1.0
This commit is contained in:
744
venv/lib/python3.11/site-packages/gpiozero/internal_devices.py
Normal file
744
venv/lib/python3.11/site-packages/gpiozero/internal_devices.py
Normal file
@@ -0,0 +1,744 @@
|
||||
# vim: set fileencoding=utf-8:
|
||||
#
|
||||
# GPIO Zero: a library for controlling the Raspberry Pi's GPIO pins
|
||||
#
|
||||
# Copyright (c) 2016-2023 Dave Jones <dave@waveform.org.uk>
|
||||
# Copyright (c) 2017-2021 Ben Nuttall <ben@bennuttall.com>
|
||||
# Copyright (c) 2019 Jeevan M R <14.jeevan@gmail.com>
|
||||
# Copyright (c) 2019 Andrew Scheller <github@loowis.durge.org>
|
||||
#
|
||||
# SPDX-License-Identifier: BSD-3-Clause
|
||||
|
||||
import os
|
||||
import io
|
||||
import warnings
|
||||
import subprocess
|
||||
from datetime import datetime, time
|
||||
|
||||
from .devices import Device
|
||||
from .mixins import EventsMixin, event
|
||||
from .threads import GPIOThread
|
||||
from .exc import ThresholdOutOfRange, DeviceClosed
|
||||
|
||||
|
||||
class InternalDevice(EventsMixin, Device):
|
||||
"""
|
||||
Extends :class:`Device` to provide a basis for devices which have no
|
||||
specific hardware representation. These are effectively pseudo-devices and
|
||||
usually represent operating system services like the internal clock, file
|
||||
systems or network facilities.
|
||||
"""
|
||||
def __init__(self, *, pin_factory=None):
|
||||
self._closed = False
|
||||
super().__init__(pin_factory=pin_factory)
|
||||
|
||||
def close(self):
|
||||
self._closed = True
|
||||
super().close()
|
||||
|
||||
@property
|
||||
def closed(self):
|
||||
return self._closed
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return f"<gpiozero.{self.__class__.__name__} object>"
|
||||
except DeviceClosed:
|
||||
return f"<gpiozero.{self.__class__.__name__} object closed>"
|
||||
|
||||
|
||||
class PolledInternalDevice(InternalDevice):
|
||||
"""
|
||||
Extends :class:`InternalDevice` to provide a background thread to poll
|
||||
internal devices that lack any other mechanism to inform the instance of
|
||||
changes.
|
||||
"""
|
||||
def __init__(self, *, event_delay=1.0, pin_factory=None):
|
||||
self._event_thread = None
|
||||
self._event_delay = event_delay
|
||||
super().__init__(pin_factory=pin_factory)
|
||||
|
||||
def close(self):
|
||||
try:
|
||||
self._start_stop_events(False)
|
||||
except AttributeError:
|
||||
pass # pragma: no cover
|
||||
super().close()
|
||||
|
||||
@property
|
||||
def event_delay(self):
|
||||
"""
|
||||
The delay between sampling the device's value for the purposes of
|
||||
firing events.
|
||||
|
||||
Note that this only applies to events assigned to attributes like
|
||||
:attr:`~EventsMixin.when_activated` and
|
||||
:attr:`~EventsMixin.when_deactivated`. When using the
|
||||
:attr:`~SourceMixin.source` and :attr:`~ValuesMixin.values` properties,
|
||||
the sampling rate is controlled by the
|
||||
:attr:`~SourceMixin.source_delay` property.
|
||||
"""
|
||||
return self._event_delay
|
||||
|
||||
@event_delay.setter
|
||||
def event_delay(self, value):
|
||||
self._event_delay = float(value)
|
||||
|
||||
def wait_for_active(self, timeout=None):
|
||||
self._start_stop_events(True)
|
||||
try:
|
||||
return super().wait_for_active(timeout)
|
||||
finally:
|
||||
self._start_stop_events(
|
||||
self.when_activated or self.when_deactivated)
|
||||
|
||||
def wait_for_inactive(self, timeout=None):
|
||||
self._start_stop_events(True)
|
||||
try:
|
||||
return super().wait_for_inactive(timeout)
|
||||
finally:
|
||||
self._start_stop_events(
|
||||
self.when_activated or self.when_deactivated)
|
||||
|
||||
def _watch_value(self):
|
||||
while not self._event_thread.stopping.wait(self._event_delay):
|
||||
self._fire_events(self.pin_factory.ticks(), self.is_active)
|
||||
|
||||
def _start_stop_events(self, enabled):
|
||||
if self._event_thread and not enabled:
|
||||
self._event_thread.stop()
|
||||
self._event_thread = None
|
||||
elif not self._event_thread and enabled:
|
||||
self._event_thread = GPIOThread(self._watch_value)
|
||||
self._event_thread.start()
|
||||
|
||||
|
||||
class PingServer(PolledInternalDevice):
|
||||
"""
|
||||
Extends :class:`PolledInternalDevice` to provide a device which is active
|
||||
when a *host* (domain name or IP address) can be pinged.
