Get rid of QtIOPubChannel class

IPython/qt/client.py

@@ -1,264 +1,257
 """ Defines a KernelClient that provides signals and slots.
 """
 import atexit
 import errno
 from threading import Thread
 import time
 
 import zmq
 # import ZMQError in top-level namespace, to avoid ugly attribute-error messages
 # during garbage collection of threads at exit:
 from zmq import ZMQError
 from zmq.eventloop import ioloop, zmqstream
 
 from IPython.external.qt import QtCore
 
 # Local imports
 from IPython.utils.traitlets import Type
 from IPython.kernel.channels import HBChannel,\
     make_shell_socket, make_iopub_socket, make_stdin_socket
 from IPython.kernel import KernelClient
 
 from .kernel_mixins import (QtHBChannelMixin, QtKernelClientMixin)
 from .util import SuperQObject
 
 class QtHBChannel(QtHBChannelMixin, HBChannel):
     pass
 
 from IPython.core.release import kernel_protocol_version_info
 
 from IPython.kernel.channelsabc import (
     ShellChannelABC, IOPubChannelABC, StdInChannelABC,
 )
 from IPython.utils.py3compat import string_types, iteritems
 
 major_protocol_version = kernel_protocol_version_info[0]
 
 class InvalidPortNumber(Exception):
     pass
 
 # some utilities to validate message structure, these might get moved elsewhere
 # if they prove to have more generic utility
 
 
 def validate_string_dict(dct):
     """Validate that the input is a dict with string keys and values.
 
     Raises ValueError if not."""
     for k,v in iteritems(dct):
         if not isinstance(k, string_types):
             raise ValueError('key %r in dict must be a string' % k)
         if not isinstance(v, string_types):
             raise ValueError('value %r in dict must be a string' % v)
 
 
 
 class QtZMQSocketChannel(SuperQObject, Thread):
     """The base class for the channels that use ZMQ sockets."""
     session = None
     socket = None
     ioloop = None
     stream = None
     _exiting = False
     proxy_methods = []
 
     # Emitted when the channel is started.
     started = QtCore.Signal()
 
     # Emitted when the channel is stopped.
     stopped = QtCore.Signal()
 
     message_received = QtCore.Signal(object)
 
     #---------------------------------------------------------------------------
     # InProcessChannel interface
     #---------------------------------------------------------------------------
 
     def call_handlers_later(self, *args, **kwds):
         """ Call the message handlers later.
         """
         do_later = lambda: self.call_handlers(*args, **kwds)
         QtCore.QTimer.singleShot(0, do_later)
 
     def process_events(self):
         """ Process any pending GUI events.
         """
         QtCore.QCoreApplication.instance().processEvents()
 
     def __init__(self, socket, session):
         """Create a channel.
 
         Parameters
         ----------
         context : :class:`zmq.Context`
             The ZMQ context to use.
         session : :class:`session.Session`
             The session to use.
         address : zmq url
             Standard (ip, port) tuple that the kernel is listening on.
         """
         super(QtZMQSocketChannel, self).__init__()
         self.daemon = True
 
         self.socket = socket
         self.session = session
         atexit.register(self._notice_exit)
         self.ioloop = ioloop.IOLoop()
 
     def _notice_exit(self):
         self._exiting = True
 
     def _run_loop(self):
         """Run my loop, ignoring EINTR events in the poller"""
         while True:
             try:
                 self.ioloop.start()
             except ZMQError as e:
                 if e.errno == errno.EINTR:
                     continue
                 else:
                     raise
             except Exception:
                 if self._exiting:
                     break
                 else:
                     raise
             else:
                 break
 
     def start(self):
         """ Reimplemented to emit signal.
         """
         super(QtZMQSocketChannel, self).start()
         self.started.emit()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
 
     def stop(self):
         """Stop the channel's event loop and join its thread.
 
         This calls :meth:`~threading.Thread.join` and returns when the thread
         terminates. :class:`RuntimeError` will be raised if
         :meth:`~threading.Thread.start` is called again.
         """
         if self.ioloop is not None:
             self.ioloop.stop()
         self.join()
         self.close()
         self.stopped.emit()
 
     def close(self):
         if self.ioloop is not None:
             try:
                 self.ioloop.close(all_fds=True)
             except Exception:
                 pass
         if self.socket is not None:
             try:
                 self.socket.close(linger=0)
             except Exception:
                 pass
             self.socket = None
 
     @property
     def address(self):
         """Get the channel's address as a zmq url string.
 
         These URLS have the form: 'tcp://127.0.0.1:5555'.
         """
         return self._address
 
     def _queue_send(self, msg):
         """Queue a message to be sent from the IOLoop's thread.
 
         Parameters
         ----------
         msg : message to send
 
         This is threadsafe, as it uses IOLoop.add_callback to give the loop's
         thread control of the action.
         """
         def thread_send():
             self.session.send(self.stream, msg)
         self.ioloop.add_callback(thread_send)
 
     def _handle_recv(self, msg):
         """Callback for stream.on_recv.
 
         Unpacks message, and calls handlers with it.
         """
         ident,smsg = self.session.feed_identities(msg)
         msg = self.session.deserialize(smsg)
         self.call_handlers(msg)
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application level
         handlers are called in the application thread.
         """
         # Emit the generic signal.
         self.message_received.emit(msg)
 
-
-class QtIOPubChannel(QtZMQSocketChannel):
-    """The iopub channel which listens for messages that the kernel publishes.
-
-    This channel is where all output is published to frontends.
-    """
-
     def flush(self, timeout=1.0):
-        """Immediately processes all pending messages on the iopub channel.
+        """Immediately processes all pending messages on this channel.
+
+        This is only used for the IOPub channel.
 
         Callers should use this method to ensure that :meth:`call_handlers`
         has been called for all messages that have been received on the
         0MQ SUB socket of this channel.
 
         This method is thread safe.
 
         Parameters
         ----------
         timeout : float, optional
             The maximum amount of time to spend flushing, in seconds. The
             default is one second.
         """
         # We do the IOLoop callback process twice to ensure that the IOLoop
         # gets to perform at least one full poll.
         stop_time = time.time() + timeout
         for i in range(2):
             self._flushed = False
             self.ioloop.add_callback(self._flush)
             while not self._flushed and time.time() < stop_time:
                 time.sleep(0.01)
 
     def _flush(self):
         """Callback for :method:`self.flush`."""
         self.stream.flush()
         self._flushed = True
 
-IOPubChannelABC.register(QtIOPubChannel)
-
 
 class QtKernelClient(QtKernelClientMixin, KernelClient):
     """ A KernelClient that provides signals and slots.
     """
     def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
         if shell:
             self.shell_channel.message_received.connect(self._check_kernel_info_reply)
         super(QtKernelClient, self).start_channels(shell, iopub, stdin, hb)
 
     def _check_kernel_info_reply(self, msg):
         if msg['msg_type'] == 'kernel_info_reply':
             self._handle_kernel_info_reply(msg)
             self.shell_channel.message_received.disconnect(self._check_kernel_info_reply)
 
-    iopub_channel_class = Type(QtIOPubChannel)
+    iopub_channel_class = Type(QtZMQSocketChannel)
     shell_channel_class = Type(QtZMQSocketChannel)
     stdin_channel_class = Type(QtZMQSocketChannel)
     hb_channel_class = Type(QtHBChannel)