| /* |
| * 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.flink.runtime.operators; |
| |
| import org.apache.flink.api.common.ExecutionConfig; |
| import org.apache.flink.api.common.functions.MapFunction; |
| import org.apache.flink.metrics.Counter; |
| import org.apache.flink.runtime.operators.util.metrics.CountingCollector; |
| import org.apache.flink.util.Collector; |
| import org.apache.flink.util.MutableObjectIterator; |
| |
| /** |
| * Map task which is executed by a Task Manager. The task has a single input and one or multiple |
| * outputs. It is provided with a MapFunction implementation. |
| * |
| * <p>The MapTask creates an iterator over all key-value pairs of its input and hands that to the |
| * <code>map()</code> method of the MapFunction. |
| * |
| * @see org.apache.flink.api.common.functions.MapFunction |
| * @param <IT> The mapper's input data type. |
| * @param <OT> The mapper's output data type. |
| */ |
| public class MapDriver<IT, OT> implements Driver<MapFunction<IT, OT>, OT> { |
| |
| private TaskContext<MapFunction<IT, OT>, OT> taskContext; |
| |
| private volatile boolean running; |
| |
| private boolean objectReuseEnabled = false; |
| |
| @Override |
| public void setup(TaskContext<MapFunction<IT, OT>, OT> context) { |
| this.taskContext = context; |
| this.running = true; |
| |
| ExecutionConfig executionConfig = taskContext.getExecutionConfig(); |
| this.objectReuseEnabled = executionConfig.isObjectReuseEnabled(); |
| } |
| |
| @Override |
| public int getNumberOfInputs() { |
| return 1; |
| } |
| |
| @Override |
| public Class<MapFunction<IT, OT>> getStubType() { |
| @SuppressWarnings("unchecked") |
| final Class<MapFunction<IT, OT>> clazz = |
| (Class<MapFunction<IT, OT>>) (Class<?>) MapFunction.class; |
| return clazz; |
| } |
| |
| @Override |
| public int getNumberOfDriverComparators() { |
| return 0; |
| } |
| |
| @Override |
| public void prepare() { |
| // nothing, since a mapper does not need any preparation |
| } |
| |
| @Override |
| public void run() throws Exception { |
| final Counter numRecordsIn = |
| this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsInCounter(); |
| final Counter numRecordsOut = |
| this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsOutCounter(); |
| // cache references on the stack |
| final MutableObjectIterator<IT> input = this.taskContext.getInput(0); |
| final MapFunction<IT, OT> function = this.taskContext.getStub(); |
| final Collector<OT> output = |
| new CountingCollector<>(this.taskContext.getOutputCollector(), numRecordsOut); |
| |
| if (objectReuseEnabled) { |
| IT record = this.taskContext.<IT>getInputSerializer(0).getSerializer().createInstance(); |
| |
| while (this.running && ((record = input.next(record)) != null)) { |
| numRecordsIn.inc(); |
| output.collect(function.map(record)); |
| } |
| } else { |
| IT record = null; |
| |
| while (this.running && ((record = input.next()) != null)) { |
| numRecordsIn.inc(); |
| output.collect(function.map(record)); |
| } |
| } |
| } |
| |
| @Override |
| public void cleanup() { |
| // mappers need no cleanup, since no strategies are used. |
| } |
| |
| @Override |
| public void cancel() { |
| this.running = false; |
| } |
| } |