Lucene example source code file (TestTransactions.java)

This example Lucene source code file (TestTransactions.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

concurrentmergescheduler, directory, directory, document, indexerthread, indexwriter, io, mockdirectorywrapper, override, searcherthread, searcherthread, throwable, throwable, timedthread, timedthread

The Lucene TestTransactions.java source code

package org.apache.lucene.index;

/**
 * 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.
 */

import java.io.IOException;

import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.MockDirectoryWrapper;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.English;
import org.apache.lucene.util.LuceneTestCase;

public class TestTransactions extends LuceneTestCase {
  
  private static volatile boolean doFail;

  private class RandomFailure extends MockDirectoryWrapper.Failure {
    @Override
    public void eval(MockDirectoryWrapper dir) throws IOException {
      if (TestTransactions.doFail && random.nextInt() % 10 <= 3)
        throw new IOException("now failing randomly but on purpose");
    }
  }

  private static abstract class TimedThread extends Thread {
    volatile boolean failed;
    private static float RUN_TIME_SEC = 0.5f * RANDOM_MULTIPLIER;
    private TimedThread[] allThreads;

    abstract public void doWork() throws Throwable;

    TimedThread(TimedThread[] threads) {
      this.allThreads = threads;
    }

    @Override
    public void run() {
      final long stopTime = System.currentTimeMillis() + (long) (1000*RUN_TIME_SEC);

      try {
        do {
          if (anyErrors()) break;
          doWork();
        } while (System.currentTimeMillis() < stopTime);
      } catch (Throwable e) {
        System.out.println(Thread.currentThread() + ": exc");
        e.printStackTrace(System.out);
        failed = true;
      }
    }

    private boolean anyErrors() {
      for(int i=0;i<allThreads.length;i++)
        if (allThreads[i] != null && allThreads[i].failed)
          return true;
      return false;
    }
  }

  private class IndexerThread extends TimedThread {
    Directory dir1;
    Directory dir2;
    Object lock;
    int nextID;

    public IndexerThread(Object lock, Directory dir1, Directory dir2, TimedThread[] threads) {
      super(threads);
      this.lock = lock;
      this.dir1 = dir1;
      this.dir2 = dir2;
    }

    @Override
    public void doWork() throws Throwable {

      IndexWriter writer1 = new IndexWriter(
          dir1,
          newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random)).
              setMaxBufferedDocs(3).
              setMergeScheduler(new ConcurrentMergeScheduler()).
              setMergePolicy(newLogMergePolicy(2))
      );
      ((ConcurrentMergeScheduler) writer1.getConfig().getMergeScheduler()).setSuppressExceptions();

      // Intentionally use different params so flush/merge
      // happen @ different times
      IndexWriter writer2 = new IndexWriter(
          dir2,
          newIndexWriterConfig( TEST_VERSION_CURRENT, new MockAnalyzer(random)).
              setMaxBufferedDocs(2).
              setMergeScheduler(new ConcurrentMergeScheduler()).
              setMergePolicy(newLogMergePolicy(3))
      );
      ((ConcurrentMergeScheduler) writer2.getConfig().getMergeScheduler()).setSuppressExceptions();

      update(writer1);
      update(writer2);

      TestTransactions.doFail = true;
      try {
        synchronized(lock) {
          try {
            writer1.prepareCommit();
          } catch (Throwable t) {
            writer1.rollback();
            writer2.rollback();
            return;
          }
          try {
            writer2.prepareCommit();
          } catch (Throwable t) { 	
            writer1.rollback();
            writer2.rollback();
            return;
          }

          writer1.commit();
          writer2.commit();
        }
      } finally {
        TestTransactions.doFail = false;
      }  

      writer1.close();
      writer2.close();
    }

    public void update(IndexWriter writer) throws IOException {
      // Add 10 docs:
      for(int j=0; j<10; j++) {
        Document d = new Document();
        int n = random.nextInt();
        d.add(newField("id", Integer.toString(nextID++), Field.Store.YES, Field.Index.NOT_ANALYZED));
        d.add(newField("contents", English.intToEnglish(n), Field.Store.NO, Field.Index.ANALYZED));
        writer.addDocument(d);
      }

      // Delete 5 docs:
      int deleteID = nextID-1;
      for(int j=0; j<5; j++) {
        writer.deleteDocuments(new Term("id", ""+deleteID));
        deleteID -= 2;
      }
    }
  }

  private static class SearcherThread extends TimedThread {
    Directory dir1;
    Directory dir2;
    Object lock;

    public SearcherThread(Object lock, Directory dir1, Directory dir2, TimedThread[] threads) {
      super(threads);
      this.lock = lock;
      this.dir1 = dir1;
      this.dir2 = dir2;
    }

    @Override
    public void doWork() throws Throwable {
      IndexReader r1, r2;
      synchronized(lock) {
        r1 = IndexReader.open(dir1, true);
        r2 = IndexReader.open(dir2, true);
      }
      if (r1.numDocs() != r2.numDocs())
        throw new RuntimeException("doc counts differ: r1=" + r1.numDocs() + " r2=" + r2.numDocs());
      r1.close();
      r2.close();
    }
  }

  public void initIndex(Directory dir) throws Throwable {
    IndexWriter writer = new IndexWriter(dir, newIndexWriterConfig( TEST_VERSION_CURRENT, new MockAnalyzer(random)));
    for(int j=0; j<7; j++) {
      Document d = new Document();
      int n = random.nextInt();
      d.add(newField("contents", English.intToEnglish(n), Field.Store.NO, Field.Index.ANALYZED));
      writer.addDocument(d);
    }
    writer.close();
  }

  public void testTransactions() throws Throwable {
    // we cant use non-ramdir on windows, because this test needs to double-write.
    MockDirectoryWrapper dir1 = new MockDirectoryWrapper(random, new RAMDirectory());
    MockDirectoryWrapper dir2 = new MockDirectoryWrapper(random, new RAMDirectory());
    dir1.setPreventDoubleWrite(false);
    dir2.setPreventDoubleWrite(false);
    dir1.failOn(new RandomFailure());
    dir2.failOn(new RandomFailure());

    initIndex(dir1);
    initIndex(dir2);

    TimedThread[] threads = new TimedThread[3];
    int numThread = 0;

    IndexerThread indexerThread = new IndexerThread(this, dir1, dir2, threads);
    threads[numThread++] = indexerThread;
    indexerThread.start();

    SearcherThread searcherThread1 = new SearcherThread(this, dir1, dir2, threads);
    threads[numThread++] = searcherThread1;
    searcherThread1.start();

    SearcherThread searcherThread2 = new SearcherThread(this, dir1, dir2, threads);
    threads[numThread++] = searcherThread2;
    searcherThread2.start();

    for(int i=0;i<numThread;i++)
      threads[i].join();

    for(int i=0;i<numThread;i++)
      assertTrue(!threads[i].failed);
    dir1.close();
    dir2.close();
  }
}