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 *     Florent Guillaume
018 */
019package org.nuxeo.ecm.core.api;
020
021import java.io.Closeable;
022import java.io.Serializable;
023import java.util.Map;
024
025/**
026 * An iterable query result based on a cursor.
027 * <p>
028 * The {@link #close()} method MUST be called when the query result is no more needed, otherwise underlying resources
029 * will be leaked. There is no auto-closing at the end of the iteration.
030 */
031public interface IterableQueryResult extends Iterable<Map<String, Serializable>>, Closeable {
032
033    /**
034     * Closes the query result and releases the underlying resources held by the cursor.
035     * <p>
036     * This MUST be called when the query result is no more needed, otherwise underlying resources will be leaked. There
037     * is no auto-closing at the end of the iteration.
038     */
039    @Override
040    void close();
041
042    /**
043     * Indicates if the query result has not been closed
044     *
045     * @return
046     * @deprecated since 8.1 (misspelled), use {@link #mustBeClosed} instead
047     */
048    @Deprecated
049    boolean isLife();
050
051    /**
052     * Indicates if the query result must be closed (because it holds resources).
053     *
054     * @return {@code true} if the query result must be closed, {@code false} otherwise
055     * @since 8.1
056     */
057    boolean mustBeClosed();
058
059    /**
060     * Gets the total size of the query result.
061     * <p>
062     * Note that this may be costly, and that some backends may not be able to do this operation, in which case
063     * {@code -1} will be returned.
064     *
065     * @return the size, or {@code -1} for an unknown size
066     */
067    long size();
068
069    /**
070     * Gets the current position in the iterator.
071     * <p>
072     * Positions start at {@code 0}.
073     *
074     * @return the position
075     */
076    long pos();
077
078    /**
079     * Skips to a given position in the iterator.
080     * <p>
081     * Positions start at {@code 0}.
082     */
083    void skipTo(long pos);
084
085}