client_context.h

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/*
 *
 * 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 GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H
#define GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H

#include <map>
#include <memory>
#include <mutex>
#include <string>

#include <grpc++/impl/codegen/config.h>
#include <grpc++/impl/codegen/core_codegen_interface.h>
#include <grpc++/impl/codegen/create_auth_context.h>
#include <grpc++/impl/codegen/metadata_map.h>
#include <grpc++/impl/codegen/security/auth_context.h>
#include <grpc++/impl/codegen/slice.h>
#include <grpc++/impl/codegen/status.h>
#include <grpc++/impl/codegen/string_ref.h>
#include <grpc++/impl/codegen/time.h>
#include <grpc/impl/codegen/compression_types.h>
#include <grpc/impl/codegen/propagation_bits.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;

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();

  static std::unique_ptr<ClientContext> FromServerContext(
      const ServerContext& server_context,
      PropagationOptions options = PropagationOptions());

  void AddMetadata(const grpc::string& meta_key,
                   const grpc::string& meta_value);

  const std::multimap<grpc::string_ref, grpc::string_ref>&
  GetServerInitialMetadata() const {
    GPR_CODEGEN_ASSERT(initial_metadata_received_);
    return *recv_initial_metadata_.map();
  }

  const std::multimap<grpc::string_ref, grpc::string_ref>&
  GetServerTrailingMetadata() const {
    // TODO(yangg) check finished
    return *trailing_metadata_.map();
  }

  template <typename T>
  void set_deadline(const T& deadline) {
    TimePoint<T> deadline_tp(deadline);
    deadline_ = deadline_tp.raw_time();
  }

  void set_idempotent(bool idempotent) { idempotent_ = idempotent; }

  void set_cacheable(bool cacheable) { cacheable_ = cacheable; }

  void set_wait_for_ready(bool wait_for_ready) {
    wait_for_ready_ = wait_for_ready;
    wait_for_ready_explicitly_set_ = true;
  }

  void set_fail_fast(bool fail_fast) { set_wait_for_ready(!fail_fast); }

  std::chrono::system_clock::time_point deadline() const {
    return Timespec2Timepoint(deadline_);
  }

  gpr_timespec raw_deadline() const { return deadline_; }

  void set_authority(const grpc::string& authority) { authority_ = authority; }

  std::shared_ptr<const AuthContext> auth_context() const {
    if (auth_context_.get() == nullptr) {
      auth_context_ = CreateAuthContext(call_);
    }
    return auth_context_;
  }

  void set_credentials(const std::shared_ptr<CallCredentials>& creds) {
    creds_ = creds;
  }

  grpc_compression_algorithm compression_algorithm() const {
    return compression_algorithm_;
  }

  void set_compression_algorithm(grpc_compression_algorithm algorithm);

  void set_initial_metadata_corked(bool corked) {
    initial_metadata_corked_ = corked;
  }

  grpc::string peer() const;

  void set_census_context(struct census_context* ccp) { census_context_ = ccp; }
  struct census_context* census_context() const {
    return census_context_;
  }

  void TryCancel();

  class GlobalCallbacks {
   public:
    virtual ~GlobalCallbacks() {}
    virtual void DefaultConstructor(ClientContext* context) = 0;
    virtual void Destructor(ClientContext* context) = 0;
  };
  static void SetGlobalCallbacks(GlobalCallbacks* callbacks);

  grpc_call* c_call() { return call_; }

 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() const { return call_; }
  void set_call(grpc_call* call, const std::shared_ptr<Channel>& channel);

  uint32_t initial_metadata_flags() const {
    return (idempotent_ ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST : 0) |
           (wait_for_ready_ ? GRPC_INITIAL_METADATA_WAIT_FOR_READY : 0) |
           (cacheable_ ? GRPC_INITIAL_METADATA_CACHEABLE_REQUEST : 0) |
           (wait_for_ready_explicitly_set_
                ? GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET
                : 0) |
           (initial_metadata_corked_ ? GRPC_INITIAL_METADATA_CORKED : 0);
  }

  grpc::string authority() { return authority_; }

  bool initial_metadata_received_;
  bool wait_for_ready_;
  bool wait_for_ready_explicitly_set_;
  bool idempotent_;
  bool cacheable_;
  std::shared_ptr<Channel> channel_;
  std::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_;
  MetadataMap recv_initial_metadata_;
  MetadataMap trailing_metadata_;

  grpc_call* propagate_from_call_;
  PropagationOptions propagation_options_;

  grpc_compression_algorithm compression_algorithm_;
  bool initial_metadata_corked_;
};

}  // namespace grpc

#endif  // GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H