In the dev server, files are not cached

scripts/redirector.py

 # Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This script is used to redirect HTTP requests to retrieve the correct
 # files from Google Cloud Storage.
 
 import logging
 import urllib2
 import os
@@ skipping 24 matching lines @@
     if os.environ['SERVER_SOFTWARE'].startswith('Development'):
       self.GetLocal()
     else:
       self.GetGoogleStorage()
 
   def GetLocal(self):
     """ Used for local, dev server HTTP requests. """
     path = LOCAL_PATH + self.request.path[len('docs/'):]
     with open(path, 'r') as file:
       result = file.read()
-    self.HandleCacheAge(path)
+    # The cache age should be zero seconds if being run locally.
+    self.response.headers['Cache-Control'] = 'max-age=%d,s-maxage=%d' % (0, 0)
     self.response.out.write(result)
 
   def GetGoogleStorage(self):
     """ Used for App Engine HTTP requests. """
     version_key = blobstore.create_gs_key(GS_VERSION)
     blob_reader = blobstore.BlobReader(version_key)
     version = blob_reader.read()
     path = GS_PATH + version + self.request.path[len('docs/'):]
     gs_key = blobstore.create_gs_key(path)
     self.HandleCacheAge(path)
     self.send_blob(gs_key)
 
   def HandleCacheAge(self, path):
     """ Assigns a document a length of time it will live in the cache. """
     age = None
     if re.search(r'(png|jpg)$', path):
       age = ONE_DAY
     elif path.endswith('.ico'):
       age = ONE_WEEK
     else:
       age = ONE_HOUR
-    self.response.headers['Cache-Control'] = 'max-age=' + \
-        str(age) + ',s-maxage=' + str(age)
+    self.response.headers['Cache-Control'] = 'max-age=%d,s-maxage=%d' % \
+      (age, age)
     
 application = WSGIApplication(
   [
     ('/docs/.*', RequestHandler),
   ], debug=True)