Class QueryCache

FontLoadInterceptor/RpcClient.cpp:55–126

	}

	class QueryCache
	{
	private:
		wil::unique_handle m_version;
		wil::unique_mapview_ptr<uint32_t> m_versionMem;
		uint32_t m_lastKnownVersion = std::numeric_limits<uint32_t>::max();
		bool m_good = false;

		std::unordered_set<std::wstring> m_cache;
		std::mutex m_lock;

		QueryCache()
		{
			try
			{
				std::wstring versionShmName = L"SubtitleFontAutoLoaderSHM-";
				versionShmName += GetCurrentProcessUserSid();
				m_version.reset(CreateFileMappingW(
					INVALID_HANDLE_VALUE,
					nullptr,
					PAGE_READWRITE,
					0, 4,
					versionShmName.c_str()));
				THROW_LAST_ERROR_IF(!m_version.is_valid());
				m_versionMem.reset(static_cast<uint32_t*>(MapViewOfFile(
					m_version.get(),
					FILE_MAP_WRITE,
					0, 0,
					sizeof(uint32_t))));
				THROW_LAST_ERROR_IF(m_versionMem.get() == nullptr);
			}
			catch (...)
			{
			}
			m_good = true;
		}

	public:
		static QueryCache& GetInstance()
		{
			static QueryCache instance;
			return instance;
		}

		void CheckNewVerison()
		{
			uint32_t newVerison = InterlockedCompareExchange(m_versionMem.get(), 0, 0);
			if (newVerison != m_lastKnownVersion)
			{
				m_lastKnownVersion = newVerison;
				m_cache.clear();
			}
		}

		bool IsQueryNeeded(const wchar_t* str)
		{
			if (!m_good)return true;
			std::lock_guard lg(m_lock);