planner_server.cpp

// Copyright (c) 2018 Intel Corporation
// Copyright (c) 2019 Samsung Research America
//
// 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.
 
#include <chrono>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <limits>
#include <iterator>
#include <memory>
#include <string>
#include <vector>
#include <utility>
 
#include "lifecycle_msgs/msg/state.hpp"
#include "nav2_util/costmap.hpp"
#include "nav2_ros_common/node_utils.hpp"
#include "nav2_util/geometry_utils.hpp"
#include "nav2_costmap_2d/cost_values.hpp"
#include "nav2_costmap_2d/costmap_layer.hpp"
#include "nav2_costmap_2d/layered_costmap.hpp"
 
#include "tf2/utils.hpp"
 
#include "nav2_planner/planner_server.hpp"
 
using namespace std::chrono_literals;
using rcl_interfaces::msg::ParameterType;
using std::placeholders::_1;
 
namespace nav2_planner
{
 
PlannerServer::PlannerServer(const rclcpp::NodeOptions & options)
: nav2::LifecycleNode("planner_server", "", options),
  gp_loader_("nav2_core", "nav2_core::GlobalPlanner"),
  costmap_(nullptr)
{
  RCLCPP_INFO(get_logger(), "Creating");
  // Setup the global costmap
  costmap_ros_ = std::make_shared<nav2_costmap_2d::Costmap2DROS>(
    "global_costmap", std::string{get_namespace()},
    get_parameter("use_sim_time").as_bool(), options);
}
 
PlannerServer::~PlannerServer()
{
  /*
   * Backstop ensuring this state is destroyed, even if deactivate/cleanup are
   * never called.
   */
  planners_.clear();
  costmap_thread_.reset();
}
 
nav2::CallbackReturn
PlannerServer::on_configure(const rclcpp_lifecycle::State & state)
{
  RCLCPP_INFO(get_logger(), "Configuring");
  auto node = shared_from_this();
 
  costmap_ros_->configure();
  costmap_ = costmap_ros_->getCostmap();
 
  // Launch a thread to run the costmap node
  costmap_thread_ = std::make_unique<nav2::NodeThread>(costmap_ros_);
 
  RCLCPP_DEBUG(
    get_logger(), "Costmap size: %d,%d",
    costmap_->getSizeInCellsX(), costmap_->getSizeInCellsY());
 
  tf_ = costmap_ros_->getTfBuffer();
  try {
    param_handler_ = std::make_unique<ParameterHandler>(
      node, get_logger());
  } catch (const std::exception & ex) {
    RCLCPP_FATAL(get_logger(), "%s", ex.what());
    on_cleanup(state);
    return nav2::CallbackReturn::FAILURE;
  }
  params_ = param_handler_->getParams();
 
  for (size_t i = 0; i != params_->planner_ids.size(); i++) {
    try {
      nav2_core::GlobalPlanner::Ptr planner =
        gp_loader_.createUniqueInstance(params_->planner_types[i]);
      RCLCPP_INFO(
        get_logger(), "Created global planner plugin %s of type %s",
        params_->planner_ids[i].c_str(), params_->planner_types[i].c_str());
      planner->configure(node, params_->planner_ids[i], tf_, costmap_ros_);
      planners_.insert({params_->planner_ids[i], planner});
    } catch (const std::exception & ex) {
      RCLCPP_FATAL(
        get_logger(), "Failed to create global planner. Exception: %s",
        ex.what());
      on_cleanup(state);
      return nav2::CallbackReturn::FAILURE;
    }
  }
 
  for (size_t i = 0; i != params_->planner_ids.size(); i++) {
    planner_ids_concat_ += params_->planner_ids[i] + std::string(" ");
  }
 
  RCLCPP_INFO(
    get_logger(),
    "Planner Server has %s planners available.", planner_ids_concat_.c_str());
 
  // Initialize pubs & subs
  plan_publisher_ = create_publisher<nav_msgs::msg::Path>("plan");
 
