Add a default implementation in metrics_default.cc of histograms methods in system_wrappers/interface/metrics.h.
Updated tests to use the default implementation and removed the test implementation (webrtc/test/histograms.h).
BUG=
Review-Url: https://codereview.webrtc.org/1915523002
Cr-Commit-Position: refs/heads/master@{#12829}
diff --git a/webrtc/system_wrappers/source/metrics_default.cc b/webrtc/system_wrappers/source/metrics_default.cc
index 48c9111..34d33a2 100644
--- a/webrtc/system_wrappers/source/metrics_default.cc
+++ b/webrtc/system_wrappers/source/metrics_default.cc
@@ -7,6 +7,10 @@
// be found in the AUTHORS file in the root of the source tree.
//
+#include "webrtc/system_wrappers/include/metrics_default.h"
+
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/thread_annotations.h"
#include "webrtc/system_wrappers/include/metrics.h"
// Default implementation of histogram methods for WebRTC clients that do not
@@ -14,16 +18,277 @@
namespace webrtc {
namespace metrics {
+class Histogram;
-Histogram* HistogramFactoryGetCounts(const std::string& name, int min, int max,
- int bucket_count) { return NULL; }
+namespace {
+// Limit for the maximum number of sample values that can be stored.
+// TODO(asapersson): Consider using bucket count (and set up
+// linearly/exponentially spaced buckets) if samples are logged more frequently.
+const int kMaxSampleMapSize = 2000;
+class RtcHistogram {
+ public:
+ RtcHistogram(const std::string& name, int min, int max, int bucket_count)
+ : min_(min), max_(max), info_(name, min, max, bucket_count) {
+ RTC_DCHECK_GT(bucket_count, 0);
+ }
+
+ void Add(int sample) {
+ if (sample < min_)
+ sample = min_ - 1; // Underflow bucket.
+ if (sample > max_)
+ sample = max_;
+
+ rtc::CritScope cs(&crit_);
+ if (info_.samples.size() == kMaxSampleMapSize &&
+ info_.samples.find(sample) == info_.samples.end()) {
+ return;
+ }
+ ++info_.samples[sample];
+ }
+
+ // Returns a copy (or nullptr if there are no samples) and clears samples.
+ std::unique_ptr<SampleInfo> GetAndReset() {
+ rtc::CritScope cs(&crit_);
+ if (info_.samples.empty())
+ return nullptr;
+
+ SampleInfo* copy =
+ new SampleInfo(info_.name, info_.min, info_.max, info_.bucket_count);
+ copy->samples = info_.samples;
+ info_.samples.clear();
+ return std::unique_ptr<SampleInfo>(copy);
+ }
+
+ const std::string& name() const { return info_.name; }
+
+ // Functions only for testing.
+ void Reset() {
+ rtc::CritScope cs(&crit_);
+ info_.samples.clear();
+ }
+
+ int NumEvents(int sample) const {
+ rtc::CritScope cs(&crit_);
+ const auto it = info_.samples.find(sample);
+ return (it == info_.samples.end()) ? 0 : it->second;
+ }
+
+ int NumSamples() const {
+ int num_samples = 0;
+ rtc::CritScope cs(&crit_);
+ for (const auto& sample : info_.samples) {
+ num_samples += sample.second;
+ }
+ return num_samples;
+ }
+
+ int MinSample() const {
+ rtc::CritScope cs(&crit_);
+ return (info_.samples.empty()) ? -1 : info_.samples.begin()->first;
+ }
+
+ private:
+ rtc::CriticalSection crit_;
+ const int min_;
+ const int max_;
+ SampleInfo info_ GUARDED_BY(crit_);
+
+ RTC_DISALLOW_COPY_AND_ASSIGN(RtcHistogram);
+};
+
+class RtcHistogramMap {
+ public:
+ RtcHistogramMap() {}
+ ~RtcHistogramMap() {}
+
+ Histogram* GetCountsHistogram(const std::string& name,
+ int min,
+ int max,
+ int bucket_count) {
+ rtc::CritScope cs(&crit_);
+ const auto& it = map_.find(name);
+ if (it != map_.end())
+ return reinterpret_cast<Histogram*>(it->second.get());
+
+ RtcHistogram* hist = new RtcHistogram(name, min, max, bucket_count);
+ map_[name].reset(hist);
+ return reinterpret_cast<Histogram*>(hist);
+ }
+
+ Histogram* GetEnumerationHistogram(const std::string& name, int boundary) {
+ rtc::CritScope cs(&crit_);
+ const auto& it = map_.find(name);
+ if (it != map_.end())
+ return reinterpret_cast<Histogram*>(it->second.get());
+
+ RtcHistogram* hist = new RtcHistogram(name, 1, boundary, boundary + 1);
+ map_[name].reset(hist);
+ return reinterpret_cast<Histogram*>(hist);
+ }
+
+ void GetAndReset(
+ std::map<std::string, std::unique_ptr<SampleInfo>>* histograms) {
+ rtc::CritScope cs(&crit_);
+ for (const auto& kv : map_) {
+ std::unique_ptr<SampleInfo> info = kv.second->GetAndReset();
+ if (info)
+ histograms->insert(std::make_pair(kv.first, std::move(info)));
+ }
+ }
+
+ // Functions only for testing.
