pysnmp-sky/pysnmp/carrier/asyncio/dispatch.py

101 lines
3.7 KiB
Python

#
# This file is part of pysnmp software.
#
# Copyright (c) 2005-2017, Ilya Etingof <etingof@gmail.com>
# License: http://pysnmp.sf.net/license.html
#
# Copyright (C) 2014, Zebra Technologies
# Authors: Matt Hooks <me@matthooks.com>
# Zachary Lorusso <zlorusso@gmail.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
# THE POSSIBILITY OF SUCH DAMAGE.
#
import sys
import traceback
from pysnmp.carrier.base import AbstractTransportDispatcher
from pysnmp.error import PySnmpError
try:
import asyncio
except ImportError:
import trollius as asyncio
loop = asyncio.get_event_loop()
class AsyncioDispatcher(AbstractTransportDispatcher):
"""AsyncioDispatcher based on asyncio event loop"""
def __init__(self, *args, **kwargs):
AbstractTransportDispatcher.__init__(self)
self.__transportCount = 0
if 'timeout' in kwargs:
self.setTimerResolution(kwargs['timeout'])
self.loopingcall = None
@asyncio.coroutine
def handle_timeout(self):
while True:
yield asyncio.From(asyncio.sleep(self.getTimerResolution()))
self.handleTimerTick(loop.time())
def runDispatcher(self, timeout=0.0):
if not loop.is_running():
try:
loop.run_forever()
except KeyboardInterrupt:
raise
except Exception:
raise PySnmpError(';'.join(traceback.format_exception(*sys.exc_info())))
def registerTransport(self, tDomain, transport):
if self.loopingcall is None and self.getTimerResolution() > 0:
self.loopingcall = asyncio.async(self.handle_timeout())
AbstractTransportDispatcher.registerTransport(
self, tDomain, transport
)
self.__transportCount += 1
def unregisterTransport(self, tDomain):
t = AbstractTransportDispatcher.getTransport(self, tDomain)
if t is not None:
AbstractTransportDispatcher.unregisterTransport(self, tDomain)
self.__transportCount -= 1
# The last transport has been removed, stop the timeout
if self.__transportCount == 0 and not self.loopingcall.done():
self.loopingcall.cancel()
self.loopingcall = None
# Trollius or Tulip?
if not hasattr(asyncio, "From"):
exec ("""\
@asyncio.coroutine
def handle_timeout(self):
while True:
yield from asyncio.sleep(self.getTimerResolution())
self.handleTimerTick(loop.time())
AsyncioDispatcher.handle_timeout = handle_timeout\
""")