Do not track Add/Remove Product when calculating basket

LEARNER-4968

ecommerce/request_cache/__init__.py

@@ -6,14 +6,73 @@ is installed in order to clear the cache after each request.
 """
 
 import logging
+from urlparse import urlparse
 
 from django.core.cache import caches
 from django.core.cache.backends.base import BaseCache
+from django.conf import settings
+from django.test.client import RequestFactory
+
+from ecommerce.request_cache import middleware
 
 
 log = logging.getLogger(__name__)
 
 
+def get_cache(name):
+    """
+    Return the request cache named ``name``.
+
+    Arguments:
+        name (str): The name of the request cache to load
+
+    Returns: dict
+    """
+    return middleware.RequestCache.get_request_cache(name)
+
+
+def get_request():
+    """
+    Return the current request.
+    """
+    return middleware.RequestCache.get_current_request()
+
+
+def get_request_or_stub():
+    """
+    Return the current request or a stub request.
+
+    If called outside the context of a request, construct a fake
+    request that can be used to build an absolute URI.
+
+    This is useful in cases where we need to pass in a request object
+    but don't have an active request (for example, in test cases).
+    """
+    request = get_request()
+
+    if request is None:
+        log.warning(
+            "Could not retrieve the current request.  "
+            "A stub request will be created instead using settings.SITE_NAME.  "
+            "This should be used *only* in test cases, never in production!"
+        )
+
+        # The settings SITE_NAME may contain a port number, so we need to
+        # parse the full URL.
+        full_url = "http://{site_name}".format(site_name=settings.SITE_NAME)
+        parsed_url = urlparse(full_url)
+
+        # Construct the fake request.  This can be used to construct absolute
+        # URIs to other paths.
+        return RequestFactory(
+            SERVER_NAME=parsed_url.hostname,
+            SERVER_PORT=parsed_url.port or 80,
+        ).get("/")
+
+    else:
+        return request
+
+
 class RequestPlusRemoteCache(BaseCache):
     """
     This Django cache backend implements two layers of caching.