cartographer/cartographer_grpc/framework/server.h

199 lines
7.2 KiB
C++

/*
* Copyright 2017 The Cartographer 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 CARTOGRAPHER_GRPC_FRAMEWORK_SERVER_H
#define CARTOGRAPHER_GRPC_FRAMEWORK_SERVER_H
#include <cstddef>
#include <memory>
#include <sstream>
#include <string>
#include <thread>
#include "cartographer/common/make_unique.h"
#include "cartographer_grpc/framework/completion_queue_thread.h"
#include "cartographer_grpc/framework/event_queue_thread.h"
#include "cartographer_grpc/framework/execution_context.h"
#include "cartographer_grpc/framework/rpc_handler.h"
#include "cartographer_grpc/framework/service.h"
#include "grpc++/grpc++.h"
namespace cartographer_grpc {
namespace framework {
class Server {
private:
// All options that configure server behaviour such as number of threads,
// ports etc.
struct Options {
size_t num_grpc_threads;
size_t num_event_threads;
std::string server_address;
};
public:
// This 'Builder' is the only way to construct a 'Server'.
class Builder {
public:
Builder() = default;
std::unique_ptr<Server> Build();
void SetNumGrpcThreads(std::size_t num_grpc_threads);
void SetNumEventThreads(std::size_t num_event_threads);
void SetServerAddress(const std::string& server_address);
template <typename RpcHandlerType>
void RegisterHandler() {
std::string method_full_name =
RpcHandlerInterface::Instantiate<RpcHandlerType>()->method_name();
std::string service_full_name;
std::string method_name;
std::tie(service_full_name, method_name) =
ParseMethodFullName(method_full_name);
CheckHandlerCompatibility<RpcHandlerType>(service_full_name, method_name);
rpc_handlers_[service_full_name].emplace(
method_name,
RpcHandlerInfo{
RpcHandlerType::RequestType::default_instance().GetDescriptor(),
RpcHandlerType::ResponseType::default_instance().GetDescriptor(),
[](Rpc* const rpc, ExecutionContext* const execution_context) {
std::unique_ptr<RpcHandlerInterface> rpc_handler =
cartographer::common::make_unique<RpcHandlerType>();
rpc_handler->SetRpc(rpc);
rpc_handler->SetExecutionContext(execution_context);
return rpc_handler;
},
RpcType<typename RpcHandlerType::IncomingType,
typename RpcHandlerType::OutgoingType>::value,
method_full_name});
}
static std::tuple<std::string /* service_full_name */,
std::string /* method_name */>
ParseMethodFullName(const std::string& method_full_name);
private:
using ServiceInfo = std::map<std::string, RpcHandlerInfo>;
template <typename RpcHandlerType>
void CheckHandlerCompatibility(const std::string& service_full_name,
const std::string& method_name) {
const auto* pool = google::protobuf::DescriptorPool::generated_pool();
const auto* service = pool->FindServiceByName(service_full_name);
CHECK(service) << "Unknown service " << service_full_name;
const auto* method_descriptor = service->FindMethodByName(method_name);
CHECK(method_descriptor) << "Unknown method " << method_name
<< " in service " << service_full_name;
const auto* request_type = method_descriptor->input_type();
CHECK_EQ(RpcHandlerType::RequestType::default_instance().GetDescriptor(),
request_type);
const auto* response_type = method_descriptor->output_type();
CHECK_EQ(RpcHandlerType::ResponseType::default_instance().GetDescriptor(),
response_type);
const auto rpc_type =
RpcType<typename RpcHandlerType::IncomingType,
typename RpcHandlerType::OutgoingType>::value;
switch (rpc_type) {
case ::grpc::internal::RpcMethod::NORMAL_RPC:
CHECK(!method_descriptor->client_streaming());
CHECK(!method_descriptor->server_streaming());
break;
case ::grpc::internal::RpcMethod::CLIENT_STREAMING:
CHECK(method_descriptor->client_streaming());
CHECK(!method_descriptor->server_streaming());
break;
case ::grpc::internal::RpcMethod::SERVER_STREAMING:
CHECK(!method_descriptor->client_streaming());
CHECK(method_descriptor->server_streaming());
break;
case ::grpc::internal::RpcMethod::BIDI_STREAMING:
CHECK(method_descriptor->client_streaming());
CHECK(method_descriptor->server_streaming());
break;
}
}
Options options_;
std::map<std::string, ServiceInfo> rpc_handlers_;
};
friend class Builder;
virtual ~Server() = default;
// Starts a server starts serving the registered services.
void Start();
// Waits for the server to shut down. Note: The server must be either shutting
// down or some other thread must call 'Shutdown()' for this function to ever
// return.
void WaitForShutdown();
// Shuts down the server and all of its services.
void Shutdown();
// Sets the server-wide context object shared between RPC handlers.
void SetExecutionContext(std::unique_ptr<ExecutionContext> execution_context);
template <typename T>
ExecutionContext::Synchronized<T> GetContext() {
return {execution_context_->lock(), execution_context_.get()};
}
template <typename T>
T* GetUnsynchronizedContext() {
return dynamic_cast<T*>(execution_context_.get());
}
protected:
Server(const Options& options);
void AddService(
const std::string& service_name,
const std::map<std::string, RpcHandlerInfo>& rpc_handler_infos);
private:
Server(const Server&) = delete;
Server& operator=(const Server&) = delete;
void RunCompletionQueue(::grpc::ServerCompletionQueue* completion_queue);
void RunEventQueue(Rpc::EventQueue* event_queue);
Rpc::EventQueue* SelectNextEventQueueRoundRobin();
Options options_;
bool shutting_down_ = false;
// gRPC objects needed to build a server.
::grpc::ServerBuilder server_builder_;
std::unique_ptr<::grpc::Server> server_;
// Threads processing the completion queues.
std::vector<CompletionQueueThread> completion_queue_threads_;
// Threads processing RPC events.
std::vector<EventQueueThread> event_queue_threads_;
cartographer::common::Mutex current_event_queue_id_lock_;
int current_event_queue_id_ = 0;
// Map of service names to services.
std::map<std::string, Service> services_;
// A context object that is shared between all implementations of
// 'RpcHandler'.
std::unique_ptr<ExecutionContext> execution_context_;
};
} // namespace framework
} // namespace cartographer_grpc
#endif // CARTOGRAPHER_GRPC_FRAMEWORK_SERVER_H