def wrapper(*args, **kwargs):
future = Future()
callback, args, kwargs = replacer.replace(future, args, kwargs)
if callback is not None:
warnings.warn("callback arguments are deprecated, use the returned Future instead",
DeprecationWarning)
future.add_done_callback(
wrap(functools.partial(_auth_future_to_callback, callback)))
def handle_exception(typ, value, tb):
if future.done():
return False
else:
future_set_exc_info(future, (typ, value, tb))
return True
with ExceptionStackContext(handle_exception, delay_warning=True):
f(*args, **kwargs)
return future
def fetch(self, request, callback=None, raise_error=True, **kwargs):
"""Executes a request, asynchronously returning an `HTTPResponse`.
The request may be either a string URL or an `HTTPRequest` object.
If it is a string, we construct an `HTTPRequest` using any additional
kwargs: ``HTTPRequest(request, **kwargs)``
This method returns a `.Future` whose result is an
`HTTPResponse`. By default, the ``Future`` will raise an
`HTTPError` if the request returned a non-200 response code
(other errors may also be raised if the server could not be
contacted). Instead, if ``raise_error`` is set to False, the
response will always be returned regardless of the response
code.
If a ``callback`` is given, it will be invoked with the `HTTPResponse`.
In the callback interface, `HTTPError` is not automatically raised.
Instead, you must check the response's ``error`` attribute or
call its `~HTTPResponse.rethrow` method.
.. deprecated:: 5.1
The ``callback`` argument is deprecated and will be removed
in 6.0. Use the returned `.Future` instead.
The ``raise_error=False`` argument currently suppresses
*all* errors, encapsulating them in `HTTPResponse` objects
with a 599 response code. This will change in Tornado 6.0:
``raise_error=False`` will only affect the `HTTPError`
raised when a non-200 response code is used.
"""
if self._closed:
raise RuntimeError("fetch() called on closed AsyncHTTPClient")
if not isinstance(request, HTTPRequest):
request = HTTPRequest(url=request, **kwargs)
else:
if kwargs:
raise ValueError("kwargs can't be used if request is an HTTPRequest object")
# We may modify this (to add Host, Accept-Encoding, etc),
# so make sure we don't modify the caller's object. This is also
# where normal dicts get converted to HTTPHeaders objects.
request.headers = httputil.HTTPHeaders(request.headers)
request = _RequestProxy(request, self.defaults)
future = Future()
if callback is not None:
warnings.warn("callback arguments are deprecated, use the returned Future instead",
DeprecationWarning)
callback = stack_context.wrap(callback)
def handle_future(future):
exc = future.exception()
if isinstance(exc, HTTPError) and exc.response is not None:
response = exc.response
elif exc is not None:
response = HTTPResponse(
request, 599, error=exc,
request_time=time.time() - request.start_time)
else:
response = future.result()
self.io_loop.add_callback(callback, response)
future.add_done_callback(handle_future)
def handle_response(response):
if raise_error and response.error:
if isinstance(response.error, HTTPError):
response.error.response = response
future.set_exception(response.error)
else:
if response.error and not response._error_is_response_code:
warnings.warn("raise_error=False will allow '%s' to be raised in the future" %
response.error, DeprecationWarning)
future_set_result_unless_cancelled(future, response)
self.fetch_impl(request, handle_response)
return future