Finding the size of xdg-apps

[Richard Hughes]

On 22 December 2015 at 11:48, Emmanuele Bassi <ebassi at gmail.com> wrote:
> I was going to ask for the same; Endless users usually have limited
> bandwidth at their disposal, and showing the download size beforehand
> allows them to decide whether or not to update the app on their
> current connection or wait until a better time (e.g. during the
> night).

So that implies we actually need a few extra things:

* space on disk of installed application that is up to date
* download size of not-ever-installed app, plus size of new runtime(s)
that the application requires
* download size of application, based on the size of the delta between
what's installed now and the new version
* increase/decrease in disk space between installed version and new
version (to check for disk space ahead of time)

I guess we could manually do the first point with lots of stat()
calls, but it seems like something the library should do for us.

Richard.