Request: progress callback

[thewh1teagle]

Hi,
I would like to pass progress callback to reflink_copy::reflink(from, to) so I can show progress bar.

Oops. I thought it's another repo

[NobodyXu]

Well for windows that is indeed possible, as copying is done with multiple syscalls in a loop.

But for unix, everything happens in kernel in one syscall, there's no way of knowing the progress on unix unfortunately.

[thewh1teagle]

Well for windows that is indeed possible, as copying is done with multiple syscalls in a loop.

But for unix, everything happens in kernel in one syscall, there's no way of knowing the progress on unix unfortunately.

Does the operation can be slow sometimes? because if not, maybe we don't need progress at all. I don't know how reflink works.

[NobodyXu]

Does the operation can be slow sometimes? because if not, maybe we don't need progress at all. I don't know how reflink works.

I'm not sure, reflink doesn't copy data but just setup a CoW reference.

How fast it would be depends on your hardware and the software, and it'd be hard to define fast or slow.

[Vaiz]

Does the operation can be slow sometimes? because if not, maybe we don't need progress at all. I don't know how reflink works.

In general it works pretty fast. You can clone terabytes of data within a few seconds.

Regarding windows implementation, the API supports up to 4GiB block per call, which means that even if there were a progress callback, it would be called only once per 4GiB. It would require a huge file, to make the progress callback useful.