package org.apache.lucene.index.store;

/**
 * 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.File;
import java.io.IOException;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.ByteArrayOutputStream;


import junit.framework.TestCase;

import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.English;

import org.apache.lucene.store.MockRAMDirectory;

/**
 * JUnit testcase to test RAMDirectory. RAMDirectory itself is used in many testcases,
 * but not one of them uses an different constructor other than the default constructor.
 * 
 * @author Bernhard Messer
 * 
 * @version $Id: RAMDirectory.java 150537 2004-09-28 22:45:26 +0200 (Di, 28 Sep 2004) cutting $
 */
public class TestRAMDirectory extends TestCase {
  
  private File indexDir = null;
  
  // add enough document so that the index will be larger than RAMDirectory.READ_BUFFER_SIZE
  private final int docsToAdd = 500;
  
  // setup the index
  public void setUp () throws IOException {
    String tempDir = System.getProperty("java.io.tmpdir");
    if (tempDir == null)
      throw new IOException("java.io.tmpdir undefined, cannot run test");
    indexDir = new File(tempDir, "RAMDirIndex");
    
    IndexWriter writer  = new IndexWriter(indexDir, new WhitespaceAnalyzer(), true);
    // add some documents
    Document doc = null;
    for (int i = 0; i < docsToAdd; i++) {
      doc = new Document();
      doc.add(new Field("content", English.intToEnglish(i).trim(), Field.Store.YES, Field.Index.UN_TOKENIZED));
      writer.addDocument(doc);
    }
    assertEquals(docsToAdd, writer.docCount());
    writer.close();
  }
  
  public void testRAMDirectory () throws IOException {
    
    Directory dir = FSDirectory.getDirectory(indexDir);
    MockRAMDirectory ramDir = new MockRAMDirectory(dir);
    
    // close the underlaying directory
    dir.close();
    
    // Check size
    assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
    
    // open reader to test document count
    IndexReader reader = IndexReader.open(ramDir);
    assertEquals(docsToAdd, reader.numDocs());
    
    // open search zo check if all doc's are there
    IndexSearcher searcher = new IndexSearcher(reader);
    
    // search for all documents
    for (int i = 0; i < docsToAdd; i++) {
      Document doc = searcher.doc(i);
      assertTrue(doc.getField("content") != null);
    }

    // cleanup
    reader.close();
    searcher.close();
  }

  public void testRAMDirectoryFile () throws IOException {
    
    MockRAMDirectory ramDir = new MockRAMDirectory(indexDir);
    
    // Check size
    assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
    
    // open reader to test document count
    IndexReader reader = IndexReader.open(ramDir);
    assertEquals(docsToAdd, reader.numDocs());
    
    // open search zo check if all doc's are there
    IndexSearcher searcher = new IndexSearcher(reader);
    
    // search for all documents
    for (int i = 0; i < docsToAdd; i++) {
      Document doc = searcher.doc(i);
      assertTrue(doc.getField("content") != null);
    }

    // cleanup
    reader.close();
    searcher.close();
  }
  
  public void testRAMDirectoryString () throws IOException {
    
    MockRAMDirectory ramDir = new MockRAMDirectory(indexDir.getCanonicalPath());
    
    // Check size
    assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
    
    // open reader to test document count
    IndexReader reader = IndexReader.open(ramDir);
    assertEquals(docsToAdd, reader.numDocs());
    
    // open search zo check if all doc's are there
    IndexSearcher searcher = new IndexSearcher(reader);
    
    // search for all documents
    for (int i = 0; i < docsToAdd; i++) {
      Document doc = searcher.doc(i);
      assertTrue(doc.getField("content") != null);
    }

    // cleanup
    reader.close();
    searcher.close();
  }
  
  private final int numThreads = 50;
  private final int docsPerThread = 40;
  
  public void testRAMDirectorySize() throws IOException, InterruptedException {
      
    final MockRAMDirectory ramDir = new MockRAMDirectory(indexDir.getCanonicalPath());
    final IndexWriter writer  = new IndexWriter(ramDir, new WhitespaceAnalyzer(), false);
    writer.optimize();
    
    assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
    
    Thread[] threads = new Thread[numThreads];
    for (int i=0; i<numThreads; i++) {
      final int num = i;
      threads[i] = new Thread(){
        public void run() {
          for (int j=1; j<docsPerThread; j++) {
            Document doc = new Document();
            doc.add(new Field("sizeContent", English.intToEnglish(num*docsPerThread+j).trim(), Field.Store.YES, Field.Index.UN_TOKENIZED));
            try {
              writer.addDocument(doc);
            } catch (IOException e) {
              throw new RuntimeException(e);
            }
            synchronized (ramDir) {
              assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
            }
          }
        }
      };
    }
    for (int i=0; i<numThreads; i++)
      threads[i].start();
    for (int i=0; i<numThreads; i++)
      threads[i].join();

    writer.optimize();
    assertEquals(ramDir.sizeInBytes(), ramDir.getRecomputedSizeInBytes());
    
    writer.close();
  }


  public void testSerializable() throws IOException {
    Directory dir = new RAMDirectory();
    ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
    assertEquals("initially empty", 0, bos.size());
    ObjectOutput out = new ObjectOutputStream(bos);
    int headerSize = bos.size();
    out.writeObject(dir);
    out.close();
    assertTrue("contains more then just header", headerSize < bos.size());
  } 

  public void tearDown() {
    // cleanup 
    if (indexDir != null && indexDir.exists()) {
      rmDir (indexDir);
    }
  }
  
  private void rmDir(File dir) {
    File[] files = dir.listFiles();
    for (int i = 0; i < files.length; i++) {
      files[i].delete();
    }
    dir.delete();
  }
}