Add a default implementation in metrics_default.cc of histograms methods in system_wrappers/interfac

webrtc/system_wrappers/source/metrics_default_unittest.cc

+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include "webrtc/system_wrappers/include/metrics.h"
+#include "webrtc/system_wrappers/include/metrics_default.h"
+
+namespace webrtc {
+
+namespace {
+const int kSample = 22;
+const char kName[] = "Name";
+
+int NumSamples(
+    const std::string& name,
+    const std::map<std::string, std::unique_ptr<metrics::SampleInfo>>&
+        histograms) {
+  const auto it = histograms.find(name);
+  if (it == histograms.end())
+    return 0;
+
+  int num_samples = 0;
+  for (const auto& sample : it->second->samples)
+    num_samples += sample.second;
+
+  return num_samples;
+}
+
+int NumEvents(const std::string& name,
+              int sample,
+              const std::map<std::string, std::unique_ptr<metrics::SampleInfo>>&
+                  histograms) {
+  const auto it = histograms.find(name);
+  if (it == histograms.end())
+    return 0;
+
+  const auto it_sample = it->second->samples.find(sample);
+  if (it_sample == it->second->samples.end())
+    return 0;
+
+  return it_sample->second;
+}
+}  // namespace
+
+class MetricsDefaultTest : public ::testing::Test {
+ public:
+  MetricsDefaultTest() {}
+
+ protected:
+  virtual void SetUp() {
+    metrics::Reset();
+  }
+};
+
+TEST_F(MetricsDefaultTest, Reset) {
+  RTC_HISTOGRAM_PERCENTAGE(kName, kSample);
+  EXPECT_EQ(1, metrics::NumSamples(kName));
+  metrics::Reset();
+  EXPECT_EQ(0, metrics::NumSamples(kName));
+}
+
+TEST_F(MetricsDefaultTest, NumSamples) {
+  RTC_HISTOGRAM_PERCENTAGE(kName, 5);
+  RTC_HISTOGRAM_PERCENTAGE(kName, 5);
+  RTC_HISTOGRAM_PERCENTAGE(kName, 10);
+  EXPECT_EQ(3, metrics::NumSamples(kName));
+  EXPECT_EQ(0, metrics::NumSamples("NonExisting"));
+}
+
+TEST_F(MetricsDefaultTest, NumEvents) {
+  RTC_HISTOGRAM_PERCENTAGE(kName, 5);
+  RTC_HISTOGRAM_PERCENTAGE(kName, 5);
+  RTC_HISTOGRAM_PERCENTAGE(kName, 10);
+  EXPECT_EQ(2, metrics::NumEvents(kName, 5));
+  EXPECT_EQ(1, metrics::NumEvents(kName, 10));
+  EXPECT_EQ(0, metrics::NumEvents(kName, 11));
+  EXPECT_EQ(0, metrics::NumEvents("NonExisting", 5));
+}
+
+TEST_F(MetricsDefaultTest, MinSample) {
+  RTC_HISTOGRAM_PERCENTAGE(kName, kSample);
+  RTC_HISTOGRAM_PERCENTAGE(kName, kSample + 1);
+  EXPECT_EQ(kSample, metrics::MinSample(kName));
+  EXPECT_EQ(-1, metrics::MinSample("NonExisting"));
+}
+
+TEST_F(MetricsDefaultTest, Overflow) {
+  const std::string kName = "Overflow";
+  // Samples should end up in overflow bucket.
+  RTC_HISTOGRAM_PERCENTAGE(kName, 101);
+  EXPECT_EQ(1, metrics::NumSamples(kName));
+  EXPECT_EQ(1, metrics::NumEvents(kName, 101));
+  RTC_HISTOGRAM_PERCENTAGE(kName, 102);
+  EXPECT_EQ(2, metrics::NumSamples(kName));
+  EXPECT_EQ(2, metrics::NumEvents(kName, 101));
+}
+
+TEST_F(MetricsDefaultTest, Underflow) {
+  const std::string kName = "Underflow";
+  // Samples should end up in underflow bucket.
+  RTC_HISTOGRAM_COUNTS_10000(kName, 0);
+  EXPECT_EQ(1, metrics::NumSamples(kName));
+  EXPECT_EQ(1, metrics::NumEvents(kName, 0));
+  RTC_HISTOGRAM_COUNTS_10000(kName, -1);
+  EXPECT_EQ(2, metrics::NumSamples(kName));
+  EXPECT_EQ(2, metrics::NumEvents(kName, 0));
+}
+
+TEST_F(MetricsDefaultTest, GetAndReset) {
+  std::map<std::string, std::unique_ptr<metrics::SampleInfo>> histograms;
+  metrics::GetAndReset(&histograms);
+  EXPECT_EQ(0u, histograms.size());
+  RTC_HISTOGRAM_PERCENTAGE("Histogram1", 4);
+  RTC_HISTOGRAM_PERCENTAGE("Histogram1", 5);
+  RTC_HISTOGRAM_PERCENTAGE("Histogram1", 5);
+  RTC_HISTOGRAM_PERCENTAGE("Histogram2", 10);
+  EXPECT_EQ(3, metrics::NumSamples("Histogram1"));
+  EXPECT_EQ(1, metrics::NumSamples("Histogram2"));
+
+  metrics::GetAndReset(&histograms);
+  EXPECT_EQ(2u, histograms.size());
+  EXPECT_EQ(0, metrics::NumSamples("Histogram1"));
+  EXPECT_EQ(0, metrics::NumSamples("Histogram2"));
+
+  EXPECT_EQ(3, NumSamples("Histogram1", histograms));
+  EXPECT_EQ(1, NumSamples("Histogram2", histograms));
+  EXPECT_EQ(1, NumEvents("Histogram1", 4, histograms));
+  EXPECT_EQ(2, NumEvents("Histogram1", 5, histograms));
+  EXPECT_EQ(1, NumEvents("Histogram2", 10, histograms));
+}
+
+TEST_F(MetricsDefaultTest, TestMinMaxBucket) {
+  const std::string kName = "MinMaxCounts100";
+  RTC_HISTOGRAM_COUNTS_100(kName, 4);
+
+  std::map<std::string, std::unique_ptr<metrics::SampleInfo>> histograms;
+  metrics::GetAndReset(&histograms);
+  EXPECT_EQ(1u, histograms.size());
+  EXPECT_EQ(kName, histograms.begin()->second->name);
+  EXPECT_EQ(1, histograms.begin()->second->min);
+  EXPECT_EQ(100, histograms.begin()->second->max);
+  EXPECT_EQ(50u, histograms.begin()->second->bucket_count);
+  EXPECT_EQ(1u, histograms.begin()->second->samples.size());
+}
+
+}  // namespace webrtc