bt_action_server.hpp

// Copyright (c) 2020 Sarthak Mittal
//
// 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 NAV2_BEHAVIOR_TREE__BT_ACTION_SERVER_HPP_
#define NAV2_BEHAVIOR_TREE__BT_ACTION_SERVER_HPP_
 
#include <chrono>
#include <functional>
#include <memory>
#include <string>
#include <vector>
 
#include "geometry_msgs/msg/pose_stamped.hpp"
#include "nav2_behavior_tree/behavior_tree_engine.hpp"
#include "nav2_behavior_tree/ros_topic_logger.hpp"
#include "nav2_ros_common/lifecycle_node.hpp"
#include "nav2_ros_common/simple_action_server.hpp"
 
namespace nav2_behavior_tree
{
template<class ActionT, class NodeT>
class BtActionServer
{
public:
  using ActionServer = nav2::SimpleActionServer<ActionT>;
 
  typedef std::function<bool (typename ActionT::Goal::ConstSharedPtr)> OnGoalReceivedCallback;
  typedef std::function<void ()> OnLoopCallback;
  typedef std::function<void (typename ActionT::Goal::ConstSharedPtr)> OnPreemptCallback;
  typedef std::function<void (typename ActionT::Result::SharedPtr,
      nav2_behavior_tree::BtStatus &)> OnCompletionCallback;
 
  explicit BtActionServer(
    const typename NodeT::WeakPtr & parent,
    const std::string & action_name,
    const std::vector<std::string> & plugin_lib_names,
    const std::string & default_bt_xml_filename,
    OnGoalReceivedCallback on_goal_received_callback,
    OnLoopCallback on_loop_callback,
    OnPreemptCallback on_preempt_callback,
    OnCompletionCallback on_completion_callback,
    const std::vector<std::string> & search_directories = std::vector<std::string>{});
 
  ~BtActionServer();
 
  bool on_configure();
 
  bool on_activate();
 
  bool on_deactivate();
 
  bool on_cleanup();
 
  void setGrootMonitoring(const bool enable, const unsigned server_port);
 
  bool loadBehaviorTree(
    const std::string & bt_xml_filename_or_id = "");
 
  BT::Blackboard::Ptr getBlackboard() const
  {
    return blackboard_;
  }
 
  std::string getCurrentBTFilenameOrID() const
  {
    return current_bt_file_or_id_;
  }
 
  std::string getDefaultBTFilenameOrID() const
  {
    return default_bt_xml_filename_or_id_;
  }
 
  const std::shared_ptr<const typename ActionT::Goal> acceptPendingGoal()
  {
    return action_server_->accept_pending_goal();
  }
 
  void terminatePendingGoal()
  {
    action_server_->terminate_pending_goal();
  }
 
  const std::shared_ptr<const typename ActionT::Goal> getCurrentGoal() const
  {
    return action_server_->get_current_goal();
  }
 
  const std::shared_ptr<const typename ActionT::Goal> getPendingGoal() const
  {
    return action_server_->get_pending_goal();
  }
 
  void publishFeedback(typename std::shared_ptr<typename ActionT::Feedback> feedback)
  {
    action_server_->publish_feedback(feedback);
  }
 
  void preemptCurrentNavigator()
  {
    muxer_preemption_requested_ = true;
  }
 
  const BT::Tree & getTree() const
  {
    return tree_;
  }
 
  void haltTree()
  {
    tree_.haltTree();
  }
 
  void setInternalError(uint16_t error_code, const std::string & error_msg);
 
  void resetInternalError(void);
 
  bool populateInternalError(typename std::shared_ptr<typename ActionT::Result> result);
 
protected:
  void executeCallback();
 
  void populateErrorCode(typename std::shared_ptr<typename ActionT::Result> result);
 
  void cleanErrorCodes();
 
  // Action name
  std::string action_name_;
 
  // Our action server implements the template action
  typename ActionServer::SharedPtr action_server_;
 
  // Behavior Tree to be executed when goal is received
  BT::Tree tree_;
 
  // The blackboard shared by all of the nodes in the tree
  BT::Blackboard::Ptr blackboard_;
 
  // The XML file that contains the Behavior Tree to create
  std::string current_bt_file_or_id_;
  std::string default_bt_xml_filename_or_id_;
  std::vector<std::string> search_directories_;
 
  // The wrapper class for the BT functionality
  std::unique_ptr<nav2_behavior_tree::BehaviorTreeEngine> bt_;
 
  // Libraries to pull plugins (BT Nodes) from
  std::vector<std::string> plugin_lib_names_;
 
  // Error code name prefixes
  std::vector<std::string> error_code_name_prefixes_;
 
  // A regular, non-spinning ROS node that we can use for calls to the action client
  nav2::LifecycleNode::SharedPtr client_node_;
 
  // Parent node
  typename NodeT::WeakPtr node_;
 
  // Clock
  rclcpp::Clock::SharedPtr clock_;
 
  // Logger
  rclcpp::Logger logger_{rclcpp::get_logger("BtActionServer")};
 
  // To publish BT logs
  std::unique_ptr<RosTopicLogger> topic_logger_;
 
  // Duration for each iteration of BT execution
  std::chrono::milliseconds bt_loop_duration_;
 
  // Default timeout value while waiting for response from a server
  std::chrono::milliseconds default_server_timeout_;
 
  // Default timeout value when cancelling actions during node halt
  std::chrono::milliseconds default_cancel_timeout_;
 
  // The timeout value for waiting for a service to response
  std::chrono::milliseconds wait_for_service_timeout_;
 
  // should the BT be reloaded even if the same xml filename is requested?
  bool always_reload_bt_ = false;
 
  // Whether to log BT transitions to IDLE state
  bool log_idle_ = true;
 
  // Parameters for Groot2 monitoring
  bool enable_groot_monitoring_ = false;
  int groot_server_port_ = 1667;
 
  // User-provided callbacks
  OnGoalReceivedCallback on_goal_received_callback_;
  OnLoopCallback on_loop_callback_;
  OnPreemptCallback on_preempt_callback_;
  OnCompletionCallback on_completion_callback_;
 
  // internal error tracking (IOW not behaviorTree blackboard errors)
  uint16_t internal_error_code_;
  std::string internal_error_msg_;
 
  std::atomic_bool muxer_preemption_requested_{false};
};
 
}  // namespace nav2_behavior_tree
 
#include <nav2_behavior_tree/bt_action_server_impl.hpp>  // NOLINT(build/include_order)
#endif  // NAV2_BEHAVIOR_TREE__BT_ACTION_SERVER_HPP_