class WebSocketClientConnection(simple_httpclient._HTTPConnection):
"""WebSocket 客户端连接
这个类不应当直接被实例化, 请使用 `websocket_connect`
"""
def __init__(self, io_loop, request, on_message_callback=None,
compression_options=None):
self.compression_options = compression_options
self.connect_future = TracebackFuture()
self.protocol = None
self.read_future = None
self.read_queue = collections.deque()
self.key = base64.b64encode(os.urandom(16))
self._on_message_callback = on_message_callback
self.close_code = self.close_reason = None
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',
})
if self.compression_options is not None:
# Always offer to let the server set our max_wbits (and even though
# we don't offer it, we will accept a client_no_context_takeover
# from the server).
# TODO: set server parameters for deflate extension
# if requested in self.compression_options.
request.headers['Sec-WebSocket-Extensions'] = (
'permessage-deflate; client_max_window_bits')
self.tcp_client = TCPClient(io_loop=io_loop)
super(WebSocketClientConnection, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.tcp_client, 65536, 104857600)
def close(self, code=None, reason=None):
"""关闭 websocket 连接
``code`` 和 ``reason`` 的文档在 `WebSocketHandler.close` 下已给出.
.. versionadded:: 3.2
.. versionchanged:: 4.0
添加 ``code`` 和 ``reason`` 这两个参数
"""
if self.protocol is not None:
self.protocol.close(code, reason)
self.protocol = None
def on_connection_close(self):
if not self.connect_future.done():
self.connect_future.set_exception(StreamClosedError())
self.on_message(None)
self.tcp_client.close()
super(WebSocketClientConnection, self).on_connection_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 headers_received(self, start_line, headers):
if start_line.code != 101:
return super(WebSocketClientConnection, self).headers_received(
start_line, headers)
self.headers = headers
self.protocol = self.get_websocket_protocol()
self.protocol._process_server_headers(self.key, self.headers)
self.protocol._receive_frame()
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream = self.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
# Once we've taken over the connection, clear the final callback
# we set on the http request. This deactivates the error handling
# in simple_httpclient that would otherwise interfere with our
# ability to see exceptions.
self.final_callback = None
self.connect_future.set_result(self)
def write_message(self, message, binary=False):
"""发送消息到 websocket 服务器."""
return self.protocol.write_message(message, binary)
def read_message(self, callback=None):
"""读取来自 WebSocket 服务器的消息.
如果在 WebSocket 初始化时指定了 on_message_callback ,那么这个方法永远不会返回消息
如果连接已经关闭,返回结果会是一个结果是 message 的 future 对象或者是 None.
如果 future 给出了回调参数, 这个参数将会在 future 完成时调用.
"""
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._on_message_callback:
self._on_message_callback(message)
elif 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
def get_websocket_protocol(self):
return WebSocketProtocol13(self, mask_outgoing=True,
compression_options=self.compression_options)
class EventSourceClient(simple_httpclient._HTTPConnection):
"""
This module opens a new connection to an eventsource server, and wait for events.
"""
def __init__(self, io_loop, request):
self.connect_future = TracebackFuture()
self.read_future = None
self.read_queue = collections.deque()
self.events = []
if old_tornado:
self.resolver = Resolver(io_loop=io_loop)
super(EventSourceClient, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.resolver)
else:
self.tcp_client = TCPClient(io_loop=io_loop)
super(EventSourceClient, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.tcp_client, 65536)
def _handle_event_stream(self):
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream.read_until_regex(b"\n\n", self.handle_stream)
self.connect_future.set_result(self)
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(EventSourceError(
"Non-websocket response"))
def _on_headers(self, data):
data = native_str(data.decode("latin1"))
first_line, _, header_data = data.partition("\n")
match = re.match("HTTP/1.[01] ([0-9]+) ([^\r]*)", first_line)
assert match
code = int(match.group(1))
headers = httputil.HTTPHeaders.parse(header_data)
reason = match.group(2)
self.headers_received(HeadersData(code=code, reason=reason), headers)
def headers_received(self, data, headers):
self.headers = headers
self.code = data.code
self.reason = data.reason
if self.headers['Content-Type'] != 'text/event-stream':
raise ValueError("Invalid headers: %s" % self.headers)
if "Content-Length" in self.headers:
if "," in self.headers["Content-Length"]:
pieces = re.split(r',\s*', self.headers["Content-Length"])
if any(i != pieces[0] for i in pieces):
raise ValueError("Multiple unequal Content-Lengths: %r" %
self.headers["Content-Length"])
self.headers["Content-Length"] = pieces[0]
self._handle_event_stream()
def handle_stream(self, message):
"""
Acts on message reception
:param message: string of an incoming message
parse all the fields and builds an Event object that is passed to the callback function
"""
logging.debug("handle_stream(...)")
event = Event()
for line in message.strip().splitlines():
(field, value) = line.split(":", 1)
field = field.strip()
if field == "event":
event.name = value.lstrip()
elif field == "data":
value = value.lstrip()
if event.data is None:
event.data = value
else:
event.data = "%s\n%s" % (event.data, value)
elif field == "id":
event.id = value.lstrip()
self.last_event_id = event.id
elif field == "retry":
try:
self.retry_timeout = int(value)
event.retry = self.retry_timeout
logging.info("timeout reset: %s" % (value,))
except ValueError:
pass
elif field == "":
logging.debug("received comment: %s" % (value,))
else:
raise Exception("Unknown field !")
self.events.append(event)
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.tcp_client = TCPClient(io_loop=io_loop)
super(WebSocketClientConnection, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response, 104857600, self.tcp_client, 65536
)
def close(self, code=None, reason=None):
"""Closes the websocket connection.
