Fix performance regression

Remove course_from_id
don't fetch whole course when the root will do
don't fetch even the root if the id will do
check for definition.data == null

common/djangoapps/course_modes/views.py

@@ -4,9 +4,7 @@ Views for the course_mode module
 
 import decimal
 from django.core.urlresolvers import reverse
-from django.http import (
-    HttpResponseBadRequest,  Http404
-)
+from django.http import HttpResponseBadRequest
 from django.shortcuts import redirect
 from django.views.generic.base import View
 from django.utils.translation import ugettext as _
@@ -18,9 +16,9 @@ from edxmako.shortcuts import render_to_response
 from course_modes.models import CourseMode
 from courseware.access import has_access
 from student.models import CourseEnrollment
-from student.views import course_from_id
 from verify_student.models import SoftwareSecurePhotoVerification
 from xmodule.modulestore.locations import SlashSeparatedCourseKey
+from xmodule.modulestore.django import modulestore
 
 
 class ChooseModeView(View):
@@ -54,7 +52,7 @@ class ChooseModeView(View):
         donation_for_course = request.session.get("donation_for_course", {})
         chosen_price = donation_for_course.get(course_key, None)
 
-        course = course_from_id(course_key)
+        course = modulestore().get_course(course_key)
         context = {
             "course_modes_choose_url": reverse("course_modes_choose", kwargs={'course_id': course_key.to_deprecated_string()}),
             "modes": modes,
@@ -80,7 +78,7 @@ class ChooseModeView(View):
 
         # This is a bit redundant with logic in student.views.change_enrollement,
         # but I don't really have the time to refactor it more nicely and test.
-        course = course_from_id(course_key)
+        course = modulestore().get_course(course_key)
         if not has_access(user, 'enroll', course):
             error_msg = _("Enrollment is closed")
             return self.get(request, course_id, error=error_msg)

common/djangoapps/external_auth/views.py

@@ -589,7 +589,7 @@ def course_specific_login(request, course_id):
        Dispatcher function for selecting the specific login method
        required by the course
     """
-    course = student.views.course_from_id(course_id)
+    course = modulestore().get_course(course_id)
     if not course:
         # couldn't find the course, will just return vanilla signin page
         return redirect_with_get('signin_user', request.GET)
@@ -607,7 +607,7 @@ def course_specific_register(request, course_id):
         Dispatcher function for selecting the specific registration method
         required by the course
     """
-    course = student.views.course_from_id(course_id)
+    course = modulestore().get_course(course_id)
 
     if not course:
         # couldn't find the course, will just return vanilla registration page

common/djangoapps/student/views.py

@@ -49,11 +49,10 @@ from verify_student.models import SoftwareSecurePhotoVerification, MidcourseReve
 from certificates.models import CertificateStatuses, certificate_status_for_student
 from dark_lang.models import DarkLangConfig
 
-from xmodule.course_module import CourseDescriptor
 from xmodule.modulestore.exceptions import ItemNotFoundError
 from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.locations import SlashSeparatedCourseKey
-from xmodule.modulestore import XML_MODULESTORE_TYPE, Location
+from xmodule.modulestore import XML_MODULESTORE_TYPE
 
 from collections import namedtuple
 
@@ -128,11 +127,6 @@ def index(request, extra_context={}, user=AnonymousUser()):
     return render_to_response('index.html', context)
 
 
-def course_from_id(course_id):
-    """Return the CourseDescriptor corresponding to this course_id"""
-    return modulestore().get_course(course_id)
-
-
 def embargo(_request):
     """
     Render the embargo page.
@@ -242,7 +236,7 @@ def get_course_enrollment_pairs(user, course_org_filter, org_filter_out_set):
     a student's dashboard.
     """
     for enrollment in CourseEnrollment.enrollments_for_user(user):
-        course = course_from_id(enrollment.course_id)
+        course = modulestore().get_course(enrollment.course_id)
         if course and not isinstance(course, ErrorDescriptor):
 
