| /* |
| * 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.gearpump.akkastream.task |
| |
| import java.time.Instant |
| |
| import org.apache.gearpump.Message |
| import org.apache.gearpump.cluster.UserConfig |
| import org.apache.gearpump.streaming.task.TaskContext |
| |
| class FoldTask[In, Out](context: TaskContext, userConf : UserConfig) |
| extends GraphTask(context, userConf) { |
| |
| val zero = userConf.getValue[Out](FoldTask.ZERO) |
| val aggregator = userConf.getValue[(Out, In) => Out](FoldTask.AGGREGATOR) |
| var aggregated: Out = _ |
| implicit val ec = context.system.dispatcher |
| |
| override def onStart(instant: Instant): Unit = { |
| zero.foreach(value => { |
| aggregated = value |
| }) |
| } |
| |
| override def onNext(msg : Message) : Unit = { |
| val data = msg.msg.asInstanceOf[In] |
| val time = msg.timestamp |
| aggregator.foreach(func => { |
| aggregated = func(aggregated, data) |
| LOG.info(s"aggregated = $aggregated") |
| val msg = new Message(aggregated, time) |
| context.output(msg) |
| }) |
| } |
| } |
| |
| object FoldTask { |
| val ZERO = "ZERO" |
| val AGGREGATOR = "AGGREGATOR" |
| } |