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Diffstat (limited to 'include/grpc++/impl/codegen/client_context.h')
-rw-r--r-- | include/grpc++/impl/codegen/client_context.h | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/include/grpc++/impl/codegen/client_context.h b/include/grpc++/impl/codegen/client_context.h new file mode 100644 index 0000000000..db2afe930c --- /dev/null +++ b/include/grpc++/impl/codegen/client_context.h @@ -0,0 +1,354 @@ +/* + * + * Copyright 2015-2016, 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. + * + */ + +/// A ClientContext allows the person implementing a service client to: +/// +/// - Add custom metadata key-value pairs that will propagated to the server +/// side. +/// - Control call settings such as compression and authentication. +/// - Initial and trailing metadata coming from the server. +/// - Get performance metrics (ie, census). +/// +/// Context settings are only relevant to the call they are invoked with, that +/// is to say, they aren't sticky. Some of these settings, such as the +/// compression options, can be made persistant at channel construction time +/// (see \a grpc::CreateCustomChannel). +/// +/// \warning ClientContext instances should \em not be reused across rpcs. + +#ifndef GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H +#define GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H + +#include <map> +#include <memory> +#include <string> + +#include <grpc++/impl/codegen/config.h> +#include <grpc++/impl/codegen/security/auth_context.h> +#include <grpc++/impl/codegen/status.h> +#include <grpc++/impl/codegen/string_ref.h> +#include <grpc++/impl/codegen/sync.h> +#include <grpc++/impl/codegen/time.h> +#include <grpc/impl/codegen/compression_types.h> +#include <grpc/impl/codegen/log.h> +#include <grpc/impl/codegen/propagation_bits.h> +#include <grpc/impl/codegen/time.h> + +struct census_context; +struct grpc_call; + +namespace grpc { + +class Channel; +class ChannelInterface; +class CompletionQueue; +class CallCredentials; +class RpcMethod; +template <class R> +class ClientReader; +template <class W> +class ClientWriter; +template <class W, class R> +class ClientReaderWriter; +template <class R> +class ClientAsyncReader; +template <class W> +class ClientAsyncWriter; +template <class W, class R> +class ClientAsyncReaderWriter; +template <class R> +class ClientAsyncResponseReader; +class ServerContext; + +/// Options for \a ClientContext::FromServerContext specifying which traits from +/// the \a ServerContext to propagate (copy) from it into a new \a +/// ClientContext. +/// +/// \see ClientContext::FromServerContext +class PropagationOptions { + public: + PropagationOptions() : propagate_(GRPC_PROPAGATE_DEFAULTS) {} + + PropagationOptions& enable_deadline_propagation() { + propagate_ |= GRPC_PROPAGATE_DEADLINE; + return *this; + } + + PropagationOptions& disable_deadline_propagation() { + propagate_ &= ~GRPC_PROPAGATE_DEADLINE; + return *this; + } + + PropagationOptions& enable_census_stats_propagation() { + propagate_ |= GRPC_PROPAGATE_CENSUS_STATS_CONTEXT; + return *this; + } + + PropagationOptions& disable_census_stats_propagation() { + propagate_ &= ~GRPC_PROPAGATE_CENSUS_STATS_CONTEXT; + return *this; + } + + PropagationOptions& enable_census_tracing_propagation() { + propagate_ |= GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT; + return *this; + } + + PropagationOptions& disable_census_tracing_propagation() { + propagate_ &= ~GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT; + return *this; + } + + PropagationOptions& enable_cancellation_propagation() { + propagate_ |= GRPC_PROPAGATE_CANCELLATION; + return *this; + } + + PropagationOptions& disable_cancellation_propagation() { + propagate_ &= ~GRPC_PROPAGATE_CANCELLATION; + return *this; + } + + uint32_t c_bitmask() const { return propagate_; } + + private: + uint32_t propagate_; +}; + +namespace testing { +class InteropClientContextInspector; +} // namespace testing + +class ClientContext { + public: + ClientContext(); + ~ClientContext(); + + /// Create a new \a ClientContext as a child of an incoming server call, + /// according to \a options (\see PropagationOptions). + /// + /// \param server_context The source server context to use as the basis for + /// constructing the client context. + /// \param options The options controlling what to copy from the \a + /// server_context. + /// + /// \return A newly constructed \a ClientContext instance based on \a + /// server_context, with traits propagated (copied) according to \a options. + static std::unique_ptr<ClientContext> FromServerContext( + const ServerContext& server_context, + PropagationOptions options = PropagationOptions()); + + /// Add the (\a meta_key, \a meta_value) pair to the metadata associated with + /// a client call. These are made available at the server side by the \a + /// grpc::ServerContext::client_metadata() method. + /// + /// \warning This method should only be called before invoking the rpc. + /// + /// \param meta_key The metadata key. If \a meta_value is binary data, it must + /// end in "-bin". + /// \param meta_value The metadata value. If its value is binary, it must be + /// base64-encoding (see https://tools.ietf.org/html/rfc4648#section-4) and \a + /// meta_key must end in "-bin". + void AddMetadata(const grpc::string& meta_key, + const grpc::string& meta_value); + + /// Return a collection of initial metadata key-value pairs. Note that keys + /// may happen more than once (ie, a \a std::multimap is returned). + /// + /// \warning This method should only be called after initial metadata has been + /// received. For streaming calls, see \a + /// ClientReaderInterface::WaitForInitialMetadata(). + /// + /// \return A multimap of initial metadata key-value pairs from the server. + const std::multimap<grpc::string_ref, grpc::string_ref>& + GetServerInitialMetadata() { + GPR_ASSERT(initial_metadata_received_); + return recv_initial_metadata_; + } + + /// Return a collection of trailing metadata key-value pairs. Note that keys + /// may happen more than once (ie, a \a std::multimap is returned). + /// + /// \warning This method is only callable once the stream has finished. + /// + /// \return A multimap of metadata trailing key-value pairs from the server. + const std::multimap<grpc::string_ref, grpc::string_ref>& + GetServerTrailingMetadata() { + // TODO(yangg) check finished + return trailing_metadata_; + } + + /// Set the deadline for the client call. + /// + /// \warning This method should only be called before invoking the rpc. + /// + /// \param deadline the deadline for the client call. Units are determined by + /// the type used. + template <typename T> + void set_deadline(const T& deadline) { + TimePoint<T> deadline_tp(deadline); + deadline_ = deadline_tp.raw_time(); + } + +#ifndef GRPC_CXX0X_NO_CHRONO + /// Return the deadline for the client call. + std::chrono::system_clock::time_point deadline() { + return Timespec2Timepoint(deadline_); + } +#endif // !GRPC_CXX0X_NO_CHRONO + + /// Return a \a gpr_timespec representation of the client call's deadline. + gpr_timespec raw_deadline() { return deadline_; } + + /// Set the per call authority header (see + /// https://tools.ietf.org/html/rfc7540#section-8.1.2.3). + void set_authority(const grpc::string& authority) { authority_ = authority; } + + /// Return the authentication context for this client call. + /// + /// \see grpc::AuthContext. + std::shared_ptr<const AuthContext> auth_context() const; + + /// Set credentials for the client call. + /// + /// A credentials object encapsulates all the state needed by a client to + /// authenticate with a server and make various assertions, e.g., about the + /// client’s identity, role, or whether it is authorized to make a particular + /// call. + /// + /// \see http://www.grpc.io/docs/guides/auth.html + void set_credentials(const std::shared_ptr<CallCredentials>& creds) { + creds_ = creds; + } + + /// Return the compression algorithm to be used by the client call. + grpc_compression_algorithm compression_algorithm() const { + return compression_algorithm_; + } + + /// Set \a algorithm to be the compression algorithm used for the client call. + /// + /// \param algorith The compression algorithm used for the client call. + void set_compression_algorithm(grpc_compression_algorithm algorithm); + + /// 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. + /// + /// \return The call's peer URI. + grpc::string peer() const; + + /// Get and set census context. + void set_census_context(struct census_context* ccp) { census_context_ = ccp; } + struct census_context* census_context() const { + return census_context_; + } + + /// Send a best-effort out-of-band cancel. The call could be in any stage. + /// e.g. if it is already finished, it may still return success. + /// + /// There is no guarantee the call will be cancelled. + void TryCancel(); + + /// Global Callbacks + /// + /// Can be set exactly once per application to install hooks whenever + /// a client context is constructed and destructed. + class GlobalCallbacks { + public: + virtual ~GlobalCallbacks() {} + virtual void DefaultConstructor(ClientContext* context) = 0; + virtual void Destructor(ClientContext* context) = 0; + }; + static void SetGlobalCallbacks(GlobalCallbacks* callbacks); + + private: + // Disallow copy and assign. + ClientContext(const ClientContext&); + ClientContext& operator=(const ClientContext&); + + friend class ::grpc::testing::InteropClientContextInspector; + friend class CallOpClientRecvStatus; + friend class CallOpRecvInitialMetadata; + friend class Channel; + template <class R> + friend class ::grpc::ClientReader; + template <class W> + friend class ::grpc::ClientWriter; + template <class W, class R> + friend class ::grpc::ClientReaderWriter; + template <class R> + friend class ::grpc::ClientAsyncReader; + template <class W> + friend class ::grpc::ClientAsyncWriter; + template <class W, class R> + friend class ::grpc::ClientAsyncReaderWriter; + template <class R> + friend class ::grpc::ClientAsyncResponseReader; + template <class InputMessage, class OutputMessage> + friend Status BlockingUnaryCall(ChannelInterface* channel, + const RpcMethod& method, + ClientContext* context, + const InputMessage& request, + OutputMessage* result); + + grpc_call* call() { return call_; } + void set_call(grpc_call* call, const std::shared_ptr<Channel>& channel); + + grpc::string authority() { return authority_; } + + bool initial_metadata_received_; + std::shared_ptr<Channel> channel_; + grpc::mutex mu_; + grpc_call* call_; + bool call_canceled_; + gpr_timespec deadline_; + grpc::string authority_; + std::shared_ptr<CallCredentials> creds_; + mutable std::shared_ptr<const AuthContext> auth_context_; + struct census_context* census_context_; + std::multimap<grpc::string, grpc::string> send_initial_metadata_; + std::multimap<grpc::string_ref, grpc::string_ref> recv_initial_metadata_; + std::multimap<grpc::string_ref, grpc::string_ref> trailing_metadata_; + + grpc_call* propagate_from_call_; + PropagationOptions propagation_options_; + + grpc_compression_algorithm compression_algorithm_; +}; + +} // namespace grpc + +#endif // GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H |