| // Copyright 2015 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 "components/scheduler/renderer/user_model.h" |
| |
| #include "base/metrics/histogram_macros.h" |
| |
| namespace scheduler { |
| |
| namespace { |
| // This enum is used to back a histogram, and should therefore be treated as |
| // append-only. |
| enum GesturePredictionResult { |
| GESTURE_OCCURED_WAS_PREDICTED = 0, |
| GESTURE_OCCURED_BUT_NOT_PREDICTED = 1, |
| GESTURE_PREDICTED_BUT_DID_NOT_OCCUR = 2, |
| GESTURE_PREDICTION_RESULT_COUNT = 3 |
| }; |
| |
| void RecordGesturePrediction(GesturePredictionResult result) { |
| UMA_HISTOGRAM_ENUMERATION( |
| "RendererScheduler.UserModel.GesturePredictedCorrectly", result, |
| GESTURE_PREDICTION_RESULT_COUNT); |
| } |
| |
| } // namespace |
| |
| UserModel::UserModel() |
| : pending_input_event_count_(0), |
| is_gesture_active_(false), |
| is_gesture_expected_(false) {} |
| UserModel::~UserModel() {} |
| |
| void UserModel::DidStartProcessingInputEvent(blink::WebInputEvent::Type type, |
| const base::TimeTicks now) { |
| last_input_signal_time_ = now; |
| if (type == blink::WebInputEvent::TouchStart || |
| type == blink::WebInputEvent::GestureScrollBegin || |
| type == blink::WebInputEvent::GesturePinchBegin) { |
| // Only update stats once per gesture. |
| if (!is_gesture_active_) { |
| last_gesture_start_time_ = now; |
| |
| RecordGesturePrediction(is_gesture_expected_ |
| ? GESTURE_OCCURED_WAS_PREDICTED |
| : GESTURE_OCCURED_BUT_NOT_PREDICTED); |
| |
| if (!last_reset_time_.is_null()) { |
| base::TimeDelta time_since_reset = now - last_reset_time_; |
| UMA_HISTOGRAM_MEDIUM_TIMES( |
| "RendererScheduler.UserModel.GestureStartTimeSinceModelReset", |
| time_since_reset); |
| } |
| |
| // If there has been a previous gesture, record a UMA metric for the time |
| // interval between then and now. |
| if (!last_continuous_gesture_time_.is_null()) { |
| base::TimeDelta time_since_last_gesture = |
| now - last_continuous_gesture_time_; |
| UMA_HISTOGRAM_MEDIUM_TIMES( |
| "RendererScheduler.UserModel.TimeBetweenGestures", |
| time_since_last_gesture); |
| } |
| } |
| |
| is_gesture_active_ = true; |
| } |
| |
| // We need to track continuous gestures seperatly for scroll detection |
| // because taps should not be confused with scrolls. |
| if (type == blink::WebInputEvent::GestureScrollBegin || |
| type == blink::WebInputEvent::GestureScrollEnd || |
| type == blink::WebInputEvent::GestureScrollUpdate || |
| type == blink::WebInputEvent::GestureFlingStart || |
| type == blink::WebInputEvent::GestureFlingCancel || |
| type == blink::WebInputEvent::GesturePinchBegin || |
| type == blink::WebInputEvent::GesturePinchEnd || |
| type == blink::WebInputEvent::GesturePinchUpdate) { |
| last_continuous_gesture_time_ = now; |
| } |
| |
| // If the gesture has ended, clear |is_gesture_active_| and record a UMA |
| // metric that tracks its duration. |
| if (type == blink::WebInputEvent::GestureScrollEnd || |
| type == blink::WebInputEvent::GesturePinchEnd || |
| type == blink::WebInputEvent::GestureFlingStart || |
| type == blink::WebInputEvent::TouchEnd) { |
| // Only update stats once per gesture. |
| if (is_gesture_active_) { |
| base::TimeDelta duration = now - last_gesture_start_time_; |
| UMA_HISTOGRAM_TIMES("RendererScheduler.UserModel.GestureDuration", |
| duration); |
| } |
| is_gesture_active_ = false; |
| } |
| |
| TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), |
| "is_gesture_active", is_gesture_active_); |
| |
| pending_input_event_count_++; |
| } |
| |
| void UserModel::DidFinishProcessingInputEvent(const base::TimeTicks now) { |
| last_input_signal_time_ = now; |
| if (pending_input_event_count_ > 0) |
| pending_input_event_count_--; |
| } |
| |
| base::TimeDelta UserModel::TimeLeftInUserGesture(base::TimeTicks now) const { |
| base::TimeDelta escalated_priority_duration = |
| base::TimeDelta::FromMilliseconds(kGestureEstimationLimitMillis); |
| |
| // If the input event is still pending, go into input prioritized policy and |
