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.workflow;
019    
020    import org.apache.hadoop.conf.Configuration;
021    
022    
023    /**
024     * The workflow library provides application parsing and storage capabilities for workflow instances. <p/> The
025     * implementation is responsible for doing the store operations in a transactional way, either in autocommit or within
026     * the scope of a transaction.
027     */
028    public interface WorkflowLib {
029    
030        /**
031         * Parse a workflow application definition.
032         *
033         * @param wfXml string containing the workflow definition.
034         * @param jobConf job configuration
035         * @return the parse workflow application.
036         * @throws WorkflowException thrown if the definition could not be parsed.
037         */
038        public WorkflowApp parseDef(String wfXml, Configuration jobConf) throws WorkflowException;
039    
040    
041        /**
042         * Create a workflow instance.
043         *
044         * @param app application to create a workflow instance of.
045         * @param conf job configuration.
046         * @return the newly created workflow instance.
047         * @throws WorkflowException thrown if the instance could not be created.
048         */
049        public WorkflowInstance createInstance(WorkflowApp app, Configuration conf) throws WorkflowException;
050    
051        /**
052         * Create a workflow instance with the given wfId. This will be used for re-running workflows.
053         *
054         * @param app application to create a workflow instance of.
055         * @param conf job configuration.
056         * @param wfId Workflow ID.
057         * @return the newly created workflow instance.
058         * @throws WorkflowException thrown if the instance could not be created.
059         */
060        public WorkflowInstance createInstance(WorkflowApp app, Configuration conf, String wfId) throws WorkflowException;
061    
062        /**
063         * Insert a workflow instance in storage.
064         *
065         * @param instance of the workflow instance to insert.
066         * @throws WorkflowException thrown if the instance could not be inserted.
067         */
068        public void insert(WorkflowInstance instance) throws WorkflowException;
069    
070        /**
071         * Load a workflow instance from storage.
072         *
073         * @param id ID of the workflow instance to load.
074         * @return the loaded workflow instance.
075         * @throws WorkflowException thrown if the instance could not be loaded.
076         */
077        public WorkflowInstance get(String id) throws WorkflowException;
078    
079        /**
080         * Update a workflow instance in storage.
081         *
082         * @param instance workflow instance to update.
083         * @throws WorkflowException thrown if the instance could not be loaded.
084         */
085        public void update(WorkflowInstance instance) throws WorkflowException;
086    
087        /**
088         * Delete a workflow instance from storage.
089         *
090         * @param id ID of the workflow instance to delete.
091         * @throws WorkflowException thrown if the instance could not be deleted.
092         */
093        public void delete(String id) throws WorkflowException;
094    
095    
096        /**
097         * Commit changes to store.
098         *
099         * @throws WorkflowException thrown if the commit could not be done.
100         */
101        public void commit() throws WorkflowException;
102    
103        /**
104         * Close store. It rollbacks if there was no commit.
105         *
106         * @throws WorkflowException thrown if the close could not be done.
107         */
108        public void close() throws WorkflowException;
109    
110    }