Make sure measurements are oreder total-last

rebench/model/data_point.py

@@ -53,7 +53,22 @@ def add_measurement(self, measurement):
                                  "'total' measurement.")
             self._total = measurement
 
+    def _get_measurements_reordered(self):
+        # re-order so that total is last.
+        out = [m for m in self._measurements if not m.is_total()]
+        def _find_total(measurements):
+            for measurement in measurements:
+                if measurement.is_total():
+                    return measurement # Highlander
+            return None
+        total = _find_total(self._measurements)
+        if total is not None:
+            out.append(total)
+        return out
+
     def get_measurements(self):
+        if self._measurements and not self._measurements[-1].is_total():
+            return self._get_measurements_reordered()
         return self._measurements
 
     def get_total_value(self):

rebench/tests/features/issue_31_multivariate_data_points_test.py

@@ -65,8 +65,8 @@ def test_associates_measurements_and_data_points_correctly(self):
         for point, i in zip(data_points, list(range(0, 10))):
             self.assertEqual(4, point.number_of_measurements())
 
-            for criterion, unit, measurement in zip(["bar", "total", "baz", "foo"],
-                                                    ["ms", "ms", "kbyte", "kerf"],
+            for criterion, unit, measurement in zip(["bar", "baz", "foo", "total"],
+                                                    ["ms", "kbyte", "kerf", "ms"],
                                                     point.get_measurements()):
                 self.assertEqual(criterion, measurement.criterion)
                 self.assertEqual(i, int(measurement.value))
@@ -81,3 +81,11 @@ def test_is_compatible_to_issue16_format(self):
                                               point.get_measurements()):
                 self.assertEqual(criterion, measurement.criterion)
                 self.assertEqual(i, int(measurement.value))
+
+    def test_measurement_ordering(self):
+        # certain parts of persistency require measurements to be ordered total-last.
+        # see _DataPointPersistence._process_lines
+        data_points = self._records_data_points('Test1', 10)
+        for point in data_points:
+            measurements = point.get_measurements()
+            self.assertTrue(measurements[-1].is_total())