Coping files and folders

[Jay Norwood]

>> I also wrote a copy version that orders file sequence on disk
>> efficiently, using write through, and posted it.  This speeds 
>> up any
>> subsequent file system operations done in the directory order 
>> as if you
>> have done a defrag. Great for hard drives, but not needed for 
>> ssd.
>>
>> https://github.com/jnorwood
>
> Any change you could turn this into a pull request and submit 
> to Phobos?

Looks like I never promoted the write through code on github.  I
just posted it on the forum.dlang.org, along with some timings. I
was only experimenting on ntfs, and so the extension I posted
doesn't force write-through on linux.

http://forum.dlang.org/thread/gmkocaqzmlmfbuozhrsj@forum.dlang.org

   After re-reading my post, I don't think I experimented with
write through in copydir.   I show the timings in the post for
ntfs operations on a 2GB layout after unzipping with a write
through version of unzip. I suspect you'd see similar improvement
following a copydir that uses write through.  The problem I saw
with ntfs was that the target directory was very fragmented when
allowing ntfs to do its lazy flushes.  I tried several
experiments, and using the write through was the only solution
that resulted in a reasonably defragged target immediately as the
result of the unzip.