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.tuple; 023 024import java.util.Iterator; 025 026import cascading.tuple.util.Resettable; 027 028/** 029 * TupleChainIterator chains the given Iterators into a single Iterator. 030 * <p> 031 * As one iterator is completed, it will be closed and a new one will start. 032 */ 033public class TupleChainIterable implements Iterable<Tuple>, Resettable<Iterable<Tuple>> 034 { 035 /** Field iterator */ 036 Iterable<Tuple>[] iterables; 037 038 public TupleChainIterable( Iterable<Tuple> first, Iterable<Tuple>... iterables ) 039 { 040 Iterable<Tuple>[] initial; 041 042 if( first instanceof TupleChainIterable ) 043 initial = ( (TupleChainIterable) first ).iterables; 044 else 045 initial = new Iterable[]{first}; 046 047 this.iterables = new Iterable[ initial.length + iterables.length ]; 048 049 System.arraycopy( initial, 0, this.iterables, 0, initial.length ); 050 System.arraycopy( iterables, 0, this.iterables, initial.length, iterables.length ); 051 } 052 053 @Override 054 public Iterator<Tuple> iterator() 055 { 056 Iterator<Tuple>[] iterators = new Iterator[ iterables.length ]; 057 058 for( int i = 0; i < iterables.length; i++ ) 059 iterators[ i ] = iterables[ i ].iterator(); 060 061 return new TupleChainIterator( iterators ); 062 } 063 064 @Override 065 public void reset( Iterable<Tuple>... iterables ) 066 { 067 this.iterables = iterables; 068 } 069 }