Marks and sweeps unreferenced objects.
Add snapshot cleanup to metadata.
Add content garbage collection
Add dirty flags for snapshotters and content store which
are set on deletion and used during the next garbage collection.
Cleanup content store backend when content metadata is removed.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Updates metadata plugin to require content and
snapshotter plugins be loaded and initializes with
those plugins, keeping the metadata database structure
static after initialization. Service plugins now only
require metadata plugin access snapshotter or content
stores through metadata, which was already required
behavior of the services.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