  // Create is path valid service
  is_path_valid_service_ = std::make_unique<IsPathValidService>(
    shared_from_this(), costmap_ros_, params_->costmap_update_timeout);
 
  // Create the action servers for path planning to a pose and through poses
  action_server_pose_ = create_action_server<ActionToPose>(
    "compute_path_to_pose",
    std::bind(&PlannerServer::computePlan, this),
    std::bind(&PlannerServer::goalReceived<ActionToPose>, this, std::placeholders::_1),
    nullptr,
    std::chrono::milliseconds(500),
    true);
 
  action_server_poses_ = create_action_server<ActionThroughPoses>(
    "compute_path_through_poses",
    std::bind(&PlannerServer::computePlanThroughPoses, this),
    std::bind(&PlannerServer::goalReceived<ActionThroughPoses>, this, std::placeholders::_1),
    nullptr,
    std::chrono::milliseconds(500),
    true);
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
PlannerServer::on_activate(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Activating");
 
  plan_publisher_->on_activate();
  action_server_pose_->activate();
  action_server_poses_->activate();
  param_handler_->activate();
  const auto costmap_ros_state = costmap_ros_->activate();
  if (costmap_ros_state.id() != lifecycle_msgs::msg::State::PRIMARY_STATE_ACTIVE) {
    return nav2::CallbackReturn::FAILURE;
  }
 
  PlannerMap::iterator it;
  for (it = planners_.begin(); it != planners_.end(); ++it) {
    it->second->activate();
  }
 
  is_path_valid_service_->initialize();
 
  // create bond connection
  createBond();
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
PlannerServer::on_deactivate(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Deactivating");
 
  action_server_pose_->deactivate();
  action_server_poses_->deactivate();
  plan_publisher_->on_deactivate();
  param_handler_->deactivate();
 
  /*
   * The costmap is also a lifecycle node, so it may have already fired on_deactivate
   * via rcl preshutdown cb. Despite the rclcpp docs saying on_shutdown callbacks fire
   * in the order added, the preshutdown callbacks clearly don't per se, due to using an
   * unordered_set iteration. Once this issue is resolved, we can maybe make a stronger
   * ordering assumption: https://github.com/ros2/rclcpp/issues/2096
   */
  costmap_ros_->deactivate();
 
  PlannerMap::iterator it;
  for (it = planners_.begin(); it != planners_.end(); ++it) {
    it->second->deactivate();
  }
 
  is_path_valid_service_->reset();
 
  // destroy bond connection
  destroyBond();
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
PlannerServer::on_cleanup(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Cleaning up");
 
  action_server_pose_.reset();
  action_server_poses_.reset();
  plan_publisher_.reset();
  tf_.reset();
 
  costmap_ros_->cleanup();
 
  PlannerMap::iterator it;
  for (it = planners_.begin(); it != planners_.end(); ++it) {
    it->second->cleanup();
  }
 
  planners_.clear();
  is_path_valid_service_.reset();
  costmap_thread_.reset();
  costmap_ = nullptr;
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
PlannerServer::on_shutdown(const rclcpp_lifecycle::State &)
{
  RCLCPP_INFO(get_logger(), "Shutting down");
  return nav2::CallbackReturn::SUCCESS;
}
 
template<typename T>
bool PlannerServer::goalReceived(std::shared_ptr<const typename T::Goal> goal)
{
  if (planners_.find(goal->planner_id) == planners_.end()) {
    if (planners_.size() == 1 && goal->planner_id.empty()) {
      RCLCPP_WARN_ONCE(
        get_logger(), "No planner was specified in action call. "
        "Server will use only plugin loaded %s. "
        "This warning will appear once.", planner_ids_concat_.c_str());
      return true;
    }
 
    RCLCPP_ERROR(
      get_logger(), "Action called with planner name %s, "
      "which does not exist. Available planners are: %s.",
      goal->planner_id.c_str(), planner_ids_concat_.c_str());
    return false;
  }
 
