/* * * Copyright 2019 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_SERVER_CONTEXT_IMPL_H #define GRPCPP_IMPL_CODEGEN_SERVER_CONTEXT_IMPL_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct grpc_metadata; struct grpc_call; struct census_context; namespace grpc_impl { class ClientContext; class CompletionQueue; class Server; template class ServerAsyncReader; template class ServerAsyncWriter; template class ServerAsyncResponseWriter; template class ServerAsyncReaderWriter; template class ServerReader; template class ServerWriter; namespace internal { template class BidiStreamingHandler; template class CallbackUnaryHandler; template class CallbackClientStreamingHandler; template class CallbackServerStreamingHandler; template class CallbackBidiHandler; template class ClientStreamingHandler; template class RpcMethodHandler; template class FinishOnlyReactor; template class ServerReaderWriterBody; template class ServerStreamingHandler; class ServerReactor; template class TemplatedBidiStreamingHandler; template <::grpc::StatusCode code> class ErrorMethodHandler; } // namespace internal } // namespace grpc_impl namespace grpc { class GenericServerContext; class ServerInterface; namespace experimental { class GenericCallbackServerContext; } // namespace experimental namespace internal { class Call; } // namespace internal namespace testing { class InteropServerContextInspector; class ServerContextTestSpouse; class DefaultReactorTestPeer; } // namespace testing } // namespace grpc namespace grpc_impl { namespace experimental { /// Base class of ServerContext. Experimental until callback API is final. class ServerContextBase { public: virtual ~ServerContextBase(); /// Return the deadline for the server call. std::chrono::system_clock::time_point deadline() const { return ::grpc::Timespec2Timepoint(deadline_); } /// Return a \a gpr_timespec representation of the server call's deadline. gpr_timespec raw_deadline() const { return deadline_; } /// Add the (\a key, \a value) pair to the initial metadata /// associated with a server call. These are made available at the client side /// by the \a grpc::ClientContext::GetServerInitialMetadata() method. /// /// \warning This method should only be called before sending initial metadata /// to the client (which can happen explicitly, or implicitly when sending a /// a response message or status to the client). /// /// \param key The metadata key. If \a value is binary data, it must /// end in "-bin". /// \param value The metadata value. If its value is binary, the key name /// must end in "-bin". /// /// Metadata must conform to the following format: /// Custom-Metadata -> Binary-Header / ASCII-Header /// Binary-Header -> {Header-Name "-bin" } {binary value} /// ASCII-Header -> Header-Name ASCII-Value /// Header-Name -> 1*( %x30-39 / %x61-7A / "_" / "-" / ".") ; 0-9 a-z _ - . /// ASCII-Value -> 1*( %x20-%x7E ) ; space and printable ASCII void AddInitialMetadata(const grpc::string& key, const grpc::string& value); /// Add the (\a key, \a value) pair to the initial metadata /// associated with a server call. These are made available at the client /// side by the \a grpc::ClientContext::GetServerTrailingMetadata() method. /// /// \warning This method should only be called before sending trailing /// metadata to the client (which happens when the call is finished and a /// status is sent to the client). /// /// \param key The metadata key. If \a value is binary data, /// it must end in "-bin". /// \param value The metadata value. If its value is binary, the key name /// must end in "-bin". /// /// Metadata must conform to the following format: /// Custom-Metadata -> Binary-Header / ASCII-Header /// Binary-Header -> {Header-Name "-bin" } {binary value} /// ASCII-Header -> Header-Name ASCII-Value /// Header-Name -> 1*( %x30-39 / %x61-7A / "_" / "-" / ".") ; 0-9 a-z _ - . /// ASCII-Value -> 1*( %x20-%x7E ) ; space and printable ASCII void AddTrailingMetadata(const grpc::string& key, const grpc::string& value); /// IsCancelled is always safe to call when using sync or callback API. /// When using async API, it is only safe to call IsCancelled after /// the AsyncNotifyWhenDone tag has been delivered. Thread-safe. bool IsCancelled() const; /// Cancel the Call from the server. This is a best-effort API and /// depending on when it is called, the RPC may still appear successful to /// the client. /// For example, if TryCancel() is called on a separate thread, it might race /// with the server handler which might return success to the client before /// TryCancel() was even started by the thread. /// /// It is the caller's responsibility to prevent such races and ensure that if /// TryCancel() is called, the serverhandler must return Status::CANCELLED. /// The only exception is that if the serverhandler is already returning an /// error status code, it is ok