Adding support to remove a subscriber.

And fixing an issue where build on a flowrule could not be
called repeatedly.

Change-Id: I85773ac7a3fb4f2970b63599d1eafbfc8b3c5879

@@ -364,6 +364,7 @@ public class DefaultFlowRule implements FlowRule {
 
         @Override
         public FlowRule build() {
+            FlowId localFlowId;
             checkArgument((flowId != null) ^ (appId != null), "Either an application" +
                     " id or a cookie must be supplied");
             checkNotNull(selector, "Traffic selector cannot be null");
@@ -377,11 +378,13 @@ public class DefaultFlowRule implements FlowRule {
             // Computing a flow ID based on appId takes precedence over setting
             // the flow ID directly
             if (appId != null) {
-                flowId = computeFlowId(appId);
+                localFlowId = computeFlowId(appId);
+            } else {
+                localFlowId = flowId;
             }
 
             return new DefaultFlowRule(deviceId, selector, treatment, priority,
-                                       flowId, permanent, timeout, tableId);
+                                       localFlowId, permanent, timeout, tableId);
         }
 
         private FlowId computeFlowId(ApplicationId appId) {

@@ -38,7 +38,6 @@ import org.onosproject.net.driver.AbstractHandlerBehaviour;
 import org.onosproject.net.flow.DefaultFlowRule;
 import org.onosproject.net.flow.DefaultTrafficSelector;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
-import org.onosproject.net.flow.FlowEntry;
 import org.onosproject.net.flow.FlowRule;
 import org.onosproject.net.flow.FlowRuleOperations;
 import org.onosproject.net.flow.FlowRuleOperationsContext;
@@ -579,12 +578,7 @@ public class OltPipeline extends AbstractHandlerBehaviour implements Pipeliner {
                 builder.add(inner.build()).add(outer.build());
                 break;
             case REMOVE:
-                Iterable<FlowEntry> flows = flowRuleService.getFlowEntries(deviceId);
-                for (FlowEntry fe : flows) {
-                    if (fe.equals(inner.build()) || fe.equals(outer.build())) {
-                        builder.remove(fe);
-                    }
-                }
+                builder.remove(inner.build()).remove(outer.build());
                 break;
             case ADD_TO_EXISTING:
                 break;