def get_snapshots(self, dataset=''):
"""Return snapshots belonging to this context."""
# get all snapshots
allsnaps = zfs.get_snapshots(dataset)
# sort out those in my context
my_snapshots = filter(lambda x: x.startswith('%s-%s-' % (DEFAULT_SNAP_PREFIX, self.tag)), allsnaps)
# sort them oldest to newest
return sorted(my_snapshots, key=lambda x: self._get_snap_time(x))
def existing_contexts(dataset=''):
"""Return the set of existing contexts found on the system"""
return set([x.split('-')[1] for x in zfs.get_snapshots(dataset) if is_snapman_snapshot(x)])
