grpc/include/grpcpp/impl/codegen/client_interceptor.h

/*
 *
 * Copyright 2018 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_CLIENT_INTERCEPTOR_H
#define GRPCPP_IMPL_CODEGEN_CLIENT_INTERCEPTOR_H

#include <vector>

#include <grpcpp/impl/codegen/interceptor.h>
#include <grpcpp/impl/codegen/string_ref.h>

namespace grpc {

class ClientContext;
class Channel;

namespace internal {
class InterceptorBatchMethodsImpl;
}

namespace experimental {
class ClientRpcInfo;

class ClientInterceptorFactoryInterface {
 public:
  virtual ~ClientInterceptorFactoryInterface() {}
  virtual Interceptor* CreateClientInterceptor(ClientRpcInfo* info) = 0;
};

class ClientRpcInfo {
 public:
  ClientRpcInfo() {}

  ~ClientRpcInfo(){};

  ClientRpcInfo(const ClientRpcInfo&) = delete;
  ClientRpcInfo(ClientRpcInfo&&) = default;
  ClientRpcInfo& operator=(ClientRpcInfo&&) = default;

  // Getter methods
  const char* method() { return method_; }
  ChannelInterface* channel() { return channel_; }
  grpc::ClientContext* client_context() { return ctx_; }

 private:
  ClientRpcInfo(grpc::ClientContext* ctx, const char* method,
                grpc::ChannelInterface* channel)
      : ctx_(ctx), method_(method), channel_(channel) {}
  // Runs interceptor at pos \a pos.
  void RunInterceptor(
      experimental::InterceptorBatchMethods* interceptor_methods, size_t pos) {
    GPR_CODEGEN_ASSERT(pos < interceptors_.size());
    interceptors_[pos]->Intercept(interceptor_methods);
  }

  void RegisterInterceptors(
      const std::vector<std::unique_ptr<
          experimental::ClientInterceptorFactoryInterface>>& creators,
      int interceptor_pos) {
    for (auto it = creators.begin() + interceptor_pos; it != creators.end();
         ++it) {
      interceptors_.push_back(std::unique_ptr<experimental::Interceptor>(
          (*it)->CreateClientInterceptor(this)));
    }
  }

  grpc::ClientContext* ctx_ = nullptr;
  const char* method_ = nullptr;
  grpc::ChannelInterface* channel_ = nullptr;
  std::vector<std::unique_ptr<experimental::Interceptor>> interceptors_;
  bool hijacked_ = false;
  size_t hijacked_interceptor_ = 0;

  friend class internal::InterceptorBatchMethodsImpl;
  friend class grpc::ClientContext;
};

}  // namespace experimental
}  // namespace grpc

#endif  // GRPCPP_IMPL_CODEGEN_CLIENT_INTERCEPTOR_H