Merge pull request #43 from OpenVicProject/add/vdf-search

1 files changed, 162 insertions, 0 deletions

diff --git a/src/openvic-simulation/dataloader/Dataloader_Windows.hpp b/src/openvic-simulation/dataloader/Dataloader_Windows.hpp
new file mode 100644
index 0000000..f4abbb6
--- /dev/null
+++ b/src/openvic-simulation/dataloader/Dataloader_Windows.hpp
@@ -0,0 +1,162 @@
+#pragma once
+
+#include <concepts>
+#pragma comment(lib, "advapi32.lib")
+
+#include <string>
+#include <string_view>
+
+#include <Windows.h>
+
+namespace OpenVic::Windows {
+	inline std::wstring convert(std::string_view as) {
+		// deal with trivial case of empty string
+		if (as.empty()) return std::wstring();
+
+		// determine required length of new string
+		size_t length = ::MultiByteToWideChar(CP_UTF8, 0, as.data(), (int)as.length(), 0, 0);
+
+		// construct new string of required length
+		std::wstring ret(length, L'\0');
+
+		// convert old string to new string
+		::MultiByteToWideChar(CP_UTF8, 0, as.data(), (int)as.length(), &ret[0], (int)ret.length());
+
+		// return new string ( compiler should optimize this away )
+		return ret;
+	}
+
+	inline std::string convert(std::wstring_view as) {
+		// deal with trivial case of empty string
+		if (as.empty()) return std::string();
+
+		// determine required length of new string
+		size_t length = ::WideCharToMultiByte(CP_UTF8, 0, as.data(), (int)as.length(), 0, 0, NULL, NULL);
+
+		// construct new string of required length
+		std::string ret(length, '\0');
+
+		// convert old string to new string
+		::WideCharToMultiByte(CP_UTF8, 0, as.data(), (int)as.length(), &ret[0], (int)ret.length(), NULL, NULL);
+
+		// return new string ( compiler should optimize this away )
+		return ret;
+	}
+
+	template<typename T, typename... U>
+	concept any_of = (std::same_as<T, U> || ...);
+
+	template<typename T>
+	concept either_char_type = any_of<T, char, wchar_t>;
+
+	template<typename T>
+	concept has_data = requires(T t) {
+		{ t.data() } -> std::convertible_to<const typename T::value_type*>;
+	};
+
+	class RegistryKey {
+	public:
+		RegistryKey(HKEY key_handle)
+			: _key_handle(key_handle) {
+		}
+
+		template<either_char_type CHAR_T, either_char_type CHAR_T2>
+		RegistryKey(HKEY parent_key_handle, std::basic_string_view<CHAR_T> child_key_name, std::basic_string_view<CHAR_T2> value_name) {
+			open_key(parent_key_handle, child_key_name);
+			query_key(value_name);
+		}
+
+		~RegistryKey() {
+			close_key();
+		}
+
+		bool is_open() const {
+			return _key_handle != nullptr;
+		}
+
+		std::wstring_view value() const {
+			return _value;
+		}
+
+		template<either_char_type CHAR_T>
+		LSTATUS open_key(HKEY parent_key_handle, std::basic_string_view<CHAR_T> key_path) {
+			if (is_open())
+				close_key();
+			if constexpr (std::is_same_v<CHAR_T, char>)
+				return RegOpenKeyExW(parent_key_handle, convert(key_path).data(), REG_NONE, KEY_READ, &_key_handle);
+			else
+				return RegOpenKeyExW(parent_key_handle, key_path.data(), REG_NONE, KEY_READ, &_key_handle);
+		}
+
+		bool is_predefined() const {
+			return (_key_handle == HKEY_CURRENT_USER) ||
+				   (_key_handle == HKEY_LOCAL_MACHINE) ||
+				   (_key_handle == HKEY_CLASSES_ROOT) ||
+				   (_key_handle == HKEY_CURRENT_CONFIG) ||
+				   (_key_handle == HKEY_CURRENT_USER_LOCAL_SETTINGS) ||
+				   (_key_handle == HKEY_PERFORMANCE_DATA) ||
+				   (_key_handle == HKEY_PERFORMANCE_NLSTEXT) ||
+				   (_key_handle == HKEY_PERFORMANCE_TEXT) ||
+				   (_key_handle == HKEY_USERS);
+		}
+
+		LSTATUS close_key() {
+			if (!is_open() || is_predefined())
+				return ERROR_SUCCESS;
+			auto result = RegCloseKey(_key_handle);
+			_key_handle = nullptr;
+			return result;
+		}
+
+		template<either_char_type CHAR_T>
+		LSTATUS query_key(std::basic_string_view<CHAR_T> value_name) {
+			DWORD data_size;
+			DWORD type;
+
+			const auto& wide_value = [&value_name]() -> has_data auto {
+				if constexpr (std::is_same_v<CHAR_T, char>) {
+					return convert(value_name);
+				} else {
+					return value_name;
+				}
+			}();
+
+			auto result = RegQueryValueExW(_key_handle, wide_value.data(), NULL, &type, NULL, &data_size);
+			if (result != ERROR_SUCCESS || type != REG_SZ) {
+				close_key();
+				return result;
+			}
+			_value = std::wstring(data_size / sizeof(wchar_t), L'\0');
+			result = RegQueryValueExW(_key_handle, wide_value.data(), NULL, NULL, reinterpret_cast<LPBYTE>(_value.data()), &data_size);
+			close_key();
+
+			std::size_t first_null = _value.find_first_of(L'\0');
+			if (first_null != std::string::npos)
+				_value.resize(first_null);
+
+			return result;
+		}
+
+	private:
+		HKEY _key_handle = nullptr;
+		std::wstring _value;
+	};
+
+	template<either_char_type RCHAR_T, either_char_type CHAR_T, either_char_type CHAR_T2>
+	std::basic_string<RCHAR_T> ReadRegValue(HKEY root, std::basic_string_view<CHAR_T> key, std::basic_string_view<CHAR_T2> name) {
+		RegistryKey registry_key(root, key, name);
+		if constexpr (std::is_same_v<RCHAR_T, char>) {
+			return convert(registry_key.value());
+		} else {
+			return registry_key.value();
+		}
+	}
+
+	template<either_char_type RCHAR_T, either_char_type CHAR_T, either_char_type CHAR_T2>
+	std::basic_string<RCHAR_T> ReadRegValue(HKEY root, const CHAR_T* key, const CHAR_T2* name) {
+		auto key_sv = std::basic_string_view(key);
+		auto name_sv = std::basic_string_view(name);
+
+		return ReadRegValue<RCHAR_T>(root, key_sv, name_sv);
+	}
+}
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