01: /* Copyright (C) 2004 - 2007 db4objects Inc. http://www.db4o.com
02:
03: This file is part of the db4o open source object database.
04:
05: db4o is free software; you can redistribute it and/or modify it under
06: the terms of version 2 of the GNU General Public License as published
07: by the Free Software Foundation and as clarified by db4objects' GPL
08: interpretation policy, available at
09: http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10: Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11: Suite 350, San Mateo, CA 94403, USA.
12:
13: db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14: WARRANTY; without even the implied warranty of MERCHANTABILITY or
15: FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16: for more details.
17:
18: You should have received a copy of the GNU General Public License along
19: with this program; if not, write to the Free Software Foundation, Inc.,
20: 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21: package com.db4o.foundation;
22:
23: /**
24: * @exclude
25: */
26: public class TimeStampIdGenerator {
27:
28: private long _last;
29:
30: public static long idToMilliseconds(long id) {
31: return id >> 15;
32: }
33:
34: public TimeStampIdGenerator() {
35: this (0);
36: }
37:
38: public TimeStampIdGenerator(long minimumNext) {
39: _last = minimumNext;
40: }
41:
42: public long generate() {
43: long t = System.currentTimeMillis();
44:
45: t = t << 15;
46:
47: if (t <= _last) {
48: _last++;
49: } else {
50: _last = t;
51: }
52: return _last;
53: }
54:
55: public long last() {
56: return _last;
57: }
58:
59: public boolean setMinimumNext(long newMinimum) {
60: if (newMinimum <= _last) {
61: return false;
62: }
63: _last = newMinimum;
64: return true;
65: }
66: }
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