[gae][bloggart] clear memoizer cache

clear_memoizer_cache.patch

diff --git a/admin.py b/admin.py
index b55e0cd..bbc08cd 100644
--- a/admin.py
+++ b/admin.py
@@ -17,6 +17,8 @@ application = webapp.WSGIApplication([
   (config.url_prefix + '/admin/regenerate', handlers.RegenerateHandler),
   (config.url_prefix + '/admin/post/delete/(\d+)', handlers.DeleteHandler),
   (config.url_prefix + '/admin/post/preview/(\d+)', handlers.PreviewHandler),
+
+  (config.url_prefix + '/admin/clear_cache', handlers.ClearHandler),
 ])
 
 
diff --git a/handlers.py b/handlers.py
index f164993..a672b1c 100644
--- a/handlers.py
+++ b/handlers.py
@@ -56,6 +56,31 @@ class BaseHandler(webapp.RequestHandler):
                                                   theme))
 
 
+class ClearHandler(webapp.RequestHandler):
+  """Clear memoizer cache for BlogPosts."""
+
+  def get(self):
+    class Runner(object):
+      """
+      Encapsulated in a class, so that we can save state in instances for deferred
+      processing.
+      """
+      def run(self, batch_size=50, start_ts=None, classes=None):
+        q = models.BlogPost.all().order('-published')
+        q.filter('published <', start_ts or datetime.datetime.max)
+        posts = q.fetch(batch_size)
+        for post in posts:
+          utils.clear_memoizer_cache(post)
+        if len(posts) == batch_size:
+          deferred.defer(self.run, batch_size, posts[-1].published)
+
+    import logging
+    logging.info("clearing memoizer cache")
+    self.response.out.write("clearing...")
+
+    Runner().run()
+
+
 class AdminHandler(BaseHandler):
   def get(self):
     from generators import generator_list