Moving LatencyInfo into a separate component.

ui/events/latency_info.cc

Index: ui/events/latency_info.cc
diff --git a/ui/events/latency_info.cc b/ui/events/latency_info.cc
deleted file mode 100644
index 272704b8121b20e461c0b826e16184578c3b60e5..0000000000000000000000000000000000000000
--- a/ui/events/latency_info.cc
+++ /dev/null
@@ -1,375 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "ui/events/latency_info.h"
-
-#include <stddef.h>
-
-#include <algorithm>
-#include <string>
-#include <utility>
-
-#include "base/json/json_writer.h"
-#include "base/lazy_instance.h"
-#include "base/macros.h"
-#include "base/strings/stringprintf.h"
-#include "base/trace_event/trace_event.h"
-
-namespace {
-
-const size_t kMaxLatencyInfoNumber = 100;
-
-const char* GetComponentName(ui::LatencyComponentType type) {
-#define CASE_TYPE(t) case ui::t:  return #t
-  switch (type) {
-    CASE_TYPE(INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT);
-    CASE_TYPE(LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_UI_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_FORWARD_SCROLL_UPDATE_TO_MAIN_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_ACK_RWH_COMPONENT);
-    CASE_TYPE(WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT);
-    CASE_TYPE(TAB_SHOW_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_MAIN_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_BROWSER_RECEIVED_RENDERER_SWAP_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_GENERATE_SCROLL_UPDATE_FROM_MOUSE_WHEEL);
-    CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_NO_SWAP_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT);
-    CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT);
-    default:
-      DLOG(WARNING) << "Unhandled LatencyComponentType.\n";
-      break;
-  }
-#undef CASE_TYPE
-  return "unknown";
-}
-
-bool IsTerminalComponent(ui::LatencyComponentType type) {
-  switch (type) {
-    case ui::INPUT_EVENT_LATENCY_TERMINATED_NO_SWAP_COMPONENT:
-    case ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT:
-    case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT:
-    case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT:
-    case ui::INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT:
-      return true;
-    default:
-      return false;
-  }
-}
-
-bool IsBeginComponent(ui::LatencyComponentType type) {
-  return (type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT ||
-          type == ui::LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
-}
-
-bool IsInputLatencyBeginComponent(ui::LatencyComponentType type) {
-  return type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT;
-}
-
-// This class is for converting latency info to trace buffer friendly format.
-class LatencyInfoTracedValue
-    : public base::trace_event::ConvertableToTraceFormat {
- public:
-  static std::unique_ptr<ConvertableToTraceFormat> FromValue(
-      std::unique_ptr<base::Value> value);
-
-  void AppendAsTraceFormat(std::string* out) const override;
-
- private:
-  explicit LatencyInfoTracedValue(base::Value* value);
-  ~LatencyInfoTracedValue() override;
-
-  std::unique_ptr<base::Value> value_;
-
-  DISALLOW_COPY_AND_ASSIGN(LatencyInfoTracedValue);
-};
-
-std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
-LatencyInfoTracedValue::FromValue(std::unique_ptr<base::Value> value) {
-  return std::unique_ptr<base::trace_event::ConvertableToTraceFormat>(
-      new LatencyInfoTracedValue(value.release()));
-}
-
-LatencyInfoTracedValue::~LatencyInfoTracedValue() {
-}
-
-void LatencyInfoTracedValue::AppendAsTraceFormat(std::string* out) const {
-  std::string tmp;
-  base::JSONWriter::Write(*value_, &tmp);
-  *out += tmp;
-}
-
-LatencyInfoTracedValue::LatencyInfoTracedValue(base::Value* value)
-    : value_(value) {
-}
-
-const char kTraceCategoriesForAsyncEvents[] = "benchmark,latencyInfo,rail";
-
-struct LatencyInfoEnabledInitializer {
-  LatencyInfoEnabledInitializer() :
-      latency_info_enabled(TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(
-          kTraceCategoriesForAsyncEvents)) {
-  }
-
-  const unsigned char* latency_info_enabled;
-};
-
