// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
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package com.google.protobuf;
/**
* <p>Abstract interface for an RPC channel. An {@code RpcChannel} represents a
* communication line to a {@link Service} which can be used to call that
* {@link Service}'s methods. The {@link Service} may be running on another
* machine. Normally, you should not call an {@code RpcChannel} directly, but
* instead construct a stub {@link Service} wrapping it. Example:
*
* <pre>
* RpcChannel channel = rpcImpl.newChannel("remotehost.example.com:1234");
* RpcController controller = rpcImpl.newController();
* MyService service = MyService.newStub(channel);
* service.myMethod(controller, request, callback);
* </pre>
*
* <p>Starting with version 2.3.0, RPC implementations should not try to build
* on this, but should instead provide code generator plugins which generate
* code specific to the particular RPC implementation. This way the generated
* code can be more appropriate for the implementation in use and can avoid
* unnecessary layers of indirection.
*
* @author kenton@google.com Kenton Varda
*/
public interface RpcChannel {
/**
* Call the given method of the remote service. This method is similar to
* {@code Service.callMethod()} with one important difference: the caller
* decides the types of the {@code Message} objects, not the callee. The
* request may be of any type as long as
* {@code request.getDescriptor() == method.getInputType()}.
* The response passed to the callback will be of the same type as
* {@code responsePrototype} (which must have
* {@code getDescriptor() == method.getOutputType()}).
*/
void callMethod(Descriptors.MethodDescriptor method,
RpcController controller,
Message request,
Message responsePrototype,
RpcCallback<Message> done);
}