Source code for microscope.clients

#!/usr/bin/env python3

## Copyright (C) 2020 Mick Phillips <mick.phillips@gmail.com>
##
## This file is part of Microscope.
##
## Microscope is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## Microscope is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Microscope.  If not, see <http://www.gnu.org/licenses/>.

"""TODO: complete this docstring
"""

import inspect
import itertools
import queue
import socket
import threading

import Pyro4


# Pyro configuration. Use pickle because it can serialize numpy ndarrays.
Pyro4.config.SERIALIZERS_ACCEPTED.add("pickle")
Pyro4.config.SERIALIZER = "pickle"

LISTENERS = {}


[docs]class Client: """Base Client object that makes methods on proxy available locally.""" def __init__(self, url): self._url = url self._proxy = None self._connect() def _connect(self): """Connect to a proxy and set up self passthrough to proxy methods.""" self._proxy = Pyro4.Proxy(self._url) self._proxy._pyroGetMetadata() # Derived classes may over-ride some methods. Leave these alone. my_methods = [ m[0] for m in inspect.getmembers(self, predicate=inspect.ismethod) ] methods = set(self._proxy._pyroMethods).difference(my_methods) # But in the case of propertyes, we need to inspect the class. my_properties = [ m[0] for m in inspect.getmembers( self.__class__, predicate=inspect.isdatadescriptor ) ] properties = set(self._proxy._pyroAttrs).difference(my_properties) for attr in itertools.chain(methods, properties): setattr(self, attr, getattr(self._proxy, attr))
[docs]class DataClient(Client): """A client that can receive and buffer data.""" def __init__(self, url): super().__init__(url) self._buffer = queue.Queue() # Register self with a listener. if self._url.split("@")[1].split(":")[0] in ["127.0.0.1", "localhost"]: iface = "127.0.0.1" else: # TODO: support multiple interfaces. Could use ifaddr.get_adapters() to # query ip addresses then pick first interface on the same subnet. iface = socket.gethostbyname(socket.gethostname()) if iface not in LISTENERS: LISTENERS[iface] = Pyro4.Daemon(host=iface) lthread = threading.Thread(target=LISTENERS[iface].requestLoop) lthread.daemon = True lthread.start() self._client_uri = LISTENERS[iface].register(self)
[docs] def enable(self): """Set the client on the remote and enable it.""" self.set_client(self._client_uri) self._proxy.enable()
[docs] @Pyro4.expose @Pyro4.oneway # noinspection PyPep8Naming # Legacy naming convention. def receiveData(self, data, timestamp, *args): del args self._buffer.put((data, timestamp))
[docs] def trigger_and_wait(self): if not hasattr(self, "trigger"): raise Exception("Device has no trigger method.") self.trigger() return self._buffer.get(block=True)