Will snap packages get differential (delta) updates?

I downloaded and installed LibreOffice 5.2.0 beta2 as described in LibreOffice 5.2.0 beta2 as a snap package. It weighed in at 1015 MiB.

There will certainly be more updates before the RC is out. My question is this: will snap packages get differential (delta) updates or will the entire snap package, 1 GiB in this case, have to be downloaded each time?

(BTW: this version fixes the long-standing vanishing clipboard content issue!)

Postscript question: I want to know if I can delete libreoffice_5.2.0.0.beta2_amd64.snap, the 1 GiB "source" file, or must it remain on the system for the delta updates to work?

Solution 1:

This OMG! Ubuntu article says delta:

Newer Apps, Larger

One side-effect of the ‘bundle’ approach is, naturally, a larger initial package size.

But Snaps are clever; transactional and delta updates allows devs to only upgrade the parts that need updating, be it a single lib, an app icon, or the entire freaking thing.

The documentation on Snappy Ubuntu Core also mentions these points:

• The OS and application files are kept completely separate, as a set of distinct read-only images.
• Transactional, image-based delta updates for the system and applications that can always be rolled back.
• These files are read-only, which means they cannot be tampered with and can be updated perfectly and predictably every time.
• Signatures and fingerprints ensure you’re running exactly what was published by the developer, no funny business even if the bits came from the internet.
• Delta management keeps the size of downloads to the bare minimum.

Solution 2:

We changed the format of snaps in 16.04, to a newer, more compact and more secure format. We have to add back delta updates in the new format, it will come soon. Also, we will add back auto-gardening so that old snap will be removed automatically in future, but you can safely delete it now yourself.