001/* 002 * Copyright (c) 2016 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.stream.element; 023 024import cascading.flow.FlowProcess; 025import cascading.flow.hadoop.HadoopFlowProcess; 026import cascading.flow.hadoop.HadoopGroupByClosure; 027import cascading.flow.hadoop.stream.HadoopGroupGate; 028import cascading.flow.stream.duct.Duct; 029import cascading.flow.stream.graph.IORole; 030import cascading.pipe.GroupBy; 031import cascading.tuple.Tuple; 032import cascading.tuple.io.TuplePair; 033import org.apache.hadoop.mapred.OutputCollector; 034 035/** 036 * 037 */ 038public class HadoopGroupByGate extends HadoopGroupGate 039 { 040 public HadoopGroupByGate( FlowProcess flowProcess, GroupBy groupBy, IORole role ) 041 { 042 super( flowProcess, groupBy, role ); 043 } 044 045 @Override 046 protected HadoopGroupByClosure createClosure() 047 { 048 // todo: collapse keyFields here if an array size > 1 049 return new HadoopGroupByClosure( flowProcess, keyFields, valuesFields ); 050 } 051 052 @Override 053 protected void wrapGroupingAndCollect( Duct previous, int ordinal, Tuple valuesTuple, Tuple groupKey ) throws java.io.IOException 054 { 055 collector.collect( groupKey, valuesTuple ); 056 } 057 058 @Override 059 protected Tuple unwrapGrouping( Tuple key ) 060 { 061 return sortFields == null ? key : ( (TuplePair) key ).getLhs(); 062 } 063 064 protected OutputCollector createOutputCollector() 065 { 066 return ( (HadoopFlowProcess) flowProcess ).getOutputCollector(); 067 } 068 }