private long calc_source_size()
{
ulong ret = 0;
var f_count = 0;
var d_count = 0;
var data = new WIN32_FIND_DATA();
for (var i = 0; i < initial_source.Length; i++)
{
if (WinAPiFSwrapper.GetFileInfo(initial_source[i], ref data))
{
if ((data.dwFileAttributes & FileAttributes.Directory) == FileAttributes.Directory)
{
ret += WinAPiFSwrapper.GetDirectoryStat
(initial_source[i], true, false, true, ref f_count, ref d_count, null);
}
else
{
ret += data.FileSize;
}
}
}
return((long)ret);
}