def fetch(self, request, callback=None, **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`. The ``Future`` wil raise an `HTTPError` if
the request returned a non-200 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.
"""
if not isinstance(request, HTTPRequest):
request = HTTPRequest(url=request, **kwargs)
# 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 = TracebackFuture()
if callback is not None:
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 response.error:
future.set_exception(response.error)
else:
future.set_result(response)
self.fetch_impl(request, handle_response)
return future
def read_message(self, callback=None):
"""Reads a message from the WebSocket server.
Returns a future whose result is the message, or None
if the connection is closed. If a callback argument
is given it will be called with the future when it is
ready.
"""
assert self.read_future is None
future = TracebackFuture()
if self.read_queue:
future.set_result(self.read_queue.popleft())
else:
self.read_future = future
if callback is not None:
self.io_loop.add_future(future, callback)
return future
def __init__(self, io_loop, request):
self.connect_future = TracebackFuture()
self.read_future = None
self.read_queue = collections.deque()
self.key = base64.b64encode(os.urandom(16))
scheme, sep, rest = request.url.partition(':')
scheme = {'ws': 'http', 'wss': 'https'}[scheme]
request.url = scheme + sep + rest
request.headers.update({
'Upgrade': 'websocket',
'Connection': 'Upgrade',
'Sec-WebSocket-Key': self.key,
'Sec-WebSocket-Version': '13',
})
self.resolver = Resolver(io_loop=io_loop)
super(WebSocketClientConnection, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.resolver)
def wrapper(*args, **kwargs):
runner = None
future = TracebackFuture()
if 'callback' in kwargs:
callback = kwargs.pop('callback')
IOLoop.current().add_future(
future, lambda future: callback(future.result()))
def handle_exception(typ, value, tb):
try:
if runner is not None and runner.handle_exception(typ, value, tb):
return True
except Exception:
typ, value, tb = sys.exc_info()
future.set_exc_info((typ, value, tb))
return True
with ExceptionStackContext(handle_exception) as deactivate:
try:
result = func(*args, **kwargs)
except (Return, StopIteration) as e:
result = getattr(e, 'value', None)
except Exception:
deactivate()
future.set_exc_info(sys.exc_info())
return future
else:
if isinstance(result, types.GeneratorType):
def final_callback(value):
deactivate()
future.set_result(value)
runner = Runner(result, final_callback)
runner.run()
return future
deactivate()
future.set_result(result)
return future
class WebSocketClientConnection(simple_httpclient._HTTPConnection):
"""WebSocket client connection.
This class should not be instantiated directly; use the
`websocket_connect` function instead.
"""
def __init__(self, io_loop, request):
self.connect_future = TracebackFuture()
self.read_future = None
self.read_queue = collections.deque()
self.key = base64.b64encode(os.urandom(16))
scheme, sep, rest = request.url.partition(':')
scheme = {'ws': 'http', 'wss': 'https'}[scheme]
request.url = scheme + sep + rest
request.headers.update({
'Upgrade': 'websocket',
'Connection': 'Upgrade',
'Sec-WebSocket-Key': self.key,
'Sec-WebSocket-Version': '13',
})
self.resolver = Resolver(io_loop=io_loop)
super(WebSocketClientConnection, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.resolver)
def close(self):
"""Closes the websocket connection.
.. versionadded:: 3.2
"""
if self.protocol is not None:
self.protocol.close()
self.protocol = None
def _on_close(self):
self.on_message(None)
self.resolver.close()
super(WebSocketClientConnection, self)._on_close()
def _on_http_response(self, response):
if not self.connect_future.done():
if response.error:
self.connect_future.set_exception(response.error)
else:
self.connect_future.set_exception(WebSocketError(
"Non-websocket response"))
def _handle_1xx(self, code):
assert code == 101
assert self.headers['Upgrade'].lower() == 'websocket'
assert self.headers['Connection'].lower() == 'upgrade'
accept = WebSocketProtocol13.compute_accept_value(self.key)
assert self.headers['Sec-Websocket-Accept'] == accept
self.protocol = WebSocketProtocol13(self, mask_outgoing=True)
self.protocol._receive_frame()
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.connect_future.set_result(self)
def write_message(self, message, binary=False):
"""Sends a message to the WebSocket server."""
self.protocol.write_message(message, binary)
def read_message(self, callback=None):
"""Reads a message from the WebSocket server.
Returns a future whose result is the message, or None
if the connection is closed. If a callback argument
is given it will be called with the future when it is
ready.
"""
assert self.read_future is None
future = TracebackFuture()
if self.read_queue:
future.set_result(self.read_queue.popleft())
else:
self.read_future = future
if callback is not None:
self.io_loop.add_future(future, callback)
return future
def on_message(self, message):
if self.read_future is not None:
self.read_future.set_result(message)
self.read_future = None
else:
self.read_queue.append(message)
def on_pong(self, data):
pass
