// Copyright 2014 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 "cc/scheduler/compositor_timing_history.h"

#include "base/metrics/histogram.h"
#include "base/trace_event/trace_event.h"
#include "cc/debug/rendering_stats_instrumentation.h"

namespace cc {

class CompositorTimingHistory::UMAReporter {
 public:
  virtual ~UMAReporter() {}

  virtual void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                                 base::TimeDelta estimate,
                                                 bool affects_estimate) = 0;
  virtual void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                                  base::TimeDelta estimate,
                                                  bool affects_estimate) = 0;
  virtual void AddPrepareTilesDuration(base::TimeDelta duration,
                                       base::TimeDelta estimate,
                                       bool affects_estimate) = 0;
  virtual void AddActivateDuration(base::TimeDelta duration,
                                   base::TimeDelta estimate,
                                   bool affects_estimate) = 0;
  virtual void AddDrawDuration(base::TimeDelta duration,
                               base::TimeDelta estimate,
                               bool affects_estimate) = 0;
};

namespace {

// Using the 90th percentile will disable latency recovery
// if we are missing the deadline approximately ~6 times per
// second.
// TODO(brianderson): Fine tune the percentiles below.
const size_t kDurationHistorySize = 60;
const double kBeginMainFrameToCommitEstimationPercentile = 90.0;
const double kCommitToReadyToActivateEstimationPercentile = 90.0;
const double kPrepareTilesEstimationPercentile = 90.0;
const double kActivateEstimationPercentile = 90.0;
const double kDrawEstimationPercentile = 90.0;

const int kUmaDurationMinMicros = 1;
const int64 kUmaDurationMaxMicros = 1 * base::Time::kMicrosecondsPerSecond;
const size_t kUmaDurationBucketCount = 100;

// Deprecated because they combine Browser and Renderer stats and have low
// precision.
// TODO(brianderson): Remove.
void DeprecatedDrawDurationUMA(base::TimeDelta duration,
                               base::TimeDelta estimate) {
  base::TimeDelta duration_overestimate;
  base::TimeDelta duration_underestimate;
  if (duration > estimate)
    duration_underestimate = duration - estimate;
  else
    duration_overestimate = estimate - duration;
  UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.DrawDuration", duration,
                             base::TimeDelta::FromMilliseconds(1),
                             base::TimeDelta::FromMilliseconds(100), 50);
  UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.DrawDurationUnderestimate",
                             duration_underestimate,
                             base::TimeDelta::FromMilliseconds(1),
                             base::TimeDelta::FromMilliseconds(100), 50);
  UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.DrawDurationOverestimate",
                             duration_overestimate,
                             base::TimeDelta::FromMilliseconds(1),
                             base::TimeDelta::FromMilliseconds(100), 50);
}

#define UMA_HISTOGRAM_CUSTOM_TIMES_MICROS(name, sample)                     \
  UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample.InMicroseconds(),                \
                              kUmaDurationMinMicros, kUmaDurationMaxMicros, \
                              kUmaDurationBucketCount);

#define REPORT_COMPOSITOR_TIMING_HISTORY_UMA(category, subcategory)            \
  do {                                                                         \
    base::TimeDelta duration_overestimate;                                     \
    base::TimeDelta duration_underestimate;                                    \
    if (duration > estimate)                                                   \
      duration_underestimate = duration - estimate;                            \
    else                                                                       \
      duration_overestimate = estimate - duration;                             \
    UMA_HISTOGRAM_CUSTOM_TIMES_MICROS(                                         \
        "Scheduling." category "." subcategory "Duration", duration);          \
    UMA_HISTOGRAM_CUSTOM_TIMES_MICROS("Scheduling." category "." subcategory   \
                                      "Duration.Underestimate",                \
                                      duration_underestimate);                 \
    UMA_HISTOGRAM_CUSTOM_TIMES_MICROS("Scheduling." category "." subcategory   \
                                      "Duration.Overestimate",                 \
                                      duration_overestimate);                  \
    if (!affects_estimate) {                                                   \
      UMA_HISTOGRAM_CUSTOM_TIMES_MICROS("Scheduling." category "." subcategory \
                                        "Duration.NotUsedForEstimate",         \
                                        duration);                             \
    }                                                                          \
  } while (false)

class RendererUMAReporter : public CompositorTimingHistory::UMAReporter {
 public:
  ~RendererUMAReporter() override {}

  void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                         base::TimeDelta estimate,
                                         bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "BeginMainFrameToCommit");
  }

  void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                          base::TimeDelta estimate,
                                          bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "CommitToReadyToActivate");
  }

  void AddPrepareTilesDuration(base::TimeDelta duration,
                               base::TimeDelta estimate,
                               bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "PrepareTiles");
  }

  void AddActivateDuration(base::TimeDelta duration,
                           base::TimeDelta estimate,
                           bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "Activate");
  }