|
||||
|
||||
The following example lights an LED while ``google.com`` is reachable::
|
||||
|
||||
from gpiozero import PingServer, LED
|
||||
from signal import pause
|
||||
|
||||
google = PingServer('google.com')
|
||||
led = LED(4)
|
||||
|
||||
google.when_activated = led.on
|
||||
google.when_deactivated = led.off
|
||||
|
||||
pause()
|
||||
|
||||
:param str host:
|
||||
The hostname or IP address to attempt to ping.
|
||||
|
||||
:type event_delay: float
|
||||
:param event_delay:
|
||||
The number of seconds between pings (defaults to 10 seconds).
|
||||
|
||||
:type pin_factory: Factory or None
|
||||
:param pin_factory:
|
||||
See :doc:`api_pins` for more information (this is an advanced feature
|
||||
which most users can ignore).
|
||||
"""
|
||||
def __init__(self, host, *, event_delay=10.0, pin_factory=None):
|
||||
self._host = host
|
||||
super().__init__(event_delay=event_delay, pin_factory=pin_factory)
|
||||
self._fire_events(self.pin_factory.ticks(), self.is_active)
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return f'<gpiozero.PingServer object host="{self.host}">'
|
||||
except DeviceClosed:
|
||||
return super().__repr__()
|
||||
|
||||
@property
|
||||
def host(self):
|
||||
"""
|
||||
The hostname or IP address to test whenever :attr:`value` is queried.
|
||||
"""
|
||||
return self._host
|
||||
|
||||
@property
|
||||
def value(self):
|
||||
"""
|
||||
Returns :data:`1` if the host returned a single ping, and :data:`0`
|
||||
otherwise.
|
||||
"""
|
||||
# XXX This is doing a DNS lookup every time it's queried; should we
|
||||
# call gethostbyname in the constructor and ping that instead (good
|
||||
# for consistency, but what if the user *expects* the host to change
|
||||
# address?)
|
||||
with io.open(os.devnull, 'wb') as devnull:
|
||||
try:
|
||||
subprocess.check_call(
|
||||
['ping', '-c1', self.host],
|
||||
stdout=devnull, stderr=devnull)
|
||||
except subprocess.CalledProcessError:
|
||||
return 0
|
||||
else:
|
||||
return 1
|
||||
|
||||
when_activated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive
|
||||
(host unresponsive) to active (host responsive).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
when_deactivated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive
|
||||
(host responsive) to active (host unresponsive).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
|
||||
class CPUTemperature(PolledInternalDevice):
|
||||
"""
|
||||
Extends :class:`PolledInternalDevice` to provide a device which is active
|
||||
when the CPU temperature exceeds the *threshold* value.
|
||||
|
||||
The following example plots the CPU's temperature on an LED bar graph::
|
||||
|
||||
from gpiozero import LEDBarGraph, CPUTemperature
|
||||
from signal import pause
|
||||
|
||||
# Use minimums and maximums that are closer to "normal" usage so the
|
||||
# bar graph is a bit more "lively"
|
||||
cpu = CPUTemperature(min_temp=50, max_temp=90)
|
||||
|
||||
print(f'Initial temperature: {cpu.temperature}C')
|
||||
|
||||
graph = LEDBarGraph(5, 6, 13, 19, 25, pwm=True)
|
||||
graph.source = cpu
|
||||
|
||||
pause()
|
||||
|
||||
:param str sensor_file:
|
||||
The file from which to read the temperature. This defaults to the
|
||||
sysfs file :file:`/sys/class/thermal/thermal_zone0/temp`. Whatever
|
||||
file is specified is expected to contain a single line containing the
|
||||
temperature in milli-degrees celsius.
