/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.nutch.crawl;
import java.io.IOException;
// Commons Logging imports
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.*;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.mapred.lib.HashPartitioner;
import org.apache.hadoop.util.*;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.nutch.util.NutchJob;
import org.apache.nutch.util.TimingUtil;
import java.text.SimpleDateFormat;
import java.util.Iterator;
import java.io.Closeable;
/** . */
public class LinkDbReader extends Configured implements Tool, Closeable {
public static final Logger LOG = LoggerFactory.getLogger(LinkDbReader.class);
private static final Partitioner<WritableComparable<?>, Writable> PARTITIONER = new HashPartitioner<WritableComparable<?>, Writable>();
private FileSystem fs;
private Path directory;
private MapFile.Reader[] readers;
public LinkDbReader() {
}
public LinkDbReader(Configuration conf, Path directory) throws Exception {
setConf(conf);
init(directory);
}
public void init(Path directory) throws Exception {
this.fs = FileSystem.get(getConf());
this.directory = directory;
}
public String[] getAnchors(Text url) throws IOException {
Inlinks inlinks = getInlinks(url);
if (inlinks == null)
return null;
return inlinks.getAnchors();
}
public Inlinks getInlinks(Text url) throws IOException {
if (readers == null) {
synchronized(this) {
readers = MapFileOutputFormat.getReaders
(fs, new Path(directory, LinkDb.CURRENT_NAME), getConf());
}
}
return (Inlinks)MapFileOutputFormat.getEntry
(readers, PARTITIONER, url, new Inlinks());
}
public void close() throws IOException {
if (readers != null) {
for (int i = 0; i < readers.length; i++) {
readers[i].close();
}
}
}
public void processDumpJob(String linkdb, String output) throws IOException {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
long start = System.currentTimeMillis();
if (LOG.isInfoEnabled()) {
LOG.info("LinkDb dump: starting at " + sdf.format(start));
LOG.info("LinkDb dump: db: " + linkdb);
}
Path outFolder = new Path(output);
JobConf job = new NutchJob(getConf());
job.setJobName("read " + linkdb);
FileInputFormat.addInputPath(job, new Path(linkdb, LinkDb.CURRENT_NAME));
job.setInputFormat(SequenceFileInputFormat.class);
FileOutputFormat.setOutputPath(job, outFolder);
job.setOutputFormat(TextOutputFormat.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Inlinks.class);
JobClient.runJob(job);
long end = System.currentTimeMillis();
LOG.info("LinkDb dump: finished at " + sdf.format(end) + ", elapsed: " + TimingUtil.elapsedTime(start, end));
}
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(NutchConfiguration.create(), new LinkDbReader(), args);
System.exit(res);
}
public int run(String[] args) throws Exception {
if (args.length < 2) {
System.err.println("Usage: LinkDbReader <linkdb> (-dump <out_dir> | -url <url>)");
System.err.println("\t-dump <out_dir>\tdump whole link db to a text file in <out_dir>");
System.err.println("\t-url <url>\tprint information about <url> to System.out");
return -1;
}
try {
if (args[1].equals("-dump")) {
processDumpJob(args[0], args[2]);
return 0;
} else if (args[1].equals("-url")) {
init(new Path(args[0]));
Inlinks links = getInlinks(new Text(args[2]));
if (links == null) {
System.out.println(" - no link information.");
} else {
Iterator<Inlink> it = links.iterator();
while (it.hasNext()) {
System.out.println(it.next().toString());
}
}
return 0;
} else {
System.err.println("Error: wrong argument " + args[1]);
return -1;
}
} catch (Exception e) {
LOG.error("LinkDbReader: " + StringUtils.stringifyException(e));
return -1;
}
}
}