Merge pull request #857 from edx/mjfrey/cache-catalog-contains

Mjfrey/cache catalog contains

ecommerce/extensions/offer/models.py

 # noinspection PyUnresolvedReferences
+import hashlib
+
+from django.conf import settings
+from django.core.cache import cache
 from django.db import models
 from oscar.apps.offer.abstract_models import AbstractRange
 from threadlocals.threadlocals import get_current_request
@@ -15,14 +19,20 @@ class Range(AbstractRange):
         """
         Retrieve the results from running the query contained in catalog_query field.
         """
+        cache_key = 'catalog_query_contains [{}] [{}]'.format(self.catalog_query, product.course_id)
+        cache_hash = hashlib.md5(cache_key).hexdigest()
+        response = cache.get(cache_hash)
+        if not response:  # pragma: no cover
             request = get_current_request()
             try:
                 response = request.site.siteconfiguration.course_catalog_api_client.course_runs.contains.get(
                     query=self.catalog_query,
                     course_run_ids=product.course_id
                 )
+                cache.set(cache_hash, response, settings.COURSES_API_CACHE_TIMEOUT)
             except:  # pylint: disable=bare-except
                 raise Exception('Could not contact Course Catalog Service.')
+
         return response
 
     def contains_product(self, product):

ecommerce/extensions/offer/tests/test_models.py

+import hashlib
+
 import httpretty
 import mock
+from django.core.cache import cache
 from django.test import RequestFactory
 from oscar.core.loading import get_model
 from oscar.test import factories
@@ -73,10 +76,18 @@ class RangeTests(CouponMixin, CourseCatalogTestMixin, CourseCatalogMockMixin, Te
         self.mock_dynamic_catalog_contains_api(query='key:*', course_run_ids=[course.id])
         request = RequestFactory()
         request.site = self.site
+        self.range.catalog_query = 'key:*'
+
+        cache_key = 'catalog_query_contains [{}] [{}]'.format('key:*', seat.course_id)
+        cache_hash = hashlib.md5(cache_key).hexdigest()
+        cached_response = cache.get(cache_hash)
+        self.assertIsNone(cached_response)
 
         with mock.patch('ecommerce.core.url_utils.get_current_request', mock.Mock(return_value=request)):
             response = self.range.run_catalog_query(seat)
             self.assertTrue(response['course_runs'][course.id])
+            cached_response = cache.get(cache_hash)
+            self.assertEqual(response, cached_response)
 
     @httpretty.activate
     @mock_course_catalog_api_client
@@ -86,6 +97,7 @@ class RangeTests(CouponMixin, CourseCatalogTestMixin, CourseCatalogMockMixin, Te
         """
         course, seat = self.create_course_and_seat()
         self.mock_dynamic_catalog_contains_api(query='key:*', course_run_ids=[course.id])
+
         false_response = self.range.contains_product(seat)
         self.assertFalse(false_response)