  RCLCPP_DEBUG(get_logger(), "Selected planner: %s.", goal->planner_id.c_str());
  return true;
}
 
template<typename T>
bool PlannerServer::isServerInactive(
  typename nav2::SimpleActionServer<T>::SharedPtr & action_server)
{
  if (action_server == nullptr || !action_server->is_server_active()) {
    RCLCPP_DEBUG(get_logger(), "Action server unavailable or inactive. Stopping.");
    return true;
  }
 
  return false;
}
 
double PlannerServer::waitForCostmap()
{
  if (params_->costmap_update_timeout > rclcpp::Duration(0, 0)) {
    auto waiting_start = now();
    bool was_waiting = !costmap_ros_->isCurrent();
    try {
      costmap_ros_->waitUntilCurrent(params_->costmap_update_timeout);
    } catch (const std::runtime_error & ex) {
      throw nav2_core::PlannerTimedOut(ex.what());
    }
    if (was_waiting) {
      return (now() - waiting_start).seconds();
    }
  }
  return 0.0;
}
 
template<typename T>
bool PlannerServer::isCancelRequested(
  typename nav2::SimpleActionServer<T>::SharedPtr & action_server)
{
  if (action_server->is_cancel_requested()) {
    RCLCPP_INFO(get_logger(), "Goal was canceled. Canceling planning action.");
    action_server->terminate_all();
    return true;
  }
 
  return false;
}
 
template<typename T>
void PlannerServer::getPreemptedGoalIfRequested(
  typename nav2::SimpleActionServer<T>::SharedPtr & action_server,
  typename std::shared_ptr<const typename T::Goal> goal)
{
  if (action_server->is_preempt_requested()) {
    goal = action_server->accept_pending_goal();
  }
}
 
template<typename T>
bool PlannerServer::getStartPose(
  typename std::shared_ptr<const typename T::Goal> goal,
  geometry_msgs::msg::PoseStamped & start)
{
  if (goal->use_start) {
    start = goal->start;
  } else if (!costmap_ros_->getRobotPose(start)) {
    return false;
  }
 
  return true;
}
 
bool PlannerServer::transformPosesToGlobalFrame(
  geometry_msgs::msg::PoseStamped & curr_start,
  geometry_msgs::msg::PoseStamped & curr_goal)
{
  if (!costmap_ros_->transformPoseToGlobalFrame(curr_start, curr_start) ||
    !costmap_ros_->transformPoseToGlobalFrame(curr_goal, curr_goal))
  {
    return false;
  }
 
  return true;
}
 
template<typename T>
bool PlannerServer::validatePath(
  const geometry_msgs::msg::PoseStamped & goal,
  const nav_msgs::msg::Path & path,
  const std::string & planner_id)
{
  if (path.poses.empty()) {
    RCLCPP_WARN(
      get_logger(), "Planning algorithm %s failed to generate a valid"
      " path to (%.2f, %.2f)", planner_id.c_str(),
      goal.pose.position.x, goal.pose.position.y);
    return false;
  }
 
  RCLCPP_DEBUG(
    get_logger(),
    "Found valid path of size %zu to (%.2f, %.2f)",
    path.poses.size(), goal.pose.position.x,
    goal.pose.position.y);
 
  return true;
}
 
void PlannerServer::computePlanThroughPoses()
{
  std::lock_guard<std::mutex> lock_reinit(param_handler_->getMutex());
 
  auto start_time = this->now();
 
  // Initialize the ComputePathThroughPoses goal and result
  auto goal = action_server_poses_->get_current_goal();
  auto result = std::make_shared<ActionThroughPoses::Result>();
  nav_msgs::msg::Path concat_path;
  RCLCPP_INFO(get_logger(), "Computing path through poses to goal.");
 
  geometry_msgs::msg::PoseStamped curr_start, curr_goal;
 
  try {
    if (isServerInactive<ActionThroughPoses>(action_server_poses_) ||
      isCancelRequested<ActionThroughPoses>(action_server_poses_))
    {
      return;
    }
 
    double costmap_wait = waitForCostmap();
 
    getPreemptedGoalIfRequested<ActionThroughPoses>(action_server_poses_, goal);
 
    if (goal->goals.goals.empty()) {
      throw nav2_core::NoViapointsGiven("No viapoints given");
    }
 
