qswiki/cache/mapcache.h

#ifndef MAPCACHE_H
#define MAPCACHE_H
#include <map>
#include <set>
#include <shared_mutex>
#include <optional>
#include <string>

/* Thread-Safe Key-Value store */
template <class T> class MapCache
{
  private:
	std::map<std::string, T> cache;
	mutable std::shared_mutex sharedMutex;

  public:
	std::optional<T> find(const std::string &key) const
	{
		std::shared_lock<std::shared_mutex> lock(this->sharedMutex);
		auto it = this->cache.find(key);
		if(it != this->cache.end())
		{
			return it->second;
		}
		return {};
	}
	void set(const std::string &key, const T &val)
	{
		std::lock_guard<std::shared_mutex> lock{sharedMutex};
		this->cache[key] = val;
	}
	void clear()
	{
		std::lock_guard<std::shared_mutex> lock{sharedMutex};
		this->cache.clear();
	}
};

#endif // MAPCACHE_H