Sliced out Provider-ish API from ClockService

Change-Id: I438815f2dc7a3a304f7dc8fb09550b2a5f779265

+package org.onlab.onos.store;
+
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+
+//TODO: Consider renaming to DeviceClockProviderService?
+/**
+* Interface for feeding term information to a logical clock service
+* that vends per device timestamps.
+*/
+public interface ClockProviderService {
+
+    /**
+     * Updates the mastership term for the specified deviceId.
+     * @param deviceId device identifier.
+     * @param term mastership term.
+     */
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
+}

 package org.onlab.onos.store;
 
-import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
 
 // TODO: Consider renaming to DeviceClockService?
@@ -15,12 +14,4 @@ public interface ClockService {
      * @return timestamp.
      */
     public Timestamp getTimestamp(DeviceId deviceId);
-
-    // TODO: Should this be here or separate as Admin service, etc.?
-    /**
-     * Updates the mastership term for the specified deviceId.
-     * @param deviceId device identifier.
-     * @param term mastership term.
-     */
-    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
 }

@@ -38,7 +38,7 @@ import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
-import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.ClockProviderService;
 import org.slf4j.Logger;
 
 /**
@@ -80,7 +80,7 @@ public class DeviceManager
     protected MastershipTermService termService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected ClockService clockService;
+    protected ClockProviderService clockProviderService;
 
     @Activate
     public void activate() {
@@ -274,7 +274,7 @@ public class DeviceManager
             if (event.master().equals(clusterService.getLocalNode().id())) {
                 MastershipTerm term = mastershipService.requestTermService()
                         .getMastershipTerm(event.subject());
-                clockService.setMastershipTerm(event.subject(), term);
+                clockProviderService.setMastershipTerm(event.subject(), term);
                 applyRole(event.subject(), MastershipRole.MASTER);
             } else {
                 applyRole(event.subject(), MastershipRole.STANDBY);

@@ -12,6 +12,7 @@ import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockProviderService;
 import org.onlab.onos.store.ClockService;
 import org.onlab.onos.store.Timestamp;
 import org.onlab.onos.store.impl.OnosTimestamp;
@@ -22,7 +23,7 @@ import org.slf4j.Logger;
  */
 @Component(immediate = true)
 @Service
-public class DeviceClockManager implements ClockService {
+public class DeviceClockManager implements ClockService, ClockProviderService {
 
     private final Logger log = getLogger(getClass());
 

@@ -4,27 +4,15 @@ import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.store.ClockService;
-import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.ClockProviderService;
 
 // FIXME: Code clone in onos-core-trivial, onos-core-hz-net
 /**
- * Dummy implementation of {@link ClockService}.
+ * Dummy implementation of {@link ClockProviderService}.
  */
 @Component(immediate = true)
 @Service
-public class NoOpClockService implements ClockService {
-
-    @Override
-    public Timestamp getTimestamp(DeviceId deviceId) {
-        return new Timestamp() {
-
-            @Override
-            public int compareTo(Timestamp o) {
-                throw new IllegalStateException("Never expected to be used.");
-            }
-        };
-    }
+public class NoOpClockProviderService implements ClockProviderService {
 
     @Override
     public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {

@@ -4,27 +4,15 @@ import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.store.ClockService;
-import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.ClockProviderService;
 
 //FIXME: Code clone in onos-core-trivial, onos-core-hz-net
 /**
- * Dummy implementation of {@link ClockService}.
+ * Dummy implementation of {@link ClockProviderService}.
  */
 @Component(immediate = true)
 @Service
-public class NoOpClockService implements ClockService {
-
-    @Override
-    public Timestamp getTimestamp(DeviceId deviceId) {
-        return new Timestamp() {
-
-            @Override
-            public int compareTo(Timestamp o) {
-                throw new IllegalStateException("Never expected to be used.");
-            }
-        };
-    }
+public class NoOpClockProviderService implements ClockProviderService {
 
     @Override
     public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {