| /* |
| * 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.serialization.HadoopFileSystemStore; |
| import org.apache.pirk.utils.FileConst; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Reducer to perform encrypted column multiplication |
| * |
| */ |
| public class ColumnMultReducer extends Reducer<LongWritable,Text,LongWritable,Text> |
| { |
| private static final Logger logger = LoggerFactory.getLogger(ColumnMultReducer.class); |
| |
| private Text outputValue = null; |
| private MultipleOutputs<LongWritable,Text> mos = null; |
| |
| private Query query = null; |
| |
| @Override |
| public void setup(Context ctx) throws IOException, InterruptedException |
| { |
| super.setup(ctx); |
| |
| outputValue = new Text(); |
| mos = new MultipleOutputs<>(ctx); |
| |
| FileSystem fs = FileSystem.newInstance(ctx.getConfiguration()); |
| String queryDir = ctx.getConfiguration().get("pirMR.queryInputDir"); |
| query = new HadoopFileSystemStore(fs).recall(queryDir, Query.class); |
| } |
| |
| @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 = BigInteger.valueOf(1); |
| for (Text val : colVals) |
| { |
| BigInteger valBI = new BigInteger(val.toString()); |
| column = (column.multiply(valBI)).mod(query.getNSquared()); |
| logger.debug("valBI = " + valBI.toString() + " column = " + column.toString()); |
| } |
| logger.debug("final column value = " + column.toString()); |
| outputValue.set(column.toString()); |
| mos.write(FileConst.PIR_COLS, colNum, outputValue); |
| } |
| |
| @Override |
| public void cleanup(Context ctx) throws IOException, InterruptedException |
| { |
| mos.close(); |
| } |
| } |