##// END OF EJS Templates
Prevent qtconsole frontend freeze on lots of output....
Prevent qtconsole frontend freeze on lots of output. The output from the kernel is now clipped to last `buffer_size` before displaying and a timer is used to flush the pending output text instead of attempting to display text on every stream output from kernel. The timer interval is adjusted based on actual time taken to append a screenful of text to widget. This throttles the widget repaints and avoids choking the Qt event loop leaving time to handle other Qt events. Test cases: In [1]: for i in xrange(1000000): print i In [2]: range(100000) Without this commit the first input causes the qtconsole frontend to freeze, not responding to `Ctrl+C`.

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zmqhandlers.py
113 lines | 4.0 KiB | text/x-python | PythonLexer
"""Tornado handlers for WebSocket <-> ZMQ sockets.
Authors:
* Brian Granger
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import Cookie
import logging
from tornado import web
from tornado import websocket
from zmq.utils import jsonapi
from IPython.kernel.zmq.session import Session
from IPython.utils.jsonutil import date_default
from IPython.utils.py3compat import PY3, cast_unicode
from .handlers import IPythonHandler
#-----------------------------------------------------------------------------
# ZMQ handlers
#-----------------------------------------------------------------------------
class ZMQStreamHandler(websocket.WebSocketHandler):
def clear_cookie(self, *args, **kwargs):
"""meaningless for websockets"""
pass
def _reserialize_reply(self, msg_list):
"""Reserialize a reply message using JSON.
This takes the msg list from the ZMQ socket, unserializes it using
self.session and then serializes the result using JSON. This method
should be used by self._on_zmq_reply to build messages that can
be sent back to the browser.
"""
idents, msg_list = self.session.feed_identities(msg_list)
msg = self.session.unserialize(msg_list)
try:
msg['header'].pop('date')
except KeyError:
pass
try:
msg['parent_header'].pop('date')
except KeyError:
pass
msg.pop('buffers')
return jsonapi.dumps(msg, default=date_default)
def _on_zmq_reply(self, msg_list):
# Sometimes this gets triggered when the on_close method is scheduled in the
# eventloop but hasn't been called.
if self.stream.closed(): return
try:
msg = self._reserialize_reply(msg_list)
except Exception:
self.log.critical("Malformed message: %r" % msg_list, exc_info=True)
else:
self.write_message(msg)
def allow_draft76(self):
"""Allow draft 76, until browsers such as Safari update to RFC 6455.
This has been disabled by default in tornado in release 2.2.0, and
support will be removed in later versions.
"""
return True
class AuthenticatedZMQStreamHandler(ZMQStreamHandler, IPythonHandler):
def open(self, kernel_id):
self.kernel_id = cast_unicode(kernel_id, 'ascii')
self.session = Session(config=self.config)
self.save_on_message = self.on_message
self.on_message = self.on_first_message
def _inject_cookie_message(self, msg):
"""Inject the first message, which is the document cookie,
for authentication."""
if not PY3 and isinstance(msg, unicode):
# Cookie constructor doesn't accept unicode strings
# under Python 2.x for some reason
msg = msg.encode('utf8', 'replace')
try:
identity, msg = msg.split(':', 1)
self.session.session = cast_unicode(identity, 'ascii')
except Exception:
logging.error("First ws message didn't have the form 'identity:[cookie]' - %r", msg)
try:
self.request._cookies = Cookie.SimpleCookie(msg)
except:
self.log.warn("couldn't parse cookie string: %s",msg, exc_info=True)
def on_first_message(self, msg):
self._inject_cookie_message(msg)
if self.get_current_user() is None:
self.log.warn("Couldn't authenticate WebSocket connection")
raise web.HTTPError(403)
self.on_message = self.save_on_message