| // 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.SerializableBinaryOperator; |
| import com.twitter.heron.streamlet.Window; |
| import com.twitter.heron.streamlet.WindowConfig; |
| import com.twitter.heron.streamlet.impl.KVStreamletImpl; |
| import com.twitter.heron.streamlet.impl.StreamletImpl; |
| import com.twitter.heron.streamlet.impl.WindowConfigImpl; |
| import com.twitter.heron.streamlet.impl.groupings.ReduceByWindowCustomGrouping; |
| import com.twitter.heron.streamlet.impl.operators.ReduceByWindowOperator; |
| |
| /** |
| * ReduceByWindowStreamlet represents a KVStreamlet that is the result of |
| * applying user supplied reduceFn on all elements within each window defined by a |
| * user supplied Window Config. |
| * ReduceByWindowStreamlet's elements are of KeyValue type where the key is |
| * KeyWindowInfo<K> type and the value is of type V. |
| */ |
| public class ReduceByWindowStreamlet<I> extends KVStreamletImpl<Window, I> { |
| private StreamletImpl<I> parent; |
| private WindowConfigImpl windowCfg; |
| private SerializableBinaryOperator<I> reduceFn; |
| |
| public ReduceByWindowStreamlet(StreamletImpl<I> parent, |
| WindowConfig windowCfg, |
| SerializableBinaryOperator<I> reduceFn) { |
| this.parent = parent; |
| this.windowCfg = (WindowConfigImpl) windowCfg; |
| this.reduceFn = reduceFn; |
| setNumPartitions(parent.getNumPartitions()); |
| } |
| |
| @Override |
| public boolean doBuild(TopologyBuilder bldr, Set<String> stageNames) { |
| if (getName() == null) { |
| setName(defaultNameCalculator("reduceByWindow", stageNames)); |
| } |
| if (stageNames.contains(getName())) { |
| throw new RuntimeException("Duplicate Names"); |
| } |
| stageNames.add(getName()); |
| ReduceByWindowOperator<I> bolt = new ReduceByWindowOperator<>(reduceFn); |
| windowCfg.attachWindowConfig(bolt); |
| bldr.setBolt(getName(), bolt, getNumPartitions()) |
| .customGrouping(parent.getName(), new ReduceByWindowCustomGrouping<I>()); |
| return true; |
| } |
| } |