from hashlib import md5 from time import sleep import os with open('/etc/hosts') as handle: content = handle.read() content_hash = '"' + md5(content).hexdigest() + '"' def application(environ, start_response): def index(): start_response("200 OK", [("Content-Type", "text/html")]) yield 'test' def initial(): status = "200 OK" start_response(status, [ ('Content-Type', 'application/javascript'), ('Cache-Control', 's-maxage=0, private, must-revalidate, max-age=0'), ('Content-Length', str(len(content))), ('ETag', content_hash), ]) middle_position = len(content)/2 yield content[:middle_position] os.system('pkill -9 uwsgi') # simulate a crash sleep(1) yield content[middle_position:] def cached(): start_response("304 NOT MODIFIED", []) yield '' if 'test' not in environ['REQUEST_URI']: return index() if environ.get('HTTP_IF_NONE_MATCH') == content_hash: return cached() return initial()