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1   /*
2    * Licensed to The Apereo Foundation under one or more contributor license
3    * agreements. See the NOTICE file distributed with this work for additional
4    * information regarding copyright ownership.
5    *
6    *
7    * The Apereo Foundation licenses this file to you under the Educational
8    * Community License, Version 2.0 (the "License"); you may not use this file
9    * except in compliance with the License. You may obtain a copy of the License
10   * at:
11   *
12   *   http://opensource.org/licenses/ecl2.txt
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
17   * License for the specific language governing permissions and limitations under
18   * the License.
19   *
20   */
21  
22  package org.opencastproject.job.api;
23  
24  import org.opencastproject.job.api.Job.Status;
25  import org.opencastproject.serviceregistry.api.ServiceRegistryException;
26  import org.opencastproject.serviceregistry.api.UndispatchableJobException;
27  
28  /**
29   * A service that creates jobs for long-running operations.
30   */
31  public interface JobProducer {
32  
33    /**
34     * The type of jobs that this producer creates.
35     *
36     * @return the job type
37     */
38    String getJobType();
39  
40    /**
41     * Get the number of jobs in a current status on all nodes.
42     *
43     * @return Number of jobs in this state
44     * @throws ServiceRegistryException
45     *           if an error occurs while communicating with the backing data source
46     */
47    long countJobs(Status status) throws ServiceRegistryException;
48  
49    /**
50     * Asks the job producer to handle the given job using the provided operation and list of arguments. The
51     * implementation of this method <b>must</b> be asynchronous if the processing takes more than a few seconds.
52     *
53     * @param job
54     *          the job being dispatched
55     * @throws ServiceRegistryException
56     *           if the producer was unable to start work as requested
57     */
58    void acceptJob(Job job) throws ServiceRegistryException;
59  
60    /**
61     * Whether new jobs can be accepted in general.
62     *
63     * @param operation
64     *          operation
65     * @throws ServiceRegistryException
66     *           if the producer was unable to start work as requested
67     * @return whether the service is ready to accept jobs
68     */
69    boolean isReadyToAcceptJobs(String operation) throws ServiceRegistryException;
70  
71    /**
72     * Whether the job can be accepted.
73     *
74     * @param job
75     *          the job being dispatched
76     * @throws ServiceRegistryException
77     *           if the producer was unable to start work as requested
78     * @throws UndispatchableJobException
79     *           if the job will never be accepted because it is unacceptable
80     * @return whether the service is ready to accept the job
81     */
82    boolean isReadyToAccept(Job job) throws ServiceRegistryException, UndispatchableJobException;
83  
84  }