``code`` and ``reason`` are documented under
`WebSocketHandler.close`.
.. versionadded:: 3.2
.. versionchanged:: 4.0
Added the ``code`` and ``reason`` arguments.
"""
if self.protocol is not None:
self.protocol.close(code, reason)
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 headers_received(self, start_line, headers):
if start_line.code != 101:
return super(WebSocketClientConnection, self).headers_received(start_line, headers)
self.headers = headers
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.stream = self.connection.detach()
self.stream.set_close_callback(self._on_close)
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
class Runner(object):
"""Internal implementation of `tornado.gen.engine`.
Maintains information about pending callbacks and their results.
The results of the generator are stored in ``result_future`` (a
`.TracebackFuture`)
"""
def __init__(self, gen, result_future, first_yielded):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = None
self.results = None
self.running = False
self.finished = False
self.had_exception = False
self.io_loop = IOLoop.current()
# For efficiency, we do not create a stack context until we
# reach a YieldPoint (stack contexts are required for the historical
# semantics of YieldPoints, but not for Futures). When we have
# done so, this field will be set and must be called at the end
# of the coroutine.
self.stack_context_deactivate = None
if self.handle_yield(first_yielded):
self.run()
def register_callback(self, key):
"""Adds ``key`` to the list of callbacks."""
if self.pending_callbacks is None:
# Lazily initialize the old-style YieldPoint data structures.
self.pending_callbacks = set()
self.results = {}
if key in self.pending_callbacks:
raise KeyReuseError("key %r is already pending" % (key,))
self.pending_callbacks.add(key)
def is_ready(self, key):
"""Returns true if a result is available for ``key``."""
if self.pending_callbacks is None or key not in self.pending_callbacks:
raise UnknownKeyError("key %r is not pending" % (key,))
return key in self.results
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
self.future.set_result(self.yield_point.get_result())
except:
self.future.set_exc_info(sys.exc_info())
self.yield_point = None
self.run()
def pop_result(self, key):
"""Returns the result for ``key`` and unregisters it."""
self.pending_callbacks.remove(key)
return self.results.pop(key)
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
try:
value = future.result()
except Exception:
self.had_exception = True
yielded = self.gen.throw(*sys.exc_info())
else:
yielded = self.gen.send(value)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
self.result_future.set_result(getattr(e, 'value', None))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
finally:
self.running = False
def handle_yield(self, yielded):
if isinstance(yielded, list):
if all(is_future(f) for f in yielded):
yielded = multi_future(yielded)
else:
yielded = Multi(yielded)
elif isinstance(yielded, dict):
if all(is_future(f) for f in yielded.values()):
yielded = multi_future(yielded)
else:
yielded = Multi(yielded)
if isinstance(yielded, YieldPoint):
self.future = TracebackFuture()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
self.future.set_result(
yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return False
else:
start_yield_point()
elif is_future(yielded):
self.future = yielded
if not self.future.done() or self.future is moment:
self.io_loop.add_future(
self.future, lambda f: self.run())
return False
else:
self.future = TracebackFuture()
self.future.set_exception(BadYieldError(
"yielded unknown object %r" % (yielded,)))
return True
def result_callback(self, key):
return stack_context.wrap(_argument_adapter(
functools.partial(self.set_result, key)))
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.future = TracebackFuture()
self.future.set_exc_info((typ, value, tb))
self.run()
return True
else:
return False
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
class Runner(object):
"""Internal implementation of `tornado.gen.engine`.
Maintains information about pending callbacks and their results.
The results of the generator are stored in ``result_future`` (a
`.TracebackFuture`)
"""
def __init__(self, gen, result_future, first_yielded):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = None
self.results = None
self.running = False
self.finished = False
self.had_exception = False
self.io_loop = IOLoop.current()
# For efficiency, we do not create a stack context until we
# reach a YieldPoint (stack contexts are required for the historical
# semantics of YieldPoints, but not for Futures). When we have
# done so, this field will be set and must be called at the end
# of the coroutine.
self.stack_context_deactivate = None
if self.handle_yield(first_yielded):
self.run()
def register_callback(self, key):
"""Adds ``key`` to the list of callbacks."""
if self.pending_callbacks is None:
# Lazily initialize the old-style YieldPoint data structures.
self.pending_callbacks = set()
self.results = {}
if key in self.pending_callbacks:
raise KeyReuseError("key %r is already pending" % (key,))
self.pending_callbacks.add(key)
def is_ready(self, key):
"""Returns true if a result is available for ``key``."""
if self.pending_callbacks is None or key not in self.pending_callbacks:
raise UnknownKeyError("key %r is not pending" % (key,))
return key in self.results
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
self.future.set_result(self.yield_point.get_result())
except:
self.future.set_exc_info(sys.exc_info())
self.yield_point = None
self.run()
def pop_result(self, key):
"""Returns the result for ``key`` and unregisters it."""