to not return Status::CANCELLED even if /// TryCancel() was called. /// /// Note that TryCancel() does not change any of the tags that are pending /// on the completion queue. All pending tags will still be delivered /// (though their ok result may reflect the effect of cancellation). void TryCancel() const; /// Return a collection of initial metadata key-value pairs sent from the /// client. Note that keys may happen more than /// once (ie, a \a std::multimap is returned). /// /// It is safe to use this method after initial metadata has been received, /// Calls always begin with the client sending initial metadata, so this is /// safe to access as soon as the call has begun on the server side. /// /// \return A multimap of initial metadata key-value pairs from the server. const std::multimap& client_metadata() const { return *client_metadata_.map(); } /// Return the compression algorithm to be used by the server call. grpc_compression_level compression_level() const { return compression_level_; } /// Set \a level to be the compression level used for the server call. /// /// \param level The compression level used for the server call. void set_compression_level(grpc_compression_level level) { compression_level_set_ = true; compression_level_ = level; } /// Return a bool indicating whether the compression level for this call /// has been set (either implicitly or through a previous call to /// \a set_compression_level. bool compression_level_set() const { return compression_level_set_; } /// Return the compression algorithm the server call will request be used. /// Note that the gRPC runtime may decide to ignore this request, for example, /// due to resource constraints, or if the server is aware the client doesn't /// support the requested algorithm. grpc_compression_algorithm compression_algorithm() const { return compression_algorithm_; } /// Set \a algorithm to be the compression algorithm used for the server call. /// /// \param algorithm The compression algorithm used for the server call. void set_compression_algorithm(grpc_compression_algorithm algorithm); /// Set the serialized load reporting costs in \a cost_data for the call. void SetLoadReportingCosts(const std::vector& cost_data); /// Return the authentication context for this server call. /// /// \see grpc::AuthContext. std::shared_ptr auth_context() const { if (auth_context_.get() == nullptr) { auth_context_ = ::grpc::CreateAuthContext(call_); } return auth_context_; } /// Return the peer uri in a string. /// WARNING: this value is never authenticated or subject to any security /// related code. It must not be used for any authentication related /// functionality. Instead, use auth_context. grpc::string peer() const; /// Get the census context associated with this server call. const struct census_context* census_context() const; /// Should be used for framework-level extensions only. /// Applications never need to call this method. grpc_call* c_call() { return call_; } protected: /// Async only. Has to be called before the rpc starts. /// Returns the tag in completion queue when the rpc finishes. /// IsCancelled() can then be called to check whether the rpc was cancelled. /// TODO(vjpai): Fix this so that the tag is returned even if the call never /// starts (https://github.com/grpc/grpc/issues/10136). void AsyncNotifyWhenDone(void* tag) { has_notify_when_done_tag_ = true; async_notify_when_done_tag_ = tag; } /// NOTE: This is an API for advanced users who need custom allocators. /// Get and maybe mutate the allocator state associated with the current RPC. /// Currently only applicable for callback unary RPC methods. /// WARNING: This is experimental API and could be changed or removed. ::grpc::experimental::RpcAllocatorState* GetRpcAllocatorState() { return message_allocator_state_; } /// Get a library-owned default unary reactor for use in minimal reaction /// cases. This supports typical unary RPC usage of providing a response and /// status. It supports immediate Finish (finish from within the method /// handler) or delayed Finish (finish called after the method handler /// invocation). It does not support reacting to cancellation or completion, /// or early sending of initial metadata. Since this is a library-owned /// reactor, it should not be delete'd or freed in any way. This is more /// efficient than creating a user-owned reactor both because of avoiding an /// allocation and because its minimal reactions are optimized using a core /// surface flag that allows their reactions to run inline without any /// thread-hop. /// /// This method should not be called more than once or called after return /// from the method handler. /// /// WARNING: This is experimental API and could be changed or removed. ::grpc_impl::experimental::ServerUnaryReactor* DefaultReactor() { auto reactor = &default_reactor_; default_reactor_used_.store(true, std::memory_order_relaxed); return reactor; } /// Constructors for use by derived classes ServerContextBase(); ServerContextBase(gpr_timespec deadline, grpc_metadata_array* arr); private: friend class ::grpc::testing::InteropServerContextInspector; friend class ::grpc::testing::ServerContextTestSpouse; friend class ::grpc::testing::DefaultReactorTestPeer; friend class ::grpc::ServerInterface; friend class ::grpc_impl::Server; template friend class ::grpc_impl::ServerAsyncReader; template friend class ::grpc_impl::ServerAsyncWriter; template friend class ::grpc_impl::ServerAsyncResponseWriter; template friend class ::grpc_impl::ServerAsyncReaderWriter; template friend class ::grpc_impl::ServerReader; template friend class ::grpc_impl::ServerWriter; template friend class ::grpc_impl::internal::ServerReaderWriterBody; template friend class ::grpc_impl::internal::RpcMethodHandler; template friend class ::grpc_impl::internal::ClientStreamingHandler; template friend class ::grpc_impl::internal::ServerStreamingHandler; template friend class ::grpc_impl::internal::TemplatedBidiStreamingHandler; template friend class ::grpc_impl::internal::CallbackUnaryHandler; template friend class ::grpc_impl::internal::CallbackClientStreamingHandler; template friend class ::grpc_impl::internal::CallbackServerStreamingHandler; template friend class ::grpc_impl::internal::CallbackBidiHandler; template <::grpc::StatusCode code> friend class ::grpc_impl::internal::ErrorMethodHandler; template friend class ::grpc_impl::internal::FinishOnlyReactor; friend class ::grpc_impl::ClientContext; friend class ::grpc::GenericServerContext; friend class ::grpc::experimental::GenericCallbackServerContext; /// Prevent copying. ServerContextBase(const ServerContextBase&); ServerContextBase& operator=(const ServerContextBase&); class CompletionOp; void BeginCompletionOp( ::grpc::internal::Call* call, std::function callback, ::grpc_impl::internal::ServerCallbackCall* callback_controller); /// Return the tag queued by BeginCompletionOp() ::grpc::internal::CompletionQueueTag* GetCompletionOpTag(); void set_call(grpc_call* call) { call_ = call; } void BindDeadlineAndMetadata(gpr_timespec deadline, grpc_metadata_array* arr); void Clear(); void Setup(gpr_timespec deadline); uint32_t initial_metadata_flags() const { return 0; } ::grpc::experimental::ServerRpcInfo* set_server_rpc_info( const char* method, ::grpc::internal::RpcMethod::RpcType type, const std::vector>& creators) { if (creators.size() != 0) { rpc_info_ = new ::grpc::experimental::ServerRpcInfo(this, method, type); rpc_info_->RegisterInterceptors(creators); } return rpc_info_; } void set_message_allocator_state( ::grpc::experimental::RpcAllocatorState* allocator_state) { message_allocator_state_ = allocator_state; } CompletionOp* completion_op_; bool has_notify_when_done_tag_; void* async_notify_when_done_tag_; ::grpc::internal::CallbackWithSuccessTag completion_tag_; gpr_timespec deadline_; grpc_call* call_; ::grpc_impl::CompletionQueue* cq_; bool sent_initial_metadata_; mutable std::shared_ptr auth_context_; mutable ::grpc::internal::MetadataMap client_metadata_; std::multimap initial_metadata_; std::multimap trailing_metadata_; bool compression_level_set_; grpc_compression_level compression_level_; grpc_compression_algorithm compression_algorithm_; ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, ::grpc::internal::CallOpSendMessage> pending_ops_; bool has_pending_ops_; ::grpc::experimental::ServerRpcInfo* rpc_info_; ::grpc::experimental::RpcAllocatorState* message_allocator_state_ = nullptr; class Reactor : public experimental::ServerUnaryReactor { public: void OnCancel() override {} void OnDone() override {} // Override InternalInlineable for this class since its reactions are // trivial and thus do not need to be run from the executor (triggering a // thread hop). This should only be used by internal reactors (thus the // name) and not by user application code. bool InternalInlineable() override { return true; } }; void SetupTestDefaultReactor(std::function func) { test_unary_.reset(new TestServerCallbackUnary(this, std::move(func))); } bool test_status_set() const { return (test_unary_ != nullptr) && test_unary_->status_set(); } ::grpc::Status test_status() const { return test_unary_->status(); } class TestServerCallbackUnary : public ::grpc_impl::experimental::ServerCallbackUnary { public: TestServerCallbackUnary(ServerContextBase* ctx, std::function func) : reactor_(&ctx->default_reactor_), func_(std::move(func)) { this->BindReactor(reactor_); } void Finish(::grpc::Status s) override { status_ = s; func_(std::move(s)); status_set_.store(true, std::memory_order_release); } void SendInitialMetadata() override {} bool status_set() const { return status_set_.load(std::memory_order_acquire); } ::grpc::Status status() const { return status_; } private: