package com.mongodb.hadoop.examples.sensors;
import com.mongodb.hadoop.io.MongoUpdateWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.Reducer;
import org.bson.BasicBSONObject;
import org.bson.types.ObjectId;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
public class DeviceReducer extends Reducer<Text, Text, NullWritable, MongoUpdateWritable>
implements org.apache.hadoop.mapred.Reducer<Text, Text, NullWritable, MongoUpdateWritable> {
@Override
public void reduce(final Text pKey, final Iterable<Text> pValues, final Context pContext) throws IOException, InterruptedException {
BasicBSONObject query = new BasicBSONObject("_id", pKey.toString());
ArrayList<ObjectId> devices = new ArrayList<ObjectId>();
for (Text val : pValues) {
devices.add(new ObjectId(val.toString()));
}
BasicBSONObject update = new BasicBSONObject("$pushAll", new BasicBSONObject("devices", devices));
pContext.write(null, new MongoUpdateWritable(query, update, true, false));
}
@Override
public void reduce(final Text key, final Iterator<Text> values, final OutputCollector<NullWritable, MongoUpdateWritable> output,
final Reporter reporter) throws IOException {
BasicBSONObject query = new BasicBSONObject("_id", key.toString());
ArrayList<ObjectId> devices = new ArrayList<ObjectId>();
while (values.hasNext()) {
Text val = values.next();
devices.add(new ObjectId(val.toString()));
}
BasicBSONObject update = new BasicBSONObject("$pushAll", new BasicBSONObject("devices", devices));
output.collect(null, new MongoUpdateWritable(query, update, true, false));
}
@Override
public void close() throws IOException {
}
@Override
public void configure(final JobConf job) {
}
}