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

[Vivek Dasmohapatra <vivek collabora co uk>]

> 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).

Ok, been hacking on this for a bit, and have a branch which implements
this feature. The branch adds:

 - index of the filez object checksums + archived size + unpacked size
 - said index is downloaded on pull if it is available
 - the index is entirely optional, pull doesn;t care if it isn't there
 - pull has a metadata flag which pulls only the .commit and .index
 - the `summary' command shows the size of a commit (archived & unpacked)
   - if invoked on a remote ref, summary pulls the metadata if it is not
     available.
 - there are tests for the index creation and metadata pull, followed by
   a pull of the rest of the content

Obviously the ideal scenario for us is if this gets absorbed by
upstream ostree - if it's not suitable for inclusion for some reason
please let me know and I'll see what I can do about any problem(s).