Remove 'hardware.instance_topology_from_instance'

Yet another function that has outstayed its welcome. This one had to
handle random object types that may have had a 'numa_topology' field or
key, which, if present, contained an instance NUMA topology in either
string, dict or object form. This was only called in two places, both of
which don't need this complexity as described below, meaning we can
remove this function.

nova/objects/request_spec.py

  The 'from_components' static method and '_from_instance' helper
  function were both using this, by way of a call to
  '_from_instance_numa_topology'. However, the former always receives an
  actual 'NUMATopology' object, while the latter always receives an
  instance, albeit possibly in serialized form. We add a check to handle
  the serialized form and we're done.

Change-Id: I5ded32a1cd33ab5b64ffa73fcfeb76683eb97df7
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

nova/objects/request_spec.py

@@ -11,13 +11,14 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+
 import copy
 import itertools
 
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import versionutils
-
+import six
 
 from nova.db.sqlalchemy import api as db
 from nova.db.sqlalchemy import api_models
@@ -26,7 +27,6 @@ from nova import objects
 from nova.objects import base
 from nova.objects import fields
 from nova.objects import instance as obj_instance
-from nova.virt import hardware
 
 LOG = logging.getLogger(__name__)
 
@@ -215,11 +215,11 @@ class RequestSpec(base.NovaObject):
             self.pci_requests = pci_requests
 
     def _from_instance_numa_topology(self, numa_topology):
-        if isinstance(numa_topology, dict):
-            self.numa_topology = hardware.instance_topology_from_instance(
-                dict(numa_topology=numa_topology))
-        else:
-            self.numa_topology = numa_topology
+        if isinstance(numa_topology, six.string_types):
+            numa_topology = objects.InstanceNUMATopology.obj_from_primitive(
+                jsonutils.loads(numa_topology))
+
+        self.numa_topology = numa_topology
 
     def _from_flavor(self, flavor):
         if isinstance(flavor, objects.Flavor):

nova/tests/unit/objects/test_request_spec.py

@@ -152,15 +152,14 @@ class _TestRequestSpecObject(object):
             user_id=fakes.FAKE_USER_ID,
             availability_zone='nova',
             pci_requests=None,
-            numa_topology={'cells': [{'id': 1, 'cpuset': ['1'], 'memory': 8192,
-                                      'pagesize': None, 'cpu_topology': None,
-                                      'cpu_pinning_raw': None}]})
+            numa_topology=fake_request_spec.INSTANCE_NUMA_TOPOLOGY,
+        )
         spec = objects.RequestSpec()
 
         spec._from_instance(instance)
         self.assertIsInstance(spec.numa_topology, objects.InstanceNUMATopology)
         cells = spec.numa_topology.cells
-        self.assertEqual(1, len(cells))
+        self.assertEqual(2, len(cells))
         self.assertIsInstance(cells[0], objects.InstanceNUMACell)
 
     def test_from_flavor_as_object(self):

nova/virt/hardware.py

@@ -18,18 +18,15 @@ import itertools
 import math
 
 from oslo_log import log as logging
-from oslo_serialization import jsonutils
 from oslo_utils import strutils
 from oslo_utils import units
 import six
 
 import nova.conf
-from nova import context
 from nova import exception
 from nova.i18n import _
 from nova import objects
 from nova.objects import fields
-from nova.objects import instance as obj_instance
 
 
 CONF = nova.conf.CONF
@@ -1933,75 +1930,3 @@ def numa_usage_from_instances(host, instances, free=False):
         cells.append(newcell)
 
     return objects.NUMATopology(cells=cells)
-
-
-# TODO(ndipanov): Remove when all code paths are using objects
-def instance_topology_from_instance(instance):
-    """Extract numa topology from myriad instance representations.
-
-    Until the RPC version is bumped to 5.x, an instance may be
-    represented as a dict, a db object, or an actual Instance object.
-    Identify the type received and return either an instance of
-    objects.InstanceNUMATopology if the instance's NUMA topology is
-    available, else None.
-
-    :param host: nova.objects.ComputeNode instance, or a db object or
-                 dict
-
-    :returns: An instance of objects.NUMATopology or None
-    """
-    if isinstance(instance, obj_instance.Instance):
-        # NOTE (ndipanov): This may cause a lazy-load of the attribute
-        instance_numa_topology = instance.numa_topology
-    else:
-        if 'numa_topology' in instance:
-            instance_numa_topology = instance['numa_topology']
-        elif 'uuid' in instance:
-            try:
-                instance_numa_topology = (
-                    objects.InstanceNUMATopology.get_by_instance_uuid(
-                            context.get_admin_context(), instance['uuid'])
-                    )
-            except exception.NumaTopologyNotFound:
-                instance_numa_topology = None
-        else:
-            instance_numa_topology = None
-
-    if instance_numa_topology:
-        if isinstance(instance_numa_topology, six.string_types):
-            instance_numa_topology = (
-                objects.InstanceNUMATopology.obj_from_primitive(
-                    jsonutils.loads(instance_numa_topology)))
-
-        elif isinstance(instance_numa_topology, dict):
-            # NOTE (ndipanov): A horrible hack so that we can use
-            # this in the scheduler, since the
-            # InstanceNUMATopology object is serialized raw using
-            # the obj_base.obj_to_primitive, (which is buggy and
-            # will give us a dict with a list of InstanceNUMACell
-            # objects), and then passed to jsonutils.to_primitive,
-            # which will make a dict out of those objects. All of
-            # this is done by scheduler.utils.build_request_spec
-            # called in the conductor.
-            #
-            # Remove when request_spec is a proper object itself!
-            dict_cells = instance_numa_topology.get('cells')
-            if dict_cells:
-                cells = [objects.InstanceNUMACell(
-                    id=cell['id'],
-                    cpuset=set(cell['cpuset']),
-                    memory=cell['memory'],
-                    pagesize=cell.get('pagesize'),
-                    cpu_topology=cell.get('cpu_topology'),
-                    cpu_pinning=cell.get('cpu_pinning_raw'),
-                    cpu_policy=cell.get('cpu_policy'),
-                    cpu_thread_policy=cell.get('cpu_thread_policy'),
-                    cpuset_reserved=cell.get('cpuset_reserved'))
-                         for cell in dict_cells]
-                emulator_threads_policy = instance_numa_topology.get(
-                    'emulator_threads_policy')
-                instance_numa_topology = objects.InstanceNUMATopology(
-                    cells=cells,
-                    emulator_threads_policy=emulator_threads_policy)
-
-    return instance_numa_topology