web.py 文件源码

def asynchronous(method):
    """Wrap request handler methods with this if they are asynchronous.

    If this decorator is given, the response is not finished when the
    method returns. It is up to the request handler to call self.finish()
    to finish the HTTP request. Without this decorator, the request is
    automatically finished when the get() or post() method returns. ::

       class MyRequestHandler(web.RequestHandler):
           @web.asynchronous
           def get(self):
              http = httpclient.AsyncHTTPClient()
              http.fetch("http://friendfeed.com/", self._on_download)

           def _on_download(self, response):
              self.write("Downloaded!")
              self.finish()

    """
    @functools.wraps(method)
    def wrapper(self, *args, **kwargs):
        if self.application._wsgi:
            raise Exception("@asynchronous is not supported for WSGI apps")
        self._auto_finish = False
        with stack_context.ExceptionStackContext(
            self._stack_context_handle_exception):
            return method(self, *args, **kwargs)
    return wrapper