| /* |
| * |
| * 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_IMPL_H |
| #define GRPCPP_IMPL_CODEGEN_METHOD_HANDLER_IMPL_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> |
| Status CatchingFunctionHandler(Callable&& handler) { |
| #if GRPC_ALLOW_EXCEPTIONS |
| try { |
| return handler(); |
| } catch (...) { |
| return Status(StatusCode::UNKNOWN, "Unexpected error in RPC handling"); |
| } |
| #else // GRPC_ALLOW_EXCEPTIONS |
| return handler(); |
| #endif // GRPC_ALLOW_EXCEPTIONS |
| } |
| |
| /// 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) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ResponseType rsp; |
| Status status = param.status; |
| if (status.ok()) { |
| status = CatchingFunctionHandler([this, ¶m, &rsp] { |
| return func_(service_, param.server_context, |
| static_cast<RequestType*>(param.request), &rsp); |
| }); |
| static_cast<RequestType*>(param.request)->~RequestType(); |
| } |
| |
| GPR_CODEGEN_ASSERT(!param.server_context->sent_initial_metadata_); |
| CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage, |
| 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.SendMessage(rsp); |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| void* Deserialize(grpc_call* call, grpc_byte_buffer* req, |
| Status* status) final { |
| ByteBuffer buf; |
| buf.set_buffer(req); |
| auto* request = new (g_core_codegen_interface->grpc_call_arena_alloc( |
| call, sizeof(RequestType))) RequestType(); |
| *status = SerializationTraits<RequestType>::Deserialize(&buf, request); |
| buf.Release(); |
| if (status->ok()) { |
| return request; |
| } |
| request->~RequestType(); |
| return nullptr; |
| } |
| |
| 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) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| ServerReader<RequestType> reader(param.call, param.server_context); |
| ResponseType rsp; |
| Status status = CatchingFunctionHandler([this, ¶m, &reader, &rsp] { |
| return func_(service_, param.server_context, &reader, &rsp); |
| }); |
| |
| CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage, |
| 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.SendMessage(rsp); |
| } |
| ops.ServerSendStatus(¶m.server_context->trailing_metadata_, status); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| 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) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| Status status = param.status; |
| if (status.ok()) { |
| ServerWriter<ResponseType> writer(param.call, param.server_context); |
| status = CatchingFunctionHandler([this, ¶m, &writer] { |
| return func_(service_, param.server_context, |
| static_cast<RequestType*>(param.request), &writer); |
| }); |
| static_cast<RequestType*>(param.request)->~RequestType(); |
| } |
| |
| CallOpSet<CallOpSendInitialMetadata, 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, |
| Status* status) final { |
| ByteBuffer buf; |
| buf.set_buffer(req); |
| auto* request = new (g_core_codegen_interface->grpc_call_arena_alloc( |
| call, sizeof(RequestType))) RequestType(); |
| *status = SerializationTraits<RequestType>::Deserialize(&buf, request); |
| buf.Release(); |
| if (status->ok()) { |
| return request; |
| } |
| request->~RequestType(); |
| return nullptr; |
| } |
| |
| private: |
| std::function<Status(ServiceType*, 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 MethodHandler { |
| public: |
| TemplatedBidiStreamingHandler( |
| std::function<Status(ServerContext*, Streamer*)> func) |
| : func_(func), write_needed_(WriteNeeded) {} |
| |
| void RunHandler(const HandlerParameter& param) final { |
| Streamer stream(param.call, param.server_context); |
| Status status = CatchingFunctionHandler([this, ¶m, &stream] { |
| return func_(param.server_context, &stream); |
| }); |
| |
| CallOpSet<CallOpSendInitialMetadata, 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 = Status(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<Status(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<Status(ServiceType*, ServerContext*, |
| ServerReaderWriter<ResponseType, RequestType>*)> |
| func, |
| ServiceType* service) |
| : TemplatedBidiStreamingHandler< |
| ServerReaderWriter<ResponseType, RequestType>, false>(std::bind( |
| func, service, std::placeholders::_1, std::placeholders::_2)) {} |
| }; |
| |
| template <class RequestType, class ResponseType> |
| class StreamedUnaryHandler |
| : public TemplatedBidiStreamingHandler< |
| ServerUnaryStreamer<RequestType, ResponseType>, true> { |
| public: |
| explicit StreamedUnaryHandler( |
| std::function<Status(ServerContext*, |
| ServerUnaryStreamer<RequestType, ResponseType>*)> |
| func) |
| : TemplatedBidiStreamingHandler< |
| ServerUnaryStreamer<RequestType, ResponseType>, true>(func) {} |
| }; |
| |
| template <class RequestType, class ResponseType> |
| class SplitServerStreamingHandler |
| : public TemplatedBidiStreamingHandler< |
| ServerSplitStreamer<RequestType, ResponseType>, false> { |
| public: |
| explicit SplitServerStreamingHandler( |
| std::function<Status(ServerContext*, |
| ServerSplitStreamer<RequestType, ResponseType>*)> |
| func) |
| : TemplatedBidiStreamingHandler< |
| ServerSplitStreamer<RequestType, ResponseType>, false>(func) {} |
| }; |
| |
| /// General method handler class for errors that prevent real method use |
| /// e.g., handle unknown method by returning UNIMPLEMENTED error. |
| template <StatusCode code> |
| class ErrorMethodHandler : public MethodHandler { |
| public: |
| template <class T> |
| static void FillOps(ServerContext* context, T* ops) { |
| Status status(code, ""); |
| 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 { |
| CallOpSet<CallOpSendInitialMetadata, CallOpServerSendStatus> ops; |
| FillOps(param.server_context, &ops); |
| param.call->PerformOps(&ops); |
| param.call->cq()->Pluck(&ops); |
| } |
| |
| void* Deserialize(grpc_call* call, grpc_byte_buffer* req, |
| Status* status) final { |
| // We have to destroy any request payload |
| if (req != nullptr) { |
| g_core_codegen_interface->grpc_byte_buffer_destroy(req); |
| } |
| return nullptr; |
| } |
| }; |
| |
| typedef ErrorMethodHandler<StatusCode::UNIMPLEMENTED> UnknownMethodHandler; |
| typedef ErrorMethodHandler<StatusCode::RESOURCE_EXHAUSTED> |
| ResourceExhaustedHandler; |
| |
| } // namespace internal |
| } // namespace grpc |
| |
| #endif // GRPCPP_IMPL_CODEGEN_METHOD_HANDLER_IMPL_H |