import ast
import statistics
import json
import time
from threading import Thread, Lock
from platypush.context import get_backend
from platypush.plugins import Plugin, action
data_throttler_lock = None
[docs]class AdafruitIoPlugin(Plugin):
"""
This plugin allows you to interact with the Adafruit IO
<https://io.adafruit.com>, a cloud-based message queue and storage.
You can send values to feeds on your Adafruit IO account and read the
values of those feeds as well through any device.
Requires:
* **adafruit-io** (``pip install adafruit-io``)
* Redis server running and Redis backend configured if you want to enable throttling
Some example usages::
# Send the temperature value for a connected sensor to the "temperature" feed
{
"type": "request",
"action": "adafruit.io.send",
"args": {
"feed": "temperature",
"value": 25.0
}
}
# Receive the most recent temperature value
{
"type": "request",
"action": "adafruit.io.receive",
"args": {
"feed": "temperature"
}
}
"""
_DATA_THROTTLER_QUEUE = 'platypush/adafruit.io'
[docs] def __init__(self, username, key, throttle_seconds=None, **kwargs):
"""
:param username: Your Adafruit username
:type username: str
:param key: Your Adafruit IO key
:type key: str
:param throttle_seconds: If set, then instead of sending the values directly over ``send`` the plugin will
first collect all the samples within the specified period and then dispatch them to Adafruit IO.
You may want to set it if you have data sources providing a lot of data points and you don't want to hit
the throttling limitations of Adafruit.
:type throttle_seconds: float
"""
from Adafruit_IO import Client
global data_throttler_lock
super().__init__(**kwargs)
self._username = username
self._key = key
self.aio = Client(username=username, key=key)
self.throttle_seconds = throttle_seconds
if not data_throttler_lock:
data_throttler_lock = Lock()
if self.throttle_seconds and not data_throttler_lock.locked():
self._get_redis()
self.logger.info('Starting Adafruit IO throttler thread')
data_throttler_lock.acquire(False)
self.data_throttler = Thread(target=self._data_throttler())
self.data_throttler.start()
@staticmethod
def _get_redis():
from redis import Redis
redis_args = {
'host': 'localhost',
}
redis_backend = get_backend('redis')
if redis_backend:
redis_args = get_backend('redis').redis_args
redis_args['socket_timeout'] = 1
return Redis(**redis_args)
def _data_throttler(self):
from redis.exceptions import TimeoutError as QueueTimeoutError
def run():
from Adafruit_IO import ThrottlingError
redis = self._get_redis()
last_processed_batch_timestamp = None
data = {}
try:
while True:
try:
new_data = ast.literal_eval(
redis.blpop(self._DATA_THROTTLER_QUEUE)[1].decode('utf-8'))
for (key, value) in new_data.items():
data.setdefault(key, []).append(value)
except QueueTimeoutError:
pass
if data and (last_processed_batch_timestamp is None or
time.time() - last_processed_batch_timestamp >= self.throttle_seconds):
last_processed_batch_timestamp = time.time()
self.logger.info('Processing feeds batch for Adafruit IO')
for (feed, values) in data.items():
if values:
value = statistics.mean(values)
try:
self.send(feed, value, enqueue=False)
except ThrottlingError:
self.logger.warning('Adafruit IO throttling threshold hit, taking a nap ' +
'before retrying')
time.sleep(self.throttle_seconds)
data = {}
except Exception as e:
self.logger.exception(e)
return run
[docs] @action
def send(self, feed, value, enqueue=True):
"""
Send a value to an Adafruit IO feed
:param feed: Feed name
:type feed: str
:param value: Value to send
:type value: Numeric or string
:param enqueue: If throttle_seconds is set, this method by default will append values to the throttling queue
to be periodically flushed instead of sending the message directly. In such case, pass enqueue=False to
override the behaviour and send the message directly instead.
:type enqueue: bool
"""
if not self.throttle_seconds or not enqueue:
# If no throttling is configured, or enqueue is false then send the value directly to Adafruit
self.aio.send(feed, value)
else:
# Otherwise send it to the Redis queue to be picked up by the throttler thread
redis = self._get_redis()
redis.rpush(self._DATA_THROTTLER_QUEUE, json.dumps({feed: value}))
[docs] @action
def send_location_data(self, feed, lat, lon, ele, value):
"""
Send location data to an Adafruit IO feed
:param feed: Feed name
:type feed: str
:param lat: Latitude
:type lat: float
:param lon: Longitude
:type lon: float
:param ele: Elevation
:type ele: float
:param value: Value to send
:type value: Numeric or string
"""
self.aio.send_data(feed=feed, value=value, metadata={
'lat': lat,
'lon': lon,
'ele': ele,
})
@classmethod
def _cast_value(cls, value):
try:
value = float(value)
except ValueError:
pass
return value
def _convert_data_to_dict(self, *data):
from Adafruit_IO.model import DATA_FIELDS
return [
{
attr: self._cast_value(getattr(i, attr))
if attr == 'value' else getattr(i, attr)
for attr in DATA_FIELDS if getattr(i, attr) is not None
} for i in data
]
[docs] @action
def receive(self, feed, limit=1):
"""
Receive data from the specified Adafruit IO feed
:param feed: Feed name
:type feed: str
:param limit: Maximum number of data points to be returned. If None,
all the values in the feed will be returned. Default: 1 (return most
recent value)
:type limit: int
"""
if limit == 1:
values = self._convert_data_to_dict(self.aio.receive(feed))
return values[0] if values else None
values = self._convert_data_to_dict(*self.aio.data(feed))
return values[:limit] if limit else values
[docs] @action
def receive_next(self, feed):
"""
Receive the next unprocessed data point from a feed
:param feed: Feed name
:type feed: str
"""
values = self._convert_data_to_dict(self.aio.receive_next(feed))
return values[0] if values else None
[docs] @action
def receive_previous(self, feed):
"""
Receive the last processed data point from a feed
:param feed: Feed name
:type feed: str
"""
values = self._convert_data_to_dict(self.aio.receive_previous(feed))
return values[0] if values else None
[docs] @action
def delete(self, feed, data_id):
"""
Delete a data point from a feed
:param feed: Feed name
:type feed: str
:param data_id: Data point ID to remove
:type data_id: str
"""
self.aio.delete(feed, data_id)
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