001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.ecm.core.api;
023
024import java.util.Iterator;
025
026/**
027 * A serializable iterator of document models. Long result sets are loaded frame by frame transparently by the
028 * DocumentModelIterator.
029 *
030 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
031 * @author <a href="mailto:dm@nuxeo.com">Dragos Mihalache</a>
032 */
033public interface DocumentModelIterator extends Iterator<DocumentModel>, Iterable<DocumentModel> {
034
035    int UNKNOWN_SIZE = -1;
036
037    /**
038     * This might return a real elements count if the implementation allow this.
039     *
040     * @return the number of elements or -1 (by convention) if it is unknown
041     */
042    long size();
043
044}