component_manager.hpp

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// Copyright 2019 Open Source Robotics Foundation, Inc.
//
// 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 RCLCPP_COMPONENTS__COMPONENT_MANAGER_HPP__
#define RCLCPP_COMPONENTS__COMPONENT_MANAGER_HPP__
 
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
 
#include "composition_interfaces/srv/load_node.hpp"
#include "composition_interfaces/srv/unload_node.hpp"
#include "composition_interfaces/srv/list_nodes.hpp"
 
#include "rclcpp/executor.hpp"
#include "rclcpp/node_options.hpp"
#include "rclcpp/rclcpp.hpp"
 
#include "rclcpp_components/node_factory.hpp"
#include "rclcpp_components/visibility_control.hpp"
 
namespace class_loader
{
class ClassLoader;
}  // namespace class_loader
 
namespace rclcpp_components
{
 
class ComponentManagerException : public std::runtime_error
{
public:
  explicit ComponentManagerException(const std::string & error_desc)
  : std::runtime_error(error_desc) {}
};
 
class ComponentManager : public rclcpp::Node
{
public:
  using LoadNode = composition_interfaces::srv::LoadNode;
  using UnloadNode = composition_interfaces::srv::UnloadNode;
  using ListNodes = composition_interfaces::srv::ListNodes;
 
 
  using ComponentResource = std::pair<std::string, std::string>;
 
 
  RCLCPP_COMPONENTS_PUBLIC
  ComponentManager(
    std::weak_ptr<rclcpp::Executor> executor,
    std::string node_name = "ComponentManager",
    const rclcpp::NodeOptions & node_options = rclcpp::NodeOptions()
    .start_parameter_services(false)
    .start_parameter_event_publisher(false));
 
  RCLCPP_COMPONENTS_PUBLIC
  virtual ~ComponentManager();
 
  /*
   * \param package_name name of the package
   * \param resource_index name of the executable
   * \throws ComponentManagerException if the resource was not found or a invalid resource entry
   * \return a list of component resources
   */
  RCLCPP_COMPONENTS_PUBLIC
  virtual std::vector<ComponentResource>
  get_component_resources(
    const std::string & package_name,
    const std::string & resource_index = "rclcpp_components") const;
 
  /*
   * \param resource a component resource (class name + library path)
   * \return a NodeFactory interface
   */
  RCLCPP_COMPONENTS_PUBLIC
  virtual std::shared_ptr<rclcpp_components::NodeFactory>
  create_component_factory(const ComponentResource & resource);
 
protected:
  /*
   * This function allows to add parameters, remap rules, a specific node, name a namespace
   * and/or additional arguments.
   *
   * \param request_header unused
   * \param request information with the node to load
   * \param response
   * \throws std::overflow_error if node_id suffers an overflow. Very unlikely to happen at 1 kHz
   *   (very optimistic rate). it would take 585 years.
   * \throws ComponentManagerException In the case that the component constructor throws an
   *   exception, rethrow into the following catch block.
   */
  RCLCPP_COMPONENTS_PUBLIC
  virtual void
  OnLoadNode(
    const std::shared_ptr<rmw_request_id_t> request_header,
    const std::shared_ptr<LoadNode::Request> request,
    std::shared_ptr<LoadNode::Response> response);
 
  /*
   * \param request_header unused
   * \param request unique identifier to remove from the component
   * \param response true on the success field if the node unload was succefully, otherwise false
   *   and the error_message field contains the error.
   */
  RCLCPP_COMPONENTS_PUBLIC
  virtual void
  OnUnloadNode(
    const std::shared_ptr<rmw_request_id_t> request_header,
    const std::shared_ptr<UnloadNode::Request> request,
    std::shared_ptr<UnloadNode::Response> response);
 
  /*
   * Return a two list: one with the unique identifiers and other with full name of the nodes.
   *
   * \param request_header unused
   * \param request unused
   * \param response list with the unique ids and full node names
   */
  RCLCPP_COMPONENTS_PUBLIC
  virtual void
  OnListNodes(
    const std::shared_ptr<rmw_request_id_t> request_header,
    const std::shared_ptr<ListNodes::Request> request,
    std::shared_ptr<ListNodes::Response> response);
 
private:
  std::weak_ptr<rclcpp::Executor> executor_;
 
  uint64_t unique_id_ {1};
  std::map<std::string, std::unique_ptr<class_loader::ClassLoader>> loaders_;
  std::map<uint64_t, rclcpp_components::NodeInstanceWrapper> node_wrappers_;
 
  rclcpp::Service<LoadNode>::SharedPtr loadNode_srv_;
  rclcpp::Service<UnloadNode>::SharedPtr unloadNode_srv_;
  rclcpp::Service<ListNodes>::SharedPtr listNodes_srv_;
};
 
}  // namespace rclcpp_components
 
#endif  // RCLCPP_COMPONENTS__COMPONENT_MANAGER_HPP__