+ void Reset() {
+ rtc::CritScope cs(&crit_);
+ for (const auto& kv : map_)
+ kv.second->Reset();
+ }
+
+ int NumEvents(const std::string& name, int sample) const {
+ rtc::CritScope cs(&crit_);
+ const auto& it = map_.find(name);
+ return (it == map_.end()) ? 0 : it->second->NumEvents(sample);
+ }
+
+ int NumSamples(const std::string& name) const {
+ rtc::CritScope cs(&crit_);
+ const auto& it = map_.find(name);
+ return (it == map_.end()) ? 0 : it->second->NumSamples();
+ }
+
+ int MinSample(const std::string& name) const {
+ rtc::CritScope cs(&crit_);
+ const auto& it = map_.find(name);
+ return (it == map_.end()) ? -1 : it->second->MinSample();
+ }
+
+ private:
+ rtc::CriticalSection crit_;
+ std::map<std::string, std::unique_ptr<RtcHistogram>> map_ GUARDED_BY(crit_);
+
+ RTC_DISALLOW_COPY_AND_ASSIGN(RtcHistogramMap);
+};
+
+// RtcHistogramMap is allocated upon call to Enable().
+// The histogram getter functions, which return pointer values to the histograms
+// in the map, are cached in WebRTC. Therefore, this memory is not freed by the
+// application (the memory will be reclaimed by the OS).
+static RtcHistogramMap* volatile g_rtc_histogram_map = nullptr;
+
+void CreateMap() {
+ RtcHistogramMap* map = rtc::AtomicOps::AcquireLoadPtr(&g_rtc_histogram_map);
+ if (map == nullptr) {
+ RtcHistogramMap* new_map = new RtcHistogramMap();
+ RtcHistogramMap* old_map = rtc::AtomicOps::CompareAndSwapPtr(
+ &g_rtc_histogram_map, static_cast<RtcHistogramMap*>(nullptr), new_map);
+ if (old_map != nullptr)
+ delete new_map;
+ }
+}
+
+// Set the first time we start using histograms. Used to make sure Enable() is
+// not called thereafter.
+#if RTC_DCHECK_IS_ON
+static volatile int g_rtc_histogram_called = 0;
+#endif
+
+// Gets the map (or nullptr).
+RtcHistogramMap* GetMap() {
+#if RTC_DCHECK_IS_ON
+ rtc::AtomicOps::ReleaseStore(&g_rtc_histogram_called, 1);
+#endif
+ return g_rtc_histogram_map;
+}
+} // namespace
+
+// Implementation of histogram methods in
+// webrtc/system_wrappers/interface/metrics.h.
+
+// Histogram with exponentially spaced buckets.
+// Creates (or finds) histogram.
+// The returned histogram pointer is cached (and used for adding samples in
+// subsequent calls).
+Histogram* HistogramFactoryGetCounts(const std::string& name,
+ int min,
+ int max,
+ int bucket_count) {
+ RtcHistogramMap* map = GetMap();
+ if (!map)
+ return nullptr;
+
+ return map->GetCountsHistogram(name, min, max, bucket_count);
+}
+
+// Histogram with linearly spaced buckets.
+// Creates (or finds) histogram.
+// The returned histogram pointer is cached (and used for adding samples in
+// subsequent calls).
Histogram* HistogramFactoryGetEnumeration(const std::string& name,
- int boundary) { return NULL; }
+ int boundary) {
+ RtcHistogramMap* map = GetMap();
+ if (!map)
+ return nullptr;
-void HistogramAdd(
- Histogram* histogram_pointer, const std::string& name, int sample) {}
+ return map->GetEnumerationHistogram(name, boundary);
+}
+
+// Fast path. Adds |sample| to cached |histogram_pointer|.
+void HistogramAdd(Histogram* histogram_pointer,
+ const std::string& name,
+ int sample) {
+ if (!histogram_pointer)
+ return;
+
+ RtcHistogram* ptr = reinterpret_cast<RtcHistogram*>(histogram_pointer);
+ RTC_DCHECK_EQ(name, ptr->name()) << "The name should not vary.";
+ ptr->Add(sample);
+}
+
+SampleInfo::SampleInfo(const std::string& name,
+ int min,
+ int max,
+ size_t bucket_count)
+ : name(name), min(min), max(max), bucket_count(bucket_count) {}
+
+SampleInfo::~SampleInfo() {}
+
+// Implementation of global functions in metrics_default.h.
+void Enable() {
+ RTC_DCHECK(g_rtc_histogram_map == nullptr);
+#if RTC_DCHECK_IS_ON
+ RTC_DCHECK_EQ(0, rtc::AtomicOps::AcquireLoad(&g_rtc_histogram_called));
+#endif
+ CreateMap();
+}
+
+void GetAndReset(
+ std::map<std::string, std::unique_ptr<SampleInfo>>* histograms) {
+ histograms->clear();
+ RtcHistogramMap* map = GetMap();
+ if (map)
+ map->GetAndReset(histograms);
+}
+
+void Reset() {
+ RtcHistogramMap* map = GetMap();
+ if (map)
+ map->Reset();
+}
+
+int NumEvents(const std::string& name, int sample) {
+ RtcHistogramMap* map = GetMap();
+ return map ? map->NumEvents(name, sample) : 0;
+}
+
+int NumSamples(const std::string& name) {
+ RtcHistogramMap* map = GetMap();
+ return map ? map->NumSamples(name) : 0;
+}
+
+int MinSample(const std::string& name) {
+ RtcHistogramMap* map = GetMap();
+ return map ? map->MinSample(name) : -1;
+}
} // namespace metrics
} // namespace webrtc
-