1 /*
2 * SymmetricDS is an open source database synchronization solution.
3 *
4 * Copyright (C) Chris Henson <chenson42@users.sourceforge.net>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 3 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see
18 * <http://www.gnu.org/licenses/>.
19 */
20
21 package org.jumpmind.symmetric.util;
22
23 import java.util.Random;
24
25 import org.jumpmind.symmetric.common.ParameterConstants;
26 import org.jumpmind.symmetric.service.IParameterService;
27
28 /***
29 * Use runtime configuration specific seeding to get a random number for use in
30 * time slotting nodes to help stagger load.
31 */
32 public class RandomTimeSlot {
33
34 int maxValue = 1000;
35
36 Random random;
37
38 public RandomTimeSlot() {
39 random = new Random();
40 }
41
42 public RandomTimeSlot(String externalId, int maxValue) {
43 this.maxValue = maxValue;
44 random = new Random(externalId.hashCode());
45 }
46
47 public void setParameterService(IParameterService s) {
48 random = new Random(s.getExternalId().hashCode());
49 maxValue = s.getInt(ParameterConstants.JOB_RANDOM_MAX_START_TIME_MS);
50 }
51
52 public int getRandomValueSeededByDomainId() {
53 return random.nextInt(maxValue);
54 }
55 }