ONOS-1871: Send Topology MastershipEvent info to Topology listeners.
The MastershipEvent info is needed by applications such as the GUI
(via the Websocket client).
NOTE: Previously, the Mastership Events were sent only when there
was any change, but no Mastership Events were sent when a listener
has just subscribed.
The solution is to add a mechanism for creating and sending Topology
Snapshot event to new listeners, and that event also includes
the Mastership Events.
The modifications are:
* Renamed and updated the ITopologyService API for adding/removing
Topology listeners:
OLD: registerTopologyListener() and deregisterTopologyListener()
NEW: addListener() and removeListener()
Also, addListener() has a second argument:
"boolean startFromSnapshot"
If that argument is true, and if the topology is not empty, the first
(expected) event to that listener should be a snapshot of the current
topology.
* Added TopologyEvents() constructor for ADDED events only. Such event
can be used to represent a snapshot of the topology.
* Added new APIs to TopologyInternal:
getAllSwitchEvents(), getAllPortEvents(), get AllLinkEvents(),
getAllHostEvents()
Those APIs are needed for creating a snapshot of the topology.
* Added a mechanism for creating empty (NO-OP) TopologyEvent instance,
and use that mechanism to "wake-up" the EventHandler processing thread
when it needs to send Topology Snapshot to a new listener.
This solution is (kind-of) a hack.
Change-Id: Ie1eb52242f58682aac61f54af29c3b5d291ac0bd
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyEventPreprocessor.java b/src/main/java/net/onrc/onos/core/topology/TopologyEventPreprocessor.java
index 69d9b07..475dca1 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyEventPreprocessor.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyEventPreprocessor.java
@@ -217,6 +217,11 @@
for (EventEntry<TopologyEvent> event : events) {
List<EventEntry<TopologyEvent>> postponedEvents = null;
+ // Ignore NO-OP events
+ if (event.isNoop()) {
+ continue;
+ }
+
TopologyEvent topologyEvent = event.eventData();
OnosInstanceId onosInstanceId = topologyEvent.getOnosInstanceId();