[VOL-1553] Improve device graph performance

This update focussed on generating routes using the device graph.
It improves the performance by at least 5 times.

Change-Id: I79bdbca8ea3d134e87848e45140d07ee3831f12c
diff --git a/rw_core/flow_decomposition/flow_decomposer_test.go b/rw_core/flow_decomposition/flow_decomposer_test.go
index a0a2e3b..d27fd21 100644
--- a/rw_core/flow_decomposition/flow_decomposer_test.go
+++ b/rw_core/flow_decomposition/flow_decomposer_test.go
@@ -29,7 +29,7 @@
 
 func init() {
 	log.AddPackage(log.JSON, log.WarnLevel, nil)
-	log.UpdateAllLoggers(log.Fields{"instanceId": "flow-descomposition"})
+	log.UpdateAllLoggers(log.Fields{"instanceId": "flow-decomposition"})
 	log.SetAllLogLevel(log.WarnLevel)
 }
 
@@ -361,7 +361,7 @@
 	tfd.defaultRules.AddFlowsAndGroup("onu4", fg)
 
 	//Set up the device graph - flow decomposer uses it only to verify whether a port is a root port.
-	tfd.deviceGraph = graph.NewDeviceGraph(tfd.getDeviceHelper)
+	tfd.deviceGraph = graph.NewDeviceGraph("ldid", tfd.getDeviceHelper)
 	tfd.deviceGraph.RootPorts = make(map[uint32]uint32)
 	tfd.deviceGraph.RootPorts[10] = 10