/*
* Cloud9: A Hadoop toolkit for working with big data
*
* 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 edu.umd.cloud9.collection.clue;
import java.io.IOException;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import com.google.common.collect.Lists;
public class ScanBlockCompressedSequenceFile {
public static void main(String[] args) throws IOException {
if (args.length != 1) {
System.out.println("usage: [SequenceFile]");
System.exit(-1);
}
List<Long> seekPoints = Lists.newArrayList();
long pos = -1;
long prevPos = -1;
int prevDocno = 0;
Path path = new Path(args[0]);
Configuration config = new Configuration();
SequenceFile.Reader reader = new SequenceFile.Reader(config, SequenceFile.Reader.file(path));
IntWritable key = new IntWritable();
ClueWarcRecord value = new ClueWarcRecord();
pos = reader.getPosition();
int cnt = 0;
while (reader.next(key, value)) {
if (prevPos != -1 && prevPos != pos) {
System.out.println("## beginning of block at " + prevPos + ", docno:" + prevDocno);
seekPoints.add(prevPos);
}
System.out.println("offset:" + pos + "\tdocno:" + key + "\tdocid:" + value.getDocid());
prevPos = pos;
pos = reader.getPosition();
prevDocno = key.get();
cnt++;
if (cnt > Integer.MAX_VALUE)
break;
}
reader.close();
reader = new SequenceFile.Reader(config, SequenceFile.Reader.file(path));
for (long p : seekPoints) {
reader.seek(p);
reader.next(key, value);
System.out.println("seeking to pos " + p + "\tdocno:" + key + "\tdocid:" + value.getDocid());
}
reader.close();
}
}