hub/venv/lib/python3.7/site-packages/ipykernel/inprocess/blocking.py

94 lines
3.0 KiB
Python

""" Implements a fully blocking kernel client.
Useful for test suites and blocking terminal interfaces.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2012 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING.txt, distributed as part of this software.
#-----------------------------------------------------------------------------
import sys
try:
from queue import Queue, Empty # Py 3
except ImportError:
from Queue import Queue, Empty # Py 2
# IPython imports
from traitlets import Type
# Local imports
from .channels import (
InProcessChannel,
)
from .client import InProcessKernelClient
class BlockingInProcessChannel(InProcessChannel):
def __init__(self, *args, **kwds):
super(BlockingInProcessChannel, self).__init__(*args, **kwds)
self._in_queue = Queue()
def call_handlers(self, msg):
self._in_queue.put(msg)
def get_msg(self, block=True, timeout=None):
""" Gets a message if there is one that is ready. """
if timeout is None:
# Queue.get(timeout=None) has stupid uninteruptible
# behavior, so wait for a week instead
timeout = 604800
return self._in_queue.get(block, timeout)
def get_msgs(self):
""" Get all messages that are currently ready. """
msgs = []
while True:
try:
msgs.append(self.get_msg(block=False))
except Empty:
break
return msgs
def msg_ready(self):
""" Is there a message that has been received? """
return not self._in_queue.empty()
class BlockingInProcessStdInChannel(BlockingInProcessChannel):
def call_handlers(self, msg):
""" Overridden for the in-process channel.
This methods simply calls raw_input directly.
"""
msg_type = msg['header']['msg_type']
if msg_type == 'input_request':
_raw_input = self.client.kernel._sys_raw_input
prompt = msg['content']['prompt']
print(prompt, end='', file=sys.__stdout__)
sys.__stdout__.flush()
self.client.input(_raw_input())
class BlockingInProcessKernelClient(InProcessKernelClient):
# The classes to use for the various channels.
shell_channel_class = Type(BlockingInProcessChannel)
iopub_channel_class = Type(BlockingInProcessChannel)
stdin_channel_class = Type(BlockingInProcessStdInChannel)
def wait_for_ready(self):
# Wait for kernel info reply on shell channel
while True:
msg = self.shell_channel.get_msg(block=True)
if msg['msg_type'] == 'kernel_info_reply':
self._handle_kernel_info_reply(msg)
break
# Flush IOPub channel
while True:
try:
msg = self.iopub_channel.get_msg(block=True, timeout=0.2)
print(msg['msg_type'])
except Empty:
break