def GETorHEAD(self, req):
        """Handle HTTP GET or HEAD requests."""
        container_info = self.container_info(
            self.account_name, self.container_name, req)
        req.acl = container_info['read_acl']
        # pass the policy index to storage nodes via req header
        policy_index = req.headers.get('X-Backend-Storage-Policy-Index',
                                       container_info['storage_policy'])
        policy = POLICIES.get_by_index(policy_index)
        obj_ring = self.app.get_object_ring(policy_index)
        req.headers['X-Backend-Storage-Policy-Index'] = policy_index
        if 'swift.authorize' in req.environ:
            aresp = req.environ['swift.authorize'](req)
            if aresp:
                return aresp
        partition = obj_ring.get_part(
            self.account_name, self.container_name, self.object_name)
        node_iter = self.app.iter_nodes(obj_ring, partition)

        resp = self._reroute(policy)._get_or_head_response(
            req, node_iter, partition, policy)

        if ';' in resp.headers.get('content-type', ''):
            resp.content_type = clean_content_type(
                resp.headers['content-type'])
        return resp
dataset/ETHPy150Open openstack/swift/swift/proxy/controllers/obj.py/BaseObjectController.GETorHEAD/original