| /* |
| * |
| * 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_METHOD_HANDLER_H |
| #define GRPCPP_IMPL_CODEGEN_METHOD_HANDLER_H |
| |
| #include <grpcpp/impl/codegen/byte_buffer.h> |
| #include <grpcpp/impl/codegen/core_codegen_interface.h> |
| #include <grpcpp/impl/codegen/rpc_service_method.h> |
| #include <grpcpp/impl/codegen/sync_stream.h> |
| |
| namespace grpc { |
| |
| namespace internal { |
| |
| // Invoke the method handler, fill in the status, and |
| // return whether or not we finished safely (without an exception). |
| // Note that exception handling is 0-cost in most compiler/library |
| // implementations (except when an exception is actually thrown), |
| // so this process doesn't require additional overhead in the common case. |
| // Additionally, we don't need to return if we caught an exception or not; |
| // the handling is the same in either case. |
| template <class Callable> |
| ::grpc::Status CatchingFunctionHandler(Callable&& handler) { |
| #if GRPC_ALLOW_EXCEPTIONS |
| try { |
| return handler(); |
| } catch (...) { |
| return ::grpc::Status(::grpc::StatusCode::UNKNOWN, |
| "Unexpected error in RPC handling"); |
| } |
| #else // GRPC_ALLOW_EXCEPTIONS |
| return handler(); |
| #endif // GRPC_ALLOW_EXCEPTIONS |
| } |
| |
| /// A helper function with reduced templating to do the common work needed to |
| /// actually send the server response. Uses non-const parameter for Status since |
| /// this should only ever be called from the end of the RunHandler method. |
| |
| template <class ResponseType> |
| void UnaryRunHandlerHelper(const MethodHandler::HandlerParameter& param, |
| ResponseType* rsp, ::grpc::Status& status) { |
| GPR_CODEGEN_ASSERT(!param.server_context->sent_initial_metadata_); |
| ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, |
| ::grpc::internal::CallOpSendMessage, |
| ::grpc::internal::CallOpServerSendStatus> |
| ops; |
| ops.SendInitialMetadata(¶m.server_context->initial_metadata_, |
| param.server_context->initial_metadata_flags()); |
| if (param.server_context->compression_level_set()) { |
| ops.set_compression_level(param.server_context->compression_level()); |
| } |
| if (status.ok()) { |
| status = ops.SendMessagePtr(rsp); |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| /// A helper function with reduced templating to do deserializing. |
| |
| template <class RequestType> |
| void* UnaryDeserializeHelper(grpc_byte_buffer* req, ::grpc::Status* status, |
| RequestType* request) { |
| ::grpc::ByteBuffer buf; |
| buf.set_buffer(req); |
| *status = ::grpc::SerializationTraits<RequestType>::Deserialize( |
| &buf, static_cast<RequestType*>(request)); |
| buf.Release(); |
| if (status->ok()) { |
| return request; |
| } |
| request->~RequestType(); |
| return nullptr; |
| } |
| |
| /// A wrapper class of an application provided rpc method handler. |
| template <class ServiceType, class RequestType, class ResponseType, |
| class BaseRequestType = RequestType, |
| class BaseResponseType = ResponseType> |
| class RpcMethodHandler : public ::grpc::internal::MethodHandler { |
| public: |
| RpcMethodHandler( |
| std::function<::grpc::Status(ServiceType*, ::grpc::ServerContext*, |
| const RequestType*, ResponseType*)> |
| func, |
| ServiceType* service) |
| : func_(func), service_(service) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ResponseType rsp; |
| ::grpc::Status status = param.status; |
| if (status.ok()) { |
| status = CatchingFunctionHandler([this, ¶m, &rsp] { |
| return func_(service_, |
| static_cast<::grpc::ServerContext*>(param.server_context), |
| static_cast<RequestType*>(param.request), &rsp); |
| }); |
| static_cast<RequestType*>(param.request)->~RequestType(); |
| } |
| UnaryRunHandlerHelper(param, static_cast<BaseResponseType*>(&rsp), status); |
| } |
| |
| void* Deserialize(grpc_call* call, grpc_byte_buffer* req, |
| ::grpc::Status* status, void** /*handler_data*/) final { |
| auto* request = |
| new (::grpc::g_core_codegen_interface->grpc_call_arena_alloc( |
| call, sizeof(RequestType))) RequestType; |
| return UnaryDeserializeHelper(req, status, |
| static_cast<BaseRequestType*>(request)); |
| } |
| |
| private: |
| /// Application provided rpc handler function. |
| std::function<::grpc::Status(ServiceType*, ::grpc::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 ::grpc::internal::MethodHandler { |
| public: |
| ClientStreamingHandler( |
| std::function<::grpc::Status(ServiceType*, ::grpc::ServerContext*, |
