Instead of opening... and... closing... files... after... every... file... operation... (which can be slow, especially if a virus scanner is running), we catch attempts to open the same file twice and only open one copy of the file.
Instead of opening... and... closing... files... after... every... file... operation... (which can be slow, especially if a virus scanner is running), we catch attempts to open the same file twice and only open one copy of the file.