Re: Extending ostree's functionality (adding a metadat index)

[Colin Walters <walters verbum org>]

Hi,

On Fri, 2013-08-09 at 15:38 +0100, Vivek Dasmohapatra wrote:

> I've been given the task of investigating ostree, and adding an index
> to it so that a client can efficiently determine how big a download
> of a given commit would be (without downloading all the individual
> metadata files).

It'd be pretty easy to compute the total size of a given commit at
commit time, and include that in the already existing metadata a{sv}.

However, that doesn't tell you how many objects you already have...which
is going to be the common case.

For making ostree efficient for major (i.e. non-continuous) upgrades,
see this thread:

https://mail.gnome.org/archives/ostree-list/2013-July/msg00005.html

With a static delta, the descriptor could provide the size of the delta,
in addition to simply being a lot more efficient.  I started to
implement static deltas at GUADEC, and I can post some code relatively
soon.

But...what's the high level goal here?  Something like an OS updater
tool that says "Update available: 45MB" ?