RobotLoader.h

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/*
 * Copyright 2015-2019 CNRS-UM LIRMM, CNRS-AIST JRL
 */
 
#pragma once
 
#include <mc_rbdyn/Robot.h>
#include <mc_rbdyn/RobotConverter.h>
#include <mc_rbdyn/RobotModule.h>
#include <mc_rtc/io_utils.h>
 
#include <mc_rtc/config.h>
#include <mc_rtc/loader.h>
 
#include <map>
#include <memory>
#include <mutex>
 
namespace mc_rbdyn
{
 
namespace details
{
 
template<typename... Args>
struct are_strings : std::true_type
{
};
 
template<typename T>
struct are_strings<T> : std::is_same<std::string, T>
{
};
 
template<typename T, typename... Args>
struct are_strings<T, Args...> : std::integral_constant<bool, are_strings<T>::value && are_strings<Args...>::value>
{
};
 
static_assert(are_strings<>::value, "OK");
static_assert(are_strings<std::string>::value, "OK");
static_assert(are_strings<std::string, std::string>::value, "OK");
static_assert(are_strings<std::string, std::string, std::string>::value, "OK");
static_assert(!are_strings<const char *>::value, "OK");
static_assert(!are_strings<std::string, std::string, bool>::value, "OK");
 
// Construct a string from a provided argument if it's not one, otherwise just return the string
template<typename T>
typename std::conditional<std::is_same<std::string, T>::value, const std::string &, std::string>::type to_string(
    const T & value)
{
  static_assert(!std::is_integral<T>::value,
                "Passing integral value here would create empty strings of the provided size");
  return value;
}
 
} // namespace details
 
struct MC_RBDYN_DLLAPI RobotLoader
{
public:
  template<typename... Args>
  static mc_rbdyn::RobotModulePtr get_robot_module(const std::string & name, const Args &... args)
  {
    if(!details::are_strings<Args...>::value) { return get_robot_module(name, details::to_string(args)...); }
    std::unique_lock<std::mutex> guard{mtx};
    init();
    mc_rbdyn::RobotModulePtr rm = nullptr;
    auto setup_canonical = [](mc_rbdyn::RobotModulePtr rm)
    {
      assert(rm);
      if(rm->_canonicalParameters.empty()) { rm->_canonicalParameters = rm->_parameters; }
      if(!rm->controlToCanonicalPostProcess)
      {
        rm->controlToCanonicalPostProcess = [](const mc_rbdyn::Robot &, mc_rbdyn::Robot &) {};
      }
    };
    if(aliases.count(name))
    {
      const auto & params = aliases[name];
      if(params.size() == 1) { rm = get_robot_module_from_lib(params[0]); }
      else if(params.size() == 2) { rm = get_robot_module_from_lib(params[0], params[1]); }
      else if(params.size() == 3) { rm = get_robot_module_from_lib(params[0], params[1], params[2]); }
      else
      {
        mc_rtc::log::error_and_throw<mc_rtc::LoaderException>(
            "Aliases can only handle 1 to 3 parameters, {} provided ({})", params.size(),
            mc_rtc::io::to_string(params));
      }
      rm->_parameters.resize(1);
      rm->_parameters[0] = name;
    }
    else { rm = get_robot_module_from_lib(name, args...); }
    setup_canonical(rm);
    return rm;
  }
 
  static RobotModulePtr get_robot_module(const std::vector<std::string> & args);
 
  template<typename RetT, typename... Args>
  static void register_object(const std::string & name, std::function<RetT *(const Args &...)> callback)
  {
    std::unique_lock<std::mutex> guard{mtx};
    init();
    robot_loader->register_object(name, callback);
  }
 
  static void update_robot_module_path(const std::vector<std::string> & paths);
 
  static inline void clear()
  {
    std::lock_guard<std::mutex> guard{mtx};
    init(true);
    robot_loader->clear();
    aliases.clear();
  }
 
  static inline bool has_robot(const std::string & name)
  {
    std::lock_guard<std::mutex> guard{mtx};
    init();
    return robot_loader->has_object(name) || aliases.count(name) != 0;
  }
 
  static inline void set_verbosity(bool verbose)
  {
    std::lock_guard<std::mutex> guard{mtx};
    verbose_ = verbose;
    if(robot_loader) { robot_loader->set_verbosity(verbose); }
  }
 
  static std::vector<std::string> available_robots();
 
  static void load_aliases(const std::string & fname);
 
private:
  static void init(bool skip_default_path = false);
 
  template<typename... Args>
  static void fill_rm_parameters(mc_rbdyn::RobotModulePtr & rm, const std::string & arg0, const Args &... args)
  {
    rm->_parameters.push_back(arg0);
    fill_rm_parameters(rm, args...);
  }
 
  static inline void fill_rm_parameters(mc_rbdyn::RobotModulePtr &) {}
 
  template<typename... Args>
  static mc_rbdyn::RobotModulePtr get_robot_module_from_lib(const std::string & name, const Args &... args)
  {
    if(!robot_loader->has_object(name))
    {
      mc_rtc::log::error("Cannot load the requested robot: {}\nIt is neither a valid alias nor a known exported robot",
                         name);
      mc_rtc::log::info("Available robots:");
      mtx.unlock();
      for(const auto & r : available_robots()) { mc_rtc::log::info("- {}", r); }
      mc_rtc::log::error_and_throw<mc_rtc::LoaderException>("Cannot load the requested robot: {}", name);
    }
    mc_rbdyn::RobotModulePtr rm = robot_loader->create_object(name, args...);
    if(!rm) { mc_rtc::log::error_and_throw("Failed to load {}", name); }
    rm->_parameters = {name};
    fill_rm_parameters(rm, args...);
    return rm;
  }
 
  static std::unique_ptr<mc_rtc::ObjectLoader<mc_rbdyn::RobotModule>> robot_loader;
  static bool verbose_;
  static std::mutex mtx;
  static std::map<std::string, std::vector<std::string>> aliases;
}; // namespace mc_rbdyn
 
} // namespace mc_rbdyn