| // Copyright 2017 Twitter. All rights reserved. |
| // |
| // Licensed 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 com.twitter.heron.streamlet.impl.streamlets; |
| |
| import java.util.Set; |
| |
| import com.twitter.heron.api.topology.TopologyBuilder; |
| import com.twitter.heron.streamlet.KeyValue; |
| import com.twitter.heron.streamlet.SerializableConsumer; |
| import com.twitter.heron.streamlet.impl.KVStreamletImpl; |
| import com.twitter.heron.streamlet.impl.sinks.ConsumerSink; |
| |
| /** |
| * ConsumerStreamlet represents en empty Streamlet that is made up of elements from the parent |
| * streamlet after consuming every element. Since elements of the parents are just consumed |
| * by the user passed consumer function, nothing is emitted, thus this streamlet is empty. |
| */ |
| public class KVConsumerStreamlet<K, V> extends KVStreamletImpl<K, V> { |
| private KVStreamletImpl<K, V> parent; |
| private SerializableConsumer<? super KeyValue<? super K, ? super V>> consumer; |
| |
| public KVConsumerStreamlet(KVStreamletImpl<K, V> parent, |
| SerializableConsumer<? super KeyValue<? super K, ? super V>> consumer) { |
| this.parent = parent; |
| this.consumer = consumer; |
| setNumPartitions(parent.getNumPartitions()); |
| } |
| |
| @Override |
| public boolean doBuild(TopologyBuilder bldr, Set<String> stageNames) { |
| if (getName() == null) { |
| setName(defaultNameCalculator("kvconsumer", stageNames)); |
| } |
| if (stageNames.contains(getName())) { |
| throw new RuntimeException("Duplicate Names"); |
| } |
| stageNames.add(getName()); |
| bldr.setBolt(getName(), new ConsumerSink<>(consumer), |
| getNumPartitions()).shuffleGrouping(parent.getName()); |
| return true; |
| } |
| } |