CacheManager.h

 
#ifndef GPGFRONTEND_CACHEMANAGER_H
#define GPGFRONTEND_CACHEMANAGER_H
 
#include <string>
 
#include "core/GpgFunctionObject.h"
 
namespace GpgFrontend {
 
template <typename Key, typename Value>
class ThreadSafeMap {
 public:
  using MapType = std::map<Key, Value>;
  using IteratorType = typename MapType::iterator;
 
  void insert(const Key& key, const Value& value) {
    std::unique_lock lock(mutex_);
    map_[key] = value;
  }
 
  std::optional<Value> get(const Key& key) {
    std::shared_lock lock(mutex_);
    auto it = map_.find(key);
    if (it != map_.end()) {
      return it->second;
    }
    return std::nullopt;
  }
 
  bool exists(const Key& key) {
    std::shared_lock lock(mutex_);
    return map_.count(key) > 0;
  }
 
  IteratorType begin() { return map_mirror_.begin(); }
 
  IteratorType end() { return map_mirror_.end(); }
 
  ThreadSafeMap& mirror() {
    std::shared_lock lock(mutex_);
    map_mirror_ = map_;
    return *this;
  }
 
 private:
  MapType map_mirror_;
  MapType map_;
  mutable std::shared_mutex mutex_;
};
 
class GPGFRONTEND_CORE_EXPORT CacheManager
    : public QObject,
      public SingletonFunctionObject<CacheManager> {
  Q_OBJECT
 public:
  CacheManager(int channel = SingletonFunctionObject::GetDefaultChannel());
 
  void SaveCache(std::string key, const nlohmann::json& value,
                 bool flush = false);
 
  nlohmann::json LoadCache(std::string key);
 
  nlohmann::json LoadCache(std::string key, nlohmann::json default_value);
 
 private:
  std::string get_data_object_key(std::string key);
 
  nlohmann::json load_cache_storage(std::string key,
                                    nlohmann::json default_value);
 
  void load_all_cache_storage();
 
  void flush_cache_storage();
 
  void register_cache_key(std::string key);
 
  ThreadSafeMap<std::string, nlohmann::json> cache_storage_;
  nlohmann::json key_storage_;
  QTimer* m_timer_;
  const std::string drk_key_ = "__cache_manage_data_register_key_list";
};
 
}  // namespace GpgFrontend
 
#endif