gecko-dev/xpcom/threads/InputEventStatistics.cpp

73 строки
2.6 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "InputEventStatistics.h"
#include "mozilla/Preferences.h"
#include "nsRefreshDriver.h"
namespace mozilla {
/*static*/ InputEventStatistics& InputEventStatistics::Get() {
static UniquePtr<InputEventStatistics> sInstance;
if (!sInstance) {
sInstance = MakeUnique<InputEventStatistics>(ConstructorCookie());
ClearOnShutdown(&sInstance);
}
return *sInstance;
}
TimeDuration InputEventStatistics::TimeDurationCircularBuffer::GetMean() {
return mTotal / (int64_t)mSize;
}
InputEventStatistics::InputEventStatistics(ConstructorCookie&&)
: mEnable(false) {
MOZ_ASSERT(Preferences::IsServiceAvailable());
uint32_t inputDuration = Preferences::GetUint(
"input_event_queue.default_duration_per_event", sDefaultInputDuration);
TimeDuration defaultDuration = TimeDuration::FromMilliseconds(inputDuration);
uint32_t count = Preferences::GetUint(
"input_event_queue.count_for_prediction", sInputCountForPrediction);
mLastInputDurations =
MakeUnique<TimeDurationCircularBuffer>(count, defaultDuration);
uint32_t maxDuration = Preferences::GetUint("input_event_queue.duration.max",
sMaxReservedTimeForHandlingInput);
uint32_t minDuration = Preferences::GetUint("input_event_queue.duration.min",
sMinReservedTimeForHandlingInput);
mMaxInputDuration = TimeDuration::FromMilliseconds(maxDuration);
mMinInputDuration = TimeDuration::FromMilliseconds(minDuration);
}
TimeStamp InputEventStatistics::GetInputHandlingStartTime(
uint32_t aInputCount) {
MOZ_ASSERT(mEnable);
Maybe<TimeStamp> nextTickHint = nsRefreshDriver::GetNextTickHint();
if (nextTickHint.isNothing()) {
// Return a past time to process input events immediately.
return TimeStamp::Now() - TimeDuration::FromMilliseconds(1);
}
TimeDuration inputCost = mLastInputDurations->GetMean() * aInputCount;
inputCost = inputCost > mMaxInputDuration ? mMaxInputDuration
: inputCost < mMinInputDuration ? mMinInputDuration
: inputCost;
return nextTickHint.value() - inputCost;
}
TimeDuration InputEventStatistics::GetMaxInputHandlingDuration() const {
MOZ_ASSERT(StaticPrefs::dom_input_events_strict_input_vsync_alignment());
return mMaxInputDuration;
}
} // namespace mozilla