1 package org.apache.helix.store;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.helix.BaseDataAccessor;
23
24 public interface HelixPropertyStore<T> extends BaseDataAccessor<T>
25 {
26 /**
27 * Perform resource allocation when property store starts
28 *
29 * Resource allocation includes: - start an internal thread for fire callbacks
30 *
31 */
32 public void start();
33
34 /**
35 * Perform clean up when property store stops
36 *
37 * Cleanup includes: - stop the internal thread for fire callbacks
38 *
39 */
40 public void stop();
41
42 /**
43 * Register a listener to a parent path.
44 *
45 * Subscribing to a parent path means any changes happening under the parent path will
46 * notify the listener
47 *
48 * @param parentPath
49 * @param listener
50 */
51 public void subscribe(String parentPath, HelixPropertyListener listener);
52
53 /**
54 * Remove a listener from a parent path.
55 *
56 * This will remove the listener from receiving any notifications happening under the
57 * parent path
58 *
59 * @param parentPath
60 * @param listener
61 */
62 public void unsubscribe(String parentPath, HelixPropertyListener listener);
63 }