| /* |
| * 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.pirk.responder.wideskies.mapreduce; |
| |
| import java.io.IOException; |
| import java.math.BigInteger; |
| |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapreduce.Reducer; |
| import org.apache.hadoop.mapreduce.lib.output.MultipleOutputs; |
| import org.apache.pirk.query.wideskies.Query; |
| import org.apache.pirk.query.wideskies.QueryInfo; |
| import org.apache.pirk.response.wideskies.Response; |
| import org.apache.pirk.serialization.HadoopFileSystemStore; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Reducer class to construct the final Response object |
| * |
| */ |
| public class FinalResponseReducer extends Reducer<LongWritable,Text,LongWritable,Text> |
| { |
| private static final Logger logger = LoggerFactory.getLogger(FinalResponseReducer.class); |
| |
| private MultipleOutputs<LongWritable,Text> mos = null; |
| |
| private Response response = null; |
| private String outputFile = null; |
| private HadoopFileSystemStore storage = null; |
| |
| @Override |
| public void setup(Context ctx) throws IOException, InterruptedException |
| { |
| super.setup(ctx); |
| |
| mos = new MultipleOutputs<>(ctx); |
| |
| FileSystem fs = FileSystem.newInstance(ctx.getConfiguration()); |
| storage = new HadoopFileSystemStore(fs); |
| String queryDir = ctx.getConfiguration().get("pirMR.queryInputDir"); |
| Query query = storage.recall(queryDir, Query.class); |
| QueryInfo queryInfo = query.getQueryInfo(); |
| |
| outputFile = ctx.getConfiguration().get("pirMR.outputFile"); |
| |
| response = new Response(queryInfo); |
| } |
| |
| @Override |
| public void reduce(LongWritable colNum, Iterable<Text> colVals, Context ctx) throws IOException, InterruptedException |
| { |
| logger.debug("Processing reducer for colNum = " + colNum.toString()); |
| ctx.getCounter(MRStats.NUM_COLUMNS).increment(1); |
| |
| BigInteger column = null; |
| for (Text val : colVals) // there is only one column value |
| { |
| column = new BigInteger(val.toString()); |
| logger.debug("colNum = " + (int) colNum.get() + " column = " + column.toString()); |
| } |
| response.addElement((int) colNum.get(), column); |
| } |
| |
| @Override |
| public void cleanup(Context ctx) throws IOException, InterruptedException |
| { |
| storage.store(outputFile, response); |
| mos.close(); |
| } |
| } |