sensor_interface.hpp

// Copyright 2020 - 2021 ros2_control Development Team
//
// 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 HARDWARE_INTERFACE__SENSOR_INTERFACE_HPP_
#define HARDWARE_INTERFACE__SENSOR_INTERFACE_HPP_
 
#include <limits>
#include <memory>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
 
#include "hardware_interface/component_parser.hpp"
#include "hardware_interface/handle.hpp"
#include "hardware_interface/hardware_info.hpp"
#include "hardware_interface/types/hardware_interface_return_values.hpp"
#include "hardware_interface/types/lifecycle_state_names.hpp"
#include "lifecycle_msgs/msg/state.hpp"
#include "rclcpp/duration.hpp"
#include "rclcpp/logger.hpp"
#include "rclcpp/node_interfaces/node_clock_interface.hpp"
#include "rclcpp/time.hpp"
#include "rclcpp_lifecycle/node_interfaces/lifecycle_node_interface.hpp"
#include "rclcpp_lifecycle/state.hpp"
#include "realtime_tools/async_function_handler.hpp"
 
namespace hardware_interface
{
 
using CallbackReturn = rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface::CallbackReturn;
 
class SensorInterface : public rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface
{
public:
  SensorInterface()
  : lifecycle_state_(rclcpp_lifecycle::State(
      lifecycle_msgs::msg::State::PRIMARY_STATE_UNKNOWN, lifecycle_state_names::UNKNOWN)),
    sensor_logger_(rclcpp::get_logger("sensor_interface"))
  {
  }
 
 
  SensorInterface(const SensorInterface & other) = delete;
 
  SensorInterface(SensorInterface && other) = default;
 
  virtual ~SensorInterface() = default;
 
 
  CallbackReturn init(
    const HardwareInfo & hardware_info, rclcpp::Logger logger,
    rclcpp::node_interfaces::NodeClockInterface::SharedPtr clock_interface)
  {
    clock_interface_ = clock_interface;
    sensor_logger_ = logger.get_child("hardware_component.sensor." + hardware_info.name);
    info_ = hardware_info;
    if (info_.is_async)
    {
      RCLCPP_INFO_STREAM(
        get_logger(), "Starting async handler with scheduler priority: " << info_.thread_priority);
      read_async_handler_ = std::make_unique<realtime_tools::AsyncFunctionHandler<return_type>>();
      read_async_handler_->init(
        std::bind(&SensorInterface::read, this, std::placeholders::_1, std::placeholders::_2),
        info_.thread_priority);
      read_async_handler_->start_thread();
    }
    return on_init(hardware_info);
  };
 
 
  virtual CallbackReturn on_init(const HardwareInfo & hardware_info)
  {
    info_ = hardware_info;
    parse_state_interface_descriptions(info_.joints, joint_state_interfaces_);
    parse_state_interface_descriptions(info_.sensors, sensor_state_interfaces_);
    return CallbackReturn::SUCCESS;
  };
 
 
  [[deprecated(
    "Replaced by vector<StateInterface::ConstSharedPtr> on_export_state_interfaces() method. "
    "Exporting is handled "
    "by the Framework.")]] virtual std::vector<StateInterface>
  export_state_interfaces()
  {
    // return empty vector by default. For backward compatibility we try calling
    // export_state_interfaces() and only when empty vector is returned call
    // on_export_state_interfaces()
    return {};
  }
 
  virtual std::vector<hardware_interface::InterfaceDescription>
  export_unlisted_state_interface_descriptions()
  {
    // return empty vector by default.
    return {};
  }
 
  virtual std::vector<StateInterface::ConstSharedPtr> on_export_state_interfaces()
  {
    // import the unlisted interfaces
    std::vector<hardware_interface::InterfaceDescription> unlisted_interface_descriptions =
      export_unlisted_state_interface_descriptions();
 
    std::vector<StateInterface::ConstSharedPtr> state_interfaces;
    state_interfaces.reserve(
      unlisted_interface_descriptions.size() + sensor_state_interfaces_.size() +
      joint_state_interfaces_.size());
 
    // add InterfaceDescriptions and create StateInterfaces from the descriptions and add to maps.
    for (const auto & description : unlisted_interface_descriptions)
    {
      auto name = description.get_name();
      unlisted_state_interfaces_.insert(std::make_pair(name, description));
      auto state_interface = std::make_shared<StateInterface>(description);
      sensor_states_map_.insert(std::make_pair(name, state_interface));
      unlisted_states_.push_back(state_interface);
      state_interfaces.push_back(std::const_pointer_cast<const StateInterface>(state_interface));
    }
 
    for (const auto & [name, descr] : sensor_state_interfaces_)
    {
      // TODO(Manuel) check for duplicates otherwise only the first appearance of "name" is inserted
      auto state_interface = std::make_shared<StateInterface>(descr);
      sensor_states_map_.insert(std::make_pair(name, state_interface));
      sensor_states_.push_back(state_interface);
      state_interfaces.push_back(std::const_pointer_cast<const StateInterface>(state_interface));
    }
 
    for (const auto & [name, descr] : joint_state_interfaces_)
    {
      auto state_interface = std::make_shared<StateInterface>(descr);
      sensor_states_map_.insert(std::make_pair(name, state_interface));
      joint_states_.push_back(state_interface);
      state_interfaces.push_back(std::const_pointer_cast<const StateInterface>(state_interface));
    }
 
    return state_interfaces;
  }
 
 
  return_type trigger_read(const rclcpp::Time & time, const rclcpp::Duration & period)
  {
    return_type result = return_type::ERROR;
    if (info_.is_async)
    {
      bool trigger_status = true;
      std::tie(trigger_status, result) = read_async_handler_->trigger_async_callback(time, period);
      if (!trigger_status)
      {
        RCLCPP_WARN(
          get_logger(),
          "Trigger read called while read async handler is still in progress for hardware "
          "interface : '%s'. Failed to trigger read cycle!",
          info_.name.c_str());
        return return_type::OK;
      }
    }
    else
    {
      result = read(time, period);
    }
    return result;
  }
 
 
  virtual return_type read(const rclcpp::Time & time, const rclcpp::Duration & period) = 0;
 
 
  virtual std::string get_name() const { return info_.name; }
 
 
  virtual std::string get_group_name() const { return info_.group; }
 
 
  const rclcpp_lifecycle::State & get_lifecycle_state() const { return lifecycle_state_; }
 
 
  void set_lifecycle_state(const rclcpp_lifecycle::State & new_state)
  {
    lifecycle_state_ = new_state;
  }
 
  void set_state(const std::string & interface_name, const double & value)
  {
    sensor_states_map_.at(interface_name)->set_value(value);
  }
 
  double get_state(const std::string & interface_name) const
  {
    return sensor_states_map_.at(interface_name)->get_value();
  }
 
 
  rclcpp::Logger get_logger() const { return sensor_logger_; }
 
 
  rclcpp::Clock::SharedPtr get_clock() const { return clock_interface_->get_clock(); }
 
 
  const HardwareInfo & get_hardware_info() const { return info_; }
 
protected:
  HardwareInfo info_;
  // interface names to InterfaceDescription
  std::unordered_map<std::string, InterfaceDescription> joint_state_interfaces_;
  std::unordered_map<std::string, InterfaceDescription> sensor_state_interfaces_;
  std::unordered_map<std::string, InterfaceDescription> unlisted_state_interfaces_;
 
  // Exported Command- and StateInterfaces in order they are listed in the hardware description.
  std::vector<StateInterface::SharedPtr> joint_states_;
  std::vector<StateInterface::SharedPtr> sensor_states_;
  std::vector<StateInterface::SharedPtr> unlisted_states_;
 
  rclcpp_lifecycle::State lifecycle_state_;
  std::unique_ptr<realtime_tools::AsyncFunctionHandler<return_type>> read_async_handler_;
 
private:
  rclcpp::node_interfaces::NodeClockInterface::SharedPtr clock_interface_;
  rclcpp::Logger sensor_logger_;
  // interface names to Handle accessed through getters/setters
  std::unordered_map<std::string, StateInterface::SharedPtr> sensor_states_map_;
};
 
}  // namespace hardware_interface
#endif  // HARDWARE_INTERFACE__SENSOR_INTERFACE_HPP_