contrib/psg/src/example/symphony/SymphonyNodeComparator.java

   1 package example.symphony;\r
   2 \r
   3 import java.util.Comparator;\r
   4 import java.util.logging.Level;\r
   5 import java.util.logging.Logger;\r
   6 import peersim.core.Node;\r
   7 \r
   8 /**\r
   9  * Comparator that measure the relative distance from a target node\r
  10  *\r
  11  * @author Andrea Esposito <and1989@gmail.com>\r
  12  */\r
  13 public class SymphonyNodeComparator implements Comparator<Node> {\r
  14 \r
  15     private final int symphonyID;\r
  16     private double target;\r
  17 \r
  18     public SymphonyNodeComparator(int symphonyID) {\r
  19         this.symphonyID = symphonyID;\r
  20     }\r
  21 \r
  22     public SymphonyNodeComparator(int symphonyID, double target) {\r
  23         this(symphonyID);\r
  24         this.target = target;\r
  25     }\r
  26 \r
  27     public SymphonyNodeComparator(int symphonyID, Node targetNode) {\r
  28         this(symphonyID);\r
  29         SymphonyProtocol symphony = (SymphonyProtocol) targetNode.getProtocol(symphonyID);\r
  30         this.target = symphony.getIdentifier();\r
  31     }\r
  32 \r
  33     public int compare(Node o1, Node o2) {\r
  34 \r
  35         SymphonyProtocol symphony1 = (SymphonyProtocol) o1.getProtocol(symphonyID);\r
  36         SymphonyProtocol symphony2 = (SymphonyProtocol) o2.getProtocol(symphonyID);\r
  37 \r
  38         Double identifier1 = symphony1.getIdentifier();\r
  39         Double identifier2 = symphony2.getIdentifier();\r
  40 \r
  41         Double distance1 = Math.abs(target - identifier1) % 1;\r
  42         Double distance2 = Math.abs(target - identifier2) % 1;\r
  43 \r
  44         identifier1 = Math.min(1.0 - distance1, distance1);\r
  45         identifier2 = Math.min(1.0 - distance2, distance2);\r
  46 \r
  47         Logger.getLogger(SymphonyNodeComparator.class.getName()).log(Level.FINEST, "id1= " + symphony1.getIdentifier() + " target= " + target + " id2= " + symphony2.getIdentifier() + " res= " + identifier1.compareTo(identifier2));\r
  48 \r
  49         return identifier1.compareTo(identifier2);\r
  50     }\r
  51 }\r