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 import org.apache.hadoop.hbase.classification.InterfaceStability;
26
27 /**
28 * Coprocessor interface.
29 */
30 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
31 @InterfaceStability.Evolving
32 public interface Coprocessor {
33 int VERSION = 1;
34
35 /** Highest installation priority */
36 int PRIORITY_HIGHEST = 0;
37 /** High (system) installation priority */
38 int PRIORITY_SYSTEM = Integer.MAX_VALUE / 4;
39 /** Default installation priority for user coprocessors */
40 int PRIORITY_USER = Integer.MAX_VALUE / 2;
41 /** Lowest installation priority */
42 int PRIORITY_LOWEST = Integer.MAX_VALUE;
43
44 /**
45 * Lifecycle state of a given coprocessor instance.
46 */
47 enum State {
48 UNINSTALLED,
49 INSTALLED,
50 STARTING,
51 ACTIVE,
52 STOPPING,
53 STOPPED
54 }
55
56 // Interface
57 void start(CoprocessorEnvironment env) throws IOException;
58
59 void stop(CoprocessorEnvironment env) throws IOException;
60
61 }