Make request_cache easier to use

common/djangoapps/request_cache/__init__.py

@@ -0,0 +1,28 @@
+"""
+A cache that is cleared after every request.
+
+This module requires that :class:`request_cache.middleware.RequestCache`
+is installed in order to clear the cache after each request.
+"""
+
+
+from request_cache import middleware
+
+
+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()

common/djangoapps/request_cache/middleware.py

@@ -1,34 +1,48 @@
 import threading
 
-_request_cache_threadlocal = threading.local()
-_request_cache_threadlocal.data = {}
-_request_cache_threadlocal.request = None
+
+class _RequestCache(threading.local):
+    """
+    A thread-local for storing the per-request cache.
+    """
+    def __init__(self):
+        super(_RequestCache, self).__init__()
+        self.data = {}
+        self.request = None
+
+
+REQUEST_CACHE = _RequestCache()
 
 
 class RequestCache(object):
     @classmethod
-    def get_request_cache(cls):
-        return _request_cache_threadlocal
+    def get_request_cache(cls, name=None):
+        """
+        This method is deprecated. Please use :func:`request_cache.get_cache`.
+        """
+        if name is None:
+            return REQUEST_CACHE
+        else:
+            return REQUEST_CACHE.data.setdefault(name, {})
 
     @classmethod
     def get_current_request(cls):
         """
-        Get a reference to the HttpRequest object, if we are presently
-        servicing one.
+        This method is deprecated. Please use :func:`request_cache.get_request`.
         """
-        return _request_cache_threadlocal.request
+        return REQUEST_CACHE.request
 
     @classmethod
     def clear_request_cache(cls):
         """
         Empty the request cache.
         """
-        _request_cache_threadlocal.data = {}
-        _request_cache_threadlocal.request = None
+        REQUEST_CACHE.data = {}
+        REQUEST_CACHE.request = None
 
     def process_request(self, request):
         self.clear_request_cache()
-        _request_cache_threadlocal.request = request
+        REQUEST_CACHE.request = request
         return None
 
     def process_response(self, request, response):