Implement host probing retry with major refactoring

- Implement probe retry
- Switch to typical core/provider design pattern for HostProbingService
  and as a result decoupling the dependency between SR and HostLocationProvider

Change-Id: I33a15af580677ea376b421ac3e26f9821dcca844
diff --git a/app/src/main/java/org/onosproject/segmentrouting/HostHandler.java b/app/src/main/java/org/onosproject/segmentrouting/HostHandler.java
index f71c1d0..3982731 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/HostHandler.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/HostHandler.java
@@ -27,8 +27,8 @@
 import org.onosproject.net.HostLocation;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.host.HostEvent;
-import org.onosproject.net.host.HostLocationProbingService.ProbeMode;
 import org.onosproject.net.host.HostService;
+import org.onosproject.net.host.ProbeMode;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -185,6 +185,9 @@
 
         // For each old location
         Sets.difference(prevLocations, newLocations).forEach(prevLocation -> {
+            // First of all, verify each old location
+            srManager.probingService.probeHost(host, prevLocation, ProbeMode.VERIFY);
+
             // Remove routing rules for old IPs
             Sets.difference(prevIps, newIps).forEach(ip -> {
                 if (doubleTaggedHost) {
@@ -392,7 +395,7 @@
             srManager.getPairDeviceId(cp.deviceId())
                     .ifPresent(pairDeviceId -> srManager.hostService.getConnectedHosts(pairDeviceId).stream()
                             .filter(host -> isHostInVlanOfPort(host, pairDeviceId, cp))
-                            .forEach(host -> srManager.probingService.probeHostLocation(host, cp, ProbeMode.DISCOVER))
+                            .forEach(host -> srManager.probingService.probeHost(host, cp, ProbeMode.DISCOVER))
                     );
         }
     }
@@ -435,7 +438,7 @@
                 .filter(i -> !i.connectPoint().port().equals(pairRemotePort))
                 .forEach(i -> {
                     log.debug("Probing host {} on pair device {}", host.id(), i.connectPoint());
-                    srManager.probingService.probeHostLocation(host, i.connectPoint(), ProbeMode.DISCOVER);
+                    srManager.probingService.probeHost(host, i.connectPoint(), ProbeMode.DISCOVER);
                 });
     }
 
diff --git a/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index 317e7f4..52ca18e 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -77,7 +77,7 @@
 import org.onosproject.net.flowobjective.FlowObjectiveService;
 import org.onosproject.net.host.HostEvent;
 import org.onosproject.net.host.HostListener;
-import org.onosproject.net.host.HostLocationProbingService;
+import org.onosproject.net.host.HostProbingService;
 import org.onosproject.net.host.HostService;
 import org.onosproject.net.host.InterfaceIpAddress;
 import org.onosproject.net.intent.WorkPartitionService;
@@ -186,7 +186,7 @@
     HostService hostService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    HostLocationProbingService probingService;
+    HostProbingService probingService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     public DeviceService deviceService;
diff --git a/app/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java b/app/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
index 26420ac..6783da3 100644
--- a/app/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
+++ b/app/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
@@ -28,7 +28,7 @@
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 import org.onosproject.net.config.ConfigApplyDelegate;
-import org.onosproject.net.host.HostLocationProbingService;
+import org.onosproject.net.host.ProbeMode;
 import org.onosproject.net.intf.Interface;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DefaultHost;
@@ -182,7 +182,7 @@
     private static final Set<Interface> INTERFACES = Sets.newHashSet(INTF11, INTF12, INTF13, INTF21,
             INTF22, INTF31, INTF32, INTF39, INTF41, INTF49);
 
-    private MockLocationProbingService mockLocationProbingService;
+    private MockHostProbingService mockLocationProbingService;
 
     @Before
     public void setUp() throws Exception {
@@ -218,7 +218,7 @@
         srManager.mastershipService = new MockMastershipService(LOCAL_DEVICES);
         srManager.hostService = new MockHostService(HOSTS);
         srManager.cfgService = mockNetworkConfigRegistry;
-        mockLocationProbingService = new MockLocationProbingService();
+        mockLocationProbingService = new MockHostProbingService();
         srManager.probingService = mockLocationProbingService;
         srManager.linkHandler = new MockLinkHandler(srManager);
 
@@ -351,7 +351,7 @@
         assertEquals(P1, BRIDGING_TABLE.get(new MockBridgingTableKey(DEV3, HOST_MAC, INTF_VLAN_UNTAGGED)).portNumber);
         assertEquals(P9, BRIDGING_TABLE.get(new MockBridgingTableKey(DEV4, HOST_MAC, INTF_VLAN_UNTAGGED)).portNumber);
         // Expect probe to be sent out on pair device
-        assertTrue(mockLocationProbingService.verifyProbe(host1, CP41, HostLocationProbingService.ProbeMode.DISCOVER));
+        assertTrue(mockLocationProbingService.verifyProbe(host1, CP41, ProbeMode.DISCOVER));
 
         // Add the second location of dual-homed host
         // Expect: no longer use the pair link
@@ -753,7 +753,7 @@
         assertEquals(P1, BRIDGING_TABLE.get(new MockBridgingTableKey(DEV3, HOST_MAC, INTF_VLAN_UNTAGGED)).portNumber);
         assertEquals(P9, BRIDGING_TABLE.get(new MockBridgingTableKey(DEV4, HOST_MAC, INTF_VLAN_UNTAGGED)).portNumber);
         // Expect probe to be sent out on pair device
-        assertTrue(mockLocationProbingService.verifyProbe(host2, CP41, HostLocationProbingService.ProbeMode.DISCOVER));
+        assertTrue(mockLocationProbingService.verifyProbe(host2, CP41, ProbeMode.DISCOVER));
 
         // Discover location
         // Expect: cancel all redirections
diff --git a/app/src/test/java/org/onosproject/segmentrouting/MockLocationProbingService.java b/app/src/test/java/org/onosproject/segmentrouting/MockHostProbingService.java
similarity index 88%
rename from app/src/test/java/org/onosproject/segmentrouting/MockLocationProbingService.java
rename to app/src/test/java/org/onosproject/segmentrouting/MockHostProbingService.java
index b0cdf43..807db0c 100644
--- a/app/src/test/java/org/onosproject/segmentrouting/MockLocationProbingService.java
+++ b/app/src/test/java/org/onosproject/segmentrouting/MockHostProbingService.java
@@ -19,12 +19,13 @@
 import com.google.common.collect.Lists;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.Host;
-import org.onosproject.net.host.HostLocationProbingService;
+import org.onosproject.net.host.HostProbingService;
+import org.onosproject.net.host.ProbeMode;
 
 import java.util.List;
 import java.util.Objects;
 
-public class MockLocationProbingService implements HostLocationProbingService {
+public class MockHostProbingService implements HostProbingService {
     List<Probe> probes;
 
     private class Probe {
@@ -58,7 +59,7 @@
         }
     }
 
-    MockLocationProbingService() {
+    MockHostProbingService() {
         probes = Lists.newArrayList();
     }
 
@@ -68,7 +69,7 @@
     }
 
     @Override
-    public void probeHostLocation(Host host, ConnectPoint connectPoint, ProbeMode probeMode) {
+    public void probeHost(Host host, ConnectPoint connectPoint, ProbeMode probeMode) {
         probes.add(new Probe(host, connectPoint, probeMode));
     }
 }