Report histogram creation results.

base/metrics/histogram_base_unittest.cc

Index: base/metrics/histogram_base_unittest.cc
diff --git a/base/metrics/histogram_base_unittest.cc b/base/metrics/histogram_base_unittest.cc
index 2d6b6df0288850cab31362762957070201ca72e3..1e3e4a7bb917875aa439d22ef4d0d480fe468fec 100644
--- a/base/metrics/histogram_base_unittest.cc
+++ b/base/metrics/histogram_base_unittest.cc
@@ -18,19 +18,26 @@ class HistogramBaseTest : public testing::Test {
   HistogramBaseTest() {
     // Each test will have a clean state (no Histogram / BucketRanges
     // registered).
-    statistics_recorder_ = NULL;
     ResetStatisticsRecorder();
   }
 
-  ~HistogramBaseTest() override { delete statistics_recorder_; }
+  ~HistogramBaseTest() override {
+    HistogramBase::report_histogram_ = nullptr;
+    delete statistics_recorder_;
+  }
 
   void ResetStatisticsRecorder() {
     delete statistics_recorder_;
     statistics_recorder_ = new StatisticsRecorder();

[Alexei Svitkine (slow), 2016/03/01 16:41:34]

Nit: While you're changing this, can you make this a scoped_ptr?

[bcwhite, 2016/03/02 19:14:19]

StatisticsRecorder is explicit about what classes are allowed to
construct/destruct the objects.  scoped_ptr needs permission to destruct the
objects it holds.  I can leave it as-is or make the SR dtor public.  Preference?

[Alexei Svitkine (slow), 2016/03/03 17:56:23]

I think making the dtor public should be fine, since the ctor is still private.
So doing that + making this a scoped ptr would be best, I think.

[bcwhite, 2016/03/07 13:39:25]

Done.

   }
 
+  HistogramBase* GetCreationReportHistogram(StringPiece name) {
+    HistogramBase::EnableCreationReportHistogram(name);
+    return HistogramBase::report_histogram_;
+  }
+
  private:
-  StatisticsRecorder* statistics_recorder_;
+  StatisticsRecorder* statistics_recorder_ = nullptr;
 };

[Alexei Svitkine (slow), 2016/03/01 16:41:34]

Nit: Add DISALLOW_COPY_AND_ASSIGN().

[bcwhite, 2016/03/02 19:14:19]

Done.

 
 TEST_F(HistogramBaseTest, DeserializeHistogram) {
@@ -152,4 +159,61 @@ TEST_F(HistogramBaseTest, DeserializeSparseHistogram) {
   EXPECT_EQ(0, deserialized->flags());
 }
 
+TEST_F(HistogramBaseTest, CreationReportHistogram) {
+  // Enabled creation report. Itself is not included in the report.
+  HistogramBase* report = GetCreationReportHistogram("CreationReportTest");
+  ASSERT_TRUE(report);
+
+  std::vector<HistogramBase::Sample> ranges;
+  ranges.push_back(1);
+  ranges.push_back(2);
+  ranges.push_back(4);
+  ranges.push_back(8);
+  ranges.push_back(10);
+
+  // Create all histogram types and verify counts.
+  Histogram::FactoryGet("CRH-Histogram", 1, 10, 5, 0);
+  LinearHistogram::FactoryGet("CRH-Linear", 1, 10, 5, 0);
+  BooleanHistogram::FactoryGet("CRH-Boolean", 0);
+  CustomHistogram::FactoryGet("CRH-Custom", ranges, 0);
+  SparseHistogram::FactoryGet("CRH-Sparse", 0);
+
+  scoped_ptr<HistogramSamples> samples = report->SnapshotSamples();
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_CREATED));
+  EXPECT_EQ(5, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_CREATED));
+  EXPECT_EQ(0, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_LOOKUP));
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_TYPE_GENERAL));
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_TYPE_LINEAR));
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_TYPE_BOOLEAN));
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_TYPE_CUSTOM));
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_TYPE_SPARSE));
+
+  // Create all flag types and verify counts.
+  Histogram::FactoryGet("CRH-Histogram-UMA-Targeted", 1, 10, 5,
+                        HistogramBase::kUmaTargetedHistogramFlag);
+  Histogram::FactoryGet("CRH-Histogram-UMA-Stability", 1, 10, 5,
+                        HistogramBase::kUmaStabilityHistogramFlag);
+  SparseHistogram::FactoryGet("CRH-Sparse-UMA-Targeted",
+                              HistogramBase::kUmaTargetedHistogramFlag);
+  SparseHistogram::FactoryGet("CRH-Sparse-UMA-Stability",
+                              HistogramBase::kUmaStabilityHistogramFlag);
+  samples = report->SnapshotSamples();
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_CREATED));
+  EXPECT_EQ(9, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_CREATED));
+  EXPECT_EQ(0, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_LOOKUP));
+  EXPECT_EQ(2, samples->GetCount(HISTOGRAM_REPORT_FLAG_UMA_TARGETED));
+  EXPECT_EQ(2, samples->GetCount(HISTOGRAM_REPORT_FLAG_UMA_STABILITY));
+
+  // Do lookup of existing histograms and verify counts.
+  Histogram::FactoryGet("CRH-Histogram", 1, 10, 5, 0);
+  LinearHistogram::FactoryGet("CRH-Linear", 1, 10, 5, 0);
+  BooleanHistogram::FactoryGet("CRH-Boolean", 0);
+  CustomHistogram::FactoryGet("CRH-Custom", ranges, 0);
+  SparseHistogram::FactoryGet("CRH-Sparse", 0);
+  samples = report->SnapshotSamples();
+  EXPECT_EQ(1, samples->GetCount(HISTOGRAM_REPORT_CREATED));
+  EXPECT_EQ(9, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_CREATED));
+  EXPECT_EQ(5, samples->GetCount(HISTOGRAM_REPORT_HISTOGRAM_LOOKUP));
+}
+
 }  // namespace base