001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     * 
010     *      http://www.apache.org/licenses/LICENSE-2.0
011     * 
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.oozie.service;
019    
020    import org.apache.oozie.DagEngine;
021    import org.apache.oozie.service.Service;
022    import org.apache.oozie.service.Services;
023    
024    /**
025     * Service that return a dag engine for a user.
026     */
027    public class DagEngineService implements Service {
028    
029        /**
030         * Initialize the service.
031         *
032         * @param services services instance.
033         */
034        public void init(Services services) {
035        }
036    
037        /**
038         * Destroy the service.
039         */
040        public void destroy() {
041        }
042    
043        /**
044         * Return the public interface of the Dag engine service.
045         *
046         * @return {@link DagEngineService}.
047         */
048        public Class<? extends Service> getInterface() {
049            return DagEngineService.class;
050        }
051    
052        /**
053         * Return a Dag engine.
054         *
055         * @param user user for the dag engine.
056         * @return the dag engine for the specified user.
057         */
058        public DagEngine getDagEngine(String user) {
059            return new DagEngine(user);
060        }
061    
062        /**
063         * Return a Dag engine for a system user (no user, no group).
064         *
065         * @return a system Dag engine.
066         */
067        public DagEngine getSystemDagEngine() {
068            return new DagEngine();
069        }
070    
071    }