/*
* Copyright 2010-2013 10gen Inc.
*
* 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 com.mongodb.hadoop.mapred.input;
import com.mongodb.hadoop.input.BSONFileSplit;
import com.mongodb.hadoop.io.BSONWritable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.RecordReader;
import java.io.IOException;
public class BSONFileRecordReader implements RecordReader<NullWritable, BSONWritable> {
public static final long BSON_RR_POSITION_NOT_GIVEN = -1L;
private final com.mongodb.hadoop.input.BSONFileRecordReader delegate;
private long pos = 0;
public BSONFileRecordReader() {
this(BSON_RR_POSITION_NOT_GIVEN);
}
public BSONFileRecordReader(final long startingPosition) {
delegate =
new com.mongodb.hadoop.input.BSONFileRecordReader(startingPosition);
}
/**
* Initialize the RecordReader with an InputSplit and a Configuration.
* Note that this method is not called from within Hadoop as in
* {@link com.mongodb.hadoop.input.BSONFileRecordReader}; it exists for
* consistency.
*
* @param inputSplit the FileSplit over which to iterate BSONWritables.
* @param conf the job's Configuration.
* @throws IOException when there is an error opening the file
*/
public void initialize(final InputSplit inputSplit, final Configuration conf)
throws IOException {
FileSplit fileSplit = (FileSplit) inputSplit;
try {
delegate.init(
new BSONFileSplit(
fileSplit.getPath(), fileSplit.getStart(),
fileSplit.getLength(), fileSplit.getLocations()), conf);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
@Override
public boolean next(final NullWritable key, final BSONWritable value)
throws IOException {
try {
boolean result = delegate.nextKeyValue();
value.setDoc(delegate.getCurrentValue());
pos++;
return result;
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
@Override
public float getProgress() throws IOException {
try {
return delegate.getProgress();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
@Override
public long getPos() throws IOException {
return pos;
}
@Override
public NullWritable createKey() {
return NullWritable.get();
}
@Override
public BSONWritable createValue() {
return new BSONWritable();
}
@Override
public void close() throws IOException {
delegate.close();
}
}