001/* 002 * Copyright (c) 2007-2016 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 021package cascading.flow.stream.element; 022 023import java.io.IOException; 024 025import cascading.CascadingException; 026import cascading.flow.FlowProcess; 027import cascading.flow.stream.duct.Duct; 028import cascading.operation.Function; 029import cascading.pipe.Each; 030import cascading.pipe.OperatorException; 031import cascading.tuple.Fields; 032import cascading.tuple.Tuple; 033import cascading.tuple.TupleEntry; 034import cascading.tuple.TupleEntryCollector; 035import cascading.tuple.Tuples; 036 037/** 038 * 039 */ 040public class FunctionEachStage extends EachStage 041 { 042 private Function function; 043 044 public FunctionEachStage( FlowProcess flowProcess, Each each ) 045 { 046 super( flowProcess, each ); 047 } 048 049 @Override 050 protected Fields getIncomingPassThroughFields() 051 { 052 return incomingScopes.get( 0 ).getIncomingFunctionPassThroughFields(); 053 } 054 055 @Override 056 protected Fields getIncomingArgumentsFields() 057 { 058 return incomingScopes.get( 0 ).getIncomingFunctionArgumentFields(); 059 } 060 061 @Override 062 public void initialize() 063 { 064 super.initialize(); 065 066 function = each.getFunction(); 067 068 operationCall.setArguments( argumentsEntry ); 069 070 operationCall.setOutputCollector( new TupleEntryCollector( getOperationDeclaredFields() ) 071 { 072 @Override 073 protected void collect( TupleEntry input ) throws IOException 074 { 075 Tuple outgoing = outgoingBuilder.makeResult( incomingEntry.getTuple(), input.getTuple() ); 076 077 outgoingEntry.setTuple( outgoing ); 078 079 try 080 { 081 next.receive( FunctionEachStage.this, outgoingEntry ); 082 } 083 finally 084 { 085 Tuples.asModifiable( outgoing ); 086 } 087 } 088 } ); 089 } 090 091 @Override 092 public void receive( Duct previous, TupleEntry incomingEntry ) 093 { 094 this.incomingEntry = incomingEntry; 095 096 argumentsEntry.setTuple( argumentsBuilder.makeResult( incomingEntry.getTuple(), null ) ); 097 098 try 099 { 100 function.operate( flowProcess, operationCall ); // adds results to collector 101 } 102 catch( CascadingException exception ) 103 { 104 handleException( exception, argumentsEntry ); 105 } 106 catch( Throwable throwable ) 107 { 108 handleException( new OperatorException( each, "operator Each failed executing operation", throwable ), argumentsEntry ); 109 } 110 } 111 }