Cache CustomCourseForEdX object lookup per-request

lms/djangoapps/ccx/overrides.py

@@ -7,6 +7,8 @@ import logging
 
 from django.db import transaction, IntegrityError
 
+import request_cache
+
 from courseware.field_overrides import FieldOverrideProvider  # pylint: disable=import-error
 from opaque_keys.edx.keys import CourseKey, UsageKey
 from ccx_keys.locator import CCXLocator, CCXBlockUsageLocator
@@ -69,7 +71,11 @@ def get_current_ccx(course_key):
     if not isinstance(course_key, CCXLocator):
         return None
 
-    return CustomCourseForEdX.objects.get(pk=course_key.ccx)
+    ccx_cache = request_cache.get_cache('ccx')
+    if course_key not in ccx_cache:
+        ccx_cache[course_key] = CustomCourseForEdX.objects.get(pk=course_key.ccx)
+
+    return ccx_cache[course_key]
 
 
 def get_override_for_ccx(ccx, block, name, default=None):

lms/djangoapps/ccx/tests/test_field_override_performance.py

@@ -5,6 +5,7 @@ Performance tests for field overrides.
 import ddt
 import itertools
 import mock
+from nose.plugins.skip import SkipTest
 
 from courseware.views import progress  # pylint: disable=import-error
 from courseware.field_overrides import OverrideFieldData
@@ -25,6 +26,8 @@ from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase, \
     TEST_DATA_SPLIT_MODULESTORE, TEST_DATA_MONGO_MODULESTORE
 from xmodule.modulestore.tests.factories import check_mongo_calls, CourseFactory, check_sum_of_calls
 from xmodule.modulestore.tests.utils import ProceduralCourseTestMixin
+from ccx_keys.locator import CCXLocator
+from ccx.tests.factories import CcxFactory, CcxMembershipFactory
 
 
 @attr('shard_1')
@@ -58,6 +61,7 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
         self.request = self.request_factory.get("foo")
         self.request.user = self.student
         self.course = None
+        self.ccx = None
 
         MakoMiddleware().process_request(self.request)
 
@@ -113,17 +117,42 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             self.course.id
         )
 
-    def grade_course(self, course):
+        if enable_ccx:
+            self.ccx = CcxFactory.create()
+            CcxMembershipFactory.create(
+                student=self.student,
+                ccx=self.ccx
+            )
+
+    def grade_course(self, course, view_as_ccx):
         """
         Renders the progress page for the given course.
         """
+        course_key = course.id
+        if view_as_ccx:
+            course_key = CCXLocator.from_course_locator(course_key, self.ccx.id)
+
         return progress(
             self.request,
-            course_id=course.id.to_deprecated_string(),
+            course_id=unicode(course_key),
             student_id=self.student.id
         )
 
-    def instrument_course_progress_render(self, course_width, enable_ccx, queries, reads, xblocks):
+    def assertMongoCallCount(self, calls):
+        """
+        Assert that mongodb is queried ``calls`` times in the surrounded
+        context.
+        """
+        return check_mongo_calls(calls)
+
+    def assertXBlockInstantiations(self, instantiations):
+        """
+        Assert that exactly ``instantiations`` XBlocks are instantiated in
+        the surrounded context.
+        """
+        return check_sum_of_calls(XBlock, ['__init__'], instantiations, instantiations, include_arguments=False)
+
+    def instrument_course_progress_render(self, course_width, enable_ccx, view_as_ccx, queries, reads, xblocks):
         """
         Renders the progress page, instrumenting Mongo reads and SQL queries.
         """
@@ -146,16 +175,16 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             OverrideFieldData.provider_classes = None
 
             with self.assertNumQueries(queries):
-                with check_mongo_calls(reads):
-                    with check_sum_of_calls(XBlock, ['__init__'], xblocks, xblocks, include_arguments=False):
-                        self.grade_course(self.course)
+                with self.assertMongoCallCount(reads):
+                    with self.assertXBlockInstantiations(xblocks):
+                        self.grade_course(self.course, view_as_ccx)
 
-    @ddt.data(*itertools.product(('no_overrides', 'ccx'), range(1, 4), (True, False)))
+    @ddt.data(*itertools.product(('no_overrides', 'ccx'), range(1, 4), (True, False), (True, False)))
     @ddt.unpack
     @override_settings(
         FIELD_OVERRIDE_PROVIDERS=(),
     )
-    def test_field_overrides(self, overrides, course_width, enable_ccx):
+    def test_field_overrides(self, overrides, course_width, enable_ccx, view_as_ccx):
         """
         Test without any field overrides.
         """
@@ -163,9 +192,18 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             'no_overrides': (),
             'ccx': ('ccx.overrides.CustomCoursesForEdxOverrideProvider',)
         }
+        if overrides == 'no_overrides' and view_as_ccx:
+            raise SkipTest("Can't view a ccx course if field overrides are disabled.")
+
+        if not enable_ccx and view_as_ccx:
+            raise SkipTest("Can't view a ccx course if ccx is disabled on the course")
+
+        if self.MODULESTORE == TEST_DATA_MONGO_MODULESTORE and view_as_ccx:
+            raise SkipTest("Can't use a MongoModulestore test as a CCX course")
+
         with self.settings(FIELD_OVERRIDE_PROVIDERS=providers[overrides]):
-            queries, reads, xblocks = self.TEST_DATA[(overrides, course_width, enable_ccx)]
-            self.instrument_course_progress_render(course_width, enable_ccx, queries, reads, xblocks)
+            queries, reads, xblocks = self.TEST_DATA[(overrides, course_width, enable_ccx, view_as_ccx)]
+            self.instrument_course_progress_render(course_width, enable_ccx, view_as_ccx, queries, reads, xblocks)
 
 
 class TestFieldOverrideMongoPerformance(FieldOverridePerformanceTestCase):
@@ -176,19 +214,25 @@ class TestFieldOverrideMongoPerformance(FieldOverridePerformanceTestCase):
     __test__ = True
 
