getOrOpenKey

        fn getOrOpenKey(self: Software, registry: *Registry) !Key {
            if (registry.cache.getSoftware(self)) |handle| {
                return .{ .handle = handle };
            }

            const is_foreign = !is_32_bit and self.wow64 == .wow64_32;
            switch (self.root) {
                .local_machine => {
                    const path = if (is_foreign) L("\\Registry\\Machine\\Software\\WOW6432Node") else L("\\Registry\\Machine\\Software");
                    var key: Key = undefined;
                    const attr: windows.OBJECT.ATTRIBUTES = .{
                        .RootDirectory = null,
                        .Attributes = .{},
                        .ObjectName = @constCast(&windows.UNICODE_STRING.init(path)),
                        .SecurityDescriptor = null,
                        .SecurityQualityOfService = null,
                    };
                    const status = windows.ntdll.NtOpenKeyEx(
                        &key.handle,
                        .{ .MAXIMUM_ALLOWED = true },
                        &attr,
                        .{},
                    );
                    switch (status) {
                        .SUCCESS => {},
                        else => return error.KeyNotFound,
                    }
                    if (is_foreign) {
                        registry.cache.hklm_software_foreign = key.handle;
                    } else {
                        registry.cache.hklm_software_native = key.handle;
                    }
                    return key;
                },
                .current_user => {
                    const cu_handle: windows.HANDLE = registry.cache.hkcu orelse hkcu: {
                        var cu_handle: windows.HANDLE = undefined;
                        const status = windows.ntdll.RtlOpenCurrentUser(
                            .{ .MAXIMUM_ALLOWED = true },
                            &cu_handle,
                        );
                        switch (status) {
                            .SUCCESS => {},
                            else => return error.KeyNotFound,
                        }
                        registry.cache.hkcu = cu_handle;
                        break :hkcu cu_handle;
                    };
                    const cu_key: Registry.Key = .{ .handle = cu_handle };
                    const path = if (is_foreign) L("Software\\WOW6432Node") else L("Software");
                    const key = try cu_key.open(path);
                    if (is_foreign) {
                        registry.cache.hkcu_software_foreign = key.handle;
                    } else {
                        registry.cache.hkcu_software_native = key.handle;
                    }
                    return key;
                },
            }
        }