Add memoization for has_changes

cms/djangoapps/contentstore/views/component.py

@@ -28,6 +28,7 @@ from opaque_keys.edx.keys import UsageKey
 
 from .access import has_course_access
 from django.utils.translation import ugettext as _
+from models.settings.course_grading import CourseGradingModel
 
 __all__ = ['OPEN_ENDED_COMPONENT_TYPES',
            'ADVANCED_COMPONENT_POLICY_KEY',

cms/djangoapps/contentstore/views/item.py

@@ -571,7 +571,7 @@ def _get_xblock(usage_key, user):
     """
     store = modulestore()
     try:
-        return store.get_item(usage_key)
+        return store.get_item(usage_key, depth=None)
     except ItemNotFoundError:
         if usage_key.category in CREATE_IF_NOT_FOUND:
             # Create a new one for certain categories only. Used for course info handouts.

cms/djangoapps/contentstore/views/tests/test_item.py

 """Tests for items views."""
-import os
 import json
 from datetime import datetime, timedelta
 import ddt
-from unittest import skipUnless
 
 from mock import patch
 from pytz import UTC

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -24,6 +24,7 @@ from opaque_keys import InvalidKeyError
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
 from xblock.runtime import Mixologist
 from xblock.core import XBlock
+import functools
 
 log = logging.getLogger('edx.modulestore')
 
@@ -559,6 +560,36 @@ class ModuleStoreReadBase(ModuleStoreRead):
             raise ValueError(u"Cannot set default store to type {}".format(store_type))
         yield
 
+    @staticmethod
+    def memoize_request_cache(func):
+        """
+        Memoize a function call results on the request_cache if there's one. Creates the cache key by
+        joining the unicode of all the args with &; so, if your arg may use the default &, it may
+        have false hits
+        """
+        @functools.wraps(func)
+        def wrapper(self, *args, **kwargs):
+            if self.request_cache:
+                cache_key = '&'.join([hashvalue(arg) for arg in args])
+                if cache_key in self.request_cache.data.setdefault(func.__name__, {}):
+                    return self.request_cache.data[func.__name__][cache_key]
+
+                result = func(self, *args, **kwargs)
+
+                self.request_cache.data[func.__name__][cache_key] = result
+                return result
+            else:
+                return func(self, *args, **kwargs)
+        return wrapper
+
+def hashvalue(arg):
+    """
+    If arg is an xblock, use its location. otherwise just turn it into a string
+    """
+    if isinstance(arg, XBlock):
+        return unicode(arg.location)
+    else:
+        return unicode(arg)
 
 class ModuleStoreWriteBase(ModuleStoreReadBase, ModuleStoreWrite):
     '''

common/lib/xmodule/xmodule/modulestore/mongo/draft.py

@@ -589,13 +589,13 @@ class DraftModuleStore(MongoModuleStore):
         _internal([root_usage.to_deprecated_son() for root_usage in root_usages])
         self.collection.remove({'_id': {'$in': to_be_deleted}}, safe=self.collection.safe)
 
+    @MongoModuleStore.memoize_request_cache
     def has_changes(self, xblock):
         """
         Check if the xblock or its children have been changed since the last publish.
         :param xblock: xblock to check
         :return: True if the draft and published versions differ
         """
-
         # don't check children if this block has changes (is not public)
         if self.compute_publish_state(xblock) != PublishState.public:
             return True