MqttClient.ros2.hpp

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/*
==============================================================================
MIT License
 
Copyright 2022 Institute for Automotive Engineering of RWTH Aachen University.
 
Permission is hereby granted, free of charge, to any person obtaining a copy
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*/
 
 
#pragma once
 
#include <filesystem>
#include <map>
#include <memory>
#include <string>
 
#define FMT_HEADER_ONLY
#include <fmt/format.h>
#include <mqtt_client_interfaces/srv/is_connected.hpp>
#include <mqtt/async_client.h>
#include <rclcpp/rclcpp.hpp>
#include <rclcpp/serialization.hpp>
#include <std_msgs/msg/float64.hpp>
 
 
namespace mqtt_client {
 
 
class MqttClient : public rclcpp::Node,
                   public virtual mqtt::callback,
                   public virtual mqtt::iaction_listener {
 
 public:
  explicit MqttClient(const rclcpp::NodeOptions& options);
 
 protected:
  void loadParameters();
 
  bool loadParameter(const std::string& key, std::string& value);
 
  bool loadParameter(const std::string& key, std::string& value,
                     const std::string& default_value);
 
  template <typename T>
  bool loadParameter(const std::string& key, T& value);
 
  template <typename T>
  bool loadParameter(const std::string& key, T& value, const T& default_value);
 
  template <typename T>
  bool loadParameter(const std::string& key, std::vector<T>& value);
 
  template <typename T>
  bool loadParameter(const std::string& key, std::vector<T>& value, const std::vector<T>& default_value);
 
  std::filesystem::path resolvePath(const std::string& path_string);
 
  void setup();
 
  void setupSubscriptions();
 
  void setupClient();
 
  void connect();
 
  void ros2mqtt(
    const std::shared_ptr<rclcpp::SerializedMessage>& serialized_msg,
    const std::string& ros_topic);
 
  void mqtt2ros(mqtt::const_message_ptr mqtt_msg,
                const rclcpp::Time& arrival_stamp);
 
  void mqtt2primitive(mqtt::const_message_ptr mqtt_msg);
 
  void connected(const std::string& cause) override;
 
  void connection_lost(const std::string& cause) override;
 
  bool isConnected();
 
  void isConnectedService(
    mqtt_client_interfaces::srv::IsConnected::Request::SharedPtr request,
    mqtt_client_interfaces::srv::IsConnected::Response::SharedPtr response);
 
  void message_arrived(mqtt::const_message_ptr mqtt_msg) override;
 
  void delivery_complete(mqtt::delivery_token_ptr token) override;
 
  void on_success(const mqtt::token& token) override;
 
  void on_failure(const mqtt::token& token) override;
 
 protected:
  struct BrokerConfig {
    std::string host;  
    int port;          
    std::string user;  
    std::string pass;  
    struct {
      bool enabled;  
      std::filesystem::path
        ca_certificate;  
    } tls;               
  };
 
  struct ClientConfig {
    std::string id;  
    struct {
      bool enabled;                     
      int size;                         
      std::filesystem::path directory;  
    } buffer;                           
    struct {
      std::string topic;         
      std::string message;       
      int qos;                   
      bool retained;             
    } last_will;                 
    bool clean_session;          
    double keep_alive_interval;  
    int max_inflight;            
    struct {
      std::filesystem::path certificate;    
      std::filesystem::path key;            
      std::string password;                 
      int version;                          
      bool verify;                          
      std::vector<std::string> alpn_protos; 
    } tls;                   
  };
 
  struct Ros2MqttInterface {
    struct {
      rclcpp::GenericSubscription::SharedPtr
        subscriber;          
      std::string msg_type;  
      int queue_size = 1;    
    } ros;                   
    struct {
      std::string topic;      
      int qos = 0;            
      bool retained = false;  
    } mqtt;                   
    bool primitive = false;   
    bool stamped = false;     
  };
 
  struct Mqtt2RosInterface {
    struct {
      int qos = 0;  
    } mqtt;         
    struct {
      std::string topic;     
      std::string msg_type;  
      rclcpp::GenericPublisher::SharedPtr publisher;  
      rclcpp::Publisher<std_msgs::msg::Float64>::SharedPtr
        latency_publisher;   
      int queue_size = 1;    
      bool latched = false;  
    } ros;                   
    bool primitive = false;  
    bool stamped = false;    
  };
 
 protected:
  static const std::string kRosMsgTypeMqttTopicPrefix;
 
  static const std::string kLatencyRosTopicPrefix;
 
  rclcpp::TimerBase::SharedPtr check_subscriptions_timer_;
 
  rclcpp::Service<mqtt_client_interfaces::srv::IsConnected>::SharedPtr
    is_connected_service_;
 
  bool is_connected_ = false;
 
  BrokerConfig broker_config_;
 
  ClientConfig client_config_;
 
  std::shared_ptr<mqtt::async_client> client_;
 
  mqtt::connect_options connect_options_;
 
  std::map<std::string, Ros2MqttInterface> ros2mqtt_;
 
  std::map<std::string, Mqtt2RosInterface> mqtt2ros_;
 
  uint32_t stamp_length_;
};
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, T& value) {
  bool found = get_parameter(key, value);
  if (found)
    RCLCPP_DEBUG(get_logger(), "Retrieved parameter '%s' = '%s'", key.c_str(),
                 std::to_string(value).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, T& value,
                               const T& default_value) {
  bool found = get_parameter_or(key, value, default_value);
  if (!found)
    RCLCPP_WARN(get_logger(), "Parameter '%s' not set, defaulting to '%s'",
                key.c_str(), std::to_string(default_value).c_str());
  if (found)
    RCLCPP_DEBUG(get_logger(), "Retrieved parameter '%s' = '%s'", key.c_str(),
                 std::to_string(value).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, std::vector<T>& value)
{
  const bool found = get_parameter(key, value);
  if (found)
    RCLCPP_WARN(get_logger(), "Retrieved parameter '%s' = '[%s]'", key.c_str(),
                  fmt::format("{}", fmt::join(value, ", ")).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, std::vector<T>& value,
                               const std::vector<T>& default_value)
{
  const bool found = get_parameter_or(key, value, default_value);
  if (!found)
    RCLCPP_WARN(get_logger(), "Parameter '%s' not set, defaulting to '%s'",
                key.c_str(), fmt::format("{}", fmt::join(value, ", ")).c_str());
  if (found)
    RCLCPP_DEBUG(get_logger(), "Retrieved parameter '%s' = '%s'", key.c_str(),
                  fmt::format("{}", fmt::join(value, ", ")).c_str());
  return found;
}
 
 
template <typename T>
void serializeRosMessage(const T& msg,
                         rclcpp::SerializedMessage& serialized_msg) {
 
  rclcpp::Serialization<T> serializer;
  serializer.serialize_message(&msg, &serialized_msg);
}
 
 
template <typename T>
void deserializeRosMessage(const rclcpp::SerializedMessage& serialized_msg,
                           T& msg) {
 
  rclcpp::Serialization<T> serializer;
  serializer.deserialize_message(&serialized_msg, &msg);
}
 
}  // namespace mqtt_client