org.apache.nutch.searcher.LuceneSearchBean.java Source code

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Here is the source code for org.apache.nutch.searcher.LuceneSearchBean.java

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/**
 * 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.searcher;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.ArchiveParallelReader;
import org.apache.lucene.index.MultiReader;

import org.apache.nutch.indexer.FsDirectory;
import org.apache.nutch.indexer.Indexer;
import org.apache.nutch.util.HadoopFSUtil;

public class LuceneSearchBean implements RPCSearchBean {

    public static final long VERSION = 1L;

    private IndexSearcher searcher;

    private FileSystem fs;

    private Configuration conf;

    /**
     * Construct in a named directory.
     * @param conf
     * @param dir
     * @throws IOException
     */
    public LuceneSearchBean(Configuration conf, Path pindexesDir, Path indexDir, Path indexesDir)
            throws IOException {
        this.conf = conf;
        this.fs = FileSystem.get(this.conf);
        init(pindexesDir, indexDir, indexesDir);
    }

    private void init(Path pindexesDir, Path indexDir, Path indexesDir) throws IOException {

        IndexReader reader = getIndexReader(pindexesDir);

        if (reader != null) {
            this.searcher = new IndexSearcher(reader, this.conf);
        } else {
            if (this.fs.exists(indexDir)) {
                LOG.info("opening merged index in " + indexDir);
                this.searcher = new IndexSearcher(indexDir, this.conf);
            } else {
                LOG.info("opening indexes in " + indexesDir);

                List<Path> vDirs = new ArrayList<Path>();
                FileStatus[] fstats = fs.listStatus(indexesDir, HadoopFSUtil.getPassDirectoriesFilter(fs));
                Path[] directories = HadoopFSUtil.getPaths(fstats);
                for (int i = 0; i < directories.length; i++) {
                    Path indexdone = new Path(directories[i], Indexer.DONE_NAME);
                    if (fs.isFile(indexdone)) {
                        vDirs.add(directories[i]);
                    }
                }

                directories = new Path[vDirs.size()];
                for (int i = 0; vDirs.size() > 0; i++) {
                    directories[i] = vDirs.remove(0);
                }

                this.searcher = new IndexSearcher(directories, this.conf);
            }
        }
    }

    public Hits search(Query query, int numHits, String dedupField, String sortField, boolean reverse)
            throws IOException {
        return searcher.search(query, numHits, dedupField, sortField, reverse);
    }

    public String getExplanation(Query query, Hit hit) throws IOException {
        return searcher.getExplanation(query, hit);
    }

    public HitDetails getDetails(Hit hit) throws IOException {
        return searcher.getDetails(hit);
    }

    public HitDetails[] getDetails(Hit[] hits) throws IOException {
        return searcher.getDetails(hits);
    }

    public boolean ping() throws IOException {
        return true;
    }

    public void close() throws IOException {
        if (searcher != null) {
            searcher.close();
        }
        if (fs != null) {
            fs.close();
        }
    }

    public long getProtocolVersion(String protocol, long clientVersion) throws IOException {
        return VERSION;
    }

    private IndexReader getIndexReader(Path pindexesDir) throws IOException {
        /*
        FileSystem fs = FileSystem.get( conf );
            
        Path dir = new Path( conf.get( "searcher.dir", "crawl") ).makeQualified( fs );
        LOG.info( "Looking for Nutch indexes in: " + dir );
        if ( ! fs.exists( dir ) )
          {
            LOG.warn( "Directory does not exist: " + dir );
            LOG.warn( "No Nutch indexes will be found and all queries will return no results." );
                
            return false;
          }
            
          Path pindexesDir = new Path( dir, "pindexes" ).makeQualified(fs);
        */

        LOG.info("Looking for NutchWax parallel indexes in: " + pindexesDir);
        if (!fs.exists(pindexesDir)) {
            LOG.warn("Parallel indexes directory does not exist: " + pindexesDir);

            return null;
        }

        if (!fs.getFileStatus(pindexesDir).isDir()) {
            LOG.warn("Parallel indexes directory is not a directory: " + pindexesDir);

            return null;
        }

        FileStatus[] fstats = fs.listStatus(pindexesDir, HadoopFSUtil.getPassDirectoriesFilter(fs));
        Path[] indexDirs = HadoopFSUtil.getPaths(fstats);

        if (indexDirs.length < 1) {
            LOG.info("No sub-dirs found in parallel indexes directory: " + pindexesDir);

            return null;
        }

        List<IndexReader> readers = new ArrayList<IndexReader>(indexDirs.length);

        for (Path indexDir : indexDirs) {
            fstats = fs.listStatus(indexDir, HadoopFSUtil.getPassDirectoriesFilter(fs));
            Path parallelDirs[] = HadoopFSUtil.getPaths(fstats);

            if (parallelDirs.length < 1) {
                LOG.info("No sub-directories, skipping: " + indexDir);

                continue;
            }

            ArchiveParallelReader reader = new ArchiveParallelReader();

            // Sort the parallelDirs so that we add them in order.  Order
            // matters to the ParallelReader.
            Arrays.sort(parallelDirs);

            for (Path p : parallelDirs) {
                LOG.info("Adding reader for: " + p);
                reader.add(IndexReader.open(new FsDirectory(fs, p, false, conf)));
            }

            readers.add(reader);
        }

        if (readers.size() == 0) {
            LOG.warn("No parallel indexes in: " + pindexesDir);

            return null;
        }

        MultiReader reader = new MultiReader(readers.toArray(new IndexReader[0]));

        return reader;
    }

}