text: /******************************************************************************
   * Copyright 2018 The Apollo Authors. All Rights Reserved.
   *
   * 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 CYBER_CLASS_LOADER_CLASS_LOADER_MANAGER_H_
  #define CYBER_CLASS_LOADER_CLASS_LOADER_MANAGER_H_
  
  #include <map>
  #include <memory>
  #include <mutex>
  #include <string>
  #include <vector>
  
  #include "cyber/class_loader/class_loader.h"
  
  namespace apollo {
  namespace cyber {
  namespace class_loader {
  
  class ClassLoaderManager {
   public:
    ClassLoaderManager();
    virtual ~ClassLoaderManager();
  
    bool LoadLibrary(const std::string& library_path);
    void UnloadAllLibraries();
  
    bool IsLibraryValid(const std::string& library_path);
  
    template <typename Base>
    std::shared_ptr<Base> CreateClassObj(const std::string& class_name);
    template <typename Base>
    std::shared_ptr<Base> CreateClassObj(const std::string& class_name,
                                         const std::string& library_path);
    template <typename Base>
    bool IsClassValid(const std::string& class_name);
  
    template <typename Base>
    std::vector<std::string> GetValidClassNames();
  
   private:
    ClassLoader* GetClassLoaderByLibPath(const std::string& library_path);
    std::vector<ClassLoader*> GetAllValidClassLoaders();
    std::vector<std::string> GetAllValidLibPath();
    int UnloadLibrary(const std::string& library_path);
  
   private:
    std::mutex libpath_loader_map_mutex_;
    std::map<std::string, ClassLoader*> libpath_loader_map_;
  };
  
  template <typename Base>
  std::shared_ptr<Base> ClassLoaderManager::CreateClassObj(
      const std::string& class_name) {
    std::vector<ClassLoader*> class_loaders = GetAllValidClassLoaders();
    for (auto class_loader : class_loaders) {
      if (class_loader->IsClassValid<Base>(class_name)) {
        return (class_loader->CreateClassObj<Base>(class_name));
      }
    }
    AERROR << "Invalid class name: " << class_name;
    return std::shared_ptr<Base>();
  }
  
  template <typename Base>
  std::shared_ptr<Base> ClassLoaderManager::CreateClassObj(
      const std::string& class_name, const std::string& library_path) {
    ClassLoader* loader = GetClassLoaderByLibPath(library_path);
    if (loader) {
      return (loader->CreateClassObj<Base>(class_name));
    }
    AERROR << "Could not create classobj, there is no ClassLoader in: "
           << class_name;
    return std::shared_ptr<Base>();
  }
  
  template <typename Base>
  bool ClassLoaderManager::IsClassValid(const std::string& class_name) {
    std::vector<std::string> valid_classes = GetValidClassNames<Base>();
    return (valid_classes.end() !=
            std::find(valid_classes.begin(), valid_classes.end(), class_name));
  }
  
  template <typename Base>
  std::vector<std::string> ClassLoaderManager::GetValidClassNames() {
    std::vector<std::string> valid_classes;
    for (auto class_loader : GetAllValidClassLoaders()) {
      std::vector<std::string> class_loaders =
          class_loader->GetValidClassNames<Base>();
      valid_classes.insert(valid_classes.end(), class_loaders.begin(),
                           class_loaders.end());
    }
    return valid_classes;
  }
  
  }  // namespace class_loader
  }  // namespace cyber
  }  // namespace apollo
  
  #endif  // CYBER_CLASS_LOADER_CLASS_LOADER_MANAGER_H_
  