Created attachment 5132 
Sample image with not much useful information in it.

I was thinking the other day while in an SSH session with a remote machine, rsync'ing very large files from one machine to the other, when I realized that everything that I was doing could be done through Thunar if it leveraged an rsync capable backend where it made sense to do so.

When a user is moving / copying a local file to a remote machine via an SFTP mount in Thunar and the destination already contains a file of the existing name, the semantics for the Replace button in the "Confirm to replace files" dialog the user is prompted with could leverage rsync when the remote shell allows it to be run. A large file with only a few bytes changed in it could be transferred in seconds instead of hours, even with the most tragic of ISPs.

Assuming this is even a good idea, the next question is how should this be integrated? Should Thunar be patched for this functionality, or would it best be deferred to a plugin? Whatever the case, any user configuration GUI aside for a moment, the "Confirm to replace files" dialog would not need any rework, save perhaps displaying some feedback that deltas are being computed and transferred instead of the entire file - perhaps even displaying the rsync speedup value at the end of the transfer briefly.

Always open to constructive criticism and feedback.