package org.paneris.bibliomania.fti;

 import org.melati.poem.transaction.ToTidyList;

 import org.melati.util.UnexpectedExceptionException;

 import com.sleepycat.db.DatabaseException;

 import com.sleepycat.db.Cursor;

 import com.sleepycat.db.DatabaseEntry;

 import com.sleepycat.db.LockMode;

 import com.sleepycat.db.OperationStatus;

 public class AnchorFinder implements ToTidyList.Closeable {

   private Cursor anchors;

   private DatabaseEntry text_index = DbUtils.userMemDatabaseEntry(IndexOther.textIdBytesLength);

   private DatabaseEntry anchor = DbUtils.userMemDatabaseEntry(IndexOther.wordTruncationLength);

   public AnchorFinder(IndexOther index, boolean blockmarkers) {

     try {

       anchors = (blockmarkers ? index.blockmarkOfIndex : index.anchorOfIndex).

                     openCursor(null, null);

     }

     catch (DatabaseException e) {

       throw new UnexpectedExceptionException(e);

     }

   }

   public AnchorFinder(IndexOther index) {

     this(index, false);

   }

   public synchronized String anchorOfIndex(long textID, int index)

       throws DatabaseException {

     IndexOther.setTI(text_index.getData(), textID, index);

     return

         anchors.getSearchKeyRange(text_index, anchor, LockMode.DEFAULT) == OperationStatus.SUCCESS &&

         anchors.getPrev(text_index, anchor, LockMode.DEFAULT) == OperationStatus.SUCCESS &&

         IndexOther.getTI_textID(text_index.getData()) == textID ?

           new String(anchor.getData(), 0, anchor.getSize()) : null;

   }

   public void close() {

     try {

       anchors.close();

     }

     catch (Exception e) {}

   } 

 }