def getall(self):
        try:
            spec = {'data': {'$exists': 1}}
            fields = {'_id': 0}
            sort = [('tid', 1)]
            cur = self.db.docs.find(spec, fields, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def get_snapshot_metadata(self, snapshot_id):
        """Get metadata of the snapshot."""
        url = "snapshots/%s/metadata" % str(snapshot_id)
        resp, body = self.get(url)
        body = json.loads(body)
        return resp, body['metadata']