| /** |
| * 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.hadoop.mapred.lib.aggregate; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| import org.apache.hadoop.mapred.JobConf; |
| import org.apache.hadoop.mapred.Mapper; |
| import org.apache.hadoop.mapred.Reducer; |
| |
| /** |
| * This abstract class implements some common functionalities of the |
| * the generic mapper, reducer and combiner classes of Aggregate. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public abstract class ValueAggregatorJobBase<K1 extends WritableComparable, |
| V1 extends Writable> |
| implements Mapper<K1, V1, Text, Text>, Reducer<Text, Text, Text, Text> { |
| |
| protected ArrayList<ValueAggregatorDescriptor> aggregatorDescriptorList = null; |
| |
| public void configure(JobConf job) { |
| this.initializeMySpec(job); |
| this.logSpec(); |
| } |
| |
| private static ValueAggregatorDescriptor getValueAggregatorDescriptor( |
| String spec, JobConf job) { |
| if (spec == null) |
| return null; |
| String[] segments = spec.split(",", -1); |
| String type = segments[0]; |
| if (type.compareToIgnoreCase("UserDefined") == 0) { |
| String className = segments[1]; |
| return new UserDefinedValueAggregatorDescriptor(className, job); |
| } |
| return null; |
| } |
| |
| private static ArrayList<ValueAggregatorDescriptor> getAggregatorDescriptors(JobConf job) { |
| String advn = "aggregator.descriptor"; |
| int num = job.getInt(advn + ".num", 0); |
| ArrayList<ValueAggregatorDescriptor> retv = new ArrayList<ValueAggregatorDescriptor>(num); |
| for (int i = 0; i < num; i++) { |
| String spec = job.get(advn + "." + i); |
| ValueAggregatorDescriptor ad = getValueAggregatorDescriptor(spec, job); |
| if (ad != null) { |
| retv.add(ad); |
| } |
| } |
| return retv; |
| } |
| |
| private void initializeMySpec(JobConf job) { |
| this.aggregatorDescriptorList = getAggregatorDescriptors(job); |
| if (this.aggregatorDescriptorList.size() == 0) { |
| this.aggregatorDescriptorList |
| .add(new UserDefinedValueAggregatorDescriptor( |
| ValueAggregatorBaseDescriptor.class.getCanonicalName(), job)); |
| } |
| } |
| |
| protected void logSpec() { |
| |
| } |
| |
| public void close() throws IOException { |
| } |
| } |