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.collect;
023
024import java.util.Collection;
025
026import cascading.provider.CascadingFactory;
027import cascading.tuple.Tuple;
028
029/**
030 * Interface TupleCollectionFactory allows developers to plugin alternative implementations of a "tuple collection"
031 * used to back in memory "join" and "co-group" operations. Typically these implementations are
032 * "spillable", in that to prevent using up all memory in the JVM, after some threshold is met or event
033 * is triggered, values are persisted to disk.
034 * <p>
035 * The {@link java.util.Collection} classes returned must take a {@link cascading.tuple.Tuple} as a value.
036 * <p>
037 * If the Collection implementation implements the {@link Spillable} interface, it will receive a {@link Spillable.SpillListener}
038 * instance that calls back to the appropriate logging mechanism for the platform.
039 * <p>
040 * The class {@link SpillableTupleList} may be used as a base class.
041 *
042 * @see cascading.tuple.hadoop.collect.HadoopTupleCollectionFactory
043 * @see SpillableTupleList
044 * @see cascading.tuple.hadoop.collect.HadoopSpillableTupleList
045 * @see TupleMapFactory
046 * @see cascading.tuple.hadoop.collect.HadoopTupleMapFactory
047 */
048public interface TupleCollectionFactory<Config> extends CascadingFactory<Config, Collection<Tuple>>
049  {
050  String TUPLE_COLLECTION_FACTORY = "cascading.factory.tuple.collection.classname";
051  }