NullLinkProvider has been rewritten to take a topology file.

Reference: ONOS-1214, ONOS-1033

Change-Id: Ia945e4c8555afd2d74f174e51e22e2fdf3dcb356

@@ -78,8 +78,6 @@ public class NullDeviceProvider extends AbstractProvider implements DeviceProvid
     private ExecutorService deviceBuilder =
             Executors.newFixedThreadPool(1, groupedThreads("onos/null", "device-creator"));
 
-
-    //currently hardcoded. will be made configurable via rest/cli.
     private static final String SCHEME = "null";
     private static final int DEF_NUMDEVICES = 10;
     private static final int DEF_NUMPORTS = 10;
@@ -99,7 +97,6 @@ public class NullDeviceProvider extends AbstractProvider implements DeviceProvid
 
     private DeviceCreator creator;
 
-
     /**
      *
      * Creates a provider with the supplier identifier.
@@ -238,11 +235,10 @@ public class NullDeviceProvider extends AbstractProvider implements DeviceProvid
             ChassisId cid;
 
             // nodeIdHash takes into account for nodeID to avoid collisions when running multi-node providers.
-            long nodeIdHash = clusterService.getLocalNode().hashCode() << 16;
+            long nodeIdHash = clusterService.getLocalNode().id().hashCode() << 16;
 
             for (int i = 0; i < numDevices; i++) {
-                // mark 'last' device to facilitate chaining of islands together
-                long id = (i + 1 == numDevices) ? nodeIdHash | 0xffff : nodeIdHash | i;
+                long id = nodeIdHash | i;
 
                 did = DeviceId.deviceId(new URI(SCHEME, toHex(id), null));
                 cid = new ChassisId(i);

+# NullLinkProvider topology description (config file).
+#
+# Dot-style topology graph. Each controller's topology begins with
+#
+#   graph <node ID>, followed by a list of links between braces.
+#
+# The links are either bidirectional (--) or directed (->). The directed
+# edges are used to connect together Null devices of different controllers.
+# The endpoint has the format:
+# 
+#   devID:port:NodeId
+#
+# The NodeId is only added if the destination is another node's device.
+#
+graph 192.168.56.20 {
+    0:0 -- 1:0
+    1:1 -> 0:0:192.168.56.30
+    1:2 -- 2:0
+    2:1 -> 1:0:192.168.56.30
+}
+graph 192.168.56.30 {
+    0:0 -> 1:1:192.168.56.20
+    0:1 -- 1:1
+    1:0 -> 2:1:192.168.56.20
+    1:2 -- 2:0
+}
+# Bugs: Comments cannot be appended to a line to be read.

@@ -2,7 +2,7 @@
 # Instance-specific configurations, in this case, the number of 
 # devices per node.
 #
-devConfigs = 192.168.97.132:5,192.168.97.131:5
+devConfigs = 192.168.56.20:3,192.168.56.30:3
 
 #
 # Number of ports per device. This is global to all devices

@@ -4,13 +4,13 @@
 
 #
 # If enabled, sets the time between LinkEvent generation,
-# in milliseconds.
+# in microseconds.
 #
 
-#eventRate = 100000
-
+#eventRate = 1000000
 
 #
-# Set order of islands to chain together, in a line.
+# If enabled, points to the full path to the topology file.
 #
-neighbors = 192.168.97.132,192.168.97.131
+
+#cfgFile = /tmp/foo.cfg