Merge pull request #522 from mininet/devel/torus

Adding number of hosts per switch option to torus topo

mininet/topolib.py

@@ -45,10 +45,18 @@ class TorusTopo( Topo ):
        without STP turned on! It can be used with STP, e.g.:
        # mn --topo torus,3,3 --switch lxbr,stp=1 --test pingall"""
 
-    def build( self, x, y ):
+    def build( self, x, y, n=1 ):
+        """x: dimension of torus in x-direction
+           y: dimension of torus in y-direction
+           n: number of hosts per switch"""
         if x < 3 or y < 3:
             raise Exception( 'Please use 3x3 or greater for compatibility '
                              'with 2.1' )
+        if n == 1:
+            genHostName = lambda loc, k: 'h%s' % ( loc )
+        else:
+            genHostName = lambda loc, k: 'h%sx%d' % ( loc, k )
+
         hosts, switches, dpid = {}, {}, 0
         # Create and wire interior
         for i in range( 0, x ):
@@ -58,8 +66,9 @@ class TorusTopo( Topo ):
                 dpid = ( i + 1 ) * 256 + ( j + 1 )
                 switch = switches[ i, j ] = self.addSwitch(
                     's' + loc, dpid='%016x' % dpid )
-                host = hosts[ i, j ] = self.addHost( 'h' + loc )
-                self.addLink( host, switch )
+                for k in range( 0, n ):
+                    host = hosts[ i, j, k ] = self.addHost( genHostName( loc, k + 1 ) )
+                    self.addLink( host, switch )
         # Connect switches
         for i in range( 0, x ):
             for j in range( 0, y ):