initial import
Change-Id: Ief25aef0066ea96bd2c329ccef974c072b3a5a73
diff --git a/of/ctl/src/main/java/net/onrc/onos/of/ctl/registry/IControllerRegistry.java b/of/ctl/src/main/java/net/onrc/onos/of/ctl/registry/IControllerRegistry.java
new file mode 100644
index 0000000..0b67338
--- /dev/null
+++ b/of/ctl/src/main/java/net/onrc/onos/of/ctl/registry/IControllerRegistry.java
@@ -0,0 +1,155 @@
+package net.onrc.onos.of.ctl.registry;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import net.onrc.onos.of.ctl.util.InstanceId;
+
+/**
+ * A registry service that allows ONOS to register controllers and switches in a
+ * way that is global to the entire ONOS cluster. The registry is the arbiter
+ * for allowing controllers to control switches.
+ * <p/>
+ * The OVS/OF1.{2,3} fault tolerance model is a switch connects to multiple
+ * controllers, and the controllers send role requests to tell the switch their
+ * role in controlling the switch.
+ * <p/>
+ * The ONOS fault tolerance model allows only a single controller to have
+ * control of a switch (MASTER role) at once. Controllers therefore need a
+ * mechanism that enables them to decide who should control a each switch. The
+ * registry service provides this mechanism.
+ */
+public interface IControllerRegistry {
+
+ /**
+ * Callback interface for control change events.
+ */
+ public interface ControlChangeCallback {
+ /**
+ * Called whenever the control changes from the point of view of the
+ * registry. The callee can check whether they have control or not using
+ * the hasControl parameter.
+ *
+ * @param dpid The switch that control has changed for
+ * @param hasControl Whether the listener now has control or not
+ */
+ void controlChanged(long dpid, boolean hasControl);
+ }
+
+ /**
+ * Request for control of a switch. This method does not block. When control
+ * for a switch changes, the controlChanged method on the callback object
+ * will be called. This happens any time the control changes while the
+ * request is still active (until releaseControl is called)
+ *
+ * @param dpid Switch to request control for
+ * @param cb Callback that will be used to notify caller of control changes
+ * @throws RegistryException Errors contacting the registry service
+ */
+ public void requestControl(long dpid, ControlChangeCallback cb)
+ throws RegistryException;
+
+ /**
+ * Stop trying to take control of a switch. This removes the entry for this
+ * controller requesting this switch in the registry. If the controller had
+ * control when this is called, another controller will now gain control of
+ * the switch. This call doesn't block.
+ *
+ * @param dpid Switch to release control of
+ */
+ public void releaseControl(long dpid);
+
+ /**
+ * Check whether the controller has control of the switch This call doesn't
+ * block.
+ *
+ * @param dpid Switch to check control of
+ * @return true if controller has control of the switch.
+ */
+ public boolean hasControl(long dpid);
+
+ /**
+ * Check whether this instance is the leader for the cluster. This call
+ * doesn't block.
+ *
+ * @return true if the instance is the leader for the cluster, otherwise
+ * false.
+ */
+ public boolean isClusterLeader();
+
+ /**
+ * Gets the unique ID used to identify this ONOS instance in the cluster.
+ *
+ * @return Instance ID.
+ */
+ public InstanceId getOnosInstanceId();
+
+ /**
+ * Register a controller to the ONOS cluster. Must be called before the
+ * registry can be used to take control of any switches.
+ *
+ * @param controllerId A unique string ID identifying this controller in the
+ * cluster
+ * @throws RegistryException for errors connecting to registry service,
+ * controllerId already registered
+ */
+ public void registerController(String controllerId)
+ throws RegistryException;
+
+ /**
+ * Get all controllers in the cluster.
+ *
+ * @return Collection of controller IDs
+ * @throws RegistryException on error
+ */
+ public Collection<String> getAllControllers() throws RegistryException;
+
+ /**
+ * Get all switches in the cluster, along with which controller is in
+ * control of them (if any) and any other controllers that have requested
+ * control.
+ *
+ * @return Map of all switches.
+ */
+ public Map<String, List<ControllerRegistryEntry>> getAllSwitches();
+
+ /**
+ * Get the controller that has control of a given switch.
+ *
+ * @param dpid Switch to find controller for
+ * @return controller ID
+ * @throws RegistryException Errors contacting registry service
+ */
+ public String getControllerForSwitch(long dpid) throws RegistryException;
+
+ /**
+ * Get all switches controlled by a given controller.
+ *
+ * @param controllerId ID of the controller
+ * @return Collection of dpids
+ */
+ public Collection<Long> getSwitchesControlledByController(String controllerId);
+
+ /**
+ * Get a unique Id Block.
+ *
+ * @return Id Block.
+ */
+ public IdBlock allocateUniqueIdBlock();
+
+ /**
+ * Get next unique id and retrieve a new range of ids if needed.
+ *
+ * @param range range to use for the identifier
+ * @return Id Block.
+ */
+ public IdBlock allocateUniqueIdBlock(long range);
+
+ /**
+ * Get a globally unique ID.
+ *
+ * @return a globally unique ID.
+ */
+ public long getNextUniqueId();
+}