void MaybeDone() override {} ::grpc_impl::internal::ServerReactor* reactor() override { return reactor_; } ::grpc_impl::experimental::ServerUnaryReactor* const reactor_; std::atomic_bool status_set_{false}; ::grpc::Status status_; const std::function func_; }; Reactor default_reactor_; std::atomic_bool default_reactor_used_{false}; std::unique_ptr test_unary_; }; } // namespace experimental /// A ServerContext or CallbackServerContext allows the code implementing a /// service handler to: /// /// - Add custom initial and trailing metadata key-value pairs that will /// propagated to the client side. /// - Control call settings such as compression and authentication. /// - Access metadata coming from the client. /// - Get performance metrics (ie, census). /// /// Context settings are only relevant to the call handler they are supplied to, /// that is to say, they aren't sticky across multiple calls. Some of these /// settings, such as the compression options, can be made persistent at server /// construction time by specifying the appropriate \a ChannelArguments /// to a \a grpc::ServerBuilder, via \a ServerBuilder::AddChannelArgument. /// /// \warning ServerContext instances should \em not be reused across rpcs. class ServerContext : public experimental::ServerContextBase { public: ServerContext() {} // for async calls using experimental::ServerContextBase::AddInitialMetadata; using experimental::ServerContextBase::AddTrailingMetadata; using experimental::ServerContextBase::IsCancelled; using experimental::ServerContextBase::SetLoadReportingCosts; using experimental::ServerContextBase::TryCancel; using experimental::ServerContextBase::auth_context; using experimental::ServerContextBase::c_call; using experimental::ServerContextBase::census_context; using experimental::ServerContextBase::client_metadata; using experimental::ServerContextBase::compression_algorithm; using experimental::ServerContextBase::compression_level; using experimental::ServerContextBase::compression_level_set; using experimental::ServerContextBase::deadline; using experimental::ServerContextBase::peer; using experimental::ServerContextBase::raw_deadline; using experimental::ServerContextBase::set_compression_algorithm; using experimental::ServerContextBase::set_compression_level; // Sync/CQ-based Async ServerContext only using experimental::ServerContextBase::AsyncNotifyWhenDone; private: // Constructor for internal use by server only friend class ::grpc_impl::Server; ServerContext(gpr_timespec deadline, grpc_metadata_array* arr) : experimental::ServerContextBase(deadline, arr) {} // CallbackServerContext only using experimental::ServerContextBase::DefaultReactor; using experimental::ServerContextBase::GetRpcAllocatorState; /// Prevent copying. ServerContext(const ServerContext&) = delete; ServerContext& operator=(const ServerContext&) = delete; }; namespace experimental { class CallbackServerContext : public ServerContextBase { public: /// Public constructors are for direct use only by mocking tests. In practice, /// these objects will be owned by the library. CallbackServerContext() {} using ServerContextBase::AddInitialMetadata; using ServerContextBase::AddTrailingMetadata; using ServerContextBase::IsCancelled; using ServerContextBase::SetLoadReportingCosts; using ServerContextBase::TryCancel; using ServerContextBase::auth_context; using ServerContextBase::c_call; using ServerContextBase::census_context; using ServerContextBase::client_metadata; using ServerContextBase::compression_algorithm; using ServerContextBase::compression_level; using ServerContextBase::compression_level_set; using ServerContextBase::deadline; using ServerContextBase::peer; using ServerContextBase::raw_deadline; using ServerContextBase::set_compression_algorithm; using ServerContextBase::set_compression_level; // CallbackServerContext only using ServerContextBase::DefaultReactor; using ServerContextBase::GetRpcAllocatorState; private: // Sync/CQ-based Async ServerContext only using ServerContextBase::AsyncNotifyWhenDone; /// Prevent copying. CallbackServerContext(const CallbackServerContext&) = delete; CallbackServerContext& operator=(const CallbackServerContext&) = delete; }; } // namespace experimental } // namespace grpc_impl static_assert(std::is_base_of<::grpc_impl::experimental::ServerContextBase, ::grpc_impl::ServerContext>::value, "improper base class"); static_assert( std::is_base_of<::grpc_impl::experimental::ServerContextBase, ::grpc_impl::experimental::CallbackServerContext>::value, "improper base class"); static_assert(sizeof(::grpc_impl::experimental::ServerContextBase) == sizeof(::grpc_impl::ServerContext), "wrong size"); static_assert(sizeof(::grpc_impl::experimental::ServerContextBase) == sizeof(::grpc_impl::experimental::CallbackServerContext), "wrong size"); #endif // GRPCPP_IMPL_CODEGEN_SERVER_CONTEXT_IMPL_H