Using the existed file for duplicated one ?

Hi, it's a great module, I'm looking for it, but I have a question when using it:
Is it possible to use existed file for duplicated files?

When a user uploading a file, our module will check it's existed or not by checking the file hash.
could it be possible that if the same file exists, the node will use the existed one for attachement, so we won't hold same files, but users will creat their node successfully. it will be nice to both users and our disk space :)

Thank you again for this module.

If you're too busy to develop this feature, a bit hint of how to do this would be a great help too, I will try to do the coding job :)