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.tuple.collect; 022 023 import java.util.Collection; 024 025 import cascading.provider.CascadingFactory; 026 import cascading.tuple.Tuple; 027 028 /** 029 * Interface TupleCollectionFactory allows developers to plugin alternative implementations of a "tuple collection" 030 * used to back in memory "join" and "co-group" operations. Typically these implementations are 031 * "spillable", in that to prevent using up all memory in the JVM, after some threshold is met or event 032 * is triggered, values are persisted to disk. 033 * <p/> 034 * The {@link java.util.Collection} classes returned must take a {@link cascading.tuple.Tuple} as a value. 035 * <p/> 036 * If the Collection implementation implements the {@link Spillable} interface, it will receive a {@link Spillable.SpillListener} 037 * instance that calls back to the appropriate logging mechanism for the platform. 038 * <p/> 039 * The class {@link SpillableTupleList} may be used as a base class. 040 * 041 * @see cascading.tuple.hadoop.collect.HadoopTupleCollectionFactory 042 * @see SpillableTupleList 043 * @see cascading.tuple.hadoop.collect.HadoopSpillableTupleList 044 * @see TupleMapFactory 045 * @see cascading.tuple.hadoop.collect.HadoopTupleMapFactory 046 */ 047 public interface TupleCollectionFactory<Config> extends CascadingFactory<Config, Collection<Tuple>> 048 { 049 String TUPLE_COLLECTION_FACTORY = "cascading.factory.tuple.collection.classname"; 050 }