bboss.org.jgroups.demos.Topology Maven / Gradle / Ivy
// $Id: Topology.java,v 1.9 2009/04/09 09:11:27 belaban Exp $
package bboss.org.jgroups.demos;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.util.Vector;
import bboss.org.jgroups.Address;
import bboss.org.jgroups.Channel;
import bboss.org.jgroups.JChannel;
import bboss.org.jgroups.MembershipListener;
import bboss.org.jgroups.View;
import bboss.org.jgroups.blocks.PullPushAdapter;
/**
* Demonstrates the membership service. Each member is represented by a rectangle that contains the
* addresses of all the members. The coordinator (= oldest member in the group) is painted in blue.
* New members can be started; all existing members will update their graphical appearance to reflect
* the new membership. When the coordinator itself is killed, another one will take over (the next in rank).
* A nice demo is to start a number of Topology instances at the same time. All of them will be blue (all are
* coordinators since they don't find each other). Then the MERGE2 protocol sets in and only one will retain
* its coordinator role.
* @todo Needs to be ported to Swing.
* @author Bela Ban
*/
public class Topology extends Frame implements WindowListener, MembershipListener {
private final Vector members=new Vector();
private final Font myFont;
private final FontMetrics fm;
private final Color node_color=new Color(250, 220, 100);
private boolean coordinator=false;
private static final int NormalStyle=0;
private static final int CheckStyle=1;
private Channel channel;
private Object my_addr=null;
private static final String channel_name="FD-Heartbeat";
public Topology() {
addWindowListener(this);
//g=getGraphics();
fm=getFontMetrics(new Font("Helvetica", Font.PLAIN, 12));
myFont=new Font("Helvetica", Font.PLAIN, 12);
}
public void addNode(Object member) {
Object tmp;
for(int i=0; i < members.size(); i++) {
tmp=members.elementAt(i);
if(member.equals(tmp))
return;
}
members.addElement(member);
repaint();
}
public void removeNode(Object member) {
Object tmp;
for(int i=0; i < members.size(); i++) {
tmp=members.elementAt(i);
if(member.equals(tmp)) {
members.removeElement(members.elementAt(i));
break;
}
}
repaint();
}
public void drawNode(Graphics g, int x, int y, String label, int style) {
Color old=g.getColor();
int width, height;
width=fm.stringWidth(label) + 10;
height=fm.getHeight() + 5;
g.setColor(node_color);
g.fillRect(x, y, width, height);
g.setColor(old);
g.drawString(label, x + 5, y + 15);
g.drawRoundRect(x - 1, y - 1, width + 1, height + 1, 10, 10);
if(style == CheckStyle) {
g.drawRoundRect(x - 2, y - 2, width + 2, height + 2, 10, 10);
g.drawRoundRect(x - 3, y - 3, width + 3, height + 3, 10, 10);
}
}
public void drawTopology(Graphics g) {
int x=20, y=50;
String label;
Dimension box=getSize();
Color old=g.getColor();
if(coordinator) {
g.setColor(Color.cyan);
g.fillRect(11, 31, box.width - 21, box.height - 61);
g.setColor(old);
}
g.drawRect(10, 30, box.width - 20, box.height - 60);
g.setFont(myFont);
for(int i=0; i < members.size(); i++) {
label=members.elementAt(i).toString();
drawNode(g, x, y, label, NormalStyle);
y+=50;
}
}
public void paint(Graphics g) {
drawTopology(g);
}
/* ------------ Callbacks ------------- */
public void viewAccepted(View view) {
setState(view.getMembers());
}
public void suspect(Address suspected_mbr) {
}
public void block() {
}
public void setState(Vector mbrs) {
members.removeAllElements();
for(int i=0; i < mbrs.size(); i++)
addNode(mbrs.elementAt(i));
if(mbrs.size() <= 1 || (mbrs.size() > 1 && mbrs.elementAt(0).equals(my_addr)))
coordinator=true;
else
coordinator=false;
repaint();
}
public void coordinatorChosen() {
coordinator=true;
repaint();
}
public void windowActivated(WindowEvent e) {
}
public void windowClosed(WindowEvent e) {
}
public void windowClosing(WindowEvent e) {
channel.close();
System.exit(0);
}
public void windowDeactivated(WindowEvent e) {
}
public void windowDeiconified(WindowEvent e) {
}
public void windowIconified(WindowEvent e) {
}
public void windowOpened(WindowEvent e) {
}
public void start() throws Exception {
//String props="TCP:" +
// "TCPPING(timeout=2000;num_initial_members=1;port_range=3;" +
// "initial_hosts=localhost[8880]):" +
// "FD:STABLE:NAKACK:FLUSH:GMS(join_timeout=12000):VIEW_ENFORCER:QUEUE";
// test for pbcast
//String props="UDP:PING:FD:" +
// "pbcast.PBCAST:UNICAST:FRAG:pbcast.GMS:" +
// "STATE_TRANSFER:QUEUE";
// test for pbcast
//String props="TCP:TCPPING(port_range=2;initial_hosts=daddy[8880],terrapin[8880]):FD:" +
// "pbcast.PBCAST:UNICAST:FRAG:pbcast.GMS:" +
// "STATE_TRANSFER:QUEUE";
// test2 for pbcast
//String props="UDP:PING:FD:" +
// "pbcast.PBCAST:UNICAST:FRAG:pbcast.GMS:" +
// "pbcast.STATE_TRANSFER";
// String props=null; // default properties
String props="udp.xml";
channel=new JChannel(props);
channel.connect(channel_name);
new PullPushAdapter(channel, this);
my_addr=channel.getAddress();
if(my_addr != null)
setTitle(my_addr.toString());
pack();
show();
}
public static void main(String[] args) {
try {
Topology top=new Topology();
top.setLayout(null);
top.setSize(240, 507);
top.start();
}
catch(Exception e) {
System.err.println(e);
e.printStackTrace();
System.exit(0);
}
}
}