cc/base/histograms_unittest.cc

   1 // Copyright 2015 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/histograms.h"
   6
   7 #include <limits>
   8
   9 #include "testing/gtest/include/gtest/gtest.h"
  10
  11 using base::TimeDelta;
  12 using Sample = base::HistogramBase::Sample;
  13
  14 namespace cc {
  15
  16 class ScopedUMAHistogramAreaTimerBaseTest : public ::testing::Test {
  17  protected:
  18   void ExpectValidHistogramValues(base::TimeDelta elapsed,
  19                                   int area,
  20                                   Sample expected_time_microseconds,
  21                                   Sample expected_pixels_per_ms) {
  22     Sample time_microseconds;
  23     Sample pixels_per_ms;
  24     ScopedUMAHistogramAreaTimerBase::GetHistogramValues(
  25         elapsed, area, &time_microseconds, &pixels_per_ms);
  26     EXPECT_EQ(expected_time_microseconds, time_microseconds);
  27     EXPECT_EQ(expected_pixels_per_ms, pixels_per_ms);
  28   }
  29 };
  30
  31 namespace {
  32
  33 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, CommonCase) {
  34   ExpectValidHistogramValues(TimeDelta::FromMicroseconds(500), 1000, 500, 2000);
  35   ExpectValidHistogramValues(TimeDelta::FromMicroseconds(300), 1000, 300, 3333);
  36 }
  37
  38 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, ZeroArea) {
  39   ExpectValidHistogramValues(TimeDelta::FromMicroseconds(500), 0, 500, 0);
  40 }
  41
  42 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, ZeroTime) {
  43   // 1M pixels/ms, since the time is limited to at least 1us.
  44   ExpectValidHistogramValues(TimeDelta(), 1000, 1, 1000000);
  45 }
  46
  47 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, ZeroTimeAndArea) {
  48   ExpectValidHistogramValues(TimeDelta(), 0, 1, 0);
  49 }
  50
  51 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, VeryLargeTime) {
  52   ExpectValidHistogramValues(TimeDelta::FromHours(24), 1000,
  53                              std::numeric_limits<Sample>::max(), 0);
  54 }
  55
  56 TEST_F(ScopedUMAHistogramAreaTimerBaseTest, VeryLargeArea) {
  57   ExpectValidHistogramValues(TimeDelta::FromMicroseconds(500), 1000000000, 500,
  58                              2000000000);
  59   ExpectValidHistogramValues(TimeDelta::FromMicroseconds(1000),
  60                              std::numeric_limits<int>::max(), 1000,
  61                              std::numeric_limits<Sample>::max());
  62 }
  63
  64 }  // namespace
  65 }  // namespace cc