// BSD License (http://www.galagosearch.org/license)

 package org.galagosearch.core.index;

 import java.io.File;

 import java.io.FileNotFoundException;

 import java.io.IOException;

 import java.io.RandomAccessFile;

 import java.nio.ByteBuffer;

 import java.nio.channels.FileChannel;

 /**

  *

  * @author trevor

  */

 public class DocumentLengthsReader {

     RandomAccessFile file;

     FileChannel channel;

     ByteBuffer buffer;

     public DocumentLengthsReader(String filename) throws FileNotFoundException, IOException {

         file = new RandomAccessFile(new File(filename), "r");

         channel = file.getChannel();

         buffer = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());

     }

     public void close() throws IOException {

         channel.close();

         file.close();

     }

     public int getLength(int document) {

         return buffer.getInt(document*4);

     }

 }