1 # Copyright 2013 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import unittest 6 7 from metrics import cpu 8 9 # Testing private method. 10 # pylint: disable=W0212 11 class CpuMetricTest(unittest.TestCase): 12 def testSubtractCpuStats(self): 13 # The result computed is a ratio of cpu time used to time elapsed. 14 start = {'Browser': {'CpuProcessTime': 0, 'TotalTime': 0}} 15 end = {'Browser': {'CpuProcessTime': 5, 'TotalTime': 20}} 16 self.assertEqual({'Browser': 0.25}, cpu._SubtractCpuStats(end, start)) 17 18 # An error is thrown if the args are called in the wrong order. 19 self.assertRaises(AssertionError, cpu._SubtractCpuStats, start, end) 20 21 # An error is thrown if there's a process type in end that's not in start. 22 end['Renderer'] = {'CpuProcessTime': 2, 'TotalTime': 20} 23 self.assertRaises(AssertionError, cpu._SubtractCpuStats, end, start) 24 25 # A process type will be ignored if there's an empty dict for start or end. 26 start['Renderer'] = {} 27 self.assertEqual({'Browser': 0.25}, cpu._SubtractCpuStats(end, start)) 28 29 # Results for multiple process types can be computed. 30 start['Renderer'] = {'CpuProcessTime': 0, 'TotalTime': 0} 31 self.assertEqual({'Browser': 0.25, 'Renderer': 0.1}, 32 cpu._SubtractCpuStats(end, start)) 33 34 # Test 32-bit overflow. 35 start = {'Browser': {'CpuProcessTime': 0, 'TotalTime': 2**32 - 20}} 36 end = {'Browser': {'CpuProcessTime': 5, 'TotalTime': 20}} 37 self.assertEqual({'Browser': 0.125}, cpu._SubtractCpuStats(end, start)) 38 self.assertRaises(AssertionError, cpu._SubtractCpuStats, start, end) 39 40
