Scp: track progress for larger transfers about ssh-rs

[HsuJv]

Maybe I can add some APIs like upload/download_with_notifier to send events via channels. Or something like upload/download_with_notify_callback to call callbacks during the process.

But this might change the current code a lot. I'll find an easiest way to approach this.

[giftig]

Yeah that's roughly what I had in mind; maybe an API like fn upload_with_progress(local: Path, remote: Path, notify: Channel) and you can run it async and read progress from the channel. Might need a little bit of factoring out common code but hopefully not super invasive if you just have to pass around an optional channel in the underlying stuff, for example.