osmo-gsm-tester/src/osmo_ms_driver/cdf.py

113 lines
3.4 KiB
Python

# osmo_ms_driver: A cumululative distribution function class.
# Help to start processes over time.
#
# Copyright (C) 2018 by Holger Hans Peter Freyther
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from datetime import timedelta
class DistributionFunctionHandler(object):
"""
The goal is to start n "mobile" processes. We like to see some
conflicts (RACH bursts being ignored) but starting n processes
at the same time is not a realistic model.
We use the concept of cumulative distribution function here. On
the x-axis we have time (maybe in steps of 10ms) and on the
y-axis we have the percentage (from 0.0 to 1.0) of how many
processes should run at the given time.
"""
def __init__(self, step, duration, fun):
self._step = step
self._fun = fun
self._x = 0.0
self._y = self._fun(self._x)
self._target = 1.0
self._duration = duration
def step_size(self):
return self._step
def set_target(self, scale):
"""
Scale the percentage to the target value..
"""
self._target = scale
def is_done(self):
return self._y >= 1.0
def current_value(self):
return self._y
def current_scaled_value(self):
return self._y * self._target
def step_once(self):
self._x = self._x + self._step.total_seconds()
self._y = self._fun(self._x)
def duration(self):
return self._duration
def immediate(step_size=timedelta(milliseconds=20)):
"""
Reaches 100% at the first step.
"""
duration = timedelta(seconds=0)
return DistributionFunctionHandler(step_size, duration, lambda x: 1)
def linear_with_slope(slope, duration, step_size=timedelta(milliseconds=20)):
"""
Use the slope and step size you want
"""
return DistributionFunctionHandler(step_size, duration, lambda x: slope*x)
def linear_with_duration(duration, step_size=timedelta(milliseconds=20)):
"""
Linear progression that reaches 100% after duration.total_seconds()
"""
slope = 1.0/duration.total_seconds()
return linear_with_slope(slope, duration, step_size)
def _in_out(x):
"""
Internal in/out function inspired by Qt
"""
assert x <= 1.0
# Needs to be between 0..1 and increase first
if x < 0.5:
return (x*x) * 2
# deaccelerate now. in_out(0.5) == 0.5, in_out(1.0) == 1.0
x = x * 2 - 1
return -0.5 * (x*(x-2)- 1)
def ease_in_out_duration(duration, step_size=timedelta(milliseconds=20)):
"""
Example invocation
"""
scale = 1.0/duration.total_seconds()
return DistributionFunctionHandler(step_size, duration,
lambda x: _in_out(x*scale))
cdfs = {
'immediate': lambda x,y: immediate(y),
'linear': linear_with_duration,
'ease_in_out': ease_in_out_duration,
}