async_generic_service.h

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/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#ifndef GRPCPP_IMPL_CODEGEN_ASYNC_GENERIC_SERVICE_H
#define GRPCPP_IMPL_CODEGEN_ASYNC_GENERIC_SERVICE_H

#include <grpcpp/impl/codegen/async_stream.h>
#include <grpcpp/impl/codegen/byte_buffer.h>

struct grpc_server;

namespace grpc {

typedef ServerAsyncReaderWriter<ByteBuffer, ByteBuffer>
    GenericServerAsyncReaderWriter;
typedef ServerAsyncResponseWriter<ByteBuffer> GenericServerAsyncResponseWriter;
typedef ServerAsyncReader<ByteBuffer, ByteBuffer> GenericServerAsyncReader;
typedef ServerAsyncWriter<ByteBuffer> GenericServerAsyncWriter;

class GenericServerContext final : public ServerContext {
 public:
  const grpc::string& method() const { return method_; }
  const grpc::string& host() const { return host_; }

 private:
  friend class Server;
  friend class ServerInterface;

  grpc::string method_;
  grpc::string host_;
};

// A generic service at the server side accepts all RPC methods and hosts. It is
// typically used in proxies. The generic service can be registered to a server
// which also has other services.
// Sample usage:
//   ServerBuilder builder;
//   auto cq = builder.AddCompletionQueue();
//   AsyncGenericService generic_service;
//   builder.RegisterAsyncGenericService(&generic_service);
//   auto server = builder.BuildAndStart();
//
//   // request a new call
//   GenericServerContext context;
//   GenericServerAsyncReaderWriter stream;
//   generic_service.RequestCall(&context, &stream, cq.get(), cq.get(), tag);
//
// When tag is retrieved from cq->Next(), context.method() can be used to look
// at the method and the RPC can be handled accordingly.
class AsyncGenericService final {
 public:
  AsyncGenericService() : server_(nullptr) {}

  void RequestCall(GenericServerContext* ctx,
                   GenericServerAsyncReaderWriter* reader_writer,
                   CompletionQueue* call_cq,
                   ServerCompletionQueue* notification_cq, void* tag);

 private:
  friend class Server;
  Server* server_;
};

}  // namespace grpc

#endif  // GRPCPP_IMPL_CODEGEN_ASYNC_GENERIC_SERVICE_H