             # if we are in a Microsite, then filter out anything that is not
@@ -603,7 +597,7 @@ def change_enrollment(request):
         # Make sure the course exists
         # We don't do this check on unenroll, or a bad course id can't be unenrolled from
         try:
-            course = course_from_id(course_id)
+            course = modulestore().get_course(course_id)
         except ItemNotFoundError:
             log.warning("User {0} tried to enroll in non-existent course {1}"
                         .format(user.username, course_id))
@@ -671,7 +665,7 @@ def _get_course_enrollment_domain(course_id):
     @param course_id:
     @return:
     """
-    course = course_from_id(course_id)
+    course = modulestore().get_course(course_id)
     if course is None:
         return None
 

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

@@ -165,7 +165,7 @@ class ModuleStoreRead(object):
         pass
 
     @abstractmethod
-    def get_course(self, course_id, depth=None):
+    def get_course(self, course_id, depth=0):
         '''
         Look for a specific course by its id (:class:`CourseKey`).
         Returns the course descriptor, or None if not found.
@@ -332,7 +332,7 @@ class ModuleStoreReadBase(ModuleStoreRead):
         """
         return {}
 
-    def get_course(self, course_id, depth=None):
+    def get_course(self, course_id, depth=0):
         """
         See ModuleStoreRead.get_course
 

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

@@ -157,7 +157,7 @@ class MixedModuleStore(ModuleStoreWriteBase):
 
         return courses.values()
 
-    def get_course(self, course_key, depth=None):
+    def get_course(self, course_key, depth=0):
         """
         returns the course module associated with the course_id. If no such course exists,
         it returns None

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

@@ -184,6 +184,7 @@ class CachingDescriptorSystem(MakoDescriptorSystem):
                 if isinstance(data, basestring):
                     data = {'data': data}
                 mixed_class = self.mixologist.mix(class_)
+                if data is not None:
                     data = self._convert_reference_fields_to_keys(mixed_class, location.course_key, data)
                 metadata = self._convert_reference_fields_to_keys(mixed_class, location.course_key, metadata)
                 kvs = MongoKeyValueStore(
@@ -350,7 +351,7 @@ class MongoModuleStore(ModuleStoreWriteBase):
         # call out to the DB
         resultset = self.collection.find(query, record_filter)
 
-        # it's ok to keep these as urls b/c the overall cache is indexed by course_key and this
+        # it's ok to keep these as deprecated strings b/c the overall cache is indexed by course_key and this
         # is a dictionary relative to that course
         results_by_url = {}
         root = None
@@ -411,7 +412,7 @@ class MongoModuleStore(ModuleStoreWriteBase):
 
             # then look in any caching subsystem (e.g. memcached)
             if self.metadata_inheritance_cache_subsystem is not None:
-                tree = self.metadata_inheritance_cache_subsystem.get(course_id, {})
+                tree = self.metadata_inheritance_cache_subsystem.get(unicode(course_id), {})
             else:
                 logging.warning('Running MongoModuleStore without a metadata_inheritance_cache_subsystem. This is OK in localdev and testing environment. Not OK in production.')
 
@@ -421,7 +422,7 @@ class MongoModuleStore(ModuleStoreWriteBase):
 
             # now write out computed tree to caching subsystem (e.g. memcached), if available
             if self.metadata_inheritance_cache_subsystem is not None:
-                self.metadata_inheritance_cache_subsystem.set(course_id, tree)
+                self.metadata_inheritance_cache_subsystem.set(unicode(course_id), tree)
 
         # now populate a request_cache, if available. NOTE, we are outside of the
         # scope of the above if: statement so that after a memcache hit, it'll get
@@ -590,7 +591,7 @@ class MongoModuleStore(ModuleStoreWriteBase):
             raise ItemNotFoundError(location)
         return item
 