    // Use start pose if provided otherwise use current robot pose
    geometry_msgs::msg::PoseStamped start;
    if (!getStartPose<ActionThroughPoses>(goal, start)) {
      throw nav2_core::PlannerTFError("Unable to get start pose");
    }
 
    auto cancel_checker = [this]() {
        return action_server_poses_->is_cancel_requested();
      };
 
    // Get consecutive paths through these points
    for (unsigned int i = 0; i != goal->goals.goals.size(); i++) {
      // Get starting point
      if (i == 0) {
        curr_start = start;
      } else {
        // pick the end of the last planning task as the start for the next one
        // to allow for path tolerance deviations
        curr_start = concat_path.poses.back();
        curr_start.header = concat_path.header;
      }
      curr_goal = goal->goals.goals[i];
 
      // Transform them into the global frame
      if (!transformPosesToGlobalFrame(curr_start, curr_goal)) {
        throw nav2_core::PlannerTFError("Unable to transform poses to global frame");
      }
 
      // Get plan from start -> goal
      nav_msgs::msg::Path curr_path;
      std::vector<geometry_msgs::msg::PoseStamped> viapoints;
      try {
        curr_path = getPlan(curr_start, curr_goal, viapoints, goal->planner_id, cancel_checker);
      } catch (nav2_core::PlannerException & ex) {
        if (i == 0 || !params_->partial_plan_allowed) {
          throw;
        }
 
        exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
        RCLCPP_WARN(get_logger(),
          "Planner server failed to compute full path. Outputting partial path instead.");
        break;
      }
 
      if (!validatePath<ActionThroughPoses>(curr_goal, curr_path, goal->planner_id)) {
        auto exception =
          nav2_core::NoValidPathCouldBeFound(goal->planner_id + " generated a empty path");
 
        if (i == 0 || !params_->partial_plan_allowed) {
          throw exception;
        }
 
        exceptionWarning(curr_start, curr_goal, goal->planner_id, exception, result->error_msg);
        RCLCPP_WARN(get_logger(),
          "Planner server failed to compute full path. Outputting partial path instead.");
        break;
      }
 
      // Concatenate paths together, but skip the first pose of subsequent paths
      // to avoid duplicating the connection point
      if (i == 0) {
        // First path: add all poses
        concat_path.poses.insert(
          concat_path.poses.end(), curr_path.poses.begin(), curr_path.poses.end());
      } else if (curr_path.poses.size() > 1) {
        // Subsequent paths: skip the first pose to avoid duplication
        concat_path.poses.insert(
          concat_path.poses.end(), curr_path.poses.begin() + 1, curr_path.poses.end());
      }
      concat_path.header = curr_path.header;
 
      if (i == goal->goals.goals.size() - 1) {
        result->last_reached_index = ActionThroughPosesResult::ALL_GOALS;
      } else {
        result->last_reached_index = i;
      }
    }
 
    // Publish the plan for visualization purposes
    result->path = concat_path;
    publishPlan(result->path);
 
    auto cycle_duration = this->now() - start_time;
    result->planning_time = cycle_duration;
 
    if (params_->max_planner_duration && cycle_duration.seconds() > params_->max_planner_duration) {
      RCLCPP_WARN(
        get_logger(),
        "Planner loop missed its desired rate of %.4f Hz. Current loop rate is %.4f Hz"
        "%s",
        1 / params_->max_planner_duration, 1 / cycle_duration.seconds(),
        costmap_wait > 0.0 ?
        (" Waited " + std::to_string(costmap_wait) + "s for costmap update.").c_str() : "");
    }
 