  void AddDrawDuration(base::TimeDelta duration,
                       base::TimeDelta estimate,
                       bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "Draw");
    DeprecatedDrawDurationUMA(duration, estimate);
  }
};

class BrowserUMAReporter : public CompositorTimingHistory::UMAReporter {
 public:
  ~BrowserUMAReporter() override {}

  void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                         base::TimeDelta estimate,
                                         bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "BeginMainFrameToCommit");
  }

  void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                          base::TimeDelta estimate,
                                          bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "CommitToReadyToActivate");
  }

  void AddPrepareTilesDuration(base::TimeDelta duration,
                               base::TimeDelta estimate,
                               bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "PrepareTiles");
  }

  void AddActivateDuration(base::TimeDelta duration,
                           base::TimeDelta estimate,
                           bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "Activate");
  }

  void AddDrawDuration(base::TimeDelta duration,
                       base::TimeDelta estimate,
                       bool affects_estimate) override {
    REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "Draw");
    DeprecatedDrawDurationUMA(duration, estimate);
  }
};

class NullUMAReporter : public CompositorTimingHistory::UMAReporter {
 public:
  ~NullUMAReporter() override {}
  void AddPrepareTilesDuration(base::TimeDelta duration,
                               base::TimeDelta estimate,
                               bool affects_estimate) override {}
  void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                         base::TimeDelta estimate,
                                         bool affects_estimate) override {}
  void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                          base::TimeDelta estimate,
                                          bool affects_estimate) override {}
  void AddActivateDuration(base::TimeDelta duration,
                           base::TimeDelta estimate,
                           bool affects_estimate) override {}
  void AddDrawDuration(base::TimeDelta duration,
                       base::TimeDelta estimate,
                       bool affects_estimate) override {}
};

}  // namespace

CompositorTimingHistory::CompositorTimingHistory(
    UMACategory uma_category,
    RenderingStatsInstrumentation* rendering_stats_instrumentation)
    : enabled_(false),
      begin_main_frame_to_commit_duration_history_(kDurationHistorySize),
      commit_to_ready_to_activate_duration_history_(kDurationHistorySize),
      prepare_tiles_duration_history_(kDurationHistorySize),
      activate_duration_history_(kDurationHistorySize),
      draw_duration_history_(kDurationHistorySize),
      uma_reporter_(CreateUMAReporter(uma_category)),
      rendering_stats_instrumentation_(rendering_stats_instrumentation) {}

CompositorTimingHistory::~CompositorTimingHistory() {
}

scoped_ptr<CompositorTimingHistory::UMAReporter>
CompositorTimingHistory::CreateUMAReporter(UMACategory category) {
  switch (category) {
    case RENDERER_UMA:
      return make_scoped_ptr(new RendererUMAReporter);
      break;
    case BROWSER_UMA:
      return make_scoped_ptr(new BrowserUMAReporter);
      break;
    case NULL_UMA:
      return make_scoped_ptr(new NullUMAReporter);
      break;
  }
  NOTREACHED();
  return make_scoped_ptr<CompositorTimingHistory::UMAReporter>(nullptr);
}

void CompositorTimingHistory::AsValueInto(
    base::trace_event::TracedValue* state) const {
  state->SetDouble("begin_main_frame_to_commit_estimate_ms",
                   BeginMainFrameToCommitDurationEstimate().InMillisecondsF());
  state->SetDouble("commit_to_ready_to_activate_estimate_ms",
                   CommitToReadyToActivateDurationEstimate().InMillisecondsF());
  state->SetDouble("prepare_tiles_estimate_ms",
                   PrepareTilesDurationEstimate().InMillisecondsF());
  state->SetDouble("activate_estimate_ms",
                   ActivateDurationEstimate().InMillisecondsF());
  state->SetDouble("draw_estimate_ms",
                   DrawDurationEstimate().InMillisecondsF());
}

base::TimeTicks CompositorTimingHistory::Now() const {
  return base::TimeTicks::Now();
}

void CompositorTimingHistory::SetRecordingEnabled(bool enabled) {
  enabled_ = enabled;
}

base::TimeDelta
CompositorTimingHistory::BeginMainFrameToCommitDurationEstimate() const {
  return begin_main_frame_to_commit_duration_history_.Percentile(
      kBeginMainFrameToCommitEstimationPercentile);
}

base::TimeDelta
CompositorTimingHistory::CommitToReadyToActivateDurationEstimate() const {
  return commit_to_ready_to_activate_duration_history_.Percentile(
      kCommitToReadyToActivateEstimationPercentile);
}

base::TimeDelta CompositorTimingHistory::PrepareTilesDurationEstimate() const {
  return prepare_tiles_duration_history_.Percentile(
      kPrepareTilesEstimationPercentile);
}

base::TimeDelta CompositorTimingHistory::ActivateDurationEstimate() const {
  return activate_duration_history_.Percentile(kActivateEstimationPercentile);
}

