    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.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  }