Few bugs that snuck in.

aosstower/model.py

@@ -48,6 +48,7 @@ class WrapErrors(object):
                 except self.exceptions as err:
                     traceback = sys.exc_info()[2]
                     raise ModelError, str(err), traceback
+            wrapped.__doc__ = fcn.__doc__
             return wrapped
         for name in dir(cls):
             value = getattr(cls, name)
@@ -63,11 +64,15 @@ class RrdModel(object):
     purposes, such as web-widgets.
     """
 
+    # data interval in seconds
+    DATA_INTERVAL = 5
+
     def __init__(self, filepath):
         self._filepath = filepath
         self._averages = tuple()
         self._datasets = None
 
+    @property
     def datasets(self):
         """Get dataset names available in the database.
         """
@@ -94,15 +99,18 @@ class RrdModel(object):
             self._averages = tuple(sorted(averages))
         return self._averages
 
-    def initialize(self, start=None):
+    def initialize(self, start=None, days=365):
         """Create a new empty RRD database.
         """
         assert not os.path.exists(self._filepath), "DB already exists"
-        start = start or (datetime.utcnow() - timedelta(days=365))
+        start = start or (datetime.utcnow() - timedelta(days=days))
+        # normalize start to data interval
         secs = to_unix_timestamp(start)
+        secs -= secs % self.DATA_INTERVAL
+
         rrdtool.create(self._filepath,
                        '--start={}'.format(secs),
-                       '--step=5',
+                       '--step={:d}'.format(self.DATA_INTERVAL),
                        'DS:air_temp:GAUGE:10:-40:50',
                        'DS:rh:GAUGE:10:0:100',
                        'DS:dewpoint:GAUGE:10:0:100',
@@ -114,15 +122,15 @@ class RrdModel(object):
                        'DS:accum_precip:GAUGE:10:0:100',
                        'DS:solar_flux:GAUGE:10:0:1000',
                        'DS:altimeter:GAUGE:10:0:100',
-                       'RRA:LAST:0.5:1:6307200',
-                       'RRA:AVERAGE:0.5:12:525600',
-                       'RRA:AVERAGE:0.5:60:105120',
-                       'RRA:AVERAGE:0.5:360:17520')
+                       'RRA:AVERAGE:0.5:1:6307200',
+                       'RRA:AVERAGE:0.5:{:d}:525600'.format(60/self.DATA_INTERVAL),
+                       'RRA:AVERAGE:0.5:{:d}:105120'.format(300/self.DATA_INTERVAL),
+                       'RRA:AVERAGE:0.5:{:d}:17520'.format(1800/self.DATA_INTERVAL))
 
     def _format_data(self, stamp, data):
         """Format data for insert into RRD.
         """
-        values = ':'.join([str(data[k]) for k in self.datasets()])
+        values = ':'.join([str(data[k]) for k in self.datasets])
         values = '{:d}@{}'.format(to_unix_timestamp(stamp), values)
         return values
 
@@ -130,7 +138,7 @@ class RrdModel(object):
         """Turn a tower record into database data.
         """
 
-        expected_keys = set(self.datasets()) - {'winddir_north', 'winddir_east'}
+        expected_keys = set(self.datasets) - {'winddir_north', 'winddir_east'}
         missing_keys = expected_keys - set(record.keys())
         if missing_keys:
             raise ModelError("Missing datasets %s" % missing_keys)
@@ -141,7 +149,7 @@ class RrdModel(object):
         data['winddir_east'] = winds[0]
         data['winddir_north'] = winds[1]
         data['wind_speed'] = winds[2]
-        for name in self.datasets():
+        for name in self.datasets:
             if name in record:
                 data[name] = record[name]
         return data
@@ -149,10 +157,12 @@ class RrdModel(object):
     def add_record(self, record):
         """Add a single record to the database.
         """
-        stamp = record.get_stamp()
+        # Normalize to data interval
+        utime = to_unix_timestamp(record.get_stamp())
+        stamp = datetime.utcfromtimestamp(utime - utime % self.DATA_INTERVAL)
         data = self._record_to_data(record)
         rrdtool.update(self._filepath,
-                       '--template=%s' % ':'.join(self.datasets()),
+                       '--template=%s' % ':'.join(self.datasets),
                        self._format_data(stamp, data))
 
     def get_slice(self, start, end, names=None, average=5):