self.pending_callbacks.remove(key)
return self.results.pop(key)
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
exc_info = None
try:
value = future.result()
except Exception:
self.had_exception = True
exc_info = sys.exc_info()
if exc_info is not None:
yielded = self.gen.throw(*exc_info)
exc_info = None
else:
yielded = self.gen.send(value)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
self.result_future.set_result(_value_from_stopiteration(e))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
finally:
self.running = False
def handle_yield(self, yielded):
# Lists containing YieldPoints require stack contexts;
# other lists are handled in convert_yielded.
if _contains_yieldpoint(yielded):
yielded = multi(yielded)
if isinstance(yielded, YieldPoint):
# YieldPoints are too closely coupled to the Runner to go
# through the generic convert_yielded mechanism.
self.future = TracebackFuture()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
self.future.set_result(
yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return False
else:
start_yield_point()
else:
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if not self.future.done() or self.future is moment:
self.io_loop.add_future(
self.future, lambda f: self.run())
return False
return True
def result_callback(self, key):
return stack_context.wrap(_argument_adapter(
functools.partial(self.set_result, key)))
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.future = TracebackFuture()
self.future.set_exc_info((typ, value, tb))
self.run()
return True
else:
return False
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
class AsyncResult(object):
"""
Essentially a wrapper for a Tornado TracebackFuture
"""
def __init__(self, future=None):
if future is not None:
self._future = future
else:
self._future = TracebackFuture()
self._future.add_done_callback(functools.partial(async_result_complete, self))
self._condition = threading.Condition()
def ready(self):
"""Return `True` if and only if it holds a value or an
exception"""
return self._future.done()
def successful(self):
"""Return `True` if and only if it is ready and holds a
value"""
return self._future.exception() is None
@property
def exception(self):
return self._future.exception()
def set(self, value=None):
"""Store the value. Wake up the waiters.
:param value: Value to store as the result.
Any waiters blocking on :meth:`get` or :meth:`wait` are woken
up. Sequential calls to :meth:`wait` and :meth:`get` will not
block at all."""
with self._condition:
self._future.set_result(value)
def set_exception(self, exception):
"""Store the exception. Wake up the waiters.
:param exception: Exception to raise when fetching the value.
Any waiters blocking on :meth:`get` or :meth:`wait` are woken
up. Sequential calls to :meth:`wait` and :meth:`get` will not
block at all."""
with self._condition:
self._future.set_exception(exception)
def get(self, block=True, timeout=None):
"""Return the stored value or raise the exception
:param block: Whether this method should block or return
immediately.
:type block: bool
:param timeout: How long to wait for a value when `block` is
`True`.
:type timeout: float
If this instance already holds a value / an exception, return /
raise it immediately. Otherwise, block until :meth:`set` or
:meth:`set_exception` has been called or until the optional
timeout occurs."""
with self._condition:
if self.ready():
return self._future.result()
elif block:
self._condition.wait(timeout)
return self._future.result()
# if we get to this point we timeout
raise KazooTimeoutError()
def get_nowait(self):
"""Return the value or raise the exception without blocking.
If nothing is available, raise the Timeout exception class on
the associated :class:`IHandler` interface."""
return self._future.result()
def wait(self, timeout=None):
"""Block until the instance is ready.
:param timeout: How long to wait for a value
:type timeout: float
If this instance already holds a value / an exception, return /
raise it immediately. Otherwise, block until :meth:`set` or
:meth:`set_exception` has been called or until the optional
timeout occurs."""
with self._condition:
self._condition.wait(timeout)
return self.ready()
def rawlink(self, callback):
"""Register a callback to call when a value or an exception is
set
:param callback:
A callback function to call after :meth:`set` or
:meth:`set_exception` has been called. This function will
be passed a single argument, this instance.
:type callback: func
"""
def on_callback(future):
callback(AsyncResult(future))
IOLoop.current().add_future(self._future, on_callback)
def unlink(self, callback):
"""Remove the callback set by :meth:`rawlink`
:param callback: A callback function to remove.
:type callback: func
"""
def notify(self):
self._condition.notify_all()
class WaitIterator(object):
"""Provides an iterator to yield the results of futures as they finish.
Yielding a set of futures like this:
``results = yield [future1, future2]``
pauses the coroutine until both ``future1`` and ``future2``
return, and then restarts the coroutine with the results of both
futures. If either future is an exception, the expression will
raise that exception and all the results will be lost.
If you need to get the result of each future as soon as possible,
or if you need the result of some futures even if others produce
errors, you can use ``WaitIterator``::
wait_iterator = gen.WaitIterator(future1, future2)
while not wait_iterator.done():
try:
result = yield wait_iterator.next()
except Exception as e:
print("Error {} from {}".format(e, wait_iterator.current_future))
else:
print("Result {} recieved from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
Because results are returned as soon as they are available the
output from the iterator *will not be in the same order as the
input arguments*. If you need to know which future produced the
current result, you can use the attributes
``WaitIterator.current_future``, or ``WaitIterator.current_index``
to get the index of the future from the input list. (if keyword
arguments were used in the construction of the `WaitIterator`,
``current_index`` will use the corresponding keyword).
.. versionadded:: 4.1
"""
def __init__(self, *args, **kwargs):
if args and kwargs:
raise ValueError(
"You must provide args or kwargs, not both")
if kwargs:
self._unfinished = dict((f, k) for (k, f) in kwargs.items())
futures = list(kwargs.values())
else:
self._unfinished = dict((f, i) for (i, f) in enumerate(args))
futures = args
self._finished = collections.deque()
self.current_index = self.current_future = None
self._running_future = None
# Use a weak reference to self to avoid cycles that may delay
# garbage collection.
self_ref = weakref.ref(self)
for future in futures:
future.add_done_callback(functools.partial(
self._done_callback, self_ref))
def done(self):
"""Returns True if this iterator has no more results."""
if self._finished or self._unfinished:
return False
# Clear the 'current' values when iteration is done.
self.current_index = self.current_future = None
return True
def next(self):
"""Returns a `.Future` that will yield the next available result.
Note that this `.Future` will not be the same object as any of
the inputs.
"""
self._running_future = TracebackFuture()
# As long as there is an active _running_future, we must
# ensure that the WaitIterator is not GC'd (due to the
# use of weak references in __init__). Add a callback that
# references self so there is a hard reference that will be
# cleared automatically when this Future finishes.
self._running_future.add_done_callback(lambda f: self)
if self._finished:
self._return_result(self._finished.popleft())
return self._running_future
@staticmethod
def _done_callback(self_ref, done):
self = self_ref()
if self is not None:
if self._running_future and not self._running_future.done():
self._return_result(done)
else:
self._finished.append(done)
def _return_result(self, done):
"""Called set the returned future's state that of the future
we yielded, and set the current future for the iterator.
