| /** |
| * 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.impl.groupings; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.heron.api.grouping.CustomStreamGrouping; |
| import org.apache.heron.api.topology.TopologyContext; |
| import org.apache.heron.api.utils.Utils; |
| import org.apache.heron.streamlet.SerializableFunction; |
| |
| /** |
| * JoinCustomGrouping is the class that routes the incoming tuples into the |
| * JoinOperator. It essentially ensures that the values being routed are of type |
| * KeyValue uses the key to route the tuple to the destination. |
| */ |
| public class JoinCustomGrouping<R, K> implements CustomStreamGrouping { |
| private static final long serialVersionUID = 2007892247960031525L; |
| private SerializableFunction<R, K> keyExtractor; |
| private List<Integer> taskIds; |
| |
| public JoinCustomGrouping(SerializableFunction<R, K> keyExtractor) { |
| this.keyExtractor = keyExtractor; |
| } |
| |
| @Override |
| public void prepare(TopologyContext context, String component, |
| String streamId, List<Integer> targetTasks) { |
| this.taskIds = targetTasks; |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public List<Integer> chooseTasks(List<Object> values) { |
| List<Integer> ret = new ArrayList<>(); |
| R obj = (R) values.get(0); |
| int key = keyExtractor.apply(obj).hashCode(); |
| ret.add(Utils.assignKeyToTask(key, taskIds)); |
| return ret; |
| } |
| } |