com.bah.applefox.main.plugins.pageranking.utilities.DampenTable.java Source code

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Here is the source code for com.bah.applefox.main.plugins.pageranking.utilities.DampenTable.java

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/**
 * Copyright 2012 Booz Allen Hamilton. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Booz Allen Hamilton 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 com.bah.applefox.main.plugins.pageranking.utilities;

import java.io.IOException;

import org.apache.accumulo.core.client.mapreduce.AccumuloInputFormat;
import org.apache.accumulo.core.client.mapreduce.AccumuloOutputFormat;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Mutation;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.security.Authorizations;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.util.Tool;

import com.bah.applefox.main.plugins.utilities.IngestUtils;

/**
 * This class is used by page rank to "dampen" the table by the given value. The
 * dampening factor is equivalent to the probability that a user will continue
 * clicking links on a page at any given time. Generally .85 is used as the
 * dampening factor, but anything greater than 0 and less than 1 may be used.
 * 
 * 
 */
public class DampenTable extends Configured implements Tool {

    private static String tablePrefix;
    private static double dampeningFactor;
    private static Log log = LogFactory.getLog(DampenTable.class);

    public static class MapperClass extends Mapper<Key, Value, Key, Value> {

        @Override
        public void map(Key key, Value value, Context context) throws IOException, InterruptedException {
            // Pass the table elements to the reduce phase
            context.write(key, value);
        }
    }

    public static class ReducerClass extends Reducer<Key, Value, Text, Mutation> {

        public void reduce(Key key, Iterable<Value> values, Context context) {

            try {
                // Take in the value, dampen it, and re write it to the table.
                Double total = (Double) IngestUtils.deserialize(values.iterator().next().get());
                total = 1 - dampeningFactor + dampeningFactor * total;
                Mutation m = new Mutation(key.getRow());
                m.put("0", "0", new Value(IngestUtils.serialize(total)));
                context.write(new Text(tablePrefix + "New"), m);
            } catch (IOException e) {
                if (e.getMessage() != null) {
                    log.error(e.getMessage());
                } else {
                    log.error(e.getStackTrace());
                }
            } catch (InterruptedException e) {
                if (e.getMessage() != null) {
                    log.error(e.getMessage());
                } else {
                    log.error(e.getStackTrace());
                }
            } catch (ClassNotFoundException e) {
                if (e.getMessage() != null) {
                    log.error(e.getMessage());
                } else {
                    log.error(e.getStackTrace());
                }
            }
        }
    }

    public int run(String[] args) throws Exception {

        String jobName = this.getClass().getSimpleName() + "_" + System.currentTimeMillis();

        Job job = new Job(getConf(), jobName);
        job.setJarByClass(this.getClass());

        tablePrefix = args[13];
        dampeningFactor = Double.parseDouble(args[14]);

        job.setInputFormatClass(AccumuloInputFormat.class);
        AccumuloInputFormat.setZooKeeperInstance(job.getConfiguration(), args[0], args[1]);
        AccumuloInputFormat.setInputInfo(job.getConfiguration(), args[2], args[3].getBytes(), tablePrefix + "New",
                new Authorizations());

        job.setMapperClass(MapperClass.class);
        job.setMapOutputKeyClass(Key.class);
        job.setMapOutputValueClass(Value.class);

        job.setReducerClass(ReducerClass.class);
        job.setOutputFormatClass(AccumuloOutputFormat.class);
        job.setOutputKeyClass(Key.class);
        job.setOutputValueClass(Value.class);
        AccumuloOutputFormat.setZooKeeperInstance(job.getConfiguration(), args[0], args[1]);
        AccumuloOutputFormat.setOutputInfo(job.getConfiguration(), args[2], args[3].getBytes(), true,
                tablePrefix + "New");

        job.waitForCompletion(true);

        return job.isSuccessful() ? 0 : 1;
    }
}