"""
chain_future(done, self._running_future)
self.current_future = done
self.current_index = self._unfinished.pop(done)
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, on_message_callback=None,
compression_options=None):
self.compression_options = compression_options
self.connect_future = TracebackFuture()
self.protocol = None
self.read_future = None
self.read_queue = collections.deque()
self.key = base64.b64encode(os.urandom(16))
self._on_message_callback = on_message_callback
self.close_code = self.close_reason = None
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',
})
if self.compression_options is not None:
# Always offer to let the server set our max_wbits (and even though
# we don't offer it, we will accept a client_no_context_takeover
# from the server).
# TODO: set server parameters for deflate extension
# if requested in self.compression_options.
request.headers['Sec-WebSocket-Extensions'] = (
'permessage-deflate; client_max_window_bits')
self.tcp_client = TCPClient(io_loop=io_loop)
super(WebSocketClientConnection, self).__init__(
io_loop, None, request, lambda: None, self._on_http_response,
104857600, self.tcp_client, 65536, 104857600)
def close(self, code=None, reason=None):
"""Closes the websocket connection.
``code`` and ``reason`` are documented under
`WebSocketHandler.close`.
.. versionadded:: 3.2
.. versionchanged:: 4.0
Added the ``code`` and ``reason`` arguments.
"""
if self.protocol is not None:
self.protocol.close(code, reason)
self.protocol = None
def on_connection_close(self):
if not self.connect_future.done():
self.connect_future.set_exception(StreamClosedError())
self.on_message(None)
self.tcp_client.close()
super(WebSocketClientConnection, self).on_connection_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 headers_received(self, start_line, headers):
if start_line.code != 101:
return super(WebSocketClientConnection, self).headers_received(
start_line, headers)
self.headers = headers
self.protocol = self.get_websocket_protocol()
self.protocol._process_server_headers(self.key, self.headers)
self.protocol._receive_frame()
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream = self.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
# Once we've taken over the connection, clear the final callback
# we set on the http request. This deactivates the error handling
# in simple_httpclient that would otherwise interfere with our
# ability to see exceptions.
self.final_callback = None
self.connect_future.set_result(self)
def write_message(self, message, binary=False):
"""Sends a message to the WebSocket server."""
return self.protocol.write_message(message, binary)
def read_message(self, callback=None):
"""Reads a message from the WebSocket server.
If on_message_callback was specified at WebSocket
initialization, this function will never return messages
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._on_message_callback:
self._on_message_callback(message)
elif 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
def get_websocket_protocol(self):
return WebSocketProtocol13(self, mask_outgoing=True,
compression_options=self.compression_options)
class Runner(object):
"""Internal implementation of `tornado.gen.engine`.
Maintains information about pending callbacks and their results.
The results of the generator are stored in ``result_future`` (a
`.TracebackFuture`)
"""
def __init__(self, gen, result_future, first_yielded):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = None
self.results = None
self.running = False
self.finished = False
self.had_exception = False
self.io_loop = IOLoop.current()
# For efficiency, we do not create a stack context until we
# reach a YieldPoint (stack contexts are required for the historical
# semantics of YieldPoints, but not for Futures). When we have
# done so, this field will be set and must be called at the end
# of the coroutine.
self.stack_context_deactivate = None
if self.handle_yield(first_yielded):
# handle_yield 在 coroutine yield 的对象有了结果时返回
# True，这个时候就会马上执行 run 方法。
self.run()
def register_callback(self, key):
"""Adds ``key`` to the list of callbacks."""
if self.pending_callbacks is None:
# Lazily initialize the old-style YieldPoint data structures.
self.pending_callbacks = set()
self.results = {}
if key in self.pending_callbacks:
raise KeyReuseError("key %r is already pending" % (key, ))
self.pending_callbacks.add(key)
def is_ready(self, key):
"""Returns true if a result is available for ``key``."""
if self.pending_callbacks is None or key not in self.pending_callbacks:
raise UnknownKeyError("key %r is not pending" % (key, ))
return key in self.results
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
self.future.set_result(self.yield_point.get_result())
except:
self.future.set_exc_info(sys.exc_info())
self.yield_point = None
self.run()
def pop_result(self, key):
"""Returns the result for ``key`` and unregisters it."""
self.pending_callbacks.remove(key)
return self.results.pop(key)
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
# 如果 run 方法已经在被执行，则返回。
return
try:
self.running = True
while True:
future = self.future
if not future.done():
# Runner 对应的 coroutine yield
# 的对象还没有准备好，则返回。
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
exc_info = None
try:
value = future.result()
except Exception:
# 如果执行过程中有抛出异常，则捕获之，并让 coroutine
# 也抛出该异常。Python 中的 generator 在 2.5 版本后才
# 提供了 throw 方法来提供实现 coroutine
# 的可能性，详情可以参考：
# https://www.python.org/dev/peps/pep-0342/
self.had_exception = True
exc_info = sys.exc_info()
if exc_info is not None:
# 如果有异常，让 coroutine 抛出。
yielded = self.gen.throw(*exc_info)
exc_info = None
else:
# 如果一切正常，则将结果反馈给 coroutine。
yielded = self.gen.send(value)
if stack_context._state.contexts \
is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)')
)
except (StopIteration, Return) as e:
# coroutine 的执行绪执行完毕，Runner 的任务也完成了。
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
# 从 Exception 对象中获得最终结果，并反馈给
# result_future，进而触发 result_future 的 done callbacks。
self.result_future.set_result(_value_from_stopiteration(e))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
finally:
self.running = False
def handle_yield(self, yielded):
