1 /**
2 * Copyright (c) 2014, stateful.co
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met: 1) Redistributions of source code must retain the above
8 * copyright notice, this list of conditions and the following
9 * disclaimer. 2) Redistributions in binary form must reproduce the above
10 * copyright notice, this list of conditions and the following
11 * disclaimer in the documentation and/or other materials provided
12 * with the distribution. 3) Neither the name of the stateful.co nor
13 * the names of its contributors may be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
19 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30 package co.stateful.spi;
31
32 import com.jcabi.aspects.Immutable;
33 import java.io.IOException;
34 import java.util.Map;
35
36 /**
37 * Locks.
38 *
39 * @author Yegor Bugayenko (yegor@tpc2.com)
40 * @version $Id$
41 * @since 1.1
42 */
43 @Immutable
44 public interface Locks {
45
46 /**
47 * Maximum allowed per account.
48 */
49 int MAX = 4096;
50
51 /**
52 * Get list of them all, and their labels.
53 * @return List of locks
54 * @throws IOException If fails
55 */
56 Map<String, String> names() throws IOException;
57
58 /**
59 * Lock it.
60 * @param name Unique name of the lock
61 * @param label Label to attach
62 * @return Empty if success or a label of a current lock
63 * @throws IOException If fails
64 */
65 String lock(String name, String label) throws IOException;
66
67 /**
68 * Unlock it.
69 * @param name Unique name of the lock
70 * @throws IOException If fails
71 */
72 void unlock(String name) throws IOException;
73
74 /**
75 * Unlock only if label matches.
76 * @param name Unique name of the lock
77 * @param label Label to match
78 * @return Empty if success or label of current lock
79 * @throws IOException If fails
80 * @since 1.6
81 */
82 String unlock(String name, String label) throws IOException;
83
84 }