base::TimeDelta CompositorTimingHistory::DrawDurationEstimate() const {
  return draw_duration_history_.Percentile(kDrawEstimationPercentile);
}

void CompositorTimingHistory::WillBeginMainFrame() {
  DCHECK_EQ(base::TimeTicks(), begin_main_frame_sent_time_);
  begin_main_frame_sent_time_ = Now();
}

void CompositorTimingHistory::BeginMainFrameAborted() {
  DidCommit();
}

void CompositorTimingHistory::DidCommit() {
  DCHECK_NE(base::TimeTicks(), begin_main_frame_sent_time_);

  commit_time_ = Now();

  base::TimeDelta begin_main_frame_to_commit_duration =
      commit_time_ - begin_main_frame_sent_time_;

  // Before adding the new data point to the timing history, see what we would
  // have predicted for this frame. This allows us to keep track of the accuracy
  // of our predictions.
  base::TimeDelta begin_main_frame_to_commit_estimate =
      BeginMainFrameToCommitDurationEstimate();
  uma_reporter_->AddBeginMainFrameToCommitDuration(
      begin_main_frame_to_commit_duration, begin_main_frame_to_commit_estimate,
      enabled_);
  rendering_stats_instrumentation_->AddBeginMainFrameToCommitDuration(
      begin_main_frame_to_commit_duration, begin_main_frame_to_commit_estimate);

  if (enabled_) {
    begin_main_frame_to_commit_duration_history_.InsertSample(
        begin_main_frame_to_commit_duration);
  }

  begin_main_frame_sent_time_ = base::TimeTicks();
}

void CompositorTimingHistory::WillPrepareTiles() {
  DCHECK_EQ(base::TimeTicks(), start_prepare_tiles_time_);
  start_prepare_tiles_time_ = Now();
}

void CompositorTimingHistory::DidPrepareTiles() {
  DCHECK_NE(base::TimeTicks(), start_prepare_tiles_time_);

  base::TimeDelta prepare_tiles_duration = Now() - start_prepare_tiles_time_;
  uma_reporter_->AddPrepareTilesDuration(
      prepare_tiles_duration, PrepareTilesDurationEstimate(), enabled_);
  if (enabled_)
    prepare_tiles_duration_history_.InsertSample(prepare_tiles_duration);

  start_prepare_tiles_time_ = base::TimeTicks();
}

void CompositorTimingHistory::ReadyToActivate() {
  // We only care about the first ready to activate signal
  // after a commit.
  if (commit_time_ == base::TimeTicks())
    return;

  base::TimeDelta time_since_commit = Now() - commit_time_;

  // Before adding the new data point to the timing history, see what we would
  // have predicted for this frame. This allows us to keep track of the accuracy
  // of our predictions.

  base::TimeDelta commit_to_ready_to_activate_estimate =
      CommitToReadyToActivateDurationEstimate();
  uma_reporter_->AddCommitToReadyToActivateDuration(
      time_since_commit, commit_to_ready_to_activate_estimate, enabled_);
  rendering_stats_instrumentation_->AddCommitToActivateDuration(
      time_since_commit, commit_to_ready_to_activate_estimate);

  if (enabled_) {
    commit_to_ready_to_activate_duration_history_.InsertSample(
        time_since_commit);
  }

  commit_time_ = base::TimeTicks();
}

void CompositorTimingHistory::WillActivate() {
  DCHECK_EQ(base::TimeTicks(), start_activate_time_);
  start_activate_time_ = Now();
}

void CompositorTimingHistory::DidActivate() {
  DCHECK_NE(base::TimeTicks(), start_activate_time_);
  base::TimeDelta activate_duration = Now() - start_activate_time_;

  uma_reporter_->AddActivateDuration(activate_duration,
                                     ActivateDurationEstimate(), enabled_);
  if (enabled_)
    activate_duration_history_.InsertSample(activate_duration);

  start_activate_time_ = base::TimeTicks();
}

void CompositorTimingHistory::WillDraw() {
  DCHECK_EQ(base::TimeTicks(), start_draw_time_);
  start_draw_time_ = Now();
}

void CompositorTimingHistory::DidDraw() {
  DCHECK_NE(base::TimeTicks(), start_draw_time_);
  base::TimeDelta draw_duration = Now() - start_draw_time_;

  // Before adding the new data point to the timing history, see what we would
  // have predicted for this frame. This allows us to keep track of the accuracy
  // of our predictions.
  base::TimeDelta draw_estimate = DrawDurationEstimate();
  rendering_stats_instrumentation_->AddDrawDuration(draw_duration,
                                                    draw_estimate);

  uma_reporter_->AddDrawDuration(draw_duration, draw_estimate, enabled_);

  if (enabled_) {
    draw_duration_history_.InsertSample(draw_duration);
  }

  start_draw_time_ = base::TimeTicks();
}

}  // namespace cc