bita VS swupd-client

Built this cdc tool for software update of embedded (Linux) systems and have deployed it with good enough performance on a couple of arm CPUs; https://github.com/oll3/bita

Though main goal has been keeping data usage low rather than speed up.

Nice write up. rsync is great as an application but I found it more cumbersome to use when wanting to integrate it into my own application. There's librsync but the documentation is threadbare and it requires an rsync server to run. I found bita/bitar (https://github.com/oll3/bita) which is inspired by rsync & family. It works more like zsync which leverages HTTP Range requests so it doesn't require anything running on the server to get chunks. Works like a treat using s3/b2 storage to serve files and get incremental differential updates on the client side!

Very cool, thanks for sharing. I did a deep dive in the past into various syncing/binary diff protocols and really liked zsync. It was probably my top choice for the application I was designing but I ended up not using it. The library I did use is called bita: https://github.com/oll3/bita. It is inspired by the same family of projects as zsync. The main advantage I found with bita is that the core logic is encapsulated in a library so that you don’t only have to use the binaries but can integrate it directly into an application. I’d be curious to know if that’s in the plans for KySync.

I have tried a simple recreate making a tar with a few hard linked files and not hit the problem. The closest equivalent I could find was this but they were writing their own extract code and messing with paths during the extract. That shouldn't happen with the tar command.