|
||||
|
||||
:param float min_temp:
|
||||
The temperature at which :attr:`value` will read 0.0. This defaults to
|
||||
0.0.
|
||||
|
||||
:param float max_temp:
|
||||
The temperature at which :attr:`value` will read 1.0. This defaults to
|
||||
100.0.
|
||||
|
||||
:param float threshold:
|
||||
The temperature above which the device will be considered "active".
|
||||
(see :attr:`is_active`). This defaults to 80.0.
|
||||
|
||||
:type event_delay: float
|
||||
:param event_delay:
|
||||
The number of seconds between file reads (defaults to 5 seconds).
|
||||
|
||||
:type pin_factory: Factory or None
|
||||
:param pin_factory:
|
||||
See :doc:`api_pins` for more information (this is an advanced feature
|
||||
which most users can ignore).
|
||||
"""
|
||||
def __init__(self, sensor_file='/sys/class/thermal/thermal_zone0/temp', *,
|
||||
min_temp=0.0, max_temp=100.0, threshold=80.0, event_delay=5.0,
|
||||
pin_factory=None):
|
||||
self.sensor_file = sensor_file
|
||||
super().__init__(event_delay=event_delay, pin_factory=pin_factory)
|
||||
try:
|
||||
if min_temp >= max_temp:
|
||||
raise ValueError('max_temp must be greater than min_temp')
|
||||
self.min_temp = min_temp
|
||||
self.max_temp = max_temp
|
||||
if not min_temp <= threshold <= max_temp:
|
||||
warnings.warn(ThresholdOutOfRange(
|
||||
'threshold is outside of the range (min_temp, max_temp)'))
|
||||
self.threshold = threshold
|
||||
self._fire_events(self.pin_factory.ticks(), self.is_active)
|
||||
except:
|
||||
self.close()
|
||||
raise
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return (
|
||||
f'<gpiozero.{self.__class__.__name__} object '
|
||||
f'temperature={self.temperature:.2f}>')
|
||||
except DeviceClosed:
|
||||
return super().__repr__()
|
||||
|
||||
@property
|
||||
def temperature(self):
|
||||
"""
|
||||
Returns the current CPU temperature in degrees celsius.
|
||||
"""
|
||||
with io.open(self.sensor_file, 'r') as f:
|
||||
return float(f.read().strip()) / 1000
|
||||
|
||||
@property
|
||||
def value(self):
|
||||
"""
|
||||
Returns the current CPU temperature as a value between 0.0
|
||||
(representing the *min_temp* value) and 1.0 (representing the
|
||||
*max_temp* value). These default to 0.0 and 100.0 respectively, hence
|
||||
:attr:`value` is :attr:`temperature` divided by 100 by default.
|
||||
"""
|
||||
temp_range = self.max_temp - self.min_temp
|
||||
return (self.temperature - self.min_temp) / temp_range
|
||||
|
||||
@property
|
||||
def is_active(self):
|
||||
"""
|
||||
Returns :data:`True` when the CPU :attr:`temperature` exceeds the
|
||||
*threshold*.
|
||||
"""
|
||||
return self.temperature > self.threshold
|
||||
|
||||
when_activated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive to
|
||||
active (temperature reaches *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
when_deactivated = event(
|
||||
"""
|
||||
The function to run when the device changes state from active to
|
||||
inactive (temperature drops below *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
|
||||
class LoadAverage(PolledInternalDevice):
|
||||
"""
|
||||
Extends :class:`PolledInternalDevice` to provide a device which is active
|
||||
when the CPU load average exceeds the *threshold* value.
|
||||
|
||||
The following example plots the load average on an LED bar graph::
|
||||
|
||||
from gpiozero import LEDBarGraph, LoadAverage
|
||||
from signal import pause
|
||||
|
||||
la = LoadAverage(min_load_average=0, max_load_average=2)
|
||||
graph = LEDBarGraph(5, 6, 13, 19, 25, pwm=True)
|
||||
|
||||
graph.source = la
|
||||
|
||||
pause()
|
||||
|
||||
:param str load_average_file:
|
||||
The file from which to read the load average. This defaults to the
|
||||
proc file :file:`/proc/loadavg`. Whatever file is specified is expected
|
||||
to contain three space-separated load averages at the beginning of the
|
||||
file, representing 1 minute, 5 minute and 15 minute averages
|
||||
respectively.
