A developer implemented component that gets registered with the Broker.
Semantically, a provider may:
- Emit Notifications
- Provide the implementation of RPCs
- Write to the operational data tree
If a class is not doing at least one of those three, consider using
a BindingAwareConsumer instead:
see
org.opendaylight.controller.sal.binding.api.BindingAwareConsumer
In addition, a BindingAwareProvider can in pursuit of its goals:
- Subscribe for Notifications
- Invoke RPCs
- Read from either the operational or config data tree
- Write to the config data tree
(All of the above are things a Consumer can also do).
Examples:
To get a NotificationService:
public void onSessionInitiated(ProviderContext session) }
For more information on sending notifications via the NotificationProviderService
see
org.opendaylight.controller.sal.binding.api.NotificationProviderService
To register an RPC implementation:
public void onSessionInitiated(ProviderContext session) }
Where MyService.class is a Service interface generated from a yang model with RPCs modeled in it and
myImplementationInstance is an instance of a class that implements MyService.
To register a Routed RPC Implementation:
public void onSessionInitiated(ProviderContext session) }
Where SalFlowService.class is a Service interface generated from a yang model with RPCs modeled in it and
salFlowServiceImplementationInstance is an instance of a class that implements SalFlowService.
The line:
flowRegistration.registerPath(NodeContext.class, nodeInstanceId);Is indicating that the RPC implementation is registered to handle RPC invocations that have their NodeContext
pointing to the node with instance id nodeInstanceId. This bears a bit of further explanation. RoutedRPCs can be
'routed' to an implementation based upon 'context'. 'context' is a pointer (instanceId) to some place in the data
tree. In this example, the 'context' is a pointer to a Node. In this way, a provider can register its ability to
provide a service for a particular Node, but not *all* Nodes. The Broker routes the RPC by 'context' to the correct
implementation, without the caller having to do extra work. Because of this when a RoutedRPC is registered, it
needs to also be able to indicate for which 'contexts' it is providing an implementation.
An example of a Routed RPC would be an updateFlow(node, flow) that would be routed based on node to the provider
which had registered to provide it *for that node*.
To get a DataBroker to allow access to the data tree:
public void onSessionInitiated(final ProviderContext session) }