-static base::LazyInstance<LatencyInfoEnabledInitializer>::Leaky
-  g_latency_info_enabled = LAZY_INSTANCE_INITIALIZER;
-
-}  // namespace
-
-namespace ui {
-
-LatencyInfo::LatencyInfo() : LatencyInfo(SourceEventType::UNKNOWN) {}
-
-LatencyInfo::LatencyInfo(SourceEventType type)
-    : input_coordinates_size_(0),
-      trace_id_(-1),
-      coalesced_(false),
-      terminated_(false),
-      source_event_type_(type) {}
-
-LatencyInfo::LatencyInfo(const LatencyInfo& other) = default;
-
-LatencyInfo::~LatencyInfo() {}
-
-LatencyInfo::LatencyInfo(int64_t trace_id, bool terminated)
-    : input_coordinates_size_(0),
-      trace_id_(trace_id),
-      terminated_(terminated),
-      source_event_type_(SourceEventType::UNKNOWN) {}
-
-bool LatencyInfo::Verify(const std::vector<LatencyInfo>& latency_info,
-                         const char* referring_msg) {
-  if (latency_info.size() > kMaxLatencyInfoNumber) {
-    LOG(ERROR) << referring_msg << ", LatencyInfo vector size "
-               << latency_info.size() << " is too big.";
-    TRACE_EVENT_INSTANT1("input,benchmark", "LatencyInfo::Verify Fails",
-                         TRACE_EVENT_SCOPE_GLOBAL,
-                         "size", latency_info.size());
-    return false;
-  }
-  return true;
-}
-
-void LatencyInfo::CopyLatencyFrom(const LatencyInfo& other,
-                                  LatencyComponentType type) {
-  for (const auto& lc : other.latency_components()) {
-    if (lc.first.first == type) {
-      AddLatencyNumberWithTimestamp(lc.first.first,
-                                    lc.first.second,
-                                    lc.second.sequence_number,
-                                    lc.second.event_time,
-                                    lc.second.event_count);
-    }
-  }
-}
-
-void LatencyInfo::AddNewLatencyFrom(const LatencyInfo& other) {
-  for (const auto& lc : other.latency_components()) {
-    if (!FindLatency(lc.first.first, lc.first.second, NULL)) {
-      AddLatencyNumberWithTimestamp(lc.first.first,
-                                    lc.first.second,
-                                    lc.second.sequence_number,
-                                    lc.second.event_time,
-                                    lc.second.event_count);
-    }
-  }
-}
-
-void LatencyInfo::AddLatencyNumber(LatencyComponentType component,
-                                   int64_t id,
-                                   int64_t component_sequence_number) {
-  AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
-                                    base::TimeTicks::Now(), 1, nullptr);
-}
-
-void LatencyInfo::AddLatencyNumberWithTraceName(
-    LatencyComponentType component,
-    int64_t id,
-    int64_t component_sequence_number,
-    const char* trace_name_str) {
-  AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
-                                    base::TimeTicks::Now(), 1, trace_name_str);
-}
-
-void LatencyInfo::AddLatencyNumberWithTimestamp(
-    LatencyComponentType component,
-    int64_t id,
-    int64_t component_sequence_number,
-    base::TimeTicks time,
-    uint32_t event_count) {
-  AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
-                                    time, event_count, nullptr);
-}
-
-void LatencyInfo::AddLatencyNumberWithTimestampImpl(
-    LatencyComponentType component,
-    int64_t id,
-    int64_t component_sequence_number,
-    base::TimeTicks time,
-    uint32_t event_count,
-    const char* trace_name_str) {
-  const unsigned char* latency_info_enabled =
-      g_latency_info_enabled.Get().latency_info_enabled;
-
-  if (IsBeginComponent(component)) {
-    // Should only ever add begin component once.
-    CHECK_EQ(-1, trace_id_);
-    trace_id_ = component_sequence_number;
-
-    if (*latency_info_enabled) {
-      // The timestamp for ASYNC_BEGIN trace event is used for drawing the
-      // beginning of the trace event in trace viewer. For better visualization,
-      // for an input event, we want to draw the beginning as when the event is
-      // originally created, e.g. the timestamp of its ORIGINAL/UI_COMPONENT,
-      // not when we actually issue the ASYNC_BEGIN trace event.
