75 lines
2.2 KiB
Python
75 lines
2.2 KiB
Python
import logging
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import threading
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import time
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from queue import Queue
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from platypush.config import Config
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from platypush.message.event import StopEvent
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logger = logging.getLogger('platypush:bus')
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class Bus(object):
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""" Main local bus where the daemon will listen for new messages """
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_MSG_EXPIRY_TIMEOUT = 60.0 # Consider a message on the bus as expired after one minute without being picked up
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def __init__(self, on_message=None):
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self.bus = Queue()
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self.on_message = on_message
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self.thread_id = threading.get_ident()
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def post(self, msg):
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""" Sends a message to the bus """
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self.bus.put(msg)
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def get(self):
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""" Reads one message from the bus """
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return self.bus.get()
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def stop(self):
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""" Stops the bus by sending a STOP event """
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evt = StopEvent(target=Config.get('device_id'),
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origin=Config.get('device_id'),
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thread_id=self.thread_id)
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self.post(evt)
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def _msg_executor(self, msg):
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def executor():
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try:
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self.on_message(msg)
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except Exception as e:
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logger.error('Error on processing message {}'.format(msg))
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logger.exception(e)
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return executor
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def poll(self):
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"""
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Reads messages from the bus until either stop event message or KeyboardInterrupt
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"""
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if not self.on_message:
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logger.warning('No message handlers installed, cannot poll')
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return
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stop = False
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while not stop:
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msg = self.get()
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timestamp = msg.timestamp if hasattr(msg, 'timestamp') else msg.get('timestamp')
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if timestamp and time.time() - timestamp > self._MSG_EXPIRY_TIMEOUT:
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logger.debug('{} seconds old message on the bus expired, ignoring it: {}'.
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format(int(time.time()-msg.timestamp), msg))
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continue
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threading.Thread(target=self._msg_executor(msg)).start()
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if isinstance(msg, StopEvent) and msg.targets_me():
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logger.info('Received STOP event on the bus')
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stop = True
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# vim:sw=4:ts=4:et:
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