01: //
02: // Copyright (C) 2005 United States Government as represented by the
03: // Administrator of the National Aeronautics and Space Administration
04: // (NASA). All Rights Reserved.
05: //
06: // This software is distributed under the NASA Open Source Agreement
07: // (NOSA), version 1.3. The NOSA has been approved by the Open Source
08: // Initiative. See the file NOSA-1.3-JPF at the top of the distribution
09: // directory tree for the complete NOSA document.
10: //
11: // THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
12: // KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
13: // LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
14: // SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
15: // A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
16: // THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
17: // DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
18: //
19: package gov.nasa.jpf.search.heuristic;
20:
21: import java.util.Comparator;
22:
23: /**
24: * depth first comparator for heuristic state ordering
25: * <2do> Hmm, that look awefully like the DefaultComparator
26: */
27: public class DFSComparator implements Comparator {
28:
29: public int compare(Object o1, Object o2) {
30: HeuristicState hs1 = (HeuristicState) o1;
31: HeuristicState hs2 = (HeuristicState) o2;
32:
33: int p1 = hs1.getPriority();
34: int p2 = hs2.getPriority();
35:
36: if (p1 == p2) {
37: int h1 = hs1.hashCode();
38: int h2 = hs2.hashCode();
39:
40: if (h1 == h2) {
41: return 0;
42: } else if (hs1.uniqueID > hs2.uniqueID) {
43: return -1;
44: } else {
45: return 1;
46: }
47: } else if (p1 < p2) {
48: return -1;
49: } else {
50: return 1;
51: }
52: }
53: }
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