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 HashtableIterator implements Iterator4 {
27:
28: private final HashtableIntEntry[] _table;
29:
30: private HashtableIntEntry _currentEntry;
31:
32: private int _currentIndex;
33:
34: public HashtableIterator(HashtableIntEntry[] table) {
35: _table = table;
36: reset();
37: }
38:
39: private void checkInvalidTable() {
40: if (_table == null || _table.length == 0) {
41: positionBeyondLast();
42: }
43: }
44:
45: public Object current() {
46: if (_currentEntry == null) {
47: throw new IllegalStateException();
48: }
49: return _currentEntry;
50: }
51:
52: public boolean moveNext() {
53: if (isBeyondLast()) {
54: return false;
55: }
56: if (_currentEntry != null) {
57: _currentEntry = _currentEntry._next;
58: }
59: while (_currentEntry == null) {
60: if (_currentIndex >= _table.length) {
61: positionBeyondLast();
62: return false;
63: }
64: _currentEntry = _table[_currentIndex++];
65: }
66: return true;
67: }
68:
69: public void reset() {
70: _currentEntry = null;
71: _currentIndex = 0;
72: checkInvalidTable();
73: }
74:
75: private boolean isBeyondLast() {
76: return _currentIndex == -1;
77: }
78:
79: private void positionBeyondLast() {
80: _currentIndex = -1;
81: }
82:
83: }
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