| // check again later. |
| if (pending_input_event_count_ > 0) |
| return escalated_priority_duration; |
| if (last_input_signal_time_.is_null() || |
| last_input_signal_time_ + escalated_priority_duration < now) { |
| return base::TimeDelta(); |
| } |
| return last_input_signal_time_ + escalated_priority_duration - now; |
| } |
| |
| bool UserModel::IsGestureExpectedSoon( |
| const base::TimeTicks now, |
| base::TimeDelta* prediction_valid_duration) { |
| bool was_gesture_expected = is_gesture_expected_; |
| is_gesture_expected_ = |
| IsGestureExpectedSoonImpl(now, prediction_valid_duration); |
| |
| // Track when we start expecting a gesture so we can work out later if a |
| // gesture actually happened. |
| if (!was_gesture_expected && is_gesture_expected_) |
| last_gesture_expected_start_time_ = now; |
| |
| if (was_gesture_expected && !is_gesture_expected_ && |
| last_gesture_expected_start_time_ > last_gesture_start_time_) { |
| RecordGesturePrediction(GESTURE_PREDICTED_BUT_DID_NOT_OCCUR); |
| } |
| return is_gesture_expected_; |
| } |
| |
| bool UserModel::IsGestureExpectedSoonImpl( |
| const base::TimeTicks now, |
| base::TimeDelta* prediction_valid_duration) const { |
| if (is_gesture_active_) { |
| if (IsGestureExpectedToContinue(now, prediction_valid_duration)) { |
| return false; |
| } else { |
| // If a gesture is not expected to continue then we expect a subsequent |
| // gesture soon. |
| *prediction_valid_duration = |
| base::TimeDelta::FromMilliseconds(kExpectSubsequentGestureMillis); |
| return true; |
| } |
| } else { |
| // If we've have a finished a gesture then a subsequent gesture is deemed |
| // likely. |
| base::TimeDelta expect_subsequent_gesture_for = |
| base::TimeDelta::FromMilliseconds(kExpectSubsequentGestureMillis); |
| if (last_continuous_gesture_time_.is_null() || |
| last_continuous_gesture_time_ + expect_subsequent_gesture_for <= now) { |
| return false; |
| } |
| *prediction_valid_duration = |
| last_continuous_gesture_time_ + expect_subsequent_gesture_for - now; |
| return true; |
| } |
| } |
| |
| bool UserModel::IsGestureExpectedToContinue( |
| const base::TimeTicks now, |
| base::TimeDelta* prediction_valid_duration) const { |
| if (!is_gesture_active_) |
| return false; |
| |
| base::TimeDelta median_gesture_duration = |
| base::TimeDelta::FromMilliseconds(kMedianGestureDurationMillis); |
| base::TimeTicks expected_gesture_end_time = |
| last_gesture_start_time_ + median_gesture_duration; |
| |
| if (expected_gesture_end_time > now) { |
| *prediction_valid_duration = expected_gesture_end_time - now; |
| return true; |
| } |
| return false; |
| } |
| |
| void UserModel::Reset(base::TimeTicks now) { |
| last_input_signal_time_ = base::TimeTicks(); |
| last_gesture_start_time_ = base::TimeTicks(); |
| last_continuous_gesture_time_ = base::TimeTicks(); |
| last_gesture_expected_start_time_ = base::TimeTicks(); |
| last_reset_time_ = now; |
| is_gesture_active_ = false; |
| is_gesture_expected_ = false; |
| } |
| |
| void UserModel::AsValueInto(base::trace_event::TracedValue* state) const { |
| state->BeginDictionary("user_model"); |
| state->SetInteger("pending_input_event_count", pending_input_event_count_); |
| state->SetDouble( |
| "last_input_signal_time", |
| (last_input_signal_time_ - base::TimeTicks()).InMillisecondsF()); |
| state->SetDouble( |
| "last_gesture_start_time", |
| (last_gesture_start_time_ - base::TimeTicks()).InMillisecondsF()); |
| state->SetDouble( |
| "last_continuous_gesture_time", |
| (last_continuous_gesture_time_ - base::TimeTicks()).InMillisecondsF()); |
| state->SetDouble("last_gesture_expected_start_time", |
| (last_gesture_expected_start_time_ - base::TimeTicks()) |
| .InMillisecondsF()); |
| state->SetDouble("last_reset_time", |
| (last_reset_time_ - base::TimeTicks()).InMillisecondsF()); |
| state->SetBoolean("is_gesture_expected", is_gesture_expected_); |
| state->SetBoolean("is_gesture_active", is_gesture_active_); |
| state->EndDictionary(); |
| } |
| |
| } // namespace scheduler |