# -*- coding: utf-8 -*-
#
# Copyright: (c) 2011 by the Serge S. Koval, see AUTHORS for more details.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
tornadio.flashserver
~~~~~~~~~~~~~~~~~~~~
This module implements customized PeriodicCallback from tornado with
support of the sliding window.
"""
import time
import logging
logger = logging.getLogger('tornadio2.periodic')
[docs]class Callback(object):
"""Custom implementation of the Tornado.Callback with support
of callback timeout delays.
"""
[docs] def __init__(self, callback, callback_time, io_loop):
"""Constructor.
`callback`
Callback function
`callback_time`
Callback timeout value (in milliseconds)
`io_loop`
io_loop instance
"""
self.callback = callback
self.callback_time = callback_time
self.io_loop = io_loop
self._running = False
self.next_run = None
[docs] def calculate_next_run(self):
"""Caltulate next scheduled run"""
return time.time() + self.callback_time / 1000.0
[docs] def start(self, timeout=None):
"""Start callbacks"""
self._running = True
if timeout is None:
timeout = self.calculate_next_run()
self.io_loop.add_timeout(timeout, self._run)
[docs] def stop(self):
"""Stop callbacks"""
self._running = False
[docs] def delay(self):
"""Delay callback"""
self.next_run = self.calculate_next_run()
def _run(self):
if not self._running:
return
# Support for shifting callback window
if self.next_run is not None and time.time() < self.next_run:
self.start(self.next_run)
self.next_run = None
return
next_call = None
try:
next_call = self.callback()
except (KeyboardInterrupt, SystemExit):
raise
except:
logger.error("Error in periodic callback", exc_info=True)
if self._running:
self.start(next_call)