/* 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 java.util.Iterator;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
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.graph.Vertex;
import com.intel.hadoop.graphbuilder.preprocess.inputformat.GraphTokenizer;
import com.intel.hadoop.graphbuilder.preprocess.mapreduce.keyvalue.VertexEdgeUnionType;
/**
* The Mapper class parses each input value provided by the {@code InputFormat},
* and outputs a list of {@code Vertex} and a list of {@code Edge} using a
* {@code GraphTokenizer}.
*
*/
public class CreateGraphMapper extends MapReduceBase implements
Mapper<LongWritable, Text, IntWritable, VertexEdgeUnionType> {
private static final Logger LOG = Logger.getLogger(CreateGraphMapper.class);
@Override
public void configure(JobConf job) {
super.configure(job);
try {
this.tokenizer = (GraphTokenizer) Class
.forName(job.get("GraphTokenizer")).newInstance();
tokenizer.configure(job);
this.valClass = job.getMapOutputValueClass();
mapVal = (VertexEdgeUnionType) 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<IntWritable, VertexEdgeUnionType> out, Reporter arg3)
throws IOException {
tokenizer.parse(value.toString());
Iterator<Edge> eiter = tokenizer.getEdges();
Iterator<Vertex> viter = tokenizer.getVertices();
try {
while (eiter.hasNext()) {
Edge e = eiter.next();
mapVal.init(VertexEdgeUnionType.EDGEVAL, e);
out.collect(new IntWritable(e.hashCode()), mapVal);
}
while (viter.hasNext()) {
Vertex v = viter.next();
mapVal.init(VertexEdgeUnionType.VERTEXVAL, v);
out.collect(new IntWritable(v.hashCode()), mapVal);
}
} catch (Exception e) {
e.printStackTrace();
}
}
private VertexEdgeUnionType mapVal;
private GraphTokenizer tokenizer;
protected Class valClass;
}