fix: make the initialization more like how it was in the past

lms/djangoapps/grades/tests/test_tasks.py

@@ -153,8 +153,8 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
             assert mock_block_structure_create.call_count == 1
 
     @ddt.data(
-        (ModuleStoreEnum.Type.split, 1, 41, True),
-        (ModuleStoreEnum.Type.split, 1, 41, False),
+        (ModuleStoreEnum.Type.split, 2, 41, True),
+        (ModuleStoreEnum.Type.split, 2, 41, False),
     )
     @ddt.unpack
     def test_query_counts(self, default_store, num_mongo_calls, num_sql_calls, create_multiple_subsections):
@@ -165,7 +165,7 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
                     self._apply_recalculate_subsection_grade()
 
     @ddt.data(
-        (ModuleStoreEnum.Type.split, 1, 41),
+        (ModuleStoreEnum.Type.split, 2, 41),
     )
     @ddt.unpack
     def test_query_counts_dont_change_with_more_content(self, default_store, num_mongo_calls, num_sql_calls):
@@ -210,7 +210,7 @@ class RecalculateSubsectionGradeTest(HasCourseWithProblemsMixin, ModuleStoreTest
         )
 
     @ddt.data(
-        (ModuleStoreEnum.Type.split, 1, 41),
+        (ModuleStoreEnum.Type.split, 2, 41),
     )
     @ddt.unpack
     def test_persistent_grades_on_course(self, default_store, num_mongo_queries, num_sql_queries):

lms/djangoapps/instructor/tests/views/test_instructor_dashboard.py

@@ -683,6 +683,6 @@ class TestInstructorDashboardPerformance(ModuleStoreTestCase, LoginEnrollmentTes
 
         # check MongoDB calls count
         url = reverse('spoc_gradebook', kwargs={'course_id': self.course.id})
-        with check_mongo_calls(5):
+        with check_mongo_calls(6):
             response = self.client.get(url)
             assert response.status_code == 200

openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py

@@ -379,7 +379,7 @@ class CourseOverviewTestCase(CatalogIntegrationMixin, ModuleStoreTestCase, Cache
         course_overview = CourseOverview._create_or_update(course)  # pylint: disable=protected-access
         assert course_overview.lowest_passing_grade is None
 
-    @ddt.data((ModuleStoreEnum.Type.mongo, 5, 5), (ModuleStoreEnum.Type.split, 1, 1))
+    @ddt.data((ModuleStoreEnum.Type.mongo, 5, 5), (ModuleStoreEnum.Type.split, 2, 2))
     @ddt.unpack
     def test_versioning(self, modulestore_type, min_mongo_calls, max_mongo_calls):
         """

xmodule/modulestore/split_mongo/caching_descriptor_system.py

@@ -75,7 +75,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
         self.default_class = default_class
         self.local_modules = {}
         self._services['library_tools'] = LibraryToolsService(modulestore, user_id=None)
-        # Cache of block field datas, keyed by their ScopeId tuples
+        # Cache of block field datas, keyed by the XBlock instance (since the ScopeId changes!)
         self.block_field_datas = weakref.WeakKeyDictionary()
 
     @lazy
@@ -185,7 +185,9 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
             block = self.construct_xblock_from_class(
                 class_,
                 ScopeIds(None, block_key.type, definition_id, block_locator),
-                for_parent=kwargs.get('for_parent')
+                for_parent=kwargs.get('for_parent'),
+                # Pass this tuple on for use by _init_field_data_for_block() when field data is initialized.
+                cds_init_args=(block_data, definition_id, kwargs.get("field_decorator")),
                 # Passing field_data here is deprecated, so we don't. Get it via block.service(block, "field-data").
                 # https://github.com/openedx/XBlock/blob/e89cbc5/xblock/mixins.py#L200-L207
             )
@@ -244,11 +246,13 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
         block_key = BlockKey.from_usage_key(block.scope_ids.usage_id)
         course_key = block.scope_ids.usage_id.context_key
         try:
-            block_data = self.get_module_data(block_key, course_key)
-            definition_id = block_data.definition
-        except ItemNotFoundError:
+            (block_data, definition_id, field_decorator) = block.get_cds_init_args()
+        except KeyError:
+            # This block was not instantiate via xblock_from_json()/modulestore but rather via the "direct" XBlock API
+            # such as using construct_xblock_from_class(). It probably doesn't yet exist in modulestore.
             block_data = BlockData()
-            definition_id = None  # Perhaps this block was newly created.
+            definition_id = LocalId()
+            field_decorator = None
         class_ = self.load_block_type(block.scope_ids.block_type)
         convert_fields = lambda field: self.modulestore.convert_references_to_keys(
             course_key, class_, field, self.course_entry.structure['blocks'],
@@ -274,7 +278,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
         except AttributeError:
             pass
 
