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.tuple.collect;
022
023import java.util.Collection;
024
025import cascading.provider.CascadingFactory;
026import 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 */
047public interface TupleCollectionFactory<Config> extends CascadingFactory<Config, Collection<Tuple>>
048  {
049  String TUPLE_COLLECTION_FACTORY = "cascading.factory.tuple.collection.classname";
050  }