lia.admin.ThreadedIndexWriter.java Source code

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Here is the source code for lia.admin.ThreadedIndexWriter.java

Source

package lia.admin;

/**
 * Copyright Manning Publications Co.
 *
 * 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 lan      
*/

import java.io.IOException;

import org.apache.lucene.store.Directory;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.Term;

import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.ArrayBlockingQueue;

// From chapter 11

/** Drop-in replacement for IndexWriter that uses multiple
 *  threads, under the hood, to index added documents. */

public class ThreadedIndexWriter extends IndexWriter {

    private ExecutorService threadPool;
    private Analyzer defaultAnalyzer;

    private class Job implements Runnable { //A
        Document doc;
        Analyzer analyzer;
        Term delTerm;

        public Job(Document doc, Term delTerm, Analyzer analyzer) {
            this.doc = doc;
            this.analyzer = analyzer;
            this.delTerm = delTerm;
        }

        public void run() { //B
            try {
                if (delTerm != null) {
                    ThreadedIndexWriter.super.updateDocument(delTerm, doc, analyzer);
                } else {
                    ThreadedIndexWriter.super.addDocument(doc, analyzer);
                }
            } catch (IOException ioe) {
                throw new RuntimeException(ioe);
            }
        }
    }

    public ThreadedIndexWriter(Directory dir, Analyzer a, boolean create, int numThreads, int maxQueueSize,
            IndexWriter.MaxFieldLength mfl) throws CorruptIndexException, IOException {
        super(dir, a, create, mfl);
        defaultAnalyzer = a;
        threadPool = new ThreadPoolExecutor( //C
                numThreads, numThreads, 0, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(maxQueueSize, false),
                new ThreadPoolExecutor.CallerRunsPolicy());
    }

    public void addDocument(Document doc) { //D
        threadPool.execute(new Job(doc, null, defaultAnalyzer)); //D
    } //D
      //D

    public void addDocument(Document doc, Analyzer a) { //D
        threadPool.execute(new Job(doc, null, a)); //D
    } //D
      //D

    public void updateDocument(Term term, Document doc) { //D
        threadPool.execute(new Job(doc, term, defaultAnalyzer)); //D
    } //D
      //D 

    public void updateDocument(Term term, Document doc, Analyzer a) { //D
        threadPool.execute(new Job(doc, term, a)); //D
    } //D

    public void close() throws CorruptIndexException, IOException {
        finish();
        super.close();
    }

    public void close(boolean doWait) throws CorruptIndexException, IOException {
        finish();
        super.close(doWait);
    }

    public void rollback() throws CorruptIndexException, IOException {
        finish();
        super.rollback();
    }

    private void finish() { //E
        threadPool.shutdown();
        while (true) {
            try {
                if (threadPool.awaitTermination(Long.MAX_VALUE, TimeUnit.SECONDS)) {
                    break;
                }
            } catch (InterruptedException ie) {
                Thread.currentThread().interrupt();
                throw new RuntimeException(ie);
            }
        }
    }
}

/*
#A Holds one document to be added
#B Does real work to add or update document
#C Create thread pool
#D Have thread pool execute job
#E Shuts down thread pool
*/