1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19
20 package org.apache.hadoop.hbase;
21
22 import java.io.IOException;
23
24 import org.apache.hadoop.hbase.classification.InterfaceAudience;
25
26 /**
27 * Coprocessor interface.
28 */
29 @InterfaceAudience.Private
30 public interface Coprocessor {
31 int VERSION = 1;
32
33 /** Highest installation priority */
34 int PRIORITY_HIGHEST = 0;
35 /** High (system) installation priority */
36 int PRIORITY_SYSTEM = Integer.MAX_VALUE / 4;
37 /** Default installation priority for user coprocessors */
38 int PRIORITY_USER = Integer.MAX_VALUE / 2;
39 /** Lowest installation priority */
40 int PRIORITY_LOWEST = Integer.MAX_VALUE;
41
42 /**
43 * Lifecycle state of a given coprocessor instance.
44 */
45 enum State {
46 UNINSTALLED,
47 INSTALLED,
48 STARTING,
49 ACTIVE,
50 STOPPING,
51 STOPPED
52 }
53
54 // Interface
55 void start(CoprocessorEnvironment env) throws IOException;
56
57 void stop(CoprocessorEnvironment env) throws IOException;
58
59 }