/*
* Copyright (c) 2002-2009 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.index;
import java.util.Iterator;
/**
* An {@link Iterator} with additional {@link #size()} and {@link #close()}
* methods on it, used for iterating over index query results. It is first and
* foremost an {@link Iterator}, but also an {@link Iterable} JUST so that it
* can be used in a for-each loop. The <code>iterator()</code> method
* <i>always</i> returns <code>this</code>.
*
* The size is calculated before-hand so that calling it's always fast.
*
* When you're done with your result and haven't reached the end of the
* iteration you must call {@link #close()}. Results which are looped through
* entirely closes automatically.
*
* @param <T> the type of items in the Iterator.
*/
public interface IndexHits<T> extends Iterator<T>, Iterable<T>
{
/**
* Returns the size of this iterable. The size is given at construction time
* so that the size is known before-hand so that it's basically just a
* simple return statement of an integer variable.
*
* @return the size if this iterable.
*/
int size();
/**
* Closes the underlying search result. This method should be called
* whenever you've got what you wanted from the result and won't use it
* anymore. It's necessary to call it so that underlying indexes can dispose
* of allocated resources for this search result.
*
* You can however skip to call this method if you loop through the whole
* result, then close() will be called automatically. Even if you loop
* through the entire result and then call this method it will silently
* ignore any consequtive call (for convenience).
*/
void close();
}