org.cloudata.examples.weblink.InLinkJob.java Source code

Introduction

Here is the source code for org.cloudata.examples.weblink.InLinkJob.java

Source

/**
 * 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.cloudata.examples.weblink;

import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.cloudata.core.client.CTable;
import org.cloudata.core.client.Cell;
import org.cloudata.core.client.Row;
import org.cloudata.core.common.conf.CloudataConf;
import org.cloudata.core.fs.CloudataFileSystem;
import org.cloudata.core.fs.GPath;
import org.cloudata.core.parallel.hadoop.CloudataMapReduceUtil;
import org.cloudata.core.parallel.hadoop.DefaultTabletInputFormat;
import org.cloudata.core.tablet.TableSchema;

public class InLinkJob {
    static Log LOG = LogFactory.getLog(InLinkJob.class.getName());

    public static void main(String[] args) throws IOException {
        if (args.length < 2) {
            System.out.println("Usage: java InLinkJob <input table> <output table>");
            System.exit(0);
        }

        String inputTableName = args[0];
        String outputTableName = args[1];

        CloudataConf nconf = new CloudataConf();
        if (!CTable.existsTable(nconf, outputTableName)) {
            TableSchema tableSchema = new TableSchema(outputTableName);
            tableSchema.addColumn("inlink");

            CTable.createTable(nconf, tableSchema);
        }

        Path tempPath = new Path("InLinkJob_tmp" + System.currentTimeMillis());

        JobConf jobConf = new JobConf(InLinkJob.class);
        String libDir = CloudataMapReduceUtil.initMapReduce(jobConf);

        //<Map>
        jobConf.setMapperClass(InLinkMap.class);
        jobConf.setInputFormat(DefaultTabletInputFormat.class);
        jobConf.set(DefaultTabletInputFormat.INPUT_TABLE, inputTableName);
        jobConf.set(DefaultTabletInputFormat.INPUT_COLUMN_LIST, "outlink");
        jobConf.setMapOutputKeyClass(Text.class);
        jobConf.setMapOutputValueClass(TextArray.class);
        //</Map>

        //<Reduce>
        FileOutputFormat.setOutputPath(jobConf, tempPath);
        jobConf.setReducerClass(InLinkReduce.class);
        jobConf.set(DefaultTabletInputFormat.OUTPUT_TABLE, outputTableName);
        //</Reduce>

        try {
            JobClient.runJob(jobConf);
        } finally {
            CloudataFileSystem fs = CloudataFileSystem.get(nconf);
            fs.delete(new GPath(tempPath.toString()), true);
            CloudataMapReduceUtil.clearMapReduce(libDir);
        }
    }

    static class InLinkMap implements Mapper<Row.Key, Row, Text, TextArray> {
        @Override
        public void map(Row.Key key, Row value, OutputCollector<Text, TextArray> output, Reporter reporter)
                throws IOException {
            //outlink.hashCode -> row.outlink.anchor_text, rowkey

            List<Cell> outlinks = value.getFirstColumnCells();
            if (outlinks == null || outlinks.size() == 0) {
                return;
            }

            for (Cell eachLink : outlinks) {
                output.collect(new Text(eachLink.getKey().toString()), new TextArray(
                        new Text[] { new Text(eachLink.getValue().toString()), new Text(key.toString()) }));
            }
        }

        @Override
        public void configure(JobConf job) {
        }

        @Override
        public void close() throws IOException {
        }
    }

    static class InLinkReduce implements Reducer<Text, TextArray, Text, Text> {
        private CTable ctable;
        private IOException exception;

        @Override
        public void reduce(Text key, Iterator<TextArray> values, OutputCollector<Text, Text> output,
                Reporter reporter) throws IOException {
            if (exception != null) {
                throw exception;
            }
            Row.Key rowKey = new Row.Key(key.toString());

            Row row = new Row(rowKey);
            int count = 0;

            long timestamp = System.currentTimeMillis();
            while (values.hasNext()) {
                TextArray value = values.next();

                String anchorText = value.get(0).toString();
                String inlink = value.get(1).toString();

                row.addCell("inlink", new Cell(new Cell.Key(anchorText), inlink.getBytes(), timestamp));
                timestamp++;
                count++;

                if (count > 100) {
                    ctable.put(row, false);
                    row = new Row(rowKey);
                    count = 0;
                }
            }

            if (count > 0) {
                ctable.put(row, false);
            }
        }

        @Override
        public void configure(JobConf job) {
            try {
                ctable = CTable.openTable(new CloudataConf(), DefaultTabletInputFormat.OUTPUT_TABLE);
            } catch (IOException e) {
                exception = e;
            }
        }

        @Override
        public void close() throws IOException {
        }
    }
}