Creating a tarball out of a directory in a bare git repository

Hello,

I am developing a web interface, part of which allows the user to download a tarball of a directory (which is in a bare repostitory on the filesystem) on clicking on a link.

This is how I am planning on doing it. Just wanted to assess whether this is efficient enough, or if anyone knows of a better way. I haven't tried this out yet though, so I don't know if it will work at all.

- list all the files/folders in the directory (i have the sha1 hash of the
directory)
- foreach file in the directory, get the file contents (recurse if there are
further subdirectories). Probably store the result in an array. 
- create a file somewhere on the filesystem out of each file output above.
Store it under the directory name.
- create a tarball out of the 'working' directory as usual.

I was wondering if I can get away without having to create a working version out of the bare version of the directory (create each file in the directory and store it somewhere on the filesystem), and then compress it as usual.

I hope someone has a much simpler answer to this problem!

Thanks, Jawad.