Move singleton accessor w/ django dependencies to same place as modulestore() singleton accessor

common/lib/xmodule/xmodule/modulestore/django.py

@@ -8,6 +8,7 @@ from __future__ import absolute_import
 from importlib import import_module
 
 from django.conf import settings
+from xmodule.modulestore.loc_mapper_store import LocMapperStore
 
 _MODULESTORES = {}
 
@@ -53,3 +54,18 @@ def modulestore(name='default'):
                                                           settings.MODULESTORE[name]['OPTIONS'])
 
     return _MODULESTORES[name]
+
+_loc_singleton = None
+def loc_mapper():
+    """
+    Get the loc mapper which bidirectionally maps Locations to Locators. Used like modulestore() as
+    a singleton accessor.
+    """
+    # pylint: disable=W0603
+    global _loc_singleton
+    # pylint: disable=W0212
+    if _loc_singleton is None:
+        # instantiate
+        _loc_singleton = LocMapperStore(settings.modulestore_options)
+    return _loc_singleton
+

common/lib/xmodule/xmodule/modulestore/loc_mapper_store.py

@@ -1,28 +1,15 @@
 '''
 Method for converting among our differing Location/Locator whatever reprs
 '''
-from __future__ import absolute_import
 from random import randint
 import re
 import pymongo
-from django.conf import settings
 
 from xmodule.modulestore.exceptions import InvalidLocationError, ItemNotFoundError, DuplicateItemError
 from xmodule.modulestore.locator import BlockUsageLocator
 from xmodule.modulestore.mongo import draft
 from xmodule.modulestore import Location
 
-def loc_mapper():
-    """
-    Get the loc mapper which bidirectionally maps Locations to Locators. Used like modulestore() as
-    a singleton accessor.
-    """
-    # pylint: disable=W0212
-    if LocMapperStore._singleton is None:
-        # instantiate
-        LocMapperStore(settings.modulestore_options)
-    return LocMapperStore._singleton
-
 class LocMapperStore(object):
     '''
     This store persists mappings among the addressing schemes. At this time, it's between the old i4x Location
@@ -38,8 +25,6 @@ class LocMapperStore(object):
     or dominant store, but that's not a requirement. This store creates its own connection.
     '''
 
-    _singleton = None
-
     def __init__(self, host, db, collection, port=27017, user=None, password=None, **kwargs):
         '''
         Constructor
@@ -55,7 +40,6 @@ class LocMapperStore(object):
 
         self.location_map = self.db[collection + '.location_map']
         self.location_map.write_concern = {'w': 1}
-        LocMapperStore._singleton = self
 
 
     # location_map functions

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

@@ -8,7 +8,7 @@ import uuid
 from xmodule.modulestore import Location
 from xmodule.modulestore.locator import BlockUsageLocator
 from xmodule.modulestore.exceptions import ItemNotFoundError, DuplicateItemError
-from xmodule.modulestore.LocMapperStore import LocMapperStore
+from xmodule.modulestore.loc_mapper_store import LocMapperStore
 
 
 class TestLocationMapper(unittest.TestCase):