| ServerReader<RequestType>*, ResponseType*)> |
| func, |
| ServiceType* service) |
| : func_(func), service_(service) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ServerReader<RequestType> reader( |
| param.call, static_cast<::grpc::ServerContext*>(param.server_context)); |
| ResponseType rsp; |
| ::grpc::Status status = CatchingFunctionHandler([this, ¶m, &reader, |
| &rsp] { |
| return func_(service_, |
| static_cast<::grpc::ServerContext*>(param.server_context), |
| &reader, &rsp); |
| }); |
| |
| ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, |
| ::grpc::internal::CallOpSendMessage, |
| ::grpc::internal::CallOpServerSendStatus> |
| ops; |
| if (!param.server_context->sent_initial_metadata_) { |
| ops.SendInitialMetadata(¶m.server_context->initial_metadata_, |
| param.server_context->initial_metadata_flags()); |
| if (param.server_context->compression_level_set()) { |
| ops.set_compression_level(param.server_context->compression_level()); |
| } |
| } |
| if (status.ok()) { |
| status = ops.SendMessagePtr(&rsp); |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| private: |
| std::function<::grpc::Status(ServiceType*, ::grpc::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 ::grpc::internal::MethodHandler { |
| public: |
| ServerStreamingHandler(std::function<::grpc::Status( |
| ServiceType*, ::grpc::ServerContext*, |
| const RequestType*, ServerWriter<ResponseType>*)> |
| func, |
| ServiceType* service) |
| : func_(func), service_(service) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ::grpc::Status status = param.status; |
| if (status.ok()) { |
| ServerWriter<ResponseType> writer( |
| param.call, |
| static_cast<::grpc::ServerContext*>(param.server_context)); |
| status = CatchingFunctionHandler([this, ¶m, &writer] { |
| return func_(service_, |
| static_cast<::grpc::ServerContext*>(param.server_context), |
| static_cast<RequestType*>(param.request), &writer); |
| }); |
| static_cast<RequestType*>(param.request)->~RequestType(); |
| } |
| |
| ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, |
| ::grpc::internal::CallOpServerSendStatus> |
| ops; |
| if (!param.server_context->sent_initial_metadata_) { |
| ops.SendInitialMetadata(¶m.server_context->initial_metadata_, |
| param.server_context->initial_metadata_flags()); |
| if (param.server_context->compression_level_set()) { |
| ops.set_compression_level(param.server_context->compression_level()); |
| } |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| if (param.server_context->has_pending_ops_) { |
| param.call->cq()->Pluck(¶m.server_context->pending_ops_); |
| } |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| void* Deserialize(grpc_call* call, grpc_byte_buffer* req, |
| ::grpc::Status* status, void** /*handler_data*/) final { |
| ::grpc::ByteBuffer buf; |
| buf.set_buffer(req); |
| auto* request = |
| new (::grpc::g_core_codegen_interface->grpc_call_arena_alloc( |
| call, sizeof(RequestType))) RequestType(); |
| *status = |
| ::grpc::SerializationTraits<RequestType>::Deserialize(&buf, request); |
| buf.Release(); |
| if (status->ok()) { |
| return request; |
| } |
| request->~RequestType(); |
| return nullptr; |
| } |
| |
| private: |
| std::function<::grpc::Status(ServiceType*, ::grpc::ServerContext*, |
| const RequestType*, ServerWriter<ResponseType>*)> |
| func_; |
| ServiceType* service_; |
| }; |
| |
| /// A wrapper class of an application provided bidi-streaming handler. |
| /// This also applies to server-streamed implementation of a unary method |
| /// with the additional requirement that such methods must have done a |
| /// write for status to be ok |
| /// Since this is used by more than 1 class, the service is not passed in. |
| /// Instead, it is expected to be an implicitly-captured argument of func |
| /// (through bind or something along those lines) |
| template <class Streamer, bool WriteNeeded> |
| class TemplatedBidiStreamingHandler : public ::grpc::internal::MethodHandler { |
| public: |
| explicit TemplatedBidiStreamingHandler( |
| std::function<::grpc::Status(::grpc::ServerContext*, Streamer*)> func) |
| : func_(func), write_needed_(WriteNeeded) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| Streamer stream(param.call, |
| static_cast<::grpc::ServerContext*>(param.server_context)); |
| ::grpc::Status status = CatchingFunctionHandler([this, ¶m, &stream] { |
| return func_(static_cast<::grpc::ServerContext*>(param.server_context), |
| &stream); |
| }); |
| |
| ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, |