-    def get_course(self, course_key, depth=None):
+    def get_course(self, course_key, depth=0):
         """
         Get the course with the given courseid (org/course/run)
         """

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

@@ -319,7 +319,7 @@ class SplitMongoModuleStore(ModuleStoreWriteBase):
                 result.append(course_list[0])
         return result
 
-    def get_course(self, course_id, depth=None):
+    def get_course(self, course_id, depth=0):
         '''
         Gets the course descriptor for the course identified by the locator
         '''

lms/djangoapps/courseware/views.py

@@ -35,7 +35,7 @@ from course_modes.models import CourseMode
 
 from open_ended_grading import open_ended_notifications
 from student.models import UserTestGroup, CourseEnrollment
-from student.views import course_from_id, single_course_reverification_info
+from student.views import single_course_reverification_info
 from util.cache import cache, cache_if_anonymous
 from xblock.fragment import Fragment
 from xmodule.modulestore.django import modulestore
@@ -719,7 +719,7 @@ def fetch_reverify_banner_info(request, course_key):
     if not user.id:
         return reverifications
     enrollment = CourseEnrollment.get_or_create_enrollment(request.user, course_key)
-    course = course_from_id(course_key)
+    course = modulestore().get_course(course_key)
     info = single_course_reverification_info(user, course, enrollment)
     if info:
         reverifications[info.status].append(info)

lms/djangoapps/instructor/views/legacy.py

@@ -72,7 +72,6 @@ from student.models import (
     unique_id_for_user,
     anonymous_id_for_user
 )
-from student.views import course_from_id
 import track.views
 from xblock.field_data import DictFieldData
 from xblock.fields import ScopeIds
@@ -1620,7 +1619,7 @@ def _do_unenroll_students(course_key, students, email_students=False):
         settings.SITE_NAME
     )
     if email_students:
-        course = course_from_id(course_key)
+        course = modulestore().get_course(course_key)
         #Composition of email
         d = {'site_name': stripped_site_name,
              'course': course}

lms/djangoapps/shoppingcart/models.py

@@ -21,12 +21,9 @@ from django.core.urlresolvers import reverse
 from model_utils.managers import InheritanceManager
 
 from xmodule.modulestore.django import modulestore
-from xmodule.course_module import CourseDescriptor
-from xmodule.modulestore.exceptions import ItemNotFoundError
 
 from course_modes.models import CourseMode
 from edxmako.shortcuts import render_to_string
-from student.views import course_from_id
 from student.models import CourseEnrollment, unenroll_done
 from util.query import use_read_replica_if_available
 from xmodule_django.models import CourseKeyField
@@ -332,7 +329,7 @@ class PaidCourseRegistration(OrderItem):
         Returns the order item
         """
         # First a bunch of sanity checks
-        course = course_from_id(course_id)  # actually fetch the course to make sure it exists, use this to
+        course = modulestore().get_course(course_id)  # actually fetch the course to make sure it exists, use this to
                                                 # throw errors if it doesn't
         if not course:
             log.error("User {} tried to add non-existent course {} to cart id {}"
@@ -528,7 +525,7 @@ class CertificateItem(OrderItem):
         item.status = order.status
         item.qty = 1
         item.unit_cost = cost
-        course_name = course_from_id(course_id).display_name
+        course_name = modulestore().get_course(course_id).display_name
         item.line_desc = _("Certificate of Achievement, {mode_name} for course {course}").format(mode_name=mode_info.name,
                                                                                                  course=course_name)
         item.currency = currency
@@ -544,7 +541,7 @@ class CertificateItem(OrderItem):
         try:
             verification_attempt = SoftwareSecurePhotoVerification.active_for_user(self.course_enrollment.user)
             verification_attempt.submit()
-        except Exception as e:
+        except Exception:
             log.exception(
                 "Could not submit verification attempt for enrollment {}".format(self.course_enrollment)
             )
@@ -560,7 +557,7 @@ class CertificateItem(OrderItem):
 
