Refactoring to move code to right locations. Attempt at breaking dependency cycles.
diff --git a/core/api/src/main/java/org/onlab/onos/net/device/DeviceMastershipStore.java b/core/api/src/main/java/org/onlab/onos/net/device/DeviceMastershipStore.java
new file mode 100644
index 0000000..ee9b253
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/device/DeviceMastershipStore.java
@@ -0,0 +1,91 @@
+package org.onlab.onos.net.device;
+
+import java.util.Set;
+
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.store.Store;
+
+/**
+ * Manages inventory of mastership roles for devices, across controller
+ * instances; not intended for direct use.
+ */
+public interface DeviceMastershipStore extends Store<DeviceMastershipEvent, DeviceMastershipStoreDelegate> {
+
+ // three things to map: NodeId, DeviceId, MastershipRole
+
+ /**
+ * Requests role of the local node for the specified device.
+ *
+ * @param deviceId device identifier
+ * @return established or newly negotiated mastership role
+ */
+ MastershipRole requestRole(DeviceId deviceId);
+
+ /**
+ * Returns the role of a device for a specific controller instance.
+ *
+ * @param nodeId the instance identifier
+ * @param deviceId the device identifiers
+ * @return the role
+ */
+ MastershipRole getRole(NodeId nodeId, DeviceId deviceId);
+
+ /**
+ * Returns the master for a device.
+ *
+ * @param deviceId the device identifier
+ * @return the instance identifier of the master
+ */
+ NodeId getMaster(DeviceId deviceId);
+
+ /**
+ * Returns the devices that a controller instance is master of.
+ *
+ * @param nodeId the instance identifier
+ * @return a set of device identifiers
+ */
+ Set<DeviceId> getDevices(NodeId nodeId);
+
+ /**
+ * Sets a device's role for a specified controller instance.
+ *
+ * @param nodeId controller instance identifier
+ * @param deviceId device identifier
+ * @return a mastership event
+ */
+ DeviceMastershipEvent setMaster(NodeId nodeId, DeviceId deviceId);
+
+ /**
+ * Returns the current master and number of past mastership hand-offs
+ * (terms) for a device.
+ *
+ * @param deviceId the device identifier
+ * @return the current master's ID and the term value for device, or null
+ */
+ DeviceMastershipTerm getTermFor(DeviceId deviceId);
+
+ /**
+ * Sets a controller instance's mastership role to STANDBY for a device.
+ * If the role is MASTER, another controller instance will be selected
+ * as a candidate master.
+ *
+ * @param nodeId the controller instance identifier
+ * @param deviceId device to revoke mastership role for
+ * @return a mastership event
+ */
+ DeviceMastershipEvent setStandby(NodeId nodeId, DeviceId deviceId);
+
+ /**
+ * Allows a controller instance to give up its current role for a device.
+ * If the role is MASTER, another controller instance will be selected
+ * as a candidate master.
+ *
+ * @param nodeId the controller instance identifier
+ * @param deviceId device to revoke mastership role for
+ * @return a mastership event
+ */
+ DeviceMastershipEvent relinquishRole(NodeId nodeId, DeviceId deviceId);
+
+}