/*
* Hibernate Search, full-text search for your domain model
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.search.query.engine.spi;
import java.io.Closeable;
import java.io.IOException;
import org.apache.lucene.search.TopDocs;
/**
* DocumentExtractor is a traverser over the full-text results (EntityInfo)
*
* This operation is as lazy as possible:
* - the query is executed eagerly
* - results are not retrieved until actually requested
*
* {@link #getFirstIndex()} and {@link #getMaxIndex()} define the boundaries available to {@link #extract(int)}.
*
* DocumentExtractor objects *must* be closed when the results are no longer traversed. See {@link #close()}
*
* @author Emmanuel Bernard
*/
public interface DocumentExtractor extends Closeable {
/**
* Retrieves entity information for the result at the given index.
*
* @param index The requested result index.
* @return The entity information for the requested result.
* @throws IOException if an error occurs while extracting the results.
*/
EntityInfo extract(int index) throws IOException;
int getFirstIndex();
int getMaxIndex();
@Override
void close();
/**
* @hsearch.experimental We are thinking at ways to encapsulate needs for exposing TopDocs (and whether or not it makes sense)
* Try to avoid it if you can
* @return {@link TopDocs} instance
*/
TopDocs getTopDocs();
}