    action_server_poses_->succeeded_current(result);
  } catch (nav2_core::InvalidPlanner & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::INVALID_PLANNER;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::StartOccupied & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::START_OCCUPIED;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::GoalOccupied & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::GOAL_OCCUPIED;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::NoValidPathCouldBeFound & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::NO_VALID_PATH;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::PlannerTimedOut & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::TIMEOUT;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::StartOutsideMapBounds & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::START_OUTSIDE_MAP;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::GoalOutsideMapBounds & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::GOAL_OUTSIDE_MAP;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::PlannerTFError & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::TF_ERROR;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::NoViapointsGiven & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::NO_VIAPOINTS_GIVEN;
    action_server_poses_->terminate_current(result);
  } catch (nav2_core::PlannerCancelled &) {
    result->error_msg = "Goal was canceled. Canceling planning action.";
    RCLCPP_INFO(get_logger(), "%s", result->error_msg.c_str());
    action_server_poses_->terminate_all();
  } catch (std::exception & ex) {
    exceptionWarning(curr_start, curr_goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionThroughPosesResult::UNKNOWN;
    action_server_poses_->terminate_current(result);
  }
}
 
void
PlannerServer::computePlan()
{
  std::lock_guard<std::mutex> lock_reinit(param_handler_->getMutex());
 
  auto start_time = this->now();
 
  // Initialize the ComputePathToPose goal and result
  auto goal = action_server_pose_->get_current_goal();
  auto result = std::make_shared<ActionToPose::Result>();
  RCLCPP_INFO(get_logger(), "Computing path to goal.");
 
  geometry_msgs::msg::PoseStamped start;
 
  try {
    if (isServerInactive<ActionToPose>(action_server_pose_) ||
      isCancelRequested<ActionToPose>(action_server_pose_))
    {
      return;
    }
 
    double costmap_wait = waitForCostmap();
 
    getPreemptedGoalIfRequested<ActionToPose>(action_server_pose_, goal);
 
    // Use start pose if provided otherwise use current robot pose
    if (!getStartPose<ActionToPose>(goal, start)) {
      throw nav2_core::PlannerTFError("Unable to get start pose");
    }
 
    // Transform them into the global frame
    geometry_msgs::msg::PoseStamped goal_pose = goal->goal;
    if (!transformPosesToGlobalFrame(start, goal_pose)) {
      throw nav2_core::PlannerTFError("Unable to transform poses to global frame");
    }
 
    auto cancel_checker = [this]() {
        return action_server_pose_->is_cancel_requested();
      };
 
    result->path = getPlan(start, goal_pose, goal->viapoints, goal->planner_id, cancel_checker);
 
    if (!validatePath<ActionThroughPoses>(goal_pose, result->path, goal->planner_id)) {
      throw nav2_core::NoValidPathCouldBeFound(goal->planner_id + " generated a empty path");
    }
 
    // Publish the plan for visualization purposes
    publishPlan(result->path);
 
    auto cycle_duration = this->now() - start_time;
    result->planning_time = cycle_duration;
 
    if (params_->max_planner_duration && cycle_duration.seconds() > params_->max_planner_duration) {
      RCLCPP_WARN(
        get_logger(),
        "Planner loop missed its desired rate of %.4f Hz. Current loop rate is %.4f Hz"
        "%s",
        1 / params_->max_planner_duration, 1 / cycle_duration.seconds(),
        costmap_wait > 0.0 ?
        (" Waited " + std::to_string(costmap_wait) + "s for costmap update.").c_str() : "");
    }
    action_server_pose_->succeeded_current(result);
  } catch (nav2_core::InvalidPlanner & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::INVALID_PLANNER;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::StartOccupied & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::START_OCCUPIED;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::GoalOccupied & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::GOAL_OCCUPIED;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::NoValidPathCouldBeFound & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::NO_VALID_PATH;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::PlannerTimedOut & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::TIMEOUT;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::StartOutsideMapBounds & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::START_OUTSIDE_MAP;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::GoalOutsideMapBounds & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::GOAL_OUTSIDE_MAP;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::PlannerTFError & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::TF_ERROR;
    action_server_pose_->terminate_current(result);
  } catch (nav2_core::PlannerCancelled &) {
    result->error_msg = "Goal was canceled. Canceling planning action.";
    RCLCPP_INFO(get_logger(), "%s", result->error_msg.c_str());
    action_server_pose_->terminate_all();
  } catch (std::exception & ex) {
    exceptionWarning(start, goal->goal, goal->planner_id, ex, result->error_msg);
    result->error_code = ActionToPoseResult::UNKNOWN;
    action_server_pose_->terminate_current(result);
  }
}
 
