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

 package org.galagosearch.core.parse;

 import java.io.FileNotFoundException;

 import java.io.IOException;

 import org.galagosearch.core.types.DocumentSplit;

 import org.galagosearch.tupleflow.Utility;

 /**

  * Reads Document data from an index file.  Typically you'd use this parser by

  * including UniversalParser in a TupleFlow Job.

  * 

  * @author trevor

  */

 public class IndexReaderSplitParser implements DocumentStreamParser {

     DocumentIndexReader.Iterator iterator;

     DocumentSplit split;

     public IndexReaderSplitParser(DocumentSplit split) throws FileNotFoundException, IOException {

         DocumentIndexReader reader = new DocumentIndexReader(split.fileName);

         iterator = reader.getIterator();

         iterator.skipTo(split.startKey);

         this.split = split;

     }

     public Document nextDocument() throws IOException {

         if (iterator.isDone()) {

             return null;

         }

         String key = iterator.getKey();

         byte[] keyBytes = Utility.makeBytes(key);

         // Don't go past the end of the split.

         if (split.endKey.length > 0 && Utility.compare(keyBytes, split.endKey) >= 0) {

             return null;

         }

         Document document = iterator.getDocument();

         iterator.nextDocument();

         return document;

     }

 }