# handle_yield 方法会对 coroutine yield 的结果进行转化，进而判断 yield
# 的异步执行的代码是否已经执行完毕并且已经得到了结果，如果没有，则将相
# 应得 future 对象放到 Event Loop 中，等待下一次 Event Loop
# 执行到时再判断执行结果
# Lists containing YieldPoints require stack contexts;
# other lists are handled in convert_yielded.
if _contains_yieldpoint(yielded):
# 如果 coroutine yield 的结果中包含 YieldPoint，则用 stack context
# 将其包装一次
yielded = multi(yielded)
if isinstance(yielded, YieldPoint):
# YieldPoints are too closely coupled to the Runner to go
# through the generic convert_yielded mechanism.
self.future = TracebackFuture()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
self.future.set_result(yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return False
else:
start_yield_point()
else:
# 经过前面的处理，YieldPoint 都已经被正确包装、转化，接下来就可以将
# coroutine yield 的内容转化成一个 future 对象。
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if not self.future.done() or self.future is moment:
# 如果 future 还没有收到结果，不是 done 的状态，则将其添加到 IOLoop
# 实例中，在后续某一次 Event Loop 中，future 被赋予了结果后再去执行
# run 方法，从而让 coroutine 获得结果并继续执行下去。
self.io_loop.add_future(self.future, lambda f: self.run())
# 这时便不用去执行 run 方法去获得 future 中的结果并反馈给 coroutine
# 了，一切都等到之后的 Event Loop 中见分晓。
return False
# Future 对象这个时候已经有了结果，便可以去执行 run 方法，并将结果反馈给
# coroutine，让之继续后面的执行绪了。
return True
def result_callback(self, key):
return stack_context.wrap(
_argument_adapter(functools.partial(self.set_result, key)))
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.future = TracebackFuture()
self.future.set_exc_info((typ, value, tb))
self.run()
return True
else:
return False
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
class Runner(object):
def __init__(self, gen, result_future, first_yielded):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = None
self.results = None
self.running = False
self.finished = False
self.had_exception = False
self.io_loop = IOLoop.current()
self.stack_context_deactivate = None
if self.handle_yield(first_yielded):
self.run()
def run(self):
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
exc_info = None
try:
value = future.result()
except Exception:
self.had_exception = True
exc_info = sys.exc_info()
if exc_info is not None:
yielded = self.gen.throw(*exc_info)
exc_info = None
else:
yielded = self.gen.send(value)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)')
)
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
self.result_future.set_result(getattr(e, 'value', None))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
finally:
self.running = False
def handle_yield(self, yielded):
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if not self.future.done() or self.future is moment:
self.io_loop.add_future(self.future, lambda f: self.run())
return False
return True
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
class Runner(object):
"""Internal implementation of `tornado.gen.engine`.
Maintains information about pending callbacks and their results.
The results of the generator are stored in ``result_future`` (a
`.TracebackFuture`)
"""
def __init__(self, gen, result_future):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = set()
self.results = {}
self.running = False
self.finished = False
self.exc_info = None
self.had_exception = False
self.io_loop = IOLoop.current()
# For efficiency, we do not create a stack context until we
# reach a YieldPoint (stack contexts are required for the historical
# semantics of YieldPoints, but not for Futures). When we have
# done so, this field will be set and must be called at the end
# of the coroutine.
self.stack_context_deactivate = None
def register_callback(self, key):
"""Adds ``key`` to the list of callbacks."""
if key in self.pending_callbacks:
raise KeyReuseError("key %r is already pending" % (key,))
self.pending_callbacks.add(key)
def is_ready(self, key):
"""Returns true if a result is available for ``key``."""
if key not in self.pending_callbacks:
raise UnknownKeyError("key %r is not pending" % (key,))
return key in self.results
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
self.future.set_result(self.yield_point.get_result())
except:
self.future.set_exc_info(sys.exc_info())
self.yield_point = None
self.run()
def pop_result(self, key):
"""Returns the result for ``key`` and unregisters it."""
self.pending_callbacks.remove(key)
return self.results.pop(key)
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
if self.exc_info is None:
try:
if not self.future.done():
return
next = self.future.result()
self.future = None
except Exception:
self.exc_info = sys.exc_info()
try:
orig_stack_contexts = stack_context._state.contexts
if self.exc_info is not None:
self.had_exception = True
exc_info = self.exc_info
self.exc_info = None
yielded = self.gen.throw(*exc_info)
else:
yielded = self.gen.send(next)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
self.result_future.set_result(getattr(e, 'value', None))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if isinstance(yielded, (list, dict)):
yielded = Multi(yielded)
if isinstance(yielded, YieldPoint):
self.future = TracebackFuture()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
self.future.set_result(
yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.exc_info = sys.exc_info()
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return
else:
start_yield_point()
elif is_future(yielded):
self.future = yielded
if not self.future.done():
self.io_loop.add_future(
self.future, lambda f: self.run())
else:
self.exc_info = (BadYieldError(
"yielded unknown object %r" % (yielded,)),)
finally:
self.running = False
def result_callback(self, key):
def inner(*args, **kwargs):
if kwargs or len(args) > 1:
result = Arguments(args, kwargs)
elif args:
result = args[0]
else:
result = None
self.set_result(key, result)
return stack_context.wrap(inner)
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.exc_info = (typ, value, tb)
self.run()
return True
else:
return False
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
class EventSourceClient(simple_httpclient._HTTPConnection):
"""
This module opens a new connection to an eventsource server, and wait for events.