     @property
     def single_item_receipt_context(self):
-        course = course_from_id(self.course_id)
+        course = modulestore().get_course(self.course_id)
         return {
             "course_id": self.course_id,
             "course_name": course.display_name_with_default,

lms/djangoapps/verify_student/views.py

@@ -23,7 +23,7 @@ from django.contrib.auth.decorators import login_required
 
 from course_modes.models import CourseMode
 from student.models import CourseEnrollment
-from student.views import course_from_id, reverification_info
+from student.views import reverification_info
 from shoppingcart.models import Order, CertificateItem
 from shoppingcart.processors.CyberSource import (
     get_signed_purchase_params, get_purchase_endpoint
@@ -36,6 +36,7 @@ import ssencrypt
 from xmodule.modulestore.exceptions import ItemNotFoundError
 from xmodule.modulestore.locations import SlashSeparatedCourseKey
 from .exceptions import WindowExpiredException
+from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
 
@@ -83,7 +84,7 @@ class VerifyView(View):
         else:
             chosen_price = verify_mode.min_price
 
-        course = course_from_id(course_id)
+        course = modulestore().get_course(course_id)
         context = {
             "progress_state": progress_state,
             "user_full_name": request.user.profile.name,
@@ -133,7 +134,7 @@ class VerifiedView(View):
             verify_mode.min_price
         )
 
-        course = course_from_id(course_id)
+        course = modulestore().get_course(course_id)
         context = {
             "course_id": course_id.to_deprecated_string(),
             "course_modes_choose_url": reverse('course_modes_choose', kwargs={'course_id': course_id.to_deprecated_string()}),
@@ -271,7 +272,6 @@ def results_callback(request):
     # If this is a reverification, log an event
     if attempt.window:
         course_id = attempt.window.course_id
-        course = course_from_id(course_id)
         course_enrollment = CourseEnrollment.get_or_create_enrollment(attempt.user, course_id)
         course_enrollment.emit_event(EVENT_NAME_USER_REVERIFICATION_REVIEWED_BY_SOFTWARESECURE)
 
@@ -288,7 +288,7 @@ def show_requirements(request, course_id):
         return redirect(reverse('dashboard'))
 
     upgrade = request.GET.get('upgrade', False)
-    course = course_from_id(course_id)
+    course = modulestore().get_course(course_id)
     context = {
         "course_id": course_id.to_deprecated_string(),
         "course_modes_choose_url": reverse("course_modes_choose", kwargs={'course_id': course_id.to_deprecated_string()}),
@@ -372,7 +372,7 @@ class MidCourseReverifyView(View):
         display this view
         """
         course_id = SlashSeparatedCourseKey.from_deprecated_string(course_id)
-        course = course_from_id(course_id)
+        course = modulestore().get_course(course_id)
         course_enrollment = CourseEnrollment.get_or_create_enrollment(request.user, course_id)
         course_enrollment.update_enrollment(mode="verified")
         course_enrollment.emit_event(EVENT_NAME_USER_ENTERED_MIDCOURSE_REVERIFY_VIEW)
@@ -440,7 +440,7 @@ def midcourse_reverify_dash(request):
     course_enrollment_pairs = []
     for enrollment in CourseEnrollment.enrollments_for_user(user):
         try:
-            course_enrollment_pairs.append((course_from_id(enrollment.course_id), enrollment))
+            course_enrollment_pairs.append((modulestore().get_course(enrollment.course_id), enrollment))
         except ItemNotFoundError:
             log.error("User {0} enrolled in non-existent course {1}"
                       .format(user.username, enrollment.course_id))

lms/templates/shoppingcart/verified_cert_receipt.html

 <%! from django.utils.translation import ugettext as _ %>
-<%! from student.views import course_from_id %>
 
 <%inherit file="../main.html" />
 <%block name="bodyclass">register verification-process step-confirmation</%block>