|
||||
|
||||
:param float min_load_average:
|
||||
The load average at which :attr:`value` will read 0.0. This defaults to
|
||||
0.0.
|
||||
|
||||
:param float max_load_average:
|
||||
The load average at which :attr:`value` will read 1.0. This defaults to
|
||||
1.0.
|
||||
|
||||
:param float threshold:
|
||||
The load average above which the device will be considered "active".
|
||||
(see :attr:`is_active`). This defaults to 0.8.
|
||||
|
||||
:param int minutes:
|
||||
The number of minutes over which to average the load. Must be 1, 5 or
|
||||
15. This defaults to 5.
|
||||
|
||||
:type event_delay: float
|
||||
:param event_delay:
|
||||
The number of seconds between file reads (defaults to 10 seconds).
|
||||
|
||||
:type pin_factory: Factory or None
|
||||
:param pin_factory:
|
||||
See :doc:`api_pins` for more information (this is an advanced feature
|
||||
which most users can ignore).
|
||||
"""
|
||||
def __init__(self, load_average_file='/proc/loadavg', *,
|
||||
min_load_average=0.0, max_load_average=1.0, threshold=0.8,
|
||||
minutes=5, event_delay=10.0, pin_factory=None):
|
||||
if min_load_average >= max_load_average:
|
||||
raise ValueError(
|
||||
'max_load_average must be greater than min_load_average')
|
||||
self.load_average_file = load_average_file
|
||||
self.min_load_average = min_load_average
|
||||
self.max_load_average = max_load_average
|
||||
if not min_load_average <= threshold <= max_load_average:
|
||||
warnings.warn(ThresholdOutOfRange(
|
||||
'threshold is outside of the range (min_load_average, '
|
||||
'max_load_average)'))
|
||||
self.threshold = threshold
|
||||
if minutes not in (1, 5, 15):
|
||||
raise ValueError('minutes must be 1, 5 or 15')
|
||||
self._load_average_file_column = {
|
||||
1: 0,
|
||||
5: 1,
|
||||
15: 2,
|
||||
}[minutes]
|
||||
super().__init__(event_delay=event_delay, pin_factory=pin_factory)
|
||||
self._fire_events(self.pin_factory.ticks(), None)
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return (
|
||||
f'<gpiozero.{self.__class__.__name__} object '
|
||||
f'load average={self.load_average:.2f}>')
|
||||
except DeviceClosed:
|
||||
return super().__repr__()
|
||||
|
||||
@property
|
||||
def load_average(self):
|
||||
"""
|
||||
Returns the current load average.
|
||||
"""
|
||||
with io.open(self.load_average_file, 'r') as f:
|
||||
file_columns = f.read().strip().split()
|
||||
return float(file_columns[self._load_average_file_column])
|
||||
|
||||
@property
|
||||
def value(self):
|
||||
"""
|
||||
Returns the current load average as a value between 0.0 (representing
|
||||
the *min_load_average* value) and 1.0 (representing the
|
||||
*max_load_average* value). These default to 0.0 and 1.0 respectively.
|
||||
"""
|
||||
load_average_range = self.max_load_average - self.min_load_average
|
||||
return (self.load_average - self.min_load_average) / load_average_range
|
||||
|
||||
@property
|
||||
def is_active(self):
|
||||
"""
|
||||
Returns :data:`True` when the :attr:`load_average` exceeds the
|
||||
*threshold*.
|
||||
"""
|
||||
return self.load_average > self.threshold
|
||||
|
||||
when_activated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive to
|
||||
active (load average reaches *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
when_deactivated = event(
|
||||
"""
|
||||
The function to run when the device changes state from active to
|
||||
inactive (load average drops below *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
|
||||
class TimeOfDay(PolledInternalDevice):
|
||||
"""
|
||||
Extends :class:`PolledInternalDevice` to provide a device which is active
|
||||
when the computer's clock indicates that the current time is between
|
||||
*start_time* and *end_time* (inclusive) which are :class:`~datetime.time`
|
||||
instances.
