Speeded up graphs.

graphs/models.py

@@ -1,8 +1,10 @@
-from django.db.models.functions import TruncMinute, TruncHour, TruncDay, TruncWeek, TruncMonth, TruncYear
-from django.db.models import Min, Max, Avg, Count
+from datetime import timedelta
 from django.db import models
+from django.db.models import Count, F, Value
+from django.db.models import F, Func, Value
+from django.db.models import Min, Max, Avg, Count
+from django.db.models.functions import TruncMinute, TruncHour, TruncDay, TruncWeek, TruncMonth, TruncYear
 from django.utils import timezone
-from datetime import timedelta
 
 
 class SensorType(models.Model):
@@ -39,7 +41,7 @@ class Sensor(models.Model):
     def __str__(self):
         return "%s (%s)" % (self.name, self.serial)
 
-    def get_data(self, aggregation_time, min_max_enabled):
+    def get_data(self, datetime_begin, datetime_end, aggregation_time, min_max_enabled):
         data = {}
         data["name"] = self.name
         data["unit"] = self.sensor_type.unit
@@ -60,10 +62,11 @@ def get_data(self, aggregation_time, min_max_enabled):
             trunc = TruncMinute
 
         measurements = (
-            self.measurement_set.annotate(date=trunc("posted_date"))
+            self.measurement_set.filter(posted_date__range=(datetime_begin, datetime_end))
+            .annotate(date=trunc("posted_date"))
             .values("date")
             .annotate(min=Min("value"), max=Max("value"), avg=Avg("value"), count=Count("id"))
-            .order_by()
+            .order_by("date")
         )
         data["mean_data"] = [[m["date"].timestamp() * 1000, m["avg"]] for m in measurements]
         if min_max_enabled:

graphs/views.py

@@ -8,6 +8,23 @@
 from monitor.settings import FALLBACK_API_KEY
 
 
+@require_http_methods(["GET"])
+def get_datetime_range(request):
+    now = timezone.now()
+    last_hours = request.GET.get("last_hours", "")
+    datetime_begin = request.GET.get("datetime_begin", "")
+    datetime_end = request.GET.get("datetime_end", "")
+
+    if not last_hours and not datetime_begin:
+        last_hours = 24
+    if last_hours:
+        datetime_begin = now - timedelta(hours=int(last_hours))
+        datetime_end = now
+    if not datetime_end:
+        datetime_end = now
+    return (datetime_begin, datetime_end)
+
+
 @require_http_methods(["GET"])
 def temperature_measurement_add(request):
     data = {"status": 0}
@@ -42,19 +59,7 @@ def temperature_measurement_add(request):
 @login_required()
 @permission_required("graphs.view_sensor", raise_exception=True)
 def prefetch_sensors_measurement(request, sensors):
-    now = timezone.now()
-    last_hours = request.GET.get("last_hours", "")
-    datetime_begin = request.GET.get("datetime_begin", "")
-    datetime_end = request.GET.get("datetime_end", "")
-
-    if not last_hours and not datetime_begin:
-        last_hours = 24
-    if last_hours:
-        datetime_begin = now - timedelta(hours=int(last_hours))
-        datetime_end = now
-    if not datetime_end:
-        datetime_end = now
-
+    (datetime_begin, datetime_end) = get_datetime_range(request)
     measurements = Measurement.objects.filter(posted_date__range=(datetime_begin, datetime_end)).order_by("posted_date")
     return sensors.prefetch_related(Prefetch("measurement_set", queryset=measurements))
 
@@ -78,7 +83,7 @@ def get_sensors(request):
             except:
                 sensors = Sensor.objects.none()
                 name = ""
-    return (prefetch_sensors_measurement(request, sensors), name)
+    return (sensors, name)
 
 
 @require_http_methods(["GET"])
@@ -90,7 +95,8 @@ def graphs(request):
         aggregation_time = request.GET.get("aggregation_time", "minute")
         min_max_enabled = "min_max" in request.GET
         (sensors, data["name"]) = get_sensors(request)
-        data["sensors"] = [s.get_data(aggregation_time, min_max_enabled) for s in sensors]
+        (datetime_begin, datetime_end) = get_datetime_range(request)
+        data["sensors"] = [s.get_data(datetime_begin, datetime_end, aggregation_time, min_max_enabled) for s in sensors]
         return JsonResponse(data, safe=False)
     else:
         (_, name) = get_sensors(request)