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.internal.query.processor;
22:
23: import com.db4o.foundation.*;
24:
25: /**
26: * @exclude
27: */
28: class QPending extends Tree {
29:
30: final QConJoin _join;
31: QCon _constraint;
32:
33: int _result;
34:
35: // Constants, so QConJoin.evaluatePending is made easy:
36: static final int FALSE = -4;
37: static final int BOTH = 1;
38: static final int TRUE = 2;
39:
40: QPending(QConJoin a_join, QCon a_constraint, boolean a_firstResult) {
41: _join = a_join;
42: _constraint = a_constraint;
43:
44: _result = a_firstResult ? TRUE : FALSE;
45: }
46:
47: public int compare(Tree a_to) {
48: return _constraint.i_id - ((QPending) a_to)._constraint.i_id;
49: }
50:
51: void changeConstraint() {
52: _constraint = _join.getOtherConstraint(_constraint);
53: }
54:
55: public Object shallowClone() {
56: QPending pending = internalClonePayload();
57: super .shallowCloneInternal(pending);
58: return pending;
59: }
60:
61: QPending internalClonePayload() {
62: QPending pending = new QPending(_join, _constraint, false);
63: pending._result = _result;
64: return pending;
65: }
66:
67: public Object key() {
68: throw new NotImplementedException();
69: }
70:
71: }
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