| /** |
| * 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.sqoop.mapreduce; |
| |
| import java.io.IOException; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * Identity reducer that continuously reports progress via a background thread. |
| */ |
| public class AutoProgressReducer<KEYIN, VALIN, KEYOUT, VALOUT> |
| extends SqoopReducer<KEYIN, VALIN, KEYOUT, VALOUT> { |
| |
| public static final Log LOG = LogFactory.getLog( |
| AutoProgressReducer.class.getName()); |
| |
| // reduce() method intentionally omitted; |
| // Reducer.reduce() is the identity reducer. |
| |
| /** |
| * Run the mapping process for this task, wrapped in an auto-progress system. |
| */ |
| @Override |
| public void run(Context context) throws IOException, InterruptedException { |
| ProgressThread thread = new ProgressThread(context, LOG); |
| |
| try { |
| thread.setDaemon(true); |
| thread.start(); |
| |
| // use default run() method to actually drive the mapping. |
| super.run(context); |
| } finally { |
| // Tell the progress thread to exit.. |
| LOG.debug("Instructing auto-progress thread to quit."); |
| thread.signalShutdown(); |
| try { |
| // And wait for that to happen. |
| LOG.debug("Waiting for progress thread shutdown..."); |
| thread.join(); |
| LOG.debug("Progress thread shutdown detected."); |
| } catch (InterruptedException ie) { |
| LOG.warn("Interrupted when waiting on auto-progress thread: " |
| + ie.toString(), ie); |
| } |
| } |
| } |
| } |