src/chrome/test/base/uma_histogram_helper.cc

   1 // Copyright (c) 2012 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 "chrome/test/base/uma_histogram_helper.h"
   6
   7 #include "base/bind.h"
   8 #include "base/metrics/statistics_recorder.h"
   9 #include "base/test/test_timeouts.h"
  10 #include "chrome/test/base/ui_test_utils.h"
  11 #include "content/public/browser/histogram_fetcher.h"
  12
  13 UMAHistogramHelper::UMAHistogramHelper() {
  14 }
  15
  16 void UMAHistogramHelper::Fetch() {
  17   base::Closure callback = base::Bind(&UMAHistogramHelper::FetchCallback,
  18                                       base::Unretained(this));
  19
  20   content::FetchHistogramsAsynchronously(
  21       base::MessageLoop::current(),
  22       callback,
  23       // If this call times out, it means that a child process is not
  24       // responding, which is something we should not ignore.  The timeout is
  25       // set to be longer than the normal browser test timeout so that it will
  26       // be prempted by the normal timeout.
  27       TestTimeouts::action_max_timeout() * 2);
  28   content::RunMessageLoop();
  29 }
  30
  31 void UMAHistogramHelper::ExpectUniqueSample(
  32     const std::string& name,
  33     base::HistogramBase::Sample sample,
  34     base::HistogramBase::Count expected_count) {
  35   base::HistogramBase* histogram =
  36       base::StatisticsRecorder::FindHistogram(name);
  37   EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
  38       << "Histogram \"" << name << "\" does not exist.";
  39
  40   if (histogram) {
  41     scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples());
  42     CheckBucketCount(name, sample, expected_count, *samples);
  43     CheckTotalCount(name, expected_count, *samples);
  44   }
  45 }
  46
  47 void UMAHistogramHelper::ExpectTotalCount(
  48     const std::string& name,
  49     base::HistogramBase::Count count) {
  50   base::HistogramBase* histogram =
  51       base::StatisticsRecorder::FindHistogram(name);
  52   EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
  53       << "Histogram \"" << name << "\" does not exist.";
  54
  55   if (histogram) {
  56     scoped_ptr<base::HistogramSamples> samples(histogram->SnapshotSamples());
  57     CheckTotalCount(name, count, *samples);
  58   }
  59 }
  60
  61 void UMAHistogramHelper::FetchCallback() {
  62   base::MessageLoopForUI::current()->Quit();
  63 }
  64
  65 void UMAHistogramHelper::CheckBucketCount(
  66     const std::string& name,
  67     base::HistogramBase::Sample sample,
  68     base::HistogramBase::Count expected_count,
  69     base::HistogramSamples& samples) {
  70   EXPECT_EQ(expected_count, samples.GetCount(sample))
  71       << "Histogram \"" << name
  72       << "\" does not have the right number of samples (" << expected_count
  73       << ") in the expected bucket (" << sample << ").";
  74 }
  75
  76 void UMAHistogramHelper::CheckTotalCount(
  77     const std::string& name,
  78     base::HistogramBase::Count expected_count,
  79     base::HistogramSamples& samples) {
  80   EXPECT_EQ(expected_count, samples.TotalCount())
  81       << "Histogram \"" << name
  82       << "\" does not have the right total number of samples ("
  83       << expected_count << ").";
  84 }