Function QueryValueEx

crates/vm/src/stdlib/winreg.rs:740–795

(key: HKEYArg, name: String, vm: &VirtualMachine)

    #[pyfunction]
    fn QueryValueEx(key: HKEYArg, name: String, vm: &VirtualMachine) -> PyResult<PyRef<PyTuple>> {
        let hkey = key.0;
        let wide_name = name.to_wide_with_nul();
        let mut buf_size: u32 = 0;
        let res = unsafe {
            Registry::RegQueryValueExW(
                hkey,
                wide_name.as_ptr(),
                core::ptr::null_mut(),
                core::ptr::null_mut(),
                core::ptr::null_mut(),
                &mut buf_size,
            )
        };
        // Handle ERROR_MORE_DATA by using a default buffer size
        if res == ERROR_MORE_DATA || buf_size == 0 {
            buf_size = 256;
        } else if res != 0 {
            return Err(os_error_from_windows_code(vm, res as i32));
        }

        let mut ret_buf = vec![0u8; buf_size as usize];
        let mut typ = 0;
        let mut ret_size: u32;

        // Loop to handle ERROR_MORE_DATA
        loop {
            ret_size = buf_size;
            let res = unsafe {
                Registry::RegQueryValueExW(
                    hkey,
                    wide_name.as_ptr(),
                    core::ptr::null_mut(),
                    &mut typ,
                    ret_buf.as_mut_ptr(),
                    &mut ret_size,
                )
            };

            if res != ERROR_MORE_DATA {
                if res != 0 {
                    return Err(os_error_from_windows_code(vm, res as i32));
                }
                break;
            }

            // Double buffer size and retry
            buf_size *= 2;
            ret_buf.resize(buf_size as usize, 0);
        }

        // Only pass the bytes actually returned by the API
        let obj = reg_to_py(vm, &ret_buf[..ret_size as usize], typ)?;
        // Return tuple (value, type)
        Ok(vm.ctx.new_tuple(vec![obj, vm.ctx.new_int(typ).into()]))
    }

    #[pyfunction]