"""
def __init__(self, io_loop, request):
self.connect_future = TracebackFuture()
self.read_future = None
self.read_queue = collections.deque()
self.events = []
self.tcp_client = TCPClient(io_loop=io_loop)
super(EventSourceClient,
self).__init__(io_loop, None, request, lambda: None,
self._on_http_response, 104857600,
self.tcp_client, 65536)
def _handle_event_stream(self):
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream.read_until_regex(b"\n\n", self.handle_stream)
self.connect_future.set_result(self)
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(
EventSourceError("Non-websocket response"))
def headers_received(self, data, headers):
self.headers = headers
self.code = data.code
self.reason = data.reason
if self.headers['Content-Type'] != 'text/event-stream':
raise ValueError("Invalid headers: %s" % self.headers)
if "Content-Length" in self.headers:
if "," in self.headers["Content-Length"]:
pieces = re.split(r',\s*', self.headers["Content-Length"])
if any(i != pieces[0] for i in pieces):
raise ValueError("Multiple unequal Content-Lengths: %r" %
self.headers["Content-Length"])
self.headers["Content-Length"] = pieces[0]
self._handle_event_stream()
def handle_stream(self, message):
"""
Acts on message reception
:param message: string of an incoming message
parse all the fields and builds an Event object that is passed to the callback function
"""
logging.debug("handle_stream(...)")
event = Event()
for line in message.strip().splitlines():
(field, value) = line.split(":", 1)
field = field.strip()
if field == "event":
event.name = value.lstrip()
elif field == "data":
value = value.lstrip()
if event.data is None:
event.data = value
else:
event.data = "%s\n%s" % (event.data, value)
elif field == "id":
event.id = value.lstrip()
self.last_event_id = event.id
elif field == "retry":
try:
self.retry_timeout = int(value)
event.retry = self.retry_timeout
logging.info("timeout reset: %s" % (value, ))
except ValueError:
pass
elif field == "":
logging.debug("received comment: %s" % (value, ))
else:
raise Exception("Unknown field !")
self.events.append(event)
class WebSocketClientConnection(simple_httpclient._HTTPConnection):
"""WebSocket 客户端连接
这个类不应当直接被实例化, 请使用 `websocket_connect`
"""
def __init__(self,
io_loop,
request,
on_message_callback=None,
compression_options=None):
self.compression_options = compression_options
self.connect_future = TracebackFuture()
self.protocol = None
self.read_future = None
self.read_queue = collections.deque()
self.key = base64.b64encode(os.urandom(16))
self._on_message_callback = on_message_callback
self.close_code = self.close_reason = None
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',
})
if self.compression_options is not None:
# Always offer to let the server set our max_wbits (and even though
# we don't offer it, we will accept a client_no_context_takeover
# from the server).
# TODO: set server parameters for deflate extension
# if requested in self.compression_options.
request.headers['Sec-WebSocket-Extensions'] = (
'permessage-deflate; client_max_window_bits')
self.tcp_client = TCPClient(io_loop=io_loop)
super(WebSocketClientConnection,
self).__init__(io_loop, None, request, lambda: None,
self._on_http_response, 104857600,
self.tcp_client, 65536, 104857600)
def close(self, code=None, reason=None):
"""关闭 websocket 连接
``code`` 和 ``reason`` 的文档在 `WebSocketHandler.close` 下已给出.
.. versionadded:: 3.2
.. versionchanged:: 4.0
添加 ``code`` 和 ``reason`` 这两个参数
"""
if self.protocol is not None:
self.protocol.close(code, reason)
self.protocol = None
def on_connection_close(self):
if not self.connect_future.done():
self.connect_future.set_exception(StreamClosedError())
self.on_message(None)
self.tcp_client.close()
super(WebSocketClientConnection, self).on_connection_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 headers_received(self, start_line, headers):
if start_line.code != 101:
return super(WebSocketClientConnection,
self).headers_received(start_line, headers)
self.headers = headers
self.protocol = self.get_websocket_protocol()
self.protocol._process_server_headers(self.key, self.headers)
self.protocol._receive_frame()
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream = self.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
# Once we've taken over the connection, clear the final callback
# we set on the http request. This deactivates the error handling
# in simple_httpclient that would otherwise interfere with our
# ability to see exceptions.
self.final_callback = None
self.connect_future.set_result(self)
def write_message(self, message, binary=False):
"""发送消息到 websocket 服务器."""
return self.protocol.write_message(message, binary)
def read_message(self, callback=None):
"""读取来自 WebSocket 服务器的消息.
如果在 WebSocket 初始化时指定了 on_message_callback ,那么这个方法永远不会返回消息
如果连接已经关闭,返回结果会是一个结果是 message 的 future 对象或者是 None.
如果 future 给出了回调参数, 这个参数将会在 future 完成时调用.
"""
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._on_message_callback:
self._on_message_callback(message)
elif 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
def get_websocket_protocol(self):
return WebSocketProtocol13(
self,
mask_outgoing=True,
compression_options=self.compression_options)
class Runner(object):
def __init__(self, gen, result_future, first_yielded):
self.gen = gen
self.result_future = result_future
self.future = _null_future
self.yield_point = None
self.pending_callbacks = None
self.results = None
self.running = False
self.finished = False
self.had_exception = False
self.io_loop = IOLoop.current()
self.stack_context_deactivate = None
if self.handle_yield(first_yielded):
self.run()
def run(self):
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
exc_info = None
try:
value = future.result()
except Exception:
self.had_exception = True
exc_info = sys.exc_info()
if exc_info is not None:
yielded = self.gen.throw(*exc_info)
exc_info = None
else:
yielded = self.gen.send(value)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
self.result_future.set_result(getattr(e, 'value', None))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
self.result_future.set_exc_info(sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
finally:
self.running = False
def handle_yield(self, yielded):
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = TracebackFuture()
self.future.set_exc_info(sys.exc_info())
if not self.future.done() or self.future is moment:
self.io_loop.add_future(
self.future, lambda f: self.run())
return False
return True
def _deactivate_stack_context(self):
if self.stack_context_deactivate is not None:
self.stack_context_deactivate()
self.stack_context_deactivate = None
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
class WaitIterator(object):
"""Provides an iterator to yield the results of futures as they finish.
