--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/service/piNode/export_to_influxdb.py	Mon Aug 01 02:26:38 2016 -0700
@@ -0,0 +1,71 @@
+import time, logging
+from influxdb import InfluxDBClient
+from rdflib import Namespace
+
+log = logging.getLogger()
+ROOM = Namespace('http://projects.bigasterisk.com/room/')
+
+class InfluxExporter(object):
+    def __init__(self, configGraph, influxHost='bang6'):
+        self.graph = configGraph
+        self.influx = InfluxDBClient(influxHost, 9060, 'root', 'root', 'main')
+        self.lastExport = 0
+        self.lastSent = {}  # (subj, measurementName, tags) : (time, value)
+
+        self.measurements = {} # (subj, predicate) : measurement
+        for s, m in self.graph.subject_objects(ROOM['influxMeasurement']):
+            self.measurements[(s, self.graph.value(m, ROOM['predicate']))] = m
+        
+    def exportToInflux(self, currentStatements):
+        graph = self.graph
+        now = int(time.time())
+      
+        log.debug('influxdb export:')
+
+        points = []
+        for stmt in currentStatements:
+            if (stmt[0], stmt[1]) in self.measurements:
+                meas = self.measurements[(stmt[0], stmt[1])]
+                measurementName = graph.value(meas, ROOM['measurement'])
+                tags = {}
+                for t in graph.objects(meas, ROOM['tag']):
+                    k = graph.value(t, ROOM['key']).toPython()
+                    tags[k] = graph.value(t, ROOM['value']).toPython()
+
+                value = self.influxValue(stmt[2])
+                    
+                if not self.shouldSendNewPoint(now, stmt[0], measurementName,
+                                               tags, value):
+                    continue
+                    
+                points.append({
+                    'measurement': measurementName,
+                    "tags": tags,
+                    "fields": {"value": value},
+                    "time": now
+                })
+                log.debug('send to influx %r', points[-1])
+        if points:
+            self.influx.write_points(points, time_precision='s')
+
+    def influxValue(self, rdfValue):
+        if rdfValue == ROOM['motion']:
+            value = 1
+        elif rdfValue == ROOM['noMotion']:
+            value = 0
+        else:
+            value = rdfValue.toPython()
+            if not isinstance(value, (int, float)):
+                raise NotImplementedError('value=%r' % value)
+        return value
+            
+    def shouldSendNewPoint(self, now, subj, measurementName, tags, value):
+        key = (subj, measurementName, tuple(sorted(tags.items())))
+        if key in self.lastSent:
+            lastTime, lastValue = self.lastSent[key]
+            if lastValue == value and lastTime > now - 3600:
+                log.debug('skip influx point %r', key)
+                return False
+
+        self.lastSent[key] = (now, value)
+        return True