Performance Issue

[Vino.B via Digitalmars-d-learn]

Hi,

  The below code is consume more memory and slower can you provide 
your suggestion on how to over come these issues.

string[][] csizeDirList (string FFs, int SizeDir) {
	ulong subdirTotal = 0;
	ulong subdirTotalGB;
	auto Subdata = appender!(string[][]);
     auto dFiles = dirEntries(FFs, SpanMode.shallow).filter!(a => 
a.isDir && !globMatch(a.baseName, "*DND*")).map!(a => 
tuple(a.name, a.size)).array;
	  foreach (d; dFiles) {
				auto SdFiles = dirEntries(join(["\\\\?\\", d[0]]), 
SpanMode.depth).map!(a => tuple(a.size)).array;
				foreach (f; parallel(SdFiles,1))
					{ subdirTotal += f[0]; }
						subdirTotalGB = (subdirTotal/1024/1024);
						if (subdirTotalGB > SizeDir) { Subdata ~= [d[0], 
to!string(subdirTotalGB)]; }
						subdirTotal = 0;
		    }
			return Subdata.data;
}

From,
Vino.B