Yielding a set of futures like this:
``results = yield [future1, future2]``
pauses the coroutine until both ``future1`` and ``future2``
return, and then restarts the coroutine with the results of both
futures. If either future is an exception, the expression will
raise that exception and all the results will be lost.
If you need to get the result of each future as soon as possible,
or if you need the result of some futures even if others produce
errors, you can use ``WaitIterator``::
wait_iterator = gen.WaitIterator(future1, future2)
while not wait_iterator.done():
try:
result = yield wait_iterator.next()
except Exception as e:
print("Error {} from {}".format(e, wait_iterator.current_future))
else:
print("Result {} received from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
Because results are returned as soon as they are available the
output from the iterator *will not be in the same order as the
input arguments*. If you need to know which future produced the
current result, you can use the attributes
``WaitIterator.current_future``, or ``WaitIterator.current_index``
to get the index of the future from the input list. (if keyword
arguments were used in the construction of the `WaitIterator`,
``current_index`` will use the corresponding keyword).
.. versionadded:: 4.1
"""
def __init__(self, *args, **kwargs):
if args and kwargs:
raise ValueError(
"You must provide args or kwargs, not both")
if kwargs:
self._unfinished = dict((f, k) for (k, f) in kwargs.items())
futures = list(kwargs.values())
else:
self._unfinished = dict((f, i) for (i, f) in enumerate(args))
futures = args
self._finished = collections.deque()
self.current_index = self.current_future = None
self._running_future = None
# Use a weak reference to self to avoid cycles that may delay
# garbage collection.
self_ref = weakref.ref(self)
for future in futures:
future.add_done_callback(functools.partial(
self._done_callback, self_ref))
def done(self):
"""Returns True if this iterator has no more results."""
if self._finished or self._unfinished:
return False
# Clear the 'current' values when iteration is done.
self.current_index = self.current_future = None
return True
def next(self):
"""Returns a `.Future` that will yield the next available result.
Note that this `.Future` will not be the same object as any of
the inputs.
"""
self._running_future = TracebackFuture()
# As long as there is an active _running_future, we must
# ensure that the WaitIterator is not GC'd (due to the
# use of weak references in __init__). Add a callback that
# references self so there is a hard reference that will be
# cleared automatically when this Future finishes.
self._running_future.add_done_callback(lambda f: self)
if self._finished:
self._return_result(self._finished.popleft())
return self._running_future
@staticmethod
def _done_callback(self_ref, done):
self = self_ref()
if self is not None:
if self._running_future and not self._running_future.done():
self._return_result(done)
else:
self._finished.append(done)
def _return_result(self, done):
"""Called set the returned future's state that of the future
we yielded, and set the current future for the iterator.
"""
chain_future(done, self._running_future)
self.current_future = done
self.current_index = self._unfinished.pop(done)
class WaitIterator(object):
"""Provides an iterator to yield the results of futures as they finish.
Yielding a set of futures like this:
``results = yield [future1, future2]``
pauses the coroutine until both ``future1`` and ``future2``
return, and then restarts the coroutine with the results of both
futures. If either future is an exception, the expression will
raise that exception and all the results will be lost.
If you need to get the result of each future as soon as possible,
or if you need the result of some futures even if others produce
errors, you can use ``WaitIterator``::
wait_iterator = gen.WaitIterator(future1, future2)
while not wait_iterator.done():
try:
result = yield wait_iterator.next()
except Exception as e:
print("Error {} from {}".format(e, wait_iterator.current_future))
else:
print("Result {} received from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
Because results are returned as soon as they are available the
output from the iterator *will not be in the same order as the
input arguments*. If you need to know which future produced the
current result, you can use the attributes
``WaitIterator.current_future``, or ``WaitIterator.current_index``
to get the index of the future from the input list. (if keyword
arguments were used in the construction of the `WaitIterator`,
``current_index`` will use the corresponding keyword).
On Python 3.5, `WaitIterator` implements the async iterator
protocol, so it can be used with the ``async for`` statement (note
that in this version the entire iteration is aborted if any value
raises an exception, while the previous example can continue past
individual errors)::
async for result in gen.WaitIterator(future1, future2):
print("Result {} received from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
.. versionadded:: 4.1
.. versionchanged:: 4.3
Added ``async for`` support in Python 3.5.
"""
def __init__(self, *args, **kwargs):
if args and kwargs:
raise ValueError("You must provide args or kwargs, not both")
if kwargs:
self._unfinished = dict((f, k) for (k, f) in kwargs.items())
futures = list(kwargs.values())
else:
self._unfinished = dict((f, i) for (i, f) in enumerate(args))
futures = args
self._finished = collections.deque()
self.current_index = self.current_future = None
self._running_future = None
for future in futures:
future.add_done_callback(self._done_callback)
def done(self):
"""Returns True if this iterator has no more results."""
if self._finished or self._unfinished:
return False
# Clear the 'current' values when iteration is done.
self.current_index = self.current_future = None
return True
def next(self):
"""Returns a `.Future` that will yield the next available result.
Note that this `.Future` will not be the same object as any of
the inputs.
