Source code for openmdao.gui.zmqstreamserver

import sys
import os
import traceback
import subprocess

from optparse import OptionParser

import zmq
from zmq.eventloop import ioloop
from zmq.eventloop.zmqstream import ZMQStream

from tornado import httpserver, web, websocket

import jsonpickle

debug = True

[docs]def DEBUG(msg): if debug: print '<<<' + str(os.getpid()) + '>>> ZMQStreamServer --', msg
[docs]def make_unicode(content): if type(content) == str: # Ignore errors even if the string is not proper UTF-8 or has # broken marker bytes. # Python built-in function unicode() can do this. content = unicode(content, "utf-8", errors="ignore") else: # Assume the content object has proper __unicode__() method content = unicode(content) return content
[docs]class ZMQStreamHandler(websocket.WebSocketHandler): ''' a handler that forwards output from a ZMQStream to a WebSocket '''
[docs] def initialize(self, addr): self.addr = addr
[docs] def open(self): stream = None try: context = zmq.Context() socket = context.socket(zmq.SUB) socket.connect(self.addr) socket.setsockopt(zmq.SUBSCRIBE, '') stream = ZMQStream(socket) except Exception, err: exc_type, exc_value, exc_traceback = sys.exc_info() print 'ZMQStreamHandler ERROR getting ZMQ stream:', err traceback.print_exception(exc_type, exc_value, exc_traceback) if stream and not stream.closed(): stream.close() else: stream.on_recv(self._write_message)
def _write_message(self, message): if len(message) == 1: message = message[0] message = make_unicode(message) # tornado websocket wants unicode self.write_message(message) elif len(message) == 2: topic = message[0] content = message[1] # package topic and content into a single json object try: content = jsonpickle.decode(content) message = jsonpickle.encode([topic, content]) except Exception, err: exc_type, exc_value, exc_traceback = sys.exc_info print 'ZMQStreamHandler ERROR decoding/encoding message:', topic, err traceback.print_exception(exc_type, exc_value, exc_traceback) return # convert to unicode (tornado websocket wants unicode) try: message = make_unicode(message) except Exception, err: exc_type, exc_value, exc_traceback = sys.exc_info print 'ZMQStreamHandler ERROR converting message to unicode:', topic, err traceback.print_exception(exc_type, exc_value, exc_traceback) return # write message to websocket self.write_message(message)
[docs] def on_message(self, message): pass
[docs] def on_close(self): DEBUG('zmqstream connection closed')
[docs]class ZMQStreamApp(web.Application): ''' a web application that serves a ZMQStream over a WebSocket ''' def __init__(self, zmqstream_addr, websocket_url): handlers = [ (websocket_url, ZMQStreamHandler, dict(addr=zmqstream_addr)) ] settings = { 'login_url': '/login', 'debug': True, } super(ZMQStreamApp, self).__init__(handlers, **settings)
[docs]class ZMQStreamServer(object): ''' runs an http server that serves a ZMQStream over a WebSocket ''' def __init__(self, options): self.options = options self.web_app = ZMQStreamApp(options.addr, options.url) self.http_server = httpserver.HTTPServer(self.web_app)
[docs] def serve(self): ''' start server listening on port & start the ioloop ''' self.http_server.listen(self.options.port, address="localhost") try: ioloop.IOLoop.instance().start() except KeyboardInterrupt: DEBUG('interrupt received, shutting down.')
[docs] def get_options_parser(): ''' create a parser for command line arguments ''' parser = OptionParser() parser.add_option("-z", "--zmqstream", dest="addr", default=0, help="the address of the zmqstream") parser.add_option("-p", "--port", dest="port", type="int", default=0, help="the port to run websocket server on") parser.add_option("-u", "--url", dest="url", help="the url to expose for the websocket") return parser
[docs] def spawn_process(zmq_url, ws_port, ws_url='/'): ''' run zmqstreamserver in it's own process, mapping a zmq stream to a websocket args: zmq_url the url of the ZMQStream ws_port the port to serve the WebSocket on ws_url the url to map to the WebSocket ''' file_path = os.path.abspath(__file__) cmd = ['python', file_path, '-z', str(zmq_url), '-p', str(ws_port), '-u', str(ws_url)] return subprocess.Popen(cmd)
[docs]def main(): ''' process command line arguments, create server and start it up ''' # make sure to install zmq ioloop before creating any tornado objects ioloop.install() # create the server and kick it off parser = ZMQStreamServer.get_options_parser() (options, args) = parser.parse_args() server = ZMQStreamServer(options) server.serve()
if __name__ == '__main__': # dont run main() if this is a forked windows process if sys.modules['__main__'].__file__ == __file__: main()
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