| ::grpc::internal::CallOpServerSendStatus> |
| ops; |
| if (!param.server_context->sent_initial_metadata_) { |
| ops.SendInitialMetadata(¶m.server_context->initial_metadata_, |
| param.server_context->initial_metadata_flags()); |
| if (param.server_context->compression_level_set()) { |
| ops.set_compression_level(param.server_context->compression_level()); |
| } |
| if (write_needed_ && status.ok()) { |
| // If we needed a write but never did one, we need to mark the |
| // status as a fail |
| status = ::grpc::Status(::grpc::StatusCode::INTERNAL, |
| "Service did not provide response message"); |
| } |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| if (param.server_context->has_pending_ops_) { |
| param.call->cq()->Pluck(¶m.server_context->pending_ops_); |
| } |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| private: |
| std::function<::grpc::Status(::grpc::ServerContext*, Streamer*)> func_; |
| const bool write_needed_; |
| }; |
| |
| template <class ServiceType, class RequestType, class ResponseType> |
| class BidiStreamingHandler |
| : public TemplatedBidiStreamingHandler< |
| ServerReaderWriter<ResponseType, RequestType>, false> { |
| public: |
| BidiStreamingHandler(std::function<::grpc::Status( |
| ServiceType*, ::grpc::ServerContext*, |
| ServerReaderWriter<ResponseType, RequestType>*)> |
| func, |
| ServiceType* service) |
| // TODO(vjpai): When gRPC supports C++14, move-capture func in the below |
| : TemplatedBidiStreamingHandler< |
| ServerReaderWriter<ResponseType, RequestType>, false>( |
| [func, service]( |
| ::grpc::ServerContext* ctx, |
| ServerReaderWriter<ResponseType, RequestType>* streamer) { |
| return func(service, ctx, streamer); |
| }) {} |
| }; |
| |
| template <class RequestType, class ResponseType> |
| class StreamedUnaryHandler |
| : public TemplatedBidiStreamingHandler< |
| ServerUnaryStreamer<RequestType, ResponseType>, true> { |
| public: |
| explicit StreamedUnaryHandler( |
| std::function< |
| ::grpc::Status(::grpc::ServerContext*, |
| ServerUnaryStreamer<RequestType, ResponseType>*)> |
| func) |
| : TemplatedBidiStreamingHandler< |
| ServerUnaryStreamer<RequestType, ResponseType>, true>( |
| std::move(func)) {} |
| }; |
| |
| template <class RequestType, class ResponseType> |
| class SplitServerStreamingHandler |
| : public TemplatedBidiStreamingHandler< |
| ServerSplitStreamer<RequestType, ResponseType>, false> { |
| public: |
| explicit SplitServerStreamingHandler( |
| std::function< |
| ::grpc::Status(::grpc::ServerContext*, |
| ServerSplitStreamer<RequestType, ResponseType>*)> |
| func) |
| : TemplatedBidiStreamingHandler< |
| ServerSplitStreamer<RequestType, ResponseType>, false>( |
| std::move(func)) {} |
| }; |
| |
| /// General method handler class for errors that prevent real method use |
| /// e.g., handle unknown method by returning UNIMPLEMENTED error. |
| template <::grpc::StatusCode code> |
| class ErrorMethodHandler : public ::grpc::internal::MethodHandler { |
| public: |
| explicit ErrorMethodHandler(const std::string& message) : message_(message) {} |
| |
| template <class T> |
| static void FillOps(::grpc::ServerContextBase* context, |
| const std::string& message, T* ops) { |
| ::grpc::Status status(code, message); |
| if (!context->sent_initial_metadata_) { |
| ops->SendInitialMetadata(&context->initial_metadata_, |
| context->initial_metadata_flags()); |
| if (context->compression_level_set()) { |
| ops->set_compression_level(context->compression_level()); |
| } |
| context->sent_initial_metadata_ = true; |
| } |
| ops->ServerSendStatus(&context->trailing_metadata_, status); |
| } |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, |
| ::grpc::internal::CallOpServerSendStatus> |
| ops; |
| FillOps(param.server_context, message_, &ops); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| void* Deserialize(grpc_call* /*call*/, grpc_byte_buffer* req, |
| ::grpc::Status* /*status*/, void** /*handler_data*/) final { |
| // We have to destroy any request payload |
| if (req != nullptr) { |
| ::grpc::g_core_codegen_interface->grpc_byte_buffer_destroy(req); |
| } |
| return nullptr; |
| } |
| |
| private: |
| const std::string message_; |
| }; |
| |
| typedef ErrorMethodHandler<::grpc::StatusCode::UNIMPLEMENTED> |
| UnknownMethodHandler; |
| typedef ErrorMethodHandler<::grpc::StatusCode::RESOURCE_EXHAUSTED> |
| ResourceExhaustedHandler; |
| |
| } // namespace internal |
| } // namespace grpc |
| |
| #endif // GRPCPP_IMPL_CODEGEN_METHOD_HANDLER_H |