/*
* Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.sal.binding.api;
import org.opendaylight.controller.md.sal.binding.api.BindingService;
import org.opendaylight.yangtools.yang.binding.RpcService;
/**
* Provides access to registered Remote Procedure Call (RPC) service implementations. The RPCs are
* defined in YANG models.
* <p>
* RPC implementations are registered using the {@link RpcProviderRegistry}.
*
*/
public interface RpcConsumerRegistry extends BindingAwareService, BindingService {
/**
* Returns an implementation of a requested RPC service.
*
* <p>
* The returned instance is not an actual implementation of the RPC service
* interface, but a proxy implementation of the interface that forwards to
* an actual implementation, if any.
* <p>
*
* The following describes the behavior of the proxy when invoking RPC methods:
* <ul>
* <li>If an actual implementation is registered with the MD-SAL, all invocations are
* forwarded to the registered implementation.</li>
* <li>If no actual implementation is registered, all invocations will fail by
* throwing {@link IllegalStateException}.</li>
* <li>Prior to invoking the actual implementation, the method arguments are are validated.
* If any are invalid, an {@link IllegalArgumentException} is thrown.
* </ul>
*
* The returned proxy is automatically updated with the most recent
* registered implementation.
* <p>
* The generated RPC method APIs require implementors to return a {@link java.util.concurrent.Future Future}
* instance that wraps the {@link org.opendaylight.yangtools.yang.common.RpcResult RpcResult}. Since
* RPC methods may be implemented asynchronously, callers should avoid blocking on the
* {@link java.util.concurrent.Future Future} result. Instead, it is recommended to use
* {@link com.google.common.util.concurrent.JdkFutureAdapters#listenInPoolThread(java.util.concurrent.Future)}
* or {@link com.google.common.util.concurrent.JdkFutureAdapters#listenInPoolThread(java.util.concurrent.Future, java.util.concurrent.Executor)}
* to listen for Rpc Result. This will asynchronously listen for future result in executor and
* will not block current thread.
*
* {@code
* final Future<RpcResult<SomeRpcOutput>> future = someRpcService.someRpc( ... );
* Futures.addCallback(JdkFutureAdapters.listenInThreadPool(future), new FutureCallback<RpcResult<SomeRpcOutput>>() {
*
* public void onSuccess(RpcResult<SomeRpcOutput> result) {
* // process result ...
* }
*
* public void onFailure(Throwable t) {
* // RPC failed
* }
* );
* }
* }
*
* @param serviceInterface the interface of the RPC Service. Typically this is an interface generated
* from a YANG model.
* @return the proxy for the requested RPC service. This method never returns null.
*/
<T extends RpcService> T getRpcService(Class<T> serviceInterface);
}