WANPING


1   // $Id: WANPING.java,v 1.9 2005/01/04 08:18:31 belaban Exp $
2   
3   package org.jgroups.protocols;
4   
5   
6   import org.jgroups.Event;
7   import org.jgroups.Message;
8   import org.jgroups.util.List;
9   
10  import java.util.Enumeration  ;
11  import java.util.Properties  ;
12  import java.util.StringTokenizer  ;
13  
14  
15  /**
16   * Similar to TCPPING, except that the initial host list is specified as a list of logical pipe names.
17   */
18  public class WANPING extends Discovery {
19      int port_range=5;        // number of ports to be probed for initial membership
20      List initial_hosts=null;  // hosts to be contacted for the initial membership
21  
22  
23      public String   getName() {
24          return "WANPING";
25      }
26  
27  
28      public boolean setProperties(Properties   props) {
29          String   str;
30          str=props.getProperty("port_range");           // if member cannot be contacted on base port,
31          if(str != null) {                              // how many times can we increment the port
32              port_range=Integer.parseInt(str);
33              props.remove("port_range");
34          }
35  
36          str=props.getProperty("initial_hosts");
37          if(str != null) {
38              props.remove("initial_hosts");
39              initial_hosts=createInitialHosts(str);
40              if(log.isInfoEnabled()) log.info("initial_hosts: " + initial_hosts);
41          }
42  
43          if(initial_hosts == null || initial_hosts.size() == 0) {
44              System.err.println("WANPING.setProperties(): hosts to contact for initial membership " +
45                                 "not specified. Cannot determine coordinator !");
46              return false;
47          }
48          return super.setProperties(props);
49      }
50  
51      public void sendGetMembersRequest() {
52          Message msg, copy;
53          PingHeader hdr;
54          String   h;
55  
56          hdr=new PingHeader(PingHeader.GET_MBRS_REQ, null);
57          msg=new Message(null, null, null);
58          msg.putHeader(getName(), hdr);
59  
60          for(Enumeration   en=initial_hosts.elements(); en.hasMoreElements();) {
61              h=(String  )en.nextElement();
62              copy=msg.copy();
63              copy.setDest(new WanPipeAddress(h));
64              passDown(new Event(Event.MSG, copy));
65          }
66      }
67  
68  
69  
70      /* -------------------------- Private methods ---------------------------- */
71  
72      /**
73       * Input is "pipe1,pipe2". Return List of Strings
74       */
75      private List createInitialHosts(String   l) {
76          List tmp=new List();
77          StringTokenizer   tok=new StringTokenizer  (l, ",");
78          String   t;
79  
80          while(tok.hasMoreTokens()) {
81              try {
82                  t=tok.nextToken();
83                  tmp.add(t.trim());
84              }
85              catch(NumberFormatException   e) {
86                  System.err.println("WANPING.createInitialHosts(): " + e);
87              }
88          }
89          return tmp;
90      }
91  
92  
93  }
94  
95
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