Reduce the load on the Emporia server by introducing a cache proxy

This is related: magico13/PyEmVue#19

Signed-off-by: Jeremy Compostella <[email protected]>

emporia_proxy.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+#
+# Author: Jeremy Compostella <[email protected]>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+#    * Redistributions of source code must retain the above copyright
+#      notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above copyright
+#      notice, this list of conditions and the following disclaimer
+#      in the documentation and/or other materials provided with the
+#      distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+# OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import os
+
+from datetime import datetime, timedelta
+from multiprocessing.connection import Listener
+
+from pyemvue.enums import Scale
+
+from sensor import MyVue2
+from tools import debug, init
+
+def main():
+    prefix = os.path.splitext(__file__)[0]
+    config = init(prefix + '.log')
+
+    vue = MyVue2(config['Emporia'])
+    cache = {}
+    listener = Listener((config['EmporiaProxy']['host'],
+                         int(config['EmporiaProxy']['port'])))
+    debug("... is now ready to run")
+    while True:
+        conn = listener.accept()
+        scale = conn.recv()
+        data = {}
+        if scale not in cache or datetime.now() > cache[scale]['expiration_time']:
+            try:
+                debug('Reading with scale %s' % scale)
+                data = vue.read(scale)
+            except:
+                debug('Failed to read from Emporia servers')
+                pass
+            if data:
+                cache[scale] = { 'data':data }
+                if scale == Scale.SECOND.value:
+                    cache[scale]['expiration_time'] = \
+                        datetime.now() + timedelta(seconds=15)
+                else:
+                    cache[scale]['expiration_time'] = \
+                        datetime.now().replace(second=0, microsecond=0) + \
+                        timedelta(minutes=1)
+        else:
+            data = cache[scale]['data']
+        conn.send(data)
+        conn.close()
+
+if __name__ == "__main__":
+    main()

emporia_proxy.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Emporia Proxy Service
+DefaultDependencies=no
+After=network.target
+
+[Service]
+Type=simple
+User=pi
+Group=pi
+ExecStart=/home/pi/emporia_proxy.sh
+TimeoutStartSec=0
+RemainAfterExit=yes
+Restart=on-failure
+RestartSec=15s
+
+[Install]
+WantedBy=default.target

emporia_proxy.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+cd /home/pi/
+python3 emporia_proxy.py
+

home.ini

@@ -1,6 +1,6 @@
 [general]
 sensor_db=sensor.csv
-sensors=Emporia,OpenWeather,Ecobee,WirelessTag,CarData
+sensors=EmporiaProxy,OpenWeather,Ecobee,WirelessTag,CarData
 producers=SolarPanels
 consumers=Pool,Aquanta,Ecobee,Range,Wallbox,Dryer
 utility=SRP
@@ -12,6 +12,11 @@ token_file = keys.json
 map=net,water heater,dryer,air handler,EV,range,A/C,solar,pool
 class=MyVue2
 
+[EmporiaProxy]
+class=EmporiaProxy
+host=localhost
+port=6001
+
 [SolarPanels]
 sensors=solar
 description=Solar Panels

sensor.py

@@ -138,6 +138,20 @@ def read(self, scale=Scale.MINUTE.value):
             self.usage[self.mapping[i]] = usage[i].usage * factor[scale]
         return self.usage
 
+class EmporiaProxy(Sensor):
+    def __init__(self, config):
+        self.address = (config['host'], int(config['port']))
+
+    def read(self, scale=Scale.MINUTE.value):
+        try:
+            proxy = Client(self.address)
+            proxy.send(scale)
+            data = proxy.recv()
+            proxy.close()
+            return data
+        except:
+            return {}
+
 class MyWirelessTag(Sensor):
     expirationTime = None