nav_msgs::msg::Path
PlannerServer::getPlan(
  const geometry_msgs::msg::PoseStamped & start,
  const geometry_msgs::msg::PoseStamped & goal,
  const std::vector<geometry_msgs::msg::PoseStamped> & viapoints,
  const std::string & planner_id,
  std::function<bool()> cancel_checker)
{
  RCLCPP_DEBUG(
    get_logger(), "Attempting to a find path from (%.2f, %.2f) to "
    "(%.2f, %.2f).", start.pose.position.x, start.pose.position.y,
    goal.pose.position.x, goal.pose.position.y);
 
  if (planners_.find(planner_id) != planners_.end()) {
    return planners_[planner_id]->createPlan(start, goal, viapoints, cancel_checker);
  } else {
    if (planners_.size() == 1 && planner_id.empty()) {
      RCLCPP_WARN_ONCE(
        get_logger(), "No planners specified in action call. "
        "Server will use only plugin %s in server."
        " This warning will appear once.", planner_ids_concat_.c_str());
      return planners_[planners_.begin()->first]->createPlan(start, goal, viapoints,
        cancel_checker);
    } else {
      RCLCPP_ERROR(
        get_logger(), "planner %s is not a valid planner. "
        "Planner names are: %s", planner_id.c_str(),
        planner_ids_concat_.c_str());
      throw nav2_core::InvalidPlanner("Planner id " + planner_id + " is invalid");
    }
  }
 
  return nav_msgs::msg::Path();
}
 
void
PlannerServer::publishPlan(const nav_msgs::msg::Path & path)
{
  auto msg = std::make_unique<nav_msgs::msg::Path>(path);
  if (plan_publisher_->is_activated() && plan_publisher_->get_subscription_count() > 0) {
    plan_publisher_->publish(std::move(msg));
  }
}
 
void PlannerServer::exceptionWarning(
  const geometry_msgs::msg::PoseStamped & start,
  const geometry_msgs::msg::PoseStamped & goal,
  const std::string & planner_id,
  const std::exception & ex,
  std::string & error_msg)
{
  std::stringstream ss;
  ss << std::fixed << std::setprecision(2)
     << planner_id << "plugin failed to plan from ("
     << start.pose.position.x << ", " << start.pose.position.y
     << ") [q: "
     << start.pose.orientation.x << ", " << start.pose.orientation.y << ", "
     << start.pose.orientation.z << ", " << start.pose.orientation.w
     << "] (yaw: " << tf2::getYaw(start.pose.orientation)
     << ") to ("
     << goal.pose.position.x << ", " << goal.pose.position.y << ")"
     << " [q: "
     << goal.pose.orientation.x << ", " << goal.pose.orientation.y << ", "
     << goal.pose.orientation.z << ", " << goal.pose.orientation.w
     << "] (yaw: " << tf2::getYaw(goal.pose.orientation)
     << ")"
     << ": \"" << ex.what() << "\"";
 
  error_msg = ss.str();
  RCLCPP_WARN(get_logger(), "%s", error_msg.c_str());
}
 
}  // namespace nav2_planner
 
#include "rclcpp_components/register_node_macro.hpp"
 
// Register the component with class_loader.
// This acts as a sort of entry point, allowing the component to be discoverable when its library
// is being loaded into a running process.
RCLCPP_COMPONENTS_REGISTER_NODE(nav2_planner::PlannerServer)