Be more consistent when removing outdated samples

When removing outdated samples, samples falling just right at the
resapmling time are used in 2 different periods.

Even if this is not technically wrong, it is unexpected, as it would be
more natural that a moving window doesn't intersect with previous moving
windows (if using one period, or after moving the window
max_data_age_in_periods_s).

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/sdk/timeseries/_resampler.py

@@ -94,7 +94,7 @@ def _remove_outdated_samples(self, threshold: datetime) -> None:
         """
         while self._buffer:
             sample: Sample = self._buffer[0]
-            if sample.timestamp >= threshold:
+            if sample.timestamp > threshold:
                 return
 
             self._buffer.popleft()

tests/timeseries/test_resampling.py

@@ -51,7 +51,6 @@ def test_component_metric_resampler_remove_outdated_samples() -> None:
 
     resampler._remove_outdated_samples(threshold=timestamp)
     assert list(resampler._buffer) == [
-        sample1,
         sample2,
     ]  # pylint: disable=protected-access
 
@@ -144,7 +143,7 @@ def test_component_metric_group_resampler() -> None:
     value22 = 999.0
 
     sample11 = Sample(now - timedelta(seconds=0.7), value=value11)
-    sample12 = Sample(now - timedelta(seconds=0.5), value=value12)
+    sample12 = Sample(now - timedelta(seconds=0.49), value=value12)
     sample21 = Sample(now - timedelta(seconds=5.05), value=value21)
     sample22 = Sample(now - timedelta(seconds=0.99), value=value22)