-      LatencyComponent begin_component;
-      base::TimeTicks ts;
-      if (FindLatency(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
-                      0,
-                      &begin_component) ||
-          FindLatency(INPUT_EVENT_LATENCY_UI_COMPONENT,
-                      0,
-                      &begin_component)) {
-        ts = begin_component.event_time;
-      } else {
-        ts = base::TimeTicks::Now();
-      }
-
-      if (trace_name_str) {
-        if (IsInputLatencyBeginComponent(component))
-          trace_name_ = std::string("InputLatency::") + trace_name_str;
-        else
-          trace_name_ = std::string("Latency::") + trace_name_str;
-      }
-
-      TRACE_EVENT_COPY_ASYNC_BEGIN_WITH_TIMESTAMP0(
-          kTraceCategoriesForAsyncEvents,
-          trace_name_.c_str(),
-          TRACE_ID_DONT_MANGLE(trace_id_),
-          ts);
-    }
-
-    TRACE_EVENT_WITH_FLOW1("input,benchmark",
-                           "LatencyInfo.Flow",
-                           TRACE_ID_DONT_MANGLE(trace_id_),
-                           TRACE_EVENT_FLAG_FLOW_OUT,
-                           "trace_id", trace_id_);
-  }
-
-  LatencyMap::key_type key = std::make_pair(component, id);
-  LatencyMap::iterator it = latency_components_.find(key);
-  if (it == latency_components_.end()) {
-    LatencyComponent info = {component_sequence_number, time, event_count, time,
-                             time};
-    latency_components_[key] = info;
-  } else {
-    it->second.sequence_number = std::max(component_sequence_number,
-                                          it->second.sequence_number);
-    uint32_t new_count = event_count + it->second.event_count;
-    if (event_count > 0 && new_count != 0) {
-      // Do a weighted average, so that the new event_time is the average of
-      // the times of events currently in this structure with the time passed
-      // into this method.
-      it->second.event_time += (time - it->second.event_time) * event_count /
-          new_count;
-      it->second.event_count = new_count;
-      it->second.last_event_time = std::max(it->second.last_event_time, time);
-    }
-  }
-
-  if (IsTerminalComponent(component) && trace_id_ != -1) {
-    // Should only ever add terminal component once.
-    CHECK(!terminated_);
-    terminated_ = true;
-
-    if (*latency_info_enabled) {
-      TRACE_EVENT_COPY_ASYNC_END2(kTraceCategoriesForAsyncEvents,
-                                  trace_name_.c_str(),
-                                  TRACE_ID_DONT_MANGLE(trace_id_),
-                                  "data", AsTraceableData(),
-                                  "coordinates", CoordinatesAsTraceableData());
-    }
-
-    TRACE_EVENT_WITH_FLOW0("input,benchmark",
-                           "LatencyInfo.Flow",
-                           TRACE_ID_DONT_MANGLE(trace_id_),
-                           TRACE_EVENT_FLAG_FLOW_IN);
-  }
-}
-
-std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
-LatencyInfo::AsTraceableData() {
-  std::unique_ptr<base::DictionaryValue> record_data(
-      new base::DictionaryValue());
-  for (const auto& lc : latency_components_) {
-    std::unique_ptr<base::DictionaryValue> component_info(
-        new base::DictionaryValue());
-    component_info->SetDouble("comp_id", static_cast<double>(lc.first.second));
-    component_info->SetDouble(
-        "time",
-        static_cast<double>(lc.second.event_time.ToInternalValue()));
-    component_info->SetDouble("count", lc.second.event_count);
-    component_info->SetDouble("sequence_number",
-                              lc.second.sequence_number);
-    record_data->Set(GetComponentName(lc.first.first),
-                     std::move(component_info));
-  }
-  record_data->SetDouble("trace_id", static_cast<double>(trace_id_));
-  return LatencyInfoTracedValue::FromValue(std::move(record_data));
-}
-
-std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
-LatencyInfo::CoordinatesAsTraceableData() {
-  std::unique_ptr<base::ListValue> coordinates(new base::ListValue());
-  for (size_t i = 0; i < input_coordinates_size_; i++) {
-    std::unique_ptr<base::DictionaryValue> coordinate_pair(
-        new base::DictionaryValue());
-    coordinate_pair->SetDouble("x", input_coordinates_[i].x());
-    coordinate_pair->SetDouble("y", input_coordinates_[i].y());
-    coordinates->Append(std::move(coordinate_pair));
-  }
-  return LatencyInfoTracedValue::FromValue(std::move(coordinates));
-}
-
-bool LatencyInfo::FindLatency(LatencyComponentType type,
-                              int64_t id,
-                              LatencyComponent* output) const {
-  LatencyMap::const_iterator it = latency_components_.find(
-      std::make_pair(type, id));
-  if (it == latency_components_.end())
-    return false;
-  if (output)
-    *output = it->second;
-  return true;
-}
-
-void LatencyInfo::RemoveLatency(LatencyComponentType type) {
-  LatencyMap::iterator it = latency_components_.begin();
-  while (it != latency_components_.end()) {
-    if (it->first.first == type)
-      it = latency_components_.erase(it);
-    else
-      it++;
-  }
-}
-
-bool LatencyInfo::AddInputCoordinate(const gfx::PointF& input_coordinate) {
-  if (input_coordinates_size_ >= kMaxInputCoordinates)
-    return false;
-  input_coordinates_[input_coordinates_size_++] = input_coordinate;
-  return true;
-}
-
-}  // namespace ui