server_builder_impl.h

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/*
 *
 * Copyright 2015-2016 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_SERVER_BUILDER_IMPL_H
#define GRPCPP_SERVER_BUILDER_IMPL_H

#include <climits>
#include <map>
#include <memory>
#include <vector>

#include <grpc/compression.h>
#include <grpc/support/cpu.h>
#include <grpc/support/workaround_list.h>
#include <grpcpp/impl/channel_argument_option.h>
#include <grpcpp/impl/codegen/server_interceptor.h>
#include <grpcpp/impl/server_builder_option.h>
#include <grpcpp/impl/server_builder_plugin.h>
#include <grpcpp/server.h>
#include <grpcpp/support/config.h>

struct grpc_resource_quota;

namespace grpc_impl {

class CompletionQueue;
class ResourceQuota;
class Server;
class ServerCompletionQueue;
class ServerCredentials;
}  // namespace grpc_impl

namespace grpc {

class AsyncGenericService;
class Service;
namespace testing {
class ServerBuilderPluginTest;
}  // namespace testing

namespace internal {
class ExternalConnectionAcceptorImpl;
}  // namespace internal

namespace experimental {
class CallbackGenericService;

// EXPERIMENTAL API:
// Interface for a grpc server to build transports with connections created out
// of band.
// See ServerBuilder's AddExternalConnectionAcceptor API.
class ExternalConnectionAcceptor {
 public:
  struct NewConnectionParameters {
    int listener_fd = -1;
    int fd = -1;
    ByteBuffer read_buffer;  // data intended for the grpc server
  };
  virtual ~ExternalConnectionAcceptor() {}
  // If called before grpc::Server is started or after it is shut down, the new
  // connection will be closed.
  virtual void HandleNewConnection(NewConnectionParameters* p) = 0;
};

}  // namespace experimental
}  // namespace grpc

namespace grpc_impl {

class ServerBuilder {
 public:
  ServerBuilder();
  virtual ~ServerBuilder();

  // Primary API's

  virtual std::unique_ptr<grpc::Server> BuildAndStart();

  ServerBuilder& RegisterService(grpc::Service* service);

  ServerBuilder& AddListeningPort(
      const grpc::string& addr_uri,
      std::shared_ptr<grpc_impl::ServerCredentials> creds,
      int* selected_port = nullptr);

  std::unique_ptr<grpc_impl::ServerCompletionQueue> AddCompletionQueue(
      bool is_frequently_polled = true);

  // Less commonly used RegisterService variants

  ServerBuilder& RegisterService(const grpc::string& host,
                                 grpc::Service* service);

  ServerBuilder& RegisterAsyncGenericService(
      grpc::AsyncGenericService* service);

  // Fine control knobs

  ServerBuilder& SetMaxReceiveMessageSize(int max_receive_message_size) {
    max_receive_message_size_ = max_receive_message_size;
    return *this;
  }

  ServerBuilder& SetMaxSendMessageSize(int max_send_message_size) {
    max_send_message_size_ = max_send_message_size;
    return *this;
  }

  ServerBuilder& SetMaxMessageSize(int max_message_size) {
    return SetMaxReceiveMessageSize(max_message_size);
  }

  ServerBuilder& SetCompressionAlgorithmSupportStatus(
      grpc_compression_algorithm algorithm, bool enabled);

  ServerBuilder& SetDefaultCompressionLevel(grpc_compression_level level);

  ServerBuilder& SetDefaultCompressionAlgorithm(
      grpc_compression_algorithm algorithm);

  ServerBuilder& SetResourceQuota(
      const grpc_impl::ResourceQuota& resource_quota);

  ServerBuilder& SetOption(std::unique_ptr<grpc::ServerBuilderOption> option);

  enum SyncServerOption {
    NUM_CQS,         
    MIN_POLLERS,     
    MAX_POLLERS,     
    CQ_TIMEOUT_MSEC  
  };

