001/* 002 * Copyright (c) 2007-2017 Xplenty, 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.tap.partition; 022 023import java.util.Iterator; 024 025import cascading.tap.TapException; 026import cascading.tuple.Fields; 027import cascading.tuple.Tuple; 028import cascading.tuple.TupleEntry; 029import cascading.tuple.TupleEntrySchemeIterator; 030import cascading.tuple.util.TupleViews; 031 032/** 033 * 034 */ 035public class PartitionTupleEntryIterator implements Iterator<Tuple> 036 { 037 private final TupleEntrySchemeIterator childIterator; 038 private final Tuple base; 039 private final Tuple view; 040 041 public PartitionTupleEntryIterator( Fields sourceFields, Partition partition, String parentIdentifier, String childIdentifier, TupleEntrySchemeIterator schemeIterator ) 042 { 043 this.childIterator = schemeIterator; 044 045 TupleEntry partitionEntry = new TupleEntry( partition.getPartitionFields(), Tuple.size( partition.getPartitionFields().size() ) ); 046 047 try 048 { 049 partition.toTuple( childIdentifier.substring( parentIdentifier.length() + 1 ), partitionEntry ); 050 } 051 catch( Exception exception ) 052 { 053 throw new TapException( "unable to parse partition given parent: " + parentIdentifier + " and child: " + childIdentifier ); 054 } 055 056 base = TupleViews.createOverride( sourceFields, partitionEntry.getFields() ); 057 058 TupleViews.reset( base, Tuple.size( sourceFields.size() ), partitionEntry.getTuple() ); 059 060 view = TupleViews.createOverride( sourceFields, childIterator.getFields() ); 061 } 062 063 @Override 064 public boolean hasNext() 065 { 066 return childIterator.hasNext(); 067 } 068 069 @Override 070 public Tuple next() 071 { 072 Tuple tuple = childIterator.next().getTuple(); 073 TupleViews.reset( view, base, tuple ); 074 075 return view; 076 } 077 078 @Override 079 public void remove() 080 { 081 childIterator.remove(); 082 } 083 }