nwangtw commented on a change in pull request #3099: Nwang/add streamlet operator interfaces with grouping v2 URL: https://github.com/apache/incubator-heron/pull/3099#discussion_r232733730
########## File path: heron/api/src/java/org/apache/heron/streamlet/StreamGrouper.java ########## @@ -0,0 +1,78 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.heron.streamlet; + +import java.util.HashMap; +import java.util.Map; + +import org.apache.heron.api.grouping.StreamGrouping; +import org.apache.heron.api.utils.Utils; + +/** + * StreamGrouper is the class to config grouping strategy in Streamlet API. Note that + * One Operator could have more than one grouping strategies (when there are more than one + * incoming streams) although it has one in most cases. + */ +public class StreamGrouper { + /* + * Map of stream id to grouping strategies. One operator can have more than one incoming streams + * and each stream needs a grouping strategies. Hence it is possible for an operator to have + * more than one entries. + */ + private HashMap<String, StreamGrouping> groupingMap; + + /** + * Construct a Grouper object with specific grouping strategy and default stream id + * @param grouping The grouping strategy to be applied + */ + public StreamGrouper(StreamGrouping grouping) { + groupingMap = new HashMap<>(); + append(Utils.DEFAULT_STREAM_ID, grouping); + } + + /** + * Construct a Grouper object with specific grouping strategy and streamid + * @param streamId The stream id that the strategy to be applied to + * @param grouping The grouping strategy to be applied + */ + public StreamGrouper(String streamId, StreamGrouping grouping) { + groupingMap = new HashMap<>(); Review comment: Good to know. Thx. Will update. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
