Make path_to_location use bulk_write_operation for performance.

common/lib/xmodule/xmodule/modulestore/mixed.py

@@ -651,5 +651,8 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
         If course_id is None, the default store is used.
         """
         store = self._get_modulestore_for_courseid(course_id)
-        with store.bulk_write_operations(course_id):
+        if hasattr(store, 'bulk_write_operations'):
+            with store.bulk_write_operations(course_id):
+                yield
+        else:
             yield

common/lib/xmodule/xmodule/modulestore/search.py

@@ -68,39 +68,41 @@ def path_to_location(modulestore, usage_key):
             newpath = (next_usage, path)
             queue.append((parent, newpath))
 
-    if not modulestore.has_item(usage_key):
-        raise ItemNotFoundError(usage_key)
-
-    path = find_path_to_course()
-    if path is None:
-        raise NoPathToItem(usage_key)
-
-    n = len(path)
-    course_id = path[0].course_key
-    # pull out the location names
-    chapter = path[1].name if n > 1 else None
-    section = path[2].name if n > 2 else None
-    # Figure out the position
-    position = None
-
-    # This block of code will find the position of a module within a nested tree
-    # of modules. If a problem is on tab 2 of a sequence that's on tab 3 of a
-    # sequence, the resulting position is 3_2. However, no positional modules
-    # (e.g. sequential and videosequence) currently deal with this form of
-    # representing nested positions. This needs to happen before jumping to a
-    # module nested in more than one positional module will work.
-    if n > 3:
-        position_list = []
-        for path_index in range(2, n - 1):
-            category = path[path_index].block_type
-            if category == 'sequential' or category == 'videosequence':
-                section_desc = modulestore.get_item(path[path_index])
-                # this calls get_children rather than just children b/c old mongo includes private children
-                # in children but not in get_children
-                child_locs = [c.location for c in section_desc.get_children()]
-                # positions are 1-indexed, and should be strings to be consistent with
-                # url parsing.
-                position_list.append(str(child_locs.index(path[path_index + 1]) + 1))
-        position = "_".join(position_list)
-
-    return (course_id, chapter, section, position)
+    # doesn't write but does multiple reads. bulk_write minimizes reads too
+    with modulestore.bulk_write_operations(usage_key.course_key):
+        if not modulestore.has_item(usage_key):
+            raise ItemNotFoundError(usage_key)
+
+        path = find_path_to_course()
+        if path is None:
+            raise NoPathToItem(usage_key)
+
+        n = len(path)
+        course_id = path[0].course_key
+        # pull out the location names
+        chapter = path[1].name if n > 1 else None
+        section = path[2].name if n > 2 else None
+        # Figure out the position
+        position = None
+
+        # This block of code will find the position of a module within a nested tree
+        # of modules. If a problem is on tab 2 of a sequence that's on tab 3 of a
+        # sequence, the resulting position is 3_2. However, no positional modules
+        # (e.g. sequential and videosequence) currently deal with this form of
+        # representing nested positions. This needs to happen before jumping to a
+        # module nested in more than one positional module will work.
+        if n > 3:
+            position_list = []
+            for path_index in range(2, n - 1):
+                category = path[path_index].block_type
+                if category == 'sequential' or category == 'videosequence':
+                    section_desc = modulestore.get_item(path[path_index])
+                    # this calls get_children rather than just children b/c old mongo includes private children
+                    # in children but not in get_children
+                    child_locs = [c.location for c in section_desc.get_children()]
+                    # positions are 1-indexed, and should be strings to be consistent with
+                    # url parsing.
+                    position_list.append(str(child_locs.index(path[path_index + 1]) + 1))
+            position = "_".join(position_list)
+
+        return (course_id, chapter, section, position)

common/lib/xmodule/xmodule/modulestore/tests/test_mixed_modulestore.py

@@ -717,7 +717,7 @@ class TestMixedModuleStore(unittest.TestCase):
     # TODO: LMS-11220: Document why draft send count is 5
     # TODO: LMS-11220: Document why draft find count is 18
     # TODO: LMS-11220: Document why split find count is 16
-    @ddt.data(('draft', [18, 5], 0), ('split', [16, 6], 0))
+    @ddt.data(('draft', [19, 5], 0), ('split', [2, 2], 0))
     @ddt.unpack
     def test_path_to_location(self, default_ms, num_finds, num_sends):
         """
@@ -736,7 +736,6 @@ class TestMixedModuleStore(unittest.TestCase):
                  (course_key, "Chapter_x", None, None)),
             )
 
-            mongo_store = self.store._get_modulestore_for_courseid(self._course_key_from_string(self.MONGO_COURSEID))
             for location, expected in should_work:
                 with check_mongo_calls(num_finds.pop(0), num_sends):
                     self.assertEqual(path_to_location(self.store, location), expected)

lms/djangoapps/courseware/model_data.py

@@ -21,6 +21,7 @@ from django.contrib.auth.models import User
 from xblock.runtime import KeyValueStore
 from xblock.exceptions import KeyValueMultiSaveError, InvalidScopeError
 from xblock.fields import Scope, UserScope
+from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
 
@@ -109,7 +110,8 @@ class FieldDataCache(object):
 
             return descriptors
 
-        descriptors = get_child_descriptors(descriptor, depth, descriptor_filter)
+        with modulestore().bulk_write_operations(descriptor.location.course_key):
+            descriptors = get_child_descriptors(descriptor, depth, descriptor_filter)
 
         return FieldDataCache(descriptors, course_id, user, select_for_update)
 

lms/djangoapps/courseware/tests/test_module_render.py

@@ -326,14 +326,15 @@ class TestTOC(ModuleStoreTestCase):
         self.request = factory.get(chapter_url)
         self.request.user = UserFactory()
         self.modulestore = self.store._get_modulestore_for_courseid(self.course_key)
+        self.toy_course = self.store.get_course(self.toy_loc, depth=2)
         with check_mongo_calls(num_finds, num_sends):
-            self.toy_course = self.store.get_course(self.toy_loc, depth=2)
             self.field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
-                self.toy_loc, self.request.user, self.toy_course, depth=2)
+                self.toy_loc, self.request.user, self.toy_course, depth=2
+            )
 
 
     # TODO: LMS-11220: Document why split find count is 21
-    @ddt.data((ModuleStoreEnum.Type.mongo, 3, 0), (ModuleStoreEnum.Type.split, 21, 0))
+    @ddt.data((ModuleStoreEnum.Type.mongo, 1, 0), (ModuleStoreEnum.Type.split, 5, 0))
     @ddt.unpack
     def test_toc_toy_from_chapter(self, default_ms, num_finds, num_sends):
         with self.store.default_store(default_ms):
@@ -361,7 +362,7 @@ class TestTOC(ModuleStoreTestCase):
             self.assertIn(toc_section, actual)
 
     # TODO: LMS-11220: Document why split find count is 21
-    @ddt.data((ModuleStoreEnum.Type.mongo, 3, 0), (ModuleStoreEnum.Type.split, 21, 0))
+    @ddt.data((ModuleStoreEnum.Type.mongo, 1, 0), (ModuleStoreEnum.Type.split, 5, 0))
     @ddt.unpack
     def test_toc_toy_from_section(self, default_ms, num_finds, num_sends):
         with self.store.default_store(default_ms):