  ServerBuilder& SetSyncServerOption(SyncServerOption option, int value);

  template <class T>
  ServerBuilder& AddChannelArgument(const grpc::string& arg, const T& value) {
    return SetOption(grpc::MakeChannelArgumentOption(arg, value));
  }

  static void InternalAddPluginFactory(
      std::unique_ptr<grpc::ServerBuilderPlugin> (*CreatePlugin)());

  ServerBuilder& EnableWorkaround(grpc_workaround_list id);

  class experimental_type {
   public:
    explicit experimental_type(grpc_impl::ServerBuilder* builder)
        : builder_(builder) {}

    void SetInterceptorCreators(
        std::vector<std::unique_ptr<
            grpc::experimental::ServerInterceptorFactoryInterface>>
            interceptor_creators) {
      builder_->interceptor_creators_ = std::move(interceptor_creators);
    }

    ServerBuilder& RegisterCallbackGenericService(
        grpc::experimental::CallbackGenericService* service);

    enum class ExternalConnectionType {
      FROM_FD = 0  // in the form of a file descriptor
    };

    std::unique_ptr<grpc::experimental::ExternalConnectionAcceptor>
    AddExternalConnectionAcceptor(ExternalConnectionType type,
                                  std::shared_ptr<ServerCredentials> creds);

   private:
    ServerBuilder* builder_;
  };

  experimental_type experimental() { return experimental_type(this); }

 protected:
  struct Port {
    grpc::string addr;
    std::shared_ptr<grpc_impl::ServerCredentials> creds;
    int* selected_port;
  };

  typedef std::unique_ptr<grpc::string> HostString;
  struct NamedService {
    explicit NamedService(grpc::Service* s) : service(s) {}
    NamedService(const grpc::string& h, grpc::Service* s)
        : host(new grpc::string(h)), service(s) {}
    HostString host;
    grpc::Service* service;
  };

  std::vector<Port> ports() { return ports_; }

  std::vector<NamedService*> services() {
    std::vector<NamedService*> service_refs;
    for (auto& ptr : services_) {
      service_refs.push_back(ptr.get());
    }
    return service_refs;
  }

  std::vector<grpc::ServerBuilderOption*> options() {
    std::vector<grpc::ServerBuilderOption*> option_refs;
    for (auto& ptr : options_) {
      option_refs.push_back(ptr.get());
    }
    return option_refs;
  }

 private:
  friend class ::grpc::testing::ServerBuilderPluginTest;

  struct SyncServerSettings {
    SyncServerSettings()
        : num_cqs(1), min_pollers(1), max_pollers(2), cq_timeout_msec(10000) {}

    int num_cqs;

    int min_pollers;

    int max_pollers;

    int cq_timeout_msec;
  };

  int max_receive_message_size_;
  int max_send_message_size_;
  std::vector<std::unique_ptr<grpc::ServerBuilderOption>> options_;
  std::vector<std::unique_ptr<NamedService>> services_;
  std::vector<Port> ports_;

  SyncServerSettings sync_server_settings_;

  std::vector<grpc_impl::ServerCompletionQueue*> cqs_;

  std::shared_ptr<grpc_impl::ServerCredentials> creds_;
  std::vector<std::unique_ptr<grpc::ServerBuilderPlugin>> plugins_;
  grpc_resource_quota* resource_quota_;
  grpc::AsyncGenericService* generic_service_{nullptr};
  grpc::experimental::CallbackGenericService* callback_generic_service_{
      nullptr};
  struct {
    bool is_set;
    grpc_compression_level level;
  } maybe_default_compression_level_;
  struct {
    bool is_set;
    grpc_compression_algorithm algorithm;
  } maybe_default_compression_algorithm_;
  uint32_t enabled_compression_algorithms_bitset_;
  std::vector<
      std::unique_ptr<grpc::experimental::ServerInterceptorFactoryInterface>>
      interceptor_creators_;
  std::vector<std::shared_ptr<grpc::internal::ExternalConnectionAcceptorImpl>>
      acceptors_;
};

}  // namespace grpc_impl

#endif  // GRPCPP_SERVER_BUILDER_IMPL_H