|
||||
|
||||
The following example turns on a lamp attached to an :class:`Energenie`
|
||||
plug between 07:00AM and 08:00AM::
|
||||
|
||||
from gpiozero import TimeOfDay, Energenie
|
||||
from datetime import time
|
||||
from signal import pause
|
||||
|
||||
lamp = Energenie(1)
|
||||
morning = TimeOfDay(time(7), time(8))
|
||||
|
||||
morning.when_activated = lamp.on
|
||||
morning.when_deactivated = lamp.off
|
||||
|
||||
pause()
|
||||
|
||||
Note that *start_time* may be greater than *end_time*, indicating a time
|
||||
period which crosses midnight.
|
||||
|
||||
:param ~datetime.time start_time:
|
||||
The time from which the device will be considered active.
|
||||
|
||||
:param ~datetime.time end_time:
|
||||
The time after which the device will be considered inactive.
|
||||
|
||||
:param bool utc:
|
||||
If :data:`True` (the default), a naive UTC time will be used for the
|
||||
comparison rather than a local time-zone reading.
|
||||
|
||||
:type event_delay: float
|
||||
:param event_delay:
|
||||
The number of seconds between file reads (defaults to 10 seconds).
|
||||
|
||||
:type pin_factory: Factory or None
|
||||
:param pin_factory:
|
||||
See :doc:`api_pins` for more information (this is an advanced feature
|
||||
which most users can ignore).
|
||||
"""
|
||||
def __init__(self, start_time, end_time, *, utc=True, event_delay=5.0,
|
||||
pin_factory=None):
|
||||
self._start_time = None
|
||||
self._end_time = None
|
||||
self._utc = True
|
||||
super().__init__(event_delay=event_delay, pin_factory=pin_factory)
|
||||
try:
|
||||
self._start_time = self._validate_time(start_time)
|
||||
self._end_time = self._validate_time(end_time)
|
||||
if self.start_time == self.end_time:
|
||||
raise ValueError('end_time cannot equal start_time')
|
||||
self._utc = utc
|
||||
self._fire_events(self.pin_factory.ticks(), self.is_active)
|
||||
except:
|
||||
self.close()
|
||||
raise
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return (
|
||||
f'<gpiozero.{self.__class__.__name__} object active between '
|
||||
f'{self.start_time} and {self.end_time} '
|
||||
f'{("local", "UTC")[self.utc]}>')
|
||||
except DeviceClosed:
|
||||
return super().__repr__()
|
||||
|
||||
def _validate_time(self, value):
|
||||
if isinstance(value, datetime):
|
||||
value = value.time()
|
||||
if not isinstance(value, time):
|
||||
raise ValueError(
|
||||
'start_time and end_time must be a datetime, or time instance')
|
||||
return value
|
||||
|
||||
@property
|
||||
def start_time(self):
|
||||
"""
|
||||
The time of day after which the device will be considered active.
|
||||
"""
|
||||
return self._start_time
|
||||
|
||||
@property
|
||||
def end_time(self):
|
||||
"""
|
||||
The time of day after which the device will be considered inactive.
|
||||
"""
|
||||
return self._end_time
|
||||
|
||||
@property
|
||||
def utc(self):
|
||||
"""
|
||||
If :data:`True`, use a naive UTC time reading for comparison instead of
|
||||
a local timezone reading.
|
||||
"""
|
||||
return self._utc
|
||||
|
||||
@property
|
||||
def value(self):
|
||||
"""
|
||||
Returns :data:`1` when the system clock reads between :attr:`start_time`
|
||||
and :attr:`end_time`, and :data:`0` otherwise. If :attr:`start_time` is
|
||||
greater than :attr:`end_time` (indicating a period that crosses
|
||||
midnight), then this returns :data:`1` when the current time is
|
||||
greater than :attr:`start_time` or less than :attr:`end_time`.
|
||||
"""
|
||||
now = datetime.utcnow().time() if self.utc else datetime.now().time()
|
||||
if self.start_time < self.end_time:
|
||||
return int(self.start_time <= now <= self.end_time)
|
||||
else:
|
||||
return int(not self.end_time < now < self.start_time)
|
||||
|
||||
when_activated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive to
|
||||
active (time reaches *start_time*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
when_deactivated = event(
|
||||
"""
|
||||
The function to run when the device changes state from active to
|
||||
inactive (time reaches *end_time*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
|
||||
class DiskUsage(PolledInternalDevice):
|
||||
"""
|
||||
Extends :class:`PolledInternalDevice` to provide a device which is active
|
||||
when the disk space used exceeds the *threshold* value.
