgoingSelector() 093 { 094 return outgoingScopes.get( 0 ).getOutGroupingSelector(); 095 } 096 097 @Override 098 public void startGroup( Duct previous, TupleEntry groupEntry ) 099 { 100 operationCall.setGroup( groupEntry ); 101 operationCall.setArguments( null ); // zero it out 102 operationCall.setOutputCollector( null ); // zero it out 103 104 try 105 { 106 aggregator.start( flowProcess, operationCall ); 107 } 108 catch( CascadingException exception ) 109 { 110 handleException( exception, groupEntry ); 111 } 112 catch( Throwable throwable ) 113 { 114 handleException( new OperatorException( every, "operator Every failed starting operation: " + every.getOperation(), throwable ), groupEntry ); 115 } 116 117 reducing.startGroup( this, groupEntry ); 118 } 119 120 @Override 121 public void receive( Duct previous, TupleEntry tupleEntry ) 122 { 123 try 124 { 125 argumentsEntry.setTuple( argumentsBuilder.makeResult( tupleEntry.getTuple(), null ) ); 126 operationCall.setArguments( argumentsEntry ); 127 128 aggregator.aggregate( flowProcess, operationCall ); 129 } 130 catch( CascadingException exception ) 131 { 132 handleException( exception, argumentsEntry ); 133 } 134 catch( Throwable throwable ) 135 { 136 handleException( new OperatorException( every, "operator Every failed executing operation: " + every.getOperation(), throwable ), argumentsEntry ); 137 } 138 139 next.receive( this, tupleEntry ); 140 } 141 142 @Override 143 public void completeGroup( Duct previous, TupleEntry incomingEntry ) 144 { 145 this.incomingEntry = incomingEntry; 146 operationCall.setArguments( null ); 147 operationCall.setOutputCollector( outputCollector ); 148 149 try 150 { 151 aggregator.complete( flowProcess, operationCall ); // collector calls next 152 } 153 catch( CascadingException exception ) 154 { 155 handleException( exception, incomingEntry ); 156 } 157 catch( Throwable throwable ) 158 { 159 handleException( new OperatorException( every, "operator Every failed completing operation: " + every.getOperation(), throwable ), incomingEntry ); 160 } 161 } 162 }