"""
self._running_future = TracebackFuture()
if self._finished:
self._return_result(self._finished.popleft())
return self._running_future
def _done_callback(self, done):
if self._running_future and not self._running_future.done():
self._return_result(done)
else:
self._finished.append(done)
def _return_result(self, done):
"""Called set the returned future's state that of the future
we yielded, and set the current future for the iterator.
"""
chain_future(done, self._running_future)
self.current_future = done
self.current_index = self._unfinished.pop(done)
@coroutine
def __aiter__(self):
raise Return(self)
def __anext__(self):
if self.done():
# Lookup by name to silence pyflakes on older versions.
raise getattr(builtins, 'StopAsyncIteration')()
return self.next()
class WaitIterator(object):
"""Provides an iterator to yield the results of futures as they finish.
Yielding a set of futures like this:
``results = yield [future1, future2]``
pauses the coroutine until both ``future1`` and ``future2``
return, and then restarts the coroutine with the results of both
futures. If either future is an exception, the expression will
raise that exception and all the results will be lost.
If you need to get the result of each future as soon as possible,
or if you need the result of some futures even if others produce
errors, you can use ``WaitIterator``::
wait_iterator = gen.WaitIterator(future1, future2)
while not wait_iterator.done():
try:
result = yield wait_iterator.next()
except Exception as e:
print("Error {} from {}".format(e, wait_iterator.current_future))
else:
print("Result {} received from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
Because results are returned as soon as they are available the
output from the iterator *will not be in the same order as the
input arguments*. If you need to know which future produced the
current result, you can use the attributes
``WaitIterator.current_future``, or ``WaitIterator.current_index``
to get the index of the future from the input list. (if keyword
arguments were used in the construction of the `WaitIterator`,
``current_index`` will use the corresponding keyword).
On Python 3.5, `WaitIterator` implements the async iterator
protocol, so it can be used with the ``async for`` statement (note
that in this version the entire iteration is aborted if any value
raises an exception, while the previous example can continue past
individual errors)::
async for result in gen.WaitIterator(future1, future2):
print("Result {} received from {} at {}".format(
result, wait_iterator.current_future,
wait_iterator.current_index))
.. versionadded:: 4.1
.. versionchanged:: 4.3
Added ``async for`` support in Python 3.5.
"""
def __init__(self, *args, **kwargs):
if args and kwargs:
raise ValueError(
"You must provide args or kwargs, not both")
if kwargs:
self._unfinished = dict((f, k) for (k, f) in kwargs.items())
futures = list(kwargs.values())
else:
self._unfinished = dict((f, i) for (i, f) in enumerate(args))
futures = args
self._finished = collections.deque()
self.current_index = self.current_future = None
self._running_future = None
for future in futures:
future.add_done_callback(self._done_callback)
def done(self):
"""Returns True if this iterator has no more results."""
if self._finished or self._unfinished:
return False
# Clear the 'current' values when iteration is done.
self.current_index = self.current_future = None
return True
def next(self):
"""Returns a `.Future` that will yield the next available result.
Note that this `.Future` will not be the same object as any of
the inputs.
"""
self._running_future = TracebackFuture()
if self._finished:
self._return_result(self._finished.popleft())
return self._running_future
def _done_callback(self, done):
if self._running_future and not self._running_future.done():
self._return_result(done)
else:
self._finished.append(done)
def _return_result(self, done):
"""Called set the returned future's state that of the future
we yielded, and set the current future for the iterator.
"""
chain_future(done, self._running_future)
self.current_future = done
self.current_index = self._unfinished.pop(done)
@coroutine
def __aiter__(self):
raise Return(self)
def __anext__(self):
if self.done():
# Lookup by name to silence pyflakes on older versions.
raise getattr(builtins, 'StopAsyncIteration')()
return self.next()
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, compression_options=None):
self.compression_options = compression_options
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',
})
if self.compression_options is not None:
# Always offer to let the server set our max_wbits (and even though
# we don't offer it, we will accept a client_no_context_takeover
# from the server).
# TODO: set server parameters for deflate extension
# if requested in self.compression_options.
request.headers['Sec-WebSocket-Extensions'] = (
'permessage-deflate; client_max_window_bits')
self.tcp_client = TCPClient(io_loop=io_loop)
super(WebSocketClientConnection,
self).__init__(io_loop, None, request, lambda: None,
self._on_http_response, 104857600,
self.tcp_client, 65536)
def close(self, code=None, reason=None):
"""Closes the websocket connection.
``code`` and ``reason`` are documented under
`WebSocketHandler.close`.
.. versionadded:: 3.2
.. versionchanged:: 4.0
Added the ``code`` and ``reason`` arguments.
"""
if self.protocol is not None:
self.protocol.close(code, reason)
self.protocol = None
def on_connection_close(self):
if not self.connect_future.done():
self.connect_future.set_exception(StreamClosedError())
self.on_message(None)
self.tcp_client.close()
super(WebSocketClientConnection, self).on_connection_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 headers_received(self, start_line, headers):
if start_line.code != 101:
return super(WebSocketClientConnection,
self).headers_received(start_line, headers)
self.headers = headers
self.protocol = WebSocketProtocol13(
self,
mask_outgoing=True,
compression_options=self.compression_options)
self.protocol._process_server_headers(self.key, self.headers)
self.protocol._receive_frame()
if self._timeout is not None:
self.io_loop.remove_timeout(self._timeout)
self._timeout = None
self.stream = self.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
# Once we've taken over the connection, clear the final callback
# we set on the http request. This deactivates the error handling
# in simple_httpclient that would otherwise interfere with our
# ability to see exceptions.
self.final_callback = 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
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
class WebSocketClientConnection(simple_httpclient._HTTPConnection):
"""WebSocket client connection."""
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 _on_close(self):
self.on_message(None)
self.resolver.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