Vehicle-Anti-Theft-Face-Rec.../venv/Lib/site-packages/ipykernel/comm/manager.py

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2020-11-12 16:05:57 +00:00
"""Base class to manage comms"""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import sys
import logging
from traitlets.config import LoggingConfigurable
from ipython_genutils.importstring import import_item
from ipython_genutils.py3compat import string_types
from traitlets import Instance, Unicode, Dict, Any, default
from .comm import Comm
class CommManager(LoggingConfigurable):
"""Manager for Comms in the Kernel"""
kernel = Instance('ipykernel.kernelbase.Kernel')
comms = Dict()
targets = Dict()
# Public APIs
def register_target(self, target_name, f):
"""Register a callable f for a given target name
f will be called with two arguments when a comm_open message is received with `target`:
- the Comm instance
- the `comm_open` message itself.
f can be a Python callable or an import string for one.
"""
if isinstance(f, string_types):
f = import_item(f)
self.targets[target_name] = f
def unregister_target(self, target_name, f):
"""Unregister a callable registered with register_target"""
return self.targets.pop(target_name)
def register_comm(self, comm):
"""Register a new comm"""
comm_id = comm.comm_id
comm.kernel = self.kernel
self.comms[comm_id] = comm
return comm_id
def unregister_comm(self, comm):
"""Unregister a comm, and close its counterpart"""
# unlike get_comm, this should raise a KeyError
comm = self.comms.pop(comm.comm_id)
def get_comm(self, comm_id):
"""Get a comm with a particular id
Returns the comm if found, otherwise None.
This will not raise an error,
it will log messages if the comm cannot be found.
"""
try:
return self.comms[comm_id]
except KeyError:
self.log.warning("No such comm: %s", comm_id)
if self.log.isEnabledFor(logging.DEBUG):
# don't create the list of keys if debug messages aren't enabled
self.log.debug("Current comms: %s", list(self.comms.keys()))
# Message handlers
def comm_open(self, stream, ident, msg):
"""Handler for comm_open messages"""
content = msg['content']
comm_id = content['comm_id']
target_name = content['target_name']
f = self.targets.get(target_name, None)
comm = Comm(comm_id=comm_id,
primary=False,
target_name=target_name,
)
self.register_comm(comm)
if f is None:
self.log.error("No such comm target registered: %s", target_name)
else:
try:
f(comm, msg)
return
except Exception:
self.log.error("Exception opening comm with target: %s", target_name, exc_info=True)
# Failure.
try:
comm.close()
except:
self.log.error("""Could not close comm during `comm_open` failure
clean-up. The comm may not have been opened yet.""", exc_info=True)
def comm_msg(self, stream, ident, msg):
"""Handler for comm_msg messages"""
content = msg['content']
comm_id = content['comm_id']
comm = self.get_comm(comm_id)
if comm is None:
return
try:
comm.handle_msg(msg)
except Exception:
self.log.error('Exception in comm_msg for %s', comm_id, exc_info=True)
def comm_close(self, stream, ident, msg):
"""Handler for comm_close messages"""
content = msg['content']
comm_id = content['comm_id']
comm = self.get_comm(comm_id)
if comm is None:
return
self.comms[comm_id]._closed = True
del self.comms[comm_id]
try:
comm.handle_close(msg)
except Exception:
self.log.error('Exception in comm_close for %s', comm_id, exc_info=True)
__all__ = ['CommManager']