     TEST_DATA = {
-        # (providers, course_width, enable_ccx): # of sql queries, # of mongo queries, # of xblocks
-        ('no_overrides', 1, True): (23, 7, 14),
-        ('no_overrides', 2, True): (68, 7, 85),
-        ('no_overrides', 3, True): (263, 7, 336),
-        ('ccx', 1, True): (23, 7, 14),
-        ('ccx', 2, True): (68, 7, 85),
-        ('ccx', 3, True): (263, 7, 336),
-        ('no_overrides', 1, False): (23, 7, 14),
-        ('no_overrides', 2, False): (68, 7, 85),
-        ('no_overrides', 3, False): (263, 7, 336),
-        ('ccx', 1, False): (23, 7, 14),
-        ('ccx', 2, False): (68, 7, 85),
-        ('ccx', 3, False): (263, 7, 336),
+        # (providers, course_width, enable_ccx, view_as_ccx): # of sql queries, # of mongo queries, # of xblocks
+        ('no_overrides', 1, True, False): (23, 7, 14),
+        ('no_overrides', 2, True, False): (68, 7, 85),
+        ('no_overrides', 3, True, False): (263, 7, 336),
+        ('ccx', 1, True, False): (23, 7, 14),
+        ('ccx', 2, True, False): (68, 7, 85),
+        ('ccx', 3, True, False): (263, 7, 336),
+        ('ccx', 1, True, True): (23, 7, 14),
+        ('ccx', 2, True, True): (68, 7, 85),
+        ('ccx', 3, True, True): (263, 7, 336),
+        ('no_overrides', 1, False, False): (23, 7, 14),
+        ('no_overrides', 2, False, False): (68, 7, 85),
+        ('no_overrides', 3, False, False): (263, 7, 336),
+        ('ccx', 1, False, False): (23, 7, 14),
+        ('ccx', 2, False, False): (68, 7, 85),
+        ('ccx', 3, False, False): (263, 7, 336),
+        ('ccx', 1, False, True): (23, 7, 14),
+        ('ccx', 2, False, True): (68, 7, 85),
+        ('ccx', 3, False, True): (263, 7, 336),
     }
 
 
@@ -200,16 +244,22 @@ class TestFieldOverrideSplitPerformance(FieldOverridePerformanceTestCase):
     __test__ = True
 
     TEST_DATA = {
-        ('no_overrides', 1, True): (23, 4, 9),
-        ('no_overrides', 2, True): (68, 19, 54),
-        ('no_overrides', 3, True): (263, 84, 215),
-        ('ccx', 1, True): (23, 4, 9),
-        ('ccx', 2, True): (68, 19, 54),
-        ('ccx', 3, True): (263, 84, 215),
-        ('no_overrides', 1, False): (23, 4, 9),
-        ('no_overrides', 2, False): (68, 19, 54),
-        ('no_overrides', 3, False): (263, 84, 215),
-        ('ccx', 1, False): (23, 4, 9),
-        ('ccx', 2, False): (68, 19, 54),
-        ('ccx', 3, False): (263, 84, 215),
+        ('no_overrides', 1, True, False): (23, 4, 9),
+        ('no_overrides', 2, True, False): (68, 19, 54),
+        ('no_overrides', 3, True, False): (263, 84, 215),
+        ('ccx', 1, True, False): (23, 4, 9),
+        ('ccx', 2, True, False): (68, 19, 54),
+        ('ccx', 3, True, False): (263, 84, 215),
+        ('ccx', 1, True, True): (33, 4, 13),
+        ('ccx', 2, True, True): (68, 19, 84),
+        ('ccx', 3, True, True): (263, 84, 335),
+        ('no_overrides', 1, False, False): (23, 4, 9),
+        ('no_overrides', 2, False, False): (68, 19, 54),
+        ('no_overrides', 3, False, False): (263, 84, 215),
+        ('ccx', 1, False, False): (23, 4, 9),
+        ('ccx', 2, False, False): (68, 19, 54),
+        ('ccx', 3, False, False): (263, 84, 215),
+        ('ccx', 1, False, True): (23, 4, 9),
+        ('ccx', 2, False, True): (68, 19, 54),
+        ('ccx', 3, False, True): (263, 84, 215),
     }

lms/djangoapps/ccx/tests/test_overrides.py

@@ -9,6 +9,7 @@ from nose.plugins.attrib import attr
 
 from courseware.field_overrides import OverrideFieldData  # pylint: disable=import-error
 from django.test.utils import override_settings
+from request_cache.middleware import RequestCache
 from student.tests.factories import AdminFactory  # pylint: disable=import-error
 from xmodule.modulestore.tests.django_utils import (
     ModuleStoreTestCase,
@@ -66,6 +67,8 @@ class TestFieldOverrides(ModuleStoreTestCase):
         get_ccx.return_value = ccx
         self.addCleanup(patch.stop)
 
+        self.addCleanup(RequestCache.clear_request_cache)
+
         # Apparently the test harness doesn't use LmsFieldStorage, and I'm not
         # sure if there's a way to poke the test harness to do so.  So, we'll
         # just inject the override field storage in this brute force manner.