docs/formats: Elaborate a bit on delta from NULL usage

See discussion on ostree-list.

Closes: #402
Approved by: gatispaeglis
This commit is contained in:
Colin Walters 2016-07-19 10:24:18 -04:00 committed by Atomic Bot
parent 29451a3999
commit d49d42b983

View File

@ -79,7 +79,10 @@ concept of a "static delta".
These deltas are targeted to be a delta between two specific commit
objects, including "bsdiff" and "rsync-style" deltas within a content
object. Static deltas also support `from NULL`, where the client can
more efficiently download a commit object from scratch.
more efficiently download a commit object from scratch - this is
mostly useful when using OSTree for containers, rather than OS images.
For OS images, one tends to download an installer ISO or qcow2 image
which is a single file that contains the tree data already.
Effectively, we're spending server-side storage (and one-time compute
cost), and gaining efficiency in client network bandwidth.