|
||||
|
||||
The following example plots the disk usage on an LED bar graph::
|
||||
|
||||
from gpiozero import LEDBarGraph, DiskUsage
|
||||
from signal import pause
|
||||
|
||||
disk = DiskUsage()
|
||||
|
||||
print(f'Current disk usage: {disk.usage}%')
|
||||
|
||||
graph = LEDBarGraph(5, 6, 13, 19, 25, pwm=True)
|
||||
graph.source = disk
|
||||
|
||||
pause()
|
||||
|
||||
:param str filesystem:
|
||||
A path within the filesystem for which the disk usage needs to be
|
||||
computed. This defaults to :file:`/`, which is the root filesystem.
|
||||
|
||||
:param float threshold:
|
||||
The disk usage percentage above which the device will be considered
|
||||
"active" (see :attr:`is_active`). This defaults to 90.0.
|
||||
|
||||
:type event_delay: float
|
||||
:param event_delay:
|
||||
The number of seconds between file reads (defaults to 30 seconds).
|
||||
|
||||
:type pin_factory: Factory or None
|
||||
:param pin_factory:
|
||||
See :doc:`api_pins` for more information (this is an advanced feature
|
||||
which most users can ignore).
|
||||
"""
|
||||
def __init__(self, filesystem='/', *, threshold=90.0, event_delay=30.0,
|
||||
pin_factory=None):
|
||||
super().__init__(
|
||||
event_delay=event_delay, pin_factory=pin_factory)
|
||||
os.statvfs(filesystem)
|
||||
if not 0 <= threshold <= 100:
|
||||
warnings.warn(ThresholdOutOfRange(
|
||||
'threshold is outside of the range (0, 100)'))
|
||||
self.filesystem = filesystem
|
||||
self.threshold = threshold
|
||||
self._fire_events(self.pin_factory.ticks(), None)
|
||||
|
||||
def __repr__(self):
|
||||
try:
|
||||
self._check_open()
|
||||
return (
|
||||
f'<gpiozero.{self.__class__.__name__} object '
|
||||
f'usage={self.usage:.2f}>')
|
||||
except DeviceClosed:
|
||||
return super().__repr__()
|
||||
|
||||
@property
|
||||
def usage(self):
|
||||
"""
|
||||
Returns the current disk usage in percentage.
|
||||
"""
|
||||
return self.value * 100
|
||||
|
||||
@property
|
||||
def value(self):
|
||||
"""
|
||||
Returns the current disk usage as a value between 0.0 and 1.0 by
|
||||
dividing :attr:`usage` by 100.
|
||||
"""
|
||||
# This slightly convoluted calculation is equivalent to df's "Use%";
|
||||
# it calculates the percentage of FS usage as a proportion of the
|
||||
# space available to *non-root users*. Technically this means it can
|
||||
# exceed 100% (when FS is filled to the point that only root can write
|
||||
# to it), hence the clamp.
|
||||
vfs = os.statvfs(self.filesystem)
|
||||
used = vfs.f_blocks - vfs.f_bfree
|
||||
total = used + vfs.f_bavail
|
||||
return min(1.0, used / total)
|
||||
|
||||
@property
|
||||
def is_active(self):
|
||||
"""
|
||||
Returns :data:`True` when the disk :attr:`usage` exceeds the
|
||||
*threshold*.
|
||||
"""
|
||||
return self.usage > self.threshold
|
||||
|
||||
when_activated = event(
|
||||
"""
|
||||
The function to run when the device changes state from inactive to
|
||||
active (disk usage reaches *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
|
||||
when_deactivated = event(
|
||||
"""
|
||||
The function to run when the device changes state from active to
|
||||
inactive (disk usage drops below *threshold*).
|
||||
|
||||
This can be set to a function which accepts no (mandatory)
|
||||
parameters, or a Python function which accepts a single mandatory
|
||||
parameter (with as many optional parameters as you like). If the
|
||||
function accepts a single mandatory parameter, the device that
|
||||
activated it will be passed as that parameter.
|
||||
|
||||
Set this property to ``None`` (the default) to disable the event.
|
||||
""")
|
||||
Reference in New Issue
Block a user