edu.yale.cs.hadoopdb.benchmark.UDFAggTaskDB.java Source code

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Here is the source code for edu.yale.cs.hadoopdb.benchmark.UDFAggTaskDB.java

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/**
 * Copyright 2009 HadoopDB Team (http://db.cs.yale.edu/hadoopdb/hadoopdb.html)
 *
 * Licensed 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 edu.yale.cs.hadoopdb.benchmark;

import java.io.IOException;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.mapred.lib.LongSumReducer;
import org.apache.hadoop.util.ToolRunner;

import edu.yale.cs.hadoopdb.connector.DBConst;
import edu.yale.cs.hadoopdb.connector.DBWritable;
import edu.yale.cs.hadoopdb.exec.DBJobBase;
import edu.yale.cs.hadoopdb.util.HDFSUtil;

/**
 * HadoopDB's implementation of UDF Aggregation Task
 * http://database.cs.brown.edu/projects/mapreduce-vs-dbms/
 */
public class UDFAggTaskDB extends DBJobBase {

    public static final String URL_PATTERN_STR = "<a href=\"http://([\\w./\\d]+\\.html)\">link</a>";

    protected static final Pattern URL_PATTERN = Pattern.compile(URL_PATTERN_STR, Pattern.CASE_INSENSITIVE);

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new UDFAggTaskDB(), args);
        System.exit(res);
    }

    @Override
    protected JobConf configureJob(String... args) throws IOException {

        JobConf conf = new JobConf(this.getClass());
        conf.setJobName("udf_agg_db");

        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(LongWritable.class);

        conf.setMapperClass(Query4Map.class);
        conf.setCombinerClass(LongSumReducer.class);
        conf.setReducerClass(LongSumReducer.class);
        conf.setOutputFormat(TextOutputFormat.class);

        if (args.length < 1) {
            throw new RuntimeException("Incorrect arguments provided for " + this.getClass());
        }

        // OUTPUT properties
        Path outputPath = new Path(args[0]);
        HDFSUtil.deletePath(outputPath);
        FileOutputFormat.setOutputPath(conf, outputPath);

        conf.set(DBConst.DB_RELATION_ID, "Documents");
        conf.set(DBConst.DB_RECORD_READER, DocumentRecord.class.getName());
        conf.set(DBConst.DB_SQL_QUERY, "SELECT url, contents FROM Documents;");

        return conf;

    }

    public static class Query4Map extends MapReduceBase
            implements Mapper<LongWritable, DocumentRecord, Text, LongWritable> {

        Text outputUrl = new Text();
        LongWritable outputPageRank1 = new LongWritable(1);

        public void map(LongWritable key, DocumentRecord value, OutputCollector<Text, LongWritable> output,
                Reporter reporter) throws IOException {

            String input = value.getContents();
            Matcher m = URL_PATTERN.matcher(input);

            while (m.find()) {
                String url = input.substring(m.start(1), m.end(1));

                outputUrl.set(url);
                output.collect(outputUrl, outputPageRank1);
            }
        }
    }

    @Override
    protected int printUsage() {
        System.out.println("<output_dir>");
        return -1;
    }

    static class DocumentRecord implements DBWritable {
        private String url;
        private String contents;

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        public String getContents() {
            return contents;
        }

        public void setContents(String contents) {
            this.contents = contents;
        }

        @Override
        public void readFields(ResultSet resultSet) throws SQLException {
            this.url = resultSet.getString("url");
            this.contents = resultSet.getString("contents");
        }

        @Override
        public void write(PreparedStatement statement) throws SQLException {
            throw new UnsupportedOperationException("No write() impl.");
        }
    }

}