我应该使用记忆快取吗？

class KMZHandler(webapp.RequestHandler):
    def add_file(self, zip_file, url, file_name):
        \"\"\"Fetch url, and add content as file_name to the zip file.\"\"\"
        result = urlfetch.fetch(url)
        if not result.content:
            return
        zip_file.writestr(file_name, result.content)

    def get(self):
        \"\"\"Attempt to create a zip file.\"\"\"
        # you could set \'count\' like this:
        # count = int(self.request.get(\'count\', 1000))

        zipstream = StringIO.StringIO()
        zip_file = zipfile.ZipFile(zipstream, \"w\")

        # repeat this for every URL that should be added to the zipfile
        url = \'http://www.koolbusiness.com/list.kml\'
        self.add_file(zip_file, url, \"list.kml\")

        # we have finished with the zip so package it up and write the directory
        zip_file.close()

        # set the headers...

        self.response.headers[\"Cache-Control\"] = \"public,max-age=%s\" % 86400
        self.response.headers[\'Content-Type\'] =\'application/zip\'
        self.response.headers[\'Content-Disposition\'] = \'attachment;filename=\"list.kmz\"\'

        # create and return the output stream
        zipstream.seek(0)
        self.response.out.write(zipstream.read())
        zipstream.close()

class KMLHandler(webapp.RequestHandler):
 def get(self):   
    self.response.headers[\"Cache-Control\"] = \"public,max-age=%s\" % 86400
    start=datetime.datetime.now()-timedelta(days=20)
    count = int(self.request.get(\'count\')) if not self.request.get(\'count\')==\'\' else 1000        
    from google.appengine.api import memcache
    memcache_key = \"ads\"
    data = memcache.get(memcache_key)
    if data is None:
      a= Ad.all().filter(\"modified >\", start).filter(\"url IN\", [\'www.koolbusiness.com\']).filter(\"published =\", True).order(\"-modified\").fetch(count)
      memcache.set(\"ads\", a)  
    else:
      a = data
    dispatch=\'templates/kml.html\'
    template_values = {\'a\': a , \'request\':self.request,}
    path = os.path.join(os.path.dirname(__file__), dispatch)
    output = template.render(path, template_values)
    self.response.headers[\'Content-Type\'] = \'application/vnd.google-earth.kml+xml\'
    self.response.headers[\'Content-Length\'] = len(output)
    self.response.out.write(output)