1 files changed, 50 insertions, 3 deletions
diff --git a/rrd/models.py b/rrd/models.py
index 6adc17f..8d995c8 100644
--- a/rrd/models.py
+++ b/rrd/models.py
@@ -1,7 +1,13 @@
+import logging
+import os
+
 import django.contrib.auth.models as amodels
+import rrdtool
 from django.conf import settings
 from django.db import models
 
+log = logging.getLogger(__name__)
+
 
 class ModelWithPerms(models.Model):
     users_read = models.ManyToManyField(
@@ -30,29 +36,70 @@ class DataSource(ModelWithPerms):
     # which is probably too much for a sensible db
     topic = models.CharField(max_length=512)
     path = models.FilePathField(
-        path=settings.RRD_DB_PATH,
+        path=settings.RRD_DB_PATH.as_posix(),
         recursive=True,
         max_length=512,
     )
-    rrd_config = models.TextField()
+    rrd_config = models.TextField(
+        default=settings.RRD_DS_CONFIG
+    )
     active = models.BooleanField(
         default=True,
     )
 
+    def __str__(self):
+        return self.topic
+
+    @property
+    def lastupdate(self):
+        try:
+            last = rrdtool.lastupdate(os.path.join(
+                settings.RRD_DB_PATH, self.path
+            ))
+        except rrdtool.OperationalError as e:
+            log.warning("Failure reading from ds: %s", e)
+            return (None, None)
+        else:
+            return last["date"], last["ds"][self.topic.split("/")[-1]]
+
+    def update(self, ts, value):
+        rrd_path = os.path.join(settings.RRD_DB_PATH, self.path)
+        if not os.path.isfile(rrd_path):
+            rrdtool.create(
+                os.path.join(settings.RRD_DB_PATH, self.path),
+                "--no-overwrite",
+                self.rrd_config.format(
+                    ds_name=self.topic.split("/")[-1]
+                ).strip().split('\n'),
+            )
+        try:
+            rrdtool.update(
+                os.path.join(settings.RRD_DB_PATH, self.path),
+                str(ts) + ":" + str(value)
+            )
+        except ValueError as e:
+            log.warning("Could not update ds: %s", e)
+
 
 class Graph(ModelWithPerms):
     title = models.CharField(max_length=64)
     data_sources = models.ManyToManyField(DataSource)
     path = models.FilePathField(
-        path=settings.RRD_GRAPH_PATH,
+        path=settings.RRD_GRAPH_PATH.as_posix(),
         recursive=True,
         max_length=512,
     )
     rrd_config = models.TextField()
 
+    def __str__(self):
+        return self.title
+
 
 class Dashboard(ModelWithPerms):
     title = models.CharField(max_length=64)
     graphs = models.ManyToManyField(Graph)
     data_sources = models.ManyToManyField(DataSource)
     template = models.TextField()
+
+    def __str__(self):
+        return self.title