cc/base/rolling_time_delta_history_unittest.cc

   1 // Copyright 2014 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 #include "cc/base/rolling_time_delta_history.h"
   6 #include "testing/gtest/include/gtest/gtest.h"
   7
   8 namespace cc {
   9 namespace {
  10
  11 TEST(RollingTimeDeltaHistoryTest, EmptyHistory) {
  12   RollingTimeDeltaHistory empty_history(0);
  13
  14   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(0.0));
  15   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(50.0));
  16   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(100.0));
  17
  18   empty_history.InsertSample(base::TimeDelta::FromMilliseconds(10));
  19   empty_history.InsertSample(base::TimeDelta::FromMilliseconds(15));
  20   empty_history.InsertSample(base::TimeDelta::FromMilliseconds(20));
  21
  22   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(0.0));
  23   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(50.0));
  24   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(100.0));
  25
  26   empty_history.Clear();
  27   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(0.0));
  28   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(50.0));
  29   EXPECT_EQ(base::TimeDelta(), empty_history.Percentile(100.0));
  30 }
  31
  32 TEST(RollingTimeDeltaHistoryTest, SizeOneHistory) {
  33   RollingTimeDeltaHistory size_one_history(1);
  34   base::TimeDelta sample1 = base::TimeDelta::FromMilliseconds(10);
  35   base::TimeDelta sample2 = base::TimeDelta::FromMilliseconds(20);
  36
  37   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(0.0));
  38   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(50.0));
  39   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(100.0));
  40
  41   size_one_history.InsertSample(sample1);
  42   EXPECT_EQ(sample1, size_one_history.Percentile(0.0));
  43   EXPECT_EQ(sample1, size_one_history.Percentile(50.0));
  44   EXPECT_EQ(sample1, size_one_history.Percentile(100.0));
  45
  46   size_one_history.InsertSample(sample2);
  47   EXPECT_EQ(sample2, size_one_history.Percentile(0.0));
  48   EXPECT_EQ(sample2, size_one_history.Percentile(50.0));
  49   EXPECT_EQ(sample2, size_one_history.Percentile(100.0));
  50
  51   size_one_history.Clear();
  52   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(0.0));
  53   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(50.0));
  54   EXPECT_EQ(base::TimeDelta(), size_one_history.Percentile(100.0));
  55 }
  56
  57 TEST(RollingTimeDeltaHistoryTest, LargeHistory) {
  58   RollingTimeDeltaHistory large_history(100);
  59   base::TimeDelta sample1 = base::TimeDelta::FromMilliseconds(150);
  60   base::TimeDelta sample2 = base::TimeDelta::FromMilliseconds(250);
  61   base::TimeDelta sample3 = base::TimeDelta::FromMilliseconds(200);
  62
  63   large_history.InsertSample(sample1);
  64   large_history.InsertSample(sample2);
  65
  66   EXPECT_EQ(sample1, large_history.Percentile(0.0));
  67   EXPECT_EQ(sample1, large_history.Percentile(25.0));
  68   EXPECT_EQ(sample2, large_history.Percentile(75.0));
  69   EXPECT_EQ(sample2, large_history.Percentile(100.0));
  70
  71   large_history.InsertSample(sample3);
  72   EXPECT_EQ(sample1, large_history.Percentile(0.0));
  73   EXPECT_EQ(sample1, large_history.Percentile(25.0));
  74   EXPECT_EQ(sample3, large_history.Percentile(50.0));
  75   EXPECT_EQ(sample2, large_history.Percentile(100.0));
  76
  77   // Fill the history.
  78   for (int i = 1; i <= 97; i++)
  79     large_history.InsertSample(base::TimeDelta::FromMilliseconds(i));
  80
  81   EXPECT_EQ(base::TimeDelta::FromMilliseconds(1),
  82             large_history.Percentile(0.0));
  83   for (int i = 1; i <= 97; i++) {
  84     EXPECT_EQ(base::TimeDelta::FromMilliseconds(i),
  85               large_history.Percentile(i - 0.5));
  86   }
  87   EXPECT_EQ(sample1, large_history.Percentile(97.5));
  88   EXPECT_EQ(sample3, large_history.Percentile(98.5));
  89   EXPECT_EQ(sample2, large_history.Percentile(99.5));
  90
  91   // Continue inserting samples, causing the oldest samples to be discarded.
  92   base::TimeDelta sample4 = base::TimeDelta::FromMilliseconds(100);
  93   base::TimeDelta sample5 = base::TimeDelta::FromMilliseconds(102);
  94   base::TimeDelta sample6 = base::TimeDelta::FromMilliseconds(104);
  95   large_history.InsertSample(sample4);
  96   large_history.InsertSample(sample5);
  97   large_history.InsertSample(sample6);
  98   EXPECT_EQ(sample4, large_history.Percentile(97.5));
  99   EXPECT_EQ(sample5, large_history.Percentile(98.5));
 100   EXPECT_EQ(sample6, large_history.Percentile(99.5));
 101
 102   large_history.Clear();
 103   EXPECT_EQ(base::TimeDelta(), large_history.Percentile(0.0));
 104   EXPECT_EQ(base::TimeDelta(), large_history.Percentile(50.0));
 105   EXPECT_EQ(base::TimeDelta(), large_history.Percentile(100.0));
 106 }
 107
 108 }  // namespace
 109 }  // namespace cc