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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef GRPCXX_IMPL_RPC_SERVICE_METHOD_H
#define GRPCXX_IMPL_RPC_SERVICE_METHOD_H
#include <functional>
#include <map>
#include <memory>
#include <vector>
#include <grpc++/impl/rpc_method.h>
#include <grpc++/status.h>
#include <grpc++/stream.h>
#include <google/protobuf/message.h>
namespace grpc {
class ServerContext;
class StreamContextInterface;
// TODO(rocking): we might need to split this file into multiple ones.
// Base class for running an RPC handler.
class MethodHandler {
public:
virtual ~MethodHandler() {}
struct HandlerParameter {
HandlerParameter(Call* c, ServerContext* context,
const grpc::protobuf::Message* req,
grpc::protobuf::Message* resp)
: call(c), server_context(context), request(req), response(resp) {}
Call* call;
ServerContext* server_context;
const grpc::protobuf::Message* request;
grpc::protobuf::Message* response;
};
virtual Status RunHandler(const HandlerParameter& param) = 0;
};
// A wrapper class of an application provided rpc method handler.
template <class ServiceType, class RequestType, class ResponseType>
class RpcMethodHandler : public MethodHandler {
public:
RpcMethodHandler(
std::function<Status(ServiceType*, ServerContext*, const RequestType*,
ResponseType*)> func,
ServiceType* service)
: func_(func), service_(service) {}
Status RunHandler(const HandlerParameter& param) GRPC_FINAL {
// Invoke application function, cast proto messages to their actual types.
return func_(service_, param.server_context,
dynamic_cast<const RequestType*>(param.request),
dynamic_cast<ResponseType*>(param.response));
}
private:
// Application provided rpc handler function.
std::function<Status(ServiceType*, ServerContext*, const RequestType*,
ResponseType*)> func_;
// The class the above handler function lives in.
ServiceType* service_;
};
// A wrapper class of an application provided client streaming handler.
template <class ServiceType, class RequestType, class ResponseType>
class ClientStreamingHandler : public MethodHandler {
public:
ClientStreamingHandler(
std::function<Status(ServiceType*, ServerContext*,
ServerReader<RequestType>*, ResponseType*)> func,
ServiceType* service)
: func_(func), service_(service) {}
Status RunHandler(const HandlerParameter& param) GRPC_FINAL {
ServerReader<RequestType> reader(param.call, param.server_context);
return func_(service_, param.server_context, &reader,
dynamic_cast<ResponseType*>(param.response));
}
private:
std::function<Status(ServiceType*, ServerContext*, ServerReader<RequestType>*,
ResponseType*)> func_;
ServiceType* service_;
};
// A wrapper class of an application provided server streaming handler.
template <class ServiceType, class RequestType, class ResponseType>
class ServerStreamingHandler : public MethodHandler {
public:
ServerStreamingHandler(
std::function<Status(ServiceType*, ServerContext*, const RequestType*,
ServerWriter<ResponseType>*)> func,
ServiceType* service)
: func_(func), service_(service) {}
Status RunHandler(const HandlerParameter& param) GRPC_FINAL {
ServerWriter<ResponseType> writer(param.call, param.server_context);
return func_(service_, param.server_context,
dynamic_cast<const RequestType*>(param.request), &writer);
}
private:
std::function<Status(ServiceType*, ServerContext*, const RequestType*,
ServerWriter<ResponseType>*)> func_;
ServiceType* service_;
};
// A wrapper class of an application provided bidi-streaming handler.
template <class ServiceType, class RequestType, class ResponseType>
class BidiStreamingHandler : public MethodHandler {
public:
BidiStreamingHandler(
std::function<Status(ServiceType*, ServerContext*,
ServerReaderWriter<ResponseType, RequestType>*)>
func,
ServiceType* service)
: func_(func), service_(service) {}
Status RunHandler(const HandlerParameter& param) GRPC_FINAL {
ServerReaderWriter<ResponseType, RequestType> stream(param.call,
param.server_context);
return func_(service_, param.server_context, &stream);
}
private:
std::function<Status(ServiceType*, ServerContext*,
ServerReaderWriter<ResponseType, RequestType>*)> func_;
ServiceType* service_;
};
// Server side rpc method class
class RpcServiceMethod : public RpcMethod {
public:
// Takes ownership of the handler and two prototype objects.
RpcServiceMethod(const char* name, RpcMethod::RpcType type,
MethodHandler* handler,
grpc::protobuf::Message* request_prototype,
grpc::protobuf::Message* response_prototype)
: RpcMethod(name, type),
handler_(handler),
request_prototype_(request_prototype),
response_prototype_(response_prototype) {}
MethodHandler* handler() { return handler_.get(); }
grpc::protobuf::Message* AllocateRequestProto() {
return request_prototype_->New();
}
grpc::protobuf::Message* AllocateResponseProto() {
return response_prototype_->New();
}
private:
std::unique_ptr<MethodHandler> handler_;
std::unique_ptr<grpc::protobuf::Message> request_prototype_;
std::unique_ptr<grpc::protobuf::Message> response_prototype_;
};
// This class contains all the method information for an rpc service. It is
// used for registering a service on a grpc server.
class RpcService {
public:
// Takes ownership.
void AddMethod(RpcServiceMethod* method) { methods_.emplace_back(method); }
RpcServiceMethod* GetMethod(int i) { return methods_[i].get(); }
int GetMethodCount() const { return methods_.size(); }
private:
std::vector<std::unique_ptr<RpcServiceMethod>> methods_;
};
} // namespace grpc
#endif // GRPCXX_IMPL_RPC_SERVICE_METHOD_H
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