Merge pull request #2352 from joshmay1/universe_cloning

Instantiate new cloned universes instead of deepcopying

openmc/universe.py

@@ -111,6 +111,13 @@ class UniverseBase(ABC, IDManagerMixin):
 
         """
 
+    @abstractmethod
+    def _partial_deepcopy(self):
+        """Deepcopy all parameters of an openmc.UniverseBase object except its cells.
+        This should only be used from the openmc.UniverseBase.clone() context.
+
+        """
+
     def clone(self, clone_materials=True, clone_regions=True, memo=None):
         """Create a copy of this universe with a new unique ID, and clones
         all cells within this universe.
@@ -138,8 +145,7 @@ class UniverseBase(ABC, IDManagerMixin):
 
         # If no memoize'd clone exists, instantiate one
         if self not in memo:
-            clone = deepcopy(self)
-            clone.id = None
+            clone = self._partial_deepcopy()
 
             # Clone all cells for the universe clone
             clone._cells = OrderedDict()
@@ -611,6 +617,15 @@ class Universe(UniverseBase):
             if not instances_only:
                 cell._paths.append(cell_path)
 
+    def _partial_deepcopy(self):
+        """Clone all of the openmc.Universe object's attributes except for its cells,
+        as they are copied within the clone function. This should only to be
+        used within the openmc.UniverseBase.clone() context.
+        """
+        clone = openmc.Universe(name=self.name)
+        clone.volume = self.volume
+        return clone
+
 
 class DAGMCUniverse(UniverseBase):
     """A reference to a DAGMC file to be used in the model.
@@ -947,3 +962,14 @@ class DAGMCUniverse(UniverseBase):
         out.auto_mat_ids = bool(elem.get('auto_mat_ids'))
 
         return out
+
+    def _partial_deepcopy(self):
+        """Clone all of the openmc.DAGMCUniverse object's attributes except for
+        its cells, as they are copied within the clone function. This should
+        only to be used within the openmc.UniverseBase.clone() context.
+        """
+        clone = openmc.DAGMCUniverse(name=self.name, filename=self.filename)
+        clone.volume = self.volume
+        clone.auto_geom_ids = self.auto_geom_ids
+        clone.auto_mat_ids = self.auto_mat_ids
+        return clone

tests/unit_tests/test_universe.py

@@ -107,11 +107,13 @@ def test_clone():
     c2.fill = openmc.Material()
     c3 = openmc.Cell()
     u1 = openmc.Universe(name='cool', cells=(c1, c2, c3))
+    u1.volume = 1.
 
     u2 = u1.clone()
     assert u2.name == u1.name
     assert u2.cells != u1.cells
     assert u2.get_all_materials() != u1.get_all_materials()
+    assert u2.volume == u1.volume
 
     u2 = u1.clone(clone_materials=False)
     assert u2.get_all_materials() == u1.get_all_materials()
@@ -120,6 +122,33 @@ def test_clone():
     assert next(iter(u3.cells.values())).region ==\
          next(iter(u1.cells.values())).region
 
+    # Change attributes, make sure clone stays intact
+    u1.volume = 2.
+    u1.name = "different name"
+    assert u3.volume != u1.volume
+    assert u3.name != u1.name
+
+    # Test cloning a DAGMC universe
+    dagmc_u = openmc.DAGMCUniverse(filename="", name="DAGMC universe")
+    dagmc_u.volume = 1.
+    dagmc_u.auto_geom_ids = True
+    dagmc_u.auto_mat_ids = True
+    dagmc_u1 = dagmc_u.clone()
+    assert dagmc_u1.name == dagmc_u.name
+    assert dagmc_u1.volume == dagmc_u.volume
+    assert dagmc_u1.auto_geom_ids == dagmc_u.auto_geom_ids
+    assert dagmc_u1.auto_mat_ids == dagmc_u.auto_mat_ids
+
+    # Change attributes, check the clone remained intact
+    dagmc_u.name = "another name"
+    dagmc_u.auto_geom_ids = False
+    dagmc_u.auto_mat_ids = False
+    dagmc_u.volume = 2.
+    assert dagmc_u1.name != dagmc_u.name
+    assert dagmc_u1.volume != dagmc_u.volume
+    assert dagmc_u1.auto_geom_ids != dagmc_u.auto_geom_ids
+    assert dagmc_u1.auto_mat_ids != dagmc_u.auto_mat_ids
+
 
 def test_create_xml(cell_with_lattice):
     cells = [openmc.Cell() for i in range(5)]