Source code for alignak.load
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2015-2015: Alignak team, see AUTHORS.txt file for contributors
#
# This file is part of Alignak.
#
# Alignak is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Alignak 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Alignak. If not, see <http://www.gnu.org/licenses/>.
#
#
# This file incorporates work covered by the following copyright and
# permission notice:
#
# Copyright (C) 2009-2014:
# Hartmut Goebel, h.goebel@goebel-consult.de
# Nicolas Dupeux, nicolas@dupeux.net
# Grégory Starck, g.starck@gmail.com
# Sebastien Coavoux, s.coavoux@free.fr
# Jean Gabes, naparuba@gmail.com
# Zoran Zaric, zz@zoranzaric.de
# This file is part of Shinken.
#
# Shinken is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Shinken 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Shinken. If not, see <http://www.gnu.org/licenses/>.
"""
This module provide a simple abstraction for load computation in satellite
"""
import time
import math
[docs]class Load:
"""This class is for having a easy Load calculation
without having to send value at regular interval
(but it's more efficient if you do this :) ) and without
having a list or other stuff. It's just an object, an update and a get
You can define mins: the average for mins minutes. The val is
the initial value. It's better if it's 0 but you can choose.
"""
def __init__(self, mins=1, initial_value=0):
self.exp = 0 # first exp
self.mins = mins # Number of minute of the avg
self.last_update = 0 # last update of the value
self.val = initial_value # first value
[docs] def update_load(self, new_val, forced_interval=None):
"""Update load with the new value
:param new_val: value used to compute new load
:type new_val: int
:param forced_interval: boolean indicating if we force the interval for the value
:type forced_interval: bool
:return: None
"""
# The first call do not change the value, just tag
# the beginning of last_update
# IF we force : bail out all time thing
if not forced_interval and self.last_update == 0:
self.last_update = time.time()
return
now = time.time()
try:
if forced_interval:
diff = forced_interval
else:
diff = now - self.last_update
self.exp = 1 / math.exp(diff / (self.mins * 60.0))
self.val = new_val + self.exp * (self.val - new_val)
self.last_update = now
except OverflowError: # if the time change without notice, we overflow :(
pass
except ZeroDivisionError: # do not care
pass
[docs] def get_load(self):
"""Get actual load. val attribute accessor
:return: the load value
:rtype: int
"""
return self.val