-        if definition_id is not None and not block_data.definition_loaded:
+        if not isinstance(definition_id, LocalId) and not block_data.definition_loaded:
             definition_loader = DefinitionLazyLoader(
                 self.modulestore,
                 course_key,
@@ -291,7 +295,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
             converted_defaults,
             parent=parent,
             aside_fields=aside_fields,
-            # field_decorator=kwargs.get('field_decorator') # FIXME: Need to get the field_decorator
+            field_decorator=field_decorator,
         )
 
         if InheritanceMixin in self.modulestore.xblock_mixins:

xmodule/modulestore/tests/test_mongo_call_count.py

@@ -159,9 +159,9 @@ class CountMongoCallsCourseTraversal(TestCase):
         (MIXED_SPLIT_MODULESTORE_BUILDER, 0, False, True, 37),
         (MIXED_SPLIT_MODULESTORE_BUILDER, 0, True, True, 37),
         (MIXED_SPLIT_MODULESTORE_BUILDER, None, False, False, 2),
-        (MIXED_SPLIT_MODULESTORE_BUILDER, None, True, False, 1),
+        (MIXED_SPLIT_MODULESTORE_BUILDER, None, True, False, 2),
         (MIXED_SPLIT_MODULESTORE_BUILDER, 0, False, False, 2),
-        (MIXED_SPLIT_MODULESTORE_BUILDER, 0, True, False, 1),
+        (MIXED_SPLIT_MODULESTORE_BUILDER, 0, True, False, 2),
     )
     @ddt.unpack
     def test_number_mongo_calls(self, store_builder, depth, lazy, access_all_block_fields, num_mongo_calls):
@@ -178,7 +178,7 @@ class CountMongoCallsCourseTraversal(TestCase):
 
     @ddt.data(
         (MIXED_OLD_MONGO_MODULESTORE_BUILDER, 324),
-        (MIXED_SPLIT_MODULESTORE_BUILDER, 2),
+        (MIXED_SPLIT_MODULESTORE_BUILDER, 3),
     )
     @ddt.unpack
     def test_lazy_when_course_previously_cached(self, store_builder, num_mongo_calls):

xmodule/x_module.py

@@ -313,9 +313,22 @@ class XModuleMixin(XModuleFields, XBlock):
 
     def __init__(self, *args, **kwargs):
         self._asides = []
+        # Initialization data used by CachingDescriptorSystem to defer FieldData initialization
+        self._cds_init_args = kwargs.pop("cds_init_args", None)
 
         super().__init__(*args, **kwargs)
 
+    def get_cds_init_args(self):
+        """ Get initialization data used by CachingDescriptorSystem to defer FieldData initialization """
+        if self._cds_init_args is None:
+            raise KeyError("cds_init_args was not provided for this XBlock")
+        if self._cds_init_args is False:
+            raise RuntimeError("Tried to get CachingDescriptorSystem cds_init_args twice for the same XBlock.")
+        args = self._cds_init_args
+        # Free the memory and set this False to flag any double-access bugs. This only needs to be read once.
+        self._cds_init_args = False
+        return args
+
     @property
     def runtime(self):
         return self._runtime