/* Copyright (C) 2012 Intel Corporation.
* All rights reserved.
*
* 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.
*
* For more about this software visit:
* http://www.01.org/GraphBuilder
*/
package com.intel.hadoop.graphbuilder.preprocess.mapreduce;
import java.io.IOException;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
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.log4j.Logger;
import com.intel.hadoop.graphbuilder.graph.Edge;
import com.intel.hadoop.graphbuilder.parser.FieldParser;
import com.intel.hadoop.graphbuilder.parser.GraphParser;
import com.intel.hadoop.graphbuilder.preprocess.mapreduce.keyvalue.PairListType;
/**
* This Mapper class maps each edge (u,v,data) into (u, (v, data)) or (v, (u,
* data)) based on {@code reduceEndPoint} parameter in the JobConf configured in
* {@code EdgeTrandFormMR}.
*
*
* @param <VidType>
*/
public class EdgeTransformMapper<VidType extends WritableComparable<VidType>>
extends MapReduceBase implements
Mapper<LongWritable, Text, VidType, PairListType> {
private static final Logger LOG = Logger.getLogger(EdgeTransformMapper.class);
@Override
public void configure(JobConf job) {
super.configure(job);
this.reduceEndPoint = job.getBoolean("reduceEndPoint",
EdgeTransformMR.SOURCE);
try {
this.graphparser = (GraphParser) Class.forName(job.get("GraphParser"))
.newInstance();
this.vidparser = (FieldParser) Class.forName(job.get("VidParser"))
.newInstance();
this.edataparser = (FieldParser) Class.forName(job.get("EdataParser"))
.newInstance();
this.valClass = job.getMapOutputValueClass();
val = (PairListType) valClass.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
@Override
public void map(LongWritable key, Text value,
OutputCollector<VidType, PairListType> out, Reporter report)
throws IOException {
String line = value.toString();
try {
if (graphparser.isEdgeData(line)) {
Edge e = graphparser.parseEdge(line, vidparser, edataparser);
if (reduceEndPoint == EdgeTransformMR.SOURCE) {
val.init(e.target(), e.EdgeData());
out.collect((VidType) e.source(), val);
} else {
val.init(e.source(), e.EdgeData());
out.collect((VidType) e.target(), val);
}
} else {
LOG.error("Skip line: " + line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
private PairListType val;
private GraphParser graphparser;
private FieldParser vidparser;
private FieldParser edataparser;
protected Class valClass;
private boolean reduceEndPoint;
}